Anomalous transport effects on magnetic field profile in a motional current sheath

The radial magnetic field profile during implosion of a reversed field current sheath in a theta-pinch was investigated through local measurements and simulation of hybrid code. The actual profile was defined by Hermite interpolation polynomial through mean value of the field at discrete radial position of measurements. Simulation profile was provided by the numerical code with appropriate initial conditions. Classical and anomalous collision process were taken in account in the theoretical model. The results indicated that anomalous effects play major role during the implosion phase of current sheath in a slow rising theta pinch device.

Direct analysis of biodiesel microemulsions using an inductively coupled plasma mass spectrometry

An analytical procedure for direct introduction of biodiesel samples into an inductively coupled plasma mass spectrometer (ICP-MS) by using microemulsion for sample preparation was developed here. Cadmium, Co, Cu, Mn, Ni, Pb, Ti, and Zn were determined in biodiesel microemulsified samples prepared from different oleaginous sources (African palm, castor beans, palm, soybeans and an unknown oleaginous). Microemulsions were prepared using 0.25 mL Triton X-100, 0.25 mL 20% v v(-1) HNO(3), 0.50 mL biodiesel sample and 4.0 mL n-propanol. Argon-oxygen mixture was added to the plasma as auxiliary gas for correcting matrix effects caused by the high carbon load due to biodiesel microemulsions. The oxygen gas flow rate was set in 37.5 mL min(-1). The accuracy of the developed procedure was evaluated by applying addition-recovery experiments for biodiesel samples from different sources. Recoveries varied from 76.5 to 116.2% for all analytes but Zn in castor beans biodiesel sample (65.0 to 76.2%). Recoveries lower than 86.6% were obtained for palm biodiesel sample, probably due to matrix effects. Detection limits calculated by using oxygen in the composition of the auxiliary gas added to the plasma were higher than those calculated without using it, probably due to the highest formation of oxides. Despite oxides formation, best analytical performance was reached by using oxygen as auxiliary gas and by proper correction of transport interferences. The developed procedure based on microemulsion formation was suitable for direct introduction of biodiesel samples in ICP-MS. (C) 2010 Elsevier B.V. All rights reserved.

An N2: CH4: H2O DC glow discharge plasma probed by optical and electric techniques: significance to the radiation chemistry of Titan's upper atmosphere in the presence of meteoritic water

This paper presents optical and electrical measurements on plasma generated by DC excited glow discharges in mixtures composed of 95% N2, 4.8% CH4 and 0.2% H2O at pressures varying from 1.064 mbar to 4.0 mbar. The discharges simulate the chemical reactions that may occur in Titan's atmosphere in the presence of meteorites and ice debris coming from Saturn's systems, assisted by cosmic rays and high energy charged particles. The results obtained from actinometric optical emission spectroscopy, combined with the results from a pulsed Langmuir probe, show that chemical species CH, CN, NH and OH are important precursors in the synthesis of the final solid products and that the chemical kinetics is essentially driven by electronic collision processes. It is shown that the presence of water is sufficient to produce complex solid products whose components are important in prebiotic compound synthesis. © 1998 Elsevier Science Ltd. All rights reserved.

Plasma confinement in tokamaks with robust torus

We present a non-linear symplectic map that describes the alterations of the magnetic field lines inside the tokamak plasma due to the presence of a robust torus (RT) at the plasma edge. This RT prevents the magnetic field lines from reaching the tokamak wall and reduces, in its vicinity, the islands and invariant curve destruction due to resonant perturbations. The map describes the equilibrium magnetic field lines perturbed by resonances created by ergodic magnetic limiters (EMLs). We present the results obtained for twist and non-twist mappings derived for monotonic and non-monotonic plasma current density radial profiles, respectively. Our results indicate that the RT implementation would decrease the field line transport at the tokamak plasma edge. © 2010 Elsevier B.V. All rights reserved.

Urban transport in the era of economic liberalization

In that decade, a different solution was required, because the Latin American economies, with only a few exceptions, were already regulated, protected and supervised by the State. One notable exception was the Chilean economy, which, at the onset of the 1970s, had been among the most controlled economies in the region after Cuba. Beginning in 1976/1977, Chile's economy underwent profound restructuring with the adoption of neoliberal policies, involving a reduction in customs tariffs, a decrease in State subsidies, the first steps towards the privatization of state-owned enterprises and a loosening of controls both over prices and production processes in general. The Chilean experience initially gave good results, but in 1982 Chile fell into a deep recession, caused to some extent by the continued fixing of one of the most important prices, that of the Chilean peso on the foreign exchange market, together with inadequate regulation of the banking sector.

Technologies applied to the transport sector: electronic fare collection systems

Electronic transactions are becoming increasingly commonplace in the countries of Latin America and the Caribbean, despite the collapse of many dotcom firms and the failure of e-commerce to make inroads in the region. In the transport sphere, the gradual incorporation of technology in support of processes and the exchange of money flows between players has brought greater versatility, security and flexibility. In public transport, such initiatives take the form of automatic ticket machines and prepaid card dispensing machines. In urban transit, electronic purses used for the supervision and payment of parking time, and in road pricing, electronic toll systems streamline the process of collecting money; this is especially the case with motorways and urban concessions. And in shipping, electronic transfers are increasingly being used for the payment of customs dues and port charges.In view of the importance of the topic and the interest expressed in it, the Transport Unit has begun a study of these issues, and recently published a paper entitled Sistemas de cobro electrónico de pasajes en el transporte público, ("Electronic systems for payment of tickets in public transport") LC/L.1752-P/E, July 2002, on which this issue of the Bulletin is based.

