Some toxicological studies on house crickets in relation to their circadian rhythms

Imperial Users onl

Water and charge transport models in proton exchange membranes: An overview

Recently, the significant role of water management in affecting the performance and durability of proton exchange membrane fuel cell (PEMFC) has been subjective to an intensive research to understand water transport phenomena which is marked by two processes: water adsorption and water diffusion. Various mathematical models have been developed to address both processes on a different basis. This article briefly reviews various water transport models in a comparative manner to have a better understanding on the role of water hydration with respect to membrane structure and transport mechanism, in affecting the proton transport in the membranes. A discussion on the validity and reliability of the models for describing the water management is also presented. The limitations that are required to be overcome to design new materials meeting the new trends of membranes development for fuel cell are also highlighted

Shape analysis of the corpus callosum of autistic and normal subjects in neuroimaging.

Early detection of human disease in today’s society can have an enormous impact on the severity of the disease that is manifested. Disease such as Autism and Dyslexia, which have no current cure or proven mechanism as to how they develop, can often have an adverse physical and physiological impact on the lifestyle of a human being. Although these disease are not fully curable, the severity handicaps that accompany them can be significantly reduced with the proper therapy, and thus the earlier that the disease is detected the faster therapy can be administered. The research in this thesis is an attempt at studying discriminatory shape measures of some brain structures that are known to carry changes from autistics to normal individuals. The focus will be on the corpus callosum. There has been considerable research done on the brain scans (MRI, CT) of autistic individuals vs. control (normal) individuals to observe any noticeable discrepancies through statistical analysis. The most common and powerful tool to analyze structures of the brain, once a specific region has been segmented, is using Registration to match like structures and record their error. The ICP algorithm (Iterative Closest Point) is commonly used to accomplish this task. Many techniques such as level sets and statistical methods can be used for segmentation. The Corpus Callosum (CC) and the cortical surface of the brain are currently where most Autism analysis is performed. It has been observed that the gyrification of the cortical surface is different in the two groups, and size as well as shape of the CC. An analysis approach for autism MRI is quite extensive and involves many steps. This thesis is limited to examination of shape measures of the CC that lend discrimination ability to distinguish between normal and autistic individuals from T1-weigheted MRI scans. We will examine two approaches for shape analysis, based on the traditional Fourier Descriptors (FD) method and shape registration (SR) using the procrustes technique. MRI scans of 22 autistic and 16 normal individuals are used to test the approaches developed in this thesis. We show that both FD and SR may be used to extract features to discriminate between the two populations with accuracy levels over 80% up to 100% depending on the technique

ORDER PICKING AND STORAGE USING STACKABLE PALLETS IN A WAREHOUSE

Quarter Billion dollars could be saved annually by double stacking pallets. A forklift storing 100 double stacked pallets saves 2.5 working hours versus single pallets. More than one billion pallets and cases handled between Wal-Mart distribution centers according to BEA White Paper (2006) [1], assume only 500 million were stackable pallets. This translates to 12.5 million working hours. If a forklift driver earns $20 per hour, then$250 million can be saved. Moreover, handling double stacked pallets takes up to 46 % of total time to pick and store. This is a significant element that was ignored in literature. All previous research focused only on travel time that is just part of the total time. In this dissertation we model dual command operations to find optimal path with minimum travel time. Combination of both picking and storage activities is also known as dual command. Our environment is a manual warehouse where full pallets can be double stacked. Accordingly, three time-based models were developed as 123 steps to reach dual command model; order picking model, storage model and combined storage and order picking model. The mathematical models find the optimal sequence of storing and picking pallets that leads to the minimum travel time. Using those models allow double stacking pallets, therefore around half of material handling time, labor cost, and equipment cost will be saved compared to single stacked pallet operations. Two heuristics were also developed that gave sub optimal but quicker solutions that can also be used by the warehouse management and reduce the travel time significantly as well

Dilemma of applying Islamic sharia’a through takhayur and talfiq principles in the modern Egyptian legal system

For many Egyptians, the only path to modernity in the Egyptian legal system is believed to be through utilizing Islamic sharia’a. Between the nineteenth and twentieth centuries, the Egyptian legal elite worked to introduce a modern interpretation and application of Islamic sharia’a. The Islamic principles takhayur and talfiq were used to do this. While the main usage of takhayur and talfiq was to legitimize the modern legal system by maintaining the usage of Islamic sharia’a, the legal practice reached a contradictory outcome. The Courts have been unable to decide on the exact relationship between Islamic sharia’a and other legal texts. This confusion has produced ambiguity and uncertainty in legal practice. This situation of uncertainty in the legal system is inevitable because of the differences in the underlying nature and philosophy of the modern and sharia’a legal systems. Accordingly, the Egyptian legal system may require additional secular reform to reduce the uncertainty by stressing the superiority of the legal text