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The effects of weld nugget size and expulsion on the performance of low carbon steel resistance spot weld have been investigated in the present paper. Failure mode, peak load and failure energy obtained in tensile-shear test have been used to describe the performance of spot weld. The influence of voids and porosity as well as electrode indentation associated with expulsion on peak load and failure energy is discussed. The results showed that although expulsion does not reduce the load carrying capacity of spot welds, it decreases their energy absorption capability which was attributed to the change of failure location due to excessive electrode indentation associated with expulsion.

Resistance spot welding was used to join austenitic stainless steel sheets. Mechanical properties of the spot welds were evaluated using tensile shear test. Mechanical behaviour was described by peak load, failure energy and failure mode. The relationship between weld fusion zone attributes and failure behaviour was studied. Generally, it was observed that increasing fusion zone size is accompanied by an increase in load carrying capacity and energy absorption capability. However, when expulsion occurs, despite almost constant weld fusion zone size, energy absorption capability reduces significantly due to increase in electrode indentation depth. Considering the failure location and failure mechanism in the tensile shear test, minimum required fusion zone size to ensure the pull-out failure mode was estimated using an analytical model. According to this model, in addition to sheet thickness, ratio of fusion zone hardness to failure location hardness is the key metallurgical factor governing failure mode of spot welds during the tensile shear test.

versus laser lithotripsy for ureteral stones. AbstractIntroduction: Several different modalities are available for ureteral stone fragmentation. From them pneumatic and holmium: yttrium-aluminum-garnet (Ho: YAG) lithotripsy have supportive outcomes. In this study we studied 250 subjects who had ureteroscopic pneumatic lithotripsy (PL) or laser lithotripsy (LL). Methods: Two-hundred fifty patients with ureteral stones underwent ureteroscopic lithotripsy (115 subjects in the PL group, 135 subjects in the LL group) from August 2010 to April 2016. The purpose of this investigation was to evaluate stone-free rate (SFR), mean operation time (MOT), mean hospital stay (MHS), stone migration and complications. Results: Two groups were similar in age, gender, mean size of stones, side of stone, and complications. There was a statistical difference in terms of SFR, stone migration and MHS in favor of the LL group (P ≤ 0.05, P ≤ 0.05 respectively), and MOT in favor of the PL group (P ≤ 0.05). Conclusion: Both the PL and LL techniques were effective and safe for ureteral stones, however a slightly higher SFR was found in the LL group.

ObjectiveIncidental prostate cancer (IPCa) is defined as a symptom-free cancer unexpectedly discovered upon microscopic examination of resected tissue. The aim of this study was to report the correlation between some specific clinical criteria in patients incidentally diagnosed with prostate cancer (PCa) during transurethral resection of the prostate (TURP) or open prostatectomy (OP) after clinically suspected benign prostatic hyperplasia.Patients and methodsThis was a cross-sectional, retrospective study. Data were collected from Shohada-e-Tajrish Hospital database during November 2006 to October 2016. Four hundred and twenty three men suffering from symptomatic benign prostatic hyperplasia who underwent either TURP or OP that provided a prostate specimen were evaluated. The data analysis was performed using Pearson correlation test and independent t-test using SPSS version 20 software.ResultsThe mean age of subjects was 68.74±9.87 years old (45–93 years). The mean prostate specific antigen (PSA) level was 21.47±13.44 ng/mL (0.6–47.1 ng/mL). Results showed that 84 patients (19.9%) had PCa (40 patients who underwent TURP [12.6%] and 44 patients who underwent OP [40.7%] groups). Cut-off point of PSA for detecting IPCa was 3.8 ng/mL in our study, and this showed sensitivity, specificity, negative predictive value, and positive predictive value of 26.08%, 100%, 100%, and 29.79%, respectively. Twenty two patients with cancer had a positive family history for PCa; thus, a significant relationship between familial history of PCa and its occurrence was shown (p=0.0001).ConclusionAccording to the results of this study, the cut-off point for PSA levels in detecting PCa was 3.8 ng/mL, which is similar to that reported by other studies. Familial history of PCa and PSA levels were two predictors in determining the PCa.

Transformation-induced plasticity (TRIP) steel resistance spot welds are delicate to low-energy interfacial failure via crack propagation through martensitic fusion zone during cross-tension (CT) loading. This paper addresses the effect of three different types of in situ postweld heat treatment (PWHT) on the mechanical properties of TRIP steel resistance spot welds. Depending on the post weld second pulse current level, three different strengthening mechanisms were found including (i) martensite tempering with reduced hardness, (ii) refining of martensite packets with improved toughness and (iii) nugget re-melting/enlargement combined with possible reduction of grain boundary impurity segregation. All designed in situ PWHTs were enabled to promote pullout failure mode with improved load-bearing capacity and energy absorption capability during CT loading.

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.

5-14% of patients underwent surgery for benign prostate hyperplasia harboring prostate cancer (PCa) focus. The best management of incidental prostate cancer (iPCa) has been debated. The decision "treatment or no treatment" should be determined by predictors which accurately foretell PCa progression after transurethral resection of the prostate (TURP). The purpose of this study is to review the available data that can be useful in daily clinical judgment. Transrectal ultrasound prostate biopsy (TRUSBx) did not provide further Gleason score (GS) data in most patients diagnosed with iPCa. TRUSBX may be useful before active surveillance, but not in all following radical prostatectomy. The decision "treatment or no treatment" should be dependent on the expected chance of having residual cancer and clinical progression. Prostate-specific antigen (PSA) levels before and after TURP are good predictors of residual cancer after TURP. Pathological report of T0 is most likely seen in patients with low PSA density after TURP and indistinguishable lesion on multiparametric magnetic resonance imaging. The decision "treatment vs no treatment" is judged by life expectancy, tumor characteristic in the pathology report of TURP sample and PSA level following TURP. Active surveillance should be contemplated in patients with iPCa who have both prostate-specific antigen density ≤0.08 after TURP and indistinguishable cancer lesion on multiparametric magnetic resonance imaging. Patients who do not meet the criteria for active surveillance are candidates for radical prostatectomy or radiotherapy (RT). Radical prostatectomy could be peacefully done after TURP with somewhat greater morbidity. RT in patients who had a history of TURP could be safely done and is associated with acceptable quality of life.