text:
Power for NXP/Freescale processors
TI's extensive power portfolio supports the requirements of the i.MX and QorIQ families of NXP/Freescale processors. The i.MX Applications Processors and i.MX Crossover Processors are heterogeneous multicore and single-core processors for automotive, consumer/industrial multimedia and display applications. The QorIQ® Layerscape Processors are Multicore SoCs for enterprise, service provider, cloud and industrial markets.
Pick a device for each Point-of-Load (POL) power requirement:
|Power Requirements||Sequence #*||Loads**||Solution Options by Regulator Type|
Powered by WEBENCH® Power Architect
WEBENCH Power Architect suggests devices that meet the basic supply voltage and current requirements of the processor. Before picking devices for your design, refer to the processor datasheet for more detailed power supply requirements that must be met, such as voltage tolerances, power-up/down sequencing, AVS/DVS, and ramp times.
* This FPGA has special features that may require additional IC to support it:
** Loads are grouped by output voltage and sequencing order.
† Linear LDO regulators dissipate power proportional to the voltage drop from input to output. Reduce LDO voltage drop and power dissipation by powering LDOs from an intermediate rail voltage that is closer to the LDO output voltage.


text:
Concrete Examples of Orderings
Last week, I noted that if you have an object with two components, each of which you know how to order independently, it requires at least a little thought to figure out how to do so. Moreover, there is a commonly used strategy, often called lexicographical order or dictionary order, for taking the ordering strategies for individual components and combining them.
The C++ library is considerate enough to implement dictionary ordering for its users in (at least) three places. The first is the
std::pair template, which defines the six comparison operators in terms of the corresponding operators of the pair's components. Specifically,
pair(x1, y1) < pair(x2, y2) is defined as x1 or ==. Part of its technique for doing so rests on the fact that the comparison x2 < x1 can take place only when it has already been established that x1 pair(x2, y2) is defined as pair(x2, y2) < pair(x1, y1) pair(x1, y1)!= pair(x2, y2) is defined as!(pair(x1, y1) == pair(x2, y2)) pair(x1, y1) <= pair(x2, y2) is defined as!(pair(x1, y1) > pair(x2, y2)) pair(x1, y1) >= pair(x2, y2) is defined as!(pair(x1, y1)< pair(x2, y2))
The underlying principles are easy to understand once explained:
- The pair template never depends on more than the == and < operations on the components.
- Order relations are defined entirely in terms of other order relations.
- Equality relations are defined entirely in terms of other equality relations.
- If the element types have relations defined that meet the library requirements, then the resulting relations on pairs will also meet the library requirements.
As a generalization of
pair, the library tuple template also implements the six comparison operators in terms of < and == on the
tuple's elements. Like
tuple does not reply on the other four comparison operators on elements.
The third place where the library implements dictionary order is in the
lexicographical_compare algorithm. This algorithm accepts two pairs of iterators, each of which defines a range of elements, and uses an extended version of this comparison procedure to compare the sequences:
- If both sequences have the same length and every element is equal to the corresponding element of the other sequence, the two sequences are considered equal. This case holds even if both sequences are empty.
- If one sequence is a prefix of the other, the shorter sequence is considered less than the other.
- Otherwise, the result of the comparison is the result of comparing the elements that make up the first discrepancy between the sequences.
This function offers an easy way to define sequence comparison in terms of element comparison when all the elements have the same type.
Unless there is a good reason to do otherwise, one's first thought about how to define comparison between two data structures should probably be to compare the data structure's elements along the lines that we've been discussing. The main mistake that beginners make is to believe that it is possible to define
pair(x1, y1) < pair(x2, y2) as something such as
x1 < x2 && y1 < y2, which doesn't work.
There is another pitfall in defining comparison relations: Sometimes the obvious way of comparing individual elements doesn't always work. We'll look at some examples of that pitfall next week.

source: HuggingFaceFW/fineweb-edu


text:
HOW IT WORKS
Pommello Sweats™ training gear is designed to help you leverage your body heat during athletic activity.
In competition, we know fractions of an edge can mean the difference between a place on the podium, winning or losing, or hitting that next big milestone. This innovative performance tool will prepare you for training, make your workouts more efficient, and help you achieve gains faster.
THE WARM UP
Pommello Sweats™ was designed to enhance your warm up by insulating your body and generating heat when you move in it. This creates an efficient condition to help you warm up faster without expending too much energy, ensuring you stay warm while you're active.
HEAT ACCLIMATION TRAINING
Heat acclimation training helps increase endurance and conditions the body to higher temperatures.
Pommello Sweats™ was designed to help you adapt to heat, preventing heat exhaustion when you need to perform the most.
Consistent exposure to heat in your training over a long period of time triggers a physiological adaptation called hyperthermic conditioning. The result is an athletic state with heightened bio markers that benefits performance.
Pommello Sweats™ was designed to help you ignite this conditioning whenever you use it to train.
THE LYMPHATIC SYSTEM
VARIOUS WAYS POMMELLO SWEATS™ CAN BE USED
Pommello Sweats™ is a multi-functional tool that can be used in a variety of different fitness disciplines:
Benefits to all athletes
- Helps warm the body when training outdoors in cold temperatures
- Reduces muscle soreness
- Warms the body faster to prevent injury and increase flexibility
- Stimulates the circulation for more efficient transfer of nutrients and oxygen throughout muscles for better gains
- Achieves the hot yoga effect without a heated room
- Increases hot yoga intensity for a practitioner whose body has acclimated to a heated room
- Helps practitioners move into Vinyasa Flow faster
- Makes muscles more supple for Yin
- Increases aerobic activity by improving VO2 max output
- Helps increase endurance by reducing the need to rely on local glycogen stores when acclimating their body to the heat, thereby breaking the "wall"
- Acclimatizes athletes for hotter climates
CrossFit and Weight Training
- Keeps tendons and joints warm for heavy lifting
- Efficiently prepares muscles for activation before a WOD
- Increases range of motion (ROM)
- Improves blood flow to muscle tissue
- Helps cut weight
- Keeps muscles warm while waiting for the next fight
- Helps muscles stay soft and limber while sparring
- Allows for faster warm up without expending too much energy
- Maintains muscle warmth between classes and rehearsals
- Keeps the body warm in cold studios
- Helps to maintain and achieve peak flexibility
USING YOUR POMMELLO SWEATS™ SAFELY

source: openbmb/Ultra-FineWeb


text:
Short Answer Questions
1. What magazine did Louis Untermeyer co-found?
2. What was one of Frost's occupations?
3. Where was Frost born?
4. Where was Frost first published?
5. What job did Frost's mother hold?
6. What job did Frost's father hold?
7. In what year was Frost born?
8. What city did Frost grow up in?
9. How old was Frost when he was first published?
10. How old was Frost when his first professional poem was published?
11. How much money did Frost receive for his first professional poem?
12. What was the name of Frost's first book of poetry?
This section contains 3,600 words
(approx. 12 pages at 300 words per page)


text:
Objective—To evaluate effect of adjunctive treatment with tetracycline analogues on time to complete corneal reepithelialization in dogs with nonhealing (ie, refractory) corneal ulcers.
Design—Randomized controlled clinical trial.
Animals—89 dogs with refractory corneal ulcers.
Procedures—Corneal ulcers were treated via debridement and grid keratotomy. Dogs were assigned to receive 1 of 3 treatment regimens for up to 6 weeks: doxycycline (5 mg/kg [2.27 mg/lb], PO, q 12 h) with topically applied ophthalmic ointment containing neomycin, polymyxin B, and bacitracin (ie, triple antibiotic ointment; q 8 h); cephalexin (22 mg/kg [10 mg/lb], PO, q 12 h) with topically applied oxytetracycline ophthalmic ointment (q 8 h); or a control treatment of cephalexin (22 mg/kg, PO, q 12 h) with topically applied triple antibiotic ointment (q 8 h). Healing was monitored via measurements of the wound with calipers and evaluation of photographs obtained every 2 weeks. Treatment effectiveness was evaluated by wound healing and decreased signs of pain.
Results—The Boxer breed was overrepresented in all groups. At the 2-week time point, wound healing was significantly more common in small-breed dogs, compared with large-breed dogs. Dogs treated with oxytetracycline ophthalmic ointment had a significantly shorter healing time than did dogs receiving the control treatment. Corneal ulcers in dogs that received doxycycline PO healed more rapidly than did ulcers in dogs in the control treatment group; however, this difference was not significant.
Conclusions and Clinical Relevance—Topical tetracycline ophthalmic ointment was a safe, inexpensive, and effective adjunctive treatment for refractory corneal ulcers in dogs.

source: m-a-p/FineFineWeb


text:
Instructions for Certified Information Security Manager-CISM Practice Test 5
This page show the instructions for Certified Information Security Manager-CISM Practice Test 5. Please read it carefully before attempting the test.
Number of Questions:
The test has 20 questions for practice
Type of Questions:
This test format is multiple choices. Each question has 4 to 10 options.
- The passing score does not mean that you must answer 80 percent of the questions correctly in order to pass the exam. The actual percentage varies from exam to exam and may be more or less than 80 percent.
- If a question specifies that you must choose multiple correct answers, you must choose the exact number of correct answers specified in the question in order to earn a point for that item.
- Attempt all questions since there are no penalties for guessing. No points are deducted for incorrect answers.
- You must answer each question before proceeding to the next question.
- If you leave the test midway through your session, you cannot resume it where you left off by returning to this page.
Click below to start:
The test is best viewed using Internet Explorer 6.0+, Mozilla Firefox 2.0+ or Google Chrome.
This practice test is included in CISM Certification Prep course. Following are all practice tests available in this course:
This course includes practice tests and articles, but it does not cover every exam question. Only the ISACA exam team has access to the exam questions for CISM exam, and ISACA regularly adds new questions to the exam, making it impossible to cover specific questions. You should consider this course a supplement to your relevant real-world experience


European Pond Terrapin (Tortoise)
European Pond Terrapin (Tortoise)
European Pond Terrapin (Tortoise) - Emys orbicularis
Relatively short-limbed terrapin. Its shell grows without ripples or ridges and the terrapin can completely withdraw its head and part of its limbs and tail inside.
Generally dark background colour, ranging from black to reddish-brown. Skin finely spotted with yellow. The males are much smaller than the females (on average 12 and 19 cm long respectively).
It lives in various types of aquatic habitat, including rivers, but prefers still or slow moving waters. During the hotter hours of the day it can often be seen basking out of the water. It spends the winter period hidden in the mud or in the ground near the water banks.
Breeding takes place in spring and summer. The females dig a little hole in the ground, where they lay 7-9 pergameneous (leathery-skinned) eggs at a time. The young hatch out after about 2 months or even the following spring.
The Pond Terrapin feeds on small vertebrates (like frogs, newts, fish and the eggs and fledglings of water birds) as well as aquatic invertebrates (molluscs, arthropods and worms).
This species is included in List II of the Habitat Directive no. 92/43/CEE and List II of the Bern Convention.


