58 research outputs found

    Initial Study of Nickel Electrolyte for EnFACE Process

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    Nickel electrolyte for a micro-pattern transfer process without photolithography, EnFACE, has been developed. Previous work on copper deposition indicated that a conductivity of ~2.7 Sm-1 is required. Electrochemical parameters of electrolyte i.e. current density and overpotential are also crucial to govern a successful pattern replication. Therefore, the investigation focused on the measurement of physicochemical properties and electrochemical behaviour of the electrolyte at different nickel concentrations and complexing agents of chloride and sulfamate. Nickel electrolytes containing sulfamate, chloride and combined sulfamate-chloride with concentrations between 0.14 M and 0.3 M were investigated. Physicochemical properties i.e. pH and conductivity were measured to ensure if they were in the desired value. The electrochemical behaviour of the electrolytes was measured by polarisation experiments in a standard three-electrode cell. The working electrode was a copper disc (surface area of 0.196 cm2) and the counter electrode was platinum mesh. The potential was measured againts a saturated calomel reference electrode (SCE). The experiments were carried out at various scan rate and Rotating Disc Electrode (RDE) rotation speed to see the effect of scan rate and agitation. Based on the measured physicochemical properties, the electrolyte of 0.19 M nickel sulfamate was chosen for experimentation. Polarisation curve of agitated solution suggested that overall nickel electrodeposition reaction is controlled by a combination of kinetics and mass transfer. Reduction potential of nickel was in the range of -0.7 to -1.0 V. The corresponding current densities for nickel deposition were in the range of -0.1 to -1.5 mA cm-2

    SHELF-LIFE ASSESSMENT OF EUPHORBIA ANTIQUORUM LINN., EUPHORBIA CADUCIFOLIA HAINES, EUPHORBIA NIVULIA BUCH. HAM AND EUPHORBIA TIRUCALLI LINN. LATEX

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    Objective: In the present study, an attempt was made to assess the shelf life of the Snuhi latex which is frequently used in fresh condition for the preparation of Ksharasutra, a medicated thread, used in Ayurveda. Methods: The latex of E. antiquorum, E. caducifolia, E. nivulia and E. tirucalli were collected individually and stored in air tight glass vials during the month of May, 2018. Physical attributes like Colour, odour, appearances, pH and microbial load of all four samples were assessed as per standard protocol. Assessment was made every day, 9 AM, for 7 d in room temperature and for 10 d in refrigerated samples. Results: Result shows that, pH range (start-end day) was 4.25-5.18, 4.79-5.12, 4.48-4.76 and 4.40-5.42 in case of E. antiquorum, E. caducifolia, E. nivulia and E. tirucalli at room temperature. It was found that, Aspergillus niger was found in Euphorbia antiquorum, Euphorbia caducifolia whereas Candida albicans was found in Euphorbia tirucalli latex in fungal culture on the 7th day after collection, when the samples were stored at room temperature. All the samples were free from microbial growth up to 10thday when stored at 4-5 °C in a refrigerator. Conclusion: Temperature, and moisture affects the quality of fresh snuhi latex. The latex remains free from microbial growth up to six days in room temperature and up to 10 d under at refrigerated temperature (4-5 °C)

    Origin of Ferroelectricity in Orthorhombic LuFeO3_3

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    We demonstrate that small but finite ferroelectric polarization (\sim0.01 μ\muC/cm2^2) emerges in orthorhombic LuFeO3_3 (PnmaPnma) at TNT_N (\sim600 K) because of commensurate (k = 0) and collinear magnetic structure. The synchrotron x-ray and neutron diffraction data suggest that the polarization could originate from enhanced bond covalency together with subtle contribution from lattice. The theoretical calculations indicate enhancement of bond covalency as well as the possibility of structural transition to the polar Pna21Pna2_1 phase below TNT_N. The Pna21Pna2_1 phase, in fact, is found to be energetically favorable below TNT_N in orthorhombic LuFeO3_3 (albeitalbeit with very small energy difference) than in isostructural and nonferroelectric LaFeO3_3 or NdFeO3_3. Application of electric field induces finite piezostriction in LuFeO3_3 via electrostriction resulting in clear domain contrast images in piezoresponse force microscopy.Comment: 12 pages, 8 figure

    Large magnetoelectric coupling in nanoscale BiFeO3_3 from direct electrical measurements

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    We report the results of direct measurement of remanent hysteresis loops on nanochains of BiFeO3_3 at room temperature under zero and \sim20 kOe magnetic field. We noticed a suppression of remanent polarization by nearly \sim40\% under the magnetic field. The powder neutron diffraction data reveal significant ion displacements under a magnetic field which seems to be the origin of the suppression of polarization. The isolated nanoparticles, comprising the chains, exhibit evolution of ferroelectric domains under dc electric field and complete 180o^o switching in switching-spectroscopy piezoresponse force microscopy. They also exhibit stronger ferromagnetism with nearly an order of magnitude higher saturation magnetization than that of the bulk sample. These results show that the nanoscale BiFeO3_3 exhibits coexistence of ferroelectric and ferromagnetic order and a strong magnetoelectric multiferroic coupling at room temperature comparable to what some of the type-II multiferroics show at a very low temperature.Comment: 7 pages with 5 figures, published in Phys. Rev.

    References for Shopping Online Versus in Stores What Do Customers Prefer and How Do Offline Retailers Cope with It?

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    The purpose of this study is to cover the importance of online shopping in todays competitive markets. How offline retailers will be able to survive. And how to sustain a good relationship between customers in providing them with the finest products or services, attractive and transparent prices, deals. In a world where online retailing and modern in-store Shopping coexist and support each other through various shopping behaviors, very little is accepted regarding the possibility of an evolving reality where shopping online or offline blends into a common trend. However, the shoppers have turned upside down due to the emergence of the Internet. Moreover, a new trend has emerged in the past years, �Online shopping.� The following offers a huge abundance of possibilities for buying products, news, book tickets, clothes, furniture, toys. Lebanese people are being used to this trend; however, they still visit stores to purchase, especially grocery stores and pharmacies. This study will also be directed to figure out its effect on retail shops that operate offline. In this study, a quantitative method will be adopted. Moreover, the research will develop analysis and understanding of the theoretical framework and models related to online Shopping and in-store Shopping, and the effect of online Shopping on offline retail shops. Adding customer satisfaction through service quality provided, whether online or in-store, maintains customer loyalty and satisfaction, which will help stores survive in the markets and sustain competitive advantage

    Chameleon field and the late time acceleration of the universe

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    In the present work, it is shown that a chameleon scalar field having a nonminimal coupling with dark matter can give rise to a smooth transition from a decelerated to an accelerated phase of expansion for the universe. It is surprising to note that the coupling with the chameleon scalar field hardly affects the evolution of the dark matter sector, which still redshifts as a3a^{-3}.Comment: 7 pages, 2 figure

    Purification and Characterization of a Sperm Motility Inhibiting Factor from Caprine Epididymal Plasma

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    Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II) has been purified from caprine epididymal plasma (EP) by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 µg/ml (12.5 nM) level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
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