Science.gov

Sample records for modelo simple para

  1. Difusión de Arnold en un modelo simple

    NASA Astrophysics Data System (ADS)

    Cincotta, P. M.; Nuñez, J. A.; Miloni, O.

    Investigadores como Merritt, Valluri, Pfenniger o Contopoulos (por citar los más relevantes) consideran seriamente la hipótesis que la difusión de Arnold juega un rol importante en la evolución dinámica de los sistemas estelares y planetarios. Sin embargo no existe ninguna evidencia. El mayor problema para investigar fenómenos como éste es que uno debe estudiar numéricamente sistemas multidimensionales (más de dos grados de libertad) y visualizar de alguna manera el espacio de fases (más de cuatro dimensiones). Más complicado aún es el caso de difusión de Arnold, donde deben considerarse tiempos de movimiento extremadamente largos y tratar con parámetros exponencialmente pequeños. El propósito de este trabajo es estudiar, en un modelo simple 3D, la existencia o no de difusión de Arnold mediante experimentos numéricos y estimaciones analíticas. Siguiendo los trabajos de Cincotta (2000) y Cincotta, Nuñez y Simo (2000), aquí se pretende ``visualizar" la difusión y, a la vez, determinar la escala de tiempo en la que ésta se podría manifestar. Este trabajo es el escalón inicial para luego abordar este problema en modelos.

  2. Comparação de modelos para o cálculo de perturbações orbitais devidas à maré terrestre

    NASA Astrophysics Data System (ADS)

    Vieira Pinto, J.; Vilhena de Moraes, R.

    2003-08-01

    Aplicações recentes de satélites artificiais com finalidades geodinâmicas requerem órbitas determinadas com bastante precisão. Em particular marés terrestres influenciam o potencial terrestre causando perturbações adicionais no movimento de satélites artificiais, as quais tem sido medidas por diversos processos. A atração exercida pela lua e pelo sol sobre a terra produz deslocamentos elásticos em seu interior e uma protuberância em sua superfície. O resultado é uma pequena variação na distribuição da massa na terra, consequentemente no geopotencial. As perturbações nos elementos orbitais de satélites artificiais terrestres devidas a maré terrestre podem ser estudadas a partir das equações de Lagrange, considerando-se um conveniente potencial. Por outro lado, como tem sido feito pelo IERS, as mudanças induzidas pela maré terrestre no geopotencial podem ser convenientemente modeladas como variações nos coeficientes Cnm e Snm do geopotencial. As duas teorias ainda não foram comparados para um mesmo satélite. Neste trabalho são apresentadas e comparadas as variações de longo período e seculares nas perturbações orbitais devidas à maré terrestre, calculadas por um modelo simples, o de Kozai, e pelo modelo do IERS. Resultados preliminares mostram, para os satélites SCD2 e CBERS1, e para a Lua em movimento elíptico e precessionando, as perturbações seculares no argumento do perigeu e na longitude do nodo ascendente.

  3. Descripción de la zona de alta difusión en un modelo bidimensional para hojas de corriente

    NASA Astrophysics Data System (ADS)

    Montero, M. F.; Paola, C. A.; Platzeck, A. M.

    Los modelos bidimensionales para describir hojas de corriente de alta simetría no suministran una descripción detallada de las regiones donde la difusión es considerablemente importante. Tal es el caso de los modelos desarrollados en la década del '60 por Sweet, Parker, Petschek y Sonnerup. En esta comunicación presentamos una solución de las ecuaciones MHD en el entorno del origen, construyendo series bidimensionales para todas las magnitudes físicas involucradas. Valiéndonos de la alta simetría y de las características del problema, logramos reducir el número de coeficientes a calcular. Utilizamos un programa autoconsistente para extender el cálculo a regiones vecinas con difusión moderada o despreciable.

  4. Análise da aplicação e dos resultados do modelo OPM3® para a área da saúde

    PubMed Central

    Augusto dos Santos, Luis; de Fátima Marin, Heimar

    2015-01-01

    Esta pesquisa procurou analisar se um modelo de questionário criado por uma comunidade internacional de gerenciamento de projetos e se é aplicavél a organizações voltadas a área de saúde. O modelo OPM3® (Organizational Project Management Maturity Model) foi criado para que organizações de qualquer área ou porte pudessem identificar a presença, ou ausência, de boas práticas de gerenciamento. O objetivo da aplicação desse modelo é avaliar sempre a organização e não o entrevistado. No presente artigo, são apresentados os resultados da aplicação desse modelo em uma organização que possuía produtos e serviços de tecnologia da informação aplicados à área de saúde. Este estudo verificou que o modelo é aplicável de forma rápida e que a organização analisada possuía um número expressivo de boas práticas. PMID:26924862

  5. Uso de modelos mecânicos em curso informal de astronomia para deficientes visuais. Resgate de uma experiência

    NASA Astrophysics Data System (ADS)

    Tavares, E. T., Jr.; Klafke, J. C.

    2003-08-01

    O presente trabalho propõe-se a resgatar uma experiência que teve lugar no Planetário de São Paulo nos anos 60. Em 1962, o Sr. Acácio, então com 37 anos, deficiente visual desde os 27, passou a assistir às aulas ministradas pelo Prof. Aristóteles Orsini aos integrantes do corpo de servidores do Planetário. O Sr. Acácio era o único deficiente da turma e, embora possuísse conhecimentos básicos e relativamente avançados de matemática, enfrentava dificuldades na compreensão e acompanhamento da exposição, como também em estudos posteriores. Com o intuito de auxiliá-lo na superação desses problemas, o Prof. Orsini solicitou a construção de modelos mecânicos que, através do sentido do tato, permitissem o acompanhamento das aulas e a transposição do modelo para o "constructo" mental. Essa prática mostrou-se tão eficaz que facilitou sobejamente o aprendizado da matéria pelo sujeito. O Sr. Acácio passou a integrar o corpo de professores do Planetário/Escola Municipal de Astrofísica, tendo ficado responsável pelo curso de "Introdução à Astronomia" por vários anos. Além disso, a experiência foi tão bem sucedida que alguns dos modelos tiveram seus elementos constitutivos pintados diferencialmente para serem utilizados em cursos regulares do Planetário, tornando-se parte integrante do conjunto de recursos didáticos da instituição. É pensando nessa eficácia, tanto em seu objetivo original permitir o aprendizado de um deficiente visual quanto no subsidiário recurso didático sistemático da instituição que decidimos resgatar essa experiência. Estribados nela, acreditamos ser extremamente produtivo, em termos educacionais, o aperfeiçoamento dos modelos originais, agora resgatados e restaurados, e a criação de outros que pudessem ser utilizados no ensino dessa ciência a deficientes visuais.

  6. Modelo de accesibilidad de conceptos matematicos aplicados en el curso de Astronomia Descriptiva para estudiantes con impedimentos visuales en la UPR

    NASA Astrophysics Data System (ADS)

    Isidro Villamizar, Gloria Maria

    Este estudio utiliza metodologia de investigacion cualitativa, con el proposito de describir, analizar y evaluar los procesos de diseno y desarrollo de un modelo de accesibilidad que consiste en estrategias de ensenanza de las matematicas para estudiantes con impedimentos visuales matriculados en el curso de Astronomia Descriptiva en la UPR. Se utilizaron las siguientes estrategias para recopilar la informacion, 1) reflexiones de la investigadora en el proceso de diseno y desarrollo de las lecciones adaptadas, que se registraron en un diario reflexivo. 2) entrevista semiestructurada luego de haber trabajado las lecciones de aprendizaje adaptadas con los participantes. 3) observaciones y notas de la investigadora del trabajo de los participantes. Para obtener la informacion de los participantes se obtuvo los permisos institucionales necesarios; se seleccionaron los participantes y se validaron los instrumentos; se realizo el desarrollo de las lecciones adaptadas con los participantes; y finalmente, se analizo la informacion obtenida. El diseno de las lecciones de aprendizaje adaptadas se hizo siguiendo las recomendaciones curriculares de los temas de matematicas aplicados en el curso de Astronomia Descriptiva realizado por la investigadora durante su semestre de internado. El testimonio de las voces de los participantes se obtuvo del proceso de desarrollo de las lecciones de aprendizaje adaptadas de temas seleccionados de conceptos matematicos requeridos en el curso de Astronomia Descriptiva y de la entrevista semiestructurada con los participantes, luego de haber trabajado las lecciones de aprendizaje. Para el desarrollo de las lecciones de aprendizaje, se utilizaron materiales tactiles adaptados, materiales tactiles disenados y materiales disponibles comercialmente. Los textos de las lecciones se imprimieron en tinta y en Braille. Se exhorta a disenar y desarrollar estrategias de ensenanza accesibles, considerando como recursos para evaluar su efectividad a

  7. Application of Three-Dimensional Models for the Teaching of Time Zones. (Breton Title: Aplicação de Modelos Tridimensionais Para o Ensino de Fusos Horários.) Aplicación de Modelos Tridimensionales Para la Enseñanza de Husos Horarios

    NASA Astrophysics Data System (ADS)

    Azevedo Sobreira, Paulo Henrique

    2012-07-01

    There are several interesting astronomical topics that must be addressed in the High School and Elementary/Middle School in the disciplines of Geography and of Sciences. Among them, the topic of time zones which is one of the most important to understand the correlation of the Earth's rotation and its implications on daily activities of citizens in local scale, regional and global scales which involve problems of time differences. For the teaching of time zones in the lessons of Geography, for example, there are bi-dimensional representations of thematic maps of world time zones, textbooks and atlas. It happens that teachers face some difficulties to permit its students to view three-dimensionally this astronomical phenomenon from the textbooks available in schools. The aim of this paper is to present two proposals with low-cost materials, which allow the preparation of three-dimensional models for the teaching of time zones. Há vários temas astronômicos interessantes que devem ser trabalhados nos Ensinos Médio e Fundamental, nas disciplinas de Geografia e de Ciências. Entre eles, o tema dos fusos horários que é um dos mais importantes para se correlacionar a rotação da Terra e suas implicações nas atividades cotidianas dos cidadãos em escala local, regional e global, que envolvem problemas de diferenças horárias. Para o ensino dos fusos horários nas aulas de Geografia, por exemplo, há representações bidimensionais de mapas temáticos de fusos horários mundiais, nos livros didáticos e nos atlas. Ocorre que os professores enfrentam algumas dificuldades para possibilitar aos seus alunos a visão tridimensional deste fenômeno astronômico, a partir dos materiais didáticos disponíveis nas escolas. O objetivo deste trabalho é apresentar duas propostas para a confecção de materiais de baixo custo, que possibilitem a elaboração de modelos tridimensionais para o ensino dos fusos horários. Hay algunos temas astronómicos interesantes que se

  8. Simple ortho- and para-hydroquinones as compounds neuroprotective against oxidative stress in a manner associated with specific transcriptional activation

    SciTech Connect

    Satoh, Takumi Saitoh, Sachie; Hosaka, Manami; Kosaka, Kunio

    2009-02-06

    Electrophilic compounds protect neurons through the activation of the Keap1/Nrf2 pathway and the induction of phase-2 enzymes [T. Satoh, S.A. Lipton, Redox regulation of neuronal survival by electrophilic compounds, Trends Neurosci. 30 (2007) 38-45; T. Satoh, S. Okamoto, J. Cui, Y. Watanabe, K. Furuta, M. Suzuki, K. Tohyama, S.A. Lipton, Activation of the Keap1/Nrf2 pathway for neuroprotection by electrophilic phase II inducers. Proc. Natl. Acad. Sci. USA 103 (2006) 768-773]. Hydroquinone-type electrophilic compounds such as tert-butyl hydroquinone (TBHQ) and carnosic acid (CA) have attracted special attention, because the oxidative conversion of 'hydroquinone' to 'quinone' is essential for the transcriptional activation of the above-mentioned enzymes [T. Satoh, K. Kosaka, K. Itoh, A. Kobayashi, M. Yamamoto, Y. Shimojo, C. Kitajima, J. Cui, J. Kamins, S. Okamoto, T. Shirasawa, S.A. Lipton, Carnosic acid, a catechol-type electrophilic compound, protect neurons both in vitro and in vivo through activation of the Keap1/Nrf2 pathway via S-alkylation of specific cysteine, J. Neurochem. 104 (2008) 1161-1131; A.D. Kraft, D.A. Johnson, J.A. Johnson, Nuclear factor E2-related factor 2-dependent antioxidant response element activation by tert-butylhydroquinone and sulforaphane occurring preferentially in astrocytes conditions neurons against oxidative insult, J. Neurosci. 24 (2004) 1101-1112]. In the present study, we examined the relationship between electrophilicity and the protective effects afforded by electrophilic compounds. Electrophilicity was assessed in terms of the ability of a compound to bind to a cysteine on bovine serum albumin, by which we found that neuroprotective hydroquinones [TBHQ (para-) and CA (ortho-)] had distinctive patterns of cysteine binding compared with other electrophilic compounds. Further, we found that isomers of simple ortho- and para-hydroquinones such as 2-methylhydroquinone (para-) and 4-methyl-catechol (ortho-) [not in abstract] had

  9. Simple Machines Made Simple.

    ERIC Educational Resources Information Center

    St. Andre, Ralph E.

    Simple machines have become a lost point of study in elementary schools as teachers continue to have more material to cover. This manual provides hands-on, cooperative learning activities for grades three through eight concerning the six simple machines: wheel and axle, inclined plane, screw, pulley, wedge, and lever. Most activities can be…

  10. Estabilidad de los modelos de Heggie y Ramamani

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.; Vergne, M. M.; Wachlin, F. C.; Carpintero, D. D.

    Los modelos de Heggie y Ramamani de satélites galácticos en órbitas circulares se basan en una teoría aproximada, por lo que es importante verificar su estabilidad mediante simulaciones numéricas. En esta forma, hemos logrado mostrar que son estables sobre intervalos de tiempo mucho mayores que los que lograron los propios autores de los modelos. Por otra parte, dado que hemos mostrado que el caos es significativo en estos modelos, son un sistema ideal para investigar si, pese a ello, se mantienen estacionarios. Nuestras simulaciones numéricas muestran que, pese al caos, la estacionariedad se mantiene sobre intervalos de centenares de tiempos de cruce del sistema, mucho mayores que los tiempos de Liapunov característicos de sus movimientos caóticos.

  11. Adapting a Common Photographic Camera to Take Pictures of the Sky. (Spanish Title: Adaptando Una Camara Fotografica Comun Para Obtener Fotografias del Cielo.) Adaptando Uma Câmera Fotográfica Manual Simples Para Fotografar o Céu

    NASA Astrophysics Data System (ADS)

    Danhoni Neves, Marcos Cesar; Pereira, Ricardo Francisco

    2007-12-01

    In this paper will be introduced a method of astrophotography using a non-reflex photographic camera (a low-cost method). It will be revised some photographic processes commonly used nowadays for comparison with the aims of this paper. En este trabajo será introducido un método de astrofotografia que utiliza una cámara fotográfica non-reflex (un método de bajo costo). Serán revisados algunos procesos fotográficos comúnmente utilizados actualmente para comparación con los objetivos de este trabajo. O presente artigo procura introduzir um método de astrofotografia utilizando uma câmera fotográfica não reflex, de baixo custo. É feita uma revisão do processo fotográfico comumente empregado para fins de comparação com os objetivos pretendidos no presente trabalho.

  12. La Enseñanza/Aprendizaje del Modelo Sol-Tierra Análisis de la Situación Actual y Propuesta de Mejora Para la Formación de los Futuros Profesores de Primaria

    NASA Astrophysics Data System (ADS)

    Martínez Sebastià, Bernat

    2004-12-01

    This work is an extened summary of the autor's PhD thesis. It deals with the teaching of astronomy (day/night, seasons) in primary school. At first, students teachers' undestanding of astronomical concepts related to Sun-Earth system have been analysed. Taking into account the results of the previous analysis and using a socio-constructivist approach a teaching sequence has been designed. This sequence has been tested with different groups of students teachers showing an improvement in their undestanding of elementary astronomical concepts. El trabajo que presentamos es un resumen extenso de la tesis doctoral del autor. El enfoque utilizado ha sido tratar de ligar la investigación sobre las ideas, razonamientos y obstáculos de los profesores de primaria con la planificación de la enseñanza del modelo Sol-Tierra que permite explicar el ciclo día/noche y las estaciones. En primer lugar, se ha procedido a realizar un análisis crítico de los resultados que se obtienen en el aprendizaje de los contenidos astronómicos en la enseñanza habitual. En segundo lugar se ha diseñado un curriculum potencialmente superador de esta situación desde una orientación que concibe la enseñanza y el aprendizaje como un proceso de construcción de conocimientos en una estructura problematizada. Finalmente, esta secuencia didáctica ha sido experimentada con diferentes grupos de estudiantes de magisterio, mostrando una mejora relevante en la comprensión de los conceptos astronómicos fundamentales.

  13. Highly selective and sensitive simple sensor based on electrochemically treated nano polypyrrole-sodium dodecyl sulphate film for the detection of para-nitrophenol.

    PubMed

    Arulraj, Abraham Daniel; Vijayan, Muthunanthevar; Vasantha, Vairathevar Sivasamy

    2015-10-29

    An ultrasensitive and highly selective electrochemical sensor for the determination of p-nitrophenol (p-NP) was developed based on electrochemically treated nano polypyrrole/sodium dodecyl sulphate film (ENPPy/SDS film) modified glassy carbon electrode. The nano polypyrrole/sodium dodecyl sulphate film (NPPy/SDS film) was prepared and treated electrochemically in phosphate buffer solution. The surface morphology and elemental analysis of treated and untreated NPPy/SDS film were characterized by FESEM and EDX analysis, respectively. Wettability of polymer films were analysed by contact angle test. The hydrophilic nature of the polymer film decreased after electrochemical treatment. Effect of the pH of electrolyte and thickness of the ENPPy/SDS film on determination of p-NP was optimised by cyclic voltammetry. Under the optimised conditions, the p-NP was determined from the oxidation peak of p-hydroxyaminophenol which was formed from the reduction of p-NP in the reduction segment of cyclic voltammetry. A very good linear detection range (from 0.1 nM to 100 μM) and the best LOD (0.1 nM) were obtained for p-NP with very good selectivity. This detection limit is below to the allowed limit in drinking water, 0.43 μM, proposed by the U.S. Environmental Protection Agency (EPA) and earlier reports. Moreover, ENPPy/SDS film based sensor exhibits high sensitivity (4.4546 μA μM(-1)) to p-NP. Experimental results show that it is a fast and simple sensor for p-NP. PMID:26547494

  14. Espectro de radiación derivado de un modelo de colapso protoestelar

    NASA Astrophysics Data System (ADS)

    Coca, S.; Rohrmann, R.

    El exceso de emisión infrarroja en objetos protoestelares es atribuido usualmente a un disco de material en torno al cuerpo central. A pesar del avance alcanzado en la elaboración de modelos, aún existen dificultades para explicar la ley de temperatura del disco necesaria para reproducir las luminosidades y perfiles de energía observados. Nuestra propuesta consiste en determinar la distribución espectral de la radiación derivada de un particular modelo de colapso protoestelar, y estudiar la evolución del espectro desde estadíos tempranos de la contracción gravitatoria. Este plan es orientado a evaluar las propiedades del modelo (distribuciones de masa y temperatura del material circunestelar) por comparación con datos observacionales, a fin de inferir de ello los posibles ajustes requeridos en la teoría actualmente empleada.

  15. The Model of Optimization of Micro Energy; HOMER: El Modelo de Optimizacin de Micro energa

    SciTech Connect

    Not Available

    2004-05-01

    HOMER, the model of optimization of micro energy, helps to disear systems out of the network and interconnected to the network. You can use HOMER to carry out the analysis to explore an extensive rank of questions of diseo. HOMER, el modelo de optimizacin de micro energa, le ayuda a disear sistemas fuera de la red e interconectados a la red. Usted puede usar HOMER para llevar a cabo el anlisis para explorar un amplio rango de preguntas de diseo.

  16. Discos de acreción circumplanares: Modelo de Co-acreción

    NASA Astrophysics Data System (ADS)

    Parisi, M. G.; de Elía, G.

    Los discos de acreción circumplanetarios precursores de los satélites regulares de los planetas gigantes, se pueden formar por cuatro mecanismos (Pollack y otros, 1991, In Uranus, Bergtralh, Miner y Mattews, Eds., p. 469, Univ. de Arizona Press, Tucson). En este trabajo estudiamos uno de tales mecanismos: el Modelo de Co-acreción. En dicho modelo, el disco circumplanetario se forma a partir de las colisiones mutuas entre planetesimales dentro de la esfera de Hill del planeta durante el proceso de formación planetaria. Realizamos un modelo semi-analítico para calcular la masa del disco y compararla con la masa requerida para formar los satélites regulares de los planetas gigantes. Hemos obtenido una cota superior para la masa del disco que resulta inferior a la masa de los satélites más grandes de los planetas gigantes. En principio, estos resultados permitirían descartar el modelo de co-acreción como uno de los procesos que podrían dar lugar a la formación de los satélites regulares. Estos resultados permiten obtener restricciones en el escenario de formación planetaria y en los mecanismos de formación de sistemas de satélites.

  17. MOBRAL: Un Modelo para la Educacion de Adultos?

    ERIC Educational Resources Information Center

    Convergence, 1974

    1974-01-01

    Written in Spanish, the article explains that expanding an adult basic education program, the Brazilian Literacy Movement (MOBRAL), necessitates considering the social orientation of MOBRAL in the context of Brazil and of Latin America as a whole. (AG)

  18. Modelo analítico del efecto de PRS sobre satélites GPS

    NASA Astrophysics Data System (ADS)

    Meza, A.; Brunini, C.; Usandivaras, J. C.

    El sistema GPS (Global Position System) es, hoy en día, la herramienta de navegación y posicionamiento más potente y lo será sin duda en la próxima década. Gran parte de su valiosa utilidad se debe a la alta precisión que permite lograr y ésta, a su vez, depende, entre otras causas, de la precisión con que se conocen las órbitas de los satélites. La presión de radiación solar (PRS) fija el límite de la precisión con que pueden calcularse en la actualidad las efemérides satelitarias. El objetivo de este trabajo es proponer una mejor resolución de este fenómeno. El modelo analítico aquí presentado, se basa en el análisis del comportamiento de los residuos de un ajuste por mínimos cuadrados en el que se utiliza el modelo de PRS propuesto por Beutler. El mismo consiste en un modelo determinista del fenómeno con dos parámetros libres. Los resultados obtenidos ponen de manifiesto que, aún después de aplicar dichos parámetros, prevalecen en los residuos efectos semidiurnos en las componentes radial,tangencial y normal. Estos resultados obtenidos se comparan con los de un trabajo desarrollado por el Instituto de Berne (Beutler et al., 1994), en el que se utilizaron como pseudo-observaciones las órbitas precisas del IGS (CODE). El intervalo de integración escogido por este centro fueron las semanas 680 y 681. En resumen se tienen arcos de 14 días para todos los satélites, donde las efemérides precisas de los mismos para los 14 días fueron utilizados como pseudo-observaciones. El modelo de fuerza que empleó dicho centro fue básicamente el tradicional en lo que respecta al modelo de las fuerzas gravitacionales, y para la PRS utilizo el modelo standard de Beutler. Los parámetros de este modelo junto con las 6 condiciones iniciales (posición y velocidad) fueron ajustados por el método general de mínimos cuadrados. Los residuos en la componente radial, tangencial y normal, para los satélites con un buen comportamiento, presentan una

  19. Simple Kidney Cysts

    MedlinePlus

    ... Organizations​​ . (PDF, 345 KB)​​​​​ Alternate Language URL Simple Kidney Cysts Page Content On this page: What are simple ... Points to Remember Clinical Trials What are simple kidney cysts? Simple kidney cysts are abnormal, fluid-filled sacs ...

  20. SIMPLE: An Introduction.

    ERIC Educational Resources Information Center

    Endres, Frank L.

    Symbolic Interactive Matrix Processing Language (SIMPLE) is a conversational matrix-oriented source language suited to a batch or a time-sharing environment. The two modes of operation of SIMPLE are conversational mode and programing mode. This program uses a TAURUS time-sharing system and cathode ray terminals or teletypes. SIMPLE performs all…

  1. Simple pulmonary eosinophilia

    MedlinePlus

    Pulmonary infiltrates with eosinophilia; Loffler syndrome; Eosinophilic pneumonia; Pneumonia - eosinophilic ... simple pulmonary eosinophilia is a severe type of pneumonia called acute idiopathic eosinophilic pneumonia.

  2. Laparoscopic simple prostatectomy.

    PubMed

    Blew, Brian D M; Fazio, Luke M; Pace, Kenneth; D'A Honey, R John

    2005-12-01

    Classically, surgical options for very large prostate glands, not amenable to transurethral resection, include suprapubic or retropubic simple prostatectomy and Holmium laser enucleation of the prostate (HoLEP). We present a case managed with a laparoscopic simple prostatectomy. Technical considerations are discussed as well as possible advantages of this approach including decreased blood loss, faster patient recovery and improved visualization. PMID:16401375

  3. Simple Machine Junk Cars

    ERIC Educational Resources Information Center

    Herald, Christine

    2010-01-01

    During the month of May, the author's eighth-grade physical science students study the six simple machines through hands-on activities, reading assignments, videos, and notes. At the end of the month, they can easily identify the six types of simple machine: inclined plane, wheel and axle, pulley, screw, wedge, and lever. To conclude this unit,…

  4. A Simple "Tubeless" Telescope

    ERIC Educational Resources Information Center

    Straulino, S.; Bonechi, L.

    2010-01-01

    Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument,…

  5. Concepciones Alternativas de "Fotosintesis" en estudiantes Universitarios del curso basico de Biologia y posibles correcciones con el Modelo Educativo MODEF

    NASA Astrophysics Data System (ADS)

    De Jesus Roman, Sandra

    Concepciones Alternativas de Fotosíntesis en estudiantes Universitariosdel curso básico de Biología y posibles correcciones con el Modelo Educativo MODEF El modelo educativo para la enseñanza de Fotosíntesis (MODEF) se implantó para trabajar el problema de las concepciones alternativas (CA) en un curso de Biología General. Se evaluaron los resultados en cuanto al logro del aprendizaje significativo. La pregunta central de la investigación fue: ¿Cómo aporta el modelo educativo en la didáctica y comprensión del tema de fotosíntesis? Se efectuó una investigación acción con una fase cuantitativa y una cualitativa. Para la fase cuantitativa se elaboró una prueba para determinar las concepciones alternativas, se validó y se sometió a los estudiantes que participaron en el estudio antes y después de ofrecer la unidad de metabolismo celular. Los participantes eran estudiantes de primer año de la Universidad de Puerto Rico en Bayamón (UPRB). Se llevó a cabo un análisis de consistencia interna de la prueba mediante el método Alfa de Cronbach. Se analizaron las contestaciones a cada pregunta mediante la prueba de Ji cuadrado de contingencia, se efectuó la prueba de t y el coeficiente r de Pearson. La fase cualitativa incluyó la observación participativa de la investigadora- profesora, las reflexiones de los estudiantes y la información de las entrevistas semi-estructuradas que se realizaron a tres estudiantes del curso. El análisis se llevó a cabo mediante el Modelo de Wolcott. Se trabajaron diez CA de las cuales siete fueron corregidas mediante el Modelo MODEF. Las actividades más importantes para el proceso de aprendizaje incluyeron el trabajo de investigación o búsqueda de información para hacer una presentación digital, la elaboración de tablas, los mapas de conceptos, el uso de visuales o videos y las analogías para explicar conceptos o procesos. En conclusión: se recomienda el uso del Modelo MODEF para la discusión del tema de

  6. Simple Bond Cleavage

    SciTech Connect

    Gary S. Groenewold

    2005-08-01

    Simple bond cleavage is a class of fragmentation reactions in which a single bond is broken, without formation of new bonds between previously unconnected atoms. Because no bond making is involved, simple bond cleavages are endothermic, and activation energies are generally higher than for rearrangement eliminations. The rate of simple bond cleavage reactions is a strong function of the internal energy of the molecular ion, which reflects a loose transition state that resembles reaction products, and has a high density of accessible states. For this reason, simple bond cleavages tend to dominate fragmentation reactions for highly energized molecular ions. Simple bond cleavages have negligible reverse activation energy, and hence they are used as valuable probes of ion thermochemistry, since the energy dependence of the reactions can be related to the bond energy. In organic mass spectrometry, simple bond cleavages of odd electron ions can be either homolytic or heterolytic, depending on whether the fragmentation is driven by the radical site or the charge site. Simple bond cleavages of even electron ions tend to be heterolytic, producing even electron product ions and neutrals.

  7. How simple are 'simple renal cysts'?

    PubMed

    Simms, Roslyn J; Ong, Albert C M

    2014-09-01

    The increasing use of medical imaging as an investigative tool is leading to the incidental and frequent finding of renal cysts in the general population. The presence of a solitary or multiple renal cysts has been generally considered benign in the absence of a family history of renal cystic disease or evidence of chronic kidney disease. Nonetheless, a number of recent studies have questioned this consensus by reported associations with the development of hypertension or malignant change. For these reasons, some clinicians consider the presence of renal cysts to be a contraindication to kidney donation. The situation is complicated by the different usage of the term 'simple' by some radiologists (to indicate non-complex lesions) or nephrologists (to indicate age-related non-hereditary lesions). We propose that the term 'simple' be replaced with the morphological description, Stage I renal cyst (Bosniak Classification). The presence of a Stage I renal cyst should not preclude kidney donation. However, occult renal disease should be excluded and appropriate donor assessment performed. PMID:25165175

  8. Early Childhood: Simple Science.

    ERIC Educational Resources Information Center

    Jones, Clare B.; Shafer, Kathryn E.

    1987-01-01

    Encourages teachers to take advantage of the natural curiosity of young children in enhancing their interest in science. Describes four simple activities involving water, living and non-living things, air pollution, and food. (TW)

  9. A Simple Water Channel

    ERIC Educational Resources Information Center

    White, A. S.

    1976-01-01

    Describes a simple water channel, for use with an overhead projector. It is run from a water tap and may be used for flow visualization experiments, including the effect of streamlining and elementary building aerodynamics. (MLH)

  10. Simple Machines Simply Put.

    ERIC Educational Resources Information Center

    Kirkwood, James J.

    1994-01-01

    Students explore the workings of the lever, wheel and axle, and the inclined plane as they build simple toys--a bulldozer and a road grader. The project takes four weeks. Diagrams and procedures are included. (PR)

  11. A Simple Raman Spectrometer.

    ERIC Educational Resources Information Center

    Blond, J. P.; Boggett, D. M.

    1980-01-01

    Discusses some basic physical ideas about light scattering and describes a simple Raman spectrometer, a single prism monochromator and a multiplier detector. This discussion is intended for British undergraduate physics students. (HM)

  12. Simple Ontology Format (SOFT)

    SciTech Connect

    Sorokine, Alexandre

    2011-10-01

    Simple Ontology Format (SOFT) library and file format specification provides a set of simple tools for developing and maintaining ontologies. The library, implemented as a perl module, supports parsing and verification of the files in SOFt format, operations with ontologies (adding, removing, or filtering of entities), and converting of ontologies into other formats. SOFT allows users to quickly create ontologies using only a basic text editor, verify it, and portray it in a graph layout system using customized styles.

  13. Strategy as simple rules.

    PubMed

    Eisenhardt, K M; Sull, D N

    2001-01-01

    The success of Yahoo!, eBay, Enron, and other companies that have become adept at morphing to meet the demands of changing markets can't be explained using traditional thinking about competitive strategy. These companies have succeeded by pursuing constantly evolving strategies in market spaces that were considered unattractive according to traditional measures. In this article--the third in an HBR series by Kathleen Eisenhardt and Donald Sull on strategy in the new economy--the authors ask, what are the sources of competitive advantage in high-velocity markets? The secret, they say, is strategy as simple rules. The companies know that the greatest opportunities for competitive advantage lie in market confusion, but they recognize the need for a few crucial strategic processes and a few simple rules. In traditional strategy, advantage comes from exploiting resources or stable market positions. In strategy as simple rules, advantage comes from successfully seizing fleeting opportunities. Key strategic processes, such as product innovation, partnering, or spinout creation, place the company where the flow of opportunities is greatest. Simple rules then provide the guidelines within which managers can pursue such opportunities. Simple rules, which grow out of experience, fall into five broad categories: how- to rules, boundary conditions, priority rules, timing rules, and exit rules. Companies with simple-rules strategies must follow the rules religiously and avoid the temptation to change them too frequently. A consistent strategy helps managers sort through opportunities and gain short-term advantage by exploiting the attractive ones. In stable markets, managers rely on complicated strategies built on detailed predictions of the future. But when business is complicated, strategy should be simple. PMID:11189455

  14. Simple Ontology Format (SOFT)

    Energy Science and Technology Software Center (ESTSC)

    2011-10-01

    Simple Ontology Format (SOFT) library and file format specification provides a set of simple tools for developing and maintaining ontologies. The library, implemented as a perl module, supports parsing and verification of the files in SOFt format, operations with ontologies (adding, removing, or filtering of entities), and converting of ontologies into other formats. SOFT allows users to quickly create ontologies using only a basic text editor, verify it, and portray it in a graph layoutmore » system using customized styles.« less

  15. A Simple Hydrogen Electrode

    ERIC Educational Resources Information Center

    Eggen, Per-Odd

    2009-01-01

    This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

  16. Entropy Is Simple, Qualitatively.

    ERIC Educational Resources Information Center

    Lambert, Frank L.

    2002-01-01

    Suggests that qualitatively, entropy is simple. Entropy increase from a macro viewpoint is a measure of the dispersal of energy from localized to spread out at a temperature T. Fundamentally based on statistical and quantum mechanics, this approach is superior to the non-fundamental "disorder" as a descriptor of entropy change. (MM)

  17. A Simple Wave Driver

    ERIC Educational Resources Information Center

    Temiz, Burak Kagan; Yavuz, Ahmet

    2015-01-01

    This study was done to develop a simple and inexpensive wave driver that can be used in experiments on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be used to produce string waves at a fixed frequency. The working principle of the apparatus is as follows: shortly after the car is turned on, the…

  18. Simple Library Bookkeeping.

    ERIC Educational Resources Information Center

    Hoffman, Herbert H.

    A simple and cheap manual double entry continuous transaction posting system with running balances is developed for bookkeeping by small libraries. A very small library may operate without any system of fiscal control but when a library's budget approaches three figures, some kind of bookkeeping must be introduced. To maintain control over his…

  19. Climate Change Made Simple

    ERIC Educational Resources Information Center

    Shallcross, Dudley E.; Harrison, Tim G.

    2007-01-01

    The newly revised specifications for GCSE science involve greater consideration of climate change. This topic appears in either the chemistry or biology section, depending on the examination board, and is a good example of "How Science Works." It is therefore timely that students are given an opportunity to conduct some simple climate modelling.…

  20. On Simple Science.

    ERIC Educational Resources Information Center

    Cole, K.C.

    1982-01-01

    Discusses San Francisco's Exploratorium, a science teaching center with 500 exhibits focusing on human perception, but extending to everything from the mechanics of voice to the art of illusion, from holograms to harmonics. The Exploratorium emphasizes "simple science" (refractions/resonances, sounds/shadows) to tune in the senses and turn on the…

  1. Simple Lookup Service

    Energy Science and Technology Software Center (ESTSC)

    2013-05-01

    Simple Lookup Service (sLS) is a REST/JSON based lookup service that allows users to publish information in the form of key-value pairs and search for the published information. The lookup service supports both pull and push model. This software can be used to create a distributed architecture/cloud.

  2. Working with Simple Machines

    ERIC Educational Resources Information Center

    Norbury, John W.

    2006-01-01

    A set of examples is provided that illustrate the use of work as applied to simple machines. The ramp, pulley, lever and hydraulic press are common experiences in the life of a student, and their theoretical analysis therefore makes the abstract concept of work more real. The mechanical advantage of each of these systems is also discussed so that…

  3. Working with simple machines

    NASA Astrophysics Data System (ADS)

    Norbury, John W.

    2006-11-01

    A set of examples is provided that illustrate the use of work as applied to simple machines. The ramp, pulley, lever and hydraulic press are common experiences in the life of a student, and their theoretical analysis therefore makes the abstract concept of work more real. The mechanical advantage of each of these systems is also discussed so that students can evaluate their usefulness as machines.

  4. Simple Schlieren Light Meter

    NASA Technical Reports Server (NTRS)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1992-01-01

    Simple light-meter circuit used to position knife edge of schlieren optical system to block exactly half light. Enables operator to check quickly position of knife edge between tunnel runs to ascertain whether or not in alignment. Permanent measuring system made part of each schlieren system. If placed in unused area of image plane, or in monitoring beam from mirror knife edge, provides real-time assessment of alignment of schlieren system.

  5. Probabilistic simple splicing systems

    NASA Astrophysics Data System (ADS)

    Selvarajoo, Mathuri; Heng, Fong Wan; Sarmin, Nor Haniza; Turaev, Sherzod

    2014-06-01

    A splicing system, one of the early theoretical models for DNA computing was introduced by Head in 1987. Splicing systems are based on the splicing operation which, informally, cuts two strings of DNA molecules at the specific recognition sites and attaches the prefix of the first string to the suffix of the second string, and the prefix of the second string to the suffix of the first string, thus yielding the new strings. For a specific type of splicing systems, namely the simple splicing systems, the recognition sites are the same for both strings of DNA molecules. It is known that splicing systems with finite sets of axioms and splicing rules only generate regular languages. Hence, different types of restrictions have been considered for splicing systems in order to increase their computational power. Recently, probabilistic splicing systems have been introduced where the probabilities are initially associated with the axioms, and the probabilities of the generated strings are computed from the probabilities of the initial strings. In this paper, some properties of probabilistic simple splicing systems are investigated. We prove that probabilistic simple splicing systems can also increase the computational power of the splicing languages generated.

  6. Dimensional analysis made simple

    NASA Astrophysics Data System (ADS)

    Lira, Ignacio

    2013-11-01

    An inductive strategy is proposed for teaching dimensional analysis to second- or third-year students of physics, chemistry, or engineering. In this strategy, Buckingham's theorem is seen as a consequence and not as the starting point. In order to concentrate on the basics, the mathematics is kept as elementary as possible. Simple examples are suggested for classroom demonstrations of the power of the technique and others are put forward for homework or experimentation, but instructors are encouraged to produce examples of their own.

  7. Simple, efficient UHV manipulator

    SciTech Connect

    Thiel, P.A.; Anderegg, J.W.

    1984-10-01

    A simple manipulator is described for use in ultrahigh vacuum. Unhindered rotation within vacuum is provided by a commercial differentially pumped adapter to which the entire XYZ stage is attached. The combination of movements provided by the XYZ stage, the rotating vacuum flange, and a gimbal permits alignment of the sample with any of the peripheral view ports. The resistively heated sample support, mounted through a cold finger, permits rapid variation of sample temperature from several hundred degrees Kelvin to near cryogenic. It is anticipated that this design could be easily used with many existing types of commercial vacuum systems, with the consequent advantage of increased ease and simplicity of both mechanical motion and cryogenic cooling.

  8. A simple radon well

    NASA Astrophysics Data System (ADS)

    Lahti, Katariina; Graeffe, Gunnar

    The development of a simple radon well, as effective but less expensive and technically easier to put into practice than is usual, was addressed. The wall was accomplished by a drill well technique. A long plastic tube, partly perforated, is put into the ground. To the top end of the tube an exhaust fan is connected to suck the air from the soil to make an underpressure. By this method radon is prevented from entering dwellings. Measurements were carried out in a one family house in four-day periods by a continuously monitoring radon detector. The radon concentration was usually 3000 to 4000 Bq/cu m without the use of the well. When the fan was turned on it reduced the radon concentration below 200 Bq/cu m.

  9. A Simple Harmonic Universe

    SciTech Connect

    Graham, Peter W.; Horn, Bart; Kachru, Shamit; Rajendran, Surjeet; Torroba, Gonzalo; /Stanford U., ITP /SLAC

    2011-12-14

    We explore simple but novel bouncing solutions of general relativity that avoid singularities. These solutions require curvature k = +1, and are supported by a negative cosmological term and matter with -1 < w < -1 = 3. In the case of moderate bounces (where the ratio of the maximal scale factor a{sub +} to the minimal scale factor a{sub -} is {Omicron}(1)), the solutions are shown to be classically stable and cycle through an infinite set of bounces. For more extreme cases with large a{sub +} = a{sub -}, the solutions can still oscillate many times before classical instabilities take them out of the regime of validity of our approximations. In this regime, quantum particle production also leads eventually to a departure from the realm of validity of semiclassical general relativity, likely yielding a singular crunch. We briefly discuss possible applications of these models to realistic cosmology.

  10. En la búsqueda de características en eyecciones coronales de masa que discriminen entre dos paradigmas físicos en modelos de ECMs

    NASA Astrophysics Data System (ADS)

    Paissan, G.; Stenborg, G.; Rovira, M.

    Se conocen tres diferentes fenómenos de gran escala que ocurren en la atmósfera solar, denominados eyecciones coronales de masa (ECMs), protuberancias eruptivas y grandes fulguraciones de dos bandas. Estos fenómenos están estrechamente relacionados y podrían ser distintas manifestaciones de un único proceso físico. Las ECMs son definidas como eyecciones de gran escala de masa y flujo magnético desde la baja corona al espacio interplanetario. Desde su descubrimiento en los '70, muchos modelos han sido propuestos para explicar su origen y evolución. La explicación física de las ECMs es un tema de debate intenso. No obstante, los modelos pueden sintetizarse en dos grandes grupos: 1) los modelos de inyección de flujo y 2) los modelos de almacenamiento y liberación. En este trabajo, se presentan los estudios realizados con una serie de eventos observados con el coronógrafo MICA (Mirror Coronograph for Argentina), el telescopio en H-alfa HASTA (H-alpha Solar Telescope for Argentina) y los coronógrafos C2 y C3 de la sonda SOHO (Solar and Heliospheric Observatory). Los eventos que pudieron ser identificados como ECMs son contrastados dentro del esquema de los dos paradigmas teóricos propuestos.

  11. A causa das estações do ano: modelos mentais

    NASA Astrophysics Data System (ADS)

    de Campos, J. A. S.; de Araujo, J. F. S.

    2003-08-01

    A década de 70 do século passado foi marcada pelo estudo das concepções alternativas que os alunos trazem para a sala de aula. A identificação destas concepções foi o ponto de partida para promover a mudança conceitual, onde as pré-concepções seriam trocadas pelas concepções científicas. Na década seguinte, surgiram muitas propostas de estratégias educacionais para facilitar esta troca, na sua maioria baseadas na idéia do conflito cognitivo, proposta por Piaget. Entretanto, os resultados pouco animadores conduziram à percepção de que a mudança conceitual é um processo mais complexo. Pelas idéias da Ciência Cognitiva, a mudança conceitual é uma mudança progressiva dos modelos mentais que o aluno tem sobre o mundo físico, através de enriquecimento e revisão. A causa das Estações do Ano é um tópico sobre o qual a maioria dos estudantes apresenta concepções alternativas. Os autores fizeram um levantamento sobre as pré-concepções encontradas em trabalhos sobre o tema (16 referências), procurando encontrar elementos comuns que indicassem a presença de modelos mentais específicos. As pré-concepções encontradas na literatura foram obtidas usando-se diversas metodologias (desde entrevistas clínicas até questionários de múltipla escolha) e envolvendo alunos e professores de diferentes regiões geográficas. A partir de uma análise aprofundada de cada trabalho, e utilizando-se a técnica das Redes Sistêmicas, chegou-se a conclusão que as diversas pré-concepções identificadas (em torno de 50), poderiam ser representadas por 6 modelos mentais, onde a explicação da causa das estações do ano tem um mecanismo causal responsável. Os mecanismos causais identificados foram: a dependência da distância, a dependência da orientação, a dependência conjunta da distância e orientação, a dependência da obstrução, a dependência da velocidade e a dependência da inclinação dos raios solares. Foram ainda identificadas

  12. Quasispecies Made Simple

    PubMed Central

    2005-01-01

    Quasispecies are clouds of genotypes that appear in a population at mutation–selection balance. This concept has recently attracted the attention of virologists, because many RNA viruses appear to generate high levels of genetic variation that may enhance the evolution of drug resistance and immune escape. The literature on these important evolutionary processes is, however, quite challenging. Here we use simple models to link mutation–selection balance theory to the most novel property of quasispecies: the error threshold—a mutation rate below which populations equilibrate in a traditional mutation–selection balance and above which the population experiences an error catastrophe, that is, the loss of the favored genotype through frequent deleterious mutations. These models show that a single fitness landscape may contain multiple, hierarchically organized error thresholds and that an error threshold is affected by the extent of back mutation and redundancy in the genotype-to-phenotype map. Importantly, an error threshold is distinct from an extinction threshold, which is the complete loss of the population through lethal mutations. Based on this framework, we argue that the lethal mutagenesis of a viral infection by mutation-inducing drugs is not a true error catastophe, but is an extinction catastrophe. PMID:16322763

  13. Feynman's simple quantum mechanics

    NASA Astrophysics Data System (ADS)

    Taylor, Edwin F.

    1997-03-01

    This sample class presents an alternative to the conventional introduction to quantum mechanics and describes its current use in a credit course. This alternative introduction rests on theory presented in professional and popular writings by Richard Feynman. Feynman showed that Nature gives a simple command to the electron: "Explore all paths." All of nonrelativistic quantum mechanics, among other fundamental results, comes from this command. With a desktop computer the student points and clicks to tell a modeled electron which paths to follow. The computer then shows the results, which embody the elemental strangeness and paradoxical behaviors of the world of the very small. Feynman's approach requires few equations and provides a largely non-mathematical introduction to the wave function of conventional quantum mechanics. Draft software and materials already used for two semesters in an e-mail computer conference credit university course show that Feynman's approach works well with a variety of students. The sample class explores computer and written material and describes the next steps in its development.

  14. A simple wave driver

    NASA Astrophysics Data System (ADS)

    Kağan Temiz, Burak; Yavuz, Ahmet

    2015-08-01

    This study was done to develop a simple and inexpensive wave driver that can be used in experiments on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be used to produce string waves at a fixed frequency. The working principle of the apparatus is as follows: shortly after the car is turned on, the wheel starts to turn at a constant angular speed. A rod that is fixed on the wheel turns at the same constant angular speed, too. A tight string that the wave will be created on is placed at a distance where the rod can touch the string. During each rotation of the wheel, the rod vibrates the string up and down. The vibration frequency of this rod equals the wheel’s rotation frequency, and this frequency value can be measured easily with a small magnet and a bicycle speedometer. In this way, the frequency of the waves formed in the rope can also be measured.

