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Hybrid Microgrids for Diesel Consumption Reduction in Remote Military Bases of India
No full textGrid connection is often not available at remote locations. As a result, diesel generators are commonly used in Indian remote military bases to generate electricity locally. Transportation of diesel to these remote locations is often difficult and expensive task. Communication and surveillance equipments along with border fences and illumination need reliable electricity supply. Any disruption in diesel supply can severely impact the operation of the military base. Fuel transportation routes are often cut off during extreme weather conditions. In addition, diesel generators are prone to failure and cause significant air pollutions. Renewable energy sources are often available at these remote locations. These renewable energy sources can be used to substitute the diesel based generation partially. In this paper, hybrid microgrids consisting of both renewable and diesel generators are proposed for remote military bases. Use of local renewable sources reduces the dependence on external diesel supply. In addition, the consumption of diesel is reduced due to the use of renewable energy sources. Detailed Cost Benefit analysis has been done to show the effectiveness of the hybrid microgrid. It is shown that this hybrid microgrid can be a possible solution for reduction of diesel consumption in remote military bases of India
Structure and dynamics of undercurrents in the western boundary current of the Bay of Bengal
No full textThe structure and variability of undercurrents in the East India Coastal Current (EICC), which is the western boundary current system in the Bay of Bengal (BoB), and the mechanisms of their formation are examined in this study. We used current data collected by Acoustic Doppler current profilers (ADCP) moored off Cuddalore (~ 12oN), Kakinada (~ 16.5oN), Visakhapatnam (~ 17.7oN), and Gopalpur (~ 19.4oN) and simulations for the period 2013�2014 from a high-resolution model configured for the BoB. The undercurrents were observed at all these locations, mainly during summer (June�August) and winter (October�December). Undercurrents were seen at relatively shallow depths (75 m), and their occurrences were more frequent off Cuddalore, whereas they were deep (100�150 m) and less frequent in the northern part of the east coast (off Visakhapatnam and Gopalpur). Numerical simulations showed that the interaction of the westward propagating anticyclonic eddies with the equatorward EICC weakened the strong surface flow and reversed the weak subsurface flow in the northern part of the western BoB. This interaction resulted in the formation of the poleward undercurrent here. Once these mesoscale eddies dissipated due to the interaction with the continental slope, the poleward undercurrents vanished and equatorward flow in the subsurface reappeared. The observed undercurrents near the shelf break region (75�200 m) in the southern part of the coast (off Cuddalore) were associated with small subsurface eddies (diameter of about 20�30 km), which developed due to large zonal gradient in the alongshore component of EICC. Subsurface anticyclonic circulations of larger spatial extent (diameter > 200 km) were responsible for the observed undercurrents in the deeper levels (deeper than 250 m) off Cuddalore. We further show that intraseasonal variability of undercurrents near the shelf break off Cuddalore was directly linked to intraseasonal variability in the strength of surface EICC itself. Results from this study suggest that the undercurrents observed below the EICC were not continuous poleward flow, but they were part of distinct anticyclonic eddies
Evaluation of cytogenotoxic potential of Morinda lucida leaf extract on Swiss albino male mice using two bioassays
No full textBackground: Utilization of Morinda lucida for the treatment of ailments such as malaria, diarrhea, infertility in women, and dysentery in many countries including Nigeria is on increase due to its efficiency, availability, and affordability. However, its cytogenotoxicity has not been elucidated. This study investigated the phytochemical constituents and possible genotoxic and cytotoxic effects of M. lucida leaf extract in Swiss albino male mice using bone marrow micronucleus and sperm morphology assays. Methods: Plant materials was collected, thoroughly washed, and air-dried at room temperature prior to maceration. The extract was assessed for the presence of the phytochemical compounds. Swiss albino male mice (Mus musculus) (n=4) were treated with different concentrations of this extract (400 mg/kg, 800 mg/kg, and 1200 mg/kg) while distilled water was used as negative control. Results: Phytochemical analysis revealed that the extract contains saponins, terpenoids, flavonoids, glycosides, and tannins. We observed micronucleated polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) of 3.20, 1.10, and 1.95 at different concentrations of 400 mg/kg, 800 mg/kg, and 1200 mg/kg respectively in the treated animals. The result showed no significant increase in the frequency of abnormalities (p < 0.05) when compared to the negative control; however, in separate analysis of mono-micronucleated PCE and mono-micronucleated NCE per group, a significant increase at 400 mg/kg and 1200 mg/kg concentrations was observed. The sperm anomalies decreased with increase in concentration. Conclusions: This study recommends 800 mg/kg concentration of the plant extract; however, it should be further and properly investigated as it contains some pharmaceutical components that can be used for pharmacological purposes
