Advanced numerical scheme and its convergence analysis for a class of two-point singular boundary value problems.

[EN]In this article, a novel approach based on the shooting projection method and the Legendre wavelet operational matrix formulation for approximating a class of two-point SBVPs with Dirichlet and Neumann–Robin boundary conditions is proposed. For the new approach, an initial guess is postulated in contrast to the boundary conditions in the first step. The second step deals with the usage of the Legendre wavelet operational matrix method to solve the initial value problem (IVP). Further, the resulting solution of the IVP is utilized at the second endpoint of the domain of a differential equation in a shooting projection method to improve the initial condition. These two steps are repeated until the desired accuracy of the solution is achieved. To support the mathematical formulation, a detailed convergence analysis of the new approach is conducted. The new approach is tested against some existing methods such as various types of the variational iteration method, considering several numerical examples to which it provides high-quality solutions

NEW APPROACH BASED ON COLLOCATION AND SHIFTED CHEBYSHEV POLYNOMIALS FOR A CLASS OF THREE-POINT SINGULAR BVPS.

[EN]In the recent decades, variety of real-life problems arises in astrophysics have been mimic using the class of three-point singular boundary value problems (BVPs). Finding an effective and accurate approach for a class of three-point BVPs is still a difficult problem, though. The goal of this paper is to design a numerical strategy for approximating a class of three-point singular boundary value problems using the collocation technique and shifted Chebyshev polynomials. Utilizing shifted Chebyshev polynomials, the problem is reduced to a matrix form, which is then converted into a system of nonlinear algebraic equations by employing the collocation points. The key advantages of the new approach are (a) it is a straightforward mathematical formulation, which makes it effortless to code, and (b) it is easily adaptable to solve various classes of three-point singular boundary value problems. The convergence analysis is carried out to ensure the viability of the proposed scheme

NMR structure of an acyl-carrier protein from Borrelia burgdorferi

The high-resolution NMR structure of the acyl-carrier protein from the pathogen B. burgdorferi determined to a r.m.s. deviation of 0.4 Å over the protein backbone is reported. The NMR structure was determined using multidimensional NMR spectroscopy and consists of four α-helices and two 310-helices. Structural comparison reveals that this protein is highly similar to the acyl-carrier protein from A. aeolicus

Characterization Studies on Lead-Zinc Tailings from Rampura-Agucha Mines

The process tailings of base metal industries contain considerable amounts of acid generating 'pyrite and sul-fides of other minerals. The recovery of sulfide minerals from the tailings not only will have environmental advan-tage but will also result in conservation of mineral wealth.For any such recovery activity, it is essential to characterize the tailings for physical, chemical and mineralogical characteristics. In the present study, typi-cal lead-zinc tailings sample from the operating plant at Rampura-Agucha mines of Hindustan Zinc Limited was collec-ted and characterized for size distribution, size by size chemical composition and mineral phase analysis through X-ray diffraction method. The size-by-size metal contents indicated increasing levels of silver and pyrite with decreasing particle size and the lead and zinc bearing minerals are segregated at relatively coarser size fract-ions. Microscopic studies of the coarser fractions have indicated that the lead and zinc minerals are in unliber-ated form. The XRD study has indicated that quartz is the major mineral phase followed by pyrite, sphalerite, galena and silver. The overall tailings sample was found to cont-ain 19.41% of pyrite, 2.02 % of zinc, 0.69 % lead, and 26.94 ppm of silver contents

MGS Studies for Recovering Iron and Silver Values from Lead-Zinc Tailings

In mineral processing plants valuable minerals are recovered by rejecting gangue materials through various physical processing techniques to produce high-grade concentrate. However, after processing these ores, the tailings generated contain considerable amount of valua-bles because of inefficient of process plant or due to fluctuations in the mineralogical composition of the ore. Therefore, recovery of these valuable minerals is prerequisite from environmental and mineral conservation point of views

Dip coating of forsterite-hydroxyapatitie-poly (ɛ-caprolactone) nanocomposites on Ti6Al4Vsubstrates for its corrosion prevention

522-528Titanium and titanium alloys are extensively used in biomedical, cardiac and cardiovascular applications for their superb properties, such as good fatigue strength, low modulus, machinability, formability, corrosion resistance and biocompatibility. However, titanium and its alloys do not meet the majority of all clinical necessities. Due to these reasons, surface modification is frequently performed to enhance the mechanical, biological and chemical properties of titanium and alloys. In this work, nanocomposites coating of poly(ɛ-caprolactone)/hydroxyapatite/forsterite (PCL/HA/F) have been successfully deposited on the Ti6Al4V substratesby dip coating at room temperature. The coatings are prepared with various concentrations of forsterite/hydroxyapatite nanopowder (2, 4, 6 and 8 wt.%) with a fixed concentration of PCL (4 wt.%) and thus coated Ti6Al4V substrates are examined for corrosion resistance. PCL/Hydroxyapatite/Forsterite coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which clearly showed the formation of nanocomposites. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) are used to investigate corrosion behavior of the coated substrates, which portrayed that the composite coating of PCL/HA/F substantially enhanced the corrosion resistance of Ti6Al4V alloy

