Fuzzy Controller for Matrix Converter System to Improve its Quality of Output

In this paper, Fuzzy Logic controller is developed for ac/ac Matrix Converter. Furthermore, Total Harmonic Distortion is reduced significantly. Space Vector Algorithm is a method to improve power quality of the converter output. But its quality is limited to 86.7%.We are introduced a Cross coupled DQ axis controller to improve power quality. The Matrix Converter is an attractive topology for High voltage transformation ratio. A Matlab / Simulink simulation analysis of the Matrix Converter system is provided. The design and implementation of fuzzy controlled Matrix Converter is described. This AC-AC system is proposed as an effective replacement for the conventional AC-DC-AC system which employs a two-step power conversion.Comment: 11 page

Neuroanatomical And Neurochemical Organization Of Compartments In The Basal Ganglia Of The Rat

The structural and neurochemical organization of the basal ganglia of the rat was investigated with highly sensitive modern anterograde and retrograde tracing methods in combination with immunocytochemical identification of intrinsic neuronal substances with the optical and laser-confocal microscope to address the fundamental organization of these centers as an integrated system.;Based on the present results and other evidence, a functional model of the basal ganglia is proposed: The corticostriatal inputs activate a large population of striatal neurons. Among these, appropriate neurons are \u27selected\u27 within each functional domain by the dopaminergic, cholinergic, and GABAergic recurrent collateral inputs. The same corticostriatal input simultaneously activates type II spiny projection neurons from each functional domain, which inhibit a population of parvalbumin-containing GABAergic pallidal neurons. These pallidal neurons disinhibit a number of pallidostriatal neurons via axon collaterals. The appropriate population of pallidostriatal neurons is \u27selected\u27, probably by subthalamic afferents. The selected GABAergic pallidostriatal neurons then inhibit striatal functional domains, thereby \u27selecting\u27 only the appropriate functional unit. The selected population of striatal projection neurons then inhibits a number of GABAergic neurons of the basal ganglia output centers. Again, appropriate neurons are \u27selected\u27 by subthalamic afferents and recurrent collaterals. The selected GABAergic neurons then disinhibit the thalamus, pedunculopontine nucleus and/or the superior colliculus via axon collaterals. The information sent to the thalamus is used to program memory, whereas that directed to the pedunculopontine nucleus or the superior colliculus participates in motor execution. The dorsolateral striatal circuit operates during sensory-guided and self-paced movements, while the medial and ventral striatal circuit operates during memory-guided movements. Striatal interneurons, globus pallidus neurons, subthalamic nuclear neurons and dopaminergic neurons play a role in \u27selecting\u27 the appropriate sets of neurons at different levels. (Abstract shortened by UMI.

A comparison between ginger and metoclopramide in the prevention of post operative nausea and vomiting in hospital universiti sains malaysia

Background: In general in today’s modern world, post operative nausea and vomiting is as common as 30 % of the total patients going under anaesthesia through multiple studies (Lermen J. et al. 1992, Saeeda I. et al. 2004) done around the globe. Post operative nausea and vomiting is a very disturbing outcome after anaesthesia. It may be managed with modern medicine, such as metoclopramide or with alternative medication, such as ginger as studied in this dissertation. Methodology: This is a randomized controlled trial study to look at effectiveness of ginger against a commonly used, metoclopramide as an anti emetic agent to prevent post operative nausea and vomiting. Patients were grouped into 2 comparable arms in a double blinded method to look at outcome symptoms of nausea, retching and vomiting. Primary and secondary statistical analysis were used to look at the association of post operative nausea, retching and vomiting against tablet metoclopramide and ginger given prior to anaesthesia. Results: The demographic characteristics were comparable between both groups. There was a significant finding statistically with p-value of 0.025 through Fisher’ exact test for association between post operative vomiting within 6 hours for ginger group against metoclopramide group. Other findings of the outcome symptoms of nausea and retching within 0 to 6 hours and more than 6 hours to 12 hours as well as vomiting more than 6 hours to 12 hours were not statistically significant. Conclusion: This significant results of effectiveness of ginger as a preventive for post operative vomiting is a very promising finding in anaesthetic medical practices. We believe the positive result of ginger will be a catalyser for future study on the effectiveness of ginger in Malaysia. Ultimately, this will help in development of our holistic medicine in Malaysia