  15. Endoscopic simple prostatectomy

    PubMed Central

    Borkowski, Tomasz; Chłosta, Piotr; Dobruch, Jakub; Fiutowski, Marek; Jaskulski, Jarosław; Słojewski, Marcin; Szydełko, Tomasz; Szymański, Michał; Demkow, Tomasz

    2014-01-01

    Introduction Many options exist for the surgical treatment of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH), including transurethral resection of the prostate (TURP), laser surgery, and open adenomectomy. Recently, endoscopic techniques have been used in the treatment of BPH. Material and methods We reviewed clinical studies in PubMed describing minimally invasive endoscopic procedures for the treatment of BPH. Results Laparoscopic adenomectomy (LA) and robotic–assisted simple prostatectomy (RASP) were introduced in the early 2000s. These operative techniques have been standardized and reproducible, with some individual modifications. Studies analyzing the outcomes of LA and RASP have reported significant improvements in urinary flow and decreases in patient International Prostate Symptom Score (IPSS). These minimally invasive approaches have resulted in a lower rate of complications, shorter hospital stays, smaller scars, faster recoveries, and an earlier return to work. Conclusions Minimally invasive techniques such as LA and RASP for the treatment BPH are safe, efficacious, and allow faster recovery. These procedures have a short learning curve and offer new options for the surgeon treating BPH. PMID:25667758

  16. Telemedicine kept simple

    PubMed Central

    Vassallo, DJ

    2000-01-01

    Telemedicine (“medicine from a distance”) is about bringing specialist knowledge to a patient from afar, by the use of communication technology. This article is based on personal experience in helping set up a simple, versatile, cheap and effective store-and-forward telemedicine system for the British Defence Medical Services. This system uses readily available still digital cameras to record clinical, radiographic and microscopic images, which are then sent by electronic mail to an organised network of specialists for secondary or tertiary opinion. The system is in use in various countries throughout the world, and has also proven to have civilian and humanitarian uses. The system is now being emulated in civilian practice in the United Kingdom, the United States, and in previously isolated hospitals in the Third World. I also describe the active role played by a telemedicine charity and by medical students on elective in the Third World in setting up telemedicine links using this system. Readers are invited to co-operate in the setting up of a global outreach telemedicine programme, linking elective students, isolated Third World hospitals, and University Teaching Hospitals. PMID:22368578

  17. [Clustering of simple obesity].

    PubMed

    Yoshida, K; Matsuda, H; Kurita, M; Umetada, Y

    1988-05-01

    An attempt was made to classify persons with simple obesity from the viewpoint of health education. Subjects of the study were 1,278 male workers in a financing company who underwent health examination. At the time of health examinations, questionnaire survey concerning their life styles was carried out on all the subjects. The obese group consisted of 127 subjects whose obesity indices were over 15% and the control group consisted of 342 subjects whose obesity indices ranged from -5 to 5%. Subjects in the obese group were classified into four clusters based on cluster analysis using five life-style parameters; that is, frequency of taking breakfast, frequency of taking staple food, drinking habits, smoking habits, and frequency of exercise. The first cluster (N = 10) included inactive persons, the second cluster (N = 46) non smokers, the third cluster (N = 39) smokers and heavy drinkers, and the fourth cluster (N = 32) smokers and non-drinkers. Comparison of the four clusters of obese persons with the control group revealed the following findings: 1) All the four clusters had significantly high frequencies of abnormal values of triglyceride (TG) and fasting blood sugar (FBS). 2) The first cluster had significantly high frequencies of abnormal values of glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT). 3) The second cluster had significantly high frequencies of abnormal values of systolic and diastolic blood pressure, total cholesterol, TG, FBS, uric acid, GOT, GPT and gamma glutamyl transferase (GGT).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3172544

  18. Simple inflationary quintessential model

    NASA Astrophysics Data System (ADS)

    de Haro, Jaume; Amorós, Jaume; Pan, Supriya

    2016-04-01

    In the framework of a flat Friedmann-Lemaître-Robertson-Walker geometry, we present a non-geodesically past complete model of our Universe without the big bang singularity at finite cosmic time, describing its evolution starting from its early inflationary era up to the present accelerating phase. We found that a hydrodynamical fluid with nonlinear equation of state could result in such scenario, which after the end of this inflationary stage, suffers a sudden phase transition and enters into the stiff matter dominated era, and the Universe becomes reheated due to a huge amount of particle production. Finally, it asymptotically enters into the de Sitter phase concluding the present accelerated expansion. Using the reconstruction technique, we also show that this background provides an extremely simple inflationary quintessential potential whose inflationary part is given by the well-known 1-dimensional Higgs potential, i.e., a double well inflationary potential, and the quintessential one by an exponential potential that leads to a deflationary regime after this inflation, and it can depict the current cosmic acceleration at late times. Moreover the Higgs potential leads to a power spectrum of the cosmological perturbations which fit well with the latest Planck estimations. Further, we compared our viable potential with some known inflationary quintessential potential, which shows that our quintessential model, that is, the Higgs potential combined with the exponential one, is an improved version of them because it contains an analytic solution that allows us to perform all analytic calculations. Finally, we have shown that the introduction of a nonzero cosmological constant simplifies the potential considerably with an analytic behavior of the background which again permits us to evaluate all the quantities analytically.

  19. MODELO PARA EVALUACION DE DERRAMES DE HIDROCARBUROS (HSSM) GUIA DEL USUARIO

    EPA Science Inventory

    The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human acti...

  20. La Educacion Continua de Profesionales de la Salud--Un Modelo para su Desarrollo

    ERIC Educational Resources Information Center

    Stensland, Per G.

    1974-01-01

    The author suggests a framework for planning and evaluating continuing education, giving attention to the learner, his objectives, and the learning process; these components are discussed in determining the special characteristics of the continuing education of professional health workers, and a model program is presented. The article is in…

  1. Study Guide: Seven Simple Secrets

    ERIC Educational Resources Information Center

    Satterfield, Nancy; Breaux, Annette; Whitaker, Todd

    2007-01-01

    This study guide has been developed to accompany the "Seven Simple Secrets" book written by Dr. Todd Whitaker and Annette Breaux. "Seven Simple Secrets" focuses on those attributes that have been found to help teachers be their absolute best in their daily challenges of teaching and improving student learning. The study guide is divided into the…

  2. Melhoramentos no código Wilson-Devinney para binárias eclipsantes

    NASA Astrophysics Data System (ADS)

    Vieira, L. A.; Vaz, L. P. R.

    2003-08-01

    A análise de curvas de luz e velocidades radiais de sistemas binários eclipsantes pode ser feita por meio de vários modelos. Um desses é o Modelo Wilson-Devinney (WD). Ao longo dos anos, esse modelo sofreu várias alterações em seus códigos principais, com a finalidade de torná-lo mais consistente tanto fíisica como numericamente. O Modelo WD tem sido melhorado de várias maneiras em seus dois códigos: um para a predição das curvas de luz teórica e de velocidade radiais e outra para as soluções destas curvas. Teoricamente, na física do modelo, nós introduzimos a possibilidade de levar em conta os efeitos do movimento apsidal. Numericamente, nós introduzimos a possibilidade de usar o Método SIMPLEX no procedimento da solução, como uma alternativa para o já implementado Método de Mínimos Quadrados (Least Squares Method). Estas modificações, juntamente com outras já introduzidas pelo nosso grupo anteriormente, tornam o código mais eficiente na solução das curvas de luz e de velocidade radiais de binárias eclipsantes. Como o modelo tem sido usado para analisar sistemas com componentes pré-sequência principal (TY CrA, Casey et al. 1998, Vaz et al. 1998), SM 790, Stassun et al. 2003), este melhoramento beneficiará estes casos também. Apresentamos os resultados obtidos com a modificação do código WD por meio do uso de dados da estrela GL Carinae, comprovando, (1) que os parâmetros orbitais calculados por nós são coerentes com os obtidos anteriormente na literatura (Giménez & Clausen, 1986) e com os obtidos por Faria (1987), e (2) que a implementação do Método SIMPLEX torna o código mais lento mas completamente consistente internamente e evita os problemas gerados pelo uso do Método de Mínimos Quadrados, tais como imprecisão no cálculo das derivadas parciais e convergência para mínimos locais.

  3. Simple ocean carbon cycle models

    SciTech Connect

    Caldeira, K.; Hoffert, M.I.; Siegenthaler, U.

    1994-02-01

    Simple ocean carbon cycle models can be used to calculate the rate at which the oceans are likely to absorb CO{sub 2} from the atmosphere. For problems involving steady-state ocean circulation, well calibrated ocean models produce results that are very similar to results obtained using general circulation models. Hence, simple ocean carbon cycle models may be appropriate for use in studies in which the time or expense of running large scale general circulation models would be prohibitive. Simple ocean models have the advantage of being based on a small number of explicit assumptions. The simplicity of these ocean models facilitates the understanding of model results.

  4. El rol de Ia colaboracion y el Modelo de Aprendizaje Basado en Proyectos (ABPr) mediante el lente de la Teoria de Actividad (CHAT): un estudio de caso con estudiantes de 9no grado

    NASA Astrophysics Data System (ADS)

    Delgado, Isabel C.

    Los modelos de eensenanza y aprendizaje constructivistas conceptualizan el aprendizaje como un proceso activo. El modelo de Aprendizaje Basado en Proyectos (ABPr) se distingue por una serie de componentes, entre los cuales se destaca el aspecto colaborativo y cooperativo como un reto al momento de su implantacion. Son pocas las investigaciones que se concentran en este aspecto del modelo. En este estudio, se analizaron las diversas interacciones que surgen durante la implantacion de una unidad curricular sobre el tema de Geologia de Puerto Rico, la cual se diseno con el modelo ABPr cuyo enfoque es orientacion a proyectos. Particularmente, se examinaron las interacciones sociales que surgen entre los pares y entre pares y docente durante el proceso de planificacion y desarrollo de los productos finales, al igual que las interacciones entre los estudiantes y el material didactico en estas etapas del modelo. La investigacion es de tipo cualitativo e incorpora como diseno el estudio de caso. Las diversas interacciones constituyen la unidad de analisis. En el estudio participaron 19 estudiantes de 9no grado, a quienes se organizaron en 5 grupos colaborativos por temas de interes (Pangea, Placas tectonicas, Volcanes, Tsunamis y Terremotos). Las tecnicas que se utilizaron para recopilar los datos fueron: observaciones participativas, grupos focales y analisis de documentos (cuadernos reflexivos y respuestas de los estudiantes a la pregunta central del proyecto). Para el analisis de los datos se aplico la teoria de actividad (CHAT) que concentra la unidad de analisis en la actividad humana en un contexto particular. Los resultados del estudio senalan que las interacciones entre pares, entre pares y docente, asi como entre estudiantes y material didactico son fundamentales en el proceso de aprendizaje. Una mayor interaccion entre pares durante las etapas de planificar y desarrollar los productos finales de la unidad, promueve una mejor comprension de los conceptos de la

  5. Science Notebook: A Simple Seismometer.

    ERIC Educational Resources Information Center

    Mims, Forrest M., III

    1991-01-01

    Describes how to construct a simple pendulum seismometer. Includes schematic drawing of the electronic circuitry, a working drawing of the apparatus, and typical seismometer outputs caused by nearby trains and various earthquake-generated waves. (JJK)

  6. Student Conceptions of Simple Circuits.

    ERIC Educational Resources Information Center

    Fredette, Norman; Lochhead, John

    1980-01-01

    Investigates some conceptual difficulties which college students have with regard to simple direct current circuits. The clinical interview technique was used with 57 students in a freshman level engineering course. (HM)

  7. Simple device measures solar radiation

    NASA Technical Reports Server (NTRS)

    Humphries, W. R.

    1977-01-01

    Simple inexpensive thermometer, insolated from surroundings by transparent glass or plastic encasement, measures intensities of solar radiation, or radiation from other sources such as furnaces or ovens. Unit can be further modified to accomplish readings from remote locations.

  8. Simple formulation of magnetoplasmadynamic acceleration

    SciTech Connect

    Sasoh, A. )

    1994-03-01

    A simple formulation of magnetoplasmadynamic acceleration has been made based on energy conservation relations and a generalized Ohm's law. An exhaust velocity is expressed using three characteristic parameters: (1) a dimensionless characteristic velocity [ital [tilde U

  9. Simple Interval Timers for Microcomputers.

    ERIC Educational Resources Information Center

    McInerney, M.; Burgess, G.

    1985-01-01

    Discusses simple interval timers for microcomputers, including (1) the Jiffy clock; (2) CPU count timers; (3) screen count timers; (4) light pen timers; and (5) chip timers. Also examines some of the general characteristics of all types of timers. (JN)

  10. Is the Simple View of Reading Too Simple?

    ERIC Educational Resources Information Center

    Hoien-Tengesdal, Ingjerd

    2010-01-01

    According to the Simple View of Reading (SVR), reading comprehension is the product of word decoding ability and linguistic comprehension (R = D x C). However, there is also evidence showing that an additive model (R = D + C) explains just as much or even more of the variance in reading comprehension than the product model. To further evaluate…

  11. Futur "simple" et futur "proche" ("Simple" Future and "Immediate" Future).

    ERIC Educational Resources Information Center

    Franckel, Jean-Jacques

    1984-01-01

    An analysis of the use of simple and immediate future tenses in French shows that the expression of time is controlled more by context and modals than by specifically temporal cues. The role of negation in this situation is discussed. (MSE)

  12. How Simple is the Simple View of Reading?

    ERIC Educational Resources Information Center

    Gustafson, Stefan; Samuelsson, Christina; Johansson, Ellinor; Wallmann, Julia

    2013-01-01

    According to the Simple View of Reading, reading ability can be divided into decoding and language comprehension. In the present study, decoding and comprehension's contribution to reading ability was studied both in children with reading difficulties and in children with typical reading ability. Decoding and comprehension was further divided…

  13. Practical Session: Simple Linear Regression

    NASA Astrophysics Data System (ADS)

    Clausel, M.; Grégoire, G.

    2014-12-01

    Two exercises are proposed to illustrate the simple linear regression. The first one is based on the famous Galton's data set on heredity. We use the lm R command and get coefficients estimates, standard error of the error, R2, residuals …In the second example, devoted to data related to the vapor tension of mercury, we fit a simple linear regression, predict values, and anticipate on multiple linear regression. This pratical session is an excerpt from practical exercises proposed by A. Dalalyan at EPNC (see Exercises 1 and 2 of http://certis.enpc.fr/~dalalyan/Download/TP_ENPC_4.pdf).

  14. A simple hindlimb suspension apparatus

    NASA Technical Reports Server (NTRS)

    Park, E.; Schultz, E.

    1993-01-01

    This paper describes the assembly of a simple, inexpensive apparatus for application of the hindlimb suspension model to studies of the effects of unloading on mammalian physiology. Construction of a cage and suspension assembly is described using materials that can be obtained from most hardware stores. The design is kept simple for easy assembly and disassembly to facilitate cleaning and storage. The suspension assembly allows the animals full access to all portions of the floor area and provides an effective environment to study the effects of unloading.

  15. Generalized Gradient Approximation Made Simple

    SciTech Connect

    Perdew, J.P.; Burke, K.; Ernzerhof, M.

    1996-10-01

    Generalized gradient approximations (GGA{close_quote}s) for the exchange-correlation energy improve upon the local spin density (LSD) description of atoms, molecules, and solids. We present a simple derivation of a simple GGA, in which all parameters (other than those in LSD) are fundamental constants. Only general features of the detailed construction underlying the Perdew-Wang 1991 (PW91) GGA are invoked. Improvements over PW91 include an accurate description of the linear response of the uniform electron gas, correct behavior under uniform scaling, and a smoother potential. {copyright} {ital 1996 The American Physical Society.}

  16. Simple Machines in the Community

    ERIC Educational Resources Information Center

    Bryan, Robert; Laroder, Aris; Tippins, Deborah; Emaz, Meliza; Fox, Ryan

    2008-01-01

    The community can be a powerful context and mini-laboratory for cultivating students' common understandings of science and mathematics. On the island of Panay in the Philippines, the community was the starting place for a group of fifth- and sixth-grade students to explore simple machines in their daily lives. What students learned in the process…

  17. Simple modeling of hydrostatic bearings

    NASA Astrophysics Data System (ADS)

    Hull, Charlie

    2014-07-01

    Hydrostatic bearings are a key component for many large telescopes due to their high load bearing capacity, stiffness and low friction. A simple technique is presented to model these bearings to understand the effects of geometry, oil viscosity, flow control, temperature, etc. on the bearings behavior.

  18. Solving Simple Kinetics without Integrals

    ERIC Educational Resources Information Center

    de la Pen~a, Lisandro Herna´ndez

    2016-01-01

    The solution of simple kinetic equations is analyzed without referencing any topic from differential equations or integral calculus. Guided by the physical meaning of the rate equation, a systematic procedure is used to generate an approximate solution that converges uniformly to the exact solution in the case of zero, first, and second order…

  19. Simple Astronomical Theory of Climate.

    ERIC Educational Resources Information Center

    Benumof, Reuben

    1979-01-01

    The author derives, applying perturbation theory, from a simple astronomical model the approximate periods of secular variation of some of the parameters of the Earth's orbit and relates these periods to the past climate of the Earth, indicating the difficulties in predicting the climate of the future. (GA)

  20. Simple Echoes and Subtle Reverberations

    ERIC Educational Resources Information Center

    Keeports, David

    2010-01-01

    Reverberation within an enclosed space can be viewed as a superposition of a large number of simple echoes. The echoes that make up the sound of reverberation fall neatly into two categories, relatively loud and sparse early reflections, and relatively soft and dense late reflections. Ways in which readily available music production software can…

  1. Simple manipulator for rotating spheres.

    PubMed

    Weinstein, B W; Hendricks, C D; Ward, C M; Willenborg, D L

    1978-06-01

    We describe a simple device for rapidly rotating a small sphere to any orientation for inspection of the surface. The ball is held between two small, flat surfaces and rolls as the surfaces are moved differentially parallel to one another. PMID:18699214

  2. Simple Games . . . or Are They?

    ERIC Educational Resources Information Center

    Arn, Susan Kyle

    2006-01-01

    Students today begin using computers and playing video games as early as two years old. The technology behind these games is more complicated than most people can imagine. In this article, the author presents some simple number games which seem easy at the beginning, but as the games are repeated, mathematical content becomes more of the focus…

  3. Simple Stringy Dynamical SUSY Breaking

    SciTech Connect

    Aharony, Ofer; Kachru, Shamit; Silverstein, Eva; /Stanford U., Phys. Dept. /SLAC

    2007-08-08

    We present simple string models which dynamically break supersymmetry without non-Abelian gauge dynamics. The Fayet model, the Polonyi model, and the O'Raifeartaigh model each arise from D-branes at a specific type of singularity. D-brane instanton effects generate the requisite exponentially small scale of supersymmetry breaking.

  4. Simple Techniques for Microclimate Measurement.

    ERIC Educational Resources Information Center

    Unwin, D. M.

    1978-01-01

    Describes simple ways of measuring the very local climate near the ground, and explains what these measurements mean. Equipment included a solar radiometer, a dew point instrument, and a thermocouple psychrometer. Examples are given of field measurements taken with some of the equipment and the results and their interpretation are discussed.…

  5. Determining Salinity by Simple Means.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    This paper describes the construction and use of a simple salinometer. The salinometer is composed, mainly, of a milliammeter and a battery and uses the measurement of current flow to determine the salinity of water. A complete list of materials is given, as are details of construction and operation of the equipment. The use of the salinometer in…

  6. Simple Machines Curriculum. [Teachers' Manual.

    ERIC Educational Resources Information Center

    Anoka-Hennepin Independent School District No. 11, Coon Rapids, MN.

    This manual provides suggestions for investigating simple machines and the teaching of certain basic concepts which pertain to them. Many of the lessons are designed to be used with the commercially available LEGO kits, in an effort to teach concepts in a way in which students must translate pictures shown in two dimension into three-dimensional…

  7. A Simple Relativistic Bohr Atom

    ERIC Educational Resources Information Center

    Terzis, Andreas F.

    2008-01-01

    A simple concise relativistic modification of the standard Bohr model for hydrogen-like atoms with circular orbits is presented. As the derivation requires basic knowledge of classical and relativistic mechanics, it can be taught in standard courses in modern physics and introductory quantum mechanics. In addition, it can be shown in a class that…

  8. Correcting Slightly Less Simple Movements

    ERIC Educational Resources Information Center

    Aivar, M. P.; Brenner, E.; Smeets, J. B. J.

    2005-01-01

    Many studies have analysed how goal directed movements are corrected in response to changes in the properties of the target. However, only simple movements to single targets have been used in those studies, so little is known about movement corrections under more complex situations. Evidence from studies that ask for movements to several targets…

  9. A Simple Plant Growth Analysis.

    ERIC Educational Resources Information Center

    Oxlade, E.

    1985-01-01

    Describes the analysis of dandelion peduncle growth based on peduncle length, epidermal cell dimensions, and fresh/dry mass. Methods are simple and require no special apparatus or materials. Suggests that limited practical work in this area may contribute to students' lack of knowledge on plant growth. (Author/DH)

  10. Grief: Difficult Times, Simple Steps.

    ERIC Educational Resources Information Center

    Waszak, Emily Lane

    This guide presents techniques to assist others in coping with the loss of a loved one. Using the language of 9 layperson, the book contains more than 100 tips for caregivers or loved ones. A simple step is presented on each page, followed by reasons and instructions for each step. Chapters include: "What to Say"; "Helpful Things to Do"; "Dealing…

  11. A Simple Audio Conductivity Device.

    ERIC Educational Resources Information Center

    Berenato, Gregory; Maynard, David F.

    1997-01-01

    Describes a simple audio conductivity device built to address the problem of the lack of sensitivity needed to measure small differences in conductivity in crude conductivity devices. Uses a 9-V battery as a power supply and allows the relative resistance differences between substances to be detected by the frequency of its audible tones. Presents…

  12. Simple Indolizidine and Quinolizidine Alkaloids.

    PubMed

    Michael, Joseph P

    2016-01-01

    This review of simple indolizidine and quinolizidine alkaloids (i.e., those in which the parent bicyclic systems are in general not embedded in polycyclic arrays) is an update of the previous coverage in Volume 55 of this series (2001). The present survey covers the literature from mid-1999 to the end of 2013; and in addition to aspects of the isolation, characterization, and biological activity of the alkaloids, much emphasis is placed on their total synthesis. A brief introduction to the topic is followed by an overview of relevant alkaloids from fungal and microbial sources, among them slaframine, cyclizidine, Steptomyces metabolites, and the pantocins. The important iminosugar alkaloids lentiginosine, steviamine, swainsonine, castanospermine, and related hydroxyindolizidines are dealt with in the subsequent section. The fourth and fifth sections cover metabolites from terrestrial plants. Pertinent plant alkaloids bearing alkyl, functionalized alkyl or alkenyl substituents include dendroprimine, anibamine, simple alkaloids belonging to the genera Prosopis, Elaeocarpus, Lycopodium, and Poranthera, and bicyclic alkaloids of the lupin family. Plant alkaloids bearing aryl or heteroaryl substituents include ipalbidine and analogs, secophenanthroindolizidine and secophenanthroquinolizidine alkaloids (among them septicine, julandine, and analogs), ficuseptine, lasubines, and other simple quinolizidines of the Lythraceae, the simple furyl-substituted Nuphar alkaloids, and a mixed quinolizidine-quinazoline alkaloid. The penultimate section of the review deals with the sizable group of simple indolizidine and quinolizidine alkaloids isolated from, or detected in, ants, mites, and terrestrial amphibians, and includes an overview of the "dietary hypothesis" for the origin of the amphibian metabolites. The final section surveys relevant alkaloids from marine sources, and includes clathryimines and analogs, stellettamides, the clavepictines and pictamine, and bis

  13. Simple model of hydrophobic hydration.

    PubMed

    Lukšič, Miha; Urbic, Tomaz; Hribar-Lee, Barbara; Dill, Ken A

    2012-05-31

    Water is an unusual liquid in its solvation properties. Here, we model the process of transferring a nonpolar solute into water. Our goal was to capture the physical balance between water's hydrogen bonding and van der Waals interactions in a model that is simple enough to be nearly analytical and not heavily computational. We develop a 2-dimensional Mercedes-Benz-like model of water with which we compute the free energy, enthalpy, entropy, and the heat capacity of transfer as a function of temperature, pressure, and solute size. As validation, we find that this model gives the same trends as Monte Carlo simulations of the underlying 2D model and gives qualitative agreement with experiments. The advantages of this model are that it gives simple insights and that computational time is negligible. It may provide a useful starting point for developing more efficient and more realistic 3D models of aqueous solvation. PMID:22564051

  14. Simple Fixed Functional Space Maintainer

    PubMed Central

    Sarawgi, Aditi; Marwah, Nikhil; Gumber, Parvind; Dutta, Samir

    2014-01-01

    ABSTRACT% Premature loss of a primary tooth is one of the most common etiology for malocclusion. Space maintainers are employed to prevent this complication. In anterior region, esthetics is an important concern along with function and space management. Fiber-reinforced composite (FRC) retained space maintainer solves all these purposes ef ficiently and ef fectively. In addition, the technique is simple and the appliance is very comfortable inside the oral cavity. Here is a case of premature loss of anterior primary tooth which was replaced by FRC retained esthetic functional space maintainer. The appliance was found to be functioning satisfactorily inside the oral cavity till the last visit (1 Year). How to cite this article: Goenka P, Sarawgi A, Marwah N, Gumber P, Dutta S. Simple Fixed Functional Space Maintainer. Int J Clin Pediatr Dent 2014;7(3):225-228. PMID:25709309

  15. Webcam classification using simple features

    NASA Astrophysics Data System (ADS)

    Pramoun, Thitiporn; Choe, Jeehyun; Li, He; Chen, Qingshuang; Amornraksa, Thumrongrat; Lu, Yung-Hsiang; Delp, Edward J.

    2015-03-01

    Thousands of sensors are connected to the Internet and many of these sensors are cameras. The "Internet of Things" will contain many "things" that are image sensors. This vast network of distributed cameras (i.e. web cams) will continue to exponentially grow. In this paper we examine simple methods to classify an image from a web cam as "indoor/outdoor" and having "people/no people" based on simple features. We use four types of image features to classify an image as indoor/outdoor: color, edge, line, and text. To classify an image as having people/no people we use HOG and texture features. The features are weighted based on their significance and combined. A support vector machine is used for classification. Our system with feature weighting and feature combination yields 95.5% accuracy.

  16. The Simple Science of Flight

    NASA Astrophysics Data System (ADS)

    Tennekes, Henk

    1997-05-01

    From the smallest gnat to the largest aircraft, all things that fly obey the same aerodynamic principles. The Simple Science of Flight offers a leisurely introduction to the mechanics of flight and, beyond that, to the scientific attitude that finds wonder in simple calculations, forging connections between, say, the energy efficiency of a peanut butter sandwich and that of the kerosene that fuels a jumbo jet. It is the product of a lifetime of watching and investigating the way flight happens. The hero of the book is the Boeing 747, which Tennekes sees as the current pinnacle of human ingenuity in mastering the science of flight. Also covered are paper airplanes, kites, gliders, and human-powered flying machines as well as birds and insects. Tennekes explains concepts like lift, drag, wing loading, and cruising speed through many fascinating comparisons, anecdotes, and examples.

  17. Four simple ocean carbon models

    NASA Technical Reports Server (NTRS)

    Moore, Berrien, III

    1992-01-01

    This paper briefly reviews the key processes that determine oceanic CO2 uptake and sets this description within the context of four simple ocean carbon models. These models capture, in varying degrees, these key processes and establish a clear foundation for more realistic models that incorporate more directly the underlying physics and biology of the ocean rather than relying on simple parametric schemes. The purpose of this paper is more pedagogical than purely scientific. The problems encountered by current attempts to understand the global carbon cycle not only require our efforts but set a demand for a new generation of scientist, and it is hoped that this paper and the text in which it appears will help in this development.

  18. Simple echoes and subtle reverberations

    NASA Astrophysics Data System (ADS)

    Keeports, David

    2010-03-01

    Reverberation within an enclosed space can be viewed as a superposition of a large number of simple echoes. The echoes that make up the sound of reverberation fall neatly into two categories, relatively loud and sparse early reflections, and relatively soft and dense late reflections. Ways in which readily available music production software can be used for the study of reverberation are suggested. Additionally, methods of adding reverberation to recorded sound are discussed.

  19. Spontaneous chirality in simple systems

    PubMed

    Pickett; Gross; Okuyama

    2000-10-23

    Two simple examples of spontaneous chiral symmetry breaking are presented. The first is close-packed cylindrically confined spheres. As the cylinder diameter is varied, one obtains a variety of chiral phases. The second example involves unconfined dipolar particles with an isotropic attraction, which also exhibits chiral ground states. We speculate that a dilute magnetorheological fluid film, with the addition of smaller particles to provide an attractive entropic interaction, will exhibit a chiral columnar ground state. PMID:11030973

  20. Correlation and simple linear regression.

    PubMed

    Eberly, Lynn E

    2007-01-01

    This chapter highlights important steps in using correlation and simple linear regression to address scientific questions about the association of two continuous variables with each other. These steps include estimation and inference, assessing model fit, the connection between regression and ANOVA, and study design. Examples in microbiology are used throughout. This chapter provides a framework that is helpful in understanding more complex statistical techniques, such as multiple linear regression, linear mixed effects models, logistic regression, and proportional hazards regression. PMID:18450049

  1. Tracking simple and complex sequences.

    PubMed

    Large, Edward W; Fink, Philip; Kelso, J A Scott

    2002-02-01

    We address issues of synchronization to rhythms of musical complexity. In two experiments, synchronization to simple and more complex rhythmic sequences was investigated. Experiment 1 examined responses to phase and tempo perturbations within simple, structurally isochronous sequences, presented at different base rates. Experiment 2 investigated responses to similar perturbations embedded within more complex, metrically structured sequences; participants were explicitly instructed to synchronize at different metrical levels (i.e., tap at different rates to the same rhythmic patterns) on different trials. We found evidence that (1) the intrinsic tapping frequency adapts in response to temporal perturbations in both simple (isochronous) and complex (metrically structured) rhythms, (2) people can synchronize with unpredictable, metrically structured rhythms at different metrical levels, with qualitatively different patterns of synchronization seen at higher versus lower levels of metrical structure, and (3) synchronization at each tapping level reflects information from other metrical levels. The latter finding provides evidence for a dynamic and flexible internal representation of the sequence's metrical structure. PMID:11963276

  2. The Simple Spectral Access protocol

    NASA Astrophysics Data System (ADS)

    Dolensky, Markus; Tody, Doug

    2004-09-01

    The goal of the Simple Spectral Access (SSA) specification is to define a uniform interface to spectral data including spectral energy distributions (SEDs), 1D spectra, and time series data. In contrast to 2D images, spectra are stored in a wide variety of formats and there is no widely used standard in astronomy for representing spectral data, hence part of the challenge of specifying SSA was defining a general spectrophotometric data model as well as definitions of standard serializations in a variety of data formats including XML and FITS. Access is provided to both atlas (pre-computed) data and to virtual data which is computed on demand. The term simple in Simple Spectrum Access refers to the design goal of simplicity in both implementing spectral data services and in retrieving spectroscopic data from distributed data collections. SSA is a product of the data access layer (DAL) working group of the International Virtual Observatory Alliance (IVOA). The requirements were derived from a survey among spectral data providers and data consumers and were further refined in a broad discussion in meetings and electronic forums as well as by prototyping efforts within the European Astrophysical Virtual Observatory (AVO) and the US National Virtual Observatory (NVO).

  3. Modelizacion, control e implementacion de un procesador energetico paralelo para aplicacion en sistemas multisalida

    NASA Astrophysics Data System (ADS)

    Ferreres Sabater, Agustin

    modelizacion, y aplicacion en convertidores PWM, esta aun por estudiar y valorar. El primer Capitulo consiste en una breve introduccion al problema de la regulacion cruzada y la impedancia cruzada para posteriormente describir las tecnicas de post-regulacion actualmente mas empleadas, con especial atencion al post-regulador con transformador controlado. El Capitulo segundo trata del estudio de las caracteristicas estaticas del postregulador con transformador controlado. Partiendo de los estudios disponibles sobre el postregulador se plantean mejoras en su modo de actuacion y se discuten tres alternativas diferentes para controlar el transformador. Las dos primeras consisten en emplear un convertidor auxiliar Boost en sus dos modos de funcionamiento, continuo y discontinuo. La tercera consiste en controlar el transformador con una tension PWM directamente, sin filtrado. Finalmente se comprueba experimentalmente, para el estado estacionario, el funcionamiento del post-regulador para cada uno de los tres metodos de control. El Capitulo tercero trata de la dinamica de la salida controlada con el post-regulador cuando este emplea un convertidor auxiliar tipo Boost. Mediante la tecnica de promediado de variables de estado se propone el modelo de pequena senal, tanto para el modo continuo como para el modo discontinuo de funcionamiento del convertidor auxiliar. Los resultados mas significativos de esta seccion son las expresiones analiticas de las impedancias cruzadas y de la impedancia de la salida post-regulada. Como complemento al modelo de pequena senal se plantea un modelo de gran senal implementado sobre el simulador Pspice. Con este nuevo modelo se reproducen los resultados obtenidos con el modelo de pequena senal y ademas es posible simular los transitorios en las tensiones de salida ante cambios de carga. La modelizacion del convertidor cuando el transformador se controla con una tension PWM sin filtrar es el objetivo del Capitulo 4. En las secciones siguientes del Capitulo

  4. What Is a Simple Liquid?

    NASA Astrophysics Data System (ADS)

    Ingebrigtsen, Trond S.; Schrøder, Thomas B.; Dyre, Jeppe C.

    2012-01-01

    This paper is an attempt to identify the real essence of simplicity of liquids in John Locke’s understanding of the term. Simple liquids are traditionally defined as many-body systems of classical particles interacting via radially symmetric pair potentials. We suggest that a simple liquid should be defined instead by the property of having strong correlations between virial and potential-energy equilibrium fluctuations in the NVT ensemble. There is considerable overlap between the two definitions, but also some notable differences. For instance, in the new definition simplicity is not a direct property of the intermolecular potential because a liquid is usually only strongly correlating in part of its phase diagram. Moreover, not all simple liquids are atomic (i.e., with radially symmetric pair potentials) and not all atomic liquids are simple. The main part of the paper motivates the new definition of liquid simplicity by presenting evidence that a liquid is strongly correlating if and only if its intermolecular interactions may be ignored beyond the first coordination shell (FCS). This is demonstrated by NVT simulations of the structure and dynamics of several atomic and three molecular model liquids with a shifted-forces cutoff placed at the first minimum of the radial distribution function. The liquids studied are inverse power-law systems (r-n pair potentials with n=18,6,4), Lennard-Jones (LJ) models (the standard LJ model, two generalized Kob-Andersen binary LJ mixtures, and the Wahnstrom binary LJ mixture), the Buckingham model, the Dzugutov model, the LJ Gaussian model, the Gaussian core model, the Hansen-McDonald molten salt model, the Lewis-Wahnstrom ortho-terphenyl model, the asymmetric dumbbell model, and the single-point charge water model. The final part of the paper summarizes properties of strongly correlating liquids, emphasizing that these are simpler than liquids in general. Simple liquids, as defined here, may be characterized in three quite

  5. Multidirectional direct simple shear apparatus

    SciTech Connect

    DeGroot, D.J.; Germaine, J.T.; Ladd, C.C.

    1993-09-01

    The paper describes a new simple shear testing device, the multidirectional direct simple shear (MDSS) apparatus, for testing soil specimens under conditions that simulate, at the element level, the state of stress acting within the foundation soil of an offshore Arctic gravity structure. The MDSS uses a circular specimen that is consolidated under both a vertical effective stress ({sigma}{sub vc}{prime}) and a horizontal shear stress ({tau}{sub 1}). The specimen is subsequently sheared undrained by applying a second independent horizontal shear stress ({tau}{sub 2}) at an angle {theta} relative to the horizontal consolidation shear stress {tau}{sub 1}. Evaluation of the MDSS first compares conventional K{sub D}-consolidated undrained direct simple shear (CK{sub 0}UDSS) test data ({tau}{sub 1} = 0) on normally consolidated Boston blue clay (BBC) with results obtained in the Geonor DSS device. The MDSS gives lower secant Young`s modulus values and on average 8% lower strengths, but produces remarkably less scatter in the test results than the Geonor DSS. Kinematic proof tests with an elastic material (rubber) confirm that the setup procedure, application of forces, and strain measurement systems in the MDSS work properly and produce repeatable results. Results from a MDSS test program on BBC wherein specimens were first normally consolidated with {sigma}{sub vc}{prime} and {tau}{sub 1} = 0.2{sigma}{sub vc}{prime} and then sheared undrained at {theta} varing in 30{degree} increments from zero (shear in same direction) to 150{degree} show dramatic differences in the response of the soil as a function of {theta}. The peak undrained strength varies almost twofold from 0 = 0 to 120{degree}, while the deformation behavior varies from very brittle at low {theta} angles to becoming ductile at higher angles. 11 refs., 15 figs.

  6. A simple theory of condensation

    SciTech Connect

    Rabinovich, S.

    2011-04-15

    A simple assumption of the emergence in gas of small atomic clusters consisting of c particles each leads to a phase separation (first-order transition). It reveals itself by the emergence of a 'forbidden' density range starting at a certain temperature. Defining this latter value as the critical temperature predicts the existence of an interval with the anomalous heat capacity behavior c{sub p} {proportional_to} {Delta}T{sup -1/c}. The value c = 13 suggested in the literature yields the heat capacity exponent {alpha} = 0.077.

  7. A simple Cavendish experimental apparatus

    NASA Astrophysics Data System (ADS)

    Kossler, W. J.; Klein, Susann; Morrow, Dominick; Juliao, Andre

    2016-03-01

    A simple Cavendish apparatus is described that allows measurement of the gravitational constant G and makes observable the gravitational attraction between commonplace objects. The apparatus consists of a torsion balance constructed from readily available materials, including lead bricks and fishing weights ("sinkers"). A computer program is used to determine the gravitational field at the location of the small mass due to a nearby lead brick, which allows students to gain experience with numerical methods. Experimental results obtained are compatible with the accepted value of G.

  8. Simple Simulations of DNA Condensation

    SciTech Connect

    STEVENS,MARK J.

    2000-07-12

    Molecular dynamics simulations of a simple, bead-spring model of semiflexible polyelectrolytes such as DNA are performed. All charges are explicitly treated. Starting from extended, noncondensed conformations, condensed structures form in the simulations with tetravalent or trivalent counterions. No condensates form or are stable for divalent counterions. The mechanism by which condensates form is described. Briefly, condensation occurs because electrostatic interactions dominate entropy, and the favored Coulombic structure is a charge ordered state. Condensation is a generic phenomena and occurs for a variety of polyelectrolyte parameters. Toroids and rods are the condensate structures. Toroids form preferentially when the molecular stiffness is sufficiently strong.

  9. Controlling chaos with simple limiters

    PubMed

    Corron; Pethel; Hopper

    2000-04-24

    New experimental results demonstrate that chaos control can be accomplished using controllers that are very simple relative to the system being controlled. Chaotic dynamics in a driven pendulum and a double scroll circuit are controlled using an adjustable, passive limiter-a weight for the pendulum and a diode for the circuit. For both experiments, multiple unstable periodic orbits are selectively controlled using minimal perturbations. These physical examples suggest that chaos control can be practically applied to a much wider array of important problems than initially thought possible. PMID:11019218

  10. Eventos de Desconexão no Cometa P/Halley sob a Ótica do Modelo de Reconexão Magnética

    NASA Astrophysics Data System (ADS)

    Voelzke, M. R.; Matsuura, O. T.

    1998-08-01

    531 imagens contidas no The International Halley Watch Atlas of Large-Scale Phenomena (Brandt et al., 1992) cobrindo o período de setembro de 1985 a julho de 1986 foram analisadas visando identificar, caracterizar as propriedades e correlacionar estruturas morfológicas da cauda de plasma do cometa P/Halley. A análise revelou 47 eventos de desconexão (DEs) (Niedner & Brandt, 1979; Jockers, 1985; Celnik et al., 1988; Delva et al., 1991). A análise completa de todas as imagens encontra-se publicada em Voelzke & Matsuura, 1998. A distribuição dos DEs na distância heliocêntrica apresenta um caráter bimodal possivelmente associado com a distribuição espacial das fronteiras de setor magnético do meio interplanetário. Os 47 DEs fotografados em 47 imagens distintas permitiram determinar 19 origens de DEs, ou seja, o instante em que supostamente o cometa cruzou a fronteira entre setores magnéticos do vento solar. Tais dados cometários foram comparados com dados do vento solar provenientes de medidas realizadas in situ pelas sondas IMP-8, ICE e PVO, que mediram a variação da velocidade do vento solar, da densidade e da pressão dinâmica durante o intervalo analisado. Os dados destas sondas espaciais em conjunto com os da sonda Vega 1 foram usados para determinar o tempo das passagens do lençol de corrente. Com base nos dados das sondas foram calculadas as coordenadas heliográficas retroativas do lençol de corrente na "superfície fonte" dos mapas sinóticos do campo magnético de Hoeksema, 1989. O cálculo retroativo é feito através de um modelo simples de expressão do vento solar com velocidade uniforme, sendo considerada a co-rotação da magnetosfera com o Sol. Este trabalho apresenta os resultados desta comparação e a análise cinemática da origem dos DEs, determinada sob a hipótese que o plasma desconectado de um dado DE afasta-se com velocidade constante do núcleo cometário (Voelzke & Matsuura, 1998) e compara esta análise com outras que

  11. A Simple Theory for Waterspouts.

    NASA Astrophysics Data System (ADS)

    Rennó, Nilton O.; Bluestein, Howard B.

    2001-04-01

    It is shown that the simple thermodynamic theory for dust devils, proposed by Rennó et al., also applies to waterspouts. The theory is based on the thermodynamics of heat engines and predicts the central pressure and the wind speed of these convective vortices. Moreover, it provides a simple physical interpretation of their general characteristics. In particular, the heat engine theory shows that convective vortices are more likely to form in the regions where the occurrence of the warmest and moistest updrafts and the coldest and driest downdrafts are supported by the local environment. These are the regions where both the heat input into the convective heat engine is maximum and the solenoidal generation of vorticity is the greatest. This explains why waterspouts are frequently observed near the boundaries between relatively warm and relatively cold waters. Moreover, since the work done by the convective heat engine is equal to the total heat input multiplied by the thermodynamic efficiency, the theory shows that another necessary condition for the formation of intense vortices is the presence of intense convection.

  12. Simple theories of complex lattices

    NASA Astrophysics Data System (ADS)

    Peyrard, Michel

    1998-11-01

    While the theory of solitons has been very successful for continuous systems, very few nonlinear discrete lattices are amenable to an exact analytical treatment. In these “complex lattices” discreteness can be hostile to the solitons, preventing them to move due to the lack of translational invariance or even to exist as localized excitations. On the other hand, lattice discreteness can sometimes be very helpful. It can stabilize solutions that otherwise would split apart as in the discrete sine-Gordon lattice, or even allow the existence of localized oscillatory modes as exact solutions in systems where they would decay in the continuum limit. It is interesting that many of these phenomena can be understood qualitatively, and sometimes quantitatively, with very simple theories that rely on the usual concepts of linear wave propagation, resonances, linear stability of waves, for instance. There are, however, phenomena specific to discrete nonlinear lattices which allow the build up of large amplitude localized excitations, sometimes out of thermal fluctuations, which are more resistant to simple approaches and could deserve further interest because they may be relevant for various physical systems.

  13. Simple photoreceptors in Limulus polyphemus.

    PubMed

    Millecchia, R; Bradbury, J; Mauro, A

    1966-12-01

    The "olfactory nerve," the endoparietal eye, and the rudimentary lateral eyes of Limulus (polyphemus) contain simple photoreceptor cells that duplicate many of the electrical responses of the retinular cells of the lateral eye; the responses are a receptor potential consisting of aninitial transient phase and a subsequent steady phase,low-amplitude fluctuations, and a small locally regenerative response to pulses of both light and current. Photic stimulation does not induce conducted action potentials, but does increase the membrane conductance. The receptor potentialrequires the presence of sodium ions in the external medium. Measurements of action and absorption spectra indicate a photopigment whose maximum absorption is of light with wavelength of 535 nanometers. The functional significance of these cells has not been ascertained. PMID:5921383

  14. Simple types of anisotropic inflation

    SciTech Connect

    Barrow, John D.; Hervik, Sigbjoern

    2010-01-15

    We display some simple cosmological solutions of gravity theories with quadratic Ricci curvature terms added to the Einstein-Hilbert Lagrangian which exhibit anisotropic inflation. The Hubble expansion rates are constant and unequal in three orthogonal directions. We describe the evolution of the simplest of these homogeneous and anisotropic cosmological models from its natural initial state and evaluate the deviations they will create from statistical isotropy in the fluctuations produced during a period of anisotropic inflation. The anisotropic inflation is not a late-time attractor in these models but the rate of approach to a final isotropic de Sitter state is slow and is conducive to the creation of observable anisotropic statistical effects in the microwave background. The statistical anisotropy would not be scale invariant and the level of statistical anisotropy will grow with scale.

  15. Quantized Cosmology: A Simple Approach

    SciTech Connect

    Weinstein, M

    2004-06-03

    I discuss the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology and show how, after a simple change of variables, to quantize the problem in a way which parallels the classical discussion. The result is that two of the Einstein equations arise as exact equations of motion and one of the usual Einstein equations (suitably quantized) survives as a constraint equation to be imposed on the space of physical states. However, the Friedmann equation, which is also a constraint equation and which is the basis of the Wheeler-deWitt equation, acquires a welcome quantum correction that becomes significant for small scale factors. To clarify how things work in this formalism I briefly outline the way in which our formalism works for the exactly solvable case of de-Sitter space.

  16. Simple lattice model of macroevolution

    NASA Astrophysics Data System (ADS)

    Borkowski, Wojciech

    2009-04-01

    In future astrobiology, like in modern astrophysics, the numerical simulations can be a very important tool for proving theories. In this paper, I propose a simple lattice model of a multi-species ecosystem suitable for the study of emergent properties of macroevolution. Unlike the majority of ecological models, the number of species is not fixed - they emerge by "mutation" of existing species, then survive or go extinct depending on the balance between local ecological interactions. The Monte-Carlo numerical simulations show that this model is able to qualitatively reproduce phenomena that have been empirically observed, like the dependence between size of the isolated area and the number of species inhabiting there, primary production and species-diversity. The model allows also studying the causes of mass extinctions and more generally, repeatability, and the role of pure chance in macroevolution.

  17. A Simple Statistical Thermodynamics Experiment

    NASA Astrophysics Data System (ADS)

    LoPresto, Michael C.

    2010-03-01

    Comparing the predicted and actual rolls of combinations of both two and three dice can help to introduce many of the basic concepts of statistical thermodynamics, including multiplicity, probability, microstates, and macrostates, and demonstrate that entropy is indeed a measure of randomness, that disordered states (those of higher entropy) are more likely than more ordered ones. It can also show that predictions based on statistics are more accurate with larger samples of data. What follows is a simple experiment introducing some of the basic elements of statistical thermodynamics that can be a light and even fun way to end a unit on thermodynamics, often the end of a challenging first semester of introductory physics.

  18. Simple aging in molecular glasses

    NASA Astrophysics Data System (ADS)

    Niss, Kristine

    2015-03-01

    The glass transition takes place when the structural (alpha) relaxation freezes in and the liquid enters a non-equilibrium solid state. This usually happens when the relaxation time, τ, reaches a timescale of 1000 seconds, and τ = 1000 s is pragmatically used as a definition of the glass transition temperature Tg. However, if the glass is studied on a long enough time scale then relaxation is still seen as physical aging. Aging is a non-linear signature of the alpha relaxation in which the relaxation dynamics changes as a function of how far the system has relaxed. If the system is studied well below Tg then equilibrium will not be achieved, but just below or around Tg it is possible to systematically monitor the non-linear relaxation all the way to equilibrium. We have developed a micro crystat which is optimized for making fast changes in temperature and keeping temperature stable over days and even weeks. Combining this micro cryostat with a small dielectric cell it is possible to monitor non-linear relaxation in a dynamical range of more than 4 decades from 10 seconds to a 105 seconds. The aging is monitored after a fast temperature jump. This means that the aging itself is isotherm, and the data therefore directly shows, how the relaxation-rate changes as volume and structure change on the isotherm. We have studied several molecular liquids and find that the data to a very large extend can be understood in terms of a TNM formalism. This implies time-aging-time superposition and suggests a simple picture where the out of equlibrium ``states'' correspond to equilibrium states - at an other temperature. If the alpha relaxation is dynamically heterogeneous as it is commonly believed, then the aging results show that fast and slow ``modes'' of the relaxation are governed in the same way by structure and volume. We hypothesize that aging according to TNM formalism is an intrinsic property of Roskilde Simple liquids.