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Spring Break: Comparative Biogeography of Pacific Island Plants
DESCRIPTION: The aim of this project is to compare the biogeographic patterns of two large and cosmopolitan plant families to better understand the overall movement of plants and origin of floras in the Pacific oceanic islands. Interns will use the collections housed at the US National Herbarium as well as primary and secondary literature to determine which genera and species of Leguminosae occur on Pacific islands; whether these species are native, endemic, or invasive/naturalized; and where the closest relatives of these taxa are found.
QUALIFICATIONS: Strong interest in botany and/or biogeography; standard computer skills and familiarity with word processing and spreadsheet software (e.g. Word, Excel); attention to detail.
LEARNING OBJECTIVES: Interns will gain experience in the following areas: collections based research; literature research and interpretation; databasing; biogeographic principles; and the Pacific flora
TIMETABLE: Spring Break
Project Contact Name: Vicki Funk and Aleks Radosavljevic
Phone: _PHONE_
E-mail: _EMAIL_


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Make sure you are logged in as superuser.
% su -
Change the directory to (or bring up and go to) the top level of the CD-ROM volume.
This should look similar to the following location:
This directory contains one directory, a README file, the installer utility, and the ab2cd script. Use the ab2cd script to run the documentation server directly from the CD.
Type the following command:
Access the documentation server using the URL:
Where server is the name of the machine to which the CD-ROM drive is attached.
Note that a documentation server run from the CD always runs on port 8888.
(Optional) If document collections are installed already on your server machine and you want the CD-driven server software to recognize those collections, use the following command:.
# ab2cd -s
This form of the command causes the CD-driven server software to look for other collections installed on this system and add them to its database.
To stop running the server from the CD, type:
# /cdrom/sol_2_7_doc/ab2cd stop
Running the documentation server directly from the CD tends to be slow. Do not use this approach if you expect other users to access this documentation server.
Keep these things in mind when you run the server from the CD:
The AnswerBook2 server always runs on port 8888 when run from the CD. If you already have an AnswerBook2 server running on your system using the default port (8888), the ab2cd script will display the following message:
A document server is already running on this system as server:8888.
Please shut down the current server before running the ab2cd command.
Use the following command to shut down the existing server:
# /usr/lib/ab2/bin/ab2admin -o stop
Always use ab2cd stop to stop the server running from the CD. Do not use /etc/init.d/ab2mgr stop to stop the CD-based server.
The ab2cd stop command stops the AnswerBook2 server process and cleans up all files in the /tmp/ab2/ and /tmp/ab2cd_config/ directories. The /etc/init.d/ab2mgr stop command stops all server processes, but does not clean up the files in the /tmp/ab2/ and /tmp/ab2cd_config/ directories.
To run two AnswerBook2 servers (one on your system, one from the CD), keep these rules in mind:
The /etc/init.d/ab2mgr start command always starts the server on your system.
The ab2cd command always starts the server from the CD.
Always use the ab2cd stop command to stop the server running from the CD.
To stop both servers, first use the ab2cd stop command to stop the server running from the CD, then use either /etc/init.d/ab2mgr stop or /usr/lib/ab2/bin/ab2admin -o stop to stop the server running on your system.


text: An autonomous guidance,navigation and control(GNC)scheme based on multi-information fusion is proposed for Mars pinpoint landing mission. Before entering the Mars atmosphere,an autonomous navigation scheme fusing X-Ray pulsars and Mars landmark images is employed to satisfy the requirement of high precision navigation. Then,during Mars entry,descent and landing(EDL)phase,a multi-information fusion navigation scheme is constructed for absolute and relative navigation with high precision, which consists of Mars landmark images, inertial measurement unit (IMU) and ranging and velocity sensors. With the demands of pinpoint landing, a guidance and control algorithm is also designed for Mars atmosphere entry phase and powered descent phase. Finally,numerical simulation is performed,which indicates that the landing accuracy is better than 100 m and the hazard avoidance accuracy is around 0.5 m when adopting the proposed GNC scheme.


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Final Documentation including Critical Design Review Information and files on all the final designs and codes.
The process of designing the palm structure for the prosthetic hand and the adjoining thumb flexion components.
The process of developing the solidworks designs of the fingers for the prosthetic hand.
General Links to the Verification and Validation Reports for both the Prosthetic Arm and the Prosthetic Hand.
This is the working process of creating the firmware for the prosthetic hand, to control the motors and the servo in the hand with the flex sensors attached to the customer's foot.
In order to control the Hand on this project, it needs two Printed Circuit Boards (PCB) to be wirelessly communicating to each other. One of the PCBs will be placed in the arm and the other in a containment box attached to the customers ankle that would have flex sensors attached on the inside of their shoe.
The Mode Selector Test is done to check if we can enter different modes using the Flex Sensors that were tested in an earlier blog post to control the movements of the Prosthetic Hand by syncing different types of movements of the hand to different modes that are achieved by syncing the modes to different movements of the flex sensors.
We completed this test to verify the hook up of the Xbee so we can design a shield for it, as well as getting the Xbee to be able to send and receive data from a wireless source. Ex hand to foot and vice versa.
The Prosthetic Hand needs feedback in order to control the force of the grasp, therefore we are testing the force sensors to see if they can detect the force difference of the most minuscule item we have to grasp.


text:
As federal IT teams know, scaling IT infrastructure can be a huge challenge. Be it the proliferation of new data centers, networks, servers or applications. To be able to successfully scale, IT teams need to understand the impacts of change.
Without an end-to-end monitoring solution, this task seemed impossible for an independent federal agency with over 3,500 end users working to promote fundamental research and education. To deploy new services, whether on premise or via the cloud, IT teams need unified visibility to properly scale components of their services.
Compounding the complexities of scaling its IT infrastructure, the agency had a number of IT teams involved in maintaining its hybrid cloud environment. This included the network, operations, server, engineering, and help/service desk teams. Each team used disparate toolsets that provided fragmented visibility across the enterprise, making it difficult to proactively troubleshoot performance or end user issues.
The agency needed a solution that could provide network performance, connectivity, and unified visibility, while ensuring IT teams were on the same page. By turning to RavenTek's consultative approach and engineering expertise and applying Riverbed's SteelCentral Network Performance Monitoring (NPM) solution set, the agency was able to boost scalability through integrated network and infrastructure visibility.
Get the full use case to learn more.


text:
How to create speed dial shortcuts of your commonly called numbers depends on which model of desk phone you actually have.
The standard desk phone is the Cisco IP Phone 7945 with two round buttons to the right side of the screen. One of these is used by your incoming line, leaving one other that can be allocated to a speed dial.
The enhanced desk phone is the Cisco IP Phone 7965 with six round buttons to the right side of the screen, with five available to be programmed as speed dial numbers.
The enhanced Cisco IP Phone 7965 can also be ordered with the 7916 expansion module, which appears as an attached unit to the right side of the phone. The expansion module allows another 24 numbers to be stored as speed dial.
Go to the configuration page to create speed dial numbers for your phone.
Remember: when using your speed dial to press the desired shortcut key before picking up the receiver.


text:
Youth from Phek trained on artificial insemination in pigs
Dimapur, Dec. 5 (EMN): Krishi Vigyan Kendra (KVK), Phek, organised an exposure-cum-training programme on artificial insemination (AI) in pigs for rural youth of Phek district to ICAR Research Complex for NEH Region, Nagaland Centre, at Medziphema from November 30 to December 4. The programme was sponsored by National Bank for Agriculture and Rural Development (NABARD).
An update from KVK Phek stated that a total of 20 educated youth from 12 villages in Phek district namely Zapami, Pfutseromi, Chetheba, Porba, Chesezu, Chozuba, Sakraba, Losami, Upper Khomi, Kutsapo, Yisisotha and Zavame participated in the programme.
It stated that the director of ICAR NRC on Mithun Dr. MH Khan, in his inaugural speech, has emphasised on the prospects of commercial pig farming in Nagaland. Besides, he also spoke on the significance of artificial insemination (AI) technology in bringing superior genetics to the herd at a potentially lower cost, minimising the expenses of keeping a breeding boar and also reducing the transmission of diseases.
During the training programme, Dr. Mahak Singh, animal reproduction and gynaecology scientist from ICAR-Nagaland, explained the basic techniques of artificial insemination in pigs, while Dr. Talimoa Mollier, research associate of mega seed project on pig, practically demonstrated the techniques in farm and field condition to the youth.
Presentations on various aspects of artificial insemination in pigs were delivered by resource persons namely Dr. Vikram R, animal reproduction and gynaecology scientist from ICAR-NRC on Mithun, Medziphema; and Dr. Ebibeni Ngullie, ACTO, KVK-Dimapur, during the training session.
It stated that the youths have also availed the opportunity to visit a scientific and modern pig farms of progressive farmers namely Achumo Ngullie and Seve Vadeo located at Seithekema C and Seithekema A respectively.
The team was led by Dr. Debojyoti Borkotoky, assistant chief technical officer (Animal Science) from KVK, ICAR-NRC on Mithun, Porba in Phek district.


