Effect of Maintenance on the Dependability and Performance of Mulitprocessor Systems

This paper presents analytic models for dependability and performance evaluation of multiprocessor systems with both on-line and off-line maintenance. Markov models are developed to compute the system reliability and performance availability incorporating the reliability of the maintenance processor. The maintenance processor failure is considered separately in order to emphasize its effect on system performance and dependability. The reliability of the maintenance processor can not be ignored for degradable multiprocessors. Probabilistic models are presented to compute the system downtime and the service cost for three off-line maintenance policies: scheduled maintenance (SM), unscheduled maintenance (UM), and scheduled & unscheduled maintenance (SUM). The SUM policy, that combines both SM and UM, can be used to give a compromise between cost and downtime.     

Instrumental testing of tea by combining the responses of electronic nose and tongue

In the tea industry, experienced tea tasters are employed for evaluation of tea quality and gradation of tea is done on the basis of their scores. This subjective method of assessment has numerous problems like inaccuracy and non-repeatability. Electronic nose and electronic tongue systems are recently being used for measurement of odor and taste of tea samples. As the senses of smell and taste are not independent, and both are interacting, the measured data from the individual systems are combined in this paper for improved estimation of black tea quality. It is found that for the combined system, both the clustering and classification rates improve when compared to the individual systems. With radial basis function neural network, the classification rate increases up to 93%, whereas with the independent systems, the classification rate obtained is 83–84% with electronic nose and 85–86% with electronic tongue.     

Purification of Lycopene by Reverse Phase Chromatography

This work investigates the potential of various hydrophobic matrices for the separation and purification of lycopene from microbial biomass obtained from fermentation using Blakeslea trispora. The lycopene purification method was developed in two steps. In the first step, carotenoids were extracted from the biomass of B. trispora with petroleum ether/acetone (1:1). In the second step, this partially purified carotenoid extract was further purified by reverse phase chromatography technique. Various binding conditions were studied to achieve maximum amount of lycopene bound onto the chromatographic matrices. Column studies on the elution conditions of lycopene using linear and step gradient method were investigated. Purification of lycopene using packed bed column by reverse phase chromatography matrix HP20 was carried out using step gradient of 55% isopropyl alcohol in acetone followed by 65% isopropyl alcohol in acetone. The purity and recovery of lycopene was checked using Knauer high-performance liquid chromatography (HPLC) system. A 89% recovery of lycopene of HPLC purity 95% was achieved with substantial success. Proton magnetic resonance of the purified sample showed close resemblance with the chemical shifts (δ values) of the standard lycopene.     

Silver hydroxyapatite reinforced poly(vinyl alcohol)—starch cryogel nanocomposites and study of biodegradation,compressive strength and antibacterial activity

In the present work polyvinyl alcohol‐starch/silver hydroxyapatite (PVA‐starch/AgHap) cryogel nanocomposites were prepared by successive freezing‐thawing of a blend of PVA and starch solutions to fabricate a cryogel followed by its reinforcement with silver hydroxyapatite (AgHap). The prepared macroporous cryogel nanocomposites were characterized by Infra‐red spectroscopy (FTIR), environmental scanning electron microscopy (ESEM), and particle size and charge analysis. The amylase induced enzymatic degradation of nanocomposites was studied gravimetrically in phosphate buffer saline (PBS) and effect of various parameters like chemical composition of the nanocomposite, number of freeze‐thaw cycles, and enzyme activity were assessed on the extent of degradation of the nanocomposite. The influence of chemical composition and experimental conditions like the number of freeze thaw cycles was studied on the elastic modulii of the cryogels. The in vitro cytotoxicity and antibacterial activity of nanocomposites was also evaluated against L‐529 fibroblast cells and gram positive and gram negative bacteria, respectively. POLYM. ENG. SCI., 59:254–263, 2019. © 2018 Society of Plastics Engineers     

Comparative Molecular Analysis of Primary Central Nervous System Lymphomas and Matched Vitreoretinal Lymphomas by Vitreous Liquid Biopsy

Primary Central Nervous System Lymphoma (PCNSL) is a lymphoid malignancy of the brain that occurs in ~1500 patients per year in the US. PCNSL can spread to the vitreous and retina, where it is known as vitreoretinal lymphoma (VRL). While confirmatory testing for diagnosis is dependent on invasive brain tissue or cerebrospinal fluid sampling, the ability to access the vitreous as a proximal biofluid for liquid biopsy to diagnose PCNSL is an attractive prospect given ease of access and minimization of risks and complications from other biopsy strategies. However, the extent to which VRL, previously considered genetically identical to PCNSL, resembles PCNSL in the same individual with respect to genetic alterations, diagnostic strategies, and precision-medicine based approaches has hitherto not been explored. Furthermore, the degree of intra-patient tumor genomic heterogeneity between the brain and vitreous sites has not been studied. In this work, we report on targeted DNA next-generation sequencing (NGS) of matched brain and vitreous samples in two patients who each harbored VRL and PCSNL. Our strategy showed enhanced sensitivity for molecular diagnosis confirmation over current clinically used vitreous liquid biopsy methods. We observed a clonal relationship between the eye and brain samples in both patients, which carried clonal CDKN2A deep deletions, a highly recurrent alteration in VRL patients, as well as MYD88 p.L265P activating mutation in one patient. Several subclonal alterations, however, in the genes SETD2, BRCA2, TERT, and broad chromosomal regions showed heterogeneity between the brain and the eyes, between the two eyes, and among different regions of the PCNSL brain lesion. Taken together, our data show that NGS of vitreous liquid biopsies in PCNSL patients with VRL highlights shared and distinct genetic alterations that suggest a common origin for these lymphomas, but with additional site-specific alterations. Liquid biopsy of VRL accurately replicates the findings for PCNSL truncal (tumor-initiating) genomic alterations; it can also nominate precision medicine interventions and shows intra-patient heterogeneity in subclonal alterations. To the best of our knowledge, this study represents the first interrogation of genetic underpinnings of PCNSL with matched VRL samples. Our findings support continued investigation into the utility of vitreous liquid biopsy in precision diagnosis and treatment of PCNSL/VRL.     

