2,130 research outputs found
Spontaneous Pregnancy Outcome after Surgical Repair of Clinically Palpable Varicocele in Young Men with Abnormal Semen Analysis
Objective: The beneficial effect of varicocele repair in male infertility remains unresolved. The aim of this study was to identify the benefit from varicocele treatment based on pregnancy rate rather than improvement of semen quality.Subjects and Methods: This study included 141 infertile men with varicocele detected by clinical examination and confirmed by venous reflux on continuous wave Doppler ultrasonography (US). Measurement of Body Mass Index (BMI) and hormonal assays were performed in all patients. A total of 233 sub-inguinal varicocele repairs were done. Couples were followed up with semen analysis and pregnancy detection for 6, 12 and 18 months. Statistical analysis was performed using the chi-square, t-test and Mann-Whitney test where appropriate (p <0.05 accepted as statistically significant).Results: The spontaneous pregnancy rate was significantly greater in men with low or normal BMI. There were statistically significant differences between postoperative mean sperm count (64.7±6.8 and 10.5±1.8 million/ml) and progressive motility (38.3±2.4 and 17.7±1.8%) for spontaneous pregnancy and non-pregnancy, respectively. There were also significant changes from pre- to postoperative mean sperm concentration (21.5±2.1 and 64.7±3.8 million/ml), progressive motility (12.9±1.8 and 31.7±1.4%) and normal morphology (54±1.3 and 81.3±4.6%) in the spontaneous pregnancy cohort. Comparing pre- and postoperative serum hormone levels, FSH and prolactin decreased significantly in spontaneous pregnancy (6.57±0.65 to 4.6±0.53 IU/L and 166.2±11.8 to 149.3±10.4 pmol/L, respectively) and increased in non-pregnancy (9.05±0.71 IU/L and 187.8±13.3 pmol/L, respectively).Conclusion: Spontaneous pregnancy after sub-inguinal varicocelectomy is significantly affected by BMI, sperm concentration, progressive motility and morphology. The decrease of FSH may predict the spontaneous pregnancy outcome
Generalized magneto-thermoelasticity in a perfectly conducting medium
AbstractA model of the equations of generalized magneto-thermoelasticity in a perfectly conducting medium is given. The formulation is applied to generalizations, Lord–Shulman theory with one relaxation time and the Green–Lindsay theory with two relaxation times, as well as to the coupled theory.Laplace transforms and Fourier transforms techniques are used to get the solution. The resulting formulation is used to solve a specific two-dimensional problem. The inverses of Fourier transforms are obtained analytically.Laplace transforms are obtained using the complex inversion formula of the transform together with Fourier expansion techniques.Numerical results for the temperature distribution, thermal stress and displacement components are represented graphically. A comparison was made with the results predicted by the three theories
Fractional order generalized thermoelasticity with variable thermal conductivity
In this work, the consideration of variable thermal conductivity as a linear function of temperature has been taken into account in the context of fractional order generalized thermoelasticity (Youssef’s model). The governing equations have been derived and used to solve the one-dimensional problems of an elastic half-space. The solution has been induced in the Laplace transform domain and applying for thermal shock half-space on the bounding plane when it is rigid. The numerical inversion of the Laplace transform has been calculated numerically by using Tzou method and the results have been represented in figures with some comparisons to stand on the effect of the fractional order parameter and the variability of the thermal conductivity on all the studied fields
Variational principle of fractional order generalized thermoelasticity
AbstractRecently, Youssef constructed a new theory of fractional order generalized thermoelasticity by taking into account the theory of heat conduction in deformable bodies, which depends upon the idea of the Riemann–Liouville fractional integral operator. In this paper, the variational theorem is obtained for the generalized thermoelasticity model for a homogeneous and isotropic body
Commercial wind turbines modeling using single and composite cumulative probability density functions
As wind turbines more widely used with newer manufactured types and larger electrical power scales, a brief mathematical modelling for these wind turbines operating power curves is needed for optimal site matching selections. In this paper, 24 commercial wind turbines with different ratings and different manufactures are modelled using single cumulative probability density functions modelling equations. A new mean of a composite cumulative probability density function is used for better modelling accuracy. Invasive weed optimization algorithm is used to estimate different models designing parameters. The best cumulative density function model for each wind turbine is reached through comparing the RMSE of each model. Results showed that Weibull-Gamma composite is the best modelling technique for 37.5% of the reached results
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