Modelling Aerothermal Heating with Conjugate Heat Transfer

Supersonic and hypersonic vehicles experience flows under complex thermodynamic conditions due to the presence of shock waves and large thermophysical gradients. A large thermal load is imparted to the vehicle from the high-speed flow, leading to the aerodynamic heating of the surface. Additionally, the vehicle must sustain heat loads from within its structure, such as the propulsion system. The accurate modelling of heat transfer at these highly non-adiabatic wall conditions is critical in designing optimal thermal protection systems for hypersonic vehicles. This thesis aims to assess the predictive capabilities of computational fluid dynamic solvers in modelling aerothermal heating in supersonic and hypersonic flows using Conjugate Heat Transfer (CHT) methodologies, and investigate the impact of internal heating sources on the thermal and aerodynamic loads on aerospace vehicles. The predictive capabilities of near-wall turbulence modelling at high-speed, non-adiabatic flow conditions are first assessed for two commercial and two open-source CFD solvers: OpenFOAM (open-source), SU2 (open-source), Star-CCM+ (commercial), and ANSYS CFX (commercial). The overall error and uncertainty that can be attributed to solver selection at these complex conditions is quantified. SU2 and Star-CCM+ are assessed on their ability to model aerodynamic heating using CHT, with comparisons to hypersonic experimental studies and prior numerical investigations. The results from the code validations are used as a basis to conduct a CHT analysis on a simplified model of a supersonic vehicle to investigate the impact of internal heating on the thermal boundary layer of the external flow. The results show notable variations between the solvers in the kinematic and thermodynamic profiles of the high-speed non-adiabatic boundary layers, which are quantified. Furthermore, the treatment of the boundary condition at the wall plays a significant role in the variation of wall properties, particularly with the wall temperature prediction. Moreover, CHT validation studies show that aerothermal heating predictions of current commercial and open-source CHT solvers agree well with experimental and numerical data, but significant prediction errors occur in regions of Shockwave Boundary Layer Interaction (SWBLI) and stagnation points. The addition of internal heating on the CHT simulations of the generic high-speed vehicle results in a reversal of the wall heat flux vector as the freestream Mach Number is increased, where the heated wall case at low supersonic speeds transforms to a cooled wall case at hypersonic speeds. This thesis work provides a solid groundwork for conducting CHT simulations of high-speed wall-bounded flows with internal heating, using RANS solvers

Sickness in Small-Scale Industries in South Punjab: Hurdles & Remedies: A Study of Bahawalpur Estate Area, Pakistan

This study was based on in-depth exploratory investigation of Bahawalpur (Pakistan) industrial estate area to find out the internal and external root causes of sickness in small industries and their solutions. Ashraf et al.(2012) noticed reasons of meager performance of small firms as lack of managerial knowledge, high rate of interest on loans, heavy taxation,  poor government policies, owner’s education level and use of outdated technology, that’s why the most of small units have poor success and growth.  Shukla (1993) and Reddy et al. (1988) found the causes of sickness in Small Scale industry which  were generally related to production, finance, environmental,  management and  marketing  factors.  Collection of data was executed through both primary and secondary sources. Both qualitative and quantitative research methods had been used for the study. Data was primarily collected through structured questionnaires as well as interviews of owners/managers of small industrial units at Bahawalpur industrial estate area. SPSS software was used to analyze the data.  In this study we found that 76.9% units were facing energy crisis and almost all the units were also facing high Mark-up problem and Inflation problem. Other obstructions that units were facing comprising the high level of taxation, lack of education, difficulty in accessing credit, lack of market information, lack of management skills etc. which leads to low level of production and unemployment etc. Keywords: Industrial obstructions, Remedies, low productio

Involvement of medical students and fresh medical graduates of Karachi, Pakistan in research

OBJECTIVE: To study the involvement in research, of final year medical students and fresh graduates of Karachi, Pakistan and to identify the factors influencing their interest in medical research. METHODS: A cross-sectional, questionnaire based study was conducted in 2007-2008. Five institutes representing the private and public hospitals in the city were selected by cluster sampling. Final year medical students and fresh graduates were included. Descriptive statistics were charted using SPSS v.16 after double data entry. RESULTS: Out of 378, 186 (49%) participants had journal reading habits due to the requirement of their institution. Mostly, 157 (41%) undergraduates had already participated in a research project, however mostly in the field as data collectors or computer work. Institutional influence and speciality of interest was found to be statistically significant factors related to a respondent\u27s interest or involvement in research. (chi2 =9.970, p-value = 0.007). CONCLUSION: There is keen interest and involvement in research, among final year medical students and fresh graduates of Karachi, Pakistan. However, the factors driving them are based on their university research encouragements and future plans

