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Sample records for frequency variators ahorro

  1. Hydraulic speed variators for electrical energy saving; Variadores de velocidad hidraulicos para el ahorro de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Valera Negrete, Adrian [Programa de Ahorro de Energia del Sector Electrico (PAESE), Mexico, D. F. (Mexico)

    1999-07-01

    This paper shows the characteristics and applications of the hydraulic speed variators, where because of the conditions of the industrial processes it is necessary to vary the operation parameters, obtaining therefore an energy saving besides improving the control of these processes. In addition, the technical and economic evaluation is presented of a project of the Mazatlan Fossil Power Plant, in which it is intended to invest in the installation of a hydraulic speed variator connected to the forced draft fan of unit number three, which operates with an induction motor of 1,865 kW (2,500 H.P.), with a Voltage of 4,180 V at 1,180 rpm. [Spanish] El presente trabajo muestra las caracteristicas y aplicaciones de los variadores de velocidad hidraulicos, donde por las condiciones de los procesos industriales sea necesario variar los parametros de operacion, obteniendose asi un ahorro de energia ademas de mejorar el control de dichos procesos. Se presenta ademas la evaluacion tecnica y economica de un proyecto de la Planta Termoelectrica Mazatlan, en donde se pretende invertir en la instalacion de un variador de velocidad hidraulico acoplado al ventilador de tiro forzado de la unidad numero tres, el cual opera con un motor de induccion de 1,865 kW (2,500 H.P.), con un voltaje de 4,180 V y una velocidad de 1,180 rpm.

  2. Energy saving with speed variators; Ahorro de energia con variadores de velocidad

    Energy Technology Data Exchange (ETDEWEB)

    Dolores Anguiano, Ramses; Dolores Vazquez, Raul [Cementos Cruz Azul, Hidalgo (Mexico)

    2005-07-01

    The cement plant Cruz Azul S.C.L. is located in the center of the Mexican republic at 70 km north of the capital. Nowadays the Direction of Cementos Cruz Azul has implemented measures allowing to reduce their production costs. The optimization department found a great area of opportunity at the ventilators of the plant. The ventilators are used in different stages of the process and their flow was normally controlled by means of dampers -due to the high costs of the initial investment and that of maintenance of the speed variation technology which in its majority used direct current equipments. In this case it existed the possibility of making a successful application in two large ventilators, with motors of 1000 HP fed in medium tension (4160 v) in our calcination unit Num. 8. This document shows the development of this project from its initial analysis to its application and results. [Spanish] La planta de cemento Cruz Azul S.C.L. se encuentra localizada en el centro de la republica mexicana a 70 Km al norte de la capital. En estos momentos la direccion de cementos Cruz Azul ha implementado medidas que permitan reducir sus costos de produccion. El departamento de optimizacion encontro una gran area de oportunidad en los ventiladores de la planta. Los ventiladores son utilizados en distintas etapas del proceso y normalmente su flujo era controlado por medio de mamparas, debido a los altos costos como inversion inicial y de mantenimiento de la tecnologia de variacion de velocidad que en su mayoria utilizaba equipos de corriente directa. Para nuestro caso existia la posibilidad de realizar una aplicacion exitosa en dos ventiladores grandes, con motores de 1000 HP alimentados en media tension (4160 v), en nuestra unidad de calcinacion Num. 8. Este documento muestra el desarrollo de este proyecto desde su analisis inicial hasta su aplicacion y resultados.

  3. Results in energy saving obtained with the application of speed variator in fossil power stations; Resultados de ahorro de energia obtenidos con la aplicacion de variadores de velocidad en centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Merlos Rueda, Rosa Maria [Programa de Ahorro de Energia del Sector Electrico (PAESE), Mexico, D. F. (Mexico)

    1999-07-01

    The project of installation of speed variator in fossil power stations (CT's) of Comision Federal de Electricidad (CFE), as an energy saving measure, is a pilot project that began with the support of the Subdivision de Generacion, and promoted by the Energy Saving Program of the Electric Sector (PAESE), with the putting in operation of an equipment in the condensate pump of the Punta Prieta II C. T. U3. The energy saving observed was substantial, fluctuating between the 19.4% at high loads (at 90% load) and the 71.1% at low loads (at 40% load) of the generating unit. With these results, it was decided to extend the scope of the project with the installation of 6 more equipment for equal number of fossil power stations, located in 4 of the 5 Regions of Generation. The fossil power stations, selected for this stage of the project were: C. T. Felipe Carrillo Puerto U1, C.T. Lerma U4, C.T. Salamanca U1, C.T. Monterrey U6, C.T. Francisco Villa U3 and the C.T. Punta Prieta II-U1. The equipment was in operation during the first quarter of 1998, and the first results indicate an energy savings average per equipment, between 39% and 52%. The recovery of the investment fluctuates between the 48.4% and the 87.6% in less than two years of operation, with which a maximum period of recovery of 3 years is expected. The estimated potential of energy saving, considering the application of these devices in condensate pumps, feedwater pumps (where no speed variator is installed) forced draft fans, induced draft fans and gas recirculation fans, as well as circulation water pumps, of the existing Generating Power stations, ascends to an annual total of 830,000, which represents an approximate 9.4% of the National consumption of self services. [Spanish] El proyecto de instalacion de variadores de velocidad en Centrales Termoelectricas (CT's) de la Comision Federal de Electricidad (CFE), como medida de ahorro de energia, es un proyecto piloto que se inicio con el apoyo de la

  4. Electrical energy saving in motors and frequency variators; Ahorro de energia electrica en motores y variadores de frecuencia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Neri, Roger [Comision Federal de Electricidad (CFE) (Mexico)

    2005-07-01

    The necessity of saving energy is urgent and undeniable. We must already begin with the rational use of energy. Which is obtaining the maximum benefit of the consumed energy and of the necessary facilities for its generation, transmission and use. Guaranteeing at the same time an operation free of interferences or interruptions for the users. The electricity in alternating current does not allow its storage, reason why it is necessary to generate and distribute it at the precise moment when it is required. This forces to determine the proportions of the generation facilities, to be able to feed the periods of maximum demand called {sup p}eaks{sup .} It is this very point where the problem of the inappropriate use of the electrical energy starts. The energy waste is self-evident during the periods of low demand because of the low efficiency of the sub-utilized facilities. Electrical motors of the induction type use approximately more than 60% of the energy in the industry. If we use high efficiency motors instead of standard motors, a better advantage of the energy demanded from Comision Federal de Electricidad (CFE) is obtained. [Spanish] Es impostergable e innegable la necesidad de ahorrar energia. Tenemos que empezar ya con el uso racional de la energia: Obtener el maximo beneficio de la energia consumida y de las instalaciones necesarias para su generacion, transmision y utilizacion. Garantizando a los usuarios un funcionamiento sin interferencias o interrupciones. La electricidad en corriente alterna no permite su almacenamiento, por lo que es necesario generarla y distribuirla en el momento preciso en que es requerida. Esto obliga a dimensionar las instalaciones de generacion, para poder alimentar los periodos de maxima demanda llamados pico. Desde esta parte inicia el problema de la mala utilizacion de la energia electrica. Ya que en los periodos de baja demanda, las instalaciones se encuentran subutilizadas y si su eficiencia es muy baja, el desperdicio de energia es mas que evidente. Aproximadamente mas del 60% de la energia en la industria es utilizada por motores electricos del tipo induccion. Si utilizamos motores de alta eficiencia en lugar de motores estandar, se obtiene un mejor aprovechamiento de la energia demandada a la Comision Federal de Electricidad (CFE)

  5. Variations of the Milankovitch frequencies in time

    Science.gov (United States)

    Loutre, Marie-France; Berger, A.

    1992-01-01

    The sensitivity of the amplitudes and frequencies in the development of the Earth's orbital and rotational elements involved in the astronomical theory of paleoclimates (eccentricity, obliquity, and climate precession), to the Earth-Moon distance and consequently to the length of the day and to the dynamical ellipticity of the Earth has been discussed for the last billions of years. The shortening of the Earth-Moon distance and of the length of the day, as well as the lengthening of the dynamical ellipticity of the Earth back in time induce a shortening of the fundamental astronomical periods for precession and obliquity. At the same time, the amplitudes of the different terms in the development of the obliquity are undergoing a relative enlargement of about 50 percent at 2 x 10(exp 9) yr BP but the independent term is increasing very weakly (less than 0.1 percent). In other words, the value of the obliquity, which lies within a range of 21.7 to 24.9 deg over the Quarternary was restricted to a range of 22.5 to 24.1 deg at 2 x 10(exp 9) yr BP. On the other hand, the amplitudes in the development of the climatic precession do not change. Moreover, these changes in the frequencies and amplitudes for both obliquity and climatic precession are larger for longer period terms. Finally, the periods in the eccentricity development are not influenced by the variation of the lunar distance. But the motion of the solar system, especially of the inner planets, was shown to be chaotic. It means that it is impossible to compute the exact motion of the planets over more than about 100 Myr, and the fundamental frequencies of the systems are not fixed quantities, but are slowly varying with time. As long as we consider the most important terms, the maximum deviation from the present-day value of the 19-kyr precessional period due to the chaotic motion of the solar system only does not reach more than a few tens of years around 80 Myr BP. Therefore the shortening of the obliquity

  6. 46 CFR 111.01-17 - Voltage and frequency variations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Voltage and frequency variations. 111.01-17 Section 111... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-17 Voltage and frequency variations. Unless... and +6 percent to −10 percent of rated voltage. This limitation does not address transient conditions....