  19. Instrumentation for Astronomy Teaching: Projecting the Sun Image. (Spanish Title: Instrumentación Para la Enseñanza de Astronomía: Proyectando la Imagen del Sol.) Instrumentação Para O Ensino de Astronomia: Projetando a Imagem do Sol

    NASA Astrophysics Data System (ADS)

    Catelli, Francisco; Giovan, Odilon; Balen, Osvaldo; Siqueira da Silva, Fernando

    2009-07-01

    In this work we describe a simple optical device to project the Sun image which is useful for solar eclipses observing and for sunspots' size estimating.

    Se describe un dispositivo óptico simple para proyectar la imagen del Sol, lo cual es apropiado para las observaciones de eclipses solares y para estimar las dimensiones de las manchas solares.

    É descrito um dispositivo ótico simples para projetar a imagem do Sol, adequado para observações de eclipses solares e à estimativa do tamanho das manchas solares.

  20. Two Simple Models for Fracking

    NASA Astrophysics Data System (ADS)

    Norris, Jaren Quinn

    Recent developments in fracking have enable the recovery of oil and gas from tight shale reservoirs. These developments have also made fracking one of the most controversial environmental issues in the United States. Despite the growing controversy surrounding fracking, there is relatively little publicly available research. This dissertation introduces two simple models for fracking that were developed using techniques from non-linear and statistical physics. The first model assumes that the volume of induced fractures must be equal to the volume of injected fluid. For simplicity, these fractures are assumed to form a spherically symmetric damage region around the borehole. The predicted volumes of water necessary to create a damage region with a given radius are in good agreement with reported values. The second model is a modification of invasion percolation which was previously introduced to model water flooding. The reservoir rock is represented by a regular lattice of local traps that contain oil and/or gas separated by rock barriers. The barriers are assumed to be highly heterogeneous and are assigned random strengths. Fluid is injected from a central site and the weakest rock barrier breaks allowing fluid to flow into the adjacent site. The process repeats with the weakest barrier breaking and fluid flowing to an adjacent site each time step. Extensive numerical simulations were carried out to obtain statistical properties of the growing fracture network. The network was found to be fractal with fractal dimensions differing slightly from the accepted values for traditional percolation. Additionally, the network follows Horton-Strahler and Tokunaga branching statistics which have been used to characterize river networks. As with other percolation models, the growth of the network occurs in bursts. These bursts follow a power-law size distribution similar to observed microseismic events. Reservoir stress anisotropy is incorporated into the model by assigning

  1. Simple method for model reference adaptive control

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1989-01-01

    A simple method is presented for combined signal synthesis and parameter adaptation within the framework of model reference adaptive control theory. The results are obtained using a simple derivation based on an improved Liapunov function.

  2. Simple Solutions for Treating Dry Mouth

    MedlinePlus

    Patient Education Sheet Simple Solutions for Treating Dry Mouth Clinicians: Please make as many copies of this ... Philadelphia, for authoring “Simple Solutions for Treating Dry Mouth.” Ask your family doctor to discontinue or provide ...

  3. Distribución espacial de órbitas con diferentes grados de caoticidad en modelos autoconsistentes de satélites galácticos

    NASA Astrophysics Data System (ADS)

    Muzzio, J. C.; Mosquera, M.

    En trabajos anteriores (Carpintero et al., Cel. Mech. Dynam. Astron. 85, 247, 2003), mostramos que las órbitas caóticas son muy importantes en los satélites galácticos. Sin embargo, los únicos modelos autoconsistentes de los que se disponía para ellos eran los de Heggie-Ramamani, cuya función de distribución depende sólo de la energía por lo que no mostraban diferencias entre las distribuciones de sus órbitas regulares y caóticas. Ahora, mediante una aproximación cuadrupolar, hemos logrado construir modelos autoconsistentes de satélites galácticos con distribuciones de velocidades anisotrópicas (lo que indica que sus funciones de distribución no dependen sólo de la energía) y hemos logrado revelar las diferencias entre las estructuras espaciales de las órbitas de distinta caoticidad.

  4. Simple molecules as complex systems.

    PubMed

    Furtenbacher, Tibor; Arendás, Péter; Mellau, Georg; Császár, Attila G

    2014-01-01

    For individual molecules quantum mechanics (QM) offers a simple, natural and elegant way to build large-scale complex networks: quantized energy levels are the nodes, allowed transitions among the levels are the links, and transition intensities supply the weights. QM networks are intrinsic properties of molecules and they are characterized experimentally via spectroscopy; thus, realizations of QM networks are called spectroscopic networks (SN). As demonstrated for the rovibrational states of H2(16)O, the molecule governing the greenhouse effect on earth through hundreds of millions of its spectroscopic transitions (links), both the measured and first-principles computed one-photon absorption SNs containing experimentally accessible transitions appear to have heavy-tailed degree distributions. The proposed novel view of high-resolution spectroscopy and the observed degree distributions have important implications: appearance of a core of highly interconnected hubs among the nodes, a generally disassortative connection preference, considerable robustness and error tolerance, and an "ultra-small-world" property. The network-theoretical view of spectroscopy offers a data reduction facility via a minimum-weight spanning tree approach, which can assist high-resolution spectroscopists to improve the efficiency of the assignment of their measured spectra. PMID:24722221

  5. Simple Substrates for Complex Cognition

    PubMed Central

    Dayan, Peter

    2008-01-01

    Complex cognitive tasks present a range of computational and algorithmic challenges for neural accounts of both learning and inference. In particular, it is extremely hard to solve them using the sort of simple policies that have been extensively studied as solutions to elementary Markov decision problems. There has thus been recent interest in architectures for the instantiation and even learning of policies that are formally more complicated than these, involving operations such as gated working memory. However, the focus of these ideas and methods has largely been on what might best be considered as automatized, routine or, in the sense of animal conditioning, habitual, performance. Thus, they have yet to provide a route towards understanding the workings of rule-based control, which is critical for cognitively sophisticated competence. Here, we review a recent suggestion for a uniform architecture for habitual and rule-based execution, discuss some of the habitual mechanisms that underpin the use of rules, and consider a statistical relationship between rules and habits. PMID:19225599

  6. Simple molecules as complex systems

    PubMed Central

    Furtenbacher, Tibor; Árendás, Péter; Mellau, Georg; Császár, Attila G.

    2014-01-01

    For individual molecules quantum mechanics (QM) offers a simple, natural and elegant way to build large-scale complex networks: quantized energy levels are the nodes, allowed transitions among the levels are the links, and transition intensities supply the weights. QM networks are intrinsic properties of molecules and they are characterized experimentally via spectroscopy; thus, realizations of QM networks are called spectroscopic networks (SN). As demonstrated for the rovibrational states of H216O, the molecule governing the greenhouse effect on earth through hundreds of millions of its spectroscopic transitions (links), both the measured and first-principles computed one-photon absorption SNs containing experimentally accessible transitions appear to have heavy-tailed degree distributions. The proposed novel view of high-resolution spectroscopy and the observed degree distributions have important implications: appearance of a core of highly interconnected hubs among the nodes, a generally disassortative connection preference, considerable robustness and error tolerance, and an “ultra-small-world” property. The network-theoretical view of spectroscopy offers a data reduction facility via a minimum-weight spanning tree approach, which can assist high-resolution spectroscopists to improve the efficiency of the assignment of their measured spectra. PMID:24722221

  7. Asymptotic safety: A simple example

    SciTech Connect

    Braun, Jens; Gies, Holger; Scherer, Daniel D.

    2011-04-15

    We use the Gross-Neveu model in 2simple fermionic example for Weinberg's asymptotic safety scenario: despite being perturbatively nonrenormalizable, the model defines an interacting quantum field theory being valid to arbitrarily high momentum scales owing to the existence of a non-Gaussian fixed point. Using the functional renormalization group, we study the uv behavior of the model in both the purely fermionic as well as a partially bosonized language. We show that asymptotic safety is realized at non-Gaussian fixed points in both formulations, the universal critical exponents of which we determine quantitatively. The partially bosonized formulation allows to make contact to the large-N{sub f} expansion where the model is known to be renormalizable to all orders. In this limit, the fixed-point action as well as all universal critical exponents can be computed analytically. As asymptotic safety has become an important scenario for quantizing gravity, our description of a well-understood model is meant to provide for an easily accessible and controllable example of modern nonperturbative quantum field theory.

  8. SSL - THE SIMPLE SOCKETS LIBRARY

    NASA Technical Reports Server (NTRS)

    Campbell, C. E.

    1994-01-01

    The Simple Sockets Library (SSL) allows C programmers to develop systems of cooperating programs using Berkeley streaming Sockets running under the TCP/IP protocol over Ethernet. The SSL provides a simple way to move information between programs running on the same or different machines and does so with little overhead. The SSL can create three types of Sockets: namely a server, a client, and an accept Socket. The SSL's Sockets are designed to be used in a fashion reminiscent of the use of FILE pointers so that a C programmer who is familiar with reading and writing files will immediately feel comfortable with reading and writing with Sockets. The SSL consists of three parts: the library, PortMaster, and utilities. The user of the SSL accesses it by linking programs to the SSL library. The PortMaster initializes connections between clients and servers. The PortMaster also supports a "firewall" facility to keep out socket requests from unapproved machines. The "firewall" is a file which contains Internet addresses for all approved machines. There are three utilities provided with the SSL. SKTDBG can be used to debug programs that make use of the SSL. SPMTABLE lists the servers and port numbers on requested machine(s). SRMSRVR tells the PortMaster to forcibly remove a server name from its list. The package also includes two example programs: multiskt.c, which makes multiple accepts on one server, and sktpoll.c, which repeatedly attempts to connect a client to some server at one second intervals. SSL is a machine independent library written in the C-language for computers connected via Ethernet using the TCP/IP protocol. It has been successfully compiled and implemented on a variety of platforms, including Sun series computers running SunOS, DEC VAX series computers running VMS, SGI computers running IRIX, DECstations running ULTRIX, DEC alpha AXPs running OSF/1, IBM RS/6000 computers running AIX, IBM PC and compatibles running BSD/386 UNIX and HP Apollo 3000

  9. Are polar liquids less simple?

    NASA Astrophysics Data System (ADS)

    Fragiadakis, D.; Roland, C. M.

    2013-03-01

    Strong correlation between equilibrium fluctuations under isochoric conditions of the potential energy, U, and the virial, W, is a characteristic of liquids that implies the presence of certain dynamic properties, such as density scaling of the relaxation times and isochronal superpositioning of the relaxation function. In this work we employ molecular dynamics simulations on methanol and two variations, lacking hydrogen bonds and a dipole moment, to assess the connection between the correlation of U and W and these dynamic properties. We show, in accord with prior results of others [T. S. Ingebrigtsen, T. B. Schrøder, and J. C. Dyre, Phys. Rev. X 2, 011011 (2012), 10.1103/PhysRevX.2.011011], that simple van der Waals liquids exhibit both strong correlations and the expected dynamic behavior. However, for polar liquids this correspondence breaks down—weaker correlation between U and W is not associated with worse conformance to density scaling or isochronal superpositioning. The reason for this is that strong correlation between U and W only requires their proportionality, whereas the expected dynamic behavior depends primarily on constancy of the proportionality constant for all state points. For hydrogen-bonded liquids, neither strong correlation nor adherence to the dynamic properties is observed; however, this nonconformance is not directly related to the concentration of hydrogen bonds, but rather to the greater deviation of the intermolecular potential from an inverse power law (IPL). Only (hypothetical) liquids having interactions governed strictly by an IPL are perfectly correlating and exhibit the consequent dynamic properties over all thermodynamic conditions.

  10. Colligative properties of simple solutions.

    PubMed

    Andrews, F C

    1976-11-01

    Vapor pressure lowering, osmotic pressure, boiling point elevation, and freezing point depression are all related quantitatively to the decrease in micro(1)(soln) upon the addition of solute in forming a solution. In any equilibrium system, regardless of whether it is in a gravitational field or whether it contains walls, semipermeable membranes, phase transitions, or solutes, all equilibria are maintained locally, in the small region of the equilibrium, by the equality of micro(1)(soln). If there are several subsystems in a gravitational field, at any fixed height, microi will have the same value in each subsystem into which substance i can get, and microi + M(i)gh is constant throughout the entire system. In a solution, there is no mechanism by which solvent and solute molecules could sustain different pressures. Both the solvent and solute are always under identical pressures in a region of solution, namely, the pressure of the solution in that region. Since nature does not know which component we call the solvent and which the solute, equations should be symmetric in the two (acknowledging that the nonvolatile component, if any, is commonly chosen to be solute). Simple molecular pictures illustrate what is happening to cause pressure (positive or negative) in liquids, vapor pressure of liquids, and the various colligative properties of solutions. The only effect of solute involved in these properties is that it dilutes the solvent, with the resulting increase in S and decrease in micro(1)(soln). Water can be driven passively up a tree to enormous heights by the difference between its chemical potential in the roots and the ambient air. There is nothing mysterious about the molecular bases for any of these phenomena. Biologists can use the well-understood pictures of these phenomena with confidence to study what is happening in the complicated living systems they consider. PMID:17818408

  11. Modelo de atmosfera solar ajustado às observações do raio solar em 17GHz

    NASA Astrophysics Data System (ADS)

    Selhorst, C. L.; Silva, A. V. R.; Costa, J. E. R.

    2003-08-01

    O estudo das variações do raio solar durante o ciclo de atividades do Sol e das diferenças em relação à sua distribuição angular nos fornece informações importantes sobre as mudanças na estrutura da atmosfera solar. Neste trabalho foram analisados mais de 3600 mapas do Sol em 17 GHz obtidos pelo Rádio Heliógrafo de Nobeyama (NoRH), durante 1 ciclo de atividade solar (1992-2003). O raio solar foi definido no ponto onde a temperatura de brilho do mapa era equivalente à metade da temperatura do Sol calmo (temperatura mais comum no mapa).Em relação à sua variação ao longo do ciclo solar, o estudo foi dividido em duas partes: a) ajuste de uma circunferência a pontos distribuídos ao redor do Sol todo. Este estudo mostrou uma variação correlacionada com o ciclo de atividade do Sol. b) ajuste da circunferência a pontos situados somente nas regiões polares. Neste caso os resultados mostraram que o raio polar sofre pouca variação durante o ciclo, com tendência à anticorrelação com este. Além disto, a média do raio polar, durante o período analisado, foi 1" menor que o raio medido no Sol todo. Para estudar a distribuição angular do raio solar, comparamos a média da distribuição de 10 mapas no período de mínima atividade solar com a média de 10 mapas no período de máximo, este estudo mostrou um grande aumento do raio na região equatorial no período de máxima atividade solar. As medidas do raio foram usadas como um dos parâmetros para a criação de um modelo atmosférico (além da temperatura de brilho do Sol e do abrilhantamento do limbo observado), onde mostramos que um modelo atmosférico com a região de transição situada a 3500 km fornece um raio 5" menor que as medidas observacionais. Esta incompatibilidade do modelo com os dados observacionais foi contornada com a inclusão de espículas, estas fazem com que o raio solar aumente proporcionalmente à altura que estas atingem na atmosfera solar. A anticorrelação do raio

  12. Tiempo para un cambio

    NASA Astrophysics Data System (ADS)

    Woltjer, L.

    1987-06-01

    En la reunion celebrada en diciembre dei ano pasado informe al Consejo de mi deseo de terminar mi contrato como Director General de la ESO una vez que fuera aprobado el proyecto dei VLT, que se espera sucedera hacia fines de este aAo. Cuando fue renovada mi designacion hace tres aAos, el Consejo conocia mi intencion de no completar los cinco aAos dei contrato debido a mi deseo de disponer de mas tiempo para otras actividades. Ahora, una vez terminada la fase preparatoria para el VLT, Y habiendose presentado el proyecto formalmente al Consejo el dia 31 de marzo, y esperando su muy probable aprobacion antes dei termino de este ano, me parece que el 10 de enero de 1988 presenta una excelente fecha para que se produzca un cambio en la administracion de la ESO.

  13. Transferências orbitais dentro do modelo quase bicircular no sistema Terra-Lua-Sol

    NASA Astrophysics Data System (ADS)

    Corrêa, A. A.; de Almeida Prado, A. F. B.; Stuchi, T. J.; Beaugé, C.

    2003-08-01

    O problema quase bicircular planar consiste na determinação da dinâmica de um corpo, de massa desprezível, que se move sob o campo gravitacional de três corpos. No caso estudado, o quarto corpo é considerado um satélite artificial e os demais são a Terra, a Lua e o Sol, formando o sistema de três corpos. Este modelo permite a construção de uma hamiltoniana similar a do problema restrito de três corpos (PRTC), incluindo termos periódicos não autônomos, provenientes da presença do Sol, portanto pode ser entendido como uma perturbação ao PRTC. Suas órbitas periódicas aparecem isoladas e possuem o mesmo período solar. Os pontos de equilíbrio colineares possuem o mesmo caráter de estabilidade linear dos pontos lagrangianos (L1, L2 e L3) do PRTC, sendo do tipo sela x centro x centro, instável na direção x e estáveis nas direções y e z. As órbitas periódicas tridimensionais ao redor do ponto colinear é chamada órbita Halo. O objetivo deste trabalho é determinar órbitas de transferências de baixo consumo de combustível para um veículo espacial partindo de uma órbita de estacionamento ao redor da Terra em direção a uma órbita Halo do ponto L1, situado entre a Terra e Lua. Esta tarefa pode ser transformada no problema de valor de contorno: dado um ponto inicial na órbita de estacionamento, um ponto final na órbita halo e o tempo de transferência, deseja-se obter a trajetória que liga estes dois pontos e que minimize os incrementos de velocidade do veículo. Essas transferências são realizadas baseadas no método de Lambert e analisadas de modo a fornecer um baixo consumo. Posteriormente, é feita uma comparação de consumo com as órbitas de transferência equivalentes do PRTC.

  14. Modelos para la Unificacion de Conceptos, Metodos y Procedimientos Administrativos (Guidelines for Uniform Administrative Concepts, Methods, and Procedures).

    ERIC Educational Resources Information Center

    Serrano, Jorge A., Ed.

    These documents, discussed and approved during the first meeting of the university administrators affiliated with the Federation of Private Universities of Central America and Panama (FUPAC), seek to establish uniform administrative concepts, methods, and procedures, particularly with respect to budgetary matters. The documents define relevant…

  15. Cuatro Modelos para Disenar Actividades de Capacitacion de Docentes (Four Models to Design In-Service Teacher Training Activities).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    In designing inservice teacher training activities, it is necessary to apply educational principles and teaching and learning techniques which are suitable for adult education programs. Four models for designing inservice teacher training programs are the Malcom Knowles Model, the Leonard Nadler Model, the Cyril O. Houle Model, and the William R.…

  16. Comunicacion, Lengua Materna: Un Modelo Holistico para su Desarollo (Communication, Mother Tongue: A Holistic Model for Development).

    ERIC Educational Resources Information Center

    Aquino, Orlando Fernandez

    2000-01-01

    Recounts the author's educational experiences between 1991-1995 as a university writing teacher and tutorial assistant for scientific papers at the secondary level. Presents a methodology integrally developed in four steps that can be applied to different levels of teaching and a series of conclusive theses about the subject. (BT)

  17. Modelos de instruccion para la educacion en la ninez temprana (Instructional Models for Early Childhood Education). ERIC Digest.

    ERIC Educational Resources Information Center

    Golbeck, Susan L.

    As teachers, researchers, and policy makers strive to ensure that all children enter school "ready to learn," no question is more pressing than: "What is the best approach for teaching young children?" This digest discusses the existing knowledge base on the differential effects of various approaches to early education. The digest first summarizes…

  18. Simple scale interpolator facilitates reading of graphs

    NASA Technical Reports Server (NTRS)

    Fetterman, D. E., Jr.

    1965-01-01

    Simple transparent overlay with interpolation scale facilitates accurate, rapid reading of graph coordinate points. This device can be used for enlarging drawings and locating points on perspective drawings.

  19. Incorporando a variabilidade no processo de identificação do modelo de máximo global no Grade of Membership (GoM): considerações metodológicas

    PubMed Central

    Guedes, Gilvan Ramalho; Siviero, Pamila Cristina Lima; Caetano, André Junqueira; Machado, Carla Jorge; Brondízio, Eduardo

    2012-01-01

    A disponibilidade de bases de dados cada vez mais complexas e multidimensionais é um dos principais motivadores para o aumento do número de estudos que utilizam análises multivariadas baseadas em lógica de conjuntos nebulosos. Apesar da disseminação do método Grade of Membership nos trabalhos empíricos brasileiros da área de ciências sociais e saúde, questões relativas à identificabilidade e estabilidade dos parâmetros finais estimados pelo programa GoM 3.4 não foram suficientemente aprofundadas. Dada a relevância de se obterem parâmetros únicos e estáveis, Guedes et al. (2010) propuseram um procedimento empírico para localizar um modelo de máximo global (MG) com parâmetros estáveis. Entretanto, seu localizador de MG não incorpora qualquer medida de variabilidade. Neste artigo, tal limitação é contornada por meio da utilização de uma estatística de ponderação – Máximo Global Ponderado (MGP) – semelhante ao coeficiente de variação. Esse indicador busca não penalizar de forma desproporcional situações nas quais os desvios médios, apesar de diferentes de zero, são muito pequenos. Apresentam-se evidências de que o localizador MGP reduz a distância do modelo identificado à real estrutura latente dos dados em análise, quando comparados ao modelo identificado pelo localizador não ponderado, MG. PMID:23293402

  20. Modelo Pedagogico de Educacion Primaria para Adultos: Guia General de Apoyo para el Estudiante de Primaria (Pedagogical Model for Adult Primary Education: General Guide for the Student).

    ERIC Educational Resources Information Center

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    This book, part of a Mexican series of instructional materials, is directed toward people over the age of 15 who are interested in beginning, continuing or finishing their basic education. It explains the pedagogical model developed for adult education in Mexico based on the following features: (1) the content of the textbooks must be useful for…

  1. A simple approach to nonlinear oscillators

    NASA Astrophysics Data System (ADS)

    Ren, Zhong-Fu; He, Ji-Huan

    2009-10-01

    A very simple and effective approach to nonlinear oscillators is suggested. Anyone with basic knowledge of advanced calculus can apply the method to finding approximately the amplitude-frequency relationship of a nonlinear oscillator. Some examples are given to illustrate its extremely simple solution procedure and an acceptable accuracy of the obtained solutions.

  2. Simple Numerical Analysis of Longboard Speedometer Data

    ERIC Educational Resources Information Center

    Hare, Jonathan

    2013-01-01

    Simple numerical data analysis is described, using a standard spreadsheet program, to determine distance, velocity (speed) and acceleration from voltage data generated by a skateboard/longboard speedometer (Hare 2012 "Phys. Educ." 47 409-17). This simple analysis is an introduction to data processing including scaling data as well as…

  3. Sunspots and Their Simple Harmonic Motion

    ERIC Educational Resources Information Center

    Ribeiro, C. I.

    2013-01-01

    In this paper an example of a simple harmonic motion, the apparent motion of sunspots due to the Sun's rotation, is described, which can be used to teach this subject to high-school students. Using real images of the Sun, students can calculate the star's rotation period with the simple harmonic motion mathematical expression.

  4. Restoration Monitoring - A Simple Photo Monitoring Method

    SciTech Connect

    Nelson, J.K.

    2000-02-14

    Through the use of a simple photo monitoring design, it is possible to visually document, with both landscape and ground views, the progression of a restoration/revegetation project in a repeatable, cost-effective manner. The use of web browser technology can display the results in a simple, informative, professional manner, suitable for presentations and displays.

  5. The Fluid Foil: The Seventh Simple Machine

    ERIC Educational Resources Information Center

    Mitts, Charles R.

    2012-01-01

    A simple machine does one of two things: create a mechanical advantage (lever) or change the direction of an applied force (pulley). Fluid foils are unique among simple machines because they not only change the direction of an applied force (wheel and axle); they convert fluid energy into mechanical energy (wind and Kaplan turbines) or vice versa,…

  6. MHD simple waves and the divergence wave

    SciTech Connect

    Webb, G. M.; Pogorelov, N. V.; Zank, G. P.

    2010-03-25

    In this paper we investigate magnetohydrodynamic (MHD) simple divergence waves in MHD, for models in which nablacentre dotBnot =0. These models are related to the eight wave Riemann solvers in numerical MHD, in which the eighth wave is the divergence wave associated with nablacentre dotBnot =0. For simple wave solutions, all physical variables (the gas density, pressure, fluid velocity, entropy, and magnetic field induction in the MHD case) depend on a single phase function phi. We consider the form of the MHD equations used by both Powell et al. and Janhunen. It is shown that the Janhunen version of the equations possesses fully nonlinear, exact simple wave solutions for the divergence wave, but no physically meaningful simple divergence wave solution exists for the Powell et al. system. We suggest that the 1D simple, divergence wave solution for the Janhunen system, may be useful for the testing and validation of numerical MHD codes.

  7. Simple shear of deformable square objects

    NASA Astrophysics Data System (ADS)

    Treagus, Susan H.; Lan, Labao

    2003-12-01

    Finite element models of square objects in a contrasting matrix in simple shear show that the objects deform to a variety of shapes. For a range of viscosity contrasts, we catalogue the changing shapes and orientations of objects in progressive simple shear. At moderate simple shear ( γ=1.5), the shapes are virtually indistinguishable from those in equivalent pure shear models with the same bulk strain ( RS=4), examined in a previous study. In theory, differences would be expected, especially for very stiff objects or at very large strain. In all our simple shear models, relatively competent square objects become asymmetric barrel shapes with concave shortened edges, similar to some types of boudin. Incompetent objects develop shapes surprisingly similar to mica fish described in mylonites.

  8. Thirty Simple Ideas for Interactive Whiteboards

    ERIC Educational Resources Information Center

    Adams, Caralee

    2011-01-01

    This article presents thirty simple ideas for interactive whiteboards and how IWB can make one's teaching life easier. These teaching ideas for the interactive whiteboard can be used by teachers every day. Tips for classroom management are also presented.

  9. Simple and Clear Proofs of Stirling's Formula

    ERIC Educational Resources Information Center

    Niizeki, Shozo; Araki, Makoto

    2010-01-01

    The purpose of our article is to show two simpler and clearer methods of proving Stirling's formula than the traditional and conventional ones. The distinction of our method is to use the simple trapezoidal formula.

  10. Pendulum: Rich physics from a simple system

    SciTech Connect

    Nelson, R.A.; Olsson, M.G.

    1986-02-01

    We provide a comprehensive discussion of the corrections needed to accurately measure the acceleration of gravity using a plane pendulum. A simple laboratory experiment is described in which g was determined to four significant figures of accuracy.

  11. The Invention Convention: Mind Meets Simple Machines.

    ERIC Educational Resources Information Center

    Hadi-Tabassum, Samina

    1997-01-01

    Describes an Earth Day celebration where students had to design an invention made of simple machines that could crush an empty aluminum can through 10 rapid mechanical movements using materials foraged from the students' homes. (JRH)

  12. A simple and inexpensive external fixator.

    PubMed

    Noor, M A

    1988-11-01

    A simple and inexpensive external fixator has been designed. It is constructed of galvanized iron pipe and mild steel bolts and nuts. It can easily be manufactured in a hospital workshop with a minimum of tools. PMID:3267638

  13. Modelo B/Dual Language Programmes in the Basque Country and the USA

    ERIC Educational Resources Information Center

    Torres-Guzman, Maria E.; Etxeberria, Feli

    2005-01-01

    In this paper, we undertake a cross-national comparison of early partial immersion programmes, known as dual language or Modelo B programmes, in the USA and the Basque Country in Spain, respectively. We attempt to make sense of their growth, the expanded social uses of the minority languages, and address seemingly contradictory pedagogical…

  14. Vínculos observacionais para o processo-S em estrelas gigantes de Bário

    NASA Astrophysics Data System (ADS)

    Smiljanic, R. H. S.; Porto de Mello, G. F.; da Silva, L.

    2003-08-01

    Estrelas de bário são gigantes vermelhas de tipo GK que apresentam excessos atmosféricos dos elementos do processo-s. Tais excessos são esperados em estrelas na fase de pulsos térmicos do AGB (TP-AGB). As estrelas de bário são, no entanto, menos massivas e menos luminosas que as estrelas do AGB, assim, não poderiam ter se auto-enriquecido. Seu enriquecimento teria origem em uma estrela companheira, inicialmente mais massiva, que evolui pelo TP-AGB, se auto-enriquece com os elementos do processo-s e transfere material contaminado para a atmosfera da atual estrela de bário. A companheira evolui então para anã branca deixando de ser observada diretamente. As estrelas de bário são, portanto, úteis como testes observacionais para teorias de nucleossíntese pelo processo-s, convecção e perda de massa. Análises detalhadas de abundância com dados de alta qualidade para estes objetos são ainda escassas na literatura. Neste trabalho construímos modelos de atmosferas e, procedendo a uma análise diferencial, determinamos parâmetros atmosféricos e evolutivos de uma amostra de dez gigantes de bário e quatro normais. Determinamos seus padrões de abundância para Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu e Gd, concluindo que algumas estrelas classificadas na literatura como gigantes de bário são na verdade gigantes normais. Comparamos dois padrões médios de abundância, para estrelas com grandes excessos e estrelas com excessos moderados, com modelos teóricos de enriquecimento pelo processo-s. Os dois grupos de estrelas são ajustados pelos mesmos parâmetros de exposição de nêutrons. Tal resultado sugere que a ocorrência do fenômeno de bário com diferentes intensidades não se deve a diferentes exposições de nêutrons. Discutimos ainda efeitos nucleossintéticos, ligados ao processo-s, sugeridos na literatura para os elementos Cu, Mn, V e Sc.

  15. The Design of SimpleITK

    PubMed Central

    Lowekamp, Bradley C.; Chen, David T.; Ibáñez, Luis; Blezek, Daniel

    2013-01-01

    SimpleITK is a new interface to the Insight Segmentation and Registration Toolkit (ITK) designed to facilitate rapid prototyping, education and scientific activities via high level programming languages. ITK is a templated C++ library of image processing algorithms and frameworks for biomedical and other applications, and it was designed to be generic, flexible and extensible. Initially, ITK provided a direct wrapping interface to languages such as Python and Tcl through the WrapITK system. Unlike WrapITK, which exposed ITK's complex templated interface, SimpleITK was designed to provide an easy to use and simplified interface to ITK's algorithms. It includes procedural methods, hides ITK's demand driven pipeline, and provides a template-less layer. Also SimpleITK provides practical conveniences such as binary distribution packages and overloaded operators. Our user-friendly design goals dictated a departure from the direct interface wrapping approach of WrapITK, toward a new facade class structure that only exposes the required functionality, hiding ITK's extensive template use. Internally SimpleITK utilizes a manual description of each filter with code-generation and advanced C++ meta-programming to provide the higher-level interface, bringing the capabilities of ITK to a wider audience. SimpleITK is licensed as open source software library under the Apache License Version 2.0 and more information about downloading it can be found at http://www.simpleitk.org. PMID:24416015

  16. The Design of SimpleITK.

    PubMed

    Lowekamp, Bradley C; Chen, David T; Ibáñez, Luis; Blezek, Daniel

    2013-01-01

    SimpleITK is a new interface to the Insight Segmentation and Registration Toolkit (ITK) designed to facilitate rapid prototyping, education and scientific activities via high level programming languages. ITK is a templated C++ library of image processing algorithms and frameworks for biomedical and other applications, and it was designed to be generic, flexible and extensible. Initially, ITK provided a direct wrapping interface to languages such as Python and Tcl through the WrapITK system. Unlike WrapITK, which exposed ITK's complex templated interface, SimpleITK was designed to provide an easy to use and simplified interface to ITK's algorithms. It includes procedural methods, hides ITK's demand driven pipeline, and provides a template-less layer. Also SimpleITK provides practical conveniences such as binary distribution packages and overloaded operators. Our user-friendly design goals dictated a departure from the direct interface wrapping approach of WrapITK, toward a new facade class structure that only exposes the required functionality, hiding ITK's extensive template use. Internally SimpleITK utilizes a manual description of each filter with code-generation and advanced C++ meta-programming to provide the higher-level interface, bringing the capabilities of ITK to a wider audience. SimpleITK is licensed as open source software library under the Apache License Version 2.0 and more information about downloading it can be found at http://www.simpleitk.org. PMID:24416015

  17. Simple microfluidic stagnation point flow geometries.

    PubMed

    Dockx, Greet; Verwijlen, Tom; Sempels, Wouter; Nagel, Mathias; Moldenaers, Paula; Hofkens, Johan; Vermant, Jan

    2016-07-01

    A geometrically simple flow cell is proposed to generate different types of stagnation flows, using a separation flow and small variations of the geometric parameters. Flows with high local deformation rates can be changed from purely rotational, over simple shear flow, to extensional flow in a region surrounding a stagnation point. Computational fluid dynamic calculations are used to analyse how variations of the geometrical parameters affect the flow field. These numerical calculations are compared to the experimentally obtained streamlines of different designs, which have been determined by high speed confocal microscopy. As the flow type is dictated predominantly by the geometrical parameters, such simple separating flow devices may alleviate the requirements for flow control, while offering good stability for a wide variety of flow types. PMID:27462382

  18. Maximal temperature in a simple thermodynamical system

    NASA Astrophysics Data System (ADS)

    Dai, De-Chang; Stojkovic, Dejan

    2016-06-01

    Temperature in a simple thermodynamical system is not limited from above. It is also widely believed that it does not make sense talking about temperatures higher than the Planck temperature in the absence of the full theory of quantum gravity. Here, we demonstrate that there exist a maximal achievable temperature in a system where particles obey the laws of quantum mechanics and classical gravity before we reach the realm of quantum gravity. Namely, if two particles with a given center of mass energy come at the distance shorter than the Schwarzschild diameter apart, according to classical gravity they will form a black hole. It is possible to calculate that a simple thermodynamical system will be dominated by black holes at a critical temperature which is about three times lower than the Planck temperature. That represents the maximal achievable temperature in a simple thermodynamical system.

  19. Interacción de resonancias y transición al caos en un modelo dinámico simple

    NASA Astrophysics Data System (ADS)

    Mestre, M.; Cincotta, P.; Giordano, C.

    In this paper we study the transition to global chaos in a perturbed 2D quartic oscillator. We estimate both, analitically and numerically, the intensity of the perturbation required to have the majority of the phase space dominated by a chaotic dynamics. FULL TEXT IN SPANISH

  20. Lunar Simple Crater Impact Melt Volumes

    NASA Technical Reports Server (NTRS)

    Plescia, Jeffrey B.; Barnouin, O. S.; Cintala, Mark J.

    2013-01-01

    Impact melt is observed in simple lunar craters having diameters as small as less than 200 m. The presence of ponds of impact melt on the floor of such small craters is interpreted to indicate vertical impacts. Data from the LRO LROC and LOLA experiments allow quantitative estimates of the volume of impact melt in simple crater. Such estimates allow for validation of theoretical models of impact melt generation and examination of target effects. Preliminary data have considerable scatter but are broadly consistent with the models.

  1. Simple cloud chambers using gel ice packs

    NASA Astrophysics Data System (ADS)

    Kamata, Masahiro; Kubota, Miki

    2012-07-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry ice or liquid nitrogen. The gel can be frozen in normal domestic freezers, and can be used repeatedly by re-freezing. The tracks of alpha-ray particles can be observed continuously for about 20 min, and the operation is simple and easy.

  2. Investigating decoherence in a simple system

    NASA Technical Reports Server (NTRS)

    Albrecht, Andreas

    1991-01-01

    The results of some simple calculations designed to study quantum decoherence are presented. The physics of quantum decoherence are briefly reviewed, and a very simple 'toy' model is analyzed. Exact solutions are found using numerical techniques. The type of incoherence exhibited by the model can be changed by varying a coupling strength. The author explains why the conventional approach to studying decoherence by checking the diagonality of the density matrix is not always adequate. Two other approaches, the decoherence functional and the Schmidt paths approach, are applied to the toy model and contrasted to each other. Possible problems with each are discussed.

  3. Simple 2-D navigation for wheeled vehicles

    SciTech Connect

    Klarer, P.R.

    1988-01-01

    This paper describes a simple algorithm to perform navigation in a two-dimensional world model. The algorithm utilizes a simple geometric approach which is first applied to a bicycle. The equations are then expeanded to apply to 3- and 4-wheeled vehicles with ''conventional'' steering mechanism (such as the Ackerman steering geometry in the 4-wheeled case). Calculations for omnidirectional robots which utilize differential odometry and differential drive are described as well. Practical considerations and sources of error are discussed, as are possible extensions of this method to a three-dimensional world model. 5 refs., 8 figs.

  4. Simple 2-D navigation for wheeled vehicles

    SciTech Connect

    Klarer, P.R.

    1988-04-01

    This paper describes a simple algorithm to perform navigation in a two-dimensional world model. The algorithm utilizes a simple geometric approach which is first applied to a bicycle. The equations are then expanded to apply to 3- and 4-wheeled vehicles with ''conventional'' steering mechanisms (such as the Ackerman steering geometry in the 4-wheeled case). Calculations for omnidirectional robots which utilize differential odometry and differential drive are described as well. Practical considerations and sources of error are discussed, as are possible extensions of this method to a three-dimensional world model. 5 refs., 8 figs.

  5. Circularly Polarized Luminescence from Simple Organic Molecules.

    PubMed

    Sánchez-Carnerero, Esther M; Agarrabeitia, Antonia R; Moreno, Florencio; Maroto, Beatriz L; Muller, Gilles; Ortiz, María J; de la Moya, Santiago

    2015-09-21

    This article aims to show the identity of "circularly polarized luminescent active simple organic molecules" as a new concept in organic chemistry due to the potential interest of these molecules, as availed by the exponentially growing number of research articles related to them. In particular, it describes and highlights the interest and difficulty in developing chiral simple (small and non-aggregated) organic molecules able to emit left- or right-circularly polarized light efficiently, the efforts realized up to now to reach this challenging objective, and the most significant milestones achieved to date. General guidelines for the preparation of these interesting molecules are also presented. PMID:26136234

  6. TRSkit: A Simple Digital Library Toolkit

    NASA Technical Reports Server (NTRS)

    Nelson, Michael L.; Esler, Sandra L.

    1997-01-01

    This paper introduces TRSkit, a simple and effective toolkit for building digital libraries on the World Wide Web. The toolkit was developed for the creation of the Langley Technical Report Server and the NASA Technical Report Server, but is applicable to most simple distribution paradigms. TRSkit contains a handful of freely available software components designed to be run under the UNIX operating system and served via the World Wide Web. The intended customer is the person that must continuously and synchronously distribute anywhere from 100 - 100,000's of information units and does not have extensive resources to devote to the problem.

  7. Precision measurements of a simple chaotic circuit

    NASA Astrophysics Data System (ADS)

    Kiers, Ken; Schmidt, Dory; Sprott, J. C.

    2004-04-01

    We describe a simple nonlinear electrical circuit that can be used to study chaotic phenomena. The circuit employs simple electronic elements such as diodes, resistors, and operational amplifiers, and is easy to construct. A novel feature of the circuit is its use of an almost ideal nonlinear element, which is straightforward to model theoretically and leads to excellent agreement between experiment and theory. For example, comparisons of bifurcation points and power spectra give agreement to within 1%. The circuit yields a broad range of behavior and is well suited for qualitative demonstrations and as a serious research tool.

  8. Using Simple Machines to Leverage Learning

    ERIC Educational Resources Information Center

    Dotger, Sharon

    2008-01-01

    What would your students say if you told them they could lift you off the ground using a block and a board? Using a simple machine, they'll find out they can, and they'll learn about work, energy, and motion in the process! In addition, this integrated lesson gives students the opportunity to investigate variables while practicing measurement…

  9. Amplitude Frequency Response Measurement: A Simple Technique

    ERIC Educational Resources Information Center

    Satish, L.; Vora, S. C.

    2010-01-01

    A simple method is described to combine a modern function generator and a digital oscilloscope to configure a setup that can directly measure the amplitude frequency response of a system. This is achieved by synchronously triggering both instruments, with the function generator operated in the "Linear-Sweep" frequency mode, while the oscilloscope…

  10. Air: Simple Experiments for Young Scientists.

    ERIC Educational Resources Information Center

    White, Larry

    This book contains simple experiments through which students explore air and its properties. Some of the topics discussed include alternative energy, bacteria, carbon dioxide, motion, weather, and flight. Experiments include: blowing a balloon up in a bottle; seeing air in water; making a lunch-bag kite, weather vanes, and paper glider;…

  11. Seismic Safety Of Simple Masonry Buildings

    SciTech Connect

    Guadagnuolo, Mariateresa; Faella, Giuseppe

    2008-07-08

    Several masonry buildings comply with the rules for simple buildings provided by seismic codes. For these buildings explicit safety verifications are not compulsory if specific code rules are fulfilled. In fact it is assumed that their fulfilment ensures a suitable seismic behaviour of buildings and thus adequate safety under earthquakes. Italian and European seismic codes differ in the requirements for simple masonry buildings, mostly concerning the building typology, the building geometry and the acceleration at site. Obviously, a wide percentage of buildings assumed simple by codes should satisfy the numerical safety verification, so that no confusion and uncertainty have to be given rise to designers who must use the codes. This paper aims at evaluating the seismic response of some simple unreinforced masonry buildings that comply with the provisions of the new Italian seismic code. Two-story buildings, having different geometry, are analysed and results from nonlinear static analyses performed by varying the acceleration at site are presented and discussed. Indications on the congruence between code rules and results of numerical analyses performed according to the code itself are supplied and, in this context, the obtained result can provide a contribution for improving the seismic code requirements.

  12. Simple high-temperature thermal diffusivity apparatus

    NASA Technical Reports Server (NTRS)

    Wood, C.; Zoltan, A.

    1984-01-01

    A simple and inexpensive thermal diffusivity apparatus is described for measurement up to 1600 K. The novel features of apparatus include a light pipe, a long furnace, and a differential thermocouple. A low heat-load sample holder for clamping the sample in a vertical position is also described. The results of measurements on AXM-5Q graphite are reported.

  13. Simple Phenomena, Slow Motion, Surprising Physics

    ERIC Educational Resources Information Center

    Koupil, Jan; Vicha, Vladimir

    2011-01-01

    This article describes a few simple experiments that are worthwhile for slow motion recording and analysis either because of interesting phenomena that can be seen only when slowed down significantly or because of the ability to do precise time measurements. The experiments described in this article are quite commonly done in Czech schools. All…

  14. Richard Kluger's "Simple Justice" after 29 Years

    ERIC Educational Resources Information Center

    Lowe, Robert

    2004-01-01

    Although it is obligatory to mark the anniversary of "Brown v. Board of Education," why it deserves to be commemorated is not necessarily obvious at a distance of fifty years. In this article, the author discusses this issue in the light of Richard Kluger's remarkable book--"Simple Justice." He states that, today the widespread existence of…

  15. Simple Analysis of Historical Lime Mortars

    ERIC Educational Resources Information Center

    Pires, Joa~o

    2015-01-01

    A laboratory experiment is described in which a simple characterization of a historical lime mortar is made by the determination of its approximate composition by a gravimetric method. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) are also used for the qualitative characterization of the lime mortar components. These…

  16. Nature versus Nurture: The Simple Contrast

    ERIC Educational Resources Information Center

    Davidoff, Jules; Goldstein, Julie; Roberson, Debi

    2009-01-01

    We respond to the commentary of Franklin, Wright, and Davies ("Journal of Experimental Child Psychology, 102", 239-245 [2009]) by returning to the simple contrast between nature and nurture. We find no evidence from the toddler data that makes us revise our ideas that color categories are learned and never innate. (Contains 1 figure.)

  17. Experimental Control of Simple Pendulum Model

    ERIC Educational Resources Information Center

    Medina, C.

    2004-01-01

    This paper conveys information about a Physics laboratory experiment for students with some theoretical knowledge about oscillatory motion. Students construct a simple pendulum that behaves as an ideal one, and analyze model assumption incidence on its period. The following aspects are quantitatively analyzed: vanishing friction, small amplitude,…

  18. Learning in a Simple Motor System

    ERIC Educational Resources Information Center

    Broussard, Dianne M.; Kassardjian, Charles D.

    2004-01-01

    Motor learning is a very basic, essential form of learning that appears to share common mechanisms across different motor systems. We evaluate and compare a few conceptual models for learning in a relatively simple neural system, the vestibulo-ocular reflex (VOR) of vertebrates. We also compare the different animal models that have been used to…

  19. Simple Enrichment System for Hydrogen Producers ▿

    PubMed Central

    Tolvanen, Katariina E. S.; Mangayil, Rahul K.; Karp, Matti T.; Santala, Ville P.

    2011-01-01

    This study presents a simple enrichment system where gas pressure produced by microbes performs functions that are normally done by labor. The system was tested with Escherichia coli strains with different hydrogen production and growth capabilities. The results show that the system can enrich the best hydrogen producer. PMID:21531834

  20. Building Simple Hidden Markov Models. Classroom Notes

    ERIC Educational Resources Information Center

    Ching, Wai-Ki; Ng, Michael K.

    2004-01-01

    Hidden Markov models (HMMs) are widely used in bioinformatics, speech recognition and many other areas. This note presents HMMs via the framework of classical Markov chain models. A simple example is given to illustrate the model. An estimation method for the transition probabilities of the hidden states is also discussed.

  1. Revisiting the Simple View of Reading

    ERIC Educational Resources Information Center

    Kendeou, Panayiota; Savage, Robert; van den Broek, Paul

    2009-01-01

    Background: Reading component models such as the Simple View of Reading (SVR; Gough & Tunmer, 1986; Hoover & Gough, 1990) provide a concise framework for describing the processes and skills involved when readers comprehend texts. According to the Independent Review of the Teaching of Early Reading (Rose, 2006) strong evidence for the SVR comes…

  2. A simple urine test for sulfonamides

    PubMed Central

    de Almeida-Filho, Juvenal; de Souza, José Maria

    1983-01-01

    The lack of a simple and reliable test for sulfonamides has created a problem because of the increasing use of these drugs in the chemotherapy of malaria. This paper describes a modification of the Bratton-Marshall technique, for which the reagents are easily obtainable and which can be carried out in simply equipped primary health care laboratories. PMID:6601540

  3. [A simple vibratome for brain slice].

    PubMed

    Xia, J H; Xing, B R; Gu, Q; Hua, S Y

    1989-12-01

    A simple vibratome was fabricated using double-function electric shaver and microscopic platform. Spontaneous discharge of neurons in hippocampal and hypothalamic brain slices (in 300-400 microns thick) prepared by the vibratome could kept above 12 hours in artificial cerebro-spinal fluid. PMID:2697084

  4. Simple Demonstration of the Seebeck Effect

    ERIC Educational Resources Information Center

    Molki, Arman

    2010-01-01

    In this article we propose a simple and low-cost experimental set-up through which science educators can demonstrate the Seebeck effect using a thermocouple and an instrumentation amplifier. The experiment can be set up and conducted during a 1-hour laboratory session. (Contains 3 tables and 3 figures.)

