Search

A bond theory model is extended to study the size and shape dependent optoelectronics properties of semiconductors solids at nanoscale. On structural miniaturization down to nano scale, the optical parameters no longer remain stable but become tunable. The fraction of surface atoms and the dangling bonds on the surface affects the properties of semiconductors at nanoscale. The theory is applied to study the size and shape dependent energy band gap, dielectric constant and phonon frequency of TiO2, CdS, CdSe, Si and GaN semiconductor nanosolids. We incorporated the relaxation factor, defined as the ratio of dangling bonds and the total bonds of atoms at nano scale. It is predicted that as the energy band increases with decrease in size, the effect becomes more when shape changes from spherical to tetrahedral. The model projects a decrease in phonon frequency and dielectric constants of semiconductor nanostructured materials with decrease in particle size. A good agreement between predicted results and the available experimental data is projected.

The fraction of surface atoms and the dangling bonds on the surface affect the thermodynamical properties of the nanostructured solids. A bond theory model is extended to study the size dependent thermodynamical properties at nanoscale. The theory is applied to analysis the size and shape dependence of cohesive energy, thermal expansion coefficient and specific heat of Ag, Au, Cu and Se nanosolids. The relaxation factor is incorporated at low dimension of nanosolids, which is expressed as the ratio of dangling bonds and the total bonds of atoms. It is predicted that the cohesive energy decreases with decrease in particle size. On the same ground, the model is proposed to analyze the thermal expansion coefficient and specific heat of the nanomaterials. It is reported that the thermal expansion coefficient and specific heat increase as particle size decreases. The predictions agree well with available experimental or simulation results.

In the light of non-zero and relatively large value of rector mixing angle ($\theta_{13}$), we have performed a detailed analysis of texture one zero neutrino mass matrix $M_{\nu}$ in the scenario of vanishing determinant/trace conditions , assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of $M_{\nu}$, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at $3\sigma$ confidence level. Numerical and some approximate analytical results are presented., Comment: 27 pages, 6 figures, Accepted for Publication in Nuclear Physics B

In the era of twenty first century where human being is moving forward from semi – automated systems to fully automatic and machine learning based systems, software development (SD) mechanisms have also moved from static and pretended process following mechanisms to fast, ready for advices and adaptability based software development methods. Due to this traditional software development methods following heavy documentation based step by step processes have become obsolete and software development industry is transitioning towards dynamic, incremental, iterative, customer – centered, light – documentation based system development mechanisms referred as Agile Software development (ASD). The transition becomes more attention grabbing in distributed environment referred as distributed Agile software development (DASD). Certain processes like – task allocation, backlog prioritization, test case reduction and prioritization use manual processes rather than semi or fully automated processes. This methodology of transformation needs transitioning changes in existing DASD systems. In this paper we have proposed framework for transitioning of plan driven software development method to distributed Agile software development. The major area of concern is to automate the manual processes followed and convert them to semi – automated and fully – automated processes.

