The use of migrating corrosion inhibitors to repair motorways' concrete structures contaminated by chlorides

The effectiveness of migrating corrosion inhibitors (MCIs) and repair mortars against rebar corrosion was studied in concrete specimens made by ordinary Portland cement with w/c ratio equal to 0.6 and containing 1 wt.% of chlorides. An alkanolamine-based inhibitor was tested in addition with a common mortar and two repair mortars. Electrochemical techniques, measurements of corrosion potential and electrochemical impedance spectroscopy (EIS) were used to determine the corrosion behaviour of the specimens when a cell containing a 3.5% NaCl solution was applied on the rehabilitation mortar. Mercury intrusion porosimetry (MIP) was also used for the characterisation of repair mortars' total porosity and a chemical analysis was made to determine the amount of chlorides penetrated in the mortar layers and in the concrete substrate. Results demonstrate that the simultaneous use of the alkanolamine-based inhibitor with a good barrier coating offers protection against rebar corrosion and allows rehabilitation of deteriorated concrete structures.     

Devolatilization rate of biomasses and coal-biomass blends: an experimental investigation

Devolatilization behavior of different coals and biomasses under heating conditions typical of conventional pyrolysis processes was investigated. Thermogravimetric analyses were performed on coals (with high and low volatile matter), biomasses (pine sawdust and dried sewage sludge) and coal-biomass blends with different weight ratios. The different behavior of coals and biomass fuels in the devolatilization process (different amount and nature of volatile species released, different rate of devolatilization and different reactivity of produced chars) was analyzed for abstracting kinetic data. In addition, analyses of coal-biomass blends revealed that in the operative conditions used (i.e. low heating rate 20 °C/min and high nitrogen flowrate), primary reactions of the thermal decomposition of biomass fuels are not significantly affected by the presence of coal, and also coal does not seem to be influenced by the release of volatile matter from biomass. This led to the first conclusion that the weight loss of a blend can be obtained from the weighted sum of reference materials.Further, a kinetic analysis was performed in order to fit the experimental results and verify simple sub-models (namely, distribution activation energy model and lumped model) to be used in comprehensive combustion codes (computational fluid dynamic) assuring a major accuracy compared with SFOR model, but maintaining both simplicity and computational velocity. A quite good fitting was obtained for all materials and blends studied.     

Hypogonadism in Patients with Prader Willi Syndrome: A Narrative Review

Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder related to the lack of a functional paternal copy of chromosome 15q11-q13. Several clinical manifestations are reported, such as short stature, cognitive and behavioral disability, temperature instability, hypotonia, hypersomnia, hyperphagia, and multiple endocrine abnormalities, including growth hormone deficiency and hypogonadism. The hypogonadism in PWS is due to central and peripheral mechanisms involving the hypothalamus-pituitary-gonadal axis. The early diagnosis and management of hypogonadism in PWS are both important for physicians in order to reach a better quality of life for these patients. The aim of this study is to summarize and investigate causes and possible therapies for hypogonadism in PWS. Additional studies are further needed to clarify the role of different genes related to hypogonadism and to establish a common and evidence-based therapy.     

Impaired Leptin Signalling in Obesity: Is Leptin a New Thermolipokine?

Leptin is a principal adipose-derived hormone mostly implicated in the regulation of energy balance through the activation of anorexigenic neuronal pathways. Comprehensive studies have established that the maintenance of certain concentrations of circulating leptin is essential to avoid an imbalance in nutrient intake. Indeed, genetic modifications of the leptin/leptin receptor axis and the obesogenic environment may induce changes in leptin levels or action in a manner that accelerates metabolic dysfunctions, resulting in a hyperphagic status and adipose tissue expansion. As a result, a vicious cycle begins wherein hyperleptinaemia and leptin resistance occur, in turn leading to increased food intake and fat enlargement, which is followed by leptin overproduction. In addition, in the context of obesity, a defective thermoregulatory response is associated with impaired leptin signalling overall within the ventromedial nucleus of the hypothalamus. These recent findings highlight the role of leptin in the regulation of adaptive thermogenesis, thus suggesting leptin to be potentially considered as a new thermolipokine. This review provides new insight into the link between obesity, hyperleptinaemia, leptin resistance and leptin deficiency, focusing on the ability to restore leptin sensitiveness by way of enhanced thermogenic responses and highlighting novel anti-obesity therapeutic strategies.     

