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Variability in vertical structure of precipitation with sea surface temperature over the Arabian Sea and the Bay of Bengal as inferred by Tropical Rainfall Measuring Mission precipitation radar measurements
No full textTropical Rainfall Measuring Mission (TRMM) precipitation radar measurements are used to examine the variation in vertical structure of precipitation with sea surface temperature (SST) over the Arabian Sea (AS) and Bay of Bengal (BOB). The variation in reflectivity and precipitation echo top with SST is remarkable over the AS but small over the BOB. The reflectivity increases with SST (from 26 to 31 degrees C) by similar to 1 and 4 dBZ above and below 6 km, respectively, over the AS, while its variation is < 0.5 dBZ over the BOB. The transition from shallow storms at lower SSTs (<= 27 degrees C) to deeper storms at higher SSTs is strongly associated with the decrease in stability and mid-tropospheric wind shear over the AS. In contrary, the storms are deeper at all SSTs over the BOB due to weaker stability and mid-tropospheric wind shear. At lower SSTs, the observed high aerosol optical depth (AOD) and low total column water (TCW) over AS results in the small cloud effective radius (CER) and weaker reflectivity. As SST increases, AOD decreases and TCW increases, leading to a large CER and high reflectivity. The changes in these parameters with SST are marginal over the BOB and hence the CER and reflectivity. The predominance of collision-coalescence process below the bright band is responsible for the observed negative slopes in the reflectivity over both the seas. The observed variations in reflectivity originate at the cloud formation stage over both the seas, and these variations are magnified during the descent of hydrometeors to the ground
Error Correction in Coded Caching With Symmetric Batch Prefetching
No full textIn coded caching, a single server is connected to a set of users through a shared bottleneck link, which is assumed to be error free. During non-peak hours, all the users fill their local cache with portions of the files available. During the delivery phase, each user requests a file and the server delivers coded transmissions to meet the demands. In this paper, the links between the server and the users are assumed to be error prone. Prefetching errors are also considered. A new delivery scheme is required to meet the demands of each user even after receiving a finite number of transmissions in error in the presence of erroneous portions of files in the cache. The minimum average rate and minimum peak rate for this problem are characterized. Closed form expressions for average and peak rates for a particular caching scheme, namely, symmetric batch prefetching are established when there are no prefetching errors. An optimal linear error correcting delivery scheme is proposed for coded caching problems with symmetric batch prefetching in the absence of prefetching errors. In addition to this, lower bounds are established for the optimal rate required when there are prefetching errors in symmetric batch prefetching
Preparation and characterization studies of La doped CuS nanospheres by microwave irradiation for high performance supercapacitors
No full textLanthanum (Rare earth metal) doped CuS (La@CuS) at different compositions (0%, 1%, 3% and 5% of La) are synthesized by encapsulation of sodium alginate biopolymer using microwave irradiation method. The prepared various compositions of La@CuS are examined by structural characterizations, particle size and identifications of elements from XRD, TEM and EDX spectrum. The surface morphological studies are conformed by SEM and TEM images. Optical properties and characteristics peak are confirmed with UV, FTIR and Raman spectroscopic tools. In addition to that the electrochemical performances are studied using Cyclic Voltammetry (CV), Galvanostatic charge and discharge (GCD) and electrochemical impedance spectroscopy (EIS) investigations. The specific capacitance is found to be 1329 F/g for 5% of La doped CuS nano spheres
Magnetic frustration in partially ordered double perovskites Ln(3)Ni(2)RuO(9) (Ln = La, Nd)
No full textLn(3)Ni(2)RuO(9) (Ln = La, Nd) oxides (prepared by a solid state metathesis route) adopt a monoclinic (P2(1)/n) A(2)BB'O-6 double perovskite structure wherein the two independent octahedral 2c and 2d sites are occupied by Ni2+ and (Ni1/32+Ru2/35+) cations, respectively. In contrast to the expected ferromagnetic behavior, Ln(3)Ni(2)RuO(9) oxides show a spin-glass behavior without long range magnetic order down to 2 K. These results reveal the importance of competing nearest neighbor (NN), next nearest neighbor (NNN) and third nearest neighbor (third NN) interactions between the magnetic Ni2+ and Ru5+ ions in the partially ordered double perovskite structure that conspire to thwart the expected ferromagnetic order in these materials
Rhizospheric life of Salmonella requires flagella-driven motility and EPS-mediated attachment to organic matter and enables cross-kingdom invasion
