50175 research outputs found
Sort by
RETRACTION: A Fluorescent molecularly-imprinted polymer gate with temperature and pH as inputs for detection of alpha-fetoprotein (Retraction of Vol 78, Pg 454, 2016)
No full textMangoNet: A deep semantic segmentation architecture for a method to detect and count mangoes in an open orchard
No full textThis work presents a method for detection and counting of mangoes in RGB images for further yield estimation. The RGB images are acquired in open field conditions from a mango orchard in the pre-harvest stage. The proposed method uses MangoNet, a deep convolutional neural network based architecture for mango detection using semantic segmentation. Further, mango objects are detected in the semantic segmented output using contour based connected object detection. The MangoNet is trained using 11,096 image patches of size 200 x 200 obtained from 40 images. Testing was carried out on 1500 image patches generated from 4 test images. The results are analyzed for performance of segmentation and detection of mangoes. Results are analyzed using the precision, recall, Fl parameters derived from contingency matrix. Results demonstrate the robustness of detection for a multitude of factors such as scale, occlusion, distance and illumination conditions, characteristic to open field conditions. The performance of the MangoNet is compared with FCN variant architectures trained on the same data. MangoNet outperforms its variant architectures
Study on charge storage mechanism in working electrodes fabricated by sol-gel derived spinel NiMn2O4 nanoparticles for supercapacitor application
No full textWe report the synthesis of porous spinel-structured binary NiMn2O4 metal oxide nanoparticles and their performance as electrode material for supercapacitors. Spherical NiMn2O4 nanoparticles of similar to 8 nm average diameter have been synthesized using inexpensive and simple sol-get method, and characterized by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The electrodes made of this single phase spinel nanoparticles exhibit superior electrochemical performance with excellent rate capability, offering highest specific capacitance value of 875 F g(-1) at 2.0 mV s(-1) scan rate in 1M Na2SO4 electrolyte solution. Furthermore, an asymmetric supercapacitor is also assembled and possesses a wide operating voltage window of 1.8 V, exhibiting an energy density of 75.01 Wh kg(-1) at a power density of 2250.91 W kg(-1). The results infer this highly porous binary metal oxide nanostructures are promising candidates for high performance energy storage applications
Measuring accessibility of various facilities by walking in world's largest mass religious gathering - Kumbh Mela
No full textAccessibility, the ease of accessing a facility, is one of the key measures for urban transportation planning. There have beenvarious studies conducted for calculation of accessibility using motorised modes in urban areas. This paper computes the accessibility to various facilities by walking in world's largest mass religious gathering, Kumbh Mela(2). In doing so, it serves as one of the missing links in the contextual studies for accessibility. The gravity type exponential method is used in this study for calculation of accessibility. Accessibility to various facilities was computed and the sectors in study area were classified into high and low accessible sectors. The impedance parameter beta of time and distance came out to be lowest for visiting the temple, which shows the willingness and motivation of the users to walk longer distances for this particular activity type. Consequently, heat maps of accessibility index were developed as a sample case for drinking water stalls with walking as a mode and time and distance being the impedance variables. Further, sectors with redundant facilities were also identified. This work, with its findings aims to equip the organizing agencies and decision-making authorities with tool/methodology to better plan and organize such mass religious gatherings and also use it to identify service gaps in planning of facilities during such events by using the knowledge and understanding of accessibility measures in similar contexts
Dendrite tip selection during isothermal free growth in multi-component alloys: Marginal stability theories and insights from phase-field simulations
No full textThe principal length scales associated with dendritic solidification, which being the dendritic tip-radius (R-tip) and the primary dendritic arm spacing, are functions of the relative solutal interdiffusivities of the different components in a multi-component alloy. In this paper, we firstly derive marginal stability based theories to predict R(tip )during isothermal free growth in any generic multi-component alloy for any generic diffusivity matrix. Here, we extend the Ivanstov solution of the diffusion problem in the liquid with a parabolic solid-liquid interface and propose the closure conditions between the The principal length scales associated with dendritic solidification, which being the dendritic tip-radius (R-tip) and the primary dendritic arm spacing, are functions of the relative solutal interdiffusivities of the different components in a multi-component alloy. In this paper, we firstly derive marginal stability based theories to predict R(tip )during isothermal free growth in any generic multi-component alloy for any generic diffusivity matrix. Here, we extend the Ivanstov solution of the diffusion problem in the liquid with a parabolic solid-liquid interface and propose the closure conditions between the R-tip and the selected dendrite tip velocity (V) based on modification of the classical marginal stability criteria for multi-component situations. Additionally, we derive the constant Rtip(2)V from phase-field simulations and using the Ivantsov parabola as the approximate interface shape compute the R-tip and the V, which we term as ``Approximate microsolvability prediction (AMP)''. Thereafter, we compare our predictions of R-tip, V as well as phase compositions with independent phase-field simulation results for different choices of the diffusivity matrix, where we show that the analytical theories based upon the marginal stability theory are unable to accurately predict variations of the dendrite tip velocity V and the R-tip. We thereby utilize the phase-field simulation results to investigate the tip selection in multi-component alloys and derive an appropriate solvability constant sigma*. We find that the sigma* in a multi-component alloy is a function of the diffusivity ratios of the components for the case of a diagonal diffusivity matrix. and the selected dendrite tip velocity (V) based on modification of the classical marginal stability criteria for multi-component situations. Additionally, we derive the constant Rtip(2)V from phase-field simulations and using the Ivantsov parabola as the approximate interface shape compute the R-tip and the V, which we term as ``Approximate microsolvability prediction (AMP)''. Thereafter, we compare our predictions of R-tip, V as well as phase compositions with independent phase-field simulation results for different choices of the diffusivity matrix, where we show that the analytical theories based upon the marginal stability theory are unable to accurately predict variations of the dendrite tip velocity V and the R-tip. We thereby utilize the phase-field simulation results to investigate the tip selection in multi-component alloys and derive an appropriate solvability constant sigma*. We find that the sigma* in a multi-component alloy is a function of the diffusivity ratios of the components for the case of a diagonal diffusivity matrix