  5. Earthways: Simple Environmental Activities for Young Children.

    ERIC Educational Resources Information Center

    Petrash, Carol

    This book presents simple environmental activities designed for young children. The contents are organized seasonally and each section features subsections: The Whole Earth Home and Classroom, Bringing Nature In, The Season Garden, Seasonal Crafts, and Supplying the Missing Links. These sections provide information on how to set up an indoor…

  6. Jacks--A Study of Simple Machines.

    ERIC Educational Resources Information Center

    Parsons, Ralph

    This vocational physics individualized student instructional module on jacks (simple machines used to lift heavy objects) contains student prerequisites and objectives, an introduction, and sections on the ratchet bumper jack, the hydraulic jack, the screw jack, and load limitations. Designed with a laboratory orientation, each section consists of…

  7. Simple suture and anchor in rabbit hips

    PubMed Central

    Garcia Filho, Fernando Cal; Guarniero, Roberto; de Godoy Júnior, Rui Maciel; Pereira, César Augusto Martins; Matos, Marcos Almeida; Garcia, Lucas Cortizo

    2012-01-01

    Objective Using biomechanical studies, this research aims to compare hip capsulorrhaphy in rabbits, carried out with two different techniques: capsulorrhaphy with simple sutures and with anchors. Method Thirteen New Zealand Albino (Oryctolaguscuniculus) male rabbits, twenty-six hip joints, were used. First, a pilot project was performed with three rabbits (six hip joints). This experiment consisted of ten rabbits divided into two groups: group 1 underwent capsulorrhaphy on both right and left hips with simple suture using polyglycolic acid absorbable thread, and group 2 underwent capsulorrhaphy with titanium anchors. After a four-week postoperative period, the animals were euthanized and the hip joints were frozen. On the same day of the biomechanical studies, after the hip joints were previously unfrozen, the following parameters were evaluated: rigidity, maximum force, maximum deformity and energy. Results There was no relevant statistical difference in rigidity, maximum force, maximum deformity and energy between the simple suture and anchor groups. Conclusion Through biomechanical analyses, using parameters of rigidity, maximum force, maximum deformity and energy, it has been shown that capsulorrhaphy with simple suture and with anchors has similar results in rabbit hip joints. Level of Evidence II, Prospective Comparative Study. PMID:24453618

  8. Simple adaptive tracking control for mobile robots

    NASA Astrophysics Data System (ADS)

    Bobtsov, Alexey; Faronov, Maxim; Kolyubin, Sergey; Pyrkin, Anton

    2014-12-01

    The problem of simple adaptive and robust control is studied for the case of parametric and dynamic dimension uncertainties: only the maximum possible relative degree of the plant model is known. The control approach "consecutive compensator" is investigated. To illustrate the efficiency of proposed approach an example with the mobile robot motion control using computer vision system is considered.

  9. SLURM: Simple Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Grondona, M

    2002-12-19

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling and stream copy modules. This paper presents an overview of the SLURM architecture and functionality.

  10. Simple Steps Can Keep Lawn Mowing Safe

    MedlinePlus

    ... FAQs Contact Us Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Latest Health News → Article URL of this page: https://www.nlm.nih.gov/medlineplus/news/fullstory_158341.html Simple Steps Can Keep Lawn Mowing Safe Before cutting the grass, review these safety tips To use ...

  11. Simple Numerical Simulation of Strain Measurement

    NASA Technical Reports Server (NTRS)

    Tai, H.

    2002-01-01

    By adopting the basic principle of the reflection (and transmission) of a plane polarized electromagnetic wave incident normal to a stack of films of alternating refractive index, a simple numerical code was written to simulate the maximum reflectivity (transmittivity) of a fiber optic Bragg grating corresponding to various non-uniform strain conditions including photo-elastic effect in certain cases.

  12. A novel and simple atrial retractor.

    PubMed

    Kofidis, Theo; Lee, Chuen Neng

    2011-05-01

    Minimally invasive cardiac operations require specialized equipment. Atrial retractors are a frequently used tool to expose heart valves for minimally invasive and open procedures. The models currently available in the market are efficient; however, they may be complex, bulky, or expensive. We introduce a novel, very simple atrial retractor we designed using ubiquitously available materials. PMID:21524488

  13. Figuring the Acceleration of the Simple Pendulum

    ERIC Educational Resources Information Center

    Lieberherr, Martin

    2011-01-01

    The centripetal acceleration has been known since Huygens' (1659) and Newton's (1684) time. The physics to calculate the acceleration of a simple pendulum has been around for more than 300 years, and a fairly complete treatise has been given by C. Schwarz in this journal. But sentences like "the acceleration is always directed towards the…

  14. Correcting the SIMPLE Model of Free Recall

    ERIC Educational Resources Information Center

    Lee, Michael D.; Pooley, James P.

    2013-01-01

    The scale-invariant memory, perception, and learning (SIMPLE) model developed by Brown, Neath, and Chater (2007) formalizes the theoretical idea that scale invariance is an important organizing principle across numerous cognitive domains and has made an influential contribution to the literature dealing with modeling human memory. In the context…

  15. Teaching Alveolar Ventilation with Simple, Inexpensive Models

    ERIC Educational Resources Information Center

    DiCarlo, Stephen E.

    2008-01-01

    When teaching and learning about alveolar ventilation with our class of 300 first-year medical students, we use four simple, inexpensive "models." The models, which encourage research-oriented learning and help our students to understand complex ideas, are distributed to the students before class. The students anticipate something new every day,…

  16. Simple Cloud Chambers Using Gel Ice Packs

    ERIC Educational Resources Information Center

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  17. A Simple Technique for High Resistance Measurement

    ERIC Educational Resources Information Center

    Aguilar, Horacio Munguia; Landin, Ramon Ochoa

    2012-01-01

    A simple electronic system for the measurement of high values of resistance is shown. This system allows the measurement of resistance in the range of a few megohm up to 10[superscript 9] [omega]. We have used this system for the evaluation of CdS thin film resistance, but other practical uses in the basic physics laboratory are presented.…

  18. Energy: Simple Experiments for Young Scientists.

    ERIC Educational Resources Information Center

    White, Larry

    This book contains simple experiments through which students can learn about the properties of energy. These experiments include making a kitchen "volcano," a soda-pop "cannon," and a puffed-rice "scooter." Topics include: energy and work, fossil fuels, solar energy, kinetic energy, potential energy, mechanical energy, heat energy, sound energy,…

  19. A Simple ELISA Exercise for Undergraduate Biology.

    ERIC Educational Resources Information Center

    Baker, William P.; Moore, Cathy R.

    Understanding of immunological techniques such as the Enzyme Linked Immuno Sorbent Assay (ELISA) is an important part of instructional units in human health, developmental biology, microbiology, and biotechnology. This paper describes a simple ELISA exercise for undergraduate biology that effectively simulates the technique using a paper model.…

  20. Simple Harmonic Motion in Harmonic Plane Waves.

    ERIC Educational Resources Information Center

    Benumof, Reuben

    1980-01-01

    Discusses the distribution of kinetic and potential energy in transverse and longitudinal waves and examines the transmission of power and momentum. This discussion is intended to aid in understanding the simple harmonic motion of a particle involved in the propagation of a harmonic mechanical plane wave. (HM)

  1. A Simple View of Linguistic Complexity

    ERIC Educational Resources Information Center

    Pallotti, Gabriele

    2015-01-01

    Although a growing number of second language acquisition (SLA) studies take linguistic complexity as a dependent variable, the term is still poorly defined and often used with different meanings, thus posing serious problems for research synthesis and knowledge accumulation. This article proposes a simple, coherent view of the construct, which is…

  2. A Simple Acronym for Doing Calculus: CAL

    ERIC Educational Resources Information Center

    Hathaway, Richard J.

    2008-01-01

    An acronym is presented that provides students a potentially useful, unifying view of the major topics covered in an elementary calculus sequence. The acronym (CAL) is based on viewing the calculus procedure for solving a calculus problem P* in three steps: (1) recognizing that the problem cannot be solved using simple (non-calculus) techniques;…

  3. Tour of a Simple Trigonometry Problem

    ERIC Educational Resources Information Center

    Poon, Kin-Keung

    2012-01-01

    This article focuses on a simple trigonometric problem that generates a strange phenomenon when different methods are applied to tackling it. A series of problem-solving activities are discussed, so that students can be alerted that the precision of diagrams is important when solving geometric problems. In addition, the problem-solving plan was…

  4. Simulated Holograms: A Simple Introduction to Holography.

    ERIC Educational Resources Information Center

    Dittmann, H.; Schneider, W. B.

    1992-01-01

    Describes a project that uses a computer and a dot matrix printer to simulate the holographic recording process of simple object structures. The process' four steps are (1) superposition of waves; (2) representing the superposition of a plane reference wave on the monitor screen; (3) photographic reduction of the images; and (4) reconstruction of…

  5. Extremely simple holographic projection of color images

    NASA Astrophysics Data System (ADS)

    Makowski, Michal; Ducin, Izabela; Kakarenko, Karol; Suszek, Jaroslaw; Kolodziejczyk, Andrzej; Sypek, Maciej

    2012-03-01

    A very simple scheme of holographic projection is presented with some experimental results showing good quality image projection without any imaging lens. This technique can be regarded as an alternative to classic projection methods. It is based on the reconstruction real images from three phase iterated Fourier holograms. The illumination is performed with three laser beams of primary colors. A divergent wavefront geometry is used to achieve an increased throw angle of the projection, compared to plane wave illumination. Light fibers are used as light guidance in order to keep the setup as simple as possible and to provide point-like sources of high quality divergent wave-fronts at optimized position against the light modulator. Absorbing spectral filters are implemented to multiplex three holograms on a single phase-only spatial light modulator. Hence color mixing occurs without any time-division methods, which cause rainbow effects and color flicker. The zero diffractive order with divergent illumination is practically invisible and speckle field is effectively suppressed with phase optimization and time averaging techniques. The main advantages of the proposed concept are: a very simple and highly miniaturizable configuration; lack of lens; a single LCoS (Liquid Crystal on Silicon) modulator; a strong resistance to imperfections and obstructions of the spatial light modulator like dead pixels, dust, mud, fingerprints etc.; simple calculations based on Fast Fourier Transform (FFT) easily processed in real time mode with GPU (Graphic Programming).

  6. Studying the Greenhouse Effect: A Simple Demonstration.

    ERIC Educational Resources Information Center

    Papageorgiou, G.; Ouzounis, K.

    2000-01-01

    Studies the parameters involved in a presentation of the greenhouse effect and describes a simple demonstration of this effect. Required equipment includes a 100-120 watt lamp, a 250mL beaker, and a thermometer capable of recording 0-750 degrees Celsius together with a small amount of chloroform. (Author/SAH)

  7. Charge operators in simple Lie groups

    NASA Astrophysics Data System (ADS)

    Taormina, A.

    1984-03-01

    Charge operators for representations of dimension less than or equal to 16 are computed in all simple Lie groups. The representations for which the charge operator reproduces the charge spectrum of leptons and quarks of one family are analyzed from a GUT point of view.

  8. Long, polymorphic microsatellites in simple organisms.

    PubMed

    Field, D; Wills, C

    1996-02-22

    We have examined the phylogenetic distribution of the longest, perfect microsatellites in GenBank. Despite the large contributions of model higher-eukaryotic organisms to GenBank, the selective cloning of long microsatellites from these organisms as genetic markers, and the relative lack of concentration on the microsatellites in lower eukaryotes and prokaryotes, we found that simple organisms, defined here as slime molds, fungi, protists, prokaryotes, viruses, organelles and plasmids, contributed 78 of the 375 examined sequences. These 78 simple-organism microsatellites are characterized predominantly by trinucleotide repeats, nearly half of which lie in exons, and in general show a bias towards A+T rich motifs. Simple-organism microsatellites represented more than once in GenBank displayed length polymorphisms when independent clones were compared. These facts collectively raise speculation as to the role of these 'junk' sequences in such highly economical genomes, especially when precise changes in long microsatellites are known to regulate critical virulence factors in several prokaryotes. Regardless of their biological significance, simple-organism microsatellites may provide a general source of molecular markers to track disease outbreaks and the evolution of microorganisms in unprecedented detail. PMID:8728984

  9. Insights into Biological Complexity from Simple Foundations.

    PubMed

    Albergante, L; Liu, D; Palmer, S; Newman, T J

    2016-01-01

    We discuss an overtly "simple approach" to complex biological systems borrowing selectively from theoretical physics. The approach is framed by three maxims, and we show examples of its success in two different applications: investigating cellular robustness at the level of gene regulatory networks and quantifying rare events of DNA replication errors. PMID:27193550

  10. Knowledge acquisition for a simple expert controller

    NASA Technical Reports Server (NTRS)

    Bieker, B.

    1987-01-01

    A method is presented for process control which has the properties of being incremental, cyclic and top-down. It is described on the basis of the development of an expert controller for a simple, but nonlinear control route. A quality comparison between expert controller and process operator shows the ability of the method for knowledge acquisition.

  11. Gravity: Simple Experiments for Young Scientists.

    ERIC Educational Resources Information Center

    White, Larry

    This book contains 12 simple experiments through which students can learn about gravity and its implications. Some of the topics included are weight, weightlessness, artificial gravity, the pull of gravity on different shapes, center of gravity, the universal law of gravity, and balancing. Experiments include: finding the balancing point; weighing…

  12. Making Simple Folk Instruments for Children.

    ERIC Educational Resources Information Center

    Cline, Dallas

    1980-01-01

    Instructions are provided for making these simple musical instruments from inexpensive materials: an Indian bull-roarer; bottle chimes; a ham can guitar; flower pot, box, and steel drums; a xylophone; a musical sawhorse; rattles; a melody box; and a box thumb harp. (SJL)

  13. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  14. A Simple Photometer to Study Skylight

    ERIC Educational Resources Information Center

    McIntosh Gordon

    2006-01-01

    A simple photometer constructed from an LED and an op amp can be used to measure light in a number of physical situations. A variety of LEDs exist to investigate different wavelength ranges. Combined with an inexpensive transit, the LED photometer can be used to carry out skylight studies and atmospheric optical depth measurements. The activities…

  15. Special Relativity as a Simple Geometry Problem

    ERIC Educational Resources Information Center

    de Abreu, Rodrigo; Guerra, Vasco

    2009-01-01

    The null result of the Michelson-Morley experiment and the constancy of the one-way speed of light in the "rest system" are used to formulate a simple problem, to be solved by elementary geometry techniques using a pair of compasses and non-graduated rulers. The solution consists of a drawing allowing a direct visualization of all the fundamental…

  16. A simple homemade polarised sunglasses test card

    NASA Astrophysics Data System (ADS)

    Bamdad, Farzad

    2016-05-01

    In this article construction of a simple and inexpensive test card which can be used to demonstrate the polarisation ability of sunglasses is described. The card was fabricated simply by using a piece of polariser sheet with one to three layers of cellophane tape fixed on it.

  17. A Simple Homemade Polarised Sunglasses Test Card

    ERIC Educational Resources Information Center

    Bamdad, Farzad

    2016-01-01

    In this article construction of a simple and inexpensive test card which can be used to demonstrate the polarisation ability of sunglasses is described. The card was fabricated simply by using a piece of polariser sheet with one to three layers of cellophane tape fixed on it.

  18. A Simple Classroom Demonstration of Natural Convection

    ERIC Educational Resources Information Center

    Wheeler, Dean R.

    2005-01-01

    This article explains a simple way to demonstrate natural convection, such as from a lit candle, in the classroom using an overhead projector. The demonstration is based on the principle of schlieren imaging, commonly used to visualize variations in density for gas flows.

  19. A Simple Laser Microphone for Classroom Demonstration

    NASA Astrophysics Data System (ADS)

    Moses, James M.; Trout, K. P.

    2006-12-01

    Communication through the modulation of electromagnetic radiation has become a foundational technique in modern technology. In this paper we discuss a modern day method of eavesdropping based upon the modulation of laser light reflected from a window pane. A simple and affordable classroom demonstration of a "laser microphone" is described.

  20. A simple animal support for convenient weighing

    USGS Publications Warehouse

    Pan, H.P.; Caslick, J.W.; Harke, D.T.; Decker, D.G.

    1965-01-01

    A simple animal support constructed of web belts to hold skittish pigs for weighing was developed. The support is easily made, noninjurious to the pigs, and compact, facilitating rapid, accurate weighing. With minor modifications, the support can probably be used in weighing other animals.

  1. Fractal surfaces from simple arithmetic operations

    NASA Astrophysics Data System (ADS)

    García-Morales, Vladimir

    2016-04-01

    Fractal surfaces ('patchwork quilts') are shown to arise under most general circumstances involving simple bitwise operations between real numbers. A theory is presented for all deterministic bitwise operations on a finite alphabet. It is shown that these models give rise to a roughness exponent H that shapes the resulting spatial patterns, larger values of the exponent leading to coarser surfaces.

  2. The Simple Gifts of Chris Raschka.

    ERIC Educational Resources Information Center

    Ammon, Richard

    1999-01-01

    Describes how writer and artist Chris Raschka creates children's books that transcend their silent, static medium to skip and sing their way into the hearts of children. Discusses Raschka's background as an artist and writer, as well as a bit of history about his "seemingly simple" style. (SR)

  3. Jarzynski's Equality Illustrated by Simple Examples

    ERIC Educational Resources Information Center

    Hijar, Humberto; Ortiz de Zarate, Jose M.

    2010-01-01

    The Jarzynski theorem is perhaps the most recently discovered simple general formula in elementary statistical physics. In this paper, written with a pedagogical aim, we illustrate the physical concepts under the Jarzynski and related results by a detailed calculation with a representative example. The physics of the model is sufficiently…

  4. A Simple Illustration of Hemihedral Faces

    ERIC Educational Resources Information Center

    Ault, Addison

    2004-01-01

    A simple way to represent hemihedral faces and to illustrate the relationship between the resulting left-handed and right-handed hemihedra is presented. The illustrations highlight that the chirality corresponds to the absence of reflective symmetry but not necessarily to the absence of a C2 axis of symmetry.

  5. Water: Simple Experiments for Young Scientists.

    ERIC Educational Resources Information Center

    White, Larry

    This book contains simple experiments and projects through which students can learn about water and its properties. Some of the topics discussed include acid rain, dehydration, distillation, electrons, tidal waves, and the water cycle. Experiments include: finding out about the amount of water in the body; why there is water in the body; how to…

  6. Design and Fabrication of a Simple Schlierenscope.

    ERIC Educational Resources Information Center

    Mitra, S. C.; And Others

    1981-01-01

    Describes details of the construction of a simple compact schlieren experimental setup as an instructional aid. This new optical method is easy to apply, noninterfering, nondestructive, free from inertia, and can produce instantaneous records of transient phenomena, and is comparatively inexpensive. (Author/SK)

  7. A Simple Band for Gastric Banding.

    PubMed

    Broadbent

    1993-08-01

    The author has noted that flexible gastric bands have occasionally stenosed the gastric stoma or allowed it to dilate. A band was developed using a soft outer silicone rubber tube over a holding mechanism made out of a nylon cable tie passed within the silicone tube. This simple, easily applied band is rigid, resisting scar contracture and dilatation. PMID:10757939

  8. Simple Test For Organic Material In Gas

    NASA Technical Reports Server (NTRS)

    Barzana, Eduardo; Klibanov, Alexander; Karel, Marcus

    1989-01-01

    Dried enzymes and color indicators test sensitively and selectively. Dehydrated enzymes used in convenient method for analyzing gases for specific organic substances, outside laboratory. Method used to detect alcohol in breath or formaldehyde in gas streams. Used for simple semiquantitative detection or for precise quantitative measurement.

  9. From Complex to Simple: Interdisciplinary Stochastic Models

    ERIC Educational Resources Information Center

    Mazilu, D. A.; Zamora, G.; Mazilu, I.

    2012-01-01

    We present two simple, one-dimensional, stochastic models that lead to a qualitative understanding of very complex systems from biology, nanoscience and social sciences. The first model explains the complicated dynamics of microtubules, stochastic cellular highways. Using the theory of random walks in one dimension, we find analytical expressions…

  10. A Simple Laser Microphone for Classroom Demonstration

    ERIC Educational Resources Information Center

    Moses, James M.; Trout, K. P.

    2006-01-01

    Communication through the modulation of electromagnetic radiation has become a foundational technique in modern technology. In this paper we discuss a modern day method of eavesdropping based upon the modulation of laser light reflected from a window pane. A simple and affordable classroom demonstration of a "laser microphone" is…

  11. Simple Activity Demonstrates Wind Energy Principles

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    Wind energy is an exciting and clean energy option often described as the fastest-growing energy system on the planet. With some simple materials, teachers can easily demonstrate its key principles in their classroom. (Contains 1 figure and 2 tables.)

  12. Unusual presentation of a simple renal cyst

    PubMed Central

    Maheshwari, Veena; Alam, Kiran; Varshney, Manoranjan; Khan, Roobina; Gaur, Kavita; Harris, S Hasan

    2011-01-01

    The authors present the case of a 23-year-old woman who presented with a lump in her right abdomen which was 7 cm in diameter. Ultrasonography showed a unilocular cyst, which was diagnosed as a simple renal cyst. This case is presented for its rare occurrence in young females and unusual clinical presentation as a huge abdominal mass. PMID:22715271

  13. Cuentos Faciles. Habia una vez.... (Simple Stories. There was a Time....) (Presenting Simple Stories in Spanish.)

    ERIC Educational Resources Information Center

    Arroyo, Nancy; And Others

    For Spanish-speaking children, simple stories in Spanish, told in a natural language suitable for their age, are not only entertaining, but a means of developing vocabulary and concepts. Non-Spanish-speaking children, too, need exposure to more language than they can understand word for word. However, the simple stories for the Spanish speaker…

  14. Simple solutions for reduced fish farm hazards.

    PubMed

    Myers, Melvin L; Cole, Henry P

    2009-01-01

    Aquaculture poses emerging challenges for agricultural safety and health. Fish farming has many of the same hazards as other types of farming, but it also poses additional hazards associated with water impoundments and night-time work. In a multidisciplinary approach, researchers from four universities are identifying occupational hazards in fish farming and identifying no-cost or low-cost "simple solutions" to reduce or eliminate them. Simple solutions are discovered through farm visits so as to understand the countermeasures that individual stakeholders have taken to protect their workforce, and these countermeasures are documented and photographed to inform other farmers of these solutions. Equipping tractors with rollover protective structures is a standard practice to protect operators from serious injury in the event of an overturn. Other solutions identified include eliminating the need to climb feed bins to open and close the hatch for feed delivery by using a pull-cable at ground level. This simple technology eliminates the exposure to falling from an elevation, a risk that accounts for at least one reported death of a worker on a fish farm. Another solution is to replace metal paddles on a hatchery trough with plastic paddles that if and when entangled in a worker's hair or clothing slip on the rotating drive shaft and thus reduce laceration and entanglement injuries. Another simple solution to prevent entanglements in large pond aerators, used to mechanically dissolve oxygen into the water, that are operated by farm tractor power take-off shafts is to use electrically powered aerators. Bubble-type aerators are safer than electrically powered paddle aerators because workers are shielded from moving parts. Many additional simple solutions have been identified for a range of tasks in this environment. PMID:19437271

  15. Simple method for locking birefringent resonators.

    PubMed

    Libson, Adam; Brown, Nicolas; Buikema, Aaron; López, Camilo Cela; Dordevic, Tamara; Heising, Matthew; Evans, Matthew

    2015-02-01

    We report on a simple method of locking a laser to a birefringent cavity using polarization spectroscopy. The birefringence of the resonator permits the simple extraction of an error signal by using one polarization state as a phase reference for another state. No modulation of the light or the resonator is required, reducing the complexity of the laser locking setup. This method of producing an error signal can be used on most birefringent optical resonators, even if the details of birefringence and eigenpolarizations are not known. This technique is particularly well suited for fiber ring resonators due to the inherent birefringence of the fiber and the unknown nature of that birefringence. We present an experimental demonstration of this technique using a fiber ring. PMID:25836232

  16. Molecular implementation of simple logic programs.

    PubMed

    Ran, Tom; Kaplan, Shai; Shapiro, Ehud

    2009-10-01

    Autonomous programmable computing devices made of biomolecules could interact with a biological environment and be used in future biological and medical applications. Biomolecular implementations of finite automata and logic gates have already been developed. Here, we report an autonomous programmable molecular system based on the manipulation of DNA strands that is capable of performing simple logical deductions. Using molecular representations of facts such as Man(Socrates) and rules such as Mortal(X) <-- Man(X) (Every Man is Mortal), the system can answer molecular queries such as Mortal(Socrates)? (Is Socrates Mortal?) and Mortal(X)? (Who is Mortal?). This biomolecular computing system compares favourably with previous approaches in terms of expressive power, performance and precision. A compiler translates facts, rules and queries into their molecular representations and subsequently operates a robotic system that assembles the logical deductions and delivers the result. This prototype is the first simple programming language with a molecular-scale implementation. PMID:19809454

  17. Characterization of simple wireless neurostimulators and sensors.

    PubMed

    Gulick, Daniel W; Towe, Bruce C

    2014-01-01

    A single diode with a wireless power source and electrodes can act as an implantable stimulator or sensor. We have built such devices using RF and ultrasound power coupling. These simple devices could drastically reduce the size, weight, and cost of implants for applications where efficiency is not critical. However, a shortcoming has been a lack of control: any movement of the external power source would change the power coupling, thereby changing the stimulation current or modulating the sensor response. To correct for changes in power and signal coupling, we propose to use harmonic signals from the device. The diode acts as a frequency multiplier, and the harmonics it emits contain information about the drive level and bias. A simplified model suggests that estimation of power, electrode bias, and electrode resistance is possible from information contained in radiated harmonics even in the presence of significant noise. We also built a simple RF-powered stimulator with an onboard voltage limiter. PMID:25570654

  18. Dynamics and kinematics of simple neural systems

    SciTech Connect

    Rabinovich, M. |; Selverston, A.; Rubchinsky, L.; Huerta, R.

    1996-09-01

    The dynamics of simple neural systems is of interest to both biologists and physicists. One of the possible roles of such systems is the production of rhythmic patterns, and their alterations (modification of behavior, processing of sensory information, adaptation, control). In this paper, the neural systems are considered as a subject of modeling by the dynamical systems approach. In particular, we analyze how a stable, ordinary behavior of a small neural system can be described by simple finite automata models, and how more complicated dynamical systems modeling can be used. The approach is illustrated by biological and numerical examples: experiments with and numerical simulations of the stomatogastric central pattern generators network of the California spiny lobster. {copyright} {ital 1996 American Institute of Physics.}

  19. Dynamics and kinematics of simple neural systems

    NASA Astrophysics Data System (ADS)

    Rabinovich, Mikhail; Selverston, Allen; Rubchinsky, Leonid; Huerta, Ramón

    1996-09-01

    The dynamics of simple neural systems is of interest to both biologists and physicists. One of the possible roles of such systems is the production of rhythmic patterns, and their alterations (modification of behavior, processing of sensory information, adaptation, control). In this paper, the neural systems are considered as a subject of modeling by the dynamical systems approach. In particular, we analyze how a stable, ordinary behavior of a small neural system can be described by simple finite automata models, and how more complicated dynamical systems modeling can be used. The approach is illustrated by biological and numerical examples: experiments with and numerical simulations of the stomatogastric central pattern generators network of the California spiny lobster.

  20. Molecular implementation of simple logic programs

    NASA Astrophysics Data System (ADS)

    Ran, Tom; Kaplan, Shai; Shapiro, Ehud

    2009-11-01

    Autonomous programmable computing devices made of biomolecules could interact with a biological environment and be used in future biological and medical applications. Biomolecular implementations of finite automata and logic gates have already been developed. Here, we report an autonomous programmable molecular system based on the manipulation of DNA strands that is capable of performing simple logical deductions. Using molecular representations of facts such as Man(Socrates) and rules such as Mortal(X) <-- Man(X) (Every Man is Mortal), the system can answer molecular queries such as Mortal(Socrates)? (Is Socrates Mortal?) and Mortal(X)? (Who is Mortal?). This biomolecular computing system compares favourably with previous approaches in terms of expressive power, performance and precision. A compiler translates facts, rules and queries into their molecular representations and subsequently operates a robotic system that assembles the logical deductions and delivers the result. This prototype is the first simple programming language with a molecular-scale implementation.

  1. Nonexponential relaxation in a simple liquid metal.

    PubMed

    Demmel, F; Morkel, C

    2012-05-01

    A hallmark of the changes in dynamics towards the glass transition is the stretched exponential structural relaxation. Quasielastic neutron scattering results on liquid rubidium demonstrate such a nonexponential relaxation process in a simple liquid metal above the melting point. The nonexponential decay is an indication of non-Markovian dynamics and points to the collective character of the relaxation process. Describing the relaxation dynamics by a two-step process, the long lasting part of the decay process is in remarkable quantitative agreement with predictions from mode coupling theory. The feedback mechanism of the slowing down process in the theoretical description suggests that this contribution is at the origin of the structural arrest. With rising temperature the intermediate scattering function transforms into a simple exponential decay at a temperature range which indicates the end of the highly viscous solidlike behavior in the liquid. PMID:23004742

  2. Simple Flame Test Techniques Using Cotton Swabs

    NASA Astrophysics Data System (ADS)

    Sanger, Michael J.; Phelps, Amy J.

    2004-07-01

    This article describes three new methods for performing simple flame tests using cotton swabs. The first method uses a Bunsen burner and solid metal salts; the second method uses a Bunsen burner and 1 M aqueous solutions of metal salts; and the third method uses candles, rubbing alcohol, and solid metal salts. These methods have the advantage of being easy to perform, require inexpensive and easily-obtained materials, and have easy cleanup and disposal methods. See the Discussion on this Tested Demonstation .

  3. Rack Protection Monitor - A Simple System

    SciTech Connect

    Orr, S.

    1997-12-01

    The Rack Protection Monitor is a simple, fail-safe device to monitor smoke, temperature and ventilation sensors. It accepts inputs from redundant sensors and has a hardwired algorithm to prevent nuisance power trips due to random sensor failures. When a sensor is triggered the Rack Protection Monitor latches and annunicates the alarm. If another sensor is triggered, the Rack Protection Monitor locally shuts down the power to the relay rack and sends alarm to central control.

  4. Simple digital pulse-programing circuit

    NASA Technical Reports Server (NTRS)

    Langston, J. L.

    1979-01-01

    Pulse-sequencing circuit uses only shift register and Exclusive-OR gates. Circuit also serves as date-transition edge detector (for rising or falling edges). It is used in sample-and-hold, analog-to-digital conversion sequence control, multiphase clock logic, precise delay control computer control logic, edge detectors, other timing applications, and provides simple means to generate timing and control signals for data transfer, addressing, or mode control in microprocessors and minicomputers.

  5. Simple analytic model of wormhole formation

    SciTech Connect

    Maeda, Hideki

    2009-01-15

    An explicit and simple solution representing the wormhole formation is presented. The spacetime is constructed by gluing the Minkowski and Roberts spacetimes at null hypersurfaces in a regular manner. The parameters in the Roberts solution are required to give the negative kinetic term for the massless scalar field. Although a curvature singularity appears at the moment of the wormhole formation, it disappears instantaneously. This instantaneous singularity is weak in the senses of both Tipler and Krolak along radial causal geodesics.

  6. A Simple Experiment for Visualizing Diffusion

    ERIC Educational Resources Information Center

    Helseth, L. E.

    2011-01-01

    We propose a simple and fascinating experiment for studying diffusion in gels using a pH-sensitive dye. By doping agar with methyl red, we obtain a gel which rapidly reacts to changes in pH by changing its absorption spectrum. The pH gradients can be followed using a digital camera, and we demonstrate here that the pH-sensitive colour changes can…

  7. SLURM: Simple Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Dunlap, C; Garlick, J; Grondona, M

    2002-07-08

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling and stream copy modules. The design also includes a scalable, general-purpose communication infrastructure. This paper presents a overview of the SLURM architecture and functionality.

  8. Badlands: too complex to be simple?

    NASA Astrophysics Data System (ADS)

    Kuhn, Nikolaus J.

    2016-04-01

    Badlands are an intensively dissected barren landscape, devoid of soil cover, with a sparse or absent vegetation. The very high drainage densities, V-shaped valleys and steep slopes, have often led to believe that badlands represent a landscape where the frequency and magnitude of overland flow and erosion processes are very high, resulting in rapid landscape evolution and a close connection between form and process. This perceived proximity between form and process is the main reason why badlands have sometimes been regarded as "ideal field laboratories" for testing landscape evolution hypothesis. Recent research has shed a critical light on the "simple landscape" perspective. Two key issues support this change in persprective. First, the erosion rates and sediment yields observed badland areas vary widely. As a consequence, only weak relationships were found between average annual rainfall and average erosion rates for annual rainfalls in the wide range of 80-1250 mm. Both the spatial variability and the limited relationship to annual rainfall present a serious barrier for the extrapolation of erosion rates from the hill slope to catchment scales and certainly to landscape evolution over longer geological time scales under changing climatic conditions. A second reason contradicting the simple landscape assessment is the mismatch observed between current erosion rates and the long-term denudation rates, indicating a hiatus between a potentially short period of badland formation and the overall age of the landform. As a consequence, the actual meaning of badland has been questioned, ranging from a description for features to a more complex meaning including current erosion and complex interaction of processes, such as pipe and tunnel erosion. In the light of this critical assessment, the idea of badlands as a "natural and simple laboratory" for landscape development can be questioned because badlands are too complex to be simple. However, one could also wonder

  9. A simple method for simulating gasdynamic systems

    NASA Technical Reports Server (NTRS)

    Hartley, Tom T.

    1991-01-01

    A simple method for performing digital simulation of gasdynamic systems is presented. The approach is somewhat intuitive, and requires some knowledge of the physics of the problem as well as an understanding of the finite difference theory. The method is explicitly shown in appendix A which is taken from the book by P.J. Roache, 'Computational Fluid Dynamics,' Hermosa Publishers, 1982. The resulting method is relatively fast while it sacrifices some accuracy.

  10. Multiphase flow in geometrically simple fracture intersections

    USGS Publications Warehouse

    Basagaoglu, H.; Meakin, P.; Green, C.T.; Mathew, M.

    2006-01-01

    A two-dimensional lattice Boltzmann (LB) model with fluid-fluid and solid-fluid interaction potentials was used to study gravity-driven flow in geometrically simple fracture intersections. Simulated scenarios included fluid dripping from a fracture aperture, two-phase flow through intersecting fractures and thin-film flow on smooth and undulating solid surfaces. Qualitative comparisons with recently published experimental findings indicate that for these scenarios the LB model captured the underlying physics reasonably well.

  11. Precision Ultrasonic Wave Measurements With Simple Equipment

    PubMed Central

    Fick, Steven E.; Palmer, C. Harvey

    2001-01-01

    We describe the design and construction of a relatively simple, inexpensive laser interferometer system for accurate measurements of ultrasonic surface displacement waveforms in reasonably friendly environments. We show how analysis of a single waveform can provide both the calibration constant required for absolute measurements and an estimate of the uncertainty of these measurements. We demonstrate the performance of this interferometer by measuring ultrasonic waveforms generated by a novel conical-element ultrasonic transducer.

  12. Simple games to illustrate Parrondo's paradox

    NASA Astrophysics Data System (ADS)

    Martin, Hal; von Baeyer, Hans Christian

    2004-05-01

    Parrondo's paradox is the proposition that two losing strategies can, by alternating randomly, produce a winner. R. D. Astumian has recently created a simple board game to illustrate this counterintuitive phenomenon. We prove that the inherent symmetry of Astumian's game prevents it from achieving its purpose, and suggest amended versions that do. We also display the additional paradoxical effect of two slow, losing games combining into a fast, winning one.

  13. A Simple Sensor Model for THUNDER Actuators

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Bryant, Robert G.

    2009-01-01

    A quasi-static (low frequency) model is developed for THUNDER actuators configured as displacement sensors based on a simple Raleigh-Ritz technique. This model is used to calculate charge as a function of displacement. Using this and the calculated capacitance, voltage vs. displacement and voltage vs. electrical load curves are generated and compared with measurements. It is shown this model gives acceptable results and is useful for determining rough estimates of sensor output for various loads, laminate configurations and thicknesses.

  14. Finite-dimensional simple graded algebras

    SciTech Connect

    Bahturin, Yu A; Zaicev, M V; Sehgal, S K

    2008-08-31

    Let R be a finite-dimensional algebra over an algebraically closed field F graded by an arbitrary group G. In the paper it is proved that if the characteristic of F is zero or does not divide the order of any finite subgroup of G, then R is graded simple if and only if it is isomorphic to a matrix algebra over a finite-dimensional graded skew field. Bibliography: 24 titles.

  15. Simple Benchmark Specifications for Space Radiation Protection

    NASA Technical Reports Server (NTRS)

    Singleterry, Robert C. Jr.; Aghara, Sukesh K.

    2013-01-01

    This report defines space radiation benchmark specifications. This specification starts with simple, monoenergetic, mono-directional particles on slabs and progresses to human models in spacecraft. This report specifies the models and sources needed to what the team performing the benchmark needs to produce in a report. Also included are brief descriptions of how OLTARIS, the NASA Langley website for space radiation analysis, performs its analysis.

  16. APPLYING SIMPLE TECHNOLOGY ACCOMPLISHES VISUAL INSPECTION CHALLENGES

    SciTech Connect

    Robinson, C

    2007-07-21

    This paper discusses the successful implementation of simple video technologies at the Savannah River Site (SRS) to perform complex visual inspection, monitoring, and surveillance tasks. Because SRS facilities are similar to those of an industrial plant, the environmental and accessibility considerations for remote viewing are the primary determining factors in the selection of technology. The constraints and challenges associated with remote viewing are discussed, and examples of applications are given.

  17. Simple Example of Backtest Overfitting (SEBO)

    SciTech Connect

    2015-01-06

    In the field of mathematical finance, a "backtest" is the usage of historical market data to assess the performance of a proposed trading strategy. It is a relatively simple matter for a present-day computer system to explore thousands, millions or even billions of variations of a proposed strategy, and pick the best performing variant as the "optimal" strategy "in sample" (i.e., on the input dataset). Unfortunately, such an "optimal" strategy often performs very poorly "out of sample" (i.e. on another dataset), because the parameters of the invest strategy have been oversit to the in-sample data, a situation known as "backtest overfitting". While the mathematics of backtest overfitting has been examined in several recent theoretical studies, here we pursue a more tangible analysis of this problem, in the form of an online simulator tool. Given a input random walk time series, the tool develops an "optimal" variant of a simple strategy by exhaustively exploring all integer parameter values among a handful of parameters. That "optimal" strategy is overfit, since by definition a random walk is unpredictable. Then the tool tests the resulting "optimal" strategy on a second random walk time series. In most runs using our online tool, the "optimal" strategy derived from the first time series performs poorly on the second time series, demonstrating how hard it is not to overfit a backtest. We offer this online tool, "Simple Example of Backtest Overfitting (SEBO)", to facilitate further research in this area.

  18. Necessity of Antibiotics following Simple Exodontia

    PubMed Central

    Yousuf, Waqas; Khan, Moiz; Mehdi, Hasan; Mateen, Sana

    2016-01-01

    Introduction. The aim of our study is to assess the need for postoperative antibiotics following simple exodontia and determine its role in minimizing patient discomfort and postoperative complications. Material and Methods. All the patients undergoing simple extractions were grouped into two categories: Group 1, patients receiving antibiotics, and Group 2, patients receiving no antibiotics. Patients were recalled on the sixth day to assess postoperative complications. On recall, patients were evaluated for signs of persistent inflammation and signs of dry socket. Presence of persistent inflammation and/or suppuration on the 6th day was considered as wound infection. Results. A total of 146 patients were included in this study. Out of the total sample, 134 (91.8%) presented with no postoperative complications and 12 (8.2%) had postoperative complications, out of which 11 (7.5%) patients presented with dry socket (alveolar osteitis), 5 (3.4%) in the antibiotic group and 6 (4.1%) in the nonantibiotic group. Only 1 patient (0.7%) was reported with infection of the extraction socket in the nonantibiotic group, whereas no case of infection was found in the antibiotic group. Conclusion. Antibiotics are not required after simple extractions in patients who are not medically comprised nor do they have any role in preventing postoperative complications. PMID:27110426

  19. Figuring the Acceleration of the Simple Pendulum

    NASA Astrophysics Data System (ADS)

    Lieberherr, Martin

    2011-12-01

    The centripetal acceleration has been known since Huygens' (1659) and Newton's (1684) time.1,2 The physics to calculate the acceleration of a simple pendulum has been around for more than 300 years, and a fairly complete treatise has been given by C. Schwarz in this journal.3 But sentences like "the acceleration is always directed towards the equilibrium position" beside the picture of a swing on a circular arc can still be found in textbooks, as e.g. in Ref. 4. Vectors have been invented by Grassmann (1844)5 and are conveniently used to describe the acceleration in curved orbits, but acceleration is more often treated as a scalar with or without sign, as the words acceleration/deceleration suggest. The component tangential to the orbit is enough to deduce the period of the simple pendulum, but it is not enough to discuss the forces on the pendulum, as has been pointed out by Santos-Benito and A. Gras-Marti.6 A suitable way to address this problem is a nice figure with a catch for classroom discussions or homework. When I plotted the acceleration vectors of the simple pendulum in their proper positions, pictures as in Fig. 1 appeared on the screen. The endpoints of the acceleration vectors, if properly scaled, seemed to lie on a curve with a familiar shape: a cardioid. Is this true or just an illusion?

  20. Simple Example of Backtest Overfitting (SEBO)

    Energy Science and Technology Software Center (ESTSC)

    2015-01-06

    In the field of mathematical finance, a "backtest" is the usage of historical market data to assess the performance of a proposed trading strategy. It is a relatively simple matter for a present-day computer system to explore thousands, millions or even billions of variations of a proposed strategy, and pick the best performing variant as the "optimal" strategy "in sample" (i.e., on the input dataset). Unfortunately, such an "optimal" strategy often performs very poorly "outmore » of sample" (i.e. on another dataset), because the parameters of the invest strategy have been oversit to the in-sample data, a situation known as "backtest overfitting". While the mathematics of backtest overfitting has been examined in several recent theoretical studies, here we pursue a more tangible analysis of this problem, in the form of an online simulator tool. Given a input random walk time series, the tool develops an "optimal" variant of a simple strategy by exhaustively exploring all integer parameter values among a handful of parameters. That "optimal" strategy is overfit, since by definition a random walk is unpredictable. Then the tool tests the resulting "optimal" strategy on a second random walk time series. In most runs using our online tool, the "optimal" strategy derived from the first time series performs poorly on the second time series, demonstrating how hard it is not to overfit a backtest. We offer this online tool, "Simple Example of Backtest Overfitting (SEBO)", to facilitate further research in this area.« less

  1. Necessity of Antibiotics following Simple Exodontia.

    PubMed

    Yousuf, Waqas; Khan, Moiz; Mehdi, Hasan; Mateen, Sana

    2016-01-01

    Introduction. The aim of our study is to assess the need for postoperative antibiotics following simple exodontia and determine its role in minimizing patient discomfort and postoperative complications. Material and Methods. All the patients undergoing simple extractions were grouped into two categories: Group 1, patients receiving antibiotics, and Group 2, patients receiving no antibiotics. Patients were recalled on the sixth day to assess postoperative complications. On recall, patients were evaluated for signs of persistent inflammation and signs of dry socket. Presence of persistent inflammation and/or suppuration on the 6th day was considered as wound infection. Results. A total of 146 patients were included in this study. Out of the total sample, 134 (91.8%) presented with no postoperative complications and 12 (8.2%) had postoperative complications, out of which 11 (7.5%) patients presented with dry socket (alveolar osteitis), 5 (3.4%) in the antibiotic group and 6 (4.1%) in the nonantibiotic group. Only 1 patient (0.7%) was reported with infection of the extraction socket in the nonantibiotic group, whereas no case of infection was found in the antibiotic group. Conclusion. Antibiotics are not required after simple extractions in patients who are not medically comprised nor do they have any role in preventing postoperative complications. PMID:27110426

  2. Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local

    NASA Astrophysics Data System (ADS)

    Ros, Rosa M.

    2009-12-01

    The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)

  3. Enhancement of orientation gradients during simple shear deformation by application of simple compression

    NASA Astrophysics Data System (ADS)

    Jahedi, Mohammad; Ardeljan, Milan; Beyerlein, Irene J.; Paydar, Mohammad Hossein; Knezevic, Marko

    2015-06-01

    We use a multi-scale, polycrystal plasticity micromechanics model to study the development of orientation gradients within crystals deforming by slip. At the largest scale, the model is a full-field crystal plasticity finite element model with explicit 3D grain structures created by DREAM.3D, and at the finest scale, at each integration point, slip is governed by a dislocation density based hardening law. For deformed polycrystals, the model predicts intra-granular misorientation distributions that follow well the scaling law seen experimentally by Hughes et al., Acta Mater. 45(1), 105-112 (1997), independent of strain level and deformation mode. We reveal that the application of a simple compression step prior to simple shearing significantly enhances the development of intra-granular misorientations compared to simple shearing alone for the same amount of total strain. We rationalize that the changes in crystallographic orientation and shape evolution when going from simple compression to simple shearing increase the local heterogeneity in slip, leading to the boost in intra-granular misorientation development. In addition, the analysis finds that simple compression introduces additional crystal orientations that are prone to developing intra-granular misorientations, which also help to increase intra-granular misorientations. Many metal working techniques for refining grain sizes involve a preliminary or concurrent application of compression with severe simple shearing. Our finding reveals that a pre-compression deformation step can, in fact, serve as another processing variable for improving the rate of grain refinement during the simple shearing of polycrystalline metals.

  4. A SIMPLE MODEL FOR QUASAR DEMOGRAPHICS

    SciTech Connect

    Conroy, Charlie; White, Martin

    2013-01-10

    We present a simple model for the relationship between quasars, galaxies, and dark matter halos from 0.5 < z < 6. In the model, black hole (BH) mass is linearly related to galaxy mass, and galaxies are connected to dark matter halos via empirically constrained relations. A simple 'scattered' light bulb model for quasars is adopted, wherein BHs shine at a fixed fraction of the Eddington luminosity during accretion episodes, and Eddington ratios are drawn from a lognormal distribution that is redshift independent. This model has two free, physically meaningful parameters at each redshift: the normalization of the M {sub BH}-M {sub gal} relation and the quasar duty cycle; these parameters are fit to the observed quasar luminosity function (LF) over the interval 0.5 < z < 6. This simple model provides an excellent fit to the LF at all epochs and also successfully predicts the observed projected two-point correlation of quasars from 0.5 < z < 2.5. It is significant that a single quasar duty cycle at each redshift is capable of reproducing the extant observations. The data are therefore consistent with a scenario wherein quasars are equally likely to exist in galaxies, and therefore dark matter halos, over a wide range in masses. The knee in the quasar LF is a reflection of the knee in the stellar-mass-halo-mass relation. Future constraints on the quasar LF and quasar clustering at high redshift will provide strong constraints on the model. In the model, the autocorrelation function of quasars becomes a strong function of luminosity only at the very highest luminosities and will be difficult to observe because such quasars are so rare. Cross-correlation techniques may provide useful constraints on the bias of such rare objects. The simplicity of the model allows for rapid generation of quasar mock catalogs from N-body simulations that match the observed LF and clustering to high redshift.

  5. THE SIMPLE SURVEY: OBSERVATIONS, REDUCTION, AND CATALOG

    SciTech Connect

    Damen, M.; Franx, M.; Taylor, E. N.; Labbe, I.; Van Dokkum, P. G.; Muzzin, A.; Brandt, W. N.; Dickinson, M.; Gawiser, E.; Illingworth, G. D.; Marchesini, D.; Papovich, C.; Rix, H.-W.