  7. Determinantes del ahorro interno: El caso argentino

    OpenAIRE

    Ricardo López-Murphy; Fernando Navajas; Santiago Urbiztondo; Cynthia Moskovitz

    1998-01-01

    Se ha señalado en numerosos debates recientes que el proceso de crecimiento y estabilización macroeconómica iniciado en Argentina a comienzos de los años noventa, vino acompañado por una insuficiencia del ahorro doméstico para financiar el fuerte crecimiento de las inversiones. La contrapartida fue un importante déficit en cuenta corriente y un incremento en el ingreso de capitales hasta 1994. Desde entonces la economía argentina debió ajustarse a las condiciones originadas luego de la devalu...

  8. FINDbase: A worldwide database for genetic variation allele frequencies updated

    NARCIS (Netherlands)

    M. Georgitsi (Marianthi); E. Viennas (Emmanouil); D.I. Antoniou (Dimitris I.); V. Gkantouna (Vassiliki); S. van Baal (Sjozef); E.F. Petricoin (Emanuel F.); K. Poulas (Konstantinos); G. Tzimas (Giannis); G.P. Patrinos (George)

    2011-01-01

    textabstractFrequency of INherited Disorders database (FIND base; http://www.findbase. org) records frequencies of causative genetic variations worldwide. Database records include the population and ethnic group or geographical region, the disorder name and the related gene, accompanied by links to

  9. When Does Frequency-Independent Selection Maintain Genetic Variation?

    Science.gov (United States)

    Novak, Sebastian; Barton, Nicholas H

    2017-10-01

    Frequency-independent selection is generally considered as a force that acts to reduce the genetic variation in evolving populations, yet rigorous arguments for this idea are scarce. When selection fluctuates in time, it is unclear whether frequency-independent selection may maintain genetic polymorphism without invoking additional mechanisms. We show that constant frequency-independent selection with arbitrary epistasis on a well-mixed haploid population eliminates genetic variation if we assume linkage equilibrium between alleles. To this end, we introduce the notion of frequency-independent selection at the level of alleles, which is sufficient to prove our claim and contains the notion of frequency-independent selection on haploids. When selection and recombination are weak but of the same order, there may be strong linkage disequilibrium; numerical calculations show that stable equilibria are highly unlikely. Using the example of a diallelic two-locus model, we then demonstrate that frequency-independent selection that fluctuates in time can maintain stable polymorphism if linkage disequilibrium changes its sign periodically. We put our findings in the context of results from the existing literature and point out those scenarios in which the possible role of frequency-independent selection in maintaining genetic variation remains unclear. Copyright © 2017 by the Genetics Society of America.

  10. Peculiar variations of white dwarf pulsation frequencies and maestro

    Science.gov (United States)

    Dalessio, James Ruland

    In Part I we report on variations of the normal mode frequencies of the pulsating DB white dwarfs EC 20058-5234 and KIC 8626021 and the pulsating DA white dwarf GD 66. The observations of EC 20058-5234 and KIC 8626021 were motivated by the possibility of measuring the plasmon neutrino production rate of a white dwarf, while the observations of GD 66 were part of a white dwarf pulsation timing based planet search. We announce the discovery of periodic and quasi-periodic variations of multiple normal mode frequencies that cannot be due to the presence of planetary companions. We note the possible signature of a planetary companion to EC 20058-5234 and show that GD 66 cannot have a planet in a several AU orbit down to half a Jupiter mass. We also announce the discovery of secular variations of the normal mode frequencies of all three stars that are inconsistent with cooling alone. Importantly, the rates of period change of several modes of KIC 8626021 are consistent with evolutionary cooling, but are not yet statistically significant. These modes offer the best possibility of measuring the neutrino production rate in a white dwarf. We also observe periodic and secular variations in the frequency of a combination mode that exactly matches the variations predicted by the parent modes, strong observational evidence that combination modes are created by the convection zone and are not normal modes. Periodic variations in the amplitudes of many of these modes is also noted. We hypothesize that these frequency variations are caused by complex variations of the magnetic field strength and geometry, analogous to behavior observed in the Sun. In Part II we describe the MAESTRO software framework and the MAESTRO REDUCE algorithm. MAESTRO is a collection of astronomy specific MatLab software developed by the Whole Earth Telescope. REDUCE is an an algorithm that can extract the brightness of stars on a set of CCD images with minimal configuration and human interaction. The key to

  11. Gravitational dynamos and the low-frequency geomagnetic secular variation

    Science.gov (United States)

    Olson, P.

    2007-01-01

    Self-sustaining numerical dynamos are used to infer the sources of low-frequency secular variation of the geomagnetic field. Gravitational dynamo models powered by compositional convection in an electrically conducting, rotating fluid shell exhibit several regimes of magnetic field behavior with an increasing Rayleigh number of the convection, including nearly steady dipoles, chaotic nonreversing dipoles, and chaotic reversing dipoles. The time average dipole strength and dipolarity of the magnetic field decrease, whereas the dipole variability, average dipole tilt angle, and frequency of polarity reversals increase with Rayleigh number. Chaotic gravitational dynamos have large-amplitude dipole secular variation with maximum power at frequencies corresponding to a few cycles per million years on Earth. Their external magnetic field structure, dipole statistics, low-frequency power spectra, and polarity reversal frequency are comparable to the geomagnetic field. The magnetic variability is driven by the Lorentz force and is characterized by an inverse correlation between dynamo magnetic and kinetic energy fluctuations. A constant energy dissipation theory accounts for this inverse energy correlation, which is shown to produce conditions favorable for dipole drift, polarity reversals, and excursions. PMID:18048345

  12. Standardization for electric energy saving; Normalizacion para el ahorro de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Diaz, Arturo [Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE), Mexico, D. F. (Mexico)

    1993-12-31

    This work describes shortly the current legislation on the standardization; as well as the participation of the entities Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE) and Programa de Ahorro de Energia (PAESE) in the consulting committees, for the elaboration of the Mexican official standards focussed to electric power saving. [Espanol] El presente trabajo, describe brevemente la legislacion actual sobre la normalizacion; asi como la participacion de las entidades Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE) y Programa de ahorro de Energia (PAESE) en los comites consultivos, para la elaboracion de normas oficiales mexicanas enfocadas al ahorro de energia electrica.

  13. Factores determinantes del ahorro interno en América Latina

    OpenAIRE

    Carlos Añez; Angel Urbina; Lionar Ojeda

    2002-01-01

    El siguiente artículo aborda el problema del financiamiento de la inversión para un país en desarrollo, específicamente de la América Latina, tratando de revisar la literatura disponible para llegar a conclusiones sobre cómo los determinantes del ahorro en todas sus versiones -ahorro externo, ahorro privado y ahorro público- ejercen influencia sobre el proceso de crecimiento. Aun cuando la dirección causal exacta entre ahorro y crecimiento no ha sido establecida, el desarrollo de ...

  14. EN LAS CAJAS DE AHORROS ESPAÑOLAS

    Directory of Open Access Journals (Sweden)

    Isidoro Guzmán

    2011-01-01

    Full Text Available El rendimiento del sector financiero español ha sido objeto de diversos estudios alo largo del decenio de los novena del sigloXXcomo consecuencia de los impor-tantes cambios a los que ha estado sometido. Las cajas de ahorros españolas nohan sido ajenas a este tipo de estudios, si bien circunscritos de manera exclusiva alexamen de su eficiencia y productividad, relegando a un segundo plano el análisisdel cumplimiento de su fin social, materializado económicamente en el gasto anualdestinado a obra social.En este contexto, la principal aportación de nuestro estudio es la obtención deevidencia empírica de la existencia de una relación de causalidad entre la creaciónde valor social de las cajas de ahorro españolas, medida por medio del estableci-miento de unratiode gasto social, y sus cambios en productividad, cuantificadosmediante el cálculo del índice de productividad de Malmquist basado en el trazadode fronteras eficientes a partir de la técnica no paramétrica del análisis envolvente dedatos (AED (Data Envelopment Analysis,DEA.Para el censo de cajas de ahorro españolas en el periodo 2003-2007, nuestrosresultados revelan que las entidades que presentan mayor productividad alcanzancotas superiores en elratiode gasto social, incluso después de controlar por medi-das tradicionales como la rentabilidad económica y el tamaño.

  15. Investigation of switching frequency variations and EMI properties in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard

    2009-01-01

    for its variation. Knowledge of switching frequency variations is of great importance with respect to electromagnetic interference (EMI). This paper will investigate, whether the switching frequency is depended on modulation index and audio reference frequency. Validation is done using simulations......, and the results are compared with measurements performed on a 50 W prototype amplifier. The switching frequency is tracked through accurate spectrum measurements, and very good compliance with simulation results are observed....

  16. Sensitivity Analysis on Variation of Vane Natural Frequency of a Typical Aero Engine Impeller

    Directory of Open Access Journals (Sweden)

    Selwyn Anbarasan

    2015-08-01

    Full Text Available Centrifugal compressors are widely used in small and medium class turbo shaft and turbo prop aero engines. Inevitably the variation in the manufacturing process will lead to variation in natural frequency of blade vanes in an impeller which usually termed as Mistuning. The variation in natural frequency will increase the forced frequency response of the vanes than the tuned vanes. In-service deterioration of vanes dimension due to erosion, corrosion and FOD also adds to further variation in natural frequency. The amplification factor of the response will lead to reduced HCF life of the vanes than the tuned vanes. It is important for the designer to envisage the variation of natural frequency of the vanes to estimate the life of the impeller to avoid premature failure. This also helps in monitoring the health of the impeller during service. This paper deals with prediction of the effects of manufacturing/geometry variation and variation in material properties on impeller vane natural frequency of a turbo shaft engine. FEM model is created to accommodate the geometry variation of the impeller. The parameters influencing the natural frequency are varied and its corresponding variation in frequency is predicted. Several conditions are also simulated and sensitivity analysis is carried out with the above result to predict the order of influencing parameters. Influencing parameters are ranked and the most influencing parameter is found to be the Young’s Modulus of the material for this case of impeller. Maximum influencing parameter Young’s modulus contributes to 5.8% variation and the least contributing factor density to 0.6% variation in natural frequency. This result enables the designer to forecast the possible range of natural frequencies in the design phase, so that he can limit the analysis to predict the response due to mistuning to the estimated range of frequencies.

