scholarly journals BREMSSTRAHLUNG OF ELECTRONS AND YIELD OF NEUTRONS FROM THICK CONVERTERS, PASSING OF GAMMA RADIATION AND NEUTRONS THROUGH BIOLOGICAL SHIELDING

2019 ◽  
pp. 65-73
Author(s):  
O.S. Deiev ◽  
G. L. Bochek ◽  
V. N. Dubina ◽  
S. K. Kiprich ◽  
G. P. Vasilyev ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Total Yield ◽  
Atomic Charge ◽  
Angular Distributions ◽  
Photonuclear Reactions ◽  
Medium Energy ◽  
Radiation Spectra ◽  
The Difference ◽  
Different Thickness ◽  
Forward Hemisphere

In GEANT4 spectral-angular distributions of the bremsstrahlung of medium-energy electrons from amorphous targets of different thickness and atomic charge were calculated. The total yield of gamma quanta in the forward hemisphere and at large scattering angles were determined depending on the converter thickness. The difference in the characteristics of gamma radiation for thin and thick targets was shown. The neutron yield is calculated due to photonuclear reactions for various converters. Numerical estimates of the radiation spectra after passing through the biological shielding for neutron and bremsstrahlung were carried out.

scholarly journals GAMMA-RADIATION SPECTRA OF 1200 MeV ELECTRONS IN THICK BERYLLIUM, SILICON AND TUNGSTEN SINGLE CRYSTALS

2019 ◽  
pp. 86-93
Author(s):  
G. L. Bochek ◽  
O. S. Deiev ◽  
V. I. Kulibaba ◽  
N. I. Maslov ◽  
V. D. Ovchinnik ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Single Crystals ◽  
Angular Distributions ◽  
Γ Radiation ◽  
Radiation Spectra ◽  
Solid Angles ◽  
Crystallographic Axes ◽  
And Tungsten

Gamma radiation spectra of 1200 MeV electrons from the single crystals of the beryllium 1.2 mm thick, silicon 1.5 mm and 15 mm thick and tungsten 1.18 mm thick along of the crystallographic axes were measured. Also spectral-angular distributions of gamma radiation from the silicon single crystals 1.5 mm thick along of the crystallographic axes < 100 >, < 110 > and < 111 > were measured. On the basis of these measurements the γ-radiation spectra for the different solid angles up to 6.97 × 10−6 sr were obtained.

A High Pressure Sensor with Circular Diaphragm Based on MEMS Technology

2011 ◽  
Vol 483 ◽  
pp. 206-211 ◽  
Author(s):  
Li Bo Zhao ◽  
Xu Dong Fang ◽  
Yu Long Zhao ◽  
Zhuang De Jiang ◽  
Yong Li
Keyword(s):  
High Pressure ◽  
Pressure Sensor ◽  
Correct Choice ◽  
Excellent Performance ◽  
Piezoresistive Sensors ◽  
Mems Technology ◽  
Circular Diaphragm ◽  
The Difference ◽  
Mems Process ◽  
Different Thickness

A pressure sensor in the range of 25 MPa with circular diaphragm is designed and fabricated, and the calibration experiments prove its excellent performance, which also reflects the correct choice of design after analyzing the effect of diaphragm dimension, location and shapes of piezoresistors. Circular diaphragms of different thickness and diameters are simulated to meet the pressure requirement of 25 MPa. It also displays the advantage of piezoresistive sensors over others and the difference characteristics between different types of piezoresistive sensors. And then the effect of piezoresistor location is analyzed and simulated to attain high accuracy and sensitivity after the circular diaphragm chip is packaged with borosilicate glass ring. The whole fabrication process of the chip is inexpensive and compatible with standard MEMS process. The experimental results show the developed high pressure sensor with the sensitivity of 2.533 mV/MPa has excellent performance, such as linearity of 0.08%FS, hysteresis of 0.03%FS, accuracy of 0.11%FS and repeatability of 0.03%FS under high temperature of 200 °C.

scholarly journals Identification of ions in experimental electrostatic potential maps

IUCrJ ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 375-381 ◽  
Author(s):  
Jimin Wang ◽  
Zheng Liu ◽  
Joachim Frank ◽  
Peter B. Moore
Keyword(s):  
Electron Scattering ◽  
Electrostatic Potential ◽  
Neutral Atom ◽  
Scattering Length ◽  
Atomic Charge ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cryo Electron Microscopy ◽  
Electron Distributions ◽  
The Difference

Cryo-electron microscopy (cryo-EM) directly images the distribution of electrostatic potential (ESP) within macromolecules, and thus can provide much more information about atomic charge than X-ray crystallography. The electron-scattering length of an isolated ion is quite different from that of the corresponding neutral atom. The difference is very large at small scattering angles where the effects of electron distributions are largest, but becomes smaller at high scattering angles where nuclear charge determines outcomes. For this reason, in cryo-EM maps that have been solved at resolutions lower than ∼2.5 Å, peaks corresponding to anions will always be less prominent than those of cations, and may even be negative. Furthermore, if a map of this kind is smeared computationally after the fact, which reduces its effective resolution, anion peaks will diminish in size, cation peaks will grow and peaks that represent uncharged atoms will remain about the same. These effects can be used to determine the sign of the charges carried by the ions associated with a macromolecule and even estimate their magnitudes. The ESP value for a cation in a cation–anion pair is smaller than the value of the cation in isolation, but the ESP value for the anion in the ionic pair is greater than the value of the anion in isolation. The experimental range of ESP values for Mg2+ relative to that of the closest C1′ atom is found to be between 0.57 and 1.27.

