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Sample records for anular vertical no-newtoniano

  1. Aplicación de la técnica tds a un yacimiento compuesto con fluidos dilatantes no newtoniano/newtoniano

    OpenAIRE

    Martínez, Javier Andrés; Escobar, Freddy Humberto; Cantillo, José Humberto

    2011-01-01

    Por muchos años, los fluidos no Newtonianos, tales como los polímeros, se han usado en la industria del petróleo como agentes de fracturamiento y en lodos de perforación. Estas soluciones las cuales normalmente contienen agua, son inyectadas en la formación para la recuperación mejorada de petróleo mediante el mejoramiento de la eficiencia de barrido. Es de resaltar que algunos crudos pesados también tienen comportamiento no Newtoniano. Los fluidos no Newtonianos no exhiben una proporcionalid...

  2. Evaluación de Coeficientes de Fricción en el Transporte de Fluidos No-Newtonianos Evaluation of Friction Coefficients for the Transport of Non-Newtonian Fluids

    Directory of Open Access Journals (Sweden)

    M.R. Bandala-Rocha

    2005-01-01

    Full Text Available El objetivo del presente trabajo fue medir las caídas de presión para obtener los coeficientes de fricción de fluidos no-newtonianos. Se empleó un sistema de transporte con varios accesorios en los que se hicieron pasar los fluidos de prueba, midiendo el flujo volumétrico y las pérdidas de presión. Los coeficientes de fricción que se obtuvieron para el agua como fluido de referencia fueron entre 0.42 y 25.7, y para las soluciones de sal de sodio de carboximetil celulosa (NaCMC entre 0.43 y 38.1. Los coeficientes de fricción obtenidos aumentaron con la concentración, lo que permitió obtener una relación potencial entre dicho coeficiente y la concentración de sal para la mayoría de los accesorios y tuberías en que fueron empleados. Las diferencias encontradas al comparar los valores determinados experimentalmente con otros informados en la literatura, se atribuyen al comportamiento reológico del fluido, al circuito de flujo empleado, y al llamado "efecto de influencia mutua" de los accesorios.The objective of the present study was to measure pressure drops to obtain friction coefficients of non-Newtonian fluids. A transport system was employed using various piping transport systems through which test fluids were passed while measuring volumetric flows and pressure drops. The friction coefficients obtained for water as a reference fluid ranged from 0.42 to 25.7, and for solutions containing the sodium salt of carboxymethyl cellulose (NaCMC were from 0.43 to 38.1. The friction coefficients increased with increases in the concentration, which allowed determination of a potential relation between this coefficient and the concentration of the salt for most of the fittings and type of pipes tested. The differences found when comparing the experimentally obtained values with those reported in the literature were attributed to the rheological behavior of the fluid, the circuit employed in transporting the fluid, and the so-called "mutual

  3. Granuloma anular asociado a linfoma no Hodgkim difuso de células B grandes

    Directory of Open Access Journals (Sweden)

    Rafael Alejandro Gómez Baute

    2011-08-01

    Full Text Available Se presenta el caso de un paciente de 55 años con antecedentes de ser hipertenso controlado, atendido en servicio de hematología por adenopatías de características linfomatosas distribuidas en cadenas ganglionares, axilares, inguinales y epitrocleares distribuidas de forma bilateral. Los exámenes permitieron arribar al diagnóstico de un linfoma no Hogdkin difuso de células B grandes y de un granuloma anular.

  4. Granuloma anular asociado a linfoma no Hodgkim difuso de células B grandes

    Directory of Open Access Journals (Sweden)

    Liermis M. Dita Salabert

    2011-12-01

    Full Text Available Se presenta el caso de un paciente de 55 años con antecedentes de ser hipertenso controlado, atendido en servicio de hematología por adenopatías de características linfomatosas distribuidas en cadenas ganglionares, axilares, inguinales y epitrocleares distribuidas de forma bilateral. Los exámenes permitieron arribar al diagnóstico de un linfoma no Hogdkin difuso de células B grandes y de un granuloma anular.Granuloma Annulare Associated with non Hodgkin Diffuse Large B-cell LymphomaThe case of a male, 55 years old patient, with a history of controlled hypertension is presented. The patient was treated in the hematology service for adenopathies of lymphomatous type distributed in nodal chains: axillary, inguinal and epitrochlear and bilaterally distributed. Tests allowed to conclude a final diagnose of non Hodgkin diffuse large B-cell lymphoma and a granuloma annulare.  

  5. Pâncreas anular: ressecção pancreática ou derivação duodenal Anular pancreas: pancreatic resection or duodenal by-pass

    Directory of Open Access Journals (Sweden)

    Marcelo Kruel Schmidt

    2004-01-01

    Full Text Available OBJETIVOS: Apresentar a experiência dos autores no tratamento do pâncreas anular, comparando os dados com os da literatura. MÉTODOS: É relatada a experiência do Departamento de Cirurgia Geral do Hospital de Clínicas de Porto Alegre em pâncreas anular com a descrição de quatro pacientes. A doença manifestou-se em três faixas etárias distintas: uma no período neonatal, outra na infância e duas na fase adulta. O quadro clínico de obstrução intestinal alta esteve presente em três dos quatro pacientes. Dor abdominal foi queixa constante entre os adultos. A investigação diagnóstica foi realizada através do estudo contrastado do estômago e duodeno, da endoscopia digestiva e da tomografia abdominal. A confirmação diagnóstica somente foi possível durante a laparotomia. A derivação duodenal foi a técnica cirúrgica empregada em dois casos e a ressecção do tecido pancreático nos pacientes adultos. RESULTADOS: Os quatros pacientes evoluíram favoravelmente no período pós-operatório. O tempo de internação hospitalar variou de 9 a 12 dias, com média de 10,5 dias. Não houve complicação cirúrgica e todos os pacientes permanecem assintomáticos em acompanhamento ambulatorial. CONCLUSÃO: A raridade desta anomalia não permite um estudo mais detalhado e comparativo. Os resultados aqui apresentados como os encontrados na literatura demonstram que a derivação duodenal e a ressecção pancreática são alternativas eficazes e seguras quando bem indicadas.PURPOSE: To present the authors experience managing anular pancreas and to compare the results found by the authors with the ones foundin the literature. METHODS: A retrospective review of four patients treated at the Departamento de Cirurgia da Faculdade de Medicina da Universidade Federal do Rio Grande do Sul with anular pancreas. The disease was present in three different ages: one in the neonatal age, one in childhood and two in the adulthood. Gastroduodenal

  6. Errores fotométricos debido al uso del filtro anular de mediana en imágenes CCD

    Science.gov (United States)

    Gil-Hutton, R.; Cañada, M.; Noel, N.

    El filtro anular de mediana tiene la importante propiedad de tener una escala claramente definida, lo que permite remover de una imagen CCD todos los objetos con tamaños menores a esta escala, independientemente de su morfología particular, y reemplazarlos por el correspondiente ``background" local. Este filtro es de gran utilidad para remover gradientes de fondo, ``fringing" y halos de objetos extendidos mediante el simple procedimiento de restar a la imagen original una imagen filtrada, repitiendo el proceso las veces que sea necesario. En este trabajo se presentan resultados sobre los errores que introduce este filtro en la fotometría de objetos con diferente relación S/N y su aplicación a imágenes con gradientes de fondo y ``fringing".

  7. Transferencia de calor incrementada en espacios anulares con elementos helicoidales insertados//Review of augmentation techniques for heat transfer coefficient in annular spaces using helical elements

    OpenAIRE

    Josué Imbert‐González; Octavio García‐Valladares; Viedma, A.; Reinaldo Guillen‐Gordín

    2014-01-01

    La transferencia de calor incrementada por métodos pasivos se emplea en diversosintercambiadores de calor de alta efectividad. El objetivo del trabajo presentado fue la evaluación del estado de las investigaciones en el campo de la transferencia de calor mejorada en espacios anulares, a partir del empleo de elementos turbulizadores helicoidales como técnicas pasivas. La revisión se centró en el empleo de láminas helicoidales y espirales, la obtención de ecuaciones de correlación del coeficien...

  8. Predicción de la transferencia de masa en cultivos no-newtonianos de Bacillus licheniformis

    Directory of Open Access Journals (Sweden)

    Mariela Rizo-Porro

    2015-01-01

    Full Text Available El objetivo de este trabajo es desarrollar un modelocapaz de predecir el valor del coeficiente volumétrico detransferencia de oxígeno (kLa en cultivos deBacilluslicheniformis,en los cuales se utiliza la sacarosa comosustrato limitante. El proceso se realiza en cuatro eta-pas: la selección de expresiones que correlacionen el kLacon la viscosidad del fluido; la determinación de lascaracterísticas reológicas de un cultivo de esta bacteriacon sobreexpresión de un exopolisacárido (EPS; ladeterminación experimental del kLa en diferentes con-diciones de viscosidad, velocidad de agitación y flujo deaire y por último; la selección de la correlación quemejor representa los resultados experimentales. Comoresultado del trabajo desarrollado se obtuvo que elmodelo de Oswald de Waele representa el comporta-miento pseudoplástico de un cultivo deBacillus licheni-formisen las condiciones estudiadas y se identificaronlos coeficientes de la correlación propuesta la cualrepresenta exitosamente el 99,45 % de los datos experi-mentales. Los valores de kLa experimental fueron obte-nidos entre 0,0056 y 0,981 s-1.

  9. Transferencia de calor incrementada en espacios anulares con elementos helicoidales insertados//Review of augmentation techniques for heat transfer coefficient in annular spaces using helical elements

    Directory of Open Access Journals (Sweden)

    Josué Imbert‐González

    2014-08-01

    Full Text Available La transferencia de calor incrementada por métodos pasivos se emplea en diversosintercambiadores de calor de alta efectividad. El objetivo del trabajo presentado fue la evaluación del estado de las investigaciones en el campo de la transferencia de calor mejorada en espacios anulares, a partir del empleo de elementos turbulizadores helicoidales como técnicas pasivas. La revisión se centró en el empleo de láminas helicoidales y espirales, la obtención de ecuaciones de correlación del coeficiente de transferencia de calor incrementado, el coeficiente de fricción y la evaluación que se realiza de este proceso por parte de diferentes autores. El análisis crítico permitió realizar valoraciones integradas y recomendar sobre los aspectos que podrían ser analizados en el futuro en esta temática.Palabras claves: transferencia de calor incrementada, láminas helicoidales, espirales, espacios anulares, métodos pasivos._______________________________________________________________________________AbstractThe transfer enhancement by passive methods is used in several heat exchanger of high effectiveness. The objective of the presented work was the evaluation of the state of the investigations in heat transfer enhancement in annular spaces, from the employment of elements helical. The revision was centered in the employment of twisted tape and wire coil in spiral, the equations of correlation obtained of the coefficient of transfer of increased heat, the coefficient of friction and the evaluation that was carried out of this process on the part of different authors. From the critical analysis of the published results, the authors recommend on the topics that can be analyzed in the future in this area.Key words: heat transfer enhancement, twisted tape, helical springs, annular spaces, passive methods.

  10. Caída de presión de un flujo turbulento en un espacio anular con hélices insertadas//The pressure drop of turbulent flow in an annular space with wire coil inserts

    Directory of Open Access Journals (Sweden)

    Josué Imbert González

    2015-05-01

    Full Text Available El trabajo presentado evaluó el comportamiento experimental de la caída de presión en un espacio anular con alambres enrollados insertados para números de Reynolds entre 1500 y 5000. La zona de prueba se seleccionó alejada de la influencia de los efectos de entrada. Anteriormente se realizaron pruebas de visualización del flujo para verificar la presencia de un flujo turbulento en esta gama del número de Reynolds. A partir de los datos experimentales se obtuvieron ecuaciones de correlación del factor de fricción para el flujo turbulento. Las ecuaciones obtenidas se compararon con los datos experimentales. Los resultados indican hasta qué punto las hélices inducen la aparición de turbulencias en un espacio anularPalabras claves: caída de presión, flujo anular, análisis hidrodinámico, visualización de flujo, hélices insertadas.______________________________________________________________________________AbstractThe work presented evaluates the experimental behavior of the pressure drop in an annular space with coiled wires inserted forReynolds numbers between 1500 and 5000. The test zone was selected away from the influence of entrance effects. Previously flow visualization tests were performed to verify the presence of a turbulent flow in this range of Reynolds number. From the experimental data were obtained correlation equations of the friction factor for turbulent flow. The equations obtained were compared with experimental data. The results indicate to what extent the helices induce the occurrence of turbulence in an annular space.Key words: drop pressure, annular flow, hydrodynamic analysis, visualization flow, wire coil inserts.

  11. Granuloma anular: distribuição tecidual dos dendrócitos dérmicos fator XIIIa+, das células dérmicas trombomodulina+ e de macrófagos CD68+

    OpenAIRE

    Soub Claudia Regina Wanderley; Carrijo Rochael Mayra; Cuzzi Tullia

    2003-01-01

    FUNDAMENTOS: Um subgrupo de células dérmicas relacionado a macrófagos expressa o fator pró-coagulante XIIIa enquanto outro subgrupo expressa o co-fator anticoagulante trombomodulina. Esses tipos celulares podem estar envolvidos em eventos de inflamação e reparo tecidual. OBJETIVOS: Investigar a participação de células dérmicas fator XIIIa+ e de células dérmicas trombomodulina+ (TM) no quadro histopatológico do granuloma anular que se caracteriza por necrobiose do colágeno e presença de infilt...

  12. Heat transfer of non Newtonian fluids in concentric annular tubes; Transferencia de calor de fluidos nao-Newtonianos em tubos e anulares concentricos

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, C.F.H. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Figueiredo, A.M.D. de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    1990-12-31

    This work investigates the natural and forced laminar convection of non-Newtonian fluids, with temperature dependent properties, flowing upward through vertical tubes or vertical concentric annuli with prescribed wall heat fluxes. 16 refs., 5 figs.

  13. Metodología para el Escalamiento de Agitadores Mecánicos Utilizados en Procesos con Fluidos No-Newtonianos

    Directory of Open Access Journals (Sweden)

    Oliveros T. Carlos E.

    1997-06-01

    Full Text Available Se determinó experimentalmente la tasa promedia de cortante (TCP generada por dos rotores utilizados para el desmucilaginado mecánico del café en Colombia: El CENICAFE III y El COLMECANO. Los valores experimentales de TCP fueron comparados con datos estimados con un modelo teórico obtenido asumiendo que el campo de flujo generado por el rotor se asemeja al flujo tipo Couette (TCP y un modelo propuesto por Oliveros (1993,1995. Se utilizó la prueba de X^2 (con 5% de significancia para comparar los valores experimentales y teóricos y se observó que hay diferencias entre ellos. A partir del modelo TCP se obtuvo una expresión semiteórica para estimar la TCP generada por el rotor COLMECANO con alta con fiabilidad (r^2 = 0.982. A una misma velocidad de rotación el agitador COLMECANO genera mayores valores de TCP que el rotor CENICAFE 1/1. luego debe generar mayores tasas de desmucilaginado. La potencia requerida para agitar suspensiones de café en baba-mucílago+agua adicionada (1 L/kg de cps. en el rango de 300 a l. 200 rpm, utilizando los rotores CENICAFE III y COLMECANO, fué medida experimentalmente y estimada teóricamente con dos modelos: el modelo propuesto por Oliveros (1993.1995 Y un modelo obtenido asumiendo que el campo de flujo generado por los rotores es del tipo Couette (modelo pc. Los valores experimentales y estimados fueron comparados por medio de la prueba de X^2 (al 5% de significancia observándose diferencias entre ellos. Mediante un análisis de regresión lineal simple aplicado a los valores obtenidos con el modelo pe se obtuvo una expresión semi-teórica la cual permite estimar con alta confiabilidad la potencia para agitar las suspensiones de café en baba-mucílago+agua (r^2 = 0,982 con el rotor COLMECANO. A una misma velocidad de rotación, el rotor COLMECANO requiere menos potencia que el CENICAFE III para agitar suspensiones de café en baba-mucílago+agua (1 litro de agua/kg de cps. Se utilizó el concepto del valor Co del proceso de desmucilaginado mecánico como criterio de escalamiento, propuesto por Oliveros (1993, en el cual se establece que el producto TCP*t (t es el tiempo de tratamiento es un parámetro adimensional relacionado con el porcentaje de remoción de mucílago (para remover el 95% del mucílago en café variedad Colombia el valor Co es 11 .595 . Con base en este criterio y las expresiones para estimar la TCP y la potencia se escaló el agitador COLMECANO para 600, 1.000 y 2.000 kg de cereza/h, operando por tandas. La potencia teórica para operar en forma continua se estimó adaptando para desmucilaginadores el modelo propuesto por Bruin et al (1978 para extrusores. La potencia a instalar en los equipos para las diferentes capacidades se obtuvo considerando las pérdidas por disipación viscosa (13% y en la transmisión de potencia (10%. La metodología propuesta en este estudio para el escalamiento de los agitadores COLMECANO permite dimensionar los desmucilaginadores, definir las condiciones de operación para obtener obtener un rendimiento específico y estimar la potencia requerida con buena confiabilidad.

  14. Vertical Farming

    OpenAIRE

    Molina Núñez, Antonio José

    2012-01-01

    El fin de la instalación es producir frutas y verduras utilizando la menor superficie posible en planta, debido a la escasez y encarecimiento de esta, incremento de la población y desertificación. Para ello esta modalidad de plantación, Vertical farming, utiliza el desarrollo en altura, aprovechando la superficie lo máximo posible combinado con una nueva técnica, hidroponia, que es la forma de cultivar las plantas sin tierra. Facultad de Ciencias de la Empresa Universidad...

  15. Evaluación de barreras vegetales en el manejo integrado de la mancha anular del papayo (PRSV-P) en Michoacán, México Evaluation of plant barriers in an integrated management of papayo ringspot in Michoacan, Mexico

    OpenAIRE

    Patricia Rivas-Valencia; Gustavo Mora-Aguilera; Daniel Téliz-Ortiz; Antonio Mora-Aguilera

    2008-01-01

    El efecto de barreras vegetales como componente de un programa de manejo integrado (MI), se validó y adaptó en 1999 en Michoacán, México, para controlar la Mancha Anular del Papayo, enfermedad causada por el Papaya ringspot potyvirus type-P (PRSV-P). Se estableció un experimento en parcelas divididas con dos factores experimentales: barreras vegetales (Hibiscus sabdariffa), y componentes de MI: MI sin aspersión de citrolina (1.5%) (MI-A), MI sin eliminación de plantas con síntomas iniciales d...

  16. Substituição valvar mitral com papilopexia cruzada e constrição anular em pacientes com insuficiência cardíaca Mitral valve replacement with crossed papillopexy and annular constriction in heart failure patients

    Directory of Open Access Journals (Sweden)

    Ricardo Adala Benfatti

    2008-09-01

    Full Text Available OBJETIVO: Analisar os resultados em curto e médio prazo de pacientes portadores de insuficiência cardíaca e insuficiência mitral moderada/grave submetidos a substituição valvar mitral com a técnica da papilopexia cruzada e constrição anular. MÉTODOS: Treze pacientes em classe funcional III ou IV (NYHA, idade média de 54,1 anos, etiologia idiopática, foram submetidos a substituição valvar mitral com constrição do anel e papilopexia cruzada. Foram analisados os parâmetros ecocardiográficos, classe funcional e curva atuarial de sobrevivência. RESULTADOS: Não houve mortes no período trans e pósoperatório imediato. A média dos diâmetros diastólicos e sistólicos ventricular esquerdo reduziu de 71 ± 8,6 mm para 65,3 ± 8,6 mm (p=0,049 e de 59,1 ± 8,5 mm para 50,4 ± 11,1 mm (p=0,002, respectivamente. Os diâmetros atriais variaram de 49,4 ± 6,4 mm para 44 ± 5,9 mm (p=0,017; o percentual de encurtamento sistólico do ventrículo esquerdo foi de 17 ± 4% para 24 ± 8,3% (p=0,014, a fração de ejeção variou de 34 ± 9% para 45 ± 14% (p=0,008, todos estatisticamente significativos. Onze (84,6% pacientes se encontram em classe funcional I e II. A sobrevivência foi de 100%, 82,6%, 71,6%, respectivamente para 1, 6 e 12 meses após a cirurgia de seguimento, mantendo-se 71,6% em período superior a 36 meses. CONCLUSÃO: Os resultados obtidos, em pacientes com insuficiência cardíaca e insuficiência mitral moderada/grave submetidos a substituição valvar mitral com papilopexia cruzada e constrição anular, apresentaram evidências de remodelamento cardíaco favorável e significativa recuperação funcional ventricular esquerda.OBJECTIVE: To analyze the short-term and mid-term follow-ups of patients with heart failure and moderate to severe mitral valve insufficiency and who have undergone mitral valve replacement with crossed papillopexy and annular constriction. METHODS: Thirteen patients in NYHA functional class III or

  17. Signatures of Currency Vertices

    Science.gov (United States)

    Holme, Petter

    2009-03-01

    Many real-world networks have broad degree distributions. For some systems, this means that the functional significance of the vertices is also broadly distributed, in other cases the vertices are equally significant, but in different ways. One example of the latter case is metabolic networks, where the high-degree vertices — the currency metabolites — supply the molecular groups to the low-degree metabolites, and the latter are responsible for the higher-order biological function, of vital importance to the organism. In this paper, we propose a generalization of currency metabolites to currency vertices. We investigate the network structural characteristics of such systems, both in model networks and in some empirical systems. In addition to metabolic networks, we find that a network of music collaborations and a network of e-mail exchange could be described by a division of the vertices into currency vertices and others.

  18. Hybrid vertical cavity laser

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2010-01-01

    A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide.......A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide....

  19. Vertical market participation

    DEFF Research Database (Denmark)

    Schrader, Alexander; Martin, Stephen

    1998-01-01

    Firms that operate at both levels of vertically related Cournot oligopolies will purchase some input supplies from independent rivals, even though they can produce the good at a lower cost, driving up input price for nonintegrated firms at the final good level. Foreclosure, which avoids this stra...

  20. Trade elasticity and vertical specialisation

    OpenAIRE

    Ines Buono; Filippo Vergara Caffarelli

    2013-01-01

    This paper shows that vertical specialisation can increase the elasticity of trade to income, hence explaining dramatic events such as the great trade collapse. We argue that a change in the extent of vertical specialisation affects the elasticity of trade to income, while a mere change in global production levels for a given extent of vertical specialisation does not. In the model we show that only large demand shocks induce firms to vary the extent of vertical specialisation. Using panel da...

  1. GPS, su datum vertical.

    Directory of Open Access Journals (Sweden)

    Esteban Dörries

    2016-03-01

    Full Text Available La introducción de la metodología GPS en aplicaciones topográficas y geodésicas pone en notoria evidencia la clásica separación de sistemas de referencia en horizontal y vertical. Con GPS el posicionamiento es tridimensional, pero el concepto de altura difiere del clásico. Si se desea utilizar la información altimétrica debe contemplarse la ondulación del geoide.

  2. Vertical organic transistors

    International Nuclear Information System (INIS)

    Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted. (topical review)

  3. Vírus da mancha anular do cafeeiro (Coffee ringspot virus - CoRSV: influência na qualidade da bebida e na produção de grãos de café Coffee ringspot virus (CoRSV: influence on the beverage quality and yield of coffee beans

    Directory of Open Access Journals (Sweden)

    Alessandra de Jesus Boari

    2006-06-01

    Full Text Available A mancha anular do cafeeiro, causada pelo Coffee ringspot virus (CoRSV que é transmitido pelo ácaro Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae, tem sido observada em altas incidências em várias regiões cafeeiras do Estado de Minas Gerais. O CoRSV causa manchas cloróticas arrendondadas ou irregulares nas folhas, caules e frutos. Foi feita uma avaliação do efeito da infecção de frutos do cafeeiro pelo CoRSV na qualidade da bebida por meio de teste bioquímico e de degustação, e também na eventual perda de peso nos grãos. Testes revelaram que grãos provenientes de frutos de café infectados pelo CoRSV apresentavam menor teor de açúcares redutores e maior condutividade elétrica. Houve também depreciação na qualidade de bebida gerada pelos frutos infectados por meio do teste de degustação (teste de xícara. O peso médio dos grãos provenientes de frutos manchados foi cerca de 5% menor do que dos grãos de frutos sem sintomas.Coffee ringspot virus (CoRSV, transmitted by the tenuipalpid mite Brevipalpus phoenicis, has been found in high incidences in several regions of the state of Minas Gerais. It induces chlorotic spots on the leaves and fruits and may induce severe fall of the leaves with implication in the yield. An evaluation was made on the effects of CoRSV-infected coffee berries on the beverage quality as well as on the weight of the beans. Infected beans had less reducing sugars and presented an increase in the electrical conductivity. The quality of the beverage prepared from infected fruits was lower than that of healthy fruits. There was a reduction of about 5% in the weight of beans from infected fruits.

  4. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 ± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  5. Vertical guidance of shearers

    International Nuclear Information System (INIS)

    Mining Engineers have always been aware of the basic need to avoid contamination of the mined product, by controlling the cutting horizon at the coal face. The ability to maintain the optimum cutting horizon results in more effective roof control and ensures a safer and more efficient working environment, for men and machinery. The cost of treatment in the surface coal preparation plant is reduced. Transportation through the total mine system of material finally destined for the spoil heap is minimised. A reduction in product contamination is achieved and makes more effective use of the mine capacity. These benefits make possible significant improvements in productivity and financial returns. Exploitation of micro computer based systems has enabled the successful development of equipment which employs sensors to detect the very low natural gamma radiation from roof strata; to determine and allow control of the position of the cut relative to the roof and floor. This paper reviews the experience gained by the National Coal Board, particularly in South Yorkshire Area, with the vertical steering of ranging drum shearers. It outlines the benefits and considers the future for this technology and its contribution to total coal face automation

  6. Evaluación de barreras vegetales en el manejo integrado de la mancha anular del papayo (PRSV-P en Michoacán, México Evaluation of plant barriers in an integrated management of papayo ringspot in Michoacan, Mexico

    Directory of Open Access Journals (Sweden)

    Patricia Rivas-Valencia

    2008-12-01

    Full Text Available El efecto de barreras vegetales como componente de un programa de manejo integrado (MI, se validó y adaptó en 1999 en Michoacán, México, para controlar la Mancha Anular del Papayo, enfermedad causada por el Papaya ringspot potyvirus type-P (PRSV-P. Se estableció un experimento en parcelas divididas con dos factores experimentales: barreras vegetales (Hibiscus sabdariffa, y componentes de MI: MI sin aspersión de citrolina (1.5% (MI-A, MI sin eliminación de plantas con síntomas iniciales de virosis antes de floración (MI-D y MI. Las barreras vegetales sembradas 20 días antes del trasplante del papayo y el desplante retrasaron en 19 días el inicio del progreso de epidemias en el MI lo que resultó en una mayor producción (14.2% que el resto de tratamientos, aunque fue superado por MI-A en vigor (4% en diámetro de tallo. La citrolina fue fitotóxica, disminuyó el vigor de plantas (5.3% y no limitó significativamente el desarrollo de la enfermedad ya que la intensidad de las epidemias (X0 = 47días, Yf = 84% y ABCPE = 3220% días fue similar al testigo. El uso de barreras vegetales por si sola aparentemente no es suficiente para la reducción de la incidencia y dispersión de la enfermedad. Los áfidos más abundantes, con reconocida capacidad transmisora del PRSV-P, fueron Aphis gossypii, A. nerii, A. spiraecola y Macrosiphum euphorbiae, los cuales representaron aproximadamente el 13% del total de áfidos capturados.The effect of plant barriers as a component of an integrated management program (IM was validated and adapted in 1999, in Michoacan, Mexico, to control papaya ringspot, caused by papaya ringspot potyvirus type-P (PRSV-P. A split-plot design was established with two experimental factors: plant barriers and components of IM: IM without oil sprinkling (IM-O, IM without plant rouging (IM-R, and complete IM. Plant barriers (Hibiscus sabdariffa, sowed 20 days before papaya transplanting, and plant rouging delayed the epidemics

  7. Vertical Collective Action: Addressing Vertical Asymmetries in Watershed Management

    OpenAIRE

    Cárdenas, Juan-Camilo; Rodriguez, Luz Angela; Johnson, Nancy

    2015-01-01

    Watersheds and irrigation systems have the characteristic of connecting people vertically by water flows. The location of users along these systems defines their role in the provision and appropriation of water which adds complexity to the potential for cooperation. Verticality thus imposes a challenge to collective action. This paper presents the results of field experiments conducted in four watersheds of Colombia (South America) and Kenya (East Africa) to study the role that location plays...

  8. Trade Liberalisation and Vertical Integration

    DEFF Research Database (Denmark)

    Laugesen, Anders Rosenstand

    2016-01-01

    We build a three-country model of international trade in final goods and intermediate inputs and study the relation between four different types of trade liberalisation and vertical integration. Firms are heterogeneous with respect to both productivity and factor (headquarter) intensity. Final......-good producers face decisions on exporting, vertical integration of intermediate-input production, and whether the intermediate-input production should be offshored to a low-wage country. We find that the fractions of final-good producers that pursue either vertical integration, offshoring, or exporting are all...... increasing when intermediate-input trade or final-goods trade is liberalised. Finally, we provide guidance for testing the open-economy property rights theory of the firm using firm-level data and surprisingly show that the relationship between factor (headquarter) intensity and the likelihood of vertical...

  9. Vertical axis wind turbine airfoil

    Science.gov (United States)

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  10. Backward integration, forward integration, and vertical foreclosure

    OpenAIRE

    Spiegel, Yossi

    2013-01-01

    I show that partial vertical integration may either alleviates or exacerbate the concern for vertical foreclosure relative to full vertical integration and I examine its implications for consumer welfare.

  11. Coexistence of Strategic Vertical Separation and Integration

    DEFF Research Database (Denmark)

    Jansen, Jos

    2003-01-01

    -part tariff, exclusive dealing) contract with its retailer. Coexistence emerges when more than two vertical Cournot oligopolists supply close substitutes. When vertical integration and separation coexist, welfare could be improved by reducing the number of vertically separating firms. The scope...

  12. Alligning vertical collection relevance with user intent

    NARCIS (Netherlands)

    Zhou, Ke; Demeester, Thomas; Nguyen, Dong; Hiemstra, Djoerd; Trieschnigg, Dolf

    2014-01-01

    Selecting and aggregating different types of content from multiple vertical search engines is becoming popular in web search. The user vertical intent, the verticals the user expects to be relevant for a particular information need, might not correspond to the vertical collection relevance, the vert

  13. Trade Liberalisation and Vertical Integration

    DEFF Research Database (Denmark)

    Bache, Peter Arendorf; Laugesen, Anders

    We build a three-country model of international trade in final goods and intermediate inputs and study the relation between different types of trade liberalisation and vertical integration. Firms are heterogeneous with respect to both productivity and factor intensity as observed in data. Final-g...... property rights theory of the firm using firm-level data. Finally, we notice that our model's sorting pattern is in line with recent evidence when the wage difference across countries is not too big.......We build a three-country model of international trade in final goods and intermediate inputs and study the relation between different types of trade liberalisation and vertical integration. Firms are heterogeneous with respect to both productivity and factor intensity as observed in data. Final...... increasing when intermediate-input or final-goods trade is liberalised and when the fixed cost of vertical integration is reduced. At the same time, one observes firms that shift away from either vertical integration, offshoring, or exporting. Further, we provide guidance for testing the open-economy...

  14. Hybrid Vertical-Cavity Laser

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention provides a light source (2) for light circuits on a silicon platform (3). A vertical laser cavity is formed by a gain region (101) arranged between a top mirror (4) and a bottom grating-mirror (12) in a grating region (11) in a silicon layer (10) on a substrate. A waveguide...

  15. INTERNATIONAL SPECIALIZATION AND VERTICAL DIFFERENTIATION

    Directory of Open Access Journals (Sweden)

    Furia Donatella

    2010-07-01

    Full Text Available During the last decades, market segmentation and intra-industry trade have become increasingly relevant. The underlying hypothesis of our work is that distinct articles have heterogeneous potential for vertical differentiation, implying that different patterns of international specialization should be identifiable. We carry out an analysis on revealed comparative advantage (through the Lafay Index in specific sectors of interest. Then we highlight the emergence of diverse degrees of product quality differentiation among sectors (through the Relative Quality Index. Results confirm our hypothesis. Indeed it appears that only certain goods, for which the pace of either creative or technological innovation (or both is particularly fast, present a high degree of vertical differentiation and market segmentation. This allows countries to specialize in a particular product variety and gain market power position for that variety. These findings should be taken in due consideration when designing trade policies.

  16. Vertically Integrated Circuits at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  17. Kinematic Fitting of Detached Vertices

    Energy Technology Data Exchange (ETDEWEB)

    Mattione, Paul [Rice Univ., Houston, TX (United States)

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  18. Strategic Inventories in Vertical Contracts

    OpenAIRE

    Krishnan Anand; Ravi Anupindi; Yehuda Bassok

    2008-01-01

    Classical reasons for carrying inventory include fixed (nonlinear) production or procurement costs, lead times, nonstationary or uncertain supply/demand, and capacity constraints. The last decade has seen active research in supply chain coordination focusing on the role of incentive contracts to achieve first-best levels of inventory. An extensive literature in industrial organization that studies incentives for vertical controls largely ignores the effect of inventories. Does the ability to ...

  19. NASA-Ames vertical gun

    Science.gov (United States)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  20. Vertical axis wind turbine acoustics

    OpenAIRE

    Pearson, Charlie

    2014-01-01

    Increasing awareness of the issues of climate change and sustainable energy use has led to growing levels of interest in small-scale, decentralised power generation. Small-scale wind power has seen significant growth in the last ten years, partly due to the political support for renewable energy and the introduction of Feed In Tariffs, which pay home owners for generating their own electricity. Due to their ability to respond quickly to changing wind conditions, small-scale vertical axis...

  1. Industrial Chain: Industrial Vertical Definition

    Institute of Scientific and Technical Information of China (English)

    YifeiDu; GuojunJiang; ShimingLi

    2004-01-01

    Like value chain and supply chain, “industrial chain” becomes the focus of attention. The implication of “industrial chain” has gained a large range of extension. It not only expresses the industrial “chain” structure and relationship of “back and forward”in order or “up and down” in direction, but also it represents a cluster of large scale of firms in an area or colony. It is a network, or a community. Consequently, we conclude that “industrial chain” is a synthesis of industrial chain, industrial cluster, or industrial network.In this article, firstly we will distinguish industry chain from industry. An industry is the collection of firms that have the same attribute, so an industry can be defined by firm collection of certain attribute. We indicate that industrial chain is a kind of vertical and orderly industrial link. It is defined according to a series of specific product or service created. Secondly we analyze the vertical orderly defiinition process from the aspects of social division of labor and requirement division, self-organization system, and value analysis.Non-symmetry and depending on system or community of large scale of industrial units lead to entire industry to “orderly” structure. On the other hand, the draught of diversity and complexity of requirement simultaneously lead to entire industry to be more “orderly”. Along with processes of self-organization, industrial will appi'oach the state of more orderly and steady, and constantly make industrial chain upgrade. Each firm or unit, who will gain the value, has to establish channels of value, which we called “industrial value chain”. Lastly,we discuss the consequence of vertical and orderly definition, which is exhibited by a certain relationship body. The typical forms of industrial chain include industrial cluster, strategy alliance and vertical integration etc.

  2. Poligonación Vertical

    Directory of Open Access Journals (Sweden)

    Esteban Dörries

    2016-03-01

    Full Text Available La poligonación vertical es un método de medición de diferencias de altura que aprovecha las posibilidades de las estaciones totales. Se presta fundamentalmente para líneas de nivelación entre nodos formando red. El nombre se debe a que las visuales sucesivas se proyectan sobre aristas verticales en lugar de un plano horizontal, como ocurre en la poligonación convencional.

  3. [Vertical fractures: apropos of 2 clinical cases].

    Science.gov (United States)

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures. PMID:1659859

  4. [Vertical fractures: apropos of 2 clinical cases].

    Science.gov (United States)

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures.

  5. Vertically aligned nanostructure scanning probe microscope tips

    Science.gov (United States)

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  6. Convection in a vertical channel

    Energy Technology Data Exchange (ETDEWEB)

    Tisserand, J-C; Creyssels, M; Gibert, M; Castaing, B; Chilla, F, E-mail: Francesca.Chilla@ens-lyon.f [Universite de Lyon, ENS Lyon, UMR 5672 CNRS, 46 Allee d' Italie, 69364 Lyon Cedex 7 (France)

    2010-07-15

    The flow generated by heat convection in a long, vertical channel is studied by means of particle imagery velocimetry techniques, with the help of the thermal measurements from a previous paper (Gibert et al 2009 Phys. Fluids 21 035109). We analyse the mean velocity profiles and the Reynolds stresses, and compare the present results with the previous ones obtained in a larger cell and at a larger Reynolds number. We calculate the horizontal temperature profile and the related horizontal heat flux. The pertinence of effective turbulent diffusivity and viscosity is confirmed by the low value of the associated mixing length. We study the one-point and two-point statistics of both velocity components. We show how the concept of turbulent viscosity explains the relations between the local probability density functions (pdf) of fluctuations for temperature, vertical and horizontal velocity components. Despite the low Reynolds number values explored, some conclusions can be drawn about the small scale velocity differences and the related energy cascade.

  7. Vertical distribution of sediment concentration

    Institute of Scientific and Technical Information of China (English)

    Sai-hua HUANG; Zhi-lin SUN; Dan XU; Shan-shan XIA

    2008-01-01

    A simple formula is proposed to predict the vertical distribution of a suspended load concentration in a 2D steady turbulent flow.The proposed formula significantly improves the well-known Rouse formula where sediment concentration has an infinitely large value at the channel bottom and a zero value at the water surface.Based on this formula and the logarithmic ve-locity profile,a theoretical elementary function for the transport rate of a suspended load is developed.This equation improves the Einstein equation in which the unit-width suspended sediment discharge must be solved by numerical integration and a contra-diction between the lower limit of the integral and that of velocity distribution exists.

  8. On Vertical Relations and Technology Adoption Timing

    OpenAIRE

    Maria Alipranti; Chrysovalantou Miliou; Emmanuel Petrakis

    2014-01-01

    This paper explores how vertical relations influence the timing of new technology adoption. It shows that both the bargaining power distribution among the vertically related firms and the contract type through which vertical trading is conducted affect crucially the speed of adoption: the downstream firms can adopt later a new technology when the upstream bargaining power increases as well as when wholesale price contracts, instead of two-part tariffs, are employed. Importantly, it shows that...

  9. Surface tension profiles in vertical soap films

    OpenAIRE

    Adami, N.; Caps, H.

    2013-01-01

    Surface tension profiles in vertical soap films are experimentally investigated. Measurements are performed introducing deformable elastic objets in the films. The shape adopted by those objects set in the film can be related to the surface tension value at a given vertical position by numerical solving of adapted elasticity equations. We show that the observed dependency of the surface tension versus the vertical position in the soap film can be reproduced by simple modeling taking into acco...

  10. Turbulence in vertical axis wind turbine canopies

    OpenAIRE

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-01-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the i...

  11. The green building envelope: vertical greening

    OpenAIRE

    Ottelé, M.

    2011-01-01

    Planting on roofs and façades is one of the most innovative and fastest developing fields of green technologies with respect to the built environment and horticulture. This thesis is focused on vertical greening of structures and to the multi-scale benefits of vegetation. Vertical green can improve the environment in urban areas and is becoming a key design consideration in modern building developments. Vertical greening of structures offers large surfaces with vegetation and at the same time...

  12. Surface tension profiles in vertical soap films

    CERN Document Server

    Adami, N

    2013-01-01

    Surface tension profiles in vertical soap films are experimentally investigated. Measurements are performed introducing deformable elastic objets in the films. The shape adopted by those objects set in the film can be related to the surface tension value at a given vertical position by numerical solving of adapted elasticity equations. We show that the observed dependency of the surface tension versus the vertical position in the soap film can be reproduced by simple modeling taking into account film thickness measurements.

  13. On the Vertical Gradient in CO2

    Science.gov (United States)

    Stine, A. R.; Fung, I. Y.

    2008-12-01

    Attempts to constrain surface fluxes of carbon from atmospheric measurements of carbon dioxide have primarily focused on surface boundary layer measurements, because information about surface fluxes is least diluted close to the locations where the fluxes occur. However, errors in model ventilation of air in the vertical can be misinterpreted as local surface fluxes. Satellites which measure column integrated CO2 are expected to represent a major advance in part because they observe the entire atmospheric column. Recent work has highlighted the fact that vertical gradients in carbon concentrations can give us information about where vertical mixing errors are likely to be misinterpreted as local surface fluxes, but passive tracer evidence suggests that models that capture vertical profiles on the ocean do poorly on the land (and vice versa), suggesting that the problem of correctly treating vertical mixing in inverse studies is more fundamental than picking the "best" model. We consider observations of the vertical gradient in CO2 from aircrafts and from a comparison of satellites that observe in the near infrared (which observe the column integrated CO2 field) and the thermal infrared (which observe the upper troposphere). We evaluate the feasibility of using these satellites for determining the vertical gradient in CO2. We examine how observations of the vertical gradient of CO2 allow us to differentiate the imprint of vertical mixing and the imprint in surface fluxes on the observed field of atmospheric CO2.

  14. The fundamental formulas for vertices of convex hull

    Directory of Open Access Journals (Sweden)

    Md. Kazi Salimullah

    2013-07-01

    Full Text Available This paper represents four formulas for solution of convex hull problem. It aims to analyze how many points are vertices out of total input points, how many vertices lie on a horizontal or vertical lines, position of vertices and number of vertices on lower and higher lines(horizontal or vertical.

  15. The Ames Vertical Gun Range

    Science.gov (United States)

    Karcz, J. S.; Bowling, D.; Cornelison, C.; Parrish, A.; Perez, A.; Raiche, G.; Wiens, J.-P.

    2016-01-01

    The Ames Vertical Gun Range (AVGR) is a national facility for conducting laboratory- scale investigations of high-speed impact processes. It provides a set of light-gas, powder, and compressed gas guns capable of accelerating projectiles to speeds up to 7 km s(exp -1). The AVGR has a unique capability to vary the angle between the projectile-launch and gravity vectors between 0 and 90 deg. The target resides in a large chamber (diameter approximately 2.5 m) that can be held at vacuum or filled with an experiment-specific atmosphere. The chamber provides a number of viewing ports and feed-throughs for data, power, and fluids. Impacts are observed via high-speed digital cameras along with investigation-specific instrumentation, such as spectrometers. Use of the range is available via grant proposals through any Planetary Science Research Program element of the NASA Research Opportunities in Space and Earth Sciences (ROSES) calls. Exploratory experiments (one to two days) are additionally possible in order to develop a new proposal.

  16. Horizontal versus vertical plate motions

    Directory of Open Access Journals (Sweden)

    M. Cuffaro

    2006-07-01

    Full Text Available We review both present and past motions at major plate boundaries, which have the horizontal component in average 10 to 100 times faster (10–100 mm/yr than the vertical component (0.01–1 mm/yr in all geodynamic settings. The steady faster horizontal velocity of the lithosphere with respect to the upward or downward velocities at plate boundaries supports dominating tangential forces acting on plates. This suggests a passive role of plate boundaries with respect to far field forces determining the velocity of plates. The forces acting on the lithosphere can be subdivided in coupled and uncoupled, as a function of the shear at the lithosphere base. Higher the asthenosphere viscosity, more significant should be the coupled forces, i.e., the mantle drag and the trench suction. Lower the asthenosphere viscosity, more the effects of uncoupled forces might result determinant, i.e., the ridge push, the slab pull and the tidal drag. Although a combination of all forces acting on the lithosphere is likely, the decoupling between lithosphere and mantle suggests that a torque acts on the lithosphere independently of the mantle drag. Slab pull and ridge push are candidates for generating this torque, but, unlike these boundary forces, the advantage of the tidal drag is to be a volume force, acting simultaneously on the whole plates, and being the decoupling at the lithosphere base controlled by lateral variations in viscosity of the low-velocity layer.

  17. Vertical gating of sketched nanodevices

    Science.gov (United States)

    Pai, Yun-Yi; Park, Dong-Wook; Huang, Mengchen; Annadi, Anil; Lee, Hyungwoo; Ma, Zhenqiang; Eom, Chang-Beom; Irvin, Patrick; Levy, Jeremy

    Conductive-atomic force microscope (c-AFM) lithography at the LaAlO3/SrTiO3 interface has enabled the creation of various classes of nanostructures, such as nanoscale transistors, single-electron transistors and has proven to be a promising testbed for mesoscopic physics. To date, these devices have used lithographically-defined side gates, which are limited by leakage currents. To reduce leakage and improve the electric field effect, we have investigated nanostructures with in-situ grown gold top gate. We will discuss designs of logic devices such as inverters, NAND, and NOR gates. In the quantum regime, we compare the performance of in-situ vertical top gates and that of written coplanar side gates with Quantum Dot devices. We gratefully acknowledge financial support from the following agencies and grants: AFOSR (FA9550-­10-­1­-0524(JL), FA9550-­12-­1-­0342(CBE)), NSF (DMR­1124131 (JL, CBE) and DMR­1234096 (CBE)), ONR (N00014-15-1-2847 (JL)).

  18. Vertical two chamber reaction furnace

    Science.gov (United States)

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  19. Silicon Micromachined Vertical Structures for Nanoparticle Separation

    NARCIS (Netherlands)

    Shen, C.

    2011-01-01

    In this thesis we described a new approach to design, fabricate, package and test three silicon based porous vertical structures for nanoparticle separations. These vertical structures stand in between two microfluidic channels. In these walls nano channels that connect the two adjacent microchannel

  20. Triangle-intersecting families on eight vertices

    CERN Document Server

    Filmus, Yuval

    2011-01-01

    Simonovits and S\\'{o}s conjectured that the maximal size of a triangle-intersecting family of graphs on $n$ vertices is $2^{\\binom{n}{2}-3}$. Their conjecture has recently been proved using spectral methods. We provide an elementary proof of the special case of $8$ vertices using a partition argument.

  1. The green building envelope: vertical greening

    NARCIS (Netherlands)

    Ottelé, M.

    2011-01-01

    Planting on roofs and façades is one of the most innovative and fastest developing fields of green technologies with respect to the built environment and horticulture. This thesis is focused on vertical greening of structures and to the multi-scale benefits of vegetation. Vertical green can improve

  2. Vertical Integration, Monopoly, and the First Amendment.

    Science.gov (United States)

    Brennan, Timothy J.

    This paper addresses the relationship between the First Amendment, monopoly of transmission media, and vertical integration of transmission and content provision. A survey of some of the incentives a profit-maximizing transmission monopolist may have with respect to content is followed by a discussion of how vertical integration affects those…

  3. Teaching Students the Verticality of Technical Documentation.

    Science.gov (United States)

    Hager, Peter J.

    1992-01-01

    Advocates making technical writing courses more vertical in structure by including an extensive study of at least one specific form of technical documentation. Examines how students can gain experience in the vertical process by designing, writing, testing, and producing user manuals for on-campus cooperative education clients. Lists the benefits…

  4. [Vertical dimension in the Begg technic].

    Science.gov (United States)

    Demange, C; Dion, J G

    1989-01-01

    This data of 25 treated cases in BEGG technic show, with RICKETTS analysis, a small augmentation of vertical dimensions during treatment. During retention, four of five factors improved. No correlation have been found between increase rate of vertical dimensions, treatment duration, and initial typology.

  5. Vertical-Cavity Surface-Emitting Lasers

    Science.gov (United States)

    Wilmsen, Carl W.; Temkin, Henryk; Coldren, Larry A.

    2002-01-01

    1. Introduction to VCSELs L. A. Coldren, C. W. Wilmsen and H. Temkin; 2. Fundamental issues in VCSEL design L. A. Coldren and Eric R. Hegblom; 3. Enhancement of spontaneous emission in microcavities E. F. Schubert and N. E. J. Hunt; 4. Epitaxy of vertical-cavity lasers R. P. Schneider Jr and Y. H. Young; 5. Fabrication and performance of vertical-cavity surface-emitting lasers Kent D. Choquette and Kent Geib; 6. Polarization related properties of vertical cavity lasers Dmitri Kuksenkov and Henryk Temkin; 7. Visible light emitting vertical cavity lasers Robert L. Thornton; 8. Long-wavelength vertical-cavity lasers Dubrakovo I. Babic, Joachim Piprek and John E. Bowers; 9. Overview of VCSEL applications Richard C. Williamson; 10. Optical interconnection applications and required characteristics Kenichi Kasahara; 11. VCSEL-based fiber-optic data communications Kenneth Hahn and Kirk Giboney; 12. VCSEL-based smart pixels for free space optoelectronic processing C. W. Wilmsen.

  6. Vertical grid of retrieved atmospheric profiles

    Science.gov (United States)

    Ceccherini, Simone; Carli, Bruno; Raspollini, Piera

    2016-05-01

    The choice of the vertical grid of atmospheric profiles retrieved from remote sensing observations is discussed considering the two cases of profiles used to represent the results of individual measurements and of profiles used for subsequent data fusion applications. An ozone measurement of the MIPAS instrument is used to assess, for different vertical grids, the quality of the retrieved profiles in terms of profile values, retrieval errors, vertical resolutions and number of degrees of freedom. In the case of individual retrievals no evident advantage is obtained with the use of a grid finer than the one with a reduced number of grid points, which are optimized according to the information content of the observations. Nevertheless, this instrument dependent vertical grid, which seems to extract all the available information, provides very poor results when used for data fusion applications. A loss of about a quarter of the degrees of freedom is observed when the data fusion is made using the instrument dependent vertical grid relative to the data fusion made using a vertical grid optimized for the data fusion product. This result is explained by the analysis of the eigenvalues of the Fisher information matrix and leads to the conclusion that different vertical grids must be adopted when data fusion is the expected application.

  7. Surface tension profiles in vertical soap films

    Science.gov (United States)

    Adami, N.; Caps, H.

    2015-01-01

    Surface tension profiles in vertical soap films are experimentally investigated. Measurements are performed by introducing deformable elastic objets in the films. The shape adopted by those objects once set in the film is related to the surface tension value at a given vertical position by numerically solving the adapted elasticity equations. We show that the observed dependency of the surface tension versus the vertical position is predicted by simple modeling that takes into account the mechanical equilibrium of the films coupled to previous thickness measurements.

