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The current research presents a novel third-order nonlinear optical single crystal named diisopropylammonium succinate by slow evaporation solution growth technique. Single-crystal X-ray diffraction and nuclear magnetic resonance techniques are utilized to validate the synthesis and formation of the titled crystal. The grown crystal belongs to monoclinic crystal system with space group P21/n, and its lattice parameters are found to be a = 8.3660 A, b = 11.4818 A, c = 13.5239 A and β = 98.3810°. 1H NMR and 13C NMR revealed the hydrogen bonds present within the molecules of crystal. The 3D visualization of intermolecular interactions was understood by the color contour of Hirshfeld surface of the grown crystal. UV–Vis and photoluminescence spectroscopic techniques are employed to understand the linear optical behavior of the reported crystal. The thermal stability of the material is facilitated by thermogravimetric analysis and differential thermal analysis. The titled crystal is found to be stable up to 140 °C. The third-order nonlinear optical behavior is determined using the z-scan technique.

Low-temperature growth of nanostructures with large yield is a basic requirement for fulfilling the demand of large-scale applications of nanomaterials. The synthesis of nanoscale materials has gained considerable attention due to their excellent properties also in photocatalysis. Catalyst and Dopant free, solar active ZnO nanostructures photocatalysts with vacancy richness were synthesized in large quantities (in grams) through the co-precipitation growth process using ZnNi2·6H2O as the zinc source at room temperature. This method has advantages such as low temperature with high yield (>8 grams per liter) at atmospheric pressure synthesis. The experimental results confirm that synthesized ZnO samples were crystallized into a wurtzite hexagonal structure. Under direct sunlight energy examined degradation of organic dye methylene blue (MB) for photocatalytic activity using ZnO nanostructures. The photocatalytic performance depends on the different defects as well as the specific surface area. After photocatalytic degradation of MB dye in 60 min under natural sunlight irradiation colorless matrix was observed. The repeatability assessments for reusability of ZnO nanostructures after photocatalytic activity was also studied and reported for degradation of organic MB dye.

Leptospirosis is a worldwide zoonotic disease which remains under diagnosed in most of the regions of our country due to the lack of proper diagnostic facility and set up. Diagnosis usually depends on Microscopy,culture and serological tests like ELISA, MAT(Microscopic agglutination test ). MAT is the gold standard diagnostic test but it requires live leptospires and it can only be done in a reference laboratory. Hence, ELISA is the most preferred cost-effective serological method with both sensitivity and specificity of 95%. The Aim of our present study was to evaluate the trends of seroprevalence of leptospirosis from January 2016 to December 2019 and to compare two ELISA kits for the serodiagnosis of Leptospirosis. The study was conducted between January 2016 to December 2019 and 1611 blood samples were collected from clinically suspected cases of leptospirosis. Detection of IgM antibodies to leptospira was done by DRG andRecombilisa (CTK) ELISA kits. Results by both the kits were analysed. Seventy samples were taken as controls from different patients on random basis to prevent any type of biasing. Samples were tested for other co-infections and Demographic parameters were studied. Seroprevalence was estimated to be 4.8% by DRG KIT and 5.5% by Recombilisa CTK kit. Average seroprevalence was noted to be 5.1%. The diagnosis of presumptive and possible Leptospirosis was made in 96(78%) and 27(22%) respectively, by modified Faine’s criteria. The seroprevalence between 2016 to 2019 varied from 0.57 – 1.8 % . The months of July to November of year 2017 noted the highest prevalence. Out of these patients, majority (96%) showed significant improvement during the follow–up period after 2-3 months with empirical treatment. Typhoid was seen as most common co- infection in these patients.

Now days, nonlinear optical materials are subjected to extensive research owing to their versatility towards various photonic applications. In the present article, twin free l -Cystine hydrochloride single crystals were grown using conventional slow evaporation solution technique. The powder X-ray diffraction pattern confirmed that the titled compound belongs to monoclinic crystal system having space group C2. Using FWHM of each diffracting peak, the strain present within the lattice was calculated. Through High Resolution XRD, the crystal quality was scrutinized and found that the grown single crystal is free from any type of defects and grain boundaries. For examination of optical homogeneity of the crystal, birefringence studies were conducted which revealed that there is only one fringe in the interferogram suggesting a good optical homogeneity. Further, various thermal transport parameters were calculated using Photopyroelectric technique. Apart from that, its mechanical strength was assessed at nanoscale through Nano indentation technique. Piezoelectric and ferroelectric studies were also carried out on the titled compound.

