264 research outputs found

    Impact of Strain on the Performance of Si Nanowires Transistors at the Scaling Limit: A 3D Monte Carlo/2D Poisson Schrodinger Simulation Study

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    In this work we investigate the correlation between channel strain and device performance in various n-type Si-NWTs. We establish a correlation between strain, gate length and cross-section dimension of the transistors. For the purpose of this paper we simulate Si NWTs with a <110> channel orientation, four different ellipsoidal channel cross-sections and five gate lengths: 4nm, 6nm, 8nm, 10nm and 12nm. We have also analyzed the impact of strain on drain-induced barrier lowering (DIBL) and the subthreshold slope (SS). All simulations are based on a quantum mechanical description of the mobile charge distribution in the channel obtained from a 2D solution of the Schrödinger equation in multiple cross sections along the current path, which is mandatory for nanowires with such ultra-scale dimensions. The current transport along the channel is simulated using 3D Monte Carlo (MC) and drift-diffusion (DD) approaches

    Fetal Pain

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    Recent studies have suggested that the fetus is capable of exhibiting a stress response to intrauterine needling, resulting in alterations in fetal stress hormone levels. Intrauterine transfusions are performed by inserting a needle either in the umbilical cord root at the placental surface (PCI), or in the intrahepatic portion of the umbilical vein (IHV). Aim of our study was to test the hypothesis that fetal hormonal changes during intrauterine transfusion are more pronounced when the needle is inserted in the fetal abdomen. Furthermore we aimed to evaluate the effect of fetal analgesia with remifentanil on the fetal stress hormone changes. Exploring the hemodynamic changes following a noxious stimulus, we saw no differences in transfusions through the IHV or the PCI. Remifentanil did not influence the stress hormone changes. We concluded that the stress hormone changes are independent of both site of transfusion and the use of remifentanil. Our results do not confirm nor deny that the fetus is capable to react to a potential painful stimulus, or to show signs of stress or even pain. However, previous research has suggested that presumably painful fetal conditions can lead to alterations in stress reactions after birth. This phenomenon is called ‘fetal programming’. Fetal programming could possibly lead to life-long changes in stress responses and even to increased susceptibility for certain diseases. With the current understanding of fetal pain and fetal analgesia we would advocate the following: 1. Fetal analgesia for invasive procedures should be provided from at least 20 weeks gestation onwards 2. All invasive fetal procedures warrant fetal analgesia, but in procedures involving more than just a single puncture with a thin needle it is obligatory. 3. Analgesics should be given intravenously to the mother. The drug of choice should be ultra-short working (like remifentanil) therefore minimising possible undesirable side-effects to both fetus and mother.LUMC / Geneeskund

    Comparative study and experimental analysis of pellets from biomass sawdust and rice husk

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    Sawdust and rice husk are available in abundance and indigenous in Nigeria but have not been exploited because they cannot be used directly in combustion processes due to their loose form unless by pelleting or briquetting. This experimental study assesses the potential of pellets from sawdust (SD) and rice husk (RH). Pallet samples collected from mills were thereafter optimized in ratios (i.e. 90%RH:10%SD, 80%RH:20%SD, 70RH:30SD, 60%RH:40%SD, 50%RH:50%SD, 100%RH and 100%SD) using mixing ratio optimization model. Seven samples were produced using a manual screw press machine and were subsequently categorized in terms of calorific value (CV), proximate and ultimate analyses using the ASTM standards. Results showed that the 100%RH pellets have higher CV of 31,026.3kJ/kg and the 100%SD a value of 26,088.3kJ/kg while the optimized pellets range from 25,867.39kJ/kg to 27,063.60kJ/kg. The CV decreases with increasing ash content of the pellets. It was also observed from the proximate analysis that the 100%RH has low percentages of moisture content, volatile matter and ash content compared to others. The optimized pellets showed that SD has the tendency to reduce the sulfur content in RH; hence, a promising alternative source of energy to the conventional fossil fuel

    Caractérisation des systÚmes de production à base de riz pluvial strict dans les exploitations agricoles de la zone Sud-soudanienne du Burkina Faso

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    Au Burkina Faso, le riz occupe la 4Ăšme place des cĂ©rĂ©ales tant du point de vue des superficies, de la production que de la consommation annuelle par habitant.  Cependant, la production nationale est faible et ne couvre que 47% des besoins des populations. Au Burkina trois, types de rizicultures se cĂŽtoient ; la riziculture pluviale ; la riziculture de bas-fond et la riziculture irriguĂ©e. La riziculture pluviale  offre un fort potentiel mais est mal maĂźtrisĂ©e avec de faibles rendements. Cette Ă©tude a Ă©tĂ© conduite sous forme d’enquĂȘte auprĂšs de 157 producteurs afin  d’identifier les potentiels et les contraintes de la riziculture pluviale dans la zone  Ouest du Burkina. Les rĂ©sultats montrent une rĂ©cente introduction de la riziculture pluviale dans la zone. La superficie individuelle moyenne est de 0,81 ha. Les  rendements moyens sont d’environ 1075 kg/ha. Les quantitĂ©s d’engrais par hectare sont faibles et sont en moyenne de 44,5 kg pour l’azote, 25,5 kg pour le phosphore et 15,5 kg pour le potassium. Le riz pluvial est cultivĂ© en pure sans rotation rĂ©guliĂšre. La faible maĂźtrise de l’itinĂ©raire technique de production nĂ©cessite une formation des producteurs pour accroĂźtre les rendements et booster la production du riz pluvial.© 2015 International Formulae Group. All rights reserved.Mots clĂ©s : Riz pluvial, rendement, enquĂȘtes, itinĂ©raire technique