Dip coating of forsterite-hydroxyapatitie-poly (ɛ-caprolactone) nanocomposites on Ti6Al4Vsubstrates for its corrosion prevention

Titanium and titanium alloys are extensively used in biomedical, cardiac and cardiovascular applications for their superb properties, such as good fatigue strength, low modulus, machinability, formability, corrosion resistance and biocompatibility. However, titanium and its alloys do not meet the majority of all clinical necessities. Due to these reasons, surface modification is frequently performed to enhance the mechanical, biological and chemical properties of titanium and alloys. In this work, nanocomposites coating of poly(ɛ-caprolactone)/hydroxyapatite/forsterite (PCL/HA/F) have been successfully deposited on the Ti6Al4V substratesby dip coating at room temperature. The coatings are prepared with various concentrations of forsterite/hydroxyapatite nanopowder (2, 4, 6 and 8 wt.%) with a fixed concentration of PCL (4 wt.%) and thus coated Ti6Al4V substrates are examined for corrosion resistance. PCL/Hydroxyapatite/Forsterite coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which clearly showed the formation of nanocomposites. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) are used to investigate corrosion behavior of the coated substrates, which portrayed that the composite coating of PCL/HA/F substantially enhanced the corrosion resistance of Ti6Al4V alloy

Time Series Analysis of SARS-CoV-2 Genomes and Correlations among Highly Prevalent Mutations

The efforts of the scientific community to tame the recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seem to have been diluted by the emergence of new viral strains. Therefore, it is imperative to understand the effect of mutations on viral evolution. We performed a time series analysis on 59,541 SARS-CoV-2 genomic sequences from around the world to gain insights into the kinetics of the mutations arising in the viral genomes. These 59,541 genomes were grouped according to month (January 2020 to March 2021) based on the collection date. Meta-analysis of these data led us to identify significant mutations in viral genomes. Pearson correlation of these mutations led us to the identification of 16 comutations. Among these comutations, some of the individual mutations have been shown to contribute to viral replication and fitness, suggesting a possible role of other unexplored mutations in viral evolution. We observed that the mutations 241C.T in the 59 untranslated region (UTR), 3037C.T in nsp3, 14408C.T in the RNA-dependent RNA polymerase (RdRp), and 23403A.G in spike are correlated with each other and were grouped in a single cluster by hierarchical clustering. These mutations have replaced the wild-type nucleotides in SARS-CoV-2 sequences. Additionally, we employed a suite of computational tools to investigate the effects of T85I (1059C.T), P323L (14408C.T), and Q57H (25563G.T) mutations in nsp2, RdRp, and the ORF3a protein of SARS-CoV-2, respectively. We observed that the mutations T85I and Q57H tend to be deleterious and destabilize the respective wild-type protein, whereas P323L in RdRp tends to be neutral and has a stabilizing effect. IMPORTANCE We performed a meta-analysis on SARS-CoV-2 genomes categorized by collection month and identified several significant mutations. Pearson correlation analysis of these significant mutations identified 16 comutations having absolute correlation coefficients of .0.4 and a frequency of .30% in the genomes used in this study. The correlation results were further validated by another statistical tool called hierarchical clustering, where mutations were grouped in clusters on the basis of their similarity. We identified several positive and negative correlations among comutations in SARS-CoV-2 isolates from around the world which might contribute to viral pathogenesis. The negative correlations among some of the mutations in SARS-CoV-2 identified in this study warrant further investigations. Further analysis of mutations such as T85I in nsp2 and Q57H in ORF3a protein revealed that these mutations tend to destabilize the protein relative to the wild type, whereas P323L in RdRp is neutral and has a stabilizing effect. Thus, we have identified several comutations which can be further characterized to gain insights into SARS-CoV-2 evolution.</p

Complete backbone assignment of a Ca<SUP>2+</SUP>-binding protein of the βγ-crystallin superfamily from Methanosarcina acetivorans, at two denaturant concentrations

We report here almost complete backbone assignment of a Ca2+-binding protein of the &#946;&#947;-crystallin superfamily from Methanosarcina acetivorans, at two denaturant (GdmCl) concentrations, using double and triple resonance experiments. These NMR assignments will be useful to understand the unfolding path of this protein

NMR assignment of M-crystallin: a novel Ca<SUP>2+</SUP> binding protein of the βγ-crystallin superfamily from Methanosarcina acetivorans

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