Electrical Devices (electrical + device)

Distribution by Scientific Domains


Selected Abstracts


Thermal expansion co-efficient of nanotube,metal composites

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11-12 2009
Sheikh M. Uddin
Abstract Thermal expansion exhibits considerable challenges developing residual stresses at the interfaces of different materials treated at high temperature. Electrical devices containing materials with different thermal expansion behaviour very often suffer this problem. Thermal expansion co-efficient (TEC) of different metals can be tuned by using carbon nanotube (CNT). Metal matrix composites (MMCs) using CNT are fabricated by hot-press sintering method and TEC of the composites are investigated throughout a wide range of temperature (,155 to 275,°C). Reduction of TEC of the composite materials was observed up to 20% compared to that of pure metals. The effect of CNTs in the matrix materials and the mechanism behind the improvement are explained from the microscopic investigation of the composites. [source]


Recent Progress in Dielectric Barrier Discharges for Aerodynamic Flow Control

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-2 2007
G. I. Font
Abstract Plasma actuators are electrical devices that use an atmospheric pressure dielectric barrier discharge for flow control. They have been employed successfully to promote boundary layer attachment. Simulations have been carried out of a plasma actuator using Direct-Simulation-Monte-Carlo and Particle-in-Cell methods. This work summarizes some recent results including: 1) the method by which force is imparted by the actuator to the neutral flow, 2) the effect of electronegative gasses, such as oxygen, and 3) the effects on the neutral flow of the plasma force. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Death due to electrocution in childhood and early adolescence

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 1 2003
RW Byard
Objectives: To delineate the clinicopathological features of fatal childhood electrocutions and to identify specific risk factors. Methods: Coronial files in Adelaide (Australia) were searched from 1967 to 2001 and Medical Examiners' files in San Diego (USA) were searched from 1988 to 2001, for cases of deaths of children and adolescents younger than 16 years attributed to electrocution. Results: Sixteen cases were identified aged between 10 months and 15 years (mean 8.0 years) with a male : female ratio of 5 : 3. Deaths were due to accidents occurring while playing with or near faulty electrical equipment at home or at school (n = 8), electrical equipment while in the bath (n = 2), damaged outdoor electrical equipment (n = 1), overhead wires (n = 1), and a high voltage electricity substation (n = 1). In addition, one death was due to suicide involving an electrical appliance placed in a bath, and two other deaths occurred in older children who were moving equipment under overhead wires. No homicides were identified. Conclusions: Childhood deaths due to electrocution are rare and are more likely to occur when children are playing around electrical wires or equipment, and often result from either faulty apparatus, or a lack of understanding of the potential dangers involved. The majority of deaths (11/16; 69%) occur in the home environment. In contrast to adult electrical deaths, high-voltage electrocutions, suicides and workplace deaths are uncommon. Strategies for eliminating childhood electrocution should concentrate on ensuring safe domestic environments with properly maintained electrical devices. [source]


Iatrogenic complications and risks of nerve conduction studies and needle electromyography

MUSCLE AND NERVE, Issue 5 2003
Amer Al-Shekhlee MD
Abstract Electrodiagnostic procedures are routinely performed in patients with a variety of neuromuscular disorders. These studies are generally well tolerated and rarely thought to be associated with any significant side effects. However, needle electromyography is an invasive procedure and under certain situations has the potential to be associated with iatrogenic complications, including bleeding, infection, nerve injury, pneumothorax, and other local trauma. Similar complications are possible if needles are used for either stimulating or recording. In addition, like all other electrical devices and monitoring equipment connected to patients, electrodiagnostic testing carries the risk of stray leakage currents that under certain circumstances can result in electrical injury, especially in patients in the intensive care setting. Similarly, certain precautions are required during nerve conduction studies (NCS) in patients with pacemakers and other similar cardiac devices. In this review, we address the known and theoretical complications of NCS and needle electrode examination, and the possible methods to avoid such hazards. Muscle Nerve 27: 517,526, 2003 [source]


Self-report of physical symptoms associated with using mobile phones and other electrical devices

BIOELECTROMAGNETICS, Issue 6 2009
Leena H. Korpinen
Abstract The aim of our work was to study the working-age population's self-reported physical symptoms associated with using mobile phones and other electrical devices. A qualitative method was applied using an open-ended question in a questionnaire, which included questions about the possible influence of new technical equipment on health. We then created subgroups of respondents for different self-reported symptoms associated with mobile phones and other electrical devices. The research questions were: (1) how the respondents described physical symptoms associated with using mobile phones and other electrical devices and (2) how the answers can be classified into subgroups based on symptoms or devices. We identified the following categories: (1) respondents with different self-reported symptoms which they associated with using mobile phones (headache, earache, or warmth sensations), (2) respondents who had skin symptoms when they stayed in front of a computer screen, (3) respondents who mentioned physical symptoms associated with using mobile phones and other electrical devices. Total prevalence of self-reported physical symptoms associated with using mobile phones and other electrical devices (categories 1 and 2) was 0.7%. In the future it will be possible to obtain new knowledge of these topics by using qualitative methods. Bioelectromagnetics 30:431,437, 2009. © 2009 Wiley-Liss, Inc. [source]


The Origin of the Halogen Effect on the Phthalocyanine Green Pigments

CHEMISTRY - AN ASIAN JOURNAL, Issue 6 2010
Uck Lee Dr.
Abstract The structure and the electronic and optical properties of halogenated copper-phthalocyanine (n,,m,(Hal)-CuPc) molecules are investigated, according to the variation in the substituted halogen-atom species (Hal=Cl or Br) at the , and , positions of isoindole ring with different numbers (n and m=0, 4, 8, or 16). Our results show that the halogen effect mainly results from a structural deformation rather than caused by electronic effects. A nonplanar deformation of the phthalocyanine chromophore of the n,,m,(Hal)-CuPc molecule causes a significant change only in the HOMO and HOMO-1 levels, rather than in the LUMO levels, which leads to the appearance of a green color arising from the large red-shifts of the Soret and Q bands. The present result may serve as an important reference point for designing novel halogen-free green pigments, in accordance with the environmental regulations for the restriction of hazardous substances (RoHS) in electronic and electrical devices. [source]