213 research outputs found

    Implementation of the fast charging concept for electric local public transport: The case-study of a minibus

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    This paper shows an effective implementation of the fast charging concept in the electric local public transport context. An electric minibus powered with a lead-acid battery is considered as a case-study. Its traction battery is redesigned using 12 V standard lithium-iron-phosphate modules to benefit from the higher performance of the lithium battery technology compared to the lead-acid one. The minibus can achieve a continuous operation characterised by 20 min of traveling alternated with 10 min of standstill for fast recharging of the battery. Experiments performed on a single module of the battery show that the load profile is sustained without appreciable issues both in temperature and life degradation of the lithium cells

    Etching kinetics of nanodiamond seeds in the early stages of CVD diamond growth

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    We present an experimental study on the etching of detonation nanodiamond (DND) seeds during typical microwave chemical vapor deposition (MWCVD)conditions leading to ultra-thin diamond film formation, which is fundamental for many technological applications. The temporal evolution of the surface density of seeds on the Si(100) substrate has been assessed by scanning electron microscopy (SEM). The resulting kinetics have been explained in the framework of a model based on the effect of the particle size, according to the Young-Laplace equation,on both chemical potential of carbon atoms in DND and activation energy of the reaction with atomic hydrogen. The model describes the experimental kinetics of seeds' disappearance by assuming that nanodiamond particles with a size smaller than a "critical radius", r*, are etched away while those greater than r* can grow. Finally, the model allows to estimate the rate coefficients for growth and etching from the experimental kinetics

    Size dependent etching of nanodiamond seeds in the early stages of CVD diamond growth

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    We present an experimental study on the etching of detonation nanodiamond (DND) seeds during typical microwave chemical vapor deposition (MWCVD) conditions leading to ultra-thin diamond film formation, which is fundamental for many technological applications. The temporal evolution of the surface density of seeds on Si(100) substrate has been assessed by scanning electron microscopy (SEM). The resulting kinetics have been explained in the framework of a model based on the effect of particle size, according to the Young-Laplace equation, on both chemical potential of carbon atoms in DND and activation energy of reaction. We found that seeds with size smaller than a critical radius, r*, are etched away while those greater than r* can grow. Finally, the model allows to estimate the rate coefficients for growth and etching from the experimental kinetics.Comment: 28 pages; 15 Figures, 3 Table

    Assessing the benefits of green super rice in sub-Saharan Africa: Evidence from Mozambique

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    In Mozambique, smallholder farmers commonly grow rice under rainfed systems with limited fertilizer application; thus, productivity remains very low. Moreover, the adoption rate of improved rice varieties is as low as 3 per cent, partly because these varieties usually require an irrigated environment with the use of fertilizer. Green super rice (GSR) varieties are expected to sustain high yield potential under severe stress conditions. This article used farm-level survey data collected in Mozambique to assess the benefits of the adoption of a GSR variety (Simão) on the yield and cost efficiency of smallholder rice producers. The econometric approach involves propensity score matching and a simultaneous equation model with endogenous switching regression to account for observable and unobservable factors that affect adoption and outcome variables. The results indicate positive and significant benefits from adopting GSR on rice yield and cost efficiency for adopters. These benefits are observed not only in irrigated environments where fertilizer is applied together with some more advanced farming practices (i.e. Gaza province), but also in Nampula and Sofala provinces where farmers grow rice under rainfed conditions with no fertilizer application. Our findings suggest that GSR varieties have the potential to bring some positive changes in the development of rice production in Mozambique

    The Efficacy of a New AMCOP® Elastodontic Protocol for Orthodontic Interceptive Treatment: A Case Series and Literature Overview

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    Background: Elastodontics is a specific interceptive orthodontic treatment that uses removable elastomeric appliances. They are functional appliances that produce neuromuscular, orthopedic and dental effects. Thus, these devices are useful in the developmental age, when skeletal structures are characterized by important plasticity and adaptation capacity, allowing to remove factors responsible for malocclusions. Elastomeric devices are generally well tolerated by patients requiring simple collaboration and management. This work can be useful to update all orthodontists already adopting these appliances or for those who want to approach them for the first time. This study aimed to describe four cases treated with new elastomeric devices called AMCOP Bio-Activators and to provide an overview of elastodontics, its evolution, indications and limits. Methods: A total of four clinical cases were presented after a treatment period of 16–20 months to evaluate the clinical and radiological effects of the elastodontic therapy. Results: The effectiveness of Bio-Activators on clinical cases was evidenced with a significant improvement in skeletal and dentoalveolar relationship, and malocclusion correction in a limited treatment period (16–20 months). Conclusions: The Bio-Activators showed clinical effectiveness to achieve therapeutic targets according to a low impact on the patient’s compliance

    Spinal cord stimulation in the treatment of refractory angina: systematic review and meta-analysis of randomised controlled trials

