Mohammad A. Batiha

MAFRAM-A new fate and risk assessment methodology for non-volatile organic chemicals

The main goal of this paper was to introduce an environmental fate and risk assessment methodology for comparing and establishing the general features of new and existing non-volatile organic chemicals (NVOCs) used in agricultural activities, based on simple and readily available properties. This methodology is a computer program called the multimedia agricultural fate and risk assessment model (MAFRAM). This model is a combination of the EQC-2V model, which describes the fate of NVOCs, with the ecological relative risk (EcoRR) approach, which assesses the ecotoxicological risk to agro-ecosystems. MAFRAM divides the agricultural environment into two main zones, which are the on- and off-farm zones. Each zone is subdivided into six compartments, including the air, water, soil, sediment, aboveground plants, and roots. The required input data are the chemical-physical properties of the pesticide, biota data, and environmental properties. The MAFRAM output includes the inter-compartmental transport and transfer rates, the primary loss mechanisms, chemical concentration, amount, residence time, and the rank of risk in each compartment. In addition, it can provide several secondary results. The MAFRAM application was illustrated using typical homogenous region properties and was run with an illustrative emission rate of 1 kg/h into air, using spinosad as a case study.

High performance thermoplastic elastomer (TPE) nanocomposite based on graphene nanoplates (GNPs)

This paper examines the enhancement in the properties of thermoplastic elastomer (TPE) reinforced by graphene nanoplates (GNPs). TPE is a blend of polypropylene (PP), natural rubber (NR) and liquid natural rubber (LNR), which is used as a compatibiliser at a percentage of volume ratio 70:10:20, respectively. Using TPE as the host matrix, TPE/GNPs nanocomposites are processed, and the mechanical, electrical and structural properties are characterised. The results extracted from the tensile and the impact tests showed that the tensile strength, Young’s modulus and the impact strength of the nanocomposites also increased as the filler loading increased until an optimum value of filler loading was reached. Based on the experimental results, GNPs strongly affected the electrical conductivity due to disruption of the GNPs percolated network. It is believed that the high aspect ratio of GNPs is a critical issue concerning the constitution of a special interface region between the GNPs and TPE matrix and the high performance of the composites.