STUDY OF COOLING TOWER SYSTEM FOR ENERGY EFFICIENCY OPERATION

This study shows how by reducing the cooling water circulation rate, improves the efficiency ofthe operations in the cooling tower system. This is done without modifying the internals of the current cooling towers such as the fills, water treatment programme and air flow rate. This study is applicable for all existing plants with the cooling tower system. This study shows the redistribution ofcooling water in the cooling tower water network. This study with detail calculations are tested for chillers, distillation condensers and air conditioners. The cooling tower performance curve is used as the tool for this analysis. The benefits of this study are colder cooling water temperature, reduce the compression work of the refrigeration cycle by 3.0 % for every 0.6 C reduction inthe cooling water temperature, reduce the cooling tower water consumption, reduce the cooling tower water treatment chemical consumption, reduce the cooling water circulation pump power consumption, and increase the heat transfer of the distillation condensers (increase production)

Oxidation Resistant Coatings on Microcelluar Carbon Foam using Simple Scalable Techniques

Carbon foam has many applications in the fields of thermal management, net-shape composites and electronic cooling due to its porous structure, low density, electrical and thermal conductivities. However it is prone to oxidation at high temperatures in air. Whereas some previous studies have reported oxidation protective coatings on other carbon structures such as graphite parts and fibers, there is very limited work on foam. Moreover, earlier methods have used vapor phase techniques such as Plasma Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD). There is no known study involving such coatings using simple scalable liquid phase method. This thesis reports our results on such coatings obtained on carbon foam. Boron Nitride was chosen as the coating material. Several solvents and processes were investigated. Finally a two step process using PVP binder in alcohol-based solution is found to be most effective. Unlike other available methods this technique does not involve toxic precursors or by-products. This method is simple and can be obtained at atmospheric pressure. Different coating combinations using various particle sizes were applied and their surface morphologies were studied using SEM (Scanning Electron Microscopy) and FESEM (Field Emission Scanning Electron Spectroscopy). It was observed that coating formed using 1μ BN followed by 0.7μ size BN particles has the best performance so far. The surface chemistry of this coating was studied using X-ray Photo Spectroscopy (XPS) and found to be that of pure BN after heat treatment. This coating was tested on several grades of aerospace foams having different porosities and cell sizes. The testing shows that this layer enhances the oxidation resistance of all foams to a certain extent. However it is most effective on the foams that have ridged ligaments compared to those having smooth ligaments. On carbon foams having high surface roughness this layer could suppress oxidation even at 800 C and enhance the survivability by 333%. This coating approach therefore shows promise as a scalable, environmentally friendly way of inhibiting oxidation in porous carbon structures

Evaluation of risk malignancy index in the pre-operative diagnosis of benign and malignant ovarian neoplasms

Background: Preoperative discrimination between benign and malignant ovarian neoplasm is necessary to optimally plan for an appropriate surgical treatment. Women with malignant ovarian tumours should be referred to a gynaecologic oncologist for the quality of cytoreductive surgery leading to increased survival. The aim of this study is to determine the role of Risk of Malignancy Index (RMI) incorporating menopausal status, serum CA 125 levels and ultrasound features in discriminating benign from malignant ovarian neoplasms.Methods: A prospective cohort study was conducted for 2 years among 110 women with ovarian neoplasms referred to Narayana Medical College and Hospital, Nellore a tertiary care centre for diagnosis and management. The sensitivity, specificity, positive and negative predictive values of menopausal status, ultrasound finding of ovarian neoplasms, levels of serum CA-125 separately and combined into the RMI were calculated and compared. (RMI = U X M X Serum CA- 125). Women of all ages admitted with ovarian masses in Narayana Medical College, Nellore. Women whose histopathology report turned out to be non-neoplastic ovarian tumours or other adnexal masses.Results: RMI >250 had a sensitivity of 70.8 % (95%CI 54.4-87.2), a specificity of 87% (95%CI 76.5-97.7), a positive predictive value of 81 % and negative predictive value of 79.4% for the diagnosis of malignant neoplasms.Conclusions: The risk of malignancy index is a simple scoring system and easily applicable and effective method for evaluating a patient in discriminating benign and malignant ovarian neoplasms efficiently to optimize therapy. It facilitates timely referral to gynecological oncology unit for adequate staging and optimal debulking

