Possibility of absolute measurements of antenna scattering and gain on the basis of radiation of a ?black? disk in the near zone without antenna focusing

1979 ◽  
Vol 22 (6) ◽  
pp. 535-537
Author(s):  
Yu. I. Belov ◽  
N. V. Veksler ◽  
L. R. Semenova ◽  
A. L. Fogel'
Keyword(s):  
Black Disk ◽  
Near Zone ◽  
Absolute Measurements

Validation of a bioelectrical impedance scale for the estimation of body fat in adolescents

2020 ◽  
Vol 19 (5) ◽  
pp. 369
Author(s):  
Andreia Pelegrini ◽  
André De Araújo Pinto ◽  
Hector Cris Colares De Angelo ◽  
Gaia Salvador Claumann ◽  
Diego Augusto Santos Silva ◽  
...  
Keyword(s):  
Body Fat ◽  
Bioelectrical Impedance ◽  
Air Displacement Plethysmography ◽  
Overweight Adolescents ◽  
The Absolute ◽  
Absolute Measurements

Several different instruments available on the market have been used for the estimation of body fat. However, many of these instruments have not been compared with reference criteria to verify their true accuracy. This study aimed to verify the validity of a bioelectrical impedance scale (OMRON-514C) for the estimation of body fat. Forty-four overweight adolescents (25 females) participated in this study, with an average age of 12.3 ± 1.1 years. All were submitted to body fat evaluations by air displacement plethysmography and bioelectrical impedance. Higher values of relative and absolute body fat were estimated by bioelectrical impedance compared to plethysmography (p < 0.05). There was no correlation between the relative body fat measurements between the two methods (r = 0.185; p = 0.228). The absolute measurements of body fat were correlated (r = 0.497, p = 0.001). Both in the measurements of relative (p= 0.034) and absolute body fat (p = 0.021), the bioelectrical impedance overestimated the measured values. Thus, in adolescents with characteristics similar to the present study, the estimate of body fat by the bioelectrical impedance (OMRON-514C) should be used with caution.Keywords: plethysmography, bioelectrical impedance, adolescents, overweight.

Mathematical Simulation of the Bearing Process in the Near Zone of a Complex Extended Object

2004 ◽  
Vol 61 (2) ◽  
pp. 141-149
Author(s):  
N. V. Barkhudaryan ◽  
S. E. Vazhinsky ◽  
V. A. Vasilets ◽  
A. Z. Sazonov ◽  
O. I. Sukharevsky
Keyword(s):  
Mathematical Simulation ◽  
Extended Object ◽  
Near Zone

On applying the perturbation theory for the evaluation of near zone scattering properties of a perturbed PEMC cylinder

Optik ◽  
2021 ◽  
pp. 166844
Author(s):  
Fahad Masood ◽  
Muhammad Arshad Fiaz ◽  
Muhammad Aqueel Ashraf
Keyword(s):  
Perturbation Theory ◽  
Near Zone

scholarly journals Saturation effects in SIDIS at very forward rapidities

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
E. Iancu ◽  
A. H. Mueller ◽  
D. N. Triantafyllopoulos ◽  
S. Y. Wei
Keyword(s):  
Inelastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Virtual Photon ◽  
Large Fraction ◽  
Quark Distribution ◽  
High Energy ◽  
Longitudinal Momentum ◽  
Black Disk ◽  
Gluon Saturation

Abstract Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.

Absolute measurements of the frequency of an He—Ne/CH4standard over a decade

1996 ◽  
Vol 26 (12) ◽  
pp. 1081-1084 ◽  
Author(s):  
Yurii S Domnin ◽  
Leonid N Kopylov ◽  
A N Malimon ◽  
V P Tenishev ◽  
P S Shumyatskii
Keyword(s):  
Absolute Measurements

scholarly journals A standard measuring machine

1912 ◽  
Vol 87 (597) ◽  
pp. 385-390
Keyword(s):  
National Physical Laboratory ◽  
Standard Measuring ◽  
Physical Laboratory ◽  
Accurate Comparison ◽  
Measuring Machine ◽  
Regular Work ◽  
Absolute Measurements ◽  
Line Standard

In some physical researches it is required to measure the dimensions of a regular solid, whether parallel-sided, cylindrical, or spherical-ended, with the greatest possible accuracy. Again, in the regular work of a metrology bureau, accurate comparison of the size of an end-standard of length with reference to a line-standard is required. Until 1906 the only apparatus available for these purposes was the measuring machine made for comparing engineering gauges. In that year the writer described a machine based on the principle of electric touch, which was much more delicate than the older mechanical machines. It also had facilities for exploring the solid under test, to prove its accuracy of figure. This machine has been installed and used in the National Physical Laboratory since 1909. Improvements in it were described later. The present paper gives an outline of an improved machine of the same type embodying the experience gained in using the 1906 machine. The chief novelties are: (1) greater strength in the supporting parts, and consequent rigidity of the whole apparatus; (2) larger and much improved table to carry the solid under test; (3) improved measuring-ends; (4) an innovation for making absolute measurements, whereby the line-standard moves but the reading microscope remains fixed; (5) side girders to relieve the bed of load and so reduce friction, abrasion, and strain.

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