Activity of Male Pheromone of Melanesian Rhinoceros Beetle Scapanes australis

Laboratory and field investigations were carried out to investigate the nature and role of the male pheromone emitted by the Dynast beetle Scapanes australis and to develop a mass trapping technique against this major coconut pest in Papua New Guinea. We report the biological data obtained from natural and synthetic pheromone, previously described as an 84:12:4 (w/w) mixture of 2-butanol (1), 3-hydoxy-2-butanone (2), and 2,3-butanediol (3). EAG recordings from natural and synthetic pheromone and a pitfall olfactometer were poorly informative. In contrast, extensive field trapping trials with various synthetic pheromone mixtures and doses showed that 1 and 2 (formulated in polyethylene sachets in 90:5 v:v ratio) were necessary and sufficient for optimum long-range attraction. Beetles were captured in traps baited with racemic 1 plus 2, with or without a stereoisomer mixture of 3 (2.5- to 2500-mg/day doses). Plant pieces, either sugarcane or coconut, enhanced captures by the synthetic pheromone, which was active alone. Traps with the pheromone caught both sexes in a 3:2 female–male ratio. A pheromone-based mass trapping led to the capture of 2173 beetles in 14 traps surrounding 40 ha of a cocoa-coconut plantation. The captures followed a log-linear decrease during the 125-week trapping program. The role of the male pheromone and its potential for crop protection are discussed.     

WEDM Parameter Optimization for Silicon@r-GO/Magneisum Composite Using Taguchi Based GRA Coupled PCA

Silicon - A combination of Taguchi methodology and Grey Relational Analysis (GRA) inturn coupled with principal component analysis (PCA) has been proposed through this paper. This methodology is...     

微指令使电动机准确运转

自动售货机已很常见,但很少有人想过它们是怎样仅仅依靠对电机的开/关控制来分发茶点的.但是,医疗器械、拾取/贴放机以及其他的设备要求更精确的运动控制.现在,设计师能在可简化电机控制电路的各种微处理器、控制器芯片和模块中作出自己的选择.示例软件和电机控制程序则可帮助人们加速代码的开发.     

Temperature dependence of the Henry's law constant for hydrogen storage in NaA zeolites: a Monte Carlo simulation study

Grand canonical Monte Carlo simulations of hydrogen adsorption in zeolites NaA were carried out for a wide range of temperatures between 77 and 300 K and pressures up to 180 MPa. A potential model was used that comprised of three main interactions: van der Waals, coulombic and induced polarization by the electric field in the system. The computed average number of adsorbed molecules per unit cell was compared with available results and found to be in agreement in the regime of moderate to high pressures. The particle insertion method was used to calculate the Henry coefficient for this model and its dependence on temperature.     

Direct nucleation of silver nanoparticles on graphene sheet

Silver (Ag) nanoparticles were synthesized on the surface of graphene sheet by the simultaneous reduction of Ag+ and graphene oxide (GO) in the presence of simple reducing agent, hydrazine hydrate (N2H4 x H2O). Both the Ag+ and GO were reduced and Ag+ was nucleated onto graphene. GO flakes were prepared by conventional chemical exfoliation method and in the presence of strong acidic medium of potassium chlorate. Silver nanoparticles were prepared using 0.01 M AgNO3 solution. The reduced GO sheet decorated with Ag is referred as G-Ag sample. G-Ag was characterized by FTIR (Fourier transform infrared) spectroscopy using GO as standard. An explicit alkene peak appeared around 1625 cm(-1) was observed in G-Ag sample. Besides, the characteristic carbonyl and hydroxyl peaks shows well reduction of GO. The FTIR therefore confirms the direct interaction of Ag into Graphene. SEM (scanning electron microscopy) and TEM (transmission electron microscopy) analysis were performed for morphological probing. The average size of Ag nanoparticles was confirmed by around 5-10 nm by the high-resolution TEM (HRTEM). The Ag quantum dots incorporated nanocomposite material could become prominent candidate for diverse applications including photovoltaic, catalysis, and biosensors etc.     

