To optimize gas flaring in Kirkuk refinery in various seasons via artificial intelligence techniques.

Unavoidable flaring in downstream oil industry causes pollutant emission in large amounts which is potentially harmful to nearby cities or farms. Hence one must manage exhaust toxic gases to raise enough in atmosphere or redirect from such places. Since Kirkuk refinery in north Iraq is next-door to agricultural farms on west yet to residential areas on east optimizing its layout for flare stacks is something acute. In this work we wrote codes in MATLAB software to simulate incomplete rather than complete oxidation as well as pollutant generation reactions. Then we made use of FLEUENT software to simulate pollutant propagation in Kirkuk oil purifier complex yet also farther to city as well as farms with respect to seasonal air currents on lowest troposphere layer. Finally, we set neural network approach to train on simulation data thereafter to unify outcomes to turn into a fast technique for layout optimization. Results show that optimization process efficiency relies on air current velocities as well as its direction. At intermediate air flow rates optimum layout includes only a selective portion of existent flare stacks. Outcomes also illustrate that heuristic techniques that have stronger local search such as particle swarm or artificial immune system can improve flare layout in seasons with intermediate air currents here summer plus early months in autumn while approaches with weak local search like Monte Carlo are more appropriate in winter for which we have no or low air flows in Kirkuk governorate.

Asymptomatic bacteriuria in candidates for active treatment of renal stones: results from an international multicentric study on more than 2600 patients.

The occurrence of asymptomatic bacteriuria concomitant to urolithiasis is an issue for patients undergoing renal stone treatment. Disposing of a preoperative urine culture is essential to reduce the risk of septic events. The endpoint of the study is to report which characteristics of candidates for renal stone treatment are frequently associated with positive urine culture. 2605 patients were retrospectively enrolled from 14 centers; inclusion criteria were age > 18 and presence of a single renal stone 1-2 cm in size. The variables collected included age, gender, previous renal surgery, comorbidities, skin-to-stone distance, stone size, location, density, presence of hydronephrosis. After a descriptive analysis, the association between continuous and categorical variables and the presence of positive urine culture was assessed using a logistic regression model. Overall, 240/2605 patients (9%) had preoperative bacteriuria. Positive urine culture was more frequent in females, patients with previous renal interventions, chronic kidney disease, congenital anomalies, larger stones, increased density. Multivariate analysis demonstrated that previous renal interventions (OR 2.6; 95% CI 1.9-3.4; p < 0.001), renal-related comorbidities (OR 1.31; 95% CI 1.19-1.4; p < 0.001), higher stone size (OR 1.06; 95% CI 1.02-1.1; p = 0.01) and density (OR 1.00; 95% CI 1.0-1.00; p = 0.02) were associated with bacteriuria; male gender and lower caliceal location were inversely related to it. Beyond expected risk factors, such as female gender, other parameters are seemingly favoring the presence of positive urine culture. The awareness of variables associated with bacteriuria allows to assess which individuals are at increased risk of presenting bacteriuria and reduce the rate of septic complications.

The role of artery-preserving varicocelectomy in subfertile men with severe oligozoospermia: a randomized controlled study.

BACKGROUND: There is wide agreement nowadays that a clinical varicocoele should be ligated to treat male factor infertility. However, the significance of testicular artery preservation in patients with severe oligozoospermia has not been addressed before. OBJECTIVES: To assess the outcome of varicocelectomy in infertile men with severe oligozoospermia and clinical varicocoeles and to compare internal spermatic artery preservation vs. artery ligation. MATERIALS AND METHODS: This prospective randomized study included 302 infertile patients with severe oligozoospermia and clinical (grade II/III) varicocoeles. Patients were randomized into two groups: group A (150 patients) underwent artery-preserving varicocelectomy (APV) and group B (152 patients) underwent artery-ligating varicocelectomy (ALV). The primary outcome was to assess the changes in sperm density and motility at 3 and 6 months postoperatively in both groups. The secondary outcome was to compare the natural pregnancy rate at 1-year of follow-up. Univariate and multivariate analyses were performed to determine factors affecting pregnancy rate. RESULTS: In both groups, there was a statistically significant improvement in sperm density and motility at 3 and 6 months postoperatively. In group A, there was a greater improvement in sperm density (p < 0.001) and motility (p < 0.001) compared to group B. At 1-year follow-up, overall 35.1% achieved a natural pregnancy. Group A achieved a significantly higher natural pregnancy rate (40% vs. 30%, p value = 0.03) compared to group B. Smaller testicular volume and ALV were the independent predictors of lower pregnancy rate ((HR = 3.2, 95% CI 1.2-8.3, p = 0.01) and (HR = 3.2, 95% CI 1.4-7.1, p = 0.003), respectively). CONCLUSION: In men with severe oligozoospermia and a clinical varicocoele, APV results in improved outcomes as compared to ALV with respect to semen parameters and natural pregnancy rates. Therefore, all attempts should be made to preserve internal spermatic arteries (ISA) during varicocelectomy in men with severe oligozoospermia.