Interface residues of transient protein-protein complexes have extensive intra-protein interactions apart from inter-protein interactions
No full textBackgroundProtein-protein interactions are crucial for normal biological processes and to regulate cellular reactions that affect gene expression and function. Several previous studies have emphasized the roles of residues at the interface of protein-protein complexes in conferring stability and specificity to the complex. Interface residues in a protein are well known for their interactions with sidechain and main chain atoms with the interacting protein. However, the extent of intra-protein interactions involving interface residues in a protein-protein complex and their relative contribution in comparison to inter-protein interactions are not clearly understood. This paper probes this feature using a dataset of protein-protein complexes of known 3-D structure.ResultsWe have analysed a dataset of 45 transient protein-protein complex structures with at least one of the interacting proteins with a known structure available also in the unbound form. We observe that a large proportion of interface residues (1608 out of 2137 interface residues, 75%) are involved in intra and inter-protein interactions simultaneously. The amino acid propensities of such interfacial residues involved in bifurcated interactions are found to be highly similar to the general propensities to occur at protein-protein interfaces. Finally, we observe that a majority (83%) of intra-protein interactions of interface residues with bifurcated interactions, are also observed in the protein uncomplexed form.ConclusionsWe have shown, to the best of our knowledge for the first time, that a vast majority of the protein-protein interface residues are involved in extensive intra-protein interactions apart from inter-protein interactions. For a majority of such interface residues the microenvironment in the tertiary structure is pre-formed and retained upon complex formation with its cognate partner during transient interactions.ReviewersThis article was reviewed by Arumay Pal and Mallur Madhusudhan
A Stochastic Model with Inflation, Growth and Technology for the Political Business Cycle
No full textThis paper analyzes an augmented political business cycle model taking into account the effect of employment creation decisions by the ruling party jointly on inflation and growth. The objective is to maximize voter support in the next election that depends on the rate of unemployment as well as that of growth and inflation. We allow for stochasticity in the New Keynesian Phillips Curve model for the relationship between inflation and unemployment as well as in a benchmark labour productivity function for analyzing the growth rate. We provide explicit solution paths of the affine Markov control problem that results from our formulation. We also provide numerical illustrations with plausible parametric configurations to generate more insight into our model. Our results are broadly in line with the conventional wisdom of Phillips curve, with inflation and unemployment being roughly negatively related. The growth rate is, as expected, negatively related to the unemployment. We observe that, in the sequel, it is the lowering of the rate of inflation that provides support for the ruling party. Thus, electoral pressures drive the government to engage in cost control rather than productive investment (e.g., boosting employment or output growth)
Solution-phase phosphorus substitution for enhanced oxygen evolution reaction in Cu2WS4
No full textTransition metal phosphides are among the most promising materials for achieving efficient electrocatalytic performance without the use of rare or expensive noble metals. However, previous research into phosphides for the hydrogen evolution reaction (HER) or oxygen evolution reaction (OER) has focused on high-temperature vapor-phase processes, which are not practical for large-scale applications. Here, we introduce a simple, one-step solution-phase method of phosphide synthesis by modifying Cu2WS4 using triphenylphosphine (TPP), which serves to substitute S with P and transform the normally inactive basal plane of Cu2WS4 into a defect-rich, activated basal plane. The OER activity was significantly enhanced by phosphorus substitution, with the resulting Tafel slope of the sample with approximate to 8 at% phosphorus reaching 194 mV dec(-1), a result close to that of the best OER catalyst (RuO2, 151 mV dec(-1)). The sample possessed stable OER performance, showing no degradation in current density over approximate to 24 hours (500 cycles), proving the robust and stable nature of the phosphorus substitution. These results open the possibility for further phosphide catalyst development using this low-cost, solution-phase method
A method to discern voltage dependent internal photoemission component from photoconductivity content in spectral response of metal-organic semiconductor-metal devices and evaluate the interface barriers
No full textThe ability to detect and determine a typically weak internal photoemission (IPE) signal from a usually strong photoconductivity (PC) signal within a spectral response (SR) measurement can be helpful in studying the interface properties of metal-semiconductor junctions, which are often critical for proper design and analysis of semiconductor electronic devices including organic photovoltaic devices. In this report, we propose a method to discern the voltage dependent IPE component from PC content in a measured SR of organic devices. The method is based on the ratio of SR measured at different voltage bias conditions in metal-organic semiconductor-metal devices. The separated IPE component, hence, can be used to estimate the associated interface barrier(s). The differentiation between IPE and PC is probably caused due to the barrier changing at the metal and organic semiconductor interface on the application of bias which causes a modulation in IPE signal with the applied bias. In this work, a theoretical basis for the method of characterisation has been developed. Based on the analysis, as an example, the barriers between 6,6] phenyl C61 butyric acid methyl ester (PCBM) and electrodes indium tin oxide and aluminium for different bias voltages have been evaluated. This simple and elegant method of studying metal and organic semiconductor barrier, when applicable, can be helpful in device design and characterisation