Complications of Measles in Malnourished Children, a Descriptive Cross-Sectional Study at a Tertiary Care Hospital Rawalpindi

Objective: To determine the frequency of common complications of measles in malnourished children. Materials and Methods: This study was conducted in the Department of Pediatrics Benazir Bhutto Hospital, Rawalpindi from January 2018 to December 2018. Through a Descriptive Cross-Sectional Study Design, a total of 110 cases of measles with malnutrition presenting to the Paediatrics Department were selected and observations were recorded on follow up. Results: The mean age was 2.7 years (SD±1.2) of which 61% (n=67) were male and 39% (n =43) were female patients. 35.5% (n=39) presented with grade I, 24.5% (n=27) in grade II and 40% (n= 44) in grade III malnutrition. On follow up, pneumonia was observed in 39.1%, diarrhea in 36.4%, otitis media in 10% and encephalitis in 8.1% of children. The most frequent complications were observed in grade II and grade III malnourished children and children of younger age groups. Conclusion: Measles and malnutrition are still calamity in our population as once together, the complications of each other are more prevalent and preventive projects must be designed with full efficacy against both these conditions

Effectiveness of Health Education Session on Knowledge of High School Students Regarding Plastic Use and Its Health Hazards

Introduction: Plastic is widely used due to its low cost and different functional properties but it has many severe adverse effects on consumer’s health in many direct and indirect ways. Plastic waste pollutes the environment and it is a threat to human life. So, there is a great need to reduce plastic use and plastic waste hazards. Methods: A quasi- experimental, quantitative, before and after study design was conducted  among the students total (n= 60) in the high school of Ali Raza Abad Raiwind Road Lahore, Pakistan from September 2018 to December 2018. The educational intervention involve three education session about plastic use and its health hazards in which the researcher educate the students about health hazards of plastics, prevention of plastic objects as well as health complications.  Results: A total of 60 children participated in the study, the majority of the participants were boys. The mean before the educational intervention is 8.98 (Standard deviation 3.281) and after the educational intervention is 16.85 (Standard deviation 3.036). The mean difference between the two mean is 7.867. There is a statistically significant difference before and after the educational intervention. The educational intervention is highly effective because the significant value is 0.00 Conclusions: The result of the study shows that students have adequate knowledge about health hazards of plastic use. The ill effects of plastic can be reduce by educational intervention among students. Keywords-Plastic use. Health education. Health hazards DOI: 10.7176/JHMN/72-09 Publication date:March 31st 202

Determination and Extraction of Acetamiprid Residues in Fruits and Vegetables

<p align="center"><span style="font-family: Times New Roman;">  <span style="font-size: medium;">Vegetables (chilies, tomato, cauliflower and cucumber) and fruits (mango and apple) samples were spiked with known quantity (0.50 mg kg-1) of acetamiprid reference standard for testing the retrieval percentage of acetamiprid residue in those vegetables and fruits. The efficiency of different extracting (ethyl acetate and dichloromethane + acetone 8:2) and eluting (ethyl acetate and dichloromethane + acetone 8:2) solvents and adsorbents (activated charcoal and florisil) for clean up purpose was calculated using HPLC. Amongst the extracting solvents ethyl-acetate was observed an effective extracting solvent alone which produced maximum 90-96%  </span><span style="font-size: medium;">recovery for acetamiprid residues while among the eluting solvents a combination of dichloromethane and acetone ( ratio 8:2) produced superior recoveries i.e. 87-95%. Similarly, between the adsorbents used for clean up purpose activated charcoal and florisil in tandem (first from charcoal and then through florisil) yielded recoveries 82-90 % whereas adsorbents used alone in form of activated florisil and charcoal recovered only 70 to 78 % and 71 to 73% acetamiprid residues, respectively in all vegetables and fruits.</span></span></p