More considerable attention to the synthesis of nanoscale materials due to their excellent applications in different fields. Sol-gel synthesis techniques have gained attention for synthesis of nanomaterials due to their simplest synthesis method, they do not require any costly equipment so as cost-effective and environment friendly. Here we successfully synthesized ZnO nanomaterials using Sol-gel techniques. Crystallite size of ZnO materials was 36.07 nm (ZnO:5NaOH) and 36.30 nm (ZnO:7NaOH) obtained by X-ray diffraction. Optical band gaps of synthesized ZnO nanomaterials were 3.30 eV (ZnO:5NaOH) and 3.31 eV (ZnO:7NaOH) found by UV-Vis spectroscopy. Synthesized ZnO nanomaterials have some interstitial defects and vacancies observed by Photoluminescence spectroscopy (PL). The study found synthesized ZnO nanomaterial have higher Photocatalytic activity.

The paper reports design and development of a PLC-based controller for pneumatic pressing machine, which performs the most critical operation in an engine bearing manufacturing plant. The paper firstly overviews the manufacturing process of engine bearing and then discusses the need of automating the pneumatic press. The proposed automation system involves (a) speed control by replacing the conventional method with a variable frequency drive (VFD), (b) feeder and pusher control using PLC, (c) fault detection and safety measures, (d) and PLC-based sequential control of all the processes carried out on pneumatic press. The control system is based on MicroLogix-1000 PLC from Allen Bradley and the ladder logic program for it has been written on RSlogix-500. For the evaluation of the proposed control system, the PLC program was emulated on RSLogix Emulate-500 and the operations of the pneumatic press were simulated on FluidSIM-P. The results of simulation validate the design of PLC-based controller in general and digital input-output connections of the PLC and PLC program in particular.

The fission yeast, Schizosaccharomyces pombe, is an excellent model for basic research but is not useful for commercial scale protein expression due to lack of strong expression vectors. Earlier, we showed that the lsd90 promoter elicited significantly greater GFP expression level than the adh1 and nmt1 promoters, albeit in different vector backbones. Here, we have systematically investigated the contribution of selectable markers, LEU2 and URA3m to GFP expression: while LEU2 elicited very low expression, the URA3m gene, with truncated promoter, elicited much greater GFP expression level with all promoters. Paradoxically, an inverse correlation was observed between the GFP transcription and translation efficiency. This system can be useful for understanding the factors governing recombinant gene expression and optimization of protein production.

Two polyurethane based triblock copolymers, namely, poly(N-isopropylacrylamide)-b-polyurethane-b-poly(N-isopropylacrylamide) (PIA-PU-PIA) and poly(tert-butylacrylate)-b-polyurethane-b-poly(tert-butylacrylate) (PtBA-PU-PtBA), were synthesized via atom transfer radical polymerization (ATRP) mechanism and characterized. The inhibition potentials of the polymers on mild steel corrosion in 0.5 M H2SO4 were studied using electrochemical, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The results obtained from potentiodynamic polarization studies showed that the two polymers are mixed-type inhibitors and exhibit passivating activities. The adsorption of PIA-PU-PIA on mild steel surface obeys the Langmuir adsorption isotherm, while that of PtBA-PU-PtBA obeys the El-Awady isotherm. The two polymers adsorb on the mild steel surface via competitive physisorption and chemisorption mechanisms. Both SEM and AFM analyses confirmed the formation of protective layers of the inhibitor mol...

In this paper, a comparative analysis is done between two bi-directional DC-DC converters i.e. transformerless and with transformer. Traditional batteries are unidirectional and large in size but bi-directional DC-DC converter (BDC) interconnected between battery and 400V DC bus provides wide voltage gain ratios and facilitates power flow in buck mode (charging) and boost mode (discharging). Energy storage is required in isolated microgrid in order to save power during OFF-load period and to deliver when excess loads are connected; therefore it is necessary that battery must be bi-directional. This bi-directional battery has applications in nanogrid or microgrid for energy storage, electric heavy vehicles, uninterrupted power supply, etc. The two BDCs are modeled, simulated, controlled and operated in different modes using MATLAB/SIMULINK. The results of comparison using various criteria are discussed in this work.

