GEMMA experiment: three years of the search for the neutrino magnetic moment

The result of the 3-year neutrino magnetic moment measurement at the Kalinin Nuclear Power Plant with the GEMMA spectrometer is presented. Antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed at a distance of 13.9 m from the 3 GW(th) reactor core is used in the spectrometer. The antineutrino flux is 2.7E13 1/scm/s. The differential method is used to extract (nu-e) electromagnetic scattering events. The scattered electron spectra taken in 5184+6798 and 1853+1021 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment < 3.2E-11 Bohr magneton at 90% CL is derived from the data processing.Comment: 4 pages, 4 figure

Germanium Detector with Internal Amplification for Investigation of Rare Processes

Device of new type is suggested - germanium detector with internal amplification. Such detector having effective threshold about 10 eV opens up fresh opportunity for investigation of dark matter, measurement of neutrino magnetic moment, of neutrino coherent scattering at nuclei and for study of solar neutrino problem. Construction of germanium detector with internal amplification and perspectives of its use are described.Comment: 13 pages, latex, 3 figures, report at NANP-99, International Conference on Non-Accelerator Physics, Dubna, Russia, June 29- July 3, 1999. To be published in the Proceeding

Yellow Blotched Map Turtles

This is where the abstract of this record would appear. This is only demonstration data

Hibiscus extract mitigates salt induced carotid adventitial changes in rats

The tunica adventitia is an active vascular compartment that actively participates in modulation of vascular structure, function and pathophysiology. Adventitial thickness has recently been accepted as a surrogate marker of atherosclerosis. The effects of salt and chemicals that ameliorate those effects are important in understanding vascular structure, function and pathology. There are few studies on hibiscus and high salt induced vascular pathology. This study, therefore, investigated the effects of hibiscus on salt induced vascular changes on rat carotid artery. The experimental animals were divided into 3 groups of 8 animals each – (i) controls; (ii) high salt diet alone and (iii) high salt + hibiscus extract for a period of eight weeks. At ages 2, 5 and 8weeks 2 – 3 animals were sacrificed for study. They were anaesthetized with ether and perfused with formal saline. Specimens were then obtained from the middle of common carotid artery, fixed in 5% formaldehyde solution, processed routinely for paraffin embedding and 5-micron thick sections stained with Hematoxylin / Eosin and also with Mason’s Trichome/ Aniline blue. Adventitial thickness and volumetric densities of collagen were measured using morphometric techniques. High salt consumption induced statistically significant increase in adventitial thickness from 297.45μm at week 2 to 659.4μm in week 8. In hibiscus fed rats, this increase progressively reduced to 482.55μm in week 8. Volumetric density of collagen was 57% in high salt fed rats but reduced to 45.66% in hibiscus fed rats (p&lt;0.001). The increase in tunica adventitial thickness and collagen density which is induced by high salt can be mitigated by hibiscus extract. This implies that hibiscus has potential to restore salt induced vascular injury. Further studies are recommended to refine the extract.Keywords: adventitial thickness, high salt, hibiscus, collagen, densit

Weak and Magnetic Inelastic Scattering of Antineutrinos on Atomic Electrons

Neutrino scattering on electrons is considered as a tool for laboratory searches of the neutrino magnetic moment. We study inelastic $\bar\nu_ee^-$-scattering on electrons bound in the germanium (Z=32) and iodine (Z=53) atoms for antineutrinos generated in a nuclear reactor core and also in the $^{90}$Sr-$^{90}$Y and $^{147}$Pm artificial sources. Using the relativistic Hartree-Fock-Dirac model, we calculate both the magnetic and weak scattering cross sections for the recoil electron energy range of 1 to 100 keV where a higher sensitivity to the neutrino magnetic moment could be achieved. Particular attention is paid to the approximate procedure which allows us to take into account the effects of atomic binding on the inelastic scattering spectra in a simple way.Comment: 7 pages in LaTeX, 10 figures in P

The first result of the neutrino magnetic moment measurement in the GEMMA experiment

