The production of the therapeutic
186g
Re radioisotope by proton-induced
nat
W(p,xn) reaction at the cyclotron C18/18 was investigated. The cyclotron is located at the A. Alikhanyan National Science ...Laboratory (Yerevan Physics Institute). The excitation function of the reaction in the proton energy range from the reaction threshold up to 18 MeV was measured. The measurements were carried out by the stack activation method followed by spectrometric analysis on the high purity germanium detector (HPGe). The activation of the obtained medical isotope
186g
Re was determined. The current experimental results are compared with theoretical calculations performed by TALYS 1.95 and EMPIRE 3.2 codes, as well as with the other available experimental data. It has been shown the possibility of production of the above-mentioned radionuclide on the cyclotron C18/18 in the amount required for medical purposes using an enriched target.
Study of the intramolecular cyclization of 3-(4-bromo(or methyl)phenylprop-2-yn-1-yl(3-phenylprop-2-en-1-yl)ammonium bromides has shown that the presence of a bromine atom or methyl group in the
para
...position of the aromatic ring inhibits the process. 6-Bromo(or methyl)-4-phenyl-2,3,3a,4-tetrahydro-1
H
-benzo
f
isoindol-2-ium bromides undergo cleavage in aqueous alkaline medium at both N
2
-C
3
and C
1
-N
2
bonds, whereas cleavage of 6-methyl-4-phenyl-1,3,3a,4-tetrahydrospirobenzo
f
isoindole-2,4′-morpholin-2-ium bromide follows only the latter path. An accessible method has been developed for the synthesis of 6-bromo(or methyl)-4-phenyl-2,3,3a,4-tetrahydro-1
H
-benzo
f
isoindol-2-ium bromides, isomeric
N
-7-bromo-2(3)-methyl-1-phenylnaphthalen-3(2)-ylmethylpiperidines and -morpholines, and their 7-methyl-substituted analogs.
Polymermineral material “PMM” has multiple cycles of swelling and drying. It does not decompose under soil, biological and atmospheric influences and is environmentally safe. By adding the proportion ...of up to 30 g/kg of PMM additive to soil and tamping, we get a waterproofing material that can be used in urban construction and water supply. Taking into account the fact it is not always technically possible to carry out high-quality ramming when repairing channel walls, the task was to conduct an experimental study in order to determine the total moisture content of the mixture of PMM additive with soil. Experimental results of laboratory studies show that when PMM is added to the soil at a ratio of 30 g/kg under evaporation conditions, the mass of excess water in the substrate increases with time.
For industrial water use planning, water usage and drainage per unit product standards must be established. This would allow for the conservation of fresh water resources without limiting irrigation ...in the face of the world’s ever-increasing drinking water deficit. Because fish farms use a lot of water, businesses that raise fish in artificial ponds usually dig deep wells to get to the valuable subsurface water they need. Because they lack a reusable water system equipped with treatment technologies, they typically discharge water into the environment after a single use, resulting in marshes, soil salinization, or transportation with surface water flow to the brackish water ecosystem. In recent years, the use of groundwater for fishing has spread in Armenia’s Ararat plain, one of the country’s most important agricultural regions. The Ararat plain has a water shortage for irrigation, which is mostly addressed by increasing water intake volumes from Lake Sean, a critical source of drinking water. In the absence of a multi-use hydrosystem with cleaning technologies, a method of utilizing fish farm wastewater for irrigation purposes is proposed as a water-saving and environmental-protection approach.
We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum ...transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.
The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the ...performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.
Abstract
Investigating the reflection and refraction of electroelastic waves at a plane interface without acoustic contact between two piezoelectric half-spaces of different textures, it was found ...that: (i)As a result of the incidence of a two-component electroelastic shear wave on the interface between the media, the same wave is reflected into the first half-space, and a three-component electroelastic plane strain wave is refracted into the second half-space. In the utmost cases, in layered inhomogeneous waveguide, a wave hybrid of electroacoustic waves is formed. This makes it possible to transmit along the boundary of non-acoustic contact of media a hybrid of electroacoustic surface waves of the Gulyaev-Bluestein type and Rayleigh type localized near this boundary. (ii)As a result of the incidence of a two-component electroelastic plane strain wave on the interface between the media, the same wave is reflected into the first half-space, and a three-component electroelastic shear wave is refracted into the second half-space. This also makes it possible to organize a hybrid of electroacoustic waves of elastic shear and plane deformation of the type of periodic electroelastic Floquet waves in a periodically transversely inhomogeneous piezoelectric composite. The conditions for the possible formation of the hybrid and the characteristics of their propagation in the layered composites of piezoelectrics of the hexagonal symmetry class 6
mm
and
6
¯
m
2 are discussed.
We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasielastic scattering on ...the deuteron, at backward angles (lab scattering angle of 108°) for Q² = 0.22 GeV²/c² and 0.63 GeV²/c² at beam energies of 362 and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single-photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (πN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasistatic deuterium approximation, and is also in agreement with theory.
Separated longitudinal and transverse structure functions for the reaction 1H(e,e(')pi(+))n were measured in the momentum transfer region Q2 = 0.6--1.6 (GeV/c)(2) at a value of the invariant mass W = ...1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parametrization fitted to very low Q2 elastic data.
We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from ...quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.
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