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21.
Bismuth borate glasses from the system: 40Bi2O3–59B2O3–1Tv2O3 (where Tv=Al, Y, Nd, Sm, and Eu) and three glasses of composition: 40Bi2O3–60B2O3, 37.5Bi2O3–62.5B2O3 and 38Bi2O3–60B2O3–2Al2O3 were prepared by melt quenching and characterized by density, UV-visible absorption spectroscopy and differential thermal analysis (DTA) studies. Bismuth borate glasses exhibit a very strong optical absorption band just below their absorption edge. Glasses were devitrified by heat treatment at temperatures above their glass transition temperatures and the crystalline phases produced in them were characterized by Fourier transform infrared (FTIR) absorption spectroscopy and X-ray diffraction (XRD). Bi3B5O12 was found to be the most abundant phase in all devitrified samples. DTA studies on glasses and FTIR and XRD analysis on crystallized samples revealed that very small amounts of trivalent ion doping causes significant changes in the devitrification properties of bismuth borate glasses; rare-earth ions promote the formation of metastable BiBO3–I and BiBO3–II phases during glass crystallization.  相似文献   
22.
We present an analysis of the signal-to-interference-plus-noise ratio (SINR) at the output of the minimum variance beamformer in the presence of steering vector errors. The analysis yields an explicit expression for the SINR in terms of the variance of the steering vector errors and the other parameters affecting performance, including signal-to-noise ratio (SNR), interference-to-noise ratio (INR), signal-to-interference ratio (SIR), angular separation between desired signal and interference, array size and shape, correlation between desired signal and interference, and finite sample size  相似文献   
23.
Charge stabilities of various polar polymer homoelectrets were determined. Although these electerts are reasonably stable in dry environments, they rapidly discharge when exposed to humidity. The rate of charge decay was found to depend directly on the ability of these polymers to absorb water under equilibrium conditions. Protection from humidity is obtained if these polar polymers are coated on both sides with nonpolar polymers. If, however, two different polymer films are laminated, the electret behavior follows a pattern that can be explained on the basis of charging at the interface. Difference in stabilities of the electrets of polar and nonpolar polymers is attributed to the differing natures of the charge traps present in these two classes of polymers.  相似文献   
24.
A local market survey of fresh, raw coriander leaves, which is a component of many ready-to-eat, Indian dishes showed large variation in their bacterial load (7.0×106–1.36×108 cfu/gm) and mold and fungi (3.0×103–1.0×104 cfu/gm) and presence of potentially pathogenic bacteria such as faecal coliforms, Listeria and Yersinia. Conventional chlorination treatment affected the structural integrity of leaves leading to enhancement of rotting. Exposure to a low dose of 1 kGy was efficient for bacterial decontamination and elimination of potential pathogens without affecting the keeping quality of coriander leaves upto two weeks storage at 8–10 °C, measured visually in terms of degree of yellowing and rotting. Irradiation at higher doses led to the increased rotting during storage. The total chlorophyll contents as well its components, chlorophyll a and b did not change significantly on irradiation and subsequent storage. Similarly, the total carotenoid levels remained unaffected by exposure to 1 kGy dose, however, a dose dependent enhancement in their extractability was observed in irradiated leaves. No qualitative differences were observed in the GLC profile of volatile oils of control and irradiated (1 kGy) samples. There were no significant quantitative changes in the constituents of the major aroma compounds obtained from these two samples. Effects of irradiation on storage of the seasoning were also assessed.  相似文献   
25.
Chronic inflammation has been associated with several chronic diseases, such as age-related macular degeneration (AMD). The NLRP3 inflammasome is a central proinflammatory signaling complex that triggers caspase-1 activation leading to the maturation of IL-1β. We have previously shown that the inhibition of the chaperone protein, Hsp90, prevents NLRP3 activation in human retinal pigment epithelial (RPE) cells; these are cells which play a central role in the pathogenesis of AMD. In that study, we used a well-known Hsp90 inhibitor geldanamycin, but it cannot be used as a therapy due to its adverse effects, including ocular toxicity. Here, we have tested the effects of a novel Hsp90 inhibitor, TAS-116, on NLRP3 activation using geldanamycin as a reference compound. Using our existing protocol, inflammasome activation was induced in IL-1α-primed ARPE-19 cells with the proteasome and autophagy inhibitors MG-132 and bafilomycin A1, respectively. Intracellular caspase-1 activity was determined using a commercial caspase-1 activity kit and the FLICA assay. The levels of IL-1β were measured from cell culture medium samples by ELISA. Cell viability was monitored by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and lactate dehydrogenase (LDH) measurements. Our findings show that TAS-116 could prevent the activation of caspase-1, subsequently reducing the release of mature IL-1β. TAS-116 has a better in vitro therapeutic index than geldanamycin. In summary, TAS-116 appears to be a well-tolerated Hsp90 inhibitor, with the capability to prevent the activation of the NLRP3 inflammasome in human RPE cells.  相似文献   
26.
