Artificial intelligence as a fundamental tool in management of infectious diseases and its current implementation in COVID-19 pandemic

Environmental Science and Pollution Research - The world has never been prepared for global pandemics like the COVID-19, currently posing an immense threat to the public and consistent pressure on...     

Landfill leachate treatment by electrochemical oxidation

This study investigated the electrochemical oxidation of stabilized leachate from Pulau Burung semi-aerobic sanitary landfill by conducting laboratory experiments with sodium sulfate Na₂SO₄ (as electrolyte) and graphite carbon electrodes. The control parameters were influent COD, current density and reaction time, while the responses were BOD removal, COD removal, BOD:COD ratio, color and pH. Na₂SO₄ concentration was 1 g/L. Experiments were conducted based on a three-level factorial design and response surface methodology (RSM) was used to analyze the results. The optimum conditions were obtained as 1414 mg/L influent COD concentration, 79.9 mA/cm² current density and 4 h reaction time. This resulted in 70% BOD removal, 68% COD removal, 84% color removal, 0.04 BOD/COD ratio and 9.1 pH. Electrochemical treatment using graphite carbon electrode was found to be effective in BOD, COD and color removal but was not effective in increasing the BOD/COD ratio or enhancing biodegradability of the leachate. The color intensity of the treated samples increased at low influent COD and high current density due to corrosion of electrode material.     

Improvement of production of lipopeptide antibiotic iturin A using fish protein

To enhance the production of lipopeptide antibiotic iturin A, nutrient contents of the culture mediums were investigated in both submerged and biofilm fermentations. As a carbon source maltose and as nitrogen source, fish protein was used. In submerged fermentation maltose uptake was found lower (12%) compared to biofilm fermentation (15%) that was associated with higher cellular growth in biofilm. However, requirement of nitrogen (fish protein) concentration was found similar in both submerged and biofilm fermentations. Production of iturin A in submerged fermentation with 12% maltose and 5% fish protein was 4450 mg/L, and in biofilm fermentation it was 5050 mg/L when 15% maltose and 5% fish protein was used.     

Development of shopping centres in Jeddah

Recently developed shopping centres have become one of the main features of shopping activities in Jeddah. In fact the city of Jeddah experienced a surprising increase in the development of shopping centres during the last decade. Developers entered the land development process with the intention of realising profits from a long‐term investment, but a considerable number of shopping centres were developed on the basis of insufficient or no feasibility studies thereby underestimating or neglecting expected rate of return and occupancy. Spatially, shopping centres present distinctive spatial and rental value patterns. This article is concerned with explaining the supply side of shopping centres by examining the development process through which they were built. The analytical framework is based on discussing the interaction of three sets of variables: contextual factors, including land policy and market mechanisms; site characteristics, and the developer's characteristics.     

Evaluation of the effectiveness of low frequency workpiece vibration in deep-hole micro-EDM drilling of tungsten carbide

The application of micro-electrical discharge machining (micro-EDM) in deep-hole drilling is still limited due to the difficulty in flushing of debris and unstable machining. Present study introduces a simplistic analytical model to evaluate the effectiveness of low frequency workpiece vibration during the micro-EDM drilling of deep micro-holes. In addition, experimental investigation has been conducted to validate the model by studying the effects of workpiece vibration on machining performance, surface quality and dimensional accuracy of the micro-holes. The effect of vibration frequency and amplitude for three different settings of aspect ratios has been studied experimentally. Moreover, the vibration experiments have been conducted at different levels of gap voltages and capacitances in order to understand the effect of electrical parameters and effectiveness of low-frequency workpiece-vibration at different levels of discharge energies. It has been shown analytically that the effectiveness of low frequency workpiece vibration during micro-EDM drilling can be evaluated by a parameter ‘K_v’ (ratio of maximum acceleration of the vibrating plate in gravitational direction to gravitational acceleration ‘g’), which can be determined from the vibration frequency, amplitude and phase angle of the vibrating workpiece. The theoretical model reveals that for K_v > 1, the position of debris particles will be above the workpiece; thus can be flushed away from machined zone effectively. The experimental reasons for improved micro-EDM drilling performance at the setting of K_v > 1 are found to be the increased effective discharge ratio, reduced short-circuits and improved dielectric flushing. The experimental results also reveal that the low frequency vibration is more effective at the low discharge energy level, thus making it more suitable for micro-EDM. Considering the effect on both the machining characteristics and micro-hole accuracy parameters, vibration frequency of 750 Hz and amplitude of 1.5 μm was found to provide improved performance for the developed vibration device.     

