Time filter

Source Type

Chantilly, VA, United States

Beier H.T.,U.S. Air force | Noojin G.D.,TASC Inc | Rockwell B.A.,U.S. Air force
Optics Express | Year: 2011

Stimulated Raman scattering (SRS) is a powerful tool for obtaining background-free chemical information about a material without extrinsic labeling. Background-free spectra are particularly important in the fingerprint region (∼800 and 1800 cm-1) where peaks are narrow, closely-spaced, and may be in abundance for a particular chemical. We demonstrate a method for obtaining SRS spectra using a single femtosecond laser oscillator. A photonic crystal fiber is used to create a supercontinuum to provide a range of Stokes shifts from ∼300 to 3400 cm-1. This SRS approach provides for collection capabilities that are easily modified between obtaining broadband spectra and single-frequency images. © 2011 Optical Society of America. Source

Hendow S.T.,Multiwave Photonics | Romero R.,Multiwave Photonics | Shakir S.A.,TASC Inc | Guerreiro P.T.,Multiwave Photonics
Optics Express | Year: 2011

The effect of ns bursting on percussion drilling of metal is investigated experimentally and analytically, and compared with the efficiency and quality of drilling using single ns pulses. Key advantages are demonstrated, correlating well with the results from a thermal theoretical model. The 1064 nm bursts contain up to 14 pulses of various pulse widths and spacing, and at frequencies of tens of MHz within the burst. The individual pulses have pulse widths of 10 to 200 ns, and up to 12 kW peak power. Burst repetition frequency is single shot to 500 kHz. © 2011 Optical Society of America. Source

Decuzzi P.,University of Texas Health Science Center at Houston | Decuzzi P.,University of Catanzaro | Decuzzi P.,TASC Inc | Ferrari M.,University of Texas Health Science Center at Houston | Ferrari M.,Rice University
Biomaterials | Year: 2010

Cellular adhesion is a fundamental process in the development of scaffolds for tissue engineering; in the design of biosensors and in preparing antibacterial substrates. A theoretical model is presented for predicting the strength of cellular adhesion to originally inert surfaces as a function of the substrate topography, accounting for both specific (ligand-receptor) and non-specific interfacial interactions. Three regimes have been identified depending on the surface energy (γ) of the substrate: for small γ, any increase in roughness is detrimental to adhesion; for large γ, an optimal roughness exists that maximizes adhesion; and for intermediate γ, surface roughness has a minor effect on adhesion. The results presented are in qualitative agreement with several experimental observations and can capture the long-term equilibrium configuration of the system. The model proposed supports the notion for rationally designing substrates where topography and physico-chemical properties are tailored to favour cellular proliferation whilst repelling bacterial adhesion. © 2009 Elsevier Ltd. All rights reserved. Source

News Article | October 5, 2015
Site: www.prweb.com

In a move that signifies its status as a leading specialist in refrigeration related ammonia hazard assessments in the UK, Star Technical Solutions has been invited to present at the upcoming Food Storage and Distribution Federation’s Ammonia Summit. The Refrigeration Consultancy helps businesses ensure compliance with legislation and good practice guidance. During the Ammonia Summit, the Star presentation will focus primarily on Ammonia Hazard Assessments and why ammonia legislation compliance is now more important than ever. Senior Consultant of Star Technical Solutions, Dr Dermot Cotter, will be on hand to discuss “The Key Issues Identified in Ammonia Hazard Assessments”, covering the following topics: The Chairman of the Institute of Refrigeration Technical Committee and Star’s Group Engineering Director Dr Andy Pearson will also argue ammonia’s case in a presentation titled “Why is ammonia such a good refrigerant?” Dr Cotter explains, “Under the legislation it is necessary to prepare specific risk assessments for all plants using ammonia refrigeration systems due to its potential flammability and toxicity – both requiring close assessment and management.” Dr Cotter continues, “With responsibilities to ensure that the requirements of legislation is implemented properly falling directly to the employer, the end-user and the owner of the facility, the new PM81 and DSEAR guidance documents are expected to set stringent guidelines for compliance with European standards and directives, and UK legislation regarding toxicity and flammability of ammonia refrigeration systems. They are also expected to outline key responsibilities placed on employers, end users and facility owners.” For the past three years, the Technical and Safety Committee (TASC) of the Food Storage and Distribution Federation, the HSE and the HSL, have been developing the new guidance for the safe management of ammonia refrigeration systems. This means big changes for businesses incorporating temperature-controlled cooling, as well as the insurance companies that cover their operations. The new to be released PM81 guide will replace the earlier version, which was published in 1995 and withdrawn from use in 2005. The new to be released DSEAR guideline document is set to highlight the latest best practice in regard to the flammability of refrigeration systems using ammonia. The Star Technical Solutions team will be joined by other leading technical experts, including Dr Robert Lamb of Star Refrigeration who will take to the stage to present “Ammonia Chillers and Low Charge Refrigeration Systems,” and Niels P Vestergaard of Danfoss A/S who will examine the “Trend in technologies supporting safe and successful use of ammonia systems in industrial applications.” This makes the summit a must attend event for any temperature controlled food chain business that supplies, utilises or maintains ammonia equipment. The STS presentations have been developed to show where common non compliances to legislation has been identified and with the new to be released PM81 and DSEAR guidelines will help businesses to comply with current legislation. David Blackhurst, Director of Star Technical Solutions, says, “Ammonia is a highly efficient, zero carbon natural refrigerant that has been used in a variety of applications for over 150 years. The new HSE guidelines will be a fantastic step forward for the ammonia cause, and we’re certain that our input will help FDSF Ammonia Summit attendees gain a thorough understanding of how to comply with current legislation.” For registration to attend the summit, visit: http://www.fsdf.org.uk/event/fsdf-ammonia-summit.

