Modeling And Simulation Of The Switched Reluctance Motor

This Paper summarizes the study conducted on the techniques used and implemented to minimize the torque ripple of the Switched reluctance Motors. These motors although offering the advantages of higher speeds, reliability and phase independence, have the limitations of the torque ripple and non-linearity in the magnetic characteristics. Thus in order to have the good understanding of the Motor, it is simulated in the MATLAB/SIMULINK environment. This paper describes details on modeling of two different configurations of Switched Reluctance Motor concentrating only on the linear model by obeying all of its characteristics. The two configurations of motors are applied with two different control techniques and the results are calculated and tabulated. Load and No load analysis are also performed to understand the behavior of motor with load. Through out the analysis, various values of turn-on and turn-off angles are selected and finally the optimum values are calculated based on the performance parameters of Average torque, speed and torque ripple. All simulations are documented through this paper including its block models and initializations performed. Finally a control technique is recommended which produces the best results with smallest torque ripple

Ergonomic Immobilization Frame for Radiotherapy

The primary purpose of this project is to demonstrate that patients can be safely immobilized using air in the general torso area so that radiation can be administered to that region. The primary target will be to treat tumors in the lungs and liver. By immobilizing patients during treatment it allows for the radiation to be consistent in targeting the desired region of the body, which would not be the case if the patient was moving. Air was chosen as the desired medium to immobilize the patient because of comfort and it provides an easy medium for radiation to travel through which does not interfere with the radiation. Through research the limiting factor of human body was the pulmonary cycle which was determined to be approximately 0.15 Psi. In order to use air for immobilization airbags were incorporated as a means to hold the air and once pressurized would be used as the restraint force on the patient. As a means to demonstrate that air in fact could be used to immobilize a patient a prototype of a radiation chamber was built to provide a proof of concept. The radiation chamber frame was built to completely encapsulate the patient 360 degrees. The two airbags were placed in the frame which provides complete immobilization of the patient from all angles. The patient had to be standing while the radiation was being administered in order to target certain areas which could not be included if the patient was sitting or lying down. A circular frame was the desired shape of the frame because it allows for radiation to enter and exit the chamber at the same angle regardless of where it is administered. The radiation chamber requires the use of radiation safe materials in any given area where the frame comes into contact with radiation, for this reason non-metallic materials were used. The chamber prototype was built using wood and plexiglass. Finite element analysis simulated an allowable applied pressure of 6.0 Psi applied to the shell. Prior to the given prototype, there was no means available to immobilize a patient while standing for radiotherapy. Experimental tests demonstrated that a person could be immobilized in the general torso area using air.https://scholarscompass.vcu.edu/capstone/1214/thumbnail.jp

Characterization of molecular functions of polyamines in fruit development and ripening in tomato (Solanum lycopersicum)

Putrescine (PUT), spermidine (SPD) and spermine (SPM) are three major polyamines (PAs) present in all living organisms. These biogenic amines have been implicated in diverse plant growth and development processes, including seed germination, tissue lignification, organogenesis, flowering, pollination, embryogenesis, fruit development, ripening, abscission, senescence, and stress responses. To elucidate molecular roles of PAs in fruit development and ripening, I characterized transgenic tomato plants ectopically expressing yeast spermidine synthase (ySpdSyn) or S-adenosylmethionine decarboxylase (ySAMdc) under constitutive CaMV 35S and/or fruit-specific SlE8 promoters. The ySpdSyn-expression enhanced PUT, SPD and SPM level in floral buds and fertilized developing ovaries by 2- to 3-fold compared to WT tissues with majority being sequestered as bound forms. Higher PA levels altered fruit shape of transgenic tomatoes to more obovoid than WT by regulating expression of fruit shape genes (SUN1 and OVATE), and cell division and expansion genes (CDKB2, CYCB2, KRP1 and CCS52B). Characterization of PA homeostasis during fruit growth and ripening revealed a strong correlation of conjugated PAs with transcripts abundance of PA biosynthesis (ODC, ADC, SAMdc3) and catabolizing genes (CuAO-like, PAO4-like) and the bound PAs to transcript levels of ySpdSyn and SAMdc2 suggesting a significant metabolic inter-conversion among the various forms of PAs. Co-expression of ySpdSyn and ySAMdc transgenes showed that SAMdc is the rate limiting step in biosynthesis of higher PAs with potential to alter PA homeostasis in fruit tissues. Characterization of ySpdSyn and ySAMdc transgenic and WT fruits showed that expression of transgenes was associated with higher firmness of ripened fruits both on-planta and after harvest up to 17 days after ripe stage. Free SPD/SPM levels were positively correlated with fruit firmness, accumulation of total solids and delay in fruit shriveling and inversely correlated with fresh fruit weight, juice pH and seed number in tomato fruits. Free PUT levels exhibited trends opposite to that seen with SPD/SPM confirming hypothesis that PUT and SPD/SPM ratios play significant roles in the outcome of biological functions of PAs. Evaluation of ySpdSyn lines under field conditions showed 50% increase in fruit yield per plant due to continued fruit set until late in the season and up to 60% increase in fruit fresh and dry weight much beyond the fruit breaker stage. The metabolomic changes in transgenic fruits were determined using the nuclear magnetic resonance spectroscopy (1H NMR) and compared to WT fruit metabolic profile during on-planta fruit ripening and post-ripening stages. Free SPD levels were positively correlated with Ile, Val, Glu, Gln, Trp, malate, citrate and trigonelline. The levels of Ala, Glu, Asp and UDP-NAcGLU were negatively correlated with free SPD levels but positively correlated with free PUT indicating differential function of these two PAs. Levels of fructose and AMP were also negatively correlated with free SPD. Conjugated and bound PAs exhibited a limited correlation with metabolome profiles. The node-edge network analyses among PAs, metabolites and their associated pathways showed that PAs upregulate many anabolic pathways, but negatively affect glycolysis, starch and sugar metabolism, and zeatin biosynthesis. Taken together these results indicate that SPD is associated with enhancing many metabolic pathways and delaying senescence-related processes leading to improved postharvest fruit quality. I have collated transcriptome of transgenic plants and mutants with altered PA levels. Its analyses revealed complex and differential relationships among PUT, SPD and SPM in regard to regulation of plant hormone biosynthesis and signaling. In summary, the use of transgenic plants with modified PA levels provide an insight into molecular functions of PAs in altering fruit architecture, improving fruit quality attributes, increasing fruit production and delaying ripening-related changes in tomatoes. Limited transcriptome profile suggest a complex crosstalk between PAs and plant growth hormones during fruit ripening. Metabolome profiles of transgenic fruits showed a significant impact of PAs on fruit quality improvement by restoring metabolic pathways during fruit ripening