Baking, the key step in the preparation of Chhana Podo, involves simultaneous heat and mass transfer that induces physicochemical and structural changes in the product. The effects of baking conditions on colour, texture and crumb grain development in the product were evaluated. The browning index of baked Podo increased from the initial value of 15.7 to 95, 101 and 112, at baking temperatures of 120, 135 and 150 °C, respectively. Browning kinetics followed the logistic model (R2 > 0.98) with an activation energy of 17.81 kJ/mol. In general, crumb grain characteristics such as mean cell area, cell density and cell‐to‐total area ratio increased with increase in baking time and temperature. Textural attributes such as hardness, chewiness and gumminess increased with baking time and temperature while springiness, cohesiveness and resilience increased up to 40 min due to the filling‐up of pores water and liquid by fat and expanding water, but decreased thereafter.  相似文献   
27.
Wireless Personal Communications - Mobile robot navigation has been a current issue in the most recent two decades. Mobile robots are necessary to explore in obscure and dynamic situations. To...  相似文献   
28.
Named entity recognition (NER) is the core part of information extraction that facilitates the automatic detection and classification of entities in natural language text into predefined categories, such as the names of persons, organizations, locations, and so on. The output of the NER task is crucial for many applications, including relation extraction, textual entailment, machine translation, information retrieval, etc. Literature shows that machine learning and deep learning approaches are the most widely used techniques for NER. However, for entity extraction, the abovementioned approaches demand the availability of a domain‐specific annotated data set. Our goal is to develop a hybrid NER system composed of rule‐based deep learning as well as clustering‐based approaches, which facilitates the extraction of generic entities (such as person, location, and organization) out of natural language texts of domains that lack generic named entities labeled domain data sets. The proposed approach takes the advantages of both deep learning and clustering approaches but separately, in combination with a knowledge‐based approach by using a postprocessing module. We evaluated the proposed methodology on court cases (judgments) as a use case since it contains generic named entities of different forms that are poorly or not present in open‐source NER data sets. We also evaluated our hybrid models on two benchmark data sets, namely, Computational Natural Language Learning (CoNLL) 2003 and Open Knowledge Extraction (OKE) 2016. The experimental results obtained from benchmark data sets show that our hybrid models achieved substantially better performance in terms of the F‐score in comparison to other competitive systems.  相似文献   
29.
In the present study, skill of an extended range forecast system has been evaluated for identifying droughts over central India 20-days in advance. Rainfall forecasts from 44 ensemble members of the forecast system developed Indian Institute of Tropical Meteorology (IITM), Pune have been used to prepare probabilistic rainfall forecasts. It is seen that the uncertainties in the forecasts (in terms of ensemble spread) increases from day-5 to day 20. As the focus of the study is for drought predictions, forecasts in the bins 0-5 mm/5 day and 5-25 mm/5 day (no rain or less rain) were studied in detail. It is found that the modeling system has a tendency to over-forecast rainfall probabilities. With bias correction, the forecasts become more reliable. Various drought indices were computed using the mean of the forecast distribution up to 20-days in advance. Standardized precipitation index (SPI) computed using Gamma and Pearson type-III distributions are similar in the study region. It was found that these are in reasonable agreement with those from observations. Probabilistic forecasts of standardized precipitation index (SPI) were made and the relative operating characteristics (ROC) scores indicate that the forecasted SPI values are suitable for application.  相似文献   
30.
SARS-CoV-2 and other respiratory viruses spread via aerosols generated by infected people. Face masks can limit transmission. However, widespread use of disposable masks consumes tremendous resources and generates waste. Here, a novel material for treating blown polypropylene filtration media used in medical-grade masks to impart antimicrobial activity is reported. To produce thin copper@ZIF-8 core-shell nanowires (Cu@ZIF-8 NWs), Cu NWs are stabilized using a pluronic F-127 block copolymer, followed by growth of ZIF-8 to obtain uniform core-shell structures. The Cu@ZIF-8 NWs are applied to filtration media by dip coating. Aerosol filtration efficiency decreases upon exposure to ethanol (solvent for dip-coating), but increases with addition of Cu@ZIF-8 NWs. Cu@ZIF-8 NWs shows enhanced antibacterial activity, compared to Cu NWs or ZIF-8 alone, against Streptococcus mutans and Escherichia coli. Antiviral activity against SARS-CoV-2 is assayed using virus-infected Vero E6 cells, demonstrating 55% inhibition of virus replication after 48 h by 1 µg of Cu@ZIF-8 NWs per well. Cu@ZIF-8 NWs’ cytotoxicity is tested against four cell lines, and their effect on inflammatory response in A549 cells is examined, demonstrating good biocompatibility. This low-cost, scalable synthesis and straightforward deposition of Cu@ZIF-8 NWs onto filter media has great potential to reduce disease transmission, resource consumption, and environmental impact of waste.  相似文献   
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