Directional couplers in trapped image guide configuration

Dispersion characteristics and wave impedance of trapped coupled image guides are computed by using mode matching techniques. Dispersion curves for trapped coupled image guide are plotted for various dielectric materials and dimensional parameters. The hybrid directional couplers in the above configuration have been theoretically designed by computing the normalization propagation constant.     

Production of the enzyme dihydrofolate reductase by methotrexate-resistant bacteria isolated from soil

Six bacterial cultures isolated from soil were capable of growing in the presence of methotrexate (MTX). Two strains, PFR-1 and 3, developed resistance to 500 μg cm^?3 MTX in the medium and produced elevated levels of the enzyme dihydrofolate reductase (EC 1.5.1.3): 2580 and 2702 U dm^?3 compared to the sensitive parent strains (28 and 35 U dm^?3). Isolate PFR-3 showed maximum enzyme production (4950 U dm^?3, specific activity 12.56 U mg^?1 in flasks and 5737 U dm^?3, specific activity 14.80 U mg^?1 in 5-dm³ fermenter) during exponential phase of growth (6 h) at 37°C and pH 7.0.     

Buprenorphine in opiate withdrawal: a comparison with clonidine

Clinical efficacy of buprenorphine in controlling withdrawal symptoms was compared against clonidine among 44 opiate dependent males. Subjective and objective withdrawal symptoms were assessed by withdrawal rating scales daily for 10 days. The subjects were randomly assigned to fixed dose schedule of either buprenorphine (0.6-1.2 mg per day, sublingually) or clonidine (0.3-0.9 mg per day, oral) for 10 days. Buprenorphine was found superior to clonidine in alleviating most of the subjective and objective opiate withdrawal symptoms. Subjective symptoms declined earlier among the subjects receiving buprenorphine. No untoward side-effects of buprenorphine were noticed.     

Process Intensification of Biodiesel Production Using a Tubular Micro-Reactor (TMR): Experimental and Numerical Assessment

The aim of this paper is to present an alternative to conventional biodiesel production by taking advantage of the flow patterns formed in micro-reactors. Biodiesel production was carried out 15 times faster in a tubular micro-reactor (TMR) than a well-mixed batch reactor (BR), achieving conversions up to ～99% with 4?min of residence time. The experimental results were analyzed using dimensionless numbers and computational fluid dynamics (CFD) simulations. The CFD results showed that under the conditions used in the present study, the slug flow pattern can be expected, and this could explain the high conversion (>90%) reached in the TMR without using high methanol-oil molar ratios. The internal movement (auto-mixing) in the slug enhanced the mass transfer. Moreover, CFD simulations showed that at low conversion (<25%), the internal velocity of the oil slug will be the key factor related to the reactor performance.     

Production of 3R-hydroxy-polyenoic fatty acids by the yeast Dipodascopsis uninucleata

Various fatty acids were fed to the yeast Dipodascopsis uninucleata UOFS Y 128, and the extracted samples were analyzed for the accumulation of 3-hydroxy metabolites with the help of electron impact gas chromatography-mass spectrometry. Fatty acids containing a 5Z,8Z-diene system (5Z,8Z,11Z-eicosatrienoic, 5Z,8Z,11Z,14Z-eicosatetraenoic, and 5Z,8Z,11Z,14Z,17Z-eicosapentaenoic acids) yielded the corresponding 3-hydroxy-all-Z-eicosapolyenoic acids. Moreover, linoleic acid (9Z,12Z-octadecadienoic acid) and 11Z,14Z,17Z-eicosatrienoic acid were converted to the 3-hydroxylated metabolites of shorter chain length, e.g., 3-hydroxy-5Z,8Z-tetradecadienoic acid and 3-hydroxy-5Z,8Z,11Z-tetradecatrienoic acid, respectively. In contrast, no accumulation of a 3-hydroxy metabolite was observed with oleic acid (9Z-octadecenoic acid), linolelaidic acid (9E,12E-octadecadienoic acid), γ-linolenic acid (6Z,9Z,12Z-octadecatrienoic acid), and eicosanoic acid as substrate. These findings pinpoint that the 3-hydroxylation of a fatty acid in Dipodascopsis uninucleata requires a 5Z,8Z-diene system either directly or following initial incomplete β-oxidation. Following analysis of the enantiomer composition, the arachidonic acid metabolite was identified as 3R-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid, which rules out a normal β-oxidation as biosynthetic route to this new class of oxylipins.     

Liquid phase residence time distribution for two phase flow in coiled tubes

The residence time distribution (RTD) of the liquid phase in air-water flow through helical coils has been studied. Upward and downward cocurrent flows have been investigated in three coils with curvature ratios ranging from 11 to 60.7. The ranges of the Reynolds numbers for the gas and the liquid varied from 1500 to 3000 and 620 to 3200, respectively. A model has been proposed that describes the liquid phase RTD as combination of two different residence time distributions applicable for turbulent and laminar liquid flows.     

RTD for diffusion-free laminar flow of non-newtonian fluids through coiled tubes

The residence time distribution (RTD) for diffusion-free laminar helical flow of non-Newtonian fluids has been numerically computed for values of the power-law index from 0.2 to 2.0. Experimental verification is also provided. Excellent agreement is also shown with independently calculated RTD's appearing in the literature.     

Single-sensor hand-vein multimodal biometric recognition using multiscale deep pyramidal approach

Biometrics has emerged as a powerful technology for person authentication in various scenarios including forensic and civilian applications. Deployment of biometric solutions that use cues from multiple modalities enhances the reliability and robustness of authentication necessary to meet the increasingly stringent security requirements. However, there are two drawbacks typically associated with multimodal biometrics. Firstly, the image acquisition process in such systems is not very user-friendly, primarily due to the time and effort required to capture biometric samples belonging to multiple modalities. Secondly, the overall cost is higher as they employ multiple biometric sensors. To overcome these drawbacks, we employ a single NIR sensor-based image acquisition in the proposed approach for hand-vein recognition. From the input hand image, a palm-vein and four finger-vein subimages are extracted. These images are then enhanced by CLAHE and transformed into illumination invariant representation using center-symmetric local binary pattern (CS-LBP). Further, a hierarchical non-rigid matching technique inspired by the architecture of deep convolutional networks is employed for matching the CS-LBP features. Finally, weighted sum rule-based matching score-level fusion is performed to combine the palm-vein and the four finger-vein modalities. A set of rigorous experiments has been performed on an in-house database collected from the left and right hands of 185 subjects and the publicly available CASIA dataset. The proposed approach achieves equal error rates of 0.13% and 1.21%, and rank-1 identification rates of 100% and 100% on the in-house and CASIA datasets, respectively. Additionally, we compare the proposed approach with the state-of-the-art techniques proposed for vascular biometric recognition in the literature. The important findings are (1) the proposed approach outperforms all the existing techniques considered in this study, (2) the fusion of palm-vein and finger-vein modalities consistently leads to better performance for all the feature extraction techniques considered in this work. (3) Furthermore, our experimental results also suggest that considering the constituent palm-vein and finger-vein images instead of the entire hand-vein images achieves better performance.