No full textSalmonella is an established pathogen of the members of the kingdom Animalia. Reports indicate that the association of Salmonella with fresh, edible plant products occurs at the pre-harvest state, i.e. in the field. In this study, we follow the interaction of Salmonella Typhimurium with the model plant Arabidopsis thaliana to understand the process of migration in soil. Plant factors like root exudates serve as chemo-attractants. Our ex situ experiments allowed us to track Salmonella from its free-living state to the endophytic state. We found that genes encoding two-component systems and proteins producing extracellular polymeric substances are essential for Salmonella to adhere to the soil and roots. To understand the trans-kingdom flow of Salmonella, we fed the contaminated plants to mice and observed that it invades and colonizes liver and spleen. To complete the disease cycle, we re-established the infection in plant by mixing the potting mixture with the fecal matter collected from the diseased animals. Our experiments revealed a cross-kingdom invasion by the pathogen via passage through a murine intermediate, a mechanism for its persistence in the soil and invasion in a non-canonical host. These results form a basis to break the life-cycle of Salmonella before it reaches its animal host and thus reduce Salmonella contamination of food products
Structural, spectral, computational and thermal studies on a new organic NLO crystal: 2-aminopyrazinium 5-nitro-2-hydroxybenzoate
No full textIn this study, a complete investigation on molecular and vibrational structure of 2-aminopyrazinium 5-nitro-2-hydroxybenzoate (2APZ5NHB) crystal was analyzed. Single crystal XRD analysis confirms that the crystal has monoclinic crystal system (a = 13.3851(16) angstrom, b = 11.7318(13) angstrom, c = 7.9004(8) angstrom, beta = 100.618(4)degrees) with P2(1)/c space group. The usual R22 ring motifs are formed through two N-H center dot center dot center dot O hydrogen bonds. The N-H center dot center dot center dot O hydrogen bonding interactions were quantitatively analyzed by Hirshfeld surface and fingerprint analyses. 2APZ5NHB has been characterized by FTIR, Raman, UV-Vis spectroscopy and TG/DTA analysis experimentally and the corresponding DFT calculations were done theoretically. The optimized molecular geometry of 2APZ5NHB and their corresponding vibrational assignments are correlated. UV-Visible transmission spectrum shows the cutoff wavelength around 340 nm. Thermal analysis revealed that 2APZ5NHB crystal was thermally stable up to 135 degrees C. The electronic band gap and the first-order hyperpolarizability calculated which signifies the 2APZ5NHB crystal for NLO applications
Observational Signature of Circumstellar Interaction and Ni-56-mixing in the Type II Supernova 2016gfy
No full textThe optical and ultraviolet broadband photometric and spectroscopic observations of the Type II supernova (SN) 2016gfy are presented. The V-band light curve (LC) shows a distinct plateau phase with a slope of s(2) similar to 0.12 mag (100 day)(-1) and a duration of 90 +/- 5 days. Detailed analysis of SN 2016gfy provided a mean Ni-56 mass of 0.033 +/- 0.003 M-circle dot, a progenitor radius of similar to 350-700 R-circle dot, a progenitor mass of similar to 12-15 M-circle dot, and an explosion energy of (0.9-1.4) x 10(51) erg s(-1). The P-Cygni profile of H alpha in the early-phase spectra (similar to 11-21 days) shows a boxy emission. Assuming that this profile arises from the interaction of the SN ejecta with the pre-existing circumstellar material (CSM), it is inferred that the progenitor underwent a recent episode (30-80 yr prior to the explosion) of enhanced mass loss. Numerical modeling suggests that the early LC peak is reproduced better with an existing CSM of 0.15 M-circle dot spread out to similar to 70 au. A late-plateau bump is seen in the VRI LCs during similar to 50-95 days. This bump is explained as a result of the CSM interaction and/or partial mixing of radioactive Ni-56 in the SN ejecta. Using strong-line diagnostics, a subsolar oxygen abundance is estimated for the supernova H II region (12 + log(O/H) = 8.50 +/- 0.11), indicating an average metallicity for the host of an SN II. A star formation rate of similar to 8.5 M-circle dot yr(-1) is estimated for NGC 2276 using the archival GALEX FUV data
Microhybrid Electricity System for Energy Access, Livelihoods, and Empowerment
No full textEnsuring reliable and affordable access to modern energy services, especially for the poorer and deprived section of the population, is a basic requisite for sustainable development. Given that a majority of the energy-deprived population lives in rural regions of developing countries, an effective rural electrification is critical for bridging the rural-urban divide. Building on energy access intervention, implementing productive energy services can influence the next stages of development through livelihood activities, microenterprises, lifestyle energy services, value-added activities, survival irrigation, and so on. Social benefits of access to healthcare, education, and longer productive hours have an equally important impact on sustainable development. In