Fatigue and liver transplantation in patients with primary biliary cirrhosis.

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Reducing Solar Dish Park Production Volatility Utilizing Lithium-ion Batteries

Solar dish-Stirling technology is the Concentrated Solar Power (CSP) technology that can be more easily integrated into Distribution networks due to its small size. However, a disadvantage of this technology is that features shorter thermal inertia and thus, the output is more volatile compared to large scale CSP plants. In this paper, the production of a solar dish-Stirling plant connected to a battery bank forming a Hybrid plant is studied, in order to determine up to what extent the production stabilization can be achieved. A modelling approach of the electricity output of a solar dish system integrated to a lithium-ion battery, is developed. A methodology based on the minimization of the mean square error between the actual and the proposed stabilized production is presented, in order to optimally size the battery bank. Results from the application of the Hybrid plant for typical days of various seasons prove the output capability of such a configuration and the guaranteed power amount of the relevant plant, along with the addition of volatility decrease

A clinicopathological study of the neuropsychiatric features of Parkinson's disease

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Prevalence of pre-transplant electrocardiographic abnormalities and post-transplant cardiac events in patients with liver cirrhosis.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Although cardiovascular disease is thouht to be common in cirrhosis, there are no systematic investigations on the prevalence of electrocardiographic (ECG) abnormalities in these patients and data on the occurrence of post-transplant cardiac events in comparison with the general population are lacking. We aimed to study the prevalence and predictors of ECG abnormalities in patients with cirrhosis undergoing liver transplantation and to define the risk of cardiac events post-transplant compared to the general population.Cirrhotic patients undergoing first-time liver transplantation between 1999-2007 were retrospectively enrolled. ECGs at pre-transplant evaluation were reviewed using the Minnesota classification and compared to healthy controls. Standardized incidence ratios for post-transplant cardiac events were calculated.234 patients with cirrhosis were included, 186 with an available ECG (36% with alcoholic and 24% with viral cirrhosis; mean follow-up 4 years). Cirrhotics had a prolonged QTc interval, a Q wave, abnormal QRS axis deviation, ST segment depression and a pathologic T wave more frequently compared to controls (p < 0.05 for all). Arterial hypertension, older age, cirrhosis severity and etiology were related to ECG abnormalities. Compared to the general Swedish population, patients were 14 times more likely to suffer a cardiac event post-transplant (p < 0.001). A prolonged QTc interval and Q wave were related to post-transplant cardiac events (p < 0.05 for all).Pre-transplant ECG abnormalities are common in cirrhosis and are associated with cardiovascular risk factors and cirrhosis severity and etiology. Post-transplant cardiac events are more common than in the general population.Medical research council of Vastra Gotaland in Sweden ALF-2210

Uncrewed Aircraft Systems for Autonomous Infrastructure Inspection

Uncrewed Aircraft Systems (UAS) are becoming increasingly popular for infrastructure inspections since they offer increased safety, decreased costs and consistent results, compared to traditional methods. However, there are still many open challenges before fully autonomous, reliable, and repeatable UAS inspections. While a UAS platform has increased mobility and can easily approach hard to reach areas, it has limited range and payload capacity and is susceptible to environmental disturbances. Therefore, current operations are limited to Visual Line of Sight (VLOS) manual inspections that usually result in just a qualitative (visual) assessment of the structure. The objective of this work is to propose solutions to these limitations in an effort to improve the effectiveness of UAS as an autonomous inspection platform. First, a heterogeneous marsupial robotic system is proposed as a solution to the limited range and flight time of UAS. The proposed system uses an Autonomous Surface Vehicle (ASV) to ferry the UAS close to the area of interest, where the latter can perform an inspection. Combining these two different platforms in a single system takes advantage of the individual strengths resulting on a platform that has the reach and high point of view of a UAS but has the range and operation time of the ASV. The proposed system was extensively tested over a six-month period in field deployments at Lake Murray and at the Congaree River, SC, USA, to validate its capabilities. As a solution to go beyond visual UAS inspections, a UAS equipped with a Stereo Digital Image Correlation (StereoDIC) system is proposed. StereoDIC is a non-contact non-destructive evaluation method that can accurately measure displacements, strains, strain rates, and geometry profiles. StereoDIC has become a method of choice in experimental mechanics with most studies performed in controlled lab environments with controlled lighting and stationary cameras positioned in the appropriate distance from the measured object. A prototype is built and tested in a lab setting to investigate its effectiveness and understand the challenges that might arise from the deployment of such a system. A comparative study using a stationary StereoDIC system validates the accuracy of the measurements while the acquisition of measurements showing the onset and evolution of defects and the dynamic response of the structure during a harmonic oscillation verifies the ability of the system to produce a quantitative assessment. Finally, using the lessons learned from the lab experiments, a new, upgraded, StereoDIC enabled UAS is developed for outdoor deployment and infrastructure inspection. To allow safe field deployments, the new system features a state estimation framework enabling operation in GNSS degraded environments while also estimating any external disturbances acting on the platform. These disturbances are utilized by the controller to make the platform adaptable to challenging weather conditions. The new system was deployed over an eight-month period at a railroad bridge in Columbia, SC. Initial data were collected that guided the investigations of effective speckle pattern applications. Experimental results from bridge measurements, while loaded from crossing trains, are presented and discussed

Absorption in ultrathin GaN-based membranes : the role of standing wave effects

A methodology is described to extract the absorption coefficient spectrum and exciton oscillator strength of GaN layers and GaN/AlGaN quantum wells by analyzing microtransmittance experiments in high-quality, free-standing membranes with thicknesses in the 160–230 nm range. The absorbance of a subwavelength GaN membrane is found to be an oscillating function of its thickness, in keeping with the standing wave effect. We analyze our results using two alternative models including interference effects and extract identical absorption coefficient values. The room-temperature absorption coefficient of bulk GaN membranes at the main exciton peak is found to be 9 × 104 cm−1. In the case of GaN/AlGaN quantum wells, the enhancement and blue shift of the excitonic absorption are observed, as a result of quantum confinement