Background: Sepsis is one of the most common causes of neonatal deaths globally. Most sepsis-related deaths occur in low-income and middle-income countries, where the epidemiology of neonatal sepsis remains poorly understood. Most of these countries lack proper surveillance networks, hampering accurate assessment of the burden of sepsis, implementation of preventive measures, and investment in research. We report results of neonates born in hospital from a multicentre collaboration on neonatal sepsis. Methods: In this cohort study, dedicated research teams prospectively followed up neonates born in one of three tertiary care centres in Delhi, India (Vardhaman Mahavir Medical College, Maulana Azad Medical College, and All India Institute of Medical Sciences [coordinating centre]) and subsequently admitted to the intensive care unit. Neonates were followed up daily until discharge or death. On clinical suspicion, neonates underwent sepsis work-up including blood cultures. The isolated organisms were identified and tested for antimicrobial susceptibility. We defined Gram-negative isolates resistant to any three of five antibiotic classes (extended-spectrum cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, and piperacillin-tazobactam) as multidrug resistant. Findings: 13 530 neonates of 88 636 livebirths were enrolled between July 18, 2011, and Feb 28, 2014. The incidence of total sepsis was 14·3% (95% CI 13·8–14·9) and of culture-positive sepsis was 6·2% (5·8–6·6). Nearly two-thirds of total episodes occurred at or before 72 h of life (defined as early onset; 1351 [83%] of 1980). Two-thirds (645 [64%]) of 1005 isolates were Gram-negative including, Acinetobacter spp (22%), Klebsiella spp (17%), and Escherichia coli (14%). The pathogen mix in early-onset sepsis did not differ from that of late-onset sepsis (ie, after 72 h). High rates of multidrug resistance were observed in Acinetobacter spp (181/222, 82%), Klebsiella spp (91/169, 54%), and Escherichia coli (52/137, 38%) isolates. Meticillin resistance prevailed in 61% (85/140) of coagulase-negative staphylococci and 38% (43/114) of Staphylococcus aureus isolates. Nearly a quarter of the deaths were attributable to sepsis. The population-attributable risks of mortality were 8·6% in culture-negative sepsis, 15·7% in culture-positive sepsis by multidrug-resistant organisms, and 12·0% in culture-positive sepsis by non-multidrug-resistant organisms. Interpretation: The high incidence of sepsis and alarming degree of antimicrobial resistance among pathogens in neonates born in tertiary hospitals underscore the need to understand the pathogenesis of early-onset sepsis and to devise measures to prevent it in low-income and middle-income countries. Funding: Indian Council of Medical Research

Agile software development has been thrust area for over a long period. A large number of researchers are still working on different aspects of Agile software development and distributed Agile software development. In this paper we have done a review of different task allocation approaches adopted by researchers in Agile Software Development quantitatively. The tabular comparison shows the techniques applied for task allocation along with their pros and cons. After the study we have identified that most the task allocation approaches follow quantitative approaches for task allocation but during this process qualitative aspect has not been addressed vastly.

Iron doped Yttrium Copper Titanate nano-ceramic with composition, Y2/3Cu3Ti3.90Fe0.10O12 (YCTFO) was prepared by semi-wet route. It displays all normal XRD peaks of Y2/3Cu3Ti4O12 (YCTO) along with a few secondary peaks of CuO. Stoichiometric purity of the composition was ascertained by EDX spectral analysis. The distribution of bimodal spherical grains confirms 0.5–1.5 µm size limit along with a few irregular shaped large grains with size 1.5–2.8 µm. The impacts of acceptor type of hetero-valent substitution of Ti4+ by Fe3+ in Y2/3Cu3Ti4O12 (YCTO) were reflected as decrease in grain size and broadening of er–T peak with simultaneous decrease in er value. The presence of temperature dependent relaxation was also rationalized by impedance and modulus spectroscopic studies which confirm ferroelectric to paraelectric phase transition at 348 K.

Ni(II) and Cu(II) complexes with 2-amino-benzoic acid (1-phenyl-propylidene)-hydrazide (Habh) and 2-hydroxy-benzoic acid (1-phenyl-propylidene)-hydrazide (Hhbh) have been synthesized and characterized by different physico-chemical and spectroscopic techniques (UV–Vis, IR & NMR). The molecular structures of the ligands and their complexes [Ni(abh)2(DMSO)2], [Ni(hbh)2(DMSO)2] and [Cu(abh)2] have also been determined by single crystal X-ray diffraction technique. In all the complexes, each ligand coordinates to metal through azomethine-N and carbonylate-O resulting a 4-coordinate distorted square planar geometry for Cu(II) complexes and 6-coordinate distorted octahedral geometry for Ni(II) complexes in which two DMSO molecules occupy the axial positions. The structure of [Cu(hbh)2] complex has been satisfactorily modeled by density functional theory (DFT) and time dependent-DFT (TD-DFT) calculations. The corrosion inhibition study of the synthesized compounds has also been performed for mild steel in 0.5 M H2SO4 medium. The activity is found in the order: Ni(II) complexes > ligands > Cu(II) complexes. The DFT study on ligands also supports the experimental observation that Habh is better corrosion inhibitor than Hhbh.

a b s t r a c t Level of variation in capsaicinoid content was evaluated in Capsicum accessions belonging to chilli land races from north-eastern India. Accessions from NE India showed enormous variation in morphological characters such as fruit shape, size, colour, and fruit position. Capsaicinoid content in 139 accessions var- ied from 0.02 to 72.05 mg/g. The ratio between two major capsaicinoids, capsaicin and dihydrocapsaicin, varied from 0.34 to 4.92. The capsaicinoid content among 92 accessions of Bhut Jolokia varied from 11.95 to 72.05 mg/g with corresponding pungency levels of 191,135-1,152,832 SHU. A strong positive correlation (r = 0.90) was obtained between capsaicin and dihydrocapsaicin content. © 2014 Elsevier B.V. All rights reserved.

