The success rate of a neural network (NN) classifier (rectified linear unit, 10 layers, softmax output layer activation)-based demodulator was proposed and evaluated for phase-shift keying (PSK) and ...quadrature amplitude modulation (QAM) modulated signals corrupted by additive white Gaussian, chisquared, uniform, and Rayleigh noise channels with signal-to-noise ratios (SNR) ranging from −20 dB to +20 dB. Low SNR are common in spectrum sensing, cognitive radio networks, underwater acoustics, target detection, remote sensing, seismic monitoring, and helicopter blade detection. This classifier-demodulator performance was compared with that of the matched filter detector (MFD) for varying channel noise, constellation type (PSK or QAM), constellation size (M=2, 4, 8, 16), sample size (N), and training to test the data ratio. The classifier demodulator had a performance equal to or better than MFD in 98% of the scenarios. A training-to-test ratio of 70:30 or 80:20 is appropriate. The classifier performances of M-PSK and M-QAM are comparable. The superior performance of the NN classifier is more pronounced for M values greater than 2. N=5000 or higher is sufficient for most scenarios, and N=20000 is necessary for M=16. A higher success rate was obtained for additive chisquare and Rayleigh noise channels. The proposed demodulator performed significantly better than the matched filter for SNR values <inline-formula> <tex-math notation="LaTeX">\le0 </tex-math></inline-formula> dB. 16-QAM over an additive uniform noise channel has a better success rate for an SNR of 0 dB or less, whereas 16-QAM over an additive Rayleigh noise channel has a better success rate for an SNR of 5 dB or higher.
The synthesis of anode electrocatalyst with high activity and durability for methanol oxidation reaction has been one of the main focuses of researchers in recent years. Several works are reviewed in ...this paper to summarize and compare the performance of electrocatalysts comprising of noble and non-noble metals. The effect of manipulating catalysts by introducing nanostructured morphology, metal alloys, support materials, acidic or basic electrolyte, and synthesis methods are also examined. The paper finally concludes with details of challenges that are generally faced in making direct methanol fuel cell (DMFC) a reliable source of energy for future prospects, and the approach to be taken to reduce the complexity in synthesizing new generations of anode electrocatalysts.
Salinity stress is one of the major abiotic stresses threatening sustainable crop production worldwide. The extent of salinity affected area is expected to cover about 50% of total agricultural land ...by 2050. Salinity stress produces various detrimental effects on plants’ physiological, biochemical, and molecular features and reduces productivity. The poor plant growth under salinity stress is due to reduced nutrient mobilization, hormonal imbalance, and formation of reactive oxygen species (ROS), ionic toxicity, and osmotic stress. Additionally, salinity also modulates physicochemical properties and reduces the microbial diversity of soil and thus decreases soil health. On the other hand, the demand for crop production is expected to increase in coming decades owing to the increasing global population. Conventional agricultural practices and improved salt-tolerant crop varieties will not be sufficient to achieve the yields desired in the near future. Plants harbor diverse microbes in their rhizosphere, and these have the potential to cope with the salinity stress. These salinity-tolerant plant growth-promoting bacteria (PGPB) assist the plants in withstanding saline conditions. These plant-associated microbes produce different compounds such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), antioxidants, extracellular polymeric substance (EPS), and volatile organic compounds (VOC). Additionally, the naturally associated microbiome of plants has the potential to protect the host through stress avoidance, tolerance, and resistance strategies. Recent developments in microbiome research have shown ways in which novel microbe-assisted technologies can enhance plant salt tolerance and enable higher crop production under saline conditions. This focused review article presents the global scenario of salinity stress and discusses research highlights regarding PGPB and the microbiome as a biological tool for mitigation of salinity stress in plants.
•ANN framework is given to predict the fracture behavior of glass-filled epoxy under impact loading.•Effect of aspect ratio on the dynamic fracture behavior has been investigated.•Inputs are found to ...be important in the order, time > aspect ratio > elastic modulus > volume fraction.