  17. Factores determinantes del ahorro interno en América Latina

    Directory of Open Access Journals (Sweden)

    Carlos Añez

    2002-01-01

    Full Text Available El siguiente artículo aborda el problema del financiamiento de la inversión para un país en desarrollo, específicamente de la América Latina, tratando de revisar la literatura disponible para llegar a conclusiones sobre cómo los determinantes del ahorro en todas sus versiones -ahorro externo, ahorro privado y ahorro público- ejercen influencia sobre el proceso de crecimiento. Aun cuando la dirección causal exacta entre ahorro y crecimiento no ha sido establecida, el desarrollo de políticas económicas que estimulen el ahorro interno por encima del procedente del exterior, fortalecerían la capacidad de inversión interna y, al existir una correlación positiva entre estas variables, se potencia el proceso de crecimiento aunque otras variables igualmente pueden difuminar tal efecto. Se concluye que el incremento de la relación Ahorro Interno / P. I. B. sólo puede alcanzarse a través de esfuerzos comunes entre empresas, gobierno y el sistema financiero de estas economías.

  18. Variation in the Input: A Case Study of Manner Class Frequencies

    Science.gov (United States)

    Daland, Robert

    2013-01-01

    What are the sources of variation in the input, and how much do they matter for language acquisition? This study examines frequency variation in manner-of-articulation classes in child and adult input. The null hypothesis is that segmental frequency distributions of language varieties are unigram (modelable by stationary, ergodic processes), and…

  19. LOWL p-mode frequencies and their variation with solar activity

    CERN Document Server

    Jiménez-Reyes, S J; Pallé, P L; Tomczyk, S; Jim\\'enez-Reyes, Sebasti\\'an J.; Corbard, Thierry; Pall\\'e, Pere L.; Tomczyk, Steve

    2000-01-01

    We present an analysis of the frequency shift and the even terms of the frequency splitting coefficients carried out using six years of LOWL data, starting in 1994. The temporal variations, and their dependences with the frequency and degree are addressed. The results are consistent with previous analysis.

  20. ABSORCIÓN DE AHORRO INTERNO POR EL GOBIERNO NACIONAL

    Directory of Open Access Journals (Sweden)

    Álvaro José Pedroza Campo

    2002-01-01

    Full Text Available El gobierno colombiano ha financiado durante los últimos cinco años el déficit fiscal en gran medida con recursos provenientes del ahorro nacional, a través de emisiones de títulos en condiciones de rentabilidad innecesariamente altas, frenando la tendencia de disminución de tasas de interés internas. Adicionalmente, la estructura institucional gubernamental a través de la cual se realiza la colocación primaria y la negociación secundaria de dichos títulos, genera una competencia desigual que desplaza a los demás agentes económicos, especialmente el sector productivo, como captadores de recursos del mercado de capitales para financiar sus negocios. Lo anterior ha ocurrido en un período caracterizado por crisis del sector financiero y recesión económica.

  1. Performance evaluation of Type-3 PLLs under wide variation in input voltage and frequency

    DEFF Research Database (Denmark)

    Aravind, C. K.; Rani, B.Indu; Chakkarapani, M.

    2017-01-01

    This paper presents a detailed analysis of Type-3 PLL under wide variation in input voltage and frequency. Using small signal modeling, the performance of both single loop and dual loop type-3 PLL for variation in input voltage and frequency is studied. The analysis shows that for the same...... bandwidth, both the single loop and dual loop Type-3 PLL exhibit similar dynamics provided the supply voltage is balanced. However, under voltage sag conditions, dual loop PLL shows improved dynamic response without affecting its stability. Further, the tracking time is reduced as the feed forward frequency...... is a function of supply frequency. To improve the filtering characteristics under frequency deviations, a dual loop Type 3 adaptive PLL which accurately tracks the phase and frequency of the input signal under wide frequency deviations is developed. Simulations are carried out in MATLAB and experimentally...

  2. Risk control in energy saving projects; Control de riesgo en los proyectos de ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Evan [Lawrence Berkeley National Laboratory, CA (United States)

    2005-10-15

    Since one of the restrictive problems when investing in energy saving is the uncertainty of obtaining the planed savings, a technique in the risk handling for energy efficiency projects, called Insurance for the Energy Saving (IES) is presented. IES economically stimulates those who implement projects for energy saving so they go beyond the normal measures and really obtain significant saving levels, thus contributing to the fulfillment of national objectives in energy saving. In order to reduce the risk of low performance in energy caused by saving projects there exist the international performance measurement and the protocol of investment (IMPVP) as well as diagnoses and starting processes, whereas in order to transfer the financial risk that a saving project represents, mechanisms such as FDIC insurance, conversion of the debt in values, Saving's Guarantees, Performance Bonuses or Guarantee Bonuses and Insurances for Energy Saving can be of great help. This article deals on the IES insurance policies, their loss control management, successful cases, benefits, particular advantages, place in the market and refers argued insurance exceptions and perception surveys. [Spanish] Dado que uno de los problemas restrictivos a la hora de invertir en el ahorro de energia es la incertidumbre de obtener los ahorros proyectados, se presenta una tecnica en el manejo del riesgo para proyectos de eficiencia energetica llamada Seguro para el Ahorro de Energia (SAE). SAE estimula financieramente a quienes implementan proyectos para el ahorro de energia con el fin de que vayan mas alla de las medidas normales y consigan niveles significativos de ahorro, contribuyendo asi al cumplimiento de objetivos nacionales de ahorro energetico. Para reducir el riesgo de bajo desempeno de energia provocados por proyectos de ahorro existe la medicion del desempeno internacional y el protocolo de inversion (IMPVP) asi como diagnosticos y procesos de arranque, mientras que para transferir el

  3. Diferencias de género en los factores asociados al ahorro de los hogares en México

    OpenAIRE

    Isalia Nava Bolaños; Flor Brown Grossman; Lilia Domínguez Villalobos

    2014-01-01

    A diferencia de los trabajos que analizan el ahorro suponiendo un hogar unitario, esta investigación se centra en las diferencias en las decisiones de ahorro de los hogares con jefaturas femenina y masculina en México. Los resultados del modelo Tobit muestran que los factores que afectan al ahorro son distintos entre ellos. La escolaridad (primaria y secundaria) y los apoyos gubernamentales no inciden en las tasas de ahorro de las jefaturas masculinas, pero sí en las femeninas. Se confirma la...

  4. Radial variation of refractive index, plasma frequency and phase velocity in laser induced air plasma

    CSIR Research Space (South Africa)

    Mathuthu, M

    2006-12-01

    Full Text Available induced air plasma to study the spatial variation of plasma parameters in the axial direction of the laser beam. In this paper, the authors report investigation on the radial variation of the refractive index, plasma frequency, and phase velocity of a...

  5. Time Delay Circuits: A Quality Criterion for Delay Variations versus Frequency

    NARCIS (Netherlands)

    Garakoui, Seyed Kasra; Klumperink, Eric A.M.; Nauta, Bram; Vliet, van Frank E.

    2010-01-01

    This paper shows that the group delay of a delay circuit does not give sufficient information to predict the delay vs. frequency. A new criterion (fϕ=0) is proposed that characterizes the delay variations over a specified frequency range. The mathematical derivation of fϕ=0 for a single delay block

  6. A fast-settling frequency-presetting PLL frequency synthesizer with process variation compensation and spur reduction

    Science.gov (United States)

    Xiaozhou, Yan; Xiaofei, Kuang; Nanjian, Wu

    2009-04-01

    This paper proposes a fast-settling frequency-presetting PLL frequency synthesizer. A mixed-signal VCO and a digital processor are developed to accurately preset the frequency of VCO and greatly reduce the settling time. An auxiliary tuning loop is introduced in order to reduce reference spur caused by leakage current. The digital processor can automatically compensate presetting frequency variation with process and temperature, and control the operation of the auxiliary tuning loop. A 1.2 GHz integer-N synthesizer with 1 MHz reference input was implemented in a 0.18 μm process. The measured results demonstrate that the typical settling time of the synthesizer is less than 3 μs, and the phase noise is -108 dBc/Hz@ 1MHz. The reference spur is -52 dBc.

  7. A fast-settling frequency-presetting PLL frequency synthesizer with process variation compensation and spur reduction

    Institute of Scientific and Technical Information of China (English)

    Yan Xiaozhou; Kuang Xiaofei; Wu Nanjian

    2009-01-01

    This paper proposes a fast-settling frequency-presetting PLL frequency synthesizer.A mixed-signal VCO and a digital processor are developed to accurately preset the frequency of VCO and greatly reduce the settling time.An auxiliary tuning loop is introduced in order to reduce reference spur caused by leakage current.The digital processor can automatically compensate presetting frequency variation with process and temperature,and control the operation of the auxiliary tuning loop.A 1.2 GHz integer-N synthesizer with 1 MHz reference input Was implemented in a 0.18μm process.The measured results demonstrate that the typical settling time of the synthesizer is less than 3μs,and the phase noise is-108 dBc/Hz@1MHz.The reference spur is-52 dBc.