NEW YORK--(BUSINESS WIRE)--Global education leader Kaplan and the adult education software experts at Aztec Software have joined forces to offer students getting ready for a High School Equivalency Diploma the most comprehensive preparation experience available. The partnership integrates Kaplan’s highly effective content into Aztec Software’s proven computer and mobile-based program. This pairing comes at a critical time for adult learners, as recent figures show a sharp drop off in the number of people who completed a High School Equivalency. GED Testing Service® , which writes the GED® , reports successful tests fell from 540,000 in 2013 to 90,000 in 2014, and both the HiSET, Educational Testing Service’s test offering, and TASC from McGraw Hill, are too new to offer much insight. This drastic decline has been attributed by many adult education experts to the increased difficulty of the tests relative to previous versions of the GED and the change in test-taking mode, from paper and pencil to computer-based. The combined course, called Kaplan Learning System powered by Aztec Software, is a tutorial program that not only gauges a student’s readiness with complete assessments, but creates individualized learning plans and the corresponding academic content that each learner needs to ensure success on high school equivalency exams like the GED, TASC, and HiSET. Available online, offline, and on every major mobile platform, the course allows students to prepare virtually anytime, anywhere. “Aztec Software’s powerful approach to learning, combined with its ability to bolster adult educational development and achievement, aligns well with Kaplan’s mission of helping individuals succeed in reaching their educational and career goals ,” said Lee Weiss, head of New Product Ventures, Kaplan Test Prep. “This partnership reinforces Kaplan’s commitment to adult learners who are already in the workforce. We know that when they succeed the American economy can succeed too.” “This partnership is a game changer in an adult education landscape that is constantly in flux,” said Jonathan Blitt, CEO of Aztec Software. “With a combined 100-plus years of experience of preparing students to successfully complete the increasingly rigorous battery of high-stakes exams, the combination of Kaplan’s deep understanding of test-taking strategies and Aztec Software’s interactive software will create the most student-centric learning experience ever offered to adults. Most importantly, adult learners, unlike their K-12 counterparts, are our current workforce. Their need is immediate, and the economic impact of more educated workers can be felt in real-time in every community in every state in the country.” For more information, please contact Russell Schaffer at russell.schaffer@kaplan.com or 212.453.7538. GED is a registered trademark of the American Council on Education, which neither sponsors nor endorses this product. Kaplan Test Prep (www.kaptest.com) is a premier provider of educational and career services for individuals, schools and businesses. Established in 1938, Kaplan is the world leader in the test prep industry. With a comprehensive menu of online offerings as well as a complete array of print books and digital products, Kaplan offers preparation for more than 90 standardized tests, including entrance exams for secondary school, college and graduate school, as well as professional licensing exams for attorneys, physicians and nurses. Kaplan also provides private tutoring and graduate admissions consulting services. Additionally, Kaplan operates new economy skills training (NEST) bootcamps designed to provide immersive training in skills that are in high demand in today’s job market and prepare participants for hire. Founded in 1980 by educators, not technologists, Aztec Software has been in the business of improving adult and young adult lives through computerized skills remediation from its inception. Used throughout the country in community colleges, correctional facilities, one-stop centers, job corps centers, middle schools, and high schools, Aztec has become an integral part of today’s complete educational curriculum. Note to editors: Kaplan is a subsidiary of The Graham Holdings Company (NYSE:GHC)

Discover hidden collaborations