  8. VERTICAL VIBRATION ANALYSIS OF AXISYMMETRIC SATURATED SOIL

    Institute of Scientific and Technical Information of China (English)

    CAI Yuan-qiang; XU Chang-jie; ZHENG Zao-feng; WU Da-zhi

    2006-01-01

    Based on Biot's dynamic consolidation equations, by means of Laplace-Hankel transform technology, the integral solutions of stress and displacement in saturated soil with subjacent rock-stratum under axisymmetric arbitrary excitations were derived. Influence of the reflected wave generated by the boundary was revealed. Numerical results indicate that the vibration frequency has some effect on the vertical displacement of saturated soil. The vertical displacement at the surface of saturated soil lags in phase with the load. Furthermore, the dynamic permeability coefficient of saturated soil has significant effect on the vertical displacement at the initial stage of load applied, but when the load becomes stable, the effect is inapparent.

  9. HL-LHC vertical cryostat during construction

    CERN Multimedia

    Lanaro, Andrea

    2016-01-01

    7m high "Cluster D" vertical test cryostat during construction at contractor's premises, Alca Technology Srl, in Schio, Italy. The inner helium vessel with its heat exchanger are visible. To be installed in the D pit in SMA18.

  10. The solid angle through the vertical rectangle

    Science.gov (United States)

    Schröer, H.

    We want to determine the solid angle through the vertical rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux (radiant flux or radiant power) is shown.

  11. Relevance ranking for vertical search engines

    CERN Document Server

    Chang, Yi

    2014-01-01

    In plain, uncomplicated language, and using detailed examples to explain the key concepts, models, and algorithms in vertical search ranking, Relevance Ranking for Vertical Search Engines teaches readers how to manipulate ranking algorithms to achieve better results in real-world applications. This reference book for professionals covers concepts and theories from the fundamental to the advanced, such as relevance, query intention, location-based relevance ranking, and cross-property ranking. It covers the most recent developments in vertical search ranking applications, such as freshness-based relevance theory for new search applications, location-based relevance theory for local search applications, and cross-property ranking theory for applications involving multiple verticals. It introduces ranking algorithms and teaches readers how to manipulate ranking algorithms for the best results. It covers concepts and theories from the fundamental to the advanced. It discusses the state of the art: development of ...

  12. Fast Vertical Mining Using Boolean Algebra

    Directory of Open Access Journals (Sweden)

    Hosny M. Ibrahim

    2015-01-01

    Full Text Available The vertical association rules mining algorithm is an efficient mining method, which makes use of support sets of frequent itemsets to calculate the support of candidate itemsets. It overcomes the disadvantage of scanning database many times like Apriori algorithm. In vertical mining, frequent itemsets can be represented as a set of bit vectors in memory, which enables for fast computation. The sizes of bit vectors for itemsets are the main space expense of the algorithm that restricts its expansibility. Therefore, in this paper, a proposed algorithm that compresses the bit vectors of frequent itemsets will be presented. The new bit vector schema presented here depends on Boolean algebra rules to compute the intersection of two compressed bit vectors without making any costly decompression operation. The experimental results show that the proposed algorithm, Vertical Boolean Mining (VBM algorithm is better than both Apriori algorithm and the classical vertical association rule mining algorithm in the mining time and the memory usage.

  13. GLOBEC NEP Vertical Plankton Tow (VPT) Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GLOBEC (GLOBal Ocean ECosystems Dynamics) NEP (Northeast Pacific) California Current Program Vertical Plankton Tow (VPT) Data For more information, see...

  14. Capacity Planning for Vertical Search Engines

    OpenAIRE

    Badue, Claudine; Almeida, Jussara; Almeida, Virgilio; Baeza-Yates, Ricardo; Ribeiro-Neto, Berthier; Ziviani, Artur; Ziviani, Nivio

    2010-01-01

    Vertical search engines focus on specific slices of content, such as the Web of a single country or the document collection of a large corporation. Despite this, like general open web search engines, they are expensive to maintain, expensive to operate, and hard to design. Because of this, predicting the response time of a vertical search engine is usually done empirically through experimentation, requiring a costly setup. An alternative is to develop a model of the search engine for predicti...

  15. Radar hydrometeorology using a vertically pointing radar

    OpenAIRE

    Cluckie, I. D.; R. J. Griffith; Lane, A; Tilford, K. A.

    2002-01-01

    International audience A Vertically Pointing Radar (VPR) has been commissioned and deployed at a number of sites in southern England, to investigate numerically spatial and temporal variations in the vertical reflectivity profile (Zvp); particularly those associated with the intersection by the radar beam of a melting layer ? the bright band. Comparisons with data from other instrumentation, notably with the S-band research radar at Chilbolton, but also with disdrometer data and rainfall m...

  16. Radar hydrometeorology using a vertically pointing radar

    OpenAIRE

    Cluckie, I. D.; R. J. Griffith; Lane, A; Tilford, K. A.

    2000-01-01

    A Vertically Pointing Radar (VPR) has been commissioned and deployed at a number of sites in southern England, to investigate numerically spatial and temporal variations in the vertical reflectivity profile (Zvp); particularly those associated with the intersection by the radar beam of a melting layer – the bright band. Comparisons with data from other instrumentation, notably with the S-band research radar at Chilbolton, but also with disdrometer data and rainfall measurements from a number ...

  17. Reliability Analysis of Existing Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Sørensen, John Dalsgaard

    1998-01-01

    Vertical wall breakwaters are used under quite different conditions where failure of the breakwater or a part of it will have very different consequences. Further a number of existing vertical wall breakwaters have been subjected to significant wave loads which have caused partial failures of the...... of the structures. The main objective of this paper is to describe how the reliability of existing breakwater structures within the expected remaining lifetime can be estimated taking into account the available information....

  18. Attaining High Performance Communications A Vertical Approach

    CERN Document Server

    Gavrilovska, Ada

    2009-01-01

    Technological Advances and Problems of High Performance Communications. An ecosystem of solutions along a stack of technology layers. Cohesively collecting state-of-the-art contributions from leading researchers in industry, national laboratories, and academia, Attaining High Performance Communications: A Vertical Approach discusses various issues pertaining to high performance communications in a particular layer of a vertical stack. It explores efficient interconnection hardware, the architectural aspects of network adapters and their integration with processor cores, the design of scalable

  19. Electrically Pumped Vertical-Cavity Amplifiers

    DEFF Research Database (Denmark)

    Greibe, Tine

    2007-01-01

    In this work, the design of electrically pumped vertical cavity semiconductor optical amplifiers (eVCAs) for use in a mode-locked external-cavity laser has been developed, investigated and analysed. Four different eVCAs, one top-emitting and three bottom emitting structures, have been designed...... and discussed. The thesis concludes with recommendations for further work towards the realisation of compact electrically pumped mode-locked vertical externalcavity surface emitting lasers....

  20. VERTICAL INTEGRATION IN AGRICULTURE AND CONTRACT FARMING

    OpenAIRE

    Rehber, Erkan

    1998-01-01

    It has been widely argued recently that agriculture is undergoing a process of vertical integration with allied industries. One of the worldwide ways of vertical integration in agriculture is contract farming. Contract farming is a continually evolving process. Worldwide applications of contract farming have shown that the terms of contracts are shaped by their own conditions and varied from product to product. Also, each country has its own experiences. Contract farming has many advantages f...

  1. Vertical Josephson Interferometer for Tunable Flux Qubit

    International Nuclear Information System (INIS)

    We present a niobium-based Josephson device as prototype for quantum computation with flux qubits. The most interesting feature of this device is the use of a Josephson vertical interferometer to tune the flux qubit allowing the control of the off-diagonal Hamiltonian terms of the system. In the vertical interferometer, the Josephson current is precisely modulated from a maximum to zero with fine control by a small transversal magnetic field parallel to the rf superconducting loop plane

  2. Fast Vertical Mining Using Boolean Algebra

    OpenAIRE

    Hosny M. Ibrahim; Marghny, M. H.; Noha M. A. Abdelaziz

    2015-01-01

    The vertical association rules mining algorithm is an efficient mining method, which makes use of support sets of frequent itemsets to calculate the support of candidate itemsets. It overcomes the disadvantage of scanning database many times like Apriori algorithm. In vertical mining, frequent itemsets can be represented as a set of bit vectors in memory, which enables for fast computation. The sizes of bit vectors for itemsets are the main space expense of the algorithm that restricts its ex...

  3. Thermal Impacts of Vertical Greenery Systems

    Science.gov (United States)

    Safikhani, Tabassom; Abdullah, Aminatuzuhariah Megat; Ossen, Dilshan Remaz; Baharvand, Mohammad

    2014-12-01

    - Using vertical greenery systems to reduce heat transmission is becoming more common in modern architecture. Vertical greenery systems are divided into two main categories; green facades and living walls. This study aims to examine the thermal performance of vertical greenery systems in hot and humid climates. An experimental procedure was used to measure indoor temperature and humidity. These parameters were also measured for the gap between the vertical greenery systems and wall surfaces. Three boxes were used as small-scale rooms. Two boxes were provided with either a living wall or a green facade and one box did not have any greenery (benchmark). Blue Trumpet Vine was used in the vertical greenery systems. The data were recorded over the course of three sunny days in April 2013. An analyses of the results showed that the living wall and green facade reduced indoor temperature up to 4.0 °C and 3.0 °C, respectively. The living wall and green facade also reduced cavity temperatures by 8.0 °C and 6.5 °C, respectively.

  4. Thermal Impacts of Vertical Greenery Systems

    Directory of Open Access Journals (Sweden)

    Safikhani Tabassom

    2014-12-01

    Full Text Available - Using vertical greenery systems to reduce heat transmission is becoming more common in modern architecture. Vertical greenery systems are divided into two main categories; green facades and living walls. This study aims to examine the thermal performance of vertical greenery systems in hot and humid climates. An experimental procedure was used to measure indoor temperature and humidity. These parameters were also measured for the gap between the vertical greenery systems and wall surfaces. Three boxes were used as small-scale rooms. Two boxes were provided with either a living wall or a green facade and one box did not have any greenery (benchmark. Blue Trumpet Vine was used in the vertical greenery systems. The data were recorded over the course of three sunny days in April 2013. An analyses of the results showed that the living wall and green facade reduced indoor temperature up to 4.0 °C and 3.0 °C, respectively. The living wall and green facade also reduced cavity temperatures by 8.0 °C and 6.5 °C, respectively.

  5. Vertical integration in the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Vertical integration in the nuclear fuel cycle and its contribution to market power of integrated fuel suppliers were studied. The industry subdivision analyzed is the uranium raw materials sector. The hypotheses demonstrated are that (1) this sector of the industry is trending toward vertical integration between production of uranium raw materials and the manufacture of nuclear fuel elements, and (2) this vertical integration confers upon integrated firms a significant market advantage over non-integrated fuel manufacturers. Under microeconomic concepts the rationale for vertical integration is the pursuit of efficiency, and it is beneficial because it increases physical output and decreases price. The Market Advantage Model developed is an arithmetical statement of the relative market power (in terms of price) between non-integrated nuclear fuel manufacturers and integrated raw material/fuel suppliers, based on the concept of the ''squeeze.'' In operation, the model compares net profit and return on sales of nuclear fuel elements between the competitors, under different price and cost circumstances. The model shows that, if integrated and non-integrated competitors sell their final product at identical prices, the non-integrated manufacturer returns a net profit only 17% of the integrated firm. Also, the integrated supplier can price his product 35% below the non-integrated producer's price and still return the same net profit. Vertical integration confers a definite market advantage to the integrated supplier, and the basic source of that advantage is the cost-price differential of the raw material, uranium

  6. Climatology of tropospheric vertical velocity spectra

    Science.gov (United States)

    Ecklund, W. L.; Gage, K. S.; Balsley, B. B.; Carter, D. A.

    1986-01-01

    Vertical velocity power spectra obtained from Poker Flat, Alaska; Platteville, Colorado; Rhone Delta, France; and Ponape, East Caroline Islands using 50-MHz clear-air radars with vertical beams are given. The spectra were obtained by analyzing the quietest periods from the one-minute-resolution time series for each site. The lengths of available vertical records ranged from as long as 6 months at Poker Flat to about 1 month at Platteville. The quiet-time vertical velocity spectra are shown. Spectral period ranging from 2 minutes to 4 hours is shown on the abscissa and power spectral density is given on the ordinate. The Brunt-Vaisala (B-V) periods (determined from nearby sounding balloons) are indicated. All spectra (except the one from Platteville) exhibit a peak at periods slightly longer than the B-V period, are flat at longer periods, and fall rapidly at periods less than the B-V period. This behavior is expected for a spectrum of internal waves and is very similar to what is observed in the ocean (Eriksen, 1978). The spectral amplitudes vary by only a factor of 2 or 3 about the mean, and show that under quiet conditions vertical velocity spectra from the troposphere are very similar at widely different locations.

  7. Vertical Integration in the Taiwan Aquaculture Industry

    Directory of Open Access Journals (Sweden)

    Tzong-Ru Lee (Jiun-Shen

    2011-12-01

    Full Text Available The study aims to improve the distribution channels in the Taiwanaquaculture industry through a better vertical integration. This studyis derived from a need to improve the distribution performance ofagricultural-based industries in response to increasing food demandsin Asia and elsewhere. Based on a four-by-eight matrix derived fromboth a value chain and a service profit chain, thirty different strategiesare developed. This development is based on key success factors andstrategies for vertical integration interviewed and cited in the literatures.The findings are identified by applying the Gray Relational Analysis(GRA. For this study, the key success factors for aquaculture wholesalemarkets include the communication, integration and cohesion ofopinion within the wholesale market; government support; andmutualtrust between members of the vertical integration scheme. The suitablevertical integration strategies are an improved safety and hygiene inspectionof aquaculture products, accuracy of aquaculture product categorization,and precision in product weighing.

  8. Vertical vibration analysis for elevator compensating sheave

    International Nuclear Information System (INIS)

    Most elevators applied to tall buildings include compensating ropes to satisfy the balanced rope tension between the car and the counter weight. The compensating ropes receive tension by the compensating sheave, which is installed at the bottom space of the elevator shaft. The compensating sheave is only suspended by the compensating ropes, therefore, the sheave can move vertically while the car is traveling. This paper shows the elevator dynamic model to evaluate the vertical motion of the compensating sheave. Especially, behavior in emergency cases, such as brake activation and buffer strike, was investigated to evaluate the maximum upward motion of the sheave. The simulation results were validated by experiments and the most influenced factor for the sheave vertical motion was clarified

  9. Vertical gradients of sunspot magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Hagyard, M.J.; Teuber, D.; West, E.A.; Tandberg-Hanssen, E.; Henze, W. Jr.; Beckers, J.M.

    1983-04-01

    The results of a Solar Maximum Mission (SMM) guest investigation to determine the vertical gradients of sunspot magnetic fields for the first time from coordinated observations of photospheric and transition-region fields are described. Descriptions are given of both the photospheric vector field of a sunspot, derived from observations using the NASA Marshall Space Flight Center vector magnetograph, and of the line-of-sight component in the transition region, obtained from the SMM Ultraviolet Spectrometer and Polarimeter instrument. On the basis of these data, vertical gradients of the line-of-sight magnetic field component are calculated using three methods. It is found that the vertical gradient of Bz is lower than values from previous studies and that the transition-region field occurs at a height of approximately 4000-6000 km above the photosphere.

  10. Plasmonic Properties of Vertically Aligned Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    Hua Qi

    2012-01-01

    Full Text Available Nanowires (NWs/Ag sheath composites were produced to investigate plasmonic coupling between vertically aligned NWs for surface-enhanced Raman scattering (SERS applications. In this investigation, two types of vertical NW arrays were studied; those of ZnO NWs grown on nanosphere lithography patterned sapphire substrate via vapor-liquid-solid (VLS mechanism and Si NW arrays produced by wet chemical etching. Both types of vertical NW arrays were coated with a thin layer of silver by electroless silver plating for SERS enhancement studies. The experimental results show extremely strong SERS signals due to plasmonic coupling between the NWs, which was verified by COMSOL electric field simulations. We also compared the SERS enhancement intensity of aligned and random ZnO NWs, indicating that the aligned NWs show much stronger and repeatable SERS signal than those grown in nonaligned geometries.

  11. Capacity Planning for Vertical Search Engines

    CERN Document Server

    Badue, Claudine; Almeida, Virgilio; Baeza-Yates, Ricardo; Ribeiro-Neto, Berthier; Ziviani, Artur; Ziviani, Nivio

    2010-01-01

    Vertical search engines focus on specific slices of content, such as the Web of a single country or the document collection of a large corporation. Despite this, like general open web search engines, they are expensive to maintain, expensive to operate, and hard to design. Because of this, predicting the response time of a vertical search engine is usually done empirically through experimentation, requiring a costly setup. An alternative is to develop a model of the search engine for predicting performance. However, this alternative is of interest only if its predictions are accurate. In this paper we propose a methodology for analyzing the performance of vertical search engines. Applying the proposed methodology, we present a capacity planning model based on a queueing network for search engines with a scale typically suitable for the needs of large corporations. The model is simple and yet reasonably accurate and, in contrast to previous work, considers the imbalance in query service times among homogeneous...

  12. Purification process for vertically aligned carbon nanofibers

    Science.gov (United States)

    Nguyen, Cattien V.; Delziet, Lance; Matthews, Kristopher; Chen, Bin; Meyyappan, M.

    2003-01-01

    Individual, free-standing, vertically aligned multiwall carbon nanotubes or nanofibers are ideal for sensor and electrode applications. Our plasma-enhanced chemical vapor deposition techniques for producing free-standing and vertically aligned carbon nanofibers use catalyst particles at the tip of the fiber. Here we present a simple purification process for the removal of iron catalyst particles at the tip of vertically aligned carbon nanofibers derived by plasma-enhanced chemical vapor deposition. The first step involves thermal oxidation in air, at temperatures of 200-400 degrees C, resulting in the physical swelling of the iron particles from the formation of iron oxide. Subsequently, the complete removal of the iron oxide particles is achieved with diluted acid (12% HCl). The purification process appears to be very efficient at removing all of the iron catalyst particles. Electron microscopy images and Raman spectroscopy data indicate that the purification process does not damage the graphitic structure of the nanotubes.

  13. Turbulence in vertical axis wind turbine canopies

    Science.gov (United States)

    Kinzel, Matthias; Araya, Daniel B.; Dabiri, John O.

    2015-11-01

    Experimental results from three different full scale arrays of vertical-axis wind turbines (VAWTs) under natural wind conditions are presented. The wind velocities throughout the turbine arrays are measured using a portable meteorological tower with seven, vertically staggered, three-component ultrasonic anemometers. The power output of each turbine is recorded simultaneously. The comparison between the horizontal and vertical energy transport for the different turbine array sizes shows the importance of vertical transport for large array configurations. Quadrant-hole analysis is employed to gain a better understanding of the vertical energy transport at the top of the VAWT arrays. The results show a striking similarity between the flows in the VAWT arrays and the adjustment region of canopies. Namely, an increase in ejections and sweeps and decrease in inward and outward interactions occur inside the turbine array. Ejections are the strongest contributor, which is in agreement with the literature on evolving and sparse canopy flows. The influence of the turbine array size on the power output of the downstream turbines is examined by comparing a streamwise row of four single turbines with square arrays of nine turbine pairs. The results suggest that a new boundary layer forms on top of the larger turbine arrays as the flow adjusts to the new roughness length. This increases the turbulent energy transport over the whole planform area of the turbine array. By contrast, for the four single turbines, the vertical energy transport due to turbulent fluctuations is only increased in the near wake of the turbines. These findings add to the knowledge of energy transport in turbine arrays and therefore the optimization of the turbine spacing in wind farms.

  14. CIRSS vertical data integration, San Bernardino study

    Science.gov (United States)

    Hodson, W.; Christenson, J.; Michel, R. (Principal Investigator)

    1982-01-01

    The creation and use of a vertically integrated data base, including LANDSAT data, for local planning purposes in a portion of San Bernardino County, California are described. The project illustrates that a vertically integrated approach can benefit local users, can be used to identify and rectify discrepancies in various data sources, and that the LANDSAT component can be effectively used to identify change, perform initial capability/suitability modeling, update existing data, and refine existing data in a geographic information system. Local analyses were developed which produced data of value to planners in the San Bernardino County Planning Department and the San Bernardino National Forest staff.

  15. Geophysical aspects of vertical streamer seismic data

    Energy Technology Data Exchange (ETDEWEB)

    Sognnes, Walter

    1998-12-31

    Vertical cable acquisition is performed by deploying a certain number of vertical hydrophone arrays in the water column, and subsequently shooting a source point on top of it. The advantage of this particular geometry is that gives a data set with all azimuths included. Therefore a more complete 3-D velocity model can be derived. In this paper there are presented some results from the Fuji survey in the Gulf of Mexico. Based on these results, improved geometries and review recommendations for future surveys are discussed. 7 figs.

  16. Thermal Stratification in Vertical Mantle Tanks

    DEFF Research Database (Denmark)

    Knudsen, Søren; Furbo, Simon

    2001-01-01

    It is well known that it is important to have a high degree of thermal stratification in the hot water storage tank to achieve a high thermal performance of SDHW systems. This study is concentrated on thermal stratification in vertical mantle tanks. Experiments based on typical operation conditions...... are carried out to investigate how the thermal stratification is affected by different placements of the mantle inlet. The heat transfer between the solar collector fluid in the mantle and the domestic water in the inner tank is analysed by CFD-simulations. Furthermore, the flow pattern in the vertical mantle...... tank is investigated....

  17. On the measurement of vertical velocity by MST radar

    Science.gov (United States)

    Gage, K. S.

    1983-01-01

    An overview is presented of the measurement of atmospheric vertical motion utilizing the MST radar technique. Vertical motion in the atmosphere is briefly discussed as a function of scale. Vertical velocity measurement by MST radars is then considered from within the context of the expected magnitudes to be observed. Examples are drawn from published vertical velocity observations.

  18. Vertical Integration and Economic Growth: An Empirical Study

    OpenAIRE

    A. Knobel

    2009-01-01

    The paper is devoted to an empirical study of determinants of vertical integration and their influence on economic growth. We verified the following hypotheses: higher quality of institutions reduces probability of vertical integration; productivity levels of participants in vertical integration influence on its probability in different ways; higher import quota of an economy helps reducing the degree of vertical integration; the degree of vertical integration in an economy influence on econo...

  19. Optical anisotropy in vertically coupled quantum dots

    DEFF Research Database (Denmark)

    Yu, Ping; Langbein, Wolfgang Werner; Leosson, Kristjan;

    1999-01-01

    We have studied the polarization of surface and edge-emitted photoluminescence (PL) from structures with vertically coupled In0.5Ga0.5As/GaAs quantum dots (QD's) grown by molecular beam epitaxy. The PL polarization is found to be strongly dependent on the number of stacked layers. While single...

  20. Vertical reflector for bifacial PV-panels

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff;

    2016-01-01

    Bifacial solar modules offer an interesting price/performance ratio, and much work has been focused on directing the ground albedo to the back of the solar cells. In this work we design and develop a reflector for a vertical bifacial panel, with the objective to optimize the energy harvest...

  1. Electrostatic comb drive for vertical actuation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A. P., LLNL

    1997-07-10

    The electrostatic comb finger drive has become an integral design for microsensor and microactuator applications. This paper reports on utilizing the levitation effect of comb fingers to design vertical-to-the-substrate actuation for interferometric applications. For typical polysilicon comb drives with 2 {micro}m gaps between the stationary and moving fingers, as well as between the microstructures and the substrate, the equilibrium position is nominally 1-2 {micro}m above the stationary comb fingers. This distance is ideal for many phase shifting interferometric applications. Theoretical calculations of the vertical actuation characteristics are compared with the experimental results, and a general design guideline is derived from these results. The suspension flexure stiffnesses, gravity forces, squeeze film damping, and comb finger thicknesses are parameters investigated which affect the displacement curve of the vertical microactuator. By designing a parallel plate capacitor between the suspended mass and the substrate, in situ position sensing can be used to control the vertical movement, providing a total feedback-controlled system. Fundamentals of various capacitive position sensing techniques are discussed. Experimental verification is carried out by a Zygo distance measurement interferometer.

  2. Manufacturing: the new case for vertical integration

    NARCIS (Netherlands)

    Kumpe, Ted; Bolwijn, Piet T.

    1988-01-01

    The article argues that the solid corporation will continue to view vertical integration as a critical part of manufacturing reform. Manufacturing reform and backward integration are related in insidious ways to the three stages of production over which the big manufacturers preside. Without integra

  3. BREAKING WAVE FORCES ON VERTICAL CYLINDERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The breaking wave forces on vertical cylinders in shallow waters were studied by means of experimental methods. The results indicate that the breaking wave pressure is distributed exponentially with respect to water depth. An experimental formula was given using the test data. Compared with test data, the calculated breaking wave forces are in good agreement with the test data.

  4. Modeling vertical coral connectivity and mesophotic refugia

    Science.gov (United States)

    Holstein, Daniel M.; Paris, Claire B.; Vaz, Ana C.; Smith, Tyler B.

    2016-03-01

    Whether mesophotic reefs will behave as refugia for corals threatened by global climate change and coastal development depends on vertical exchange of larvae between diverse habitats. Here we use a biophysical model of larval dispersal to estimate vertical connectivity of a broadcasting ( Orbicella faveolata) and a brooding ( Porites astreoides) species of coral in the US Virgin Islands. Modeling predicts subsidy to shallow areas by mesophotic larvae of both species based on local hydrology, adult reproductive characteristics, larval traits, and a wide range of scenarios developed to test depth-sensitive factors, such as fertilization rates and post-settlement survivorship. In extreme model scenarios of reduced fertilization and post-settlement survivorship of mesophotic larvae, 1-10 % local mesophotic subsidy to shallow recruitment is predicted for both species, which are demographically significant. Although direct vertical connectivity is higher for the broadcaster, the brooder demonstrates higher local multigenerational vertical connectivity, which suggests that local P. astreoides populations are more resilient than those of O. faveolata, and corroborates field studies. As shallow habitat degrades, mesophotic-shallow subsidy is predicted to increase for both species. This study is the first of its kind to simulate larval dispersal and settlement between habitats of different depths, and these findings have local, regional, and global implications for predicting and managing coral reef persistence in a changing climate.

  5. Certified standards and vertical coordination in aquaculture

    DEFF Research Database (Denmark)

    Trifkovic, Neda

    2014-01-01

    This paper explores the interaction between food standards and vertical coordination in the Vietnamese pangasius sector. For farmers and processors alike, the adoption of standards is motivated by a desire to improve market access by ensuring high quality supply. Instead of encouraging the applic...

  6. Safety Aspects for Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, H. F.; Christiani, E.

    1996-01-01

    In this appendix some safety aspects in relation to vertical wall breakwaters are discussed. Breakwater structures such as vertical wall breakwaters are used under quite different conditions. The expected lifetime can be from 5 years (interim structure) to 100 years (permanent structure) and the ......In this appendix some safety aspects in relation to vertical wall breakwaters are discussed. Breakwater structures such as vertical wall breakwaters are used under quite different conditions. The expected lifetime can be from 5 years (interim structure) to 100 years (permanent structure......) and the accepted level of probability of failure in the expected lifetime can vary from a very small number, e.g. 10-4 if failure of the breakwater results in significant damage to large probabilities, e.g. 0.5 if the consequences are insignificant. This has to be taken into account when discussing safety aspects...... and possible level I and D code formats. In the following first the most important failure modes are briefly described, see section 2. It is assumed that the failure modes can be modelled by limit state functions. Wave load models are described in section 3. In section 5 uncertainties related to the parameters...

  7. Dynamic Voluntary Advertising and Vertical Product Quality

    OpenAIRE

    Tenryu, Yohei; Kamei, Keita

    2012-01-01

    We investigate the dynamic relationship between advertising and product quality under duopolistic competition. By using a simplified vertical product differentiation model with voluntary advertising, we show that the firm with larger market share has a larger advertising share and that there is a positive relationship between the difference in product quality and the number of customers in an industry.

  8. Vertically aligned biaxially textured molybdenum thin films

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Rahul [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Riley, Michael [Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lee, Sabrina [US Army Armament Research, Development and Engineering Center, Benet Labs, Watervliet, New York 12189 (United States); Lu, Toh-Ming [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2011-09-15

    Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85 degrees with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85 degrees without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

  9. On the vertical structure of wind gusts

    DEFF Research Database (Denmark)

    Suomi, I.; Gryning, Sven-Erik; Floors, Rogier Ralph;

    2015-01-01

    The increasing size of wind turbines, their height and the area swept by their blades have revised the need for understanding the vertical structure of wind gusts. Information is needed for the whole profile. In this study, we analyzed turbulence measurements from a 100m high meteorological mast...

  10. Oblique patterned etching of vertical silicon sidewalls

    Science.gov (United States)

    Bruce Burckel, D.; Finnegan, Patrick S.; David Henry, M.; Resnick, Paul J.; Jarecki, Robert L.

    2016-04-01

    A method for patterning on vertical silicon surfaces in high aspect ratio silicon topography is presented. A Faraday cage is used to direct energetic reactive ions obliquely through a patterned suspended membrane positioned over the topography. The technique is capable of forming high-fidelity pattern (100 nm) features, adding an additional fabrication capability to standard top-down fabrication approaches.

  11. Vertical distribution of natural radionuclides in soils

    Directory of Open Access Journals (Sweden)

    Lozano J. C.

    2012-04-01

    Full Text Available Low-level alpha spectrometry techniques using semiconductor detectors (PIPS and liquid scintillation counters (LKB Quantulus 1220™ were used in order to determine the activity concentration of 238U, 232Th, 234U, 230Th, 226Ra, and 210Pb in soil samples. The soils were collected from an old disused uranium mine located in southwest Spain. The soils were selected with different levels of influence from the installation, in such a way that they had different levels of radioactive contamination. The vertical profiles in the soils (down to 40 cm depth were studied in order to evaluate the vertical distribution of the natural radionuclides. The possible contamination of subsurface waters depends strongly on vertical migration, and the transfer to plants (herbs, shrubs, and trees also will depend on the distribution of the radionuclides in the root zone. The study of the activity ratios between radionuclides belonging to the same series allowed us to assess the differing behaviour of the radionuclides involved. The vertical profiles for these radionuclides were different at each sampling point, showing the local impact of the installation. However, the profiles per point were similar for the long-lived radionuclides of the 238TJ series (238U, 234U, 230Th, and 226Ra. Also, a major disequilibrium was observed between 210Pb and 226Ra in the surface layer, due to 222Rn emanation and subsequent surface deposition of 210Pb.

  12. Vertical Integration Spurs American Health Care Revolution.

    Science.gov (United States)

    Phillips, Richard C.

    1986-01-01

    Under new "managed health care systems," the classical functional separation of risk taker, claims payor, and provider are vertically integrated into a common entity. This evolution should produce a competitive environment with medical care rendered to all Americans on a more cost-effective basis. (CJH)

  13. A note on partial vertical integration

    NARCIS (Netherlands)

    G.W.J. Hendrikse (George); H.J.M. Peters (Hans)

    1989-01-01

    textabstractA simple model is constructed to show how partial vertical integration may emerge as an equilibrium market structure in a world characterized by rationing, differences in the reservation prices of buyers, and in the risk attitudes of buyers and sellers. The buyers with the high reservati

  14. Vertical Integration: Teachers' Knowledge and Teachers' Voice.

    Science.gov (United States)

    Corrie, L.

    1995-01-01

    Traces the theoretical basis for vertical integration in early school years. Contrasts transmission-based pedagogy with a higher level of teacher control, and acquirer-based pedagogy with a higher level of student control. Suggests that early childhood pedagogy will be maintained when teachers are able to articulate their pedagogical knowledge and…

  15. Vertical root fractures and their management

    Science.gov (United States)

    Khasnis, Sandhya Anand; Kidiyoor, Krishnamurthy Haridas; Patil, Anand Basavaraj; Kenganal, Smita Basavaraj

    2014-01-01

    Vertical root fractures associated with endodontically treated teeth and less commonly in vital teeth represent one of the most difficult clinical problems to diagnose and treat. In as much as there are no specific symptoms, diagnosis can be difficult. Clinical detection of this condition by endodontists is becoming more frequent, where as it is rather underestimated by the general practitioners. Since, vertical root fractures almost exclusively involve endodontically treated teeth; it often becomes difficult to differentiate a tooth with this condition from an endodontically failed one or one with concomitant periodontal involvement. Also, a tooth diagnosed for vertical root fracture is usually extracted, though attempts to reunite fractured root have been done in various studies with varying success rates. Early detection of a fractured root and extraction of the tooth maintain the integrity of alveolar bone for placement of an implant. Cone beam computed tomography has been shown to be very accurate in this regard. This article focuses on the diagnostic and treatment strategies, and discusses about predisposing factors which can be useful in the prevention of vertical root fractures. PMID:24778502

  16. Vertical eddy heat fluxes from model simulations

    Science.gov (United States)

    Stone, Peter H.; Yao, Mao-Sung

    1991-01-01

    Vertical eddy fluxes of heat are calculated from simulations with a variety of climate models, ranging from three-dimensional GCMs to a one-dimensional radiative-convective model. The models' total eddy flux in the lower troposphere is found to agree well with Hantel's analysis from observations, but in the mid and upper troposphere the models' values are systematically 30 percent to 50 percent smaller than Hantel's. The models nevertheless give very good results for the global temperature profile, and the reason for the discrepancy is unclear. The model results show that the manner in which the vertical eddy flux is carried is very sensitive to the parameterization of moist convection. When a moist adiabatic adjustment scheme with a critical value for the relative humidity of 100 percent is used, the vertical transports by large-scale eddies and small-scale convection on a global basis are equal: but when a penetrative convection scheme is used, the large-scale flux on a global basis is only about one-fifth to one-fourth the small-scale flux. Comparison of the model results with observations indicates that the results with the latter scheme are more realistic. However, even in this case, in mid and high latitudes the large and small-scale vertical eddy fluxes of heat are comparable in magnitude above the planetary boundary layer.

  17. Vertical strategic alignment and public service performance

    NARCIS (Netherlands)

    Andrews, R.; Boyne, G.A.; Meier, K.J.; O'Toole, L.J.; Walker, R.M.

    2012-01-01

    We report the results of a study examining the effects of vertical strategic alignment (that is, the degree to which strategic stances are consistent across different organizational levels) on public service performance. Longitudinal multivariate analysis is undertaken on a panel of public organizat

  18. Vertical field and equilibrium calculation in ETE

    International Nuclear Information System (INIS)

    The free-boundary MHD equilibrium code HEQ is used to study the plasma behaviour in the tokamak ETE, with optimized compensations coils and vertical field coils. The changes on the equilibrium parameters for different plasma current values are also investigated. (author). 5 refs., 4 figs., 2 tabs

  19. Vertical interconnection of SOI photonic integrated circuits

    NARCIS (Netherlands)

    Hagen, R.; Pozo Torres, J.M.; Kazmierczak, A.; Westerveld, W.J.; Harmsma, P.J.; Berg, J.H. van den; Schmits, R.; Yousefi, M.; Cabezon, M.; Villafranca, A.; Izquierdo, D.; Garces, J.I.

    2011-01-01

    One of the important issues of System-on-a-package integration is the interconnection between independent Photonic Integrated Circuits (PICs). In this work, this issue is addressed by the use of Vertical Grating Couplers (VGCs) as the element for the interconnection between two Silicon-on-Insulator

  20. Experiments and modelling on vertical flame spread

    Energy Technology Data Exchange (ETDEWEB)

    Keski-Rahkonen, O.; Mangs, J. [VTT Building and Transport, Espoo (Finland)

    2004-07-01

    he principle and some preliminary results are shown of a new vertical flame spread modelling effort. Quick experimental screenings on relevant phenomena are made, some models are evaluated, and a new set of needed measuring instruments is proposed. Finally a single example of FRNC cable is shown as application of the methods. (orig.)

  1. Vertical integration of HRD policy within companies

    NARCIS (Netherlands)

    Wognum, A.A.M.

    2001-01-01

    This study concerns HRD policy making in companies. More specifically, it explores whether so-called vertical integration of HRD policy at different organizational levels occurs within companies. The study involved forty-four large companies in the industrial and the financial and commercial service

  2. Project Plan for Vertical Lift Machine

    Energy Technology Data Exchange (ETDEWEB)

    Ellsworth, G F

    2002-08-05

    This document describes the Project Plan for the development and manufacture of a Vertical Lift Machine. It is assumed by this project plan that the Vertical Lift Machine will be developed, designed, manufactured, and tested by a qualified vendor. LLNL will retain review and approval authority for each step given in this project plan. The Vertical Lift Machine is a single linear axis positioning device capable of lifting objects vertically at controlled rates and positioning them repeatedly at predetermined heights, in relation to other objects suspended from above, for high neutron multiplication experiments. Operation of the machine during the experiments is done remotely. The lift mechanism shall accommodate various platforms (tables) that support the objects to be raised. A frame will support additional subassemblies from above such that the lower subassembly can be raised close to and/or interface with those above. The structure must be stiff and motion of the table linear such that radial alignment is maintained (e.g. concentricity). The safe position for the Vertical Lift Machine is the lift mechanism fully retracted with the subassemblies fully separated. The machine shall reside in this position when not in use. It must return to this safe condition from any position upon failure of power sources, open safety interlocks, or operator initiated SCRAM. The Vertical Lift Machine shall have the capability of return to the safe position with no externally applied power. The Vertical Lift Machine shall have dual operator interfaces, one near the machine and another located in a remote control room. Conventional single key, key-lock switching shall be implemented to lock out the control interface not in use. The interface at the machine will be used for testing and ''dry running'' experimental setup(s) with inert subassemblies (i.e. Setup Mode). The remote interface shall provide full control and data recording capability (i.e. Assembly Mode

  3. SIMBA - A global fit approach to vertical stroke Vub vertical stroke

    International Nuclear Information System (INIS)

    The parton distribution function for a b quark in the B-meson (called the shape function) plays an important role in the analysis of the B→Xsγ and B→Xul anti ν data, and gives raise to one of the dominant uncertainties in the determination of vertical stroke Vub vertical stroke. We implement a new model independent framework to treat the shape function with reliable theoretical uncertainties based on an expansion in a suitable complete set of orthonormal basis functions. This is a significant improvement over fits to model functions. We present the current status of combined fits to BaBar and Belle data and extract vertical stroke Vub vertical stroke.

  4. Effect of gravity on vertical eye position.

    Science.gov (United States)

    Pierrot-Deseilligny, C

    2009-05-01

    There is growing evidence that gravity markedly influences vertical eye position and movements. A new model for the organization of brainstem upgaze pathways is presented in this review. The crossing ventral tegmental tract (CVTT) could be the efferent tract of an "antigravitational" pathway terminating at the elevator muscle motoneurons in the third nerve nuclei and comprising, upstream, the superior vestibular nucleus and y-group, the flocculus, and the otoliths. This pathway functions in parallel to the medial longitudinal fasciculus pathways, which control vertical eye movements made to compensate for all vertical head movements and may also comprise the "gravitational" vestibular pathways, involved in the central reflection of the gravity effect. The CVTT could provide the upgaze system with the supplement of tonic activity required to counteract the gravity effect expressed in the gravitational pathway, being permanently modulated according to the static positions of the head (i.e., the instantaneous gravity vector) between a maximal activity in the upright position and a minimal activity in horizontal positions. Different types of arguments support this new model. The permanent influence of gravity on vertical eye position is strongly suggested by the vertical slow phases and nystagmus observed after rapid changes in hypo- or hypergravity. The chin-beating nystagmus, existing in normal subjects with their head in the upside-down position, suggests that gravity is not compensated for in the downgaze system. Upbeat nystagmus due to brainstem lesions, most likely affecting the CVTT circuitry, is improved when the head is in the horizontal position, suggesting that this circuitry is involved in the counteraction of gravity between the upright and horizontal positions of the head. In downbeat nystagmus due to floccular damage, in which a permanent hyperexcitation of the CVTT could exist, a marked influence of static positions of the head is also observed. Finally

  5. The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates

    OpenAIRE

    Fraser, Lindsey E.; Bobbak Makooie; Harris, Laurence R.

    2015-01-01

    The subjective visual vertical (SVV) and the subjective haptic vertical (SHV) both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert) and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning "opposite", i.e., opposite to the A-ef...

  6. Escrita Escolar Brasileira: a escrita vertical

    Directory of Open Access Journals (Sweden)

    Carlos André Xavier Villela

    2014-12-01

    Full Text Available O exame grafoscópico visa essencialmente a determinar se duas escritas partiram ou não de um mesmo punho. A fim de buscar dados empíricos capazes de melhor embasar uma valoração de raridade, diversos pesquisadores se dedicaram ao estudo dos sistemas de escrita. O presente trabalho analisa algumas bibliografias nacionais e estrangeiras que descrevem como se deu o alvorecer da escrita vertical e sua implantação no universo escolar brasileiro. Foi a partir das últimas décadas do século XIX que alógrafos cursivos verticais começaram a ser utilizados para o ensino da escrita. Os novos sistemas, sob a denominação escrita vertical, tiveram presença marcante em todo o mundo ocidental, sendo até hoje os sistemas predominantes em diversos países.

  7. Vertically Integrated Multiple Nanowire Field Effect Transistor.

    Science.gov (United States)

    Lee, Byung-Hyun; Kang, Min-Ho; Ahn, Dae-Chul; Park, Jun-Young; Bang, Tewook; Jeon, Seung-Bae; Hur, Jae; Lee, Dongil; Choi, Yang-Kyu

    2015-12-01

    A vertically integrated multiple channel-based field-effect transistor (FET) with the highest number of nanowires reported ever is demonstrated on a bulk silicon substrate without use of wet etching. The driving current is increased by 5-fold due to the inherent vertically stacked five-level nanowires, thus showing good feasibility of three-dimensional integration-based high performance transistor. The developed fabrication process, which is simple and reproducible, is used to create multiple stiction-free and uniformly sized nanowires with the aid of the one-route all-dry etching process (ORADEP). Furthermore, the proposed FET is revamped to create nonvolatile memory with the adoption of a charge trapping layer for enhanced practicality. Thus, this research suggests an ultimate design for the end-of-the-roadmap devices to overcome the limits of scaling. PMID:26544156

  8. Wave Forces Acting on Vertical Walls

    Institute of Scientific and Technical Information of China (English)

    LI Ben-xia; YU Yu-xiu; YU Xi-ping

    2008-01-01

    Regular and irregular wave forces acting on vertical walls are studied by a previously developed numerical model. The computed wave forces are compared with the available experimental data to verify the numerical model, and satisfactory agreements are obtained. The variation of wave forces with incident angles and the shape of simultaneous pressure distribution are investigated, and the comparisons between numerical results and Goda's predictions are also carried out. It is concluded that the maximum wave forces acting on the unit length of vertical wall is often induced by the obliquely incident waves instead of normally incident waves, while Goda's formula may be inapplicable for oblique wave incidence. The shape of simultaneous pressure distribution is not significantly influenced by incident angles, and it can be favorably predicted by Goda's formula. When regular wave heights are taken as the same as irregular wave height H1%, the irregular wave forces Ph,1% are slightly larger than regular wave forces in most cases.

  9. Vertical external cavity surface emitting semiconductor lasers

    CERN Document Server

    Holm, M

    2001-01-01

    Active stabilisation showed a relative locked linewidth of approx 3 kHz. Coarse tuning over 7 nm was achieved using a 3-plate birefingent filter plate while fine-tuning using cavity length change allowed tuning over 250 MHz. Vertical external cavity semiconductor lasers have emerged as an interesting technology based on current vertical cavity semiconductor laser knowledge. High power output into a single transverse mode has attracted companies requiring good fibre coupling for telecommunications systems. The structure comprises of a grown semiconductor Bragg reflector topped with a multiple quantum well gain region. This is then included in an external cavity. This device is then optically pumped to promote laser action. Theoretical modelling of AIGaAs based VECSEL structures was undertaken, showing the effect of device design on laser characteristics. A simple 3-mirror cavity was constructed to assess the static characteristics of the structure. Up to 153 mW of output power was achieved in a single transver...

  10. New Urban Vertical Axis Wind Turbine Design

    Directory of Open Access Journals (Sweden)

    Alexandru-Mihai CISMILIANU

    2015-12-01

    Full Text Available This paper develops a different approach for enhancing the performance of Vertical Axis Wind Turbines for the use in the urban or rural environment and remote isolated residential areas. Recently the vertical axis wind turbines (VAWT have become more attractive due to the major advantages of this type of turbines in comparison to the horizontal axis wind turbines. We aim to enhance the overall performance of the VAWT by adding a second set of blades (3 x 2=6 blades following the rules of biplane airplanes. The model has been made to operate at a maximum power in the range of the TSR between 2 to 2.5. The performances of the VAWT were investigated numerically and experimentally and justify the new proposed design.

  11. Lunar vertical-shaft mining system

    Science.gov (United States)

    Introne, Steven D. (Editor); Krause, Roy; Williams, Erik; Baskette, Keith; Martich, Frederick; Weaver, Brad; Meve, Jeff; Alexander, Kyle; Dailey, Ron; White, Matt

    1994-01-01

    This report proposes a method that will allow lunar vertical-shaft mining. Lunar mining allows the exploitation of mineral resources imbedded within the surface. The proposed lunar vertical-shaft mining system is comprised of five subsystems: structure, materials handling, drilling, mining, and planning. The structure provides support for the exploration and mining equipment in the lunar environment. The materials handling subsystem moves mined material outside the structure and mining and drilling equipment inside the structure. The drilling process bores into the surface for the purpose of collecting soil samples, inserting transducer probes, or locating ore deposits. Once the ore deposits are discovered and pinpointed, mining operations bring the ore to the surface. The final subsystem is planning, which involves the construction of the mining structure.

  12. Film cooling of vertical fuel rods

    International Nuclear Information System (INIS)

    Spray cooling of vertical rods has been studied at low heat fluxes appropriate to the removal of fission product heating following a reactor shut down. A series of tests have been made at atmospheric pressure using electrically heated rods, both singly and in a seven rod cluster, cooled by a falling film of water. Four modes of film breakdown were observed; progressive evaporation of the film; dry-patch formation due to surface tension effects at high inlet subcooling; stripping of the film by the flooding action of counterflow steam; and the disruption of the film on a hot rod caused by sputtering. Each of these phenomena is described in relation to the application of film cooling to long vertical fuel rod clusters. (author)

  13. Vertical integration by oil exporting countries

    OpenAIRE

    Siebert, Horst; Rauscher, Michael

    1985-01-01

    Most oil-producing countries have now nationalised their oil reserves and are pursuing their own pricing and marketing policies; in recent years some of them have attempted to extend their influence over the oil market by undertaking processing activities downstream from oil production. What motives underlie this strategy of vertical integration? What is its economic justification? What effects will it have on oil-importing countries?

  14. Location in a Vertically Differentiated Industry

    OpenAIRE

    Bacchiega, Emanuele; Minniti, Antonio

    2005-01-01

    We analyze a two-stage game in a vertically differentiated duopoly with two regions which can differ for the willingness to pay of their consumers or for the market size; firms sequentially choose to settle in one region and then simultaneously compete in prices, selling their products both on the local market and on the foreigner one by exporting them at a fixed cost. We study how strategic interaction influences firms’ location choices and we show that the decision whether...

  15. Vertical Differentiation with Variety-Seeking Consumers

    OpenAIRE

    Robert Zeithammer; Raphael Thomadsen

    2013-01-01

    We analyze price and quality competition in a vertically differentiated duopoly in which consumers have a preference for variety. The preference for variety is a consequence of diminishing marginal utility for repeated experiences with the same product. We find consumer variety seeking can either soften or intensify price competition, depending on the difference in firm qualities and the strength of consumer preference for variety. When the qualities are similar (or the consumer preference fo...

  16. Vertical teaching principles: pregnancy induced hypertension

    Directory of Open Access Journals (Sweden)

    Nidhi Sharma

    2016-06-01

    Conclusions: Vertical integration of medical disciplines helps medical students to understand a clinical problem in the light of basic sciences. The modules beginning with the pathophysiology of pregnancy induced hypertension and concluded with anesthetic considerations. An elaborate module helps to translate an understanding of pharmaco therapeutics of hypertension in pregnancy. A well-trained medical student can help to reduce maternal mortality due to preeclampsia. [Int J Reprod Contracept Obstet Gynecol 2016; 5(6.000: 1739-1743

  17. Product innovation in a vertically differentiated model

    OpenAIRE

    L. Filippini; C. Vergari

    2012-01-01

    We study the licensing incentives of an independent input producer owning a patented product innovation which allows the downstream firms to improve the quality of their final goods. We consider a general two-part tariff contract for both outside and incumbent innovators. We find that technology diffusion critically depends on the nature of market competition (Cournot vs. Bertrand). Moreover, the vertical merger with either downstream firm is always privately profitable and it is welfare impr...

  18. Radially Magnetized Protoplanetary Disk: Vertical Profile

    Science.gov (United States)

    Russo, Matthew; Thompson, Christopher

    2015-11-01

    This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, wound up by the disk shear, and pushed downward by a combination of turbulent mixing and ambipolar and ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field Br ˜ (10-4-10-2)(r/ AU)-2 G. Careful attention is given to the radial and vertical ionization structure resulting from irradiation by stellar X-rays. The disk is more strongly magnetized closer to the star, where it can support a higher rate of mass transfer. As a result, the inner ˜1 AU of a PPD is found to evolve toward lower surface density. Mass transfer rates around 10-8 M⊙ yr-1 are obtained under conservative assumptions about the MRI-generated stress. The evolution of the disk and the implications for planet migration are investigated in the accompanying paper.

  19. Vertical Carbon Nanotube Device in Nanoporous Templates

    Science.gov (United States)

    Maschmann, Matthew Ralph (Inventor); Fisher, Timothy Scott (Inventor); Sands, Timothy (Inventor); Bashir, Rashid (Inventor)

    2014-01-01

    A modified porous anodic alumina template (PAA) containing a thin CNT catalyst layer directly embedded into the pore walls. CNT synthesis using the template selectively catalyzes SWNTs and DWNTs from the embedded catalyst layer to the top PAA surface, creating a vertical CNT channel within the pores. Subsequent processing allows for easy contact metallization and adaptable functionalization of the CNTs and template for a myriad of applications.