  8. Observational Evidence for Variations of the Acoustic Cutoff Frequency with Height in the Solar Atmosphere

    Science.gov (United States)

    Wiśniewska, A.; Musielak, Z. E.; Staiger, J.; Roth, M.

    2016-03-01

    Direct evidence for the existence of an acoustic cutoff frequency in the solar atmosphere is given by observations performed by using the HELioseismological Large Regions Interferometric DEvice operating on the Vacuum Tower Telescope located on Tenerife. The observational results demonstrate variations of the cutoff with atmospheric heights. The observed variations of the cutoff are compared to theoretical predictions made by using five acoustic cutoff frequencies that have been commonly used in helioseismology and asteroseismology. The comparison shows that none of the theoretical predictions is fully consistent with the observational data. The implication of this finding is far reaching as it urgently requires either major revisions of the existing methods of finding acoustic cutoff frequencies or developing new methods that would much better account for the physical picture underlying the concept of cutoff frequencies in inhomogeneous media.

  9. Cylindrically-bent rectangular patch antennas: novel modeling techniques for resonance frequency variation and uncertainty

    OpenAIRE

    Vallozzi, Luigi; Boeykens, Freek; Rogier, Hendrik

    2015-01-01

    Wearable textile antennas are basic components in body-centric communication systems. Flexible wearable patch antennas, when integrated into a body-worn garment are subjected to bending, causing variation in the resonance frequency when compared to the flat-antenna. Bending conditions vary statistically among different human subjects. Therefore, it is very important to be able to predict performance variations due to bending. We propose novel models which allow to predict the deterministic an...

  10. Interactive applications for energy saving; Aplicaciones interactivas para ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Adame Gonzalez, Alejandro; Ramirez Anaya, Cesar; Gutierrez, Hector; Dominguez Ojeda, Xerxes; Aguilar Galvan, Alfredo [Ingenieria Energetica Integral S. A. de C. V., Mexico, D. F. (Mexico)

    1998-12-31

    A series of ideas are presented that can help in the development of interactive applications for energy saving. Emphasis is made on the Fideicomiso de Apoyo al Programa de Ahorro de Energia (FIDE)`s Interactive Course on Demand Management and Power Factor Compensation, in order to demonstrate how far one can go with the multimedia development. [Espanol] Se presenta un conjunto de ideas que pueden auxiliar en la elaboracion de aplicaciones interactivas para ahorro de energia. Se hace principal enfasis sobre el curso interactivo Administracion de la Demanda y Compensacion del Factor de Potencia del Fideicomiso de Apoyo al Programa de Ahorro de Energia (FIDE) con la finalidad de mostrar hasta donde puede llegarse con un desarrollo multimedia.

  11. Diferencias de género en los factores asociados al ahorro de los hogares en México

    Directory of Open Access Journals (Sweden)

    Isalia Nava Bolaños

    2014-01-01

    Full Text Available A diferencia de los trabajos que analizan el ahorro suponiendo un hogar unitario, esta investigación se centra en las diferencias en las decisiones de ahorro de los hogares con jefaturas femenina y masculina en México. Los resultados del modelo Tobit muestran que los factores que afectan al ahorro son distintos entre ellos. La escolaridad (primaria y secundaria y los apoyos gubernamentales no inciden en las tasas de ahorro de las jefaturas masculinas, pero sí en las femeninas. Se confirma la asociación negativa de las horas dedicadas al trabajo doméstico con la tasa de ahorro en los hogares de jefatura femenina.

  12. Analysis of the variation of Hurricane frequency over Atlantic region during 1851-2010

    Science.gov (United States)

    Banerjee, Dhruba; Bondyopadhaya, Ramaprosad

    Analysis of the variation of Hurricane frequency over Atlantic region during 1851-2010 The variation of number of Hurricane over Atlantic and East Caribbean region during more than 150 years (1851-2010) have been analyzed. The general observations regarding characteristics are (ref{GrindEQ__1_}) the frequency increases monotonically, (ref{GrindEQ__2_}) the monthly variation of the frequencies also exists and the frequency of Hurricanes are much more during August to October, September being the month of maximum hurricane nearly 3.2 per year. Reverse is the situation during December to June. If we note the 30 years variation of Hurricane frequency we find 1941-1970 and 1971-2000 are two spans of years when total Hurricane number over Atlantic region was maximum. When we analyze these rates of increase we find this rate is monotonically increasing from 1851upto1910 but after that it begins to drop slowly. The maximum rate was 1.22 per yr.(roughly).In recent decade during 1971-2010, actually decadal analysis shows that it was less than 10 before1991 but more than 10 after that time and during 2001-10 it was 13.3. Another very important observation is that while the average frequency of hurricane over the period 1851-2010 is 8.8, the average frequency during solar maxima years is 8.3but the said frequency during solar minima is 9.53.This is very significant. Because this implies that solar influence must have negative effect on Hurricane formation. We may note that similar situation prevail for the formation of tropical cyclone like 1957. In fact, in many solar maximum years Hurricane does not form over Atlantic and East Caribbean region. On the contrary many deadliest hurricanes over USA occurred in solar minima years or in the neighborhood. Finally it is outlined the possible mechanism due to which solar activities may decrease the formation of hurricane. It may be worth noting that the nature variation of solar phase/cycle is more predictable than the hurricane

  13. Power-line Interference Removal from ECG in Case of Power-line Frequency Variations

    Directory of Open Access Journals (Sweden)

    Todor Stoyanov

    2008-10-01

    Full Text Available The original version of the most successful approach for power-line (PL interference removal from ECG, called subtraction procedure, is based on linear segment detection in the signal and hardware synchronised analogue-to-digital conversion to cope with the PL frequency variations. However, this is not feasible for battery supplied devices and some computer-aided ECG systems. Recent improvements of the procedure apply software measurement of the frequency variations that allow a re-sampling of the contaminated signal with the rated PL frequency followed by interference removal and back re-sampling for restoration of the original time intervals. This study deals with a more accurate software frequency measurement and introduces a notch filtration as alternative to the procedure when no linear segments are encountered for long time, e.g. in cases of ventricular fibrillation or tachycardia. The result obtained with large PL frequency variations demonstrate very small errors, usually in the range of ± 20 μV for the subtraction procedure and ± 60 μV for the notch filtration, the last values strongly depending on the frequency contents of the QRS complexes.

  14. Formant-frequency variation and its effects on across-formant grouping in speech perception.

    Science.gov (United States)

    Roberts, Brian; Summers, Robert J; Bailey, Peter J

    2013-01-01

    How speech is separated perceptually from other speech remains poorly understood. In a series of experiments, perceptual organisation was probed by presenting three-formant (F1+F2+F3) analogues of target sentences dichotically, together with a competitor for F2 (F2C), or for F2+F3, which listeners must reject to optimise recognition. To control for energetic masking, the competitor was always presented in the opposite ear to the corresponding target formant(s). Sine-wave speech was used initially, and different versions of F2C were derived from F2 using separate manipulations of its amplitude and frequency contours. F2Cs with time-varying frequency contours were highly effective competitors, whatever their amplitude characteristics, whereas constant-frequency F2Cs were ineffective. Subsequent studies used synthetic-formant speech to explore the effects of manipulating the rate and depth of formant-frequency change in the competitor. Competitor efficacy was not tuned to the rate of formant-frequency variation in the target sentences; rather, the reduction in intelligibility increased with competitor rate relative to the rate for the target sentences. Therefore, differences in speech rate may not be a useful cue for separating the speech of concurrent talkers. Effects of competitors whose depth of formant-frequency variation was scaled by a range of factors were explored using competitors derived either by inverting the frequency contour of F2 about its geometric mean (plausibly speech-like pattern) or by using a regular and arbitrary frequency contour (triangle wave, not plausibly speech-like) matched to the average rate and depth of variation for the inverted F2C. Competitor efficacy depended on the overall depth of frequency variation, not depth relative to that for the other formants. Furthermore, the triangle-wave competitors were as effective as their more speech-like counterparts. Overall, the results suggest that formant-frequency variation is critical for

  15. Instituciones microfinancieras y cajas de ahorro en Santo Tomás Hueyotlipan, Puebla

    OpenAIRE

    2014-01-01

    La exigua presencia de los intermediarios financieros formales en los municipios rurales mexicanos impulsa el uso de tandas y solicitud de dinero a prestamistas, familiares o amigos. Las cajas de ahorro constituyen una alternativa a estos métodos tradicionales y aprovechan el capital social comunitario. Esta investigación, fundamentado en una muestra realizada en el municipio de Santo Tomás Hueyotlipan (Puebla, México), analiza los factores que impulsan la participación en las cajas de ahorro...

  16. Acción Nulidad en Afiliaciones al Régimen de Ahorro Individual

    OpenAIRE

    Buriticá Atehortúa, Carlos Arturo; Ing Pensiones y Cesantías – Manizales

    2015-01-01

    Objetivo: determinar la posibilidad de la acción de nulidad de las afiliaciones al Régimen de Ahorro Individual. Metodología: este es un ensayo argumentativo que estudia con Prestación Definida al Régimen de Ahorro Individual con Solidaridad bajo los preceptos jurídicos desde la entrada en vigencia de la ley 100 de 1993 y la comparación con otros países como Argentina y Chile, y se encuentra que esta acción es posible. Conclusiones: según los argumentos en materia de proyección económica y de...

