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[en] This paper reports on an experimental investigation that was conducted to evaluate the effect of tube spacing and liquid temperature on the average and local heat transfer coefficients of tubes in a tube bundle. The dependency on these two parameters was found to be controlled by the flow field around the tubes
Journal
International Communications in Heat and Mass Transfer; ISSN 0735-1933; 
; CODEN IHMTD; v. 18(3); p. 321-332
; CODEN IHMTD; v. 18(3); p. 321-332
[en] An Fe-Co-Mn catalysts series after hydrogenation of carbon monoxide has been characterized. The XRD analysis shows the magnetite as main crystalline phase after reaction, in addition of carbon and carbide phases. All these phases lead to hydrogen consumption and oxidation rate changes on Fe-Co-Mn catalysts. A phase transformation superficial diagram is analysed. (Author)
Journal
[en] We present tight-binding calculations of the hole level structure of δ-doped Field Effect Transistor in a Si matrix within the first neighbors sp3s* semi-empirical tight-binding model including spin. We employ analytical expressions for Schottky barrier potential and the p-type δ-doped well based on a Thomas-Fermi approximation, we consider these potentials as external ones, so in the computations they are added to the diagonal terms of the tight-binding Hamiltonian, by this way we have the possibility to study the energy levels behavior as we vary the backbone parameters in the system: the two-dimensional impurity density (p2d) of the p-type δ-doped well and the contact voltage (Vc). The aim of this calculation is to demonstrate that the tight-binding approximation is suitable for device characterization that permits us to propose optimal values for the input parameters involved in the device design.
Journal
Journal of Physics. Conference Series (Online); ISSN 1742-6596; ; v. 167(1); [5 p.]
; v. 167(1); [5 p.]
[en] The main characteristics of the quantum confined Stark effect (QCSE) are studied theoretically in quantum wells of Gaussian profile. The semi-empirical tight-binding model and the Green function formalism are applied in the numerical calculations. A comparison of the QCSE in quantum wells with different kinds of confining potential is presented
Journal
[en] In this work we use the standard T-matrix method to study the tunneling of Dirac electrons through graphene multilayers. A graphene sheet is deposited on top of slabs of Silicon-Oxide (SiO2) and Silicon-Carbide (SiC) substrates, in which we applied the Cantor’s series. We calculate the transmittance as a function of energy for different incident angles and different generations of the Cantor’s series. Comparing the transmittance, we found three types of self-similarity: (a) local - into generations, (b) between incident angles and (c) between generations. We also compute the angular distribution of the transmittance for fixed energies finding a self-similar pattern between generations. To our knowledge is the first time that four different self-similar patterns are presented in Cantor-based multilayers
Journal
[en] This paper describes the thermal power calibration and neutron flux measurement performed in order to have an approach to the IAN-R1 reactor core characterization in the framework of the recently acquired operating license for five years. (author)
Source
International Atomic Energy Agency, Division of Nuclear Fuel Cycle and Waste Technology, Division of Physical and Chemical Sciences and Division of Nuclear Installation Safety, Vienna (Austria); [1 CD-ROM]; ISBN 978-92-0-105117-2; ; Jul 2017; 7 p; International Conference on Research Reactors: Safe Management and Effective Utilization; Vienna (Austria); 16-20 Nov 2015; IAEA-CN--231-D.10; ISSN 0074-1884; ; Also available on-line: http://www-pub.iaea.org/books/iaeabooks/12207/Research-Reactors-Safe-Management-and-Effective-Utilization and on 1 CD-ROM attached to the printed STI/PUB/1793 from IAEA, Marketing and Sales Unit, Publishing Section, E-mail: sales.publications@iaea.org; Web site: http://www.iaea.org/books; 2 refs., 10 figs.
