A Nomographic Methodology for Use in Performance Trade-Off Studies of Parabolic Dish Solar Power Modules

A simple graphical method was developed to undertake technical design trade-off studies for individual parabolic dish models comprising a two-axis tracking parabolic dish with a cavity receiver and power conversion assembly at the focal point. The results of these technical studies are then used in performing the techno-economic analyses required for determining appropriate subsystem sizing. Selected graphs that characterize the performance of subsystems within the module were arranged in the form of a nomogram that would enable an investigator to carry out several design trade-off studies. Key performance parameters encompassed in the nomogram include receiver losses, intercept factor, engine rating, and engine efficiency. Design and operation parameters such as concentrator size, receiver type (open or windowed aperture), receiver aperture size, operating temperature of the receiver and engine, engine partial load characteristics, concentrator slope error, and the type of reflector surface, are also included in the graphical solution. Cost considerations are not included

Final results of nu-e-bar electron scattering cross-section measurements and constraints on new physics

The nu-e-bar electron elastic scattering cross-section was measured with a CsI(Tl) scintillating crystal detector array with a total mass of 187 kg at the Kuo-Sheng Nuclear Power Station. The detectors were exposed to a reactor nu-e-bar flux of 6.4 X 10^{12} cm^{-2}s^{-1} originated from a core with 2.9 GW thermal power. Using 29882/7369 kg-days of Reactor ON/OFF data, the Standard Model (SM) of electroweak interaction was probed at the 4-momentum transfer range of Q^2 ~ 3 X 10^{-6} GeV^2. A cross-section ratio of R_{expt} = [1.08 +- 0.21(stat) +- 0.16(sys)] X R_{SM} was measured. Constraints on the electroweak parameters (g_V,g_A) were placed, corresponding to a weak mixing angle measurement of \s2tw = [0.251 +- 0.031(stat) +- 0.024(sys)]. Destructive interference in the SM nu-e-bar+e processes was verified. Bounds on neutrino anomalous electromagnetic properties (neutrino magnetic moment and neutrino charge radius), non-standard neutrino interactions, upparticle physics and non-commutative physics were placed. We summarize the experimental details and results, and discuss projected sensitivities with realistic and feasible hardware upgrades.Comment: 4 pages, 4 figures, 2 tables ; To appear in Proceedings of TAUP-2011 Conferenc

Assessment of material properties of gallium orthophosphate piezoelectric elements for development of phased array probes for continuous operation at 580 degrees C

In this paper, the thickness extension mode gallium orthophosphate single crystal elements were characterised using the impedance analyser. Impedance characteristics of piezoelectric elements were investigated at temperatures from 25°C up to 580°C at first and then at a constant temperature of 580°C for a period of 25 days. The resonant and anti-resonant frequencies extracted from the impedance characteristics, capacitance (measured at 1 kHz), density and dimensions of the gallium orthophosphate elements were used to calculate electromechanical, piezoelectric and elastic properties of these elements at high temperatures as a function of time. The tested gallium orthophosphate elements proved to possess very stable efficiency and sensing capability when subjected to high temperature. The results are very encouraging for proceeding with development of phased array probes using gallium orthophosphate, for inspection and condition monitoring of high temperature pipelines in power plants at a temperature up to 580°C

Fuel tank leakage detection based on acoustic emission

The Plastic Fuel Tanks are widely used in the automotive industry besides steel tanks as they offer numerous advantages such as lower weight, higher corrosion resistance, better crash performance and lower total system costs. Tank manufacturing from plastics and composites has been adapted to mass production to meet the ever growing demand. The management of quality control (QC) systems for the factory environment poses challenges in the absence of relevant experience in the development and use of insitu non-destructive evaluation technologies. The problem currently faced by the automotive industry is that most techniques that meet accepted leak detection sensitivity requirements are operator-dependent. Mechanized leak detection techniques are characterized by high investment and operational costs. Hence, their implementation is not economically feasible as the related costs outweigh their benefits for automotive QC purposes. The proposed Leak Detection project was targeted at bringing a low cost leak detection system that is fast, accurate, traceable and automated for the mass production environment of the fuel tank production industry. The system eliminates the disadvantages associated with the manual-intensive and operator dependent techniques currently employed by the industry, through the use of Acoustic Emission. In this approach, hydrophones were used to listen to the sound induced by gas escaping from tanks under pressure. When pressurized gas leaks from a tank it creates an acoustic signal that can travel through the liquid medium. At the core of the system denoising techniques were designed and developed in order to obtain the highest possible signal to noise ratio (SNR) in the noisy industrial conditions. Experiments were carried out at different conditions including bubble size, distance from hydrophone to the bubble source. Furthermore, experiments were carried out at real industrial plant in order to validate the signal processing techniques and the hardware to detect the bubbles produced by leakage in the real scenario.This work was supported by the EU Horizon 2020 funded project Leak detection, Development of a reliable quality control system using advanced Non-Destructive Evaluation (NDE) technologies for the production environment of leak-free fuel tanks from plastics and composites, (Project reference: 673155)