  17. Negative frequency-dependent preferences and variation in male facial hair.

    Science.gov (United States)

    Janif, Zinnia J; Brooks, Robert C; Dixson, Barnaby J

    2014-01-01

    Negative frequency-dependent sexual selection maintains striking polymorphisms in secondary sexual traits in several animal species. Here, we test whether frequency of beardedness modulates perceived attractiveness of men's facial hair, a secondary sexual trait subject to considerable cultural variation. We first showed participants a suite of faces, within which we manipulated the frequency of beard thicknesses and then measured preferences for four standard levels of beardedness. Women and men judged heavy stubble and full beards more attractive when presented in treatments where beards were rare than when they were common, with intermediate preferences when intermediate frequencies of beardedness were presented. Likewise, clean-shaven faces were least attractive when clean-shaven faces were most common and more attractive when rare. This pattern in preferences is consistent with negative frequency-dependent selection.

  18. Effect of frequency variation on electromagnetic pulse interaction with charges and plasma

    NARCIS (Netherlands)

    Khachatryan, A.G.; Goor, van F.A.; Verschuur, J.W.J.; Boller, K.-J.

    2005-01-01

    The effect of frequency variation (chirp) in an electromagnetic (EM) pulse on the pulse interaction with a charged particle and plasma is studied. Various types of chirp and pulse envelopes are considered. In vacuum, a charged particle receives a kick in the polarization direction after interaction

  19. CHARACTERISTICS OF FREQUENCY SPECTRUM VARIATION OF INTRASEASONAL OSCILLATION OF CONVECTION DURING SOUTH CHINA SEA SUMMER MONSOON

    Institute of Scientific and Technical Information of China (English)

    LIN Ai-lan; LIANG Jian-yin; LI Chun-hui

    2006-01-01

    Datasets of equivalent temperature of black body (TBB) and sea surface temperature (SST) ranging from 1980 to 1997 are used to diagnose and analyze the characteristics of frequency spectrum and strength of intraseasonal variation of convection. The relationship between the strength of intraseasonal oscillation of convection, strength of convection itself and SST in the South China Sea (SCS) is studied. It is shown that, there are distinguishable annual, interannual and interdecadal variations in both strength and frequency spectrum of intraseasonal variation of convection in SCS. There are connections between strength of convection, strength of ISO1 in the summer half (s.h.) year and SST in ensuing winter half (w.h.) year in SCS.The strong (weak) convection and strong (weak) ISO1 are associated with negative (positive) bias of SST in ensuing w.h. year in SCS.

  20. Comparing of Two Farsi Passages in Laboratory Evaluation of Mean and Fundamental Frequency Variations Range

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Keyhani

    2012-03-01

    Full Text Available Background and Aim: Voice disorders assess with the help of laboratory equipments and perceptual evaluation. Voice samples involve vowel prolongation, text-reading or conversational speech. In Iran, Rainbow text and Grandfather text, were developed for assessing voice.Methods: This study was cross-sectional and descriptive-analytical. Mean and fundamental frequency variations range in 120 normal males and females aging from 20-59 years old were studied. Voice samples of reading both texts were gathered and compared.Results: Mean fundamental frequency in males in Grandfather text was 137.93 with SD 1.2 and in Rainbow text was 135.09 with SD 1.1 (p>0.05, in females Grandfather and Rainbow texts were 206.07 with SD 0.9 and 204.23 with SD 2.1, respectively (p>0.05. Fundamental frequency variations range in Grandfather text in males was 88.10 with SD 0.8 and in females was 116.77 with SD 1.3 and in Rainbow text in males was 90.92 with SD 1.1, in females was 116.08 with SD 1.2 (p>0.05. Mean fundamental frequency of males in each text didn't show significant difference in age groups and just in 50-59 age group of the female population showed significant difference. Fundamental frequency variations range didn't show significant difference in males and females in both texts.Conclusion: These two texts were the same in measurement of average and fundamental frequency variations range in adults. Significant difference showed between 50-59 age group of the female population and other groups.

  1. Frequency variations of the earth's obliquity and the 100-kyr ice-age cycles

    Science.gov (United States)

    Liu, Han-Shou

    1992-01-01

    Changes in the earth's climate are induced by variations in the earth's orbital parameters which modulate the seasonal distribution of solar radiation. Periodicities in the geological climate record with cycles of 100, 41, and 23 kyr have been linked with changes in obliquity, eccentricity, and precession of the equinoxes. The effect of variations of eccentricity during a 100 kyr period is weak relative to the signals from obliquity and precession variations and it may therefore be expected that the 100 kyr signal in the climate record would be of low intensity. However, this signal dominates the climate record and internal nonlinear processes within the climate system have previously been proposed to account for this fact. The author shows that variations in the frequency of the obliquity cycle can give rise to strong 100-kyr forcing of climate.

  2. Parametrizing the time variation of the `surface term' of stellar p-mode frequencies: application to helioseismic data

    Science.gov (United States)

    Howe, R.; Basu, S.; Davies, G. R.; Ball, W. H.; Chaplin, W. J.; Elsworth, Y.; Komm, R.

    2017-02-01

    The solar-cycle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic modes includes a significant frequency-dependent term known as the surface term, which is also related to the inverse mode inertia. We parametrize both the surface term and the frequency variations for low-degree solar data from Birmingham Solar-Oscillations Network (BiSON) and medium-degree data from the Global Oscillations Network Group (GONG) using the mode inertia together with cubic and inverse frequency terms. We find that for the central frequency of rotationally split multiplets, the cubic term dominates both the average surface term and the temporal variation, but for the medium-degree case, the inverse term improves the fit to the temporal variation. We also examine the variation of the even-order splitting coefficients for the medium-degree data and find that, as for the central frequency, the latitude-dependent frequency variation, which reflects the changing latitudinal distribution of magnetic activity over the solar cycle, can be described by the combination of a cubic and an inverse function of frequency scaled by inverse mode inertia. The results suggest that this simple parametrization could be used to assess the activity-related frequency variation in solar-like asteroseismic targets.

  3. Microfinanzas y Remesas: La Experiencia de Cooperativas de Ahorro y Crédito

    OpenAIRE

    Dave Grace

    2003-01-01

    Presentación que da a conocer el funcionamiento de la Red Internacional de Remesas - IRnet en los países de México, Honduras, Jamaica, El Salvador y Guatemala. Asimismo, brinda información acerca de las lecciones aprendidas del Consejo Mundial de Cooperativas de Ahorro y Crédito (WOCCU), así como sus futuros proyectos.

  4. Microfinanzas y Remesas: La Experiencia de Cooperativas de Ahorro y Crédito

    OpenAIRE

    Dave Grace

    2003-01-01

    Presentación que da a conocer el funcionamiento de la Red Internacional de Remesas - IRnet en los países de México, Honduras, Jamaica, El Salvador y Guatemala. Asimismo, brinda información acerca de las lecciones aprendidas del Consejo Mundial de Cooperativas de Ahorro y Crédito (WOCCU), así como sus futuros proyectos.

  5. Novel Complete Probabilistic Models of Random Variation in High Frequency Performance of Nanoscale MOSFET

    Directory of Open Access Journals (Sweden)

    Rawid Banchuin

    2013-01-01

    Full Text Available The novel probabilistic models of the random variations in nanoscale MOSFET's high frequency performance defined in terms of gate capacitance and transition frequency have been proposed. As the transition frequency variation has also been considered, the proposed models are considered as complete unlike the previous one which take only the gate capacitance variation into account. The proposed models have been found to be both analytic and physical level oriented as they are the precise mathematical expressions in terms of physical parameters. Since the up-to-date model of variation in MOSFET's characteristic induced by physical level fluctuation has been used, part of the proposed models for gate capacitance is more accurate and physical level oriented than its predecessor. The proposed models have been verified based on the 65 nm CMOS technology by using the Monte-Carlo SPICE simulations of benchmark circuits and Kolmogorov-Smirnov tests as highly accurate since they fit the Monte-Carlo-based analysis results with 99% confidence. Hence, these novel models have been found to be versatile for the statistical/variability aware analysis/design of nanoscale MOSFET-based analog/mixed signal circuits and systems.

  6. Top down and bottom up selection drives variations in frequency and form of a visual signal.

    Science.gov (United States)

    Yeh, Chien-Wei; Blamires, Sean J; Liao, Chen-Pan; Tso, I-Min

    2015-03-30

    The frequency and form of visual signals can be shaped by selection from predators, prey or both. When a signal simultaneously attracts predators and prey selection may favour a strategy that minimizes risks while attracting prey. Accordingly, varying the frequency and form of the silken decorations added to their web may be a way that Argiope spiders minimize predation while attracting prey. Nonetheless, the role of extraneous factors renders the influences of top down and bottom up selection on decoration frequency and form variation difficult to discern. Here we used dummy spiders and decorations to simulate four possible strategies that the spider Argiope aemula may choose and measured the prey and predator attraction consequences for each in the field. The strategy of decorating at a high frequency with a variable form attracted the most prey, while that of decorating at a high frequency with a fixed form attracted the most predators. These results suggest that mitigating the cost of attracting predators while maintaining prey attraction drives the use of variation in decoration form by many Argiope spp. when decorating frequently. Our study highlights the importance of considering top-down and bottom up selection pressure when devising evolutionary ecology experiments.

  7. Theoretical analysis of the EAST 4-strap ion cyclotron range of frequency antenna with variational theory

    Science.gov (United States)

    Zhang, Jia-Hui; Zhang, Xin-Jun; Zhao, Yan-Ping; Qin, Cheng-Ming; Chen, Zhao; Yang, Lei; Wang, Jian-Hua

    2016-08-01

    A variational principle code which can calculate self-consistently currents on the conductors is used to assess the coupling characteristic of the EAST 4-strap ion cyclotron range of frequency (ICRF) antenna. Taking into account two layers of antenna conductors without lateral frame but with slab geometry, the antenna impedances as a function of frequency and the structure of RF field excited inside the plasma in various phasing cases are discussed in this paper. Project supported by the National Magnetic Confinement Fusion Science Program, China (Grant No. 2015GB101001) and the National Natural Science Foundation of China (Grant Nos. 11375236 and 11375235).