In this paper, an accurate missing data prediction method using Long Short-Term Memory (LSTM) based deep learning for health care is proposed. Physiological signal monitoring, especially with missing data, is a challenging task in health-care monitoring. The reliable and accurate acquisition of many physiological signals can help doctors to identify and detect potential health risks. In general, the missing data problem arises due to patient movement, faulty kits, incorrect observation or interference of the network. Subsequently, this problem leads to poorly diagnosed results. The ability of LSTM model to learn long-term dependencies enables it for efficient missing data prediction. In this paper, we proposed two LSTM model for 5-step and 10-step prediction. The dataset used is MIT-BIH normal person ECG data. The experimental results obtained using the LSTM method outperforms the Linear Regression and Gaussian Process Regression (GPR) method.

Human Activity Recognition has a wide range of applications such as remote patient monitoring, assisting disables and rehabilitation. This paper investigates the use of wearable bio-medical sensors to recognize human activities using supervised learning algorithms in cyber physical systems. We use five bio-medical sensors such as ECG, EMG, Respiration, Force sensitive resistor and a Tri-axial Accelerometer to collect the raw data. All the sensor data is collected in the real-world environment with three human subjects. The received raw data is preprocessed to extract the time domain features. The feature information is used for the training and testing the classifiers. Three classifiers k nearest neighbour (kNN), SVM using the linear kernel and SVM using Gaussian kernel are used for training and testing phases. The kNN classifier provides good accuracy of 99.86 %.

Purpose: Epstein-Barr virus (EBV) is a member of the family Gamma Herpes viridae and is usually implicated in malignancies like non-Hodgkin's lymphoma, Hodgkin's lymphoma and Burkitt's lymphoma. The present study was designed with the aim to estimate the seroprevalence of EBV in people with hematological malignancies and further follow up was planned by viral load quantitation by Real time PCR in positive cases. Methods: The current study was planned for a period of three years and a total of 272 serum samples were tested from patients with hematological malignancies namely; HL, NHL, ALL, CLL. Serological testing was performed for the presence of IgM and IgG antibodies against EBV viral capsid antigen. Sera of the patients found positive for IgM was further subjected to viral DNA extraction and Real Time Quantitative PCR was performed by a commercial kit. Results: The overall seropositivity rate was 89.2% for EBV IgG antibodies and 56.1% for IgM antibodies. The seroprevalence for anti-EBV VCA IgM was found to be highest in the age group

This paper presents real time simulation of hybrid microgrid consist AC microgrid along with DC microgrid and utility grid, where developed Hill Climbing algorithm for even power transfer between AC microgrid plus DC microgrid ensuring stable and reliable system operation under different loading conditions. Also generalized function generated to deal with the power flow from utility grid to AC microgrid and DC microgrid. Typhoon HIL control centre used for the accomplishment of hybrid micro grid. The proposed system is developed in the Schematic Editor. Hybrid microgrids are simulated using the real-time emulator HIL402 for real-time simulation within the SCADA environment.

Two-dimensional (2D) semiconductor nanostructures have gained tremendous interest in the field of environmental remediation and water purification. Nanostructures coated surfaces provide new insight for the development of cost-effective advanced photocatalyst. In this study, 2D-MoS2 nanosheets based coating has been developed through the combined effort of the exfoliation and a spin coating method. Microscopy analysis inferred the formation of nanosheets from the bulk structured MoS2 with the reduction in their average dimensions. Exfoliated MoS2 nanosheets formed in 18 h reaction time has average length ~1019 nm and width~544 nm. Cross-sectional SEM studies confirm the formation of MoS2-PVA thin films with different orientation of MoS2 nanosheets. UV–Vis absorption spectroscopy studies exhibit two peaks at 619 nm and 680 nm with improved optical absorption. The XRD and Raman spectroscopy analysis reveals the 2H-phase of MoS2 nanosheets. 2D-MoS2-PVA composite thin film was tested as an advanced photocatalyst coating for the breakdown of methylene blue (MB) and malachite green (MG) pollutant molecules under sunlight. 2D-MoS2-PVA composite thin film decomposed the 5 μM solution of MB and MG molecule solutions in 80 min and 40 min, respectively, under sunlight (800 W/cm2). The efficient photodegradation performance of the 2D-MoS2-PVA composite indicates their potential usage in other environmental applications.

Some imputation techniques are suggested for estimating the population mean when the data values are missing completely at random under a simple random sample without replacement scheme. Two classes of point estimators are proposed. The bias and mean squared error expressions of the proposed point estimators are derived up to first order of approximation. It has been shown that the proposed point estimators are more efficient than some existing point estimators due to Lee, Rancourt, and Sarndal (1994) and Singh and Horn (2000). Theoretical findings are supported by an empirical study based on five populations to show the superiority of the constructed estimators and methods of imputation over others.