  20. Understanding Vertical Jump Potentiation: A Deterministic Model.

    Science.gov (United States)

    Suchomel, Timothy J; Lamont, Hugh S; Moir, Gavin L

    2016-06-01

    This review article discusses previous postactivation potentiation (PAP) literature and provides a deterministic model for vertical jump (i.e., squat jump, countermovement jump, and drop/depth jump) potentiation. There are a number of factors that must be considered when designing an effective strength-power potentiation complex (SPPC) focused on vertical jump potentiation. Sport scientists and practitioners must consider the characteristics of the subject being tested and the design of the SPPC itself. Subject characteristics that must be considered when designing an SPPC focused on vertical jump potentiation include the individual's relative strength, sex, muscle characteristics, neuromuscular characteristics, current fatigue state, and training background. Aspects of the SPPC that must be considered for vertical jump potentiation include the potentiating exercise, level and rate of muscle activation, volume load completed, the ballistic or non-ballistic nature of the potentiating exercise, and the rest interval(s) used following the potentiating exercise. Sport scientists and practitioners should design and seek SPPCs that are practical in nature regarding the equipment needed and the rest interval required for a potentiated performance. If practitioners would like to incorporate PAP as a training tool, they must take the athlete training time restrictions into account as a number of previous SPPCs have been shown to require long rest periods before potentiation can be realized. Thus, practitioners should seek SPPCs that may be effectively implemented in training and that do not require excessive rest intervals that may take away from valuable training time. Practitioners may decrease the necessary time needed to realize potentiation by improving their subject's relative strength.

  1. Vertical dynamics of disk galaxies in MOND

    OpenAIRE

    Nipoti, Carlo; Londrillo, Pasquale; Zhao, HongSheng; Ciotti, Luca

    2007-01-01

    We investigate the possibility of discriminating between Modified Newtonian Dynamics (MOND) and Newtonian gravity with dark matter, by studying the vertical dynamics of disk galaxies. We consider models with the same circular velocity in the equatorial plane (purely baryonic disks in MOND and the same disks in Newtonian gravity embedded in spherical dark matter haloes), and we construct their intrinsic and projected kinematical fields by solving the Jeans equations under the assumption of a t...

  2. Rescuing the concept of vertical fiscal imbalance

    OpenAIRE

    Sharma, Chanchal Kumar

    2007-01-01

    This article restores the concept of vertical fiscal imbalance (VFI) to its original meaning. The literature shows that there is neither a universally accepted definition of VFI nor a commonly accepted approach to measuring it. Estimates of VFI are derived, much like accounting or deficit measurements, by comparing the revenues and expenditures of two levels of government. VFI is, however, too nuanced an issue to be described by this kind of national accounting procedure. We argue that ease ...

  3. Thermal radiation from vertical jet fires

    OpenAIRE

    Palacios, Adriana; Muñoz, Miguel; Darbra Roman, Rosa Maria; Casal Fàbrega, Joaquim

    2012-01-01

    Geometric and thermal data, obtained from a series of large outdoor jet fire experiments, were used to estimate the thermal radiation intensity from the flames towards targets located at diverse distances. Vertical turbulent sonic and subsonic exit velocity propane jet fires, up to 10.3 m in length released in still air, were studied. The temperatures of the flame surface and the surface emissive power of the flame were also analysed by processing infrared images. Thermal radiation intensity ...

  4. Inverse scattering problem for quantum graph vertices

    CERN Document Server

    Cheon, Taksu; Turek, Ondrej

    2011-01-01

    We demonstrate how the inverse scattering problem of a quantum star graph can be solved by means of diagonalization of Hermitian unitary matrix when the vertex coupling is of the scale invariant (or F\\"ul\\H{o}p-Tsutsui) form. This enables the construction of quantum graphs with desired properties in a tailor-made fashion. The procedure is illustrated on the example of quantum vertices with equal transmission probabilities.

  5. Numerical Simulation of Rotating Vertical Bridgman Growth

    OpenAIRE

    S. Nouri; P. Spiterri; Ghezal, A.

    2016-01-01

    The present work is proposed a numerical parametric study of heat and mass transfer in a rotating vertical cylinder during the solidification of a binary metallic alloy. The aim of this paper is to present an enthalpy formulation based on the fixed grid methodology for the numerical solution of convective-diffusion during the phase change in the case of the steady crucible rotation. The extended Darcy model including the time derivative and Coriolis terms was applied as momentum equation. It...

  6. Vertical relationships, competition, knowledge search and innovation

    OpenAIRE

    Köhler, Christian

    2014-01-01

    This thesis deals with modern topics in industrial organization and in economics of innovation in particular. It encompasses four empirical studies which are related to both the aims expressed in the Europe 2020 strategy as well as the means to reach them. Chapter 2 deals with issues of bargaining in vertical relationships. The first study of this chapter explores how bargaining affects the R&D profitability of suppliers. The results show that a supplier’s bargaining power is a crucial determ...

  7. Understanding Vertical Jump Potentiation: A Deterministic Model.

    Science.gov (United States)

    Suchomel, Timothy J; Lamont, Hugh S; Moir, Gavin L

    2016-06-01

    This review article discusses previous postactivation potentiation (PAP) literature and provides a deterministic model for vertical jump (i.e., squat jump, countermovement jump, and drop/depth jump) potentiation. There are a number of factors that must be considered when designing an effective strength-power potentiation complex (SPPC) focused on vertical jump potentiation. Sport scientists and practitioners must consider the characteristics of the subject being tested and the design of the SPPC itself. Subject characteristics that must be considered when designing an SPPC focused on vertical jump potentiation include the individual's relative strength, sex, muscle characteristics, neuromuscular characteristics, current fatigue state, and training background. Aspects of the SPPC that must be considered for vertical jump potentiation include the potentiating exercise, level and rate of muscle activation, volume load completed, the ballistic or non-ballistic nature of the potentiating exercise, and the rest interval(s) used following the potentiating exercise. Sport scientists and practitioners should design and seek SPPCs that are practical in nature regarding the equipment needed and the rest interval required for a potentiated performance. If practitioners would like to incorporate PAP as a training tool, they must take the athlete training time restrictions into account as a number of previous SPPCs have been shown to require long rest periods before potentiation can be realized. Thus, practitioners should seek SPPCs that may be effectively implemented in training and that do not require excessive rest intervals that may take away from valuable training time. Practitioners may decrease the necessary time needed to realize potentiation by improving their subject's relative strength. PMID:26712510

  8. Autonomous vehicle development for vertical submarine observation

    OpenAIRE

    Gomáriz Castro, Spartacus; Prat Tasias, Jordi; Arbós, Alejandro; Viñolo Monzoncillo, Carlos; Pallares, Oriol

    2009-01-01

    This work proposes the development of an ocean observation vehicle. This vehicle, a hybrid between Autonomous Underwater Vehicles (AUV) and Autonomous Surface Vehicles (ASV) moves on the surface of the sea and makes vertical immersions to obtain the profiles of a water column according to a pre-established plan. Its design provides lower production cost and higher efficiency. GPS navigation allows the platform to move along the surface of the water while a radio-modem provid...

  9. Electrically floating, near vertical incidence, skywave antenna

    Science.gov (United States)

    Anderson, Allen A.; Kaser, Timothy G.; Tremblay, Paul A.; Mays, Belva L.

    2014-07-08

    An Electrically Floating, Near Vertical Incidence, Skywave (NVIS) Antenna comprising an antenna element, a floating ground element, and a grounding element. At least part of said floating ground element is positioned between said antenna element and said grounding element. The antenna is separated from the floating ground element and the grounding element by one or more electrical insulators. The floating ground element is separated from said antenna and said grounding element by one or more electrical insulators.

  10. Centro-lateral subperiosteal vertical midface lift

    Directory of Open Access Journals (Sweden)

    Hönig, Johannes Franz

    2014-03-01

    Full Text Available The use of fiberendoscopic video-assisted technique in facial rejuvenation is one of the most advances in aesthetic plastic surgery of the face. It substitutes the coronal incision without the necessity of skin resection and allows a vertical reposition of the mobile soft tissue of the midface in indicated cases. It can easily be done through a small incision of the scalp just behind the coronal incision and in the temporal area.

  11. Orthogonal Thin Film Photovoltaics on Vertical Nanostructures.

    Science.gov (United States)

    Ahnood, Arman; Zhou, H; Suzuki, Y; Sliz, R; Fabritius, T; Nathan, Arokia; Amaratunga, G A J

    2015-12-01

    Decoupling paths of carrier collection and illumination within photovoltaic devices is one promising approach for improving their efficiency by simultaneously increasing light absorption and carrier collection efficiency. Orthogonal photovoltaic devices are core-shell type structures consisting of thin film photovoltaic stack on vertical nanopillar scaffolds. These types of devices allow charge collection to take place in the radial direction, perpendicular to the path of light in the vertical direction. This approach addresses the inherently high recombination rate of disordered thin films, by allowing semiconductor films with minimal thicknesses to be used in photovoltaic devices, without performance degradation associated with incomplete light absorption. This work considers effects which influence the performance of orthogonal photovoltaic devices. Illumination non-uniformity as light travels across the depth of the pillars, electric field enhancement due to the nanoscale size and shape of the pillars, and series resistance due to the additional surface structure created through the use of pillars are considered. All of these effects influence the operation of orthogonal solar cells and should be considered in the design of vertically nanostructured orthogonal photovoltaics.

  12. Sunrise enhancement of equatorial vertical plasma drift

    Science.gov (United States)

    Liu, Libo; Zhang, Ruilong; Le, Huijun

    2016-04-01

    Sunrise enhancement in vertical plasma drift over equatorial regions is not discernible in the statistical picture compared with the significant enhancement during dusk hours. In this report, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag. Moreover, we will report the effects of the sunrise enhancement of vertical plasma drift on the equatorial ionosphere as indicated from the observations and model simulations. We thanks National Central University of Taiwan providing the ROCSAT-1 data. The Ap and F107 indices are obtained from the National Geophysical Data Center (http://spidr.ngdc.noaa.gov/spidr/). This research is supported by National Natural Science Foundation of China (41231065), the Chinese Academy of Sciences project (KZZD-EW-01-3), National Key Basic Research Program of China (2012CB825604) and National Natural Science Foundation of China (41321003).

  13. A Vertically Integrated Junctionless Nanowire Transistor.

    Science.gov (United States)

    Lee, Byung-Hyun; Hur, Jae; Kang, Min-Ho; Bang, Tewook; Ahn, Dae-Chul; Lee, Dongil; Kim, Kwang-Hee; Choi, Yang-Kyu

    2016-03-01

    A vertically integrated junctionless field-effect transistor (VJ-FET), which is composed of vertically stacked multiple silicon nanowires (SiNWs) with a gate-all-around (GAA) structure, is demonstrated on a bulk silicon wafer for the first time. The proposed VJ-FET mitigates the issues of variability and fabrication complexity that are encountered in the vertically integrated multi-NW FET (VM-FET) based on an identical structure in which the VM-FET, as recently reported, harnesses a source and drain (S/D) junction for its operation and is thus based on the inversion mode. Variability is alleviated by bulk conduction in a junctionless FET (JL-FET), where current flows through the core of the SiNW, whereas it is not mitigated by surface conduction in an inversion mode FET (IM-FET), where current flows via the surface of the SiNW. The fabrication complexity is reduced by the inherent JL structure of the JL-FET because S/D formation is not required. In contrast, it is very difficult to dope the S/D when it is positioned at each floor of a tall SiNW with greater uniformity and with less damage to the crystalline structure of the SiNW in a VM-FET. Moreover, when the proposed VJ-FET is used as nonvolatile flash memory, the endurance and retention characteristics are improved due to the above-mentioned bulk conduction. PMID:26885948

  14. Vertical variations of coral reef drag forces

    Science.gov (United States)

    Asher, Shai; Niewerth, Stephan; Koll, Katinka; Shavit, Uri

    2016-05-01

    Modeling flow in a coral reef requires a closure model that links the local drag force to the local mean velocity. However, the spatial flow variations make it difficult to predict the distribution of the local drag. Here we report on vertical profiles of measured drag and velocity in a laboratory reef that was made of 81 Pocillopora Meandrina colony skeletons, densely arranged along a tilted flume. Two corals were CT-scanned, sliced horizontally, and printed using a 3-D printer. Drag was measured as a function of height above the bottom by connecting the slices to drag sensors. Profiles of velocity were measured in-between the coral branches and above the reef. Measured drag of whole colonies shows an excellent agreement with previous field and laboratory studies; however, these studies never showed how drag varies vertically. The vertical distribution of drag is reported as a function of flow rate and water level. When the water level is the same as the reef height, Reynolds stresses are negligible and the drag force per unit fluid mass is nearly constant. However, when the water depth is larger, Reynolds stress gradients become significant and drag increases with height. An excellent agreement was found between the drag calculated by a momentum budget and the measured drag of the individual printed slices. Finally, we propose a modified formulation of the drag coefficient that includes the normal dispersive stress term and results in reduced variations of the drag coefficient at the cost of introducing an additional coefficient.

  15. Dynamic stiffness of suction caissons - vertical vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.; Andersen, Lars

    2006-12-15

    The dynamic response of offshore wind turbines are affected by the properties of the foundation and the subsoil. The purpose of this report is to evaluate the dynamic soil-structure interaction of suction caissons for offshore wind turbines. The investigation is limited to a determination of the vertical dynamic stiffness of suction caissons. The soil surrounding the foundation is homogenous with linear viscoelastic properties. The dynamic stiffness of the suction caisson is expressed by dimensionless frequency-dependent dynamic stiffness coefficients corresponding to the vertical degree of freedom. The dynamic stiffness coefficients for the foundations are evaluated by means of a dynamic three-dimensional coupled Boundary Element/Finite Element model. Comparisons are made with known analytical and numerical solutions in order to evaluate the static and dynamic behaviour of the Boundary Element/Finite Element model. The vertical frequency dependent stiffness has been determined for different combinations of the skirt length, Poisson's ratio and the ratio between soil stiffness and skirt stiffness. Finally the dynamic behaviour at high frequencies is investigated. (au)

  16. Longitudinal variability of black carbon vertical profiles

    Science.gov (United States)

    Schwarz, J. P.; Weinzierl, B.; Samset, B. H.; Perring, A. E.; Dollner, M.; Heimerl, K.; Markovic, M. Z.; Ziemba, L. D.

    2015-12-01

    Black carbon (BC) aerosol contributes substantially to both climate forcing and climate forcing uncertainty. An important source of this uncertainty derives from the difficulty in predicting BC's global abundance and vertical distribution. Here we present a multi-year record of black carbon (BC) vertical concentration profiles from both sides of the Atlantic, obtained from airborne Single Particle Soot Photometers (SP2s) flown on the NASA DC-8, and the DLR Falcon research aircraft from the CONCERT, ACCESS, DC3, SEAC4RS, and SALTRACE campaigns. The measurements constrain the relative rates of BC transport/removal from, and zonal mixing in, the upper troposphere, as well as the range of BC loadings in these regions. They also constrain the time-rates of change of BC loads in altitudes at which it is a highly efficient (although sparse) climate forcer, and a relatively long-lived aerosol tracer. We find that concentration of BC in the upper troposphere can vary by a factor 10. Over the Northern mid-latitudes concentrations are however consistent to a fraction of this range over wide longitudinal ranges, over month-long timescales. The data show that BC becomes zonally mixed here starting at 500 hPa and extending to near the tropopause. These results imply broader value than previously associated with measured vertical profiles in constraining global scale BC loadings aloft.

  17. Wind speed vertical distribution at Mt. Graham

    CERN Document Server

    Hagelin, S; Lascaux, F

    2010-01-01

    The characterization of the wind speed vertical distribution V(h) is fundamental for an astronomical site for many different reasons: (1) the wind speed shear contributes to trigger optical turbulence in the whole troposphere, (2) a few of the astroclimatic parameters such as the wavefront coherence time (tau_0) depends directly on V(h), (3) the equivalent velocity V_0, controlling the frequency at which the adaptive optics systems have to run to work properly, depends on the vertical distribution of the wind speed and optical turbulence. Also, a too strong wind speed near the ground can introduce vibrations in the telescope structures. The wind speed at a precise pressure (200 hPa) has frequently been used to retrieve indications concerning the tau_0 and the frequency limits imposed to all instrumentation based on adaptive optics systems, but more recently it has been proved that V_200 (wind speed at 200 hPa) alone is not sufficient to provide exhaustive elements concerning this topic and that the vertical d...

  18. Radially Magnetized Protoplanetary Disk: Vertical Profile

    CERN Document Server

    Russo, Matthew

    2015-01-01

    This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, is wound up by the disk shear, and is pushed downward by a combination of turbulent mixing and ambipolar and Ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field $B_r \\sim (10^{-4}$-$10^{-2})(r/{\\rm AU})^{-2}$ G. Careful attention is giv...

  19. Gating Technology for Vertically Parted Green Sand Moulds

    DEFF Research Database (Denmark)

    Larsen, Per

    Gating technology for vertically parted green sand moulds. Literature study of different ways of designing gating systems.......Gating technology for vertically parted green sand moulds. Literature study of different ways of designing gating systems....

  20. Vertical Structure and Vertical Evolution of Halogen Activation Events Observed by Autonomous Buoys

    Science.gov (United States)

    Simpson, W. R.; Peterson, P.; Burd, J.

    2015-12-01

    Heterogeneous reactions on saline surfaces release reactive halogen species in the Arctic during late winter / spring (Feb--May). These reactive halogens drastically alter the photooxidative environment, removing ozone and oxidizing mercury and hydrocarbons. Both the snowpack and suspended particles / blowing snow possess surfaces that can sustain this chemistry, leading to variations in reactive halogen vertical profiles and temporal evolution of those profiles. This chemistry also occurs in a typically stable (inverted) atmospheric structure that hinders vertical mixing, limiting the vertical extent of snowpack influence. In this presentation, Multiple-AXis Differential Optical Absorption Spectroscopy (MAXDOAS) of bromine monoxide (BrO) along with optimal estimation inversions are used to measure the vertical structure of BrO. The effective mixing height of the BrO layer varies with atmospheric stability, and an event is shown where a shallow but highly concentrated layer of surface BrO encounters sea-ice-lead-induced convection that vertically mixes the BrO higher, initially diluting the surface concentration. Over time, the surface concentration recovers and the now thicker layer grows to a higher column density of BrO. Understanding of the relationship between BrO event intensity and meteorological situations can help to understand BrO chemistry and remote sensing and assist in prediction of how reactive halogens may respond to a changing Arctic climate.

  1. Vertical emission profiles for Europe based on plume rise calculations

    NARCIS (Netherlands)

    Bieser, J.; Aulinger, A.; Matthias, V.; Quante, M.; Denier Van Der Gon, H.A.C.

    2011-01-01

    The vertical allocation of emissions has a major impact on results of Chemistry Transport Models. However, in Europe it is still common to use fixed vertical profiles based on rough estimates to determine the emission height of point sources. This publication introduces a set of new vertical profile

  2. Mechanical design of NASA Ames Research Center vertical motion simulator

    Science.gov (United States)

    Engelbert, D. F.; Bakke, A. P.; Chargin, M. K.; Vallotton, W. C.

    1976-01-01

    NASA has designed and is constructing a new flight simulator with large vertical travel. Several aspects of the mechanical design of this Vertical Motion Simulator (VMS) are discussed, including the multiple rack and pinion vertical drive, a pneumatic equilibration system, and the friction-damped rigid link catenaries used as cable supports.

  3. Vertical deformation at western part of Sumatra

    Science.gov (United States)

    Febriyani, Caroline; Prijatna, Kosasih; Meilano, Irwan

    2015-04-01

    This research tries to make advancement in GPS signal processing to estimate the interseismic vertical deformation field at western part of Sumatra Island. The data derived by Continuous Global Positioning System (CGPS) from Badan Informasi Geospasial (BIG) between 2010 and 2012. GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) software are used to process the GPS signal to estimate the vertical velocities of the CGPS station. In order to minimize noise due to atmospheric delay, Vienna Mapping Function 1 (VMF1) is used as atmospheric parameter model and include daily IONEX file provided by the Center for Orbit Determination in Europe (CODE) as well. It improves GAMIT daily position accuracy up to 0.8 mm. In a second step of processing, the GLOBK is used in order to estimate site positions and velocities in the ITRF08 reference frame. The result shows that the uncertainties of estimated displacement velocity at all CGPS stations are smaller than 1.5 mm/yr. The subsided deformation patterns are seen at the northern and southern part of west Sumatra. The vertical deformation at northern part of west Sumatra indicates postseismic phase associated with the 2010 and 2012 Northern Sumatra earthquakes and also the long-term postseismic associated with the 2004 and 2005 Northern Sumatra earthquakes. The uplifted deformation patterns are seen from Bukit Tinggi to Seblat which indicate a long-term interseismic phase after the 2007 Bengkulu earthquake and 2010 Mentawai earthquake. GANO station shows a subsidence at rate 12.25 mm/yr, indicating the overriding Indo-Australia Plate which is dragged down by the subducting Southeast Asian Plate.

  4. Vertical deformation at western part of Sumatra

    International Nuclear Information System (INIS)

    This research tries to make advancement in GPS signal processing to estimate the interseismic vertical deformation field at western part of Sumatra Island. The data derived by Continuous Global Positioning System (CGPS) from Badan Informasi Geospasial (BIG) between 2010 and 2012. GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) software are used to process the GPS signal to estimate the vertical velocities of the CGPS station. In order to minimize noise due to atmospheric delay, Vienna Mapping Function 1 (VMF1) is used as atmospheric parameter model and include daily IONEX file provided by the Center for Orbit Determination in Europe (CODE) as well. It improves GAMIT daily position accuracy up to 0.8 mm. In a second step of processing, the GLOBK is used in order to estimate site positions and velocities in the ITRF08 reference frame. The result shows that the uncertainties of estimated displacement velocity at all CGPS stations are smaller than 1.5 mm/yr. The subsided deformation patterns are seen at the northern and southern part of west Sumatra. The vertical deformation at northern part of west Sumatra indicates postseismic phase associated with the 2010 and 2012 Northern Sumatra earthquakes and also the long-term postseismic associated with the 2004 and 2005 Northern Sumatra earthquakes. The uplifted deformation patterns are seen from Bukit Tinggi to Seblat which indicate a long-term interseismic phase after the 2007 Bengkulu earthquake and 2010 Mentawai earthquake. GANO station shows a subsidence at rate 12.25 mm/yr, indicating the overriding Indo-Australia Plate which is dragged down by the subducting Southeast Asian Plate

  5. Vertical deformation at western part of Sumatra

    Energy Technology Data Exchange (ETDEWEB)

    Febriyani, Caroline, E-mail: caroline.fanuel@students.itb.ac.id; Prijatna, Kosasih, E-mail: prijatna@gd.itb.ac.id; Meilano, Irwan, E-mail: irwan.meilano@gd.itb.ac.id

    2015-04-24

    This research tries to make advancement in GPS signal processing to estimate the interseismic vertical deformation field at western part of Sumatra Island. The data derived by Continuous Global Positioning System (CGPS) from Badan Informasi Geospasial (BIG) between 2010 and 2012. GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) software are used to process the GPS signal to estimate the vertical velocities of the CGPS station. In order to minimize noise due to atmospheric delay, Vienna Mapping Function 1 (VMF1) is used as atmospheric parameter model and include daily IONEX file provided by the Center for Orbit Determination in Europe (CODE) as well. It improves GAMIT daily position accuracy up to 0.8 mm. In a second step of processing, the GLOBK is used in order to estimate site positions and velocities in the ITRF08 reference frame. The result shows that the uncertainties of estimated displacement velocity at all CGPS stations are smaller than 1.5 mm/yr. The subsided deformation patterns are seen at the northern and southern part of west Sumatra. The vertical deformation at northern part of west Sumatra indicates postseismic phase associated with the 2010 and 2012 Northern Sumatra earthquakes and also the long-term postseismic associated with the 2004 and 2005 Northern Sumatra earthquakes. The uplifted deformation patterns are seen from Bukit Tinggi to Seblat which indicate a long-term interseismic phase after the 2007 Bengkulu earthquake and 2010 Mentawai earthquake. GANO station shows a subsidence at rate 12.25 mm/yr, indicating the overriding Indo-Australia Plate which is dragged down by the subducting Southeast Asian Plate.

  6. Intelligent Vertical Handoffs between Heterogeneous Communication Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi; WANG Yi-hong; VICTOR O.K.; WANG Ying; ZHANG Ping

    2005-01-01

    This paper proposes an intelligent vertical handoff algorithm to maintain an ongoing call between a cellular mobile network and a Wireless Local Area Network (WLAN), based on the Received Signal Strength (RSS) threshold and an adaptive RSS hysteresis generated by fuzzy logic. In addition, the proposed algorithm accounts for the WLAN traffic loading and the direction of movement and speed of the Mobile Station (MS). Simulation results indicate that the proposed algorithm offers better system performance in terms of number of handoffs and probability of call dropping.

  7. Opportunity's Surroundings on Sol 1818 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  8. Vertical Cable Seismic Survey for Hydrothermal Deposit

    Science.gov (United States)

    Asakawa, E.; Murakami, F.; Sekino, Y.; Okamoto, T.; Ishikawa, K.; Tsukahara, H.; Shimura, T.

    2012-04-01

    The vertical cable seismic is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. This type of survey is generally called VCS (Vertical Cable Seismic). Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the hydrothermal deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS system, including not only data acquisition hardware but data processing and analysis technique. Our first experiment of VCS surveys has been carried out in Lake Biwa, JAPAN in November 2009 for a feasibility study. Prestack depth migration is applied to the 3D VCS data to obtain a high quality 3D depth volume. Based on the results from the feasibility study, we have developed two autonomous recording VCS systems. After we carried out a trial experiment in the actual ocean at a water depth of about 400m and we carried out the second VCS survey at Iheya Knoll with a deep-towed source. In this survey, we could establish the procedures for the deployment/recovery of the system and could examine the locations and the fluctuations of the vertical cables at a water depth of around 1000m. The acquired VCS data clearly shows the reflections from the sub-seafloor. Through the experiment, we could confirm that our VCS system works well even in the severe circumstances around the locations of seafloor hydrothermal deposits. We have, however, also confirmed that the uncertainty in the locations of the source and of the hydrophones could lower the quality of subsurface image. It is, therefore, strongly necessary to develop a total survey system that assures a accurate positioning and a deployment techniques

  9. Vertical distributor in the Booster injection line

    CERN Multimedia

    1979-01-01

    The beam from the 50 MeV linac filled the 4 rings of the PS Booster(originally 800 MeV, now 1.4 GeV) one after the other (in multiturn injection). A fast-switchable vertical steering magnet, the "distributor", directed the beam first to the top ring (nb.4), and after a preset number of turns to next lower ring, and so on. After filling the bottom ring, the tail of the linac beam was directed into a dump.

  10. Escrita Escolar Brasileira: a escrita vertical

    OpenAIRE

    Carlos André Xavier Villela

    2014-01-01

    O exame grafoscópico visa essencialmente a determinar se duas escritas partiram ou não de um mesmo punho. A fim de buscar dados empíricos capazes de melhor embasar uma valoração de raridade, diversos pesquisadores se dedicaram ao estudo dos sistemas de escrita. O presente trabalho analisa algumas bibliografias nacionais e estrangeiras que descrevem como se deu o alvorecer da escrita vertical e sua implantação no universo escolar brasileiro. Foi a partir das últimas décadas do século XIX que a...

  11. Optimisation of vertical axis wind turbines

    OpenAIRE

    Roynarin, Wirachai

    2004-01-01

    A practical Vertical Axis Wind Turbine (VAWTs) based on a Darrieus rotor has been designed and tested and found to be capable of self-starting at wind speeds above 4m/s. The self-start feature has been achieved by replacing the usual symmetrical aerofoil blade in the VAWT rotor and by using a concentric Savonius rotor or semi-cylinder turbine. A computer program was produced to compute the power coefficient versus tip speed ratio characteristics of a selected aerofoil profile employed in a VA...

  12. Vertically Polarized Omnidirectional Printed Slot Loop Antenna

    DEFF Research Database (Denmark)

    Kammersgaard, Nikolaj Peter Iversen; Kvist, Søren H.; Thaysen, Jesper;

    2015-01-01

    A novel vertically polarized omnidirectional printed slot loop antenna has been designed, simulated, fabricated and measured. The slot loop works as a magnetic loop. The loop is loaded with inductors to insure uniform and in-phase fields in the slot in order to obtain an omnidirectional radiation...... pattern. The antenna is designed for the 2.45 GHz Industrial, Scientific and Medical band. Applications of the antenna are many. One is for on-body applications since it is ideal for launching a creeping waves due to the polarization....

  13. Analytical Study on Wave Diffraction from a Vertical Circular Cylinder in Front of Orthogonal Vertical Walls

    Institute of Scientific and Technical Information of China (English)

    NING Dezhi; TENG Bin; SONG Xiangqun

    2005-01-01

    In this paper, the principle of mirror image is used to transform the problem of wave diffraction from a circular cylinder in front of orthogonal vertical walls into the problem of diffraction of four symmetric incident waves from four symmetrically arranged circular cylinders, and then the eigenfunction expansion of velocity potential and Grafs addition theorem are used to give the analytical solution to the wave diffraction problem. The relation of the total wave force on cylinder to the distance between the cylinder and orthogonal vertical walls and the incidence angle of wave is also studied by numerical computation.

  14. Principle of Cross Coupling Between Vertical Heat Turbulent Transport and Vertical Velocity and Determination of Cross Coupling Coefficient

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    It has been proved that there exists a cross coupling between vertical heat turbulent transport and vertical velocity by using linear thermodynamics. This result asserts that the vertical component of heat turbulent transport flux is composed of both the transport of the vertical potential temperature gralient and the coupling transport of the vertical velocity. In this paper, the coupling effect of vertical velocity on vertical heat turbulent transportation is validated by using observed data from the atmospheric boundary layer to determine cross coupling coefficients, and a series of significant properties of turbulent transportation are opened out. These properties indicate that the cross coupling coefficient is a logarithm function of the dimensionless vertical velocity and dimensionless height, and is not only related to the friction velocity u*,but also to the coupling roughness height zwo and the coupling temperature Two of the vertical velocity.In addition, the function relations suggest that only when the vertical velocity magnitude conforms to the limitation |W/u* | ≠ 1, and is above the level zwo, then the vertical velocity leads to the cross coupling effect on the vertical heat turbulent transport flux. The cross coupling theory and experimental results provide a challenge to the traditional turbulent K closure theory and the Monin-Obukhov similarity theory.

  15. Role of the vertical pressure gradient in wave boundary layers

    DEFF Research Database (Denmark)

    Jensen, Karsten Lindegård; Sumer, B. Mutlu; Vittori, Giovanna;

    2014-01-01

    By direct numerical simulation (DNS) of the flow in an oscillatory boundary layer, it is possible to obtain the pressure field. From the latter, the vertical pressure gradient is determined. Turbulent spots are detected by a criterion involving the vertical pressure gradient. The vertical pressure...... gradient is also treated as any other turbulence quantity like velocity fluctuations and statistical properties of the vertical pressure gradient are calculated from the DNS data. The presence of a vertical pressure gradient in the near bed region has significant implications for sediment transport....

  16. Experimental gas-solid vertical transport

    Science.gov (United States)

    Luo, Kuo Ming

    1987-05-01

    Gas-solid transport in dilute and dense phase conveying is studied. A new experimental system for vertical pneumatic conveying incorporates a screw feeder for dilute transport and an L-valve for dense flow. For measuring solid volume fractions a novel method using an x-ray densitometer was developed. The pressure in the system was measured using a strip chart recorder (SCR) and a manometer. The solids flux was estimated by collecting the particles from the system for a known time. The porosity and pressure drop data in the fully developed region were translated into drag coefficients and friction factors. The drag coefficients are in reasonable agreement with literature values. The friction factors with the wall were sometimes negative, reflecting downward flow, as observed in two-dimensional studies. Four available hydrodynamic models for vertical pneumatic conveying were used to predict the porosity and the pressure for the experimental conditions. Experimental data for porosity and pressure agree well with theoretical predictions. However, the predictions from the relative velocity model were in the best agreement for pressure drop values.

  17. Determinants of Arbovirus Vertical Transmission in Mosquitoes.

    Directory of Open Access Journals (Sweden)

    Sebastian Lequime

    2016-05-01

    Full Text Available Vertical transmission (VT and horizontal transmission (HT of pathogens refer to parental and non-parental chains of host-to-host transmission. Combining HT with VT enlarges considerably the range of ecological conditions in which a pathogen can persist, but the factors governing the relative frequency of each transmission mode are poorly understood for pathogens with mixed-mode transmission. Elucidating these factors is particularly important for understanding the epidemiology of arthropod-borne viruses (arboviruses of public health significance. Arboviruses are primarily maintained by HT between arthropod vectors and vertebrate hosts in nature, but are occasionally transmitted vertically in the vector population from an infected female to her offspring, which is a proposed maintenance mechanism during adverse conditions for HT. Here, we review over a century of published primary literature on natural and experimental VT, which we previously assembled into large databases, to identify biological factors associated with the efficiency of arbovirus VT in mosquito vectors. Using a robust statistical framework, we highlight a suite of environmental, taxonomic, and physiological predictors of arbovirus VT. These novel insights contribute to refine our understanding of strategies employed by arboviruses to persist in the environment and cause substantial public health concern. They also provide hypotheses on the biological processes underlying the relative VT frequency for pathogens with mixed-mode transmission that can be tested empirically.

  18. Determinants of Arbovirus Vertical Transmission in Mosquitoes.

    Science.gov (United States)

    Lequime, Sebastian; Paul, Richard E; Lambrechts, Louis

    2016-05-01

    Vertical transmission (VT) and horizontal transmission (HT) of pathogens refer to parental and non-parental chains of host-to-host transmission. Combining HT with VT enlarges considerably the range of ecological conditions in which a pathogen can persist, but the factors governing the relative frequency of each transmission mode are poorly understood for pathogens with mixed-mode transmission. Elucidating these factors is particularly important for understanding the epidemiology of arthropod-borne viruses (arboviruses) of public health significance. Arboviruses are primarily maintained by HT between arthropod vectors and vertebrate hosts in nature, but are occasionally transmitted vertically in the vector population from an infected female to her offspring, which is a proposed maintenance mechanism during adverse conditions for HT. Here, we review over a century of published primary literature on natural and experimental VT, which we previously assembled into large databases, to identify biological factors associated with the efficiency of arbovirus VT in mosquito vectors. Using a robust statistical framework, we highlight a suite of environmental, taxonomic, and physiological predictors of arbovirus VT. These novel insights contribute to refine our understanding of strategies employed by arboviruses to persist in the environment and cause substantial public health concern. They also provide hypotheses on the biological processes underlying the relative VT frequency for pathogens with mixed-mode transmission that can be tested empirically.

  19. The capillary interaction between two vertical cylinders

    KAUST Repository

    Cooray, Himantha

    2012-06-27

    Particles floating at the surface of a liquid generally deform the liquid surface. Minimizing the energetic cost of these deformations results in an inter-particle force which is usually attractive and causes floating particles to aggregate and form surface clusters. Here we present a numerical method for determining the three-dimensional meniscus around a pair of vertical circular cylinders. This involves the numerical solution of the fully nonlinear Laplace-Young equation using a mesh-free finite difference method. Inter-particle force-separation curves for pairs of vertical cylinders are then calculated for different radii and contact angles. These results are compared with previously published asymptotic and experimental results. For large inter-particle separations and conditions such that the meniscus slope remains small everywhere, good agreement is found between all three approaches (numerical, asymptotic and experimental). This is as expected since the asymptotic results were derived using the linearized Laplace-Young equation. For steeper menisci and smaller inter-particle separations, however, the numerical simulation resolves discrepancies between existing asymptotic and experimental results, demonstrating that this discrepancy was due to the nonlinearity of the Laplace-Young equation. © 2012 IOP Publishing Ltd.

  20. Pseudocapacitive performance of vertical copper oxide nanoflakes

    International Nuclear Information System (INIS)

    Vertical copper oxide (CuO) nanoflakes have been formed by oxidation in NaOH solution. Their structural, surface morphology and oxidation states were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) respectively. Pseudocapacitive behavior of CuO nanoflakes was investigated by cyclic voltammetry and constant current charge–discharge test. CuO nanoflakes were vertically grown with high lateral aspect ratio and consist of monoclinic lattice as shown by the presence of two peaks close to 2θ = 35.6o and 38.7o in the XRD. Charge–discharge test gave a capacitance value of 190 F g−1 in 1.0 M KOH electrolyte at 2 mA cm−2 current density. The cycling test showed 67% stability after 2000 cycles and reduced specific capacitance from 190 F g−1 to 125 F g−1. Specific capacitance of CuO nanoflakes is higher than 26.44 F g−1 of globular CuO at 2 mA cm−2 as reported in literature due to enhanced specific surface area. - Highlights: ► CuO nanoflakes prepared by chemical oxidation in alkaline baths ► Porosity of nanoflakes enhanced electrochemical capacitance. ► Suitable for low cost binder-free supercapacitor electrode

  1. Experimental Analysis of a Vertical Drop Shaft

    Directory of Open Access Journals (Sweden)

    Giuseppe Del Giudice

    2013-09-01

    Full Text Available An experimental campaign is undertaken in order to investigate the hydraulic features of a vertical drop shaft, also considering the influence of a venting system consisting of a coaxial vertical pipe, projecting within the drop shaft with different plunging rates. Three different flow regimes are observed: a “weir flow” for very low head values, where the flow profile is subject to the atmospheric pressure; a “full flow” for high head values, where water flows in a pressurized regime along the whole shaft; and a “transitional flow” for intermediate water head values. Weir flow and full flow can be experimentally investigated under steady-state conditions, whereas transitional flow is a pulsating condition, alternately switching from full flow to weir flow. Considering some significant geometric parameters, a head-discharge relation is sought both for the non-vented and for the vented configurations, by means of an energy balance equation, with specific assumptions about intake losses.

  2. Vertical Crossing Angle in IR8

    CERN Document Server

    Holzer , B J; Alemany, R

    2013-01-01

    The operation of the LHCb spectrometer dipole has a considerably larger and more challenging impact on the geometry of the LHC beams than the magnets in the high luminosity regions [1]. The integrated dipole field of 4 Tm deflects the beams in the horizontal plane, and using a set of three dipole magnets, called "compensators" a closed horizontal orbit bump is created. This paper summarizes the basic layout of the beam geometry in IR8 under the influence of the LHCb dipole and its compensators and shows the theoretically expected beam orbits, envelopes and aperture needs in the originally designed version. LHCb operation with both field polarities leads to unequal net crossing angles between the two beams and affects the experiment acceptance. It had been proposed therefore to establish a LHC operation mode where the originally designed horizontal crossing angle is shifted at high energy into the vertical plane leading to a vertical crossing scheme at luminosity operation. The new scheme has been successfully...

  3. Control of the vertical instability in tokamaks

    International Nuclear Information System (INIS)

    The problem of control of the vertical instability is formulated for a massless filamentary plasma. The massless approximation is justified by an examination of the role of inertia in the control problem. The system is solved using Laplace transform techniques. The linear system is studied to determine the stability boundaries. It is found that the system can be stabilized up to a critical decay index, which is predominantly a function of the geometry of the passive stabilizing shell. A second, smaller critical index, which is a function of the geometry of the control coils, determines the limit of stability in the absence of derivative gain in the control circuit. The system is also studied numerically in order to incorporate the non-linear effects of power supply dynamics. The power supply bandwidth requirement is determined by the open-loop growth rate of the instability. The system is studied for a number of control coil options which are available on the DIII-D tokamak. It is found that many of the coils will not provide adequate stabilization and that the use of inboard coils is advantageous in stabilizing the system up to the critical index. Experiments carried out on DIII-D confirm the appropriateness of the model. Using the results of the model study, we have stabilized DIII-D plasmas with decay indices up to 98% of the critical index. Measurement of the plasma vertical position is also discussed. (author) 27 figs., 6 refs

  4. Annular flow of cement slurries; Escoamento anular de pastas de cimento

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Maria das Gracas Pena; Martins, Andre Leibsohn; Oliveira, Antonio Augusto J. de [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Setor de Tecnologia de Perfuracao

    1989-12-31

    This paper considers the analysis of laminar, transitory and turbulent flow regimes of cement slurries of various compositions flowing in annular sections. It is an experimental study to evaluate the performance of dozens of equations found in the literature that reflect the rheological behavior of non-Newtonian fluids, the dimensioning of annular sections, the delimitation of the transitory zone and the estimative of friction losses in the turbulent flow regime. A large-scale physical simulator (SHS-Surface Hydraulic Simulator), was designed and constructed at the PETROBRAS Research Center in order to obtain flow parameters. A computer program capable of analysing and drawing conclusions from the behavior of non-Newtonian fluids flowing in different geometries and energetic conditions was also developed. These were considered as essential stages for the development of the project. (author) 17 refs., 9 figs., 18 tabs.

  5. Your highness: vertical positions as perceptual symbols of power.

    Science.gov (United States)

    Schubert, Thomas W

    2005-07-01

    Metaphorically, power equals up. Drawing on embodied theories of cognition, the author argues that thinking about power involves mental simulation of space and can be interfered with by perception of vertical differences. Study 1 assessed image schemas for power and found a shared vertical difference metaphor. Studies 2, 3, and 4 showed that the judgment of a group's power is influenced by the group's vertical position in space and motor responses implying vertical movement. Study 5 ruled out that the influence of vertical position on power judgments is driven by valence differences. Study 6 showed that vertical position also influences the power judgment result itself. The evidence suggests that the concept of power is partly represented in perceptual form as vertical difference.

  6. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator - presentation slides

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, Kent

    2015-09-17

    Direct emittance measurement based on vertical undulator is discussed. Emittance was evaluated from peak ratios, the smallest measured being =0.9 ±0.3 pm rad. The angular distribution of undulator radiation departs from Gaussian approximations, a fact of which diffraction-limited light sources should be aware.

  7. Muscle activation history at different vertical jumps and its influence on vertical velocity

    NARCIS (Netherlands)

    Kopper, Bence; Csende, Zsolt; Safar, Sandor; Hortobagyi, Tibor; Tihanyi, Jozsef

    2013-01-01

    In the present study we investigated displacement, time, velocity and acceleration history of center of mass (COM) and electrical activity of knee extensors to estimate the dominance of the factors influencing the vertical velocity in squat jumps (SJs), countermovement jumps (CMJs) and drop jumps (D

  8. Predicting vertical jump height from bar velocity.

    Science.gov (United States)

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Strojnik, Vojko; Feriche, Belén

    2015-06-01

    The objective of the study was to assess the use of maximum (Vmax) and final propulsive phase (FPV) bar velocity to predict jump height in the weighted jump squat. FPV was defined as the velocity reached just before bar acceleration was lower than gravity (-9.81 m·s(-2)). Vertical jump height was calculated from the take-off velocity (Vtake-off) provided by a force platform. Thirty swimmers belonging to the National Slovenian swimming team performed a jump squat incremental loading test, lifting 25%, 50%, 75% and 100% of body weight in a Smith machine. Jump performance was simultaneously monitored using an AMTI portable force platform and a linear velocity transducer attached to the barbell. Simple linear regression was used to estimate jump height from the Vmax and FPV recorded by the linear velocity transducer. Vmax (y = 16.577x - 16.384) was able to explain 93% of jump height variance with a standard error of the estimate of 1.47 cm. FPV (y = 12.828x - 6.504) was able to explain 91% of jump height variance with a standard error of the estimate of 1.66 cm. Despite that both variables resulted to be good predictors, heteroscedasticity in the differences between FPV and Vtake-off was observed (r(2) = 0.307), while the differences between Vmax and Vtake-off were homogenously distributed (r(2) = 0.071). These results suggest that Vmax is a valid tool for estimating vertical jump height in a loaded jump squat test performed in a Smith machine. Key pointsVertical jump height in the loaded jump squat can be estimated with acceptable precision from the maximum bar velocity recorded by a linear velocity transducer.The relationship between the point at which bar acceleration is less than -9.81 m·s(-2) and the real take-off is affected by the velocity of movement.Mean propulsive velocity recorded by a linear velocity transducer does not appear to be optimal to monitor ballistic exercise performance.

  9. Predicting vertical jump height from bar velocity.

    Science.gov (United States)

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Strojnik, Vojko; Feriche, Belén

    2015-06-01

    The objective of the study was to assess the use of maximum (Vmax) and final propulsive phase (FPV) bar velocity to predict jump height in the weighted jump squat. FPV was defined as the velocity reached just before bar acceleration was lower than gravity (-9.81 m·s(-2)). Vertical jump height was calculated from the take-off velocity (Vtake-off) provided by a force platform. Thirty swimmers belonging to the National Slovenian swimming team performed a jump squat incremental loading test, lifting 25%, 50%, 75% and 100% of body weight in a Smith machine. Jump performance was simultaneously monitored using an AMTI portable force platform and a linear velocity transducer attached to the barbell. Simple linear regression was used to estimate jump height from the Vmax and FPV recorded by the linear velocity transducer. Vmax (y = 16.577x - 16.384) was able to explain 93% of jump height variance with a standard error of the estimate of 1.47 cm. FPV (y = 12.828x - 6.504) was able to explain 91% of jump height variance with a standard error of the estimate of 1.66 cm. Despite that both variables resulted to be good predictors, heteroscedasticity in the differences between FPV and Vtake-off was observed (r(2) = 0.307), while the differences between Vmax and Vtake-off were homogenously distributed (r(2) = 0.071). These results suggest that Vmax is a valid tool for estimating vertical jump height in a loaded jump squat test performed in a Smith machine. Key pointsVertical jump height in the loaded jump squat can be estimated with acceptable precision from the maximum bar velocity recorded by a linear velocity transducer.The relationship between the point at which bar acceleration is less than -9.81 m·s(-2) and the real take-off is affected by the velocity of movement.Mean propulsive velocity recorded by a linear velocity transducer does not appear to be optimal to monitor ballistic exercise performance. PMID:25983572

  10. Vertical and Interfacial Transport in Wetlands (Invited)

    Science.gov (United States)

    Variano, E. A.

    2010-12-01

    The objective of this work is to understand the fluxes connecting the water column, substrate, and atmosphere in wetland environments. To do this, analytical, numerical, and laboratory models have been used to quantify the hydrodynamic contributions to vertical fluxes. A key question is whether the hydrodynamic transport can be modeled as a diffusivity, and, if so, what the vertical structure of this diffusivity is. This question will be addressed in a number of flow types and for a number of fluxes. The fluxes of interest are heat, sediment, dissolved gases (such as methane and oxygen) and other dissolved solutes (such as nutrients and pollutants). The flows of interest include: unidirectional current, reversing flow (under waves, seiches, and tides), wind-sheared surface flows, and thermal convection. Rain and bioturbation can be important, but are not considered in the modeling work discussed herein. Specifically, we will present results on gas transport at wind-sheared free surface, sediment transport in unidirectional flow, and heat transfer in an oscillating flow cause by a seiche. All three of these will be used to consider the question of appropriate analytical models for vertical transport. The analytic models considered here are all 1D models that assume homogeneity in the horizontal plane. The numerical models use finite element methods and resolve the flow around individual vegetation stems in an idealized geometry. Laboratory models discussed herein also use an idealized geometry. Vegetation is represented by an array of cylinders, whose geometry is modeled after Scirpus spp. wetlands in Northern California. The laboratory model is constructed in a way that allows optical access to the flow, even in dense vegetation and far from boundaries. This is accomplished by using fluoropolymer plastics to construct vegetation models. The optical access allows us to employ particle image velocimetry (PIV) and planar laser induced fluorescence (PLIF) to measure

  11. Multiloop string vertices from the path integral

    Science.gov (United States)

    Bochicchio, M.; Lerda, A.

    1989-02-01

    We derive the multiloop vertices for the bosonic string using path integral methods and establish a precise equivalence between the functional approach to string perturbation theory and the operator formalism on Riemann surfaces recently developed by various authors. One of us (A.L.) would like to thank P. Di Vecchia and S. Sciuto for helpful discussions and INFN, Sezione di Torino, for the kind hospitality extended to him during the completion of this work. The work of M.B. was partially supported by the National Science Foundation under Grant NSF-PHY85-07627. The work of A.L. was partially supported by the US Department of Energy under grant DE-AC02-76ER03069.

  12. Adaptive vertical handoff algorithm in heterogeneous networks

    Institute of Scientific and Technical Information of China (English)

    XIE Sheng-dong; WU Meng

    2007-01-01

    The integration of cellular network (CN) and wireless local area network (WLAN) is the trend of the next generation mobile communication systems, and nodes will handoff between the two kinds of networks. The received signal strength (RSS) is the dominant factor consijered when handoff occurs. In order to improve the handoff efficiency, this study proposes an adaptive decision algorithm for vertical handoff on the basis of fast Fourier transform (FFT). The algorithm makes handoff decision after analyzing the signal strength fluctuation which is caused by slow fading through FFT. Simulations show that the algorithm reduces the number of handoff by 35%, shortens the areas influenced by slow fading, and enables the nodes to make full use of WLAN in communication compared with traditional algorithms.

  13. Gas-solid flow in vertical tubes

    International Nuclear Information System (INIS)

    This paper reports on a computational study of fully-developed flow of gas-particle suspensions in vertical pipes which was carried out, using the model proposed recently by Sinclair and Jackson, to understand the predicted scale-up characteristics. It was shown that the model can capture the existence of steady-state multiplicity wherein different pressure gradients can be obtained for the same gas and solids fluxes. A pronounced and nonmonotonic variation of the pressure gradient required to achieve desired fluxes of solid and gas with tube diameter was predicted by the model, and this is explained on a physical basis. The computed results were compared with the experimental data. The model manifests an unsatisfactory degree of sensitivity to the inelasticity of the particle-particle collisions and the damping of particle-phase fluctuating motion by the gas

  14. Opportunity's Surroundings on Sol 1687 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a vertical projection with geometric seam correction.

