Simulation and analysis of the forward bias current–voltage–temperature characteristics of W/4H-SiC Schottky barrier diodes for temperature-sensing applications

Abstract The current-voltage (ID-VD) characteristics of W/4H-SiC Schottky barrier diodes (SBDs) are investigated in the 303–448 K temperature range by means of a numerical simulation study. Results showed a good agreement with measurements for a bias current ranging from 100 nA up to 10 mA. The main device parameters, such as the barrier height and ideality factor are found strongly temperature-dependent. The observed behaviours are interpreted by using the thermionic emission (TE) theory with a single Gaussian distribution of the barrier height (BH). The corresponding Richardson constant is A* = 148.8 Acm−2K−2. This value is close to the theoretical one of 146 Acm−2K−2 for n-type 4H-SiC

Marine Propulsion by the Injection of Compressed Air

International audienc

Robocasting of advanced ceramics: ink optimization and protocol to predict the printing parameters - A review

Direct-Ink-Writing (or robocasting) is a subset of extrusion-based additive manufacturing techniques that has grown significantly in recent years to design simple to complex ceramic structures. Robocasting, relies on the use of high-concentration powder pastes, also known as inks. A successful optimization of ink rheology and formulation constitutes the major key factor to ensure printability for the fabrication of self-supporting ceramic structures with a very precise dimensional resolution. However, to date achieving a real balance between a comprehensive optimization of ink rheology and the determination of a relevant protocol to predict the printing parameters for a given ink is still relatively scarce and has been not yet standardized in the literature. The current review reports, in its first part, a detailed survey of recent studies on how ink constituents and composition affect the direct-ink-writing of ceramic parts, taking into account innovative ceramic-based-inks formulations and processing techniques. Precisely, the review elaborates the major factors influencing on ink rheology and printability, specifically binder type, particle physical features (size, morphology and density) and ceramic feedstock content. In the second part, this review suggests a standardized guideline to effectively adapt a suitable setting of the printing parameters, such as printing speed and pressure, printing substrate, strut spacing, layer height, nozzle diameter in function of ink intrinsic rheology

Seasonal Migration and Home Ranges of Female Elk in the Black Hills of South Dakota and Wyoming

Understanding the movement and dispersion patterns of elk (Cervus elaphus) on public lands and the underlying factors that affect each will facilitate elk management and help resolve conflicts between management that benefit elk and other uses of land resources. Consequently, there is a need to identify and examine the movement and dispersion patterns of elk in the Black Hills of South Dakota and Wyoming. Our study quantified seasonal movements, determined home ranges of female elk in two areas of the Black Hills, and examined underlying factors associated with each. Elk in the northern area did not demonstrate seasonal migration patterns. Rather, winter ranges in the northern area were contained mostly within the boundaries of the summer range. Elk in the southern area exhibited a north-south migration pattern that coincided with seasonal patterns of snowfall. These elk migrated to winter range in late November and returned to summer range in late April. Home ranges of elk in the southern area were larger (P \u3c 0.01) than home ranges in the northern area. Landscape characteristics with marginally-significant correlations to elk home range area included road density (P = 0.10), and forage:cover ratio (P = 0.08); density of primary and secondary roads and average slope were significantly correlated with elk home range area (P \u3c 0.01). Managers can use this information to develop strategies that meet population goals and reduce conflicts between management for elk and with other resources

STEATOSE HEPATIQUE AIGUE GRAVIDIQUE A PROPOS DE QUATRE CAS

Introduction : La stéatose hépatique aiguë gravidique (SHAG) est une maladie hépatique rare, responsable d’une insuffisance hépatocellulaire aiguë, d’un trouble de l’hémostase et d’une insuffisance rénale .C’est une urgence médicale et obstétricale mettant en jeu le pronostic maternel et foetal. L’objectif de notre travail est de décrire les caractéristiques cliniques, détailler la prise en charge thérapeutique et dégager les éléments de mauvais pronostic maternel de la SHAG.Observations : Nous rapportons quatre observations de SHAG, l age gestationnel de nos patientes était réparti entre 32 et 35 semaines. Deux entre elles étaient des multipares, avec des grossesses antérieures normales. Deux de nos patientes avaient une HTAG dont l’une a présenté initialement une pré éclampsie. Les signes digestifs sont retrouvés dans les quatre observations. Trois de nos patientes ont présenté un ictère entre quatre et dix jours avant l’accouchement tandis qu’une seule l’a présenté en post partum immédiat. L’hypoglycémie a été présente dans les trois observations. Deux de nos patientes avaient un taux de prothrombine inférieur à 50% et une patiente avait présenté un trouble sévère d’hémostase ayant nécessité une transfusion sanguine. L’accouchement a eu lieu par voie basse dans un cas et par césarienne urgente dans trois cas, en ce qui concerne le pronostic on a noté un décès dans un tableau de défaillance hépatorénale et d’hémorragie gastrointestinale, et une rémission complète pour les trois autres patientes.Conclusion : La SHAG reste une pathologie grave. le diagnostic de la phase préictérique et l’évacuation utérine précoce constituent les seuls éléments pouvant améliorer sensiblement son pronostic