; Jul 2017; 7 p; International Conference on Research Reactors: Safe Management and Effective Utilization; Vienna (Austria); 16-20 Nov 2015; IAEA-CN--231-D.10; ISSN 0074-1884; ; Also available on-line: http://www-pub.iaea.org/books/iaeabooks/12207/Research-Reactors-Safe-Management-and-Effective-Utilization and on 1 CD-ROM attached to the printed STI/PUB/1793 from IAEA, Marketing and Sales Unit, Publishing Section, E-mail: sales.publications@iaea.org; Web site: http://www.iaea.org/books; 2 refs., 10 figs.
[en] In this work we present the results obtained from the calculation of the level structure of a n-type delta-doped well Field Effect Transistor when is subjected to hydrostatic pressure. We study the energy level structure as a function of hydrostatic pressure within the range of 0 to 6 kbar for different Schottky barrier height (SBH). We use an analytical expression for the effect of hydrostatic pressure on the SBH and the pressure dependence of the basic parameters of the system as the effective mass m(P) and the dielectric constant ε(P) of GaAs. We found that due to the effects of hydrostatic pressure, in addition to electronic level structure alteration, the profile of the differential capacitance per unit area C−2 is affected
Journal
[en] Parkinson's disease (PD) is characterized by progressive degeneration of nigrostriatal system with loss of neurons dopamineergicas. TRODAT is an analogue of cocaine which together with the dopamine transporter DAT) is located in the terminal axons of the striatum and reflects the integrity of the dopaminergic system. Objective: To describe the experience with 99mTc-TRODAT1 in patients with differential diagnosis of abnormal movements or EP novo
[es]
La enfermedad de Parkinson (EP) se caracteriza por una progresiva degeneracion del sistema nigroestriatal con perdida de las neuronas dopamineergicas. El TRODAT, es un analogo de la cocaina que unido al transportador de la dopamina DAT), se localiza en los axones terminales del estriatum y refleja la integridad del sistema dopaminergico. Objetivo: Describir la experiencia con 99mTc-TRODAT1 en pacientes con diagnostico diferencial entre movimientos anormales o EP de novo. Metodos: Estudio de casos. Pacientes con uno o mas de los siguientes sintomas: temblor en reposo, rigidez, bradiquinesia o acinesia, clasificado en la Escala N/Y grado III, sin diagnostico de EP , que acuden para gamagrafia 99mTC-TRODAT1. En la gamagrafia se evaluo cualitativamente la captacion del cuerpo estriado (CE), nucleo caudado (NC) y el putamen (P). La interpretacion gamagrafica fue realizada por dos observadores en forma independiente; se registro como anormal la ausencia o hipocaptacion del trazador en NC, P, CE. La correlacion clinico/gamagrafica se considero cuando la anormalidad de la gamagrafia era opuesta a los sintomas clinicos predominantes, Se clasificaron en grados 0 a V de acuerdo con la captacion en CE. Resultados: Entre Diciembre 2006-Agosto 2007 se realizaron 19 gamagrafias con 99mTc-TRODA T1. El promedio de edad: 61 anos ± 13 (rango:32-85anos),17/19 fueron hombres; los sintomas predominantes fueron: bradiquinesia (9/21), temblor (15/21) y rigidez (15/21); en cinco pacientes que consultaron por temblor se encontro bradicinesia y rigidez en el examen fisico; el tiempo promedio de evolucion de los sintomas fue 24 meses 8- 36m). Los hallazgos gamagraficos fueron anormales en 18/19. Se identifico compromiso bilateral del putamen (10/18). El NC fue hipocaptante unilatertal (izquierdo /derecho)en 9/18 En tres pacientes se encontro ausencia bilateral del CE. Se encontraron 8/19GI, 8/19GII, 2-19GV; la correlacion clinico/gamagrafica se encontro en 17/18 pacientes. Conclusiones: En el grupo estudiado se encontro correlacion clinico-gamagrafica. La gamagrafia con 99mTC- TRODAT permite evaluar en forma temprana la degeneracion dopaminergica nigroestriatal en pacientes con sintomas inespecificos leves o no conclusivos, lo que permite un diagnostico mas temprano y un tratamiento oportuno. (author)Journal
World Journal of Nuclear Medicine; ISSN 1450-1147; ; v. 7(3); p. 198
; v. 7(3); p. 198
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