Observation of the shock wave propagation induced by a high-power laser irradiation into an epoxy material

The propagation of laser-induced shock waves in a transparent epoxy sample is investigated by optical shadowgraphy. The shock waves are generated by a focused laser (3 ns pulse duration—1.2 to 3.4TWcm−2) producing pressure from 44 to 98.9 GPa. It is observed that the shock wave and the release wave created by the shock reverberation at the rear face are both followed by a dark zone in the pictures. This corresponds to the creation of a tensile zone resulting from the crossing on the loading axis of the release waves coming from the edge of the impact area (2D effects). After the laser shock experiment, the residual stresses in the targets are identified and quantified through a photoelasticimetry analysis of the recovered samples. This work results in a new set of original data which can be directly used to validate numerical models implemented to reproduce the behaviour of epoxy under extreme strain rate loading. The residual stresses observed prove that the high-pressure shocks can modify the pure epoxy properties, which could have an influence on the use made of these materials

Prospectus, September 1, 2010

MAYBE MONEY DOES GROW ON TREES: A GUIDE TO YOUR FINANCIAL AID PAPERWORK PROCESS; Colleges say new health law may imperil student policies; Chuck Shepherd\u27s News of the Weird; Passion Pit Finally Makes it to the C-U, Finally!; Campus wants greater attire awareness; Older adults\u27 use social networks growing fast, study finds; How to save public television: The PBS Channel; Pricy conditions for new book editions; Bicycle safety a growing concern in Illinois; Dogs and other pets welcome at Florida dorm; Prospectus Pick: Murder By Death; Understanding Islamhttps://spark.parkland.edu/prospectus_2010/1020/thumbnail.jp

Prospectus, October 20, 2010

WILL TEACHERS TWEET? NOT ANYTIME SOON.; Change in AP exams should relieve stress for high school pupils; Chuck Shepherd\u27s News of the Weird; Human Pandora, Part 1: Band of Horses; Didn\u27t your mama ever tell ya? Parkland\u27s Civility Committee hopes to enlighten students and staff; A Prospectus guide to transferring; A quiet shift in GOP stance on gay marriage; A touching example of respect for Old Glory; Fashion lads that shouldn\u27t be seen at school; How to catch up when you\u27re falling behind; Don\u27t let the flu bugs bite; Prospectus Pick: BIood Meridian by Cormac McCarthy; Hester ties NFL record for career TD returns; Do you have any secrets on staying healthy during flu season?; Twisted pumpkinshttps://spark.parkland.edu/prospectus_2010/1026/thumbnail.jp

Prospectus, November 3, 2010

CHAMPAIGN-URBANA RANKS TOP 5 IN COLLEGE DESTINATIONS INDEX; Interested, but not smothering: Student-Parent relationships are continuing on in college; Chuck Shepherd\u27s News of the Weird; Human Pandora, Part 2: Death Cab Cor Cutie; Why you should tune in to PCTV, Autumn Learning Opportunities: Non-credit classes at Parkland; The Illinois Traction Society; Can Republicans rescind \u27Obamacare\u27?; Voters, beware a bum\u27s rush; DIY or DIE: Reconstructing Clothes; Public Symposium on Digital Technology in Champaign-Urbana; Prospectus Pick: MTV\u27s Daria; Quidditch dies off the page and onto campus fields; PCTV Broadcast Schedule: Novemberhttps://spark.parkland.edu/prospectus_2010/1028/thumbnail.jp

Prospectus, March 30, 2011

APRIL FOOLS\u27 ARTICLES A NO-GO THIS YEAR, Parkland Offers New Hip Course, New Rules in Effect on Campus, Chuck Shepherd\u27s News of the Weird, Album Review: Justin Bieber\u27s My World 2.0, Parkland President to Resign, Parkland Announces New Dress Code Policy, Fine Dining to Arrive at Parkland, Cyber-Clowning for College Credit!, End of the Line for Free Wireless, Chuck Shepherd\u27s News of the Weird, First Sims Medieval, Now Sims Halo?, New Mascot in the Works for Parklandhttps://spark.parkland.edu/prospectus_2011/1000/thumbnail.jp

An introduction to schoenberg's approximation

AbstractFor a given function B and a non-zero real number h, Schoenberg's approximation defines from some data (jh, yj)jϵZd the function ΣjϵZd yj B(•h − j). For people not used to this kind of approximation, this paper intends to do a summary of the main definitions, properties and utilizations of Schoenberg's approximation: we show that the main tool to handle Schoenberg's approximation is the Fourier transform of B and even more its modified version, the transfer function of B; we give conditions for convergence of ΣjϵZd f(jh) B(•h − j) when h tends to zero, and we give various ways to define various B as combinations of translates of some function ϕ (usually ϕ is either some radial function, or obtained by a tensor product of some radial function), depending on the properties we want for the associated Schoenberg's approximation. Last, we show how multi-resolution analysis, subdivision techniques, and wavelets techniques, are nicely connected to Schoenberg's approximation

Prospectus, October 27, 2010

GIVING FUTURE GENERATIONS A CHANCE TO LEARN; The College Students Guide to Statewide Elections; Chuck Shepherd\u27s News of the Weird; The Perfect Soundtrack for Your Halloween Party; The Origin of Halloween; What Should You do This Halloween?; A Trend That is Taking Over Faster Thank Skinny Jeans: Kindness; Skinny Celebrity Chefs Can\u27t be Trusted; Zuckerberg Left With Plenty of Success, but Not Many Friends : Facebook Creator Shown as More than a Computer Genius in New Film, The Social Network; How to Stay Safe This Halloween Weekend; Former Parkland Instructor Wins Gold Medal; Nebraska Brings Tradition to Big Ten Table; In Search of Spiritshttps://spark.parkland.edu/prospectus_2010/1027/thumbnail.jp

Prospectus, February 9, 2011

STUDENT STRESS LEVELS INTENSIFYING; Students, faculty to break Spring tradition; Chuck Shepherd\u27s News of the Weird; Album Review: Cage The Elephant Thank You Happy Birthday; Targeting the next crime; Conflicting report frustrates economists, job-seekers; People Are People, Too; Parents vs. Skins\u27; Distance makes the heart grow fond; Bonus Stage! The official gaming column of the Prospectus; Prospectus Pick: Monty Python\u27s Flying Circus; The White Stripes split, are we really surprised?; New diet guidelines to push Americans toward better health; She!! to postpone Arctic drilling again; The world is leaving U S. students in the dust; Parkland personal training helps athletes bring their A game ; PCTV Broadcast Schedule: Februaryhttps://spark.parkland.edu/prospectus_2011/1026/thumbnail.jp