The present study discusses about the effect of the aspect ratio of the fillers on the fracture toughness of the glass-filled epoxy composites under impact loading. Three different kinds of fillers (spheres, flakes and rods) were used with different volume fractions (5%, 10% and 15%). Experimental results for Stress Intensity Factor (SIF) were obtained using a gas gun setup and a high speed camera. Further experimental investigation was done using fractographs obtained from Scanning Electron Microscope (SEM). Then the potential of using Artificial Neural Network (ANN) in predicting the effect of filler shape on the fracture behavior is studied. The framework of Multi-Layer Perceptron (MLP) feed forward network was used to predict the SIF history using four input parameters viz. time, dynamic elastic modulus, aspect ratio and volume fraction of the glass fillers. Experimental results of fracture test under impact loading were fed to train the ANN network and later the predicted results were compared with the experimental ones. Owing to the fact that predicted values had an accuracy of 91%, crack initiation toughness was predicted corresponding to the intermediate values of aspect ratio for which the experiments were not performed. Among the four input parameters, aspect ratio (largest/shortest dimension) was found to be the most important parameter in the prediction of SIF after time, followed by the dynamic modulus and volume fraction. The significance of aspect ratio lies in increasing the surface area to volume ratio which is responsible for the interfacial strength between the matrix and the filler and hence affects the fracture toughness of the overall composite material.
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•Indian oil sardine fish was used as a feedstock for biodiesel production.•Transesterification reaction was carried out at 150 °C and atmospheric pressure.•Reaction time for ...completion was reduced to 25 min from 60–120 min.•Biodiesel yield of 96.57% was obtained in 25 min using optimum process condition.•Cost assessment of this experiment shows a reduction in 7.7% of total biodiesel production.
This experiment focused on biodiesel production using Indian oil sardine fish as a new low-cost feedstock. Bligh and Dyer’s method was followed for oil extraction from Indian oil sardine fishes. Biodiesel was produced by KOH catalyzed transesterification reaction with a reaction temperature of 150 °C. Optimization of the process parameters influencing the biodiesel production was performed using response surface methodology (RSM). Box-Behnken experimental design was used for the statistical analysis. The effect of methanol vol%, KOH wt% and reaction time over the reaction were studied. Chemical characterization of the biodiesel produced was carried out by Gas Chromatography-Mass Spectroscopy (GCMS) analysis. Physicochemical properties of the biodiesel were characterized according to ASTM 6751 standard. The optimum process conditions for the biodiesel yield of 96.57% were found to be 20 vol% methanol, 1.25 wt% KOH and 25 min reaction time. The 150 °C reaction temperature used in this process enhances the transesterification reaction by reducing the reaction time from the normally observed 60–120 min to 25 min with a high yield of biodiesel.
Groundwater is the most important source of drinking waters supply in the National Capital Territory (NCT) of, New Delhi, India. A diverse geological and topographical set up along with the fast ...growing population and anthropogenic activities has created a need of groundwater quality assurance for drinking and domestic water supply in the region. The major hydro-geochemical process and impacts of anthropogenic activities can be deciphered using multivariate statistical analysis, conventional graphical plots and saturation indices. Groundwater samples were collected from 170 locations spread over entire region and were analysed for a total of 12 water quality physico-chemical parameters. It is observed that the groundwater is neutral to alkaline in nature with electrical conductivity (EC) value ranging from 460 to 8980μs/cm. Chemometric analysis was performed along with geochemical modeling. The 3 clusters obtained through HCA were clearly differentiated based on their chemical characteristics i.e. concentration of major ions. High concentration of nitrate (NO3−) and fluoride (F−) exceeding WHO standards was found in 29% and 27% of the water samples respectively. It is observed that semi-arid climatic conditions along with rock-water interaction, weathering and ion-exchange are the major factors controlling groundwater quality in the region. Oversaturation of fluorite and gypsum has resulted into high concentration of F− in study area. It is found that the results from statistical and geochemical models compliment the findings using conventional plots and are able to decipher comprehensive geochemistry of groundwater in the region.
•PCA, HCA and DA performed of 170 groundwater samples spread in entire region.•PCA generated 4 principal components explaining 76% of variance in the data.•3 cluster were obtained on performing HCA based on electrical conductivity values.•The values of Wilk's Lambda and Chi square indicates DA is statistically significant.•Fluoride and nitrate contamination found in 27% and 29% of samples respectively.