  15. Opportunity's Surroundings on Sol 1798 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a vertical projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  16. Opportunity's Surroundings After Sol 1820 Drive (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

  17. Matrix model and dimensions at hypercube vertices

    CERN Document Server

    Morozov, A; Popolitov, A

    2015-01-01

    In hypercube approach to correlation functions in Chern-Simons theory (knot polynomials) the central role is played by the numbers of cycles, in which the link diagram is decomposed under different resolutions. Certain functions of these numbers are further interpreted as dimensions of graded spaces, associated with hypercube vertices. Finding these functions is, however, a somewhat non-trivial problem. In arXiv:1506.07516 it was suggested to solve it with the help of the matrix model technique, in the spirit of AMM/EO topological recursion. In this paper we further elaborate on this idea and provide a vast collection of non-trivial examples, related both to ordinary and virtual links and knots. Remarkably, most powerful versions of the formalism freely convert ordinary knots/links to virtual and back -- moreover, go beyond the knot-related set of the (2,2)-valent graphs.

  18. Development of Vertical Cable Seismic System (2)

    Science.gov (United States)

    Asakawa, E.; Murakami, F.; Tsukahara, H.; Ishikawa, K.

    2012-12-01

    The vertical cable seismic is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. This type of survey is generally called VCS (Vertical Cable Seismic). Because VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed the method for the hydrothermal deposit survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We are now developing a VCS system, including not only data acquisition hardware but data processing and analysis technique. Our first experiment of VCS surveys has been carried out in Lake Biwa, JAPAN in November 2009 for a feasibility study. Prestack depth migration is applied to the 3D VCS data to obtain a high quality 3D depth volume. Based on the results from the feasibility study, we have developed two autonomous recording VCS systems. After we carried out a trial experiment in the actual ocean at a water depth of about 400m and we carried out the second VCS survey at Iheya Knoll with a deep-towed source. In this survey, we could establish the procedures for the deployment/recovery of the system and could examine the locations and the fluctuations of the vertical cables at a water depth of around 1000m. The acquired VCS data clearly shows the reflections from the sub-seafloor. Through the experiment, we could confirm that our VCS system works well even in the severe circumstances around the locations of seafloor hydrothermal deposits. We have carried out two field surveys in 2011. One is a 3D survey with a boomer for a high-resolution surface source and the other one for an actual field survey in the Izena Cauldron an active hydrothermal area in the Okinawa Trough. Through these surveys, we have confirmed that the

  19. Regular tetrahedra whose vertices have integer coordinates

    Directory of Open Access Journals (Sweden)

    E. J. Ionascu

    2011-09-01

    Full Text Available In this paper we introduce theoretical arguments for constructing a procedure that allows one to find the number of all regular tetrahedra that have coordinates in the set {0,1, . . . , n}. The terms of this sequence are twice the values of the sequence A103158 in the Online Encyclopedia of Integer Sequences.These results lead to the consideration of an infinite graph having a fractal nature which is tightly connected to the set of orthogonal 3-by-3 matrices with rational coefficients. The vertices of this graph are the primitive integer solutions of the Diophantine equation a2 + b2 + c2 = 3d2. Our aim here is to laid down the basis of finding good estimates, if not exact formulae, for the sequence A103158.

  20. Lift Augmentation for Vertical Axis Wind Turbines

    Directory of Open Access Journals (Sweden)

    Gerald M Angle II

    2010-12-01

    Full Text Available The concept of harnessing wind power has been around for centuries, and is first recorded by the Persians in 900 AD. These early uses of wind power were for the processing of food, particularly grinding grains, and consisted of stationary blades around a horizontal axis, the precursor to today’s horizontal axis wind turbines (HAWT. Technology for these wind mills was essentially the same until the 1930’s when advances in aircraft propeller theories were applied to the blades of the turbine. During this development period, which has since remained basically unchanged, the design push was for increasingly larger propellers requiring heavy and costly transmissions, generators, and support towers to be installed. An alternative concept to the HAWT was developed by Georges Darrieus [5], which utilized a vertical shaft and is known as a vertical axis wind turbine (VAWT. The scientific development of the concept did not gain strong attention until the 1970’s due to the perceived low efficiency of this style. This perception was due in part to the portion of the blade’s rotary path that is adverse to the generation of power. This efficiency loss can be minimized by the mechanical movement of the blade, relative to the airflow during the upwind portion of the blades’ rotational path. Since, circulation control can alter the forces generated by an airfoil, it could be used to increase the efficiency of a VAWT by increasing the torque produced on the downwind portion of the path, while removing the need for a physical change in angle of attack. With the recent upturn in petroleum costs and global warming concerns, interest in renewable energy technologies have been reinvigorated, in particular the desire for advanced wind energy technologies, including the application of lift augmentation techniques. One of these techniques is to utilize circulation control to enhance the lifting capacity of the blades based on the location of the blade in the

  1. Premixed flame propagation in vertical tubes

    CERN Document Server

    Kazakov, Kirill A

    2015-01-01

    Analytical treatment of premixed flame propagation in vertical tubes with smooth walls is given. Using the on-shell flame description, equations describing quasi-steady flame with a small but finite front thickness are obtained and solved numerically. It is found that near the limits of inflammability, solutions describing upward flame propagation come in pairs having close propagation speeds, and that the effect of gravity is to reverse the burnt gas velocity profile generated by the flame. On the basis of these results, a theory of partial flame propagation driven by the gravitational field is developed. A complete explanation is given of the intricate observed behavior of limit flames, including dependence of the inflammability range on the size of the combustion domain, the large distances of partial flame propagation, and the progression of flame extinction. The role of the finite front-thickness effects is discussed in detail. Also, various mechanisms governing flame acceleration in smooth tubes are ide...

  2. Carbon export by vertically migrating zooplankton

    DEFF Research Database (Denmark)

    Hansen, Agnethe Nøhr; Visser, André W.

    2016-01-01

    of the active transport of carbon by different size fractions of the migrating zooplankton population as function of time and space. The approach is motivated by the difficulty in incorporating behavioral aspects of carbon transport into large scale carbon budgets of the world's oceans. The results show......Through diel vertical migration (DVM), zooplankton add an active transport to the otherwise passive sinking of detrital material that constitutes the biological pump. This active transport has proven difficult to quantify. We present a model that estimates both the temporal and depth characteristic...... that despite their lower abundance, large zooplankton (length circa 1–2 mm) migrate deeper and transport approximately twice as much carbon as do the smaller zooplankton (length circa 0.2–0.3 mm). In mid- latitudes (∼30°N to ∼45°N), where pronounced spring blooms are observed, up to 20% more carbon...

  3. Hypotropic Dissociated Vertical Deviation; a Case Report

    Directory of Open Access Journals (Sweden)

    Zhale Rajavi

    2013-01-01

    Full Text Available Purpose: To report the clinical features of a rare case of hypotropic dissociated vertical deviation (DVD. Case report: A 25-year-old female was referred with unilateral esotropia, hypotropia and slow variable downward drift in her left eye. She had history of esotropia since she had been 3-4 months of age. Best corrected visual acuity was 20/20 in her right eye and 20/40 in the left one when hyperopia was corrected. She underwent bimedial rectus muscle recession of 5.25mm for 45 prism diopters (PDs of esotropia. She was orthophoric 3 months after surgery and no further operation was planned for correction of the hypotropic DVD. Conclusion: This rare case of hypotropic DVD showed only mild amblyopia in her non-fixating eye. The etiology was most probably acquired considering hyperopia as a sign of early onset accommodative esotropia.

  4. Vertical Footbridge Vibrations: The Response Spectrum Methodology

    DEFF Research Database (Denmark)

    Georgakis, Christos; Ingólfsson, Einar Thór

    2008-01-01

    of a reference response spectrum. The simulations use known statistical data for pedestrian and population walking characteristics to generate loads for a 50m long simply-supported bridge, with a fixed level of damping and a mean pedestrian flow rate of 1 pedestrian / sec. The response obtained from...... the reference spectrum is then modified to take into account actual span length, bridge damping, pedestrian pacing frequency, variation on mode shapes and predicted bridge-specific flow rates. Furthermore, the response is modified to account for a specific event return period. The concept of a cumulative event...... of a universally applicable reference response spectrum is introduced, from which the pedestrian-induced vertical response of any footbridge may be determined, based on a defined “event” and the probability of occurrence of that event. A series of Monte Carlo simulations are undertaken for the development...

  5. Analysis of Vertical Architecture Photogalvanic Cells

    CERN Document Server

    Mahmoudzadeh, Mohammad Ali

    2013-01-01

    A new configuration of the photogalvanic cells (PGCs) is proposed that relaxes some of the hard to achieve requirements for efficient conventional photogalvanic cells. Instead of illuminating the device perpendicular to the electrode as was done classically, the vertical alignment of PGCs is suggested so that the light comes in from the gap between the two electrodes. This way, the electron generation extends to the depth of the device and therefore slower kinetics are allowed for deep cells. The depth can also be adjusted according to the concentration of the dyes, which solves the high solubility problem of the electrode-illuminated cells. The configuration is mathematically modeled and the advantages over the conventional cell are shown. A computer model is built for more detailed analysis.

  6. A vertically resolved model for phytoplankton aggregation

    Indian Academy of Sciences (India)

    Iris Kriest; Geoffrey T Evans

    2000-12-01

    This work presents models of the vertical distribution and flux of phytoplankton aggregates, including changes with time in the distribution of aggregate sizes and sinking speeds. The distribution of sizes is described by two parameters, the mass and number of aggregates, which greatly reduces the computational cost of the models. Simple experiments demonstrate the effects of aggregation on the timing and depth distribution of primary production and export. A more detailed ecological model is applied to sites in the Arabian Sea; it demonstrates that aggregation can be important for deep sedimentation even when its effect on surface concentrations is small, and it presents the difference in timing between settlement of aggregates and fecal pellets.

  7. Ultrahigh efficiencies in vertical epitaxial heterostructure architectures

    Science.gov (United States)

    Fafard, S.; York, M. C. A.; Proulx, F.; Valdivia, C. E.; Wilkins, M. M.; Arès, R.; Aimez, V.; Hinzer, K.; Masson, D. P.

    2016-02-01

    Optical to electrical power converting semiconductor devices were achieved with breakthrough performance by designing a Vertical Epitaxial Heterostructure Architecture. The devices are featuring modeled and measured conversion efficiencies greater than 65%. The ultrahigh conversion efficiencies were obtained by monolithically integrating several thin GaAs photovoltaic junctions tailored with submicron absorption thicknesses and grown in a single crystal by epitaxy. The heterostructures that were engineered with a number N of such ultrathin junctions yielded an optimal external quantum efficiencies approaching 100%/N. The heterostructures are capable of output voltages that are multiple times larger than the corresponding photovoltage of the input light. The individual nanoscale junctions are each generating up to ˜1.2 V of output voltage when illuminated in the infrared. We compare the optoelectronic properties of phototransducers prepared with designs having 5 to 12 junctions and that are exhibiting voltage outputs between >5 V and >14 V.

  8. Predicting Vertical Jump Height from Bar Velocity

    Directory of Open Access Journals (Sweden)

    Amador García-Ramos, Igor Štirn, Paulino Padial, Javier Argüelles-Cienfuegos, Blanca De la Fuente, Vojko Strojnik, Belén Feriche

    2015-06-01

    Full Text Available The objective of the study was to assess the use of maximum (Vmax and final propulsive phase (FPV bar velocity to predict jump height in the weighted jump squat. FPV was defined as the velocity reached just before bar acceleration was lower than gravity (-9.81 m·s-2. Vertical jump height was calculated from the take-off velocity (Vtake-off provided by a force platform. Thirty swimmers belonging to the National Slovenian swimming team performed a jump squat incremental loading test, lifting 25%, 50%, 75% and 100% of body weight in a Smith machine. Jump performance was simultaneously monitored using an AMTI portable force platform and a linear velocity transducer attached to the barbell. Simple linear regression was used to estimate jump height from the Vmax and FPV recorded by the linear velocity transducer. Vmax (y = 16.577x - 16.384 was able to explain 93% of jump height variance with a standard error of the estimate of 1.47 cm. FPV (y = 12.828x - 6.504 was able to explain 91% of jump height variance with a standard error of the estimate of 1.66 cm. Despite that both variables resulted to be good predictors, heteroscedasticity in the differences between FPV and Vtake-off was observed (r2 = 0.307, while the differences between Vmax and Vtake-off were homogenously distributed (r2 = 0.071. These results suggest that Vmax is a valid tool for estimating vertical jump height in a loaded jump squat test performed in a Smith machine.

  9. Vertical profiles of BC direct radiative effect over Italy: high vertical resolution data and atmospheric feedbacks

    Science.gov (United States)

    Močnik, Griša; Ferrero, Luca; Castelli, Mariapina; Ferrini, Barbara S.; Moscatelli, Marco; Grazia Perrone, Maria; Sangiorgi, Giorgia; Rovelli, Grazia; D'Angelo, Luca; Moroni, Beatrice; Scardazza, Francesco; Bolzacchini, Ezio; Petitta, Marcello; Cappelletti, David

    2016-04-01

    Black carbon (BC), and its vertical distribution, affects the climate. Global measurements of BC vertical profiles are lacking to support climate change research. To fill this gap, a campaign was conducted over three Italian basin valleys, Terni Valley (Appennines), Po Valley and Passiria Valley (Alps), to characterize the impact of BC on the radiative budget under similar orographic conditions. 120 vertical profiles were measured in winter 2010. The BC vertical profiles, together with aerosol size distribution, aerosol chemistry and meteorological parameters, have been determined using a tethered balloon-based platform equipped with: a micro-Aethalometer AE51 (Magee Scientific), a 1.107 Grimm OPC (0.25-32 μm, 31 size classes), a cascade impactor (Siuotas SKC), and a meteorological station (LSI-Lastem). The aerosol chemical composition was determined from collected PM2.5 samples. The aerosol absorption along the vertical profiles was measured and optical properties calculated using the Mie theory applied to the aerosol size distribution. The aerosol optical properties were validated with AERONET data and then used as inputs to the radiative transfer model libRadtran. Vertical profiles of the aerosol direct radiative effect, the related atmospheric absorption and the heating rate were calculated. Vertical profile measurements revealed some common behaviors over the studied basin valleys. From below the mixing height to above it, a marked concentration drop was found for both BC (from -48.4±5.3% up to -69.1±5.5%) and aerosol number concentration (from -23.9±4.3% up to -46.5±7.3%). These features reflected on the optical properties of the aerosol. Absorption and scattering coefficients decreased from below the MH to above it (babs from -47.6±2.5% up to -71.3±3.0% and bsca from -23.5±0.8% up to -61.2±3.1%, respectively). Consequently, the Single Scattering Albedo increased above the MH (from +4.9±2.2% to +7.4±1.0%). The highest aerosol absorption was

  10. Vertical semiconducting single-walled carbon nanotube Schottky diode

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sunghwan [Dankook University, Yongin (Korea, Republic of)

    2014-07-15

    This paper presents a vertical semiconducting single-walled carbon nanotube (s-SWCNT)-based Schottky device. For the first time, the author successfully demonstrated a vertical s-SWCNT Schottky diode on an anodized aluminum oxide (AAO) template. In the vertical pores of an AAO template s-SWCNTs were vertically grown and aligned. The vertical growth of s-SWCNTs inside the pores was achieved by successfully isolating the catalyst at the bottom of the pores by using redeposition enabled angled ion milling. The ends of the grown s-SWCNTs were coated with palladium and titanium to form Schottky and Ohmic contacts, respectively. The I-V characteristics of the vertical s-SWCNT paths engaging the Schottky and Ohmic contacts well demonstrated Schottky diode rectification.

  11. Decoration of vertical graphene with aerosol nanoparticles for gas sensing

    Science.gov (United States)

    Cui, Shumao; Guo, Xiaoru; Ren, Ren; Zhou, Guihua; Chen, Junhong

    2015-08-01

    A facile method was demonstrated to decorate aerosol Ag nanoparticles onto vertical graphene surfaces using a mini-arc plasma reactor. The vertical graphene was directly grown on a sensor electrode using a plasma-enhanced chemical vapor deposition (PECVD) method. The aerosol Ag nanoparticles were synthesized by a simple vapor condensation process using a mini-arc plasma source. Then, the nanoparticles were assembled on the surface of vertical graphene through the assistance of an electric field. Based on our observation, nonagglomerated Ag nanoparticles formed in the gas phase and were assembled onto vertical graphene sheets. Nanohybrids of Ag nanoparticle-decorated vertical graphene were characterized for ammonia gas detection at room temperature. The vertical graphene served as the conductance channel, and the conductance change upon exposure to ammonia was used as the sensing signal. The sensing results show that Ag nanoparticles significantly improve the sensitivity, response time, and recovery time of the sensor.

  12. Verticality perception during and after galvanic vestibular stimulation.

    Science.gov (United States)

    Volkening, Katharina; Bergmann, Jeannine; Keller, Ingo; Wuehr, Max; Müller, Friedemann; Jahn, Klaus

    2014-10-01

    The human brain constructs verticality perception by integrating vestibular, somatosensory, and visual information. Here we investigated whether galvanic vestibular stimulation (GVS) has an effect on verticality perception both during and after application, by assessing the subjective verticals (visual, haptic and postural) in healthy subjects at those times. During stimulation the subjective visual vertical and the subjective haptic vertical shifted towards the anode, whereas this shift was reversed towards the cathode in all modalities once stimulation was turned off. Overall, the effects were strongest for the haptic modality. Additional investigation of the time course of GVS-induced changes in the haptic vertical revealed that anodal shifts persisted for the entire 20-min stimulation interval in the majority of subjects. Aftereffects exhibited different types of decay, with a preponderance for an exponential decay. The existence of such reverse effects after stimulation could have implications for GVS-based therapy. PMID:25157799

  13. Infants' sensitivity to vertical disparity for depth perception

    Science.gov (United States)

    Tsuruhara, Aki; Kaneko, Hirohiko; Kanazawa, So; Otsuka, Yumiko; Shirai, Nobu; Yamaguchi, Masami K.

    2013-05-01

    Both horizontal and vertical binocular disparities produce depth perception in adults. In developmental studies, infants aged around 4 to 6 months were shown to perceive depth from horizontal disparity. However, infants' sensitivity to vertical disparity has not been shown clearly. To examine the sensitivity in infants, this study measured preferential looking behavior of infants aged 20 to 27 weeks. Results showed a significant preference for the stimulus with vertical disparity, providing the first evidence of infants' sensitivity to vertical disparity. The infants in the same age group did not show preference for stimulus with horizontal disparity when the stimulus were comparable to the stimulus with vertical disparity, while their sensitivity to horizontal disparity was confirmed with the stimuli used in a previous study. Our results would suggest that properties in processing horizontal and vertical disparities are different in infancy, and that the sensitivity to horizontal disparity are still premature in 27 weeks after birth.

  14. Bargaining in vertical relationships and suppliers' R&D profitability

    OpenAIRE

    Köhler, Christian

    2014-01-01

    This paper explores the effect of bargaining in vertical relationships on the profitability of suppliers' R&D investments. Studies on the relationship between R&D and firm profitability mostly concentrate on the impact of horizontal market structure and neglect vertical interac-tions. Building on theoretical and empirical evidence about the effects of bargaining in vertical relationships, the crucial determinants of a supplier's bargaining power are identified as the market position and the d...

  15. Vertical Test Reuse for Embedded Systems: A Systematic Mapping Study

    OpenAIRE

    Flemström, Daniel; Sundmark, Daniel; Afzal, Wasif

    2015-01-01

    Abstract —Vertical test reuse refers to the the reuse of test cases or other test artifacts over different integration levels in the software or system engineering process. Vertical test reuse has previously been proposed for reducing test effort and improving test effectiveness, particularly for embedded system development. The goal of this study is to provide an overview of the state of the art in the field of vertical test reuse for e...

  16. Estudio del transporte vertical de un edificio de oficinas

    OpenAIRE

    Sánchez Gámez, Isabel

    2013-01-01

    El presente documento estudia un proyecto completo de ingeniería del transporte vertical de un edificio de oficinas. El transporte vertical de un edificio es una de las instalaciones fundamentales a la hora de diseñar el edificio. Un diseño incorrecto del núcleo de ascensores puede originar graves problemas a los usuarios y un sobredimensionamiento puede elevar los costes de mantenimiento innecesariamente. El estudio del transporte vertical de un edificio consta de dos parte...

  17. Analysis and design of a vertical axis wind turbine

    OpenAIRE

    Goyena Iriso, Joseba

    2011-01-01

    The main objective of this project is to design a new vertical axis wind turbine, specifically one Giromill wind turbine. The project development requires performing a previous study of the vertical axis wind turbines currently development. This study has to be performed before starting to design the wind turbine. Other very important aim is the development of a new vertical axis wind turbine. The after analyses that will result in the final design of the wind turbine will b...

  18. Structural reasons for vertical integration in the international oil industry

    International Nuclear Information System (INIS)

    Once upon a time, the international oil industry was vertically integrated. A small group of companies controlled a very substantial share of international oil flows, extending their operations from the oil well to the gas pump, and relying on intracorporate transfers for most in-between transactions. The historical reasons for vertical disintegration, the market role, and structural reasons for vertical reintegration are examined. (author)

  19. Vertical integration and pricing outcomes in retail gasoline markets

    OpenAIRE

    Joshua Karl Austin

    2015-01-01

    The real world impact of vertical integration on prices for consumers remains a controversial topic. Economic theory suggests that there are multiple effects of vertical integration on prices which work in opposite directions. This paper employs high frequency panel data from a regional U.S. market to determine which effects are dominant at retail gasoline stations. Using two different techniques, I find that vertically-integrated company-operated gasoline stations charge prices five to eleve...

  20. EXPERIMENTAL STUDY ON WHOLE TREE VERTICAL TENSILE STRENGTH

    Institute of Scientific and Technical Information of China (English)

    Lihua CHEN; Xinxiao YU; Dongsheng ZHANG

    2004-01-01

    This paper studies the vertical tensile strength of whole tree roots under the same soil and landform conditions.The experiments show that the shape of a root system's distribution affects the vertical tensile strength of roots.Rhododendron trees have horizontal root systems,so the whole roots were pulled out in the experiment process.Populous purdomii has vertical roots,so the experiment continued quite a long time.Abies fabric has both vertical and horizontal main roots,so the P-S curve shows a multi-peak shape.

  1. Reconstruction of the vertical electron density profile based on vertical TEC using the simulated annealing algorithm

    Science.gov (United States)

    Jiang, Chunhua; Yang, Guobin; Zhu, Peng; Nishioka, Michi; Yokoyama, Tatsuhiro; Zhou, Chen; Song, Huan; Lan, Ting; Zhao, Zhengyu; Zhang, Yuannong

    2016-05-01

    This paper presents a new method to reconstruct the vertical electron density profile based on vertical Total Electron Content (TEC) using the simulated annealing algorithm. The present technique used the Quasi-parabolic segments (QPS) to model the bottomside ionosphere. The initial parameters of the ionosphere model were determined from both International Reference Ionosphere (IRI) (Bilitza et al., 2014) and vertical TEC (vTEC). Then, the simulated annealing algorithm was used to search the best-fit parameters of the ionosphere model by comparing with the GPS-TEC. The performance and robust of this technique were verified by ionosonde data. The critical frequency (foF2) and peak height (hmF2) of the F2 layer obtained from ionograms recorded at different locations and on different days were compared with those calculated by the proposed method. The analysis of results shows that the present method is inspiring for obtaining foF2 from vTEC. However, the accuracy of hmF2 needs to be improved in the future work.

  2. Vertical Cable Seismic Survey for SMS exploration

    Science.gov (United States)

    Asakawa, Eiichi; Murakami, Fumitoshi; Tsukahara, Hotoshi; Mizohata, Shigeharu

    2014-05-01

    The Vertical Cable Seismic (VCS) survey is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by sea-surface, deep-towed or ocean bottom sources. Analyzing the reflections from the sub-seabed, we could look into the subsurface structure. Because the VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed it for the SMS survey tool development program that the Ministry of Education, Culture, Sports, Science and Technology (MEXT) started in 2009. We have been developing the VCS survey system, including not only data acquisition hardware but data processing and analysis technique. We carried out several VCS surveys combining with surface towed source, deep towed source and ocean bottom source. The water depths of these surveys are from 100m up to 2100 m. Through these experiments, our VCS data acquisition system has been also completed. But the data processing techniques are still on the way. One of the most critical issues is the positioning in the water. The uncertainty in the positions of the source and of the hydrophones in water degraded the quality of subsurface image. GPS navigation system is available on sea surface, but in case of deep-towed source or ocean bottom source, the accuracy of shot position with SSBL/USBL is not sufficient for the very high-resolution imaging. We have developed a new approach to determine the positions in water using the travel time data from the source to VCS hydrophones. In 2013, we have carried out the second VCS survey using the surface-towed high-voltage sparker and ocean bottom source in the Izena Cauldron, which is one of the most promising SMS areas around Japan. The positions of ocean bottom source estimated by this method are consistent with the VCS field records. The VCS data with the sparker have been processed with 3D PSTM. It gives the very high resolution 3D volume deeper than two

  3. Functionalization of vertically aligned carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Eloise Van Hooijdonk

    2013-02-01

    Full Text Available This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs. The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.

  4. A vertical approach to cardiac arrhythmias.

    Science.gov (United States)

    Vaughan Williams, E M

    1987-10-01

    Study of cardiac arrhythmia may be pursued vertically, as up the rungs of a ladder, from symptom to ECG, to EPS, to local lesion, to intracellular metabolism and to alterations of the latter and their effects on charge-transfer by ions across the cell membrane. Raised intracellular cAMP and calcium concentrations are responses to normal physiological controls, and highly abnormal ECGs occur in normal people under stress without progressing to life threatening arrhythmias, yet do so in susceptible individuals. Conversely, appropriate stimulation can precipitate ventricular fibrillation in normal myocardium. Selective stimulation of different types of adrenoceptor has differing electrophysiological effects. Beta 1-adrenoceptors increase contraction and calcium current, and shorten action potential duration (APD) by increasing potassium conductance. Beta 2-adrenoceptors do not increase calcium entry, but shorten APD by stimulating electrogenic Na/K pumping, alpha-adrenoceptors prolong contractions and lengthen APD. It is suggested that the tachycardia, extrasystoles and shortening of APD occurring in response to adrenergic stimuli and hypoxia, are accessory factors, not primary causes, in the development of arrhythmias, and constitute a danger when there is an appropriate anatomical substrate for re-entry. Serious arrhythmias are of multifactorial origin, of which "calcium overload" is but one, not proven to be a frequent one.

  5. Vertical transmission of Theileria lestoquardi in sheep.

    Science.gov (United States)

    Zakian, Amir; Nouri, Mohammad; Barati, Farid; Kahroba, Hooman; Jolodar, Abbas; Rashidi, Fardokht

    2014-07-14

    This is the first report of an outbreak of Theileria lestoquardi abortion and stillbirth in a mob of 450 ewes in July 2012, during which, approximately 35 late-term ewes lost their fetuses over a 5-day period. A dead ewe and her aborted fetus were transported to the Ahvaz Veterinary Hospital for the diagnostic evaluation. The microbial cultures from the ewe vaginal discharges and fetal abomasal contents and the liver were negative. The blood films of the ewe and her fetus contained Theileria piroplasms and the impression smears from ewe liver and fetal spleen were positive for Theileria Koch blue bodies. The DNA was extracted from the liver and spleen of ewe and her fetus, respectively, and analyzed by polymerase chain reaction (PCR) using specific primers derived from the nucleotide sequences of 18S ribosomal DNA (rDNA) gene of T. lestoquardi. A single fragment of 428-bp fragment was amplified. The PCR product was directly sequenced and the alignment of the sequence with similar sequences in GenBank(®) showed 100% identities with 18S rDNA gene of T. lestoquardi. The present study is the first report of the T. lestoquardi vertical transmission that could be related to the abortion.

  6. Condensation of refrigerants on vertical fluted tubes

    Energy Technology Data Exchange (ETDEWEB)

    Combs, S.K.; Mailen, G.S.; Murphy, R.W.

    1978-08-01

    Experiments were run to determine heat transfer performance of single vertical fluted tubes with selected fluids condensing on the outside. Working fluids included six fluorocarbons (Refrigerants 11, 21, 22, 113, 114, and 115) and a hydrocarbon (Refrigerant 600a or isobutane). The nine test tubes were of 2.54-cm (1-in.) nominal outside diameter and 1.2 m (4 ft) in length with from 0 (smooth) to 60 axial flutes. Condensing heat transfer coefficients ranged from 620 to 7900 W/m/sup 2/ . K (110 to 1400 Btu/hr . ft/sup 2/ . /sup 0/F) over the heat flux range of 2000 to 43,000 W/m/sup 2/ (920 to 13,600 Btu/hr . ft/sup 2/). All parameters are based on total condensing surface area. The data show that, for a given heat flux, a fluted tube can increase condensing coefficients up to 6.0 times smooth tube values. Further heat transfer enhancement was achieved by the use of drainage skirts on fluted tubes; these skirts effectively divided the 1.2-m (4-ft) tubes into two, four, and eight equal condensing lengths.

  7. Free convective condensation in a vertical enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Fox, R.J.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States); Corradini, M.L.; Pernsteiner, A.P. [Univ. of Wisconsin, Madison, WI (United States)

    1995-09-01

    Free convective condensation in a vertical enclosure was studied numerically and the results were compared with experiments. In both the numerical and experimental investigations, mist formation was observed to occur near the cooling wall, with significant droplet concentrations in the bulk. Large recirculation cells near the end of the condensing section were generated as the heavy noncondensing gas collecting near the cooling wall was accelerated downward. Near the top of the enclosure the recirculation cells became weaker and smaller than those below, ultimately disappearing near the top of the condenser. In the experiment the mist density was seen to be highest near the wall and at the bottom of the condensing section, whereas the numerical model predicted a much more uniform distribution. The model used to describe the formation of mist was based on a Modified Critical Saturation Model (MCSM), which allows mist to be generated once the vapor pressure exceeds a critical value. Equilibrium, nonequilibrium, and MCSM calculations were preformed, showing the experimental results to lie somewhere in between the equilibrium and nonequilibrium predictions of the numerical model. A single adjustable constant (indicating the degree to which equilibrium is achieved) is used in the model in order to match the experimental results.

  8. Numerical Simulation of Rotating Vertical Bridgman Growth

    Directory of Open Access Journals (Sweden)

    S. Nouri

    2016-01-01

    Full Text Available The present work is proposed a numerical parametric study of heat and mass transfer in a rotating vertical cylinder during the solidification of a binary metallic alloy. The aim of this paper is to present an enthalpy formulation based on the fixed grid methodology for the numerical solution of convective-diffusion during the phase change in the case of the steady crucible rotation. The extended Darcy model including the time derivative and Coriolis terms was applied as momentum equation. It was found that the buoyancy driven flow and solute distribution can be affected significantly by the rotating cylinder. The problem is governed by the Navier-Stokes equations coupled with the conservation laws of energy and solute. The resulting system was discretized by the control volume method and solved by the SIMPLER algorithm proposed by Patankar. A computer code was developed and validated by comparison with previous studies. It can be observed that the forced convection introduced by rotation, dramatically changes the flow and solute distribution at the interface (liquid-mushy zone. The effect of Reynolds number on the Nusselt number, flow and solute distribution is presented and discussed.

  9. Vertical Distribution of Vibrationally Excited Hydroxyl

    Science.gov (United States)

    Grygalashvyly, Mykhaylo; Becker, Erich; Sonnemann, Gerd

    2016-04-01

    Knowledge about the vertical distribution of the vibrationally excited states of hydroxyl (OH*) is important for the interpretation of airglow measurements with respect to dynamical processes in the mesopause region. We derive an approximate analytical expression for the distribution of OH* that highlights the dependence on atomic oxygen and temperature. In addition, we use an advanced numerical model for the formation and relaxation of OH* and investigate the distributions of the different vibrationally exited states of OH*. For the production of OH*, the model includes the reaction of atomic hydrogen with ozone, as well as the reaction of atomic oxygen with hydroperoxy radicals. As loss processes we include 1) deactivation by atomic oxygen, molecular oxygen, and molecular nitrogen, 2) spontaneous emission, and 3) loss due to chemical reaction with atomic oxygen. All these processes take the dependence on the vibrational number into account. The quenching by molecular and atomic oxygen is parameterized by a multi-quantum relaxation scheme. This diagnostic model for OH* has been implemented as part of a chemistry-transport model that is driven by the dynamics simulated with the KMCM (Kühlungsborn Mechanistic general Circulation Model). Numerical results confirm that emission from excited states with higher vibrational number is weaker and emanates from higher altitudes. In addition we find that the OH*-peak altitudes depend significantly on season and latitude. This behavior is mainly controlled by the corresponding variations of atomic oxygen and temperature, as is also confirmed by the aforementioned approximate theory.

  10. Vertical structure of Advection dominated Accretion Flows

    CERN Document Server

    Zeraatgari, Fateme Zahra

    2015-01-01

    We solve the set of hydrodynamic (HD) equations for optically thin Advection Dominated Accretion Flows (ADAFs) by assuming radially self-similar in spherical coordinate system $ (r, \\theta, \\phi) $. The disk is considered to be steady state and axi-symmetric. We define the boundary conditions at the pole and the equator of the disk and to avoid singularity at the rotation axis, the disk is taken to be symmetric with respect to this axis. Moreover, only the $ \\tau_{r \\phi} $ component of viscous stress tensor is assumed and we have set $ v_{\\theta} = 0 $. The main purpose of this study is to investigate the variation of dynamical quantities of the flow in the vertical direction by finding an analytical solution. As a consequence, we found that the advection parameter, $ f^{adv} $, varies along the $ \\theta $ direction and reaches to its maximum near the rotation axis. Our results also show that, in terms of no-outflow solution, thermal equilibrium still exists and consequently advection cooling can balance vis...

  11. ATLAS LTCS Vertically Challenged System Lessons Learned

    Science.gov (United States)

    Patel, Deepak; Garrison, Matt; Ku, Jentung

    2014-01-01

    Re-planning of LTCS TVAC testing and supporting RTA (Receiver Telescope Assembly) Test Plan and Procedure document preparation. The Laser Thermal Control System (LTCS) is designed to maintain the lasers onboard Advanced Topographic Laser Altimeter System (ATLAS) at their operational temperatures. In order to verify the functionality of the LTCS, a thermal balance test of the thermal hardware was performed. During the first cold start of the LTCS, the Loop Heat Pipe (LHP) was unable to control the laser mass simulators temperature. The control heaters were fully on and the loop temperature remained well below the desired setpoint. Thermal analysis of the loop did not show these results. This unpredicted behavior of the LTCS was brought up to a panel of LHP experts. Based on the testing and a review of all the data, there were multiple diagnostic performed in order to narrow down the cause. The prevailing theory is that gravity is causing oscillating flow within the loop, which artificially increased the control power needs. This resulted in a replan of the LTCS test flow and the addition of a GSE heater to allow vertical operation.

  12. Vertical landscraping, a big regionalism for Dubai.

    Science.gov (United States)

    Wilson, Matthew

    2010-01-01

    Dubai's ecologic and economic complications are exacerbated by six years of accelerated expansion, a fixed top-down approach to urbanism and the construction of iconic single-phase mega-projects. With recent construction delays, project cancellations and growing landscape issues, Dubai's tower typologies have been unresponsive to changing environmental, socio-cultural and economic patterns (BBC, 2009; Gillet, 2009; Lewis, 2009). In this essay, a theory of "Big Regionalism" guides an argument for an economically and ecologically linked tower typology called the Condenser. This phased "box-to-tower" typology is part of a greater Landscape Urbanist strategy called Vertical Landscraping. Within this strategy, the Condenser's role is to densify the city, facilitating the creation of ecologic voids that order the urban region. Delineating "Big Regional" principles, the Condenser provides a time-based, global-local urban growth approach that weaves Bigness into a series of urban-regional, economic and ecological relationships, builds upon the environmental performance of the city's regional architecture and planning, promotes a continuity of Dubai's urban history, and responds to its landscape issues while condensing development. These speculations permit consideration of the overlooked opportunities embedded within Dubai's mega-projects and their long-term impact on the urban morphology.

  13. Vertical shear of the galactic interstellar medium

    Directory of Open Access Journals (Sweden)

    Robert A. Benjamin

    2000-01-01

    Full Text Available La detecci on de absorci on en UV, 21 cm, H y otras l neas difusas de emisi on en el optico de gas de hasta 10 kpc sobre el plano de la V a L actea y de otras galaxias, permite estudiar la rotaci on de las \\atm osferas" ionizadas de las galaxias. Esta rotaci on tiene implicaciones al entendimiento del potencial gravitacional Gal actico, al transporte del momento angular del disco y al mantenimiento del di- namo Gal actico. Las evidencias indican que el gas rota de forma casi cil ndrica hasta varios kiloparsecs. Esto va en contra de la idea de que, suponiendo un mod- elo de masa razonable para la Galaxia, deb a de haber un gradiente de rotaci on pronunciado como funci on de la altura sobre el plano. Por ejemplo, en el corte vertical a un radio galactoc entrico de R = 5 kpc en NGC 891 hecho por Rand, la velocidad de rotaci on baja 30 km s de z = 1 a 5 kpc y deb a bajar unos 80 km s La tensi on magn etica puede resolver la discrepancia y se examinar an otras posibilidades en el futuro.

  14. Premixed flame propagation in vertical tubes

    Science.gov (United States)

    Kazakov, Kirill A.

    2016-04-01

    Analytical treatment of the premixed flame propagation in vertical tubes with smooth walls is given. Using the on-shell flame description, equations for a quasi-steady flame with a small but finite front thickness are obtained and solved numerically. It is found that near the limits of inflammability, solutions describing upward flame propagation come in pairs having close propagation speeds and that the effect of gravity is to reverse the burnt gas velocity profile generated by the flame. On the basis of these results, a theory of partial flame propagation driven by a strong gravitational field is developed. A complete explanation is given of the intricate observed behavior of limit flames, including dependence of the inflammability range on the size of the combustion domain, the large distances of partial flame propagation, and the progression of flame extinction. The role of the finite front-thickness effects is discussed in detail. Also, various mechanisms governing flame acceleration in smooth tubes are identified. Acceleration of methane-air flames in open tubes is shown to be a combined effect of the hydrostatic pressure difference produced by the ambient cold air and the difference of dynamic gas pressure at the tube ends. On the other hand, a strong spontaneous acceleration of the fast methane-oxygen flames at the initial stage of their evolution in open-closed tubes is conditioned by metastability of the quasi-steady propagation regimes. An extensive comparison of the obtained results with the experimental data is made.

  15. Vertical barriers with increased sorption capacities

    Energy Technology Data Exchange (ETDEWEB)

    Bradl, H.B. [Bilfinger + Berger Bauaktiengesellschaft, Mannheim (Germany)

    1997-12-31

    Vertical barriers are commonly used for the containment of contaminated areas. Due to the very small permeability of the barrier material which is usually in the order of magnitude of 10-10 m/s or less the advective contaminant transport can be more or less neglected. Nevertheless, there will always be a diffusive contaminant transport through the barrier which is caused by the concentration gradient. Investigations have been made to increase the sorption capacity of the barrier material by adding substances such as organoclays, zeolites, inorganic oxides and fly ashes. The contaminants taken into account where heavy metals (Pb) and for organic contaminants Toluole and Phenantrene. The paper presents results of model calculations and experiments. As a result, barrier materials can be designed {open_quotes}tailor-made{close_quotes} depending on the individual contaminant range of each site (e.g. landfills, gasworks etc.). The parameters relevant for construction such as rheological properties, compressive strength and permeability are not affected by the addition of the sorbents.

  16. First plasma operation of the enhanced JET vertical stabilisation system

    NARCIS (Netherlands)

    Rimini, F. G.; Crisanti, F.; Albanese, R.; Ambrosino, G.; Ariola, M.; Artaserse, G.; Bellizio, T.; Coccorese, V.; De Tommasi, G.; P. de Vries,; Lomas, P. J.; Maviglia, F.; Neto, A.; Nunes, I.; Pironti, A.; Ramogida, G.; Sartori, F.; Shaw, S. R.; Tsalas, M.; Vitelli, R.; Zabeo, L.

    2011-01-01

    A project dedicated to the enhancement of the JET vertical stabilization system was launched in 2006, including an upgrade of the Power Supply of the Radial Field Amplifier, of hardware and software of the vertical stabilization control system. The main aim was to double the JET capability in stabil

  17. Subjective visual vertical and postural performance in healthy children.

    Directory of Open Access Journals (Sweden)

    Chrystal Gaertner

    Full Text Available INTRODUCTION: Verticality is essential in our life, especially for postural stability. Subjective vertical as well as postural stability depends on different sensorial information: visual, vestibular and somesthesic. They help to build the spatial referentials and create a central representation of verticality. Children are more visuo-dependant than adults; however, we did not find any study focusing on how children develop their sense of verticality. METHODS: WE STUDIED TWO GROUPS OF SUBJECTS: 10 children (from 6 to 8 years and 12 young adults. We recorded postural stability with a Techno Concept plateform and perception of subjective visual vertical in the following conditions: while adjusting the vertical in the dark or with visual perturbation, while fixating the vertical bar, and with eyes closed. RESULTS: Children are more instable than adults in terms of postural parameters, and also while performing a double task, especially when no visual references are present. They also present a higher variability and lower accuracy than adults in reporting their perception of true vertical reference. DISCUSSION: Children might have limited attentional resources, and focus their attention on the more demanding task, corresponding to the U-shaped non-linear model.

  18. Characteristics of Vertical Mantle Heat Exchangers for Solar Water Heaters

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Morrison, G.L.; Behnia, M.

    1999-01-01

    - The flow structure in vertical mantle heat exchangers was investigated using a full-scale tank designed to facilitate flow visualisation. The flow structure and velocities in the mantle were measured using a particle Image Velocimetry (PIV) system. A CFD simulation model of vertical mantle heat...

  19. Vertically Conductive MoS2 Spiral Pyramid.

    Science.gov (United States)

    Ly, Thuc Hue; Zhao, Jiong; Kim, Hyun; Han, Gang Hee; Nam, Honggi; Lee, Young Hee

    2016-09-01

    MoS2 spirals grown by the chemical vapor deposition method, driven by a threading dislocation, has a peculiar rhombohedral-like structure. This threading dislocation can carry helical current in the vertical direction and greatly enhances the vertical conductance in the MoS2 multilayer samples.

  20. A Buried Vertical Filter for Micro and Nanoparticle Filtration

    NARCIS (Netherlands)

    Li, S.J.; Shen, C.; Sarro, P.M.

    2011-01-01

    This paper presents a silicon micromachined filter for micro- and nanoparticles. The filter is vertical and completely buried beneath the surface. The buried aspect allows additional features to be integrated above the filter, while the vertical aspect allows the creation of highly uniform pores and

  1. The bending of rectangular weakened by a vertical crack

    OpenAIRE

    Babloyan A.H.; Baghdasaryan A.V.

    2008-01-01

    The solution of a problem of elasticity theory for rectangular weakened by a centrally located vertical crack is brought. On the horizontal sides of the rectangular and on the crack faces the stresses are given. On the vertical sides of the rectangular three types of boundary conditions are given.

  2. Mechanistic simulation of the vertical structure of mixed swards

    NARCIS (Netherlands)

    Schulte, R.P.O.; Lantinga, E.A.

    2002-01-01

    The vertical structure is an important feature of mixed swards, as it influences the inter-species competition for light, as well as the patterns of grazing. Although the experimental measurement of the vertical sward structure is relatively straightforward, the mechanistic and dynamic modelling of

  3. Vertically Integrated Thermo-Optic Waveguide Switch Using Optical Polymers

    Institute of Scientific and Technical Information of China (English)

    Ki-Hong Kim; Sang-Yung Shin; Doo-Sun Choi

    2003-01-01

    We propose and fabricate a vertically integrated thermo-optic waveguide switch. It controls the optical path between two vertically stacked waveguides using the thermo-optic effect of optical polymer. The measured crosstalk is less than-10 dB.

  4. Vertically Integrated Thermo-Optic Waveguide Switch Using Optical Polymers

    Institute of Scientific and Technical Information of China (English)

    Ki-Hong; Kim; Sang-Yung; Shin; Doo-Sun; Choi

    2003-01-01

    We propose and fabricate a vertically integrated thermo-optic waveguide switch. It controls the optical path between two vertically stacked waveguides using the thermo-optic effect of optical polymer. The measured crosstalk is less than -10 dB.

  5. The vertical birthing position of the Trobrianders, Papua New Guinea.

    Science.gov (United States)

    Pöschl, U

    1987-05-01

    During an ethnomedical field study the author succeeded in participating and photographing 4 traditional birthgivings among the Trobrianders/Papua New Guinea. Their various vertical postures are described with special reference to specific Trobriand practices and discussed by literature review. The results suggest that vertical birthing positions are advantageous to horizontal ones and should be reconsidered by modern Western obstetrics.

  6. Finding people, papers, and posts: Vertical search algorithms and evaluation

    NARCIS (Netherlands)

    R.W. Berendsen

    2015-01-01

    There is a growing diversity of information access applications. While general web search has been dominant in the past few decades, a wide variety of so-called vertical search tasks and applications have come to the fore. Vertical search is an often used term for search that targets specific conten

  7. CREATING EFFECTIVE MODELS OF VERTICAL INTEGRATED STRUCTURES IN UKRAINE

    Directory of Open Access Journals (Sweden)

    D. V. Koliesnikov

    2011-01-01

    Full Text Available The results of scientific research aimed at development of methodology-theoretical mechanisms of building the effective models of vertically-integrated structures are presented. A presence of vertically-integrated structures on natural-monopolistic markets at private and governmental sectors of economy and priority directions of integration are given.

  8. Vertical cross-spectral phases in neutral atmospheric flow

    DEFF Research Database (Denmark)

    Chougule, Abhijit S.; Mann, Jakob; Kelly, Mark C.;

    2012-01-01

    increase with stream-wise wavenumber and vertical separation distance, but there is no significant change in the phase angle of vertical velocity, which remains close to zero. The phases are also calculated using a rapid distortion theory model and large-eddy simulation. The results from the models show...

  9. HYDRAULIC CHARACTERISTICS OF VERTICAL VORTEX AT HYDRAULIC INTAKES

    Institute of Scientific and Technical Information of China (English)

    CHEN Yun-liang; WU Chao; YE Mao; JU Xiao-ming

    2007-01-01

    The trace of vertical vortex flow at hydraulic intakes is of the shape of spiral lines, which was observed in the presented experiments with the tracer technique. It represents the fluid particles flow spirally from the water surface to the underwater and rotate around the vortex-axis multi-cycle. This process is similar to the movement of screw. To describe the multi-circle spiral characteristics under the axisymmetric condition, the vertical vortex would change not only in the radial direction but also in the axial direction. The improved formulae for three velocity components for the vertical vortex flow were deduced by using the method of separation of variables in this article. In the improved formulae, the velocity components are the functions of the radial and axial coordinates, so the multi-circle spiral flow of vertical vortex could be simulated. The calculated and measured results for the vertical vortex flow were compared and the causes of errors were analyzed.

  10. Vertical Transport of Subwavelength Localized Surface Electromagnetic Modes

    CERN Document Server

    Gao, Fei; Zhang, Youming; Shi, Xihang; Yang, Zhaoju; Zhang, Baile

    2015-01-01

    Transport of subwavelength electromagnetic (EM) energy has been achieved through near-field coupling of highly confined surface EM modes supported by plasmonic nanoparticles, in a configuration usually staying on a two-dimensional (2D) substrate. Vertical transport of similar modes along the third dimension, on the other hand, can bring more flexibility in designs of functional photonic devices, but this phenomenon has not been observed in reality. In this paper, designer (or spoof) surface plasmon resonators (plasmonic meta-atoms) are stacked in the direction vertical to their individual planes in demonstrating vertical transport of subwavelength localized surface EM modes. Dispersion relation of this vertical transport is determined from coupled mode theory and is verified with near-field transmission spectrum and field mapping with a microwave near-field scanning stage. This work extends the near-field coupled resonator optical waveguide (CROW) theory into the vertical direction, and may find applications ...

  11. Doppler Lidar Vertical Velocity Statistics Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, R. K. [DOE ARM Climate Research Facility, Washington, DC (United States); Sivaraman, C. [DOE ARM Climate Research Facility, Washington, DC (United States); Shippert, T. R. [DOE ARM Climate Research Facility, Washington, DC (United States); Riihimaki, L. D. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-07-01

    Accurate height-resolved measurements of higher-order statistical moments of vertical velocity fluctuations are crucial for improved understanding of turbulent mixing and diffusion, convective initiation, and cloud life cycles. The Atmospheric Radiation Measurement (ARM) Climate Research Facility operates coherent Doppler lidar systems at several sites around the globe. These instruments provide measurements of clear-air vertical velocity profiles in the lower troposphere with a nominal temporal resolution of 1 sec and height resolution of 30 m. The purpose of the Doppler lidar vertical velocity statistics (DLWSTATS) value-added product (VAP) is to produce height- and time-resolved estimates of vertical velocity variance, skewness, and kurtosis from these raw measurements. The VAP also produces estimates of cloud properties, including cloud-base height (CBH), cloud frequency, cloud-base vertical velocity, and cloud-base updraft fraction.

  12. Layer-by-layer assembly of vertically conducting graphene devices.

    Science.gov (United States)

    Chen, Jing-Jing; Meng, Jie; Zhou, Yang-Bo; Wu, Han-Chun; Bie, Ya-Qing; Liao, Zhi-Min; Yu, Da-Peng

    2013-01-01

    Graphene has various potential applications owing to its unique electronic, optical, mechanical and chemical properties, which are primarily based on its two-dimensional nature. Graphene-based vertical devices can extend the investigations and potential applications range to three dimensions, while interfacial properties are crucial for the function and performance of such graphene vertical devices. Here we report a general method to construct graphene vertical devices with controllable functions via choosing different interfaces between graphene and other materials. Two types of vertically conducting devices are demonstrated: graphene stacks sandwiched between two Au micro-strips, and between two Co layers. The Au|graphene|Au junctions exhibit large magnetoresistance with ratios up to 400% at room temperature, which have potential applications in magnetic field sensors. The Co|graphene|Co junctions display a robust spin valve effect at room temperature. The layer-by-layer assembly of graphene offers a new route for graphene vertical structures. PMID:23715280

  13. A vertical handoff decision algorithm based on ARMA prediction model

    Science.gov (United States)

    Li, Ru; Shen, Jiao; Chen, Jun; Liu, Qiuhuan

    2012-01-01

    With the development of computer technology and the increasing demand for mobile communications, the next generation wireless networks will be composed of various wireless networks (e.g., WiMAX and WiFi). Vertical handoff is a key technology of next generation wireless networks. During the vertical handoff procedure, handoff decision is a crucial issue for an efficient mobility. Based on auto regression moving average (ARMA) prediction model, we propose a vertical handoff decision algorithm, which aims to improve the performance of vertical handoff and avoid unnecessary handoff. Based on the current received signal strength (RSS) and the previous RSS, the proposed approach adopt ARMA model to predict the next RSS. And then according to the predicted RSS to determine whether trigger the link layer triggering event and complete vertical handoff. The simulation results indicate that the proposed algorithm outperforms the RSS-based scheme with a threshold in the performance of handoff and the number of handoff.