Differential contributions of pre- And post-EMT tumor cells in breast cancer metastasis
No full textMetastases are responsible for the majority of breast cancer�associated deaths. The contribution of epithelial-to-mesenchymal transition (EMT) in the establishment of metastases is still controversial. To obtain in vivo evidence of EMT in metastasis, we established an EMT lineage tracing (Tri-PyMT) model, in which tumor cells undergoing EMT would irreversibly switch their fluorescent marker from RFPþ to GFPþ due to mesenchymal-specific Cre expression. Surprisingly, we found that lung metastases were predominantly derived from the epithelial compartment of breast tumors. However, concerns were raised on the fidelity and sensitivity of RFP-to-GFP switch of this model in reporting EMT of metastatic tumor cells. Here, we evaluated Tri-PyMT cells at the single-cell level using single-cell RNA-sequencing and found that the Tri-PyMT cells exhibited a spectrum of EMT phenotypes, with EMT-related genes concomitantly expressed with the activation of GFP. The fluorescent color switch in these cells precisely marked an unequivocal change in EMT status, defining the pre-EMT and post-EMT compartments within the tumor. Consistently, the pre-EMT cells played dominant roles in metastasis, while the post-EMT cells were supportive in promoting tumor invasion and angiogenesis. Importantly, the post-EMT (GFPþ) cells in the Tri-PyMT model were not permanently committed to the mesenchymal phenotype; they were still capable of reverting to the epithelial phenotype and giving rise to secondary tumors, suggesting their persistent EMT plasticity. Our study addressed major concerns with the Tri-PyMT EMT lineage tracing model, which provides us with a powerful tool to investigate the dynamic EMT process in tumor biology
On the origin of metallicity and stability of the metastable phase in chemically exfoliated MoS2
No full textChemical exfoliation of MoS2 via Li-intercalation route has led to many desirable properties and spectacular applications due to the presence of a metastable state in addition to the stable H phase. However, the nature of the specific metastable phase formed, and its basic charge conduction properties have remained controversial. Using spatially resolved Raman spectroscopy (�1 μm resolution) and photoelectron spectroscopy (�130 nm resolution), we probe such chemically exfoliated MoS2 samples in comparison to a mechanically exfoliated H phase sample and confirm that the dominant metastable state formed by this approach is a distorted T� state with a small semiconducting gap. Investigating two such samples with different extents of Li residues present, we establish that Li+ ions, not only help to exfoliate MoS2 into few layer samples, but also contribute to enhancing the relative stability of the metastable state as well as dope the system with electrons, giving rise to a lightly doped small bandgap system with the T� structure, responsible for its spectacular properties
Ballistic response of double layered 1100-H12 aluminium hemispherical shell structure
No full textThe ballistic resistance and energy absorption characteristics of the thin hemispherical shells were evaluated against ogive and blunt nosed projectile impact with varying span and configuration of the shell. The span diameter of the 1100-H12 aluminium shell was varied as 68, 100, 150 and 200 mm whereas the configuration of the shell was varied as monolithic and double layered (0.5/0.5, 0.33/0.67 and 0.67/0.33) which was hit at the crown by 19 mm diameter, 50.8 mm length and 52.5 g mass projectile. Three dimensional numerical simulations were carried out through commercially available finite element code ABAQUS. The accuracy of the numerical model was validated by comparing the numerical result of monolithic shell with experimental result conducted through the pressure gun. Numerical simulation result were further employed to extract the total energy absorption in plastic deformation by computing the strain energy in stretching in polar, radial, elevation and shear directions of the shell by using a user defined programme written in python. The influence of projectile nose shape, incidence velocity of the projectile and configuration of the hemispherical shell on the mechanics of failure, ballistic resistance, ballistic limit and energy dissipation characteristics were studied. The double layer hemispherical target showed better performance against ogive nosed projectile however opposite behaviour was observed against blunt nosed projectile
Strong Converse Using Change of Measure Arguments