European Association of Urology and European Society for Paediatric Urology Guidelines on Paediatric Urinary Stone Disease

Context: Paediatric stone disease is an important clinically entity and management is often challenging. Although it is known that the condition is endemic in some geographic regions of the world, the global incidence is also increasing. Patient age and sex; the number, size, location, and composition of the stone; and the anatomy of the urinary tract are factors that need to be taken into consideration when choosing a treatment modality. Objective: To provide a general insight into the evaluation and management of urolithiasis in the paediatric population in the era of minimally invasive surgery. Evidence acquisition: A nonsystematic review of the literature on management of paediatric urolithiasis was conducted with the aim of presenting the most suitable treatment modality for different scenarios. Evidence synthesis: Because of high recurrence rates, open surgical intervention is not the first option for paediatric stone disease, except for very young patients with very large stones in association with congenital abnormalities. Minimally invasive surgeries have become the first option with the availability of appropriately sized instruments and accumulating experience. Extracorporeal shockwave lithotripsy (SWL) is noninvasive and can be carried out as an outpatient procedure under sedation, and is the initial choice for management of smaller stones. However, for larger stones, SWL has lower stone-free rates and higher retreatment rates, so minimally invasive endourology procedures such as percutaneous nephrolithotomy and retrograde intrarenal surgery are preferred treatment options. Conclusions: Contemporary surgical treatment for paediatric urolithiasis typically uses minimally invasive modalities. Open surgery is very rarely indicated. Patient summary: Cases of urinary stones in children are increasing. Minimally invasive surgery can achieve high stone-free rates with low complication rates. After stone removal, metabolic evaluation is strongly recommended so that medical treatment for any underlying metabolic abnormality can be given. Regular follow-up with imaging such as ultrasound is required because of the high recurrence rates

Internal supravesical hernia as a rare cauase of intestinal obstruction: a case report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Practical recommendations of the EAU-ESPU guidelines committee for monosymptomatic enuresis-Bedwetting

Background and Aims The objective of this update of the EAU-ESPU guidelines recommendations for nocturnal enuresis was to review the recent published literature of studies, reviews, guidelines regarding the etiology, diagnosis and treatment options of nocturnal enuresis and transform the information into a practical recommendation strategy for the general practitioner, pediatrician, pediatric urologist and urologist. Material and Methods Since 2012 a monthly literature search using Scopus (R) was performed and the relevant literature was reviewed and prospectively registered on the European Urology bedwetting enuresis resource center (). In addition, guideline papers and statements of the European Society for Paediatric Urology (ESPU), the European Association of Urology (EAU), the National Institute for Health and Care Excellence (NICE) and the International Children Continence Society (ICCS) were used to update the knowledge and evidence resulting in this practical recommendation strategy. Recommendations have been discussed and agreed within the working group of the EAU-ESPU guidelines committee members. Results The recommendations focus to place the child and his family in a control position. Pragmatic analysis is made of the bedwetting problem by collecting voiding and drinking habits during the day, measuring nighttime urine production and identification of possible risk factors such as high-volume evening drinking, nighttime overactive bladder, behavioral or psychological problems or sleep disordered breathing. A questionnaire will help to identify those risk factors. Conclusion Motivation of the child is important for success. Continuous involvement of the child and the family in the treatment will improve treatment compliance, success and patient satisfaction

Are there any benefits of using an inlay graft in the treatment of primary hypospadias in children?:A systematic review and metanalysis

INTRODUCTION: Dorsal inlay graft urethroplasty (DIGU) has been described as an effective method for hypospadias repair with the proposed advantage of reducing the risk of complications. We aimed to systematically assess whether DIGU has any additional advantages over standard tubularized incised plate urethroplasty (TIPU) repair in children with primary hypospadias. MATERIALS AND METHODS: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. The a priori protocol is available at the PROSPERO database (CRD42020168305). A literature search was conducted for relevant publications from 1946 until January 10, 2020 in seven different databases. Randomized controlled trials (RCTs), comparative studies (TIPU vs DIGU) and single arm case series (>20 cases) of DIGU were eligible for inclusion. Secondary hypospadias, two-stage repairs, disorders of sex development, significant curvature of >30°, and a mean or median follow-up of less than 12 months were excluded. DISCUSSION: A total of 499 articles were screened and 14 studies (3 RCTs, 5 non-randomized studies (NRSs), and 6 case series) with a total of 1753 children (distal: 1334 (76%) and proximal: 419 (24%)) were found eligible. Mean follow-up of the studies was between 16 and 77 months. DIGU was found superior to TIPU in decreasing meatal/neourethral stenosis (p = 0.02, 95% CI 0.02-0.78). All other parameters were found comparable including overall complications, fistula and glans dehiscence rates. Success rates were similar among the groups ranging between 48% and 96% for DIGU and 43-96% in the TIPU group. The lack of standardization in the definition of complications and success was the major limitation of this study. CONCLUSIONS: Using an inlay graft during primary hypospadias repair decreases the risk of meatal/neourethral stenosis. However, current evidence does not demonstrate superiority of DIGU over TIPU in terms of treatment success and overall complication rates