    2011-01-20

    We present the Spitzer IRAC/MUSYC Public Legacy Survey in the Extended CDF-South (SIMPLE), which consists of deep IRAC observations covering the {approx}1600 arcmin{sup 2} area surrounding GOODS-S. The limiting magnitudes of the SIMPLE IRAC mosaics typically are 23.8, 23.6, 21.9, and 21.7, at 3.6 {mu}m, 4.5 {mu}m, 5.8 {mu}m, and 8.0 {mu}m, respectively (5{sigma} total point source magnitudes in AB). The SIMPLE IRAC images are combined with the 10' x 15' GOODS IRAC mosaics in the center. We give detailed descriptions of the observations, data reduction, and properties of the final images, as well as the detection and photometry methods used to build a catalog. Using published optical and near-infrared data from the Multiwavelength Survey by Yale-Chile (MUSYC), we construct an IRAC-selected catalog, containing photometry in UBVRIz'JHK, [3.6 {mu}m], [4.5 {mu}m], [5.8 {mu}m], and [8.0 {mu}m]. The catalog contains 43,782 sources with S/N >5 at 3.6 {mu}m, 19,993 of which have 13-band photometry. We compare this catalog to the publicly available MUSYC and FIREWORKS catalogs and discuss the differences. Using a high signal-to-noise sub-sample of 3391 sources with ([3.6] + [4.5])/2 < 21.2, we investigate the star formation rate history of massive galaxies out to z {approx} 1.8. We find that at z {approx} 1.8 at least 30% {+-} 7% of the most massive galaxies (M{sub *} >10{sup 11} M{sub sun}) are passively evolving, in agreement with earlier results from surveys covering less area.

  6. Physical fitness gains following simple environmental change.

    PubMed

    Linenger, J M; Chesson, C V; Nice, D S

    1991-01-01

    Inactivity is the risk factor with potentially the greatest public health impact, according to the 1989 U.S. Preventive Services Task Force report. Our study reports changes in subjects' physical fitness level after simple changes aimed at enabling community members to adopt more easily active lifestyles. Simple environmental and social alterations occurred at a San Diego Naval air station. We administered to a cohort of active-duty personnel from within this community (n = 1,609) both a physical readiness test (PRT) and a lifestyle questionnaire at baseline and at one year. The PRT consisted of a 1.5-mile timed run, sit-ups, push-ups, and percentage body fat components, and the questionnaire addressed demographics, current exercise behavior, and attitudes toward exercise. We took similar measures within a comparison community cohort (n = 217) and within a Navy-wide sample cohort (n = 546). Both overall PRT category and 1.5-mile run time improved significantly (P less than .05) over time in the intervention community (0.3 category points and 18 seconds, respectively). The increase was significantly greater (P less than .01) than in either the control community or the Navy-wide sample. Subgroup analysis showed that, in the intervention community, 12.4% failed the overall fitness test in 1987, but only 5.1% failed in 1988. Similarly, the 1.5-mile run failures decreased from 8.4% to 4%. Reported leisure time kilocalorie expenditure showed no significant improvement. This simple program successfully improved fitness performance. The improvement was distributed throughout the community and included those who were substandard at baseline. Similar programs could easily be adopted in a variety of communities. PMID:1790036

  7. Simple analytic potentials for linear ion traps

    NASA Technical Reports Server (NTRS)

    Janik, G. R.; Prestage, J. D.; Maleki, L.

    1989-01-01

    A simple analytical model was developed for the electric and ponderomotive (trapping) potentials in linear ion traps. This model was used to calculate the required voltage drive to a mercury trap, and the result compares well with experiments. The model gives a detailed picture of the geometric shape of the trapping potenital and allows an accurate calculation of the well depth. The simplicity of the model allowed an investigation of related, more exotic trap designs which may have advantages in light-collection efficiency.

  8. Simple analytic potentials for linear ion traps

    NASA Technical Reports Server (NTRS)

    Janik, G. R.; Prestage, J. D.; Maleki, L.

    1990-01-01

    A simple analytical model was developed for the electric and ponderomotive (trapping) potentials in linear ion traps. This model was used to calculate the required voltage drive to a mercury trap, and the result compares well with experiments. The model gives a detailed picture of the geometric shape of the trapping potential and allows an accurate calculation of the well depth. The simplicity of the model allowed an investigation of related, more exotic trap designs which may have advantages in light-collection efficiency.

  9. Desiccant cooling system performance: A simple approach

    NASA Astrophysics Data System (ADS)

    Epstein, M.; Grolmes, M. A.

    1982-10-01

    The wave nature of heat and mass transfer in fixed desiccant bed adsorption is explained. A simple algebraic model of wave motion under single low desiccant bed operation is developed and applied to the prediction of the performance potential of the overall desiccant cooling system. The model is used to explain the increase in cooling system performance that is realized through the use of mixed inert desiccant material adsorption beds. The response of cooling system performance to changes in external process conditions is examined and conclusions are drawn relative to optimization of system characteristics.

  10. Simple novel all-optical wavelength converter

    NASA Astrophysics Data System (ADS)

    Chen, Zhixin

    2009-02-01

    Based on Sagnac interferometric structure, a simple novel ultrafast scheme for an all-optical wavelength converter is proposed. The operations of this scheme with a 80-Gbits/s return to zero (RZ) pseudorandom bit sequence (PRBS) are simulated correctly with an output extinction ratio of more than 17.2 dB. Through numerical analysis, by comparison of the performance at 40- and 80-Gbits/s operation, the operating characteristics of the scheme are illustrated. Furthermore, the carrier recovery time of the semiconductor amplifier (SOA) is no longer a crucial parameter to restrict the operation speed of this scheme.

  11. Detection and recognition of simple spatial forms

    NASA Technical Reports Server (NTRS)

    Watson, A. B.

    1983-01-01

    A model of human visual sensitivity to spatial patterns is constructed. The model predicts the visibility and discriminability of arbitrary two-dimensional monochrome images. The image is analyzed by a large array of linear feature sensors, which differ in spatial frequency, phase, orientation, and position in the visual field. All sensors have one octave frequency bandwidths, and increase in size linearly with eccentricity. Sensor responses are processed by an ideal Bayesian classifier, subject to uncertainty. The performance of the model is compared to that of the human observer in detecting and discriminating some simple images.

  12. Simple orbital theory for the molecular electrician.

    PubMed

    Ernzerhof, Matthias

    2011-07-01

    Theories of molecular electronic devices (MEDs) are quite involved in general. However, various prominent features of MEDs can be understood drawing only on elementary quantum theory. To support this point of view, we provide a two component orbital theory that enables one to reproduce various important features of MEDs. In this theory, the device orbitals are divided into two components, each of which is obtained from simple rules. To illustrate our two-component model, we apply it to explain, among other things, the conductance suppression in cross-conjugated systems and the dependence of the conductance on the contact position in aromatic systems. PMID:21744885

  13. Oscillatory dissipation of a simple confined liquid.

    PubMed

    Maali, Abdelhamid; Cohen-Bouhacina, Touria; Couturier, Gérard; Aimé, Jean-Pierre

    2006-03-01

    We present a sensitive measurement of the dissipation and the effective viscosity of a simple confined liquid (octamethylcyclotetrasiloxane) using an atomic force microscope. The experimental data show that the damping and the effective viscosity increase and present oscillations as the gap between the cantilever tip and the surface is diminished. To our knowledge, the damping and the viscosity modulation are reported here with such good accuracy for the first time. Such an experimental result is different from what has been reported earlier where only a continuous increase of the damping and the viscosity are observed. PMID:16606201

  14. Simple microwave preionization source for ohmic plasmas

    NASA Astrophysics Data System (ADS)

    Choe, W.; Kwon, Gi-Chung; Kim, Junghee; Kim, Jayhyun; Jeon, Sang-Jean; Huh, Songwhe

    2000-07-01

    A simple economical 2.45 GHz microwave system has been developed and utilized for preionization on the Korea Advanced Institute of Science and Technology (KAIST)-TOKAMAK. The magnetron microwave source was obtained from a widely used, household microwave oven. Since ac operation of the magnetron is not suitable for tokamak application, the magnetron cathode bias circuit was modified to obtain continuous and stable operation of the magnetron for several hundred milliseconds. Application of the developed microwave system to KAIST-TOKAMAK resulted in a reduction of ohmic flux consumption.

  15. [Simple partial frontal nonconvulsive status epilepticus].

    PubMed

    Thomas, P; Mottin, Y

    1997-07-01

    Non convulsive status epilepticus (NCSE) of frontal origin is a rare cause of mental confusion. The present case of possible frontal-onset NCSE proved to have a neuropsychological examination that was suggestive either of a disruption of attentional function or a left prefrontal dysfunction, exhibiting disturbances of immediate memory and logical programmation, perseverations and affective disinhibition. Vigilance was not impaired. This case was therefore, on a nosographic point of view, more consistent with a simple partial status epilepticus with cognitive and affective symptomatology rather than with a complex partial status epilepticus of extra-temporal origin. PMID:9684010

  16. A Simple Apparatus for Optical Polarization Experiments

    NASA Astrophysics Data System (ADS)

    Krieble, Kelly; Powlette, Joseph L.

    2003-12-01

    The phenomenon of polarization is usually covered, although very briefly, in most introductory college and high school physics classes. Experiments such as Malus's law are often performed with inexpensive linear polarization filters or lenses from polarized sunglasses. Investigations of more complex forms of polarization, using retarders such as quarter-wave plates (QWPs) and half-wave plates (HWPs), are often omitted because the acquisition of equipment necessary for multiple setups can be cost-prohibitive. We present here a simple rotational apparatus for accurate polarization measurements and applications using inexpensive substitutes of QWP and HWP for use with common laser wavelengths.

  17. Uncertainty relations from simple entropic properties.

    PubMed

    Coles, Patrick J; Colbeck, Roger; Yu, Li; Zwolak, Michael

    2012-05-25

    Uncertainty relations provide constraints on how well the outcomes of incompatible measurements can be predicted, and as well as being fundamental to our understanding of quantum theory, they have practical applications such as for cryptography and witnessing entanglement. Here we shed new light on the entropic form of these relations, showing that they follow from a few simple properties, including the data-processing inequality. We prove these relations without relying on the exact expression for the entropy, and hence show that a single technique applies to several entropic quantities, including the von Neumann entropy, min- and max-entropies, and the Rényi entropies. PMID:23003225

  18. Simple approach for ranking structure determining residues

    PubMed Central

    Luna-Martínez, Oscar D.; Vidal-Limón, Abraham; Villalba-Velázquez, Miryam I.; Sánchez-Alcalá, Rosalba; Garduño-Juárez, Ramón; Uversky, Vladimir N.

    2016-01-01

    Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology. PMID:27366642

  19. Simple analytic approximations for the Blasius problem

    NASA Astrophysics Data System (ADS)

    Iacono, R.; Boyd, John P.

    2015-08-01

    The classical boundary layer problem formulated by Heinrich Blasius more than a century ago is revisited, with the purpose of deriving simple and accurate analytical approximations to its solution. This is achieved through the combined use of a generalized Padé approach and of an integral iteration scheme devised by Hermann Weyl. The iteration scheme is also used to derive very accurate bounds for the value of the second derivative of the Blasius function at the origin, which plays a crucial role in this problem.

  20. Simple effective interaction for dimensional crossover

    NASA Astrophysics Data System (ADS)

    Constantin, Lucian A.

    2016-03-01

    We show that the effective electron-electron interaction veff[n ] (r ,r') =erf [|r - r'|b (n ) ]/|r -r'| , with n being the electronic density and b (n ) fixed from the compressibility sum rule, is remarkably accurate in both three and two dimensions, competing with the actual state-of-the-art exchange-correlation static kernels. Using this result, we propose a simple isotropic approximation for the quasi-two-dimensional regime, which gives a realistic wave vector analysis of the correlation energy, in the context of the linear response time-dependent density functional theory.

  1. Simple Forest Canopy Thermal Exitance Model

    NASA Technical Reports Server (NTRS)

    Smith J. A.; Goltz, S. M.

    1999-01-01

    We describe a model to calculate brightness temperature and surface energy balance for a forest canopy system. The model is an extension of an earlier vegetation only model by inclusion of a simple soil layer. The root mean square error in brightness temperature for a dense forest canopy was 2.5 C. Surface energy balance predictions were also in good agreement. The corresponding root mean square errors for net radiation, latent, and sensible heat were 38.9, 30.7, and 41.4 W/sq m respectively.

  2. Term rules for simple metal clusters

    NASA Astrophysics Data System (ADS)

    Yoshida, Daisuke; Raebiger, Hannes

    2015-10-01

    Hund’s term rules are only valid for isolated atoms, but have no generalization for molecules or clusters of several atoms. We present a benchmark calculation of Al2 and Al3, for which we find the high and low-spin ground states 3Πu and , respectively. We show that the relative stabilities of all the molecular terms of Al2 and Al3 can be described by simple rules pertaining to bonding structures and symmetries, which serve as guiding principles to determine ground state terms of arbitrary multi-atom clusters.

  3. A simple laser system for atom interferometry

    NASA Astrophysics Data System (ADS)

    Merlet, S.; Volodimer, L.; Lours, M.; Pereira Dos Santos, F.

    2014-07-01

    We present here a simple laser system for a laser-cooled atom interferometer, where all functions (laser cooling, interferometry and detection) are realized using only two extended cavity laser diodes, amplified by a common tapered amplifier. One laser is locked by frequency modulation transfer spectroscopy, the other being phase locked with an offset frequency determined by an field-programmable gate array-controlled direct digital synthesizer, which allows for efficient and versatile tuning of the laser frequency. Raman lasers are obtained with a double pass acoustooptic modulator. We demonstrate a gravimeter using this laser system, with performances close to the state of the art.

  4. Drift estimation from a simple field theory

    SciTech Connect

    Mendes, F. M.; Figueiredo, A.

    2008-11-06

    Given the outcome of a Wiener process, what can be said about the drift and diffusion coefficients? If the process is stationary, these coefficients are related to the mean and variance of the position displacements distribution. However, if either drift or diffusion are time-dependent, very little can be said unless some assumption about that dependency is made. In Bayesian statistics, this should be translated into some specific prior probability. We use Bayes rule to estimate these coefficients from a single trajectory. This defines a simple, and analytically tractable, field theory.

  5. A simple method for global sequence comparison.

    PubMed Central

    Pizzi, E; Attimonelli, M; Liuni, S; Frontali, C; Saccone, C

    1992-01-01

    A simple method of sequence comparison, based on a correlation analysis of oligonucleotide frequency distributions, is here shown to be a reliable test of overall sequence similarity. The method does not involve sequence alignment procedures and permits the rapid screening of large amounts of sequence data. It identifies those sequences which deserve more careful analysis of sequence similarity at the level of resolution of the single nucleotide. It uses observed quantities only and does not involve the adoption of any theoretical model. PMID:1738591

  6. Implementing successful strategic plans: a simple formula.

    PubMed

    Blondeau, Whitney; Blondeau, Benoit

    2015-01-01

    Strategic planning is a process. One way to think of strategic planning is to envision its development and design as a framework that will help your hospital navigate through internal and external changing environments over time. Although the process of strategic planning can feel daunting, following a simple formula involving five steps using the mnemonic B.E.G.I.N. (Begin, Evaluate, Goals & Objectives, Integration, and Next steps) will help the planning process feel more manageable, and lead you to greater success. PMID:26058285

  7. Fourier's law: insight from a simple derivation.

    PubMed

    Dubi, Y; Di Ventra, M

    2009-04-01

    The onset of Fourier's law in a one-dimensional quantum system is addressed via a simple model of weakly coupled quantum systems in contact with thermal baths at their edges. Using analytical arguments we show that the crossover from the ballistic (invalid Fourier's law) to diffusive (valid Fourier's law) regimes is characterized by a thermal length scale, which is directly related to the profile of the local temperature. In the same vein, dephasing is shown to give rise to classical Fourier's law, similarly to the onset of Ohm's law in mesoscopic conductors. PMID:19518279

  8. Simple approach for ranking structure determining residues.

    PubMed

    Luna-Martínez, Oscar D; Vidal-Limón, Abraham; Villalba-Velázquez, Miryam I; Sánchez-Alcalá, Rosalba; Garduño-Juárez, Ramón; Uversky, Vladimir N; Becerril, Baltazar

    2016-01-01

    Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology. PMID:27366642

  9. A simple statistical model for geomagnetic reversals

    NASA Technical Reports Server (NTRS)

    Constable, Catherine

    1990-01-01

    The diversity of paleomagnetic records of geomagnetic reversals now available indicate that the field configuration during transitions cannot be adequately described by simple zonal or standing field models. A new model described here is based on statistical properties inferred from the present field and is capable of simulating field transitions like those observed. Some insight is obtained into what one can hope to learn from paleomagnetic records. In particular, it is crucial that the effects of smoothing in the remanence acquisition process be separated from true geomagnetic field behavior. This might enable us to determine the time constants associated with the dominant field configuration during a reversal.

  10. Progress with simple binary alloy solidification problems

    SciTech Connect

    Wilson, D.G.; Solomon, A.D.; Alexiades, V.

    1981-01-01

    We give a preliminary report of our studies on binary alloy solidification. In what follows we state the mathematical problem, which we assume represents the solidification of a simple binary alloy; we give a very brief introduction to two component phase diagrams, whose relations we assume hold at the solidification front; we describe our phlogiston formulation of the problem, which is derived by analogy with the enthalpy method for simpler problems; we describe the finite difference scheme, with which we computer the various constituents of our phlogiston formulation; and finally we relate our computational experience with the model so far.

  11. Simple and Clean Photoinduced Aromatic Trifluoromethylation Reaction.

    PubMed

    Li, Lu; Mu, Xiaoyue; Liu, Wenbo; Wang, Yichen; Mi, Zetian; Li, Chao-Jun

    2016-05-11

    We describe a simple, metal- and oxidant-free photochemical strategy for the direct trifluoromethylation of unactivated arenes and heteroarenes under either ultraviolet or visible light irradiation. We demonstrated that photoexcited aliphatic ketones, such as acetone and diacetyl, can be used as promising low-cost radical initiators to generate CF3 radicals from sodium triflinate efficiently. The broad utility of this strategy and its benefit to medicinal chemistry are demonstrated by the direct trifluoromethylation of unprotected bidentate chelating ligand, xanthine alkaloids, nucleosides, and related antiviral drug molecules. PMID:27137478

  12. Term rules for simple metal clusters

    PubMed Central

    Yoshida, Daisuke; Raebiger, Hannes

    2015-01-01

    Hund’s term rules are only valid for isolated atoms, but have no generalization for molecules or clusters of several atoms. We present a benchmark calculation of Al2 and Al3, for which we find the high and low-spin ground states 3Πu and , respectively. We show that the relative stabilities of all the molecular terms of Al2 and Al3 can be described by simple rules pertaining to bonding structures and symmetries, which serve as guiding principles to determine ground state terms of arbitrary multi-atom clusters. PMID:26497089

  13. Degenerate polygonal tilings in simple animal tissues

    NASA Astrophysics Data System (ADS)

    Ziherl, Primoz; Hocevar, Ana

    2009-03-01

    We study 2D polygonal tilings as models of the en-face structure of single-layer biological tissues. Using numerical simulations, we explore the phase diagram of equilibrium tilings of equal-area, equal-perimeter convex polygons whose energy is independent of their shape. We identify 3 distinct phases, which are all observed in simple epithelial tissues: The disordered phase of polygons with 4-9 sides, the hexatic phase, and the hexagonal phase with perfect 6-fold coordination. We quantify their structure using Edwards' statistical mechanics of cellular systems.

  14. A simple proof of Bell's inequality

    NASA Astrophysics Data System (ADS)

    Maccone, Lorenzo

    2013-11-01

    Bell's theorem is a fundamental result in quantum mechanics: it discriminates between quantum mechanics and all theories where probabilities in measurement results arise from the ignorance of pre-existing local properties. We give an extremely simple proof of Bell's inequality; a single figure suffices. This simplicity may be useful in the unending debate over what exactly the Bell inequality means, because the hypotheses underlying the proof become transparent. It is also a useful didactic tool, as the Bell inequality can be explained in a single intuitive lecture.

  15. 40 CFR 80.42 - Simple emissions model.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Simple emissions model. 80.42 Section...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.42 Simple emissions model. (a) VOC emissions. The following equations shall comprise the simple model for VOC emissions. The simple model...

  16. Modelo Pedagogico de Educacion Primaria para Adultos: Manual para la Vinculacion y Funcionamiento de los Comites de Educacion para Adultos (A Teaching Model for Adult Primary Education: Manual for the Continuation and Operation of Adult Education Committees).

    ERIC Educational Resources Information Center

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    This manual is part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. This document describes the concept of a model for community adult education for the purpose of supporting local educational committees…

  17. Local energy landscape in a simple liquid

    SciTech Connect

    Iwashita, T.; Egami, Takeshi

    2014-11-26

    It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure that defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly the effect of temperature and history. However, because of the highly multidimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL), which is limited in phase space, and demonstrate its usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest-neighbor atoms. The excitation in the LEL corresponds to the so-called β-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.

  18. Simple animal model of Helicobacter pylori infection

    PubMed Central

    Werawatganon, Duangporn

    2014-01-01

    Helicobacter pylori (H. pylori) has become accepted as a human pathogen for the development of gastritis and gastroduodenal ulcer. To develop a simple rat model of chronic H. pylori infection, male Sprague-Dawley rats were pretreated with streptomycin suspended in tap water (5 mg/mL) for 3 d. The rats were inoculated by gavage at 1 mL/rat with H. pylori suspension (5 × 108-5 × 1010 CFU/mL) twice daily at an interval of 4 h for three consecutive days. Two weeks after inoculation, rats were sacrificed and the stomachs were removed. Antral biopsies were performed for urease test and the stomachs were taken for histopathology. Successful H. pylori inoculation was defined as a positive urease test and histopathology. We reported a 69.8%-83.0% success rate for H. pylori infection using the urease test, and hematoxylin and eosin staining confirmed the results. Histopathological analysis detected bacteria along the mucous lining of the surface epithelium and crypt lumen and demonstrated mild to moderate gastric inflammation in successfully inoculated rats. We developed a simple rat model of chronic H. pylori infection for research into gastric microcirculatory changes and therapy with plant products. PMID:24914363

  19. Simple replica micromolding of biocompatible styrenic elastomers.

    PubMed

    Borysiak, Mark D; Bielawski, Kevin S; Sniadecki, Nathan J; Jenkel, Colin F; Vogt, Bryan D; Posner, Jonathan D

    2013-07-21

    In this work, we introduce a simple solvent-assisted micromolding technique for the fabrication of high-fidelity styrene-ethylene/butylene-styrene (SEBS) microfluidic devices with high polystyrene (PS) content (42 wt% PS, SEBS42). SEBS triblock copolymers are styrenic thermoplastic elastomers that exhibit both glassy thermoplastic and elastomeric properties resulting from their respective hard PS and rubbery ethylene/butylene segments. The PS fraction gives SEBS microdevices many of the appealing properties of pure PS devices, while the elastomeric properties simplify fabrication of the devices, similar to PDMS. SEBS42 devices have wettable, stable surfaces (both contact angle and zeta potential) that support cell attachment and proliferation consistent with tissue culture dish substrates, do not adsorb hydrophobic molecules, and have high bond strength to wide range of substrates (glass, PS, SEBS). Furthermore, SEBS42 devices are mechanically robust, thermally stable, as well as exhibit low auto-fluorescence and high transmissivity. We characterize SEBS42 surface properties by contact angle measurements, cell culture studies, zeta potential measurements, and the adsorption of hydrophobic molecules. The PS surface composition of SEBS microdevices cast on different substrates is determined by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The attractive SEBS42 material properties, coupled with the simple fabrication method, make SEBS42 a quality substrate for microfluidic applications where the properties of PS are desired but the ease of PDMS micromolding is favoured. PMID:23670166

  20. Simple Deterministically Constructed Recurrent Neural Networks

    NASA Astrophysics Data System (ADS)

    Rodan, Ali; Tiňo, Peter

    A large number of models for time series processing, forecasting or modeling follows a state-space formulation. Models in the specific class of state-space approaches, referred to as Reservoir Computing, fix their state-transition function. The state space with the associated state transition structure forms a reservoir, which is supposed to be sufficiently complex so as to capture a large number of features of the input stream that can be potentially exploited by the reservoir-to-output readout mapping. The largely "black box" character of reservoirs prevents us from performing a deeper theoretical investigation of the dynamical properties of successful reservoirs. Reservoir construction is largely driven by a series of (more-or-less) ad-hoc randomized model building stages, with both the researchers and practitioners having to rely on a series of trials and errors. We show that a very simple deterministically constructed reservoir with simple cycle topology gives performances comparable to those of the Echo State Network (ESN) on a number of time series benchmarks. Moreover, we argue that the memory capacity of such a model can be made arbitrarily close to the proved theoretical limit.

  1. Simple gas chromatographic method for furfural analysis.

    PubMed

    Gaspar, Elvira M S M; Lopes, João F

    2009-04-01

    A new, simple, gas chromatographic method was developed for the direct analysis of 5-hydroxymethylfurfural (5-HMF), 2-furfural (2-F) and 5-methylfurfural (5-MF) in liquid and water soluble foods, using direct immersion SPME coupled to GC-FID and/or GC-TOF-MS. The fiber (DVB/CAR/PDMS) conditions were optimized: pH effect, temperature, adsorption and desorption times. The method is simple and accurate (RSD<8%), showed good recoveries (77-107%) and good limits of detection (GC-FID: 1.37 microgL(-1) for 2-F, 8.96 microgL(-1) for 5-MF, 6.52 microgL(-1) for 5-HMF; GC-TOF-MS: 0.3, 1.2 and 0.9 ngmL(-1) for 2-F, 5-MF and 5-HMF, respectively). It was applied to different commercial food matrices: honey, white, demerara, brown and yellow table sugars, and white and red balsamic vinegars. This one-step, sensitive and direct method for the analysis of furfurals will contribute to characterise and quantify their presence in the human diet. PMID:18976770

  2. Reanalysis of the equation for simple action

    PubMed Central

    Warren-Boulton, Frederick R.; Silberberg, Alan; Gray, Michael; Ollom, Randolph

    1985-01-01

    De Villiers and Herrnstein (1976) have shown that the equation for simple action, derived from the matching law, predicts change in behavioral output for some 40 experiments in which the value of a single source of reinforcement has been varied. Using only the positive-reinforcement studies they cite that used five or more different reinforcement values, we found the high percentage of variance they report accommodated by this equation (94%) is predicated on instances of averaging rates of behavioral output before making a least-squares fit of the equation. In our reanalysis, which minimizes rate averaging, only 78% of the data variance is accommodated. This diminished data-variance accommodation can be improved by adding parameters that permit the equation's scaling constant to change as a function of reinforcement. Although these parameters permit acceptable levels of accommodation of data variance, they correspond to no obvious psychological processes. These findings support the view that the equation for simple action is an inadequate model for behavioral output. PMID:16812416

  3. Local energy landscape in a simple liquid

    DOE PAGESBeta

    Iwashita, T.; Egami, Takeshi

    2014-11-26

    It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure that defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly the effect of temperature and history. However, because of the highly multidimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL), which is limited in phase space, and demonstrate itsmore » usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest-neighbor atoms. The excitation in the LEL corresponds to the so-called β-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.« less

  4. Foreshock and aftershocks in simple earthquake models.

    PubMed

    Kazemian, J; Tiampo, K F; Klein, W; Dominguez, R

    2015-02-27

    Many models of earthquake faults have been introduced that connect Gutenberg-Richter (GR) scaling to triggering processes. However, natural earthquake fault systems are composed of a variety of different geometries and materials and the associated heterogeneity in physical properties can cause a variety of spatial and temporal behaviors. This raises the question of how the triggering process and the structure interact to produce the observed phenomena. Here we present a simple earthquake fault model based on the Olami-Feder-Christensen and Rundle-Jackson-Brown cellular automata models with long-range interactions that incorporates a fixed percentage of stronger sites, or asperity cells, into the lattice. These asperity cells are significantly stronger than the surrounding lattice sites but eventually rupture when the applied stress reaches their higher threshold stress. The introduction of these spatial heterogeneities results in temporal clustering in the model that mimics that seen in natural fault systems along with GR scaling. In addition, we observe sequences of activity that start with a gradually accelerating number of larger events (foreshocks) prior to a main shock that is followed by a tail of decreasing activity (aftershocks). This work provides further evidence that the spatial and temporal patterns observed in natural seismicity are strongly influenced by the underlying physical properties and are not solely the result of a simple cascade mechanism. PMID:25768785

  5. Understanding target delineation using simple probabilistic modelling

    NASA Astrophysics Data System (ADS)

    Willis, Chris J.

    2015-10-01

    Performance assessment is carried out for a simple target delineation process based on thresholding and shape fitting. The method uses the information contained in Receiver Operating Characteristic curves together with basic observations regarding target sizes and shapes. Performance is gauged by considering the delineations that might result from having particular arrangements of detected pixels within the vicinity of a hypothesized target. In particular, the method considers the qualities of delineations generated when having various combinations of detected pixels at a number of locations around the inner and outer boundaries of the underlying object. Three distinct types of arrangement for pixels on the inner target boundary are considered. Each has the potential to lead to a good quality delineation in a thresholding and shape fitting scheme. The deleterious effect of false alarms within the surrounding local region is also taken into account. The resulting ensembles of detected pixels are treated using familiar rules for combination to form probabilities for the delineations as a whole. Example results are produced for simple target prototypes in cluttered SAR imagery.

  6. Simple Correction of the Congenital Cleft Earlobe.

    PubMed

    Karaci, Selman; Köse, Rüştü

    2016-07-01

    The appearance of the ear is an important component of the facial characteristics. Lower auricular malformations are less frequent than total or upper auricular malformations. The patients are affected unilaterally in general. Cleft earlobe is frequently encountered among earlobe anomalies. The presented case may be classified as longitudinal type according to Kitayama (Jpn J Plast Reconstr Surg 11:663-670, 1980). Many of the correction methods may lead to patient discomfort due to possible conspicuous scar. The patient was a 5 year old girl. In the presented case, a simple method has been performed. Satisfactory outcome is achieved. As a simple method applying longitudinal division and rotation procedure does not have marginal excision. Furthermore there is no additional incision outside the cleft margin. Local flap and graft are not applied. Conservative approach was maintained with respect to scar occurrence. This method is not favourable in the case of acquired split earlobe deformities due to the wide cleft surface. Postoperative 3rd-month appearance demonstrated adequate correction. PMID:27408464

  7. Foreshock and Aftershocks in Simple Earthquake Models

    NASA Astrophysics Data System (ADS)

    Kazemian, J.; Tiampo, K. F.; Klein, W.; Dominguez, R.

    2015-02-01

    Many models of earthquake faults have been introduced that connect Gutenberg-Richter (GR) scaling to triggering processes. However, natural earthquake fault systems are composed of a variety of different geometries and materials and the associated heterogeneity in physical properties can cause a variety of spatial and temporal behaviors. This raises the question of how the triggering process and the structure interact to produce the observed phenomena. Here we present a simple earthquake fault model based on the Olami-Feder-Christensen and Rundle-Jackson-Brown cellular automata models with long-range interactions that incorporates a fixed percentage of stronger sites, or asperity cells, into the lattice. These asperity cells are significantly stronger than the surrounding lattice sites but eventually rupture when the applied stress reaches their higher threshold stress. The introduction of these spatial heterogeneities results in temporal clustering in the model that mimics that seen in natural fault systems along with GR scaling. In addition, we observe sequences of activity that start with a gradually accelerating number of larger events (foreshocks) prior to a main shock that is followed by a tail of decreasing activity (aftershocks). This work provides further evidence that the spatial and temporal patterns observed in natural seismicity are strongly influenced by the underlying physical properties and are not solely the result of a simple cascade mechanism.

  8. Simple Replica Micromolding of Biocompatible Styrenic Elastomers†

    PubMed Central

    Bielawski, Kevin S.; Sniadecki, Nathan J.; Jenkel, Colin F.; Vogt, Bryan D.; Posner, Jonathan D.

    2013-01-01

    In this work, we introduce a simple solvent-assisted micromolding technique for the fabrication of high-fidelity styrene-ethylene/butylene-styrene (SEBS) microfluidic devices with high polystyrene (PS) content (42 wt% PS). SEBS triblock copolymers are styrenic thermoplastic elastomers that exhibit both glassy thermoplastic and elastomeric properties resulting from their respective hard PS and rubbery ethylene/butylene fractions. The PS fraction gives SEBS microdevices many of the appealing properties of pure PS devices, while the elastomeric fraction simplifies fabrication of the devices, similar to PDMS. SEBS42 devices have wettable, stable surfaces (both contact angle and zeta potential) that support cell attachment and proliferation consistent with tissue culture dish substrates, do not adsorb hydrophobic molecules, and have high bond strength to wide range of substrates (glass, PS, SEBS). Furthermore, SEBS42 devices are mechanically robust, thermally stable, as well as exhibit low auto-fluorescence and high transmissivity. We characterize SEBS42 surface properties by contact angle measurements, cell culture studies, zeta potential measurements, and the adsorption of hydrophobic molecules. The PS surface composition of SEBS microdevices cast on different substrates is determined by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The attractive SEBS42 material properties, coupled with the simple fabrication method, make SEBS42 a quality substrate for microfluidic applications where the properties of PS are desired but the ease of PDMS micromolding is favoured. PMID:23670166

  9. A SIMPLE Perspective on Europa's Habitability

    NASA Astrophysics Data System (ADS)

    Schmidt, B. E.

    2014-12-01

    While on the surface, Europa and the Earth may seem very different worlds, below their respective icy crusts, the two share remarkably similar conditions, temperatures, pressures (within a factor of a few) and potentially salinity. Thus the interface between Earth's thick permanent ice shelves and ocean is an important and little explored analog for the physicochemical, and possibly microbial, characteristics of Europa. Here, processes of melt, freeze, and marine ice accretion are controlled by gradients in ice thickness, currents, and ocean temperatures. The details of this process are not well characterized, even on Earth, in particular for the impact these have on the biological potential of these ices. For Europa, such a process may not only provide a habitable niche at ice-ocean interface, but also potentially within the ice shell. In addition, any material formed at the interface may be subject to transport upward through convection or diapirism, potentially delivering ocean-derived materials to the shallow subsurface, participating in an ice "conveyor belt" that will affect the habitability of Europa's ice and ocean alike. In the 2012, 2014 and 2015 austral summer antarctic field seasons, NASA's SIMPLE project (Sub-Ice Marine and PLanetary-analog Ecosystems), has been tasked with characterizing these processes in the McMurdo Ice Shelf, a small ice shelf easily accessible from USAP's McMurdo Station. Using sub-ice vehicles, ice penetrating radar, and other measurements of this unexplored region, the SIMPLE team is building a comprehensive picture of processes at the ice-ocean interface and within the brine-infiltrated ice shelf in order to advance hypotheses for Europa. In addition, the technologies supported by the project are advancing NASA's capabilities to detect processes and properties within ice by ice penetrating radar, and with in situ measurements, that will support Europa Clipper and future landers. The SIMPLE team consists of members from Georgia

  10. A Simple Weighing Method for Spherical Cells.

    PubMed

    Zhao, Qili; Shirinzadeh, Bijan; Cui, Maosheng; Sun, Mingzhu; Zhao, Xin

    2015-08-01

    This article presents a simple weighing method for spherical cells to avoid the high cost of correlated devices in traditional cell-weighing methods. In this method, the constant falling speeds of the spherical objects in liquid are derived to estimate their masses online. Using this method, the detected density of one type of microbead is highly in accordance with the known value. This method is proved to be capable of detecting tiny variations of the cell mass (at least within 1% of the cell mass). Finally, the proposed method is applied in nuclear transplantation operations, and, for the first time, the proper amount of the removed cytoplasm in porcine enucleation is estimated. The proposed method is able to weigh cells with a success rate of 92% at an average speed of 22 s/cell, and it can be performed on traditional microoperation systems, which makes it easily applicable in biological applications. PMID:25911396

  11. A general relaxation theory of simple liquids

    NASA Technical Reports Server (NTRS)

    Merilo, M.; Morgan, E. J.

    1973-01-01

    A relatively simple relaxation theory to account for the behavior of liquids under dynamic conditions was proposed. The general dynamical equations are similar in form to the phenomenological relaxation equations used in theories of viscoelasticity, however, they differ in that all the coefficients of the present equations are expressed in terms of thermodynamic and molecular quantities. The theory is based on the concept that flow in a liquid distorts both the radial and the velocity distribution functions, and that relaxation equations describing the return of these functions to their isotropic distributions, characterizing a stationary liquid, can be written. The theory was applied to the problems of steady and oscillatory shear flows and to the propagation of longitudinal waves. In all cases classical results are predicted for strain rates, and an expression for the viscosity of a liquid, simular to the Macedo-Litovitz equation, is obtained.

  12. A Simple Structure for Signal Amplification

    NASA Astrophysics Data System (ADS)

    Ding, Wan-Xiang; Gu, Chang-Gui; Liang, Xiao-Ming

    2016-02-01

    It has been found that a triple-node feed-forward motif has a function of signal amplification, where two input nodes receive the external weak signal and jointly modulate the response of the third output node [Liang et al., Phys. Rev. E 88 (2013) 012910]. We here show that the signal amplification can be further enhanced by adding a link between the two input nodes in the feed-forward motif. We further reveal that the coupling strength of the link regulates the enhancement of signal amplification in the modified feed-forward motif. We finally analyze the mechanism of signal amplification of such simple structure. Supported by the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning under Grant No. QD2015016, the National Natural Science Foundation of China under Grant Nos. 11505114 and 11305078

  13. Simple LDAP Schemas for Grid Monitoring

    NASA Technical Reports Server (NTRS)

    Smith, Warren; Gunter, Dan; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The purpose of this document is to provide an initial definition of the data we need in a directory service or database so that we can implement a performance monitoring testbed. To begin with, this document describes how to represent producers of events and event schemes. The representation of producers is simple and does not contain information such as who has access to the events and what protocols can be used to access the events. In the future, we will define how to describe consumers of events and add details to our representations. A popular choice for a directory service or database for grid computing is a distributed directory service that is accessed using the Lightweight Directory Access Protocol (LDAP). This document uses LDAP terminology, schemes, and formats to represent the directory service schemes.

  14. Simple implementation of general dark energy models

    SciTech Connect

    Bloomfield, Jolyon K.; Pearson, Jonathan A. E-mail: jonathan.pearson@durham.ac.uk

    2014-03-01

    We present a formalism for the numerical implementation of general theories of dark energy, combining the computational simplicity of the equation of state for perturbations approach with the generality of the effective field theory approach. An effective fluid description is employed, based on a general action describing single-scalar field models. The formalism is developed from first principles, and constructed keeping the goal of a simple implementation into CAMB in mind. Benefits of this approach include its straightforward implementation, the generality of the underlying theory, the fact that the evolved variables are physical quantities, and that model-independent phenomenological descriptions may be straightforwardly investigated. We hope this formulation will provide a powerful tool for the comparison of theoretical models of dark energy with observational data.

  15. Dynamics of a Simple Evolutionary Process

    NASA Astrophysics Data System (ADS)

    Stauffer, Dietrich; Newman, M. E. J.

    We study the simple evolutionary process in which we repeatedly find the least fit agent in a population of agents and give it a new fitness, which is chosen independently at random from a specified distribution. We show that many of the average properties of this process can be calculated exactly using analytic methods. In particular, we find the distribution of fitnesses at arbitrary time, and the distribution of the lengths of runs of hits on the same agent, the latter being found to follow a power law with exponent -1, similar to the distribution of times between evolutionary events in the Bak-Sneppen model and models based on the so-called record dynamics. We confirm our analytic results with extensive numerical simulations.

  16. Simple proposal for radial 3D needlets

    NASA Astrophysics Data System (ADS)

    Durastanti, C.; Fantaye, Y.; Hansen, F.; Marinucci, D.; Pesenson, I. Z.

    2014-11-01

    We present here a simple construction of a wavelet system for the three-dimensional ball, which we label radial 3D needlets. The construction envisages a data collection environment in which an observer located at the center of the ball is surrounded by concentric spheres with the same pixelization at different radial distances, for any given resolution. The system is then obtained by weighting the projector operator built on the corresponding set of eigenfunctions and performing a discretization step which turns out to be computationally very convenient. The resulting wavelets can be shown to have very good localization properties in the real and harmonic domain; their implementation is computationally very convenient, and they allow for exact reconstruction as they form a tight frame system. Our theoretical results are supported by an extensive numerical analysis.

  17. SLURM: Simple Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Dunlap, C; Garlick, J; Grondona, M

    2002-04-24

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, and scheduling modules. The design also includes a scalable, general-purpose communication infrastructure. Development will take place in four phases: Phase I results in a solid infrastructure; Phase II produces a functional but limited interactive job initiation capability without use of the interconnect/switch; Phase III provides switch support and documentation; Phase IV provides job status, fault-tolerance, and job queuing and control through Livermore's Distributed Production Control System (DPCS), a meta-batch and resource management system.

  18. Genealogies in simple models of evolution

    NASA Astrophysics Data System (ADS)

    Brunet, Éric; Derrida, Bernard

    2013-01-01

    We review the statistical properties of the genealogies of a few models of evolution. In the asexual case, selection leads to coalescence times which grow logarithmically with the size of the population, in contrast with the linear growth of the neutral case. Moreover for a whole class of models, the statistics of the genealogies are those of the Bolthausen-Sznitman coalescent rather than the Kingman coalescent in the neutral case. For sexual reproduction in the neutral case, the time to reach the first common ancestors for the whole population and the time for all individuals to have all their ancestors in common are also logarithmic in the population size, as predicted by Chang in 1999. We discuss how these times are modified by introducing selection in a simple way.

  19. A simple, high efficiency, high resolution spectropolarimeter

    NASA Astrophysics Data System (ADS)

    Barden, Samuel C.

    2012-09-01

    A simple concept is described that uses volume phase holographic gratings as polarizing dispersers for a high efficiency, high resolution spectropolarimeter. Although the idea has previously been mentioned in the literature as possible, such a concept has not been explored in detail. Performance analysis is presented for a VPHG spectropolarimeter concept that could be utilized for both solar and night-time astronomy. Instrumental peak efficiency can approach 100% with spectral dispersions permitting R~200,000 spectral resolution with diffraction limited telescopes. The instrument has 3-channels: two dispersed image planes with orthogonal polarization and an undispersed image plane. The concept has a range of versatility where it could be configured (with appropriate half-wave plates) for slit-fed spectroscopy or without slits for snapshot/hyperspectral/tomographic spectroscopic imaging. Multiplex gratings could also be used for the simultaneous recording of two separate spectral bands or multiple instruments could be daisy chained with beam splitters for further spectral coverage.

  20. Simple nonlinear models suggest variable star universality

    NASA Astrophysics Data System (ADS)

    Lindner, John F.; Kohar, Vivek; Kia, Behnam; Hippke, Michael; Learned, John G.; Ditto, William L.

    2016-02-01

    Dramatically improved data from observatories like the CoRoT and Kepler spacecraft have recently facilitated nonlinear time series analysis and phenomenological modeling of variable stars, including the search for strange (aka fractal) or chaotic dynamics. We recently argued [Lindner et al., Phys. Rev. Lett. 114 (2015) 054101] that the Kepler data includes "golden" stars, whose luminosities vary quasiperiodically with two frequencies nearly in the golden ratio, and whose secondary frequencies exhibit power-law scaling with exponent near -1.5, suggesting strange nonchaotic dynamics and singular spectra. Here we use a series of phenomenological models to make plausible the connection between golden stars and fractal spectra. We thereby suggest that at least some features of variable star dynamics reflect universal nonlinear phenomena common to even simple systems.

  1. Simple sequence repeats in bryophyte mitochondrial genomes.

    PubMed

    Zhao, Chao-Xian; Zhu, Rui-Liang; Liu, Yang

    2016-01-01

    Simple sequence repeats (SSRs) are thought to be common in plant mitochondrial (mt) genomes, but have yet to be fully described for bryophytes. We screened the mt genomes of two liverworts (Marchantia polymorpha and Pleurozia purpurea), two mosses (Physcomitrella patens and Anomodon rugelii) and two hornworts (Phaeoceros laevis and Nothoceros aenigmaticus), and detected 475 SSRs. Some SSRs are found conserved during the evolution, among which except one exists in both liverworts and mosses, all others are shared only by the two liverworts, mosses or hornworts. SSRs are known as DNA tracts having high mutation rates; however, according to our observations, they still can evolve slowly. The conservativeness of these SSRs suggests that they are under strong selection and could play critical roles in maintaining the gene functions. PMID:24491104

  2. Simple Resonance Hierarchy for Surmounting Quantum Uncertainty

    SciTech Connect

    Amoroso, Richard L.

    2010-12-22

    For a hundred years violation or surmounting the Quantum Uncertainty Principle has remained a Holy Grail of both theoretical and empirical physics. Utilizing an operationally completed form of Quantum Theory cast in a string theoretic Higher Dimensional (HD) form of Dirac covariant polarized vacuum with a complex Einstein energy dependent spacetime metric, M{sub 4{+-}}C{sub 4} with sufficient degrees of freedom to be causally free of the local quantum state, we present a simple empirical model for ontologically surmounting the phenomenology of uncertainty through a Sagnac Effect RF pulsed Laser Oscillated Vacuum Energy Resonance hierarchy cast within an extended form of a Wheeler-Feynman-Cramer Transactional Calabi-Yau mirror symmetric spacetime bachcloth.

  3. Supernova neutrino oscillations: A simple analytical approach

    NASA Astrophysics Data System (ADS)

    Fogli, G. L.; Lisi, E.; Montanino, D.; Palazzo, A.

    2002-04-01

    Analyses of observable supernova neutrino oscillation effects require the calculation of the electron (anti)neutrino survival probability Pee along a given supernova matter density profile. We propose a simple analytical prescription for Pee, based on a double-exponential form for the crossing probability and on the concept of maximum violation of adiabaticity. In the case of two-flavor transitions, the prescription is shown to reproduce accurately, in the whole neutrino oscillation parameter space, the results of exact numerical calculations for generic (realistic or power-law) profiles. The analytical approach is then generalized to cover three-flavor transitions with (direct or inverse) mass spectrum hierarchy, and to incorporate Earth matter effects. Compact analytical expressions, explicitly showing the symmetry properties of Pee, are provided for practical calculations.

  4. A simple controller for bidimensional image detectors

    NASA Astrophysics Data System (ADS)

    Angeles, F.; Martínez, L. A.

    2012-07-01

    The increasing use of many and different kind of light detectors to acquire, monitor and control various aspects of the observation imposes the need to standardize the acquisition and processing of images and data. While scientific image acquisition systems usually include a complex controller, some less demanding subsystems require the development of electronics and software to read the image. Most of the times these image detectors are rather small and high speed is of no concern, so controllers need not to be fast; take for instance a telescope guider. With these directives in mind, in this work we present a very simple image acquisition system based on a Texas Instruments microcontroller of the family MSP430 and a serial static memory as a standard instrumentation starting for small image acquisition controllers.

