Performance Enhancement of Building-Integrated Concentrator Photovoltaic System Using Phase Change Materials

Building-integrated Concentrator Photovoltaic (BICPV) technology produces noiseless and pollution free electricity at the point of use. With a potential to contribute immensely to the increasing global need for a sustainable and low carbon energy, the primary challenges such as thermal management of the panels are overwhelming. Although significant progress has been made in the solar cell efficiency increase, the concentrator photovoltaic industry has still to go a long way before it becomes competitive and economically viable. Experiencing great losses in their electrical efficiencies at high temperatures that may eventually lead to permanent degradation over time, affects the market potential severely. With a global PV installed capacity of 303 GW, a nominal 10 °C decrease in their average temperatures could theoretically lead to a 5 % electricity efficiency improvement resulting in 15 GW increase in electricity production worldwide. However, due to a gap in the research knowledge concerning the effectiveness of the available passive thermal regulation techniques both individually and working in tandem, this lucrative potential is yet to be realised. The work presented in this thesis has been focussed on incremental performance improvement of BICPV by developing innovative solutions for passive cooling of the low concentrator based BICPV. Passive cooling approaches are selected as they are generally simpler, more cost-effective and considered more reliable than active cooling. Phase Change Materials (PCM) have been considered as the primary means to achieve this. The design, fabrication and the characterisation of four different types of BIPCV-PCM assemblies are described. The experimental investigations were conducted indoors under the standard test conditions. In general, for all the fabricated and assembled BICPV-PCM systems, the electrical power output showed an increase of 2 %-17 % with the use of PCM depending on the PCM type and irradiance. The occurrence of hot spots due to thermal disequilibrium in the PV has been a cause of high degradation rates for the modules. With the use of PCM, a more uniform temperature within the module could be realised, which has the potential to extend the lifetime of the BICPV in the long-term. Consequentially, this may minimise the intensive energy required for the production of the PV cells and mitigate the associated environmental impacts. Following a parallel secondary approach to the challenge, the design of a micro-finned back plate integrated with a PCM containment has been proposed. This containment was 3D printed to save manufacturing costs and time and for reducing the PCM leakage. An organic PCM dispersed with high thermal conductivity nanomaterial was successfully tested. The cost-benefit analysis indicated that the cost per degree temperature reduction (£/°C) with the sole use of micro-fins was the highest at 1.54, followed by micro-fins + PCM at 0.23 and micro-fins + n-PCM at 0.19. The proposed use of PCM and application of micro-finned surfaces for BICPV heat dissipation in combination with PCM and n-PCM is one the novelties reported in this thesis. In addition, an analytical model for the design of BICPV-PCM system has been presented which is the only existing model to date. The results from the assessment of thermal regulation benefits achieved by introducing micro-finning, PCM and n-PCM into BICPV will provide vital information about their applicability in the future. It may also influence the prospects for how low concentration BICPV systems will be manufactured in the future.The financial support provided jointly by Engineering and Physical Science Research Council, UK (EP/J000345/1 and EP/K03619X/1) and Department of Science and Technology (DST), India is greatly acknowledged

A prospective study of simultaneous myomectomy with cesarean section at a tertiary care hospital

Background: Simultaneous surgical removal of a previously diagnosed myoma during cesarean section is preferred these days to reduce multiple operative procedures. The aim of present study was to determine the safety, cost effectiveness and complications of myomectomy at the time of cesarean delivery and its related peri-operative morbidity. Methods: This prospective study was conducted in total 50 pregnant cases during the period of 6 months. The analysis focused on age and gender, the number, size and location of fibroids, the need for hysterectomy and blood transfusion. Results: The mean age of patient was 28.2 years. Out of the 50 patients, 66% were primiparous and only 17% were multiparous. 56% patients underwent caesarean section for indications like primigravida head floating, IUGR, oligohydroaminos. 48% patients had myoma size 2-4 cm. Most of the myomas were located anteriorly (64%). The most common type of leiyomyoma found was subserosal (31%) and 17% with intramural fibroid. Only one patient required post operative blood transfusion whereas none of the patients underwent hysterectomy. Conclusions: Cesarean myomectomy is a safe and effective procedure and it is a feasible undertaking in experienced hands