Effect of dietary energy, tallow and B-vitamin levels on laying performance of broiler-breeders

1972 ◽  
Vol 12 (56) ◽  
pp. 255
Author(s):  
H Karunajeewa
Keyword(s):  
B Vitamins ◽  
Dietary Energy ◽  
Medium Energy ◽  
Broiler Breeders ◽  
Broiler Breeder ◽  
Lower Energy Level ◽  
Laying Performance ◽  
The Difference ◽  
B Vitamin ◽  
Harmful Effects

The effects of feeding two levels of energy, tallow and B-vitamins on the laying performance of broiler-breeders of two strains (C and D) in individual cages were studied. Strain C differed significantly from strain D in producing larger eggs, a higher percentage of settable eggs, greater gains in bodyweight, a higher mortality, and lower hen-housed production. Egg weight was affected by a significant interaction between strains, energy, and B-vitamin levels. Birds fed diets with 2,421 kcal ME/kg laid at a higher rate, produced more hen-day settable eggs and gained less bodyweight than those fed diets with 2,638 kcal ME/kg. The birds fed diets with the lower energy level consumed significantly more feed than those fed the medium energy diet. However, the difference in intake may have been associated with the different amounts of wheat in the diets. The addition of two per cent stabilized tallow to broiler-breeder diets did not produce any beneficial or harmful effects. The lower level of B-vitamins added appeared to be as effective as the higher level in maintaining production in broiler-breeders fed either low or medium energy diet

ANGULAR DISTRIBUTION OF FAST PHOTONEUTRONS

1961 ◽  
Vol 39 (8) ◽  
pp. 1158-1171 ◽  
Author(s):  
R. G. Baker ◽  
K. G. McNeill
Keyword(s):  
Angular Distribution ◽  
Shell Model ◽  
High Energy ◽  
Angular Distributions ◽  
Silicon Detectors ◽  
Photonuclear Reactions

The angular distributions and the yields of the high-energy neutrons emitted in photodisintegration have been studied by silicon detectors (25 elements) and aluminum detectors (6 elements). With the silicon detectors systematic variations are apparent in the coefficient a2 of W(θ) = a0(P0 + a2P2), and these variations are interpreted in terms of the Wilkinson shell model of photonuclear reactions.

Evaluation of different cropping systems for marginal uplands in Barangay Caticugan, Sta. Rita, Samar

2017 ◽  
pp. 20-30
Author(s):  
Ulysses Cagasan ◽  
Ed Allan Alcober ◽  
Mark Gil Gerona ◽  
Gretchen Mae Prado
Keyword(s):  
Cropping Systems ◽  
Block Design ◽  
Total Yield ◽  
Cropping System ◽  
Crop Productivity ◽  
Growth And Yield ◽  
Net Income ◽  
Land Equivalent Ratio ◽  
The Difference ◽  
Increase Crop Yield

To help improve the lives of upland farmers in Barangay Caticugan, Sta. Rita, Samar, there is a need to find ways to increase crop yield and income. This study aimed to determine cropping systems that improve crop productivity, increase income and promote cropping systems technology to upland farmers in Barangay Caticugan, Sta Rita, Samar. The experimental units were arranged in Randomized Complete Block Design with three replications. The cropping systems tested were monocropping on corn, peanut and mungbean and intercropping corn + peanut and corn + mungbean. This paper considered only the data for one cropping planted during dryseason. The growth and yield characteristics of all crops under study were not significantly (p<0.05) affected bythe cropping systems. Fresh herbage yield (t ha-1) and total yield (t ha-1) in all crops (corn, peanut & mungbean) and harvest index of peanut were significantly affected by the treatments. The significant variations on the said treatments were due to the difference in the plant population of monocultures and the intercrops. On the other hand, corn + mungbean gave a land equivalent ratio (LER) of 1.16, which means that such practice is more productive than growing corn or mungbean as monocrop. Likewise, corn + peanut have an LER value of 1.20 which means corn + peanut intercropping system is more advantageous over monocropping. Economic analysis revealed that monoculture of peanut and mungbean is the most profitable cropping system as it provides a relatively higher yield and net income.

Sign in / Sign up

Export Citation Format

Share Document