Experimental Study of Fatigue Durability in Bending Effect on Welded Joints in Steel Profiles

Ships are always prone to fatigue through high periodic loads, usually caused by waves and changing load conditions. So, fatigue is an important factor in design. One of the reasons for fatigue in welding parts is variable bending loads. In this paper, a specimen of low-carbon steel T-Bar profiles is used, along with plates of the same type of steel that have been welded by the manual electrode welding process. To determine the distribution of static and dynamic forces created by welding, the specimens were subjected to bending (three-point loading) and tensile tests, and finally fatigue tests. The T-Bar Steel profile has more tolerance for fatigue loads than welded. The load T-Bar profile has not failed until the two million cycles, while the welding specimen has failed in about 3×105 cycles. Finally, strong penetrating welds should be used if a stronger welding joint is required

Efficacy and Safety of Laser Lithotripsy in Pregnancy

Introduction: The aim of our study was to assess the efficacy and safety of laser lithotripsy in pregnant patients.Methods: In this retrospective study, we reviewed the 15 pregnant women who have been treated for ureteral stones with semi-rigid ureteroscope and holmium laser at our center between Januarys 2007and April 2015.Results: The mean age of patients and mean gestational age was 29.3 years old 27.3 weeks respectively. Mean size of stones was 7.84 mm. Twelve patients had renal colic, and hematuria was found in 3 cases. Irritative urinary symptoms such as frequency and urgency detected in 6 ones and 2 patients had fever. The stone of all patients were fragmented by using holmium laser lithotripter. In 5 patients stone residual fragments were removed by grasper while other 10 patients were left to pass fragments spontaneously. No intraoperative and postoperative urological or obstetric complication was seen.Conclusion: Laser lithotripsy is safe and efficacious in pregnant patients who have ureteral stone that does not respond to conservative management