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    <p>Abstract</p> <p>Background</p> <p>The aim of this paper was undertake a systematic review and meta-analysis of the use of spinal cord stimulation (SCS) in the management of refractory angina.</p> <p>Methods</p> <p>We searched a number of electronic databases including Medline, Embase and Cochrane Library up to February 2008 to identify randomised controlled trials (RCTs) reporting exercise capacity, ischemic burden, functional class, quality of life, usage of anti-anginal medication, costs and adverse events including mortality. Results were reported both descriptively for each study and using random effects meta-analysis. Given the variety in outcomes reported, some outcome results were pooled as standardised mean differences (SMD) and reported in standard deviation units.</p> <p>Results</p> <p>Seven RCTs were identified in a total of 270 refractory angina patients. The outcomes of SCS were found to be similar when directly compared to coronary artery bypass grafting (CABG) and percutaneous myocardial laser revascularisation (PMR). Compared to a 'no stimulation' control, there was some evidence of improvement in all outcomes following SCS implantation with significant gains observed in pooled exercise capacity (SMD: 0.76, 0.07 to 1.46, <it>p </it>= 0.03) and health-related quality of life (SMD: 0.83, 95% CI: 0.32 to 1.34, <it>p </it>= 0.001). Trials were small and were judged to range considerably in their quality. The healthcare costs of SCS appeared to be lower than CABG at 2-years follow up.</p> <p>Conclusion</p> <p>SCS appears to be an effective and safe treatment option in the management of refractory angina patients and of similar efficacy and safety to PMR, a potential alternative treatment. Further high quality RCT and cost effectiveness evidence is needed before SCS can be accepted as a routine treatment for refractory angina.</p

    Are Geese Flying by Themselves Inside China? An LSTR-SEM Approach to Income Convergence of Chinese Counties

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    In this paper, we examine beta-convergence of real per-capita income of Chinese counties. We account for both the spatial dependences between counties and the possibility of different convergence regimes. The first feature is captured by the spatial error term, whereas the second one is modeled using the spatial logit smooth transition approach. Two groups of counties can be identified: 1) counties, which have relatively poor neighbors and tend to grow faster and converge, and 2) counties, which have relatively rich neighbors and tend to grow slower and hence fail to converge. The counties belonging to the first group are concentrated mainly in western interior provinces, such as Qinghai, Sichuan, Yunnan, western part of Xinjiang Uygur. The counties of the second group are located mainly in coastal regions. Whereas in the benchmark model the estimated convergence rate is 0.8% for unconditional regression and 1.7% for condtional regression, the alternative models produce the convergence rate of 1.3-1.5% for unconditional regressions and 2.3-2.6% for conditional regressions, which is quite close to the estimates reported typically in the literature

    Gabapentin as add-on to morphine for severe neuropathic or mixed pain in children from age 3 months to 18 years - Evaluation of the safety, pharmacokinetics, and efficacy of a new gabapentin liquid formulation: Study protocol for a randomized controlled trial

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    Background: Gabapentin has shown efficacy in the treatment of chronic neuropathic or mixed pain in adults. Although pediatric pain specialists have extensive experience with gabapentin for the treatment of neuropathic pain, its use is off-label. Its efficacy and safety in this context have never been shown. The aim of this trial is to compare gabapentin with placebo as add-on to morphine for the treatment of severe chronic mixed or neuropathic pain in children. This trial is part of the European Union Seventh Framework Programme project Gabapentin in Paediatric Pain (GAPP) to develop a pediatric use marketing authorization for a new gabapentin suspension. Methods/design: The GAPP-2 study is a randomized, double-blind, placebo-controlled, multicenter superiority phase II study in children with severe chronic neuropathic or mixed pain. Its primary objective is to evaluate the efficacy of a gabapentin liquid formulation as adjunctive therapy to morphine. Sixty-six eligible children 3 months to 18 years of age with severe pain (pain scores ≥ 7), stratified in three age groups, will be randomized to receive gabapentin (to an accumulating dose of 45 to 63 mg/kg/day, dependent on age) or placebo, both in addition to morphine, for 12 weeks. Randomization will be preceded by a short washout period, and treatment will be initiated by a titration period of 3 weeks. After the treatment period, medication will be tapered during 4 weeks. The primary endpoint is the average pain scores in the two treatment groups (average of two measures each day for 3 days before the end-of-study visit [V10] assessed by age-appropriate pain scales (Face, Legs, Activity, Cry, Consolability scale; Faces Pain Scale-Revised; Numeric Rating Scale). Secondary outcomes include percentage responders to treatment (subjects with 30% reduction in pain scale), number of episodes of breakthrough pain, number of rescue interventions, number of pain-free days, participant dropouts, quality of life (Pediatric Quality of Life Inventory), and acceptability of treatment. Outcomes will be measured at the end-of-study visit after 12 weeks of treatment at the optimal gabapentin dose. Groups will be compared on an intention-to-treat basis. Discussion: We hope to provide evidence that the combination of morphine and gabapentin will provide better analgesia than morphine alone and will be safe. We also aim to obtain confirmation of the recommended pediatric dose. Trial registration: EudractCT, 2014-004897-40. Registered on 7 September 2017. ClinicalTrials.gov, NCT03275012. Registered on 7 September 2017
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