Synthesis and characterization of poly(2-aminothiophenol-co-2-methylaniline)/silver nanoparticles as antisulfate-reducing bacteria

Poly(2-aminothiophenol) (P2ATH), poly(2-methylaniline) (P2MeANI), and poly(2ATH-co-2MeANI) are synthesized using ammonium persulfate as an oxidant in aqueous hydrochloric acid (HCl) medium at room temperature. The obtained polymeric samples are assembling on silver nanoparticles. The structures of prepared polymeric samples are characterized by ultraviolet–visible, infrared, proton nucleus magnetic resonance (¹H NMR), X-ray diffraction, electron microscope, transmittance electron microscope, and thermogravimetric analysis. The antibacterial efficiency of the prepared polymeric and polymer/Ag nanoparticle samples is studied for the removal of sulfate-reducing bacteria. The results reveal that the assembling of both P2ATH and P2MeANI on Ag nanoparticles enhances the antisulfate-reducing bacteria’s efficiencies, but in a case of P2ATH-co-2MeANI the efficiency is more than its Ag nanoparticles.     

An Efficient Estimator of the Mean in a Two-Stage Nested Model

To estimate the mean in a two-stage nested model one would usually use a weighted average of the group sample means with the weights summing to one. Among all those with nonrandom weights we find the estimator that maximizes the minimum possible efficiency. It is found to perform very well in comparison with other estimators that have been proposed.     

Phase shifts in frustrated total internal reflection and optical tunneling by an embedded low-index thin film

Simple and explicit expressions for the phase shifts that p- and s-polarized light experience in frustrated total internal reflection (FTIR) and optical tunneling by an embedded low-index thin film are obtained. The differential phase shifts in reflection and transmission deltar, deltat are found to be identical, and the associated ellipsometric parameters psir, psit are governed by a simple relation, independent of film thickness. When the Fresnel interface reflection phase shifts for the p and s polarizations or their average are quarter-wave, the corresponding overall reflection phase shifts introduced by the embedded layer are also quarter-wave for all values of film thickness. In the limit of zero film thickness (i.e., for an ultrathin embedded layer), the reflection phase shifts are also quarter-wave independent of polarization (p or s) or angle of incidence (except at grazing incidence). Finally, variable-angle FTIR ellipsometry is shown to be a sensitive technique for measuring the thickness of thin uniform air gaps between transparent bulk media.     

Performance optimization and light-beam-deviation analysis of the parallel-slab division-of-amplitude photopolarimeter

A division-of-amplitude photopolarimeter that uses a parallel-slab multiple-reflection beam splitter was described recently [Opt. Lett. 21, 1709 (1996)]. We provide a general analysis and an optimization of a specific design that uses a fused-silica slab that is uniformly coated with a transparent thin film of ZnS on the front surface and with an opaque Ag or Au reflecting layer on the back. Multiple internal reflections within the slab give rise to a set of parallel, equispaced, reflected beams numbered 0, 1, 2, and 3 that are intercepted by photodetectors D(0), D(1), D(2), and D(3), respectively, to produce output electrical signals i(0), i(1), i(2), and i(3), respectively. The instrument matrix A, which relates the output-signal vector I to the input Stokes vector S by I = AS, and its determinant D are analyzed. The instrument matrix A is nonsingular; hence all four Stokes parameters can be measured simultaneously over a broad spectral range (UV-VIS-IR). The optimum film thickness, the optimum angle of incidence, and the effect of light-beam deviation on the measured input Stokes parameters are considered.     

Early stage white etching crack identification using artificial neural networks

White Etching Cracks (WEC) in gearbox bearings is a major concern in the wind turbine industry, which can lead to a premature failure of the gearbox. Though many hypotheses regarding the generation of WEC have been proposed over the decades, the answer is still disputable. To trace back the failures to earlier stages before they occur, an innovative sensor-set has been utilized on a test rig to monitor the influencing factors that lead to WEC. This paperwork seeks to recognize abnormal patterns from recorded sensor data and derive statements of sensible sensor combinations in WEC early detection. A Long Short Term Memory (LSTM) network-based autoencoder is proposed for the anomaly detection (AD) task. Employing an auto-associative sequence-to-sequence predictor, a model is trained to reconstruct the normal time series data without WEC. The reconstruction error of testing time series data is evaluated for the determination of its anomaly. The results show that the specified LSTM autoencoder framework can qualitatively distinguish anomalies from collected multivariate time series data. Moreover, the anomaly score evaluated via reconstruction-error-based metrics can discriminate normal and abnormal behaviors in the study. This investigation’s results entail a significant step towards early WEC risk detection and more cost-efficient wind turbine technology if this approach can be further applied on stream data with plausible thresholds in monitoring system.