A band notch rectangular patch UWB antenna with time domain analysis

Design and construction of band notch microstrip Ultra-wideband (UWB) antenna is proposed. As the WLAN 802.11a operates ranging from 5.15GHz to 5.35GHz and 5.725GHz to 5.825GHz. In contrast, HIPERLAN/2 operates ranging from 5.15GHz to 5.35GHz and 5.47GHz to 5.725GHz. Therefore, a band notched filter is required in order to reduce potential interferences between the UWB antenna and WLAN or HIPERLAN/2 bands. The proposed UWB antenna has capability of notching these operating frequencies approximately around 5GHz to 6GHz. The antenna parameters in frequency domain analysis have been investigated to show its capability as an effective radiating element. Furthermore, time domain Gaussian pulse excitation analysis in UWB systems is also demonstrated in this paper. As a result, the simulation results demonstrated reasonable agreement with the measurement results and good band notched ultra-wideband linear transmission performance has also been achieved in time domain

Chronic liver disease (CLD) research in SAARC countries: A scientometric analysis of research output during 1996-2015

The study focuses on the pattern of literature growth, global publication share and ranking, authorship pattern, collaborative coefficient, productivity and impact of most productive institutions and authors, sources and highly cited articles based on data obtained on chronic liver disease research from Scopus. It is found that SAARC countries together contributed 2312 documents during 1996–2015, which is only about 3.49 % of the global CLD output of 66200 publications. The study further revealed that the amount of literature related to CLD research has considerably increased over the last five years. India is leading among SAARC member countries in terms of publication share, leading institutions and authors. The results of study call for more collaboration among the member countries of SAARC as well as with other leading countries, which will increase both quantity and quality of research in CLD

Prevalence of subclinical and overt hypothyroidism in infertile women

Background: Hypothyroidism has a significant effect on fertility causing anovulatory cycles, luteal phase defect, hyperprolactinemia and sex hormone imbalances. To identify potential and overt hypothyroidism, thyroid screening should be done for all infertile women. The objective of the study was to find the prevalence of subclinical and overt hypothyroidism among infertile women, to find the correlation of hypothyroidism with hormonal and metabolic parameters associated with infertility.Methods: Hospital based analytical cross sectional study was conducted for one and half years among 300 infertile women with primary and secondary infertility. Women with primary and secondary infertility. All hypothyroid women on thyroxine supplementation, male factor infertility, female factor infertility like tubal factor, anomalies of the urogenital tract, obvious organic lesions in the pelvis and women unwilling to participate or sign the informed consent.Results: The prevalence of hypothyroidism in infertile women was 27%. Among them, 25% were subclinical hypothyroid and 2.33% overt hypothyroid. Menstrual dysfunction was observed in 52% of subclinical and 51.15% of overt hypothyroid women, predominant type being oligomenorrhea. We found a negative correlation of hypothyroidism with the family history of thyroid disease. 91.4% of hypothyroid infertile women were obese and the association was strongly significant. Prevalence of hyperprolactinemia in infertile women was 24.67%. The association of hyperprolactinemia with hypothyroidism was 23%. Raised LDL levels were observed in 80% of subclinical and 100% overt hypothyroidism infertile women.Conclusions: Hypothyroidism alters the Hypothalamo-Pituitary ovarian axis and is one of the important etiological factors of female infertility. Most of the women were asymptomatic. Hence every infertile woman should be screened for thyroid profile to open better prospects of conception

XRD, AFM and UV-Vis optical studies of PbSe thin films produced by chemical bath deposition method.

PbSe thin �films have been deposited on microscope glass substrates by chemical bath deposition technique. The chemical bath consisted of lead nitrate, sodium selenate and triethanolamine solutions. The influence of bath temperature on the properties of PbSe �lms was investigated. The X-ray diff�raction, atomic force microscope and UV/Vis Spectrophotometer were used to obtain the structural characterization, surface morphological and absorbance data, respectively. Based on the X-ray diff�raction results, the thin �films obtained were found to be polycrystalline in nature with cubic structure. The intensity of the (111) peak showed a signifi�cant increased as the bath temperature was increased from 40 to 80C. The �films deposited at 80C indicated that the crystallinity was improved and more PbSe peaks were observed. On the other hand, the grain size, fi�lm thickness and surface roughness were increased while band gap energy decreased as could be observed in atomic force microscope and UV-Vis optical studies, respectively