Ecotoxicological assessment of oil-based paint using three-dimensional multi-species bio-testing model: pre- and post-bioremediation analysis

The present study validates the oil-based paint bioremediation potential of Bacillus subtilis NAP1 for ecotoxicological assessment using a three-dimensional multi-species bio-testing model. The model included bioassays to determine phytotoxic effect, cytotoxic effect, and antimicrobial effect of oil-based paint. Additionally, the antioxidant activity of pre- and post-bioremediation samples was also detected to confirm its detoxification. Although, the pre-bioremediation samples of oil-based paint displayed significant toxicity against all the life forms. However, post-bioremediation, the cytotoxic effect against Artemia salina revealed substantial detoxification of oil-based paint with LD₅₀ of 121 μl ml^?1 (without glucose) and >?400 μl ml^?1 (with glucose). Similarly, the reduction in toxicity against Raphanus raphanistrum seeds germination (%FG?=?98 to 100%) was also evident of successful detoxification under experimental conditions. Moreover, the toxicity against test bacterial strains and fungal strains was completely removed after bioremediation. In addition, the post-bioremediation samples showed reduced antioxidant activities (% scavenging?=?23.5?±?0.35 and 28.9?±?2.7) without and with glucose, respectively. Convincingly, the present multi-species bio-testing model in addition to antioxidant studies could be suggested as a validation tool for bioremediation experiments, especially for middle and low-income countries.

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Green examination: integration of technology for sustainability

The recent development of infrastructure all around the world has resulted in an increasing trend of online examination in universities. The paper is an approach in theory and practical aimed at analyzing the feasibility of sustainable examination in four universities and its environmental impact reducing the paper use terming it as green examination. The paper studied the integration of sustainability through the use of computers and technology in the examination of the universities viz. King Khalid University (KKU), Saudi Arabia, Integral University (IU), India, Aligarh Muslim University (AMU), India, and The Hague University (HU), The Netherlands. The study has analyzed the trend of paper requirement, paper utilized and paper wasted in all the four universities. The environmental impact resulting from reduced paper use has been also analyzed. The feasibility of e-examination, its implementation and the implications has been undertaken in the study. The study concludes that the e-examination can almost make the examinations paperless and feasible in the four universities.     

Enhanced transfer of arsenic to grain for Bangladesh grown rice compared to US and EU

A field survey was conducted in arsenic impacted and non-impacted paddies of Bangladesh to assess how arsenic levels in rice (Oryza sativa L.) grain are related to soil and shoot concentrations. Ten field sites from an arsenic contaminated tubewell irrigation region (Faridpur) were compared to 10 field sites from a non-affected region (Gazipur). Analysis of the overall data set found that both grain and shoot total arsenic concentrations were highly correlated (P<0.001) with soil arsenic. Median arsenic concentrations varied by 14, 10 and 3 fold for soil, shoot and grain respectively comparing the two regions. The reason for the sharp decline in the magnitude of difference between Gazipur and Faridpur for grain arsenic was due to an exponential decline in the grain/shoot arsenic concentration ratio with increasing shoot arsenic concentration. When the Bangladesh data were compared to EU and US soil-shoot-grain transfers, the same generic pattern could be found with the exception that arsenic was more efficiently transferred to grain from soil/shoot in the Bangladesh grown plants. This may reflect climatic or cultivar differences.     

Influence of Fiber Treatment on the Mechanical and Morphological Properties of Sawdust Reinforced Polypropylene Composites

In the present work, sawdust reinforced polypropylene composites were fabricated using an extruder and an injection molding machine. Raw sawdust was chemically treated with benzene diazonium salt in order to improve the mechanical properties of the composites. The effect of the chemically treated sawdust reinforced PP composites was evaluated from their mechanical and surface morphological properties. The values of the mechanical properties of the chemically treated sawdust–PP composites were found to be significantly higher than those of the raw ones. Water uptake tests revealed that composites prepared from the chemically treated sawdust absorb lower amount of water compared to the ones prepared from raw sawdust, suggesting that hydrophilic nature of the cellulose in the sawdust has significantly decreased upon chemical treatment. The surface morphology obtained from scanning electron microscopy (SEM) showed that raw sawdust–PP composites possess surface roughness with extruded filler moieties, and weak interfacial adhesion between the matrix and the filler while the chemically treated one showed improved filler–matrix interaction. This indicates that better dispersion of the filler with the PP matrix has occurred upon chemical treatment of the filler.     

Effect of liquid municipal biosolid application method on tile and ground water quality

This study examined bacteria and nutrient quality in tile drainage and shallow ground water resulting from a fall land application of liquid municipal biosolids (LMB), at field application rates of 93,500 L ha(-1), to silt-clay loam agricultural field plots using two different land application approaches. The land application methods were a one-pass AerWay SSD approach (A), and surface spreading plus subsequent incorporation (SS). For both treatments, it took between 3 and 39 min for LMB to reach tile drains after land application. The A treatment significantly (p < 0.1) reduced application-induced LMB contamination of tile drains relative to the SS treatment, as shown by mass loads of total Kjeldahl N (TKN), NH(4)-N, Total P (TP), PO(4)-P, E. coli., and Clostridium perfringens. E. coli contamination resulting from application occurred to at least 2.0-m depth in ground water, but was more notable in ground water immediately beneath tile depth (1.2 m). Treatment ground water concentrations of selected nutrients and bacteria for the study period ( approximately 46 d) at 1.2-m depth were significantly higher in the treatment plots, relative to control plots. The TKN and TP ground water concentrations at 1.2-m depth were significantly (p < 0.1) higher for the SS treatment, relative to the A treatment, but there were no significant (p > 0.1) treatment differences for the bacteria. For the macroporous field conditions observed, pre-tillage by equipment such as the AerWay SSD, will reduce LMB-induced tile and shallow ground water contamination compared to surface spreading over non-tilled soil, followed by incorporation.