234 research outputs found
Spin dynamics and frequency dependence of magnetic damping study in soft ferromagnetic FeTaC film with a stripe domain structure
Perpendicular magnetic anisotropy (PMA) and low magnetic damping are the key
factors for the free layer magnetization switching by spin transfer torque
technique in magnetic tunnel junction devices. The magnetization precessional
dynamics in soft ferromagnetic FeTaC thin film with a stripe domain structure
was explored in broad band frequency range by employing micro-strip
ferromagnetic resonance technique. The polar angular variation of resonance
field and linewidth at different frequencies have been analyzed numerically
using Landau-Lifshitz-Gilbert equation by taking into account the total free
energy density of the film. The numerically estimated parameters Land\'{e}
-factor, PMA constant, and effective magnetization are found to be 2.1,
2 erg/cm and 7145 Oe, respectively. The frequency
dependence of Gilbert damping parameter () is evaluated by considering
both intrinsic and extrinsic effects into the total linewidth analysis. The
value of is found to be 0.006 at 10 GHz and it increases with
decreasing precessional frequency.Comment: 5 Pages, 6 Figures, Regular Submissio
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Broad-band Light Emission From Ion Implanted Silicon Nanocrystals Via Plasmonic and Non-plasmonic Effects for Optoelectronics
Broad band light emission ranging from the ultraviolet (UV) to the near infrared (NIR) has been observed from silicon nanoparticles fabricated using low energy (30-45 keV) metal and non-metal ion implantation with a fluence of 5*1015 ions/cm2 in crystalline Si(100). It is found from a systematic study of the annealing carried out at certain temperatures that the spectral characteristics remains unchanged except for the enhancement of light emission intensity due to annealing. The annealing results in nucleation of metal nanoclusters in the vicinity of Si nanoparticles which enhances the emission intensity. Structural and optical characterization demonstrate that the emission originates from both highly localized defect bound excitons at the Si/Sio2 interface, as well as surface and interface traps associated with the increased surface area of the Si nanocrystals. The emission in the UV is due to interband transitions from localized excitonic states at the interface of Si/SiO2 or from the surface of Si nanocrystals. The radiative efficiency of the UV emission from the Si nanoparticles can be modified by the localized surface plasmon (LSP) interaction induced by the nucleation of silver nanoparticles with controlled annealing of the samples. The UV emission from Si nanoclusters are coupled resonantly to the LSP modes. The non-resonant emission can be enhanced by electrostatic-image charge effects. The emission in the UV (~3.3 eV) region can also be significantly enhanced by electrostatic image charge effects induced by Au nanoparticles. The UV emission from Si nanoclusters, in this case, can be coupled without LSP resonance. The recombination of carriers in Si bound excitons is mediated by transverse optical phonons due to the polarization of the surface bound exciton complex. The low energy side of emission spectrum at low temperature is dominated by 1st and 2nd order phonon replicas. Broad band emission ranging from the UV to the NIR wavelength range can be obtained from Ag implanted onto a single silicon substrate
Report of Potato grouper and Cloudy grouper in fishery landings at Mumbai
Grouper fishery of Maharashtra is dominated by
Epinephelus diacanthus with occasional landing of
E. bleekeri, E. malabaricus, E.coioides, E.
areolatus, E. polylepis, E. morrhua, E. latifasciatus,
E. epistictus, E. radiatus and Cephalopholis
sonnerati. During the routine fishery survey at
Sassoon Dock on 9th October 2016 a single specimen
of Potato grouper Epinephelus tukula measuring 35
cm TL (1.7 kg) was observed in the landings of a
trawler operated at a depth of 40 off Ratnagiri.
Reports of E. tukula is rare from Indian coast and
other reports are from Lakshadweep, Vizhinjam
(Kerala), Grand Island (Goa), Muttom, Enayam
(Tamil Nadu) coasts (Sluka and Lazarus, 2010 Marine
Biodiversity Records 3:1-3). Potato grouper, is a
widely distributed Indo-Pacific species, but sparsely
known in their distribution range from Red Sea to
Kenya and Australia. The name refers to the potatoshaped
dark blotches on the body
Report of dorsal fin abnormality in silver pomfret
During a routine sampling for silver pomfret
Pampus argenteus, specimens with dorsal fin
abnormality were collected from Ratnagiri and
Mumbai, Maharashtra. On 29th April, 2016 a single
silver pomfret with deformed dorsal region and a
deep pit in the dorsal region was observed in the
purse seine landings at Mirkarwada fish landing
centre, Ratnagir
Artisanal longline fishing for high value fishes off Mumbai, Maharashtra
Sassoon Dock is one of oldest and a major landing
center located in Mumbai from where several
multiday and single day fishing vessels including
trawlers, dolnetters, gillnetters and hook and line
units operate. Marine fisheries of Maharashtra is
mostly dominated by trawlers and dolnetters while
line fishing is done by only a few fishers. The
artisanal fishers in Juhu, Colaba and nearby areas
of Mumbai are operating a few long line units in
small wooden boats (6 - 7 m OAL) or fibre boats
fitted with engines of 16 – 24 hp from Sassoon Dock
landing centre
Management of Rangelands and Forests for Sustainable Mithun Farming by Chakhesang Tribe of Nagaland
Mithun (Bos frontalis) belonging to the family Bovidae is a unique bovine mainly found in the North-Eastern hilly region of India and neighbouring countries (Dhali et al., 2009). The animal has an important place in the socio-economic life of the tribal communities and primarily reared as sacrificial animal during religio-cultural ceremonies. Feeding habits of Mithun differs from their domestic counterparts cattle; like they prefer browsing as compared to the grazing behaviour of the later. Mithun forage on forest grasses, shrubs and tree leaves available in the jungle and they nibble them like goats (Gupta et al., 1996). As mithun prefers browsing, so they are reared in demarcated forests and rangelands under natural conditions by the tribal communities and during the course of rearing, these communities manage both, the mithun and forest ranges.