Transport in the Americas: linking regional systems

On 15 and 16 December 1998, in New Orleans, United States, the third Western Hemisphere Transportation Ministerial Meeting will take place. This is part of a work programme which has been incorporated into the Plan of Action of the Americas. The Summit of the Americas held in Santiago, Chile, in April 1998, and the adoption of negotiations mechanisms for the Free Trade Area of the Americas constitute two major landmarks of the continental integration processes this year. The current issue of the FAL Bulletin focuses on the relationship between trade and transport in the Americas, and includes a discussion of transport systems and the supporting integration progress in the continent.

Caracterização estrutural e propriedades óticas e mecânicas do diglime polimerizado a plasma

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propriedades estruturais e ópticas de filmes finos a-C:H:CI obtidos por deposição à vapor químico assistido por plasma e deposição e implantação iônica por imersão em plasma

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Estudo de cerâmicas de SiC e Al2O3 tratadas por expansor de plasma de nitrogênio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Plasma rico em plaquetas empregado na cirurgia reconstrutiva em coelhos (Oryctolagus cuniculus): avaliação da exequibilidade da técnica, achados macroscópicos e histopatológicos

Pós-graduação em Cirurgia Veterinária - FCAV

Avaliação de ciclo de vida comparativa dos processos de anodização e oxidação eletrolítica com plasma de liga de alumínio

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Fluazuron-induced morphological changes in Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae) nymphs: An ultra-structural evaluation of the cuticle formation and digestive processes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rest stops during road transport: Impacts on performance and acute-phase protein responses of feeder cattle

Angus x Hereford steers (n = 42) and heifers (n = 21) were ranked by gender and BW on d 0 of the experiment and randomly assigned to 1 of 3 treatments: 1) no transport and full access to feed and water (CON); 2) continuous road transport for 1,290 km (TRANS), or 3) road transport for 1,290 km, with rest stops every 430 km (STOP; total of 2 rest stops). Treatments were applied from d 0 to 1 of the experiment. Cattle from TRANS and STOP treatments were transported in separate commercial livestock trailers, within a single 2.1 x 7.2 m compartment, but through the exact same route. During each rest stop, STOP cattle were unloaded and offered mixed alfalfa-grass hay and water for ad libitum consumption for 2 h. Upon arrival of STOP and TRANS on d 1, cattle were ranked by sex and BW within each treatment and assigned to 21 feedlot pens (7 pens/treatment; 2 steers and 1 heifer/pen). Full BW was recorded before (d -1 and 0) treatment application and at the end of experiment (d 28 and 29). Total DMI was evaluated daily from d 1 to 28. Blood samples were collected on d 0 (before loading of TRANS and STOP cattle), 1 (immediately after unloading of TRANS and STOP cattle), 4, 7, 10, 14, 21, and 28. Body weight shrink from d 0 to d 1 was reduced (P < 0.01) in CON compared to TRANS and STOP, and reduced in STOP compared to TRANS. Mean ADG was greater (P < 0.05) in CON compared to TRANS and STOP, but similar (P = 0.68) between TRANS and STOP. No treatment effects were detected (P >= 0.18) on hay, concentrate, and total DMI. Mean G: F was greater (P = 0.05) in CON compared to STOP, tended to be greater (P = 0.08) in CON compared to TRANS, and similar (P = 0.85) between TRANS and STOP. Plasma cortisol concentrations were greater (P <= 0.04) in TRANS compared to CON and STOP on d 1, and greater (P = 0.04) in TRANS compared to CON on d 4. Serum NEFA concentrations were greater (P < 0.01) in TRANS compared to CON and STOP on d 1, and greater (P <= 0.05) in TRANS compared to CON on d 4 and 7. Mean plasma ceruloplasmin concentrations were similar (P = 0.19) among treatments. Plasma haptoglobin concentrations were greater (P <= 0.04) in TRANS compared to CON and STOP on d 1, and in STOP compared to CON on d 1. In conclusion, inclusion of rest stops during a 1,290-km transport prevented the increase in circulating cortisol and alleviated the NEFA and haptoglobin response elicited by transport, but did not improve feedlot receiving performance of transported cattle.

Tratamento da superfície do alumínio via eletrólise a plasma

This paper presents the study on the application of the electrolytic plasma for surface treatment of aluminum. A bibliographical study on the material of interest was preliminarily performed and later designed and built an electrolytic cell, including the excitation source. Unlike conventional electrolysis process, the plasma assisted carry on in the non-linear region of characteristic current/voltage curve. Therefore it requires for the on set of the process that the power supply operates on harder conditions than those on high current process. The plasma produced during the present investigation has temperatures in the range o 6,0.10 3 -7,0 .10 3 K, well above those found in conventional chemical process. It also shows a particular dynamic to promote changes on surface and to produce new materials. The plasma is generated by microdischarge in vapor or gas bubbles involved in physic-chemical processes in electrode regions of the electrolytic cell. The electrode material was the aluminum (7075). The Process Electrolytic Plasma Processing (EPP) is sensitive to various parameters such as operating voltage, current density, electrolyte, concentration of electrolyte, geometry of reactor, temperature of electrolytic solution and dynamic of the fluid in the cell. The experiments were carried on in order to find parameters for a stable abd steady operation. The choice for the electrolytic was silicate/alkali solution in various concentrations to operate in various voltage as well. Plasma was produced on negative (cathode) and positive (anode) electrode, in specific conditions. A stable operation on the cathode process was obtained with low concentration of the electrolytic in aqueous solution, current density around 250V effective voltage. For the evolution of plasma in anodic process it was required higher concentrations and higher... (Complete abstract click electronic access below)