Kraft pulping is the pulping process that is mostly used in paper mills. This is because the chemicals used in cooking are being recovered, and environmental pollution is minimized, as the chemicals are not discarded into the environment, but rather recycled. These chemicals are recovered by burning the black liquor that leaves the digester in a reactor called a recovery boiler. Feeding the black liquor directly from the digester to the recovery boiler will cause a water/smelt explosion. This explosion happens if the percentage of water in the liquor is high, the solid content of the black liquor leaving the digester is usually between 13-18%. To avoid such disaster the concentration of the black liquor has to be increased, which should in the range of 60-70%, this is done in a single or multiple effect evaporator. In this paper, a single effect evaporator control has been designed using a Proportional Integral Derivative (PID) controller. During the first design a simple PID controller with a feedback control was used. Then taking into consideration the load disturbance in the process, a feed forward control has then been introduced into the controller design. Subsequently the concept of boiling point rise (BPR) to measure concentration has then been used in the controller design of a single effect evaporator.

In this article, we have proposed a generalized class of estimators, exponential class of estimators based on adaption of Sharma and Singh (2015) and Solanki and Singh (2013) and simple difference estimator for estimating unknown population mean in case of Poisson distributed population in simple random sampling without replacement. The expressions for mean square errors of the proposed classes of estimators are derived to the first order of approximation. It is shown that the adapted version of Solanki and Singh (2013), exponential class of estimator, is always more efficient than usual estimator, ratio, product, exponential ratio and exponential product type estimators and equal efficient to simple difference estimator. Moreover, the adapted version of Sharma and Singh (2015) estimator are always more efficient than all the estimators available in literature. In addition, theoretical findings are supported by an empirical study to show the superiority of the constructed estimators over others with earthquake data of Turkey., Comment: 16 pages, 3 tables

ZnO being most avid semiconductor metal oxide with a wide band gap of 3.37 eV. ZnO nanostructures were synthesized in the shape of nano rods and flowers to finds their proficiency in the field of photocatalysis and photovoltaics. ZnO nanostructures were investigated in the shape of nano rods and flowers by, X Ray Diffractometer (XRD) confirms pure hexagonal wurtzite structure of ZnO, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) images showed high crystalline morphology and the formation of nano rods and flowers. Ultraviolet and Photoluminescence (PL) study confirms the absorption at 375, 371 nm for ZnO rods and flower which leads to an increase in the band gap and the peak observed at the violet, blue and green emission. The peaks shift is due to increase in defect in flower nanostructures of ZnO, Dynamic Light Scattering (DLS) calculated the average particles size 617 and 823 nm for rods and flower respectively. Conductivity analysis prove that nano flowers are more conductive having more defects and large number of photocatalytic active sites and large number of electron-hole pairs make best suited for photocatalytic specie. Thus, ZnO nano flowers were observed ideal for photocatalysis and photovoltaic applications due its large number of active sites and defects.

A novel color feature descriptor, Multichannel Distributed Local Pattern (MDLP) is proposed in this manuscript. The MDLP combines the salient features of both local binary and local mesh patterns in the neighborhood. The multi-distance information computed by the MDLP aids in robust extraction of the texture arrangement. Further, MDLP features are extracted for each color channel of an image. The retrieval performance of the MDLP is evaluated on the three benchmark datasets for CBIR, namely Corel-5000, Corel-10000 and MIT-Color Vistex respectively. The proposed technique attains substantial improvement as compared to other state-of- the-art feature descriptors in terms of various evaluation parameters such as ARP and ARR on the respective databases., Accepted in INDICON-2017

Singh and Kumar (A family of estimators of population variance using information on auxiliary attribute. Studies in sampling techniques and time series analysis, 2011) and Singh and Malik (Appl Math Comput 235:43–49, 2014) suggested some estimators for estimating the population variance using an auxiliary attribute. This paper suggests a generalized class of estimators based on the adaption of the estimator presented by Koyuncu (Appl Math Comput 218:10900–10905, 2012) for population variance using information on an auxiliary attribute in simple random sampling. The properties of the suggested class of estimators are derived and asymptotic optimum estimator identified with its properties. The large numbers of known estimators are member of the suggested generalized class and it has been shown that proposed generalized class of estimators are more efficient than usual unbiased estimator, ratio, exponential ratio and regression estimator, estimators due to Singh and Malik (Appl Math Comput 235:43–49, 2014) and Singh and Kumar (A family of estimators of population variance using information on auxiliary attribute. Studies in sampling techniques and time series analysis, 2011) using information on auxiliary attribute. In addition, theoretical results are supported by an empirical study and findings are encouraging and support the soundness of present study.

