Formation of organic tracers for isoprene SOA under acidic conditions

The chemical compositions of a series of secondary organic aerosol (SOA) samples, formed by irradiating mixtures of isoprene and NO in a smog chamber in the absence or presence of acidic aerosols, were analyzed using derivatization-based GC–MS methods. In addition to the known isoprene photooxidation products 2-methylglyceric acid, 2-methylthreitol, and 2-methylerythritol, three other peaks of note were detected: one of these was consistent with a silylated-derivative of sulfuric acid, while the remaining two were other oxidized organic compounds detected only when acidic aerosol was present. These two oxidation products were also detected in field samples, and their presence was found to be dependent on both the apparent degree of aerosol acidity as well as the availability of isoprene aerosol. The average concentrations of the sum of these two compounds in the ambient PM_2.5 samples ranged from below the GC–MS detection limit during periods when the isoprene emission rate or apparent acidity were low to approximately 200 ng m^?3 (calibrations being based on a surrogate compound) during periods of high isoprene emissions. These compounds presently unidentified have the potential to serve as organic tracers of isoprene SOA formed exclusively in the presence of acidic aerosol and may also be useful in assessments in determining the importance and impact of aerosol acidity on ambient SOA formation.     

Modelling the connection between energy consumption and carbon emissions in North Africa: Evidence from panel models robust to cross-sectional dependence and slope heterogeneity

Environment, Development and Sustainability - This paper explored the link between energy consumption and carbon emissions in North Africa through an Environmental Kuznets Curve (EKC) framework....     

Factors affecting vehicle exhaust emissions,driver motivations as a mediator

Environmental Economics and Policy Studies - Reducing the negative effects of vehicle emissions is one of the main priorities for governments worldwide. Comprehensive understanding of the costs and...     

Zinc,lead, and cadmium tolerance and accumulation in Cistus libanotis,Cistus albidus,and Cistus salviifolius: Perspectives on phytoremediation

Heavy metal contamination is of particular concern for human health and the environment. Phytoremediation is an emerging cost‐effective strategy to remediate heavy metal contaminated soil. However, this technique is limited by the small number of plants that are tolerant to heavy metals and are also accumulators. This study assayed zinc, lead, and cadmium tolerance and accumulation in Cistus libanotis, Cistus albidus, and Cistus salviifolius. The plants were cultivated in hydroponic conditions and exposed to different concentrations of Pb(NO₃)₂ (100 and 200 µM), ZnSO₄ (100 and 200 µM), or CdCl₂ (10 and 20 µM) for 3 weeks. Plant biomass and metal accumulation in roots and aboveground parts varied greatly among the species. All three species appeared to be sensitive to Zn. However, C. albidus displayed strong tolerance to Pb and accumulated large quantities of Pb and Cd in its roots. C. libanotis accumulated large quantities of Pb and Cd in its aboveground parts. C. libanotis can thus be classified as a Pb and Cd accumulator species. The study results show that C. albidus is suitable for phytostabilization of Pb‐contaminated soils, while C. libanotis can be used for phytoextraction of both Pb and Cd.     

How have we,do we,and will we measure time perspective? A review of methodological and measurement issues

Despite the demonstrated importance of time perspective on key outcomes, its growing popularity, and its wide reach in terms of samples and disciplines, the construct has been plagued with definitional and measurement problems since its inception. Given the historical and current confusion regarding both conceptualization and operationalization, the purpose of this article is to provide an overview of methodological and measurement issues related to time perspective. Clearly, definitional and measurement clarity are critical for the success of future research. Through integrating the fragmented and eclectic time perspective literature fraught with ambiguity, we help to clarify measurement options and their psychometric evidence for future researchers. Specifically, we provide an in-depth comparison of four (and their offshoots) commonly used, scale-based measures of time perspective with respect to their dimensional content, psychometric properties, and validation evidence. We end with recommendations for time perspective research.     

Detection of hazardous pollutants in chrome-tanned leather using locally developed laser-induced breakdown spectrometer

K?z?l?rmak River has been used as Ankara??s drinking water source for approximately 1.5?years. Therefore, this region??s water, sediment, and fish samples are measured for detecting the heavy metals. This is important for the current situation as well as the future in terms of potential impact. The amount of heavy metals in drinking water should be within the limited values; otherwise, the accumulation of heavy metals will cause many problems to living organisms. Especially high levels of arsenic, cadmium, nickel, mercury, etc. are very dangerous to freshwater ecosystems as for human if the water is being use as drinking water. In this study, water, sediment samples, muscle, and gills of three fish species (Capoeta tinca, Capoeta capoeta, Leuciscus cephalus) were analyzed for the presence of heavy metals such as (Al, Fe, As, Cd, Ni, Mn, Se, Si) to determine present accumulation levels and possible toxic effect. The accumulation pattern of heavy metals in the water, sediment, and fish tissue follows the sequence: Si > Fe > Al > Mn > As > Ni > Se > Cd, Fe > Al > Mn > Ni > As > Se > Cd, and Fe > Al > Mn > As > Ni > Si > Cd. In addition, the detected concentrations of heavy metals in the K?z?l?rmak and Delice Rivers are compared with other heavy metal studies in the other main rivers and lakes in Turkey.     

Performance enhancement of single-slope solar still using phase change materials

Environmental Science and Pollution Research - Freshwater scarcity appears clearly in coastal areas of Egypt despite the existence of a large amount of seawater around. Solar still is the cheapest...     

Antitumor effect of copper nanoparticles on human breast and colon malignancies

Environmental Science and Pollution Research - Breast and colon carcinomas are two types of common cancers which lead to cancer-related deaths. Due to their cytotoxic potential against cancer...