15 research outputs found
Perturbative Bottom-up Approach for Neutrino Mass Matrix in Light of Large \theta_{13} and Role of Lightest Neutrino Mass
We discuss the role of lightest neutrino mass (m_0) in the neutrino mass
matrix, defined in a flavor basis, through a bottom-up approach using the
current neutrino oscillation data. We find that if m_0 < 10^{-3} eV, then the
deviation \delta M_\nu in the neutrino mass matrix from a tree-level, say
tribimaximal neutrino mass matrix, does not depend on m_0. As a result \delta
M_\nu's are exactly predicted in terms of the experimentally determined
quantities such as solar and atmospheric mass squared differences and the
mixing angles. On the other hand for m_0 \gsim 10^{-3} eV, \delta M_\nu
strongly depends on m_0 and hence can not be determined within the knowledge of
oscillation parameters alone. In this limit, we provide an exponential
parameterization for \delta M_\nu for all values of m_0 such that it can
factorize the m_0 dependency of \delta M_\nu from rest of the oscillation
parameters. This helps us in finding \delta M_\nu as a function of the solar
and atmospheric mass squared differences and the mixing angles for all values
of m_0. We use this information to build up a model of neutrino masses and
mixings in a top-down scenario which can predict large \theta_{13}
perturbatively.Comment: 26 pages, 42 eps figures, revtex (references are added, more
discussions are added in section-III
Selective separation and recovery of cobalt from leach liquor of discarded Li-ion batteries using thiophosphinic extractant
Plenty of valuable metals especially cobalt is present in spent batteries. The conventional process of disposing
the spent batteries as land fill or metal recovery through pyrometallurgical process was not sustainable
step to resolve problems. Present work is a part of systematic study involving solvent extraction
for the separation and recovery of cobalt from leach liquor of spent batteries containing 21.83 g/L, 2.77 g/
L, 9.14 g/L and 4.14 g/L of cobalt, lithium, copper and aluminum, respectively. Initially bench scale studies
were carried out using synthetic solution of 10.44 g/L cobalt and 1.33 g/L lithium (composition similar to
the leach liquor diluted two times) in sulfate medium to optimize the condition for the metal recovery
from the leach liquor of available batteries. 15% Cyanex 272 as extractant, 3% isodecanol as phase modifier
and kerosene as diluent extracted about 99.9% cobalt from synthetic solution at equilibrium pH 5, O/A ratio 1:1 within 5 min of contact time in two stages. The metal loaded organic was scrubbed with 10% Na2CO3 and stripped with 10% H2SO4. The optimized condition obtained was compared with the leach liquor of batteries which shows the presence of about 99.99% cobalt in the stripped solution and about 95% Li in the raffinate. Hydrated salt of cobalt can be further obtained by using evaporation, Crystallization,precipitation and cementation process
TG/DTA studies of the mixture of Korean monazite and sodium carbonate to get optimum condition for phosphate decomposition
TG/DTA is one of the important thermal pre-treatment processes in which material sare heated at high temperature in a furnace to identify the change in the properties due to thermal decomposition of sample i.e, loss in weight, melting point, type of reaction, etc. as well as compounds emitted. Present paper reports the TG/DTA studies of Korean monazite when mixed with an hydrous sodium carbonate and its decomposition behavior particularly for phosphate. A weak peak of decalescence was observed on DTA curve between 750˚C to 850˚C indicating the reaction of monazite. The shape of the peak suggests a phase shift between the two temperatures. The peak indicated that the decomposition starts after 700˚C and it requires energy i.e. an endothermic reaction. The first depletion in the TG curve noticed around 100˚C shows the reaction of sodium carbonate with SiO2 present in the monazite to form metal silicate whch is followed by the formation of meta disilicate starting at ~700˚C with the evolution of CO2. An equivalent amount of CO2 would have been released during the reaction between sodium carbonate and Korean monazite i.e. a rare earth(RE) phosphate mineral(REPO4)at 850˚C, which melts and react with REPO4 to form RE oxide sand sodium phosphate. XRD analysis of the sample after TG-DTA test was performed to confirm the phases present after heat treatment. The optimum condition obtained by TG-DTA for dephosphorisation of monazite was validated in muffle furnace in laboratory scale and found the result similar and satisfactory. The roasted sample could be processed further to recover RE metals by hydrometallurgical processes
Strain-mediated ferromagnetism and low-field magnetic reversal in Co doped monolayer WS2
Strain-mediated magnetism in 2D materials and dilute magnetic semiconductors hold multifunctional applications for future nano-electronics. Herein, First principles calculations are employed to study the influence of biaxial strain on the magnetic properties of Co-doped monolayer WS2. The non-magnetic WS2 shows ferromagnetic signature upon Co doping due to spin polarization, which is further improved at low compressive (-2 %) and tensile (+2 %) strains. From the PDOS and spin density analysis, the opposite magnetic ordering is found to be favourable under the application of compressive and tensile strains. The double exchange interaction and p-d hybridization mechanisms make Co-doped WS2 a potential host for magnetism. More importantly, the competition between exchange and crystal field splittings, i.e. (Delta(ex) > Delta(cfs)), of the Co-atom play pivotal roles in deciding the values of the magnetic moments under applied strain. Micromagnetic simulation reveals, the ferromagnetic behavior calculated from DFT exhibits low-field magnetic reversal (190 Oe). Moreover, the spins of Co-doped WS2 are slightly tilted from the easy axis orientations showing slanted ferromagnetic hysteresis loop. The ferromagnetic nature of Co-doped WS2 suppresses beyond +/- 2 strain, which is reflected in terms of decrease in the coercivity in the micromagnetic simulation. The understanding of low-field magnetic reversal and spin orientations in Co-doped WS2 may pave the way for next-generation spintronics and straintronics applications
