CFD Analysis and optimization of the DEMO WCLL central outboard segment bottom-Cap elementary cell

In the design of magnetic confinement nuclear fusion power plants, the Breeding Blanket (BB) plays a crucial role, since it must fulfil key functions such as tritium breeding, radiation-shielding and removing of the heat power generated by the plasma. The latter task is achieved by the First Wall (FW) and Breeding Zone (BZ) cooling systems, that in the Water-Cooled Lithium-Lead (WCLL) BB employs pressurized water. Different arrangements of BZ coolant conduits have been investigated in the recent past to identify an efficient layout, which could meet the structural materials operational temperature constraint and that could provide the optimal coolant outlet temperature. However, most of the Computational Fluid-Dynamic (CFD) analysis carried out until now have been focused on the equatorial WCLL elementary cell of the Central Outboard Segment (COB). The aim of this work is to broaden the analysis to other relevant locations in the blanket. An assessment of the design of the cooling system of the COB bottom-cap elementary BZ cell has been identified as the top design priority due to its different geometry and thermal loads. The cooling efficiency of the BZ and FW systems is investigated to assess if the coolant appropriate design conditions are matched and the temperature distribution in the cell is analyzed to identify the onset of hot spots. Different layouts of the FW systems are proposed and compared in terms of thermal-hydraulics reliability

Modified partial circumcision for phimosis: techniques and surgical outcomes

Objectives: In the last years, many surgical techniques of preputioplasty have aimed to preserve the foreskin in case of phimosis. These techniques are not reliable for patients affected by phimosis linked to balanitis xerotica obliterans (BXO) and scarred foreskin. We tried an original technique of resection of the pathological foreskin, removing the mucosal internal layer followed by reconstruction of the foreskin. The aim was to evaluate the outcome of paediatric patients who underwent modified partial circumcision for pathological phimosis.Patients and methods: In all, 360 patients with phimosis underwent modified partial circumcision at our institution. The mean age of the boys was 8.9 years, range 5–15 years. In 145 (40.3%) cases, indication for surgery was clinical suspicion of BXO, in 215 (59.7%) cases it was chronic inflammation of the foreskin.Results: In all cases, the postoperative period was uneventful. Cosmesis was considered by parents as excellent in 95.2% of patients. In these patients, the glans was almost completely covered by soft foreskin. Histopathological examination of the removed foreskin documented BXO in 162 (45%). Twelve (3.3%) patients complained of recurrences and five (1.4%) patients of smegmatic cysts.Conclusion: The described surgical technique of modified partial circumcision for the correction of pathological phimosis appears cosmetically well accepted, safe, and simple with low rate of late postoperative complications.Keywords: balanitis xerotica obliterans, circumcision, partial circumcision, phimosi

Robot-assisted excision of urachal cyst: case report in a child

Abstract Background The urachus is an embryological structure of the urogenital sinus and allantoid that connects the allantois to the early bladder in fetal life and then remains as the median umbilical ligament connecting the umbilicus to the dome of the bladder. An early laparoscopic procedure could trigger a quiescent urachal remnant to become symptomatic, causing a lesion or infection either during carbon oxide contamination or insufflation or a periumbilical or suprapubic port placement. Case presentation A 15-year-old girl complaining of supra-pubic abdominal pain. About 2 months previously, she had undergone laparoscopic appendectomy for acute appendicitis, and early postoperative period was uneventful. She underwent a robotic-assisted excision of a urachal cyst. Conclusions It has been suggested that early laparoscopic procedures could trigger previously asymptomatic urachal remnants to become symptomatic. Robot-assisted excision of a urachal cyst is a safe, effective alternative to open surgery in children

Modeling the Transport of Activated Corrosion Products in the WCLL PbLi Loop for ITER and the EU DEMO With the GETTHEM Code

This work presents the results of the implementation in the GEneral Tokamak THErmal-hydraulic Model of available models for the generation and transport of any dispersed material in flowing PbLi eutectic mixture. In particular, the focus is on Activated Corrosion Products circulating as solid suspension in the PbLi loop of the Water-Cooled Lithium-Lead Breeding Blanket of the EU DEMO fusion reactor. A simple test case is used to show that the distribution of the concentration of activated corrosion products at any point of the PbLi loop, both in the water-cooled lithium-lead breeding blanket and in the related ITER Test Blanket System, can be determined by the model. Moreover, thanks to the model’s dynamic nature, operational transients can be simulated; for instance, starting from zero impurities in the PbLi alloy, the evolution of the concentration of corrosion products is shown, until the steady-state is reached. The results obtained with this tool can be useful not only for radiological safety purposes, but also because activated corrosion products may affect the PbLi flow itself and the efficiency of the tritium removal system, with consequences on the achievable Tritium Breeding Ratio. A rigorous verification of the model is also performed