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Question: Is it safe to refreeze a partially thawed turkey? I started to defrost a frozen turkey for a holiday dinner, but now I've had a change in plans. Can I refreeze the turkey?
Answer: It's fine to refreeze a thawed turkey — as long as you thawed it in the refrigerator. If that was the case, you can put it right back into the freezer according to the United States Department of Agriculture. If your turkey is fully thawed, you can safely keep it refrigerated for an additional one or two days before refreezing it. When you eventually thaw the turkey a second time, you may notice a decrease in quality, but it'll certainly be safe to eat.
If, on the other hand, you thawed the turkey in cold water or the microwave, the USDA advises that you should cook it immediately. That's because with either method, the turkey could have at least temporarily warmed up to a temperature higher than 40°F. At that point, harmful bacteria can begin to multiply and only further cooking will destroy it; simply refreezing the turkey won't do the trick.
Finally, if you thawed the turkey on the counter or in hot water, you shouldn't eat it at all. The USDA cautions that it's dangerous to eat any meat or poultry that's been thawed under those two methods, as the outer layer of the food would have been allowed to sit between the bacteria-breeding temperatures of 40° F and 140° F for far too long to be safe.


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I have the following assignment question, and I'm having trouble even getting started:
Consider the set of functions $\mathcal{F}=\{f,g\}$, with $f:\mathbb{R}^2\to\mathbb{R}$, and $g:\mathbb{R}\to\mathbb{R}$, defined by $f(x,y)=xy$ and $g(x)=x+1$. Let $A=cl_\mathcal{F}(B)$, with $B=\{0\}$. I.e., $A$ is the closure of $B$ under the operations in $\mathcal{F}$. Then clearly $A=\mathbb{N}$. How would you go about showing that the following three equations, uniquely determine a function $h$?
$h(g(x))=h(x)+2$, and
What is $A$ good for? Is it necessary to show what we're being asked to show? And also, we're on the topic of primitive recursive functions and such, so I don't understand how this would fit into that topic anyway.
share|improve this question
I'd suggest replacing $f,g$ in the properties of $h$ with their given values, i.e. $xy$ and $x+1$ respectively. – hardmath Aug 16 '12 at 14:17
Are you sure about $h(f(x,y))=f(h(x),h(y))$? Maybe a typo for $h(f(x,y))=f(h(x),y)$ or something similar. – André Nicolas Aug 16 '12 at 14:20
1 Answer 1
up vote 1 down vote accepted
Using the second two equations, we have that $h(0)=0$ and $h(x+1)=h(x)+2$. Thus we can use induction to find the value of $h(x)$ for any value $x\in\Bbb N$. In fact, it is easy to see that if $x\in \Bbb N$ we have $h(x)=2x$.
Now the first condition $h(xy)=h(x)h(y)$ provides a contradiction, however, since we can take $y=1$ and find that $h(x)=2h(x)$, i.e. $2x=4x$ for $x\in\Bbb N$. Thus no function $h$ exists satisfying all three conditions, which is why André Nicolas asked if there was perhaps a typo.
share|improve this answer
Ah, I see. There must be typo (although I double checked the assignment, and that's exactly what it says). – FPP Aug 16 '12 at 14:36
Nice and simple. – mick Dec 10 '14 at 22:15
Your Answer


text:
18.12 Entitled extraction of allocated groundwater to urban water system
The volume recognised in the water accounting statements (757 ML) represents the volume of water extracted for urban water supply in the Daly region during the 2011–12 year.
The urban water supply licences relate to groundwater extraction from the Tindall aquifer for Katherine town supply.
Water Resource Licensing database and meter readings from licensees.
Department of Land Resource Management.
The volume of groundwater extracted for urban water supply is based on measured data collected at each source site within the Tindall aquifer using a cumulative water meter.
Assumptions, limitations, caveats and approximations
Expected error for water meters is +/– 2%.
The Department of Land Resource Management requires that all water meters, when tested under in situ conditions, must be within 2% accuracy across the full flow rate range. See the Department's Water meters fact sheet for more information.


text:
EVALUATION OF AN ARTIFICIAL NEURAL NETWORK TECHNIQUE APPLIED TO MULTIPLE-SENSOR WEIGH-IN-MOTION SYSTEMS
ridership - commuting, economics - appraisal/evaluation
WIM, Weigh in motion, Noise (Communications), Neural networks, Calibration, Calibrating, Axle loads, Artificial neural networks, ANNs (Artificial neural networks), Algorithms, Accuracy
Weigh-in-motion (WIM) accuracy in measuring static axle loads is affected by vehicle dynamics and noise. Neural networks can identify underlying relationships, such as the spatial repeatability in axle dynamics, and can efficiently remove noise. Furthermore, they can adapt to changing circumstances (e.g., traffic characteristics, road profile, or sensor failure), unlike conventional WIM calibration algorithms. The performance of a multilayer feed-forward artificial neural network algorithm applied to a multiple-sensor WIM is analyzed. Numerical simulations of the axle forces applied on a smooth road profile are used to train, validate, and test the artificial neural network algorithm. This dynamic axle load variation is predicted with the vehicle simulation model VESYM. The mechanical parameters of the truck models and their speeds are randomly varied over a range established from real traffic measurements. Once the theoretical WIM data are obtained at the sensor locations, the measurements are artificially corrupted with noise up to the typical level of WIM accuracy. Details are given on the process of the neural network design, the size of the training sample, and the length of the training period. The artificial neural networks approach resulted in higher accuracy than the traditional average-based calibration method, especially at high noise levels. As a result, it shows promise for estimating static axle loads from multiple WIM measurements.
Gonzalez, A, Papagiannakis, A, O'Brien, E. (2003). EVALUATION OF AN ARTIFICIAL NEURAL NETWORK TECHNIQUE APPLIED TO MULTIPLE-SENSOR WEIGH-IN-MOTION SYSTEMS. Transportation Research Record, Vol. 1855, p. 151-159.


text:
What is Sekolah Bogor Raya?
Sekolah Bogor Raya is Bogor's leading "National Plus" school. Founded in 1995, we provide both locally and internationally accredited curricula in a green and pleasant environment in the picturesque Bogor Lakeside residential complex, near the main Bogor Toll exit.
Vision & Mission
- To be a leading international standard school providing high-quality education to equip our students to excel in a rapidly-changing world.
- Sekolah Bogor Raya exists to provide international standard education to our students. Through a commitment to English Language fluency, technological expertise, and inquiry-based teaching and learning, we deliver an international program that integrates global concepts with respect for national culture and identity.
- Play Group & Kindergarten (PG/TK)
- Primary Years Programme (PYP), for students aged 3 to 12, focuses on the development of the whole child as an inquirer.... read more
- Primary School (SD)
- This is a challenging programme that demands the best from both motivated students and teachers.... read more


text:
The Tennessee School Counseling and Career Guidance Standards are statements of what students should know and be able to do as a result of participating in a school counseling program. Since the purpose of such a program is to ensure that all students can achieve school success through academic, career and personal/social development experiences, these standards represent what a school counseling and career guidance program should contain and establish similar goals, expectations, support systems and experiences for every student. The standards address the needs outlined in the educational reform agenda articulated in the State Board of Education's MASTER PLAN FOR TENNESSEE SCHOOLS by advocating school counseling programs that promote school success through a focus on academic achievement, prevention and intervention, and social/emotional and career development. The organizational design of the standards reflects the nine standards in the National Standards for School Counseling Programs developed by the American School Counselor Association, which, in turn, are based on the three widely accepted and interrelated areas of student development: academic, career, and personal and social development.
The standards and expectations
The standards were developed by a team of 33 Tennessee school counselors, teachers, administrators, parents, community members and department personnel.


