Ultraviolet sensing properties of polyvinyl alcohol-coated aluminium-doped zinc oxide nanorods

Undoped and aluminium (Al)-doped zinc oxide (ZnO) nanorods have been synthesized by electrochemical route. The synthesized materials have been characterized by X-ray diffraction, UV–visible spectrometer and scanning electron microscope. The Al-doped ZnO nanorods have been coated with polyvinyl alcohol. Current–voltage characteristics have been investigated in dark and under UV-light illumination. Aluminium doping in ZnO increase its electrical conductivity and further polyvinyl alcohol coating on Al-doped ZnO increase UV sensitivity of the material. Response and recovery time of Al-doped ZnO and PVA-coated Al-doped ZnO nanorods have been recorded. PVA-coated Al-doped ZnO nanorods shows very fast response and recovery time of 10 s in comparison to uncoated ZnO (20 min) nanorods.     

Isolation and identification of proteolytic psychrotrophic sporeforming bacteria from raw milk supplies at an experimental dairy in India

Of 51 samples of raw milk produced at the National Dairy Research Institute, 65% were found to contain proteolytic psychrotrophic sporeforming bacilli. The protease activity of 50 isolates selected ranged from 20 to 480 units/ml. Twenty/four per cent (12) of the total isolates exhibited enzyme activity in the range 51–100 units/ml, while 20% (10) had protease activity of more than 300 units/ml. Of the 50 isolates, 36% were Bacillus cereus, 20% B. polymyxa, 14% each B. laterosporus and B. circulans. 10% B. pumilus. 4% B. subtilis and 2% were identified as B. coagulans.     

Isolation and identification of protease-producing psychrotrophic bacteria from dairy products in India

Of the 259 proteolytic psychrotrophic bacterial cultures isolated from different dairy products produced at the National Dairy Research Institute, 39 cultures exhibited more than 150 units/ml protease activity. These isolates were identified and grouped into five genera, viz ., Pseudomonas spp ., Flavobacterium spp ., Alcaligenes spp ., Micrococcus spp., and Staphylococcus spp. The culture supernatants from six isolates retained more than 50% enzyme activity after heating at 50° C for 10 min, protease of Pseudomonas sp. 8–25 having maximum heat resistance.     

Calcium supplementation in colorectal cancer prevention: A systematic meta-analysis of adverse events

Despite the multiple systematic reviews and meta-analyses accumulating evidence on the preventive effect of calcium supplementation for colorectal cancer, most of the associated adverse effects are not systematically analyzed. The aim of the study is evaluating adverse events associated with calcium supplementation for colorectal cancer prevention through a systematic meta-analysis. We searched Medline, PubMed Central, EMBASE (Excerpta Medica database), Scopus, Cochrane Central Register of Controlled Trials, and Web of Science published in English from database inception up to 31 July 2019. In the current systematic meta-analysis, we included human studies (including cohort studies, clinical trials, case-control studies) on supplementation of calcium in patients with or at risk of colorectal cancer. Assessment of the quality of included studies was performed by Jadad score. Information on the patient population, number of enrolled subjects in each group, dose of calcium supplementation, duration of calcium supplementation, and reported adverse events were gathered. The data were pooled for incidence rates for any adverse event during the study period regardless of causality association. We identified 6 studies, comprising 4583 participants that met the inclusion criteria. Meta-analysis on pooled incidence rates for adverse event during study period showed no statistically significant increased risk for cancer (OR = 0.92, 95% CI: 0.70–1.21, P = 0.577; I² = 0.0%, P = 0.731), coronary revascularization (OR = 1.12, 95% CI: 0.79–1.59, P = 0.492; I² = 0.0%, P = 0.957), myocardial infarction (OR = 0.81, 95% CI: 0.34–1.91, P = 0.634; I² = 67.9%, P = 0.047), stroke (OR = 0.75, 95% CI: 0.42–1.33, P = 0.332, I² = 0.00%, P = 0.717), Transient Ischemic Attack (TIA) (OR = 1.37, 95% CI: 0.28–6.51, P = 0.692, I² = 81.9%, P = 0.002), urolithiasis (OR = 1.23, 95% CI: 0.75–2.01, P = 0.410; I² = 0.0%, P = 0.851), fracture (OR = 0.98, 95% CI: 0.70–1.37, P = 0.938; I² = 37.8%, P = 0.152) and death (OR = 1.05, 95% CI: 0.71–1.56, P = 0.786, I² = 12.2%, P = 0.317) in patients receiving calcium supplementation for colorectal cancer prevention compared to control. Based on the results of Egger test, publication bias was not observed among the studies (P = 0.262). The current result of the meta-analysis on human studies reporting adverse events associated with calcium supplementation for the prevention of colorectal cancer demonstrated no statistically significant increased risk for the development of adverse events compared to control groups.     

