Circular polarized dual‐band antenna for WLAN/Wi‐MAX application

A novel square ring printed antenna has been suggested for dual‐band circular polarization (CP). The geometry contains a square patch and a square ring structure for dual‐band operation. Circular polarization is achieved using triangular cut at the boundary and right angle bend with inner perturbation. The suggested antenna is excited from the lower layer through electromagnetic (EM) coupling technique. The antenna shows good impedance bandwidths of 90 MHz (2.43‐2.52 GHz) and 800 MHz (5.7‐6.5 GHz, respectively. The antenna shows 3 dB axial ratio bandwidth of 20 MHz at lower band and 120 MHz at upper band with improved gain > 6 dBi. The simulated and measured results are well agreed with each other. The antenna is promising wideband operation at the upper band. This antenna was implemented on fiberglass reinforcement laminated Arlon substrate with dielectric constant (?_r = 2.55), and the overall physical dimension of 30 × 30 × 3.048 mm³. The designed antenna can be extensibly applicable in WLAN/Wi‐MAX communication. The presented antenna is designed using hyperlynx IE3D and the simulated results are presented.     

The Molecular Basis and Pathophysiology of Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a complex orofacial pain syndrome characterized by the paroxysmal onset of pain attacks in the trigeminal distribution. The underlying mechanism for this debilitating condition is still not clearly understood. Decades of basic and clinical evidence support the demyelination hypothesis, where demyelination along the trigeminal afferent pathway is a major driver for TN pathogenesis and pathophysiology. Such pathological demyelination can be triggered by physical compression of the trigeminal ganglion or another primary demyelinating disease, such as multiple sclerosis. Further examination of TN patients and animal models has revealed significant molecular changes, channelopathies, and electrophysiological abnormalities in the affected trigeminal nerve. Interestingly, recent electrophysiological recordings and advanced functional neuroimaging data have shed new light on the global structural changes and the altered connectivity in the central pain-related circuits in TN patients. The current article aims to review the latest findings on the pathophysiology of TN and cross-examining them with the current surgical and pharmacologic management for TN patients. Understanding the underlying biology of TN could help scientists and clinicians to identify novel targets and improve treatments for this complex, debilitating disease.     

Inspection model and correlation functions to assist in the correction of qualitative defects of injected parts

To perform quality inspection in the injection process is a complex task due to high number of defects that could occur in an injected part and the high number of process parameters that could produce them. Injection defects, in particular qualitative ones, are not a clear reference to determine correct process parameter value setting to produce good quality parts. Research results show that the occurrence of each injection defect could be caused by specific parameters with values above or below an optimal one. Although this information is a guide for the defect correction, the effective correction of qualitative defects with parameter modifications is very complex. This is due to the problems that arise when transforming a qualitative defect into a quantitative inspection. This article shows an inspection model to assist the qualitative defect intensity classification using defect behavior tendency curves. These curves have been deduced from generic analytical relationships established between injection defects and injection process parameters. Conducted tests allow validating the approach and its initial effectiveness. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Temporally massed CS presentations generate more fear extinction than spaced presentations.

Rodent fear conditioning models both excitatory learning and the pathogenesis of human anxiety, whereas extinction of conditional fear is a paradigm of inhibitory learning and the explicit model for behavior therapy. Many studies support a general learning rule for acquisition: Temporally spaced training is more effective than massed training. The authors asked whether this rule applies to extinction of conditional fear in mice. The authors find that both short- and long-term fear extinction are greater with temporally massed presentations of the conditional stimulus (CS). The data also indicate that once CS presentations are sufficiently massed to initiate, or "induce," extinction learning, further CS presentations are more effective when spaced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of metal doping agent on the properties of Nb2−xMxO5 (M = Mn,Fe, and Ni) system

In order to improve the behavior Niobium pentoxide on oxidation‐reductionreactions to degrade organic compounds in aqueous solutions, we developed the synthesis of Niobium pentoxide with the metal doping agents: manganese,iron, and nickel (Nb_2?xM_xO₅), respectively, and analyzing its effects on the structural and vibrational properties. The synthesis of the Nb_2?xM_xO₅ (M = Mn, Fe, and Ni; x = 0.02 and 0.05) was performed according the Pechini method, but before the annealing, the samples were submitted to Thermogravimetric analysis study showing better pre‐calcination annealing temperatures at 500 and 700°C for the materials. Then, we performed the crystal structural analysis by X‐ray Diffraction, obtaining crystallite sizes between 15 and 47 nm, the accurate size analysis was calculated by Scherrer equation. Structural analysis was also performed by IR spectroscopy to evaluate the vibrational modes of synthetized samples. The dopping effects were evaluated by UV‐Vis spectrophotometry through the energy band gap values, showing that doped samples with manganese and iron had lower values than undoped, except the sample doped with nickel. However, samples doped with iron at 2.5% showed better photocatalytic performance.     