one that needs to be supplied to AnnotationDbi functions for running queries and retrieving annotations.
Listing information available in an annotation package
The function columns() can be used to display the annotations available in the object.
Here, the word 'column' refers to columns of tables used to store information in database, the very same concept as 'attributes' in BioMart. In other words, columns represent all the types of annotations that may be retrieved from the object.
This is convenient as users do not need to memorise the names of the columns of annotations available in the package.
R
columns(org.Hs.eg.db)
OUTPUT
 [1] "ACCNUM" "ALIAS" "ENSEMBL" "ENSEMBLPROT" "ENSEMBLTRANS"
 [6] "ENTREZID" "ENZYME" "EVIDENCE" "EVIDENCEALL" "GENENAME"
[11] "GENETYPE" "GO" "GOALL" "IPI" "MAP"
[16] "OMIM" "ONTOLOGY" "ONTOLOGYALL" "PATH" "PFAM"
[21] "PMID" "PROSITE" "REFSEQ" "SYMBOL" "UCSCKG"
[26] "UNIPROT"
Listing keys and key types
In database terminology, keys are the values by which information may be queried from a database table.
Information being organised in columns, key types are the names of the columns in which the key values are stored.
Given the variable number of columns in database tables, some tables may allow information to be queried by more than one key. As a result, it is crucial to specify both the keys and the type of key as part of the query.
The function keytypes() can be used to display the names of the columns that may be used to query information from the object.
R
keytypes(org.Hs.eg.db)
OUTPUT
 [1] "ACCNUM" "ALIAS" "ENSEMBL" "ENSEMBLPROT" "ENSEMBLTRANS"
 [6] "ENTREZID" "ENZYME" "EVIDENCE" "EVIDENCEALL" "GENENAME"
[11] "GENETYPE" "GO" "GOALL" "IPI" "MAP"
[16] "OMIM" "ONTOLOGY" "ONTOLOGYALL" "PATH" "PFAM"
[21] "PMID" "PROSITE" "REFSEQ" "SYMBOL" "UCSCKG"
[26] "UNIPROT"
The function keys() can be used to display all the possible values for a given key type.
It is generally better practice to specify the type of key being queried (to avoid ambiguity), although database tables typically have a 'primary key' used if users do not specify a type themselves.
In the example below, we restrict the list of gene symbol keys to the first few values, as the full set comprises 193279 values.
R
head(keys(org.Hs.eg.db, keytype = "SYMBOL"))
OUTPUT
[1] "A1BG" "A2M" "A2MP1" "NAT1" "NAT2" "NATP"
Querying information from an annotation package
The function select() is the main AnnotationDbi query function. Given an AnnotationDb object, key values, and columns (and optionally the type of key supplied if not the primary key), it retrieves the columns requested by the user from the annotation object.
In the example below, we re-use the vector of arbitrary gene identifiers used in the BioMart example a few sections above.
As you can see from the output of the columns() function, the annotation object does not contain some of the attributes that we queried in the Biomart example. In this case, let us query:
 - the gene symbol
 - the gene name
 - the gene type
R
select(
 x = org.Hs.eg.db,
 keys = query_gene_ids,
 columns = c(
 "SYMBOL",
 "GENENAME",
 "GENETYPE"
 ),
 keytype = "ENSEMBL"
)
OUTPUT
'select()' returned 1:1 mapping between keys and columns
OUTPUT
 ENSEMBL SYMBOL GENENAME GENETYPE
1 ENSG00000133101 CCNA1 cyclin A1 protein-coding
2 ENSG00000145386 CCNA2 cyclin A2 protein-coding
3 ENSG00000134057 CCNB1 cyclin B1 protein-coding
4 ENSG00000157456 CCNB2 cyclin B2 protein-coding
5 ENSG00000147082 CCNB3 cyclin B3 protein-coding
One small but notable difference with biomaRt is that the output of select() automatically contains the column that correspond to the key type used in the query. In other words, there is no need to specify the key type(s) again in the column(s) to retrieve.
Vectorized 1:1 mapping
It is sometimes possible for annotations to display 1-to-many relationships. For instance, individual genes typically have a unique Ensembl gene identifier, while they may be known under multiple gene name aliases.
The select() function demonstrated in the previous section automatically returns all values in the columns requested, for the key specified. This is possible thanks to the tabular format in which annotations are returned; rows are added, repeating values as necessary to display them on the same row as every other values they are associated with.
In some cases, that behaviour is not desirable. Instead, users may wish to retrieve a single value for each key that they input. One common scenario arises during differential gene expression (DGE), where gene identifiers are used to uniquely identify genes throughout the analysis, while gene symbols are added to the final table of DGE statistics, to provide more readable human-friendly gene identifiers. However, it is not desirable to duplicate rows of DGE statistics, and thus only a single gene symbol is required to annotate each gene.
The function mapIds() can be used for this purpose. A major difference between the functions mapIds() and select() are their arguments column (singular) and columns (plural), respectively. The function mapIds() accepts a single column name and returns a named character vector where names are the input query values, and values are the corresponding values in the requested column.
To deal with 1-to-many relationships, the function mapIds() has an argument multiVals which can be used to specify how the function should handle multiple values. The default is to take the first value and ignore any other value.
In the example below, we query the gene symbol for a set of Ensembl gene identifiers.
R
mapIds(
 x = org.Hs.eg.db,
 keys = query_gene_ids,
 column = "SYMBOL",
 keytype = "ENSEMBL"
)
OUTPUT
'select()' returned 1:1 mapping between keys and columns
OUTPUT
ENSG00000133101 ENSG00000145386 ENSG00000134057 ENSG00000157456 ENSG00000147082
 "CCNA1" "CCNA2" "CCNB1" "CCNB2" "CCNB3"
Challenge
Load the packages EnsDb.Hsapiens.v86 and TxDb.Hsapiens.UCSC.hg38.knownGene. Then, display the columns of annotations available in those packages.
R
library(EnsDb.Hsapiens.v86)
columns(EnsDb.Hsapiens.v86)
OUTPUT
 [1] "ENTREZID" "EXONID" "EXONIDX"
 [4] "EXONSEQEND" "EXONSEQSTART" "GENEBIOTYPE"
 [7] "GENEID" "GENENAME" "GENESEQEND"
[10] "GENESEQSTART" "INTERPROACCESSION" "ISCIRCULAR"
[13] "PROTDOMEND" "PROTDOMSTART" "PROTEINDOMAINID"
[16] "PROTEINDOMAINSOURCE" "PROTEINID" "PROTEINSEQUENCE"
[19] "SEQCOORDSYSTEM" "SEQLENGTH" "SEQNAME"
[22] "SEQSTRAND" "SYMBOL" "TXBIOTYPE"
[25] "TXCDSSEQEND" "TXCDSSEQSTART" "TXID"
[28] "TXNAME" "TXSEQEND" "TXSEQSTART"
[31] "UNIPROTDB" "UNIPROTID" "UNIPROTMAPPINGTYPE"
R
library(TxDb.Hsapiens.UCSC.hg38.knownGene)
columns(TxDb.Hsapiens.UCSC.hg38.knownGene)
OUTPUT
 [1] "CDSCHROM" "CDSEND" "CDSID" "CDSNAME" "CDSPHASE"
 [6] "CDSSTART" "CDSSTRAND" "EXONCHROM" "EXONEND" "EXONID"
[11] "EXONNAME" "EXONRANK" "EXONSTART" "EXONSTRA


text:
A Short Biographical Dictionary of English Literature/Simms, William Gilmore
|←Sigourney, Mrs. Lydia||A Short Biographical Dictionary of English Literature by
Simms, William Gilmore
Simms, William Gilmore (_PHONE_). -- Novelist, etc., b. at Charleston, South Carolina, began his literary life with journalism. He then for some time tried poetry, but without any distinct success except occasionally in Southern Passages and Pictures (1839). But in fiction, which he began in 1833 with Martin Faber, he was more successful, though rather an imitator of Cooper. The Yemassee (1835) is generally considered his best novel. He was less happy in his attempts at historical romance, such as Count Julian and The Damsel of Darien. During the war, in which he was naturally a strong partisan of the South, he was ruined, and his library was burned; and from these disasters he never recovered. He hadpage 345 a high repute as a journalist, orator, and lecturer. He was the first Southerner to achieve any name in literature.


Making A Behaviour Flow Cosmograph
behaviour-flow (1)Making a what? I saw an article on the E90E50fx guys blog about making a bilateral flow chart — a cosmograph — in Excel, and it made me think of the behaviour flow chart in Google Analytics. I got thinking this would be a great application for the idea, and I love great visualizations, especially in Excel reports! Download the workbook.
behaviour-flow-diagramCosmographs have been around since at least 1939, and they show how a set of items splits into sub-groups. Google used a version of them in the Behaviour Flow diagrams they use, and I always liked them. In case you didn't notice, you can click on one of the starting groups and select to highlight traffic through the chart from that source. Visually powerful!
In the source article, the guys provide a somewhat working example of a flow diagram, but it is very heavy in formulas and advanced Excel techniques. In a somewhat uncharacteristic move for me, I have layered yet more formulas on top of it to enable the chart to be used with Google Analytics data from the Analytics Edge Simply Free tools.
The result: an interactive behaviour flow chart showing how the top 10 sources for your website map to the top 10 landing pages. The workbook uses a mouse rollover, or interactive hyperlink technique so you simply move the cursor over the text in the left (source/medium) or right (landing page) columns and the display will highlight the traffic from/to the selected item.
Adding the Google Analytics Data
After looking at the sample provided, I quickly realized I didn't want to mess with the thousands of formulas spread across 5 worksheets. My objective was to clean it up and get it working with some Source-Landing Page data. Their visualization is based on a table of data, so my first challenge was to populate that table with my data without breaking all the formula references.
I wanted the top 10 Sources and the top 10 Landing Pages, and I while there may be some Excel wizardry that can produce an Excel pivot table like I want, dropping it into the worksheet without breaking all the formulas was highly unlikely. I took a different approach: I made three queries using Analytics Edge: the first was the Source/Medium, Landing Page, and Sessions data for my site; the second was the top 10 Source/Mediums by Sessions, and the third was the top 10 Landing Pages by Sessions.
top-10-queryGetting the top 10 reports is simply sorting the queries by Sessions and restricting the output to only 10 rows.
The big query with everything may give you problems if your site is really busy and has lots of unique pages and/or sources. In that case, you can sort descending Sessions and cap the query to 10,000 rows to limit all the little stuff. Since we are only interested in the top 10 of each, it is very likely all the meaningful combinations of the two will appear in the first 10,000 rows.
The next thing I did was to create a typical Excel pivot table of the big query results, pivoting the landing pages to the columns and the sources to the rows with the sum of sessions in the cells. The pivot table is BIG, but it should contain the combinations we are interested in. The next challenge is to get the specific combinations of the top source and the top landing page to appear in the target table. For that, I used Excel's GETPIVOTTABLE function.
=GETPIVOTDATA("Sessions",QueryResults!$E$13,$B$6,$B7,$C$5,D$6)
using-getpivottable-formula-for-top-10I grabbed the row and column labels from my top 10 queries, then grabbed each of the table cell values using the GETPIVOTTABLE function. That allowed me to lookup the #1 source and #1 landing page from the pivot table and place it in the correct position in the target table. Since I was just changing the formulas in the table cells, all the other worksheet formulas referencing them were unaffected, and they simply used the new values.
Not So Smooth
smoothing-overshoot-300x230Next on the list of modifications was to turn off the smoothing they applied to the curves in the chart. Excel's smoothing algorithm has a side effect that is overshoots the original point, and I found that distracting, so I turned it off.
You do that by selecting the chart, then from the Chart Tools-Layout ribbon, pick the Series "all", and Format Selection to open the format dialog. On the Line Style section, uncheck Smoothed line. Repeat for the Series "my_selection".
Adding Space For a Logo
I like my reports to have space at the top for a logo and a description of some kind, but the original worksheet packed everything to the top of the sheet. Inserting a few rows caused some problems with the formulas…sigh. It ended up being a simple fix, but took a while to figure it out.
=IF(ROW(A1)>ROWS(label_x),"",IF(AND(ROW(A1)=my_x...
The left and right listings used a technique of indexing based on the row number, and by inserting rows at the top, the indexes were thrown off. I had to change them to start at ROW(A1) again, and then the mouse rollover worked properly. The background highlighting was still out of sync, though.
conditional-formatting-rule-300x291It turns out they use Conditional Formatting to get that background highlighting effect, so I had to edit the Conditional Formatting Rules and perform a similar re-alignment back to ROW(A1).
=AND(ROW(A1)=my_x,2=my_y)
Now everything highlights as it should! Keep that in mind if you want a little more space…
I also moved a handful of cells from the worksheet with the chart on it to one of the other worksheets. I find it is just a bad idea to expose configuration or intermediate cells to the user on the report worksheet.
Purging Excess Formulas
The original worksheet could handle a table about 20 x 20 in size, and I was intentionally restricting it to 10 x 10. Since that translates to 4 times more formulas that must be recalculated as you move the mouse around, I took a big dive into spreadsheet hell and purged the non-essential formulas form the workbook.
If you want to get them back, you'll have to learned about the magic and mysteries of array formulas in Excel (Step1 worksheet).
Also, depending on the settings of line n_mult cell and the one immediately below it, you can affect the number of lines and gap between item groups in the chart. That, in turn must be supported by enough rows on sheets Step2 and Step3. You have been warned.
Modification Possibilities
So many things could be done with this visualization…but the easiest is to change the dimensions for the Analytics Edge queries. You can map pretty much anything to anything, and it would be done without affecting any of the formulas, so you could be done in a minute.
If you are a real glutton for punishment, you could try creating a conversion funnel with the technique. There comes a point, though, where you have to ask yourself whether Excel is the right tool for this type of visualization?
For now, this little bit works, and it's free. Enjoy!