Two new Schiff bases, ferrocene carboxaldehyde propanoylhydrazone (fcph) and ferrocene carboxaldehyde furoylhydrazone (fcfh) have been synthesized and characterized by elemental analyses, electronic, IR and NMR spectral studies. Molecular structures of fcph and fcfh are determined by single crystal X-ray diffraction technique. The Schiff bases fcph and fcfh display E-configuration about the >C N– bond. The structures of both the compounds are stabilized by inter-molecular H-bonding. The electrochemical study of these compounds exhibits quasi-reversible one electron redox behaviour. The corrosion inhibition study of the Schiff bases have been performed by using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The compounds fcph and fcfh show an appreciable corrosion inhibition property against corrosion of mild steel in 0.5 M H2SO4 solution at 298 K. It has been observed that fcfh shows greater corrosion inhibition efficiency than fcph. As the concentration of the Schiff bases increases, corrosion inhibition property of the compounds increases.

Seed development in Jatropha curcas L. was studied with respect to morphology, oil content and lipid profiles. Seeds were collected at 8 different stages of development starting from 6 days after pollination till maturity. Seed oil content increased from 6.15% to 35.86%. Palmitic acid (16:0) decreased from 34.27-15.62, whereas linolenic acid (18:3) reduced from 26.32 to 0.65%. A sharp increase in oleic acid (18:1) content from 8.05 to 29.56% was observed at stage 5 which increased further to 44.38% at maturity. Linoleic acid (18:2) increased steadily from 33.38 to 47.19 % till stage 7 but reduced to 33.02% at maturity with a simultaneous increase in oleic acid. Remarkable changes in fatty acid composition were observed after stage 4 (27 DAP). The biodiesel quality of oil at stage 8 was better than at stage 7 as indicated by lower iodine number and higher cetane number.

A new green polymeric material, polyacrylamide grafted with Okra mucilage, a natural grade polysaccharide, was tested as corrosion inhibitor for mild steel in 0.5 M H 2 SO 4 using gravimetric and electrochemical techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration up to maximum 96.6% for 100 ppm at 25 °C. The effects of immersion time (3–72 h) and temperature (25–65 °C) on the inhibition of corrosion have also been discussed. The adsorption of this inhibitor on the mild steel surface obeys a Langmuir adsorption isotherm. The scanning electron micrographs of the inhibited specimens show smoothening of the surface.

A comparative study of the effect of commonly used dietary spices on the pitting behavior of orthodontic bands made of AISI 304L was carried out using electrochemical experiments. Corrosion parameters were measured after immersing the steel for 24 h in artificial saliva containing spice extract. Cinnamon, cumin, red chili and turmeric caused pitting even in the absence of chloride ions. On adding NaCl, red chili, cinnamon and fenugreek caused severe pitting and coriander was found to inhibit pitting. Micrographs of the specimens show formation of hemispherical pits covered with remnants of passive film.

In this paper, we describe image encryption by combining the images with several matrices made with letters/numerals and placed in the input plane of a double random phase encoding (DRPE) system. Addition or multiplication of several such matrices with an input image provides a modified image pattern which is encrypted in a DRPE system utilizing the 4-f geometry. For gray scale images, the results of encryption in case of addition of matrices are found more reliable and secure as compared to the results of multiplication. Simulation results are presented in support of the idea. Reliability of the technique has been established by evaluating the mean square-error (MSE) between the decrypted and the original image.

