66 research outputs found
On the Possibility of Using Mn4N as a Neutron Polarizer
Abstract. Manganese nitride, Mn4N has been investigated by means of unpolarized as well as polarized neutron diffraction technique. It was found that both (100) and (110) reflections of this compound could produce almost 100% polarized, monochromatic neutrons. Furthermore, the two reflections provide opposite senses of polarization. While (100) reflects neutrons with spins aligned opposite to the magnetization, (110) reflection provides neutrons with spins parallel to the magnetization. This would offer possibility of producing polarized, monochromatic neutrons of either state of polarization by switching from one reflection to the other, without the use of electronic flipping devices. Sari. Nitrida mangan, Mn4N telah diteliti dengan teknik difraksi neutron tak-terpolarisasi maupun terpolarisasi. Ternyata kedua refleksi, (100) dan (110), dapat menghasilkan hampir 100% neutron terpolarisasi serta monokromatik. Lebih lanjut diketahui bahwa kedua refleksi tersebut menghasilkan polarisasi yang berlawanan arah. Refleksi (100) hanya memantulkan neutron dengan polarisasi yang berlawanan arah dengan magnetisasi, sedangkan refleksi (110) menghasilkan neutron dengan polarisasi searah dengan magnetisasi. Hal ini membuka kemungkinan untuk memproduksi neutron monokromatik dengan salah satu keadaan polarisasi, dengan cara berpindah dari suatu refleksi ke refleksi lainnya tanpa menggunakan alat elektronik
Partial Purification and Biochemical Characterization of Extracellular Pectinase from Aspergillus Niger Isolated from Groundnut Seeds
To produce and partially purify pectinases from Aspergillus niger isolateJGIm2, characterize the enzymes for potential industrial applications in clarifying fruit juices.
Methodology and results: Isolates of Aspergillus niger were screened for ability to produce pectinases by the enzymatic index method. All the 34 isolates screened were producers with isolates JGIm2, JGIm3 and JGIm5 being the best. Optimum enzyme production was found with medium containing 1.5% pectin after 48 h of fermentation. Partial purification of the enzyme was carried out by ethanol precipitation to give two fold purification and 56% yield. The enzyme had pH & temperature optima of 4.0 and 45°C, Km and Vmax values of 0.178 g/dl & 11.62 IU/mg protein, respectively. Clarification of banana and pineapple juice using the partially purified enzyme resulted in 38 and 41% reduction in viscosity as determined spectroscopically
Kondo Effect of Quantum Dots in the Quantum Hall Regime
Quantum dots in the quantum Hall regime can have pairs of single Slater
determinant states that are degenerate in energy. We argue that these pairs of
many body states may give rise to a Kondo effect which can be mapped into an
ordinary Kondo effect in a fictitious magnetic field. We report on several
properties of this Kondo effect using scaling and numerical renormalization
group analysis. We suggest an experiment to investigate this Kondo effect.Comment: To appear in Phys. Rev. B (5 pages, 4 figures); references added;
several changes in tex
Nonequilibrium Transport through a Kondo Dot in a Magnetic Field: Perturbation Theory
Using nonequilibrium perturbation theory, we investigate the nonlinear
transport through a quantum dot in the Kondo regime in the presence of a
magnetic field. We calculate the leading logarithmic corrections to the local
magnetization and the differential conductance, which are characteristic of the
Kondo effect out of equilibrium. By solving a quantum Boltzmann equation, we
determine the nonequilibrium magnetization on the dot and show that the
application of both a finite bias voltage and a magnetic field induces a novel
structure of logarithmic corrections not present in equilibrium. These
corrections lead to more pronounced features in the conductance, and their form
calls for a modification of the perturbative renormalization group.Comment: 16 pages, 7 figure
Risk Factors for Graft-versus-Host Disease in Haploidentical Hematopoietic Cell Transplantation Using Post-Transplant Cyclophosphamide
