Influence of horn length on radiation pattern of oblique-flare-angle corrugated horn

The influence of horn length on the radiation pattern of an oblique-flare-angle corrugated horn is described. Two experiments with a 110° horn are reported. These show that a horn with three slots has a radiation pattern which is essentially the same as that of a horn with five slots. It is also demonstrated that the innermost slot has a dominant effect on the pattern.     

Development of ceramic microstructures

For the production of microstructured ceramic parts, development efforts are necessary in the field of powder synthesis as well as in the area of shaping. Several processes have been developed. Powder synthesis was performed starting from metal organic precursors and using a two stage thermal process. Shaping was performed by sol-gel methods, by pressing of a ceramic slurry or an organic precursor paste as well as by direct electrophoretic deposition of gels in a microstructured form. An overview is given on the methods and the results.     

On the Optimality of a Simplified Multicharacteristic Component Inspection Model

Inspection for multicharacteristic components is an important means to assure product quality. A component is inspected with respect to its characteristics of which non-conformance of one would result in the rejection of the component. Based on a cost-minimization model developed recently by Raoul et al., this paper develops a simplified version of the model to capture the cost implication of false rejection, false acceptance and inspection of the components. The simplified model is computationally more efficient than the earlier one. Optimality of the sequencing of characteristics to be inspected is explored. Based on the simplified model, the optimal number of cycles for inspection can be readily determined. A stopping rule is developed for the search of the optimal number of cycles. Sufficient conditions for performing one cycle of inspection or no multicharacteristic inspection at all are given. Finally, the results are extended to the case where the probabilities of defectives are random.     

Service Domains for Ambient Services: Concept and Experimentation

We investigate ambient services, which we define as services that are related to the surrounding physical environment of the user, are locally useful and can be considered a form of location-based services. We introduce the notion of service domain which refers to the geographical area of relevance and utility for ambient services. We also consider a stereotypical case where a user might be within multiple service domains at the same time (when the service domains containing the user overlap) and so, can utilize a collection of services comprising services selected from each of the service domains containing the user. A language of operators is given for defining such a collection of services in terms of constituent services from the overlapping service-domains. Moreover, we describe and evaluate a prototype system that shows how to compute the services for a user in multiple service domains. The result is a framework for reasoning about ambient services for filtering or proactively suggesting mobile services based on geographical boundaries. Seng Wai Loke is a Faculty of Information Technology Research Fellow at Monash University. He is author and co-author of more than 90 research papers published in journals, books, conferences, and workshops. His research interests are intelligent and mobile agents, service-oriented computing, and pervasive computing including device ecologies, context-aware systems, mobile services, and ubiquitous e-commerce. He has been on the program committee of more than ten conferences and workshops in the area of mobile computing and agents. Shonali Krishnaswamy received a PhD in Computer Science from Monash University (Australia) in 2003. She currently holds the position of a Research Fellow in the School of Computer Science and Software Engineering at Monash University. Her research interests include Service Oriented Systems, Software Agents and Distributed/Ubiquitous Data Mining. She is a member of ACM and IEEE Computer Societies. Thin Thin Naing has completed her Masters by Information Technology (MIT by Minor Thesis) from the School of Computer Science and Software Engineering at Monash University, Australia. Her research interests include Mobile Services, Location-based Services and Ambient services.This revised version was published online in August 2005 with a corrected cover date.     

A seismic refraction survey for an expressway project in Singapore

Bulletin of Engineering Geology and the Environment - Geophysical methods of site investigation have been used in civil engineering for many years. Of these methods, seismic refraction survey is...     

Wastewater Treatment for Edible Oil Refineries

Systems and practices for successful treatment of edible oil refinery wastewater are reviewed, including: total plant good housekeeping, conservation of water usage, integrated system design, by-product handling, and process control and operation.     