  14. Steerable vertical to horizontal energy transducer for mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Spletzer, Barry L. (Albuquerque, NM); Fischer, Gary J. (Albuquerque, NM); Feddema, John T. (Albuquerque, NM)

    2001-01-01

    The present invention provides a steerable vertical to horizontal energy transducer for mobile robots that less complex and requires less power than two degree of freedom tilt mechanisms. The present invention comprises an end effector that, when mounted with a hopping actuator, translates along axis (typically vertical) actuation into combined vertical and horizontal motion. The end effector, or foot, mounts with an end of the actuator that moves toward the support surface (typically a floor or the earth). The foot is shaped so that the first contact with the support surface is off the axis of the actuator. Off-axis contact with the support surface generates an on-axis force (typically resulting in vertical motion) and a moment orthogonal to the axis. The moment initiates a horizontal tumbling motion, and tilts the actuator so that its axis is oriented with a horizontal component and continued actuation generates both vertical and horizontal force.

  15. Spirit Near 'Stapledon' on Sol 1802 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA Mars Exploration Rover Spirit used its navigation camera for the images assembled into this full-circle view of the rover's surroundings during the 1,802nd Martian day, or sol, (January 26, 2009) of Spirit's mission on the surface of Mars. North is at the top. This view is presented as a vertical projection with geometric seam correction. Spirit had driven down off the low plateau called 'Home Plate' on Sol 1782 (January 6, 2009) after spending 12 months on a north-facing slope on the northern edge of Home Plate. The position on the slope (at about the 9-o'clock position in this view) tilted Spirit's solar panels toward the sun, enabling the rover to generate enough electricity to survive its third Martian winter. Tracks at about the 11-o'clock position of this panorama can be seen leading back to that 'Winter Haven 3' site from the Sol 1802 position about 10 meters (33 feet) away. For scale, the distance between the parallel wheel tracks is about one meter (40 inches). Where the receding tracks bend to the left, a circular pattern resulted from Spirit turning in place at a soil target informally named 'Stapledon' after William Olaf Stapledon, a British philosopher and science-fiction author who lived from 1886 to 1950. Scientists on the rover team suspected that the soil in that area might have a high concentration of silica, resembling a high-silica soil patch discovered east of Home Plate in 2007. Bright material visible in the track furthest to the right was examined with Spirit's alpha partical X-ray spectrometer and found, indeed, to be rich in silica. The team laid plans to drive Spirit from this Sol 1802 location back up onto Home Plate, then southward for the rover's summer field season.

  16. Graphene vertical hot-electron terahertz detectors

    International Nuclear Information System (INIS)

    We propose and analyze the concept of the vertical hot-electron terahertz (THz) graphene-layer detectors (GLDs) based on the double-GL and multiple-GL structures with the barrier layers made of materials with a moderate conduction band off-set (such as tungsten disulfide and related materials). The operation of these detectors is enabled by the thermionic emissions from the GLs enhanced by the electrons heated by incoming THz radiation. Hence, these detectors are the hot-electron bolometric detectors. The electron heating is primarily associated with the intraband absorption (the Drude absorption). In the frame of the developed model, we calculate the responsivity and detectivity as functions of the photon energy, GL doping, and the applied voltage for the GLDs with different number of GLs. The detectors based on the cascade multiple-GL structures can exhibit a substantial photoelectric gain resulting in the elevated responsivity and detectivity. The advantages of the THz detectors under consideration are associated with their high sensitivity to the normal incident radiation and efficient operation at room temperature at the low end of the THz frequency range. Such GLDs with a metal grating, supporting the excitation of plasma oscillations in the GL-structures by the incident THz radiation, can exhibit a strong resonant response at the frequencies of several THz (in the range, where the operation of the conventional detectors based on A3B5 materials, in particular, THz quantum-well detectors, is hindered due to a strong optical phonon radiation absorption in such materials). We also evaluate the characteristics of GLDs in the mid- and far-infrared ranges where the electron heating is due to the interband absorption in GLs.

  17. Coastal influence on vertical pollutant partitioning

    Science.gov (United States)

    Peake, D.

    Coastal outflow describes the horizontal ventilation of pollutants from the continental boundary layer (CBL) by advection above the shallower marine boundary layer. Passive tracers incorporated in the Met Office Unified Model (MetUM) are used to simulate coastal outflow over the eastern United States for the summer of 2004. The results are interpreted with a simple box-model containing a diurnally varying CBL height and uniform wind flow. Ventilation by coastal outflow from the US occurs at the same magnitude as vertical ventilation into the free troposphere for the eastern half of the US. The diurnal variability in coastal outflow is determined by the lifetime of the tracer and the cycle of CBL height. Over the diurnal cycle, pollutants with lifetimes less than 24 hours experience a maximum in the evening and a minimum in the mid-morning. Pollutants with lifetimes greater than 24 hours undergo continuous coastal outflow with little diurnal variability. The dominant parameters in this study are tracer lifetime α, wind-speed U and width of emissions (i.e. land) L. The box-model indicates the presence of a critical threshold, αU/L ≈ 10, above which increasing the cross-coastal wind speed decreases coastal out-flow by reducing the availability of tracer in the residual layer to undergo coastal outflow at night. Of tracer advected across the coast in the MetUM simulation, 65% and 67% of tracer with 3- and 24-hour lifetimes undergo coastal outflow respectively. For the 24-hour tracer, the box-model has the highest correlation with the MetUM simulation when the advection rate U/L≈ 2 x 10-5s-1. Given the observed wind speed the distance near the coast over which emissions significantly contribute to coastal outflow is ≈ 100-110km.

  18. Risks Facing the Retailers and Vertical Restraints

    Directory of Open Access Journals (Sweden)

    Dzagurova Nataliya, B.

    2016-07-01

    Full Text Available Vertical restraints such as exclusive territories may be considered as an alternative to the compensation paid to retailers for taking the risks associated with market shocks. For the first time this approach has been put forward in (Rey and Tirole, 1986. In (Hansen and Motta, 2015 this concept has been further developed, but these authors have come a diametrically opposite result to what Rey & Tirole had reported. The goal of both papers was to compare exclusive territories and retailers’ competition from the point of view of the supplier. In (Rey and Tirole, 1986 the competition was the preferred solution, in (Hansen and Motta, 2015 - the exclusive territories. The explanation of this discrepancy proposed in (Hansen and Motta, 2015 doesn't look convincing enough. The paper proposes a new explanation based on the analysis of the attractiveness of the considered lotteries for the retailers. In (Rey and Tirole, 1986 they were ready to pay for the lottery, but in (Hansen and Motta, 2015 - pretend to get a compensation. Accordingly, in the first case the supplier prefers to allow competition between dealers, in the second - to provide exclusive territories in order to reduce the compensation to be paid to the dealer for participating in the lottery. The paper discusses that the better solution is to consider not the risks associated with market shocks, but the retailers’ risks associated with the so called «cooperative specific investments» (manufacturer can prefer another partner on ex post stage. Trying to support the retailers’ incentives to make cooperative investments, supplier voluntarily redistributes control in favor of retailers.

  19. The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates.

    Science.gov (United States)

    Fraser, Lindsey E; Makooie, Bobbak; Harris, Laurence R

    2015-01-01

    The subjective visual vertical (SVV) and the subjective haptic vertical (SHV) both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert) and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning "opposite", i.e., opposite to the A-effect). We compared the two methods in a series of five experiments and provide evidence that the two measures access two different but related estimates of gravitational vertical. Experiment 1 compared SVV and SHV across three levels of whole-body tilt and found that SVV showed an A-effect at larger tilts while SHV was accurate. Experiment 2 found that tilting either the head or the trunk independently produced an A-effect in SVV while SHV remained accurate when the head was tilted on an upright body but showed an A-effect when the body was tilted below an upright head. Experiment 3 repeated these head/body configurations in the presence of vestibular noise induced by using disruptive galvanic vestibular stimulation (dGVS). dGVS abolished both SVV and SHV A-effects while evoking a massive E-effect in the SHV head tilt condition. Experiments 4 and 5 show that SVV and SHV do not combine in an optimally statistical fashion, but when vibration is applied to the dorsal neck muscles, integration becomes optimal. Overall our results suggest that SVV and SHV access distinct underlying gravity percepts based primarily on head and body position information respectively, consistent with a model proposed by Clemens and colleagues. PMID:26716835

  20. The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates.

    Directory of Open Access Journals (Sweden)

    Lindsey E Fraser

    Full Text Available The subjective visual vertical (SVV and the subjective haptic vertical (SHV both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning "opposite", i.e., opposite to the A-effect. We compared the two methods in a series of five experiments and provide evidence that the two measures access two different but related estimates of gravitational vertical. Experiment 1 compared SVV and SHV across three levels of whole-body tilt and found that SVV showed an A-effect at larger tilts while SHV was accurate. Experiment 2 found that tilting either the head or the trunk independently produced an A-effect in SVV while SHV remained accurate when the head was tilted on an upright body but showed an A-effect when the body was tilted below an upright head. Experiment 3 repeated these head/body configurations in the presence of vestibular noise induced by using disruptive galvanic vestibular stimulation (dGVS. dGVS abolished both SVV and SHV A-effects while evoking a massive E-effect in the SHV head tilt condition. Experiments 4 and 5 show that SVV and SHV do not combine in an optimally statistical fashion, but when vibration is applied to the dorsal neck muscles, integration becomes optimal. Overall our results suggest that SVV and SHV access distinct underlying gravity percepts based primarily on head and body position information respectively, consistent with a model proposed by Clemens and colleagues.

  1. Metrics of hurricane-ocean interaction: vertically-integrated or vertically-averaged ocean temperature?

    Directory of Open Access Journals (Sweden)

    J. F. Price

    2009-05-01

    Full Text Available The ocean thermal field is often represented in hurricane-ocean interaction by a metric termed the upper Ocean Heat Content (OHC, the vertical integral of ocean temperature in excess of 26°C. High values of OHC have proven useful for identifying ocean regions that are especially favorable for hurricane intensification. Nevertheless, it is argued here that a more direct and robust metric of the ocean thermal field may be afforded by a vertical average of temperature, in one version from the surface to 100 m, a typical depth of vertical mixing by a mature hurricane. OHC and the depth-averaged temperature, dubbed T100, are well correlated over the deep open ocean in the high range of OHC, OHC≥75 kJ cm−2. They are poorly correlated in the low range of OHC, ≤50 kJ cm−2, in part because OHC is degenerate when evaluated on cool ocean temperatures ≤26°C. OHC and T100 can be qualitatively different also over shallow continental shelves: OHC will generally indicate comparatively low values regardless of the ocean temperature, while T100 will take on high values over a shelf that is warm and upwelling neutral or negative, since there will be little cool water that could be mixed into the surface layer. Some limited evidence is that continental shelves may be regions of comparatively small sea surface cooling during a hurricane passage, but more research is clearly required on this important issue.

  2. Longitudinal Differences of Ionospheric Vertical Density Distribution and Equatorial Electrodynamics

    Science.gov (United States)

    Yizengaw, E.; Zesta, E.; Moldwin, M. B.; Damtie, B.; Mebrahtu, A.; Valledares, C.E.; Pfaff, R. F.

    2012-01-01

    Accurate estimation of global vertical distribution of ionospheric and plasmaspheric density as a function of local time, season, and magnetic activity is required to improve the operation of space-based navigation and communication systems. The vertical density distribution, especially at low and equatorial latitudes, is governed by the equatorial electrodynamics that produces a vertical driving force. The vertical structure of the equatorial density distribution can be observed by using tomographic reconstruction techniques on ground-based global positioning system (GPS) total electron content (TEC). Similarly, the vertical drift, which is one of the driving mechanisms that govern equatorial electrodynamics and strongly affect the structure and dynamics of the ionosphere in the low/midlatitude region, can be estimated using ground magnetometer observations. We present tomographically reconstructed density distribution and the corresponding vertical drifts at two different longitudes: the East African and west South American sectors. Chains of GPS stations in the east African and west South American longitudinal sectors, covering the equatorial anomaly region of meridian approx. 37 deg and 290 deg E, respectively, are used to reconstruct the vertical density distribution. Similarly, magnetometer sites of African Meridian B-field Education and Research (AMBER) and INTERMAGNET for the east African sector and South American Meridional B-field Array (SAMBA) and Low Latitude Ionospheric Sensor Network (LISN) are used to estimate the vertical drift velocity at two distinct longitudes. The comparison between the reconstructed and Jicamarca Incoherent Scatter Radar (ISR) measured density profiles shows excellent agreement, demonstrating the usefulness of tomographic reconstruction technique in providing the vertical density distribution at different longitudes. Similarly, the comparison between magnetometer estimated vertical drift and other independent drift observation

  3. Mt. Graham: Optical turbulence vertical distribution at standard and high vertical resolution

    CERN Document Server

    Masciadri, E; Hagelin, S; S.,; Lascaux, F; di Arcetri, INAF - Osservatorio Astrofisico; 10.1117/12.856904

    2010-01-01

    A characterization of the optical turbulence vertical distribution and all the main integrated astroclimatic parameters derived from the CN2 and the wind speed profiles above Mt. Graham is presented. The statistic includes measurements related to 43 nights done with a Generalized Scidar (GS) used in standard configuration with a vertical resolution of ~1 km on the whole 20-22 km and with the new technique (HVR-GS) in the first kilometer. The latter achieves a resolution of ~ 20-30 m in this region of the atmosphere. Measurements done in different periods of the year permit us to provide a seasonal variation analysis of the CN2. A discretized distribution of the typical CN2 profiles useful for the Ground Layer Adaptive Optics (GLAO) simulations is provided and a specific analysis for the LBT Laser Guide Star system ARGOS case is done including the calculation of the 'gray zones' for J, H and K bands. Mt. Graham confirms to be an excellent site with median values of the seeing without dome contribution equal to...

  4. Vertical nystagmus: clinical facts and hypotheses.

    Science.gov (United States)

    Pierrot-Deseilligny, C; Milea, D

    2005-06-01

    The pathophysiology of spontaneous upbeat (UBN) and downbeat (DBN) nystagmus is reviewed in the light of several instructive clinical findings and experimental data. UBN due to pontine lesions could result from damage to the ventral tegmental tract (VTT), originating in the superior vestibular nucleus (SVN), coursing through the ventral pons and transmitting excitatory upward vestibular signals to the third nerve nucleus. A VTT lesion probably leads to relative hypoactivity of the drive to the motoneurons of the elevator muscles with, consequently, an imbalance between the downward and upward systems, resulting in a downward slow phase. The results observed in internuclear ophthalmoplegia suggest that the medial longitudinal fasciculus (MLF) is involved in the transmission of both upward and downward vestibular signals. Since no clinical cases of DBN due to focal brainstem damage have been reported, it may be assumed that the transmission of downward vestibular signals depends only upon the MLF, whereas that of upward vestibular signals involves both the MLF and the VTT. The main focal lesions resulting in DBN affect the cerebellar flocculus and/or paraflocculus. Apparently, this structure tonically inhibits the SVN and its excitatory efferent tract (i.e. the VTT) but not the downward vestibular system. Therefore, a floccular lesion could result in a disinhibition of the SVN-VTT pathway with, consequently, relative hyperactivity of the drive to the motoneurons of the elevator muscles, resulting in an upward slow phase. UBN also results from lesions affecting the caudal medulla. An area in this region could form part of a feedback loop involved in upward gaze-holding, originating in a collateral branch of the VTT and comprising the caudal medulla, the flocculus and the SVN, successively. Therefore, it is suggested that the main types of spontaneous vertical nystagmus due to focal central lesions result from a primary dysfunction of the SVN-VTT pathway, which becomes

  5. Sliding response of gravity dams including vertical seismic accelerations

    Institute of Scientific and Technical Information of China (English)

    Constantin Christopoulos; Pierre Léger; André Filiatrault

    2003-01-01

    Seismic safety assessment of gravity dams has become a major concern in many regions of the world while the effects of vertical seismic accelerations on the response of structures remain poorly understood. This paper first investigates the effect of including vertical accelerations in the sliding response analysis of gravity dams subjected to a range of historical ground motion records separated in two groups according to their source-to-site distance. Analyses showed that the incidence of vertical accelerations on the sliding response of gravity dams is significantly higher for near-source records than for farsource records. The pseudo-static 30% load combination rule, commonly used in practice to account for the non-simultaneous occurrence of the peak horizontal and vertical accelerations, yielded good approximations of the minimum safety factors against sliding computed from time-history analyses. A method for empirically estimating the vertical response spectra based on horizontal spectra, accounting for the difference in frequency content and amplitudes between the two components is investigated. Results from analyses using spectrum compatible horizontal and vertical synthetic records also approximated well the sliding response of a gravity dam subjected to series of simultaneous horizontal and vertical historical earthquake records.

  6. Simulation of EAST vertical displacement events by tokamak simulation code

    Science.gov (United States)

    Qiu, Qinglai; Xiao, Bingjia; Guo, Yong; Liu, Lei; Xing, Zhe; Humphreys, D. A.

    2016-10-01

    Vertical instability is a potentially serious hazard for elongated plasma. In this paper, the tokamak simulation code (TSC) is used to simulate vertical displacement events (VDE) on the experimental advanced superconducting tokamak (EAST). Key parameters from simulations, including plasma current, plasma shape and position, flux contours and magnetic measurements match experimental data well. The growth rates simulated by TSC are in good agreement with TokSys results. In addition to modeling the free drift, an EAST fast vertical control model enables TSC to simulate the course of VDE recovery. The trajectories of the plasma current center and control currents on internal coils (IC) fit experimental data well.

  7. Vertical evolution of photochemical ozone over greater Ravenna (Italy)

    International Nuclear Information System (INIS)

    Measurement of photochemical ozone were carried out by a plane during the 1996 summer season over a coastal area of Northern Italy (Ravenna) in order to describe the daily vertical evolution of this pollutant. Results confirmed the presence of well marked layers in which ozone concentration notably changed. The evolution of these atmospheric layers are strictly linked with the evolution of the land-sea breeze circulation. Ozone, which undergoes horizontal transport, due to the local anemological field, resulted also subject to vertical transport mechanisms. The vertical evolution of pollutant concentrations through the day led to the presence on the land's surface of episodes of fumigation potentially dangerous to human health

  8. A Compact Vertical Scanner for Atomic Force Microscopes

    Directory of Open Access Journals (Sweden)

    Jae Hong Park

    2010-11-01

    Full Text Available A compact vertical scanner for an atomic force microscope (AFM is developed. The vertical scanner is designed to have no interference with the optical microscope for viewing the cantilever. The theoretical stiffness and resonance of the scanner are derived and verified via finite element analysis. An optimal design process that maximizes the resonance frequency is performed. To evaluate the scanner’s performance, experiments are performed to evaluate the travel range, resonance frequency, and feedback noise level. In addition, an AFM image using the proposed vertical scanner is generated.

  9. Flambage vertical des conduites en souillées Vertical Buckling of Buried Pipes

    OpenAIRE

    Bournazel C.

    2006-01-01

    Si l'apparition d'un flambage vertical des conduites rigides enfouies dans une tranchée est un phénomène assez rare, il peut ne pas en être de même pour des conduites flexibles dont les propriétés mécaniques sont de nature différente. Une étude théorique et expérimentale, ayant pour but de proposer une méthode analytique de calcul de l'apparition du flambage et de son évolution sous l'effet de la pression interne, a été réalisée. II apparaît que les conduites flexibles actuelles sont très sen...

  10. Tree STEM Reconstruction Using Vertical Fisheye Images: a Preliminary Study

    Science.gov (United States)

    Berveglieri, A.; Tommaselli, A. M. G.

    2016-06-01

    A preliminary study was conducted to assess a tree stem reconstruction technique with panoramic images taken with fisheye lenses. The concept is similar to the Structure from Motion (SfM) technique, but the acquisition and data preparation rely on fisheye cameras to generate a vertical image sequence with height variations of the camera station. Each vertical image is rectified to four vertical planes, producing horizontal lateral views. The stems in the lateral view are rectified to the same scale in the image sequence to facilitate image matching. Using bundle adjustment, the stems are reconstructed, enabling later measurement and extraction of several attributes. The 3D reconstruction was performed with the proposed technique and compared with SfM. The preliminary results showed that the stems were correctly reconstructed by using the lateral virtual images generated from the vertical fisheye images and with the advantage of using fewer images and taken from one single station.

  11. Boiling visualization on vertical fins with tunnel-pore structures

    Directory of Open Access Journals (Sweden)

    Kaniowski Robert

    2012-04-01

    Full Text Available The paper presents experimental studies of nucleate boiling heat transfer from a system of connected horizontal and vertical subsurface tunnels. The experiments were carried out for water at atmospheric pressure. The tunnel external covers were manufactured out of perforated copper foil (holes diameter 0.3 mm, sintered with the mini-fins, formed on the vertical side of the 10 mm high rectangular fins and horizontal inter-fin surface. The image acquisition speed was 493 fps (at resolution 400 × 300 pixels with Photonfocus PHOT MV-D1024-160-CL camera. Visualization investigations aimed to identify nucleation sites and flow patterns and to determine the bubble departure diameter and frequency at various superheats for vertical tunnels. At low superheat vapor bubbles are generated nearly exclusively by the vertical tunnel. At medium values of superheat, pores of the horizontal tunnel activate.

  12. TREE STEM RECONSTRUCTION USING VERTICAL FISHEYE IMAGES: A PRELIMINARY STUDY

    Directory of Open Access Journals (Sweden)

    A. Berveglieri

    2016-06-01

    Full Text Available A preliminary study was conducted to assess a tree stem reconstruction technique with panoramic images taken with fisheye lenses. The concept is similar to the Structure from Motion (SfM technique, but the acquisition and data preparation rely on fisheye cameras to generate a vertical image sequence with height variations of the camera station. Each vertical image is rectified to four vertical planes, producing horizontal lateral views. The stems in the lateral view are rectified to the same scale in the image sequence to facilitate image matching. Using bundle adjustment, the stems are reconstructed, enabling later measurement and extraction of several attributes. The 3D reconstruction was performed with the proposed technique and compared with SfM. The preliminary results showed that the stems were correctly reconstructed by using the lateral virtual images generated from the vertical fisheye images and with the advantage of using fewer images and taken from one single station.

  13. Vertical emission profiles for Europe based on plume rise calculations.

    Science.gov (United States)

    Bieser, J; Aulinger, A; Matthias, V; Quante, M; Denier van der Gon, H A C

    2011-10-01

    The vertical allocation of emissions has a major impact on results of Chemistry Transport Models. However, in Europe it is still common to use fixed vertical profiles based on rough estimates to determine the emission height of point sources. This publication introduces a set of new vertical profiles for the use in chemistry transport modeling that were created from hourly gridded emissions calculated by the SMOKE for Europe emission model. SMOKE uses plume rise calculations to determine effective emission heights. Out of more than 40,000 different vertical emission profiles 73 have been chosen by means of hierarchical cluster analysis. These profiles show large differences to those currently used in many emission models. Emissions from combustion processes are released in much lower altitudes while those from production processes are allocated to higher altitudes. The profiles have a high temporal and spatial variability which is not represented by currently used profiles. PMID:21561695

  14. Incoherent vertical ion losses during multiturn stacking cooling beam injection

    Science.gov (United States)

    Syresin, E. M.

    2014-07-01

    The efficiency of the multiturn ion injection with electron cooling depends on two parameters, namely, cooling efficiency and ion lifetime. The lifetime of freshly injected ions is usually shorter than the lifetime of strongly cooled stacked ions. Freshly injected ions are lost in the vertical direction because the vertical acceptance of the synchrotron is usually a few times smaller than the horizontal acceptance. Incoherent vertical losses of freshly injected ions arise from their multiple scattering by residual gas atoms and transverse diffusion caused by stack noise. Reduced ion lifetime limits the multiturn injection efficiency. Analytical estimations and BETACOOL-based numerical evaluations of the vertical ion losses during multiturn injection are presented in comparison with the experimental data obtained at the HIMAC synchrotron and the S-LSR storage ring.

  15. Vertical ionization energies of halogen anions in solution

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the constrained equilibrium state theory,the nonequilibrium solvation energy is derived in the framework of the continuum model.The formula for spectral shift and vertical ionization energy are deduced for a single sphere cavity with the point charge assumption.The new model is adopted to investigate the vertical ionization for halogen atomic and molecular anions X(X = Cl,Br,I,Cl2,Br2,I2) in aqueous solution.According to the calculation using the CCSD-t/aug-cc-pVQZ method in vacuum,our final estimated vertical ionization energies in solution are very close to the experimental observations,while the traditional nonequilibrium solvation theory overestimates these vertical ionization energies.

  16. Horizontal-vertical coupling for three dimensional laser cooling

    International Nuclear Information System (INIS)

    In order to achieve three dimensional crystal beam, laser cooling forces are required not only in the longitudinal direction, but also in the transverse directions. With the resonance coupling method, transverse temperature is transmitted into longitudinal direction, and we have already demonstrated the horizontal laser cooling experimentally. In the present paper, we will describe an approach to extend this result to three dimensional cooling. The vertical cooling requires that the horizontal oscillation couples with the vertical oscillation. For achieving horizontal-vertical coupling, the solenoid in electron beam cooling apparatus is utilized with an experiment (νx =2.07, νy=1.07). For various solenoidal magnetic fields from 0 to 100 Gauss, horizontal and vertical betatron tunes are measured by beam transfer function. For a certain region of the solenoidal magnetic field, these tunes are mixed up each other. (author)

  17. Tracing the vertical composition of disc galaxies through colour gradients

    CERN Document Server

    De Grijs, R; Grijs, Richard de; Peletier, Reynier F.

    1999-01-01

    (Abbreviated) Optical observations of a statistically complete sample of edge-on disc galaxies are used to study the intrinsic vertical colour gradients in the galactic discs, to constrain the effects of population gradients, residual dust extinction and gradients in the galaxies' metal abundance. It appears that the intrinsic vertical colour gradients are either non-existent, or small and relatively constant as a function of position along the galaxies' major axes. Our results are consistent with the absence of any vertical colour gradient in the discs of the early-type sample galaxies. In most galaxies small-scale variations in the magnitude and even the direction of the vertical gradient are observed: at larger galactocentric distances they generally display redder colours with increasing z height, whereas the opposite is often observed in and near the galactic centres. For a significant fraction of our sample galaxies another mechanism in addition to the effects of stellar population gradients is required...

  18. A Method for Modeling of Floating Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Wang, Kai; Hansen, Martin Otto Laver; Moan, Torgeir

    2013-01-01

    It is of interest to investigate the potential advantages of floating vertical axis wind turbine (FVAWT) due to its economical installation and maintenance. A novel 5MW vertical axis wind turbine concept with a Darrieus rotor mounted on a semi-submersible support structure is proposed in this paper....... In order to assess the technical and economic feasibility of this novel concept, a comprehensive simulation tool for modeling of the floating vertical axis wind turbine is needed. This work presents the development of a coupled method for modeling of the dynamics of a floating vertical axis wind turbine....... This integrated dynamic model takes into account the wind inflow, aerodynamics, hydrodynamics, structural dynamics (wind turbine, floating platform and the mooring lines) and a generator control. This approach calculates dynamic equilibrium at each time step and takes account of the interaction between the rotor...

  19. Vertical Wave Impacts on Offshore Wind Turbine Inspection Platforms

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Jacobsen, Niels Gjøl

    2011-01-01

    on a horizontal inspection platform is computed for five different platform levels. The computational results show details of monopile impact such as slamming pressures from the overturning wave front and the formation of run-up flow. The results show that vertical platform impacts can occur at 20 m water depth......Breaking wave impacts on a monopile at 20 m depth are computed with a VOF (Volume Of Fluid) method. The impacting waves are generated by the second-order focused wave group technique, to obtain waves that break at the position of the monopile. The subsequent impact from the vertical run-up flow....... The dependence of the vertical platform load to the platform level is discussed. Attention is given to the significant downward force that occur after the upward force associated with the vertical impact. The effect of the numerical resolution on the results is assessed. The position of wave overturning is found...

  20. On the vertical-shear instability in astrophysical discs

    CERN Document Server

    Barker, Adrian J

    2015-01-01

    We explore the linear stability of astrophysical discs exhibiting vertical shear, which arises when there is a radial variation in the temperature or entropy. Such discs are subject to a "vertical-shear instability", which recent nonlinear simulations have shown to drive hydrodynamic activity in the MRI-stable regions of protoplanetary discs. We first revisit locally isothermal discs using the quasi-global reduced model derived by Nelson et al. (2013). This analysis is then extended to global axisymmetric perturbations in a cylindrical domain. We also derive and study a reduced model describing discs with power law radial entropy profiles ("locally polytropic discs"), which are somewhat more realistic in that they possess physical (as opposed to numerical) surfaces. In all cases the fastest growing modes have very short wavelengths and are localised at the disc surfaces (if present), where the vertical shear is maximal. An additional class of modestly growing vertically global body modes is excited, correspon...

  1. Digital Photo Analysis as a Predictor of Physiological Vertical Dimension

    Directory of Open Access Journals (Sweden)

    Andy Wirahadikusumah

    2013-05-01

    Full Text Available Determination of the vertical dimension is based on patient's resting jaw position, which is the physiological vertical dimension. Objective: To examine the accuracy of physiological vertical dimension using digital photography. Methods: The research was done on 64 students who meet the criterias. The measurements of eyes-lips angles and lower nose-chin distance was performed. Then photo shoot of subject faces was taken from 56cm distance between the camera lens and the tip of the subjects’ nose with tripoded camera. Results: Distance of eyes-lips angles, and lower the nose-chin of the face and the photo has no meaningful differences. Conclusions: Analysis of digital photos can be applied to predict physiological vertical dimension.DOI: 10.14693/jdi.v18i2.62

  2. INSTITUTIONAL ANALYSIS OF FINANCE VERTICALLY INTEGRATED STRUCTURE IN UKRAINE

    Directory of Open Access Journals (Sweden)

    Yu. Petlenko

    2014-01-01

    Full Text Available The article defines the content of the economic and institutional conditions of the financial mechanism of vertically integrated structures in Ukraine, considered the organizational form of vertical integration and describes their impact on the distribution of property between the parties depending vertically integrated structure based on ownership interests. The role of the financial mechanism of the vertically integrated company, identified ways of harmonizing relations between the state, the owners, managers and lenders that promote economic growth and high levels of capitalization. Therefore, the value of the company must be regarded as one of the main indicators of its effectiveness, so the task of identifying and managing the value refers to the priorities of corporations.

  3. Flambage vertical des conduites en souillées Vertical Buckling of Buried Pipes

    Directory of Open Access Journals (Sweden)

    Bournazel C.

    2006-11-01

    Full Text Available Si l'apparition d'un flambage vertical des conduites rigides enfouies dans une tranchée est un phénomène assez rare, il peut ne pas en être de même pour des conduites flexibles dont les propriétés mécaniques sont de nature différente. Une étude théorique et expérimentale, ayant pour but de proposer une méthode analytique de calcul de l'apparition du flambage et de son évolution sous l'effet de la pression interne, a été réalisée. II apparaît que les conduites flexibles actuelles sont très sensibles à ce phénomène et qu'il serait nécessaire, pour l'éliminer à coup sûr, de réexaminer la structure des flexibles ou d'imaginer des artifices dans la procédure d'ensouillage Whereas the appearance of vertical buckling in rigid pipes buried in a trench is a relatively rare phenomenon, the same cannot be said for flexible pipes which have mechanical properties of a different nature. A theoretical and experimental study has been made with the aim of proposing an analytical method for computing the appearance of buckling and its evolution under the effect of outside pressure. Current flexible pipes appear to be very sensitive to this phenomenon, and to be certain of eliminating it the structure of flexible pipes should be reexamined or stratagems in the burying procedure should be devised.

  4. Supply Chain Control: A Theory of Vertical Integration

    OpenAIRE

    Ursino, Giovanni

    2009-01-01

    Improving a company's bargaining position is often cited as a chief motivation to vertically integrate with suppliers. This paper expands on that view in building a new theory of vertical integration. In my model firms integrate to gain bargaining power against other suppliers in the production process. The cost of integration is a loss of flexibility in choosing the most suitable suppliers for a particular final product. I show that the firms who make the most specific investments in the pro...

  5. Influence of aerosol vertical distribution on radiative budget and climate

    Science.gov (United States)

    Nabat, Pierre; Michou, Martine; Saint-Martin, David; Watson, Laura

    2016-04-01

    Aerosols interact with shortwave and longwave radiation with ensuing consequences on radiative budget and climate. Aerosols are represented in climate models either using an interactive aerosol scheme including prognostic aerosol variables, or using climatologies, such as monthly aerosol optical depth (AOD) fields. In the first case, aerosol vertical distribution can vary rapidly, at a daily or even hourly scale, following the aerosol evolution calculated by the interactive scheme. On the contrary, in the second case, a fixed aerosol vertical distribution is generally imposed by climatological profiles. The objective of this work is to study the impact of aerosol vertical distribution on aerosol radiative forcing, with ensuing effects on climate. Simulations have thus been carried out using CNRM-CM, which is a global climate model including an interactive aerosol scheme representing the five main aerosol species (desert dust, sea-salt, sulfate, black carbon and organic matter). Several multi-annual simulations covering the past recent years are compared, including either the prognostic aerosol variables, or monthly AOD fields with different aerosol vertical distributions. In the second case, AOD fields directly come from the first simulation, so that all simulations have the same integrated aerosol loads. The results show that modifying the aerosol vertical distribution has a significant impact on radiative budget, with consequences on global climate. These differences, highlighting the importance of aerosol vertical distribution in climate models, probably come from the modification of atmospheric circulation induced by changes in the heights of the different aerosols. Besides, nonlinear effects in the superposition of aerosol and clouds reinforce the impact of aerosol vertical distribution, since aerosol radiative forcing depends highly upon the presence of clouds, and upon the relative vertical position of aerosols and clouds.

  6. Seasonal and longitudinal dependence of equatorialdisturbance vertical plasma drifts

    OpenAIRE

    Fejer, Bela G.; Jensen, J. W.; Su, S.Y.

    2008-01-01

    [1] We used equatorial measurements from the ROCSAT-1 satellite to determine the seasonal and longitudinal dependent equatorial F region disturbance vertical plasma drifts. Following sudden increases in geomagnetic activity, the prompt penetration vertical drifts are upward during the day and downward at night, and have strong local time dependence at all seasons. The largest prompt penetration drifts near dusk and dawn occur during June solstice. The daytime disturbance dynamo drifts are sma...

  7. A note on unionized firms' incentive to integrate vertically

    OpenAIRE

    Thomas Grandner

    2000-01-01

    In this paper I analyze a vertically structured monopolized market with unionized firms. I compare two types of contracts: vertical integration and franchising. With franchising and wage bargaining at the firm level the union in the downstream firm is either very powerful or has no bargaining power at all, depending on the specific time structure of the model. These arguments could make integration preferable for the profit owners even if integration is accompanied by small transaction costs....

  8. Vertical heterostructures based on graphene and other 2D materials

    Energy Technology Data Exchange (ETDEWEB)

    Antonova, I. V. [Rzhanov Institute of Semiconductor Physics, Russian Academy of Sciences, Siberian Branch (Russian Federation)

    2016-01-15

    Recent advances in the fabrication of vertical heterostructures based on graphene and other dielectric and semiconductor single-layer materials, including hexagonal boron nitride and transition-metal dichalcogenides, are reviewed. Significant progress in this field is discussed together with the great prospects for the development of vertical heterostructures for various applications, which are associated, first of all, with reconsideration of the physical principles of the design and operation of device structures based on graphene combined with other 2D materials.

  9. The Vertical Integration of Mechatronics at Virginia Tech

    OpenAIRE

    Grove, Donald E

    2001-01-01

    The focus of this thesis is on the vertical integration of mechatronics in the mechanical engineering curriculum at Virginia Tech. It reports the details of an experimental strategy to integrate mechatronics at an early level in the education of engineers. A proposal was submitted to and accepted by the NSF/SUCCEED coalition to fund this experiment. Through this assistance, the experiment of vertically integrating mechatronics was initiated. The methodology in which it was inte...

  10. Vertical flow of a multiphase mixture in a channel

    OpenAIRE

    Massoudi Mehrdad; Rao C. Lakshmana

    2000-01-01

    The flow of a multiphase mixture consisting of a viscous fluid and solid particles between two vertical plates is studied. The theory of interacting continua or mixture theory is used. Constitutive relations for the stress tensor of the granular materials and the interaction force are presented and discussed. The flow of interest is an ideal one where we assume the flow to be steady and fully developed; the mixture is flowing between two long vertical plates. The non-linear boundary value pro...

  11. NASA Airborne-simulated Vertical Data in Google Earth

    Science.gov (United States)

    Chen, A.; Leptoukh, G.; Kempler, S.; Liu, Z.

    2008-12-01

    Google Earth has been widely used as a tool to visualize scientific data that have geospatial elements. The data can be two dimensional and three dimensional, or even four-dimensional. NASA A-Train constellation satellites such as CloudSat, CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation), and Aqua have been producing lots of vertical data about the atmosphere. Those data are being used for such scientific research as global climate change, weather forecast, etc. NASA also uses airplanes to load some instruments to simulate satellite flying for establishing the sensitivity, calibration, and initial validation of the instruments that will be loaded at satellites. The airborne simulated flying produces simulated vertical data of the atmosphere. Visualization of these kinds of vertical data in Google Earth is helpful for scientific research. Here, a new method is proposed to visualize the simulated vertical data in Google Earth to expose cloud, aerosol, and other atmospheric profiles in the form of curtain along the flying track of the airplane. An interface description language-based render is designed and implemented to process and display the simulated vertical data in the format of image. The image is further processed and cut into transparent small image slices according to the track of the airplane. A COLLADA (COLLAborative Design Activity) 3D model, which is supported by Google Earth, is devised to make the image slices vertically displayed in Google Earth. Using the COLLADA models and airplane flying track coordinates, an airplane track model is implemented in the format of KML (Keyhole Markup Language). The track curtain makes simulated vertical data viewable, transparently or opaquely, in Google Earth. Thus, airborne simulated vertical geospatial data are available to scientists and the general public in a popular venue.

  12. Mathematical model of induced flow on the airplane vertical tail

    Science.gov (United States)

    Rotaru, Constantin; Cîrciu, Ionicǎ; Edu, Raluca Ioana

    2016-06-01

    In this paper is presented a mathematical model of the flow around the vertical tail of an airplane, based on the general elements of the aerodynamic design, with details leading to the separate formulation of the Fourier coefficients in the series solution of the Prandtl's lifting-line equation. Numerical results are obtained in Maple soft environment, for a standard configuration of an airplane geometry. The results include the discussion of the vortex model for the sidewash gradient on the vertical stabilizer.

  13. Assemblage of the vertical: commercial drones and algorithmic life

    OpenAIRE

    Crampton, Jeremy W.

    2016-01-01

    This paper takes up the increasingly popular topic of drones – including unmanned aerial vehicles (UAVs), small unmanned aerial systems (sUAS), remotely piloted aircraft (RPA), and a vast panoply of commercial drones and copters – to argue that our analysis should lie not so much on drones as objects, but as assemblages of the vertical. Drones, I argue, constitute a socio-technical assemblage of the sky and vertical space, which means that our focus should be not (only) on thei...

  14. Location of Foreign Direct Investment in Vertically Related Markets

    OpenAIRE

    Milliou, Chrysovalantou

    2013-01-01

    We provide an alternative explanation for the commonly observed FDI in developed countries (DCs) considering a vertically related market structure and endogenizing vertical technology transfer (VTT). We show that even though VTT is more costly in a less developed country (LDC), a multinational does not always transfer less technology there than in a DC. Moreover, we show that a multinational sometimes locates its FDI in a DC where, although downstream competition is stronger than in a LDC, it...

  15. Wind Velocity Vertical Extrapolation by Extended Power Law

    OpenAIRE

    Zekai Şen; Abdüsselam Altunkaynak; Tarkan Erdik

    2012-01-01

    Wind energy gains more attention day by day as one of the clean renewable energy resources. We predicted wind speed vertical extrapolation by using extended power law. In this study, an extended vertical wind velocity extrapolation formulation is derived on the basis of perturbation theory by considering power law and Weibull wind speed probability distribution function. In the proposed methodology not only the mean values of the wind speeds at different elevations but also their standard dev...

  16. Mixed multilayered vertical heterostructures utilizing strained monolayer WS2.

    OpenAIRE

    Sheng, Y.; Xu, W.; Wang, X.; He, Z.; Rong, Y.; Warner, JH

    2016-01-01

    Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer ...

  17. Floating rings in vertical soap films : capillary driven bidimensional buoyancy

    CERN Document Server

    Adami, N

    2013-01-01

    The present study aims to investigate the motion of buoyant rings in vertical soap films. Thickness differences and related bi-dimensional densities are considered as the motor leading to bi-dimensional buoyancy. We show how this effect can be re-interpreted thanks to surface tension profiles in soap films. We propose a model involving surface tension profiles in order to describe the motion of buoyant particles in vertical soap films, and compare it to experimental data.

  18. Upscaling in vertically fractured oil reservoirs using homogenization

    OpenAIRE

    Salimi, H.; Bruining, H.

    2009-01-01

    Flow modeling in fractured reservoirs is largely confined to the so-called sugar cube model. Here, however, we consider vertically fractured reservoirs, i.e., the situation that the reservoir geometry can be approximated by fractures enclosed columns running from the base rock to the cap rock (aggregated columns). This article deals with the application of the homogenization method to derive an upscaled equation for fractured reservoirs with aggregated columns. It turns out that vertical flow...

  19. Vertical Distribution and Seasonal Abundance of Zooplankters in Lake Tanganyika

    OpenAIRE

    NARITA, Tetsuya; NISIBULA, Mulimbwa; MIZUNO, Toshihiko

    1986-01-01

    Vertical distribution and seasonal abundance of zooplankters were studied in Lake Tanganyika. Faunal composition of zooplankton was simple. Limnocnida tanganicae, copepod nauplii, Diaptomus simplex, cyclopoids, and shrimp were collected by closing nets. Nauplii were dominant in number, but cyclopoid copepodites were dominant in biomass. The biomass calculated was in the range of 1.2-3.7 (average 2.3) g/m² excluding shrimp and medusa. For the vertical distribution of the copepods, the larger t...

  20. Bacterial Community Composition in Lake Tanganyika: Vertical and Horizontal Heterogeneity

    OpenAIRE

    De Wever, Aaike; Muylaert, Koenraad; Van der Gucht, Katleen; Pirlot, Samuel; Cocquyt, Christine; Descy, Jean-Pierre; Plisnier, Pierre-Denis; Vyverman, Wim

    2005-01-01

    Vertical and latitudinal differences in bacterial community composition (BCC) in Lake Tanganyika were studied during the dry season of 2002 by means of denaturing gradient gel electrophoresis analysis of PCR-amplified 16S RNA fragments. Dominant bands were sequenced and identified as members of the Cyanobacteria, Actinobacteria, Nitrospirae, green nonsulfur bacteria, and Firmicutes divisions and the Gamma- and Deltaproteobacteria subdivisions. The BCC in the lake displayed both vertical and l...

  1. Design and Fabrication of Vertically-Integrated CMOS Image Sensors

    OpenAIRE

    Orit Skorka; Dileepan Joseph

    2011-01-01

    Technologies to fabricate integrated circuits (IC) with 3D structures are an emerging trend in IC design. They are based on vertical stacking of active components to form heterogeneous microsystems. Electronic image sensors will benefit from these technologies because they allow increased pixel-level data processing and device optimization. This paper covers general principles in the design of vertically-integrated (VI) CMOS image sensors that are fabricated by flip-chip bonding. These sensor...

  2. Experimental Investigations of Vertical and Horizontal Heat Pipes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Kim, Kyuung Mo; Jeong, Young Shin; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The interest in the application of heat pipes for heat transfer system is well known in industrial fields. Heat pipe uses the working fluid in containment as cylindrical shape tube. Vaporization occurs in evaporation section due to the heat input and vapor is transferred to condensation section. At the condensation area, the working fluid is condensed and immersed in the wick structure, which has highly porous media. The condensed working fluid returns to evaporator section by capillary wicking of wick structure. The driving force for working fluid is affected by capillary and gravitational force. The heat pipes for nuclear systems have been suggested as horizontal loop heat pipes for reactor core cooling system or vertical heat pipes for passive cooling for spent fuel. In the present research, preliminary tests of horizontal and vertical heat pipe were studied for its heat transfer performance. The main purpose of the research was the analysis of heat transfer behavior of heat pipe and the performance of heat transfer. The thermal performances of horizontal and vertical heat pipe were measured experimentally. Vertical heat pipe showed better performance compared to horizontal one, at high heat input region. The heat transfer coefficients of horizontal heat pipe were lower than vertical one because of gravitational force. Overall heat transfer coefficient of vertical heat pipes were enhanced to 28.5 % compared to the horizontal heat pipes. The horizontal heat pipes revealed high thermal resistance up to 54.3 % compared to vertical heat pipes. Therefore, vertical heat pipes analyzed better heat transfer performance than horizontal heat pipe.

  3. R&D incentives in vertically related markets

    OpenAIRE

    Memar, Ahmad Reza Saboori; Götz, Georg

    2013-01-01

    This paper focuses on incentives to invest in research and development (R&D) in vertically related markets. In a bilateral duopoly setup, we consider how process R&D incentives of the firms in both upstream and downstream market depend on the intensity of simultaneous interbrand and intrabrand competition. Among the results: both interbrand and intrabrand competition have twofold effects on R&D incentives. Existence of a vertically related market with imperfect competition lowers both the inc...

  4. Determination of Vertical Alignment of Track using Accelerometer Readings

    OpenAIRE

    O'Brien, Eugene J.; Bowe, Cathal; Quirke, Paraic

    2015-01-01

    Railway track vertical alignment is an important indicator of serviceability condition. Through comparisons with past history, track alignment also informs maintenance planning. The vertical alignment of a railway track excites a dynamic response in a train which can potentially be used to determine that alignment. A method is proposed in this paper for the detection of the alignment through an analysis of vehicle accelerations resulting from the train/track dynamic interaction. The Cross Ent...

  5. Experimental Investigations of Vertical and Horizontal Heat Pipes

    International Nuclear Information System (INIS)

    The interest in the application of heat pipes for heat transfer system is well known in industrial fields. Heat pipe uses the working fluid in containment as cylindrical shape tube. Vaporization occurs in evaporation section due to the heat input and vapor is transferred to condensation section. At the condensation area, the working fluid is condensed and immersed in the wick structure, which has highly porous media. The condensed working fluid returns to evaporator section by capillary wicking of wick structure. The driving force for working fluid is affected by capillary and gravitational force. The heat pipes for nuclear systems have been suggested as horizontal loop heat pipes for reactor core cooling system or vertical heat pipes for passive cooling for spent fuel. In the present research, preliminary tests of horizontal and vertical heat pipe were studied for its heat transfer performance. The main purpose of the research was the analysis of heat transfer behavior of heat pipe and the performance of heat transfer. The thermal performances of horizontal and vertical heat pipe were measured experimentally. Vertical heat pipe showed better performance compared to horizontal one, at high heat input region. The heat transfer coefficients of horizontal heat pipe were lower than vertical one because of gravitational force. Overall heat transfer coefficient of vertical heat pipes were enhanced to 28.5 % compared to the horizontal heat pipes. The horizontal heat pipes revealed high thermal resistance up to 54.3 % compared to vertical heat pipes. Therefore, vertical heat pipes analyzed better heat transfer performance than horizontal heat pipe

  6. Thermal evaluation of vertical greenery systems for building walls

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Nyuk Hien; Kwang Tan, Alex Yong; Chen, Yu. [Department of Building, School of Design and Environment, National University of Singapore, 4 Architecture Drive, Singapore 117566 (Singapore); Sekar, Kannagi [Department of Building, School of Design and Environment, National University of Singapore, 4 Architecture Drive, Singapore 117566 (Singapore); National Parks Board, Singapore Botanic Garden, 1 Cluny Road, Singapore 259569 (Singapore); Tan, Puay Yok; Chan, Derek; Chiang, Kelly [National Parks Board, Singapore Botanic Garden, 1 Cluny Road, Singapore 259569 (Singapore); Wong, Ngian Chung [Building and Construction Authority, 5 Maxwell Road, Singapore 069110 (Singapore)

    2010-03-15

    This research involves the study of 8 different vertical greenery systems (VGSs) installed in HortPark to evaluate the thermal impacts on the performance of buildings and their immediate environment based on the surface and ambient temperatures. VGSs 3 and 4 have the best cooling efficiency according to the maximum temperature reduction of the wall and substrate surfaces. These results point to the potential thermal benefits of vertical greenery systems in reducing the surface temperature of buildings facades in the tropical climate, leading to a reduction in the cooling load and energy cost. In terms of the lowest diurnal range of average wall surface temperature fluctuation, VGSs 4 and 1 show the highest capacities. No vertical greenery system performs well in term of the diurnal range of average substrate temperature fluctuation. By limiting the diurnal fluctuation of wall surface temperatures, the lifespan of building facades is prolonged, slowing down wear and tear as well as savings in maintenance cost and the replacement of facade parts. The effects of vertical greenery systems on ambient temperature are found to depend on specific vertical greenery systems. VGS 2 has hardly any effect on the ambient temperature while the effects of VGS 4 are felt as far as 0.60 m away. Given the preponderance of wall facades in the built environment, the use of vertical greenery systems to cool the ambient temperature in building canyons is promising. Furthermore, air intakes of air-conditioning at a cooler ambient temperature translate into saving in energy cooling load. (author)

  7. Gold Mine or Minefield: Understanding Russian Law on Vertical Restraints

    Directory of Open Access Journals (Sweden)

    Valentina Rucker

    2014-01-01

    Full Text Available While the Russian Federation represents a significant opportunity for growth, that opportunity is coupled with serious risks. As it relates to managing product distribution, Russian vertical restraint law remains significantly more restrictive than that of the U.S. and, since unless a company is fully integrated, it must manage its distribution system by way of vertical agreements, presents a large problem for businesses seeking to conduct business in Russia. While Russia has made significant steps in the right direction, the lack of consistent application of economic analysis to evaluation of vertical restraints leaves companies exposed. Further, the sometimes inconsistent application of the laws also makes it hard to predict how any particular vertical agreement would be evaluated. Neither American nor Russian antitrust laws establish a list of possible vertical restraints. Thus, there is no exhaustive guidance regarding how these restraints should be treated. U.S. antitrust laws, however, generally place all vertical restraints into one of two categories, intrabrand restraints and interbrand restraints. Intrabrand restraints are those that restrain the downstream firm’s freedom with regard to the resale of the product at issue (distribution restrictions. Interbrand restraints are those that restrict a downstream or upstream firm’s freedom to deal with competitors of the firm imposing the restraint (interbrand restrictions. It should be noted that Russian law does not make this distinction.