  5. A simple framework for complex system improvement.

    PubMed

    Kraft, Sally; Carayon, Pascale; Weiss, Jennifer; Pandhi, Nancy

    2015-05-01

    The need to rapidly improve health care value is unquestioned, but the means to accomplish this task is unknown. Improving performance at the level of the health care organization frequently involves multiple interventions, which must be coordinated and sequenced to fit the specific context. Those responsible for achieving large-scale improvements are challenged by the lack of a framework to describe and organize improvement strategies. Drawing from the fields of health services, industrial engineering, and organizational behavior, a simple framework was developed and has been used to guide and evaluate improvement initiatives at an academic health center. The authors anticipate that this framework will be helpful for health system leaders responsible for improving health care quality. PMID:24723664

  6. Simple device for treating prolapsing loop colostomy.

    PubMed

    Hsieh, Ming-Yu; Liu, Chinsu; Ho, Shin-Huei; Wung, Shin-Huev; Chin, Taiwai; Wei, Choufu

    2006-03-01

    Stoma prolapse is a common complication of intestinal stoma. Although various surgical methods yield satisfactory results, nonsurgical treatment may be better for a temporary stoma. We report a case of a patient with a distal limb prolapse of a right transverse colostomy who received nonsurgical treatment with satisfactory results. For the treatment of a temporary transverse loop colostomy with distal limb prolapse, we designed a simple device consisting of a pediatric plastic medicine cup, which was rolled into a towel to shape the bottom of the cup into a compressor. The towel was put on the stoma outside of the colostomy bag with the compressor above the prolapsing limb of the colostomy. An abdominal binder was applied to fix the towel. PMID:16599021

  7. The semipermeability of simple spherical virus capsids.

    PubMed

    Durham, A C; Witz, J; Bancroft, J B

    1984-02-01

    Hydrogen-ion titration curves are reported for tomato bushy stunt virus, two strains of cowpea chlorotic mottle virus, and turnip crinkle virus, with particular attention to the hysteresis loops associated with the swelling and contraction of virions. There appears to be an archetypal shape of hysteresis loops, which is shared by viruses in several groups, suggestive of many intermediate states in the swelling of any one particle. In contrast, eggplant mosaic virus behaves as if its protein capsid is impermeable to small ions in mild conditions; its cation-binding sites were revealed by treatment with high concentrations of salt or urea, or at raised temperatures. Putting these observations together with the fact that a spherical virus capsid is a closed, holey, charged surface leads to a theory of titration hysteresis: its key feature is that the protein capsids of simple viruses are inherently semipermeable, with many of the ion-handling properties usually attributed only to complex lipid membranes. PMID:18639804

  8. Fundamental Constants and Tests with Simple Atoms

    NASA Astrophysics Data System (ADS)

    Tan, Joseph

    2015-05-01

    Precise measurements with simple atoms provide stringent tests of physical laws, improving the accuracy of fundamental constants--a set of which will be selected to fully define the proposed New International System of Units. This talk focuses on the atomic constants (namely, the Rydberg constant, the fine-structure constant, and the proton charge radius), discussing the impact of the proton radius obtained from the Lamb-shift measurements in muonic hydrogen. Significant discrepancies persist despite years of careful examination: the slightly smaller proton radius obtained from muonic hydrogen requires the Rydberg constant and the fine-structure constant to have values that disagree significantly with the CODATA recommendations. After giving a general overview, I will discuss our effort to produce one-electron ions in Rydberg states, to enable a different test of theory and measurement of the Rydberg constant.

  9. Versatile microrobotics using simple modular subunits.

    PubMed

    Cheang, U Kei; Meshkati, Farshad; Kim, Hoyeon; Lee, Kyoungwoo; Fu, Henry Chien; Kim, Min Jun

    2016-01-01

    The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size. PMID:27464852

  10. Versatile microrobotics using simple modular subunits

    PubMed Central

    Cheang, U Kei; Meshkati, Farshad; Kim, Hoyeon; Lee, Kyoungwoo; Fu, Henry Chien; Kim, Min Jun

    2016-01-01

    The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size. PMID:27464852

  11. Simple theory of a Malone engine

    NASA Astrophysics Data System (ADS)

    Swift, G. W.

    Practical liquid engines called Malone engines use a regenerative or recuperative cycle, like the Stirling cycle. A theoretical model of the Malone engine that is realistic enough for comparison to experiment, yet still simple enough for intuitive grasp of the engine's features, is presented. The principal results obtained with the model are the time-averaged heat and work resulting from each of the most important effects taking place in the engine. It is shown that Rankine heat pumps and Malone heat pumps with equal heat-pumping capabilities require compressors of comparable volumetric flow rates and hence of comparable complexity and size, but the heat exchangers for the Malone heat pump are expected to be orders of magnitude smaller than those for the Rankine-cycle heat pump.

  12. Search without Boundaries Using Simple APIs

    USGS Publications Warehouse

    Tong, Qi

    2009-01-01

    The U.S. Geological Survey (USGS) Library, where the author serves as the digital services librarian, is increasingly challenged to make it easier for users to find information from many heterogeneous information sources. Information is scattered throughout different software applications (i.e., library catalog, federated search engine, link resolver, and vendor websites), and each specializes in one thing. How could the library integrate the functionalities of one application with another and provide a single point of entry for users to search across? To improve the user experience, the library launched an effort to integrate the federated search engine into the library's intranet website. The result is a simple search box that leverages the federated search engine's built-in application programming interfaces (APIs). In this article, the author describes how this project demonstrated the power of APIs and their potential to be used by other enterprise search portals inside or outside of the library.

  13. A simple model of a swing

    NASA Astrophysics Data System (ADS)

    Mayer, V. V.; Varaksina, E. I.

    2016-07-01

    The paper presents a simple model of a swing meant for undergraduates’ educational experiments. The purpose of these experiments is the experimental study of physical principles of self-oscillations, free, forced and parametric oscillations. The model contains a pendulum. A coil with a movable steel core serves as its load. A neodymium magnet is placed at the lower end of the core. A magnetically operated sealed switch is stationed under the magnet at the equilibrium position of the pendulum. The switch is connected in series with the coil and a battery. If we displace the pendulum from the equilibrium position, the pendulum makes undamped oscillations. The system receives energy every time the core is drawn into the coil at the lower position of the pendulum.

  14. Electrokinetic Remediation: I. Modeling of simple systems

    SciTech Connect

    Wilson, D.J.; Rodriguez-Maroto, J.M.; Gomez-Lahoz, C.

    1995-09-01

    A one-dimensional model is developed for simulating the electrokinetic treatment of saturated porous media contaminated with an ionic salt. Simulations of simple, unenhanced electrokinetic treatment for the removal of a nonamphoteric salt such as cadmium sulfate exhibit a severe drop-off in electric current and in remediation rate after about 50-60% of the cation has been removed. Simulation of electrokinetic treatment in which the OH{sup -} generated in the cathode compartment is partially neutralized by the addition of acid show rapid and complete removal of the cation. Partial neutralization of H{sup +} in the anode compartment by addition of base results in immobilization of the toxic metal as the solid hydroxide, although this should be a useful technique for the removal of arsenate and selenate.

  15. A simple and reproducible capacitive electrode.

    PubMed

    Spinelli, Enrique; Guerrero, Federico; García, Pablo; Haberman, Marcelo

    2016-03-01

    Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling for ultra-high value resistors and special components and construction techniques. A simple CE that uses bootstrap techniques to avoid ultra-high value components and special materials is proposed. When electrodes are placed on the skin; that is, with coupling capacitances CS of around 100 pF, they present a noise level of 3.3 µVRMS in a 0.5-100 Hz bandwidth, which is appropriate for electrocardiography (ECG) measurements. Construction details of the CE and the complete circuit, including a fast recovery feature, are presented. PMID:26792172

  16. Simple probabilistic algorithm for detecting community structure

    NASA Astrophysics Data System (ADS)

    Ren, Wei; Yan, Guiying; Liao, Xiaoping; Xiao, Lan

    2009-03-01

    With the growing number of available social and biological networks, the problem of detecting the network community structure is becoming more and more important which acts as the first step to analyze these data. The community structure is generally regarded as that nodes in the same community tend to have more edges and less if they are in different communities. We propose a simple probabilistic algorithm for detecting community structure which employs expectation-maximization (SPAEM). We also give a criterion based on the minimum description length to identify the optimal number of communities. SPAEM can detect overlapping nodes and handle weighted networks. It turns out to be powerful and effective by testing simulation data and some widely known data sets.

  17. A simple EHF hemispheric coverage antenna

    NASA Astrophysics Data System (ADS)

    Lee, J. C.

    1994-08-01

    A circulary polarized, axially symmetric, wide-beam radiator is required in many applications, including TT&C for UAV's and satellites. This report discusses some existing wide-beam antenna designs including divergent lenses and reflectors and introduces a new antenna design. Using a simple dielectric ring in conjunction with a dielectric loaded circular waveguide opening, a near ideal, axially symmetric, hemispheric coverage antenna with circular polarization of good axial ratio and wide-band impedance match is realized. Mechanically, the antenna is small, lightweight, and low cost. The dielectric used is the common Rexolite. Since no lossy materials or resonant scatterers are used, the antenna performance is inherently broadband and low loss. A K sub a-band prototype as well as compact designs for both Q- and K-bands are described.

  18. Simple Thermal Environment Model (STEM) User's Guide

    NASA Technical Reports Server (NTRS)

    Justus, C.G.; Batts, G. W.; Anderson, B. J.; James, B. F.

    2001-01-01

    This report presents a Simple Thermal Environment Model (STEM) for determining appropriate engineering design values to specify the thermal environment of Earth-orbiting satellites. The thermal environment of a satellite, consists of three components: (1) direct solar radiation, (2) Earth-atmosphere reflected shortwave radiation, as characterized by Earth's albedo, and (3) Earth-atmosphere-emitted outgoing longwave radiation (OLR). This report, together with a companion "guidelines" report provides methodology and guidelines for selecting "design points" for thermal environment parameters for satellites and spacecraft systems. The methods and models reported here are outgrowths of Earth Radiation Budget Experiment (ERBE) satellite data analysis and thermal environment specifications discussed by Anderson and Smith (1994). In large part, this report is intended to update (and supersede) those results.

  19. A Simple XML Producer-Consumer Protocol

    NASA Technical Reports Server (NTRS)

    Smith, Warren; Gunter, Dan; Quesnel, Darcy

    2000-01-01

    This document describes a simple XML-based protocol that can be used for producers of events to communicate with consumers of events. The protocol described here is not meant to be the most efficient protocol, the most logical protocol, or the best protocol in any way. This protocol was defined quickly and it's intent is to give us a reasonable protocol that we can implement relatively easily and then use to gain experience in distributed event services. This experience will help us evaluate proposals for event representations, XML-based encoding of information, and communication protocols. The next section of this document describes how we represent events in this protocol and then defines the two events that we choose to use for our initial experiments. These definitions are made by example so that they are informal and easy to understand. The following section then proceeds to define the producer-consumer protocol we have agreed upon for our initial experiments.

  20. A Simple HCCI Engine Model for Control

    SciTech Connect

    Killingsworth, N; Aceves, S; Flowers, D; Krstic, M

    2006-06-29

    The homogeneous charge compression ignition (HCCI) engine is an attractive technology because of its high efficiency and low emissions. However, HCCI lacks a direct combustion trigger making control of combustion timing challenging, especially during transients. To aid in HCCI engine control we present a simple model of the HCCI combustion process valid over a range of intake pressures, intake temperatures, equivalence ratios, and engine speeds. The model provides an estimate of the combustion timing on a cycle-by-cycle basis. An ignition threshold, which is a function of the in-cylinder motored temperature and pressure is used to predict start of combustion. This model allows the synthesis of nonlinear control laws, which can be utilized for control of an HCCI engine during transients.

  1. A Simple shower and matching algorithm

    SciTech Connect

    Giele, Walter T.; Kosower, David A.; Skands, Peter Z.; /Fermilab

    2007-07-01

    We present a simple formalism for parton-shower Markov chains. As a first step towards more complete 'uncertainty bands', we incorporate a comprehensive exploration of the ambiguities inherent in such calculations. To reduce this uncertainty, we then introduce a matching formalism which allows a generated event sample to simultaneously reproduce any infrared safe distribution calculated at leading or next-to-leading order in perturbation theory, up to sub-leading corrections. To enable a more universal definition of perturbative calculations, we also propose a more general definition of the hadronization cutoff. Finally, we present an implementation of some of these ideas for final-state gluon showers, in a code dubbed VINCIA.

  2. A simple apparatus for electrostatic force measurement

    NASA Astrophysics Data System (ADS)

    Hale, D. P.

    1981-01-01

    Electrostatic attraction can explain as a first approximation the binding of ionic solids. One of the two reasons for constructing the apparatus described was to demonstrate that electrostatic forces can be large, thus giving at least some plausibility to the theory of ionic solids. Secondly, it is an attempt to create a cheap and simple apparatus for measuring these forces and relating them to other physical quantities. An apparatus giving similar results of some precision has already been described (Hale 1978a). That was constructed by skilled instrument makers for undergraduate teaching, cost several hundred pounds and needed a considerable amount of time to iron out the problems encountered. The present apparatus was made in a few hours largely from scrap and using only ordinary hand tools. Although it is somewhat crude, quite acceptable results can be obtained from it. It could be used to advantage in courses dealing with fields and potential for example Nuffield advanced physics, unit 3.

  3. Versatile microrobotics using simple modular subunits

    NASA Astrophysics Data System (ADS)

    Cheang, U. Kei; Meshkati, Farshad; Kim, Hoyeon; Lee, Kyoungwoo; Fu, Henry Chien; Kim, Min Jun

    2016-07-01

    The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size.

  4. Simple delay monitor for droplet sorters.

    PubMed

    De Grooth, B G; Doornbos, R M; Van Der Werf, K O; Greve, J

    1991-01-01

    We have constructed a simple device by which the optimal delay time between optical measurement of a cell and the application of the droplet charging pulse can be determined directly in a flow sorter. The device consists of a stainless steel chamber in which the sorted droplets are collected. In the collection chamber the collected droplets run through a capillary where a continuous fluorescence measurement is made. With a sample of fluorescent particles, the delay time is optimal when the measured fluorescence is maximal. The measuring volume is always filled with the last droplets sorted (about 3,000). With this device, the setting of the delay time can be done in a few seconds without the need for microscopical verification. The fluorescence in the collection chamber is excited and detected via optical fibers using about 10% of the light of the existing laser from the flow cytometer and an extra photomultiplier. PMID:1935461

  5. Simple scaling of catastrophic landslide dynamics.

    PubMed

    Ekström, Göran; Stark, Colin P

    2013-03-22

    Catastrophic landslides involve the acceleration and deceleration of millions of tons of rock and debris in response to the forces of gravity and dissipation. Their unpredictability and frequent location in remote areas have made observations of their dynamics rare. Through real-time detection and inverse modeling of teleseismic data, we show that landslide dynamics are primarily determined by the length scale of the source mass. When combined with geometric constraints from satellite imagery, the seismically determined landslide force histories yield estimates of landslide duration, momenta, potential energy loss, mass, and runout trajectory. Measurements of these dynamical properties for 29 teleseismogenic landslides are consistent with a simple acceleration model in which height drop and rupture depth scale with the length of the failing slope. PMID:23520108

  6. Magnetoelectric effect in simple collinear antiferromagnetic spinels

    NASA Astrophysics Data System (ADS)

    Saha, Rana; Ghara, Somnath; Suard, Emmanuelle; Jang, Dong Hyun; Kim, Kee Hoon; Ter-Oganessian, N. V.; Sundaresan, A.

    2016-07-01

    We report the discovery of the linear magnetoelectric effect in a family of spinel oxides, C o3O4 and Mn B2O4 (B =Al ,Ga) with simple collinear antiferromagnetic spin structure. An external magnetic field induces a dielectric anomaly at TN, accompanied by the generation of electric polarization that varies linearly with magnetic field. Magnetization and magnetoelectric measurements on a single crystal of MnG a2O4 together with a phenomenological theory suggest that the easy axis direction is [111] with the corresponding magnetic symmetry R 3¯'m' . The proposed theoretical model of single-ion contribution of magnetic ions located in a noncentrosymmetric crystal environment stands for a generic mechanism for observing magnetoelectric effects in these and other similar materials.

  7. Simple Models for Polymeric and Anisotropic Liquids

    NASA Astrophysics Data System (ADS)

    Kröger, Martin

    We hope that the complexity of the world is neither in contrast with the simplicity of the basic laws of physics [1] nor with the simple physical models to be reviewed or proposed in the following. However, physical phenomena occurring in complex materials cannot be encapsulated within a single numerical paradigm. In fact, they should be described within hierarchical, multi-level numerical models in which each sub-model is responsible for different spatio-temporal behavior and passes out the averaged parameters to the model, which is next in the hierarchy (Fig. 1.1). Polymeric liquids far from equilibrium belong to the class of anisotropic liquids.1 This monograph is devoted to the understanding of the anisotropic properties of polymeric and complex fluids such as viscoelastic and orientational behavior of polymeric liquids, the rheological properties of ferrofluids and liquid crystals subjected to external fields, based on the architecture of their molecular constituents. The topic is of considerable concern in basic research for which models should be as simple as possible, but not simpler. Certainly, it is also of technological relevance. Statistical physics and nonequilibrium thermodynamics are challenged by the desired structure-property relationships. Experiments such as static and dynamic light and neutron scattering, particle tracking, flow birefringence etc. together with rheological measurements have been essential to adjust or test basic theoretical concepts, such as a ‘linear stressoptic rule’ which connects orientation and stress, or the effect of molecular weight, solvent conditions, and external field parameters on shape, diffusion, degradation, and alignment of molecules.

  8. The SIMPLE Phase II dark matter search

    NASA Astrophysics Data System (ADS)

    Felizardo, M.; Girard, T. A.; Morlat, T.; Fernandes, A. C.; Ramos, A. R.; Marques, J. G.; Kling, A.; Puibasset, J.; Auguste, M.; Boyer, D.; Cavaillou, A.; Poupeney, J.; Sudre, C.; Carvalho, F. P.; Prudêncio, M. I.; Marques, R.; Simple Collaboration

    2014-04-01

    Phase II of SIMPLE (Superheated Instrument for Massive ParticLe Experiments) searched for astroparticle dark matter using superheated liquid C2ClF5 droplet detectors. Each droplet generally requires an energy deposition with linear energy transfer (LET) ≳150 keV/μm for a liquid-to-gas phase transition, providing an intrinsic rejection against minimum ionizing particles of order 10-10, and reducing the backgrounds to primarily α and neutron-induced recoil events. The droplet phase transition generates a millimetric-sized gas bubble that is recorded by acoustic means. We describe the SIMPLE detectors, their acoustic instrumentation, and the characterizations, signal analysis and data selection, which yield a particle-induced, "true nucleation" event detection efficiency of better than 97% at a 95% C.L. The recoil-α event discrimination, determined using detectors first irradiated with neutrons and then doped with alpha emitters, provides a recoil identification of better than 99%; it differs from those of COUPP and PICASSO primarily as a result of their different liquids with lower critical LETs. The science measurements, comprising two shielded arrays of fifteen detectors each and a total exposure of 27.77 kgd, are detailed. Removal of the 1.94 kgd Stage 1 installation period data, which had previously been mistakenly included in the data, reduces the science exposure from 20.18 to 18.24 kgd and provides new contour minima of σp=4.3×10-3 pb at 35 GeV /c2 in the spin-dependent sector of astroparticle dark matter-proton interactions and σN=3.6×10-6 pb at 35 GeV /c2 in the spin-independent sector. These results are examined with respect to the fluorine spin and halo parameters used in the previous data analysis.

  9. Emulating AOGCM results using simple climate models

    NASA Astrophysics Data System (ADS)

    Olivié, Dirk; Stuber, Nicola

    2010-12-01

    Three simple climate models (SCMs) are calibrated using simulations from atmosphere ocean general circulation models (AOGCMs). In addition to using two conventional SCMs, results from a third simpler model developed specifically for this study are obtained. An easy to implement and comprehensive iterative procedure is applied that optimises the SCM emulation of global-mean surface temperature and total ocean heat content, and, if available in the SCM, of surface temperature over land, over the ocean and in both hemispheres, and of the global-mean ocean temperature profile. The method gives best-fit estimates as well as uncertainty intervals for the different SCM parameters. For the calibration, AOGCM simulations with two different types of forcing scenarios are used: pulse forcing simulations performed with 2 AOGCMs and gradually changing forcing simulations from 15 AOGCMs obtained within the framework of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. The method is found to work well. For all possible combinations of SCMs and AOGCMs the emulation of AOGCM results could be improved. The obtained SCM parameters depend both on the AOGCM data and the type of forcing scenario. SCMs with a poor representation of the atmosphere thermal inertia are better able to emulate AOGCM results from gradually changing forcing than from pulse forcing simulations. Correct simultaneous emulation of both atmospheric temperatures and the ocean temperature profile by the SCMs strongly depends on the representation of the temperature gradient between the atmosphere and the mixed layer. Introducing climate sensitivities that are dependent on the forcing mechanism in the SCMs allows the emulation of AOGCM responses to carbon dioxide and solar insolation forcings equally well. Also, some SCM parameters are found to be very insensitive to the fitting, and the reduction of their uncertainty through the fitting procedure is only marginal, while other parameters

  10. Simple Check Valves for Microfluidic Devices

    NASA Technical Reports Server (NTRS)

    Willis, Peter A.; Greer, Harold F.; Smith, J. Anthony

    2010-01-01

    A simple design concept for check valves has been adopted for microfluidic devices that consist mostly of (1) deformable fluorocarbon polymer membranes sandwiched between (2) borosilicate float glass wafers into which channels, valve seats, and holes have been etched. The first microfluidic devices in which these check valves are intended to be used are micro-capillary electrophoresis (microCE) devices undergoing development for use on Mars in detecting compounds indicative of life. In this application, it will be necessary to store some liquid samples in reservoirs in the devices for subsequent laboratory analysis, and check valves are needed to prevent cross-contamination of the samples. The simple check-valve design concept is also applicable to other microfluidic devices and to fluidic devices in general. These check valves are simplified microscopic versions of conventional rubber- flap check valves that are parts of numerous industrial and consumer products. These check valves are fabricated, not as separate components, but as integral parts of microfluidic devices. A check valve according to this concept consists of suitably shaped portions of a deformable membrane and the two glass wafers between which the membrane is sandwiched (see figure). The valve flap is formed by making an approximately semicircular cut in the membrane. The flap is centered over a hole in the lower glass wafer, through which hole the liquid in question is intended to flow upward into a wider hole, channel, or reservoir in the upper glass wafer. The radius of the cut exceeds the radius of the hole by an amount large enough to prevent settling of the flap into the hole. As in a conventional rubber-flap check valve, back pressure in the liquid pushes the flap against the valve seat (in this case, the valve seat is the adjacent surface of the lower glass wafer), thereby forming a seal that prevents backflow.

  11. Separating para and ortho water.

    PubMed

    Horke, Daniel A; Chang, Yuan-Pin; Długołęcki, Karol; Küpper, Jochen

    2014-10-27

    Water exists as two nuclear-spin isomers, para and ortho, determined by the overall spin of its two hydrogen nuclei. For isolated water molecules, the conversion between these isomers is forbidden and they act as different molecular species. Yet, these species are not readily separated, and no pure para sample has been produced. Accordingly, little is known about their specific physical and chemical properties, conversion mechanisms, or interactions. The production of isolated samples of both spin isomers is demonstrated in pure beams of para and ortho water in their respective absolute ground state. These single-quantum-state samples are ideal targets for unraveling spin-conversion mechanisms, for precision spectroscopy and fundamental symmetry-breaking studies, and for spin-enhanced applications, for example laboratory astrophysics and astrochemistry or hypersensitized NMR experiments. PMID:25196938

  12. Un modelo general de eyección de materia estelar

    NASA Astrophysics Data System (ADS)

    Rotstein, N. O.

    Posiblemente, la más directa y dramática evidencia de la pérdida de masa por parte de diferentes objetos astrofísicos la constituye el fenómeno de eyección persistente de materia. En el caso particular de las estrellas, las características y los mecanismos que impulsan a sus atmósferas externas hacia el medio interestelar varían a lo largo del diagrama evolutivo. En parte por este motivo, en parte por las dificultades matemáticas involucradas, es muy difícil elaborar un modelo que pueda dar cuenta de los diferentes mecanismos que originan e impulsan el viento estelar. Cabe entonces preguntarse si es posible desarrollar un único modelo en el que estos mecanismos puedan ser considerados (y variados) como parámetros externos que responden a las características de cada región de la secuencia evolutiva. La respuesta es que, en función de la geometría del campo electromagnético involucrado, todo depende de la simetría del problema. En este trabajo se presenta el análisis detallado de una de tales simetrías, discutiendo en particular los resultados obtenidos a la luz de las observaciones disponibles.

  13. A simple procedure for estimating soil porosity

    NASA Astrophysics Data System (ADS)

    Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Holden, Nick

    2016-04-01

    Soil degradation from mismanagement is of international concern. Simple, accessible tools for rapidly assessing impacts of soil management are required. Soil structure is a key component of soil quality and porosity is a useful indicator of structure. We outline a version of a procedure described by Piwowarczyk et al. (2011) used to estimate porosity of samples taken during a soil quality survey of 38 sites across Ireland as part of the Government funded SQUARE (Soil Quality Assessment Research) project. This required intact core (r = 2.5 cm, H = 5cm) samples taken at 5-10 cm and 10-20 cm depth, to be covered with muslin cloth at one end and secured with a jubilee clip. Samples were saturated in sealable water tanks for ≈ 64 hours, then allowed to drain by gravity for 24 hours, at which point Field Capacity (F.C.) was assumed to have been reached, followed by oven drying with weight determined at each stage. This allowed the calculation of bulk density and the estimation of water content at saturation and following gravitational drainage, thus total and functional porosity. The assumption that F.C. was reached following 24 hours of gravitational drainage was based on the Soil Moisture Deficit model used in Ireland to predict when soils are potentially vulnerable to structural damage and used nationally as a management tool. Preliminary results indicate moderately strong, negative correlations between estimated total porosity at 5-10 cm and 10-20 cm depth (rs = -0.7, P < 0.01 in both cases) and soil quality scores of the Visual Evaluation of Soil Structure (VESS) method which was conducted at each survey site. Estimated functional porosity at 5-10 cm depth was found to moderately, negatively correlate with VESS scores (rs = - 0.5, P < 0.05). This simple procedure requires inexpensive equipment and appears useful in indicating porosity of a large quantity of samples taken at numerous sites or if done periodically, temporal changes in porosity at a field scale

  14. Decoding the photochemistry of simple astrophysical molecules

    NASA Astrophysics Data System (ADS)

    Jackson, William M.; Ng, Cheuk Y; Lu, Zhou; Chang, Yih C

    2014-06-01

    An experimental apparatus with two tunable vacuum ultraviolet (VUV) lasers in a windowless pump-probe configuration with slice imaging detection has been used to study the photochemistry of simple astrophysical molecules such as N2, NO, CO, and CO2. The VUV pump laser is set at the desired photodissociation wavelength and the VUV probe laser is set detect the atom by setting it to excite a one-photon transition in the VUV region and then using a visible photon to ionize the excited atoms. The photodissociation of CO2 in the energy region between 94,000.3 and 98,496.4 cm-1 (11.655-12.212eV) is studied and we have been able to show that all of the energetically accessible photochemical channels occur.CO2+ hν → O(3P”J”) + CO(X1Σ+) hν ≥ 5.45 eV→ O(1D) + CO(X1Σ+) hν ≥ 7.42 eV→ O(1S) + CO(X1Σ+) hν ≥ 9.64 eV→ O(3PJ) + CO(a3Π) hν ≥ 11.46 eV→ C(3PJ) + O2 (X3ΣJ-) hν ≥ 11.44 eVThis is the first time that all of these channels in CO2 have been determined by the direct detection of the atomic fragments. It shows that even simple molecules made up of first row atoms that do not contain H atoms can dissociate into spin forbidden products. We have also been able to use this apparatus to systematically determine the branching ratios between the 4S, 2D, and 2P states of N atoms produced in the photolysis of N2 in the wavelength range from 100,819.7 to 121,870.1 cm-1(12.500-15.110 eV). These examples show that the photodissociation of the major molecules that occur in the atmospheres of planets, comets, moons and the interstellar medium can be studied in the windowless region of the VUV spectrum. Acknowledgements:William M. Jackson and Zhou Lu gratefully acknowledge the support of the National Science Foundation (NSF) under Grant No. CHE-1301501. Cheuk Y. Ng acknowledges the support by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, (U.S.) Department of Energy (DOE) under Contract No

  15. Proton NMR Spectra: Deceptively Simple and Deceptively Complex Examples.

    ERIC Educational Resources Information Center

    Gurst, J. E.; And Others

    1985-01-01

    Describes relatively simple nuclear magnetic resonance (NMR) experiments that demonstrate unexpected results of the deceptively simple and deceptively complex types. Background information, experimental procedures, and typical results obtained are included. (JN)

  16. Creating Simple Admin Tools Using Info*Engine and Java

    NASA Technical Reports Server (NTRS)

    Jones, Corey; Kapatos, Dennis; Skradski, Cory; Felkins, J. D.

    2012-01-01

    PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create a simple Info*Engine Tasks capable of saving Windchill 10.0 administration of tedious work.

  17. More Realistics Treatment of the Simple Pendulum without Difficult Mathematics

    ERIC Educational Resources Information Center

    Miller, B. J.

    1974-01-01

    Discusses the use of a simple computer exercise to derive a general law for simple pendulum phenomena with square-law damping. Indicates that less mathematical skills are requires in the computer treatment than in the analytical treatment.

  18. Mensaje para alumnos y padres

    NASA Video Gallery

    El astronauta de la NASA José Hernández alienta a los estudiantes a que sigan sus sueños. Hernández también habla acerca del papel que juegan los padres para ayudar a que sus hijos hagan realidad s...

  19. Simple Cassegrain scanning system for infrared astronomy

    NASA Technical Reports Server (NTRS)

    Apt, J.; Goody, R.; Mertz, L.

    1980-01-01

    To meet the need for a reliable, fast imaging system capable of being taken rapidly on and off the telescope, a simple, inexpensive, and compact Cassegrain reimaging system for scanning IR images was constructed. Using commercially available components without requiring close mechanical tolerances, the design solves the problem of beam stability pointed out by Koornneef and van Overbeeke (1976). For the moving-iron galvanometer scanner, it is noted that at the imaging frequency of 0.5 Hz, hysteresis in image plane motion was found to be less than 0.2 arc sec for a 64-arc sec scan, and the deviation from linearity with a triangular wave input was found to be less than 0.3 arc sec. This system and a scanning secondary were used to image Venus at 11.5 microns, and compared with the scanning secondary, the reimaging system did not appear to contribute any additional noise, considerably improved mechanical reliability, and eliminated cross-scan motion

  20. Laparoscopic Pyloromyotomy: A Modified Simple Technique

    PubMed Central

    Anwar, Mohammed Omer; Omran, Yasser Al; Al-Hindi, Saeed

    2016-01-01

    Background: A modified laparoscopic pyloromyotomy (LP) technique may provide an alternative to treating infantile hypertrophic pyloric stenosis (IHPS) by improving operative timing with reduction of postoperative complication rates, compared with a three-port trocar system. Methods: Thirty-three infants were treated with IHPS at a single-centre between January 2002 and December 2011. The local surgical incision to the pylorus was performed according to Ramstedt’s pyloromyotomy; but with a two-port trocar system (umbilical and right lower abdominal crease ports), following a controlled stab wound into the epigastric region and a 3mm incision to allow introduction of ophthalmic knife. With the aid of atraumatic forceps and camera guidance, the ophthalmic knife was used to carefully incise the seromuscular layer, which allows improved manual tactile sensation compared to ergonomic laparoscopic spreaders. A Benson pyloric spreader was then used to further separate the pyloric muscle layer to complete the procedure. Results: In all 33 infants treated, LP was safely performed with no evidence of duodenal or mucosal perforation with complete pyloromyotomy achieved in each case. The postoperative course was rather uneventful apart from an umbilical wound infection. Conclusion: This modified approach is simple, safe and allows improved operative timing, whilst increasing surgeon’s confidence by tactile sensation. PMID:26793595

  1. Simple models of the hydrofracture process.

    PubMed

    Marder, M; Chen, Chih-Hung; Patzek, T

    2015-12-01

    Hydrofracturing to recover natural gas and oil relies on the creation of a fracture network with pressurized water. We analyze the creation of the network in two ways. First, we assemble a collection of analytical estimates for pressure-driven crack motion in simple geometries, including crack speed as a function of length, energy dissipated by fluid viscosity and used to break rock, and the conditions under which a second crack will initiate while a first is running. We develop a pseudo-three-dimensional numerical model that couples fluid motion with solid mechanics and can generate branching crack structures not specified in advance. One of our main conclusions is that the typical spacing between fractures must be on the order of a meter, and this conclusion arises in two separate ways. First, it arises from analysis of gas production rates, given the diffusion constants for gas in the rock. Second, it arises from the number of fractures that should be generated given the scale of the affected region and the amounts of water pumped into the rock. PMID:26764704

  2. It Is Not That Simple nor Compelling!

    PubMed Central

    Bucknall, Tracey; Fossum, Mariann

    2015-01-01

    Healthcare decisions are often made under pressure, with varying levels of information in a changing clinical context. With limited resources and a focus on improving patient outcomes, healthcare managers and health professionals strive to implement both clinical and cost-effective care. However, the gap between research evidence and health policy/clinical practice persists despite our best efforts. In an attempt to close the gap through behaviour change interventions, there has been a strong held belief that ‘more is better,’ without understanding the mechanisms and circumstances of knowledge translation (KT). We argue that even a single intervention or strategy in translating evidence into healthcare policy or practice is rarely simple to implement. Nor is the evidence compelling on the best approach. As Harvey and Kitson argued, designing and evaluating KT interventions requires flexibility and responsiveness. If we are to move forward in translation science then we need to use rigorous designs such as randomised controlled trials to test effectiveness of interventions or strategies with embedded process evaluations to understand the reason interventions do or do not work! PMID:26673344

  3. Simple, Script-Based Science Processing Archive

    NASA Technical Reports Server (NTRS)

    Lynnes, Christopher; Hegde, Mahabaleshwara; Barth, C. Wrandle

    2007-01-01

    The Simple, Scalable, Script-based Science Processing (S4P) Archive (S4PA) is a disk-based archival system for remote sensing data. It is based on the data-driven framework of S4P and is used for data transfer, data preprocessing, metadata generation, data archive, and data distribution. New data are automatically detected by the system. S4P provides services such as data access control, data subscription, metadata publication, data replication, and data recovery. It comprises scripts that control the data flow. The system detects the availability of data on an FTP (file transfer protocol) server, initiates data transfer, preprocesses data if necessary, and archives it on readily available disk drives with FTP and HTTP (Hypertext Transfer Protocol) access, allowing instantaneous data access. There are options for plug-ins for data preprocessing before storage. Publication of metadata to external applications such as the Earth Observing System Clearinghouse (ECHO) is also supported. S4PA includes a graphical user interface for monitoring the system operation and a tool for deploying the system. To ensure reliability, S4P continuously checks stored data for integrity, Further reliability is provided by tape backups of disks made once a disk partition is full and closed. The system is designed for low maintenance, requiring minimal operator oversight.

  4. Advanced Joining Technology: Simple, Strong, and Secure

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The space-age materials that NASA employs in its spacecraft and satellites have different attributes than the building materials that can work for Earthly uses. These materials do not behave like the typical construction materials, and therefore, require new methods for construction. Work done at NASA s Langley Research Center in the realm of active solder joining has led to a new, self-bonding solder that enables high conductivity, as well as the metallic joining of carbon and ceramic materials to a wide range of metals. The original work involved evaluating high- and low-temperature joining technologies for joining carbon composite structures for use in thermal management and reusable launch vehicles. The initial plan for this innovation was to lower the weight of battery packs in satellites. It was a success. NASA scientists found use for this technology in fabricating a thermal management package for battery compartments in the Earth Observing System (EOS) satellites, but it is also being used by the Agency for space radiator panels. Because it is light, simple to use, and economical, NASA will likely find other uses for this solder, just as outside of the Space Agency, this unique bond is finding many practical applications.

  5. Simple fiber optic coupled luminescence cryostat

    NASA Astrophysics Data System (ADS)

    Meyer, G. D.; Ortiz, T. P.; Costello, A. L.; Brozik, J. A.; Kenney, J. W.

    2002-12-01

    An easy to fabricate, easy to operate, miniature liquid helium insert cryostat has been designed for variable low-temperature luminescence investigations in the 2.7-77 K region with minimal liquid helium consumption. The cryostat, which can be used inside of a standard liquid helium storage Dewar, is optically coupled both to the luminescence spectrophotometer and to the chosen luminescence excitation source (laser or conventional) by a single 1 mm fused silica fiber optic cable. This extremely simple and compact optical system is designed to give highly reproducible luminescence excitation and collection efficiencies for quantitative luminescence intensity studies. Temperature control in the cryostat is achieved through the dynamic balance of up to three distinct heating/cooling processes: raising or lowering the cryostat with respect to the liquid helium level in the Dewar, heating the cryostat with a small resistance heater, or pumping on the cryostat for sub-4.2 K temperatures. The cryostat can operate effectively throughout the 2.7-77 K range in liquid helium storage Dewars containing less than a liter of liquid helium. The wide range of spectroscopic experiments that this novel optical cryostat design can support is illustrated by a temperature-dependent zero field splitting luminescence lifetime study of Ru(bpy)3Cl2, a temperature-dependent relative luminescence intensity (quantum yield) study of Ru(bpy)3Cl2, and a temperature-dependent luminescence vibronic fine structure study of Ti(Cp)2(NCS)2.

  6. A Simple Model for Microchannel Plate Output

    NASA Astrophysics Data System (ADS)

    Harding, E. C.; Weaver, J. L.

    2005-10-01

    Microchannel plates (MCPs) are an essential component in an imaging diagnostic known as an x-ray framing camera, which is currently used by NIF, Omega, Nike, and Z to image radiation imploded targets. An MCP is used to convert incident x-ray photons into electrons with gains of 10^2 to 10^4. These electrons are accelerated into a phosphor and the subsequent visible light is captured with a CCD. A variety of parameters, such as photocathode material type (Au, Ni, CsI), photocathode coating depth, and MCP bias angle, affect the gain and gain variations in the MCP electron output. This poster presents initial results of a simple 3D MCP computer model along with an experimental comparison. Several ideas for increasing MCP imaging performance by reducing gain variations and increasing MCP quantum efficiency are presented. Work supported by the Naval Research Laboratory, National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grant DE-FG52-03NA00064, and through DE FG53 2005 NA26014, and Livermore National Laboratory.

  7. A simple image display application for windows.

    PubMed

    Conrad, G R

    1997-08-01

    The purpose of this project was to develop a simple application for displaying low-to-moderate resolution digital images under the Windows operating environment. The display of scintigraphic images was of special interest, and for this reason the program was designed to show sequences of images and to account for broad ranges of pixel values. In order to function under a variety of Windows versions, the program was developed using the 16-bit Microsoft C +2 compiler and targeted for Windows 3.1 enhanced. It was tested with Trionix images for nuclear medicine and Siemens for computed tomography (CT) and magnetic resonance (MR). The resulting application, called SID, successfully read Magnetom, Somatom, Trionix, and Interfile images of dimension 512 or less on Intel-based Windows PCs with 256 color SVGA-compatible (Super Video Graphics Adapters) video hardware. Early applications of the program included remote monitoring of image studies, resident review of teaching cases, review of research images, and preparation of educational materials. This article describes the features, operation, and potential applications of SID. PMID:9268906

  8. Simple mathematical law benchmarks human confrontations.

    PubMed

    Johnson, Neil F; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

    2013-01-01

    Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a 'lone wolf'; identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds. PMID:24322528

  9. Simple mathematical law benchmarks human confrontations

    NASA Astrophysics Data System (ADS)

    Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

    2013-12-01

    Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a `lone wolf' identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds.

  10. Simple kinetic sensor to structural transitions

    NASA Astrophysics Data System (ADS)

    Chandni, U.; Ghosh, Arindam

    2010-04-01

    Driven nonequilibrium structural phase transformation has been probed using time-varying resistance fluctuations or noise. We demonstrate that the non-Gaussian component (NGC) of noise obtained by evaluating the higher-order statistics of fluctuations, serves as a simple kinetic detector of these phase transitions. Using the Martensite transformation in free-standing wires of nickel-titanium binary alloys as a prototype, we observe clear deviations from the Gaussian background in the transformation zone, indicative of the long-range correlations in the system as the phase transforms. The viability of non-Gaussian statistics as a robust probe to structural phase transition was also confirmed by comparing the results from differential scanning calorimetry measurements. We further studied the response of the NGC to the modifications in the microstructure on repeated thermal cycling, as well as the variations in the temperature-drive rate, and explained the results using established simplistic models based on the different competing time scales. Our experiments (i) suggest an alternative method to estimate the transformation temperature scales with high accuracy and (ii) establish a connection between the material-specific evolution of microstructure to the statistics of its linear response. Since the method depends on an in-built long-range correlation during transformation, it could be portable to other structural transitions, as well as to materials of different physical origin and size.

  11. A simple model for studying interacting networks

    NASA Astrophysics Data System (ADS)

    Liu, Wenjia; Jolad, Shivakumar; Schmittmann, Beate; Zia, R. K. P.

    2011-03-01

    Many specific physical networks (e.g., internet, power grid, interstates), have been characterized in considerable detail, but in isolation from each other. Yet, each of these networks supports the functions of the others, and so far, little is known about how their interactions affect their structure and functionality. To address this issue, we consider two coupled model networks. Each network is relatively simple, with a fixed set of nodes, but dynamically generated set of links which has a preferred degree, κ . In the stationary state, the degree distribution has exponential tails (far from κ), an attribute which we can explain. Next, we consider two such networks with different κ 's, reminiscent of two social groups, e.g., extroverts and introverts. Finally, we let these networks interact by establishing a controllable fraction of cross links. The resulting distribution of links, both within and across the two model networks, is investigated and discussed, along with some potential consequences for real networks. Supported in part by NSF-DMR-0705152 and 1005417.

  12. Simple models for reading neuronal population codes.

    PubMed Central

    Seung, H S; Sompolinsky, H

    1993-01-01

    In many neural systems, sensory information is distributed throughout a population of neurons. We study simple neural network models for extracting this information. The inputs to the networks are the stochastic responses of a population of sensory neurons tuned to directional stimuli. The performance of each network model in psychophysical tasks is compared with that of the optimal maximum likelihood procedure. As a model of direction estimation in two dimensions, we consider a linear network that computes a population vector. Its performance depends on the width of the population tuning curves and is maximal for width, which increases with the level of background activity. Although for narrowly tuned neurons the performance of the population vector is significantly inferior to that of maximum likelihood estimation, the difference between the two is small when the tuning is broad. For direction discrimination, we consider two models: a perceptron with fully adaptive weights and a network made by adding an adaptive second layer to the population vector network. We calculate the error rates of these networks after exhaustive training to a particular direction. By testing on the full range of possible directions, the extent of transfer of training to novel stimuli can be calculated. It is found that for threshold linear networks the transfer of perceptual learning is nonmonotonic. Although performance deteriorates away from the training stimulus, it peaks again at an intermediate angle. This nonmonotonicity provides an important psychophysical test of these models. PMID:8248166

  13. Robot navigation using simple sensor fusion

    SciTech Connect

    Jollay, D.M.; Ricks, R.E.

    1988-01-01

    Sensors on an autonomous mobile system are essential in enviornment determination for navigation purposes. As is well documented in previous publications, sonar sensors are inadequate in providing a depiction of a real world environment and therefore do not provide accurate information for navigation, it not used in conjunction with another type of sensor. This paper describes a simple, inexpensive, and relatively fast navigation algorithm involving vision and sonar sensor fusion for use in navigating an autonomous robot in an unknown and potentially dynamic environment. Navigation of the mobile robot was accomplished by use of a TV camera as the primary sensor. Input data received from the camera were digitized through a video module and then processed using a dedicated vision system to enable detection of obstacles and to determine edge positions relative to the robot. Since 3D vision was not attempted due to its complex and time consuming nature, sonar sensors were then sued as secondary sensors in order to determine the proximity of detected obstacles. By then fusing the sensor data, the robot was able to navigate (quickly and collision free) to a given goal, achieving obstacle avoidance in real-time.

  14. Simple model of the slingshot effect

    NASA Astrophysics Data System (ADS)

    Fiore, Gaetano; De Nicola, Sergio

    2016-07-01

    We present a detailed quantitative description of the recently proposed "slingshot effect." Namely, we determine a broad range of conditions under which the impact of a very short and intense laser pulse normally onto a low-density plasma (or matter locally completely ionized into a plasma by the pulse) causes the expulsion of a bunch of surface electrons in the direction opposite to the one of propagation of the pulse, and the detailed, ready-for-experiments features of the expelled electrons (energy spectrum, collimation, etc). The effect is due to the combined actions of the ponderomotive force and the huge longitudinal field arising from charge separation. Our predictions are based on estimating 3D corrections to a simple, yet powerful plane 2-fluid magnetohydrodynamic (MHD) model where the equations to be solved are reduced to a system of Hamilton equations in one dimension (or a collection of) which become autonomous after the pulse has overcome the electrons. Experimental tests seem to be at hand. If confirmed by the latter, the effect would provide a new extraction and acceleration mechanism for electrons, alternative to traditional radio-frequency-based or Laser-Wake-Field ones.

  15. Sheath fold morphology in simple shear

    NASA Astrophysics Data System (ADS)

    Reber, Jacqueline E.; Dabrowski, Marcin; Galland, Olivier; Schmid, Daniel W.

    2013-08-01

    Sheath folds are highly non-cylindrical structures often associated with shear zones. We investigate the formation of sheath folds around a weak inclusion acting as a slip surface in simple shear by means of an analytical model. We present results for different slip surface orientations and shapes. Cross-sections perpendicular to the shear direction through the sheath fold display closed contours, so called eye-structures. The aspect ratio of the outermost closed contour is strongly dependent on the initial slip surface configuration. The center of the eye-structure is subject to change in height with respect to the upper edge of the outermost closed contour for different cross-sections perpendicular to the shear direction. This results in a large variability in layer thickness across the sheath fold length, questioning the usefulness of eye-structures as shear sense indicators. The location of the center of the eye structure is largely invariant to the initial configurations of the slip surface as well as to strain. The values of the aspect ratios of the closed contours within the eye-pattern are dependent on the strain and the cross-section location. The ratio (R') of the aspect ratios of the outermost closed contour (Ryz) and the innermost closed contour (Ry'z') shows values above and below 1. R' shows dependence on the slip surface shape and orientation but not on the number of involved contours. Using R' measurements to deduce the bulk strain type may be erroneous.

  16. Dynamic Characteristics of a Simple Brayton Cryocycle

    NASA Astrophysics Data System (ADS)

    Kutzschbach, A.; Kauschke, M.; Haberstroh, Ch.; Quack, H.

    2006-04-01

    The goal of the overall program is to develop a dynamic numerical model of helium refrigerators and the associated cooling systems based on commercial simulation software. The aim is to give system designers a tool to search for optimum control strategies during the construction phase of the refrigerator with the help of a plant "simulator". In a first step, a simple Brayton refrigerator has been investigated, which consists of a compressor, an after-cooler, a counter-current heat exchanger, a turboexpander and a heat source. Operating modes are "refrigeration" and "liquefaction". Whereas for the steady state design only component efficiencies are needed and mass and energy balances have to be calculated, for the dynamic calculation one needs also the thermal masses and the helium inventory. Transient mass and energy balances have to be formulated for many small elements and then solved simultaneously for all elements. Starting point of the simulation of the Brayton cycle is the steady state operation at design conditions. The response of the system to step and cyclic changes of the refrigeration or liquefaction rate are calculated and characterized.

