Coffee,its roasted form,and their residues cause birth failure and shorten lifespan in dengue vectors

Environmental Science and Pollution Research - In dengue mosquitoes, successful embryonic development and long lifespan are key determinants for the persistence of both virus and vector. Therefore,...     

Economic growth and energy consumption in Iran: an ARDL approach including renewable and non-renewable energies

Iran experiences a high level of energy consumption which is threatening not only economically but also politically and environmentally. This study aims to estimate the relationship between the economic growth with the various kinds of energies, non-hydroelectric, renewable, non-renewable, and total energies in Iran during 1967–2012, using an autoregressive distributed lags (ARDL) model. The results show the ineffective relationship between the economic growth and energy consumption in Iran, considering non-hydroelectric energy, renewable energy, non-renewable energy, and total energy, one by one as the energy proxy. It implies the ineffectiveness of both the quantitative and qualitative deflationary policies over the energy sector. In another word, neither decreasing energy consumption nor changing energy portfolio affects the economic growth. Therefore, the policy makers are advised to formulate those policies which reduce the quantity of energy consumption or increase the segment of renewable energies in the portfolio of energy consumption because they do not lead to the considerable negative consequence on the economic growth, while they increase both the environmental quality and energy security.     

Reactivity of sulfate radicals with natural organic matters

Advanced oxidation processes based on sulfate radicals (SO ₄ ^·? ) are capable of efficiently degrade organic pollutants from ground, surface and wastewaters. However, this degradation may be limited by aqueous natural organic matter (NOM). Here we measured the absolute rate constants of reaction of SO ₄ ^·? with four types of organic matter: two fulvic acids and two lake organic matter. We used laser flash photolysis technique to monitor the SO ₄ ^·? decay and the formation of the transients from organic matters. Reaction rate constants comprised between 1530 and 3500 s^?1 mgC^?1 L were obtained by numerical analysis of differential equations and the weighted average of the extinction coefficient of the generated organic matters radicals between 400 and 800 M^?1 cm^?1.     

Composition and distribution of surfactants around Lake Chini,Malaysia

This study aims to determine the composition of surfactants in the lake surface microlayer, rainwater, and atmospheric aerosols in the area surrounding Lake Chini, Pahang. Surfactants in the lake surface microlayer were taken from seven different stations around the lake, while samples of rainwater were taken from five different sampling stations. The samples of atmospheric aerosols were collected from the Lake Chini Research Centre which is in close proximity to the lake. The colorimetric analysis method was used to determine the composition and concentration of anionic surfactants as methylene blue active substances (MBAS) and cationic surfactants as disulphine blue active substances (DBAS). The concentration of anionic surfactants, as MBAS, in the surface microlayer ranged between 0.08 to 0.23 μmol L^− 1, while the range of concentration of cationic surfactants as DBAS ranged from 0.09 to 0.11 μmol L^− 1. The concentration of MBAS was higher in rainwater when compared to surfactants in the lake surface microlayer. The high concentration of surfactants in the fine mode of atmospheric aerosols suggests that natural and anthropogenic sources of surfactants contribute to the atmospheric surfactants.     

Application of chemometrics in understanding the spatial distribution of human pharmaceuticals in surface water

The growing interest in the environmental occurrence of veterinary and human pharmaceuticals is essentially due to their possible health implications to humans and ecosystem. This study assesses the occurrence of human pharmaceuticals in a Malaysian tropical aquatic environment taking a chemometric approach using cluster analysis, discriminant analysis and principal component analysis. Water samples were collected from seven sampling stations along the heavily populated Langat River basin on the west coast of peninsular Malaysia and its main tributaries. Water samples were extracted using solid-phase extraction and analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) for 18 pharmaceuticals and one metabolite, which cover a range of six therapeutic classes widely consumed in Malaysia. Cluster analysis was applied to group both pharmaceutical pollutants and sampling stations. Cluster analysis successfully clustered sampling stations and pollutants into three major clusters. Discriminant analysis was applied to identify those pollutants which had a significant impact in the definition of clusters. Finally, principal component analysis using a three-component model determined the constitution and data variance explained by each of the three main principal components.     

Heavy metal concentrations in water and sediments in Tasik Chini, a freshwater lake, Malaysia

The purpose of this paper are to determine the concentration of heavy metals namely cadmium (Cd), copper (Cu) and lead (Pb) in water and sediment; and to investigate the effect of sediment pH and sediment organic matter on concentration of cadmium, copper and lead in sediment at oxidation fraction. For this purpose the concentration of heavy metals were measured in water and sediments at 15 sites from Tasik Chini, Peninsular Malaysia. The sequential extraction procedure used in this study was based on defined fractions: exchangeable, acid reduction, oxidation, and residual. The concentration of heavy metals in residual fraction was higher than the other fractions. Among the non-residual fractions, the concentration of heavy metals in organic matter fraction was much higher than other fractions collected from all sampling sites. The pH of the sediment in all sites was acidic. The mean pH ranges from 4.8 to 5.5 with the higher value observed at site 15. Results of organic matter analysis showed that the percentage of organic matter present in sediment samples varies throughout the lake and all sites of sediments were relatively rich in organic matter ranging from 13.0% to 34.2%. The highest mean percentage of organic matter was measured at sampling site 15, with value of 31.78%.     