An Empirical Study of Risk-Return Profile of Islamic Mutual Funds: A Case from Pakistan

The remarkable growth of the Islamic mutual funds over the globe has increased demand among investors to include these funds in their portfolio of investments. With the emergence of Islamic Mutual Fund Muslim investors are increasingly shifting to Islamic Mutual Fund. Since 1990s equity investment the total wealth under the management of Islamic equity funds (excluding capital appreciation) has grown at an annual rate in excess of 15%.The growth of the Islamic funds operating in Pakistan is very rapid for example; Islamic Mutual Funds started in 1995 with Al Meezan Investment Management Limited introducing first Islamic Mutual Fund (Al Meezan Mutual Fund) as on July 13, 1995. The value of the total assets for the Islamic equity funds have risen from USD 800 million during the year 1996 to USD 3.6 Billion in just seven years period i.e. 2003. Hence, this research paper is an attempt to investigate risk and returns profile of these funds relative to the respective market Islamic and Conventional benchmarks using panel data analysis from July 2007 to June 2012. Consistent with previous studies conducted to analyze the performance of Islamic funds; on average the results indicate that there is statistically insignificant difference in return performance of the Islamic funds relative to the benchmarks. The result also reveals that there is a superior fund selectivity skill but inferior market timing expertise among the Islamic fund managers within the period of the study. On the contrary, results signify that the Islamic funds have been able minimize the risks as compared to the benchmarks and their returns performance is comparable to the market benchmark. Hence, the outcome of this study would benefit potential investor and market players towards participating in mutual fund industry, particularly in Malaysia. Additionally, the study will add knowledge on Islamic mutual fund’s performance in the finance literatures. Keywords:Islamic Mutual Fund, Performance Evaluation, Panel Data

Metagenomic Profile of the Bacterial Communities Associated With Ornithodoros Muesebecki (Acari: Argasidae) Ticks On Socotra Cormorant Colony in the United Arab Emirates and Presence of Three Important Pathogenic Groups in Them

Ticks are well known to transmit various pathogens including bacteria, viruses and protozoa to humans and animals. The soft tick (Omithodoro muesebecki) was common on a breeding colony of the Socotra cormorant (Phalacrocorax nigrogularis) in Siniya Island, the United Arab Emirates (UAE). The aims of the study were: i) instigating the prevalence and conduct genetic characterization of the important bacterial pathogens Borrelia spp. (causal agents of relapsing fever), Rickettsia spp. (causal agent s of spotted fever), and Coxiella burnetii (causal agent of Q fever); ii) understanding the overall bacterial community associated with 0. Muesebecki by using Illumina-based metagenomics approach; and iii) establishing a molecular record of 0. Muesebecki based on molecular markers. Ticks were collected from the largest breeding colony of Socotra Cormorant in 2013 and 2016. Subsequently, genomic D A was extracted from each t ick, and conventional PCR assays were used to detect certain pathogens. Borrelia spp. and Rickettsia spp., were not detected. However, PCR assay and metagenomics analysis is indicated the presence of the Coxiella genus. Sequencing results revealed 809 bacterial operational taxonomic units (OTUs) within the five samples from 2013 and 2686 OTUs within the 5 samples from 2016. Metagenomic analysis showed that Firmicutes, Proteobacteria, and Bacteroidetes are the most dominant phyla. C. burnetii was the most prevalent species in all samples in 2013 and 2016. This data provides the complete picture to date o f t he bacteria l communities present within 0. Muesebecki under natural conditions in the UAE using high-throughput sequencing technologies. In addition, this study provided the first DNA molecular record of O. muesebecki in GenBank. Further investigations regarding the functional role of Coxiella in seabird colonies is neede

Knowledge, attitude and practice of parturients regarding Epidural Analgesia for labour in a university hospital in Karachi

Objective: To assess the knowledge, sources of knowledge, attitude (fears and misconceptions) regarding Epidural Analgesia (EA) and practices of parturients delivery at Aga Khan University hospital (AKUH).Methods: A hospital based cross sectional study was conducted at the obstetric unit of AKUH, from November to December 2003. A questionnaire was filled through verbal interviews conducted on 448 parturients fulfilling the inclusion criteria.Results: Seventy six percent of the females were aware of epidural analgesia as a labor pain relieving method. However, only 19% availed EA. About 40% had heard about EA from their obstetricians and 64% from friends or relatives. Twenty even percent believed that EA has detrimental effects on the baby while 9% stated that EA can prolong the duration of labour.CONCLUSION: Majority of the pregnant females delivering at Aga Khan University Hospital were aware of epidural analgesia for labour. However, only a small proportion are availing this service, due to fears and misconceptions