  8. Gold Mine or Minefield: Understanding Russian Law on Vertical Restraints

    Directory of Open Access Journals (Sweden)

    Valentina Rucker

    2015-02-01

    Full Text Available While the Russian Federation represents a significant opportunity for growth, that opportunity is coupled with serious risks. As it relates to managing product distribution, Russian vertical restraint law remains significantly more restrictive than that of the U.S. and, since unless a company is fully integrated, it must manage its distribution system by way of vertical agreements, presents a large problem for businesses seeking to conduct business in Russia. While Russia has made significant steps in the right direction, the lack of consistent application of economic analysis to evaluation of vertical restraints leaves companies exposed. Further, the sometimes inconsistent application of the laws also makes it hard to predict how any particular vertical agreement would be evaluated. Neither American nor Russian antitrust laws establish a list of possible vertical restraints. Thus, there is no exhaustive guidance regarding how these restraints should be treated. U.S. antitrust laws, however, generally place all vertical restraints into one of two categories, intrabrand restraints and interbrand restraints. Intrabrand restraints are those that restrain the downstream firm’s freedom with regard to the resale of the product at issue (distribution restrictions. Interbrand restraints are those that restrict a downstream or upstream firm’s freedom to deal with competitors of the firm imposing the restraint (interbrand restrictions. It should be noted that Russian law does not make this distinction.

  9. Vertical load capacities of roof truss cross members

    Institute of Scientific and Technical Information of China (English)

    Gearhart David F.; Mohamed Khaled Morsy

    2016-01-01

    Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine the vertical load capacity and deflection of three different types of cross members. Single-point load tests, with the load applied in the center of the specimen and double-point load tests, with a span of 2.4 m, were con-ducted. For the single-point load configuration, the yield of the 25 mm solid bar cross member was nom-inally 98 kN of vertical load, achieved at 42 cm of deflection. For cable cross members, yield was not achieved even after 45 cm of deflection. Peak vertical loads were about 89 kN for 17 mm cables and 67 kN for the 15 mm cables. For the double-point load configurations, the 25 mm solid bar cross mem-bers yielded at 150 kN of vertical load and 25 cm of deflection. At 25 cm of deflection individual cable strands started breaking at 133 and 111 kN of vertical load for the 17 and 15 mm cable cross members respectively.

  10. Mixed multilayered vertical heterostructures utilizing strained monolayer WS2.

    Science.gov (United States)

    Sheng, Yuewen; Xu, Wenshuo; Wang, Xiaochen; He, Zhengyu; Rong, Youmin; Warner, Jamie H

    2016-02-01

    Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer of WS2, with Boron Nitride and Graphene. The 2D materials are all grown by CVD, enabling large area vertical heterostructures to be formed. WS2 monolayers grown by CVD directly on Si substrates with SiO2 surface are easily washed off by water and this makes aqueous based transfer methods challenging for creating vertical stacks on the growth substrate. 2D hexagonal Boron Nitride films are used to provide an insulating layer that limits interactions with a top graphene layer and preserve the strong photoluminescence from the WS2. This transfer method is suitable for layer by layer control of 2D material vertical stacks and is shown to be possible for all CVD grown samples, which opens up pathways for the rapid large scale fabrication of vertical heterostructure systems with atomic thickness depth control and large area coverage. PMID:26758782

  11. Coupled vertical and lateral preferential flow on a forested slope

    Science.gov (United States)

    Buttle, J. M.; McDonald, D. J.

    2002-05-01

    Coupling of vertical and lateral preferential flow paths was examined on a forested slope with thin soil cover during artificial irrigations. Point-scale infiltration was measured at sites with differing soil macroporosities using vertical profiles of time domain reflectometry probes and suction samplers. Lateral fluxes of water and solutes from the slope were determined at a through flow trench. Sites with greater macroporosities tended to exhibit vertical preferential flow, while infiltration at sites with relatively small macroporosities was largely by vertical propagation of a well defined wetting front through the soil profile. Generation of vertical preferential flow at sites with relatively large macroporosities increased with input intensity. Lateral macropores made a minor contribution to slope runoff. Instead, runoff largely occurred in a thin saturated layer at the soil-bedrock interface, both in a highly conductive zone at the bedrock surface and in the overlying saturated soil matrix. Some assumptions underlying the use of isotopic and geochemical tracers to study runoff generation are called into question by complex mixing of event and pre-event water in this saturated layer. Soil depth, bedrock topography, and antecedent soil wetness determine the thickness, connectivity, and upslope extent of the pre-event saturated layer above the bedrock surface. These, in turn, control whether vertical preferential and matrix flow reaching the bedrock surface participate in slope runoff.

  12. The upper bound on number of graphs, with fixed number of vertices, that vertices can be colored with n colors

    OpenAIRE

    Kulesza, Kamil; Kotulski, Zbigniew

    2003-01-01

    In the paper we state and prove theorem describing the upper bound on number of the graphs that have fixed number of vertices |V| and can be colored with the fixed number of n colors. The bound relates both numbers using power of 2, while the exponent is the difference between |V| and n. We also state three conjectures on the number of graphs that have fixed number of vertices |V| and chromatic number n.

  13. Advanced Si solid phase crystallization for vertical channel in vertical NANDs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangsoo [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Son, Yong-Hoon [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Semiconductor R and D Center, Samsung Electronics Co., Ltd., Hwasung 445-701 (Korea, Republic of); Hwang, Kihyun; Shin, Yoo Gyun [Semiconductor R and D Center, Samsung Electronics Co., Ltd., Hwasung 445-701 (Korea, Republic of); Yoon, Euijoon, E-mail: eyoon@snu.ac.kr [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of)

    2014-07-01

    The advanced solid phase crystallization (SPC) method using the SiGe/Si bi-layer structure is proposed to obtain high-mobility poly-Si thin-film transistors in next generation vertical NAND (VNAND) devices. During the SPC process, the top SiGe thin film acts as a selective nucleation layer to induce surface nucleation and equiaxial microstructure. Subsequently, this SiGe thin film microstructure is propagated to the underlying Si thin film by epitaxy-like growth. The initial nucleation at the SiGe surface was clearly observed by in situ transmission electron microscopy (TEM) when heating up to 600 °C. The equiaxial microstructures of both SiGe nucleation and Si channel layers were shown in the crystallized bi-layer plan-view TEM measurements. Based on these experimental results, the large-grained and less-defective Si microstructure is expected to form near the channel region of each VNAND cell transistor, which may improve the electrical characteristics.

  14. Advanced Si solid phase crystallization for vertical channel in vertical NANDs

    Directory of Open Access Journals (Sweden)

    Sangsoo Lee

    2014-07-01

    Full Text Available The advanced solid phase crystallization (SPC method using the SiGe/Si bi-layer structure is proposed to obtain high-mobility poly-Si thin-film transistors in next generation vertical NAND (VNAND devices. During the SPC process, the top SiGe thin film acts as a selective nucleation layer to induce surface nucleation and equiaxial microstructure. Subsequently, this SiGe thin film microstructure is propagated to the underlying Si thin film by epitaxy-like growth. The initial nucleation at the SiGe surface was clearly observed by in situ transmission electron microscopy (TEM when heating up to 600 °C. The equiaxial microstructures of both SiGe nucleation and Si channel layers were shown in the crystallized bi-layer plan-view TEM measurements. Based on these experimental results, the large-grained and less-defective Si microstructure is expected to form near the channel region of each VNAND cell transistor, which may improve the electrical characteristics.

  15. Vertical control in the Class III compensatory treatment

    Directory of Open Access Journals (Sweden)

    Márcio Costa Sobral

    2013-04-01

    Full Text Available INTRODUCTION: Compensatory orthodontic treatment, or simply orthodontic camouflage, consists in an important alternative to orthognathic surgery in the resolution of skeletal discrepancies in adult patients. It is important to point that, to be successfully performed, diagnosis must be detailed, to evaluate, specifically, dental and facial features, as well as the limitations imposed by the magnitude of the discrepancy. The main complaint, patient's treatment expectation, periodontal limits, facial pattern and vertical control are some of the items to be explored in the determination of the viability of a compensatory treatment. Hyperdivergent patients who carry a Class III skeletal discrepancy, associated with a vertical facial pattern, with the presence or tendency to anterior open bite, deserve special attention. In these cases, an efficient strategy of vertical control must be planned and executed. OBJECTIVE: The present article aims at illustrating the evolution of efficient alternatives of vertical control in hiperdivergent patients, from the use, in the recent past, of extra-oral appliances on the lower dental arch (J-hook, until nowadays, with the advent of skeletal anchorage. But for patients with a more balanced facial pattern, the conventional mechanics with Class III intermaxillary elastics, associated to an accentuated curve of Spee in the upper arch and a reverse Curve of Spee in the lower arch, and vertical elastics in the anterior region, continues to be an excellent alternative, if there is extreme collaboration in using the elastics.

  16. Vertical Dynamic Impedance of Tapered Pile considering Compacting Effect

    Directory of Open Access Journals (Sweden)

    Wenbing Wu

    2013-01-01

    Full Text Available Based on complex stiffness transfer model, the vertical vibration of tapered pile embedded in layered soil is theoretically investigated by considering the compacting effect of the soil layer surrounding the tapered pile in the piling process. Allowing for the stratification of the surrounding soil and variable crosssection of the tapered pile, the pile-soil system is discretized into finite segments. By virtue of the complex stiffness transfer model to simulate the compacting effect, the complex stiffness of different soil segments surrounding the tapered pile is obtained. Then, substituting the complex stiffness into the vertical dynamic governing equation of tapered pile, the analytical solution of vertical dynamic impedance of tapered pile under vertical exciting force is derived by means of the Laplace technique and impedance function transfer method. Based on the presented solutions, the influence of compacting effect of surrounding soil on vertical dynamic impedance at the pile head is investigated within the low frequency range concerned in the design of dynamic foundation.

  17. Scaling of Retinal Image Induced by Vertical Magnification Disparity

    Directory of Open Access Journals (Sweden)

    Minoru Fujii

    2011-05-01

    Full Text Available A surface lying in a frontal plane appears slanted about a vertical axis when the image in one eye is horizontally magnified relative to the image in the other eye. This is predicted from the geometry of the situation. The same surface appears to slant in the opposite direction when the image in the first eye is vertically magnified relative to the image in the other eye (induced effect. One explanation of the induced effect is that the retinal image is isotropically scaled to the same height and the horizontal magnification disparity as a by-product elicits the slant impression. In the current study, scaling of retinal image induced by the stereogram with vertical magnification disparity is investigated. Two horizontal lines were superimposed on the stereogram to measure the scaling. One line presented to one eye was parallel to the other line presented to the other eye, to avoid problems of rivalry or fusion. Three subjects responded apparent lengths of the lines. The result showed that the line superimposed on the vertically magnified image appeared longer than the other line. This supports that scaling of retinal image induced by vertical magnification exists.

  18. Influence of gravity on cat vertical vestibulo-ocular reflex

    Science.gov (United States)

    Tomko, D. L.; Wall, C., III; Robinson, F. R.; Staab, J. P.

    1988-01-01

    The vertical vestibulo-ocular reflex (VOR) was recorded in cats using electro-oculography during sinusoidal angular pitch. Peak stimulus velocity was 50 deg/s over a frequency range from 0.01 to 4.0 Hz. To test the effect of gravity on the vertical VOR, the animal was pitched while sitting upright or lying on its side. Upright pitch changed the cat's orientation relative to gravity, while on-side pitch did not. The cumulative slow component position of the eye during on-side pitch was less symmetric than during upright pitch. Over the mid-frequency range (0.1 to 1.0 Hz), the average gain of the vertical VOR was 14.5 percent higher during upright pitch than during on-side pitch. At low frequencies (less than 0.05 Hz) changing head position relative to gravity raised the vertical VOR gain and kept the reflex in phase with stimulus velocity. These results indicate that gravity-sensitive mechanisms make the vertical VOR more compensatory.

  19. Study of vertical breakwater reliability based on copulas

    Science.gov (United States)

    Dong, Sheng; Li, Jingjing; Li, Xue; Wei, Yong

    2016-04-01

    The reliability of a vertical breakwater is calculated using direct integration methods based on joint density functions. The horizontal and uplifting wave forces on the vertical breakwater can be well fitted by the lognormal and the Gumbel distributions, respectively. The joint distribution of the horizontal and uplifting wave forces is analyzed using different probabilistic distributions, including the bivariate logistic Gumbel distribution, the bivariate lognormal distribution, and three bivariate Archimedean copulas functions constructed with different marginal distributions simultaneously. We use the fully nested copulas to construct multivariate distributions taking into account related variables. Different goodness fitting tests are carried out to determine the best bivariate copula model for wave forces on a vertical breakwater. We show that a bivariate model constructed by Frank copula gives the best reliability analysis, using marginal distributions of Gumbel and lognormal to account for uplifting pressure and horizontal wave force on a vertical breakwater, respectively. The results show that failure probability of the vertical breakwater calculated by multivariate density function is comparable to those by the Joint Committee on Structural Safety methods. As copulas are suitable for constructing a bivariate or multivariate joint distribution, they have great potential in reliability analysis for other coastal structures.

  20. The WZNW model on PSU(1, 1 vertical stroke 2)

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, G. [CEA Centre d' Etudes de Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique; Quella, T. [King' s College London (United Kingdom). Dept. of Mathematics]|[Amsterdam Univ. (Netherlands). KdV Institute for Mathematics; Schomerus, V. [CEA Centre d' Etudes de Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-10-15

    According to the work of Berkovits, Vafa and Witten, the non-linear sigma model on the supergroup PSU(1,1 vertical stroke 2) is the essential building block for string theory on AdS{sub 3}xS{sup 3}xT{sup 4}. Models associated with a non-vanishing value of the RR flux can be obtained through a psu(1,1 vertical stroke 2) invariant marginal deformation of the WZNW model on PSU(1,1 vertical stroke 2). We take this as a motivation to present a manifestly psu(1,1 vertical stroke 2) covariant construction of the model at the Wess-Zumino point, corresponding to a purely NSNS background 3-form flux. At this point the model possesses an enhanced psu(1,1 vertical stroke 2) current algebra symmetry whose representation theory, including explicit character formulas, is developed systematically in the first part of the paper. The space of vertex operators and a free fermion representation for their correlation functions is our main subject in the second part. Contrary to a widespread claim, bosonic and fermionic fields are necessarily coupled to each other. The interaction changes the supersymmetry transformations, with drastic consequences for the multiplets of localized normalizable states in the model. It is only this fact which allows us to decompose the full state space into multiplets of the global supersymmetry. We analyze these decompositions systematically as a preparation for a forthcoming study of the RR deformation. (orig.)

  1. Application of the oblique ionogram as vertical ionogram

    Institute of Scientific and Technical Information of China (English)

    CHEN Gang; ZHAO ZhengYu; ZHANG YuanNong; YANG GuoBin; ZHOU Chen; HUANG Shuo; LI Ting; LI Ning; SUN HengQing

    2012-01-01

    The vertical ionogram can provide the important ionospheric parameters,such as critical frequency,virtual height and electron density,for ionospheric research.The oblique ionosonde has the ability to detect the ionosphere over sea and other terrain where it is not practical to deploy vertical sounder and provide more ionograms with less transmitting and receiving devices.Therefore,the conversion of the oblique ionogram to vertical ionogram for obtaining the important ionospheric parameters is a very useful inversion technology.The experimental comparison between oblique and vertical detections was carried out in the equatorial ionospheric anomaly (EIA) region of south China on 25 and 26 August 2010.The oblique detecting path was from Wuhan to Shenzhen and the Ⅵ ionosonde was located in the midpoint of the oblique path.The oblique ionogram reversion results showed a small deviation of the critical frequency,minimum virtual height as well as the electron density profile of the ionospheric F layer,as compared with the real vertical observations.

  2. Mixed multilayered vertical heterostructures utilizing strained monolayer WS2

    Science.gov (United States)

    Sheng, Yuewen; Xu, Wenshuo; Wang, Xiaochen; He, Zhengyu; Rong, Youmin; Warner, Jamie H.

    2016-01-01

    Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer of WS2, with Boron Nitride and Graphene. The 2D materials are all grown by CVD, enabling large area vertical heterostructures to be formed. WS2 monolayers grown by CVD directly on Si substrates with SiO2 surface are easily washed off by water and this makes aqueous based transfer methods challenging for creating vertical stacks on the growth substrate. 2D hexagonal Boron Nitride films are used to provide an insulating layer that limits interactions with a top graphene layer and preserve the strong photoluminescence from the WS2. This transfer method is suitable for layer by layer control of 2D material vertical stacks and is shown to be possible for all CVD grown samples, which opens up pathways for the rapid large scale fabrication of vertical heterostructure systems with atomic thickness depth control and large area coverage.Creating alternating layers of 2D materials forms vertical heterostructures with diverse electronic and opto-electronic properties. Monolayer WS2 grown by chemical vapour deposition can have inherent strain due to interactions with the substrate. The strain modifies the band structure and properties of monolayer WS2 and can be exploited in a wide range of applications. We demonstrate a non-aqueous transfer method for creating vertical stacks of mixed 2D layers containing a strained monolayer of WS2, with Boron Nitride and Graphene. The 2D materials are all grown by CVD, enabling large area vertical heterostructures to be formed. WS2 monolayers grown by

  3. Surgical Management of Significant Maxillary Anterior Vertical Ridge Defects.

    Science.gov (United States)

    Urban, Istvan A; Monje, Alberto; Nevins, Myron; Nevins, Marc L; Lozada, Jamie L; Wang, Hom-Lay

    2016-01-01

    Severe vertical ridge deficiency in the anterior maxilla represents one of the most challenging scenarios in bone regeneration. Under ideal circumstances, guided bone regeneration in combination with soft tissue management has shown predictable esthetic and functional outcomes. Success largely relies on primary wound closure during and after the surgical procedure. Surgical sites present different challenges that need to be considered when designing the flap. The goal of this article is to propose a classification of flap designs that considers vestibular depth and scar formation around the periosteum when performing vertical ridge augmentation in the atrophic anterior maxilla. The four clinical conditions proposed under this classification are (1) shallow vestibule with healthy periosteum, (2) deep vestibule with healthy periosteum, (3) shallow vestibule with scarred periosteum, and (4) deep vestibule with scarred periosteum. The classification will allow clinicians to achieve tension-free closure and more predictable vertical bone gain.

  4. An optimal real-time controller for vertical plasma stabilization

    CERN Document Server

    Cruz, N; Coda, S; Duval, B P; Le, H B; Rodrigues, A P; Varandas, C A F; Correia, C M B A; Goncalves, B S

    2014-01-01

    Modern Tokamaks have evolved from the initial axisymmetric circular plasma shape to an elongated axisymmetric plasma shape that improves the energy confinement time and the triple product, which is a generally used figure of merit for the conditions needed for fusion reactor performance. However, the elongated plasma cross section introduces a vertical instability that demands a real-time feedback control loop to stabilize the plasma vertical position and velocity. At the Tokamak \\`a Configuration Variable (TCV) in-vessel poloidal field coils driven by fast switching power supplies are used to stabilize highly elongated plasmas. TCV plasma experiments have used a PID algorithm based controller to correct the plasma vertical position. In late 2013 experiments a new optimal real-time controller was tested improving the stability of the plasma. This contribution describes the new optimal real-time controller developed. The choice of the model that describes the plasma response to the actuators is discussed. The ...

  5. Vertically-oriented nanoparticle dimer based on focused plasmonic trapping.

    Science.gov (United States)

    Shen, Zhe; Su, Lei; Shen, Yao-Chun

    2016-07-11

    We proposed a vertically-oriented dimer structure based on focused plasmonic trapping of metallic nanoparticle. Quantitative FDTD calculations and qualitative analysis by simplified dipole approximation revealed that localized surface plasmon coupling dominates in the plasmon hybridization, and the vertically-oriented dimer can effectively make use of the dominant longitudinal component of the surface plasmon virtual probe thus providing much stronger electric field in the gap. Furthermore, for practical application the top nanoparticle of the dimer can be replaced with an atomic force microscope tip which enables the precise control of the gap distance of the dimer. Therefore the proposed vertically-oriented dimer structure provides both the scanning capability and the extremely-high electrical field necessary for the high sensitivity Raman imaging. PMID:27410874

  6. Experimental Assessment of Moisture Transfer in the Vertical Ventilated Channel

    Directory of Open Access Journals (Sweden)

    Musorina Tatyana

    2016-01-01

    Full Text Available This article considers the moisture transfer phenomenon in the vertical ventilated channel. Also the article considers innovative structures for the vertical ventilated channel.The negative factors connected with moisture accumulation and excessive moistening of a heat insulation are given. Optimum design parameters for definition of the most intensive moisture transfer are discovered: systems with and without grooved lines. Influence that existence of technological gaps (grooved lines has on the speed of air flows in a gap is investigated. Dependence of speed on width of the ventilated gap for a design with the opened and closed grooved lines is established empirically. The dehumidification properties of the vertical ventilated channel are described, as well as dependence of mass evaporation rate on time is established. Processes of drying-out in various conditions are compared.

  7. Unsupervised Anomalous Vertices Detection Utilizing Link Prediction Algorithms

    CERN Document Server

    Kagan, Dima; Elovici, amd Yuval

    2016-01-01

    In the past decade, complex network structures have penetrated nearly every aspect of our lives. The detection of anomalous vertices in these networks can uncover important insights, such as exposing intruders in a computer network. In this study, we present a novel unsupervised two-layered meta classifier that can be employed to detect irregular vertices in complex networks using solely features extracted from the network topology. Our method is based on the hypothesis that a vertex having many links with low probabilities of existing has a higher likelihood of being anomalous. We evaluated our method on ten networks, using three fully simulated, five semi-simulated, and two real world datasets. In all the scenarios, our method was able to identify anomalous and irregular vertices with low false positive rates and high AUCs. Moreover, we demonstrated that our method can be applied to security-related use cases and is able to detect malicious profiles in online social networks.

  8. THEORETICAL ANALYSIS ON THE VERTICAL DISTRIBUTION OF PARTICLE CONCENTRATION

    Institute of Scientific and Technical Information of China (English)

    Guangqian WANG; Xudong FU

    2001-01-01

    In steady, solid-liquid two-phase turbulent flows, there exist two typical patterns of the vertical distribution of particle concentration. The pattern I shows a maximum concentration at an elevation above the bed. The pattern II shows an increase of the particle concentration downward over the whole vertical,with the maximum at the bed. Most of the theories on particle concentration distribution have been done with the pattern II, and it is lack of a successful theory coveting both of the two patterns. This paper reviews the particle distribution theories, including the diffusion theory, the mixture theory, the energy theory, the similarity theory, the stochastic theory and the kinetic theory. The kinetic theory is also applied to describe the vertical distribution of particle concentration in both dilute and dense flows.

  9. Metatarsal strapping tightness effect to vertical jump performance.

    Science.gov (United States)

    Zhang, Yan; Baker, Julien S; Ren, Xuejun; Feng, Neng; Gu, Yaodong

    2015-06-01

    The study investigated the effect of metatarsal strapping on vertical jump performance and evaluated the difference in lower limb kinematics and electromyographic signal (EMG) between different strapping force levels. Twelve male callisthenic athletes completed single vertical jump from a squat posture with hands on hips under three conditions as non-strapping (NS), moderate strapping (MS) and high strapping (HS) round metatarsals. Ground reaction force (GRF) was recorded with KISTLER force platform to calculate the vertical jump height. Angles of ankle, knee and hip were measured with VICON motion analysis system and EMG data were recorded with mega6000 system. Data showed that jump height was significantly higher under HS than NS condition. Compared with NS, ankle inversion decreased significantly during take-off and external rotation increased significantly during landing with MS. Significant difference was also found in the muscle activity of tibialis anterior between non-strapping and strapping conditions.

  10. LIQUEFACTION AND DISPLACEMENT OF SATURATED SAND UNDER VERTICAL VIBRATION LOADING

    Institute of Scientific and Technical Information of China (English)

    LU Xiaobing; TAN Qingming; CHENG C.M.; YU Shanbing; CUI Peng

    2004-01-01

    In order to investigate the influence of the vertical vibration loading on the liquefaction of saturated sand, one dimensional model for the saturated sand with a vertical vibration is presented based on the two phase continuous media theory. The development of the liquefaction and the liquefaction region are analyzed. It is shown that the vertical vibration loading could induce liquefaction.The rate of the liquefaction increases with the increase of the initial limit strain or initial porosity or amplitude and frequency of loading, and increases with the decrease of the permeability or initial modulus. It is shown also that there is a phase lag in the sand column. When the sand permeability distribution is non-uniform, the pore pressure and the strain will rise sharply where the permeability is the smallest, and fracture might be induced. With the development of liquefaction, the strength of the soil foundation becomes smaller and smaller. In the limiting case, landslides or debris flows could occur.

  11. Requirements of Vertical Handoff Mechanism in 4G Wireless Networks

    CERN Document Server

    Gondara, Mandeep Kaur

    2011-01-01

    The importance of wireless communication is increasing day by day throughout the world due to cellular and broadband technologies. Everyone around the world would like to be connected seamlessly anytime anywhere through the best network. The 4G wireless system must have the capability to provide high data transfer rates, quality of services and seamless mobility. In 4G, there are a large variety of heterogeneous networks. The users for variety of applications would like to utilize heterogeneous networks on the basis of their preferences such as real time, high availability and high bandwidth. When connections have to switch between heterogeneous networks for performance and high availability reasons, seamless vertical handoff is necessary. The requirements like capability of the network, handoff latency, network cost, network conditions, power consumption and user's preferences must be taken into consideration during vertical handoff. In this paper, we have extracted the requirements of a vertical handoff fro...

  12. Vertically aligned carbon nanotube field-effect transistors

    KAUST Repository

    Li, Jingqi

    2012-10-01

    Vertically aligned carbon nanotube field-effect transistors (CNTFETs) have been developed using pure semiconducting carbon nanotubes. The source and drain were vertically stacked, separated by a dielectric, and the carbon nanotubes were placed on the sidewall of the stack to bridge the source and drain. Both the effective gate dielectric and gate electrode were normal to the substrate surface. The channel length is determined by the dielectric thickness between source and drain electrodes, making it easier to fabricate sub-micrometer transistors without using time-consuming electron beam lithography. The transistor area is much smaller than the planar CNTFET due to the vertical arrangement of source and drain and the reduced channel area. © 2012 Elsevier Ltd. All rights reserved.

  13. Review on Vertical Handover Techniques among Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Hoshang Karanjekar

    2014-03-01

    Full Text Available One of the major design issues in heterogeneous wireless networks is the support of vertical handover. Vertical handover occurs when a mobile terminal switches from one network to another (e.g., from WLAN to CDMA 1xRTT. Seamless handover between different access technologies is a great challenge as it needs to obey different performance of QoS and security constraints. Vertical handover decision (VHD algorithms are essential components of the architecture of the forthcoming Fourth Generation (4G heterogeneous wireless networks. These algorithms need to be designed to provide the required Quality of Service (QoS to a wide range of applications while allowing seamless roaming among a multitude of access network technologies. This paper is about the comprehensive survey of the VHD algorithms designed to satisfy these requirements.

  14. Performance Analysis of Vertical Handover Strategy for Heterogeneous Overlay Network

    Institute of Scientific and Technical Information of China (English)

    BINGHongyan; HEChen; JIANGLingge

    2004-01-01

    Future wireless networks are envisioned to integrate cellular network and hot spots (e.g. ultrawideband network, UWB) in virtue of the individual coverage and capacity complementary characteristics. In this heterogeneous overlay network, seamless Vertical handover (VHO) is one of the important issues because users expect to be provided with continuous service at anytime, anywhere. This paper presents an analytical vertical handover initiation model based on Received signal strength(RSS) criterion and network blocking probability criterion. Meanwhile, the handover performance criteria of interest are: the handover probability and call-dropping probability. The analytical formulas are derived in details and the handover performance is evaluated by computer simulations. The simulation results show that our model can give improved performance compared with vertical HO algorithm only based on RSS criterion and can perform well when UWB hot spot is in heavy network load.

  15. Vertical pressure gradient and particle motions in wave boundary layers

    DEFF Research Database (Denmark)

    Jensen, Karsten Lindegård

    The present study covers both a numerical and experimental investigation of the processes in the oscillatory boundary layer. In the first part a direct numerical simulation (DNS) is conducted to study the vertical pressure gradient, and its role in relation to laminar to turbulent transition...... and its role in the fully turbulent boundary layer. The pressure in the flow is obtained from the flow fields of the oscillatory boundary layer. What differs, the vertical pressure gradient, from other turbulent quantities, like e.g. velocity fluctuations is that it can detect newly generated turbulence....... This is in contrast to velocity fluctuations that are diffusive, so they can also contain residual turbulence from the previous half cycle until they are dissipated. Furthermore, the magnitude of the mean value of conditionally averaged vertical pressure gradient (for −∂p∗/∂x∗ 2 > 0) is compared to the submerged...

  16. Field Emission of ITO-Coated Vertically Aligned Nanowire Array.

    KAUST Repository

    Lee, Changhwa

    2010-04-29

    An indium tin oxide (ITO)-coated vertically aligned nanowire array is fabricated, and the field emission characteristics of the nanowire array are investigated. An array of vertically aligned nanowires is considered an ideal structure for a field emitter because of its parallel orientation to the applied electric field. In this letter, a vertically aligned nanowire array is fabricated by modified conventional UV lithography and coated with 0.1-μm-thick ITO. The turn-on electric field intensity is about 2.0 V/μm, and the field enhancement factor, β, is approximately 3,078 when the gap for field emission is 0.6 μm, as measured with a nanomanipulator in a scanning electron microscope.

  17. The GL(1 vertical stroke 1)-symplectic fermion correspondence

    Energy Technology Data Exchange (ETDEWEB)

    Creutzig, Thomas; Roenne, Peter B.

    2008-12-15

    In this note we prove a correspondence between the Wess-Zumino-Novikov-Witten model of the Lie supergroup GL(1 vertical stroke 1) and a free model consisting of two scalars and a pair of symplectic fermions. This model was discussed earlier by LeClair. Vertex operators for the symplectic fermions include twist fields, and correlation functions of GL(1 vertical stroke 1) agree with the known results for the scalars and symplectic fermions. We perform a detailed study of boundary states for symplectic fermions and apply them to branes in GL(1 vertical stroke 1). This allows us to compute new amplitudes of strings stretching between branes of different types and confirming Cardy's condition. (orig.)

  18. MHD Simulations of Global Accretion Disks with Vertical Magnetic Fields

    CERN Document Server

    Suzuki, Takeru K

    2013-01-01

    (Abridged) We report results of three dimensional MHD simulations of global accretion disks threaded with weak vertical magnetic fields. We perform the simulations in the spherical coordinates with different temperature profiles and accordingly different rotation profiles. In the cases with a spatially constant temperature, because the rotation frequency is vertically constant in the equilibrium condition, general properties of the turbulence are quantitatively similar to those obtained in local shearing box simulations. On the other hand, in the cases with a radially variable temperature profile, the vertical differential rotation, which is inevitable in the equilibrium condition, winds up the magnetic field lines, in addition to the usual radial differential rotation. As a result, the coherent wound magnetic fields contribute to the Maxwell stress in the surface regions. We obtain nondimensional density and velocity fluctuations ~0.1-0.2 at the midplane. The azimuthal power spectra of the magnetic fields sh...

  19. The vertical velocity dispersion profile of the Galactic thick disk

    CERN Document Server

    Bidin, C Moni; Carraro, G; Méndez, R A; Van Altena, W F; Korchagin, V I; Casetti-Dinescu, D I

    2007-01-01

    We present the results of radial velocity measurements of 770 thick disk red giants toward the South Galactic Pole, vertically distributed from 0.5 kpc to 5 kpc with respect to the Galactic plane. We find a small gradient in the vertical velocity dispersion (sigma_W) of 3.8+/-0.8 km/s kpc. Even more noteworthy, our values of $\\sigma_W$ are small compared to literature values: in the middle of the vertical height range we find sigma_W(z=2kpc)=30 km/s. We found no possible explanation for this small value of sigma_W in terms of sample contamination by thin disk stars, nor by wrong assumptions regarding the metallicity distribution and the derived distances.

  20. Sufficient Conditions for Vertical Composition of Security Protocols (Extended Version)

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander; Viganò, Luca

    Vertical composition of security protocols means that an application protocol (e.g., a banking service) runs over a channel established by another protocol (e.g., a secure channel provided by TLS). This naturally gives rise to a compositionality question: given a secure protocol P1 that provides...... a certain kind of channel as a goal and another secure protocol P2 that assumes this kind of channel, can we then derive that their vertical composition P2[P1] is secure? It is well known that protocol composition can lead to attacks even when the individual protocols are all secure in isolation....... In this paper, we formalize seven easy-to-check static conditions that support a large class of channels and applications and that we prove to be su_cient for vertical security protocol composition....

  1. NEW TYPE OF VIBRATION STRUCTURE OF VERTICAL DYNAMIC BALANCING MACHINE

    Institute of Scientific and Technical Information of China (English)

    Li Dinggen; Cao Jiguang; Chen Chuanyao; Wang Junwen

    2004-01-01

    A new type of vibration structure of vertical dynamic balancing machine is designed, which is based on the analysis for swing frame of a traditional vertical dynamic balancing machine. The static unbalance and couple unbalance can be separated effectively by using the new machine with the new swing frame. By building the dynamics model, the advantages of the new structure are discussed in detail. The modal and harmonic response are analyzed by using the ANSYS7.0. By comparing the finite element modal analysis with the experimental modal analysis, the natural frequencies and vibration modes are found out. There are many spring boards in the new swing frame. Their stiffness is different and assort with each other. Furthermore, there are three sensors on the measurement points. Therefore, the new dynamic balancing machine can measure the static unbalance and couple unbalance directly, and the influence between them is faint. The new structure has the function of belt-strain compensation to improve the measurement precision. The practical result indicates that the new vertical dynamic balancing machine is suitable for inertial measurement of flying objects, and can overcome the shortcomings of traditional double-plane vertical dynamic balancing machines. The vertical dynamic balancing machine with the new vibration structure can be widely used in the future applications. The modeling and analysis of the new vibration structure provide theoretic instruction and practical experience for designing new type of vertical dynamic balancing machines. Based on the design principles such as stiffness-matching, frequency-adjacence and strain-compensation and so on, various new type of vibration structures can be designed.

  2. Isokinetic knee extension and vertical jumping: are they related?

    Science.gov (United States)

    Iossifidou, Anna; Baltzopoulos, Vasilios; Giakas, Giannis

    2005-10-01

    The aim of this study was to examine joint power generation during a concentric knee extension isokinetic test and a squat vertical jump. The isokinetic test joint power was calculated using four different methods. Five participants performed concentric knee extensions at 0.52, 1.57, 3.14 and 5.23 rad x s(-1) on a Lido isokinetic dynamometer. The squat vertical jump was performed on a Kistler force plate. Kinematic data from both tests were collected and analysed using an ELITE optoelectronic system. An inverse dynamics model was applied to measure knee joint moment in the vertical jump. Knee angular position data from the kinematic analysis in the isokinetic test were used to derive the actual knee angular velocity and acceleration, which, in turn, was used to correct the dynamometer moment for inertial effects. Power was measured as the product of angular velocity and moment at the knee joint in both tests. Significant differences (P knee joint power in the two tests (squat vertical jump: 2255 +/- 434 W; isokinetic knee extension: 771 +/- 81 W). Correlation analysis revealed that there is no relationship between the peak knee joint power during the vertical jump and the slow velocity isokinetic tests. Higher isokinetic velocity tests show better relationships with the vertical jump but only if the correct method for joint power calculation is used in the isokinetic test. These findings suggest that there are important differences in muscle activation and knee joint power development that must be taken into consideration when isokinetic tests are used to predict jumping performance.

  3. Reconstruction of Vertical Profile of Permittivity of Layered Media which is Probed Using Vertical Differential Antenna

    Science.gov (United States)

    Pochanin, Gennadiy P.; Poyedinchuk, Anatoliy Y.; Varianytsia-Roshchupkina, Liudmyla A.; Pochanina, Iryna Ye.

    2016-04-01

    Results of this research are intended to use at GPR investigations of layered media (for example, at roads' inspection) for the processing of collected data and reconstruction of dependence of permittivity on the depth. Recently, an antenna system with a vertical differential configuration of receiving module (Patent UA81652) for GPR was suggested and developed The main advantage of the differential antennas in comparison with bistatic antennas is a high electromagnetic decoupling between the transmitting and receiving modules. The new vertical differential configuration has an additional advantage because it allows collecting GPR data reflected by layered media without any losses of information about these layers [1] and, potentially, it is a more accurate instrument for the layers thickness measurements [2]. The developed antenna system is tested in practice with the GPR at asphalt thickness measurements [3] and shown an accuracy which is better than 0.5 cm. Since this antenna system is good for sounding from above the surface (air coupled technique), the mobile laboratory was equipped with the developed GPR [3]. In order to process big set of GPR data that collected during probing at long routes of the roads, for the data processing it was tested new algorithm of the inverse problem solution. It uses a fast algorithm for calculation of electromagnetic wave diffraction by non-uniform anisotropic layers [4]. The algorithm is based on constructing a special case solution to the Riccati equation for the Cauchy problem and enables a qualitative description of the wave diffraction by the electromagnetic structure of the type within a unitary framework. At this stage as initial data we used synthetic GPR data that were obtained as results of the FDTD simulation of the problem of UWB electromagnetic impulse diffraction on layered media. Differential and bistatic antenna configurations were tested at several different profiles of permittivity. Meanings of permittivity of

  4. CONDENSATION OF WATER VAPOR IN A VERTICAL TUBE CONDENSER

    OpenAIRE

    Jan Havlík; Tomáš Dlouhý

    2015-01-01

    This paper presents an analysis of heat transfer in the process of condensation of water vapor in a vertical shell-and-tube condenser. We analyze the use of the Nusselt model for calculating the condensation heat transfer coefficient (HTC) inside a vertical tube and the Kern, Bell-Delaware and Stream-flow analysis methods for calculating the shell-side HTC from tubes to cooling water. These methods are experimentally verified for a specific condenser of waste process vapor containing air. The...

  5. Investigation on collapse mechanism of super-deep vertical shaft

    International Nuclear Information System (INIS)

    Recent interests in the development of deep underground facilities have been drawing significant attention for the importance of vertical shafts at great depth. However, due to shrinkage of domestic coal production, any deep shafts in the order of 1000m have not been constructed in more than 20 years. For the purposes of technical transfer and establishment of fundamentals for rational design method of vertical shafts, intensive literature review and interviews to engineers with relevant experiences were conducted. As the results, there are two distinctive modes of failure mechanism originated by the common cause, that is 'takanuke' collapse and lining failure due to unexpected earth pressure. (author)

  6. Vertical Capacity of Bucket Foundations in Undrained Soil

    DEFF Research Database (Denmark)

    Barari, Amin; Ibsen, Lars Bo

    2014-01-01

    Offshore wind turbine structures are traditionally founded on gravity concrete foundations or mono-piles. Bucket foundations were developed for the offshore oil and gas industry and are now being used in wind turbine construction. The loading in this application is characterized by a vertical load...... due to the slender construction combined with horizontal forces inducing a large overturning moment. Field tests on bucket foundations were performed to gain insight into the vertical load response of bucket foundations in clay soils. The field tests were accompanied by finite element numerical...... simulations in order to provide a better understanding of the parameters influencing bucket foundation behavior....

  7. Application of Prefabricated Vertical Drain in Soil Improvement

    Directory of Open Access Journals (Sweden)

    Tedjakusuma B.

    2012-01-01

    Full Text Available Although the use of Prefabricated Vertical Drain (PVD in soil improvement is not new, this paper is interesting since it gives the full spectrum from preliminary design stage; trial embankment and pilot test to final soil improvement. The final installation of the PVD was based on the soil investigation report and the results of instrumentation monitoring. Finally, using back analysis, vertical and horizontal coefficients of consolidation and compression index can be determined, which can be applied to predict a more accurate prediction of settlement.

  8. Explicit Dynamic FEM Analysis of Multipass Vertical-Horizontal Rolling

    Institute of Scientific and Technical Information of China (English)

    YU Hai-liang; LIU Xiang-hua; ZHAO Xian-ming; WU Di; Y.Kusaba

    2006-01-01

    Three passes of plate rolling during vertical-horizontal rolling process are simulated with explicit dynamic finite element method and updating geometric method. The equivalent strain and stress fields, and shape change at the head and tail of slab during rolling are obtained. The calculated result of the shape at the head and tail of slab is in good agreement with the measured one. The explicit dynamic finite element method and updating geometric method can be used effectively to analyze the multipass vertical-horizontal (V-H) rolling process.

  9. The effects of vertical outflows on disk dynamos

    OpenAIRE

    Bardou, A.; Rekowski, B. v.; Dobler, W.; Brandenburg, A.; Shukurov, A.

    2000-01-01

    We consider the effect of vertical outflows on the mean-field dynamo in a thin disk. These outflows could be due to winds or magnetic buoyancy. We analyse both two-dimensional finite-difference numerical solutions of the axisymmetric dynamo equations and a free-decay mode expansion using the thin-disk approximation. Contrary to expectations, a vertical velocity can enhance dynamo action, provided it is not too strong. In the nonlinear regime this can lead to super-exponential growth of the ma...

  10. Sufficient Conditions for Vertical Composition of Security Protocols (Extended Version)

    OpenAIRE

    Mödersheim, Sebastian Alexander; Viganò, Luca

    2014-01-01

    Vertical composition of security protocols means that an application protocol (e.g., a banking service) runs over a channel established by another protocol (e.g., a secure channel provided by TLS). This naturally gives rise to a compositionality question: given a secure protocol P1 that provides a certain kind of channel as a goal and another secure protocol P2 that assumes this kind of channel, can we then derive that their vertical composition P2[P1] is secure? It is well known that protoco...

  11. Vertical vibration and shape oscillation of acoustically levitated water drops

    Science.gov (United States)

    Geng, D. L.; Xie, W. J.; Yan, N.; Wei, B.

    2014-09-01

    We present the vertical harmonic vibration of levitated water drops within ultrasound field. The restoring force to maintain such a vibration mode is provided by the resultant force of acoustic radiation force and drop gravity. Experiments reveal that the vibration frequency increases with the aspect ratio for drops with the same volume, which agrees with the theoretical prediction for those cases of nearly equiaxed drops. During the vertical vibration, the floating drops undergo the second order shape oscillation. The shape oscillation frequency is determined to be twice the vibration frequency.

  12. Seasonal variations in vertical migration of glacier lanternfish, Benthosema glaciale

    OpenAIRE

    Dypvik, Eivind; Røstad, Anders; Kaartvedt, Stein

    2012-01-01

    The seasonal variations in glacier lanternfish (Benthosema glaciale) vertical distribution and diel vertical migration (DVM) were studied by use of a bottom-mounted upward-facing 38 kHz echo sounder deployed at 392 m depth and cabled to shore in Masfjorden (~60°52′N, ~5°24′E), Norway. Acoustic data from July 2007–October 2008 were analyzed, and scattering layers below ~220 m during daytime were attributed to glacier lanternfish based on net sampling in this, and previous studies, as well as f...

  13. Vertical vibration and shape oscillation of acoustically levitated water drops

    Energy Technology Data Exchange (ETDEWEB)

    Geng, D. L.; Xie, W. J.; Yan, N.; Wei, B., E-mail: bbwei@nwpu.edu.cn [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-09-08

    We present the vertical harmonic vibration of levitated water drops within ultrasound field. The restoring force to maintain such a vibration mode is provided by the resultant force of acoustic radiation force and drop gravity. Experiments reveal that the vibration frequency increases with the aspect ratio for drops with the same volume, which agrees with the theoretical prediction for those cases of nearly equiaxed drops. During the vertical vibration, the floating drops undergo the second order shape oscillation. The shape oscillation frequency is determined to be twice the vibration frequency.

  14. ELDRS and dose-rate dependence of vertical NPN transistor

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yu-Zhan; LU Wu; REN Di-Yuan; WANG Gai-Li; YU Xue-Feng; GUO Qi

    2009-01-01

    The enhanced low-dose-rate sensitivity (ELDRS) and dose-rate dependence of vertical NPN transistors are investigated in this article.The results show that the vertical NPN transistors exhibit more degradation at low dose rate,and that this degradation is attributed to the increase on base current.The oxide trapped positive charge near the SiO2-Si interface and interface traps at the interface can contribute to the increase on base current and the two-stage hydrogen mechanism associated with space charge effect can well explain the experimental results.

  15. Evaluation of vertical profiles to design continuous descent approach procedure

    Science.gov (United States)

    Pradeep, Priyank

    The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics and Base of Aircraft and Data (BADA) Total Energy Model (TEM) in this research gives insight into dependency of vertical profile of CDA on various factors like wind speed and gradient, weight, aircraft type and configuration, thrust settings, atmospheric factors (deviation from ISA (DISA), pressure and density of the air) and descent speed profile. Application of the derived equations to idle-thrust CDA gives an insight into sensitivity of its vertical profile to multiple factors. This suggests fixed geometric flight path angle (FPA) CDA has higher degree of predictability and lesser variability at the cost of non-idle and low thrust engine settings. However, with optimized design this impact can be overall minimized. The CDA simulations were performed using Future ATM Concept Evaluation Tool (FACET) based on radar-track and aircraft type data (BADA) of the real air-traffic to some of the busiest airports in the USA (ATL, SFO and New York Metroplex (JFK, EWR and LGA)). The statistical analysis of the vertical profiles of CDA shows 1) mean geometric FPAs derived from various simulated vertical profiles are consistently shallower than 3° glideslope angle and 2) high level of variability in vertical profiles of idle-thrust CDA even in absence of

  16. Thermally optimum spacing of vertical, natural convection cooled, parallel plates

    Science.gov (United States)

    Bar-Cohen, A.; Rohsenow, W. M.

    Vertical two-dimensional channels formed by parallel plates or fins are a frequently encountered configuration in natural convection cooling in air of electronic equipment. In connection with the complexity of heat dissipation in vertical parallel plate arrays, little theoretical effort is devoted to thermal optimization of the relevant packaging configurations. The present investigation is concerned with the establishment of an analytical structure for analyses of such arrays, giving attention to useful relations for heat distribution patterns. The limiting relations for fully-developed laminar flow, in a symmetric isothermal or isoflux channel as well as in a channel with an insulated wall, are derived by use of a straightforward integral formulation.

  17. VERTICAL STRUCTURE OF SECOND-MOMENT TURBULENT VARIABLES

    Institute of Scientific and Technical Information of China (English)

    AL-JIBOORI,M.H; 徐玉貌; 钱永甫

    2001-01-01

    Two kinds of observational data, fluctuation and mean profile measurements, from a 325 m meteorological tower in Beijing, China, are used to evaluate local scales of velocity and temperature for higher heights by flux-gradient mean profiles and eddy-correlation techniques. A comparison of these methods each other was made in terms of vertical turbulence fluxes for momentum and heat at the same height. The vertical profiles of non-dimensional second moments,such as vertical turbulent fluxes of momentum and heat, velocity and temperature standard deviations, were derived by local similarity theory. The local similarity relations expressed that the vertical distributions of non-dimensional second-moment variables were found to be functions of z/A and z/h in the stable boundary layer and the function of z/Zi for the convective boundary layer, where A the local Monin-Obukhov (M-O) length, h the height of stable boundary layer and Zi the height of mixed-layer. These relations are shown to agree well with the observational data.

  18. Cotunneling effects in GaAs vertical double quantum dot

    OpenAIRE

    Badrutdinov, A. O.; Huang, S. M.; Kono, K; Ono, K.; Tayurskii, D. A.

    2010-01-01

    We observed lifting of Coulomb blockade in GaAs vertical double quantum dot with low potential barriers, induced by cotunneling mechanisms at dilution fridge temperature of 10 mK. Several distinct features were observed, compared to single dot case, and appropriate explanation for them was given

  19. Novel vertical silicon photodiodes based on salicided polysilicon trenched contacts

    International Nuclear Information System (INIS)

    The classical concept of silicon photodiodes comprises of a planar design characterized by heavily doped emitters. Such geometry has low collection efficiency of the photons absorbed close to the surface. An alternative, promising, approach is to use a vertical design. Nevertheless, realization of such design is technologically challenged, hence hardly explored. Herein, a novel type of silicon photodiodes, based on salicided polysilicon trenched contacts, is presented. These contacts can be prepared up to 10 μm in depth, without showing any leakage current associated with the increase in the contact area. Consequently, the trenched photodiodes revealed better performance than no-trench photodiodes. A simple two dimensional model was developed, allowing to estimate the conditions under which a vertical design has the potential to have better performance than that of a planar design. At large, the deeper the trench is, the better is the vertical design relative to the planar (up to 10 μm for silicon). The vertical design is more advantageous for materials characterized by short diffusion lengths of the carriers. Salicided polysilicon trenched contacts open new opportunities for the design of solar cells and image sensors. For example, these contacts may passivate high contact area buried contacts, by virtue of the conformity of polysilicon interlayer, thus lowering the via resistance induced recombination enhancement effect

  20. Imaging a vertical shaft from a tunnel using muons

    Science.gov (United States)

    Bonal, N.; Preston, L. A.; Dorsey, D. J.; Schwellenbach, D.; Green, A.; Smalley, D.

