2,559 research outputs found
High-pressure x-ray diffraction study of bulk and nanocrystalline PbMoO4
We studied the effects of high-pressure on the crystalline structure of bulk
and nanocrystalline scheelite-type PbMoO4. We found that in both cases the
compressibility of the materials is highly non-isotropic, being the c-axis the
most compressible one. We also observed that the volume compressibility of
nanocrystals becomes higher that the bulk one at 5 GPa. In addition, at 10.7(8)
GPa we observed the onset of an structural phase transition in bulk PbMoO4. The
high-pressure phase has a monoclinic structure similar to M-fergusonite. The
transition is reversible and not volume change is detected between the low- and
high-pressure phases. No additional structural changes or evidence of
decomposition are found up to 21.1 GPa. In contrast nanocrystalline PbMoO4
remains in the scheelite structure at least up to 16.1 GPa. Finally, the
equation of state for bulk and nanocrystalline PbMoO4 are also determined.Comment: 18 pages, 4 figure
Reliability Analysis of a Series and Parallel Network using Triangular Intuitionistic Fuzzy Sets
This paper describes a novel approach, based on intuitionistic fuzzy set theory for reliability analysis of series and parallel network. The triangular intuitionistic fuzzy sets are used to represent the failure possibility of each basic (terminal) event to get more comprehensive results for the failure possibility of the top event. The proposed technique is demonstrated on a web server LOG data used to illustrate HTTP (Hyper Text Transfer Protocol) failur
Magnetotelluric investigations for imaging electrical structure of Garhwal Himalayan corridor, Uttarakhand, India
Magnetotelluric investigations have been carried out in the Garhwal Himalayan corridor to delineate the electrical structure of the crust along a profile extending from Indo-Gangetic Plain to Higher Himalayan region in Uttarakhand, India. The profile passing through major Himalayan
thrusts: Himalayan Frontal Thrust (HFF), Main Boundary Thrust (MBT) and Main Central Thrust (MCT), is nearly perpendicular to the regional geological strike. Data processing and impedance analysis indicate that out of 44 stations MT data recorded, only 27 stations data show in general, the validity of 2D assumption. The average geoelectric strike, N700W, was estimated for the profile using tensor decomposition. 2D smooth geoelectrical model has been presented, which provides the electrical image of the shallow and deeper crustal structure. The major features of
the model are (i) a low resistivity (<50Ωm), shallow feature interpreted as sediments of Siwalik and Indo-Gangetic Plain, (ii) highly resistive (> 1000Ωm) zone below the sediments at a depth of 6 km, interpreted as the top surface of the Indian plate, (iii) a low resistivity (< 10Ωm) below the depth of 6 km near MCT zone coincides with the intense micro-seismic activity in the region. The zone is interpreted as the partial melting or fluid phase at mid crustal depth. Sensitivity test indicates that the major features of the geoelectrical model are relevant and desired by the MT data
Humanized Mice Are Instrumental to the Study of Plasmodium falciparum Infection
Research using humanized mice has advanced our knowledge and understanding of human haematopoiesis, non-adaptive and adaptive immunity, autoimmunity, infectious disease, cancer biology, and regenerative medicine. Challenges posed by the human-malaria parasite Plasmodium falciparum include its complex life cycle, the evolution of drug resistance against anti-malarials, poor diagnosis, and a lack of effective vaccines. Advancements in genetically engineered and immunodeficient mouse strains, have allowed for studies of the asexual blood stage, exoerythrocytic stage and the transition from liver-to-blood stage infection, in a single vertebrate host. This review discusses the process of “humanization” of various immunodeficient/transgenic strains and their contribution to translational biomedical research. Our work reviews the strategies employed to overcome the remaining-limitations of the developed human-mouse chimera(s)
High-pressure structural investigation of several zircon-type orthovanadates
Room temperature angle-dispersive x-ray diffraction measurements on
zircon-type EuVO4, LuVO4, and ScVO4 were performed up to 27 GPa. In the three
compounds we found evidence of a pressure-induced structural phase
transformation from zircon to a scheelite-type structure. The onset of the
transition is near 8 GPa, but the transition is sluggish and the low- and
high-pressure phases coexist in a pressure range of about 10 GPa. In EuVO4 and
LuVO4 a second transition to a M-fergusonite-type phase was found near 21 GPa.
The equations of state for the zircon and scheelite phases are also determined.
