Deflection of suspended graphene by a transverse electric field

We investigate the electromechanical response of doubly clamped graphene nanoribbons to a transverse gate voltage. An analytical model is developed to predict the field-induced deformation of graphene nanoribbons as a function of field intensity and graphene geometry. This model is validated thought atomistic simulations using the combination of a constitutive charge-dipole model and a pseudo-chemical many-body potential. As a newly observed effect of electric polarization, this field-induced deflection allows the graphene to oscillate at its natural frequency, which is found to decrease dramatically with increasing graphene size.Comment: 4 Figure

Las resecciones hepáticas por hidatidosis en España: estudio multicentro hospitalario en un trienio 1984-1986

Tesis de la Universidad Complutense de Madrid, Facultad de Medicina, Departamento de Cirugia, leída el 04-12-1989Depto. de CirugíaFac. de MedicinaTRUEpu

Antenas MIMO

Se han diseñado y fabricado dos antenas MIMO. Para ello se ha diseñado primero una antena de un elemento para facilitar el diseño de las antenas MIMO de dos y cuatro elementos. Se han realizado simulaciones y se han comparado con los resultados prácticos y todos sus parámetros S tienen una frecuencia máxima de 20 GHz. La banda de trabajo como resultado práctico es mejor que la simulación, es decir una frecuencia mínima menor que la teórica, para la antena MIMO de dos elementos su banda de trabajo trabaja desde 3.3 a 20 GHz en el caso teórico y en el caso práctico desde 2.7 hasta 20 GHz, para la antena MIMO de cuatro elementos trabaja desde 2.89 hasta 20 GHz en el caso teórico y en el caso práctico desde 2.24 hasta 20 GH

Taguchi Based Self-Configure Data Rate Optimization AODVUU Routing Parameters In MANET Over Optical Network Performances

Research and development advancements in the area of wireless technologies give rises of mobile ad hoc networks (MANET) domain but is constrained to the single networks and stand alone. Furthermore, the communication networking applications requirements mostly still depends on fixed infrastructure networks that lead to MANET need to communicate with internet. Consequently, the traditional mobile routing protocols proposed for MANET are inefficient but play an equivalent important role in the performances of mobile wireless network over optical backhaul with focusing of MANET of the wireless domain in access network. Routing protocols procedures are controlled with a set of parameters from being dragged to undesired situations such as un-optimized Quality of Service (QoS) resource consumption. These parameters have a direct impact on the efficiency of a routing protocol and the overall MANET network performances. This paper proposed an offline optimization through simulation design of experiment of the AODV-UU parameters of MANET is evaluated by performing Taguchi signal to noise ratio (SNR) method for fine-tuning the AODV-UU routing parameters using the OMNeT++ software. The work is further extended with self-configure multiple data rates (SCMDR) scheme-a cross-layer-specific technique. AODV-UU with Taguchi tuned under the proposed SCMDR scheme is compared with AODV-UU configuration of oRiG scheme also as respects to previous work is examined based on capacity consumption, end-to-end delay metric and energy consumption metric under the varying speed scenario. The obtained results showed that, AODV-UU with Taguchi configuration outperformed the AODV-UU for the mention performance metrics here. The existing of current access network of the telco operators can benefit from the proposed improvement here

Electrodeposition and impedance spectroscopy characterization of ZnO nanowire arrays

An overview of the electrodeposition of ZnO nanowire arrays from the reduction of dissolved molecular oxygen in zinc chloride solutions was reported. In spite of the internal structure of ZnO which favours the anisotropic growth along the [0001] direction, the change in the local composition of the electrolyte around the nanowire during the electrodeposition was proposed as a major parameter to affect the nanowire growth mechanism. The influence of the ratio between the O2 reduction rate and the diffusion of Zn2+ to the cathode was emphasized. Due to the particular morphology of the nanowire arrays, no lateral growth was observed when the reduction of O2 was relatively fast, while the corresponding deposition efficiency was very low. The decrease of the O2 reduction rate resulted in an enhancement of the deposition efficiency. The highest efficiencies (40–55%) were attained by using high chloride concentrations ([KCl] = 3.4 M) resulting not only in an enhancement of the longitudinal growth, but also in a considerable lateral growth. The influence of the electrodeposition conditions on the donor density of ZnO nanowires was investigated by using electrochemical impedance spectroscopy. Donor densities from 5 × 1019 cm–3 to 3 × 1020 cm–3 were obtained for as deposited samples. They decreased to values in the range of 1017–1018 cm–3 after annealing in air (1 hour at 450 °C). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim

ZnO Nanowires, Nanotubes, and Complex Hierarchical Structures Obtained by Electrochemical Deposition

Increasing the aspect ratio of ZnO nanostructures is one possible strategy to improve their thermoelectric properties. ZnO nanostructures with one-dimensional (1D) and three-dimensional (3D) morphologies were obtained using electrochemical deposition. Adjusting various deposition parameters made it possible to obtain arrays of vertically aligned ZnO nanowires (NWs) with controlled dimensions, density, and electrical properties. The concentrations of zinc or chloride ions in the solution were found to be key parameters. ZnO NWs were transformed into ZnO nanotubes (NTs), with an increased aspect ratio compared with the NWs, by selectively dissolving the core of the ZnO NWs in a concentrated KCl solution. The aspect ratio was strongly increased when the ZnO NWs were hierarchically organized in a 3D morphology. The synthesis of thin films composed of ordered hollow urchin-like ZnO NW structures was performed by combining the electrochemical deposition and polystyrene sphere templating methods. The electronic properties of the urchin-like ZnO structures were investigated by means of photoluminescence and transmission measurement