India, for example, 240 million people lack electricity access. While grid extension in India is on the rise through various government programs, specific rural problems of low energy demand, poor rural economy, inaccessible terrain, and low purchasing power can render grid extension expensive and inefficient. Microgrid electricity systems, especially with hybrid renewable energy resources, can be a good alternative for addressing above-mentioned challenges. India enjoys high solar intensity, and the predominantly agrarian rural society has enough biomass resources, abundant cattle dung, forest foliage, and agricultural waste. A solar-biomass hybrid electricity system can solve the problem of intermittency of solar. Such a hybrid electricity system is being implemented in a remote Indian unelectrified village for electricity access, livelihoods, and economic empowerment. In this paper, we report the technoeconomic feasibility and sustainability analysis of this hybrid system. The system consists of 30-kW solar photo voltaic (PV) and 20-kW biomass gasifier modules. Energy demand and resource availability are estimated with inputs from extensive stakeholder discussions and field surveys, and they account for daily and seasonal variations in both supply and end uses and availability and productive hours. The expected temporal electricity demand is estimated for households, community, irrigation, and commercial needs. The technoeconomic feasibility is assessed using hybrid optimization model for electric renewable energy (HOMER). Furthermore, opportunities for the development of productive uses and their expansion through a sustainable business model are explored
Bossed diaphragm coupled fixed guided beam structure for MEMS based piezoresistive pressure sensor
No full textPurpose Structures play a very important role in developing pressure sensors with good sensitivity and linearity, as they undergo deformation to the input pressure and function as the primary sensing element of the sensor. To achieve high sensitivity, thinner diaphragms are required; however, excessively thin diaphragms may induce large deflection and instability, leading to the unfavorable performances of a sensor in terms of linearity and repeatability. Thereby, importance is given to the development of innovative structures that offer good linearity and sensitivity. This paper aims to investigate the sensitivity of a bossed diaphragm coupled fixed guided beam three-dimensional (3D) structure for pressure sensor applications. Design/methodology/approach The proposed sensor comprises of mainly two sensing elements: the first being the 3D mechanical structure made of bulk silicon consisting of boss square diaphragm along with a fixed guided beam landing on to its center, forming the primary sensing element, and the diffused piezoresistors, which form the secondary sensing element, are embedded in the tensile and compression regions of the fixed guided beam. This micro mechanical 3 D structure is packaged for applying input pressure to the bottom of boss diaphragm. The sensor without pressure load has no deflection of the diaphragm; hence, no strain is observed on the fixed guided beam and also there is no change in the output voltage. When an input pressure P is applied through the pressure port, there is a deformation in the diaphragm causing a deflection, which displaces the mass and the fixed guided beam vertically, causing strain on the fixed guided beam, with tensile strain toward the guided end and compressive strain toward the fixed end of the close magnitudes. The geometrical dimensions of the structure, such as the diaphragm, boss and fixed guided beam, are optimized for linearity and maximum strain for an applied input pressure range of 0 to 10 bar. The structure is also analyzed analytically, numerically and experimentally, and the results are compared. Findings The structure offers equal magnitudes of tensile and compressive stresses on the surface of the fixed guided beam. It also offers good linearity and sensitivity. The analytical, simulation and experimental studies of this sensor are introduced and the results correlate with each other. Customized process steps are followed wherein two silicon-on-insulator (SOI) wafers are fusion bonded together, with SOI-1 wafer used to realize the diaphragm along with the boss and SOI-2 wafer to realize the fixed guided beam, leading to formation of a 3D structure. The geometrical dimensions of the structure, such as the diaphragm, boss and fixed guided beam, are optimized for linearity and maximum strain for an applied input pressure range of 0 to10 bar. Originality/value This paper presents a unique and compact 3D micro-mechanical structure pressure sensor with a rigid center square diaphragm (boss diaphragm) and a fixed guided beam landing at its center, with diffused piezoresistors embedded in the tensile and compression regions of the fixed guided beam. A total of six masks were involved to realize and fabricate the 3D structure and the sensor, which is presumed to be the first of its kind in the fabrication of MEMS-based piezoresistive pressure sensor