Land owning pattern in Nagaland is different and most of the land is owned by the community that gives right to use and manage the resources to mithun owners. Forest departments owns certain category of forests classified as Reserved forest, Protected forests, Wildlife sanctuaries, National Parks and Botanical gardens that comprises of about 16.7% of the total available forest area. Remaining around 83.3% of forests are owned by the villagers and Government has no control over these (Singh et al., 2009). Since the Government has very limited role, so management practices largely varies with the communities residing there. Communities have their own way of exploiting resources and to replenish them and that differs with the communities. The farmers who owns mithun has more proximity with forests and rangelands so management practices adopted by them is being presented in this paper
Protein phosphatase complement in rice: genome-wide identification and transcriptional analysis under abiotic stress conditions and reproductive development
<p>Abstract</p> <p>Background</p> <p>Protein phosphatases are the key components of a number of signaling pathways where they modulate various cellular responses. In plants, protein phosphatases constitute a large gene family and are reportedly involved in the regulation of abiotic stress responses and plant development. Recently, the whole complement of protein phosphatases has been identified in <it>Arabidopsis </it>genome. While PP2C class of serine/threonine phosphatases has been explored in rice, the whole complement of this gene family is yet to be reported.</p> <p>Results</p> <p><it>In silico </it>investigation revealed the presence of 132-protein phosphatase-coding genes in rice genome. Domain analysis and phylogenetic studies of evolutionary relationship categorized these genes into PP2A, PP2C, PTP, DSP and LMWP classes. PP2C class represents a major proportion of this gene family with 90 members. Chromosomal localization revealed their distribution on all the 12 chromosomes, with 42 genes being present on segmentally duplicated regions and 10 genes on tandemly duplicated regions of chromosomes. The expression profiles of 128 genes under salinity, cold and drought stress conditions, 11 reproductive developmental (panicle and seed) stages along with three stages of vegetative development were analyzed using microarray expression data. 46 genes were found to be differentially expressing in 3 abiotic stresses out of which 31 were up-regulated and 15 exhibited down-regulation. A total of 82 genes were found to be differentially expressing in different developmental stages. An overlapping expression pattern was found for abiotic stresses and reproductive development, wherein 8 genes were up-regulated and 7 down-regulated. Expression pattern of the 13 selected genes was validated employing real time PCR, and it was found to be in accordance with the microarray expression data for most of the genes.</p> <p>Conclusions</p> <p>Exploration of protein phosphatase gene family in rice has resulted in the identification of 132 members, which can be further divided into different classes phylogenetically. Expression profiling and analysis indicate the involvement of this large gene family in a number of signaling pathways triggered by abiotic stresses and their possible role in plant development. Our study will provide the platform from where; the expression pattern information can be transformed into molecular, cellular and biochemical characterization of members belonging to this gene family.</p
Inherent photoluminescence Stokes shift in GaAs
The intrinsic photoluminescence Stokes shift, i.e., the energy difference between optical band gap and emission peak, of 350 μm thick semi-insulating GaAs wafers is found to be 4 meV at room temperature. The result is based on the determination of the optical bulk band gap from the transmission trend via modified Urbach rule whose result is confirmed with the transmission derivative method. The findings reveal the detailed balance of the optically evoked transitions and disclose the intrinsic link between Stokes shift and the Urbach tail slope parameter
Development and evaluation of acyclovir mucoadhesive tablet using a novel starch based platform
The present study evaluated novel polymer mixtures prepared by spray drying of an aqueous
dispersion of moth bean starch with Carbopol 934P and HPMC K4M for to be used as platform for peroral
mucoadhesive drug delivery. 32 factorial designs were employed to evaluate influence of different concentrations
of hydrophilic polymers i.e. Carbopol 934P and HPMC K4M with constant concentration of
moth bean starch on the drug release as well as in vitro adhesion time. All the formulations were studied
for physical evaluation i.e. hadness, friability, content uniformity, drug-excipient compatibility as well as
stability study. Two formulations F1 and F4 out of nine containing low amount of synthetic polymer exhibited
desirable in vitro mucoadhesion time >8 h and drug release >90 % in controlled manner.Colegio de Farmacéuticos de la Provincia de Buenos Aire
A tetragonal core with asymmetric iron environments supported solely by bis(μ-OH){μ-(O-H···O)} bridging and terminal pyridine amide (N, O) coordination: a new member of the tetrairon(III) family
Room-temperature aerobic reaction of [Fe(MeCN)4][ClO4]2 with 1,3-bis(2-pyridinecarboxamido)propane (H2bpp) yields the tetrairon(III) complex [Fe4(H2bpp)4(μ-OH)2(μ-OHO)][ClO4]7·2H2O·xMeCN (1·xMeCN, 0≤x≤3). Crystal structure determination reveals that 1·3MeCN is a new member of the tetrairon(III) family, bridged solely by two hydroxido ligands and a localized {O-H···O}3- bridging unit. The properties of the "tetragonal" core [Fe4(μ-OH)2{μ-(O-H···O)}]7+ have been investigated by variable-temperature magnetic and Mossbauer spectroscopic measurements. Successful modeling of the data has revealed asymmetric iron environments and three types of magnetic exchange interactions [through μ-OH and μ-O/μ-OH of μ-(O-H···O) bridges]. This tetragonal core is a valuable addition to the tetrairon(III) cluster family from inorganic and bioinorganic perspectives
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