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Today, Chemistry has reached a point in technology where some of the wet chemistry experiments can be mimicked with computers; saving extensive time and effort in the process of research and development. Molecular modeling programs such as Hyperchem give a good representation of the effectiveness of molecular modeling in the world of chemistry. With Hyperchem, values such as electron density, charge, heat of formation, molecular orbitals, bond lengths, etc. can be obtained. Analysis of the computational values of known molecules and reactions allows scientists to understand chemical behavior. Correlation of the computational analysis with the experimental results reported in literature validate a computational method. Hyperchem is an excellent tool that will not only explain known reactions and experimental data but will also provide insight into unknown reactions. A reaction involving the nucleophilic attack on cyclopropane will be mimicked using Hyperchem. This is a reaction similar to the one Danishefsky and Singh performed in 1975 using wet chemistry methods. Bellow is the schematic of a similar reaction which is predicted. (Seescheme I)
The purpose of this project is to redesign a quadratic buck converter, where the dc voltage conversion ratio has a quadratic dependence on duty-cycle, providing a large step down. By introducing two resonant networks, soft switching is attained, providing high efficient operating condition for wide load range at high switching frequency. The converter will be redesigned for the following specifications:
Input voltage range:--- to be determined
Output voltage:---5 V DC
Output current:--- O A to 2 A DC
Switching frequency:---500 kHz to I Mhz (fixed frequency)
Output ripple voltage:--- 1% of Vout at Vin= 24 V, full load
The circuit will be implemented on SABER and Cadence to optimize the design for overall power conversion efficiency. The power loss will be calculated in each semiconductor component and the overall power conversion efficiency will be computed. There are seven stages at which the circuit will be analyzed. Stage one (to -tl) begins when the auxiliary switches are turned on under ZCS conditions. The second stage (tl - t2) is the resonant stage. The third stage (t2 - t3) is where the
conduction of the diode D3 allows the main switch S3 to turn on under soft switching (ZVS condition) at t = t2 when the gate signal is applied. In the forth stage (t3-t4), the voltages V CRI and V CR2 keep clamped and the currents i LR1 and i LR2 and Io. The fifth stage (t4 - tS) switches the auxiliary switch Sl and S2 off with soft commutation, while S3 is turned off in stage six (tS - t6). Finally in stage seven (t6 - t7), the resonant capacitor voltage falls to zero and DRI and DR2 are turned on. This stage ends at t = t7 when the auxiliary switches are turned on again beginning a new switch cycle
The objective of this experiment was to study the effects of the anti-epileptic drug Diphenylhydantoin (DPH) on A/J (A) and A/JWySn (W) mice, the reciprocal F1 outcrosses and backcrosses between them. DPH is a teratogen which is known to cause cleft lip (Cl) in children when administered to pregnant woman. In this study we discovered that DPH substantially increased the frequency of cleft lip in each strain of mouse. Several mice in this study were injected with 75mg/kg of DPH in 0.05% NaOH ip on day 10 of gestation to pregnant females. Other mice were left untreated as the control in this experiment. Still others received only the solution in which the DPH was dissolved, as a vehicle control. In the F1 outcrosses (OC) of the untreated and vehicle mice we found that the variation was entirely dependenton the uterine environment of the dam; the strain of the sire and the genotype of the fetus are irrelevant: &Wx% W(17.7%)= ~Wx% A(17.7%)>&Ax% A (3.0%)=&Ax% W(5.5%). Backcrosses (BC) of the F1progeny to A or to W mice, revealed a different pattern: &Flx%W (8.6%)=&Wx %F1 (8.2%)>& Flx%A(3.6%)= &Ax% F1 (1.6%), showing both heterosis and strain differences acting through a genotypic array. Therefore, this suggests a multifactorial genetic system, including embryonic contributions. Treatment with DPH significantly increased CL in all mating. Treated &Ax% A produced a higher frequency of CL ( 41%) than the untreated W (18-30%). The lower spontaneous frequency of CL in A mice then, only shows reduced sensitivity not resistance: &Wx%W ( 56.8%)=&Wx%A (60.9)>&Ax%A (41.9%)=&Ax%W(38.7%). Not one of the BC showed hetereosis, and the pattern seen was the same as that of the pure-line and F1-OC: &Flx%W (70.7%)=&Wx%F1 (59.9%); &Ax%F1 (43.3%)=&cFlx%A(37.8%). Regardless of dam (F1 or pure-line), if the genotypic array in BC embryos was mostly W, cleft lip frequency was greater; if they were mostly from A, cleft lip frequency was lower.