Qualitative-based QoS performance study using hybrid ACO and PSO algorithm routing in MANET

In today's accelerated growth of mobile device technology, resource utilization in access network will continue to draw more attention to the increasing mobile user devices and applications. The main objective is to address the issue of QoS resource utilization efficiency. This paper combines the Ant Colony Optimization (ACO) algorithm and the Particle Swarm Optimization (PSO) algorithm to provide the optimum routing and to improve the QoS resource utilization efficiency. This proposed hybrid ACO-PSO algorithm uses the IEEE 802.11 DCF standard with multi-antenna scheme (MIMO) of Mobile Ad-hoc Network (MANET) to apply into integrated wireless (MANET) optical (PON network) based in Software Defined Network (SDN) with cloud computing. IEEE 802.11 Wireless Local Area Network (WLAN) gives the opportunity to its users to practice the wireless environment and full functionality of "anything, anytime, anywhere" concept. The proposed work is implemented using the OMNeT++ software where it investigates the QoS performance. These metrics include all nodes throughput, bandwidth, and load balance, routing and control overhead improvement with reduction. They also comprise of RSSI, end to end delay, Packet Delivery Ratio, network capacity, packet loss probability, as well as power consumption in all wireless nodes and energy consumption from wireless domain to wired domain

Effects of sports nutrition education intervention on sports nutrition knowledge, attitude and practice, and dietary intake of Malaysian team sports athletes

Introduction: The purpose of this study was to determine the effects of sports nutrition education intervention on improvements in sports nutrition knowledge, attitude and practice (KAP), and dietary intake among Malaysian team sports athletes. Methods: A total of 105 male participants representing four team sports under the elite sports programme were recruited based on a name list provided by National Sports Council of Malaysia. Teams were assigned by stratified random sampling to either the experimental group (EG) (n=52) or the comparison group (CG) (n=53). The EG received seven weeks of education intervention programme based on a validated booklet covering basic sports nutrition for team sports. A self-administered sports nutrition KAP questionnaire and dietary intake assessment of total energy, carbohydrates, proteins and fats based on three-day food records was conducted before and after the intervention. Results: There were significant increments (p<0.001) in the EG’s post-intervention mean scores for knowledge (6.21±2.95), attitude (9.04±6.65) and practice (4.39±4.27) compared to decrements in the respective mean scores of the CG (-2.15±1.45; -1.72±5.06; -0.74±2.32). Significant improvements were found in the EG’s total energy intake, total carbohydrate and total protein intake compared to those of the CG. Conclusion: The sports nutrition education intervention was useful in improving the sports nutrition KAP scores, total carbohydrate and total protein intake of team sports athletes

Effects of different diet alternatives to replace the use of pharmacological levels of zinc on growth performance and fecal dry matter of weanling pigs

A total of 300 weanling pigs (Line 400 × 200, DNA, Columbus, NE, initially 4.83 kg) were used in a 46-d trial to evaluate the effects of different nutritional strategies to replace pharmacological levels of Zn, provided by zinc oxide (ZnO), in nursery diets on growth performance and fecal dry matter (DM). Six treatments with 10 replicate pens per treatment and 5 pigs per pen were used. Diets consisted of: (1) positive control (ZnO providing 3,000 mg/kg added Zn from d 0 to 7 and 2,000 mg/kg added Zn from d 8 to 25 and 21% crude protein, CP); (2) negative control (NC; no added ZnO); (3) NC plus 1.2% Na diformate; (4) NC with 4% coarse ground wheat bran; (5) NC but formulated to 18% CP; and (6) the combination of NC with 18% CP, 1.2% Na diformate, and 4% coarse ground wheat bran. The diets formulated to 18% CP contained 1.2% standardized ileal digestible (SID) Lys from d 0 to 25, whereas the 21% CP diets contained 1.4% SID Lys from d 0 to 7 and 1.35% SID Lys from d 7 to 25. From d 25 to 46, all pigs were fed a common diet. From d 0 to 7, no differences in any variables were observed between treatments. From d 7 to 25, pigs fed the diet with added ZnO had greater (P < 0.01) average daily gain (ADG) and average daily feed intake (ADFI) than all other treatments. Pigs fed the diet formulated to 18% CP had decreased (P < 0.01) ADG when compared with pigs fed the other diets. From d 25 to 46, no previous treatment effects on ADG or gain to feed ratio (G:F) were observed. Overall (d 0 to 46), pigs fed the diet with added ZnO from d 0 to 25 had greater (P < 0.01) ADG, ADFI, and final body weight than pigs fed added Na Diformate, or 4% coarse ground wheat bran, or with the 18% CP diet, or with pigs fed the combination of the additives intermediate. There was no evidence for differences in overall G:F. Pigs fed the NC diet had the lowest fecal DM and highest fecal scores (P < 0.05), indicating the greatest incidence of loose stools. Pigs fed added ZnO had greater fecal DM than pigs fed the NC, 4% added wheat bran, or 18% CP diets, or with pigs fed the combination of additives intermediate (P < 0.01). These results suggest that adding pharmacological levels of Zn from ZnO improves nursery pig performance and increases DM content of feces when compared with pigs fed diets with either Na diformate, 4% course wheat bran, or 18% CP alone. However, a combination of all three alternatives appeared to be additive and partially restored growth performance similar to adding pharmacological levels of Zn