A rare case scenario of didelphic uterus with ovarian serous cystadenocarcinoma: an unusual clinical finding

Uterine didelphys in women is uncommon. The improper development of the Mullerian ducts during the intrauterine period leads to congenital abnormalities of the female genital system. Mullerian duct canalization or improper fusion leads to a didelphic uterus. About 60% of ovarian neoplasms are epithelial in origin, and the surface epithelium is typically most affected. This case report describes the management of a patient who had previously undergone two caesarean sections for a rare gynecological case of didelphic uterus with unilateral serous cystadenocarcinoma of the ovary

Case Report on Intrahepatic Cholestasis of Pregnancy

This case report concerns a primigravida woman (period of gestation-37 weeks) diagnosed with intrahepatic cholestasis of pregnancy (IHCP). She had been married since 2 years and this is her first pregnancy. The patient is an Rh-negative mother. She did not receive anti-D at 28 weeks of gestation. The patient was admitted to antenatal ward of Hakeem Abdul Hakeem Centenary (HAHC) Hospital, New Delhi, with chief complaints of itching all over the body since 15–20 days with severe itching over the umbilical area and presence of rashes on legs and breasts since last 10 days. During the physical examination the rashes were seen on legs and breast. Per abdomen examination revealed cephalic presentation of the fetus with FHR as 140 bpm. Routine blood investigations revealed that the patient was also a case of moderate anemia and the blood group of the patient was AB-negative. After all the required investigations, she was diagnosed with IHCP with moderate anemia with Rh-negative pregnancy. IHCP is a pregnancy-specific liver disorder characterized by pruritus, most often, in the late-second or early third trimester of pregnancy and raised serum bile acids. The maternal outcome after treatment is good but fetal outcomes become adverse in most of the conditions.

Sanctions as a Tool of Foreign Policy: A Conceptual Framework

Sanctions are a type of policy instrument that have emerged as one of the most popular and effective tools of foreign policy. According to sanction theory analysts, sanctions are seldom regarded as the “ideal” weapon; rather they are seen as the “least bad” alternative. Both as an alternative to armed force and, conversely, the often burdensome diplomatic solutions on offer, the salience of sanctions to international security politics is increasingly apparent. It is the increased use of economic or political leverage that has triggered the debate among the host of scholars and foreign policy experts. There are many scholars who have detailed about the efficacy of sanction whereas others have out rightly rejected the imposition of sanctions as a successful foreign policy tool. This paper seeks to look at the various aspects of sanctions as a foreign policy tool in detail

IMPACT OF COVID-19 PANDEMIC ON MATERNAL MORTALITY RATIO IN A TERTIARY CARE HOSPITAL OF RAJASTHAN: A RETROSPECTIVE ANALYSIS

Objectives: Pregnancy and delivery are an important risk factor for COVID-19. The present study was carried out to see the impact of COVID 19 on maternal mortality ratio (MMR). Methods: This retrospective study was performed in the Department of Obstetrics and Gynaecology, Mahila Chikitsalya, and SMS Medical College Jaipur from January 2018 to December 2021. Data were collected from the hospital records and MMR was calculated for every year. The causes of death were also recorded and changing trends were noted. Results: In the present study, the MMR for the years 2018, 2019, 2020, and 2021 were 159.03, 112.72, 354.58, and 603, respectively, which reflects enormous increase in MMR during COVID pandemic years (2020 and 2021). Before the pandemic (2018 and 2019), maximum deaths were from direct obstetric causes (77.35%) while 22.64% maternal deaths were from indirect causes. During COVID pandemic a large percentage (53.12%) of maternal deaths were due to indirect obstetric causes, COVID pneumonitis (ARDS) being the most common cause of death. Conclusions: There was 3.59 times increase in MMR during COVID-19 pandemic in our institute. COVID pneumonitis was responsible for significant number of maternal deaths

Uterine artery doppler indices may predict intrauterine contraceptive device-related abnormal uterine bleeding