Bipolar Resistive Switching in TiO<sub>2</sub> Artificial Synapse Mimicking Pavlov’s Associative Learning
Memristive devices are among the most emerging electronic
elements
to realize artificial synapses for neuromorphic computing (NC) applications
and have potential to replace the traditional von-Neumann computing
architecture in recent times. In this work, pulsed laser deposition-manufactured
Ag/TiO2/Pt memristor devices exhibiting digital and analog
switching behavior are considered for NC. The TiO2 memristor
shows excellent performance of digital resistive switching with a
memory window of order ∼103. Furthermore, the analog
resistive switching offers multiple conductance levels supporting
the development of the bioinspired synapse. A possible mechanism for
digital and analog switching behavior in our device is proposed. Remarkably,
essential synaptic functions such as pair-pulse facilitation, long-term
potentiation (LTP), and long-term depression (LTD) are successfully
realized based on the change in conductance through analog memory
characteristics. Based on the LTP-LTD, a neural network simulation
for the pattern recognition task using the MNIST data set is investigated,
which shows a high recognition accuracy of 95.98%. Furthermore, more
complex synaptic behavior such as spike-time-dependent plasticity
and Pavlovian classical conditioning is successfully emulated for
associative learning of the biological brain. This work enriches the
TiO2-based resistive random-access memory, which provides
information about the simultaneous existence of digital and analog
behavior, thereby facilitating the further implementation of memristors
in low-power NC
Estimates of interseismic deformation in northeast india from GPS measurements
Estimates of interseismic deformation in northeastern India based on GPS measurements at eight permanent stations (2003-2006) and six campaign sites (1997-2006) are presented here. The Euler pole of rotation of Indian tectonic plate in ITRF2000 determined from the present data set is located at 51.7 ± 0.5 °N, - 15.1 ± 1.5 °E with angular velocity of 0.469 ± 0.01 Myr- 1. The results show that there is a statistically insignificant present-day active deformation within the Shillong Plateau and in the foreland spur north of the plateau in the Brahmaputra valley. Convergence rate of the northeastern GPS sites with respect to the IGS station Lhasa along baselines that are normal to the Himalayan arc in this region is 16 ± 0.5 mm/yr. This represents the arc-normal Indo-Eurasian convergence rate across the northeastern boundary, similar to arc-normal convergence rates determined in central Nepal along the Himalayan arc. However, unlike central Nepal, in the Arunachal Himalaya the 16 mm/yr shortening is distributed between the Lesser as well as Higher and Tethyan Himalayas. Baselines between sites on the Indo-Burmese Fold and Thrust Belt (IBFTB) and Shillong Plateau indicate variations in the shortening rate from 1.5 mm/yr on the Tripura-Mizoram salient (TRS) south of the plateau, to 6 mm/yr in the Imphal Recess (IR) to the east and 8 mm/yr in Naga salient (NS) to the northeast. This suggests that the deformation in the IBFTB is segmented into N-S blocks along E-W transverse zones exhibiting dextral slip between NS-IR and sinistral slip between IR and TRS. Baselines between the IBFTB sites also show 10 ± 0.6 mm/yr convergence pointing to the existence of an active transverse zone between Aizawl and Imphal
From the Climate Change Threat to the Securitisation of Development: An Analysis of China
Curcumin-encapsulated MePEG/PCL diblock copolymeric micelles: a novel controlled delivery vehicle for cancer therapy
Sputum Proteomics Reveals a Shift in Vitamin D-binding Protein and Antimicrobial Protein Axis in Tuberculosis Patients
Abstract Existing understanding of molecular composition of sputum and its role in tuberculosis patients is variously limited to its diagnostic potential. We sought to identify infection induced sputum proteome alteration in active/non tuberculosis patients (A/NTB) and their role in altered lung patho-physiology. Out of the study population (n = 118), sputum proteins isolated from discovery set samples (n = 20) was used for an 8-plex isobaric tag for relative and absolute concentration analysis. A minimum set of protein with at least log2(ATB/NTB) >±1.0 in ATB was selected as biosignature and validated in 32 samples. Predictive accuracy was calculated from area under the receiver operating characteristic curve (AUC of ROC) using a confirmatory set (n = 50) by Western blot analysis. Mass spectrometry analysis identified a set of 192 sputum proteins, out of which a signature of β-integrin, vitamin D binding protein:DBP, uteroglobin, profilin and cathelicidin antimicrobial peptide was sufficient to differentiate ATB from NTB. AUC of ROC of the biosignature was calculated to 0.75. A shift in DBP-antimicrobial peptide (AMP) axis in the lungs of tuberculosis patients is observed. The identified sputum protein signature is a promising panel to differentiate ATB from NTB groups and suggest a deregulated DBP-AMP axis in lungs of tuberculosis patients