نتایج جستجو برای: x rays and radioactivities

تعداد نتایج: 16920893  

فخاریان, محمدعلی, کلهر, مرتضی,

    Background & Aim: Inferior heel pain is a common complaint in patients referred to orthopedic clinics. Etiology of this pain is unknown, but one of the suggestible causes is heel spur. The present descriptive comparative cross-sectional study was undertaken to evaluate the prevalence of heel spur in patients with painful heels and compare it with general population in order to determine spu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اراک - دانشکده علوم پایه 1389

abstract in this thesis at first we comput the determinant of hankel matrix with enteries a_k (x)=?_(m=0)^k??((2k+2-m)¦(k-m)) x^m ? by using a new operator, ? and by writing and solving differential equation of order two at points x=2 and x=-2 . also we show that this determinant under k-binomial transformation is invariant.

2006
M. Spaans

The ISM of active galaxy centers is exposed to a combination of cosmic ray, FUV and X-ray radiation. We apply PDR models to this ISM with both 'nor-mal' and highly elevated (5 × 10 −15 s −1) cosmic-ray rates and compare the results to those obtained for XDRs. Our existing PDR-XDR code is used to construct models over a 10 3 − 10 5 cm −3 density range and for 0.16-160 erg s −1 cm −2 im-pingent f...

Journal: :Cell 2014
Joseph M. Jez Robert E. Blankenship

Photosystem II uses metal ions to oxidize water to form O2. Two recent papers employ the new technique of serial femtosecond crystallography utilizing X-ray free-electron lasers and nanocrystals to obtain initial structures of intermediate states of photosystem II catalysis at the site of oxygen production.

Journal: :Physical review letters 2005
A L Cavalieri D M Fritz S H Lee P H Bucksbaum D A Reis J Rudati D M Mills P H Fuoss G B Stephenson C C Kao D P Siddons D P Lowney A G Macphee D Weinstein R W Falcone R Pahl J Als-Nielsen C Blome S Düsterer R Ischebeck H Schlarb H Schulte-Schrepping Th Tschentscher J Schneider O Hignette F Sette K Sokolowski-Tinten H N Chapman R W Lee T N Hansen O Synnergren J Larsson S Techert J Sheppard J S Wark M Bergh C Caleman G Huldt D van der Spoel N Timneanu J Hajdu R A Akre E Bong P Emma P Krejcik J Arthur S Brennan K J Gaffney A M Lindenberg K Luening J B Hastings

Linear-accelerator-based sources will revolutionize ultrafast x-ray science due to their unprecedented brightness and short pulse duration. However, time-resolved studies at the resolution of the x-ray pulse duration are hampered by the inability to precisely synchronize an external laser to the accelerator. At the Sub-Picosecond Pulse Source at the Stanford Linear-Accelerator Center we solved ...

Journal: :iranian journal of medical physics 0
mehdi zehtabian ray medical engineering department, school of mechanical engineering, shiraz university, shiraz iran elham piruzan ray medical engineering department, school of mechanical engineering, shiraz university, shiraz iran zahra molaiemanesh ray medical engineering department, school of mechanical engineering, shiraz university, shiraz iran

introduction lead-based shields are the most widely used attenuators in x-ray and gamma ray fields. the heavy weight, toxicity and corrosion of lead have led researchers towards the development of non-lead shields. materials and methods the purpose of this study was to design multi-layered shields for protection against x-rays and gamma rays in diagnostic radiology and nuclear medicine. in this...

2000
Kazuhiro Oyamatsu

The fission rate during JCO criticality accident is estimated from fission-product (FP) radioactivities in a uranium solution sample taken from the preparation basin 20 days after the accident. The FP radioactivity data are taken from a report by JAERI released in the Accident Investigation Committee. The total fission number is found quite dependent on the FP radioactivities and estimated to b...

2001
W. K. Röntgen

The 1996 centenary of W. K. Röntgen’s discovery of x rays celebrated the penetrating visions offered by these “strange rays.” Aside from their ubiquitous application to imaging the interior structure of visually opaque systems, x rays continue to have important applications in elucidating the geometrical and electronic structure of matter. In addition to the synchrotron radiation facilities, co...

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