This paper presents the comparative performance evaluation of three commercially available photovoltaic modules (monocrystalline, polycrystalline, and single junction amorphous silicon) in Taxila, Pakistan. The experimentation was carried out at outdoor conditions for winter months. Power output, module efficiency, and performance ratio were calculated for each module and the effect of module temperature and solar irradiance on these parameters was investigated. Module parameters showed strong dependence on the solar irradiance and module temperature. Monocrystalline and polycrystalline modules showed better performance in high irradiance condition whereas it decreased suddenly with decrease in irradiance. Amorphous solar module also showed good performance in low irradiance due to its better light absorbing characteristics and thus showed higher average performance ratio. Monocrystalline photovoltaic module showed higher monthly average module efficiency and was found to be more efficient at this site. Module efficiency and performance ratio showed a decreasing trend with increase of irradiance and photovoltaic module back surface temperature.

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Background and objective The effectiveness of deferred surgical repair of ventricular septal rupture (VSR) post-myocardial infarction (MI) with cardiogenic shock remains limited to case reports. Our study aimed to investigate the outcomes and survival analysis following mechanical circulatory support (MCS) in patients after VSR who develop cardiogenic shock. Methods We analyzed 27 patients with post-MI VSR and cardiogenic shock who received deferred surgical repair while stabilized on MCS between January 2018 and March 2020. After normality test adjustments, continuous variables were expressed as mean ± standard deviation (SD). These were compared using the Mann-Whitney U test and Student’s t-test. Categorical variables were compared using chi-square or Fisher’s exact test. To identify predictors of operative mortality, univariate analysis of clinical characteristics and interventions followed by logistic regression was carried out. P-value of < 0.05 was considered significant. Results All patients had preoperative MCS. Emergency repair was avoided in all the patients. The mean age of the participants was 64.96 with the majority being males (74.1%). On average, the mean time from MI to VSR repair was 18.85 days. Delayed revascularization was associated with increased mortality (OR 17.500, 95% CI 2.365–129.506, P = 0.005). Other factors associated with increased mortality were ejection fraction (EF), three-vessel disease, Killip class, early surgery, and prolonged use of inotropes. The operative mortality was 11% with an overall mortality of 33.3%. The one-year survival rate was 66.7%. Conclusion The use of MCS in adjunct to a deferred surgical approach shows an improved survival outcome of patients with VSR complicated by cardiogenic shock. Further investigations are required regarding the optimal time for MCS and surgical repair.

The behaviour of steels with (%) 17.3 Cr, 5.3 Ni, 0.3–13.9 Mn during potentiodynamic polarization k tests is comparable to that of 18 8 CrNi steels. Sharp peaks are found in the polarization curves; they correspond to the dissolution of the iron base: This region is followed by a passive zone characterized by low and potential‐independent current flow. At a certain potential, however, a steep current rise sets in. In diluted acid there is even a transpassivity zone corresponding to the dissolution of Cr and Mn. The beginning of this zone corresponds to the beginning of the steep current rise in more concentrated solution. Cyclic cathodic reduction and anodic oxidation results in a considerable reduction of the height of the peaks in the active region, while this treatment has no effect on the transpassive region. The optimum composition of a steel would be (%) 17.3 Cr, 5.3 Ni, 5.6 Mn; higher Mn contents deteriorate the corrosion behaviour.

In this present study, cold flow properties of biodiesel produced from palm oil were improved by adding cotton seed oil into palm oil. Three different mixtures of palm and cotton oil were prepared as P50C50, P60C40, and P70C30. Among three oil mixtures, P60C40 was selected for biodiesel production via ultrasound assisted transesterification process. Physiochemical characteristics—including density, viscosity, calorific value, acid value, and oxidation stability—were measured and the free fatty acid composition was determined via GCMS. Response surface methodology (RSM) and artificial neural network (ANN) techniques were utilized for the sake of relation development among operating parameters (reaction time, methanol-to-oil ratio, and catalyst concentration) ultimately optimizing yield of palm–cotton oil sourced biodiesel. Maximum yield of P60C40 biodiesel estimated via RSM and ANN was 96.41% and 96.67% respectively, under operating parameters of reaction time (35 min), M:O molar ratio (47.5 v/v %), and catalyst concentration (1 wt %), but the actual biodiesel yield obtained experimentally was observed 96.32%. The quality of the RSM model was examined by analysis of variance (ANOVA). ANN model statistics exhibit contented values of mean square error (MSE) of 0.0001, mean absolute error (MAE) of 2.1374, and mean absolute deviation (MAD) of 2.5088. RSM and ANN models provided a coefficient of determination (R2) of 0.9560 and a correlation coefficient (R) of 0.9777 respectively.