Characterization of metal (Fe,Co, Ni,Cu) and fluorine codoped barium strontium titanate thick-films for microwave applications

The influence of codoping of Fe, Co, Ni, Cu as acceptors and F as donor on the dielectric properties of screen-printed Ba_0.6Sr_0.4TiO₃ ceramic thick-films has been investigated. The undoped and codoped Ba_0.6Sr_0.4TiO₃ powders were synthesized through a sol-gel route. The thermal gravimetric analysis revealed the difference of the thermal decomposition behaviour between the undoped and codoped precursors. The ceramic powders were characterized with x-ray diffraction, scanning electron microscopy and BET measurements. Larger crystallite sizes of the codoped powders were observed. The densification behaviour of the powders was recorded by dilatometry and indicated that codoping influences the sintering mechanism. The permittivity, dielectric loss and tunability of the undoped and codoped thick-films were characterized with coplanar waveguide structures up to 30 GHz.     

Indium tin oxide-free semi-transparent inverted polymer solar cells using conducting polymer as both bottom and top electrodes

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is investigated as a transparent cathode to replace indium tin oxide (ITO) in inverted polymer solar cells. Increasing the thickness of the PEDOT:PSS electrode leads to a reduction in transparency and sheet resistance which lowers the photocurrent but increases the fill factor of the solar cells. The offset of photocurrent and fill factor as the thickness is increased leads to a saturation of the power conversion efficiency to 3%. These electrodes were applied to flexible substrates showing similar device performance to glass based devices. Cyclic bending test of these flexible polymer electrodes show improved conversion efficiency retention (92%) when compared to flexible ITO based electrodes (50%) after 300 bend cycles. In addition to using PEDOT:PSS as a cathode replacement for ITO in inverted solar cells, its use as a semi-transparent anode replacement to Ag is also examined. Semi-transparent inverted solar cells fabricated with ITO as the cathode and PEDOT:PSS as the top anode electrode were demonstrated showing efficiencies of 2.51% while replacement of both ITO and Ag with PEDOT:PSS as both the cathode and anode show efficiencies of 0.47%.     

A Low Complexity Decoding Algorithm for Extended Turbo Product Codes

In this letter, we propose a low complexity algorithm for extended turbo product codes by considering both the encoding and decoding aspects. For the encoding part, a new encoding scheme is presented for which the operations of looking up and fetching error patterns are no longer necessary, and thus the lookup table can be omitted. For the decoder, a new algorithm is proposed to extract the extrinsic information and reduce the redundancy. This new algorithm can reduce decoding complexity greatly and enhance the performance of the decoder. Simulation results are presented to show the effectiveness of the proposed scheme.     

Toxicological evaluation of transgenic rice flour with an Escherichia coli phytase gene appA by sub‐chronic feeding study in Wistar rats

BACKGROUND: Phytase is increasingly used as an ingredient in swine and poultry feeds to improve the bioavailability of phytate‐bound phosphorus and reduce the supplement of elemental phosphorus in feeds. Recently, a transgenic rise (TGR) with phytase appA gene from E. coli has been developed in Taiwan. To assure the food safety of this TGR, we performed a sub‐chronic whole‐food feeding study with Wistar rats. RESULTS: Weaned feeding male and female rats were divided into TGR and non‐TGR (NTGR) groups (20 rats per group), and fed diets containing 76.8% rice flour of TGR and NTGR, respectively. After 93 days feeding, although some hematological findings and blood chemistry values differed significantly between the TGR and NTGR groups, all values were still within the normal range for rats of this age and sex. No adverse effects of TGR were observed in terms of animal behavior, weight gain, or feed utilization rate. Necropsy at the end of the experiment indicated that neither pathological lesions nor histopathological abnormalities were present in organs such as liver, kidney, intestines and testes of rats in TGR and NTGR groups. In addition, no significant differences (P > 0.05) were observed in relative organ weights, hemograms and blood indices of rats between the two groups. CONCLUSION: These results demonstrated that in a 93‐day feeding study with Wistar rats a diet containing 76.8% of TGR flour having a phytase activity of about 1500 U kg^?1 body weight per day has no adverse effects. Copyright © 2007 Society of Chemical Industry