This paper represents the three phase Photovoltaic system connected with variable load in a standalone mode’s mathematical modeling using MATLAB/ Simulink environment. The sy stem consist of a PV Array, Boost converter, three phase inverter and its control to maintain load in standalone mode. The 40 kW systems at the college site is under the study with a variable inductive load of 30kW which has to be fed by PV system in continuous mode .This paper gives analysis of each components of system while maintaining the load. The constant and boosted DC v oltage is obtained with the help of boost converter from PV Array. The three phase IGBT inverter PWM control scheme is proposed here to normalize the voltage imbalance during vari able load.

We have constructed a pUC19-based multipurpose ATG vector in Schizosaccharomyces pombe with higher copy number and mitotic stability possible with commonly used vectors. The vector, having an NdeI site in its polylinker to provide ATG site for expression, carries a greatly truncated version of URA3 gene, URA3m, of Saccharomyces cerevisiae as a selection marker. In addition, it contains the mat2P-right flank region (mat2P-RF) of S. pombe as an autonomous replicating sequence (ARS) and a polylinker with wider choice of restriction sites. While URA3m confers an increase in plasmid copy number up to 200 copies/cell, mat2P-RF imparts greater mitotic stability than the standard ars1 element of S. pombe. Finally, the vector also includes the transcription termination signal of the nmt1 gene (Tnmt1). This basic vector should serve as a versatile tool for studies of gene function in S. pombe.

Novel telechelic tribromo terminated polyurethane (Br3-PU-Br3) was used as a macroinitiator in atom transfer radical polymerization (ATRP) of methyl methacrylate using CuBr as a catalyst and NN,N',N”,N”-pentamethyldiethylenetriamine (PMDETA) as a ligand. During the course of polymerization, poly(methyl methacrylate)-b-polyurethane-b-poly(methyl methacrylate) (PMMA-b-PU-b-PMMA) tri-block copolymers were formed. The resulting tri-block copolymers were characterized by gel permeation chromatography (GPC) and 1H nuclear magnetic resonance (NMR) spectroscopy. Molecular weight of the tri-block copolymers increases with increasing conversion. This result shows Br3-PU-Br3/CuBr/PMDETA initiating system polymerized methyl methacrylate through ATRP mechanism. NMR spectroscopy results revealed that apart from bromine atom transfer from Br3-PU-Br3 to PMDETA-CuBr complex, bromine atom transfer from the initially formed tri-block copolymer to PMDETA-CuBr complex also takes place, and, as a result, double bond terminated...

Atom transfer radical polymerization of 2-(dimethylamino) ethylmethacrylate and styrene was carried out using tertiary bromine-terminated telechelic polyurethane as a macroinitiator. The resulting ABA-type amphiphilic, poly (2-(dimethylamino) ethylmethacrylate)-b-polyurethane-b-poly (2-(dimethylamino) ethylmethacrylate) and hydrophobic, polystyrene-b-polyurethane-b-polystyrene tri-block copolymers were characterized by spectral, thermal, and chromatographic techniques. As the conversion increases, $$ {\overline M_{_{\text{n}}}} $$ also increases linearly. Theoretical M n values of the tri-block copolymers were comparable with the experimental $$ {\overline M_{_{\text{n}}}} $$ values. These results show that the polymerization of styrene and 2-(dimethylamino) ethylmethacrylate occurred through controlled radical polymerization mechanism. Mole percentage of polystyrene and poly (2-(dimethylamino) ethylmethacrylate) blocks in the tri-block copolymers was calculated using proton nuclear magnetic resonance spectroscopy, and the results were comparable with the gel permeation chromatography results. The glass transition temperatures of polystyrene and poly (2-(dimethylamino) ethylmethacrylate) blocks in the tri-block copolymers appeared at 72 °C and 110 °C, respectively. These results confirm the presence of two phases in the tri-block copolymers.