  8. High Frequency Variations of Earth Rotation Parameters from GPS and GLONASS Observations

    Directory of Open Access Journals (Sweden)

    Erhu Wei

    2015-01-01

    Full Text Available The Earth’s rotation undergoes changes with the influence of geophysical factors, such as Earth’s surface fluid mass redistribution of the atmosphere, ocean and hydrology. However, variations of Earth Rotation Parameters (ERP are still not well understood, particularly the short-period variations (e.g., diurnal and semi-diurnal variations and their causes. In this paper, the hourly time series of Earth Rotation Parameters are estimated using Global Positioning System (GPS, Global Navigation Satellite System (GLONASS, and combining GPS and GLONASS data collected from nearly 80 sites from 1 November 2012 to 10 April 2014. These new observations with combining different satellite systems can help to decorrelate orbit biases and ERP, which improve estimation of ERP. The high frequency variations of ERP are analyzed using a de-trending method. The maximum of total diurnal and semidiurnal variations are within one milli-arcseconds (mas in Polar Motion (PM and 0.5 milli-seconds (ms in UT1-UTC. The semidiurnal and diurnal variations are mainly related to the ocean tides. Furthermore, the impacts of satellite orbit and time interval used to determinate ERP on the amplitudes of tidal terms are analyzed. We obtain some small terms that are not described in the ocean tide model of the IERS Conventions 2010, which may be caused by the strategies and models we used or the signal noises as well as artifacts. In addition, there are also small differences on the amplitudes between our results and IERS convention. This might be a result of other geophysical excitations, such as the high-frequency variations in atmospheric angular momentum (AAM and hydrological angular momentum (HAM, which needs more detailed analysis with more geophysical data in the future.

  9. Variational approach to low-frequency kinetic-MHD in the current coupling scheme

    Science.gov (United States)

    Burby, Joshua W.; Tronci, Cesare

    2017-04-01

    Hybrid kinetic-MHD models describe the interaction of an MHD bulk fluid with an ensemble of hot particles, which obeys a kinetic equation. In this work we apply Hamilton’s variational principle to formulate new current-coupling kinetic-MHD models in the low-frequency approximation (i.e. large Larmor frequency limit). More particularly, we formulate current-coupling schemes, in which energetic particle dynamics are expressed in either guiding center or gyrocenter coordinates. When guiding center theory is used to model the hot particles, we show how energy conservation requires corrections to the standard magnetization term. On the other hand, charge and momentum conservation in gyrokinetic-MHD lead to extra terms in the usual definition of the hot current density as well as modifications to conventional gyrocenter dynamics. All these new features arise naturally from the underlying variational structure of the proposed models.

  10. Variational approach to low-frequency kinetic-MHD in the current coupling scheme

    CERN Document Server

    Burby, J W

    2016-01-01

    Hybrid kinetic-MHD models describe the interaction of an MHD bulk fluid with an ensemble of hot particles, which is described by a kinetic equation. When the Vlasov description is adopted for the energetic particles, different Vlasov-MHD models have been shown to lack an exact energy balance, which was recently recovered by the introduction of non-inertial force terms in the kinetic equation. These force terms arise from fundamental approaches based on Hamiltonian and variational methods. In this work we apply Hamilton's variational principle to formulate new current-coupling kinetic-MHD models in the low-frequency approximation (i.e. large Larmor frequency limit). More particularly, we formulate current-coupling hybrid schemes, in which energetic particle dynamics are expressed in either guiding-center or gyrocenter coordinates.

  11. Variational approach to low-frequency kinetic-MHD in the current-coupling scheme

    Science.gov (United States)

    Tronci, Cesare; Burby, Joshua

    2016-10-01

    Hybrid kinetic-MHD models describe the interaction of an MHD bulk fluid with an ensemble of hot particles, which is described by a kinetic equation. When the Vlasov description is adopted for the energetic particles, different Vlasov-MHD models have been shown to lack an exact energy balance, unless non-inertial force terms are inserted in the kinetic equation. These force terms arise from fundamental approaches based on Hamiltonian and variational methods. In this work we apply Hamilton's variational principle to formulate new current-coupling kinetic-MHD models in the low-frequency approximation (i.e. large Larmor frequency limit). More particularly, we formulate current-coupling hybrid schemes, in which energetic particle dynamics are expressed in either guiding-center or gyrocenter coordinates. Financial support by the Leverhulme Trust Research Project Grant No. 2014-112 is greatly acknowledged.

  12. The role of low-frequency variation in the manifestation of warming trend and ENSO amplitude

    Science.gov (United States)

    Yeo, Sae-Rim; Yeh, Sang-Wook; Kim, Kwang-Yul; Kim, WonMoo

    2017-08-01

    Despite the increase in greenhouse gas concentration, the sea surface temperature (SST) over the tropical eastern Pacific during the period of 1999-2014 exhibits less warming trend compared to the earlier decades. It has been noted that this warming hiatus is accompanied by a negative phase of the Pacific Decadal Oscillation (PDO), which represents low-frequency variability over the Pacific. On the other hand, the 2015/2016 El Niño is among the strongest comparable to the 1997/1998 event, which coincides with the recently altered PDO phase from negative to positive. These observational evidences have generated substantial interest in the role of low-frequency variations in modulating El Niño-Southern Oscillation amplitude as well as manifestation of warming signal in the tropical Pacific. Therefore, it is necessary to appropriately separate low-frequency variability and global warming signal from SST records. Here, we present three primary modes of global SST that include secular warming trend, low-frequency variability, and biennial oscillation. Based on the independent behavior of these three modes, global warming is clearly continuing but its manifestation is enhanced (depressed) when the low-frequency variation is in the positive (negative) phase. Further, possibility of strong El Niño increases under the positive phase of the low-frequency mode, which amplifies warming over the tropical eastern Pacific. Indeed, the strong 2015/2016 El Niño is largely attributed to the positive phase of the low-frequency mode. In order to examine the climate models' ability to simulate the three SST modes as obtained in the observational record, the Coupled Model Intercomparison Project phase 5 (CMIP5) datasets are also analyzed. The spatial and temporal characteristics of the three modes have been replicated closely by the selected CMIP5 models forced by the historical condition, which provides an analogy of the interplay of three modes in the observed tropical Pacific SST.

  13. Analysis and Comprehensive Analytical Modeling of Statistical Variations in Subthreshold MOSFET's High Frequency Characteristics

    Directory of Open Access Journals (Sweden)

    Rawid Banchuin

    2014-01-01

    Full Text Available In this research, the analysis of statistical variations in subthreshold MOSFET's high frequency characteristics defined in terms of gate capacitance and transition frequency, have been shown and the resulting comprehensive analytical models of such variations in terms of their variances have been proposed. Major imperfection in the physical level properties including random dopant fluctuation and effects of variations in MOSFET's manufacturing process, have been taken into account in the proposed analysis and modeling. The up to dated comprehensive analytical model of statistical variation in MOSFET's parameter has been used as the basis of analysis and modeling. The resulting models have been found to be both analytic and comprehensive as they are the precise mathematical expressions in terms of physical level variables of MOSFET. Furthermore, they have been verified at the nanometer level by using 65~nm level BSIM4 based benchmarks and have been found to be very accurate with smaller than 5 % average percentages of errors. Hence, the performed analysis gives the resulting models which have been found to be the potential mathematical tool for the statistical and variability aware analysis and design of subthreshold MOSFET based VHF circuits, systems and applications.

  14. p-mode frequency variation in relation to global solar activity

    Science.gov (United States)

    Bachmann, Kurt T.; Brown, Timothy M.

    1993-01-01

    We show that p-mode frequency variations correlate remarkably well with the variations of six solar activity indices over a 6 yr period from 1984 October to 1990 November, including both the large variation from solar minimum to solar maximum and smaller variations observed over approximately 1 month intervals during solar maximum. The quality of correlation as seen visually and as measured by two statistical tests differs significantly among the six activity indices, and we briefly speculate on possible reasons for this. Observations used in this study come from the HAO/NSO Fourier tachometer (FTACH) and include the spherical harmonic degree range l greater than 20 and equal to 60 or less and frequency range between 2600 and 3200 micro-Hz. The data are divided into 18 separate epochs with time string duration ranging from a minimum of 18 days to a maximum of 45 days. We have particularly good coverage during the early part of solar maximum of cycle 22.

  15. Accuracy estimation of the 16O2+ transition frequencies targeting the search for the variation in mp/me

    CERN Document Server

    Kajita, Masatoshi

    2016-01-01

    The precise measurement of molecular vibrational transition frequencies is useful in the search for variation in the proton-to-electron mass ratio {\\mu}. Homonuclear diatomic molecules are particularly advantageous for precise measurement because of the small Stark shift. This paper discusses the Stark and Zeeman shifts in the 16O2+ vibrational transition frequencies.To search for the variation {\\mu}(1)in transition frequencies are much more advantageous than the transition frequencies between the X2{\\Pi}1/2 v=21 and a4{\\Pi}1/2 v=0 states, whose sensitivity to the variation in {\\mu} is high because of the accidental degeneracy.