Determination and Extraction of Acetamiprid Residues in Fruits and Vegetables

  Vegetables (chilies, tomato, cauliflower and cucumber) and fruits (mango and apple) samples were spiked with known quantity (0.50 mg kg-1) of acetamiprid reference standard for testing the retrieval percentage of acetamiprid residue in those vegetables and fruits. The efficiency of different extracting (ethyl acetate and dichloromethane + acetone 8:2) and eluting (ethyl acetate and dichloromethane + acetone 8:2) solvents and adsorbents (activated charcoal and florisil) for clean up purpose was calculated using HPLC. Amongst the extracting solvents ethyl-acetate was observed an effective extracting solvent alone which produced maximum 90-96%  recovery for acetamiprid residues while among the eluting solvents a combination of dichloromethane and acetone ( ratio 8:2) produced superior recoveries i.e. 87-95%. Similarly, between the adsorbents used for clean up purpose activated charcoal and florisil in tandem (first from charcoal and then through florisil) yielded recoveries 82-90 % whereas adsorbents used alone in form of activated florisil and charcoal recovered only 70 to 78 % and 71 to 73% acetamiprid residues, respectively in all vegetables and fruits

Enhancement of Extender Excellence of Frozen Bull Semen Using α-Tocopherol as an Antioxidant

Background: Addition of the antioxidant to extender media is the most appropriate attempt to reduce structural losses encounter during the process of cryopreservation. Hence semen excellence could be maintained for longer duration without adverse impact. Additionally antioxidants are not only capturing the reactive oxygen species but also improve the sperm quality indicators and fertility. Accordingly, current elucidation has been executed to explore the dose depended appraisal of varied concentration of α-tocopherol in Tris-based extender on frozen-thawed bull semen quality parameters for enhancement of bull semen cryopreservation in the subtropical ecosystem of Peshawar.Materials, Methods & Results: Experiments were carried out on semen that has been collected from both Achai-an indigenous breed and Holstein Friesian (HF) - the exotic breed in artificial vagina maintained at 42°C from the experimental bulls of either breed and processed independently breed wise. Semen specimens with above 70% motility were evaluated separately breed-wise under same environmental condition. Standard procedure was adopted to extend the collected semen in the experimental extenders and frozen subsequently. After thawing, further Analysis of the frozen straws of semen was carried out for sperm excellence indicators that include motility, viability, acrosomal integrity and functional integrity of spermatozoa under the subtropical condition. Sperm viability and acrosomal integrity were determined by dual staining procedure i.e. Trypan-blue and Giemsa stains. The hypo-osmotic swelling (HOS) test was used to assess plasma membrane integrity. The current elucidation demonstrated that α-tocopherol 1.5 mg/mL supplemented in extender had significantly (P < 0.05) increased sperm excellence gauge that includes motility, viability, acrosomal integrity and functional membrane integrity in both the breeds. On the other hand, the result further elucidated those concentrations higher or lower than 1.5-1 mg/mL α-tocopherol supplemented in the present study resulted in a lower semen functional attributes subsequent to freezing.Discussion: Biological samples were preserved by various methods such cryopreservation at low temperature to maintain them intact and facilitate downstream experiments. Antioxidants were associated with the chemical breakage of the substrate consequential from oxidation and counterbalance the free radicals thus diminish the damaging impacts to spermatozoa in cryopreservation. There is lack of data with respect to lipid peroxidation and cell reinforcement limit in cryopreserved semen, and cryopreservation is related with the generation of receptive oxygen species (ROS) which lead to lipid peroxidation (LPO) of sperm membranes, bringing about lost motility, viability and fertility of sperm. Recently, in the reproductive management of the dairy animals, an important focus of research is to overcome the deleterious impact associated with semen cryopreservation. Elucidation of differential dose depended expression of α-tocopherol in semen extender has been evident in this study. The results were corroborated with diverse mammalian species under varied ecological management setups. Furthermore the detrimental impact of high doses of α-tocopherol in the semen extender has been demonstrated. It was deduced from the current finding that addition of α-tocopherol via dose depended approach in Tri extender enhanced the cryosurvivability of both Achai indigenous breed and HF the exotic breed, under existing reproductive management in the local ecosystem of Peshawar