The complex permittivity (
ε′–
jε″), complex permeability (μ′–
jμ″) and microwave absorption properties of ferrite–polymer composites prepared with different ferrite ratios of 50%, 60%, 70% and 80% ...in polyurethane (PU) matrix have been investigated in X-band (8.2–12.4
GHz) frequency range. The M-type hexaferrite composition BaCo
+2
0.9Fe
+2
0.05Si
+4
0.95Fe
+3
10.1O
19 was prepared by solid-state reaction technique, whereas commercial PU was used to prepare the composites. At higher GHz frequencies, ferrite's permeabilities are drastically reduced, however, the forced conversion of Fe
+3 to Fe
+2 ions that involves electron hopping, could have increased the dielectric losses in the chosen composition. We have measured complex permittivity and permeability using a vector network analyzer (HP/Agilent model PNA E8364B) and software module 85071. All the parameters
ε′,
ε″,
μ′ and
μ″ are found to increase with increased ferrite contents. Measured values of these parameters were used to determine the reflection loss at various sample thicknesses, based on a model of a single-layered plane wave absorber backed by a perfect conductor. The composite with 80% ferrite content has shown a minimum reflection loss of −24.5
dB (>99% power absorption) at 12
GHz with the −20
dB bandwidth over the extended frequency range of 11–13
GHz for an absorber thickness of 1.6
mm. The prepared composites can fruitfully be utilized for suppression of electromagnetic interference (EMI) and reduction of radar signatures (stealth technology).
•Plague, a classified re-emerging disease requires diagnosis at early stage for timely clinical management of patients and containment of infection.•PCR-LF assay being a molecular assay can rapidly ...detect Y. pestis obviating the requirement of agarose gel electrophoresis for end point detection of amplicons.•The described assay detected as low as 1 pg genomic DNA of Y. pestis and also detected Y. pestis in artificially spiked blood samples.•PCR-LF is a simple assay and may prove useful for plague diagnosis in peripheral laboratories with poor resources in endemic regions of plague.
Plague is a zoonotic disease caused by Yersinia pestis, a Gram-negative, rod shaped coccobacillus, which is primarily found in rodents and can be transmitted to humans through flea bite. The disease has three major clinical forms bubonic (by flea bite), pneumonic (by respiratory droplets) and septicemic plague. Y. pestis is classified as a category ‘A’ agent by NIAID, USA due to its high mortality and easy person to person dissemination. The conventional diagnostic methods available for Y. pestis show cross-reactivity with other enteropathogenic bacteria making its detection difficult. There is a need to develop sensitive and specific molecular assay for accurate detection of Y. pestis. PCR is well suited molecular biology tool for rapid diagnosis of plague but after completion of thermal cycling steps, it requires additional time to analyze amplified product using agarose gel electrophoresis. In the present study, PCR assay coupled with lateral flow strips has been developed for rapid detection of Y. pestis. Lateral flow strips give an alternative to gel electrophoresis and permit easy and rapid detection of PCR products. The PCR was performed with 5′ 6-FAM and biotin tagged primers specific for Y. pestis, targeting yihN gene located on chromosome. The PCR product was analyzed using lateral flow strips which yielded result within 2-3 minutes. The analytical sensitivity of PCR-lateral flow (PCR-LF) assay was 1 pg genomic DNA of Y. pestis and 500 copies of target DNA sequence harboured in a recombinant plasmid. The assay could detect Y. pestis DNA extracted from spiked human blood samples containing ≥104 CFU per mL of bacteria. The assay was found to be specific and did not cross react with other closely related bacterial species. The developed assay was highly specific, sensitive and also did not require agarose gel electrophoresis for post amplification analysis.
Yersinia pestis, the causative agent of plague mainly infects rodents, while humans are the accidental host. The conventional diagnostic methods available for Y. pestis exhibit cross-reactivity with ...other enteropathogenic bacteria which makes its detection difficult. Rapid and reliable point-of-care detection of Y. pestis is essential for timely initiation of medical treatment. In the present study, a pair of loop mediated isothermal amplification (LAMP) assays has been developed for rapid detection of Y. pestis. Two sets of LAMP primers, each containing 6 primers were specifically designed targeting caf1 and 3a genes located on pFra plasmid and chromosome of Y. pestis, respectively. Isothermal amplification was accomplished at 65 °C for 40 min for caf1 target, and at 63 °C for 50 min for 3a choromosomal target. The analytical sensitivity of the assay for the caf1 and 3a targets was found to be 500 fg and 100 fg genomic DNA of Y. pestis, respectively. The caf1 and 3a LAMP assays detected as few as 100 copies of caf1 and 10 copies of 3a gene targets harboured in the respective recombinant plasmids. The amplified products were detected visually under visible and UV light using SYBR Green 1 dye. The assay pair was found to be highly specific as it did not cross-react with closely related and other bacterial species.
