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Background and Aim: Gastro esophageal reflux disease (GERD) affects more than 30% of the Asian population, and its symptoms are common. The high prevalence of atrophic gastritis in the Pakistani population is exacerbated by gastro esophageal reflux disease. The present study aims was to assess the high prevalence of gastro esophageal reflux symptoms in patients with both acute and no acute cough. Materials and Methods: This cross-sectional study was conducted on 426 consecutive patients who attended the General Medicine and Emergency department of Sheikh Khalifa bin Zayed Hospital Rawalakot and Avicenna Hospital, Lahore from February 2021 to July 2021. Informed consent in written form was taken from all the patients. Patients with partial gastrectomy previous history and user of antagonist H2-receptor, steroids, proton pump inhibitor (PPI), and other inflammatory drugs two months prior to the investigation were excluded. Helsinki Declaration was utilized for this study with ethical approval taken from the hospital ethics committee. SPSS version 24 was used for data analysis. Results: Of the total 426 patients, GERD diagnosed patients were 248 (58.2%) and 178 (41.8%) had respiratory symptoms. The prevalence of GERD symptoms was higher in respiratory symptoms patients compared to without respiratory symptoms patients (p-value=0.05). Out of 178respiratory symptoms patients, GERD symptoms were present in 71 (39.9%) of acute cough while 107 (60.1%) of non-acute cough while 86 (34.7%) of 248 had no respiratory symptoms. The GERD development has no significant association with respiratory symptoms duration, however, patients having respiratory symptoms are at substantially elevated risk for GERD development. Conclusion: Our study found that respiratory symptoms patients are considerably more likely to develop GERD. GERD prevalence was similar in both acute and non-acute cough patients, implying that the presence of respiratory diseases is associated with the development of GERD regardless of the duration of respiratory symptoms. Keywords: Gastro esophageal reflux; Acute cough; Respiratory symptoms

Background and Aim: Chronic kidney disease patients are more likely to develop cardiovascular diseases caused by atherosclerosis accelerated rate and variety of other factors, of which they exhibit the abnormality of lipid profile atherogonic characteristics. The current study aim was to investigate the lipid profile abnormalities pattern in non-diabetic chronic kidney disease patients and to evaluate the association between the lipid profile alteration extent and renal impairment degree. Methods: This cross-sectional study was carried out on 118 chronic disease patients in the Department of Nephrology, Shaikh Zayed Hospital Lahore during the period, from August 2020 to May 2021. All the patients were carefully chosen based on their eligibility criteria. A history was taken, clinical investigation was performed, and biochemical tests were conducted. Blood was drawn for lipid profile analysis after 9 hours abstaining. The Institutional Ethical Committee approved the study and informed consent was taken from each individual. Chronic Kidney Disease as defined by the KDOQI Criteria Kidney damage for three months, defined as functional kidney abnormalities with or without decreased GFR, manifested by either: Pathological abnormalities; kidney damage markers such as changes in blood or urine composition, or abnormalities in imaging tests. GFR of less than 60 mL/min/1.73m2 for 3 months, with or without kidney damage. SPSS version 20 was used for data analysis. Results: The study included 118 patients, 79 (66.9%) of whom were males and 39 (33.1%) were females. The mean age of patients was 49.46 + 9.35 years with an age range of 28 to 78 years. Stage 5CKD patients were 23 who underwent dialysis. Chronic kidney disease patients had lower HDL and higher levels of triglyceride whereas, with chronic kidney disease stage progression, the HDL and TGL levels increased. In both stages 4 and 5 CKD, there is a positive correlation between triglyceride levels and serum phosphorous and TGL and calcium had inverse correlation. Dialysis patients' lipid profiles do not differ from those of non-dialysis patients. Conclusion: Our study found that patients with non-diabetic CKD have high triglyceride levels, low HDL, and had LDL and total cholesterol unchanged levels. As the CKD stage advances and GFR declines, triglyceride increases, and HDL decreases. TGL and serum phosphorous had a positive association in chronic kidney disease stage 4 and 5 whereas TGL and serum calcium had an inverse correlation in stages 4 and 5. Moreover, no significant difference between dialysed and non-dialysed chronic kidney disease patients’ lipid profiles was observed. Keywords: Chronic Kidney Disease; Lipid Profile; Lipid Profile Abnormalities

Automatic defect classification in photovoltaic (PV) modules is gaining significant attention due to the limited application of manual/visual inspection. However, the automatic classification of defects in crystalline silicon solar cells is a challenging task due to the inhomogeneous intensity of cell cracks and complex background. The present study is carried out for automatic defects classification of PV cells in electroluminescence images. Two machine learning approaches, features extraction-based support vector machine (SVM) and convolutional neural network (CNN) are used for the solar cell defect classifications. Suitable hyperparameters, algorithm optimisers, and loss functions are used to achieve the best performance. Solar cell defects are divided into seven classes such as one non-defective and six defective classes. Feature extraction algorithms such as histograms of oriented gradients (HOG), KAZE, Scale-Invariant Feature Transform (SIFT) and speeded-up-robust features (SURF) are used to train the SVM classifier. Finally, the performance results are compared. It is concluded that CNN's accuracy for solar cell defect classification is 91.58% which outperforms the state-of-the-art methods. With features extraction-based SVM, accuracies of 69.95, 71.04, 68.90, and 72.74% are obtained for HOG, KAZE, SIFT, and SURF, respectively. The present study may contribute to making a PV system more efficient for classifying defects to improve the power system efficiency.