    2015-12-01

    We use muon technology to image a vertical shaft from a tunnel. The density of the materials through which cosmic ray muons pass influences the flux of muons because muons are more attenuated by higher density material. Additionally, muons can travel several kilometers allowing measurements through deep rock. Density maps are generated from muon flux measurements to locate subsurface features like tunnel structures and ore bodies. Additionally, muon data can be jointly inverted with other data such as gravity and seismic to produce higher quality earth models than produced from a single method. We collected several weeks of data in a tunnel to image a vertical shaft. The minimum length of rock between the vertical shaft and the detector is 120 meters and the diameter of the vertical shaft is 4.6 meters. The rock the muons traveled through consists of Tertiary age volcanic tuff and steeply dipping, small-displacement faults. Results will be presented for muon flux in the tunnel and Monte-Carlo simulations of this experiment. Simulations from both GEANT4 (Geometry And Tracking version 4) and MCNP6 (Monte-Carlo N-Particle version 6) models will be compared. The tunnel overburden from muon measurements is also estimated and compared with actual the overburden. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. Terminal Velocity of a Shuttlecock in Vertical Fall.

    Science.gov (United States)

    Peastrel, Mark; And Others

    1980-01-01

    Describes a straightforward vertical fall experiment using a badminton shuttlecock, a tape measure, and a millisecond timer. The effects of air resistance are important and directly measurable. The experimental data best fit a predictive model which assumes a resistive force quadratic in the instantaneous speed of the falling object. (GS)

  2. The Power of Pictures : Vertical Picture Angles in Power Pictures

    NARCIS (Netherlands)

    Giessner, Steffen R.; Ryan, Michelle K.; Schubert, Thomas W.; van Quaquebeke, Niels

    2011-01-01

    Conventional wisdom suggests that variations in vertical picture angle cause the subject to appear more powerful when depicted from below and less powerful when depicted from above. However, do the media actually use such associations to represent individual differences in power? We argue that the d

  3. Mechanistic modelling of the vertical soil organic matter profile

    NARCIS (Netherlands)

    Braakhekke, M.C.

    2014-01-01

    Soil organic matter (SOM) constitutes a large global pool of carbon that may play a considerable role for future climate. The vertical distribution of SOM in the profile may be important due to depth-dependence of physical, chemical, and biological conditions, and links to physical processes such as

  4. Vertical Partnerships: Do They Pay Off For The Supplier?

    OpenAIRE

    Donada, C

    1999-01-01

    This article presents the statistical results of a questionnaire survey sent to a sample of 2500 automotive suppliers around the world. Its shows that intense vertical cooperation can be an opportunity for a dependent supplier to build a "force of proposition" through cooperation with a powerful customer.

  5. Vertical Scope, Turbulence, and the Benefits of Commitment and Flexibility

    DEFF Research Database (Denmark)

    Claussen, Jörg; Kretschmer, Tobias; Stieglitz, Nils

    2015-01-01

    externally. We show that increasing turbulence first increases but then decreases the relative value of vertical integration. Moderate turbulence reduces the value of flexibility by making supplier selection more difficult and increases the value of commitment by mitigating the status quo bias of integrated...

  6. Near vertical incidence skywave: interaction of antenna and propagation mechanism

    NARCIS (Netherlands)

    Witvliet, Benjamin Axel

    2015-01-01

    In areas where no telecommunication infrastructure exists, or when that infrastructure is destroyed by a natural disaster, Near Vertical Incidence Skywave (NVIS) radio wave propagation may provide a lifeline to the outside world. In NVIS propagation, radio waves are transmitted straight up; the iono

  7. Characteristic wave diversity in near vertical incidence skywave propagation

    NARCIS (Netherlands)

    Witvliet, Ben A.; Maanen, van Erik; Petersen, George J.; Westenberg, Albert J.; Bentum, Mark J.; Slump, Cornelis H.; Schiphorst, Roel

    2015-01-01

    In Near Vertical Incidence Skywave (NVIS) propagation, effective diversity reception can be realized using a dual channel receiver and a dual polarization antenna with polarization matched to the (left hand and right hand) circular polarization of the characteristic waves propagating in the ionosphe

  8. Vertical susceptibility profiles : its use in magnetic pollution screening

    OpenAIRE

    Blaha, Ulrich

    2010-01-01

    In this work magnetic methods were used for systematic and high-resolution investigation of industrially polluted soils, where soil pollution is caused by heavy metal bearing air-borne particulate matter. The focus of the study is on the characteristic magnetic signals determined from ultra-shallow (~0.5 m) vertical profiles acquired in areas of

  9. TRANSMISIÓN VERTICAL DE HTLV-1 EN EL PERÚ

    Science.gov (United States)

    Villaverde, Jorge Alarcón; Romaní, Franco Romaní; Torres, Silvia Montano; Zunt, Joseph R.

    2012-01-01

    La infección por el virus linfotrópico humano de células T tipo 1 (HTLV-1) ha sido descrita en muchas áreas del mundo, como en los países del Caribe, Japón, África, Oceanía y en Sudamérica. En la presente revisión definimos la endemicidad del HTLV-1 en el país, planteando cuatro criterios epidemiológicos. Luego discutimos el tema central de la revisión: la transmisión vertical del HTLV-1, que en nuestro país sería uno de los principales mecanismos de transmisión. Dentro del desarrollo de este aspecto en particular, presentamos una estimación de la tasa de transmisión vertical y los factores de riesgo asociados con la transmisión vertical sobre la base de una revisión exhaustiva de estudios nacionales y extranjeros. Con esta revisión pretendemos dar una primera aproximación al estudio de la trasmisión vertical de HTLV-1, un aspecto poco estudiado en nuestro medio. PMID:21537777

  10. MHV Vertices And Tree Amplitudes In Gauge Theory

    OpenAIRE

    Cachazo, Freddy; Svrcek, Peter; Witten, Edward

    2004-01-01

    As an alternative to the usual Feynman graphs, tree amplitudes in Yang-Mills theory can be constructed from tree graphs in which the vertices are tree level MHV scattering amplitudes, continued off shell in a particular fashion. The formalism leads to new and relatively simple formulas for many amplitudes, and can be heuristically derived from twistor space.

  11. Numerical modeling of vertical stratification of Lake Shira in summer

    NARCIS (Netherlands)

    Belolipetsky, P.; Belolipetsky, V.M.; Genova, S.N.; Mooij, W.M.

    2010-01-01

    A one-dimensional numerical model and a two-dimensional numerical model of the hydrodynamic and thermal structure of Lake Shira during summer have been developed, with several original physical and numerical features. These models are well suited to simulate the formation and dynamics of vertical st

  12. Vertical-aware click model-based effectiveness metrics

    NARCIS (Netherlands)

    I. Markov; E. Kharitonov; V. Nikulin; P. Serdyukov; M. de Rijke; F. Crestani

    2014-01-01

    Today's web search systems present users with heterogeneous information coming from sources of different types, also known as verticals. Evaluating such systems is an important but complex task, which is still far from being solved. In this paper we examine the hypothesis that the use of models that

  13. Novel vertical silicon photodiodes based on salicided polysilicon trenched contacts

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Yelena [Department of Chemical Engineering, Technion, Haifa (Israel); TowerJazz Ltd. Migdal Haemek (Israel); Shauly, Eitan [TowerJazz Ltd. Migdal Haemek (Israel); Paz, Yaron, E-mail: paz@tx.technion.ac.il [Department of Chemical Engineering, Technion, Haifa (Israel)

    2015-12-07

    The classical concept of silicon photodiodes comprises of a planar design characterized by heavily doped emitters. Such geometry has low collection efficiency of the photons absorbed close to the surface. An alternative, promising, approach is to use a vertical design. Nevertheless, realization of such design is technologically challenged, hence hardly explored. Herein, a novel type of silicon photodiodes, based on salicided polysilicon trenched contacts, is presented. These contacts can be prepared up to 10 μm in depth, without showing any leakage current associated with the increase in the contact area. Consequently, the trenched photodiodes revealed better performance than no-trench photodiodes. A simple two dimensional model was developed, allowing to estimate the conditions under which a vertical design has the potential to have better performance than that of a planar design. At large, the deeper the trench is, the better is the vertical design relative to the planar (up to 10 μm for silicon). The vertical design is more advantageous for materials characterized by short diffusion lengths of the carriers. Salicided polysilicon trenched contacts open new opportunities for the design of solar cells and image sensors. For example, these contacts may passivate high contact area buried contacts, by virtue of the conformity of polysilicon interlayer, thus lowering the via resistance induced recombination enhancement effect.

  14. Normal incidence intersubband absorption in vertical quantum wells

    Science.gov (United States)

    Berger, V.; Vermeire, G.; Demeester, P.; Weisbuch, C.

    1995-01-01

    N-doped vertical AlGaAs quantum wells have been fabricated by metalorganic vapor phase epitaxial growth of a single-doped AlGaAs layer on a submicron grating. Intersubband absorption at normal incidence is demonstrated in those quantum wells. This opens new possibilities for infrared quantum well devices using intersubband transitions.

  15. Using Dynamic Solution Exercises to Achieve Vertical Course Alignment

    Science.gov (United States)

    Ostler, Elliot; Flesch, Michael

    2012-01-01

    This paper justifies the need for, and offers some suggestions on, the selection and implementation of mathematical problems known as dynamic solution exercises (DSEs). The intent of this article is to help provide insight into how mathematics teachers can go about making "vertical articulation" a cooperative and tangible part of the mathematics…

  16. Cooling Requirements for the Vertical Shear Instability in Protoplanetary Disks

    CERN Document Server

    Lin, Min-Kai

    2015-01-01

    It is difficult to understand how cold circumstellar disks accrete onto their central stars. A hydrodynamic mechanism, the vertical shear instability (VSI), offers a means to drive angular momentum transport in cold accretion disks such as protoplanetary disks (PPDs). The VSI is driven by a weak vertical gradient in the disk's orbital motion. In order to grow, the VSI must overcome vertical buoyancy, a strongly stabilizing influence in cold disks, where heating is dominated by external irradiation. Rapid cooling, via radiative losses, reduces the effective buoyancy and allows the VSI to operate. In this paper, we quantify the cooling timescale, $t_c$, needed for growth of the VSI. We perform a linear analysis of the VSI with cooling in vertically global and radially local disk models. For irradiated disks, we find that the VSI is most vigorous for rapid cooling with $t_c < \\Omega_\\mathrm{K}^{-1} h |q| / (\\gamma -1)$ in terms of the Keplerian orbital frequency, $\\Omega_\\mathrm{K}$, the disk's aspect ratio, ...

  17. A seismic vertical vibrator driven by linear motors

    NARCIS (Netherlands)

    Noorlandt, R.P.; Drijkoningen, G.G.; Schneider, R.M.

    2012-01-01

    In this paper we present a newly developed vertical seismic vibrator driven by linear motors. We explain the different components the vibrator consists of. We show that the harmonic distortion of the linear-motor vibrator signal is very small. We also show that, without applying a feedback loop on t

  18. Vertical velocity variances and Reynold stresses at Brookhaven

    DEFF Research Database (Denmark)

    Busch, Niels E.; Brown, R.M.; Frizzola, J.A.

    1970-01-01

    Results of wind tunnel tests of the Brookhaven annular bivane are presented. The energy transfer functions describing the instrument response and the numerical filter employed in the data reduction process have been used to obtain corrected values of the normalized variance of the vertical wind v...... velocity component....

  19. Vertical and horizontal permeability measurements in organic soils

    Directory of Open Access Journals (Sweden)

    Malinowska Edyta E.

    2015-06-01

    Full Text Available The paper is referring to vertical and horizontal laboratory permeability measurements in soft organic soils. The estimation of anisotropic permeability in soft organic soils, as peats, requires to use a special apparatus and the knowledge of proper analysis of the test results. During loading the void ratio decreases substantially that causes the changeability of the permeability. The change of permeability during the compression is very important because of the influence of the consolidation co-efficient. Initial strain in soft organic soils appears very quickly, just after loading, and brings immediately the decrease of permeability. In most of the estimations, it is assumed that during the consolidation process the water flows just in the vertical direction. In soft organic soils, like peats, the consolidation theory should consider the changes of mechanical and physical properties in consolidation period, in both directions. The direct measurement of vertical and horizontal permeability of organic soil and the non-Darcian flow theory may be of considerable importance in estimating pore water pressure dissipation, and settlement rates in the consolidation model. In the paper, the method of investigation and the test results of the vertical and horizontal permeability are presented. The Modified Rowe Cell Set for obtaining consolidation and flow characteristics in different directions is used.

  20. Characteristics and optimisation of vertical and planar tunnelling-FETs

    International Nuclear Information System (INIS)

    Scaling MOSFETs becomes more and more difficult. The tunnelling-FET is a possible successor of today's MOSFET with better scaling possibilities. Two different device structures, a vertical and a planar version of a tunnelling-FET are presented and evaluated

  1. Serotyping of Salmonella Isolates from Broiler Vertical Integrations in Colombia

    Science.gov (United States)

    This study analyzed 106 Salmonella isolates from different points in broiler vertical integrations of two important poultry areas of Colombia. It was possible to identify the presence of Salmonella in five categories: breeder farm (17.9%), hatchery (6.6 %), broiler farm (38.7 %), processing plant (9...

  2. Scour at the head of a vertical-wall breakwater

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Fredsøe, Jørgen

    1997-01-01

    This paper presents the results of an experimental investigation on the near-bed flow patterns, the bed shear stress amplification and scour around the head of a vertical-wall breakwater, using regular waves. The Keulegan-Carpenter number (KC), based on the diameter of the breakwater head, is fou...

  3. Diatom vertical migration within land-fast Arctic sea ice

    Science.gov (United States)

    Aumack, C. F.; Juhl, A. R.; Krembs, C.

    2014-11-01

    Light levels inside first-year, landfast sea ice were experimentally altered by manipulating overlying snow depths. Irradiance available for ice algae growing near the ice-bottom, and under the ice, was highly dependent on snow depths ranging from 0 to > 30 cm. Importantly, algal vertical distributions also changed under different irradiances. Under thick snow (low light), the majority of algae were found several cm above the ice-seawater interface, while progressively more were found nearer the interface at locations with thinner overlying snow (higher light). Short-term field experiments suggested that ice algae were able to reposition themselves within the ice column within 3 days after manipulating snow depths. Laboratory gliding rate measurements of a cultured ice diatom suggested that it is capable of daily cm-scale movement. Vertical migration may help ice diatoms balance opposing light and nutrient resource gradients, similar to strategies used by some benthic and pelagic algae. Moreover, when ice algae congregate near the ice-seawater interface, they may be especially susceptible to loss from the ice environment. Vertical repositioning in response to changing light dynamics may be a mechanism to optimize between vertically-opposing environmental factors and help explain the connection between melting snow cover and export of biomass from sea ice.

  4. Continental seismic events observed by the MPL vertical DIFAR array

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D.B. [Lawrence Livermore National Lab., CA (United States); D`Spain, G. [Scripps Institution of Oceanography, San Diego, CA (United States). Marine Physical Lab.

    1993-11-01

    The vertical DIFAR array, an underwater acoustic sensor system, deployed by the Marine Physical Laboratory (MPL) was in place over the continental shelf off of Southern California and recorded the HUNTERS TROPHY nuclear test and nearly a score of after-shocks of the Landers/Big Bear earthquakes. Data from this array raise the possibility that detection thresholds for continental events may be significantly lower for arrays over the continental shelf than for arrays in the deep ocean basins. Offshore stations could be used to fill gaps in land-based seismic networks for monitoring the NPT and a CTBT, especially for monitoring non-cooperating nations with large coastlines. This preliminary report provides an analysis of the HUNTERS TROPHY observation as well as one of the Landers aftershocks. The analysis suggests detection thresholds for vertical hydrophone arrays below mb 3.0 at ranges between 3 and 4 degrees, and below mb 4.4 out to 6 degrees. This report also describes two signal processing techniques that enhance the detection potential of short vertical arrays. These methods are deterministic null steering to suppress horizontally propagating ambient ocean noise, and matched field processing for vertically-incident acoustic fields. The latter technique is ideally suited for acoustic fields derived from incident seismic waves, and may be viewed as a {open_quotes}synthetic aperture{close_quotes} approach to increase the effective aperture of the array.

  5. Reliability Analysis of Geotechnical Failure Modes for Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, H. F.

    2000-01-01

    Vertical wall breakwaters are usually designed as concrete caissons placed on the top of a rubble mound foundation or a rubble bedding layer. The purpose of the breakwater is usually to protect the area behind the breakwater from being flooded by large waves. The area protected can for example...

  6. Modeling of Aerosol Vertical Profiles Using GIS and Remote Sensing

    Directory of Open Access Journals (Sweden)

    Kwon Ho Lee

    2009-06-01

    Full Text Available The use of Geographic Information Systems (GIS and Remote Sensing (RS by climatologists, environmentalists and urban planners for three dimensional modeling and visualization of the landscape is well established. However no previous study has implemented these techniques for 3D modeling of atmospheric aerosols because air quality data is traditionally measured at ground points, or from satellite images, with no vertical dimension. This study presents a prototype for modeling and visualizing aerosol vertical profiles over a 3D urban landscape in Hong Kong. The method uses a newly developed technique for the derivation of aerosol vertical profiles from AERONET sunphotometer measurements and surface visibility data, and links these to a 3D urban model. This permits automated modeling and visualization of aerosol concentrations at different atmospheric levels over the urban landscape in near-real time. Since the GIS platform permits presentation of the aerosol vertical distribution in 3D, it can be related to the built environment of the city. Examples are given of the applications of the model, including diagnosis of the relative contribution of vehicle emissions to pollution levels in the city, based on increased near-surface concentrations around weekday rush-hour times. The ability to model changes in air quality and visibility from ground level to the top of tall buildings is also demonstrated, and this has implications for energy use and environmental policies for the tall mega-cities of the future.

  7. Horizontal or vertical photobioreactors? How to improve microalgae photosynthetic efficiency

    NARCIS (Netherlands)

    Cuaresma, M.; Janssen, M.G.J.; Vilchez, C.; Wijffels, R.H.

    2011-01-01

    The productivity of a vertical outdoor photobioreactor was quantitatively assessed and compared to a horizontal reactor. Daily light cycles in southern Spain were simulated and applied to grow the microalgae Chlorella sorokiniana in a flat panel photobioreactor. The maximal irradiance around noon di

  8. Vertical Flow Lithography for Fabrication of 3D Anisotropic Particles.

    Science.gov (United States)

    Habasaki, Shohei; Lee, Won Chul; Yoshida, Shotaro; Takeuchi, Shoji

    2015-12-22

    A microfluidics-based method for the 3D fabrication of anisotropic particles is reported. The method uses a vertical microchannel where tunable light patterns solidify photocurable resins for stacking multiple layers of the resins, thus enabling an application of stereolithography concepts to conventional flow lithography. Multilayered, tapered, and angular compartmental microparticles are demonstrated. PMID:26551590

  9. AFC-Enabled Vertical Tail System Integration Study

    Science.gov (United States)

    Mooney, Helen P.; Brandt, John B.; Lacy, Douglas S.; Whalen, Edward A.

    2014-01-01

    This document serves as the final report for the SMAAART AFC-Enabled Vertical Tail System Integration Study. Included are the ground rule assumptions which have gone into the study, layouts of the baseline and AFC-enabled configurations, critical sizing information, system requirements and architectures, and assumed system properties that result in an NPV assessment of the two candidate AFC technologies.

  10. Vertical Integration at Junior and Intermediate Levels. School Research Newsletter.

    Science.gov (United States)

    Marklund, Inger, Ed.; Hanse, Mona-Britt, Ed.

    1984-01-01

    In recent years, there has been a rapid growth of interest in Sweden in vertically integrated classes in compulsory schools, especially at junior high school and intermediate grade levels. This development is supported in various ways by the curriculum, partly because it puts more emphasis than previous curricula on the occurrence of teaching…

  11. Wave Forces on a Vertical Smooth Cylinder in Directional Waves

    DEFF Research Database (Denmark)

    Høgedal, M.; Skourup, J.; Burcharth, H. F.

    1994-01-01

    In this paper the results from physical experiments with an instrumented cylinder conducted in laboratory environments are presented. The primary aim of the study has been to investigate the effect from wave directionality on the local and depth integrated maximum wave forces on a smooth vertical...

  12. Simulation of vertical merged MOS elements with optical power supply

    NARCIS (Netherlands)

    Bubennikov, AN; Rakitin, VV; Zykov, AV

    2002-01-01

    Functional optoelectronic vertical merged MOS (OVMMOS) elements with optical power supply increasing the packaging density for advanced high-speed low-voltage low-power deep-submicron ULSI are considered. Two types of new OVVMOS logical elements are proposed, analyzed and simulated. The simple reduc

  13. Requirements of Vertical Handoff Mechanism in 4G Wireless Networks

    Directory of Open Access Journals (Sweden)

    Mandeep Kaur Gondara

    2011-05-01

    Full Text Available The importance of wireless communication is increasing day by day throughout the world due to cellularand broadband technologies. Everyone around the world would like to be connected seamlessly anytimeanywhere through the best network. The 4G wireless system must have the capability to provide highdata transfer rates, quality of services and seamless mobility. In 4G, there are a large variety ofheterogeneous networks. The users for variety of applications would like to utilize heterogeneousnetworks on the basis of their preferences such as real time, high availability and high bandwidth. Whenconnections have to switch between heterogeneous networks for performance and high availabilityreasons, seamless vertical handoff is necessary. The requirements like capability of the network, handofflatency, network cost, network conditions, power consumption and user’s preferences must be taken intoconsideration during vertical handoff. In this paper, we have extracted the requirements of a verticalhandoff from the literature surveyed. The evaluation of the existing work is also being done on the basisof required parameters for vertical handoff. A sophisticated, adaptive and intelligent approach isrequired to implement the vertical handoff mechanism in 4G wireless networks to produce an effectiveservice for the user by considering dynamic and non dynamic parameters.

  14. The vertical fingerprint of earthquake cycle loading in southern California

    Science.gov (United States)

    Howell, Samuel; Smith-Konter, Bridget; Frazer, Neil; Tong, Xiaopeng; Sandwell, David

    2016-08-01

    The San Andreas Fault System, one of the best-studied transform plate boundaries on Earth, is well known for its complex network of locked faults that slowly deform the crust in response to large-scale plate motions. Horizontal interseismic motions of the fault system are largely predictable, but vertical motions arising from tectonic sources remain enigmatic. Here we show that when carefully treated for spatial consistency, global positioning system-derived vertical velocities expose a small-amplitude (+/-2 mm yr-1), but spatially considerable (200 km), coherent pattern of uplift and subsidence straddling the fault system in southern California. We employ the statistical method of model selection to isolate this vertical velocity field from non-tectonic signals that induce velocity variations in both magnitude and direction across small distances (less than tens of kilometres; ref. ), and find remarkable agreement with the sense of vertical motions predicted by physical earthquake cycle models spanning the past few centuries. We suggest that these motions reveal the subtle, but identifiable, tectonic fingerprint of far-field flexure due to more than 300 years of fault locking and creeping depth variability. Understanding this critical component of interseismic deformation at a complex strike-slip plate boundary will better constrain regional mechanics and crustal rheology, improving the quantification of seismic hazards in southern California and beyond.

  15. Restart plan for the prototype vertical denitration calciner

    Energy Technology Data Exchange (ETDEWEB)

    SUTTER, C.S.

    1999-09-01

    Testing activities on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The Restart Plan will govern the transition of the test program from the completion of the activity based startup review; through equipment checkout and surrogate material runs; to resumption of the testing program and transition to unrestricted testing.

  16. Vertical Pointing Weather Radar for Built-up Urban Areas

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Thorndahl, Søren; Schaarup-Jensen, Kjeld

    2008-01-01

      A cost effective vertical pointing X-band weather radar (VPR) has been tested for measurement of precipitation in urban areas. Stationary tests indicate that the VPR performs well compared to horizontal weather radars, such as the local area weather radars (LAWR). The test illustrated...

  17. Vertical leadership in highly complex and unpredictable health systems.

    Science.gov (United States)

    Till, Alex; Dutta, Nina; McKimm, Judy

    2016-08-01

    This article explores how the concept of vertical leadership development might help health organizations cope with and thrive within highly complex and unpredictable health systems, looking at concepts of VUCA (volatility, uncertainty, complexity and ambiguity) and RUPT (rapid, unpredictable, paradoxical and tangled). PMID:27487058

  18. Active vertical tail buffeting suppression based on macro fiber composites

    Science.gov (United States)

    Zou, Chengzhe; Li, Bin; Liang, Li; Wang, Wei

    2016-04-01

    Aerodynamic buffet is unsteady airflow exerting forces onto a surface, which can lead to premature fatigue damage of aircraft vertical tail structures, especially for aircrafts with twin vertical tails at high angles of attack. In this work, Macro Fiber Composite (MFC), which can provide strain actuation, was used as the actuator for the buffet-induced vibration control, and the positioning of the MFC patches was led by the strain energy distribution on the vertical tail. Positive Position Feedback (PPF) control algorithm has been widely used for its robustness and simplicity in practice, and consequently it was developed to suppress the buffet responses of first bending and torsional mode of vertical tail. However, its performance is usually attenuated by the phase contributions from non-collocated sensor/actuator configuration and plants. The phase lag between the input and output signals of the control system was identified experimentally, and the phase compensation was considered in the PPF control algorithm. The simulation results of the amplitude frequency of the closed-loop system showed that the buffet response was alleviated notably around the concerned bandwidth. Then the wind tunnel experiment was conducted to verify the effectiveness of MFC actuators and compensated PPF, and the Root Mean Square (RMS) of the acceleration response was reduced 43.4%, 28.4% and 39.5%, respectively, under three different buffeting conditions.

  19. Full-scale fire experiments on vertical horizontal cable trays

    Energy Technology Data Exchange (ETDEWEB)

    Mangs, J.; Keski-Rahkonen, O. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

    1997-10-01

    Two full-scale fire experiments on PVC cables used in nuclear power plants were carried out, one with cables in vertical position and one with cables in horizontal position. The vertical cable bundle, 3 m high, 300 mm wide and 30 mm thick, was attached to a steel cable ladder. The vertical bundle experiment was carried out in nearly free space with three walls near the cable ladder guiding air flow in order to stabilise flames. The horizontal cable experiment was carried out in a small room with five cable bundles attached to steel cable ladders. Three of the 2 m long cable bundles were located in an array, equally spaced above each other near one long side of the room and two correspondingly near the opposite long side. The vertical cable bundle was ignited with a small propane gas burner beneath the lower edge of the bundle. The horizontal cable bundles were ignited with a small propane burner beneath the lowest bundle in an array of three bundles. Rate of heat release by means of oxygen consumption calorimetry, mass change, CO{sub 2}, CO and smoke production rate and gas, wall and cable surface temperatures were measured as a function of time, as well as time to sprinkler operation and failure of test voltage in cables. Additionally, the minimum rate of heat release needed to ignite the bundle was determined. This paper concentrates on describing and recording the experimental set-up and the data obtained. (orig.)

  20. Vertically tapered layers for optical applications fabricated using resist reflow

    NARCIS (Netherlands)

    Emadi, A.; Wu, H.; Grabarnik, S.; De Graaf, G.; Wolffenbuttel, R.F.

    2009-01-01

    This paper reports on the IC-compatible fabrication of vertically tapered optical layers for use in linear variable optical filters (LVOF). The taper angle is fully defined by a mask design. Only one masked lithography step is required for defining strips in a photoresist with trenches etched therei

  1. Support schemes and vertical integration - who skims the cream?

    DEFF Research Database (Denmark)

    Ropenus, Stephanie; Jensen, Stine Grenaa

    2009-01-01

    produced. Under vertical integration, a rise in the feed-in tariff induces the monopolist to raise access charges for fringe firms and skim part of their additional income. This partially offsets the supply increase of the fringe firms stimulated by the feed-in tariff. However, in the case of effective...

  2. Flooding velocities for air and water in vertical tubes

    International Nuclear Information System (INIS)

    An investigation of the limiting, or flooding, velocities for countercurrent annular flow of air and water in vertical tubes is reported. The data are correlated in terms of dimensionless groups which are similar to those already in use for describing flooding in packed towers. The relevance of the results to the problem of burnout in boiling equipment is discussed. (author)

  3. Some cases of vertical ascent of a rocket

    Directory of Open Access Journals (Sweden)

    M. Narsing Rao

    1960-07-01

    Full Text Available The differential equations of motion of vertically ascending rocket are integrated in closed form in terms of Bessel functions. During burning the drag co-efficient and acceleration due to gravity are assumed to be constant. Four different cases of motion are treated under different assumptions regarding the law of mass-variations of the rocket.

  4. Estimation of sand dune thickness using a vertical velocity profile

    International Nuclear Information System (INIS)

    Previous field and mathematical studies have shown that sand dunes may have vertical velocity profiles (i.e. continuous increase of velocity with depth). Therefore, computing the dunes thickness using conventional seismic refraction methods that assume a vertically homogeneous layer will likely produce some errors. The purpose of this study is to quantify the effect of the vertical velocity profile in a sand dune on the process of thickness estimation using seismic refraction data. First, the time distance (T-X) data of the direct wave in the dune is calculated using a vertical velocity profile, V (z), derived from Hertz-Mindlin contact theory. Then the thickness is estimated from the calculated T-X data, intercept time and velocity of the refractor at the dune's base assuming a constant velocity in the dune. The error in the estimated thickness due to the constant-velocity assumption increases with increasing thickness and decreasing porosity of the dune. For sand dunes with porosities greater than 0.2 and thickness less than 200 meter, the error is less than 15%. (author)

  5. Mathematical modeling of treating water in vertical settlers

    Directory of Open Access Journals (Sweden)

    H.K.Nagornaya

    2012-12-01

    Full Text Available The 2D-numerical model was developed and used to simulate the pollutant transfer in the vertical settler. The model is based on the numerical integration of the K-gradient transport model and the model of the potential flow. The results of numerical experiment are presented.

  6. Modeling Quantum Transport in Nanoscale Vertical SOI nMOSFET

    Institute of Scientific and Technical Information of China (English)

    TONG Jian-nong; ZOU Xue-chang; SHEN Xu-bang

    2004-01-01

    The electron transports in micro-architecture semiconductor are simulated using vertical SOI nMOSFET with different models. Some details in transport can be presented by changing channel length, channel thickness and drain voltage. An interesting phenomenon similar to collimation effect in mesoscopic system is observed. This may suggest the quite intriguing possibility that scattering may open new channel in sufficiently narrow devices.

  7. Vertically Integrating Professional Skills throughout a Mathematics Major

    Science.gov (United States)

    Dziak, Clarice; Leventhal, Brian; Luttman, Aaron; Skufca, Joseph

    2014-01-01

    In response to a university mandate to include "professional issues" as a component of every major, we have developed a vertically integrated approach to incorporating the study of professional skills and issues into the mathematics curriculum. Beginning in the first year of study, mathematics majors take an inquiry-based course in…

  8. Dynamic optimal foraging theory explains vertical migrations of bigeye tuna

    DEFF Research Database (Denmark)

    Thygesen, Uffe Høgsbro; Sommer, Lene; Evans, Karen;

    2016-01-01

    Bigeye tuna are known for remarkable daytime vertical migrations between deep water, where food is abundant but the water is cold, and the surface, where water is warm but food is relatively scarce. Here we investigate if these dive patterns can be explained by dynamic optimal foraging theory...

  9. Horizontal and Vertical Attentional Orienting in Parkinson's Disease

    Science.gov (United States)

    Nys, Gudrun M. S.; Santens, Patrick; Vingerhoets, Guy

    2010-01-01

    Patients with Parkinson's disease (PD) typically suffer from an asymmetric degeneration of dopaminergic cells in the substantia nigra, resulting in right-sided (RPD) or left-sided (LPD) predominance of motor symptomatology. As the dopaminergic system is also involved in attention, we examined horizontal and vertical orienting of attention in LPD…

  10. Viral lysis of marine microbes in relation to vertical stratification

    NARCIS (Netherlands)

    Mojica, K.D.A.

    2015-01-01

    Marine microorganisms represent the largest reservoir of living organic carbon in the ocean and collectively manage the pools and fluxes of nutrients and energy. Climate-induced increases in sea surface temperature and associated modifications to vertical stratification are affecting the structure a

  11. Ionospheric vertical drift response at a mid-latitude station

    Science.gov (United States)

    Kouba, Daniel; Koucká Knížová, Petra

    2016-07-01

    Vertical plasma drift data measured at a mid-latitude ionospheric station Pruhonice (50.0 ° N, 14.6 ° E) were collected and analysed for the year 2006, a year of low solar and geomagnetic activity. Hence these data provide insight into the drift behaviour during quiet conditions. The following typical diurnal trend is evident: a significant decay to negative values (downward peak) at dawn; generally less pronounced downward peak at dusk hours. Magnitude of the downward drift varies during the year. Typically it reaches values about 20 ms-1 at dawn hours and 10 ms-1 at dusk hours. Maximum dawn magnitude of about 40 ms-1 has been detected in August. During daytime the vertical drifts increases from the initial small downward drifts to zero drift around noon and to small upward drifts in the afternoon. Night-time drift values display large variability around a near zero vertical drift average. There is a significant trend to larger downward drift values near dawn and a less pronounced decrease of the afternoon upward vertical drifts near sunset. Two regular downward peaks of the drift associated with the dawn and dusk are general characteristics of the analysed data throughout the year 2006. Their seasonal course corresponds to the seasonal course of the sunrise and sunset. The duration of prevailing negative drift velocities forming these peaks and thus the influence of the dawn/dusk on the drift velocity is mostly 1.5-3 h. The dawn effect on vertical drift tends to be larger than the effect of the dusk. The observed magnitude of the sunrise and sunset peaks show significant annual course. The highest variability of the magnitude is seen during winter. High variability is detected till March equinox and again after September equinox. Around solstice, both peaks reaches lowest values. After that, the magnitudes of the drift velocity increase smoothly till maxima in summer (August). The vertical drift velocity course is smooth between June solstice and September

  12. Vertically-integrated Approaches for Carbon Sequestration Modeling

    Science.gov (United States)

    Bandilla, K.; Celia, M. A.; Guo, B.

    2015-12-01

    Carbon capture and sequestration (CCS) is being considered as an approach to mitigate anthropogenic CO2 emissions from large stationary sources such as coal fired power plants and natural gas processing plants. Computer modeling is an essential tool for site design and operational planning as it allows prediction of the pressure response as well as the migration of both CO2 and brine in the subsurface. Many processes, such as buoyancy, hysteresis, geomechanics and geochemistry, can have important impacts on the system. While all of the processes can be taken into account simultaneously, the resulting models are computationally very expensive and require large numbers of parameters which are often uncertain or unknown. In many cases of practical interest, the computational and data requirements can be reduced by choosing a smaller domain and/or by neglecting or simplifying certain processes. This leads to a series of models with different complexity, ranging from coupled multi-physics, multi-phase three-dimensional models to semi-analytical single-phase models. Under certain conditions the three-dimensional equations can be integrated in the vertical direction, leading to a suite of two-dimensional multi-phase models, termed vertically-integrated models. These models are either solved numerically or simplified further (e.g., assumption of vertical equilibrium) to allow analytical or semi-analytical solutions. This presentation focuses on how different vertically-integrated models have been applied to the simulation of CO2 and brine migration during CCS projects. Several example sites, such as the Illinois Basin and the Wabamun Lake region of the Alberta Basin, are discussed to show how vertically-integrated models can be used to gain understanding of CCS operations.

  13. Assessment of vertical fracture using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Moudi, Ehsan; Madani, Zahrasadat; Alhavaz, Abdolhamid; Bijani, Ali [Dental Material Research Center, Dental School, Babol University of Medical Sciences, Babol, (Korea, Republic of); Bagheri, Mohammad [Social Determinants of Health Research Center, Babol University of Medical Sciences, Babol (Korea, Republic of)

    2014-03-15

    The aim of this study was to investigate the accuracy of cone-beam computed tomography (CBCT) in the diagnosis of vertical root fractures in a tooth with gutta-percha and prefabricated posts. This study selected 96 extracted molar and premolar teeth of the mandible. These teeth were divided into six groups as follows: Groups A, B, and C consisted of teeth with vertical root fractures, and groups D, E, and F had teeth without vertical root fractures; groups A and D had teeth with gutta-percha and prefabricated posts; groups B and E had teeth with gutta-percha but without prefabricated posts, and groups C and F had teeth without gutta-percha or prefabricated posts. Then, the CBCT scans were obtained and examined by three oral and maxillofacial radiologists in order to determine the presence of vertical root fractures. The data were analyzed using IBM SPSS 20.0 (IBM Corp., Armonk, NY, USA). The kappa coefficient was 0.875 ± 0.049. Groups A and D showed a sensitivity of 81% and a specificity of 100%; groups E and B, a sensitivity of 94% and a specificity of 100%; and groups C and F, a sensitivity of 88% and a specificity of 100%. The CBCT scans revealed a high accuracy in the diagnosis of vertical root fractures; the accuracy did not decrease in the presence of gutta-percha. The presence of prefabricated posts also had little effect on the accuracy of the system, which was, of course, not statistically significant.

  14. Vertical transmission of hepatitis C virus: Current knowledge and perspectives

    Institute of Scientific and Technical Information of China (English)

    Chun-Yan; Yeung; Hung-Chang; Lee; Wai-Tao; Chan; Chun-Bin; Jiang; Szu-Wen; Chang; Chih-Kuang; Chuang

    2014-01-01

    Hepatitis C virus(HCV) infection is a major global health issue.Infection by the HCV can cause acute and chronic liver diseases and may lead to cirrhosis,hepatocellular carcinoma or liver failure.The World Health Organization estimates that approximately 3% of the world population have been infected with HCVand the worldwide prevalence is between 1% and 8% in pregnant women and between 0.05% and 5% in children.Following the introduction of blood product screening,vertical transmission becomes the leading cause of childhood HCV infection.The prevalence of pediatric HCV infection varies from 0.05% to 0.36% in developed countries and between 1.8% and 5% in the developing world.All children born to women with antiHCV antibodies should be checked for HCV infection.Though universal screening is controversial,selective antenatal HCV screening on high-risk populations is highly recommended and should be tested probably.Multiple risk factors were shown to increase the possibility of HCV vertical transmission,including coinfections with human immunodeficiency virus,intravenous drug use and elevated maternal HCV viral load,while breastfeeding and HCV genotypes have been studied to have little impact.At present,no clinical intervention has been clearly studied and proved to reduce the HCV vertical transmission risk.Cesarean section should not be recommended as a procedure to prevent vertical transmission,however,breastfeeding is generally not forbidden.The high prevalence of global HCV infection necessitates renewed efforts in primary prevention,including vaccine development,as well as new approaches to reduce the burden of chronic liver disease.Future researches should focus on the interruption of vertical transmission,developments of HCV vaccine and directacting antivirals in infancy and early childhood.

  15. Proposed standardized definitions for vertical resolution and uncertainty in the NDACC lidar ozone and temperature algorithms - Part 1: Vertical resolution

    Science.gov (United States)

    Leblanc, Thierry; Sica, Robert J.; van Gijsel, Joanna A. E.; Godin-Beekmann, Sophie; Haefele, Alexander; Trickl, Thomas; Payen, Guillaume; Gabarrot, Frank

    2016-08-01

    A standardized approach for the definition and reporting of vertical resolution of the ozone and temperature lidar profiles contributing to the Network for the Detection for Atmospheric Composition Change (NDACC) database is proposed. Two standardized definitions homogeneously and unequivocally describing the impact of vertical filtering are recommended. The first proposed definition is based on the width of the response to a finite-impulse-type perturbation. The response is computed by convolving the filter coefficients with an impulse function, namely, a Kronecker delta function for smoothing filters, and a Heaviside step function for derivative filters. Once the response has been computed, the proposed standardized definition of vertical resolution is given by Δz = δz × HFWHM, where δz is the lidar's sampling resolution and HFWHM is the full width at half maximum (FWHM) of the response, measured in sampling intervals. The second proposed definition relates to digital filtering theory. After applying a Laplace transform to a set of filter coefficients, the filter's gain characterizing the effect of the filter on the signal in the frequency domain is computed, from which the cut-off frequency fC, defined as the frequency at which the gain equals 0.5, is computed. Vertical resolution is then defined by Δz = δz/(2fC). Unlike common practice in the field of spectral analysis, a factor 2fC instead of fC is used here to yield vertical resolution values nearly equal to the values obtained with the impulse response definition using the same filter coefficients. When using either of the proposed definitions, unsmoothed signals yield the best possible vertical resolution Δz = δz (one sampling bin). Numerical tools were developed to support the implementation of these definitions across all NDACC lidar groups. The tools consist of ready-to-use "plug-in" routines written in several programming languages that can be inserted into any lidar data processing software and

  16. Efficient organic photovoltaic cells with vertically ordered bulk heterojunctions.

    Science.gov (United States)

    Yu, Bo; Wang, Haibo; Yan, Donghang

    2013-12-01

    Nanoscale morphology has been proved to be the key parameter deciding the exciton dissociation and charge transportation in bulk heterojunction (BHJ) solar cells. In this paper, we report a kind of small molecular organic photovoltaic cell (OPV) with a vertically ordered BHJ prepared by the weak epitaxial growth method. By this method, zinc phthalocyanine (ZnPc) can easily be formed into a highly ordered and continuous thin film and C60 is inclined to become dispersed crystalline grains in ZnPc film. Furthermore, we can control both the size and distribution density of C60 crystalline grains in ZnPc thin film without destroying the order of the ZnPc thin film. The OPVs with the vertically ordered BHJ show a high fill factor and a power conversion efficiency over 3% has been achieved.

  17. Vertical elliptic operator for efficient wave propagation in TTI media

    KAUST Repository

    Waheed, Umair bin

    2015-08-19

    Elliptic wave extrapolation operators require significantly less computational cost than the ones for transversely isotropic (TI) media. However, it does not provide accurate wavefield representation or imaging for the prevalent TI media. We propose a new vertical elliptically anisotropic (VEA) wave equation by decomposing the acoustic TI pseudo-differential wave equation. The decomposition results in a vertical elliptic differential equation and a scalar operator. The new VEA-like wave equation shares the same dispersion relation as that of the original acoustic TI wave equation. Therefore, the kinematic contents are correctly matched to the original equation. Moreover, the proposed decomposition yields better amplitude properties than the isotropic decomposition without increasing the computational load. Therefore, it exhibits better cost versus accuracy tradeoff compared to the isotropic or the tilted elliptic decompositions. We demonstrate with numerical examples that the proposed methodology is numerically stable for complex models and is free from shear-wave artifacts.

  18. Export industry structure upgrading and China's vertical specialization

    Science.gov (United States)

    Meng, Yinghua

    2011-10-01

    We computed the ratio of China's vertical specialization with revising method of Hummels et al. (2001). We found that China's export has the traits of processing trade, and Asian countries are the main exporter of intermediate goods to China; there is strong positive relationship between export ratio and ratio of China's vertical specialization, indicates that importing of intermediate goods play an important role in China's industry upgrading, China's comparative advantage of export still lies in low price of labor; even if China's production still locates in low value added stage in international supply chain, but China has began to advance its industry structure, and change the mode of production and trade that rely processing trade too much.

  19. Realization of an Automated Vertical Warp Stop Motion Positioning

    Directory of Open Access Journals (Sweden)

    Frederik Cloppenburg

    2015-02-01

    Full Text Available The tension in the warp yarns is a critical variable in the weaving process. If the warp tension is too high or too low the weaving process will be interrupted. A parameter that directly affects the warp tension is the vertical warp stop motion position. The position of the warp stop motion must be set for every produced new article. The setting procedure is performed completely manual. In this paper we present a mechatronic modification of an air jet-weaving machine to adjust the vertical warp stop motion position with the help of actuators. The parameters for the automated movement are determined and an open loop control, which uses a PLC, is proposed.

  20. Jets generated by a sphere moving vertically in stratified fluids

    Science.gov (United States)

    Hanazaki, Hideshi; Okino, Shinya; Nakamura, Shota; Akiyama, Shinsaku

    2013-11-01

    Unsteady development of buoyant jets generated by a sphere moving vertically at constant speeds in stratified fluids is investigated. Initially, the sphere simply drags light upper fluids or isopycnal surfaces as it goes down, as long as the molecular diffusion of density is negligible. In the succeeding period, molecular diffusion of density in the boundary layer on the sphere surface becomes increasingly significant, especially in the lower hemisphere. Then, the density is no longer conserved and a vertical jet starts from the rear/upper stagnation point of the sphere, since the fluid particle of altered but small density tends to go back to its original height. Strength and radius of those jets depend significantly on stratification (Froude number), as well as the Reynolds number and the Schmidt number. These mechanisms are investigated by numerical simulations and measurements by laser induced fluorescence (LIF).

  1. Increasing occlusal vertical dimension--why, when and how.

    Science.gov (United States)

    Bloom, D R; Padayachy, J N

    2006-03-11

    Cosmetic dentistry has evolved with the advent of more robust porcelain materials and ever-stronger bonding agents. This series of three articles aims to provide a practical overview of what is now possible both functionally and cosmetically from the preparation of a small number of teeth, through a whole smile, to full mouth rehabilitation. A complete diagnosis is the starting point to planning any cosmetic or functional changes. Guidance is given on the techniques used but adequate training must be considered essential before embarking upon modification in occlusal schemes or even minor adjustments in smile design. Understanding vertical dimension and how and when it can be changed has always been a challenging prospect for the general dental practitioner. This article aims to discuss the rationale behind changes in vertical dimension and demonstrate how it can be achieved in general practice assuming adequate hands-on postgraduate training has been completed.

  2. Liquid Crystal Microlens Using Nanoparticle-Induced Vertical Alignment

    Directory of Open Access Journals (Sweden)

    Shug-June Hwang

    2015-01-01

    Full Text Available The nanoparticle-induced vertical alignment (NIVA of the nematic liquid crystals (LC is applied to achieve an adaptive flat LC microlens with hybrid-aligned nematic (HAN mode by dropping polyhedral oligomeric silsesquioxane (POSS nanoparticle solution on a homogeneous alignment layer. The vertical alignment induced by the POSS nanoparticles resulted in the formation of a hybrid-aligned LC layer with concentric nonuniform distribution of the refractive index in the planar LC cell, which subsequently played the role of the lens, even in the absence of any applied voltages. The dimensions of the concentric HAN structure significantly depend on the volume of the microdroplet and the POSS concentration. The focus effect of this flat microlens was observed while electrically controlling its focal length using the applied voltages from −50 mm to −90 mm.

  3. The dawn enhancement of the equatorial ionospheric vertical plasma drift

    Science.gov (United States)

    Zhang, Ruilong; Liu, Libo; Chen, Yiding; Le, Huijun

    2015-12-01

    Previous studies have reported that a dawn enhancement does not present in the statistical picture of the equatorial ionospheric vertical plasma drift, while it clearly shows in case measurements. In this statistical study, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag.

  4. Vertical Integration and Reverse Engineering of Agricultural Enterprises

    Institute of Scientific and Technical Information of China (English)

    Gang; WU; Yong; DU

    2014-01-01

    This paper studies the potential effects of agricultural enterprise’s vertical integration and reverse engineering on downstream firms.Suppliers who invest reverse engineering technology can exploit customer’s information. An integrated supplier can obtain at no cost the information from its subsidiary. Based on repeated game and considered corporate " good" or " bad" type,this paper analysis supplier’s selection and downstream investment in innovation. The results showed that: when the cost is higher than the threshold value no company invest in reverse engineering,when the cost is lower than the threshold value the integration company invest in reverse engineering; in the second period,vertical integration reduce the downstream independent enterprise’s innovation investment and profits,integrated enterprise increase innovation investment and profits; during the first period of the game,the independent downstream firms being " completely foreclosure".

  5. Natural convection between a vertical cylinder and a surrounding array

    International Nuclear Information System (INIS)

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 104 to 4.6 x 105. Results indicate that the convective heat transfer data could be approximated as NuD (Tts/Tct)0.14 = 0.156 RaD1/3 in the apparent turbulent region for RaL > 1.2 x 1011

  6. Evidence for Vertical Transmission of HPV from Mothers to Infants

    Directory of Open Access Journals (Sweden)

    Elaine M. Smith

    2010-01-01

    Full Text Available Few large studies have evaluated concordance based on a broad spectrum of human papillomavirus (HPV types in oral and genital specimens of mothers and their recently born infants. This information is important in determining whether HPV vaccines administered prior to pregnancy may be useful for preventing vertical transmission. HPV DNA was positive in 30% of mothers and 1.5% of newborns. Maternal/newborn concordance (HPV+/+ or HPV−/− was 71%. Among HPV DNA+ mothers, only 3% of their infants were DNA+ and only 1 pair had the same HPV type. Among HPV− women, 0.8% of infants were HPV+. HPV DNA detected in hospitalized newborns reflects current infection transmitted to infants during pregnancy or delivery. None of the mother/baby HPV DNA+ concordance pairs detected viral types found in HPV vaccines suggesting that vaccination prior to pregnancy is unlikely to be efficacious in preventing vertical transmission.

  7. Black Carbon Vertical Profiles Strongly Affect its Radiative Forcing Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, Susanne E.; Berntsen, T.; Bian, Huisheng; Bellouin, N.; Diehl, T.; Easter, Richard C.; Ghan, Steven J.; Iversen, T.; Kinne, Stefan; Kirkevag, A.; Lamarque, J.-F.; Lin, G.; Liu, Xiaohong; Penner, Joyce E.; Seland, O.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, K.; Zhang, Kai

    2013-03-01

    The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF) is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project (AeroCom). Additionally, a significant fraction of the variability is shown to come from high altitudes, as, globally, more than 40% of the total BC RF is exerted above 5 km. BC emission regions and areas with transported BC are found to have differing characteristics. These insights into the importance of the vertical profile of BC lead us to suggest that observational studies are needed to better characterize the global distribution of BC, including in the upper troposphere.