Biomass-based gasifiers for internal combustion (IC) engines—A review

The world is facing severe problems of energy crisis and environmental problem. This situation makes people to focus their attention on sustainable energy resources for their survival. Biomass is recognized to be the major potential source for energy production. There are ranges of biomass utilization technologies that produce useful energy from biomass. Gasification is one of the important techniques out of direct combustion, anaerobic digestion – Biogas, ethanol production. Gasification enables conversion of these materials into combustible gas (producer gas), mechanical and electrical power, synthetic fuels, and chemical. The gasification of biomass into useful fuel enhances its potential as a renewable energy resource. This paper gives a comprehensive review of the techniques used for utilizing biomass, experimental investigation on biomass fuels, characterization, merits, demerits and challenges faced by biomass fuels.     

The isolation of salt-tolerant lactic acid bacteria from ovine and bovine milks for use in the production of nabulsi cheese

Nabulsi cheese is one of the most popular white brined cheeses produced in Jordan and, traditionally, no starter cultures are employed for ripening. However, the resultant high pH means that spoilage problems arise in cheeses stored at ambient temperatures. Direct acidification or the use of commercial starter cultures have an adverse effect on flavour, but cultures derived from lactic acid bacteria isolated from local milks gave rise to cheeses that were as acceptable as the traditional products. In addition, the pHs of the cheese brines were in the range associated with stability during storage (pH 5.1–5.3), and hence it is suggested that these locally derived cultures could be employed by the industry to manufacture a nabulsi cheese from pasteurized milk that should: (a) be free from pathogens; (b) not deteriorate in-store at ambient temperature; and (c) have a flavour profile similar to traditional nabulsi cheese.     

Combining virtual simulation and physical vehicle test data to optimize durability testing

This paper describes an ongoing project to model a vehicle on a computer with a multibody dynamics simulation software package and to merge that work with physical proving ground and laboratory tests in order to shorten vehicle development time. The intention is to mirror as closely as possible the behaviour of a physical vehicle in order to assist in determining its durability characteristics under varying road conditions. This modelling work is important because, if done with sufficient fidelity, it can be used in order to assess vehicle responses by using different suspension components or payloads. Also, potential issues associated with vehicle structure, suspension components or payload positioning can be observed on a computer prior to performing physical tests. The process has the potential to reduce vehicle development cost and time. The virtual dynamic vehicle model has been created by using Automatic dynamic analysis of mechanical systems (ADAMS) software package. The calculated outputs from the model are being compared to force and displacement data collected from actual vehicle on‐road testing or a servo‐hydraulic road test simulator (RTS). The virtual model can be adjusted until the calculated responses are in close agreement with those of the physical vehicle, thus linking the virtual and real‐world results.     

POWER GENERATION CONTROL USING DUAL-MODE CONTROL

Abstract

Dual-mode control is applied to the problem of power generation control. The proposed controller is simple in structure and easily implementable. The effect of changes in some important system parameters like self-regulation parameter, turbine time constant and generation rate constraints, on the dynamic performance of the system for reheat and non-reheat type steam turbines is also studied     

A MICROPROCESSOR-BASED FAULT MONITOR FOR ROTATING RECTIFIERS OF BRUSHLESS AC EXCITERS USING A PATTERN-RECOGNITION APPROACH

ABSTRACT

A microprocessor-based fault monitor for rotating rectifiers of brushless ac exciters using a pattern-recognition approach is presented in this paper. The features of the frequency spectrum of the voltage waveform induced in a search coil placed in the stator slots of the brushless ac exciter are used in pattern recognition. Based on these features a classifier is designed using the nearest-neighbour rules. A prototype of the microprocessor-based fault monitor has been built. Studies show that the fault monitor can accurately recognize the various classes of faults of the rotating rectifier of the brushless ac exciter.