The t-complex includes a variety of unrelated genes on a large segment of DNA (20-30 X 103 kb) at the proximal region of Chromosome 17 in the mouse genome. The t-complex is found in 25% of wild Mus domesticus (the house mouse). In 1924, the first t- complex characteristics were discovered in studies on the effects of mutations causing carcinogenesis. The genes that are located in the t-complex region affect tail length, male sterility, embryonic viability, meiotic transmission and recombination. In this project, an interspecific cross between M. domesticus strain C57BL10/J and Mus spretus is being used to accomplish two objectives: (1) To establish congenic lines of mice whose segments contain a discrete segment of Mus spretus on a Mus domesticus background and (2) To measure the genetic recombination distance between two simple sequence repeat (SSR) loci, D17Nds2 and D17Nds3, located on the proximal region of Chr 17. We have addressed this second objective by typing 93 backcross offspring and measuring the recombination distance between D17Nds21 and D17Nds3 to be 15.1 cm. This recombination distance is much larger than that previously reported, probably owing to the nature of the interspecific cross used by us. Currently, this cross has generated offspring at the tenth backcross (N=10) generation with less than 1% of the Mus spretus retained. The selection for retention of the proximal region of Chr 17 from the M. spretus genome is done by typing backcross offspring using several SSR markers. The ultimate goal of this project is to create inbred strains of mice which are homozygous for small portions of Chr 17 from M. spretus on a M. Domesticus genetic background. These inbred mice will be used to construct genomic DNA libraries from which the M. spretus chromosome segments will be cloned by differential hybridization.
We have developed a methodology to implement customer satisfaction surveys on the World Wide Web as well as store and retrieve data from them for analysis. First, we completed a literature review of existing surveys to examine proper format and content for a customer satisfaction survey. We also conducted focus group discussions with potential survey users. During the focus groups, we asked some of the survey questions and recorded responses. We also asked about the types of surveys users prefer to complete and what could induce them to complete a survey. Based on the results of the survey responses and the literature review, we were able to design an effective format for a survey with a customized content. Our Web survey was able to obtain critical feedback on customer satisfaction. A process to collect and store user responses from the survey was also designed. Unlike many existing surveys that e-mail the responses to a survey administrator, our approach stores the responses to a single data file, allowing an administrator to quickly download the file for analysis. We used this methodology to develop a pilot survey that will be posted on the Illinois Institute of Technology (IIT) web site. This poster session will discuss the scope of the design and collection processes for the IIT pilot survey.
In our study, student investigators determined that thematic teaching of the subject Weather, Seasons and Climate was more successful than teaching content area in isolation. Special care and attention were given to the selection of resource materials used in preparation of the unit lesson. Lesson plans and hands-on activities were designed to motivate and challenge both the physical and learning disabled students. It was determined that as a result of studying this unit, students were better prepared to evaluate literature from different genres and discuss the elements of weather, seasons and climate. Students also learned how to use maps, charts, graphs, tables, photographs, booksand computer applications to gather and interpret data. The students learned how to formulate a hypothesis, conduct experiments, and accurately relate findings to everyday life experiences. Lastly, the students became knowledgeable about various conditions of weather, seasons and climate. By using of integrated lesson plans, the students were ableto stay on task and relate the scientific materials to other disciplines. The unit was taught for seven and a half hours per week and the population of students was 6-8th graders in an elementary school setting. The core discipline was science; however the other integrated disciplines were Mathematics, Language Arts, Fine Arts and Social Studies. The mathematics discipline required students to calculate wind speed for air pressure, relative humidity, measurement of rainfall in various cities, and computer applications on the construction of graphs. The Language Arts discipline included the reading of several books from different genres, and a performance of an African rain dance and poetry recitation fulfilled the fine arts requirements. The social studies aspect included map reading from different geological regions with emphasis on the United States. In conclusion, the unit lessons conformed to the regulations of the State Goals for learning in Illinois as well as the Standards for the Chicago Public Schools.
