Simulation Studies of Annealing Effect on a mc-Si Ingot for Photovoltaic Application

Silicon - A multi-crystalline silicon (mc-Si) ingot was grown by the directional solidification (DS) process for photovoltaic (PV) application. We have numerically investigated shear stress and...     

Enhancement of photoluminescence properties of green to yellow emitting Y3Al5O12: Ce phosphor by AlN addition for white LED applications

AlN-substituted in Y₃Al₅O₁₂: Ce³⁺ phosphor was synthesized to improve the phosphor efficiency of phosphor-converted white light emitting diodes. The photoluminescence properties of AlN-substitued for Al₂O₃ in Y₃Al₅O₁₂: Ce³⁺ phosphor showed excellent green to yellow emission intensity under 460 nm. The highest emission intensity was observed at an AlN concentration of 0.3 mol and a Ce³⁺ concentration in the optimized flux of 0.20 mol. The green to yellow emitting AlN-substituted in Y₃Al₅O₁₂: Ce³⁺ phosphor can be applied to white LEDs.     

Sliding of general frictional complete contacts

The interfacial contact pressure distribution beneath a complete sliding contact between elastically similar components, in the presence of friction, has been studied, with particular reference to contacts whose edge angles are 60°, 90° and 120°. The possible types of behaviour at the edge of contacts, namely power order singularity, power order bounded and square-root bounded, are discussed. The details of the behaviour require a detailed study of a characteristic equation and this shows that the kinds of pressure distribution to be anticipated, which can vary very markedly.     

Crack tip stress intensity factors for a crack emanating from a sharp notch

Accurate calibrations are provided for the crack tip stress intensity factor for a crack of finite length emanating from the symmetric tip of a sharp notch, of arbitrary angle, in terms of the generalised stress intensity quantifying remote loading of the notch. The solution is applied to example problems and shown to be accurate for cases where the crack is much shorter then the notch depth.     

Erratum to “PI and fuzzy logic controllers for shunt active power filter—A report” [Isa Transactions 51, 163–169]

The authors acknowledge certain errors in their recently published paper titled “PI and fuzzy logic controllers for shunt active power filter—A report. The ambiguity in bandwidth calculation of adaptive hysteresis controller and control aspects of dc-link voltage issues are addressed. The shunt APF system is validated through extensive simulation and the results are support features of the proposed technique.     

Effects of water quality on mangroves in an urban lake system

This study assessed the extent of anthropogenic stresses on two mangrove species (Sonneratia caseolaris and Cerbera odollam) in a tropical coastal lake system. An anaerobic factor, organic pollution and salt factors were identified as being responsible for the risks to mangroves. A flora risk tolerance index was developed to ascertain the spatial and temporal risk of plants to water pollution. This study revealed the risk to the Cerbera odollam species is high, compared to Sonneratia caseolaris. Further, the flora risk tolerance index is a good index for assessing the risks to the mangrove species.     

PI and fuzzy logic controllers for shunt Active Power Filter--a report

This paper presents a shunt Active Power Filter (APF) for power quality improvements in terms of harmonics and reactive power compensation in the distribution network. The compensation process is based only on source current extraction that reduces the number of sensors as well as its complexity. A Proportional Integral (PI) or Fuzzy Logic Controller (FLC) is used to extract the required reference current from the distorted line-current, and this controls the DC-side capacitor voltage of the inverter. The shunt APF is implemented with PWM-current controlled Voltage Source Inverter (VSI) and the switching patterns are generated through a novel Adaptive-Fuzzy Hysteresis Current Controller (A-F-HCC). The proposed adaptive-fuzzy-HCC is compared with fixed-HCC and adaptive-HCC techniques and the superior features of this novel approach are established. The FLC based shunt APF system is validated through extensive simulation for diode-rectifier/R-L loads.     

Chemical Composition,Amino Acid Content and Protein Quality of the Little-Known Legume Bauhinia purpurea L

Some nutritional and antinutritional characteristics and biological value of Bauhinia purpurea L seeds were studied. The mature seeds contained (g kg^-1 as is) 271·7 crude protein, 58·7 crude fibre, 124·5 crude fat, 29·3 ash and 515·3 carbohydrates. Potassium, phosphorus and iron occurred in higher concentrations when compared with commonly consumed legumes. The globulins and albumins together constituted major storage proteins (82% total protein). The essential amino acid profile of total seed proteins compared well with the FAO/WHO reference pattern except for a deficiency of sulphur-containing amino acids and tryptophan. When compared with the globulins, the albumins appeared to be a rich source of cystine, methionine, threonine, lysine and tryptophan. Seed lipids contained high levels of the unsaturated fatty acids, oleic and linoleic, which accounted for 62·6% of total fatty acids recovered. Both dry heating and autoclaving significantly reduced the antinutritional compounds. The in vitro protein digestibilities of raw, dry-heated and autoclaved seeds were 59·5, 72·3 and 78·7%, respectively. True digestibility and net protein utilisation were significantly higher in processed seed samples compared with raw seeds. Regarding utilisable protein, autoclaved samples exhibited relatively higher values than raw seeds. © 1997 SCI.