Insecticidal Effects of Organotin(IV) Compounds on Plutella Xylostella (L.) Larvae. II. Inhibitory Potencies Against Acetylcholinesterase and Evidence for Synergism in Tests With Bacillus Thuringiensis(BER.) and Malathion

Features of pesticide synergism and acetylcholinesterase (AChE) inhibition (in vitro) were studied using a selected range of organotin compounds against the early 4th instar larvae of a highly resistant strain of the diamondback moth (DBM), Plutella xylostella, a major universal pest of cruciferous vegetables.Fourteen triorganotin compounds were evaluated for their ability to enhance the toxicity of the microbial insecticide, Bacillus thuringiensis (BT) and of the commercial insecticide, Malathion to Plutella xylostella larvae. Supplemental synergism was observed with triphenyl- and tricyclopentyltin hydroxides in combinations with Bacillus thuringiensis. Increased synergism was observed with an increase in the number of cyclopentyl groups on tin in the mixed series, Cyp(n) Ph(3-n) SnX, where X = OH, and 1-(1,2,4-triazolyl). The combination of (p-chlorophenyl)diphenyltin N,N-dimethyldithiocarbamate at LD(10) and LD(25) concentrations with sublethal concentrations of Malathion as well as of tricyclohexyltin methanesulphonate at the 0.01% (w/v) concentration with Malathion exerted strong synergistic effects (supplemental synergism) with toxicity index (T.I) values of 7.2, 19.8 and 10.1, respectively.Studies on the in vitro inhibition of acetylcholinesterase prepared from the DBM larvae showed that while most of the triorganotin Compounds tested were without effect on the enzyme, compounds containing the thiocarbamylacetate or the dithiocarbamylacetate moieties demonstrated appreciable levels of inhibition, being comparable in efficacy to commercial grades of Malathion and Methomyl.     

PM-10 emissions and power of a Diesel engine fueled with crude and refined Biodiesel from salmon oil

Power response and level of particulate emissions were assessed for blends of Diesel-crude Biodiesel and Diesel-refined Biodiesel. Crude Biodiesel and refined Biodiesel or methyl ester, were made from salmon oil with high content of free fatty acids, throughout a process of acid esterification followed by alkaline transesterification. Blends of Diesel-crude Biodiesel and Diesel-refined Biodiesel were tested in a diesel engine to measure simultaneously the dynamometric response and the particulate material (PM-10) emission performance. The results indicate a maximum power loss of about 3.5% and also near 50% of PM-10 reduction with respect to diesel when a 100% of refined Biodiesel is used. For blends with less content of either crude Biodiesel or refined Biodiesel, the observed power losses are lower but at the same time lower reduction in PM-10 emissions are attained.     

Diesel engine performance and emission evaluation using emulsified fuels stabilized by conventional and gemini surfactants

Diesel engines exhausting gaseous emission and particulate matter have long been regarded as one of the major air pollution sources, particularly in metropolitan areas, and have been a source of serious public concern for a long time. The emulsification method is not only motivated by cost reduction but is also one of the potentially effective techniques to reduce exhaust emission from diesel engines. Water/diesel (W/D) emulsified formulations are reported to reduce the emissions of NO_x, SO_x, CO and particulate matter (PM) without compensating the engine’s performance. Emulsion fuels with varying contents of water and diesel were prepared and stabilized by conventional and gemini surfactant, respectively. Surfactant’s dosage, emulsification time, stirring intensity, emulsifying temperature and mixing time have been reported. Diesel engine performance and exhaust emission was also measured and analyzed with these indigenously prepared emulsified fuels. The obtained experimental results indicate that the emulsions stabilized by gemini surfactant have much finer and better-distributed water droplets as compared to those stabilized by conventional surfactant. A comparative study involving torque, engine brake mean effective pressure (BMEP), specific fuel consumption (SFC), particulate matter (PM), NO_x and CO emissions is also reported for neat diesel and emulsified formulations. It was found that there was an insignificant reduction in engine’s efficiency but on the other hand there are significant benefits associated with the incorporation of water contents in diesel regarding environmental hazards. The biggest reduction in PM, NO_x, CO and SO_x emission was achieved by the emulsion stabilized by gemini surfactant containing 15% water contents.     

Analysis of epoxidized natural rubber. A comparative study of d.s.c., n.m.r., elemental analysis and direct titration methods

A comparative analysis of epoxidized natural rubber samples by ¹H and ¹³C n.m.r., titrimetric, elemental and d.s.c. techniques has been made. Whereas the titrimetric method is only applicable at low epoxy contents (< 15 mol%) both n.m.r. methods give reasonable precision over the compositional range of 20–75 mol%. Elemental analysis appears less reliable. D.s.c. analysis through measurement of T_g provides the highest precision of measurement but requires independent calibration by one or more of the primary methods. The epoxy content may also be related to the polymer density.     