No full textThe strong converse for a coding theorem shows that the optimal asymptotic rate possible with vanishing error cannot be improved by allowing a fixed error. Building on a method introduced by Gu and Effros for centralized coding problems, we develop a general and simple recipe for proving strong converse that is applicable for distributed problems as well. Heuristically, our proof of strong converse mimics the standard steps for proving a weak converse, except that we apply those steps to a modified distribution obtained by conditioning the original distribution on the event that no error occurs. A key component of our recipe is the replacement of the hard Markov constraints implied by the distributed nature of the problem with a soft information cost using a variational formula introduced by Oohama. We illustrate our method by providing a short proof of the strong converse for the Wyner-Ziv problem and strong converse theorems for interactive function computation, common randomness and secret key agreement, and the wiretap channel; the latter three strong converse problems were open prior to this work
Design considerations for effective thermal management in mobile nanotweezers
No full textControlled manipulation of nanoscale objects in fluids is relevant to both fundamental studies and technological advances in nanotechnology. While standard techniques of nanomanipulation, such as optical and plasmonic tweezers have limitations in simultaneous trapping and transport of nanoscale cargo, magnetically driven plasmonic nanorobots under optical illumination provide a promising solution. These so called mobile nanotweezers (MNT) use strongly localized electromagnetic field near plasmonic nanostructures to trap objects with high efficiency and can simultaneously be driven by magnetic fields to selectively trap, transport and release colloidal cargo. Upon illumination, apart from strong optical gradient forces due to local electric field enhancement, additional fluidic forces arise due to the heat generated by absorption of light. Here, we present a method to understand and engineer thermally induced fluidic forces in mobile nanotweezers. The temperature enhancement and associated thermofluidic forces are studied as a function of MNT geometry. We also discuss illumination at wavelengths slightly detuned from plasmon resonance frequency, which produces sufficient field enhancement with negligible generation of heat, and therefore much reduced thermophoretic and convective forces. This allowed us to engineer thermoplasmonic forces in MNTs for enhanced trapping performance and diverse applications
Mechanistic insight into the effect of BT-benzo-29 on the Z-ring in Bacillus subtilis
No full textThe assembly and disassembly of FtsZ play an essential role in bacterial cell division. Using single-cell imaging, we report that short exposure to BT-benzo-29 inhibits Z-ring formation in live Bacillus subtilis cells. Fluorescence recovery after photobleaching of the Z-ring in live bacteria demonstrated that BT-benzo-29 strongly suppressed the assembly dynamics of FtsZ in the Z-ring. Furthermore, B. subtilis cells expressing V275A-FtsZ resisted the antibacterial activity of BT-benzo-29 providing evidence that BT-benzo-29 inhibits bacterial proliferation by targeting FtsZ. In addition, a brief (8 min) exposure of BT-benzo-29 destroyed the Z-ring without perturbing the localization of a late cell division protein, DivIVA, the nucleoid segregation, and membrane permeability. BT-benzo-29, when used in combination with vancomycin and polymyxin B (PMB), produced a much stronger inhibitory effect on Bacillus subtilis and Escherichia coli cells, respectively. The combination index of BT-benzo-29 with vancomycin and PMB was determined to be <1, suggesting that BT-benzo-29 exhibits synergistic inhibitory effects on bacterial proliferation when used along with these antibiotics
Numerical investigation of a conducting drop's interaction with a conducting liquid pool under an external electric field
No full textA charged conducting drop suspended in an insulating medium shows non-coalescence with an interface under high strength of an externally applied electric field. We perform numerical simulations of the non-coalescence phenomenon to understand the underlying physical mechanisms and the effect of electric field strength and fluid conductivity on the coalescence behavior of a conducting drop with a conducting liquid pool under highly viscous conditions. We show that two factors primarily govern the coalescence or non-coalescence of the drop with the interface. First, the magnitude of the charge transfer time scale (which governs the rate of charge transfer during contact between the drop and the pool) relative to the time scale of the capillary waves. Second, the strength of the electric forces compared to the viscous forces. We further show that for the case of macro drops (D�2 mm), charge transfer by fluid convection dominates charge conduction at lower electric conductivities (��10�8 S/m) only. Finally, we explain the non-dependence of secondary droplet's size and charge on the fluid's electric conductivity as observed in the experiments