  16. THE EVALUATION OF FREQUENCY AND SEASONAL VARIATIONS OF ACID PEPTIC DISEASE: A SEVEN YEARS STUDY

    Directory of Open Access Journals (Sweden)

    Syed Iftikhar Haider

    2016-06-01

    Full Text Available Acid peptic disease (APD is a worldwide health problem. It includes a variety of inflammatory and ulcerative lesions involving esophagus, stomach and duodenum. The disease condition may persist with multiple symptoms, one of them being dyspepsia. The object of the present study was to determine the frequency and seasonal variations of APD in patients presenting with dyspeptic symptoms. This observational study was carried out at the endoscopy unit in Baqai Medical University from December 2003 to December 2010, over a period of seven years. The evolution of APD frequency remained equivocal throughout the study period. However, a decline was noted in the frequency of peptic ulcer disease (PUD especially for gastric and duodenal ulcer cases but a rise during autumn and winter seasons was also noted in duodenal ulcer cases.

  17. Misleading variations in estimated rotational frequency splittings of solar p modes: Consequences for helio- and asteroseismology

    CERN Document Server

    Broomhall, Anne-Marie; Chaplin, William J; Garcia, Rafael A; Elsworth, Yvonne; Howe, Rachel; Mathur, Savita

    2012-01-01

    The aim of this paper is to investigate whether there are any 11-yr or quasi-biennial solar cycle-related variations in solar rotational splitting frequencies of low-degree solar p modes. Although no 11-yr signals were observed, variations on a shorter timescale (~2yrs) were apparent. We show that the variations arose from complications/artifacts associated with the realization noise in the data and the process by which the data were analyzed. More specifically, the realization noise was observed to have a larger effect on the rotational splittings than accounted for by the formal uncertainties. When used to infer the rotation profile of the Sun these variations are not important. The outer regions of the solar interior can be constrained using higher-degree modes. While the variations in the low-l splittings do make large differences to the inferred rotation rate of the core, the core rotation rate is so poorly constrained, even by low-l modes, that the different inferred rotation profiles still agree within...

  18. Frequency of sternal foramen evaluated by MDCT: a minor variation of great relevance.

    Science.gov (United States)

    Babinski, Marcio A; de Lemos, Leandro; Babinski, Monique S D; Gonçalves, Marianna V T; De Paula, Rafael C; Fernandes, Rodrigo M P

    2015-04-01

    Due to inadvertent cardiac or great vessel injury, sternal foramina may pose as a great hazard during sternal puncture. They can also be misinterpreted as osteolytic lesions in cross-sectional imaging of the sternum. The distribution of these variations differs between populations, but data from Brazilians are scarcely reported. Therefore, this study aimed to verify the frequency of midline sternal foramen and double-ended xiphoid process, as developmental variations, in order to avoid fatal complications following sternal puncture of sternal acupuncture treatment. A total of 114 chest computed tomograms were evaluated. The frequency of midline sternal foramen in a complication risk bearing feature is of approximately 10.5%. The double-ended xiphoid process was present in 17.5%. We conclude that sternal acupuncture should be planned in the region of corpus-previous CT should be done to rule out this variation. Furthermore, we strongly recommend the acupuncture technique which prescribes a safe superficial-oblique approach to the sternum.

  19. Does infectious disease cause global variation in the frequency of intrastate armed conflict and civil war?

    Science.gov (United States)

    Letendre, Kenneth; Fincher, Corey L; Thornhill, Randy

    2010-08-01

    Geographic and cross-national variation in the frequency of intrastate armed conflict and civil war is a subject of great interest. Previous theory on this variation has focused on the influence on human behaviour of climate, resource competition, national wealth, and cultural characteristics. We present the parasite-stress model of intrastate conflict, which unites previous work on the correlates of intrastate conflict by linking frequency of the outbreak of such conflict, including civil war, to the intensity of infectious disease across countries of the world. High intensity of infectious disease leads to the emergence of xenophobic and ethnocentric cultural norms. These cultures suffer greater poverty and deprivation due to the morbidity and mortality caused by disease, and as a result of decreased investment in public health and welfare. Resource competition among xenophobic and ethnocentric groups within a nation leads to increased frequency of civil war. We present support for the parasite-stress model with regression analyses. We find support for a direct effect of infectious disease on intrastate armed conflict, and support for an indirect effect of infectious disease on the incidence of civil war via its negative effect on national wealth. We consider the entanglements of feedback of conflict into further reduced wealth and increased incidence of disease, and discuss implications for international warfare and global patterns of wealth and imperialism.

  20. La reforma del sistema financiero: cajas de ahorros.- (Años 2011-2012

    Directory of Open Access Journals (Sweden)

    Octavio Vázquez Sotelo

    2013-04-01

    Full Text Available Este trabajo forma parte del libro “La dimensión social de las Cajas de Ahorro: España y Galicia”, publicado por la Editorial Académica Española, del cual soy autor.A través de la legislación promulgada en los años 2010, 2011 y 2012, se analiza la estrategia de privatización de las Cajas de Ahorro seguida por los gobiernos de turno que, en la mayor parte de los casos, ha supuesto la entrega de las mismas a precios irrisorios a su tradicionales competidores: la gran Banca.. Ello ha comportado la desfiguración o, incluso, la desaparición del rasgo más distintivo de aquellas: la Obra Social.

  1. Instituciones microfinancieras y cajas de ahorro en Santo Tomás Hueyotlipan, Puebla

    Directory of Open Access Journals (Sweden)

    Kristiano Raccanello

    2014-01-01

    Full Text Available La exigua presencia de los intermediarios financieros formales en los municipios rurales mexicanos impulsa el uso de tandas y solicitud de dinero a prestamistas, familiares o amigos. Las cajas de ahorro constituyen una alternativa a estos métodos tradicionales y aprovechan el capital social comunitario. Esta investigación, fundamentado en una muestra realizada en el municipio de Santo Tomás Hueyotlipan (Puebla, México, analiza los factores que impulsan la participación en las cajas de ahorro informales y su interacción con otros intermediarios financieros informales. Los resultados del modelo probit indican que la participación responde a la posibilidad de poder ahorrar atrayendo a aquellos individuos que no utilizan tandas, prestamistas o deudas con familiares o amigos.

  2. El efecto del alfabetismo financiero en el ahorro para el retiro en México.

    OpenAIRE

    F. Alejandro Villagómez; Alayn González

    2014-01-01

    En este trabajo analizamos si es posible incrementar el ahorro para el retiro por medio de alfabetismo financiero en México. Con información de la Encuesta Nacional de los Niveles de Vida de los Hogares 2005 (ENNVIH-2) construimos un índice de alfabetizo financiero siguiendo la metodología propuesta por Atkinson y Messy (2012) que considera tres factores: conocimiento, actitudes y comportamiento financiero. Nuestros resultados sugieren que el alfabetismo financiero tiene un impacto positivo e...

  3. Temporal and spatial variations in road traffic noise for different frequency components in metropolitan Taichung, Taiwan.

    Science.gov (United States)

    Wang, Ven-Shing; Lo, Ei-Wen; Liang, Chih-Hsiang; Chao, Keh-Ping; Bao, Bo-Ying; Chang, Ta-Yuan

    2016-12-01

    Road traffic noise exposure has been associated with auditory and non-auditory health effects, but few studies report noise characteristics. This study determines 24-h noise levels and analyzes their frequency components to investigate associations between seasons, meteorology, land-use types, and traffic. We set up 50 monitoring stations covering ten different land-use types and conducted measurements at three times of the year to obtain 24-h-average A-weighted equivalent noise levels (LAeq,24h) and frequency analyses from 2013 to 2014 in Taichung, Taiwan. Information on land-use types, road parameters, traffic flow rates, and meteorological variables was also collected for analysis with the annual averages of road traffic noise and its frequency components. The annual average LAeq,24h in Taichung was 66.4 ± 4.7 A-weighed decibels (dBA). Significant differences in LAeq,24h and frequency components were observed between land-use types (all p-values traffic flow rates, and land-use types were significantly associated with annual average LAeq,24h (all p-values traffic (Spearman's coefficient = 0.795) and the highest prediction in the multiple linear regression (R(2) = 0.803; adjusted R(2) = 0.765). These findings reveal the spatial variation in road traffic noise exposure in Taichung. The highest correlation and predictive capacity was observed between this variation and noise levels at 125 Hz. We recommend that governmental agencies should take actions to reduce noise levels from traffic vehicles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Variation in drug injection frequency among out-of-treatment drug users in a national sample.

    Science.gov (United States)

    Singer, M; Himmelgreen, D; Dushay, R; Weeks, M R

    1998-05-01

    This article analyzes data on drug injection frequency in a sample of more than 13,000 out-of-treatment drug injectors interviewed across 21 U.S. cities and Puerto Rico through the National Institute on Drug Abuse (NIDA) Cooperative Agreement for AIDS Community-Based Outreach/Intervention Research Program. The goals of the article are to present findings on injection frequency and to predict variation in terms of a set of variables suggested by previous research, including location, ethnicity, gender, age, educational attainment, years since first use of alcohol and marijuana, income, living arrangement, homelessness, drugs injected, and duration of injection across drugs. Three models were tested. Significant intersite differences were identified in injection frequency, although most of the other predictor variables we tested accounted for little of the variance. Ethnicity and drugs injected, however, were found to be significant. Taken together, location, ethnicity, and type of drug injected provide a configuration that differentiated and (for the variables available for the analysis) best predicted injection frequency. The public health implications of these findings are presented.