  8. Dynamic Modal Analysis of Vertical Machining Centre Components

    Directory of Open Access Journals (Sweden)

    Anayet U. Patwari

    2009-01-01

    Full Text Available The paper presents a systematic procedure and details of the use of experimental and analytical modal analysis technique for structural dynamic evaluation processes of a vertical machining centre. The main results deal with assessment of the mode shape of the different components of the vertical machining centre. The simplified experimental modal analysis of different components of milling machine was carried out. This model of the different machine tool's structure is made by design software and analyzed by finite element simulation using ABAQUS software to extract the different theoretical mode shape of the components. The model is evaluated and corrected with experimental results by modal testing of the machine components in which the natural frequencies and the shape of vibration modes are analyzed. The analysis resulted in determination of the direction of the maximal compliance of a particular machine component.

  9. Dynamics and stability of a vertical water bridge

    CERN Document Server

    Namin, Reza Montazeri

    2013-01-01

    A vertical connection of water is formed when a high voltage electrode is dipped in and pulled out of a container of deionized water. We considered the formation, stability and dynamical characteristics of this vertical water bridge. For the first time in this field, we observed instabilities in the bridge that led to an oscillatory behaviour which is categorized in three dynamical regimes and supplied explanations on the physics behind these varied motions. We report the formation of macroscopic droplets during this motion, which their dynamics revealed that they are electrically charged. In some cases the droplets would be levitating when the electric force opposes the gravity. Also the steady bridge is thoroughly studied regarding its geometry and a set of quantitative data is presented using dimensionless numbers, which brings the possibility of direct quantitative comparison between theory and experiments. Our results shed light on the physics behind this phenomenon and the horizontal water bridge, which...

  10. Wind Velocity Vertical Extrapolation by Extended Power Law

    Directory of Open Access Journals (Sweden)

    Zekai Şen

    2012-01-01

    Full Text Available Wind energy gains more attention day by day as one of the clean renewable energy resources. We predicted wind speed vertical extrapolation by using extended power law. In this study, an extended vertical wind velocity extrapolation formulation is derived on the basis of perturbation theory by considering power law and Weibull wind speed probability distribution function. In the proposed methodology not only the mean values of the wind speeds at different elevations but also their standard deviations and the cross-correlation coefficient between different elevations are taken into consideration. The application of the presented methodology is performed for wind speed measurements at Karaburun/Istanbul, Turkey. At this location, hourly wind speed measurements are available for three different heights above the earth surface.

  11. Extreme wave run-up on a vertical cliff

    CERN Document Server

    Carbone, Francesco; Dudley, John M; Dias, Frédéric

    2013-01-01

    Wave impact and run-up onto vertical obstacles are among the most important phenomena which must be taken into account in the design of coastal structures. From linear wave theory, we know that the wave amplitude on a vertical wall is twice the incident wave amplitude with weakly nonlinear theories bringing small corrections to this result. In this present study, however, we show that certain simple wave groups may produce much higher run-ups than previously predicted, with particular incident wave frequencies resulting in run up heights exceeding the initial wave amplitude by a factor of 5, suggesting that the notion of the design wave used in coastal structure design may need to be revisited. The results presented in this study can be considered as a note of caution for practitioners, on one side, and as a challenging novel material for theoreticians who work in the field of extreme wave - coastal structure interaction.

  12. Vertical Organic Field-Effect Transistors for Integrated Optoelectronic Applications.

    Science.gov (United States)

    Yu, Hyeonggeun; Dong, Zhipeng; Guo, Jing; Kim, Doyoung; So, Franky

    2016-04-27

    Direct integration of a vertical organic field-effect transistor (VOFET) and an optoelectronic device offers a single stacked, low power optoelectronic VOFET with high aperture ratios. However, a functional optoelectronic VOFET could not be realized because of the difficulty in fabricating transparent source and gate electrodes. Here, we report a VOFET with an on/off ratio up to 10(5) as well as output current saturation by fabricating a transparent gate capacitor consisting of a perforated indium tin oxide (ITO) source electrode, HfO2 gate dielectric, and ITO gate electrode. Effects of the pore size and the pore depth within the porous ITO electrodes on the on/off characteristic of a VOFET are systematically explained in this work. By combining a phosphorescent organic light-emitting diode with an optimized VOFET structure, a vertical organic light-emitting transistor with a luminance on/off ratio of 10(4) can be fabricated. PMID:27082815

  13. Search for R-parity violating supersymmetry with displaced vertices

    CERN Document Server

    CMS Collaboration

    2016-01-01

    A search for $R$-parity violating supersymmetry has been performed using proton-proton collision data collected by the CMS experiment at a center-of-mass energy of $\\sqrt{s}=8~\\mathrm{TeV}$. The data analyzed correspond to an integrated luminosity of $17.6~\\mathrm{fb}^{-1}$. This search assumes a minimal flavor violating model where the lightest supersymmetric particle is a long-lived neutralino or gluino, leading to a signal with jets emanating from displaced vertices. Based on a sample of events with two displaced vertices, the pair production cross section is bounded as a function of mass and lifetime of the neutralino or gluino. For a mass of 400 GeV and mean proper decay length of 10 mm, the analysis excludes cross sections above $0.6~\\mathrm{fb}$ at $95\\%$ confidence level.

  14. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O' Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-01-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  15. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O`Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-09-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  16. Optimal Control of Vertically Transmitted Disease: An Integrated Approach

    Directory of Open Access Journals (Sweden)

    Samit Bhattacharyya

    2010-01-01

    horizontal transmission, administration of the antiviral drug to infected individuals lessens the chance of vertical transmission. Thus the vaccine and antiviral drug play different roles in controlling the disease, which has both vertical and horizontal transmission. We develop a 3D model with Susceptible–Infected–Recovered under vaccination to the susceptible and antiviral treatment to the infected and consider a control theoretic approach using the Pontryagin maximum principle to analyse the costeffectiveness of the control process. Our results demonstrate that a mixed intervention strategy of vaccination and antiviral drug in a proper ratio is the most effective way to control the disease. We show that cost-effectiveness of both intervention strategies intimately depends on disease-related parameters, such as force of infection, probability of being infected to offspring from infected mothers, loss of immunity or reinfection and also on cost of treatment.

  17. Analysis of an Underground Vertical Electrically Small Wire Antenna

    Directory of Open Access Journals (Sweden)

    Shuwei Dong

    2015-01-01

    Full Text Available The problem considered is a vertical electrically small wire antenna located underground, which transmits electromagnetic signals to the ground. Getting Green’s function of the vertical dipole underground was the first step to calculate this issue. A quasistatic situation was considered to make an approximation on Sommerfeld integral for easy solution. The method of moments was used to solve the current distribution on the antenna surface at different frequencies, which laid a good foundation for obtaining the electric field of the antenna. Then the axial and radial components of the electric field with the radial distance on the ground were investigated, as well as the voltage received on the ground. Furthermore, the influence of the frequency and stratum parameters on current and electric field was studied to understand the variation clearly.

  18. Flow Structure Around the Intake of a Vertical Pump

    Institute of Scientific and Technical Information of China (English)

    Akihiro WADA

    2006-01-01

    The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their installation area is demanded to be minimum without losing the high performance. We concentrate our attention on the expansion ratio of the intake as a representative characteristic of the shape of the pumps and investigate the effect of the expansion ratio on pump performance. It is concluded that the optimum expansion ratio ranges in 1.1~1.2 if we take into consideration that the area needed for the installation of the pump should be minimum.

  19. A MARTe based simulator for the JET Vertical Stabilization system

    Energy Technology Data Exchange (ETDEWEB)

    Bellizio, Teresa, E-mail: teresa.bellizio@unina.it [Associazione EURATOM-ENEA-CREATE, University di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); De Tommasi, Gianmaria; Risoli, Nicola; Albanese, Raffaele [Associazione EURATOM-ENEA-CREATE, University di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Neto, Andre [Associacao EURATOM/IST, Inst. de Plasmas e Fusao Nuclear - Laboratorio Associado, Instituto Superior, Tecnico, P-1049-001 Lisboa (Portugal)

    2011-10-15

    Validation by means of simulation is a crucial step when developing real-time control systems. Modeling and simulation are an essential tool since the early design phase, when the control algorithms are designed and tested. This phase is commonly carried out in off-line environments such as Matlab and Simulink. A MARTe-based simulator has been recently developed to validate the new JET Vertical Stabilization (VS) system. MARTe is the multi-thread framework used at JET to deploy hard real-time control systems. This paper presents the software architecture of the MARTe-based simulator and it shows how this tool has been effectively used to evaluate the effects of Edge Localized Modes (ELMs) on the VS system. By using the simulator it is possible to analyze different plasma configurations, extrapolating the limit of the new vertical amplifier in terms of the energy of the largest rejectable ELM.

  20. Ozone measurements along vertical transects in the Alps.

    Science.gov (United States)

    Werner, H; Kirchner, M; Welzl, G; Hangartner, M

    1999-01-01

    To investigate the vertical profiles of air pollutants in the boundary layer, aircraft and balloon-born measurements and measurements using a cable car as an instrument platform have been performed in different parts of the Alps. This on-line monitoring of atmospheric pollutants requires expensive and sophisticated techniques. In order to control ambient air quality in remote regions, where no infrastructure like power supply is available, simple instruments are required. The objective of this study, which was coordinated and evaluated by the GSF-Forschungszentrum für Umwelt und Gesundheit was first, to investigate the vertical distribution of ozone in different parts of the Alps and secondly, in addition to continuous analyser measurements, to test monitoring by means of two types of passive samplers. The selection of these samplers - one for one week use and another one for two week application - was based on a passive sampler intercomparison done in a preliminary study one year earlier.

  1. A new vertical axis wind turbine design for urban areas

    Science.gov (United States)

    Frunzulica, Florin; Cismilianu, Alexandru; Boros, Alexandru; Dumitrache, Alexandru; Suatean, Bogdan

    2016-06-01

    In this paper we aim at developing the model of a Vertical Axis Wind Turbine (VAWT) with the short-term goal of physically realising this turbine to operate at a maximmum power of 5 kW. The turbine is designed for household users in the urban or rural areas and remote or isolated residential areas (hardly accsessible). The proposed model has a biplane configuration on each arm of the VAWT (3 × 2 = 6 blades), allowing for increased performance of the turbine at TSR between 2 and 2.5 (urban area operation) compared to the classic vertical axis turbines. Results that validate the proposed configuration as well as passive control methods to increase the performance of the classic VAWTs are presented.

  2. Risk Assessment of Vertical Breakwaters -- A Case Study in Turkey

    Institute of Scientific and Technical Information of China (English)

    Can Elmar BALAS; Levent KOC

    2002-01-01

    In the reliability-risk assessment, the second order reliability index (βⅡ) method and the Conditional ExpectationMonte Carlo (CEMC) simulation are interrelated as a new Level Ⅲ approach for the analysis of the safety level of theDalaman yacht harbor vertical wall breakwater in Turkey. The missing wave data of the Dalaman measurement station arehindcasted by use of muhi-layer feed-forward neural networks with the steepest descent and conjugate gradient algorithms.The structural failure probabilities of sliding and overturning failure modes are forecasted by approximation of the failure sur-face with a second-degree polynomial of an equal curvature at the design point. In the new approach, for each randomlygenerated load and tide combination, the joint failure probability reflects both the occurrence probability of loading conditionand the structural failure risk at the limit state. The approach can be applied to risk assessment of vertical breakwaters inshort CPU durations of portable computers.

  3. ESTIMATION OF SCOUR HOLE PROPERTIES AROUND VERTICAL PILE USING ANNs

    Institute of Scientific and Technical Information of China (English)

    A.KHOSRONEJAD; G. A. MONTAZER; M. GHODSIAN

    2003-01-01

    Correct estimation of the scour around vertical piles in the field exposed to oscillatory waves is very important for many offshore structures and coastal engineering projects. Conventional predictive formulas for the geometric properties of scour hole, however, are not able to provide sufficiently accurate results. Artificial Neural Networks (ANNs) are simplified mathematical representation of the human brain. Three-layer normal feed-forward ANN is a powerful tool for input-output mapping and has been widely used in civil engineering problems. In this article the ANNs approach is used to predict the geometric properties of the scour around vertical pile. Two different ANNs including multilayer perceptron (with four different learning rules) and radial basis functions neural networks are used for this purpose. The results show that a three-layer normal feed-forward multilayer perceptron with quick propagation (QP) learning rule can predict the scour hole properties successfully.

  4. Rewetting of hot vertical rod during jet impingement surface cooling

    Science.gov (United States)

    Agrawal, Chitranjan; Kumar, Ravi; Gupta, Akhilesh; Chatterjee, Barun

    2016-06-01

    A stainless steel (SS-316) vertical rod of 12 mm diameter at 800 ± 10 °C initial temperature was cooled by normal impinging round water jet. The surface rewetting phenomenon was investigated for a range of jet diameter 2.5-4.8 mm and jet Reynolds number 5000-24,000 using a straight tube type nozzle. The investigation were made from the stagnation point to maximum 40 mm downstream locations, simultaneously for both upside and downside directions. The cooling performance of the vertical rod was evaluated on the basis of rewetting parameters i.e. rewetting temperature, wetting delay, rewetting velocity and the maximum surface heat flux. Two separate Correlations have been proposed for the dimensionless rewetting velocity in terms of rewetting number and the maximum surface heat flux that predicts the experimental data within an error band of ±20 and ±15 % respectively.

  5. Taxel-addressable matrix of vertical nanowire piezotronic transistors

    Science.gov (United States)

    Wang, Zhong Lin; Wu, Wenzhuo; Wen, Xiaonan

    2015-05-05

    A tactile sensing matrix includes a substrate, a first plurality of elongated electrode structures, a plurality of vertically aligned piezoelectric members, an insulating layer infused into the piezoelectric members and a second plurality of elongated electrode structures. The first plurality of elongated electrode structures is disposed on the substrate along a first orientation. The vertically aligned piezoelectric members is disposed on the first plurality of elongated electrode structures and form a matrix having columns of piezoelectric members disposed along the first orientation and rows of piezoelectric members disposed along a second orientation that is transverse to the first orientation. The second plurality of elongated electrode structures is disposed on the insulating layer along the second orientation. The elongated electrode structures form a Schottky contact with the piezoelectric members. When pressure is applied to the piezoelectric members, current flow therethrough is modulated.

  6. Aerodynamic performance of vertical and horizontal axis wind turbines

    Science.gov (United States)

    Maydew, R. C.; Klimas, P. C.

    1981-06-01

    The aerodynamic performance of vertical and horizontal axis wind turbines is investigated, and comparison of data of the 17-m Darrieus VAWT with the 60.7-m Mod-1 HAWT and 37.8-m Mod-0A HAWT is discussed. It is concluded that the maximum average measured power coefficients of the VAWT are about 0%-15% higher than those of the HAWTs. It is suggested that vertical wind shear may have lowered the Mod-1 HAWT aerodynamic performance, but, the magnitude of this effect could not be evaluated. It is included that generalizations which refer to the Darrieus VAWT as aerodynamically less efficient than the HAWT should be used carefully.

  7. Small Vertical Axis Wind Turbines: aerodynamics and starting behavior

    Directory of Open Access Journals (Sweden)

    Horia DUMITRESCU

    2013-12-01

    Full Text Available In urban areas the wind is very turbulent and unstable with fast changes in direction andvelocity. In these environments, the use of small vertical axis wind turbines (VAWT becomesincreasingly attractive due to several advantages over horizontal axis wind turbines (HAWT.However, such designs have received much less attention than the more common propeller-typedesigns and the understanding of same aspects of their operation remains, to this day, incomplete.This is particularly true of their starting characteristics. Indeed, same authors heuristically maintainthat they cannot start without external assistance. This paper reviews the cause of the inability of thelow solidity fixed pitch vertical axis wind turbines to self-start, and investigates the way ofovercoming this draw back.

  8. Determination of Geopotential of Local Vertical Datum Surface

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper first develops the approaches to determine the geopotential of the local mean sea level,and then investigates the offset of the 1985 vertical datum surface defined by the mean sea level of Yellow Sea at the Dagang Tide Gauge in Qingdao city using the developed approaches and GPS/leveling data.It shows that the geopotential of the local mean sea level at the tide gauge is equal to 62 636 853.5±0.2 m2*s-2 and that the 1985 vertical datum surface is 24.6±5.4 cm above the geoid realized by the geopotential W0=62 636 856.0±0.5 m2*s-2.

  9. Thermal structure of a lake with water in vertical motion

    Energy Technology Data Exchange (ETDEWEB)

    Zito, G.; Mongelli, F. (Bari Univ. (Italy). Ist. di Geodesia e Geofisica)

    The vertical temperature structures of the seasonal thermocline of two lakes in temperate latitude with different feedings have been examined experimentally and reproduced theoretically by the basic equation of heat diffusion. One of these lakes is fed mainly from springs emerging from the lake bottom: as a consequence a vertical motion of water is established. The other lake is fed from the former by a small superficial channel. It is argued that the observed quantitative features of the stratification cycle agree with the theoretical calculations in both lakes with the same value of the molecular thermal diffusivity. Moreover, the seasonal thermocline of the lake with the bottom feeding is reduced: this involves a faster drop in the temperature amplitude of the annual cycle.

  10. Flow regimes and heat transfer in vertical narrow annuli

    Energy Technology Data Exchange (ETDEWEB)

    Ulke, A.; Goldberg, I.

    1993-11-01

    In shell side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local thermal-hydraulic conditions which differ significantly from bulk fluid conditions. Understanding of the processes of boiling and dryout in flow restricted crevices can help in designing of tube support geometries to minimize the likelihood of tube support plate and tube corrosion observed in commercial power plant steam generators. This paper describes a one dimensional thermal-hydraulic model of a vertical crevice between a tube and a support plate with cylindrical holes. The annulus formed by the support plate hole and an eccentrically located tube has been represented by vertical strips. The formation, growth and collapse of a steam bubble in each strip has been determined. Based on the bubble history, and flow regimes characterized by ``isolated`` bubbles, ``coalesced`` bubbles and liquid deficient regions have been defined.

  11. Flow regimes and heat transfer in vertical narrow annuli

    International Nuclear Information System (INIS)

    In shell side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local thermal-hydraulic conditions which differ significantly from bulk fluid conditions. Understanding of the processes of boiling and dryout in flow restricted crevices can help in designing of tube support geometries to minimize the likelihood of tube support plate and tube corrosion observed in commercial power plant steam generators. This paper describes a one dimensional thermal-hydraulic model of a vertical crevice between a tube and a support plate with cylindrical holes. The annulus formed by the support plate hole and an eccentrically located tube has been represented by vertical strips. The formation, growth and collapse of a steam bubble in each strip has been determined. Based on the bubble history, and flow regimes characterized by ''isolated'' bubbles, ''coalesced'' bubbles and liquid deficient regions have been defined

  12. Two loop QCD vertices at the symmetric point

    CERN Document Server

    Gracey, J A

    2011-01-01

    We compute the triple gluon, quark-gluon and ghost-gluon vertices of QCD at the symmetric subtraction point at two loops in the MSbar scheme. In addition we renormalize each of the three vertices in their respective momentum subtraction schemes, MOMggg, MOMq and MOMh. The conversion functions of all the wave functions, coupling constant and gauge parameter renormalization constants of each of the schemes relative to MSbar are determined analytically. These are then used to derive the three loop anomalous dimensions of the gluon, quark, Faddeev-Popov ghost and gauge parameter as well as the beta-function in an arbitrary linear covariant gauge for each MOM scheme. There is good agreement of the latter with earlier Landau gauge numerical estimates of Chetyrkin and Seidensticker.

  13. Vertical bearing capacity of pile based on load transfer model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ming-hua; YANG Ming-hui; ZOU Xin-jun

    2005-01-01

    The load transfer analytical method is applied to study the bearing mechanism of piles with vertical load in this paper. According to the different hardening rules of soil or rock around the pile shaft, such as work-softening, ideal elasto-plastic and work-hardening, a universal tri-linear load transfer model is suggested for the development of side and tip resistance by various types of soil (rock) with the consideration of sediment at the bottom of the pile. Based on the model, a formula is derived for the relationship between the settlement and load on the pile top to determine the vertical bearing capacity, taking into account such factors as the characteristics of the stratum, the side resistance along the shaft, and tip resistance under the pile tip. A close agreement of the calculated results with the measured data from a field test pile lends confidence to the future application of the present approach in engineering practice.

  14. Vertical stability requirements for ARIES-I reactor

    International Nuclear Information System (INIS)

    The vertical stability of the ARIES-I reactor design is analyzed with the NOVA-W, PSTAB, and TSC codes. A growth rate of ∼5.7 s-1 is predicted for a vacuum vessel positioned behind the scrapeoff, first wall, and blanket (0.7 in inboard and 0.9 in outboard thickness) and acting as a passive stabilizer. A reactive power of ∼2 MV A would be required for active feedback coils located outside of the TF coils ∼3 m to correct a 50-mm vertical displacement of the magnetic axis. A multipolar expansion technique used in the TSC analysis is also used to examine options that minimize stored energy. 10 refs., 8 figs., 2 tabs

  15. Application of circulation controlled blades for vertical axis wind turbines

    OpenAIRE

    Velissarios Kourkoulis; Andrew Shires

    2013-01-01

    The blades of a vertical axis wind turbine (VAWT) rotor see an inconsistent angle of attack through its rotation. Consequently, VAWT blades generally use symmetrical aerofoils with a lower lift-to-drag ratio than cambered aerofoils tailored to maximise horizontal axis wind turbine rotor performance. This paper considers the feasibility of circulation controlled (CC) VAWT blades, using a tangential air jet to provide lift and therefore power augmentation. However CC blade sections require a hi...

  16. Local Vertical/Local Horizontal Attitude Control for Spartan Spacecraft

    OpenAIRE

    Morrissey, James; Olney, David

    1996-01-01

    A Spartan spacecraft attitude control system was reconfigured to provide attitude pointing with respect to a Local Vertical/Local Horizontal reference frame even though the baseline system uses only an initial start attitude, sun sensors, and star tracker/gyros for defining the spacecraft attitude. No earth sensors of any kind are used. Deployed from the orbiter for two days, usually for solar and stellar inertial pointing, Spartan missions use pointing programs that must be written months pr...

  17. Abrasion of 6 dentifrices measured by vertical scanning interference microscopy

    OpenAIRE

    Florence Pascaretti-Grizon; Guillaume Mabilleau; Daniel Chappard

    2013-01-01

    OBJECTIVES: The abrasion of dentifrices is well recognized to eliminate the dental plaque. The aims of this study were to characterize the abrasive powders of 6 dentifrices (3 toothpastes and 3 toothpowders) and to measure the abrasion on a test surface by Vertical Scanning Interference microscopy (VSI). MATERIAL AND METHODS: Bright field and polarization microscopy were used to identify the abrasive particles on the crude dentifrices and after prolonged washes. Scanning electron microscop...

  18. Water Absorbing Plantation Clay for Vertical Greenery System

    OpenAIRE

    Yu Lih-Jiun; De Vera Santos Aegil; Tan Khang-Wei; Tawawneh Mou’ad A

    2016-01-01

    With the arises of environmental conscious, the usage of vertical garden system has become more popular in urban cities. Citizens can enjoys the benefits of energy and cost saving besides ornamental effect. More investigations have been conducted on green facades led to the cities ecological enhancement.However, limited plants species can be planted for green facades systems as this system does not provide sufficient soil and nutrients for common plants. Alternative plantation methods such as...

  19. Simulation of Vertical Plane Turbulent Jet in Shallow Water

    OpenAIRE

    Aziz, T. N.; Khan, A.A.

    2011-01-01

    A plane, turbulent, nonbuoyant, vertical jet in shallow water is simulated numerically using a three-dimensional computation model employing standard - and renormalized group - turbulent closure schemes. Existing data of mean and turbulent flow quantities, measured using laser Doppler velocimeter, are used to assess the two turbulent closure schemes. Comparisons between the measured and simulated flow field data are made in the free jet region, within the zone of surface impingement, ...

  20. Vertical-Cavity In-plane Heterostructures: Physics and Applications

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

    2015-01-01

    We show that the in-plane heterostructures realized in vertical cavities with high contrast grating(HCG) reflector enables exotic configurations of heterostructure and photonic wells. In photonic crystal heterostructures forming a photonic well, the property of a confined mode is determined by th...... discuss the rich potential of this heterostructure as a platform for various physics studies and propose a system of two laterally coupled cavities which shows the breaking of parity-time symmetry as an example....

  1. Vertical Integration and Market Foreclosure with Convex Downstream Costs

    OpenAIRE

    Baake, Pio; Kamecke, Ulrich; Normann, Hans-Theo

    2001-01-01

    In a framework with an upstream monopoly and a downstream duopoly, we analyze the impact of convex costs on the downstream level. In contrast to the case of constant marginal costs, vertical integration does not imply complete market foreclosure. While the non-integrated downstream firm receives a strictly positive amount of the intermediate good, the downstream allocation is inefficient. However, a parametrized example indicates that competition at the downstream level may increase aggregate...

  2. Endogenous Contracts Under Bargaining in Competing Vertical Chains

    OpenAIRE

    Milliou, Chrysovalantou; Petrakis, Emmanuel; Vettas, Nikolaos

    2003-01-01

    We investigate the endogenous determination of contracts in competing vertical chains where upstream and downstream firms bargain first over the type of contract and then over the contract terms. Upstream firms always opt for non-linear contracts, which specify the input quantity and its total price. Downstream firms also opt for non-linear contracts, unless their bargaining power is low, in which case they prefer wholesale price contracts. While welfare is maximized under two-part tariffs, t...

  3. Product line pricing in a vertically differentiated oligopoly

    OpenAIRE

    George Deltas; Thanasis Stengos; Eleftherios Zacharias

    2011-01-01

    This paper empirically examines the joint pricing decision of products in a firm's product line. When products are distinguished by a vertical characteristic, those products with higher values of that characteristic will command higher prices. We investigate whether, holding the value of the characteristic constant, there is a price premium for products on the industry and/or the firm frontier, i.e., for the products with the highest value of the characteristic in the market or in a firm's pr...

  4. Horizontal and vertical concentrations in the evolution of hospital competition.

    Science.gov (United States)

    Starkweather, D B; Carman, J M

    1987-01-01

    Summing across the three phases, the pattern of evolution was as follows: (1) the emergence of a market orientation by hospitals as the industry moved away from regulation; (2) steady expansion of what the hospitals considered to be their business, to include nonacute and wellness services, with vertical integration and diversification the vehicle for accomplishing this; (3) remarkable change with respect to who was competing with whom, stemming from restructuring of the market toward horizontal concentration and domination by a few rather than continuing open competition among many; (4) a shift in the market from one of competitive consumer choices among physicians and hospitals toward one of competitive choice among health plans; and (5) the beginnings of price dynamics within the context of oligopoly, due primarily to heightened power of corporate and other purchasers. A striking feature of this evolution was the role of concentration as both a response to increased competition and a vector of change in restructuring the market. Another notable feature was the relationship of vertical and horizontal integrations to each other: Stage I corporate reorganization and limited vertical integration provided the vehicle for horizontal integration in Stage II; then horizontal integration achieved a new critical mass and market dominance, yielding more vertical integration in Stage III. Finally, we note that of the numerous reasons advanced for mergers in industrial sectors and among hospitals in particular, a singular motivation was pursued in Community A: in an era of increasing competition, the stronger hospitals moved with determination to reduce competition and establish domination. The fundamental motive was market control. PMID:10291980

  5. Comparison of vertical and horizontal systems of constructed wetlands

    OpenAIRE

    Vidmar, Urša

    2011-01-01

    The constructed wetlands (CW) or artificial wetlands with the wastewater treatment as their primary function are complex systems of water, substrate, plants, animals and microorganisms (bacteria). In practice there are two general systems in use, the system with the surface and the system with the subsurface flow, which is further divided into the system with the horizontal water flow and in the system with the vertical water flow. Understanding of constructed wetlands function...

  6. Which Hydraulic Model To Use In Vertical Flow Constructed Wetlands?

    OpenAIRE

    Morvannou, A.; Forquet, N.; M. Vanclooster; Molle, P.

    2012-01-01

    International audience Modeling water flow in a VFCW is a prerequisite to model wastewater treatment using process based filtering models. As for soils, when the vertical structure varies in different material types, it has a significant impact on water flow passing through it. The heterogeneous filtering material is composed of a mix of mineral porous material, and organic matter which makes its hydraulic characterization a difficult task. Indeed, the porosity may serve as preferential fl...

  7. Two-Dimensional Weak Pseudomanifolds on Eight Vertices

    Indian Academy of Sciences (India)

    Basudeb Datta; Nandini Nilakantan

    2002-05-01

    We explicitly determine all the two-dimensional weak pseudomanifolds on 8 vertices. We prove that there are (up to isomorphism) exactly 95 such weak pseudomanifolds, 44 of which are combinatorial 2-manifolds. These 95 weak pseudomanifolds triangulate 16 topological spaces. As a consequence, we prove that there are exactly three 8-vertex two-dimensional orientable pseudomanifolds which allow degree three maps to the 4-vertex 2-sphere.

  8. THE PRIORITIES OF DEVELOPMENT OF VERTICALLY INTEGRATED STRUCTURES

    OpenAIRE

    Natalja Chorna

    2014-01-01

    Ways of attainment of the competitiveness are different for each enterprise, but, at the same time, they have a mutual feature, i.e. anenterprise cannot become a competitive one without the implementation of strategic plans of its development. Despite the diversity ofstrategies enterprises frequently choose the strategy of external increase, which includes a type such as the vertical integration strategy.A purpose of the research is the determination of the main priorities of development of v...

  9. Ray Tracing Modelling of Reflector for Vertical Bifacial Panel

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff;

    2016-01-01

    Bifacial solar panels have recently become a new attractive building block for PV systems. In this work we propose a reflector system for a vertical bifacial panel, and use ray tracing modelling to model the performance. Particularly, we investigate the impact of the reflector volume being filled...... with a refractive medium, and shows the refractive medium improves the reflector performance since it directs almost all the light incident on the incoming plane into the PV panel....

  10. Role of vertical migration in biogenic ocean mixing

    OpenAIRE

    Dabiri, John O.

    2010-01-01

    Recent efforts to empirically measure and numerically simulate biogenic ocean mixing have consistently observed low mixing efficiency. This suggests that the buoyancy flux achieved by swimming animals in the ocean may be negligible in spite of the observed large kinetic energy dissipation rates. The present letter suggests that vertical migration across isopycnals may be necessary in order to generate overturning and subsequent mixing at length scales significantly larger than the individual ...

  11. Vertical axis wind turbine in a falling soap film

    OpenAIRE

    Araya, Daniel B.; Dabiri, John O.

    2015-01-01

    Vertical axis wind turbines (VAWTs) have demonstrated a potential to significantly enhance the efficiency of energy harvesting within a wind farm. One mechanism that contributes to this enhancement is a VAWT’s inherent insensitivity to wind direction coupled with blockage within an array of turbines. Much like the flow around a bluff body, turbine blockage can locally accelerate the flow near one turbine, providing faster inflow conditions for a well-placed neighboring turbine. Since the powe...

  12. Buyer power and exclusion in vertically related markets

    OpenAIRE

    Gabrielsen, Tommy Staahl; Johansen, Bjørn Olav

    2012-01-01

    We explore how the incentives for exclusion, both in upstream and downstream vertical markets, are related to the bargaining position of suppliers and retailers. We consider a model with a dominant upstream manufacturer and a competitive fringe of producers of imperfect substitutes offering their products to two differentiated downstream retailers. In this model we contrast the equilibrium outcome in two alternative situations. The first one is when the dominant supplier holds all the bargain...

  13. Collusion and downstream entry in a vertically integrated industry

    OpenAIRE

    Éric Avenel; Stéphane Caprice

    2012-01-01

    We analyse the impact of an entry threat at the downstream level on the ability of a pair of vertically integrated incumbents to collude. We present an original model of horizontal product differentiation on the final market and characterize the structures of this market for which an entry threat facilitates collusion between incumbents. While the entry threat leaves collusion and deviation profits unchanged, it lowers profits in punishment periods. Consequently, an entry threat discourages d...

  14. Vertical transmission of consumption behavior and the distribution of surnames

    OpenAIRE

    Collado, M. Dolores; Ortuño Ortin, Ignacio; Romeu, Andrés

    2006-01-01

    This paper attempts to detect the existence of links in consumption preferences between generations. Preferences for consumption goods may be determined by the preferences of parents (vertical transmission) and/or by preferences arising from the environment (horizontal transmission). We propose an indirect methodology to overcome the lack of data on consumption choices of dynasties, i.e., parents and their adult offspring. This new approach is based on the analysis of the correlation between ...

  15. Study of the Vertical Distribution of Air Temperature in Warehouses

    Directory of Open Access Journals (Sweden)

    César Porras-Amores

    2014-02-01

    Full Text Available Warehouses are usually large, plain industrial buildings commonly used for storage of goods. Vertical distribution of air temperature is an important aspect for indoor environment design, which must be taken into account by architects and engineers in the early stages of warehouse design. The aim of this work is to analyze the vertical temperature gradients existing in warehouses, quantifying their value and analyzing their evolution along the year. To do so, the study outlines the monitoring of several warehouses with different building typology and height located in different areas of Spain for a complete annual cycle. The results obtained when applying a simple linear regression analysis to 175,200 vertical temperature profiles show that there is a strong influence of the outdoor temperature over the stratification of the indoor air. During warm months, the ceiling and the upper strata get warmer, whereas the cold air accumulates in the lower levels, increasing the stratification of indoor air (maximum values between 0.3 °C/m and 0.7 °C/m. During cold months, the ceiling gets cold due to its contact with the outdoor air, therefore, the colder, heavier air moves down to the lower strata, registering insignificant vertical temperature differences. Air conditioning of the warehouse, besides controlling the temperature, limits the influence of the outdoor environment on the stratification of temperatures. The results of the study may be of great use for warehouses for products sensitive to temperature, which may suffer a different evolution, conservation or maturation when the temperature differences are maintained for a long time.

  16. Corner waves downstream from a partially submerged vertical plate

    OpenAIRE

    Martínez-Legazpi Aguiló, Pablo

    2011-01-01

    In this dissertation, the high-Reynolds-number flow near the corner of a vertical at plate partially submerged across an uniform stream has been studied using a combination of experimental, numerical and analytical tools. In this configuration, a three dimensional wave forms at the corner of the plate which evolves downstream in a similar way as a time-evolving two dimensional plunging or spilling breaker, depending the occurrence of one or the other type of breaker on the flow conditions. Ex...

  17. EXPORT SUBSIDIES AND PROFIT-SHIFTING IN VERTICAL MARKETS

    OpenAIRE

    Sheldon, Ian M.; Pick, Daniel H.; McCorriston, Steve

    2001-01-01

    This study examines the interaction between export subsidies and profit-shifting in a vertical production system consisting of agricultural commodity production, and intermediate and final good processing, where the latter two stages may be characterized by imperfect competition. Using a model with general functional forms for demand, comparative statics indicate that an export subsidy to an unprocessed agricultural commodity, under certain circumstances, can have greater profit-shifting effe...

  18. Ageostrophic instability in rotating, stratified interior vertical shear flows

    OpenAIRE

    Wang, Peng; Mcwilliams, James C.; Menesguen, Claire

    2014-01-01

    The linear instability of several rotating, stably stratified, interior vertical shear flows (U) over bar (z) is calculated in Boussinesq equations. Two types of baroclinic, ageostrophic instability, AI1 and AI2, are found in odd-symmetric (U) over bar (z) for intermediate Rossby number (R-0). AI1 has zero frequency; it appears in a continuous transformation of the unstable mode properties between classic baroclinic instability (BCI) and centrifugal instability (CI). It begins to occur at int...

  19. Horizontal and vertical concentrations in the evolution of hospital competition.

    Science.gov (United States)

    Starkweather, D B; Carman, J M

    1987-01-01

    Summing across the three phases, the pattern of evolution was as follows: (1) the emergence of a market orientation by hospitals as the industry moved away from regulation; (2) steady expansion of what the hospitals considered to be their business, to include nonacute and wellness services, with vertical integration and diversification the vehicle for accomplishing this; (3) remarkable change with respect to who was competing with whom, stemming from restructuring of the market toward horizontal concentration and domination by a few rather than continuing open competition among many; (4) a shift in the market from one of competitive consumer choices among physicians and hospitals toward one of competitive choice among health plans; and (5) the beginnings of price dynamics within the context of oligopoly, due primarily to heightened power of corporate and other purchasers. A striking feature of this evolution was the role of concentration as both a response to increased competition and a vector of change in restructuring the market. Another notable feature was the relationship of vertical and horizontal integrations to each other: Stage I corporate reorganization and limited vertical integration provided the vehicle for horizontal integration in Stage II; then horizontal integration achieved a new critical mass and market dominance, yielding more vertical integration in Stage III. Finally, we note that of the numerous reasons advanced for mergers in industrial sectors and among hospitals in particular, a singular motivation was pursued in Community A: in an era of increasing competition, the stronger hospitals moved with determination to reduce competition and establish domination. The fundamental motive was market control.

  20. Influence of Whipping on Long term Vertical Bending Moment

    DEFF Research Database (Denmark)

    Baarholm, G. S.; Jensen, Jørgen Juncher

    2004-01-01

    This paper is concerned with estimating the response value corresponding to a long return period, say a twenty years. Time domain simulation is required to obtain the nonlinear response, and long time series are required to limit the statistical uncertainty in the simulations. It is crucial to in......). Results are presented for the S-175 container ship, (15th & 16th ITTC Seakeeping Committee 1983). The analysis shoes that whipping increases the vertical bending moment and that the correlation is significant...

  1. Influence of quartz particles on wear in vertical roller mills

    DEFF Research Database (Denmark)

    Jensen, Lucas R.D.; Friis, Henrik; Fundal, Erling;

    2010-01-01

    The standard closed circuit comminution process commonly employed in industrial vertical roller mills has been analyzed to determine the influence of typical abrasive minerals on wear rates. With the main focus on raw mixes used in cement plants, synthetic mixtures imitating were prepared. Using...... in an increased concentration of abrasive particles in the grinding bed ðR2 > 0:99Þ. The present study shows that the quartz concentration in the grinding bed is determining the wear rate....

  2. Segregation in Vertically Vibrated Binary Granular Mixtures with Same Size

    Institute of Scientific and Technical Information of China (English)

    SHI Qing-Fan; SUN Gang; HOU Mei-Ying; LU Kun-Quan

    2006-01-01

    @@ Segregation in vertically vibrated binary granular mixtures with same size is studied experimentally. A new partial segregated state is found in this system. This state exists between the completely mixed state and the pure segregated state, and has the characteristic that the lighter particles tend to rise and form a pure layer on the top of the system while the heavier particles and some of the lighter ones stay at the bottom and form a mixed layer.

  3. Vertical Tax Externalities in the Theory of Fiscal Federalism

    OpenAIRE

    Michael Keen

    1998-01-01

    Vertical tax externalities between levels of government can occur in federal structures, with responses to the tax policies of one level of government affecting the tax base of the other. Such effects mostly arise when federal and state governments co-occupy the same tax base. This paper examines these externalities by considering their implications for a range of issues in fiscal federalism: the relationship between state and federal tax rates, the equilibrium levels of these taxes, the rele...

  4. Vertical Integration and Reverse Engineering of Agricultural Enterprises

    OpenAIRE

    Wu, Gang; Du, Yong

    2014-01-01

    This paper studies the potential effects of agricultural enterprise’s vertical integration and reverse engineering on downstream firms. Suppliers who invest reverse engineering technology can exploit customer’s information. An integrated supplier can obtain at no cost the information from its subsidiary. Based on repeated game and considered corporate "good" or "bad" type, this paper analysis supplier’s selection and downstream investment in innovation. The results showed that: when the...

  5. Application of factor decomposition techniques to vertical specialisation measurements

    OpenAIRE

    Meng, Bo; Yamano, Norihiko; Webb, Colin; 孟, 渤; 山野, 紀彦

    2011-01-01

    The increasing importance of vertical specialisation (VS) trade has been a notable feature of rapid economic globalisation and regional integration. In an attempt to understand countries’ depth of participation in global production chains, many Input-Output based VS indicators have been developed. However, most of them focus on showing the overall magnitude of a country’s VS trade, rather than explaining the roles that specific sectors or products play in VS trade and what factors make the VS...

  6. Analytical Aerodynamic Simulation Tools for Vertical Axis Wind Turbines

    International Nuclear Information System (INIS)

    Wind power is a renewable energy source that is today the fastest growing solution to reduce CO2 emissions in the electric energy mix. Upwind horizontal axis wind turbine with three blades has been the preferred technical choice for more than two decades. This horizontal axis concept is today widely leading the market. The current PhD thesis will cover an alternative type of wind turbine with straight blades and rotating along the vertical axis. A brief overview of the main differences between the horizontal and vertical axis concept has been made. However the main focus of this thesis is the aerodynamics of the wind turbine blades. Making aerodynamically efficient turbines starts with efficient blades. Making efficient blades requires a good understanding of the physical phenomena and effective simulations tools to model them. The specific aerodynamics for straight bladed vertical axis turbine flow are reviewed together with the standard aerodynamic simulations tools that have been used in the past by blade and rotor designer. A reasonably fast (regarding computer power) and accurate (regarding comparison with experimental results) simulation method was still lacking in the field prior to the current work. This thesis aims at designing such a method. Analytical methods can be used to model complex flow if the geometry is simple. Therefore, a conformal mapping method is derived to transform any set of section into a set of standard circles. Then analytical procedures are generalized to simulate moving multibody sections in the complex vertical flows and forces experienced by the blades. Finally the fast semi analytical aerodynamic algorithm boosted by fast multipole methods to handle high number of vortices is coupled with a simple structural model of the rotor to investigate potential aeroelastic instabilities. Together with these advanced simulation tools, a standard double multiple streamtube model has been developed and used to design several straight bladed

  7. Design, Operation and Diagnostics of a Vertical Axis Wind Turbine

    OpenAIRE

    Colley, Gareth

    2012-01-01

    The need for sustainable energy sources becomes greater each year due to the continued depletion of fossil fuels and the resulting energy crisis. Solutions to this problem are potentially in the form of wind turbines which have been receiving increased support at a micro level. At present a number of wind turbines are being developed that are of cross-flow vertical axis operation which have shown significant increases in performance compared to existing technologies. From an extensive literat...

  8. Velocity measurement of model vertical axis wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.A.; McWilliam, M. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering

    2006-07-01

    An increasingly popular solution to future energy demand is wind energy. Wind turbine designs can be grouped according to their axis of rotation, either horizontal or vertical. Horizontal axis wind turbines have higher power output in a good wind regime than vertical axis turbines and are used in most commercial class designs. Vertical axis Savonius-based wind turbine designs are still widely used in some applications because of their simplistic design and low wind speed performance. There are many design variables that must be considered in order to optimize the power output in a given wind regime in a typical wind turbine design. Using particle image velocimetry, a study of the air flow around five different model vertical axis wind turbines was conducted in a closed loop wind tunnel. A standard Savonius design with two semi-circular blades overlapping, and two variations of this design, a deep blade and a shallow blade design were among the turbine models included in this study. It also evaluated alternate designs that attempt to increase the performance of the standard design by allowing compound blade curvature. Measurements were collected at a constant phase angle and also at random rotor orientations. It was found that evaluation of the flow patterns and measured velocities revealed consistent and stable flow patterns at any given phase angle. Large scale flow structures are evident in all designs such as vortices shed from blade surfaces. An important performance parameter was considered to be the ability of the flow to remain attached to the forward blade and redirect and reorient the flow to the following blade. 6 refs., 18 figs.

  9. viscosity and density stratification in vertical Poiseuille flow

    OpenAIRE

    Renardy, Y

    1987-01-01

    The linear stability of plane three_layer vertical Poiseuille flow is considered. The layers are composed of two immiscible fluids, one next to the walls and one centrally located. The fluids have different viscosities and densities and surface tension effects are included. Intuitively, an analogy with the concentric Hagen-Poiseuille flow is expected and the similarities and differences are investigated. The ability of heuristic reasoning to predict which arrangements are more likely to be ob...

  10. Infrared vertically-illuminated photodiode for chip alignment feedback

    Science.gov (United States)

    Alloatti, L.; Ram, R. J.

    2016-08-01

    We report on vertically-illuminated photodiodes fabricated in the GlobalFoundries 45nm 12SOI node and on a packaging concept for optically-interconnected chips. The photodiodes are responsive at 1180 nm -a wavelength currently used in chip-to-chip communications. They have further a wide field-of-view which enables chip-to-board positional feedback in chip-board assemblies. Monolithic integration enables on-chip processing of the positional data.

  11. CFD Simulation of Twin Vertical Axis Tidal Turbines System

    OpenAIRE

    Syed Shah Khalid; Zhang Liang; Sheng Qi-hu

    2013-01-01

    As concerns about rising fossil-fuel prices, energy security and climate-change increase, renewable energy can play a vital role in producing local, clean and inexhaustible energy to supply world rising demand for electricity. In this study, hydrodynamic analysis of vertical axis tidal turbine operating side-by-side is numerically analyzed. Two-dimensional numerical modeling of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX; this is based on a ...

  12. Sintered Nickel Powder Wicks for Flat Vertical Heat Pipes

    OpenAIRE

    Geir Hansen; Erling Næss; Kolbeinn Kristjansson

    2015-01-01

    The fabrication and performance of wicks for flat heat pipe applications produced by sintering a filamentary nickel powder has been investigated. Tape casting was used as an intermediate step in the wick production process. Thermogravimetric analysis was used to study the burn-off of the organic binder used and to study the oxidation and reduction processes of the nickel. The wicks produced were flat, rectangular and intended for liquid transport in the upwards vertical direction. Rate-of-ris...

  13. Onset of fluidization in vertically shaken granular material

    OpenAIRE

    Poeschel, Thorsten; Schwager, Thomas; Saluena, Clara

    1997-01-01

    When granular material is shaken vertically one observes convection, surface fluidization, spontaneous heap formation and other effects. There is a controversial discussion in literature whether there exists a threshold for the Froude number $\\Gamma=A_0\\omega_0^2/g$ below which these effects cannot be observed anymore. By means of theoretical analysis and computer simulation we find that there is no such single threshold. Instead we propose a modified criterion which coincides with critical F...

  14. The optimal industry structure in a vertically related market

    OpenAIRE

    Fiocco, Raffaele

    2010-01-01

    We consider a vertically related market characterized by down- stream imperfect competition and by the monopolistic provision of an essential facility-based input, whose price is set by a social-welfare maximizing regulator. Our model shows that the regulatory knowl- edge about the cost for providing the monopolistic input crucially af- fects the design of the optimal industry structure. In particular, we compare ownership separation, which prevents a single company from having the control of...

  15. Numerical study of vertical pneumatic conveying: Effect of friction coefficient

    Science.gov (United States)

    Li, K.; Kuang, S. B.; Zou, R. P.; Pan, R. H.; Yu, A. B.

    2013-06-01

    This paper presents a numerical study of vertical pneumatic conveying by a combined approach of computational fluid dynamics for gas phase and discrete element method for solid phase. The effects of friction coefficient on the flows in regard with particle flow patterns and their transition, reverse flow, and gas pressure behavior are qualified. The forces acting on particles are analyzed in detail to understand the underlying mechanisms.

  16. Infrared vertically-illuminated photodiode for chip alignment feedback

    CERN Document Server

    Alloatti, Luca

    2016-01-01

    We report on vertically-illuminated photodiodes fabricated in the GlobalFoundries 45nm 12SOI node and on a packaging concept for optically-interconnected chips. The photodiodes are responsive at 1180 nm, a wavelength currently used in chip-to-chip communications. They have further a wide field-of-view which enables chip-to-board positional feedback in chip-board assemblies. Monolithic integration enables on-chip processing of the positional data.

  17. Vertical transport in graphene-hexagonal boron nitride heterostructure devices

    OpenAIRE

    Samantha Bruzzone; Demetrio Logoteta; Gianluca Fiori; Giuseppe Iannaccone

    2015-01-01

    Research in graphene-based electronics is recently focusing on devices based on vertical heterostructures of two-dimensional materials. Here we use density functional theory and multiscale simulations to investigate the tunneling properties of single- and double-barrier structures with graphene and few-layer hexagonal boron nitride (h-BN) or hexagonal boron carbon nitride (h-BC2N). We find that tunneling through a single barrier exhibit a weak dependence on energy. We also show that in double...

  18. Single Mode Photonic Crystal Vertical Cavity Surface Emitting Lasers

    Directory of Open Access Journals (Sweden)

    Kent D. Choquette

    2012-01-01

    Full Text Available We review the design, fabrication, and performance of photonic crystal vertical cavity surface emitting lasers (VCSELs. Using a periodic pattern of etched holes in the top facet of the VCSEL, the optical cavity can be designed to support the fundamental mode only. The electrical confinement is independently defined by proton implantation or oxide confinement. By control of the refractive index and loss created by the photonic crystal, operation in the Gaussian mode can be insured, independent of the lasing wavelength.

  19. A note on horizontal mergers in vertically related industries

    OpenAIRE

    Marie-Laure Allain; Saïd Souam

    2011-01-01

    We analyze horizontal mergers in vertically related industries. In a successive Cournot oligopoly model, we first compare the profitability of mergers in the upstream and in the downstream sectors. We characterize conditions on the concavities of the input supply function and the final demand function such that, ceteris paribus, an upstream merger is more protable than a downstream merger. We then provide a simple comparison of the relative losses of firms in an industry induced by a merger i...

  20. Horizontal concentration and vertical relationships / Concentration horizontale et relations verticales

    OpenAIRE

    Allain, Marie-Laure; Souam, Saïd

    2006-01-01

    This paper studies horizontal mergers in vertically related markets. In a two-level Cournot model, with an intermediate and a final market, we show that downstream mergers inducing size effects are, ceteris paribus, more profitable than upstream ones. Moreover, a merger at one level reduces the incentives to merge at the other level. Endogenizing the firms' decisions to merge by considering a merger game supports the previous results.