Demand-side management opportunities through the use ofenergy-efficient motor systems

The key issues related to efficient motor systems operation are presented, with a particular emphasis on electronic adjustable speed drives (ASD), due to their comparatively larger potential for savings. The potential for savings associated with the use of ASD in the residential, commercial, and industrial sectors are presented. With ASD it is estimated that one-fifth of the drive power consumption can be saved, that, is over 250 TWh/yr. The combined use of ASD with other efficient motor technologies can increase the savings to 30%. Research, development, demonstration, and training options are proposed which can significantly expand the cost effectiveness, performance, and scope of efficient motor systems applications     

Doping of molecular beam epitaxy HgCdTe using an arsenic cracker source (As2)

This study investigated the incorporation of arsenic dimers (As₂), delivered from a “cracker” effusion cell. The HgCdTe epilayers were deposited under standard growth conditions. During deposition, arsenic was incorporated using both a standard arsenic effusion cell and a cracker cell. It was found that arsenic concentration rose dramatically as a function of cracker-zone temperature, particularly at temperatures above 600°C. This behavior was consistent with the temperature dependence of the effusion cell’s cracking efficiency, as determined by residual gas analysis. The temporal stability of the arsenic source was excellent. Arsenic concentrations of 2.8×10²⁰ cm⁻³ were achieved at a cracker temperature of 800°C. The arsenic beam-equivalent pressure, estimated from an uncorrected, nude ion-gauge reading, was ∼8×10⁻⁷ mbar.     

Male and female spoken language differences: Stereotypes and evidence.

Male speech and female speech have been observed to differ in their form, topic, content, and use. Early writers were largely introspective in their analyses; more recent work has begun to provide empirical evidence. Men may be more loquacious and directive; they use more nonstandard forms, talk more about sports, money, and business, and more frequently refer to time, space, quantity, destructive action, perceptual attributes, physical movements, and objects. Women are often more supportive, polite, and expressive, talk more about home and family, and use more words implying feeling, evaluation, interpretation, and psychological state. It is concluded that a comprehensive theory of "genderlect" must include information about linguistic features under a multiplicity of conditions. (59 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Porosity control of hydroxyapatite implants

Conformation of hydroxyapatite (HAp) bodies was carried out using a multiple slip-casting technique, in order to obtain dual-layer samples with differential sized porosities. The external layer, because of its porosity, controlled by the addition of organic compounds (polyvinyl polyacrylate, PVC), will promote bone ingrowth. The internal denser layer, due to the addition of lithium phosphate (Li₃PO₄) as sintering additive, will give mechanical resistance to the implant. HAp aqueous suspensions were characterized by rheological measurements. Scanning electron microscopy (SEM) and intrusion mercury porosimetry (MP) were used to characterize sintered bodies. It can be concluded that it is possible to introduce gross porosity in HAp bodies by the addition of organic compounds. The results show that a compatible shrinking of the layers during the sintering process and a good frequency of pores with an appropriate size in the external layer can be achieved with the use of organic additives. © 1999 Kluwer Academic Publishers     

Continuous production of pectinase by immobilized yeast cells on spent grains

A yeast strain secreting endopolygalacturonase was used in this work to study the possibility of continuous production of this enzyme. It is a feasible and interesting alternative to fungal batch production essentially due to the specificity of the type of pectinase excreted by Kluyveromyces marxianus CCT 3172, to the lower broth viscosity and to the easier downstream operations. In order to increase the reactors' productivity, a cellulosic carrier obtained from barley spent grains was tested as an immobilization support. Two types of reactors were studied for pectinase production using glucose as a carbon and energy source--a continuous stirred tank reactor (CSTR) and a packed bed reactor (PBR) with recycled flow. The highest value for pectinase volumetric productivity (P(V)=0.98 U ml(-1) h(-1)) was achieved in the PBR for D=0.40 h(-1), a glucose concentration on the inlet of S(in)=20 g l(-1), and a biomass load in the support of X(i)=0.225 g g(-1). The results demonstrate the attractiveness of the packed bed system for pectinase production.     