Embrittlement of WCLL blanket and its fracture mechanical assessment

In the European fusion programme, the Water Cooled Lithium Lead breeding blanket (WCLL BB) uses EUROFER as a structural material cooled with water at temperatures between 295 °C–328 °C and a pressure of 155 bar. The WCLL BB will be significantly irradiated (>2 dpa), while some parts will not receive significant heat loads, e.g. the sidewalls or the back-supporting structures. The irradiation, together with the irradiation temperature of EUROFER below 350 °C, produces a shift of the ductile-to-brittle-transition temperature (DBTT) to levels above room temperature at neutron doses, causing material damage as low as 2–3 dpa. Even though the DBTT does not reach the operating temperature level, brittle/non-ductile fracture is a concern during in-vessel maintenance when the BB temperature is below the DBTT. Two loading scenarios were identified as severe in this respect: (i) re-pressurization of the WCLL BB cooling loop after in-vessel maintenance, and (ii) dead weight loads during lifting of the BB segment. The embrittlement of the WCLL BB was investigated by quantifying the local DBTT shift in its parts based on current knowledge of the embrittlement behaviour of EUROFER under neutron irradiation. Therefore, a suitable, not overly conservative procedure was derived considering dpa damage and transmuted helium effects. The results demonstrate the ability to identify the 3D spread of the severely embrittled zones in the structure whose impact on the structural integrity was assessed considering the risk of brittle/non-ductile fracture. Thereby, the fracture mechanics approach established in nuclear codes was applied assuming its applicability to EUROFER. The embrittled zones in the first wall (FW) and its sidewalls pass the criteria when assessing the relatively low stresses resulting from the coolant pressure. The assessment was then continued considering stresses appearing in the FW during maintenance, in particular, when lifting the BB segment and transporting it out of the vacuum vessel. In this context, the maximum tolerable flaw sizes were determined in a parameter study considering designs of the FW with different cooling channel wall thicknesses

Survival and Prognostic Factors in Patients with Hepatocellular Carcinoma Treated by Percutaneous Ethanol Injection: A 10-Year Experience

The treatment of early and intermediate stage hepatocellular carcinoma (HCC) is still debated. Surgical treatments are considered to be the only curative procedures available, and only for a minority of patients. Percutaneous ethanol injection (PEI) is an established technique for the ablation of HCC nodules, and shows survival rates similar to those of resection. The efficacy of PEI in patients with biopsy-proven viral cirrhosis and small to intermediate inoperable HCC was evaluated. One hundred twenty-seven patients (85 men, 42 women, mean age 63 years, range 51 to 92 years, 115 hepatitis C virus-positive, 12 hepatitis B virus-positive) were enrolled between January 1993 and December 2002. They all underwent a standard PEI procedure and were prospectively followed-up. Overall median survival rate was 28 months (range six to 112 months). The following parameters were associated with a significantly longer survival: nodule diameter smaller than 30 mm (P=0.0480), the presence of a perinodular boundary (P=0.0008), serum alpha-fetoprotein less than 20 ng/mL (P=0.0104), a Child-Pugh A class score (PÃ0.0001) or a Cancer of the Liver Italian Program score of 0 (PÃ0.0001) and the presence or absence of small esophageal varices (P=0.013). The 19 patients with all these favourable characteristics showed an overall median survival of 61 months. An alpha-fetoprotein below 20 ng/mL was associated with significantly longer disease-free survival (P=0.0009). The Child-Pugh and Cancer of the Liver Italian Program scores were effective in predicting prognosis of these patients. In conclusion, PEI still represents a safe and economically sound treatment for HCC

Utility of uroflowmetry during the follow-up of children affected by balanitis xerotica obliterans (BXO)

Introduction: To evaluate the outcome of circumcised patients with balanitis xerotica obliterans (BXO) using uroflowmetry (UF). Methods: Between 2011 and 2013, 180 children underwent a circumcision for phimosis. The foreskin was examined on microscopy. Patients with an histological diagnosis of BXO were included in the study. Patients with BXO underwent UF two weeks after surgery and treatment with clobetasol propionate ointment. Patients were re-evaluated at 6, 12, 18 and 24 months postoperatively clinically and using UF. Results: 75 of 180 circumcised patients (41.6%) were included. At two weeks, Thirtytwo of 75 patients (42.7%) displayed a pathological UF. At six months, 15 patients (20%) had pathological UF and a new cycle of clobetasol was prescribed. At one year, 10 patients (13.3%) displayed patholgocial UF and underwent progressive urethral dilatation or meatoplasty. At 18 months, 71 patients (94.7%) displayed regular UF, 3 underwent a meatoplasty and one a staged urethroplasty for a severe urethral stenosis. At two years, UF was normal in 74 out of 75 (98.7%). Conclusions: We recommend to send for hystological examination all foreskins excised after circumcision. We believe that a clinical and uroflowmetric follow-up of pediatric patients with BXO is mandatory for a prompt identification of post-voiding dysfunction

Incidentally discovered enteric duplication cyst: a case report

Enteric duplications are rare congenital diseases with heterogeneous clinical pictures ranging from an asymptomatic course to life-threatening consequences, most commonly arising at the ileal and ileocecal region. The antenatal discovery is possible when it concerns a voluminous cystic form enabling an early management. The radiologic examinations are nonspecific and no diagnostic tools can allow a certain diagnosis on its own. Sometimes, the diagnosis of intestinal duplication is only made during the surgical exploration and confirmed after a histopathological examination. We report a 4 years old girl with antenatal diagnosed ovarian cystic mass of about 4 mm. She was admitted to our unit for abdominal pain and constipation. Abdominal ultrasonography showed a cystic mass in the right iliac fossa. MRI revealed a well-defined cystic mass (6 x 4.2 x 5.4 cm) in the right mid abdomen displacing the bowel to the left, likely to be strongly adherent to the last part of the ileum. 99mtc pertechnetate scan was negative for ectopic gastric mucosa. A laparoscopic approach was eventually necessary and the diagnosis of duplication cyst was confirmed. Children with antenatal diagnosis of abdominal mass need a close follow up and enteric duplication should be considered as potential diagnosis. The laparoscopic approach has an important role in differential diagnosis between intestinal duplications and other mass