The half-lives of biological activity of some pesticides in water

In the absence of analytical methods, the half-lives of biological activity of pesticides can be estimated by bioassays. To determine the half-lives of biological acivity of pesticides to fish, static bioassays were conducted in the laboratory with ten different formulations of pesticides using Labeo rohita as a bio-indicator. The half-lives of biological activity for ten different pesticides in soft water at pH 7.5 and 27°C, ranged from 4.6 days to 11.8 days. The half-life of biological activity of Sumithion 50% EC was only 4.6 days. In contrast, Dimecron 50% EC degraded very slowly and its half-life of biological activity on L. rohita was about 11.8 days. Sumithion 50% EC, Padan 50% SP, EPN 45% EC, Diazinon 40% EC and Diazinon 10 G degraded in less than five to seven days indicating that these pesticides are desirable for rice-fish culture. Contamination by pesticides with long-term residual toxicity in waters may eventually cause high levels of fish mortality

National hazard exposure worker surveillance: exposure to biomechanical demands, pain and fatigue symptoms and the provision of controls in Australian workplaces

Biomechanical demands such as repetitive hand or arm movements, lifting heavy loads or working in awkward postures contribute to the development or worsening of inflammatory or degenerative musculoskeletal disorders. However, little is known about patterns of exposure to different biomechanical demands and how they relate to the demographic and employment characteristics of Australian workers. To address this, in 2008 the National Hazard Exposure Worker Surveillance [NHEWS] survey collected information on 4500 Australian workers’ exposure to nine biomechanical demands, pain and fatigue symptoms and the provision of various risk controls. Almost all workers reported some level of exposure to the biomechanical demands surveyed and 22 per cent were deemed to have high overall (composite) biomechanical demand exposure. In particular, young workers, male workers, night workers and lower skilled workers were most likely to report exposure and had the highest overall biomechanical demand exposure. The reporting of pain and fatigue symptoms was highly related to the level of biomechanical demand exposure. Workplace size (number of workers at a site) and the overall level of biomechanical demand exposure were the best predictors of control provision: workers from large workplaces and those with high exposure were most likely to be provided with biomechanical demand controls. This report presents detailed findings of the NHEWS survey and discusses the implications of these findings for work health and safety policy

Structural Integrity Re-Use Assessment for Fixed Structures

In a time not far from now, there will be a significant increase in the decommissioning activities of fixed offshore platforms in Asia Pacific Region. The usual methods of decommissioning comprise the complete removal, partial removal, reefing or re-using of the offshore structure. The major challenges that encounter during the complete or partial removal decommissioning is the shortage of decommissioning yards for managing onshore disposal. Therefore, reefing or re-using of the structure has better aspect of sustainability rather than the complete removal and disposal method. Reusing of the old structure can be not only cost saving but also will much reduce the emission of carbon dioxide during the steel manufacturing process from iron ore. In this report, it will be focused on the jacket of the fixed offshore structure and there will be two parts to discuss; structural integrity assessment and structural analysis. Before the structure is being reused, a structural integrity assessment is carried out to determine the current integrity of the structure. Based on the integrity assessment, modifications and/ or refurbishing are made if there is any and structural analysis is carried out to assess the strength of the offshore structure for reuse purpose

The Igneous Rocks of the Lamlash Region

Abstract Not Provided

Safe use of pesticide in rice-fish culture

Results of the study on the relative safety of nine different pesticides: Diazinon 40% EC, Diazinon 10 G, Elsan 50% EC, Sumithion 50% EC, Furadan 3 G, Padan 50% SP, Kitazin 48% EC, Kitasin 17% G and EPN 45% EC for various fish species: Cyprinus carpio, Labeo rohita, Oreochromis mossambicus, Channa punctata, Clarias batrachus and Anabas testudineus used in rice-fish culture are presented and discussed

Simulation of Energy Bands for Metal and Semiconductor Junction

This paper presents the metal-semiconductor band structure analysis for metal-oxide semiconductor field effect transistor (MOSFET). The energy bands were observed at metal-semiconductor and semiconductor-metal junctions. The simulation results show energy variations by using gallium-nitride (GaN) material. Gallium nitride based MOSFETs have some special material properties and wide band-gap. From the energy band, the condition of contact potential, conduction and valence band-edges can be analyzed. The computerized simulation results for getting the band layers are investigated with MATLAB programming language

QSAR METHODS DEVELOPMENT, VIRTUAL AND EXPERIMENTAL SCREENING FOR CANNABINOID LIGAND DISCOVERY

G protein coupled receptors (GPCRs) are the largest receptor family in mammalian genomes and are known to regulate wide variety of signals such as ions, hormones and neurotransmitters. It has been estimated that GPCRs represent more than 30% of current drug targets and have attracted many pharmaceutical industries as well as academic groups for potential drug discovery. Cannabinoid (CB) receptors, members of GPCR superfamily, are also involved in the activation of multiple intracellular signal transductions and their endogenous ligands or cannabinoids have attracted pharmacological research because of their potential therapeutic effects. In particular, the cannabinoid subtype-2 (CB2) receptor is known to be involved in immune system signal transductions and its ligands have the potential to be developed as drugs to treat many immune system disorders without potential psychotic side-effects. Therefore, this work was focused on discovering novel CB2 ligands by developing novel quantitative structure-activity relationship (QSAR) methods and performing virtual and experimental screenings. Three novel QSAR methods were developed to predict biological activities and binding affinities of ligands. In the first method, a traditional fragment-based approach was improved by introducing a fragment similarity concept that enhanced the prediction accuracy remarkably. In the second method, pharmacophoric and morphological descriptors were incorporated to derive a novel QSAR regression model with good prediction accuracy. In the third method, a novel fingerprint-based artificial neural network QSAR model was developed to overcome the similar scaffold requirement of many fragment-based and other 3D-QSAR methods. These methods provide a foundation for virtual screening and hit ranking of chemical ligands from large chemical space. In addition, several novel CB2 selective ligands within nM binding affinities were discovered. These ligands were proven to be inverse agonists as validated by functional assays and could be useful probes to study CB2 signaling as well as potential drug candidates for autoimmune disesases

Effects of energy band structure on gallium arsenide based MOSFET

This research work is focused on material science and semiconductor engineering. It emphasized on the semiconductor material such as Gallium arsenide (GaAs). The Gallium arsenide semiconductor material was used as a group III-V compound for metal-oxide semiconductor field effect transistor (MOSFET) modeling.  The band-gap energy structures were analyzed by using material parameters such as Varshni parameters, temperature and doping concentrations. Then, an electrical characteristic was carried out depending on the current and voltage relationship. The current flowing in the device is associated with a gate voltage applied to the device. From this paper, the analysis of MOSFET modeling was investigated using mathematical equations and MATLAB simulation