background: gonad shielding has been recommended during pelvic x-rays since the 1950s. the popular method of gonad shielding is placement a lead shield in the midline of the pelvis. the aim of this study was to evaluate the prevalence and utility of gonad shielding in pediatrics undergoing pelvic x-rays.materials and methodsfollowing study approval, we retrospectively retrieved data from the di...

results the results showed that the epoxy plates 6 and 2 mm thick had the highest and the lowest averages of shielding effectiveness at 4.48 db and 1.90 db, respectively. however, increasing the thickness was useful up to 4 mm. in addition, in a similar attenuation pattern, x-band frequency was divided into lower, middle, and upper sections. the lower section had the highest shielding effective...

Conserved muonic number may turn out to be a conserved muonic charge, coupled to muonic photons, γμ. Muons and muonic neutrinos would emit γμ’s, which might be discovered by analysing the data from the past and future high energy neutrino experiments (like CHARM II, CCFR, CHORUS, NOMAD, etc.). There are two sources of γμ’s in these experiments: 1) internal bremsstrahlung in pion and kaon decays...

Dependence of NMR isotropic shift averages and nuclear shielding tensors on the internal rotation of the functional group X about the C± X bond in seven simple vinylic derivatives H2C5 CH± X M. BAADEN , P. GRANGER and A. STRICH* UMR 7510, Laboratoire de Re sonance Magne tique Nucle aireÐ RM3 UMR 7551, Laboratoire de Chimie Quantique, Universite Louis Pasteur, 4 rue B. Pascal, 67000 Strasbou...

Previous traditional surgery is simple removal of nucleus pulposus, but the study of Eie et al. shows high recurrence rate of lumbago and herniation after such surgery, 3 therefore, fusion internal fixation of interbody fusion cage combined with bilateral pedicle internal fixation system is often used for treatment at present, so that three-dimensional fixation can be achieved at fused lumbar s...

Internal energy changes during the electrospray process have been studied. Our results suggest that, contrary to conventional wisdom, ions that are quite hot are formed in electrospray, even without acceleration in the cone-skimmer region. The main role of the curtain gas seems to be not to break up existing clusters but, rather, to cool down the nascent ions and to prevent cluster formation by...

the complete 3d nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. for describing the dynamics of the system, the newtonian derivation procedure is followed. the velocity field inside the pipe formulated using hydrostatic and bernoulli equations. the hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in var...