Background: The aim of the study was to assess the role of colour Doppler velocimetry of the uterine arteries as a predictor of intrauterine contraceptive devices (IUCD)-induced abnormal uterine bleeding.Methods: A prospective study was performed on 120 women (60 without AUB and 60 with AUB) who had copper IUCD inserted as a method of contraception. Detailed history, general and local examination and relevant investigations were done. Pulsatility index (PI) and resistance index (RI) of uterine artery measured at 3 months after IUCD insertion.Results: Cut-off levels for PI and RI of uterine arteries were set. PI cut-off level <2.09 with sensitivity of 58.3%, specificity of 61.67% and area under the curve (AUC) of 0.666. RI cut-off level ≤0.83 with sensitivity of 53.33%, specificity of 66.67% and AUC of 0.703. These cut-off levels were associated with abnormal uterine bleeding.Conclusions: Initial measurement of uterine artery Doppler indices (PI and RI) before IUCD insertion could be useful in predicting IUCD-induced abnormal uterine bleeding which is the major cause of method withdrawal during the first year of use and accordingly women could be counseled to consider another method of contraception.

Calculating Great Britains half-hourly electrical demand from publicly available data

Here we present a method to combine half-hourly publicly available electrical generation and interconnector data to create a timeseries that approximates Great Britains electrical demand. Publishing the method and the data provides a resource to the wider community that can be further enhanced or adapted and allows the method itself to be considered and critiqued. The method adds value by combining transmission and distribution generation data into a single dataset and adding ISO 8601 compatible datetimes to increase interoperability with other data. The published data is therefore more useable by a wider group of researchers and stakeholders interested in an example of the rapid decarbonisation of a countries electrical system.Comment: 33 pages, 3 Figures, 6 table

Determinants of Reproductive Tract Infection among married women in rural and peri-urban areas of Aligarh: A cross sectional Study

Background: Reproductive Tract Infections (RTI) have a direct impact on reproductive and child health through infertility, cancers, and pregnancy complications, and they have an indirect impact through their role in facilitating the sexual transmission of the human immunodeficiency virus. Objectives: To find the prevalence and determinants of RTI/STI among married women of reproductive age group in rural and peri-urban areas of Aligarh. Methods: The data were collected by using a pretested, semi-structured with both open and closed-ended questionnaire from 500 married women of reproductive age group. The collected data were analyzed using IBM SPSS 20.0 Proportion, frequencies, ?2, and logistic regression were used to interpret the data. Results: Prevalence of RTI/STI symptoms was found to (42.8%) in rural areas and 37.6 % in peri-urban areas. Strong association was found in study subjects having lower educational status, who were not using any contraceptive method, not following good menstrual hygiene, early marriage age had husband history of RTI/STI, had a history of abortion, had a history of violence, and increased parity. Conclusions: Prevalence of symptoms found to be associated with these females having low educational status, early age of marriage, high parity, partner history of reproductive Tract Infections, history of violence etc. So, there should be more focus on improvement in these factors to reduce the prevalence

Nickel(II) complexes of m-ethylphenylxanthate with nitrogen donors and their biological screening

A series of five adducts of m-ethylphenylxanthate of nickel(II) [(m-C2H5C6H4OCS2)2Ni] with nitrogen donors have been synthesized in 1:2 molar ratio by the reaction of aqueous solution of NiCl2.6H2O with aqueous solution of sodium salt of m-ethylphenylxanthate. These metal complexes are reacted with nitrogen donors to give donor stabilized complex, [(m-C2H5C6H4OCS2)2(L)2Ni] where, L= 2-, 3-, 4-ethylpyridine and 2-, 3-chloropyridine. The adducts have been characterized by elemental analysis, molar conductance and magnetic susceptibility measurements, IR, electronic, mass spectral studies, thermogravimetric analysis, powder X-ray diffraction, biological studies. The spectral studies have revealed the octahedral coordination of ligands around Ni(II) metal ion. The adducts are found to be paramagnetic and non-ionic in nature. Mass studies show the monomeric nature of the adducts. The complexes have depicted potential antifungal activity against Bipolaris maydis and Rhizoctonia solani. Some of the synthesized Ni(II) xanthate complexes display in vitro cytotoxic efficacy against human cancer cell lines