    Effet des prĂ©cĂ©dents culturaux et de diffĂ©rents niveaux d’azote sur la productivitĂ© du riz pluvial strict sur sols ferrugineux tropicaux de la zone sudsoudanienne du Burkina Faso

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    L’azote constitue un Ă©lĂ©ment essentiel dans la nutrition minĂ©rale du riz. Au Burkina Faso, le riz pluvial entre de plus en plus dans les assolements. Cependant, le  rendement du riz pluvial reste largement en deçà du potentiel des variĂ©tĂ©s. Afin de contribuer Ă  une meilleure connaissance de la nutrition minĂ©rale du riz pluvial, un dispositif expĂ©rimental en split plot a Ă©tĂ© mis en place en station de recherche de Farako-BĂą en 2013 et 2014 pour Ă©valuer l’effet des rotations et de la fertilisation azotĂ©e sur le rendement. Les rĂ©sultats montrent que les meilleurs prĂ©cĂ©dents du riz pluvial sont les lĂ©gumineuses niĂ©bĂ© et arachide. Ces deux prĂ©cĂ©dents permettent un gain de rendements respectivement de 104% et 92% par rapport Ă  la  monoculture du riz. La dose de 90 kg N/ha a permis d’obtenir le rendement paddy le plus Ă©levĂ© soit une augmentation de 395% par rapport Ă  la dose sans apport d’azote 0 kg N/ha et le poids de 1000 grains le plus Ă©levĂ©. Cependant la dose agronomique la plus efficace quel que soit le prĂ©cĂ©dent cultural est de 60 kg N/ha. Les rotations et les doses d’azote ont un effet sur l’augmentation des rendements du riz paddy en culture pluviale.© 2015 International Formulae Group. All rights reserved.Mots clĂ©s: Riz pluvial, rotations, azote, lĂ©gumineuses, Burkina Faso. Effect of previous crops and different nitrogen levels on the productivity of upland  rice on ferruginous tropical soils of the South Sudan region of  Burkina FasoNitrogen is an essential element in the mineral nutrition of rice. In Burkina Faso, more and more, upland rice enters in the crop rotation. However, the yield of upland rice remains under the potential of varieties. To contribute to a better understanding of the mineral nutrition of upland rice, an experimental split plot was tested in Farako-BĂą research station in 2013 and 2014. This was to evaluate the effect of crop rotations and the effect of nitrogen fertilization on yield of upland rice. The results show that the best previous crops of upland rice are legumes, cowpea and peanut. Both previous crops allow a gain of respectively 104% and 92% of yields compared to rice monoculture. The dose of 90 kg N/ha permitted to have highest paddy yield and an increase of 395% compared to the dose without nitrogen 0 kg N/ha and the highest weight of 1000 grains. However, the most effective agronomic dose regardless of the previous crop is obtained with the dose of 60 kg N/ha. Crops rotation and nitrogen level have an effect on upland rice yield.© 2015 International Formulae Group. All rights reserved.Keywords: Upland rice, rotations, nitrogen, legumes, Burkina Faso

    Factors associated with treatment gap in children and adolescents with epilepsy in a rural Nigerian community.

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    Background: The campaign against epilepsy is hampered by the difference between those with the active disorder and the number of them receiving appropriate treatment (treatment gap) in sub-Saharan Africa. Identifying the determinants of this gap is crucial to providing and achieving optimal care.Objective: To identify the determinants of epilepsy treatment gap (ETG) in children and adolescents (Subjects) with epilepsy in a rural community.Methods: Subjects were identified through a community house to house survey. Information obtained from Subjects and their care givers included: sociodemographic characteristics, type and frequency of epileptic seizures,current and past treatment options utilized, reasons for treatment options used, and treatment options utilized for other health complaints.Results: Twenty three Subjects (6.4/1000 of the child and adolescent population) were identified as having epilepsy. Their age range was 4-19 years (mean 14.3±4.7 years). Most were males (82.6%) and adolescents (78.3%). Seizures were mostly generalized (95.7%) and occurred most frequently daily. Current treatment modalities were use of traditional medication (100%) and prayers (34.8%).None was currently on orthodox medical therapy (ETG, 100%) but 5(21.7%) had utilized orthodox medical therapy in the past. The main determinants of the ETG were strong cultural belief, weakness in the health system to epilepsy treatment and low socioeconomic status. Fever was the commonest other health complaint and use of orthodox medical therapy was significantly (p˂ 0.05) the main (16, 69.6%) treatment option utilized.Conclusion: Cultural belief, weak health system and low socioeconomic status were determinants of an absolute ETG. It highlights the need to strengthen initiatives that enhance accessibility to standard epilepsy treatment.Key words: Epilepsy treatmentgap, determinants, children, adolescents, rural communit

    Transfer learning in assistive robotics: from human to robot domain

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    Transfer Learning (TL) aims to learn a problem from a source reference to improve on the performance achieved in a target reference. Recently, this concept has been applied in different domains, especially, when the data in the target is insufficient. TL can be applied across domains or across tasks. However, the challenges related to what to transfer, how to transfer and when to transfer create limitations in the realisation of this concept in day to day applications. To address the challenges, this paper presents an overview of the concept of TL and how it can be applied in human-robot interaction for assistive robots requiring to learn human tasks in Ambient Assisted Living environments. The differences in feature spaces between a human (source domain) and robot (target domain) makes it difficult for tasks to be directly learned by robots. To address the challenges of this task, we propose a model for learning across feature spaces by mapping the features in the source domain to the target domain features
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