A study of the kinetics of nucleation in a palm oil melt

Nucleation from a supercooled melt of palm oil was studied by optical microscopy and differential scanning calorimetry (DSC). Despite being a multicomponent system, palm oil exhibits a rather simple cooling thermogram with its high- and low-T exotherms exclusively related to the “hard” and “soft” components of the oil. As the “hard” components are being removed, the position of the high-T peak shifts down toward the low-T peak with diminishing peak intensity, while the position of the latter remains virtually unchanged. At 288°K, nucleation in a palm oil melt is instantaneous. Its induction time-temperature curve shows an abrupt discontinuity at 297°K, which demarcates the occurrence of one polymorph from another. Nucleation data fit very well into the Fisher-Turnbull equation. Its larger activation free energy of nucleation is accompanied by lowering of the melting point and an increase in the crystal/melt interfacial free energy as compared to palm stearin. The slow rate of nucleation in palm oil is attributed to intermolecular interaction between its “hard” and “soft” components. Partly presented at the 1989 PORIM International Palm Oil Development Conference, September 5–9, Kuala Lumpur, Malaysia.     

Splicing of reinforcement bars with epoxy joints

The splicing of reinforcement bars in tension using epoxy-sleeve joints is described. The optimum length of the splicing sleeve required and the optimum bonding layer of epoxy resin in the joint were determined in direct tension tests. The performance of the epoxy-sleeve joint made to these optimum dimensions is then compared to that of a lap splice made according to the provisions of CP 110 in a beam flexure test. A sleeve length of 12 bar diameters and an optimum average thickness of 2 mm of the bonding layer of epoxy are shown to develop the full strength of the splices bar. Tensile reinforcement bars spliced using epoxy-sleeve joints are shown to perform satisfactorily as flexural reinforcement in beams and compare favourably with the standard CP 110 lap splice. Epoxy-sleeve joints are shown to produce stiffer beams and reduced crack width at the joints.     

A survey on video content rating: taxonomy,challenges and open issues

Multimedia Tools and Applications - Rating a video based on its content is one of the most important solutions to classify videos for audience age groups. In this regard, Film content rating and TV...     

Deep learning approaches for speech emotion recognition: state of the art and research challenges

Speech emotion recognition (SER) systems identify emotions from the human voice in the areas of smart healthcare, driving a vehicle, call centers, automatic translation systems, and human-machine interaction. In the classical SER process, discriminative acoustic feature extraction is the most important and challenging step because discriminative features influence the classifier performance and decrease the computational time. Nonetheless, current handcrafted acoustic features suffer from limited capability and accuracy in constructing a SER system for real-time implementation. Therefore, to overcome the limitations of handcrafted features, in recent years, variety of deep learning techniques have been proposed and employed for automatic feature extraction in the field of emotion prediction from speech signals. However, to the best of our knowledge, there is no in-depth review study is available that critically appraises and summarizes the existing deep learning techniques with their strengths and weaknesses for SER. Hence, this study aims to present a comprehensive review of deep learning techniques, uniqueness, benefits and their limitations for SER. Moreover, this review study also presents speech processing techniques, performance measures and publicly available emotional speech databases. Furthermore, this review also discusses the significance of the findings of the primary studies. Finally, it also presents open research issues and challenges that need significant research efforts and enhancements in the field of SER systems.

     

Enhancing power transfer capability through flexible AC transmission system devices:a review

Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from variou...     

EFFECT OF TOOL WEAR ON MICROSTRUCTURE, MECHANICAL PROPERTIES AND ACOUSTIC EMISSION OF FRICTION STIR WELDED 6061 Al ALLOY

Tool condition is one of the main concerns in friction stir welding （FSW）, because the geometrical condition of the tool pin including size and shape is strongly connected to the microstrueture and mechanical performance of the weld. Tool wear occurs during FSW, especially for welding metal matrix composites with large amounts of abrasive particles, and high melting point materials, which significantly expedite tool wear and deteriorate the mechanical performance of welds. Tools with different pin-wear levels are used to weld 6061 Al alloy, while acoustic emission （AE） sensing, metallographic sectioning, and tensile testing are employed to evaluate the weld quality in various tool wear conditions. Structural characterization shows that the tool wear interferes with the weld quality and accounts for the formation of voids in the nugget zone. Tensile test analysis of samples verifies that both the ultimate tensile strength and the yield strength are adversely affected by the formation of voids in the nugget due to the tool wear. The failure location during tensile test clearly depends on the state of the tool wear, which led to the analysis of the relationships between the structure of the nugget and tool wear. AE signatures recorded during welding reveal that the AE hits concentrate on the higher amplitudes with increasing tool wear. The results show that the AE sensing provides a potentially effective method for the on-line manitoring of tool wear.