Showing papers by "Universiti Teknologi Petronas published in 2005"

Effects of discharge permit trading on water quality reliability

Abstract: Transferable discharge permit (TDP) programs show potential as cost-effective methods of pollution control. Nevertheless, there remain uncertainties that, if not adequately addressed, might impair their success. Concerns include modeling difficulties that might cause erroneous predictions of cost savings and environmental performance. This study focuses on environmental modeling associated with the stochastic environment. The mean-value first-order second-moment (MFOSM) method is extended to demonstrate how changes, due to discharge permit trading, in the environmental quality mean and/or variance of a system will cause the environmental quality reliability of the system to either decrease, increase, or remain unchanged. The Willamette River in Oregon and the Athabasca River in Alberta, Canada, are used as example case studies. These river systems are simulated to predict how they might respond if trading were implemented. In this study, environmental quality reliability is defined as the probability of the minimum dissolved oxygen (DO) concentration over the length of the river meeting a predetermined standard. Generally, for the Willamette River, trading improves the reliability, while for the Athabasca River, trading makes the reliability worse.

Glass-formation region of ternary Sn–Sb–Se-based chalcogenide glasses

Abstract: Tin-antimony-selenium (TAS)-based system belongs to the ternary chalcogenide compounds of IV-V-VI group owing to their heavy elemental masses, their glass formation region was assumed to be small comparing to their counterpart elements in the same group. However, there were rare published reports on their glass structure, while their glass boundary formation region was not yet reported. It was the aim of this paper to map their glass-forming region experimentally using XRD and validate it theoretically using the average co-ordination number, μ, and the fraction of the bond distributions, f, from chemical order model. Theoretically, it was validated that the glass formation was arrested between μ ≤ 2.4 and the fraction of Sn–Se bonds, fSn–Se < 44.5%. XRD analyses of 66-as-prepared samples revealed that the glass formation region was located within the predicted area that mapped in structural triangle.

Optimization and elucidation of interactions between ammonium, nitrate and phosphate in Centella asiatica cell culture using response surface methodology

Abstract: The effects of macronutrients (NO3 −, NH4 + and PO4 3−) on cell growth and triterpenoids production inCentella asiatica cell suspension cultures were analyzed using the Box-Behnken response surface model experimental design. In screening and optimization experiments, PO4 3− as a single factor significantly influenced cell growth where increasing the phosphate level from 0.1 to 2.4 or 2.6 mM, elevated cell growth from 3.9 to 14–16 g/L. The optimum values predicted from the response surface model are 5.05 mM NH4 +, 15.0 mM NO3 − and 2.6 mM PO4 3−, yielding 16.0 g/L cell dry weight with 99% fitness to the experimental data. While the NH4 +-NO3 − interaction influenced cell growth positively in the optimization experiment, NH4 + and NO3 − as single factors; and interactions of NO3 −-PO4 3−, NH4 +-PO4 3− and NH4 +-NO3 − were all negative in the screening experiment. Cell growth and the final pH level were positively affected by PO4 3−, but negatively affected by NH4 + and NH4 +-PO4 3− interactions. The different effects of factors and their interactions on cell growth and final pH are influenced by a broad or narrow range of macronutrient concentrations. The productions of triterpenoids however were lower than 4 mg/g cell dry weight.

Measurement of wood grain angle using free-space microwave measurement system in 8-12 GHz frequency range

Abstract: Microwave nondestructive testing (MNDT) methods are fast, contactless, accurate and continuous techniques for evaluation of moisture content, grain angle and density of the wood MNDT techniques using free-space microwave measurement (FSMM) system involve measurement of reflection and transmission coefficients in free-space Materials such as wood which are lossy and anisotropic causes a linearly polarized electromagnetic wave to be depolarized (elliptically polarized) upon transmission through the material The FSMM system can be used to measure polarization angle (/spl theta/) and axial ratio (AR) of elliptically polarized wave transmitted by the wood specimen Strength and stiffness along the grain direction are at least ten times greater than perpendicular to the grain for Malaysian wood There is a critical need to know the wood grain angle for structural applications The FSMM system consists of a pair of spot-focusing horn lens antennas, mode transitions, coaxial cables and a vector network analyzer AR and /spl theta/ of the elliptically polarized transmitted signal of Malaysian wood specimens were measured in the frequency range of 8 to 12 GHz for species such as Nyatuh and Light Red Meranti Wood specimens (12 cm by 12 cm by lcm) were prepared such that they are at different grain angles Results are reported for AR, /spl theta/ and wood grain angle for different Malaysian wood specimens The relationship between wood grain angle and measured /spl theta/ is discussed

Fuzzy patterns in multi-level of satisfaction for MCDM model using modified smooth S -curve MF

Abstract: Present research work relates to a methodology using modified smooth logistic membership function (MF) in finding out fuzzy patterns in multi-level of satisfaction (LOS) for Multiple Criteria Decision-Making (MCDM) problem Flexibility of this MF in applying to real world problem has been validated through a detailed analysis An example elucidating an MCDM model applied in an industrial engineering problem is considered to demonstrate the veracity of the proposed methodology The key objective of this paper is to guide decision makers (DM) in finding out the best candidate-alternative with higher degree of satisfaction with lesser degree of vagueness under tripartite fuzzy environment The approach presented here provides feedback to the decision maker, implementer and analyst

Hábitos de consumo alimentar dos curitibanos.

Abstract: This study intends to describe the alimentary habits of the Curitiba citizens older than 17 years old, belonging to the social classes A, B and C (Criterio Brasil), to identify segmentation patterns starting from characteristic psicografics and behaviory. A cross sectional descriptive conclusive research was accomplished with a sample of 280 interviews. Using frequencies analyses to identify the main victuals consumed in each meal, standing out the differences among the behavior in the days of week and weekends. The adoption of the multivaried procedures, cluster analysis and variance analysis, allowed to identify three groups of consumers withdifferent alimentary habits: "the gluttons", that eat everything without any special care with the feeding; "the unworried" ones, that eats sandwiches during lunch time, consume beverages alcoholics and smokes more than the members of the other groups and "the healthy" ones, that prefers salads and grilled meats and is more worried about the health. Key Words: Consume habits; alimentation; Curitiba citizens.

Expert system with an embedded imaging module for diagnosing lung diseases

Abstract: Lung diseases are one of the biggest killers in the world. Improved survival rate amid be obtained if the diseases can be detected at its early stage. The diagnosis of complex lung problems often requires the use of specialized diagnostic imaging methods such as X-Rays, MRI, CT Scan, etc. Medical consultants and radiologists are scarce in rural areas and mostly based in major hospitals in the cities. In this work, a rule-based expert system with an embedded imaging module has been developed. This system can assist general physicians for the early detection of lung diseases. A chest X-ray image processing tool (CIPT) consisting of imaging functions, a modified greyscale top hat (MGTH) function and a fuzzy inference system (FIS) are incorporated for the analysis of chest X-ray images. MGTH will improve the detectability of lung nodules and the fuzzy inference technique is used to diagnose the level of malignancy. The system was tested with 30 tests cases and was found to have an accuracy level of 90%.