In the present paper, we describe the encryption and decryption of two-dimensional images. The encryption is done by employing a sandwich phase diffuser made by using two elongated speckle patterns, and placed in the Fourier plane of a double random phase encoding system. After encryption, the two constituent phase diffusers of such a sandwich diffuser are separated. During decryption, if the conjugate of either of the two elongated phase speckle patterns is used, the image cannot be retrieved. Correct decryption is also not possible if a sandwich diffuser with any of the phase speckle patterns is shifted in position with respect to the other. For decryption, the encrypted image is Fourier transformed and multiplied by the conjugate of the sandwich diffuser, and then the product is further Fourier transformed. It is possible to generate the image only if both the elongated phase speckle patterns are matched point-to-point and then the proper conjugate is made. The use of elongated speckle patterns in constituting a sandwich phase diffuser makes the system less complicated as compared to the use of a sandwich diffuser made with normal speckle patterns, enabling an easy alignment of the random phase diffuser at the time of rejoining the constituent diffusers for making the right key. The ease of alignment is due to the reduction of the requirement of 360° scanning at the time of rejoining these diffusers with little reduction in the security of the system. Simulation results are presented in support of the proposed idea. For optical implementation, the decrypted image may be obtained by generating a phase conjugate wave by the phase conjugation technique, and passing through the same sandwich phase diffuser. To evaluate the reliability of the technique, mean square error (MSE) between the decrypted and original image has been calculated.

The ligand benzyl N′-(2-methoxybenzoyl)hydrazinecarbodithioate (H2mbhcd) (1), having a NOS donor sequence, formed a series of complexes [M(Hmbhcd)2]n {M = Mn(II), Co(II) and Ni(II) (2, 5 and 6)}, [Mn(Hmbhcd)2(o-phen)] · DMSO (3) and [Mn2(Hmbhcd)2(2,2′-bpy)2(μ-OAc)2] (4). The complexes 3 and 4 have been obtained as single crystals, containing o-phen/2,2′-bpy as coligands. The compounds 2, 5 and 6 have been characterized with the aid of elemental analyses, IR, UV–Vis, magnetic susceptibility and mass spectrometry. Compound 3 crystallized in the triclinic system with the space group P 1 ¯ while 4 crystallized in the monoclinic system with the space group P21/c. The (N,O) donor sites of the uninegative bidentate ligand chelates the Mn(II) center to form a five-membered MnOCN2 ring in both complexes 3 and 4.

Two novel Ni(II) complexes {[Ni(en)2(pot)2]0.5CHCl3} (3) {pot = 5-phenyl-1,3,4-oxadiazole-2-thione} (1) and [Ni(en)2](3-pytol)2 (4) {3-pytol = 5-(3-pyridyl)-1,3,4-oxadiazole-2-thiol} (2) have been synthesized using en as coligand. The metal complexes have been characterized by physical and analytical techniques and also by single crystal X-ray studies. The complexes 3 and 4 crystallize in monoclinic system with space group P21/a and P121/c, respectively. The complex 3 has a slightly distorted octahedral geometry with trans (pot)− ligands while 4 has a square planar geometry around the centrosymmetric Ni(II) center with ionically linked trans (3-pytol)− ligands. The π⋯π (face to face) interaction plays an important role along with hydrogen bondings to form supramolecular architecture in both complexes.

We propose the encryption and multiplexing of two-dimensional input images by rotating the constituent diffusers of a sandwich random phase diffuser kept in the Fourier plane of a double random phase encoding system. Successive recording of encrypted images is done by taking the input images one by one. The results of multiplexing in encryption and decryption due to different sets of rotation of one or both of the random constituent phase masks have been presented. The use of an aperture system in addition to the rotation of one or both of the random phase masks enhances the multiplexing capability and security of the system avoiding the generation of cross-talk images at the time of decryption. Simulation results are presented in support of the proposed techniques. The decrypted images obtained from a multiplexed encrypted image have been recorded successfully. Mean square-error (MSE) and signal-to-noise ratio (SNR) values as a function of the number of multiplexed images have been calculated.