Evaluation of antioxidant potential in selected green leafy vegetables

Green leafy vegetables represent a class of underexploited plants that are stipulated to be rich sources of natural antioxidants. A fundamental study of free radical-scavenging activity in four plant species, namely Trigonella foenum-graecum, Centella asiatica, Sauropus androgynus and Pisonia alba, was carried out by measuring the ability of methanol extracts of these plants to scavenge radicals generated by in vitro systems and by their ability to inhibit lipid peroxidation. The levels of non-enzymatic antioxidants were also determined by standard spectrophotometric methods. Correlation and regression analysis established a positive correlation between some of these antioxidants and the in vitro free radical-scavenging activity of the plant extracts. The conclusions drawn from the study indicate that in vivo studies, isolation and analysis of individual bioactive components will reveal the crucial role that these plants may play in several therapeutic formulations.     

Use of response surface methodology to investigate the effects of milling conditions on damaged starch,dough stickiness and chapatti quality

Response surface methodology was used to investigate the influence of three factors namely mill aperture, feed rate and moisture content of wheat grain on the damaged starch content of whole wheat flour from Lokwan wheat cultivar, dough stickiness and chapatti (Indian unleavened flat bread) quality. Each predictor variable was tested at three levels. Aperture was varied as 2, 3 and 4 mm in a stone mill, feed rate as 0.21, 0.63 and 1.05 min for 200 g wheat grains and grain moisture content as 8.6, 14.3 and 20% w/w. Flours containing varying amounts of damaged starch ranging from 6.1% to 26.90% were obtained and these were evaluated for dough stickiness and chapatti quality. Dough stickiness was increased with decreased aperture. With decreased aperture and increased grain moisture content softness of the chapatti was improved.     

Highly conducting doped poly-Si deposited by hot wire CVD and its applicability as gate material for CMOS devices

Highly conducting p- and n-type poly-Si:H films were deposited by hot wire chemical vapor deposition (HWCVD) using SiH₄+H₂+B₂H₆ and SiH₄+H₂+PH₃ gas mixtures, respectively. Conductivity of 1.2×10² (Ω cm)⁻¹ for the p-type films and 2.25×10² (Ω cm)⁻¹ for the n-type films was obtained. These are the highest values obtained so far by this technique. The increase in conductivity with substrate temperature (T_s) is attributed to the increase in grain size as reflected in the atomic force microscopy results. Interestingly conductivity of n-type films is higher than the p-type films deposited at the same T_s. To test the applicability of these films as gate contact Al/poly-Si/SiO₂/Si capacitor structures with oxide thickness of 4 nm were fabricated on n-type c-Si wafers. Sputter etching of the poly-Si was optimized in order to fabricate the devices. The performance of the HWCVD poly-Si as gate material was monitored using C–V measurements on a MOS test device at different frequencies. The results reveal that as deposited poly-Si without annealing shows low series resistance.     

Biometric Verification System Using Hyperparameter Tuned Deep Learning Model

Deep learning (DL) models have been useful in many computer vision, speech recognition, and natural language processing tasks in recent years. These models seem a natural fit to handle the rising number of biometric recognition problems, from cellphone authentication to airport security systems. DL approaches have recently been utilized to improve the efficiency of various biometric recognition systems. Iris recognition was considered the more reliable and accurate biometric detection method accessible. Iris recognition has been an active research region in the last few decades due to its extensive applications, from security in airports to homeland security border control. This article presents a new Political Optimizer with Deep Transfer Learning Enabled Biometric Iris Recognition (PODTL-BIR) model. The presented PODTL-BIR technique recognizes the iris for biometric security. In the presented PODTL-BIR model, an initial stage of pre-processing is carried out. In addition, the MobileNetv2 feature extractor is utilized to produce a collection of feature vectors. The PODTL-BIR technique utilizes a bidirectional gated recurrent unit (BiGRU) model to recognise iris for biometric verification. Finally, the political optimizer (PO) algorithm is used as a hyperparameter tuning strategy to improve the PODTL-BIR technique’s recognition efficiency. A wide-ranging experimental investigation was executed to validate the enhanced performance of the PODTL-BIR system. The experimental outcome stated the promising performance of the PODTL-BIR system over other existing algorithms.