Spatial analysis of mortality rate of pedestrian accidents in Iran during 2012–2013

Objectives: Considering the high mortality rate of pedestrians in traffic accidents in Iran, the present study aimed to determine the high-risk and low-risk areas of accidents resulting in pedestrian deaths and the spatial analysis of their mortality rates.

Methods: This cross-sectional study included 4,371 deceased pedestrians reported by the Legal Medicine Organization in Iran from March 2012 to March 2013. For spatial analysis, the collected data were entered into ArcGIS software version 10.2 and a spatial map of the mortality rate was drawn according to the distribution of data in the provinces. Using this software, high-risk and low-risk areas were identified by calculating the spatial autocorrelation of the data. The Moran’s index of road accident patterns was surveyed and high-risk and low-risk points were identified using the local Getis index.

Results: The age-standardized incidence rate was 6.8 per 100,000. After analyzing the data using ArcGIS software, the local Moran’s index showed a cluster pattern with a high mortality rate in 3 provinces of Mazandaran, Gilan, and Qazvin. In identifying high-risk and low-risk points, the local Getis index showed 3 hot spots with a confidence interval of 99% in Qom, Qazvin, and Mazandaran and 5 hot spots with a 95% confidence interval in Markazi, Tehran, Zanjan, Gilan, and Golestan provinces.

Conclusions: According to the cluster pattern of accidents in the 3 provinces and the presence of hot spots in 9 provinces, it is necessary to identify factors that increase the risk of death in the study provinces in order to reduce the mortality rate among pedestrians due to traffic accidents. Therefore, to reduce the pedestrian mortality rate, especially in high-risk provinces, some studies need to be conducted to determine the risk factors in pedestrian mortality.     

Higher efficiency and lower environmental impact of membrane separation for carbon dioxide capture in coal power plants

Environmental Chemistry Letters - Global warming may be slowed down by carbon capture and storage systems that allow to sequester carbon dioxide from large fixed point sources such as power plants...     

Factorial analysis of diesel engine performance using different types of biofuels

In this study, several bio-source-fuels like fresh and waste vegetable oil and waste animal fat were tested at different injector pressures (120, 140, 190, 210 bar) in a direct-injection, naturally aspirated, single-cylinder diesel engine with a design injection pressure of 190 bar. Using 2k factorial analysis, the effect of injection pressure (Pi) and fuel type on three engine parameters, namely, combustion efficiency (etac), mass fuel consumption (mf), and engine speed (N) was examined. It was found that Pi and fuel type significantly affected both etac and mf while they had a slight effect on engine speed. Moreover, with diesel and biodiesels, the etac increased to a maximum at 190 bar but declined at the higher Pi value. In contrast, higher Pi had a favorable effect on etac over the whole Pi range with all the other more viscous fuels tested. In addition, the mass fuel consumption consistently decreased with an increase in Pi for all the fuels including the baseline diesel fuel, with which the engine consistently attained higher etac and higher rpm compared to all the other fuels tested.     

Psychosocial safety climate: Conceptual distinctiveness and effect on job demands and worker psychological health

Psychosocial safety climate is an emerging construct that refers to shared perceptions regarding policies, practices, and procedures for the protection of worker psychological health and safety. The purpose of the research was to: (1) demonstrate that psychosocial safety climate is a construct distinct from related climate measures (i.e., physical safety climate, team psychological safety, and perceived organizational support); and (2) test the proposition that organizational psychosocial safety climate determines work conditions (i.e., job demands) and subsequently worker psychological health. We used samples from two different cultures; an Australian sample (N = 126 workers in 16 teams within a primary health care organization) and a Malaysian sample (N = 180 workers in 31 teams from different organizations and diverse industries). In both samples confirmatory factor analysis verified that psychosocial safety climate is a construct distinct from related climate measures. Using hierarchical linear modeling, psychosocial safety climate was superior to other team level climate measures in its negative relationship to both job demands and psychological health problems. Results supported a mediation process, psychosocial safety climate → job demands → psychological health problems, corroborating psychosocial safety climate as a preeminent stress risk factor, and an efficient target for intervention. We found both physical and psychosocial safety climates were stronger in the Australian, compared with the Malaysian work context. Levels of psychosocial safety climate were significantly lower than those of physical safety climate in both countries indicating a ‘universal’ lack of attention to workplace psychological health.