  17. Star clusters as simple stellar populations.

    PubMed

    Bruzual A, Gustavo

    2010-02-28

    In this paper, I review to what extent we can understand the photometric properties of star clusters, and of low-mass, unresolved galaxies, in terms of population-synthesis models designed to describe 'simple stellar populations' (SSPs), i.e. groups of stars born at the same time, in the same volume of space and from a gas cloud of homogeneous chemical composition. The photometric properties predicted by these models do not readily match the observations of most star clusters, unless we properly take into account the expected variation in the number of stars occupying sparsely populated evolutionary stages, owing to stochastic fluctuations in the stellar initial mass function. In this case, population-synthesis models reproduce remarkably well the full ranges of observed integrated colours and absolute magnitudes of star clusters of various ages and metallicities. The disagreement between the model predictions and observations of cluster colours and magnitudes may indicate problems with or deficiencies in the modelling, and does not necessarily tell us that star clusters do not behave like SSPs. Matching the photometric properties of star clusters using SSP models is a necessary (but not sufficient) condition for clusters to be considered SSPs. Composite models, characterized by complex star-formation histories, also match the observed cluster colours. PMID:20083506

  18. Simple light gas guns for hypervelocity studies

    SciTech Connect

    Combs, S.K.; Haselton, H.H.; Milora, S.L.

    1990-01-01

    Two-stage light guns are used extensively in hypervelocity research. The applications of this technology include impact studies and special materials development. Oak Ridge National Laboratory (ORNL) has developed two-stage guns that accelerate small projectiles (4-mm nominal diameter) to velocities of up to {approx}5 km/s. These guns are relatively small and simple (thus, easy to operate), allowing a significant number of test shots to be carried out and data accumulated in a short time. Materials that have been used for projectiles include plastics, frozen isotopes of hydrogen, and lithium hydride. One gun has been used to demonstrate repetitive operation at a rate of 0.7 Hz; and, with a few design improvements, it appears capable of performing at firing frequencies of 1--2 Hz. A schematic of ORNL two-stage device is shown below. Unlike most such devices, no rupture disks are used. Instead, a fast valve (high-flow type) initiates the acceleration process in the first stage. Projectiles can be loaded into the gun breech via the slide mechanism; this action has been automated which allows repetitive firing. Alternatively, the device is equipped with pipe gun'' apparatus in which gas can be frozen in situ in the gun barrel to form the projectile. This equipment operates with high reliability and is well suited for small-scale testing at high velocity. 17 refs., 6 figs., 2 tabs.

  19. Simple road detection based on vanishing point

    NASA Astrophysics Data System (ADS)

    Ziyu, Chen; Zhen, He

    2014-05-01

    Vision-based road detection is one of the key techniques of autonomous driving, intelligent vehicles, and visual navigation. At present, methods based on vanishing point perform best with general roads. However, it is difficult for them to meet the needs of a real-time system due to high time consumption. This paper presents a fast detection method, namely simple road detection, which achieves high efficiency by employing sky segmentation and two new optimization schemes-sample convolution and fast voting. The optimizations are based on lookup tables, sample computing, and computing simplification. The interval sampling in sample convolution makes the proposed method flexible to meet various efficiency and accuracy demands by different sample-step values. Mean filter and vote orientation limitation are also proposed to help improve detection accuracy. Experiments have been conducted with a large number of road images under different environmental conditions, and the results demonstrate that our proposed method is efficient and effective in detecting both structured and unstructured roads.

  20. A scalable and operationally simple radical trifluoromethylation

    PubMed Central

    Beatty, Joel W.; Douglas, James J.; Cole, Kevin P.; Stephenson, Corey R. J.

    2015-01-01

    The large number of reagents that have been developed for the synthesis of trifluoromethylated compounds is a testament to the importance of the CF3 group as well as the associated synthetic challenge. Current state-of-the-art reagents for appending the CF3 functionality directly are highly effective; however, their use on preparative scale has minimal precedent because they require multistep synthesis for their preparation, and/or are prohibitively expensive for large-scale application. For a scalable trifluoromethylation methodology, trifluoroacetic acid and its anhydride represent an attractive solution in terms of cost and availability; however, because of the exceedingly high oxidation potential of trifluoroacetate, previous endeavours to use this material as a CF3 source have required the use of highly forcing conditions. Here we report a strategy for the use of trifluoroacetic anhydride for a scalable and operationally simple trifluoromethylation reaction using pyridine N-oxide and photoredox catalysis to affect a facile decarboxylation to the CF3 radical. PMID:26258541

  1. A scalable and operationally simple radical trifluoromethylation.

    PubMed

    Beatty, Joel W; Douglas, James J; Cole, Kevin P; Stephenson, Corey R J

    2015-01-01

    The large number of reagents that have been developed for the synthesis of trifluoromethylated compounds is a testament to the importance of the CF3 group as well as the associated synthetic challenge. Current state-of-the-art reagents for appending the CF3 functionality directly are highly effective; however, their use on preparative scale has minimal precedent because they require multistep synthesis for their preparation, and/or are prohibitively expensive for large-scale application. For a scalable trifluoromethylation methodology, trifluoroacetic acid and its anhydride represent an attractive solution in terms of cost and availability; however, because of the exceedingly high oxidation potential of trifluoroacetate, previous endeavours to use this material as a CF3 source have required the use of highly forcing conditions. Here we report a strategy for the use of trifluoroacetic anhydride for a scalable and operationally simple trifluoromethylation reaction using pyridine N-oxide and photoredox catalysis to affect a facile decarboxylation to the CF3 radical. PMID:26258541

  2. Squid – a simple bioinformatics grid

    PubMed Central

    Carvalho, Paulo C; Glória, Rafael V; de Miranda, Antonio B; Degrave, Wim M

    2005-01-01

    Background BLAST is a widely used genetic research tool for analysis of similarity between nucleotide and protein sequences. This paper presents a software application entitled "Squid" that makes use of grid technology. The current version, as an example, is configured for BLAST applications, but adaptation for other computing intensive repetitive tasks can be easily accomplished in the open source version. This enables the allocation of remote resources to perform distributed computing, making large BLAST queries viable without the need of high-end computers. Results Most distributed computing / grid solutions have complex installation procedures requiring a computer specialist, or have limitations regarding operating systems. Squid is a multi-platform, open-source program designed to "keep things simple" while offering high-end computing power for large scale applications. Squid also has an efficient fault tolerance and crash recovery system against data loss, being able to re-route jobs upon node failure and recover even if the master machine fails. Our results show that a Squid application, working with N nodes and proper network resources, can process BLAST queries almost N times faster than if working with only one computer. Conclusion Squid offers high-end computing, even for the non-specialist, and is freely available at the project web site. Its open-source and binary Windows distributions contain detailed instructions and a "plug-n-play" instalation containing a pre-configured example. PMID:16078998

  3. Simple trachelectomy during pregnancy for cervical cancer

    PubMed Central

    Moreno-Luna, Estefania; Alonso, Patricia; Santiago, Javier De; Zapardiel, Ignacio

    2016-01-01

    Invasive cervical cancer is rare during a pregnancy, even though it is one of the most frequently diagnosed neoplasias during that time. It is noted that around 30% of women diagnosed with cervical cancer are of reproductive age. This means that up to 3% of cases of cervical cancer are found in pregnant women or those who are in the post-birth period. A cervicovaginal Pap smear is performed as part of the regular checkup for a pregnant woman during the first visit so that cervical cancer can easily be diagnosed early in these women, detecting it early in up to 70–80% of cases. We present here the case of a patient with initial diagnosis of cervical cancer made around 20th week of pregnancy. It was then treated by a simple trachelectomy and cerclage during week 24. The pregnant woman gave birth to a healthy baby at the end of her pregnancy. Definitive treatment was completed three months after giving birth with a total hysterectomy and laparoscopic bilateral salpingectomy while preserving both ovaries. After 17 months of monitoring the patient showed no signs of reoccurrence. In conclusion, during the early stage of cervical cancer conservative management may be a reasonable option to preserve the current pregnancy. PMID:27610199

  4. Simple Broadband Circular Polarizer in Oversized Waveguide

    NASA Astrophysics Data System (ADS)

    Stange, Torsten

    2016-02-01

    In this paper, a possibility is shown to realize a simple waveguide polarizer producing nearly the same circular polarization over a broad frequency range up to an octave. It is based upon the combination of two smoothly squeezed oversized waveguides with different diameters. The principle is similar to an achromatic lens in optics, where two counteracting lenses with differently sloped wavelength dependencies of the refractive index are combined to compensate the dispersion in the desired wavelength range. Consequently, two different wavelengths of light are brought into focus at the same plane. A waveguide for the transmission of microwaves has a similar frequency dependence of the refractive index resulting in a frequency-dependent phase shift between two propagating waves polarized along the symmetry axes of a waveguide with an elliptical cross section. For this reason, an incident wave with a linear polarization between the axes of symmetry can be only converted into a circularly polarized wave over a limited frequency range. However, the diameter and the shape along two counteracting squeezed waveguides can be adjusted in such a way that the frequency dependence of the resultant phase shift is finally canceled out.

  5. Simple quantification of in planta fungal biomass.

    PubMed

    Ayliffe, Michael; Periyannan, Sambasivam K; Feechan, Angela; Dry, Ian; Schumann, Ulrike; Lagudah, Evans; Pryor, Anthony

    2014-01-01

    An accurate assessment of the disease resistance status of plants to fungal pathogens is an essential requirement for the development of resistant crop plants. Many disease resistance phenotypes are partial rather than obvious immunity and are frequently scored using subjective qualitative estimates of pathogen development or plant disease symptoms. Here we report a method for the accurate comparison of total fungal biomass in plant tissues. This method, called the WAC assay, is based upon the specific binding of the plant lectin wheat germ agglutinin to fungal chitin. The assay is simple, high-throughput, and sensitive enough to discriminate between single Puccinia graminis f.sp tritici infection sites on a wheat leaf segment. It greatly lends itself to replication as large volumes of tissue can be pooled from independent experiments and assayed to provide truly representative quantification, or, alternatively, fungal growth on a single, small leaf segment can be quantified. In addition, as the assay is based upon a microscopic technique, pathogen infection sites can also be examined at high magnification prior to quantification if desired and average infection site areas are determined. Previously, we have demonstrated the application of the WAC assay for quantifying the growth of several different pathogen species in both glasshouse grown material and large-scale field plots. Details of this method are provided within. PMID:24643560

  6. Simple models of the hydrofracture process

    NASA Astrophysics Data System (ADS)

    Marder, M.; Chen, Chih-Hung; Patzek, T.

    2015-12-01

    Hydrofracturing to recover natural gas and oil relies on the creation of a fracture network with pressurized water. We analyze the creation of the network in two ways. First, we assemble a collection of analytical estimates for pressure-driven crack motion in simple geometries, including crack speed as a function of length, energy dissipated by fluid viscosity and used to break rock, and the conditions under which a second crack will initiate while a first is running. We develop a pseudo-three-dimensional numerical model that couples fluid motion with solid mechanics and can generate branching crack structures not specified in advance. One of our main conclusions is that the typical spacing between fractures must be on the order of a meter, and this conclusion arises in two separate ways. First, it arises from analysis of gas production rates, given the diffusion constants for gas in the rock. Second, it arises from the number of fractures that should be generated given the scale of the affected region and the amounts of water pumped into the rock.

  7. A simple model for Geyser Flat, Whakarewarewa

    SciTech Connect

    Weir, G.J.; Young, R.M.; McGavin, P.N. )

    1992-04-01

    The work presented in this paper is based on records of geyser activity and other data collected at Geyser Flat, Whakarewarewa, New Zealand. The data is used to used to construct a simple quasi-steady mass, heat, and chemical balance model to account for the interactions between the three geysers Pohutu, Prince of Wales Feathers, Waikorohihi, and the non-eruptive Te Horu cauldron. This model has provided order of magnitude estimates for mass and energy flows, and geyser cavern properties. The importance of the west-south-west wind component on the Te Horu waterlevel is established from the data. Te Horu waterlevels are also shown to correlate significantly with geyser performance. High waterlevels are connected with regular geyser behavior, while low waterlevels are associated with rapid irregular eruptions. Cavern temperatures of 118{degrees} C, 107{degrees} C and 109{degrees} C are inferred from the observed full column plume heights of 20, 8 and 8 meters from Pohutu, Prince of Wales Feathers, and Waikorohihi respectively.

  8. Simple Rules Yield Complex Food Webs

    NASA Astrophysics Data System (ADS)

    Martinez, Neo

    2003-03-01

    Several of the most ambitious theories in ecology describe food webs that document the structure of strong and weak trophic links among diverse assemblages of species. Early mechanism-based theory asserted that food webs have little omnivory and several properties that are independent of species richness. This theory was overturned by empirical studies that found food webs to be much more complex, but these studies did not provide mechanistic explanations for the complexity. Here we show that a remarkably simple model fills this scientific void by successfully predicting key structural properties of the most complex and comprehensive food webs in the primary literature. These properties include the fractions of species at top, intermediate and basal trophic levels, the means and variabilities of generality, vulnerability and food-chain length, and the degrees of cannibalism, omnivory, looping and trophic similarity. More recent tests using an expanded empirical base show that our model also successfully predicts the degrees of separation, degree distributions, and sensitivities to error and attack found in large complex food webs. Using only two empirical parameters, species number and connectance, our `niche model' extends the existing `cascade model' and improves its fit by constraining species to consume a contiguous sequence of prey in a one-dimensional trophic niche. The simplicity and success of the model has allowed new advances in the combined study of the structure and nonlinear dynamics of ecological networks.

  9. Simple rules yield complex food webs.

    PubMed

    Williams, R J; Martinez, N D

    2000-03-01

    Several of the most ambitious theories in ecology describe food webs that document the structure of strong and weak trophic links that is responsible for ecological dynamics among diverse assemblages of species. Early mechanism-based theory asserted that food webs have little omnivory and several properties that are independent of species richness. This theory was overturned by empirical studies that found food webs to be much more complex, but these studies did not provide mechanistic explanations for the complexity. Here we show that a remarkably simple model fills this scientific void by successfully predicting key structural properties of the most complex and comprehensive food webs in the primary literature. These properties include the fractions of species at top, intermediate and basal trophic levels, the means and variabilities of generality, vulnerability and food-chain length, and the degrees of cannibalism, omnivory, looping and trophic similarity. Using only two empirical parameters, species number and connectance, our 'niche model' extends the existing 'cascade model and improves its fit ten-fold by constraining species to consume a contiguous sequence of prey in a one-dimensional trophic niche. PMID:10724169

  10. Simple rules yield complex food webs

    NASA Astrophysics Data System (ADS)

    Williams, Richard J.; Martinez, Neo D.

    2000-03-01

    Several of the most ambitious theories in ecology describe food webs that document the structure of strong and weak trophic links that is responsible for ecological dynamics among diverse assemblages of species. Early mechanism-based theory asserted that food webs have little omnivory and several properties that are independent of species richness. This theory was overturned by empirical studies that found food webs to be much more complex, but these studies did not provide mechanistic explanations for the complexity. Here we show that a remarkably simple model fills this scientific void by successfully predicting key structural properties of the most complex and comprehensive food webs in the primary literature. These properties include the fractions of species at top, intermediate and basal trophic levels, the means and variabilities of generality, vulnerability and food-chain length, and the degrees of cannibalism, omnivory, looping and trophic similarity. Using only two empirical parameters, species number and connectance, our `niche model' extends the existing `cascade model' and improves its fit ten-fold by constraining species to consume a contiguous sequence of prey in a one-dimensional trophic niche.

  11. Simple trachelectomy during pregnancy for cervical cancer.

    PubMed

    Moreno-Luna, Estefania; Alonso, Patricia; Santiago, Javier De; Zapardiel, Ignacio

    2016-01-01

    Invasive cervical cancer is rare during a pregnancy, even though it is one of the most frequently diagnosed neoplasias during that time. It is noted that around 30% of women diagnosed with cervical cancer are of reproductive age. This means that up to 3% of cases of cervical cancer are found in pregnant women or those who are in the post-birth period. A cervicovaginal Pap smear is performed as part of the regular checkup for a pregnant woman during the first visit so that cervical cancer can easily be diagnosed early in these women, detecting it early in up to 70-80% of cases. We present here the case of a patient with initial diagnosis of cervical cancer made around 20th week of pregnancy. It was then treated by a simple trachelectomy and cerclage during week 24. The pregnant woman gave birth to a healthy baby at the end of her pregnancy. Definitive treatment was completed three months after giving birth with a total hysterectomy and laparoscopic bilateral salpingectomy while preserving both ovaries. After 17 months of monitoring the patient showed no signs of reoccurrence. In conclusion, during the early stage of cervical cancer conservative management may be a reasonable option to preserve the current pregnancy. PMID:27610199

  12. Simple mathematical law benchmarks human confrontations

    PubMed Central

    Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

    2013-01-01

    Many high-profile societal problems involve an individual or group repeatedly attacking another – from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a ‘lone wolf'; identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds. PMID:24322528

  13. Simple Waves in Ideal Radiation Hydrodynamics

    SciTech Connect

    Johnson, B M

    2008-09-03

    In the dynamic diffusion limit of radiation hydrodynamics, advection dominates diffusion; the latter primarily affects small scales and has negligible impact on the large scale flow. The radiation can thus be accurately regarded as an ideal fluid, i.e., radiative diffusion can be neglected along with other forms of dissipation. This viewpoint is applied here to an analysis of simple waves in an ideal radiating fluid. It is shown that much of the hydrodynamic analysis carries over by simply replacing the material sound speed, pressure and index with the values appropriate for a radiating fluid. A complete analysis is performed for a centered rarefaction wave, and expressions are provided for the Riemann invariants and characteristic curves of the one-dimensional system of equations. The analytical solution is checked for consistency against a finite difference numerical integration, and the validity of neglecting the diffusion operator is demonstrated. An interesting physical result is that for a material component with a large number of internal degrees of freedom and an internal energy greater than that of the radiation, the sound speed increases as the fluid is rarefied. These solutions are an excellent test for radiation hydrodynamic codes operating in the dynamic diffusion regime. The general approach may be useful in the development of Godunov numerical schemes for radiation hydrodynamics.

  14. A Simple Model of Ostracism Formation

    PubMed Central

    Kim, Pilwon

    2014-01-01

    We study formation of ostracism in a society from a game theoretical perspective. The dynamics of group formation is complicated in that the choices of the individuals and the form of the groups mutually affect each other in the process. A suggested simple model shows that individual efforts to increase his/her own sense of belonging is responsible for both growth of groups and creation of an outcast. Once a person happens to get behind in synchronizing with others, tendency to alienate him may grow among others, possibly making him left out in the end. Alienating minority occurs even when there is a penalty for disliking and people are encouraged to favor others. Considering that the target is accidentally picked, we can understand ostracism as an inherent part of the group formation, rather than a result of specific discrepancy among people. Another finding is that a single individual who seeks for unconditional unification of the society (“philanthropist”) likely invites his/her own isolation from the society, while the existence of such person generally promotes coalition of others. PMID:24781530

  15. Simple, parallel virtual machines for extreme computations

    NASA Astrophysics Data System (ADS)

    Chokoufe Nejad, Bijan; Ohl, Thorsten; Reuter, Jürgen

    2015-11-01

    We introduce a virtual machine (VM) written in a numerically fast language like Fortran or C for evaluating very large expressions. We discuss the general concept of how to perform computations in terms of a VM and present specifically a VM that is able to compute tree-level cross sections for any number of external legs, given the corresponding byte-code from the optimal matrix element generator, O'MEGA. Furthermore, this approach allows to formulate the parallel computation of a single phase space point in a simple and obvious way. We analyze hereby the scaling behavior with multiple threads as well as the benefits and drawbacks that are introduced with this method. Our implementation of a VM can run faster than the corresponding native, compiled code for certain processes and compilers, especially for very high multiplicities, and has in general runtimes in the same order of magnitude. By avoiding the tedious compile and link steps, which may fail for source code files of gigabyte sizes, new processes or complex higher order corrections that are currently out of reach could be evaluated with a VM given enough computing power.

  16. Simple neuron models of ITD sensitive neurons

    NASA Astrophysics Data System (ADS)

    Dasika, Vasant; White, John A.; Colburn, H. Steven

    2002-05-01

    Neurons which show sensitivity to interaural time delay (ITD) exist in both mammalian medial superior olive (MSO), and bird nucleus laminaris (NL). In this study, we examine simple mathematical models of single MSO and NL cells which respond probabilistically to a pair of isolated inputs with a response probability that depends on the input interpulse interval. Inputs are either isolated pulse pairs or pairs of periodic trains, with or without random jitter added to their event times. Refractoriness is incorporated in the input description and/or in the cell model in specified simulations. We find that periodic rate-ITD shapes are shaped by three interacting factors: the cell's temporal response (described by the paired-pulse response), input frequency, and the degree of input synchrony. Paired-pulse responses are able to predict the widths of rate-ITD curves obtained from deterministic periodic input simulations. Reduced input synchrony predictably smears rate-ITD curves. Larger numbers of weaker inputs yield stronger rate-ITD modulation than a few strong inputs. Model response is compared with in vivo and in vitro MSO and NL physiological data. Comparisons with published analytical models as well as more complex and realistic physiological cell models are examined.

  17. Mental chronometry with simple linear regression.

    PubMed

    Chen, J Y

    1997-10-01

    Typically, mental chronometry is performed by means of introducing an independent variable postulated to affect selectively some stage of a presumed multistage process. However, the effect could be a global one that spreads proportionally over all stages of the process. Currently, there is no method to test this possibility although simple linear regression might serve the purpose. In the present study, the regression approach was tested with tasks (memory scanning and mental rotation) that involved a selective effect and with a task (word superiority effect) that involved a global effect, by the dominant theories. The results indicate (1) the manipulation of the size of a memory set or of angular disparity affects the intercept of the regression function that relates the times for memory scanning with different set sizes or for mental rotation with different angular disparities and (2) the manipulation of context affects the slope of the regression function that relates the times for detecting a target character under word and nonword conditions. These ratify the regression approach as a useful method for doing mental chronometry. PMID:9347535

  18. A Simple Model to Study Tau Pathology

    PubMed Central

    Houck, Alexander L.; Hernández, Félix; Ávila, Jesús

    2016-01-01

    Tau proteins play a role in the stabilization of microtubules, but in pathological conditions, tauopathies, tau is modified by phosphorylation and can aggregate into aberrant aggregates. These aggregates could be toxic to cells, and different cell models have been used to test for compounds that might prevent these tau modifications. Here, we have used a cell model involving the overexpression of human tau in human embryonic kidney 293 cells. In human embryonic kidney 293 cells expressing tau in a stable manner, we have been able to replicate the phosphorylation of intracellular tau. This intracellular tau increases its own level of phosphorylation and aggregates, likely due to the regulatory effect of some growth factors on specific tau kinases such as GSK3. In these conditions, a change in secreted tau was observed. Reversal of phosphorylation and aggregation of tau was found by the use of lithium, a GSK3 inhibitor. Thus, we propose this as a simple cell model to study tau pathology in nonneuronal cells due to their viability and ease to work with. PMID:26949341

  19. A simple, approximate model of parachute inflation

    SciTech Connect

    Macha, J.M.

    1992-11-01

    A simple, approximate model of parachute inflation is described. The model is based on the traditional, practical treatment of the fluid resistance of rigid bodies in nonsteady flow, with appropriate extensions to accommodate the change in canopy inflated shape. Correlations for the steady drag and steady radial force as functions of the inflated radius are required as input to the dynamic model. In a novel approach, the radial force is expressed in terms of easily obtainable drag and reefing fine tension measurements. A series of wind tunnel experiments provides the needed correlations. Coefficients associated with the added mass of fluid are evaluated by calibrating the model against an extensive and reliable set of flight data. A parameter is introduced which appears to universally govern the strong dependence of the axial added mass coefficient on motion history. Through comparisons with flight data, the model is shown to realistically predict inflation forces for ribbon and ringslot canopies over a wide range of sizes and deployment conditions.

  20. A simple, approximate model of parachute inflation

    SciTech Connect

    Macha, J.M.

    1992-01-01

    A simple, approximate model of parachute inflation is described. The model is based on the traditional, practical treatment of the fluid resistance of rigid bodies in nonsteady flow, with appropriate extensions to accommodate the change in canopy inflated shape. Correlations for the steady drag and steady radial force as functions of the inflated radius are required as input to the dynamic model. In a novel approach, the radial force is expressed in terms of easily obtainable drag and reefing fine tension measurements. A series of wind tunnel experiments provides the needed correlations. Coefficients associated with the added mass of fluid are evaluated by calibrating the model against an extensive and reliable set of flight data. A parameter is introduced which appears to universally govern the strong dependence of the axial added mass coefficient on motion history. Through comparisons with flight data, the model is shown to realistically predict inflation forces for ribbon and ringslot canopies over a wide range of sizes and deployment conditions.

  1. A simple model of ostracism formation.

    PubMed

    Kim, Pilwon

    2014-01-01

    We study formation of ostracism in a society from a game theoretical perspective. The dynamics of group formation is complicated in that the choices of the individuals and the form of the groups mutually affect each other in the process. A suggested simple model shows that individual efforts to increase his/her own sense of belonging is responsible for both growth of groups and creation of an outcast. Once a person happens to get behind in synchronizing with others, tendency to alienate him may grow among others, possibly making him left out in the end. Alienating minority occurs even when there is a penalty for disliking and people are encouraged to favor others. Considering that the target is accidentally picked, we can understand ostracism as an inherent part of the group formation, rather than a result of specific discrepancy among people. Another finding is that a single individual who seeks for unconditional unification of the society ("philanthropist") likely invites his/her own isolation from the society, while the existence of such person generally promotes coalition of others. PMID:24781530

  2. 10 CFR 436.23 - Estimated simple payback time.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Estimated simple payback time. 436.23 Section 436.23 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of...

  3. Simple yet Hidden Counterexamples in Undergraduate Real Analysis

    ERIC Educational Resources Information Center

    Shipman, Barbara A.; Shipman, Patrick D.

    2013-01-01

    We study situations in introductory analysis in which students affirmed false statements as true, despite simple counterexamples that they easily recognized afterwards. The study draws attention to how simple counterexamples can become hidden in plain sight, even in an active learning atmosphere where students proposed simple (as well as more…

  4. How Surprising Is a Simple Pattern? Quantifying ''Eureka!''

    ERIC Educational Resources Information Center

    Feldman, Jacob

    2004-01-01

    Simple patterns are compelling. When all the observed facts fit into a simple theory or ''story,'' we are intuitively convinced that the pattern must be "real" rather than random. But how surprising is a simple pattern, really? That is, given a pattern of featural data, such as the properties of a set of objects, how unlikely would the pattern be…

  5. SIMPLIMAX: Oblique Rotation to an Optimal Target with Simple Structure.

    ERIC Educational Resources Information Center

    Kiers, Henk A. L.

    1994-01-01

    A class of oblique rotation procedures is proposed to rotate a pattern matrix so that it optimally resembles a matrix that has an exact simple pattern. It is demonstrated that the method can recover relatively complex simple structures where other simple structure rotation techniques fail. (SLD)

  6. Emergent Biosynthetic Capacity in Simple Microbial Communities

    PubMed Central

    Chiu, Hsuan-Chao; Levy, Roie; Borenstein, Elhanan

    2014-01-01

    Microbes have an astonishing capacity to transform their environments. Yet, the metabolic capacity of a single species is limited and the vast majority of microorganisms form complex communities and join forces to exhibit capabilities far exceeding those achieved by any single species. Such enhanced metabolic capacities represent a promising route to many medical, environmental, and industrial applications and call for the development of a predictive, systems-level understanding of synergistic microbial capacity. Here we present a comprehensive computational framework, integrating high-quality metabolic models of multiple species, temporal dynamics, and flux variability analysis, to study the metabolic capacity and dynamics of simple two-species microbial ecosystems. We specifically focus on detecting emergent biosynthetic capacity – instances in which a community growing on some medium produces and secretes metabolites that are not secreted by any member species when growing in isolation on that same medium. Using this framework to model a large collection of two-species communities on multiple media, we demonstrate that emergent biosynthetic capacity is highly prevalent. We identify commonly observed emergent metabolites and metabolic reprogramming patterns, characterizing typical mechanisms of emergent capacity. We further find that emergent secretion tends to occur in two waves, the first as soon as the two organisms are introduced, and the second when the medium is depleted and nutrients become limited. Finally, aiming to identify global community determinants of emergent capacity, we find a marked association between the level of emergent biosynthetic capacity and the functional/phylogenetic distance between community members. Specifically, we demonstrate a “Goldilocks” principle, where high levels of emergent capacity are observed when the species comprising the community are functionally neither too close, nor too distant. Taken together, our results

  7. Simple visual cues of event boundaries.

    PubMed

    Tauzin, Tibor

    2015-06-01

    A stream of sensory information is organized into discrete temporal units through event segmentation. On the basis of several studies measuring participants' explicit decisions about event boundaries, some theorists suggest that this segmentation is induced by increased unpredictability. Since this approach cannot describe the segmentation of unfamiliar events, we assumed that event segmentation might be perceptually driven. We hypothesized that when a new event-relevant object is represented, it triggers event segmentation. In addition to explicit decisions, we measured memory performance, since it has previously been found to be a strong indicator of event segmentation. We presented simple videos to the participants in which geometric objects were flashing consecutively while an unpredictable change occurred. In the New Object condition flashing objects were replaced, while in the Same Object condition one non-kind-relevant feature of the objects was changed. In Experiment 1 the participants' task was to press a button when they detected a meaningful change in the stimuli. In line with the predictability-based theories, we found that both changes triggered the detection of an event boundary. To contrast our hypothesis with the predictions of earlier theories, in Experiments 2 and 3 memory accuracy was measured using the stimuli of Experiment 1. We only found a significant change in memory accuracy in the New Object condition, which suggests that the appearance of an event-relevant object can induce segmentation on its own, and indicates that the explicit-decisions methodology might lead to the improper conclusion that event segmentation is solely based on predictability. PMID:25867112

  8. An Arduino Investigation of Simple Harmonic Motion

    NASA Astrophysics Data System (ADS)

    Galeriu, Calin; Edwards, Scott; Esper, Geoffrey

    2014-03-01

    We cannot hope for a new generation of scientists and engineers if we don't let our young students take ownership of their scientific and engineering explorations, if we don't let them enjoy the hands-on cycle of design and production, and if we don't let them implant their creativity into a technologically friendly environment. With this educational philosophy in mind, Massimo Banzi and his team have developed and popularized the open source Arduino microcontroller board. The Arduino board has helped countless people in their science, electronics, robotics, or engineering projects, allowing them to build things that we have not even dreamed of. Physics instructors have also realized the advantages of using Arduino boards for lab experiments. The schools are saving money because the homemade experimental equipment is much cheaper than the commercial alternatives. The students are thankful for an educational experience that is more interesting, more loaded with STEM content, and more fun. As further proof of this new trend in physics education, Vernier5 is now documenting the use of their probes with Arduino boards. This is why we have developed an Arduino-based physics investigation of the simple harmonic motion (SHM) of a mass on a spring. The experimental data are collected with the help of an ultrasonic distance sensor and an Arduino Uno board. The data are then graphed and analyzed using Origin 9. This rich cross-curricular STEM activity integrates electronics, computer programming, physics, and mathematics in a way that is both experimentally exciting and intellectually rewarding.

  9. Simple sequence repeats in prokaryotic genomes

    PubMed Central

    Mrázek, Jan; Guo, Xiangxue; Shah, Apurva

    2007-01-01

    Simple sequence repeats (SSRs) in DNA sequences are composed of tandem iterations of short oligonucleotides and may have functional and/or structural properties that distinguish them from general DNA sequences. They are variable in length because of slip-strand mutations and may also affect local structure of the DNA molecule or the encoded proteins. Long SSRs (LSSRs) are common in eukaryotes but rare in most prokaryotes. In pathogens, SSRs can enhance antigenic variance of the pathogen population in a strategy that counteracts the host immune response. We analyze representations of SSRs in >300 prokaryotic genomes and report significant differences among different prokaryotes as well as among different types of SSRs. LSSRs composed of short oligonucleotides (1–4 bp length, designated LSSR1–4) are often found in host-adapted pathogens with reduced genomes that are not known to readily survive in a natural environment outside the host. In contrast, LSSRs composed of longer oligonucleotides (5–11 bp length, designated LSSR5–11) are found mostly in nonpathogens and opportunistic pathogens with large genomes. Comparisons among SSRs of different lengths suggest that LSSR1–4 are likely maintained by selection. This is consistent with the established role of some LSSR1–4 in enhancing antigenic variance. By contrast, abundance of LSSR5–11 in some genomes may reflect the SSRs' general tendency to expand rather than their specific role in the organisms' physiology. Differences among genomes in terms of SSR representations and their possible interpretations are discussed. PMID:17485665

  10. A SIMPLE LAW OF STAR FORMATION

    SciTech Connect

    Padoan, Paolo; Haugbolle, Troels; Nordlund, Ake E-mail: haugboel@nbi.dk

    2012-11-10

    We show that supersonic MHD turbulence yields a star formation rate (SFR) as low as observed in molecular clouds, for characteristic values of the free-fall time divided by the dynamical time, t{sub ff}/t{sub dyn}, the Alfvenic Mach number, M{sub a}, and the sonic Mach number, M{sub s}. Using a very large set of deep adaptive-mesh-refinement simulations, we quantify the dependence of the SFR per free-fall time, {epsilon}{sub ff}, on the above parameters. Our main results are (1) that {epsilon}{sub ff} decreases exponentially with increasing t{sub ff}/t{sub dyn}, but is insensitive to changes in M{sub s}, for constant values of t{sub ff}/t{sub dyn} and M{sub a}. (2) Decreasing values of M{sub a} (stronger magnetic fields) reduce {epsilon}{sub ff}, but only to a point, beyond which {epsilon}{sub ff} increases with a further decrease of M{sub a}. (3) For values of M{sub a} characteristic of star-forming regions, {epsilon}{sub ff} varies with M{sub a} by less than a factor of two. We propose a simple star formation law, based on the empirical fit to the minimum {epsilon}{sub ff}, and depending only on t{sub ff}/t{sub dyn}: {epsilon}{sub ff} Almost-Equal-To {epsilon}{sub wind}exp (- 1.6 t{sub ff}/t{sub dyn}). Because it only depends on the mean gas density and rms velocity, this law is straightforward to implement in simulations and analytical models of galaxy formation and evolution.

  11. A simple tool for neuroimaging data sharing

    PubMed Central

    Haselgrove, Christian; Poline, Jean-Baptiste; Kennedy, David N.

    2014-01-01

    Data sharing is becoming increasingly common, but despite encouragement and facilitation by funding agencies, journals, and some research efforts, most neuroimaging data acquired today is still not shared due to political, financial, social, and technical barriers to sharing data that remain. In particular, technical solutions are few for researchers that are not a part of larger efforts with dedicated sharing infrastructures, and social barriers such as the time commitment required to share can keep data from becoming publicly available. We present a system for sharing neuroimaging data, designed to be simple to use and to provide benefit to the data provider. The system consists of a server at the International Neuroinformatics Coordinating Facility (INCF) and user tools for uploading data to the server. The primary design principle for the user tools is ease of use: the user identifies a directory containing Digital Imaging and Communications in Medicine (DICOM) data, provides their INCF Portal authentication, and provides identifiers for the subject and imaging session. The user tool anonymizes the data and sends it to the server. The server then runs quality control routines on the data, and the data and the quality control reports are made public. The user retains control of the data and may change the sharing policy as they need. The result is that in a few minutes of the user’s time, DICOM data can be anonymized and made publicly available, and an initial quality control assessment can be performed on the data. The system is currently functional, and user tools and access to the public image database are available at http://xnat.incf.org/. PMID:24904398

  12. Simple cost model for EV traction motors

    NASA Astrophysics Data System (ADS)

    Cuenca, R. M.

    1995-02-01

    A simple cost model has been developed that allows the calculation of the OEM (original equipment manufacturer) cost of electric traction motors of three different types, normalized as a function of power in order to accommodate different power and size. The model includes enough information on the various elements integrated in the motors to allow analysis of individual components and to factor-in the effects of changes in commodities prices. A scalable cost model for each of the main components of an electric vehicle (EV) is a useful tool that can have direct application in computer simulation or in parametric studies. For the cost model to have wide usefulness, it needs to be valid for a range of values of some parameter that determines the magnitude or size of the component. For instance, in the case of batteries, size may be determined by energy capacity, usually expressed in kilowatt-hours (kWh), while in the case of traction motors, size is better determined by rated power, usually expressed in kilowatts (kW). The simplest case is when the cost of the component in question is a direct function of its size; then cost is simply the product of its specific cost ($/unit size) and the number of units (size) in the vehicle in question. Batteries usually fall in this category (cost = energy capacity x $/kWh). But cost is not always linear with size or magnitude; motors (and controllers), for instance, become relatively less expensive as power rating increases. Traction motors, one of the main components for EV powertrains, are examined in this paper, and a simplified cost model is developed for the three most popular design variations.

  13. Controlling exposure to chemicals: a simple guide.

    PubMed

    Hay, Alastair

    2006-09-01

    Controlling exposure to chemicals in the workplace has been made easier by the use of a guide published by the U.K. Health and Safety Executive (HSE). Known as COSHH (Control of Substances Hazardous to Health Regulations) Essentials, the guide is a simple five-step procedure to devise appropriate control strategies to reduce exposures to various substances under different conditions. U.K. health and safety law requires risk assessments prior to use of hazardous substances and installation of appropriate control strategies before work commences. A 1996 survey of 1500 safety managers and trade union safety representatives revealed that the majority had little understanding of occupational safety limits for chemicals. Small- and medium-sized companies had little understanding of limits, and most could not develop control strategies. A new approach was required. COSHH Essentials is it. Developed over 3 years by a working group of hygienists and toxicologists representing HSE, industry, trade unions, and independent experts, the guide is now available in both paper-based and internet versions. It applies a hazard banding approach validated by data for 111 substances that have well-founded U.K. occupational exposure limits. New users select an appropriate hazard band for chemicals based on risk phrases. Details about dustiness for powders or volatility for liquids are inserted, and the guide allocates substances to one of four exposure bands linked, in turn, to specific control strategies. Now accessible through the HSE web site, COSHH Essentials will offer control strategies for both single chemicals and whole processes. To date over 300,000 risk assessments have been carried out using the internet version of COSHH Essentials. PMID:17119256

  14. Simple sequence repeats in Haemophilus influenzae.

    PubMed

    Power, Peter M; Sweetman, W A; Gallacher, N J; Woodhall, M R; Kumar, G A; Moxon, E R; Hood, D W

    2009-03-01

    Simple sequence repeat (SSRs) of DNA are subject to high rates of mutation and are important mediators of adaptation in Haemophilus influenzae. Previous studies of the Rd KW20 genome identified the primacy of tetranucleotide SSRs in mediating phase variation (the rapid reversible switching of gene expression) of surface exposed structures such as lipopolysaccharide. The recent sequencing of the genomes of multiple strains of H. influenzae allowed the comparison of the SSRs (repeat units of one to nine nucleotides in length) in detail across four complete H. influenzae genomes and then comparison with a further 12 genomes when they became available. The SSR loci were broadly classified into three groups: (1) those that did not vary; (2) those for which some variation between strains was observed but this could not be linked to variation of gene expression; and (3) those that both varied and were located in regions consistent with mediating phase variable gene expression. Comparative analysis of 988 SSR associated loci confirmed that tetranucleotide repeats were the major mediators of phase variation and extended the repertoire of known tetranucleotide SSR loci by identifying ten previously uncharacterised tetranucleotide SSR loci with the potential to mediate phase variation which were unequally distributed across the H. influenzae pan-genome. Further, analysis of non-tetranucleotide SSR in the 16 strains revealed a number of mononucleotide, dinucleotide, pentanucleotide, heptanucleotide, and octanucleotide SSRs which were consistent with these tracts mediating phase variation. This study substantiates previous findings as to the important role that tetranucleotide SSRs play in H. influenzae biology. Two Brazilian isolates showed the most variation in their complement of SSRs suggesting the possibility of geographic and phenotypic influences on SSR distribution. PMID:19095084

  15. A Simple Model for Protein Folding

    NASA Astrophysics Data System (ADS)

    Henry, Eric R.; Eaton, William A.

    We describe a simple Ising-like statistical mechanical model for folding proteins based on the α-carbon contact map of the native structure. In this model residues can adopt two microscopic states corresponding to the native and non-native conformations. In order to exactly enumerate the large number of possible configurations, structure is considered to grow as continuous sequences of native residues, with no more than two sequences in each molecule. Inter-residue contacts can only form within each sequence and between residues of the two native sequences. As structure grows there is a tradeoff between the stabilizing effect of inter-residue contacts and the entropy losses from ordering residues in their native conformation and from forming a disordered loop to connect two continuous sequences. Folding kinetics are calculated from the dynamics on the free energy profile, as in Kramers' reaction rate theory. Although non-native interactions responsible for roughness in the energy landscape are not explicitly considered in the model, they are implicitly included by determining the absolute rates for motion on the free energy profile. With the exception of α-helical proteins, the kinetic progress curves exhibit single exponential time courses, consistent with two state behavior, as observed experimentally. The calculated folding rates are in remarkably good agreement with the measured values for the 25 two-state proteins investigated, with a correlation coefficient of 0.8. With its coarse-grained description of both the energy and entropy, and only three independently adjustable parameters, the model may be regarded as the simplest possible analytical model of protein folding capable of predicting experimental properties of specific proteins.

  16. Thermal Forces in Simple and Complex Fluids

    NASA Astrophysics Data System (ADS)

    Piazza, Roberto; Giglio, Marzio

    2004-11-01

    This topical issue of The European Physical Journal E deals with mass transport effects driven by thermal gradients, or, as we shall call them, with “thermal forces”. In simple fluid mixtures, coupling of heat and mass diffusion is due to the Ludwig-Soret effect, also known as thermal diffusion. The Soret effect dramatically lowers the thermal convection threshold, since concentration gradients relax much more slowly than temperature gradients, due to the disparate values of the mass diffusion coefficient and of the thermal diffusivity. Therefore, thermal diffusion plays an important role in naturally occurring processes like thermohaline convection (“salt fingering”) in oceans, crystal growth, component segregation in metallic alloys, volcanic lava and the Earth crust. More recently, its has been shown that thermal diffusion is a very convenient process in the generation of giant non-equilibrium fluctuations in fluid mixtures. Thermophoresis is a closely akin process that takes place both in aerosols and in liquid suspensions, consisting in the drift of dispersed particles induced by thermal inhomogeneities. Thermophoresis of airborne particles has an important role in atmospheric physics and ambient pollution, and can seriously affect semiconductor manufacturing. In macromolecular solutions and colloidal suspensions, these “thermal forces” are generally much stronger than in simple mixtures or in gases: for instance, recent experiments on DNA solutions have shown that thermophoresis may concur with thermal convection in leading to patterns where the local macromolecular concentration is amplified up to a thousandfold. Although known since a long time and clearly framed in terms of non-equilibrium thermodynamics concepts, both the Soret effect and particle thermophoresis in liquids still lack a general microscopic picture. For instance, in most cases the denser component of a binary mixture drifts to the cold, but examples of reverse behaviour are

  17. Simulation Studies of the Vibrational Dynamics of para-HYDROGEN Clusters

    NASA Astrophysics Data System (ADS)

    Faruk, Nabil F.; Yang, Jing; Le Roy, Robert J.; Roy, Pierre-Nicholas

    2011-06-01

    This paper discusses the construction and application of reduced-dimensional potential energy surfaces for use in performing simulation of para-hydrogen clusters. Simple spherical averaging and `adiabatic-hindered-rotor' averaging treatments of the angular degrees of freedom are considered and compared. The resulting one-dimensional surface is used in quantum Monte Carlo simulations of para-hydrogen clusters of varying sizes. Energetic, and structural properties are computed and compared to previously published results, and vibrational frequency shifts are predicted and compared to available experimental measurements. H. Li, P.N. Roy and R.J. Le Roy, J. Chem. Phys. 133, 104305 (2010).

  18. Black Holes Have Simple Feeding Habits

    NASA Astrophysics Data System (ADS)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  19. Black Holes Have Simple Feeding Habits

    NASA Astrophysics Data System (ADS)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  20. A simple and accurate algorithm for path integral molecular dynamics with the Langevin thermostat.

    PubMed

    Liu, Jian; Li, Dezhang; Liu, Xinzijian

    2016-07-14

    We introduce a novel simple algorithm for thermostatting path integral molecular dynamics (PIMD) with the Langevin equation. The staging transformation of path integral beads is employed for demonstration. The optimum friction coefficients for the staging modes in the free particle limit are used for all systems. In comparison to the path integral Langevin equation thermostat, the new algorithm exploits a different order of splitting for the phase space propagator associated to the Langevin equation. While the error analysis is made for both algorithms, they are also employed in the PIMD simulations of three realistic systems (the H2O molecule, liquid para-hydrogen, and liquid water) for comparison. It is shown that the new thermostat increases the time interval of PIMD by a factor of 4-6 or more for achieving the same accuracy. In addition, the supplementary material shows the error analysis made for the algorithms when the normal-mode transformation of path integral beads is used. PMID:27421393

  1. A simple and accurate algorithm for path integral molecular dynamics with the Langevin thermostat

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Li, Dezhang; Liu, Xinzijian

    2016-07-01

    We introduce a novel simple algorithm for thermostatting path integral molecular dynamics (PIMD) with the Langevin equation. The staging transformation of path integral beads is employed for demonstration. The optimum friction coefficients for the staging modes in the free particle limit are used for all systems. In comparison to the path integral Langevin equation thermostat, the new algorithm exploits a different order of splitting for the phase space propagator associated to the Langevin equation. While the error analysis is made for both algorithms, they are also employed in the PIMD simulations of three realistic systems (the H2O molecule, liquid para-hydrogen, and liquid water) for comparison. It is shown that the new thermostat increases the time interval of PIMD by a factor of 4-6 or more for achieving the same accuracy. In addition, the supplementary material shows the error analysis made for the algorithms when the normal-mode transformation of path integral beads is used.

  2. Modelo Crosscultural de Pasantias para Lideres de la Educacion: Cooperacion entre Estados Unidos y Venezuela (Designing an Effective School Administrator Internship Program: United States and Venezuela Cooperation).

    ERIC Educational Resources Information Center

    Serafin, Ana Gil; Thompson, Eugene W.

    A model was developed of an internship program designed to give valuable cross-cultural experience to school administrators in training at universities in the United States and Venezuela. A naturalistic approach was used to develop the model. Leading school administrators and educational leadership theorists in both countries were interviewed by…

  3. Un modelo para el control de calidad academica de los textos de instruccion a distancia (A Model for Controlling the Academic Quality of Distance Education Texts).

    ERIC Educational Resources Information Center

    Bolanos-Mora, Guiselle; And Others

    1992-01-01

    In response to the need for a system of control over the academic quality of distance education texts, this article proposes a methodological model based on criteria that evaluate written materials based on their instructional quality, design, and production. A discussion and figures evaluate educational aspects of content, communication,…

  4. Un Modelo Basico de Instruccion Directa Para la Ensenanza de la Metodologia de la Investigacion (Using the Basic Direct Model of Instruction To Teach an Introductory Research Model).

    ERIC Educational Resources Information Center

    Serafin, Ana Gil

    This study examined the application of the Basic Direct Instruction Model (BDIM), a methodology designed to maximize student interest in instrumental and methodological courses, to graduate level educational leadership students. The research used qualitative techniques and a participatory approach with a sample of 92 beginning level Masters…

  5. Resazurin Microtiter Assay Plate Testing of Mycobacterium tuberculosis Susceptibilities to Second-Line Drugs: Rapid, Simple, and Inexpensive Method

    PubMed Central

    Martin, Anandi; Camacho, Mirtha; Portaels, Françoise; Palomino, Juan Carlos

    2003-01-01

    The emergence of multidrug-resistant tuberculosis calls for new, rapid drug susceptibility tests. We have tested 150 Mycobacterium tuberculosis isolates against the second-line drugs ethionamide, kanamycin, capreomycin, ofloxacin, and para-aminosalicylic acid by the colorimetric resazurin microtiter assay and the proportion method. By visual reading, MICs were obtained after 8 days. A very good correlation between results by the colorimetric resazurin microtiter assay and the proportion method was obtained. The colorimetric resazurin microtiter assay is inexpensive, rapid, and simple to perform, and implementation of the assay is feasible for low-resource countries. PMID:14576129

  6. No Generalization of Practice for Nonzero Simple Addition

    ERIC Educational Resources Information Center

    Campbell, Jamie I. D.; Beech, Leah C.