Among the three studied compounds, we found that ScVO4 is less compressible
than EuVO4 and LuVO4, being the most incompressible orthovanadate studied to
date. The sequence of structural transitions and compressibilities are
discussed in comparison with other zircon-type oxides.Comment: 34 pages, 2 Tables, 11 Figure
Room temperature Ferromagnetism in Th1-xFexO2-d (x = 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) nanoparticles
Nanocrystalline (Th1-xFex)O2-d particles with different Fe concentrations (x
= 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) have been prepared by a gel combustion
method. Rietveld refinement analyses of X-ray diffraction data revealed the
formation of an impurity free cubic type Th1-xFexO2-d structure up to x = 0.20.
This observation is further confirmed from the detailed studies conducted on 10
at. percent Fe doped ThO2 using high-resolution transmission electron
microscopy (HRTEM) imaging and indexing of the selected-area electron
diffraction (SAED) patterns. DC Magnetization studies as a function field
indicate that they are ferromagnetic with Curie temperature (Tc) well above
room temperature.Comment: 10 pages, 5 figure
Phonons and Colossal Thermal Expansion Behavior of Ag3Co(CN)6 and Ag3Fe(CN)6
Recently colossal positive volume thermal expansion has been found in the
framework compounds Ag3Co(CN)6 and Ag3Fe(CN)6. Phonon spectra have been
measured using the inelastic neutron scattering technique as a function of
temperature and pressure. The data has been analyzed using ab-initio
calculations. We find that the bonding is very similar in both compounds. At
ambient pressure modes in the intermediate frequency part of the vibrational
spectra in the Co compound are shifted to slightly higher energies as compared
to the Fe compound. The temperature dependence of the phonon spectra gives
evidence for large explicit anharmonic contribution to the total anharmonicity
for low-energy modes below 5 meV. We found that modes are mainly affected by
the change in the size of unit cell, which in turn changes the bond lengths and
vibrational frequencies. Thermal expansion has been calculated via the volume
dependence of phonon spectra. Our analysis indicates that Ag phonon modes in
the energy range from 2 to 5 meV are strongly anharmonic and major contributors
to thermal expansion in both compounds. The application of pressure hardens the
low-energy part of the phonon spectra involving Ag vibrations and confirms the
highly anharmonic nature of these modes.Comment: 19 pages, 14 figures and one tabl
Characterization of Extracellular Polymeric Substances (Eps) Produced by \u3ci\u3eCloacibacterium normanense\u3c/i\u3e Isolated from Wastewater Sludge for Sludge Settling and Dewatering
In this study, extracellular polymeric substances (EPSs) producing strain was isolated from municipal wastewater sludge (MWWS). Growth profile and the EPS production by Cloacibacterium normanense using wastewater sludge as raw material in shake flask fermentation for 96 h were investigated. The highest concentration of S-EPS (13.0 ± 0.8 g/L) and C-EPS (0.3 ± 0.1 g/L) were attained at 48 h of fermentation. S-EPS revealed higher flocculation activity (94.2%) and dewaterability (59.9%) than other types of EPS in kaolin suspension. The dewaterability of MWWS with 2 g suspended solids (SS)/L was improved by 37.6% using 0.02 ± 0.01 g/L of S-EPS and 600 mg/L of Al2(SO4)3. The study showed a promising approach of new isolated strain to produce high concentration EPS in sludge with high flocculation activity as well as good settlin
Characterization of Extracellular Polymeric Substances (Eps) Produced by \u3ci\u3eCloacibacterium normanense\u3c/i\u3e Isolated from Wastewater Sludge for Sludge Settling and Dewatering
In this study, extracellular polymeric substances (EPSs) producing strain was isolated from municipal wastewater sludge (MWWS). Growth profile and the EPS production by Cloacibacterium normanense using wastewater sludge as raw material in shake flask fermentation for 96 h were investigated. The highest concentration of S-EPS (13.0 ± 0.8 g/L) and C-EPS (0.3 ± 0.1 g/L) were attained at 48 h of fermentation. S-EPS revealed higher flocculation activity (94.2%) and dewaterability (59.9%) than other types of EPS in kaolin suspension. The dewaterability of MWWS with 2 g suspended solids (SS)/L was improved by 37.6% using 0.02 ± 0.01 g/L of S-EPS and 600 mg/L of Al2(SO4)3. The study showed a promising approach of new isolated strain to produce high concentration EPS in sludge with high flocculation activity as well as good settlin
- …