Clinical use and efficacy of biphasic insulin lispro 50/50 in people with insulin treated diabetes-A nationwide evaluation of clinical practice

© 2015 Informa UK Ltd. Objectives: This study aims to investigate the metabolic effects of biphasic insulin lispro 50/50 in routine clinical practice. A total of 229 patients who were 18 years old with diabetes, newly treated with biphasic insulin lispro 50/50, were sourced from six secondary care services in England. Methods: Detailed clinical parameters were compared at baseline, and 3 and 6 months post-initiation. Responders was defined as those with HbA1c 1% (11mmol/mol) at 6 months. Results: HbA1c showed significant reduction:-0.93% (-10mmol/mol) and-1.2% (-13mmol/mol) at 3 and 6 months respectively, while no significant change was noted for all the other parameters. When analyzed according to frequencies of injections/day, the greatest reduction was observed with the three times a day regimen (-1.0% [-11.0mmol/mol] and-1.3% [-14.6mmol/mol] at 3 and 6 months respectively). HbA1c reduction was greatest in the group who previously received a basal-bolus insulin regimen: (-0.8% [-9.0mmol/mol] and-1.5% [-16.2mmol/mol] at 3 and 6 months respectively). Reduction in weight was observed at 3 months (-1.8kg±4.3) only for those who were previously on a basal-bolus insulin regimen. Insulin doses increased following conversion to biphasic insulin lispro 50/50, irrespective of the types of insulin used prior to biphasic insulin lispro 50/50, but this was not associated with weight gain. The independent predictors of response to biphasic insulin lispro 50/50 were baseline HbA1c, Caucasian, presence of nephropathy, prior use of basal-bolus insulin and prior use of other premixed combination. Conclusion: Biphasic insulin lispro 50/50 is therefore an effective therapeutic option for achieving glycemic control in patients with suboptimal HbA1c levels, especially among those who were previously on a basal-bolus insulin regimen and those who received it three times daily, with a neutral effect on weight parameters. Limitations: This was a retrospective study of routine clinical practice and is therefore limited by allocation bias and some missing data. Information on rates of hypoglycemia and quality of life are not available

Collaborative filtering to quarterly index subjective well-being: case of Morocco

This paper presents the results of a study conducted in Morocco to measure happiness of its citizens based on data regrouped from four surveys. Each participant in these surveys is characterized by Sex, age group, region, place of residence, family situation, and profession. 380 participants answered 45 questions in each survey. In the case of missing data, a collaborative filtering approach was adopted to predict the missing answer from gathered answers by exploiting the similarity between participants according to their characteristics. The obtained results were analyzed using simple random analysis regarding each key variation under the main theory. Kruskal-Wallis test and Mann-Whitney test were conducted

Experimental investigation of the natural and forced convection on solidification of Sn-3wt. %Pb alloy using a benchmark experiment

International audienceWe deal with the development of a solidification benchmark experiment in order to investigate the structure formation as well as solute macro-mesosegregation, by means of a well-controlled solidification experiment. The experiment consists in solidifying a rectangular ingot of Sn-3wt.%Pb alloy, by using two lateral heat exchangers which allow extraction of the heat flux from one or two vertical sides of the sample. The domain is a quasi two dimensional parallepipedic ingot (100x60x10) mm. The temperature difference ΔT between the two lateral sides is 40 K and the cooling rate CR= 0.03 K/s. The instrumentation consists in recording the instantaneous temperature maps by means of an array of 50 thermocouples in order to provide the time evolution of the isotherms. After each experiment the patterns of the segregations have been obtained by X-ray radiograph and confirmed by eutectic fraction measurements. The local solute distribution determined by means of induction coupled plasma analysis is provided. The originality of the present study is to examine the effect of the forced convection driven by a travelling magnetic field (TMF) induced by a linear inductor located on the bottom part of the sample. A periodically reversed stirring with a modulation frequency equal to 0.5 Hz stirring have been investigated. This study allows us to evaluate the evolution due to the forced convection induced by a TMF field, as well as its influence on the initial conditions, the solidification macrostructure and the segregation behavior. Measurements of the velocity field by ultrasonic Doppler velocimetry (UDV) method in a Ga-In-Sn pool were performed and transposed to the tin-lead alloy case before solidification. Post-mortem patterns of the macro-mesosegregations have been obtained by X-ray radiography. The results show the transport effects of the flow on both the macrosegregations and the channel formation. The reversal of the TMF produces a decrease of the level of mesosegregations, namely channel formation