    2014-01-01

    Several types of converging evidence have suggested recently that skilled adults solve very simple addition problems (e.g., 2 + 1, 4 + 2) using a fast, unconscious counting algorithm. These results stand in opposition to the long-held assumption in the cognitive arithmetic literature that such simple addition problems normally are solved by fact…

  7. Operator Priming and Generalization of Practice in Adults' Simple Arithmetic

    ERIC Educational Resources Information Center

    Chen, Yalin; Campbell, Jamie I. D.

    2016-01-01

    There is a renewed debate about whether educated adults solve simple addition problems (e.g., 2 + 3) by direct fact retrieval or by fast, automatic counting-based procedures. Recent research testing adults' simple addition and multiplication showed that a 150-ms preview of the operator (+ or ×) facilitated addition, but not multiplication,…

  8. Palladium-catalyzed arylation of simple arenes with iodonium salts.

    PubMed

    Storr, Thomas E; Greaney, Michael F

    2013-03-15

    The development of an arylation protocol for simple arenes with diaryliodonium salts using the Herrmann-Beller palladacycle catalyst is reported. The reaction takes simple aromatic feedstocks and creates valuable biaryls for use in all sectors of the chemical industry. PMID:23461706

  9. Vector Majorization Technique for Rotation to a Specified Simple Structure.

    ERIC Educational Resources Information Center

    Trendafilov, Nickolay T.

    In the technique developed by K. G. Joreskog to solve the problem for oblique rotation to a specified simple structure, the basic concept is that the simple structure solution itself is determined only by the zero coefficients of the reference-structure matrix and not by the coefficients of non-zero magnitude. Following this, prior information…

  10. 10 CFR 436.23 - Estimated simple payback time.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Estimated simple payback time. 436.23 Section 436.23 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The...

  11. Haptics-Augmented Simple-Machine Educational Tools.

    ERIC Educational Resources Information Center

    Williams, Robert L., II; Chen, Meng-Yun; Seaton, Jeffrey M.

    2003-01-01

    Describes a unique project using commercial haptic interfaces to augment the teaching of simple machines in elementary school. Suggests that the use of haptics in virtual simple-machine simulations has the potential for deeper, more engaging learning. (Contains 13 references.) (Author/YDS)

  12. Learn about Physical Science: Simple Machines. [CD-ROM].

    ERIC Educational Resources Information Center

    2000

    This CD-ROM, designed for students in grades K-2, explores the world of simple machines. It allows students to delve into the mechanical world and learn the ways in which simple machines make work easier. Animated demonstrations are provided of the lever, pulley, wheel, screw, wedge, and inclined plane. Activities include practical matching and…

  13. Early Prediction of Reading Comprehension within the Simple View Framework

    ERIC Educational Resources Information Center

    Catts, Hugh W.; Herrera, Sarah; Nielsen, Diane Corcoran; Bridges, Mindy Sittner

    2015-01-01

    The simple view of reading proposes that reading comprehension is the product of word reading and language comprehension. In this study, we used the simple view framework to examine the early prediction of reading comprehension abilities. Using multiple measures for all constructs, we assessed word reading precursors (i.e., letter knowledge,…

  14. Misconceptions of Mexican Teachers in the Solution of Simple Pendulum

    ERIC Educational Resources Information Center

    Garcia Trujillo, Luis Antonio; Ramirez Díaz, Mario H.; Rodriguez Castillo, Mario

    2013-01-01

    Solving the position of a simple pendulum at any time is apparently one of the most simple and basic problems to solve in high school and college physics courses. However, because of this apparent simplicity, teachers and physics texts often assume that the solution is immediate without pausing to reflect on the problem formulation or verifying…

  15. 10 CFR 436.23 - Estimated simple payback time.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy...

  16. 10 CFR 436.23 - Estimated simple payback time.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy...

  17. 12 CFR 3.152 - Simple risk weight approach (SRWA).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Simple risk weight approach (SRWA). 3.152... STANDARDS Risk-Weighted Assets-Internal Ratings-Based and Advanced Measurement Approaches Risk-Weighted Assets for Equity Exposures § 3.152 Simple risk weight approach (SRWA). (a) General. Under the SRWA,...

  18. 10 CFR 436.23 - Estimated simple payback time.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Estimated simple payback time. 436.23 Section 436.23 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The...

  19. CMOS Active-Pixel Image Sensor With Simple Floating Gates

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R.; Nakamura, Junichi; Kemeny, Sabrina E.

    1996-01-01

    Experimental complementary metal-oxide/semiconductor (CMOS) active-pixel image sensor integrated circuit features simple floating-gate structure, with metal-oxide/semiconductor field-effect transistor (MOSFET) as active circuit element in each pixel. Provides flexibility of readout modes, no kTC noise, and relatively simple structure suitable for high-density arrays. Features desirable for "smart sensor" applications.

  20. A Simple Laboratory Exercise Illustrating Active Transport in Yeast Cells.

    ERIC Educational Resources Information Center

    Stambuk, Boris U.

    2000-01-01

    Describes a simple laboratory activity illustrating the chemiosmotic principles of active transport in yeast cells. Demonstrates the energy coupling mechanism of active a-glucoside uptake by Saccaromyces cerevisiae cells with a colorimetric transport assay using very simple equipment. (Contains 22 references.) (Author/YDS)

  1. Using "Tracker" to Prove the Simple Harmonic Motion Equation

    ERIC Educational Resources Information Center

    Kinchin, John

    2016-01-01

    Simple harmonic motion (SHM) is a common topic for many students to study. Using the free, though versatile, motion tracking software; "Tracker", we can extend the students experience and show that the general equation for SHM does lead to the correct period of a simple pendulum.

  2. Using Tracker to prove the simple harmonic motion equation

    NASA Astrophysics Data System (ADS)

    Kinchin, John

    2016-09-01

    Simple harmonic motion (SHM) is a common topic for many students to study. Using the free, though versatile, motion tracking software; Tracker, we can extend the students experience and show that the general equation for SHM does lead to the correct period of a simple pendulum.

  3. Simple Sequence Repeats in Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simple sequence repeat length polymorphisms were utilized to examine genetic relatedness among accessions of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai). A size-fractionated TaqI genomic library was screened for the occurrence of dimer and trimer simple sequence repeats (SSRs). A total o...

  4. Secondary School Students' Misconceptions about Simple Electric Circuits

    ERIC Educational Resources Information Center

    Küçüközer, Hüseyin; Kocakülah, Sabri

    2007-01-01

    The aim of this study is to reveal secondary school students' misconceptions about simple electric circuits and to define whether specific misconceptions peculiar to Turkish students exist within those identified. Data were obtained with a conceptual understanding test for simple electric circuits and semi-structured interviews. Conceptual…

  5. Item Selection, Evaluation, and Simple Structure in Personality Data

    PubMed Central

    Pettersson, Erik; Turkheimer, Eric

    2010-01-01

    We report an investigation of the genesis and interpretation of simple structure in personality data using two very different self-reported data sets. The first consists of a set of relatively unselected lexical descriptors, whereas the second is based on responses to a carefully constructed instrument. In both data sets, we explore the degree of simple structure by comparing factor solutions to solutions from simulated data constructed to have either strong or weak simple structure. The analysis demonstrates that there is little evidence of simple structure in the unselected items, and a moderate degree among the selected items. In both instruments, however, much of the simple structure that could be observed originated in a strong dimension of positive vs. negative evaluation. PMID:20694168

  6. Petrology and provenance of the Modelo Formation, Santa Monica Mountains, southern California: Constraints on displacement along the San Gabriel fault

    SciTech Connect

    Rumelhart, P.E.; Ingersoll, R.V. . Dept. of Earth and Space Sciences)

    1993-04-01

    The Modelo Formation of the central and eastern Santa Monica Mountains is an Upper Miocene siliceous-diatomaceous shale and sandstone submarine-fan sequence, which was deposited in the northern Los Angeles basin. The graded, poorly sorted, and angular sandstones comprise channelized mid-fan facies deposited at middle-to-upper-bathyal depths; they are arkosic (58% feldspar) with variable amounts of matrix. Published paleocurrent data yield a south-southwest flow direction. The direction of the paleocurrents constrains the timing of deposition to be after rotation of the Transverse Ranges (after 15 Ma.) Biostratigraphic data indicate that deposition commenced during the Late Mohnian (after 10.8 Ma). QFL plots indicate that the provenance was basement uplift to transitional arc (e.g. Dickinson, 1985). The meta-igneous lithic fragments and the high feldspar content of the rocks suggest an anorthositic, gneissic, tonalitic, or mylonitic source terrane. Sandstone modes and conglomerate clasts indicate that the basal section was derived locally from the Santa Monica Slate. The upper section represents a volcanic unroofing sequence, as evidenced by decreasing volcanic lithic fragments upsection. Crowell (1982) suggested 60 km of right slip on the San Gabriel fault between 12 and 5 Ma. Palinspastic restoration places the Santa Monica Mountains immediately south of the San Gabriel Mountains, which wee the likely source for Modelo sandstones. Based on plagioclase composition (95% oligoclase and albite) of Modelo sandstone, the anorthosite body in the western San Gabriel Mountains is an unlikely source. However, a source in the mylonitic, gneissic, and tonalitic bodies of the eastern San Gabriel Mountains could explain the observed petrography. This source for the Modelo is consistent with 60 km of movement on the San Gabriel fault.

  7. Desarrollo curricular, conciencia ambiental y tecnologia para estudiantes de intermedia: Una investigacion en accion

    NASA Astrophysics Data System (ADS)

    Rodriguez Ramos, Teresita

    Se llevó a cabo una investigación en acción con los propósitos de 1) documentar las relaciones de las tecnologías de la información y la comunicación en las clases de ciencias de escuela intermedia como elemento de apoyo cuando se aborda el tema ambiental y sus conceptos pertinentes, a partir de las observaciones de la investigadora, así como las entrevistas y diarios reflexivos de los estudiantes de una escuela intermedia en la zona metropolitana, y luego 2) diseñar una unidad instruccional sobre el tema ambiental que integre actividades tecnologías para el curso de ciencias de la escuela intermedia según el modelo PROCIC y las observaciones que hayan iniciado los estudiantes participantes. Finalmente, se plantearon las implicaciones educativas para el currículo del Programa de Ciencias al instrumentar este modelo de unidad mediante PROCIC, e integrado la tecnología y el tema ambiental. Los hallazgos se analizaron y se categorizaron de acuerdo con las preguntas de investigación. El hallazgo principal de la investigación aborda las cuatro relaciones centrales en las que se articula la utilización de las tecnologías y sus aplicaciones en la clase de ciencias. Estas cuatro relaciones que recogen la posición de los estudiantes son: 1) Perspectiva de los estudiantes hacia la tecnología. 2) Participación de los estudiantes en los aspectos docentes. 3) Aprendizaje estudiantil sobre el ambiente, y 4) Conciencia ambiental en relación con la vida diaria. Estas relaciones ponen de manifiesto,cómo se plantea en las implicaciones, la necesidad de más investigación en acción en la sala de clases, la importancia—como tema transversal—de la conciencia ambiental mediante la tecnología al construir conocimientos significativos dentro y fuera de la escuela, asó como, valorar la investigación y la dialogicidad en la sala de clases como actividades que obligan al reexamen de la práctica didáctica en su formas curriculares de objetivos, recursos

  8. Nonequilibrium Green's functions and atom-surface dynamics: Simple views from a simple model system

    NASA Astrophysics Data System (ADS)

    Boström, E.; Hopjan, M.; Kartsev, A.; Verdozzi, C.; Almbladh, C.-O.

    2016-03-01

    We employ Non-equilibrium Green's functions (NEGF) to describe the real-time dynamics of an adsorbate-surface model system exposed to ultrafast laser pulses. For a finite number of electronic orbitals, the system is solved exactly and within different levels of approximation. Specifically i) the full exact quantum mechanical solution for electron and nuclear degrees of freedom is used to benchmark ii) the Ehrenfest approximation (EA) for the nuclei, with the electron dynamics still treated exactly. Then, using the EA, electronic correlations are treated with NEGF within iii) 2nd Born and with iv) a recently introduced hybrid scheme, which mixes 2nd Born self-energies with non-perturbative, local exchange- correlation potentials of Density Functional Theory (DFT). Finally, the effect of a semi-infinite substrate is considered: we observe that a macroscopic number of de-excitation channels can hinder desorption. While very preliminary in character and based on a simple and rather specific model system, our results clearly illustrate the large potential of NEGF to investigate atomic desorption, and more generally, the non equilibrium dynamics of material surfaces subject to ultrafast laser fields.

  9. Development of simple sequence repeat markers in cymbopogon species.

    PubMed

    Kumar, Jitendra; Verma, Vijeshwar; Shahi, Ashok Kumar; Qazi, Gulam Nab; Balyan, Harindra Singh

    2007-03-01

    The genus Cymbopogon comprises about 140 species, which produce characteristic aromatic essential oils. However, the phenotypic identification of species of Cymbopogon has been difficult as a result of widespread occurrence of natural variants, which differ in ploidy levels and chemotaxonomic complexities. Therefore, we have developed a set of simple sequence repeat markers from a genomic library of Cymbopogon jwarancusa to help in the precise identification of the species (including accessions) of Cymbopogon. For this purpose, we isolated 16 simple sequence repeat containing genomic deoxyribonucleic acid clones of C. jwarancusa, which contained a total of 32 simple sequence repeats with a range of 1 to 3 simple sequence repeats per clone. The majority (68.8%) of the 32 simple sequence repeats comprised dinucleotide repeat motifs followed by simple sequence repeats with trinucleotide (21.8%) and other higher order repeat motifs. Eighteen (81.8%) of the 22 designed primers for the above simple sequence repeats amplified products of expected sizes, when tried with genomic DNA of C. jwarancusa, the source species. Thirteen (72.2%) of the 18 functional primers detected polymorphism among the three species of Cymbopogon (C. flexuosus, C. pendulus and C. jwarancusa) and amplified a total of 95 alleles (range 1-18 alleles) with a PIC value of 0.44 to 0.96 per simple sequence repeat. Thus, the higher allelic range and high level of polymorphism demonstrated by the newly developed simple sequence repeat markers are likely to have many applications such as in improvement of essential oil quality by authentication of Cymbopogon species and varieties and mapping or tagging the genes controlling agronomically important traits of essential oils, which can further be utilized in marker assisted breeding. PMID:17318781

  10. Early occipital injury affects numerosity counting but not simple arithmetic.

    PubMed

    Zhang, Han; Chen, Chuansheng; Sun, Zhaohui; Lin, Jiuluan; Zhou, Wenjing; Zhou, Xinlin

    2016-01-01

    This study investigated the effects of early occipital injury on the development of counting and simple arithmetic abilities in an occipital epileptic patient. This patient had obvious softening lesions in the bilateral occipital regions due to viral encephalitis at the age of 1.5 years. Results showed that she could perform subitizing and simple arithmetic very well, but could not perform numerosity counting tasks. These results suggest that the occipital cortex plays an important role in the development of numerosity counting skills, but not in the development of subitizing and simple arithmetic. PMID:25771703

  11. Generalized Lotka—Volterra systems connected with simple Lie algebras

    NASA Astrophysics Data System (ADS)

    Charalambides, Stelios A.; Damianou, Pantelis A.; Evripidou, Charalambos A.

    2015-06-01

    We devise a new method for producing Hamiltonian systems by constructing the corresponding Lax pairs. This is achieved by considering a larger subset of the positive roots than the simple roots of the root system of a simple Lie algebra. We classify all subsets of the positive roots of the root system of type An for which the corresponding Hamiltonian systems are transformed, via a simple change of variables, to Lotka-Volterra systems. For some special cases of subsets of the positive roots of the root system of type An, we produce new integrable Hamiltonian systems.

  12. Lateral Magnification-Angular Magnification Relationship for a Simple Magnifier.

    ERIC Educational Resources Information Center

    Keating, Michael P.

    1980-01-01

    Discusses the lateral magnification-angular magnification relationship in the case of a simple magnifying lens. This discussion intends to show how the relationship can be treated in undergraduate optics courses as well as in many general physics courses. (HM)

  13. Creating Simple Windchill Admin Tools Using Info*Engine

    NASA Technical Reports Server (NTRS)

    Jones, Corey; Kapatos, Dennis; Skradski, Cory

    2012-01-01

    Being a Windchill administrator often requires performing simple yet repetitive tasks on large sets of objects. These can include renaming, deleting, checking in, undoing checkout, and much more. This is especially true during a migration. Fortunately, PTC has provided a simple way to dynamically interact with Windchill using Info*Engine. This presentation will describe how to create simple Info*Engine tasks capable of saving Windchill 10.0 administrators hours of tedious work. It will also show how these tasks can be combined and displayed on a simple JSP page that acts as a "Windchill Administrator Dashboard/Toolbox". The attendee will learn some valuable tasks Info*Engine capable of performing. The attendee will gain a basic understanding of how to perform and implement Info*Engine tasks. The attendee will learn what's involved in creating a JSP page that displays Info*Engine tasks

  14. Effectiveness of Simple Individual Psychoeducation for Bipolar II Disorder

    PubMed Central

    Tsujimoto, Emi; Taketani, Reiko; Yamamoto, Ami

    2016-01-01

    Several studies have proven the effectiveness of psychoeducation in bipolar II disorder patients; however, simpler psychoeducation is needed in daily medical practice. Therefore, we devised a simple individual psychoeducation program, which involved 20-minute sessions spent reading a textbook aloud in the waiting time before examination. Here, we report a successful case of simple individual psychoeducation with a patient with bipolar II disorder, a 64-year-old woman who had misconceptions surrounding her mood due to 24 years of treatment for depression. Her perception of mood state, particularly mixed state, was dramatically changed, and her quality of life was improved after the simple individual psychoeducation. This case suggests that the simple individual psychoeducation could be effective for bipolar II disorder by improving understanding of the disease and by meeting different individual needs. PMID:27559486

  15. Lightweight simulation of air traffic control using simple temporal networks

    NASA Technical Reports Server (NTRS)

    Knight, Russell

    2005-01-01

    We provide a formulation of the air traffic control problem and a solver for this problem that makes use of temporal constraint networks and simple geometric reasoning. We provide results showing that this approach is practical for realistic simulated problems.

  16. A Simple Parallel Photochemical Reactor for Photodecomposition Studies

    ERIC Educational Resources Information Center

    Xiaobo Chen; Halasz, Sarah M.; Giles, Eric C.; Mankus, Jessica V.; Johnson, Joseph C.; Burda, Clemens

    2006-01-01

    A simple and useful parallel photochemical reactor intended to study the photodecomposition of dyes using semiconductor photocatalysis is presented. The photochemical reactions are followed through time-dependent changes in the ground-state absorption spectra of the dyes.

  17. Describing Simple Data Access Services Version 1.0

    NASA Astrophysics Data System (ADS)

    Plante, Raymond; Delago, Jesus; Harrison, Paul; Tody, Doug; IVOA Registry Working Group; Plante, Raymond

    2013-11-01

    An application that queries or consumes descriptions of VO resources must be able to recognize a resource's support for standard IVOA protocols. This specification describes how to describe a service that supports any of the four fundamental data access protocols Simple Cone Search (SCS), Simple Image Access (SIA), Simple Spectral Access (SSA), Simple Line Access (SLA) using the VOResource XML encoding standard. A key part of this specification is the set of VOResource XML extension schemas that define new metadata that are specific to those protocols. This document describes in particular rules for describing such services within the context of IVOA Registries and data discovery as well as the VO Standard Interface (VOSI) and service selfdescription. In particular, this document spells out the essential markup needed to identify support for a standard protocol and the base URL required to access the interface that supports that protocol.

  18. Solvent-Ion Interactions in Salt Water: A Simple Experiment.

    ERIC Educational Resources Information Center

    Willey, Joan D.

    1984-01-01

    Describes a procedurally quick, simple, and inexpensive experiment which illustrates the magnitude and some effects of solvent-ion interactions in aqueous solutions. Theoretical information, procedures, and examples of temperature, volume and hydration number calculations are provided. (JN)

  19. Measured and Modeled Morphometry of Simple Impact Craters

    NASA Astrophysics Data System (ADS)

    Watters, W. A.; Collins, G. S.

    2015-09-01

    We discuss the measured diameter dependence of well-preserved simple crater morphometry on Mars and compare with iSALE simulations. We also describe future work to fully characterize the dependence on impactor velocity and mass, and target properties.

  20. SIMPLE-icity in Direct Dark Matter Searches

    SciTech Connect

    Giuliani, F.; Morlat, T.; Ramos, A. R.; Girard, T. A.; Felizardo da Costa, M.; Marques, J. G.; Martins, R. C.; Miley, Harry S.; Limagne, D.; Waysand, G.

    2007-11-01

    SIMPLE is the European WIMP search based on Superheated Droplet Detectors (SDDs). An SDD consists of an emulsion of metastable liquid droplets in an organic gel, each of which operates on the same principle of the bubble chamber.

  1. A Simple Experimental Demonstration of Microbial Growth and Interaction.

    ERIC Educational Resources Information Center

    Wainwright, Milton

    1988-01-01

    Described is a simple, safe, and inexpensive experiment which allows secondary school pupils to observe how fungi and bacteria grow and interact with each other. Included are discussions of materials, methods, observations, and a historical comment. (Author/CW)

  2. The Training Wheel. A Simple Model for Instructional Design.

    ERIC Educational Resources Information Center

    Rogoff, Rosalind L.

    1984-01-01

    The author developed an instructional-design model consisting of four simple steps. The model is in a circular format, rather than the usual linear series form, so it is named the training wheel. (SSH)

  3. Liquid Crystal Displays: A Motivator for Some Simple Investigations.

    ERIC Educational Resources Information Center

    Selkirk, Keith

    1980-01-01

    The format of digits in liquid crystal displays (LCDs) on calculators and watches can motivate some simple investigations appropriate for school mathematics. Several sample problems or investigations are provided. (MK)

  4. Simple Experiments on the Use of Solar Energy

    ERIC Educational Resources Information Center

    Vella, G. J.; Goldsmid, H. J.

    1976-01-01

    Describes 5 solar energy experiments that can be used in secondary school: flat-plate collector, solar thermoelectric generator, simple concentrators, solar cell, and natural storage of solar energy. (MLH)

  5. Highly Informative Simple Sequence Repeat (SSR) Markers for Fingerprinting Hazelnut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simple sequence repeat (SSR) or microsatellite markers have many applications in breeding and genetic studies of plants, including fingerprinting of cultivars and investigations of genetic diversity, and therefore provide information for better management of germplasm collections. They are repeatab...

  6. Educational Materials Development in Primary Science: Simple Machines

    ERIC Educational Resources Information Center

    Franks, Frank L.; Butterfield, Lawrence H., Jr.

    1977-01-01

    Evaluated was the ability of 27 legally blind elementary students to identify and manipulate the parts of the following adapted simple machines: lever, inclined plane, wheel and axle, and pulley. (SBH)

  7. A VBA-based Simulation for Teaching Simple Linear Regression

    ERIC Educational Resources Information Center

    Jones, Gregory Todd; Hagtvedt, Reidar; Jones, Kari

    2004-01-01

    In spite of the name, simple linear regression presents a number of conceptual difficulties, particularly for introductory students. This article describes a simulation tool that provides a hands-on method for illuminating the relationship between parameters and sample statistics.

  8. Simple Steps Can Ease Care of Loved One with Alzheimer's

    MedlinePlus

    ... Steps Can Ease Care of Loved One With Alzheimer's Limit their choices and distractions and always keep ... 2016 FRIDAY, March 25, 2016 (HealthDay News) -- As Alzheimer's disease progresses, patients find that simple tasks become ...

  9. Effectiveness of Simple Individual Psychoeducation for Bipolar II Disorder.

    PubMed

    Saito-Tanji, Yuka; Tsujimoto, Emi; Taketani, Reiko; Yamamoto, Ami; Ono, Hisae

    2016-01-01

    Several studies have proven the effectiveness of psychoeducation in bipolar II disorder patients; however, simpler psychoeducation is needed in daily medical practice. Therefore, we devised a simple individual psychoeducation program, which involved 20-minute sessions spent reading a textbook aloud in the waiting time before examination. Here, we report a successful case of simple individual psychoeducation with a patient with bipolar II disorder, a 64-year-old woman who had misconceptions surrounding her mood due to 24 years of treatment for depression. Her perception of mood state, particularly mixed state, was dramatically changed, and her quality of life was improved after the simple individual psychoeducation. This case suggests that the simple individual psychoeducation could be effective for bipolar II disorder by improving understanding of the disease and by meeting different individual needs. PMID:27559486

  10. A Simple Computer Interface To Time Relatively Slow Physical Events.

    ERIC Educational Resources Information Center

    Ocaya, R. O.

    2000-01-01

    Describes a simple computer interface that can be used to make reliable time measurements, such as when timing the swings of a pendulum. Presents a sample experiment involving a form of pendulum known as the compound pendulum. (Author/YDS)

  11. CLOSEUP VIEW OF PORTION OF SIMPLE THROUGH TRUSS SPAN LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CLOSE-UP VIEW OF PORTION OF SIMPLE THROUGH TRUSS SPAN LOOKING UP AND NORTHEAST. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  12. Simple Experiments on the Physics of Vision: The Retina

    ERIC Educational Resources Information Center

    Cortel, Adolf

    2005-01-01

    Many simple experiments can be performed in the classroom to explore the physics of vision. Students can learn of the two types of receptive cells (rods and cones), their distribution on the retina and the existence of the blind spot.

  13. [A simple peritoneovenous shunt in the treatment of chronic ascites].

    PubMed

    Pafko, P; Hladík, P

    2001-02-01

    The authors describe their own initial experience with a peritoneo-venous shunt in otherwise incurable ascites. It is a simple procedure which is more satisfactory than the formerly used technique of implantation of Le Veen's system. PMID:12881921

  14. A Simple Demonstration of High Tc Superconductive Powder.

    ERIC Educational Resources Information Center

    Baker, Roger; Thompson, James C.

    1987-01-01

    Described is a simple demonstration that provides a way to determine if a given sample contains even a small fraction of superconducting material. The repulsion of the powder from a magnetic field is indicative of superconductivity. (RH)

  15. A simple empirical stream flow prediction model for ungauged watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of streamflow is important for estimating groundwater recharge rates, forecasting floods, and designing hydropower structures and irrigation systems. However, many watersheds throughout the developing world remain ungauged. This fact demands a simple hydrological model that requires minima...

  16. Simple Database Construction: Using Local Sources of Data

    ERIC Educational Resources Information Center

    Gerber, D. Timothy; Reineke, David M.

    2005-01-01

    Different simple and inexpensive ways of building a database using common computer software and data from local newspaper are presented. Creating one's own database provides an opportunity to discuss ethical issues in data collection as well as data integrity.

  17. Simple, analytical criteria for the sequencing of distillation columns

    SciTech Connect

    Malone, M.F.; Douglas, J.M.; Glinos, K.; Marquez, F.E.

    1985-04-01

    A quantitative criterion for the selection of simple distillation sequences is derived for ideal mixtures. A simple cost model, along with a short-cut solution of Underwood's equations, gives an analytical form for the total vapor rate, which is the key design variable. The results for column sequencing that are based on the analytical criterion agree well with more exact solutions, but they indicate that in numerous situations the commonly accepted heuristics are incorrect.

  18. Poroelastic Foams for Simple Fabrication of Complex Soft Robots.

    PubMed

    Mac Murray, Benjamin C; An, Xintong; Robinson, Sanlin S; van Meerbeek, Ilse M; O'Brien, Kevin W; Zhao, Huichan; Shepherd, Robert F

    2015-11-01

    Open-celled, elastomeric foams allow the simple design of fully 3D pneumatic soft machines using common forming techniques. This is demonstrated through the fabrication of simple actuators and an entirely soft, functional fluid pump formed in the shape of the human heart. The device pumps at physiologically relevant frequencies and pressures and attains a flow rate higher than all previously reported soft pumps. PMID:26384472

  19. Simple optical setup implementation for digital Fourier transform holography

    NASA Astrophysics Data System (ADS)

    de Oliveira, G. N.; Rodrigues, D. M. C.; dos Santos, P. A. M.

    2011-01-01

    In the present work a simple implementation of Digital Fourier Transform Holography (DFTH) setup is discussed. This is obtained making a very simple modification in the classical setup arquiteture of the Fourier Transform holography. It is also demonstrated the easy and practical viability of the setup in an interferometric application for mechanical parameters determination. The work is also proposed as an interesting advanced introductory training for graduated students in digital holography.

  20. SIMPLE Imaging and Mosaicking PipeLinE

    NASA Astrophysics Data System (ADS)

    Wang, W.-H.

    2010-12-01

    The SIMPLE Imaging and Mosaicking PipeLinE (SIMPLE) is an Interactive Data Language based data reduction environment designed for processing optical and near-IR data obtained from wide-field mosaic cameras. It has standard functions for flat fielding, sky subtraction, distortion correction, and photometric and astrometric calibrations. One of the key features of SIMPLE is the ability to correct for image distortion from a set of dithered exposures without relying on any external information (e.g., distortion function of the optics, or an external astrometric catalog). This is achieved by deriving the first-order derivatives of the distortion function directly out of the dithered images. This greatly help to produce accurate astrometry as well as to preserve image sharpness in the mosaicked/stacked image. Although SIMPLE is designed toward a general reduction environment, the current distribution of SIMPLE has two highly optimized packages, one for the Wide-field InfraRed Camera on the Canada-France-Hawaii Telescope and the other for the Multi-Object InfraRed Camera and Spectrograph on the Subaru Telescope. Future SIMPLE distributions will include more optimized reduction packages for different instruments.

  1. The Edge-On Perspective of Bulgeless, Simple Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Kautsch, Stefan J.

    2009-12-01

    This review focuses on flat and superthin galaxies. These are edge-on bulgeless galaxies, which are composed of a simple, stellar disk. The properties of these simple disks are at the end of a continuum that extends smoothly from bulge-dominated disk galaxies to the pure disks. On average, simple disks are low-mass galaxies with low surface brightnesses, blue colors, and slow rotational velocities. Widely-accepted cosmological models of galaxy formation and evolution were challenged by a relatively large observed fraction of pure disk galaxies, and only very recent models can explain the existence of simple disk galaxies. This makes simple disks an optimal galaxy type for the study of galaxy formation in a hierarchical universe. They enable us to analyze the environmental and internal influence on galaxy evolution, to study the stability of the disks, and to explain the nature and distribution of dark matter in galaxies. This review summarizes the current status of edge-on simple disk galaxies in the universe.

  2. Modelo Pedagogico de Educacion Primaria para Adultos: Manual para el Asesor de Estudiantes Libres. Primera Parte (A Pedagogical Model for Adult Primary Education: Manual for the Student Advisor. Part One).

    ERIC Educational Resources Information Center

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    This guide, part of a Mexican series of instructional materials, is intended for advisors of students participating in an adult education program offered through public and private organizations in communities in Mexico. The first part of the program comprises Spanish and math; the second, education for family life, education for community life,…

  3. Validation Evidence for the Elementary School Version of the MUSIC® Model of Academic Motivation Inventory (Pruebas de validación para el Modelo MUSIC® de Inventario de Motivación Educativa para Escuela Primaria)

    ERIC Educational Resources Information Center

    Jones, Brett D.; Sigmon, Miranda L.

    2016-01-01

    Introduction: The purpose of our study was to assess whether the Elementary School version of the MUSIC® Model of Academic Motivation Inventory was valid for use with elementary students in classrooms with regular classroom teachers and student teachers enrolled in a university teacher preparation program. Method: The participants included 535…

  4. Functional Expression of Drosophila para Sodium Channels

    PubMed Central

    Warmke, Jeffrey W.; Reenan, Robert A.G.; Wang, Peiyi; Qian, Su; Arena, Joseph P.; Wang, Jixin; Wunderler, Denise; Liu, Ken; Kaczorowski, Gregory J.; Ploeg, Lex H.T. Van der; Ganetzky, Barry; Cohen, Charles J.

    1997-01-01

    The Drosophila para sodium channel α subunit was expressed in Xenopus oocytes alone and in combination with tipE, a putative Drosophila sodium channel accessory subunit. Coexpression of tipE with para results in elevated levels of sodium currents and accelerated current decay. Para/TipE sodium channels have biophysical and pharmacological properties similar to those of native channels. However, the pharmacology of these channels differs from that of vertebrate sodium channels: (a) toxin II from Anemonia sulcata, which slows inactivation, binds to Para and some mammalian sodium channels with similar affinity (Kd ≅ 10 nM), but this toxin causes a 100-fold greater decrease in the rate of inactivation of Para/TipE than of mammalian channels; (b) Para sodium channels are >10-fold more sensitive to block by tetrodotoxin; and (c) modification by the pyrethroid insecticide permethrin is >100-fold more potent for Para than for rat brain type IIA sodium channels. Our results suggest that the selective toxicity of pyrethroid insecticides is due at least in part to the greater affinity of pyrethroids for insect sodium channels than for mammalian sodium channels. PMID:9236205

  5. Um satélite brasileiro para observação do diâmetro solar

    NASA Astrophysics Data System (ADS)

    Emilio, M.; Leister, N. V.; Benevides Soares, P.; Teixeira, R.; Kuhn, J.

    2003-08-01

    Propomos uma missão espacial para medir a forma e o diâmetro solar com o objetivo de ajudar a determinar o potencial gravitacional do Sol e a sua rotação com precisão, testar modelos teóricos de variação de energia e pela primeira vez medir os modos g de oscilação. As observações serão obtidas através do instrumento denominado APT (Astrometric and Photometric Telescope) descrito por Kuhn(1983). A sensibilidade do instrumento é de 0,2 mas em 27 dias para as observações do diâmetro solar feitas a cada minuto. Esta é uma missão de três anos de duração e pode complementar as medidas que serão feitas pelo satélite PICARD (a ser lançado em 2007). Outros parâmetros físicos podem ser obtidos com as mesmas imagens o que certamente interessará à comunidade de física solar. Um primeiro contato foi realizado com a agência espacial brasileira que pretende lançar um satélite científico a cada dois anos.

  6. Simple Reaction Structures in a "complicated" Kinematic Range

    NASA Astrophysics Data System (ADS)

    Arash, Firooz; Moravcsik, Micheal J.; Goldstein, Gary R.

    The energy range between 500 and 1000 MeV is usually considered a "complicated" one for elastic proton-proton scattering in which there is no simple description. It is shown that in that energy range, for much of the angular range, two simple features of the magnitudes and relative phases of the invariant amplitudes in the planar transverse frame give a good approximation of the observed data on unpolarized cross section as well as all the various polarization measurements. The features appear to be particularly pronounced at the larger scattering angles and higher energies, thus suggesting a connection with the small distance part of the internucleon force which thus may shed light on the validity of various quark models. Similar regularities also appear in a similar energy and angular range for pion-nucleon scattering. A simple way is presented on a quark level to summarize these regularities.

  7. Discovering simple DNA sequences by the algorithmic significance method.

    PubMed

    Milosavljević, A; Jurka, J

    1993-08-01

    A new method, 'algorithmic significance', is proposed as a tool for discovery of patterns in DNA sequences. The main idea is that patterns can be discovered by finding ways to encode the observed data concisely. In this sense, the method can be viewed as a formal version of the Occam's Razor principle. In this paper the method is applied to discover significantly simple DNA sequences. We define DNA sequences to be simple if they contain repeated occurrences of certain 'words' and thus can be encoded in a small number of bits. Such definition includes minisatellites and microsatellites. A standard dynamic programming algorithm for data compression is applied to compute the minimal encoding lengths of sequences in linear time. An electronic mail server for identification of simple sequences based on the proposed method has been installed at the Internet address pythia/anl.gov. PMID:8402207

  8. A Simple Case Study of a Grid Performance System

    NASA Technical Reports Server (NTRS)

    Aydt, Ruth; Gunter, Dan; Quesnel, Darcy; Smith, Warren; Taylor, Valerie; Biegel, Bryan (Technical Monitor)

    2001-01-01

    This document presents a simple case study of a Grid performance system based on the Grid Monitoring Architecture (GMA) being developed by the Grid Forum Performance Working Group. It describes how the various system components would interact for a very basic monitoring scenario, and is intended to introduce people to the terminology and concepts presented in greater detail in other Working Group documents. We believe that by focusing on the simple case first, working group members can familiarize themselves with terminology and concepts, and productively join in the ongoing discussions of the group. In addition, prototype implementations of this basic scenario can be built to explore the feasibility of the proposed architecture and to expose possible shortcomings. Once the simple case is understood and agreed upon, complexities can be added incrementally as warranted by cases not addressed in the most basic implementation described here. Following the basic performance monitoring scenario discussion, unresolved issues are introduced for future discussion.

  9. The simple fly larval visual system can process complex images.

    PubMed

    Justice, Elizabeth Daubert; Macedonia, Nicholas James; Hamilton, Catherine; Condron, Barry

    2012-01-01

    Animals that have simple eyes are thought to only detect crude visual detail such as light level. However, predatory insect larvae using a small number of visual inputs seem to distinguish complex image targets. Here we show that Drosophila melanogaster larvae, which have 12 photoreceptor cells per hemisphere, are attracted to distinct motions of other, tethered larvae and that this recognition requires the visual system but not the olfactory system. In addition, attraction to tethered larvae still occurs across a clear plastic barrier, does not occur significantly in the dark and attraction occurs to a computer screen movie of larval motion. By altering the artificial attractant movie, we conclude that visual recognition involves both spatial and temporal components. Our results demonstrate that a simple but experimentally tractable visual system can distinguish complex images and that processing in the relatively large central brain may compensate for the simple input. PMID:23093193

  10. User manual for two simple postscript output FORTRAN plotting routines

    NASA Technical Reports Server (NTRS)

    Nguyen, T. X.

    1991-01-01

    Graphics is one of the important tools in engineering analysis and design. However, plotting routines that generate output on high quality laser printers normally come in graphics packages, which tend to be expensive and system dependent. These factors become important for small computer systems or desktop computers, especially when only some form of a simple plotting routine is sufficient. With the Postscript language becoming popular, there are more and more Postscript laser printers now available. Simple, versatile, low cost plotting routines that can generate output on high quality laser printers are needed and standard FORTRAN language plotting routines using output in Postscript language seems logical. The purpose here is to explain two simple FORTRAN plotting routines that generate output in Postscript language.

  11. Simple Fully Automated Group Classification on Brain fMRI

    SciTech Connect

    Honorio, J.; Goldstein, R.; Honorio, J.; Samaras, D.; Tomasi, D.; Goldstein, R.Z.

    2010-04-14

    We propose a simple, well grounded classification technique which is suited for group classification on brain fMRI data sets that have high dimensionality, small number of subjects, high noise level, high subject variability, imperfect registration and capture subtle cognitive effects. We propose threshold-split region as a new feature selection method and majority voteas the classification technique. Our method does not require a predefined set of regions of interest. We use average acros ssessions, only one feature perexperimental condition, feature independence assumption, and simple classifiers. The seeming counter-intuitive approach of using a simple design is supported by signal processing and statistical theory. Experimental results in two block design data sets that capture brain function under distinct monetary rewards for cocaine addicted and control subjects, show that our method exhibits increased generalization accuracy compared to commonly used feature selection and classification techniques.

  12. Application of simple ramsauer model to neutron total cross sections

    SciTech Connect

    Bauer, R.W.; Anderson, J.D.; Grimes, S.M.; Madsen, V.A.

    1997-04-29

    The simple nuclear Ramsauer model has been used successfully to fit neutron cross sections for three decades, but has not been widely used because the foundations of the model seem to be so unrealistic. We have shown that the Glauber calculations with the inclusion of refraction and optical model calculations essentially validate this simple model for neutron total cross sections in the neutron energy range of 5-50 MeV. This model yields a simple formula for parameterizing the energy dependence of the neutron cross section. We have applied the model to nuclei ranging from vanadium to bismuth. With the addition of a single parameter, we can improve these fits to less than 1.5%.

  13. A Simple Method for Automated Equilibration Detection in Molecular Simulations.

    PubMed

    Chodera, John D

    2016-04-12

    Molecular simulations intended to compute equilibrium properties are often initiated from configurations that are highly atypical of equilibrium samples, a practice which can generate a distinct initial transient in mechanical observables computed from the simulation trajectory. Traditional practice in simulation data analysis recommends this initial portion be discarded to equilibration, but no simple, general, and automated procedure for this process exists. Here, we suggest a conceptually simple automated procedure that does not make strict assumptions about the distribution of the observable of interest in which the equilibration time is chosen to maximize the number of effectively uncorrelated samples in the production timespan used to compute equilibrium averages. We present a simple Python reference implementation of this procedure and demonstrate its utility on typical molecular simulation data. PMID:26771390

  14. Thermal-mechanical response to simple shear extension

    NASA Technical Reports Server (NTRS)

    Furlong, K. P.

    1985-01-01

    The mechanism of extension in the continental crust is apparently much more complex than that acting in the oceanic lithosphere. Recently, Wernicke has proposed that a significant fraction of extension in the continental lithosphere may occur by a simple shear mechanism along discrete fault/shear zones which cut the crust, and perhaps extend into the uppermost mantle. Clearly much of the surface evidence for extension supports this concept, but the depth extent of simple shear extension in the continental crust is unclear. Using numerical simulations, the thermal and associated mechanical behavior of the continental lithosphere in response to lithosphere extension along a low-angle simple shear zone which cuts through the lithospheric plate was determined in order to evaluate the resolving ability of thermal (heat flow and metamorphic P-T-time paths) and elevation observations in constraining the mode of continental extension.

  15. Management of a simple renal cyst in a complex patient

    PubMed Central

    Khan, Mohammad Qasim; Ponor, Ileana Lucia; Ross, Ashley E; Khaliq, Waseem

    2013-01-01

    Renal cysts are generally classified as simple or complex and are further characterised under the Bosniak classification system. Most simple cysts are benign, asymptomatic and discovered incidentally. However, over time, these simple cysts can enlarge, become symptomatic and develop complications, requiring intervention. We present a case of a 70-year-old man with multiple comorbidities who presented with left lower quadrant abdominal pain and haematuria. An abdominal CT scan revealed a large, 26 cm exophytic cyst with high attenuation areas, septations and haemorrhage. Given the patient's tenuous condition and poor functional status, an interventional radiology-guided renal cyst aspiration was performed, resulting in successful reduction of size and symptom resolution. A follow-up ultrasound at 6 months showed no evidence of recurrence. Primary care providers should be aware of the prevalence of renal cysts and their complications, especially haemorrhage, particularly in high risk and elderly patients on anticoagulation or antiplatelet therapy. PMID:23744857

  16. Superlattice band structure: New and simple energy quantification condition

    NASA Astrophysics Data System (ADS)

    Maiz, F.

    2014-10-01

    Assuming an approximated effective mass and using Bastard's boundary conditions, a simple method is used to calculate the subband structure for periodic semiconducting heterostructures. Our method consists to derive and solve the energy quantification condition (EQC), this is a simple real equation, composed of trigonometric and hyperbolic functions, and does not need any programming effort or sophistic machine to solve it. For less than ten wells heterostructures, we have derived and simplified the energy quantification conditions. The subband is build point by point; each point presents an energy level. Our simple energy quantification condition is used to calculate the subband structure of the GaAs/Ga0.5Al0.5As heterostructures, and build its subband point by point for 4 and 20 wells. Our finding shows a good agreement with previously published results.

  17. A Simple and Portable Setup for Thermopower Measurements.

    PubMed

    Mulla, Rafiq; Rabinal, M K

    2016-04-11

    Thermoelectric energy conversion technology has received significant attention because of its promising applications and environmentally clean nature. The innovative design of efficient thermoelectric materials is assisted by simple and reliable techniques for fast and accurate testing. Here, a simple approach for rapid measurement of the Seebeck coefficient is described using commonly available materials based on hot and cold probes; both probes are heated by built-in microheaters. A spring-loaded sample mounting arrangement provides easy sample loading/unloading. The setup is suitable for measurements on a wide range of materials, such as pellets, films, and even soft surfaces without damage. Several known thermoelectric materials, such as alumel, bismuth, and silicon, yielded values close to reported ones. The setup is very compact, simple, fast, low cost, and reliable to develop as a laboratory characterization tool. PMID:26908018

  18. Emulation of MIROC5 with a simple climate model

    NASA Astrophysics Data System (ADS)

    Ishizaki, Yasuhiro; Emori, Seita; Shiogama, Hideo; Takahashi, Kiyoshi; Yokohata, Tokuta; Yoshimori, Masakazu

    2014-05-01

    We developed a simple climate model based on MAGICC6, and investigated the ability of the simple climate model to emulate global mean surface air temperature (SAT) changes of an atmosphere-ocean general circulation model (MIROC5) in the twenty-first century in representative concentration pathways (RCPs). Some previous research indicated that climate sensitivity, ocean vertical diffusion and forcing of anthropogenic aerosols (direct and indirect effects of sulfate aerosol, black carbon and organic carbon) are important factors to emulate global mean SAT changes of atmosphere-ocean general circulation models CMIP3. We therefore estimate these important parameters in the simple climate model using a Metropolis-Hastings Markov chain Monte Carlo (MCMC) approach. The estimated values of the important parameters by the MCMC are physically valid, and our simple climate model can successfully emulate global mean SAT changes of MIROC5 in RCPs with the estimated parameters by the MCMC approach. In addition, we estimated the relative contributions f each important parameter in sensitivity experiments, in which we change the value of an important parameter from the estimated one by the MCMC to the default value of MAGICC6. As a result, we found that the estimation of climate sensitivity is the most important factor for the emulation of the AOGCM, and the stimation of ocean vertical diffusion is also important factor. Although the estimations of the anthropogenic aerosols forcing are very important for the emulation of the AOGCM in the twenty century, the influence of them on the emulation of the AOGCM in the twenty first century is very small. This is because emissions of anthropogenic aerosols are projected to decrease in the twenty first century, and relative contributions of the forcing of anthropogenic aerosols also decrease. Carbon cycle models are not incorporated into our simple climate model yet. A sophisticated carbon cycle model is required to be incorporated into

  19. Laparoscopic extraperitoneal para-aortic lymphadenectomy

    PubMed Central

    Iserte, Pablo Padilla; Minig, Lucas; Zorrero, Cristina

    2015-01-01

    Lymph nodes are the main pathway in the spread of gynaecological malignancies, being a well-known prognostic factor. Lymph node dissection is a complex surgical procedure and requires surgical expertise to perform the procedure, thereby minimising complications. In addition, lymphadenectomy has value in the diagnosis, prognosis, and treatment of patients with gynaecologic cancer. Therefore, a video focused on the para-aortic retroperitoneal anatomy and the surgical technique of the extraperitoneal para-aortic lymphadenectomy is presented. PMID:26435746

  20. Simple and Intuitive Mathematics for Learning Elementary Physics

    NASA Astrophysics Data System (ADS)

    Kobayashi, Yukio

    Mathematics is the language of physics and simple and intuitive mathematics is effective for imaging physical pictures of phenomena. This is important because geometrical viewpoints inspire ideas in physics. For example, some problems on the motion of a particle in a uniform gravitational field can be well illustrated by simple diagrams. Calculus is not only a way of calculating but is also closely related to the law of inertia through slope on a position-time graph. As such, cross-curricular study between mathematics and physics is effective for broadly developing thinking power at the high school and college levels.