In aerospace industry ejectors are employed to reduce infrared signatures of hot exhaust gases and ducts. The ambient air, entrained from the surrounding, acts as a cushion between hot exhaust and the ejector walls. This reduces the temperature and hence the infrared signature of exhaust ducts. In many applications the ejectors are bent upward to hide the hot engine from heat seeking missiles. Due to the bend, the hot gases from the turbine hit the side walls leading to hot spots on the ejector walls. This study was aimed to see the effectiveness of a series of bent oblong ejectors as infrared signature suppressors. Wall temperatures were measured with infrared thermal imaging camera and pressures were measured with static wall taps. The wall static pressure shows rise in pressure along the length of the ejector. It also identifies areas of flow separation and the areas where the primary flow hits the ejector walls and produces hot spots. Wall temperature distribution shows that the oblong nozzle has a detrimental effect by creating hot spots on the ejector surface. Wall temperature of the ejectors increased with the degree of bend. The normalized maximum wall temperature (T*w(max)) of 67.5° bent ejector was 45% higher than the straight ejector. The swirl in the primary flow also increased the wall temperature. On a straight ejector the T*w(max) with the 30° swirl was 35% higher than the no swirl case.

This paper presents experimental data from subsonic air-air bent ejectors with ring type entraining diffusers. Three oblong ejectors with different degrees of bend in the mixing tubes were used in the study. The experiments were performed on a wind tunnel capable of providing air up to 2 kg/s. The performance was studied at different primary flow temperature and swirl conditions. Pressure, velocity and temperature was measured upstream of the primary nozzle and at the exit of the diffuser. Detailed traverses were done with 7-hole probes and thermocouples. As would be expected, the performance of the ejector decreases with the degree of bend. The diffusers were added to improve the pressure recovery in the ejector and for self cooling of the diffuser. Improved pressure recovery typically leads to improved pumping in ejectors. With the diffuser added, the overall length of the ejectors was increased from 2.5 to 3.8 times the mixing tube equivalent diameter. Different trends of pumping ratio with the swirl conditions were obtained with hot and cold primary flows.

This paper presents the results of an experimental study on the performance of oblong ejectors with a bend in the mixing tube. In the aerospace industry, space limitations can lead to the design of exhaust ducts of oblong cross section. These ducts can also include ejectors for engine space ventilation or exhaust cooling or infrared signature suppression. In some cases these systems require bends after the primary driving nozzle. Each ejector consisted of a nozzle and a constant area mixing tube. A series of bent mixing tubes with the same radius of curvature was tested and the results were compared with the baseline straight ejector. A hot flow wind tunnel was used to provide the primary air flow at temperatures up to 450°C and mass flow rates up to 2 kg/s. Ambient air from the surroundings was allowed to enter the mixing tubes and mix with the primary air issuing from the primary nozzle. Velocity, pressure and temperature measurements were taken upstream of the nozzle, at the mixing tube inlet and at the exit of the mixing tube. Seven-hole probes were used to resolve the velocity vector at the exit of the mixing tube to identify large-scale flow structures. Mass flow ratio, temperature distribution and the losses in the different ejectors were compared to estimate the degradation of ejector performance with the degree of bend. Significant reduction in the performance was observed with the degree of bend in the ejector.Copyright © 2007 by ASME

This paper presents preliminary results of a study performed on bent ejectors having applications in the aerospace industry. The ejectors consisted of a simple round primary nozzle and a bent mixing tube. The effects of bend angles on pumping characteristics were studied. A cold flow wind tunnel was used to provide the primary flow of air at ambient temperature at a maximum mass flow rate of 1.6 kg/sec. Velocity and pressure measurements were taken upstream of the nozzle and at the exit of mixing tube. The study was done with and without swirl in the primary flow. It was observed that swirl in primary flow improved the pumping performance of the bent. CFD analysis was performed using a commercial CFD code and the results were compared with the experiments. It was observed that the bend in the ejector had a significant effect on the pumping performance. The entrainment ratio decreased and then increased with the degree of bend. An ejector with a 45° bend in the geometry had 28% less entrainment ratio than a same size straight ejector. It was found that swirl in the primary flow improves the performance of the bent ejector. A maximum 17% increase in the entrainment ratio was observed with swirl in the case of a 67.5° bent ejector. In both 22.5° and 67.5° bent ejectors the pressure rise was slightly improved by 20° swirl in the primary flow. CFD was generally successful in predicting the trends as observed in the experiment results. CFD predictions of pumping were within ± 7% of the experiments.Copyright © 2005 by ASME