Stability Study of Cantilever-Beams – Numerical Analysis and Analytical Calculation (LTB)

According to Eurocode, the computation of bending strength for steel cantilever beams is a straightforward process. The approach is based on an Ayrton-Perry formula adaptation of buckling curves for steel members in compression, which involves the computation of an elastic critical buckling load for considering the instability. NCCI documents offer a simplified formula to determine the critical bending moment for cantilevers beams with symmetric cross-section. Besides the NCCI recommendations, other approaches, e.g. research literature or Finite-Element-Analysis, may be employed to determine critical buckling loads. However, in certain cases they render different results. Present paper summarizes and compares the abovementioned analytical and numerical approaches for determining critical loads and it exemplarily analyses corresponding cantilever beam capacities using numerical approaches based on plastic zones theory (GMNIA)

Clinical cases Zinner syndrome: a case report and literature review

Abstract Introduction and objective: Zinner syndrome is a rare congenital abnormality of the mesonephric duct (Wolffian) consisting of unilateral renal agenesis, seminal vesicle cyst and ipsilateral ejaculatory duct obstruction. Abnormalities involving the contralateral seminal vesicle or ejaculatory duct are extremely rare. We present the therapeutic approach in a patient with renal agensesis and large contralateral seminal vesicle cyst. Patient, Method and Results: A 24 years old patient known with right congenital solitary kidney presents with dysuria, pollakiuria, nocturia, hypospermia, ejaculatory pain and diffuse hypogastric and perineal pain. The imaging exams (abdominal ultrasound, contrast-enhanced computed tomography) reveal a cystic mass of the lower mid-abdomen of 14/11 cm with mass-effect, the absence of the left kidney, grade II right hydronephrosis and right megaureter. Preoperatively, the transonic mass has been interpreted as a seminal vesicle cyst. We performed the robotic-assisted laparoscopic cyst resection by using an approach similar as for radical prostatectomy. The intraoperative assessment revealed a cystic mass with a point of origin in the right seminal vesicle, contralateral to the renal agenesis, with an aspect suggestive for Zinner syndrome. Conclusions: Zinner syndrome is a rare urological condition that must be suspected in the young adult with recurrent irritative-obstructive lower urinary tract symptoms associated with pelvic pain syndrome, pelvic cystic mass, unilateral renal agenesis and significant alteration in sperm parameters. The conservative approach is limited to asymptomatic cases. The robotic-assisted minimally invasive approach facilitates the accurate delineation and isolation of anatomical structures, in a territory where subsequent to pericystic inflammation and changes in surgical plans, the classic surgical approach to adjacent structures proves difficult