     

The OTIS hyper hexa-cell optoelectronic architecture

Optical transpose interconnection system (OTIS) is an optoelectronic architecture that promises to be a great choice for future-generation parallel systems. OTIS combines the advantages of electronic and optical links, where electronic links are used for short distances which require low material cost, and optical links are used for long distances which provide high speed network with low power consumption. Taking into account the advantageous characteristics of OTIS and based on the attractive properties of hyper hexa-cell (HHC) interconnection topology from low diameter and good minimum node degree, this paper introduces a new optoelectronic architecture referred to as OTIS hyper hexa-cell (OHHC). This paper also provides an evaluation and a comparison of the new topology with OTIS-mesh in terms of the following topological properties: size, diameter, maximum and minimum node degree, bisection width, total cost and optical cost. The results of this study proved the excellence of the proposed OHHC over OTIS-mesh in terms of diameter, minimum node degree, bisection width, and optical cost.     

Rapid and simple chromatographic method for the determination of diazepam and its major metabolites in human plasma and urine

A simple, rapid, sensitive and selective HPLC method has been developed for the analysis of diazepam (DZP) and its major metabolites, N-desmethyldiazepam (DMDZP), temazepam (TZP) and oxazepam (OZP), in plasma and urine, using clonazepam (CZP) as the internal standard and chloroform as the extracting solvent, with a 10 ng/ml limit of quantitation for the four assayed drugs, and an average (+/-S.D.) recovery of 87.7+/-6.46%, 92.9+/-5.31%, 91.4+/-4.01% and 91.7+/-2.68% for DZP, DMDZP, TZP and OZP, respectively (from plasma), and 89.6+/-2.26%, 90+/-4.24%, 87.45+/-0.64% and 94.50+/-0.71% for DZP, DMDZP, TZP and OZP, respectively (from urine). The method has also proved to be selective and reproducible.     

Differentiation of rice tungro bacilliform virus strains by restriction analysis and DNA hybridization

The present study evaluates the postnatal efficacy of Momordica charantia peel, pulp, seed and whole fruit extract via assessing the modulation in the biotransformation system enzymes of suckling neonates and lactating mice. The peel, seed or whole fruit extract of Momordica (100 microl/animal/day) independently induced a significant increase in the hepatic levels of glutathione S-transferase (GST) and acid soluble sulfhydryl (-SH) after 14 or 21 days treatment in lactating dams (P < 0.01) and translactationally exposed neonates (P < 0.05). However, the elevation (P < 0.05) in hepatic cytochrome b5 (Cyt. b5) and cytochrome P-450 (Cyt. P-450) levels was observed only in the lactating dams treated with the respective extracts of peel, seed or whole fruit of Momordica. In lactating dams and suckling neonates the modulated levels of biotransformation system enzymes suggest the potential for the translactational passage of active principle(s) and/or metabolites of Momordica.     

Single-layer-coated beam splitters for the division-of-amplitude photopolarimeter

A design procedure is presented for a near-optimal, single-layer-coated prism beam splitter that serves as the key optical element of the division-of-amplitude photopolarimeter (DOAP). For given film and substrate refractive indices, the angle of incidence and film thickness are selected such that the ellipsometric differential phase shifts in reflection and transmission deltar, and deltat, differ by +/- pi/2, and the normalized determinant of the instrument matrix is maximized. The best results are obtained by using high-index films on low-index substrates. This is illustrated by examples of ZnS and GaP films on silica prisms in the visible and Si, Ge, and PbTe films on Irtran 1 substrates in the infrared. A 16 degrees Si-prism DOAP beam splitter at the 1.55-microm lightwave-communications wavelength is also presented. It uses a 163-nm SiO2 coating on the entrance face to satisfy the optimum delta condition at 73 degrees incidence, and the determinant of the instrument matrix is 78.23% of its theoretical maximum. The exit face of the Si prism is antireflection coated with a 208-nm Si3N4 film.