Atom transfer radical polymerization was successfully used to synthesize polystyrene-b-polyurethane-b-polystyrene tri-block copolymers (PSt-b-PU-b-PSt) using telechelic multifunctional polyurethane (Br3C-PU-CBr3) as a macroinitiator. Along with macroinitiator, CuBr and N,N,N′,N″,N″-pentamethyldiethyltetramine (PMDETA) were also used as catalyst and ligand, respectively to polymerize styrene. The linear increase of with conversion shows that Br3C-PU-CBr3/CuBr/PMDETA initiating system polymerizes styrene through controlled radical polymerization mechanism. Mole ratio of polyurethane and polystyrene present in PSt-b-PU-b-PSt tri-block copolymers was calculated using proton nuclear magnetic resonance spectroscopy and the results were found to be comparable with the gel permeation chromatography results. Differential scanning calorimetric results confirmed the presence of polyurethane and polystyrene phases in the tri-block copolymers.

Novel telechelic 2-methyl-2-bromopropionate terminated polyurethane macroinitiator was synthesized and used further to polymerize methyl methacrylate to yield poly(methyl methacrylate)-block-polyurethane-block-poly(methyl methacrylate) tri-block copolymers through atom transfer radical polymerization. Number-average molecular weight (Mn) was increased linearly with increasing polymerization time and conversion. Molecular weight distribution becomes narrower as the polymerization time increases and theoretical Mn values of the tri-block copolymers were comparable to the experimental Mn values. Structures of the macroinitiator and the tri-block copolymers were confirmed by 1H NMR, 13C NMR and FT-IR spectroscopic techniques. Mole percentage of poly(methyl methacrylate) in the triblock copolymers was calculated using 1H NMR spectroscopy and was found to be comparable with the gel permeation chromatography results. Presence of two phases in the tri-block copolymers has been confirmed through differential scanning calorimetric studies.

Reverse atom transfer radical polymerization was successfully used for the first time to synthesis tri-block copolymers. Poly (methyl methacrylate)-block-polyurethane-block-poly (methyl methacrylate) tri-block copolymers were synthesized using tetraphenylethane-based polyurethane as a macroiniferter, copper(II) halide as a catalyst and N, N, N', N", N"-pentamethyldiethylenetriamine as a ligand. Controlled nature of the polymerization was confirmed by the linear increase of number average molecular weight with increasing conversion. Mole contents of poly (methyl methacrylate) present in the tri-block copolymers were calculated using proton nuclear magnetic resonance spectroscopy and the results were comparable with the gel permeation chromatography results. Differential scanning calorimetric results confirmed the presence of two different types of blocks in the tri-block copolymers.

Poly(methyl methacrylate)-block-polyurethane-block-poly(methyl methacrylate) tri-block copolymers have been synthesized successfully through atom transfer radical polymerization of methyl methacrylate using telechelic bromo-terminated polyurethane/CuBr/N,N,N,N″,N″-pentamethyldiethylenetriamine initiating system. As the time increases, the number-average molecular weight increases linearly from 6400 to 37,000. This shows that the poly methyl methacrylate blocks were attached to polyurethane block. As the polymerization time increases, both conversion and molecular weight increased and the molecular weight increases linearly with increasing conversion. These results indicate that the formation of the tri-block copolymers was through atom transfer radical polymerization mechanism. Proton nuclear magnetic resonance spectral results of the triblock copolymers show that the molar ratio between polyurethane and poly (methyl methacrylate) blocks is in the range of 1 : 16.3 to 1 : 449.4. Differential scanning calorimetry results show Tg of the soft segment at −35°C and Tg of the hard segment at 75°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Background: Radical polymerization is used widely to polymerize more than 70% of vinyl monomers in industry, but the control over molecular weight and end group of the resulting polymers is always a challenging task with this method. To prepare polymers with desired molecular weight and end groups, many controlled radical polymerization (CRP) ideas have been proposed over the last decade. Atom transfer radical polymerization (ATRP) is one of the successful CRP techniques. Using ATRP, there is no report on the synthesis of polystyrene-block-polyurethane-block-polystyrene (PSt-b-PU-b-PSt) tri-block copolymers. Hence this paper describes the method of synthesizing these tri-block copolymers. To accomplish this, first telechelic bromo-terminated polyurethane was synthesized and used further to synthesize PSt-b-PU-b-PSt tri-block copolymers using CuBr as a catalyst and N,N,N,N″,N″-pentamethyldiethylenetriamine as a complexing agent. Results: The ‘living’ nature of the initiating system was confirmed by linear increase of number-average molecular weight and conversion with time. A semi-logarithmic kinetics plot shows that the concentration of propagating radical is steady. The results from nuclear magnetic resonance spectroscopy, gel permeation chromatography and differential scanning calorimetry show that the novel PSt-b-PU-b-PSt tri-block copolymers were formed through the ATRP mechanism. Conclusion: For the first time, PSt-b-PU-b-PSt tri-block copolymers were synthesized through ATRP. The advantage of this method is that the controlled incorporation of polystyrene block in polyurethane can be achieved by simply changing the polymerization time. Copyright © 2007 Society of Chemical Industry