Jeff of the Jungle swings on a vine that is 7.20 {\rm m} long (see the figure). Atthe bottom of the swing, just before hitting the tree, Jeff'slinear speed is 8.50 {\rm m}/{\rm s}. Suppose that atsome point in his swing Jeff of the Jungle has an angular speed of0.750 rad/s and an angular acceleration of0.640 rad/s^2.
the magnitude of his centripetal acceleration is 4.05m/s2
the magnitude of his tangential accelerationi 4.61 m/s2
I don't know how the find the magnitude of his total accelerationand the angle of his acceleration makes with respect to thetangential direction of motion?
I keep getting the angle wrong. the magnitude of his totalacceleration is 6.13 but the angle is not 48.7
Get this answer with Chegg Study


RIVER VOLUME
The river volume is determined by these four factor mentioned below. There are 1. The size of drainage basin A larger drainage basin will have a greater volume of water. This is because there is a greater tributaries bringing water to the river resulting in a higher surface runoff. 2. The presence of vegetation The […]
Read More RIVER VOLUME


licenciatura en educación preescolar"
Discussion in 'Spanish-English Vocabulary / Vocabulario Español-Inglés' started by KateNicole, Mar 29, 2007.
 1. KateNicole Senior Member
 Miami, Florida
 English (USA)
 Again, this question pertains to someone's transcripts. This person studied "educación preescolar" which includes kindergarten. I don't want to translate this as "preschool education," because in the United States, people can teach preschool with a two-year degree. This person studied at a four-year university. I was thinking about translating it as Preschool and Kindergarten Education, but am wondering if anyone has a better idea. Thanks!
 2. chileno1975 Junior Member
 How about something like "BA in Early Childhood Education," just to cover everything? That wouldn't cover "elementary education," right?
 3. KateNicole Senior Member
 Miami, Florida
 English (USA)
 That's exactly what I was thinking, but I am hesitant because I believe that in certain 2-year technical schools, people that teach day care (not even preschool) can get a degree in Early Childhood Education. Not that I am belittling that degree, but I don't want to "water down" what this person studied. Maybe if I put "B.A." like you have suggested, it will be more clear. Thanks.
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text:
Purpose: We conducted a phase I study in chemotherapy-naive patients with advanced non-small-cell lung cancer (NSCLC) to determine the maximumtolerated dose (MTD) of paclitaxel using an extended weekly schedule. Patients and Methods: Patients with stage IIIB/IV NSCLC were treated with paclitaxel administered weekly over 3 hours for 6 weeks of an 8-week cycle. Doses were modified for granulocyte counts less than 1,800/μL or neurotoxicity greater than grade I. Groups of three patients were entered at each dose level. The dose was escalated to the next level if less than 50% of patients developed unacceptable toxicity and received more than 80% of the intended first-cycle dose. Results: Twenty-six patients were entered through six dose levels (100, 125, 135, 150, 175, and 200 mg/m2/wk). Four of six patients at the 175-mg/m2 dose level and only one of six patients at the 200-mg/m2 level received all scheduled doses of paclitaxel during cycle I. Neutropenia was dose-limiting. Four-teen patients were treated with subsequent cycles of paclitaxel. Grade II to III neuropathy developed in five of 24 patients. It occurred more commonly with greater duration of therapy, but improved following dose reduction. Nine of 26 (35% ± 10%) patients demonstrated an objective response. Conclusion: The MTD of paclitaxel using a weekly schedule is 175 mg/m2/wk for 6 of 8 weeks. Neutropenia limits dosing acutely, but neuropathy is limiting with sustained therapy. This schedule of paclitaxel results in a twofold to threefold increase in dose-intensity with less toxicity than anticipated from conventional dosing. Further evaluation of this schedule is warranted to assess efficacy and toxicity of prolonged administration.
All Science Journal Classification (ASJC) codes
- Cancer Research


5 Traits of Successful Law School Applicants
On your applications, prove you possess these characteristics.
Business team at a meeting.
You already know that you typically need a high GPA and LSAT score to earn admission to the top law schools, but those are not the only important factors in your law school application.
Here are five traits that every law school candidate should ideally demonstrate in his or her application:
1. Intellectual curiosity: While your college transcript and GPA may speak for themselves in terms of your academic potential and work ethic, you should consider highlighting a specific academic project, like a thesis, to illustrate your intellectual curiosity.
Lawyers spend much of their time reading about, researching, and analyzing complex situations, so law schools want to see that you not only have these skills but also enjoy this type of work.
2. Ethics: Lawyers are held to an extraordinarily strict code of conduct, and one serious infraction can lead to disbarment. No law school wants its name to be associated with such a case, so admissions officers are looking for applicants who hold themselves to the highest ethical standards.
You do not need to (and should not) explicitly profess your honesty, but you should include examples that show your commitment to integrity. You might also ask your recommenders to speak to this critical factor.
If you have any kind of criminal record (even if it has been expunged) or you have been arrested, you will almost certainly have to disclose this in your application. Honestly and directly explain the situation and show the admissions committee that you learned from this misstep and are not defined by it. Do not be tempted to lie about criminal matters on your application as the consequences can be very severe and could even include not being admitted to the bar.
3. A passion for law: Having a personal and meaningful reason for going to law school is essential for a successful application. With many college graduates still applying to law school because they are having trouble finding employment, you need to prove to the law schools that you truly want to practice law.
Try to pinpoint a defining moment in your life that made you decide to go into law. You might also discuss what you plan to do with your law degree in the short and long term.
4. Tenacity: Lawyers are often up against seemingly impossible odds, whether in a courtroom or a boardroom, so law school admissions committees are looking for applicants who have faced challenges in the past and successfully overcame them.
Think back to a time when you faced an obstacle in a class, in a job or internship, or in a more personal context, and use that experience in your application to demonstrate your determination, resilience, and perseverance. Be sure to focus on your role in surmounting the challenge and what you learned from this trying ordeal.
5. Leadership: Holding a leadership position requires a range of skills that law schools highly value, such as organization, the ability to communicate effectively with diverse individuals, and assertiveness. You can gain leadership experience in clubs at your undergraduate institution, through class projects, and at work or in your internships.
When explaining a leadership experience in your essays, mention how you were selected to undertake this role, what positive impact you were able to make, and any lessons you learned from your experience.
What makes you an excellent law school applicant? Let me know in the comments below, E-mail me at _EMAIL_, or contact me via Twitter at _USER_.


text:
European consumption experts today called for a new research policy on sustainable food consumption. Facing recent food crises around the globe, European food research should set new priorities, advocated researchers and policy makers from all over Europe. More than 100 experts have jointly developed a "Research Agenda for Sustainable Food Consumption in Europe", which sets the stage for pressing challenges to be addressed in coming years. Hot topics on the agenda include sustainable diets such as the reduction of meat consumption and animal-based products as well as sustainable food supply chains, e.g., strengthening local food systems. In light of the current hunger crisis in East Africa, reducing global food inequality gains a new and special significance.
"Going forward towards more sustainable food consumption requires a sound prioritisation of the relevant topics involved", states Gerd Scholl, scientist at the Berlin-based Institute for Ecological Economy Research (IÖW). "The new research agenda is the result of collaboration between food and consumption specialists from all over Europe. It offers a strategic and comprehensive approach for designing an innovative research policy in this domain."
The research agenda has been developed by the European consortium CORPUS, which connects researchers and policy makers from all over Europe, in order to work jointly on sustainable consumption policies. The agenda results from a series of three workshops addressing, amongst other topics, current food trends, policy instruments and future visions for sustainable food. "Such a close cooperation on this topic is unique", says Gerd Scholl. "The expertise of the different professionals involved gives weight to the topics listed in the common research agenda. We call on European research policy to further endorse strategic research on sustainable food consumption."
The consortium "CORPUS – Enhancing the connectivity between research and policy-making in sustainable consumption" is funded within the EU Seventh Framework programme. It aims to experiment with, and develop, new integrative modalities of knowledge brokerage on sustainable consumption policies. In addition to sustainable food, the consortium addresses the domains of sustainable mobility and sustainable housing. The website _URL_ has been established as a platform for knowledge exchange and professional networking. The documentation of the food workshop series is available at: _URL_
Further information on the CORPUS Food Group:


text:
In an effort to help mitigate the spread of COVID-19, we were not able to host Kadir Nelson for the Marian McFadden Memorial Lecture in either 2020 or 2021. We are working to explore the possibility of rescheduling the lecture and will continue to communicate the details for 2022. We still plan to welcome Kadir and hope you can join us!
Kadir Nelson is a painter, illustrator, and author well known for his work featuring African-American culture and history. Just a few weeks after high school graduation his career was launched as a conceptual artist for Steven Spielberg's film, Amistad. Since that time he has had work featured in both Sports Illustrated and National Geographic, painted numerous covers for The New Yorker magazine, and created cover art for albums by the recording artists Drake and Michael Jackson. His paintings include a portrait of Shirley Chisholm which hangs in the US Capitol Building and other works shown in the National Museum of African American History & Culture and the Baseball Hall of Fame.
In addition to these distinguished accomplishments, Nelson has also authored and/or illustrated over 30 books for children. His most recently published illustrative work, The Undefeated, is a poetic love letter to black America written by Kwame Alexander. The Undefeated was recently awarded both The 2020 Randolph Caldecott Medal and the 2020 Coretta Scott King Award for Illustration.
Take a Look at Kadir Nelson's Work:
"I feel that art's highest function is that of a mirror, reflecting the innermost beauty and divinity of the human spirit; and is most effective when it calls the viewer to remember one's highest self. I choose subject matter that has emotional and spiritual resonance and focuses on the journey of the hero as it relates to the personal and collective stories of people."
~ Kadir Nelson
The Marian McFadden Memorial Lecture Series was established after the Library Foundation received a gift from the estate of Marian McFadden, Director of Public Libraries in Indianapolis from _PHONE_. This annual author lecture series, which typically takes place in the Spring, was named in her honor.
Made possible by Friends of the Library through gifts to The Indianapolis Public Library Foundation.