Post-transplant cyclophosphamide (PTCy) has significantly increased the successful use of haploidentical donors with a relatively low incidence of graft-versus-host disease (GVHD). Given its increasing use, we sought to determine risk factors for GVHD after haploidentical hematopoietic cell transplantation (haplo-HCT) using PTCy. Data from the Center for International Blood and Marrow Transplant Research on adult patients with acute myeloid leukemia, acute lymphoblastic leukemia, myelodysplastic syndrome, or chronic myeloid leukemia who underwent PTCy-based haplo-HCT (2013 to 2016) were analyzed and categorized into 4 groups based on myeloablative (MA) or reduced-intensity conditioning (RIC) and bone marrow (BM) or peripheral blood (PB) graft source. In total, 646 patients were identified (MA-BM = 79, MA-PB = 183, RIC-BM = 192, RIC-PB = 192). The incidence of grade 2 to 4 acute GVHD at 6 months was highest in MA-PB (44%), followed by RIC-PB (36%), MA-BM (36%), and RIC-BM (30%) (P =.002). The incidence of chronic GVHD at 1 year was 40%, 34%, 24%, and 20%, respectively (P <.001). In multivariable analysis, there was no impact of stem cell source or conditioning regimen on grade 2 to 4 acute GVHD; however, older donor age (30 to 49 versus <29 years) was significantly associated with higher rates of grade 2 to 4 acute GVHD (hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.11 to 2.12; P =.01). In contrast, PB compared to BM as a stem cell source was a significant risk factor for the development of chronic GVHD (HR, 1.70; 95% CI, 1.11 to 2.62; P =.01) in the RIC setting. There were no differences in relapse or overall survival between groups. Donor age and graft source are risk factors for acute and chronic GVHD, respectively, after PTCy-based haplo-HCT. Our results indicate that in RIC haplo-HCT, the risk of chronic GVHD is higher with PB stem cells, without any difference in relapse or overall survival
Not Available
Not AvailableSeven females were crossed with three males in a line x tester mating design. The resulting 21 hybrids
along with 10 parents were evaluated for combining ability and gene effects. The results revealed
significant differences among genotypes (parents and crosses) for yield and its components. Combining ability variance and the ratio of GCA versus total genetic variance showed predominance of non-additive gene action for all the characters except plant height and days taken for maturity where additive gene action was predominant. Lines, Lichchavi and Bori Bargama were found to possess significantly high GCA effects for yield and its components while the crosses Lichchavi x Vaishali special and Sonapatti-2 x PT-76 exhibited
significant desired SCA effects for first grade leaf yield and spangle score, respectively. Parents
Lichchavi and Bori Bargama can be subjected to diallel selective mating for fostering greater
recombinations, if simultaneous improvement of developmental characters related to productivity
is sought. The results suggest adoption of reciprocal recurrent selection for improving the yield potential
in chewing tobacco.Not Availabl
Effect of stress on the free volume content of poly(chlorotrifluoroethylene)
The effect of stress (hydrostatic compression) on the free volume of poly(chlorotrifluoroethylene) has been investigated using the positron annihilation lifetime (PAL) technique in the pressure range of 0-14 kbar at room temperature. The variation of the annihilation parameters indicates that the free volume compression occurs at a higher pressure (>8 kbar) compared to molecular compression (4 kbar). The measured free volume size decreases from 95 to 73 Angstrom(3) under the influence of compression. The results also indicate a crystalline-amorphous transformation. The free volume compressibility (beta(f)) is found to be maximum around 9 kbar (10(-3) atm(-1)). (C) 1998 Elsevier Science Ltd. All rights reserved
Stress intensity factor determination of radially cracked circular rings subjected to tension using photoelastic technique
A parametric study was carried out to determine the Stress Intensity Factor (SIF) in a cracked circular ring by using the photoelastic technique. The stress intensity factors for mode I deformation were determined by subjecting the specimens to the tensile loading from inner boundary and through the holes. The results of Non-Dimensional Stress Intensity Factor (NDSIF) variation with non-dimensional crack length for both methods of loading are compared with each other and with published results. © 1989
Integrated intensities and the band strengths of the C-X system of LaO
Relative integrated intensities have been measured for the astrophysically interesting C2Π3 2-X2Σ+ and C2Π1 2-X2Σ+ band systems of LaO by the technique of photographic phonometry. The Franck-Condon factors and r-centroids are computed, the variations of electronic transition moments (Re) with internuclear separation (r̄) are evaluated and band strengths are presented
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