A purified alkaline thermo-tolerant lipase from Pseudomonas aeruginosa MTCC-4713 was immobilized on a series of five noble weakly hydrophilic poly(AAc-co-HPMA-cl MBAm) hydrogels. The hydrogel synthesized by copolymerizing acrylic acid and 2-hydroxy propyl methacrylate in a ratio of 5 : 1 (HG5:1 matrix) showed maximum binding efficiency for lipase (95.3%, specific activity 1.96 IU mg−1 of protein). The HG5:1 immobilized lipase was evaluated for its hydrolytic potential towards p-NPP by studying the effect of various physical parameters and salt-ions. The immobilized lipase was highly stable and retained ∼92% of its original hydrolytic activity after fifth cycle of reuse for hydrolysis of p-nitrophenyl palmitate at pH 7.5 and temperature 55°C. However, when the effect of pH and temperature was studied on free and bound lipase, the HG5:1 immobilized lipase exhibited a shift in optima for pH and temperature from pH 7.5 and 55°C to 8.5 and 65°C in free and immobilized lipase, respectively. At 1 mM concentration, Fe3+, Hg2+, NH4+, and Al3+ ions promoted and Co2+ ions inhibited the hydrolytic activities of free as well as immobilized lipase. However, exposure of either free or immobilized lipase to any of these ions at 5 mM concentration strongly increased the hydrolysis of p-NPP (by ∼3–4 times) in comparison to the biocatalysts not exposed to any of the salt ions. The study concluded that HG5:1 matrix efficiently immobilized lipase of P. aeruginosa MTCC-4713, improved the stability of the immobilized biocatalyst towards a higher pH and temperature than the free enzyme and interacted with Fe3+, Hg2+, NH4+, and Al3+ ions to promote rapid hydrolysis of the substrate (p-NPP). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4252–4259, 2006

Four series of noble networks were synthesized with acrylic acid (AAc) copolymerized with varying amount of 2-hydroxy propyl methacrylate or dodecyl methacrylate (AAc/HPMA or AAc/DMA; 5:1 to 5:5, w/w) in the presence of ethylene glycol dimethacrylate (EGDMA; 1, 5, 10, 15, and 20%, w/w) as a crosslinker and ammonium per sulfate (APS) as an initiator. Each of the networks was used to immobilize a purified lipase from Pseudomonasaeruginosa MTCC-4713. The lipase was purified by successive salting out with (NH4)2SO4, dialysis, and DEAE anion exchange chromatography. Two of the matrices, E15a, i.e. [poly (AAc5-co-DMA1-cl-EGDMA15)] and I15c, i.e. [poly (AAc5-co-HPMA3-cl-EGDMA15)], that showed relatively higher binding efficiency for lipase were selected for further studies. I15c-hydrogel retained 58.3% of its initial activity after 10th cycle of repetitive hydrolysis of p-NPP, and I15c was thus catalytically more stable and efficient than the other matrix. The I15c-hydrogel-immobilized enzyme showed maximum activity at 65°C and pH 9.5. The hydrolytic activity of free and I15c-hydrogel-immobilized enzyme increased profoundly in the presence of 5 mM chloride salts of Hg2+, NH4+, Al3+, K+, and Fe3+. The immobilized lipase was preferentially active on medium chain length p-nitrophenyl acyl ester (C:8, p-nitrophenyl caprylate). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4636–4644, 2006

A purified alkaline thermo-tolerant bacterial lipase from Pseudomonas aeruginosa BTS-2 was immobilized on a poly (AAc-co-HPMA-cl-MBAm) hydrogel network. The hydrogel showed approximately 95% binding efficiency for lipase (specific activity 1.96 U mg−1). The immobilized enzyme achieved 65.1% conversion of ethanol and propionic acid (100 mM each) into ethyl propionate in n-nonane at 65 °C in 9 h. When alkane of C-chain length lower than n-nonane was used as the organic solvent, the conversion of ethanol and propionic acid into ethyl propionate decreased with a decrease in the log P value of alkanes. The immobilized lipase retained approximately 30% of its original catalytic activity after five cycles of reuse for esterification of ethanol and propionic acid into ethyl propionate at temperature 65 °C in 3 h. Addition of a molecular sieve (3 A) to the reaction mixture enhanced the formation of ethyl propionate to 89.3%. Moreover, ethanol and propionic acid when taken a molar ratio of 3:1 further promoted the conversion rate to 94%. However, an increase in the molar ratio of propionic acid with respect to ethanol resulted in a decline of ethyl propionate synthesis.