text:
Textures and UVs
Textures are pixel maps, usually image files, you use to control surface values such as color, opacity, displacement, and so on.
To map textures to surfaces, Houdini must know which parts of the pixel map should appear on which parts of the surface. You do this by putting UV coordinates attributes on the surface, which map to pixels in the texture. In Houdini, you need to add UVs to all surface types. NURBS surfaces do not automatically have UV coordinates.


text:
simulation as a substitution for human annotation efforts to train high-performing prediction algorithms such as the DNNs.
Recent work has focused on generating synthetic imagery to increase the size and variability of training data for learning visual tasks in urban scenes. This includes increasing the occurrence of occlusions or varying environmental and weather effects. However, few have addressed modeling variation in the sensor domain. Sensor effects can degrade real images, limiting generalizability of network performance on visual tasks trained on synthetic data and tested in real environments. This paper proposes an efficient, automatic, physically-based augmentation pipeline to vary sensor effects --chromatic aberration, blur, exposure, noise, and color cast-- for synthetic imagery. In particular, this paper illustrates that augmenting synthetic training datasets with the proposed pipeline reduces the domain gap between synthetic and real domains for the task of object detection in urban driving scenes.
Performance on benchmark datasets has drastically improved with advances in deep learning. Still, cross- dataset generalization performance remains relatively low due to the domain shift that can occur between two different datasets. This domain shift is especially exaggerated between synthetic and real datasets. Significant research has been done to reduce this gap, specifically via modeling variation in the spatial layout of a scene, such as occlusions, and scene environmental factors, such as time of day and weather effects. However, few works have addressed modeling the variation in the sensor domain as a means of reducing the synthetic to real domain gap. The camera or sensor used to capture a dataset introduces artifacts into the image data that are unique to the sensor model, suggesting that sensor effects may also contribute to domain shift. To address this, we propose a learned augmentation network composed of physically-based augmentation functions. Our proposed augmentation pipeline transfers specific effects of the sensor model --chromatic aberration, blur, exposure, noise, and color temperature-- from a real dataset to a synthetic dataset. We provide experiments that demonstrate that augmenting synthetic training datasets with the proposed learned augmentation framework reduces the domain gap between synthetic and real domains for object detection in urban driving scenes.
Recent work has shown that convolutional neural networks (CNNs) can be applied successfully in disparity estimation, but these methods still suffer from errors in regions of low-texture, occlusions and reflections. Concurrently, deep learning for semantic segmentation has shown great progress in recent years. In this paper, we design a CNN architecture that combines these two tasks to improve the quality and accuracy of disparity estimation with the help of semantic segmentation. Specifically, we propose a network structure in which these two tasks are highly coupled. One key novelty of this approach is the two-stage refinement process. Initial disparity estimates are refined with an embedding learned from the semantic segmentation branch of the network. The proposed model is trained using an unsupervised approach, in which images from one half of the stereo pair are warped and compared against images from the other camera. Another key advantage of the proposed approach is that a single network is capable of outputting disparity estimates and semantic labels. These outputs are of great use in autonomous vehicle operation; with real-time constraints being key, such performance improvements increase the viability of driving applications. Experiments on KITTI and Cityscapes datasets show that our model can achieve state-of-the-art results and that leveraging embedding learned from semantic segmentation improves the performance of disparity estimation.
Path planning for autonomous vehicles in arbitrary environments requires a guarantee of safety, but this can be impractical to ensure in real-time when the vehicle is described with a high-fidelity model. To address this problem, this paper develops a method to perform trajectory design by considering a low-fidelity model that accounts for model mismatch. The presented method begins by computing a conservative Forward Reachable Set (FRS) of a high-fidelity model's trajectories produced when tracking trajectories of a low-fidelity model over a finite time horizon. At runtime, the vehicle intersects this FRS with obstacles in the environment to eliminate trajectories that can lead to a collision, then selects an optimal plan from the remaining safe set. By bounding the time for this set intersection and subsequent path selection, this paper proves a lower bound for the FRS time horizon and sensing horizon to guarantee safety. This method is demonstrated in simulation using a kinematic Dubin's car as the low-fidelity model and a dynamic unicycle as the high-fidelity model.
An accurate depth map of the environment is critical to the safe operation of autonomous robots and vehicles. Currently, either light detection and ranging (LIDAR) or stereo matching algorithms are used to acquire such depth information. However, a high-resolution LIDAR is expensive and produces sparse depth map at large range; stereo matching algorithms are able to generate denser depth maps but are typically less accurate than LIDAR at long range. This paper combines these approaches together to generate high-quality dense depth maps. Unlike previous approaches that are trained using ground-truth labels, the proposed model adopts a self-supervised training process. Experiments show that the proposed method is able to generate high-quality dense depth maps and performs robustly even with low-resolution inputs. This shows the potential to reduce the cost by using LIDARs with lower resolution in concert with stereo systems while maintaining high resolution.
One of the major open challenges in self-driving cars is the ability to detect cars and pedestrians to safely navigate in the world. Deep learning-based object detector approaches have enabled great advances in using camera imagery to detect and classify objects. But for a safety critical application, such as autonomous driving, the error rates of the current state of the art are still too high to enable safe operation. Moreover, the characterization of object detector performance is primarily limited to testing on prerecorded datasets. Errors that occur on novel data go undetected without additional human labels. In this letter, we propose an automated method to identify mistakes made by object detectors without ground truth labels. We show that inconsistencies in the object detector output between a pair of similar images can be used as hypotheses for false negatives (e.g., missed detections) and using a novel set of features for each hypothesis, an off-the-shelf binary classifier can be used to find valid errors. In particular, we study two distinct cues - temporal and stereo inconsistencies - using data that are readily available on most autonomous vehicles. Our method can be used with any camera-based object detector and we illustrate the technique on several sets of real world data. We show that a state-of-the-art detector, tracker, and our classifier trained only on synthetic data can identify valid errors on KITTI tracking dataset with an average precision of 0.94. We also release a new tracking dataset with 104 sequences totaling 80,655 labeled pairs of stereo images along with ground truth disparity from a game engine to facilitate further research. The dataset and code are available at _URL_
This paper reports on WaterGAN, a generative adversarial network (GAN) for generating realistic underwater images from in-air image and depth pairings in an unsupervised pipeline used for color correction of monocular underwater images. Cameras onboard autonomous and remotely operated vehicles can capture high resolution images to map the seafloor, however, underwater image formation is subject to the complex process of light propagation through the water column. The raw images retrieved are characteristically different than images taken in air due to effects such as absorption and scattering, which cause attenuation of light at different rates for different wavelengths. While this physical process is well described theoretically, the model depends on many parameters intrinsic to the water column as well as the objects in the scene. These factors make recovery of these parameters difficult without simplifying assumptions or field calibration, hence, restoration of underwater images is a non-trivial problem. Deep learning has demonstrated great success in modeling complex nonlinear systems but requires a large amount of training data, which is difficult to compile in deep sea environments. Using WaterGAN, we generate a large training dataset of paired imagery, both raw underwater and true color in-air, as well as depth data. This data serves as input to a novel end-to-end network for color correction of monocular underwater images. Due to the depth-dependent water column effects inherent to underwater environments, we show that our end-to-end network implicitly learns a coarse depth estimate of the underwater scene from monocular underwater images. Our proposed pipeline is validated with testing on real data collected from both a pure water tank and from underwater surveys in field testing. Source code is made publicly available with sample datasets and pretrained models.
Online control design using a high-fidelity, full-order model for a bipedal robot can be challenging due to the size of the state space of the model. A commonly adopted solution to overcome this challenge is to approximate the full-order model (anchor) with a simplified, reduced-order model (template), while performing control synthesis. Unfortunately it is challenging to make formal guarantees about the safety of an anchor model using a controller designed in an online fashion using a template model. To address this problem, this paper proposes a method to generate safety-preserving controllers for anchor models by performing reachability analysis on template models while bounding the modeling error. This paper describes how this reachable set can be incorporated into a Model Predictive Control framework to select controllers that result in safe walking on the anchor model in an


Faking a Graphical Link
Having text links is extremely important for your internal site navigation since internal links do count for link popularity purposes and the context of your incoming links is very important. Graphical links simply do not provide the same amount of context as a text link does. So basically you can choose to have a graphical menu and get almost no context benefit from it, or you can have a text based menu with your keywords in the links and get a significant context benefit from it.
But what if you could have your cake and eat it too? There is a way. You can fake graphical links.
Now before I get into the meat of this article let me say that you don't always need to have text links in your menu. Changing a graphical link to your "Contact" page to a text link isn't going to give you any real benefit. However, using this site as an example, by using "Search Engine Optimization" as the text we use to link to our SEO category on the menu to the left we are giving that category page a substantial benefit.
So if you're not going to use keywords in your menu you might as well not worry about if it is text based or not.
Now lets talk about faking graphical links. There are two main ways you can get the appearance of a graphical menu while keeping keyword rich text. I will describe each below.
Method 1: Giving Links a Background
We'll start with the best method first so you can skip the remaining pages of this article. Using CSS you can specify a background image for just about anything, including a text link. You can also change this background image using the hover pseudo-class. The end result is a javascript-less image rollover on a text link. Simple huh? Well yes, but not quite that simple. There are a few quirks you should be aware of.
First of all, like any other image rollover, you'll want to preload your images using the javascript below:


Your position:Home > News
Baking-free brick machine investment is booming in China
Baking-free brick machine, be capable of producing the products divided into baking-free brick, hollow brick, standard brick or block is widely used in new type wall buildings. Baking-free brick features cannot be achieved by any other wall bricks in that baking-free brick uses reasonable scientific formula and join into coagulate agent and trace chemical additive according to certain proportion. As a result, the degree of granularity, moisture mixed with reasonable reinforcement processing equipment technology bring the best plastic state after the high pressure molding and rapid hardening make brick.The longer, the better the results will be.
Compared with the traditional red brick, baking-free brick has many advantages as follows:
1. The recycling, saving soil, energy saving
2. The source of raw materials is extremely broad
3. To protect environment—environmental friendly
4. High strength weathering resistance, corrosion resistance and freeze resistance is not afraid of water
Baking-free brick without natural maintenance will greatly improve the work efficiency and increase our output so as to raise our profit, which makes baking-free brick machine more prevailing in different building site.
SKYPE: kevinlee02
QQ: 81573401
Tel: 0086-371-87091886
Design & Development by sinoart


Reviewing Code for Race Conditions
Revision as of 11:10, 13 August 2007 by EoinKeary (Talk | contribs)
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OWASP Code Review Guide Table of Contents
Race conditions: Race Conditions occur when a piece of code does not work as it is supposed to (like many security issues). They are the result of an unexpected ordering of events which can result in the finite state machine of the code to transition to a undefined state and also give rise to contention of more than one thread of execution over the same resource. Multiple threads of execution acting or manipulating the same area in memory or persisted data which gives rise to integrity issues.
How they work:
With competing tasks manipulating the same resource we can easly get a race condition as the resource is not in step-lock or utilises a token based multi-use system such as semaphores.
Say we have two processes (Thread 1, T1) and (Thread 2, T2). The code in question adds 10 to an integer X. The initial valus of X is 5.
X = X + 10
So with no controls surrounding this code in a multithreaded environment we get the following problem:
T1 places X into a register in thread 1
T2 places X into a register in thread 2
T1 adds 10 to the value in T1's register resutling in 15
T2 adds 10 to the value in T2's register resulting in 15
T1 saves the register value (15) into X.
T1 saves the register value (15) into X.
The value shoild actually be 25 as each Thread added 10 to the initial value of 5. But the actual value is 15 due to T2 not letting T1 save into X before it takes a value of X for its addition.
How to locate the potentially vulnerable code
Look for code which used multithreaded environments:
Keywords such as:
Vulnerable Patterns for Race Conditions
Static methods (One per class, not one per object) are an issue perticularly if there is a shared state among multiple threads. For example in Apache struts static members should not be used to store information relating to a particular request. The same instance of a class can be used by multiple threads and the value of the static member can not be guarenteed.
Instances of classes do not need to be thread safe as one is made per operation/request. Static states must be thread safe.
 1. References to static variables, these much be thread locked.
 2. Releasing a lock in places other then finally{} may cause issues
 3. Static methods that alter static state
Good Patterns & procedures to prevent Race Conditions
Related Articles


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The Gather Procedure takes an input vector that is distributed across all the processors and gathers it into another distributed vector or array according to an indirect index vector or array. No collisions are possible, since this call is effectively pulling values out of a distributed variable, and there is a different location for each pulled value. This is the opposite of the Scatter procedure.
|call Gather (Output, Input, Index, Trace)|
|Index||An optional integer vector or array of indirect references to positions in the Input vector. This must be included on the first call to this procedure with a given data structure, but may be omitted on subsequent calls if the Trace variable is present. [Optional]|
|Input||A real, integer or logical vector that is distributed across all the processors.|
|Trace||An optional structure that stores the setup from a previous Gather/Scatter call using the same Index variable and Input vector length. If Trace is present and uninitialized, it is set by this procedure. If Trace is present, it is used regardless of whether Index is present.|
|Output||The gathered version of the Input vector, distributed across the processors.|
|Trace||If present, Trace is set to the setup information for this Gather/Scatter. [Optional]|
The Gather code listing contains additional documentation.
Michael L. Hall


text:
Feel the Flow
How are reactor technologies supporting pharma companies?
Maryam Mahdi | | Interview
This article was published in our sister publication, The Small Molecule Manufacturer, which celebrates the field of small molecule drug development and manufacturing with interviews and articles focusing on success stories, equipment, and new processing techniques. Read more about The Small Molecule Manufacturer here _URL_
Continuous flow reactor technologies are used by pharma companies for the flexible optimization and production of chemical products. The technologies rely on micro channels to facilitate chemical reactions and have become a staple for the industry. Here, we talk to Alessandra Vizza, regional business director, Corning Advanced-Flow Reactors, at Corning Inc, about the benefits of these tools – and how she expects them to evolve in coming years.
How do flow reactor technologies work? And why are they so important for pharma?
Flow chemistry is an inherently safer alternative to traditional batch processing and involves the continuous flow of process chemicals through tubes or channels. In a continuous flow application, two or more reagents are continuously supplied into the reactor, where they react in tubes to produce the required product. Though batch processing techniques are the norm in pharma, they can have shortcomings when it comes to efficiency, quality control, and safety. There are less inherent risks associated with flow reactors because they have much lower reaction volumes than batch reactors. In addition, due to the precise control offered by flow reactors, there is greater capability to optimize and scale reactions than is available in batch reactors. Parameters such as time, temperature, and molecular ratios of reagents can be fine tuned.
The technology has a number of applications but can be particularly useful for rapid library synthesis. Small amounts of drug compounds can be quickly synthesized and screened, allowing companies to build robust libraries in a cost-efficient way.
When the systems were first introduced, some were dubious about their capabilities; after all, pharma is generally a conservative industry and companies like to stick to what they know, to avoid potential downtime, additional costs or changes to the manufacturing process. Unlike other reactor technologies, flow reactors allow improved heat transfer and mass balance control, which gives companies the opportunity to reap the rewards of more selective and cleaner reactions. Our reactor technologies feature the HEART design fluidic module, a uniquely designed and meticulously engineered reactor plate made of either specialty glass or specialty silicon carbide, which allows for rapid scale-up from lab scale to commercial production, as well as improvements to heat and mass transfer.
How have reactor technologies changed over the years?
Flow reactor technologies were originally used by chemical engineers in other industries as process intensification tools, but the technologies have changed over the years to accommodate the needs of the pharmaceutical industry. For example, in the 1990s to early 2000s, microreactors were increasingly used in academia, mainly for process intensification. We saw an opportunity to leverage our expertise in glass science to build a microreactor for pharmaceutical applications. The existing technology could only serve small quantities of chemicals, so we moved from micro- to meso-scale reactors to accommodate larger quantities of chemicals, while maintaining the advantages (small footprint, increased efficiency, scalability, yields, and quality of chemical processing, and so on.)
We set up our first reactor – the G1 – in 2007, and it's still available today. We have made mechanical and aesthetic improvements over the years, but the base technology remains the same.
Options since then have expanded significantly. A range of reactor products are now available for lab to industrial unit production, as well as a combination of glass and silicon carbide materials. Reactors are also available that can be used in process development and for small production, as well as plug and play lab reactor systems that can be scaled up when needed. There are also reactors that specialize in low flow, using lower quantities of reactants.
In 2018, we added a G3 photo reactor to our portfolio. The G3 is dedicated to large tonnage photochemical production, and features high chemical durability, thermal control, mixing with LED illumination panels that offer light penetration on both sides of glass fluidic modules, each with an internal volume of 60 ml. The G3 also features a tunable LED light source with one dedicated wavelength that can be selected based on requirements.
Whether companies are focused on R&D or final stage production, a catalog of tools that can manage different production scales and lab specifications must be the cornerstone of any company with a vested interest in creating technologies for the pharma industry.
How do you advise your customers to maintain technologies to ensure longevity?
Other than thorough and regular cleaning, reactor technologies don't require challenging or time-consuming upkeep to maintain quality function. But I think it's important to train customers how to use technologies effectively – because they will ultimately be interacting with the systems on a daily basis. You can't just sell a system; your application engineers need to be available for on-site visits to modify reactor configurations when customers need support.
What will the reactor technologies of the future look like?
I think it is important to focus on short-term goals. The priority for advanced flow reactor technology now is to respond quickly and efficiently to market and pharma industry needs. We must facilitate adoption of continuous manufacturing for pharma production to help lower manufacturing costs, reduce quality issues in the manufacturing of pharmaceutical products, and increase availability of quality medicines for patients.
Creating technologies better suited to customer needs and ironing out quality issues should help to avoid shortages and make medicines available more quickly. Designing smaller flow reactors will also save room in manufacturing plants, reduce the risk of injuries, and cut down on costs, creating inherently safer and economically viable options for companies. Small and achievable steps forward will ultimately lead to great successes for these tools and the professionals who work with them.
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Frequently Asked Questions
What is stucco?
Stucco is a plaster made from Portland cement, sand and water which is applied to exterior or interior building surfaces and dries to a hard dense finish. Stucco is used for siding or to cover concrete, wood framing, cinderblock and brick.
What are the advantages of stucco?
Stucco is a strong and durable cost effective finish that can be used in a wide variety of climates. It offers versatility in color and texture and it can be used over wood framing, brick, steel, and concrete. Stucco offers a high degree of energy efficiency, is durable in high humidity environments, offers fire resistance and is low maintenance.
What kind of versatility does stucco offer?
A lot! Stucco can be applied in virtually any color and a wide variety of textures. Pigments are used to achieve color and texture is achieved through the use of different sized aggregates and through the application technique. The proper use of color, texture and technique can even manipulate the appearance of stucco to resemble other materials such as wood and metal.
Is there only one stucco system?
No, there are three different stucco systems in common use:
I. Exterior Insulating Finish Systems or EIFS:
a. Typically, EIFS is a layer of foam laminated or mechanically fastened to a substrate with mesh and a polymer base coat over the top of the foam, and then an acrylic finish over the top of everything.
II. Portland cement based three-coat or conventional stucco systems.
a. Conventional – or three-coat – stucco will have a mechanically fastened weather barrier, or sprayed or rolled-on air and moisture barriers. Over the weather barrier will be expanded or woven wire lath, and then a portland cement scratch and brown coat. The finish can be a variety of products used individually – or in combination – to provide color and texture to the surface.
III. Portland cement based one-coat stucco system.
a. The weather barriers and lath for these systems are similar to three-coat stucco. Typically, a one-coat system has a layer of foam insulation (referred to as continuous insulation) between the lath and the portland cement base coat.
How long does stucco last on a building?
The service life of stucco can't be quantified as a specific number of years, properly applied and maintained, stucco is as durable as any commonly used cladding material. Its hard surface resists abrasion and can take a lot of physical abuse. It stands up to all sorts of climates, from cold to hot and wet to dry.
Does stucco add any R-Value (insulation value)?
EIFS and one-coat stucco offer superior energy efficiency and have an advantage over most exterior claddings. This benefit is delivered by placing a continuous layer of insulation on the outside of the building providing a superior R-Value and greater energy savings. R-Value measures how hard it is for energy to move through a wall assembly. The higher the R-Value, the more resistance there is to energy movement through the wall. The less your building's HVAC system has to work, the more energy and money you save
PCAPortland Cement Association
Parex Stucco and EIFS
SMA – Stucco Manufacturers Association