Increased gas solubility in nanoliquids: Improved performance in interfacial catalytic membrane contactors

The kinetics of gas‐liquid catalytic reactions can be strongly promoted when these are performed in interfacial catalytic membrane reactors instead of other three‐phase reactors such as slurry stirrers or trickle beds. The well‐defined gas‐liquid‐catalyst contact in this system avoiding diffusional limitations is usually argued as the main reason for such enhancement. In this work, using nitrobenzene hydrogenation as a model reaction, we propose that this increased catalytic performance might also be attributed, at least partially, to increased gas solubilities in mesoconfined solvents (or simply “nanoliquids”) in interfacial contactors overcoming the values predicted by Henry's Law. To support this hypothesis, we provide experimental evidence of a dramatic increase of H₂ solubility in confined ethanol using mesoporous γ‐Al₂O₃ as confining solid. Gas‐liquid solubilities can be enhanced up to five times over the corresponding bulk values for nanoliquid sizes lower than 15 nm as long as the gas‐liquid interface is confined in a mesoporous array. In such a situation, the volume of the gas‐liquid interface is no longer negligible compared to the total volume of the confined liquid, and the high surface excess concentrations of the gas adsorbed on the liquid surface make solubility grow up dramatically. According to these measurements, we discuss how nanoliquids might form in catalytic membrane contactors, which gas‐liquid configuration in the reactor appears to be more appropriate, and how the structure of the mesoporous catalytic layer contributes to their increased gas solubilization performance. © 2008 American Institute of Chemical Engineers AIChE J, 2009     

Development and performance evaluation of a dead weight force machine in 2–50N range

Results of the performance evaluation of a newly designed, developed and fabricated dead weight machines to realize forces in the range of (2–50) N are reported in this paper. Precision load cells of 20N, 50N and 100N having an expanded uncertainty of ± 0.03% are used for this evaluation. The calibration of these load cells against the dead weight force machine shows that the repeatability (Rep) and reproducibility (Repr) are better than 0.003% and 0.005% respectively, over the entire range. The calibration data observed is found to closely agree with the calibration results obtained directly against the Physikalsich-Technische Bundesanstalt (PTB), Germany force standard machine having the relative measurement uncertainty of the force scale in the measuring range ≤ 0.002%.     

Environmental factors in woodfuel production: Opportunities,risks, and criteria and indicators for sustainable practices

Bioenergy from sustainably managed forest ecosystems could provide a renewable, carbon-neutral source of energy in many nations and communities throughout the world. In order for forest bioenergy to be an ecologically sustainable fuel source, woodfuel procurement systems must not adversely impact forest ecosystems or the environment. Sustainable forest management (SFM) certification schemes are one mechanism for applying standards and monitoring regimes to forest management systems to ensure ecological sustainability. This paper provides a global review of the main environmental risks to forest ecosystems that can arise from household- to industrial-scale woodfuel production systems, including forest soil quality and site productivity, water resources, biodiversity and carbon budgets. A set of regionally adaptable principles, criteria, indicators and verifiers of sustainable forest management were developed, based on criteria and indicators from existing internationally recognized certification frameworks and scientific literature and tailored to address issues relevant to producing and harvesting forest bioenergy feedstocks. A variable monitoring approach and a three-tiered certification approach are proposed as two methods for enabling the adoption of certification and associated monitoring requirements across a wide range of forest operations in regions with widely differing levels of development. The importance of the Adaptive Forest Management framework inherent in certification systems to ensuring the efficacy and continual improvement in woodfuel sustainability is stressed. The proposed principles, criteria, indicators and verifiers can be adapted to local conditions and incorporated into existing sustainable forest management and green energy certification schemes, as well as other criteria and indicator frameworks, to ensure the environmental sustainability of woodfuel production systems.