An experimental study on the applicability of acoustic emission for wind turbine gearbox health diagnosis

Condition monitoring of wind turbine gearboxes has mainly relied upon vibration, oil analysis and temperature monitoring. However, these techniques are not well suited for detecting early stage damage. Acoustic emission is gaining ground as a complementary condition monitoring technique as it offers earlier fault detection capability compared with other more established techniques. The objective of early fault detection in wind turbine gearboxes is to avoid unexpected catastrophic breakdowns, thereby reducing maintenance costs and increase safety. The aim of this investigation is to present an experimental study the impact of operational conditions (load and torque) in the acoustic emission activity generated within the wind turbine gearbox. The acoustic emission signature for a healthy wind turbine gearbox was obtained as a function of torque and power output, for the full range of operational conditions. Envelope analysis was applied to the acoustic emission signals to investigate repetitive patterns and correlate them with specific gearbox components. The analysis methodology presented herewith can be used for the reliable assessment of wind turbine gearbox subcomponents using acoustic emission.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: IntelWind Project is an FP7 project partly funded by the EC under the Research for the Benefit of SMEs programme, Grant Agreement Number 283277, coordinated and managed by Innovative Technology and Science Ltd

Impact of SARS-CoV-2 on training and mental well-being of surgical gynecological oncology trainees

Introduction: The SARS-CoV-2 global pandemic has caused a crisis disrupting health systems worldwide. While efforts are being made to determine the extent of the disruption, the impact on gynecological oncology trainees/training has not been explored. We conducted an international survey of the impact of SARS-CoV-2 on clinical practice, medical education, and mental well-being of surgical gynecological oncology trainees. Methods: In our cross-sectional study, a customized web-based survey was circulated to surgical gynecological oncology trainees from national/international organizations from May to November 2020. Validated questionnaires assessed mental well-being. The Wilcoxon rank-sum test and Fisher's exact test were used to analyse differences in means and proportions. Multiple linear regression was used to evaluate the effect of variables on psychological/mental well-being outcomes. Outcomes included clinical practice, medical education, anxiety and depression, distress, and mental well-being. Results: A total of 127 trainees from 34 countries responded. Of these, 52% (66/127) were from countries with national training programs (UK/USA/Netherlands/Canada/Australia) and 48% (61/127) from countries with no national training programs. Altogether, 28% (35/125) had suspected/confirmed COVID-19, 28% (35/125) experienced a fall in household income, 20% (18/90) were self-isolated from households, 45% (57/126) had to re-use personal protective equipment, and 22% (28/126) purchased their own. In total, 32.3% (41/127) of trainees (16.6% (11/66) from countries with a national training program vs 49.1% (30/61) from countries with no national training program, p=0.02) perceived they would require additional time to complete their training fellowship. The additional training time anticipated did not differ between trainees from countries with or without national training programs (p=0.11) or trainees at the beginning or end of their fellowship (p=0.12). Surgical exposure was reduced for 50% of trainees. Departmental teaching continued throughout the pandemic for 69% (87/126) of trainees, although at reduced frequency for 16.1% (14/87), and virtually for 88.5% (77/87). Trainees reporting adequate pastoral support (defined as allocation of a dedicated mentor/access to occupational health support services) had better mental well-being with lower levels of anxiety/depression (p=0.02) and distress (p<0.001). Trainees from countries with a national training program experienced higher levels of distress (p=0.01). Mean (SD) pre-pandemic mental well-being scores were significantly higher than post-pandemic scores (8.3 (1.6) vs 7 (1.8); p<0.01). Conclusion: SARS-CoV-2 has negatively impacted the surgical training, household income, and psychological/mental well-being of surgical gynecological oncology trainees. The overall clinical impact was worse for trainees in countries with no national training program than for those in countries with a national training program, although national training program trainees reported greater distress. COVID-19 sickness increased anxiety/depression. The recovery phase must focus on improving mental well-being and addressing lost training opportunities