Development of a Friction Rig and Experimental Results

The development of a friction rig, which is integrated into a milling machine for testing the frictional characteristics of various types of materials and specimen shapes are described. This is followed by the experimental technique used to measure the friction coefficient for different experimental conditions. The results obtained indicate the frictional coefficient obtained changes with the specimen type, contact area and lubrication condition. The results obtained are also compared to available published results. The discussions and conclusions related to the development and experimental results are finally presented

Wideband outdoor MIMO channel model derived from directional channel measurements at 2 GHz

This paper describes the use of directional channel measurements to derive a MIMO channel model. The measurements were obtained using a wideband channel sounder and eight element circular array in a metropolitan area in central Bristol, U.K. The raw measurements were processed using SAGE to extract the parameters of multipath components. The analysis of these parameters revealed several interesting features, notably that their amplitude distribution was well modelled as log-normal, and that there was little evidence of clustering in the angles of arrival. Hence a MIMO channel based on the assumption of finite scattering was derived, using the distributions obtained. The model allows the channel matrix H to be derived in the narrow-band case, and a tapped delay line model is also obtained for wideband systems. While the model derived is based on only a small set of measurements, it provides a case study for MIMO modelling based on measurements

Foreign direct investment and investment environment in Dongguan Municipality of southern China

Based on 26 case studies, this paper investigates the socio-economic causes of the inflow of FDI and its policy implications in Dongguan. The favourable factors for foreign investors in Dongguan can be categorised under the Dunning's OLI (ownership, locational and internalisation advantages) framework. This paper argues that factors other than policy incentive, such as sub-contractual and pseudo integration, are playing more important roles in attracting the inflow of FDI and maintaining the high level of economic growth in Dongguan. This finding questions the effectiveness of policy incentives, such as tax-breaks, implemented by the Government as a means to attract FDI in Dongguan. The existence of 'Chinese crony capitalism' calls for further improvement in the implementation of laws and regulations in Dongguan and the reduction of bureaucratic red-tape by the central and local governments

Gradient-Free Stochastic Sensitivity Analysis of the Shipboard Power System

Sensitivity analysis results are useful both for the early design stage – where the parametric space can be substantially reduced – but also in operating conditions, e.g. of the future electric ship, resulting in reduced operational costs and increased reliability. Here we discuss variance-based methods to analyze the sensitivity of stochastic electro-mechanical systems with multirate dynamics. We present results for an illustrative example and for a model of an integrated power system.United States. Office of Naval Research (N00014-02-1-0623); United States. Office of Naval Research (N00014-07-1-0846); Massachusetts Institute of Technology. Sea Grant College Program (NA060AR4170019 NOAA/DOC

Effects of interpregnancy interval on pregnancy complications: protocol for systematic review and meta-analysis

Introduction: Interpregnancy interval (IPI) is the length of time between a birth and conception of the next pregnancy. Evidence suggests that both short and long IPIs are at increased risk of adverse pregnancy and perinatal outcomes. Relatively less attention has been directed towards investigating the effect of IPI on pregnancy complications, and the studies that have been conducted have shown mixed results. This systematic review will aim to provide an update to the most recent available evidence on the effect of IPI on pregnancy complications. Method and Analysis: We will search electronic databases such as Ovid/MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and PubMed to identify peer-reviewed articles on the effects of IPI on pregnancy complications. We will include articles published from start of indexing until 12 February 2018 without any restriction to geographic setting. We will limit the search to literature published in English language and human subjects. Two independent reviewers will screen titles and abstracts and select full-text articles that meet the eligibility criteria. The Newcastle-Ottawa tool will be used to assess quality of observational studies. Where data permit, meta-analyses will be performed for individual pregnancy complications. A subgroup analyses by country categories (high-income vs low and middle-income countries) based on World Bank income group will be performed. Where meta-analysis is not possible, we will provide a description of data without further attempt to quantitatively pool results. Ethics and Dissemination: Formal ethical approval is not required as primary data will not be collected. The results will be published in peer-reviewed journals and presented at national and international conferences. Prospero Registration Number: CRD42018088578

An improved constraint satisfaction adaptive neural network for job-shop scheduling

Copyright @ Springer Science + Business Media, LLC 2009This paper presents an improved constraint satisfaction adaptive neural network for job-shop scheduling problems. The neural network is constructed based on the constraint conditions of a job-shop scheduling problem. Its structure and neuron connections can change adaptively according to the real-time constraint satisfaction situations that arise during the solving process. Several heuristics are also integrated within the neural network to enhance its convergence, accelerate its convergence, and improve the quality of the solutions produced. An experimental study based on a set of benchmark job-shop scheduling problems shows that the improved constraint satisfaction adaptive neural network outperforms the original constraint satisfaction adaptive neural network in terms of computational time and the quality of schedules it produces. The neural network approach is also experimentally validated to outperform three classical heuristic algorithms that are widely used as the basis of many state-of-the-art scheduling systems. Hence, it may also be used to construct advanced job-shop scheduling systems.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/01 and in part by the National Nature Science Fundation of China under Grant 60821063 and National Basic Research Program of China under Grant 2009CB320601

Intravenous lidocaine infusion as a component of multimodal analgesia for colorectal surgery-measurement of plasma levels

Abstract Background Growing evidence suggests that intravenous lidocaine as a component of multimodal analgesia improves recovery after major colorectal surgery. There is little published data regarding ideal dosing and target plasma concentration in this context, and we wanted to establish our dosing schedule was safe by measuring blood levels of lidocaine. Methods We measured the plasma lidocaine concentration of 32 patients at 30 min, 6 h and 12 h after starting intravenous lidocaine infusion for analgesia after major colorectal surgery. Patients received a bolus of 1.5 mg kg−1 over 20 min at the time of induction of anaesthesia. This was followed by a continuous infusion of 2% w/v lidocaine at 3 ml hr−1 (60 mg hr−1) for patients weighing up to 70 kg and 6 ml hr−1 (120 mg hr−1) for patients weighing over 70 kg, using actual body weight. Results The overall mean plasma lidocaine concentration was 4.0 μg ml−1 (range 0.6–12.3 μg ml−1). In patients treated with the higher infusion dose, the mean concentration was 4.6 μg ml−1 compared to 3.2 μg ml−1 in those patients on the lower dose. Mean levels were higher at 6 h than 30 min and higher again at 12 h. There were no adverse events or reports of symptoms of local anaesthetic toxicity. Conclusions Whilst there were no signs or symptoms of lidocaine toxicity in our patients, there was a wide range of plasma concentrations including some over 10 μg ml−1; a level above which symptoms of toxicity may be expected. We have changed our dosing protocol to using ideal rather than actual body weight based on these results

Fermi surface and quasiparticle dynamics of Na(x)CoO2 {x=0.7} investigated by Angle-Resolved Photoemission Spectroscopy

We present an angle-resolved photoemission study of Na0.7CoO2, the host cobaltate of the NaxCoO2.yH2O series. Our results show a large hexagonal-like hole-type Fermi surface, an extremely narrow strongly renormalized quasiparticle band and a small Fermi velocity. Along the Gamma to M high symmetry line, the quasiparticle band crosses the Fermi level from M toward Gamma consistent with a negative sign of effective single-particle hopping (t ): t is estimated to be about 8 meV which is on the order of exchange coupling J in this system. This suggests that t ~ J ~ 10 meV is an important energy scale in the system. Quasiparticles are well defined only in the T-linear resistivity regime. Small single particle hopping and unconventional quasiparticle dynamics may have implications for understanding the unusual behavior of this new class of compounds.Comment: Revised text, Added Figs, Submitted to PR