•Plague necessitates an early stage diagnosis for timely medical management and to control spread of the disease.•Two LAMP assays in present study present simple and rapid tools for detection of Y. pestis without using a thermal cycler.•The assays are highly sensitive and specific and detected Y. pestis in artificially spiked blood samples.•The isothermal assays can be useful in detection of Y. pestis in plague endemic regions with limited laboratory resources.
Abstract
Road Safety is a matter of great concern throughout the world. As number of casualties is increasing more than 4% annually in all age groups. It has been predicted that due to road accidents ...causality rate will grow around 8% till 2030. It’s entirely admissible and saddening to let citizens get killed in road accidents. As a result, to handle this sort of situation, an in-depth analysis is required. The Data of Road accidents are very heterogeneous in nature so analysis of such type of data is tricky. Segmentation is the main task for analyzing such data. So, K-means clustering method is mainly used for it as proposed in the research work. Second task of this model is to extract the data, images and hidden patterns by using Supervised Machine Learning algorithm that will help to form the policies for the prevention from road accidents. The combination of segmentation machine learning algorithm produces meaning full information.
Resveratrol, a phytochemical commonly found in the skin of grapes and berries, was tested for its biofilm inhibitory activity against Vibrio cholerae. Biofilm inhibition was assessed using crystal ...violet assay. MTT assay was performed to check the viability of the treated bacterial cells and the biofilm architecture was analysed using confocal laser scanning microscopy. The possible target of the compound was determined by docking analysis. Results showed that subinhibitory concentrations of the compound could significantly inhibit biofilm formation in V. cholerae in a concentration-dependent manner. AphB was found to be the putative target of resveratrol using docking analysis. The results generated in this study proved that resveratrol is a potent biofilm inhibitor of V. cholerae and can be used as a novel therapeutic agent against cholera. To our knowledge, this is the first report of resveratrol showing antibiofilm activity against V. cholerae.
Partially or fully buried explosive on detonation releases a large amount of kinetic energy a part of which gets dissipated during creation of crater and the rest gets converted into ground shock. ...Both phenomena are of complex nature with involvement of non-linearity in both loading and material characteristics. This review aims at providing an insight into mechanisms involved during an event of buried explosion with varying degree of confinement. Factors affecting crater formation and ground shock propagation in media are discussed in detail. An overview of various prediction methods developed over the years based on dimensional analysis and theory of similarity to estimate crater dimensions and magnitude of ground shock and ground motion along with their limitations is presented. Prediction models used to define and optimise rock fragmentation distribution in surface mining operations are additionally reviewed and discussed. Various state-of-the-art experimental and numerical techniques are discussed in brief. Finally, it discusses the challenges involved in both experimental and numerical analysis and thereby provides alternative solutions and suggestions for further investigations in specific areas of lacuna.
Underground structures are a major part of public and military infrastructure with national and strategic importance. Blast loading generated by intentional and accidental explosions can cause severe ...damage to their structural integrity. Any abrupt halt in their continuous functioning could result in drastic consequences. Understanding the effect of blast loading on underground structures becomes crucial in order to enhance their resistance against blast. This paper overviews the mechanics behind blast loading and its interaction with soil and underground structure while considering possible blast scenarios. And also phenomena associated with external and internal explosion such as cavitation, soil compaction, soil liquefaction, multiple reflection, quasi-static gas pressure phase and Mach stem formation are explained. Special attention has been given in elaborating various recent studies and development made in analysing soil-structure interaction during an event of explosion considering various factors. Major research gaps identified during the review, current challenges and future scope for research have been highlighted lastly. This review aims at providing a foundation to new researchers interested in exploring this field in addition to provide new perspective for future research work.
Direct measurement of discharge in a stream is not only difficult and time consuming but also expensive. Therefore, the discharge in a stream is related to the stage through a number of carefully ...measured discharge values. A relationship between stages and corresponding measured discharges is usually derived using various graphical and analytical methods. As the relationship between stages and measured discharges is not linear, conventional methods based on least squares regression analysis for fitting a relationship are unable to model the non-linearity in the relationship and spatially in the cases when hysteresis is present in the data. The aim of the present study is to investigate the potential of Takagi–Sugeno (TS) fuzzy inference system for modeling stage–discharge relationships and the investigations are illustrated by application of the model to observed gauge and discharges of various gauging stations in Narmada river system, India. A step by step procedure for developing TS fuzzy model is also presented. The results show that the TS fuzzy modeling approach is superior than the conventional and artificial neural network (ANN) based approaches. Comparison of the models on hypothetical data set also reveals that the fuzzy logic based approach is also able to model the hysteresis effect (loop rating curve) more accurately than the ANN approach.
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