A coordination polymer {[Mn(3-pyt)2(H2O)2][N(n-Bu)4]+[3-pyt]−}n (3) has been synthesized from the reaction of tetra-n-butylammonium[5-(3-pyridyl)-1,3,4-oxadiazole-2-thiolate] {[N(n-Bu)4]+[3-pyt]−} and Mn(OAc)2 · 4H2O. The ligand and the Mn(II) complex 3 have been characterized by elemental analyses, IR, 1H and 13C NMR spectroscopy, in addition 3 has also been studied crystallographically. The single crystal X-ray structure of the 3 shows that the ligand is bonded to Mn(II) via its pyridyl and oxadiazole nitrogen atoms. This bonding pattern connects the Mn(II) centres to afford an uniform two dimensional coordination frame work where the [Mn(3-pyt)2(H2O)2]n molecules are stacked in a parallel layers. The overall arrangement of molecules in crystal lattice results in open channels in which the enclosed tetra-n-butylammonium cations are stabilized by anionic oxadiazole molecules through N+···S− ionic interactions.

The ligand N2-[bis(benzylsulfanyl)methylene]-2-methoxybenzohydrazide (N2-bmbh) (1) on reaction with CuCl2.2H2O yielded the mononuclear complex [Cu(bzsmp)2Cl2] (2) (2-benzylsulfanyl-5-(2-methoxyphenyl)-1,3,4-oxadiazole, bzsmp). Complex 2 has been characterized by analytical, spectroscopic and X-ray data. X-ray study of 2 reveals that the cyclized ligand 2-benzylsulfanyl-5-(2-methoxyphenyl)-1,3,4-oxadiazole (bzsmp) acts as neutral bidentate ligand to form six membered chelate ring and the presence of C–H⋯π (face to edge) and C–H⋯S and two type of C–H⋯Cl weak interactions.

In this paper, we have described a simple and secure double random phase encoding and decoding system to encrypt and decrypt a two-dimensional gray scale image. We have used jigsaw transforms of the second random phase mask and the encrypted image. The random phase mask placed in the Fourier plane is broken into independent non-overlapping segments by applying the jigsaw transform. To make the system more secure, a jigsaw transform on the encrypted image is also carried out. The encrypted image is also broken into independent non-overlapping segments. The jigsaw transform indices of random phase code and the encrypted image form the keys for the successful retrieval of the data. Encrypting with this technique makes it almost impossible to retrieve the image without using both the right keys. Results of computer simulation have been presented in support of the proposed idea. Mean square error (MSE) between the decrypted and the original image has also been calculated in support of the technique.

In this paper, the implementation of a secure optical system using fully phase encryption is described. A two-dimensional phase image obtained from an amplitude image is encrypted and decrypted by using a spatial light modulator working in phase mode. The fully phase encryption is achieved using double random phase encoding. The encrypted image is holographically recorded in a photorefractive crystal and is then decrypted by generating, through phase conjugation, the conjugate of the encrypted image. A lithium niobate crystal has been used as a phase contrast filter to change the decrypted phase image into an amplitude image, thus alleviating the need for alignment of the phase contrast set-up in the Fourier plane. Simulation results are provided to verify the proposed study. The mean square error between the primary image and decrypted image has been calculated to study the sensitivity of the system.

In the present paper, we describe multiplexing in optical encryption of two-dimensional images, by using apertures and rotation of one of the constituent phase diffusers of a sandwich phase diffuser in the Fourier plane. The sandwich phase diffuser is made with two random constituent phase-diffusing surfaces sandwiched together. The apertures of different sizes and shapes are made with the help of ‘paint brush’ software. Simulation results are presented showing the effects of size, shape, and orientation of the apertures on the decrypted images obtained via multiplexing techniques. In addition to the results of using aperture systems in encryption and decryption, the results of rotation of one of the constituent phase diffusers in decryption are analyzed and used in multiplexing. Due to the use of aperture systems and the rotation of the constituent phase diffuser, the multiplexing capability of the system in encryption is enhanced along with the enhanced security due to using a sandwich diffuser. To evaluate the reliability of the technique, mean square error between the decrypted and the original image has been calculated.

For studying genetic diversity in natural populations of Terminalia, a medicinal plant, our attempts to isolate high quality DNA using several previously reported protocols and even modifications were unsuccessful. We therefore combined CTAB based isolation, and column based purification step, to isolate DNA from Terminalia arjuna. The DNA isolated using this standardized protocol was high in quality and suitable for restriction digestion and generation of random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP).

