The dependence of the beta coefficient of REA system with dynamic deadband on atmospheric conditions

We simulated the REA system with dynamic deadband to study numerical value and the effect of atmospheric conditions on the empirical constant beta which relates vertical flux to concentration difference between updrafts and downdrafts. We found that the value of beta depends only weakly on the friction velocity and atmospheric stability. In agreement with previous studies, the median value obtained for a system with dynamic deadband proportional to 0.5 times the running mean of the standard deviation of vertical wind speed was beta=0.42+/-0.03. For a single half-hour measurement one has to consider the large uncertainty of +/-0.2. According to our study, the dynamic deadband enables the use of a constant value of beta in flux calculation.     

Standardising and mapping open-source information for crisis regions: the case of post-conflict Iraq

Painting an accurate picture of the situation on the ground in countries in crisis is vital for the efficiency of humanitarian aid and reconstruction agencies. This study describes a method for standardising and mapping the plethora of open-source information. The test site for the study is post-conflict Iraq. Important information on aid distribution, reconstruction and security in Iraq can be derived from the reports of humanitarian aid agencies and the media, before being formatted, inserted into a database and mapped. The product is a visual, cartographic structure of otherwise random information, showing which organisations are working in the country, which thematic and geographic areas are being prioritized in the field, and which areas most frequently experience security events. This type of mapping not only highlights the overall working environment within different parts of the country, but it may also serve as a decision-making tool for donors and humanitarian aid agencies planning to deploy personnel.     

Modification of wood with environmentally friendly chemicals to improve decay resistance

Turkish pine (Pinus brutia Ten.) solid wood was chemically modified to various weight percent gains (WPG) using either acetic, methacrylic, hexanoic and succinic anhydrides. Laboratory soil block decay testing using the brown rot fungus C. puteana and G. trabeum was performed and weight loss calculated. All high degree of modified samples showed good biological resistance and severely reduced degradation. Chemical modification of wood is very important for the prevention of biodeterioration which are environmentally friendly and also not hazardous to human beings.     

Accumulation of Cu,Zn, Cd,and Pb by Scenedesmus obliquus under nongrowth conditions

The aim of this work has been to assess the accumulation of copper, zinc, cadmium and lead by a test alga, Scenedesmus obliquus, under nongrowth conditions. The results provide an evidence that metals can be readily accumulated by algae and that accumulation is a function of the metal-to-algae exposure ratio. When the metals were added in combination in equimolar concentrations, the following order of affinity to algal surface was detected Zn > Cu ? Cd > Pb. However, when EDTA was added to the test water, metal accumulation was greatly retarded. Moreover, when algae loaded with one of the metals were washed with EDTA solution the major part of the accumulated metal was mobilized, indicating that EDTA had stronger metal binding affinity than any ligands liable to exist on algal surface. Metal accumulation by algal cells isolated from a culture in the logarithmic growth phase was of much higher magnitude than that displayed by cells isolated from a culture in the decline phase.     

Deflective effect and the effect of prey detectability on anti-predator function of eyespots

Eyespots (patterns of roughly concentric rings) are often thought to have an anti-predator function. Previous experiments have lent support for the intimidation hypothesis by demonstrating a deterring effect of eyespots, but so far there is little evidence for the deflective effect (direction of attacks toward less vital body parts). We studied predators’ responses towards large and small eyespots and towards prey with no, one, or a pair of eyespots and if this response is influenced by whether or not prey blend into background. In two experiments, we used artificial, triangular prey items and blue tits (Cyanistes caeruleus) as predators. In experiment 1, we found evidence for the deflective effect of small but not large eyespots, independent of whether the prey was presented on a concealing or exposing background. In experiment 2, we found that predators avoided the prey with a pair of small eyespots more than the prey without eyespots, but interestingly, we only found this deterring effect on the concealing background. There was no difference in attacks between the prey with one large and two small or one large and no eyespots. We conclude that deflective function may select for eyespots, and background may influence the deterring function of eyespots.     