The first result of the neutrino magnetic moment measurement at the Kalininskaya Nuclear Power Plant (KNPP) with the GEMMA spectrometer is presented. An antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed 13.9 m away from the 3 GW reactor core is used in the spectrometer. The antineutrino flux is $2.73\times 10^{13} \nu_e / cm^2 / s$. The differential method is used to extract the $\nu$-e electromagnetic scattering events. The scattered electron spectra taken in 6200 and 2064 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment $\mu_\nu < 5.8\times 10^{-11}$ Bohr magnetons at 90{%} CL is derived from the data processing.Comment: 9 pages, 10 figures, 2 table

Neutrino scattering on polarized electron target and neutrino magnetic moment

The completed and proposed experiments for the measurement of the neutrino magnetic moment are discussed. To improve the sensitivity of the search for the neutrino magnetic moment we suggest to use a polarized electron target in the processes of neutrino (antineutrino) -- electron scattering. It is shown that in this case the weak interaction term in the total cross section is few times smaller comparing with unpolarized case, but the electromagnetic term does not depend on electron polarization.Comment: 12 pages, 7 figures. Talk given at the XXVIII ITEP Winter School of Physics, Snegiri, Russia, February 22 - March 1, 200

Semi-vitrified porous kyanite mullite ceramics: Young modulus, microstructure and pore size evolution

Microporous porcelain formulations are successfully carried out through sintering processing. During the thermal treatment of ceramic products, it was found that the addition of kyanite together with ϕ- and γ-Al2O3 allowed to enhance interconnected pores network with micrometric size from 0.1 to 9 µm in a semi-vitrified composite. Between 1200 and 1350 °C, the mullitization of kyanite hindered the extension of vitrification and the growth of acicular mullite from the transformation of metakaolin. The main pores size decreased from 4.33 to 1.54 µm for the formulation containing 32 wt% of kyanite. In this interval the specific pore area increased from 0.64 to 8.75 m2 g−1 due to the total conversion of the kyanite to fibrous and acicular mullite that reduced the voids provided by the earlier mullitization. The improvement in the mullitization without extensive vitrification and grain growth and the reduction of the pores size with the increase in the specific pore area contributed to the formation of a microporous matrix with the Young's modulus increased from 7 to > 20 GPa. The microstructure of the microporous porcelain, their specific pore area and pores size as well as the interconnection of pores was found innovative for the applications in the field of engineering filtration where high mechanical strength, strain, stiffness and pressure resistance are required

Anatomical features of renal artery in a black Kenyan population: Correlation with markers of atherosclerosis

Knowledge of anatomical features of the renal artery is important in prediction,  management and control of atherosclerotic renal artery stenosis. These features show population variations but data from black African populations are scarce. The aim of this study was therefore to describe the anatomical features of the renal artery in a black Kenyan population. Six hundred and ten (610) single renal arteries from 305 adult black Kenyans [206 males, 99 females; age range 22 – 79 years] were studied by dissection at Department of Human Anatomy, University of Nairobi, Kenya. Specimens with macroscopic features of stenosis and dilatation were excluded. The implantation angle, length and branching pattern were studied. These features were correlated with intima-media thickness and luminal diameter. The  latter were determined by micrometry on Eosin/hematoxylin stained 5 micron  sections obtained from the proximal segment of the renal artery. Data was analysed by SPSS version 16.0. Student’s t-test, was used to test for statistical significance at 95% confidence interval where P value of &lt; 0.05 was taken as significant. The results are presented in a bar graph, tables and macrographs. The mean  implantation angle was 940±150 (range 580-1250). In 26.7% cases, the angle was more than 1000. Mean length was 34±1.4 mm with 21.6 % of arteries measuring ≤ 20 mm. Variant branching pattern was present in 40.5 % of cases. It comprised trifurcation (33 %), quadrifurcation (6.6 %) and pentafurcation (0.8 %). Higher implantation angle, short arteries and variant branching were associated with  statistically significant higher intima - media thickness and luminal diameter. These results suggest that higher implantation angle, shorter length and variant branching pattern constitute geometric risk factors for renal artery atherosclerosis.  Ultrasound screening for individuals with suboptimal geometric features for renal artery atherosclerosis is recommended.Keywords: anatomical risk factors, atherosclerosis, renal arter