Mediterranean diet and the metabolic syndrome

The metabolic syndrome (also referred to as syndrome X or the insulin resistance syndrome) has emerged as an important cluster of risk factors for atherosclerotic disease. Patients with the syndrome also are at increased risk for developing type 2 diabetes mellitus. Common features are central (abdominal) obesity, insulin resistance, hypertension, and dyslipidemia. Weight reduction deserves first priority in individuals with abdominal obesity and the metabolic syndrome. Both weight reduction and maintenance of a lower weight are best achieved by a combination of reduced caloric intake and increased physical activity. Dietary patterns close to the Mediterranean diet and rich in fruit and vegetables, and high in monounsaturated fats are negatively associated with features of the metabolic syndrome. Some recent studies dealing specifically with the effect of interventions on the resolution of the metabolic syndrome have demonstrated a 25% net reduction in the prevalence of the syndrome following lifestyle changes mainly based on nutritional recommendations. Similar rates of resolution have been obtained with drugs, such as rosiglitazone and rimonabant. The favourable benefit/hazard ratio makes Mediterranean-style diets particularly promising to reduce the cardiovascular burden associated with the metabolic syndrome.     

Linking improvement models to manufacturing strategies - a methodology for SMEs and other enterprises

Small Manufacturing Enterprises (SMES) are of major importance to the future economic growth of the European Community. To sustain this role, they need support in defining their specific technological and organizational needs and in finding the right approach to respond to these needs. The main objective of the research described in this article is to develop a supporting methodology for determining the improvement priorities of SMEs through a process similar to the manufacturing strategy formulation. However, the tools and techniques proposed in this paper are of a general nature and need not be restricted to SMEs. The methodology uses Quality Function Deployment (QFD), a product oriented quality technique, to apply a contingency oriented approach to improvement priorities. The essence of the QFD method is to extract the customer needs or desires and then to translate them into technical product quality characteristics. Here, the customers are interviewees from a sample of Small Manufacturing Enterprises. We assume that the manufacturing system improvement needs stem from strategic manufacturing priorities and from concerns that express unsatisfied needs. To propagate the improvement needs from the strategic level to the action level, two QFD oriented matrices were developed. The first matrix was used to define the operating improvement needs of an enterprise while the second was used to determine its improvement priorities. Cluster analysis, a multivariate technique, identified several generic improvement models of the sampled enterprises.     

Ginzburg–Landau Simulation of Superconducting Matter in a Semicircular Film

We numerically investigate the superconductor matter of a film type-II superconductor with circular geometry numerically in a computational simulation using the link variable method to solve the time dependent Ginzburg–Landau equation. We apply the implemented algorithm to a half circular film surrounded by a thin layer of another superconductor at a higher critical temperature. The film is immersed in an external magnetic field applied perpendicularly to its plane. The boundary condition is taken into account with the de Gennes extrapolation length b. We calculate the magnetization, vortex number, the third critical thermodynamical field as a function of the external magnetic field, and the b parameter. We find that for these interfaces the third critical field $H_{\mathrm{c}_{3}}$ and the magnetization M are largely increased.     

Flexibility and types of changes in FMSs: A timed petri-nets assessment of machine flexibility

This paper discusses the flexibility concept in the light of the production-systems capabilities needed to cope with changes occurring at different time horizons. Two basic flexibility components emerge: set-up (in time units) and variety (operations and transfer). The paper further describes a timed Petri-nets approach to machine-flexibility evaluation (set-up and operations variety). A timed Petrinets decomposition technique is used to derive measures of flexible machines' performance under changes that a flexible system has to cope with, such as failures, changeover interruptions, fluctuations in demand, and re-routing.