Evidence for enhanced dissipation of chlorpyrifos in an agricultural soil inoculated with Serratia rubidaea strain ABS 10

The insecticide ¹⁴C-chlorpyrifos was found mineralized in a Tunisian soil with repeated exposure to it. From this soil, a bacterial strain was isolated that was able to grow in a minimal salt medium (MSM) supplemented with 25 mg L^?1 of chlorpyrifos. It was characterized as Serratia rubidaea strain ABS 10 using morphological and biochemical analyses, as well as 16S rRNA sequencing. In a liquid culture, the S. rubidaea strain ABS 10 was able to dissipate chlorpyrifos almost entirely within 48 h of incubation. Although the S. rubidaea strain ABS 10 was able to grow in an MSM supplemented with chlorpyrifos and dissipate it in a liquid culture, it was not able to mineralize ¹⁴C-chlorpyrifos. Therefore, it can be concluded that the dissipation capability of this bacteria might be attributed to its capacity to adsorb CHL. It can also be ascribed to other reasons such as the formation of biogenic non-extractable residues. In both non-sterile and sterile soil inoculated with S. rubidaea strain ABS 10, chlorpyrifos was more rapidly dissipated than in controls with DT₅₀ of 1.38 and 1.05 days, respectively.

     

Effects of gasoline engine emissions on health status of auto rickshaw drivers at DIR (L) Khyber Pukhtunkhwa

A total of 50 blood samples were collected from auto rickshaw drivers who were exposed to environmental gasoline in different sites of Dir (L), Khyber Pukhtunkhwa, Pakistan, in July and August, 2009. Control group was selected among the individuals who were not regularly exposed to gasoline emissions. The samples were analyzed for calcium, cholesterol, glucose, phosphorus, potassium, and triglycerides levels. A significant increase was found in the blood levels of calcium, glucose, phosphorus, and triglycerides. A significant decrease was detected in the blood levels of potassium without any significant effect on the blood levels of cholesterol and magnesium.     

Experimental investigation of cross-shore sandbar volumes

Sandbars are critical to the cross-shore movement of sediment. Prediction of cross-shore sandbar volumes requires knowledge about the functional relationship of sediment transport rate conditions with waves, currents, base slope, sediment property and water depth. In this study, experiments on cross- shore sediment transport were carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using regular waves with different deep-water wave steepness generated by a pedal-type wave generator, bar volumes caused by cross-shore sediment transport are investigated for beach materials with the medium diameter of d₅₀?=?0.25, 0.32, 0.45, 0.62 and 0.80 mm. A non-dimensional equation for sandbar volume was obtained by using linear and non-linear regression methods through the experimental data and was compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equation with respect to the previously developed equations.     

Municipal wastewater viral pollution in Saudi Arabia: effect of hot climate on COVID-19 disease spreading

Environmental Science and Pollution Research - The viral RNA of SARS-Coronavirus-2 is known to be contaminating municipal wastewater. We aimed to assess if COVID-19 disease is spreading through...     

Leak detection of hydrogen–natural gas mixtures in pipes using the characteristics method of specified time intervals

This paper presents a technique for detection and location of leaks in a single pipe, by means of transient analysis, of hydrogen–natural gas mixtures flows. The method uses transient pressure waves initiated by the sudden closure of a downstream shut-off valve. The presence of a leak in a pipe partially reflects these pressure waves and allows for the location of the leak. Pressure waves are governed by two coupled non-linear, hyperbolic partial differential equations with pressure dependent coefficients. The fluid pressure and velocity are considered as two principal dependent variables. To determine the leak location, the mathematical formulation has been solved by the characteristics method of specified time intervals. The computed results describe the influence of the leak on pressure time-history and the effect of hydrogen mass fraction in the mixture on the leak discharge behaviour. It was found that transient pressure is much important in the case of hydrogen than that in the case of natural gas.