Thermodynamically Stable Synthesis of Large‐Scale and Highly Crystalline Transition Metal Dichalcogenide Monolayers and their Unipolar n–n Heterojunction Devices

Transition metal dichalcogenide (TMDC) monolayers are considered to be potential materials for atomically thin electronics due to their unique electronic and optical properties. However, large‐area and uniform growth of TMDC monolayers with large grain sizes is still a considerable challenge. This report presents a simple but effective approach for large‐scale and highly crystalline molybdenum disulfide monolayers using a solution‐processed precursor deposition. The low supersaturation level, triggered by the evaporation of an extremely thin precursor layer, reduces the nucleation density dramatically under a thermodynamically stable environment, yielding uniform and clean monolayer films and large crystal sizes up to 500 µm. As a result, the photoluminescence exhibits only a small full‐width‐half‐maximum of 48 meV, comparable to that of exfoliated and suspended monolayer crystals. It is confirmed that this growth procedure can be extended to the synthesis of other TMDC monolayers, and robust MoS₂/WS₂ heterojunction devices are easily prepared using this synthetic procedure due to the large‐sized crystals. The heterojunction device shows a fast response time (≈45 ms) and a significantly high photoresponsivity (≈40 AW^?1) because of the built‐in potential and the majority‐carrier transport at the n–n junction. These findings indicate an efficient pathway for the fabrication of high‐performance 2D optoelectronic devices.     

Naturally nonanemic dialysis patients: Who are they?

Introduction Not only anemia, but also erythropoiesis stimulating agent (ESA)s for treating anemia may adversely affect prognosis of chronic hemodialysis patients. Various features of naturally (with no ESA usage) nonanemic patients may be useful for defining several factors in the pathogenesis of anemia. Methods Data, retrieved from the European Clinical Database (EuCliD)‐Turkey on naturally nonanemic prevalent chronic hemodialysis patients (n: 201) were compared with their anemic (those who required ESA treatment) counterparts (n: 3948). Findings Mean hemoglobin values were 13.5 ± 0.8 and 11.5 ± 0.9 g/dL in nonanemic and anemic patients, respectively (P < 0.001). Nonanemia status was associated with younger age, male gender, longer dialysis vintage, nondiabetic status, more frequent hepatitis‐C virus seropositivity and more frequent arteriovenous fistula usage. Serum ferritin and CRP levels and urea reduction ratio were higher in ESA‐requiring patients. One (99%) and two (95.3%) years survival rates of the “naturally nonanemic” patients were superior as compared to anemics (91.0% and 82.6%, respectively), (P < 0.001). Discussion “Naturally nonanemic” status is associated with better survival in prevalent chronic hemodialysis patients; underlying mechanisms in this favorable outcome should be investigated by randomized controlled trials including large number of patients.     

A rare cause of abdominal pain: Catheter in the middle hepatic vein

Hemodialysis catheters are vital for chronic renal failure patients. Permanent tunneled dialysis catheters may be inserted through the jugular, subclavian, and femoral veins. In this paper, we aimed to present the computed tomography findings of a chronic renal failure patient who had referred our clinic with abdominal pain and dyspnea symptoms. This patient had a formerly inserted hemodialysis catheter for chronic renal failure and her catheter was found to be extending towards the middle hepatic vein with the tip leaning onto the parenchyma. Hemodialysis catheters can provide instant vascular access and can also be used for the consecutive procedures. Permanent hemodialysis catheters are ideal for long‐term use when placing an arteriovenous fistula is contraindicated or is no longer possible under conditions like advanced heart failure, peripheral artery disease or short life expectancy. The internal jugular, subclavian, the femoral veins, and the inferior vena cava can be used for catheter insertion. The tip of the catheters inserted in the neck or the thorax must extend to the vena cava superior. Catheter malposition may both lead to fatal outcomes and ineffective dialysis. It is important to obtain chest X‐rays after the procedure, particularly to detect catheter malposition.     

Embedded model control: reconciling modern control theory and error-based control design

The paper addresses the problem of reconciling the modern control paradigm developed by R. Kalman in the sixties of the past century, and the centenary error based design of the proportional, integrative and derivative (PID) controllers. This is done with the help of the error loop whose stability is proved to be necessary and sufficient for the close loop plant stability. The error loop is built by cascading the uncertain plant to model discrepancies (causal, parametric, initial state, neglected dynamics), which are driven by the design model output and by arbitrary bounded signals, with the control unit transfer functions. The embedded model control takes advantage of the error loop and its equations to design appropriate algorithms of the modern control theory (state predictor, control law, reference generator), which guarantee the error loop stability and performance. A simulated multivariate case study shows modeling and control design steps and the coherence of the predicted and simulated performance.     

Near real-time SAR-based processing to support flood monitoring

Earth Observation has proven to be a synoptic and objective source of information to derive crisis and damage maps. In case of flood events, often characterized by weather conditions which prevent the possibility of exploiting data acquired by optical sensors, synthetic aperture radar (SAR) sensors become the only space-born source of information due to their all-weather capability. In order to assure the delivery of damage maps as soon as possible after a disaster, the access and the exploitation of SAR data must be accelerated and simplified with respect to the current procedures. In this context, two issues needed to be addressed: fast access to large data archives, and provision of near real-time on demand processing services. This paper presents a near real-time SAR processing service to support the mapping of flooded areas. The service exploits Grid technology to manage large volumes of data and to provide the computational resources to cope with SAR processing demanding tasks. The algorithm for the implemented orthorectification of the final products is presented. The validation of the derived products shows a reliable accuracy for co-registration of half a pixel. The geolocation accuracy resulted below 100 m. The service makes a significant contribution to accelerating the access and exploitation of ESA SAR data.