This paper proposes a family of exponential estimators for estimating the population mean Y of study variable y using an auxiliary variable x in circular systematic sampling design under single and two phase sampling. The expression of the bias and mean square error of proposed class of estimators are derived in general form. It has been shown that the proposed class of estimators are more efficient than ratio, product, regression and other estimators considered here in circular systematic sampling under single and two phase sampling. An empirical study is carried out in support of theoretical study. Keywords: Circular systematic sampling; Efficiency; Ratio estimator; Regression estimator; Two-phase sampling 1. Introduction In sample surveys, the utilization of auxiliary information is frequently acknowledged to higher the accuracy of the estimation of population characteristics under study. The auxiliary data might either be promptly accessible or may be made accessible without much trouble by occupy a part of the survey resources or available from previous experience, census or administrative databases. It is well known that when the auxiliary information is to be used at the estimation stage, the ratio, product and regression methods are widely employed. Many authors including Singh et al. (2007), Shabbir and Gupta (2007), Singh and Kumar (2011), and Sharma and Singh (2013, 2014) suggested estimators using auxiliary variable. The usual systematic sampling design is quite simple and most commonly used in sample survey. Systematic sampling has an advantage of selecting the whole sample with just one random start. In

In this paper we have considered the problem of estimating the population mean in systematic sampling using information on an auxiliary variable in presence of non response. Some modified ratio, product and difference type estimators in systematic sampling have been suggested and their properties are studied. The expressions of mean squared errors (MSEs) up to the first order of approximation are derived. An empirical study is carried out to judge the best estimator out of the suggested estimators., Comment: 13 pages, 1 table. arXiv admin note: text overlap with arXiv:1306.6157

Because of a large number of molecular similarities with higher eukaryotes, the fission yeast Schizosaccharomyces pombe has been considered a potentially ideal host for expressing human proteins having therapeutic and pharmaceutical applications. However, efforts in this direction are hampered by lack of a strong promoter. Here, we report the isolation and characterization of a strong, constitutive promoter from S. pombe. A new expression vector was constructed by cloning the putative promoter region of the lsd90 gene (earlier reported to be strongly induced by heat stress) into a previously reported high copy number vector pJH5, which contained an ARS element corresponding to the mat2P flanking region and a truncated URA3m selectable marker. The resulting vector was used to study and compare the level of expression of the luciferase reporter with that achieved with the known vectors containing regulatable promoter nmt1 and the strong constitutive promoter adh1 in S. pombe and the methanol-inducible AOX1 promoter in Pichia pastoris. Following growth in standard media the new vector containing the putative lsd90 promoter provided constitutive expression of luciferase, at a level, which was 19-, 39- and 10-fold higher than that achieved with nmt1, adh1 and AOX1 promoters, respectively. These results indicate a great potential of the new lsd90 promoter-based vector for commercial scale expression of therapeutic proteins in S. pombe.

A purified alkaline thermo-tolerant bacterial lipase from Pseudomonas aeruginosa MTCC-4713 was immobilized on a poly (AAc-co-HPMA-cl-MBAm) hydrogel. The hydrogel-bound lipase achieved 93.6% esterification of ethanol and propionic acid (300 mM: 100 mM) into ethyl propionate at temperature 65 degrees C in 3 h in the presence of a molecular sieve (3 angstroms). In contrast, hydrogel-immobilized lipase pre-exposed to 5 mM of HgCl2 orNH4Cl resulted in approximately 97% conversion of reactants in 3 h into ethyl propionate under identical conditions. The salt-exposed hydrogel was relatively more efficient in repetitive esterification than the hydrogel-bound lipase not exposed to any of the cations. Moreover, bound lipase exposed Hg2+ or NH4+ ions showed altered specificity towards p-nitrophenyl esters and was more hydrolytic towards higher C-chain p-nitrophenyl esters (p-nitrophenyl laurate and p-nitrophenyl palmitate with C 12 and C 16 chain) than the immobilized lipase not exposed to any of the salts. The later showed greater specificity towards p-nitrophenyl caprylate (C 8).