Multisensor Demining Robot

The paper describes an advanced multisensor demining robot. The robot transport system is based on a simple structure using pneumatic drive elements. The robot has robust design and can carry demining equipment up to 100 kg over rough terrains. Due to the adaptive possibilities of pedipulators to obstacles, the robot can adjust the working position of the demining sensors while searching for mines. The detection block consists of a metal detector, an infrared detector, and a chemical explosive sensor. The robot is controlled by means of an on-board processor and by an operator remote station in an interactive mode. Experimental results of the transport, control, and detection systems of the robot are presented.Michael Yu. Rachkov is Professor of Automation at the Moscow State Industrial University. He graduated in Automatic Control Systems from Moscow Higher Technical School, 1979. He held academic posts at the Institute for Problems in Mechanics, Russian Academy of Sciences. In 1986 he completed his PhD in industrial robotics and received his DSc in mobile robotics in 1997. Professor Rachkov has been leading in several international projects like EUREKA and REMAPHOS. He has published over 170 papers and several books in the field of automation, robotics and optimal control. He is a member of Russian Cosmonautics Academy and International Informatization Academy.Lino Marques is a research engineer at the Institute of Systems and Robotics of the University of Coimbra. He received the Engineering and MsC. degrees in Electrical Engineering from the Faculty of Science and Technology of this University in 1992 and 1997 respectively. He is currently working toward the Ph.D. degree and teaching in the Electrical and Computer Engineering Department. His current research interests include sensors, mechatronics, mobile robotics and industrial automation.Anábal T. De Almeida graduated in Electrical Engineering, University of Porto, 1972, and received a Ph.D. in Electrical Engineering, from Imperial College, University of London, 1977. Currently he is a Professor in the Department of Electrical Engineering, University of Coimbra, and he is the Director of the Institute of Systems and Robotics since 1993. Professor De Almeida is a consultant of the European Commission Framework Programmes. He is the co-author of five books and more than one hundred papers in international journals, meetings and conferences. He has coordinated several European and national research projects.     

Pressure-Induced Quantum Limit in a Q1D System in High Magnetic Fields

The quasi-one-dimensional (Q1D) materials, (Per)₂M(mnt)₂, have transition temperatures of 12 and 8 K for M = Au and Pt, respectively, as samples are cooled from a metallic state to an insulating, charge density wave (CDW) ground state. In these proceedings, we present results regarding the effect of quasi-hydrostatic pressure and high magnetic fields on the CDW and field-induced density wave (FIDW) states of these materials. With pressures greater than 4 kbar, Shubnikov de Haas oscillations appear in the M = Au compound, which reach the n=1 Landau level before the limit of the applied magnetic field. While lower field (B < 20 T) results are similar for M = Pt, the FIDW state persists in higher fields, even under 5.3 kbar of pressure.     

Thin Films of Molecular Materials Grown on Silicon Substrates by Chemical Vapor Deposition and Electrodeposition

Chemical vapor deposition (CVD) and electrodeposition (ED) were applied to grow thin films of molecule-based magnets and conductors. Chemical vapor deposited films are illustrated by the M(TCNE) _x (M = V, Cr, Nb, Mo) magnet series. V(TCNE) _x and Cr(TCNE) _x are room-temperature magnets. XANES/EXAFS studies on the air-stable Cr(TCNE) _x have been performed to determine the chemical environment of the chromium within the polymeric network. Electrodeposition on a silicon working electrode was applied to process thin films of numerous molecule-based conductors, namely, nonintegral oxidation state compounds, charge transfer complexes, and single-component molecular conductors. Among the series of conductive thin films, TTF[Ni(dmit₂)]₂ and Ni(tmdt)₂ exhibit a metal-like behavior.     

Mercury distribution, speciation and flux in the Sepetiba Bay tributaries, SE Brazil

Dissolved gaseous Hg, reactive Hg, total dissolved Hg and particulate Hg concentrations were measured in samples of majors tributaries of the Sepetiba Bay, SE Brazil (Itimirim, Itingu?u, Guarda, Guandu, S?o Francisco and Ita rivers), in dry and rainy seasons. The average Hg concentrations found varied from 0.02 to 0.18 ng L(-1) for dissolved gaseous Hg, from 0.1 to 18.1 ng L(-1) for reactive Hg, from 0.1 to 66.6 ng L(-1) for total dissolved Hg and from 0.3 to 250 ng L(-1) for particulate Hg. During the rainy season, a decrease in the dissolved Hg concentrations and an increase in the particulate Hg concentrations was observed. Positive correlations were found between the reactive Hg and the total dissolved Hg concentrations (r = 0.99), between the particulate Hg and TSS concentrations (r = 0.82) and between total Hg and particulate Hg concentrations (r = 0.95). The instantaneous Hg fluxes varied among rivers from 0.02 to 412 microgs(-1) for total dissolved Hg and from 0.03 to 12,572 microgs(-1) for particulate Hg. The log Kd varied from 3.76 to 6.43 and showed a significant increase in rainy season following an increase in particulate Hg and a decrease in dissolved Hg concentrations. These results suggest that erosion and runoff are the major pathways of Hg transport to rivers and eventually to Sepetiba Bay.