text:
GIPSA relays it wants to ensure the standards remain relevant to the US and global corn industry and continue to facilitate the marketing of US corn. All aspects of the corn standards are being reviewed, including definitions, grade and non-grade determining factors, grade limits, damages, as well as grading procedures and new services GIPSA might offer.
"Since the standards were last revised, the use of corn for ethanol and the number of different varieties of corn has increased tremendously," said J. Dudley Butler, GIPSA administrator. "To ensure that standards and official grading practices remain relevant, GIPSA invites interested parties to comment on whether the current corn standards and grading procedures need to be changed."
GIPSA establishes standards for corn, and other grains, under authority of the US Grain Standards Act. The standards facilitate corn marketing and define US corn quality in the domestic and global marketplace by defining commonly used industry terms and outlining basic procedures for testing corn. Together, the grading standards and procedures allow buyers and sellers to communicate quality requirements, compare corn quality using equivalent forms of measurement, and assist in price discovery.
The advance notice of proposed rulemaking seeking public comment on the corn standards was published in the Sept. 17 Federal Register. Comments must be received on or before Dec. 16.


Column Triage
October 1, 2011
John W. Dolan
John W. Dolan
John Dolan has been writing "LC Troubleshooting" for LCGC for over 25 years. One of the industry's most respected professionals, John is currently a principal instructor for LC Resources, Walnut Creek, California He is also a member of LCGC's editorial advisory board.
LCGC Europe
LCGC Europe, LCGC Europe-10-01-2011, Volume 24, Issue 10
Page Number: 530–536
How do you react to symptoms that indicate your liquid chromatography column has major problems?
With the popularity of medical shows on television, you'd think we'd all know how to act in a medical emergency. After all, we know what to do when we have an emergency with our liquid chromatography (LC) column, don't we? Or is it really an emergency? In this month's "LC Troubleshooting," we'll consider the process of column triage. When will the column survive on its own? When does it have recoverable injuries? And when is it beyond resuscitation? We'll concentrate on three primary symptoms of column failure: increased peak tailing, increased pressure and changed retention times.
"Good Enough" May Be Trying to Tell You Something
A well-designed LC method should have a system suitability test that truly evaluates the ability of the method to perform. Usually the system suitability test includes a measure of peak tailing (tailing factor, TF, or asymmetry factor, As) and a retention time, tR, or retention-time window for the peak or peaks of interest. Often, resolution, Rs, is included. I also suggest that system pressure should be noted on a daily basis. If your LC system doesn't record the pressure automatically, add an item to the run summary that is usually part of each method. Rarely is a change in pressure alone a predictor of poor data quality, but it is one of the early warning signs that the column may encounter problems.
When one or more of the system suitability parameters fails to meet the pre-defined limits, something must be done to correct the problem, such as mixing a new batch of mobile phase or cleaning or replacing the column. However, if this is the only way system suitability results are used — as a pass–fail decision — you are not taking advantage of the information that is available. You may find system suitability failure comes as a surprise: One day everything is OK, then the next day it fails. This is rarely the case, however; instead, the system often gives hints of what is happening, if you pay close attention. I recommend making a control chart to follow the trend of each of the system-suitability parameters, and I would track pressure in the same way. The control chart is simply a plot of the value of the parameter over time or number of injections, with the acceptable limit of the parameter plotted as well. You can be fancy and add more traditional control-chart features, such as those described in reference 1, but that may be overkill for what you need for system suitability.
I have created three control charts in Figure 1 to illustrate the point. These are data for a fictitious method over 30 batches of samples. In the top panel, the pressure at the beginning of the run is plotted (solid line) with a dashed line added at a 2500-psi boundary. Normally the method runs in the 1500–2000 psi range, and when it gets to ≈2500 psi it is time to change the frit in the in-line filter. This 2500-psi boundary is a "soft" limit, because data quality is seldom compromised if the pressure exceeds this value. The middle panel plots the tailing factor, with a system suitability requirement is that TF should be ≤1.6 (dashed line). With a new column, TF ≈ 1.4 is observed. The lower panel shows the retention time during system suitability with a normal value of ≈4.7 min and a requirement of 4.5 ≤ tR ≤ 4.9. How do you react to symptoms that indicate your liquid chromatography column has major problems?
Figure 1: Example control charts to trend column performance. Pressure (top), tailing factor (middle) and retention (bottom) are plotted as solid lines over 30 runs with method limits shown as dashed lines.
If we blindly use the system suitability data of Figure 1 to tell us whether the system is "good enough" to make it though the next batch of samples, we may be surprised when system suitability fails. Instead, think of how these data are trying to give us early warning signs. For example, you can see that variation in retention and tailing seem fairly random until approximately batch 20, when they begin trending toward the limits. It looks like the limits are reached for both these parameters after ≈25 batches. If column replacement reset the system suitability parameters to where they started, and similar trends were observed for additional columns, these data could be used to establish a preventive maintenance strategy. For example, proactive replacement of the column after 20 sample batches would avoid any problems created by system suitability failure, and excessive pressure would be avoided, too. My recommendation is that if you can anticipate when a part (the column in the present example) will fail, replacement of the part at 70–80% of its expected lifetime is a good strategy. You get most of the useful life out of the part and avoid any problems associated with a failure of that part.
Crash Cart Time
So what happens when system suitability fails? The three most common symptoms that something is not right with the column are increased pressure, increased tailing and a change in retention times, either individually or in combination. The causes of column problems are physical or chemical in nature. Let's look at each of these.
Physical problems with the column are most commonly manifested as a build-up of particulate matter on the inlet frit of the column. This will cause increased pressure and often similar peak distortion of all the peaks in the chromatogram. For example, all peaks will tail excessively or may be split or doubled. When these symptoms are observed, you know that whatever happened occurred before the sample was separated. About a third of the time you can rescue a column exhibiting these symptoms by reversing it and back-flushing it.
Simply remove the column, reverse it and route the new outlet end to waste (not to the detector). Flush the column with 15–20 mL of mobile phase, or better yet, with the strong solvent of the mobile phase (generally acetonitrile or methanol). The hope is that this will wash the particulate matter off the inlet frit and reduce the pressure back to acceptable levels. If the column is packed with 3.5- or 5-μm silica-based particles, you can leave the column reversed. Reconnect it to the detector and check system suitability again to see if it will pass now. Columns packed with particles ≤ 3 μm in diameter may use inlet frits that are too large to allow you to continue operation of the column in the reversed direction, so you should return the column to its original direction in such cases. It is a good idea to consult the column care-and-use instructions to see if there are any limitations on column reversal. If you are lucky, this procedure will revitalize the column and you'll be able to use it a bit longer.
Chemical problems with the column usually show up as changes in retention for one or more peaks, as increased peak tailing or as a combination of retention changes and peak tailing. Strongly retained materials from the sample can build up on the column over time, causing a change in the column chemistry, and thus a change in the appearance of the peaks. Sometimes these materials can be removed by flushing the column with a strong solvent. Another cause of retention and tailing changes is that something has attacked the stationary phase or otherwise permanently changed the chemical surface of the column. In such cases, the column cannot be restored. It is not easy to distinguish between the two forms of failure, so the same treatment should be tried to see if it will help. Remove strongly retained material by flushing the column with 10–20 column volumes (15–20 mL) of the strong solvent of the mobile phase. If you are lucky, this will revive the column.
If symptoms of physical or chemical problems with the column occur regularly before 500–1000 injections have been performed, you may be able to extend column life by improving the sample cleanup or adding column protection to the system. Because sample cleanup is more involved, I recommend starting with column protection. Every system should be operated with an in-line filter immediately downstream from the autosampler. For 3- or 5-μm columns, this filter contains an 0.5-μm porosity frit. This will trap particulate matter that would otherwise get caught on the 2.0- or 0.5-μm frit at the head of the column. When the pressure begins to rise, replace the frit. The frit in the in-line filter can be changed in a few minutes and is very inexpensive, especially when compared to the cost of the column. The use of a guard column is another option to help extend column life. The frit at the head of the guard column will trap debris that would otherwise block the column inlet frit, but even this can be avoided if you use the in-line filter in addition to the guard column. Guard columns have been shown to extend the life of the analytical column, but