The inhibition of copper corrosion in 1.5% NaCl solution has been studied at 25, 35 and 45 °C using three structurally different inhibitors thiosemicarbazide (Inh I), phenyl isothiocyanate (Inh II), and their condensation product 1-pheny1-2,5-dithiohydrazodicarbonamide (Inh III). The inhibition efficiencies of these compounds have been evaluated by weight loss and electrochemical polarisation techniques. The inhibition efficiencies of the inhibitors follow the sequence: Inh III > Inh I > Inh II. Thiosemicarbazide appears to inhibit corrosion process through formation of Cu(I) complex of thiosemicarbazide and its subsequent oxidation into Cu(II) complex, phenyl isothiocyanate inhibits only through adsorption while the condensation product inhibits the process through its adsorption as well as complex formation.

The corrosion behaviour of mild steel in formic acid of different concentrations has been studied by weight loss and electrochemical techniques. It was found that the corrosion rate of mild steel in formic acid is a function of acid concentration and temperature. The maximum corrosion rate was observed in 20% formic acid solution by both techniques. The anodic polarization curves show active corrosion behaviour of mild steel over the whole range of potential at each concentration and temperature. Cathodic polarization curves are almost identical irrespective of the concentration of the formic acid. An attempt has been made to throw some light on the possible mechanism for corrosion of mild steel in formic acid solution on the basis of the results of the present investigation.

In the present communication, thermal modelling and energy conservation studies on the steam Rankine cycle cooling system [Rankine engine (RE) cycle coupled with vapour compression (VC) cycle] have been undertaken using steam + NH3, steam + R-22 and steam + R-12 as the working fluids, and their comparative studies are presented having parametric variations of various operating conditions. The overall performance is dependent on the thermal efficiency of the RE-cycle and the COP of the VC-cycle subsystems. Subsequently, various methods of improvement of the efficiency of the Rankine engine cycle, viz. regeneration, superheating, recompression, etc. have been analysed quantitatively and their influences on Rankine engine efficiency performance are presented herewith. It has been found that the steam Rankine cycle cooling system performance is higher than a freon based cooling system [1] and the Rankine cycle performance can also be further improved by using external superheating and/or recompression of the turbine exhaust. Numerical results are presented for the sake of illustration.

A simple and straightforward method for the determination of thermal expansion is investigated and applied for four minerals of geophysical importance. The results obtained for four minerals such as Mg2SiO3, Al2O3, Grossular garnet and Pyrope garnet at different temperatures are found to be in excellent agreement with the experimental data. The simplicity of the method is discussed in the light of another method in high temperature research on minerals.

This paper is devoted to the development of a transient model of the performance of a double-basin solar still. Integration of the still with a heat exchanger has been suggested in order to enhance its distillate output per unit area. This integration can be achieved by flowing hot fluid through the still. A detailed analysis has been carried out for the integrated system, incorporating the effects of various system parameters such as water mass in the upper and lower basins, heat-exchanger length, inlet temperature, mass-flow rate of heat-exchanger fluid, various heat-transfer coefficients, etc., as well as meteorological parameters. Data corresponding to a typical cold day (15 January 1987) at New Delhi have been used for computations. It is found that use of the heat exchanger increases the system efficiency significantly.

In this communication, an analysis of a PCCM (phase change component material) storage water heater has been presented by incorporating the effect of water flow through a parallel plate placed at the solid-liquid interface. In order to reduce the night heat losses from the exposed surface, a provision of covering the system by movable insulation has been made. It is concluded that (i) water can be made available at a temperature 15–20°C higher than the ambient air temperature throughout the day and night, and (ii) the fluctuations in water temperature decrease with an increase in the melted region of the PCCM water heater.

A simple transient analytical approach has been adopted for developing an explicit expression for the water temperature of an indoor swimmingpool coupled to a panel of collectors. For qualitative assessment of the analytical results, computations have been made for the winter climatic conditions of Sri Nagar, India. The effects of several parameters, viz. inlet temperature, heat removal factors, collector, etc. on the performance of the proposed systems have been studied in detail. It is observed that (i) the proposed model agrees with the experimental results of the Australian passive solar swimming pool and (ii) the desired temperature for the indoor swimming pool can be achieved by the active method.