Antibiotic resistance, and, in a broader perspective, antimicrobial resistance (AMR), continues to evolve and spread beyond all boundaries. As a result, infectious diseases have become more ...challenging or even impossible to treat, leading to an increase in morbidity and mortality. Despite the failure of conventional, traditional antimicrobial therapy, in the past two decades, no novel class of antibiotics has been introduced. Consequently, several novel alternative strategies to combat these (multi-) drug-resistant infectious microorganisms have been identified. The purpose of this review is to gather and consider the strategies that are being applied or proposed as potential alternatives to traditional antibiotics. These strategies include combination therapy, techniques that target the enzymes or proteins responsible for antimicrobial resistance, resistant bacteria, drug delivery systems, physicochemical methods, and unconventional techniques, including the CRISPR-Cas system. These alternative strategies may have the potential to change the treatment of multi-drug-resistant pathogens in human clinical settings.
NiO and NiO–TiO2 nano-catalysts were synthetized using solution combustion synthesis (SCS) method and tested toward ammonia oxidation in synthetic and real wastewater. As-synthesized NiO ...nano-catalyst showed a tightly agglomerated nano-porous spherical structure with sizes ranging from 10 to 50 nm. NiO–TiO2 nano powders have homogenous structure with an average size of 19.5 ± 0.03 nm and a lattice spacing of 0.22 ± 0.03 nm corresponding to cubic planes of NiO and 0.25 ± 0.01 nm corresponding to TiO2. Cyclic voltammetry under alkaline condition at low potential ranging from 0.95 to 1.35 V vs. HgO/Hg improved the electro-chemical activity of the nano-catalysts by the formation of Ni(OH)2 film on the surface of catalyst as confirmed by XPS measurements. Ammonia electro-oxidation on nano-catalysts occurred at approximately 1.28 V vs. HgO/Hg and was highly pH-dependent. Ammonia removals up to 92.9 and 96.4% were achieved by NiO and NiO–TiO2, respectively. Total nitrogen material balance showed that the electro-chemical oxidation of ammonia produce small amounts of NO2− and NO3 and the balance N2. Ammonia oxidation at concentration less than 150 mM followed direct electron transfer mechanism, whereas at higher concentrations, the oxidation mechanism shifted to the indirect oxidation regime. Ammonia electro-oxidation kinetics followed zero order reaction at ammonia concentration ≤100 mM and first order kinetics at higher concentrations. More than 93% of ammonia, 35% of organic matter and 40% phosphorous were removed from real wastewater samples using electro-oxidation process confirming the suitability of this technology as advanced wastewater treatment.
•Electro-chemical activity of NiO improved by formation of Ni(OH)2 film at high pH.•Ammonia elctro-chemical oxidation produced les oxygenated species and the balance N2.•Synthesized nano-particles were activated toward ammonia oxidation in alkaline phase.•NiO and NiO–TiO2 nano-catalysts were used as advanced wastewater treatment technology.
Imaging techniques for highly specific detection of cancer cells
can have applications ranging from preclinical drug discovery studies to clinical cancer diagnosis and surgical therapy. Although ...fluorescence imaging using cancer-targeted antibodies has shown promise, nonspecific probe accumulation in tissue results in significant background fluorescence, reducing detection sensitivity using traditional intensity-based continuous-wave (CW) fluorescence imaging. Here we demonstrate that fluorescence lifetime (FLT) imaging can provide significant tumor contrast enhancement over CW intensity in preclinical models of human breast cancer.
Mice bearing MDA-MB-231 tumors were injected with anti-EGFR antibody conjugated to the fluorescent dye IRDye 800CW (anti-EGFR-800). Time domain fluorescence imaging was performed
and
up to 48 hours after dye injection.
Mice injected with anti-EGFR-800 showed a significantly longer FLT (0.7 ± 0.03 ns) compared with the FLT of nonspecific probe uptake in liver (0.63 ± 0.05 ns), providing a dramatic improvement in sensitivity and specificity compared with CW intensity. IgG antibody-conjugated IRDye 800CW did not show an increased FLT compared with normal tissue, suggesting that the FLT increase of anti-EGFR-800 in tumors was associated with receptor expression. Using serial surgery, we show that FLT allows the detection of smaller residual tumors in the surgical bed than possible using CW intensity.
Our data suggest that FLT can significantly enhance tumor contrast using fluorescently labeled antibodies, thereby accelerating the efficient clinical application of these probes for margin assessment in image-guided surgery and for highly specific detection of tumor receptors
.
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