  5. Active noise control using noise source having adaptive resonant frequency tuning through stiffness variation

    Science.gov (United States)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor); Renshaw, Anthony A. (Inventor); Hedeen, Robert A. (Inventor)

    1995-01-01

    A noise source for an aircraft engine active noise cancellation system in which the resonant frequency of a noise radiating element is tuned to permit noise cancellation over a wide range of frequencies. The resonant frequency of the noise radiating element is tuned by a plurality of force transmitting mechanisms which contact the noise radiating element. Each one of the force transmitting mechanisms includes an expandable element and a spring in contact with the noise radiating element so that excitation of the element varies the spring force applied to the noise radiating element. The elements are actuated by a controller which receives input of a signal proportional to displacement of the noise radiating element and a signal corresponding to the blade passage frequency of the engine's fan. In response, the controller determines a control signal which is sent to the elements and causes the spring force applied to the noise radiating element to be varied. The force transmitting mechanisms can be arranged to either produce bending or linear stiffness variations in the noise radiating element.

  6. México: la economía de los sectores institucionales, distribución del ingreso, ahorro y crecimiento

    OpenAIRE

    Roberto Michel Padilla

    2003-01-01

    A partir del análisis de las cuentas nacionales de México por sector institucional se descubre una relación de sustitución perfecta entre el ahorro externo y el ahorro interno. Cambios en la disponibilidad de ahorro externo generan, mediante diferentes mecanismos, variaciones en el mismo sentido en la participación de los salarios y los dividendos en el producto y en sus propensiones al consumo; y en sentido opuesto en el ahorro interno de las empresas. La relación de causalidad es clara; a m...

  7. Jump Variation Estimation with Noisy High Frequency Financial Data via Wavelets

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2016-08-01

    Full Text Available This paper develops a method to improve the estimation of jump variation using high frequency data with the existence of market microstructure noises. Accurate estimation of jump variation is in high demand, as it is an important component of volatility in finance for portfolio allocation, derivative pricing and risk management. The method has a two-step procedure with detection and estimation. In Step 1, we detect the jump locations by performing wavelet transformation on the observed noisy price processes. Since wavelet coefficients are significantly larger at the jump locations than the others, we calibrate the wavelet coefficients through a threshold and declare jump points if the absolute wavelet coefficients exceed the threshold. In Step 2 we estimate the jump variation by averaging noisy price processes at each side of a declared jump point and then taking the difference between the two averages of the jump point. Specifically, for each jump location detected in Step 1, we get two averages from the observed noisy price processes, one before the detected jump location and one after it, and then take their difference to estimate the jump variation. Theoretically, we show that the two-step procedure based on average realized volatility processes can achieve a convergence rate close to O P ( n − 4 / 9 , which is better than the convergence rate O P ( n − 1 / 4 for the procedure based on the original noisy process, where n is the sample size. Numerically, the method based on average realized volatility processes indeed performs better than that based on the price processes. Empirically, we study the distribution of jump variation using Dow Jones Industrial Average stocks and compare the results using the original price process and the average realized volatility processes.

  8. Wolbachia in European Populations of the Invasive Pest Drosophila suzukii: Regional Variation in Infection Frequencies.

    Science.gov (United States)

    Cattel, Julien; Kaur, Rupinder; Gibert, Patricia; Martinez, Julien; Fraimout, Antoine; Jiggins, Francis; Andrieux, Thibault; Siozios, Stefanos; Anfora, Gianfranco; Miller, Wolfgang; Rota-Stabelli, Omar; Mouton, Laurence

    2016-01-01

    The invasive pest Drosophila suzukii is characterized by a specific fresh-fruit targeting behavior and has quickly become a menace for the fruit economy of newly infested North American and European regions. D. suzukii carries a strain of the endosymbiotic bacterium Wolbachia, named wSuz, which has a low infection frequency and no reproductive manipulation capabilities in American populations of D. suzukii. To further understand the nature of wSuz biology and assess its utility as a tool for controlling this pest's populations, we investigated the prevalence of Wolbachia in 23 European D. suzukii populations, and compared our results with those available in American populations. Our data showed a highly variable infection frequency with a mean prevalence of 46%, which is significantly higher than the 17% found in American populations. Based on Multilocus Sequence Typing analysis, a single wSuz strain was diagnosed in all European populations of D. suzukii. In agreement with American data, we found no evidence of cytoplasmic incompatibility induced by wSuz. These findings raise two questions: a) why Wolbachia is maintained in field populations of D. suzukii and b) what are the selective forces responsible for the variation in prevalence within populations, particularly between European and American continents? Our results provide new insights into the D. suzukii-Wolbachia association and highlight regional variations that await further investigation and that should be taken into account for using Wolbachia-based pest management programs.

  9. Relative importance of precipitation frequency and intensity in inter-annual variation of precipitation in Singapore during 1980-2013

    Science.gov (United States)

    Li, Xin; Babovic, Vladan

    2017-04-01

    Observed studies on inter-annual variation of precipitation provide insight into the response of precipitation to anthropogenic climate change and natural climate variability. Inter-annual variation of precipitation results from the concurrent variations of precipitation frequency and intensity, understanding of the relative importance of frequency and intensity in the variability of precipitation can help fathom its changing properties. Investigation of the long-term changes of precipitation schemes has been extensively carried out in many regions across the world, however, detailed studies of the relative importance of precipitation frequency and intensity in inter-annual variation of precipitation are still limited, especially in the tropics. Therefore, this study presents a comprehensive framework to investigate the inter-annual variation of precipitation and the dominance of precipitation frequency and intensity in a tropical urban city-state, Singapore, based on long-term (1980-2013) daily precipitation series from 22 rain gauges. First, an iterative Mann-Kendall trend test method is applied to detect long-term trends in precipitation total, frequency and intensity at both annual and seasonal time scales. Then, the relative importance of precipitation frequency and intensity in inducing the inter-annual variation of wet-day precipitation total is analyzed using a dominance analysis method based on linear regression. The results show statistically significant upward trends in wet-day precipitation total, frequency and intensity at annual time scale, however, these trends are not evident during the monsoon seasons. The inter-annual variation of wet-day precipitation is mainly dominated by precipitation intensity for most of the stations at annual time scale and during the Northeast monsoon season. However, during the Southwest monsoon season, the inter-annual variation of wet-day precipitation is mainly dominated by precipitation frequency. These results have

  10. Dual frequency microstrip antenna sensor for water content measurements independent of temperature variation

    Science.gov (United States)

    Ghretli, Mohamed; Khalid, Kaida; Valeriu Grozescu, Ionel; Sahri, Hamami; Abbas, Zulkifly

    2007-04-01

    Temperature variation causes errors in all indirect moisture measurement methods. To increase the accuracy of moisture content determination and to reduce the influence of temperature, a two-parameter measurement is used. The method uses the magnitude of reflected waves at two microwave frequencies in the X-band region. A dual frequency sensor system is developed to measure moisture content of dielectric-lossy liquids. The experiment is based on measurements of far-field reflection magnitudes at two different frequencies 8.48 GHz and 10.69 GHz using circular microstrip antennas. A calibration equation is sought that instantly gives temperature-independent moisture content of the samples under consideration. The sensor is integrated with a data acquisition card to record the detected reflection signals. The data analysis and error-correction technique are implemented using custom designed software. The system is tested using diluted rubber latex with moisture content ranging from 39.8% to 91.2% wet basis. The moisture content was predicted with a standard error less than 1.3% for the temperature range of 25 °C to 63 °C compared to the standard oven-drying technique.

  11. Variation in ultrasonic frequency and time as pre-treatments to air-drying of carrot

    Directory of Open Access Journals (Sweden)

    Ernest Ekow Abano

    2013-03-01

    Full Text Available Vegetable drying is an alternative method to curb post harvest decay of vegetables and a process to produce dried vegetables, which can be directly consumed or used as ingredients for the preparation of soups, stews, baby foods, cakes, puddings, and many other foods. In this study, the effect of ultrasound frequency and sonication time as pre-treatment prior to air drying at 70°C at an air velocity of 0.5 m/s, on carrot drying kinetics, flavour, colour, and non-enzymatic browning was investigated using a 3-level factorial response surface method. The result showed that an increase in sonication frequency and time did not significantly increase moisture diffusivity but in comparison with the control, water diffusivity increased after ultrasound application and the overall drying time was reduced. Application of the ultrasound pre-treatment in distilled water resulted in water gain and sugar loss, indicating that the ultrasonic pre-treatment can be an important step to produce low sugar content dried products. The brightness and redness to yellowness values of the ultrasonically pre-treated dried carrots were better than those without ultrasound application. In comparison with the flavour of the control, the ultrasound pre-treated samples recorded higher flavour response signals, indicating that the application of ultrasound improved the flavour of the dried carrot. The variation in sonication frequency and time did not significantly affect the non-enzymatic browning index of the dried products but were better than the control.

  12. Regional frequency analysis to asses wind resource spatial and temporal variations in Washington State

    Science.gov (United States)

    Mortuza, M.; Demissie, D.

    2013-12-01

    According to the U.S. Department of Energy's annual wind technologies market report, the wind power capacity in the country grew from 2.5 gigawatts in early 2000 to 60 gigawatts in 2012, making it one of the largest new sources of electric capacity additions in the U.S. in recent years. With over 2.8 gigawatts of current capacity (eighth largest in the nation), Washington State plays a significant role in this rapidly increasing energy resource. To further expand and/or optimize these capacities, assessment of wind resource and its spatial and temporal variations are important. However, since at-site frequency analysis using meteorological data is not adequate for extending wind frequency to locations with no data, longer return period, and heterogeneous topography and surface, a regional frequency analysis based on L-moment method is adopted in this study to estimate regional wind speed patterns and return periods in Washington State using hourly mean wind speed data from 1979 - 2010. The analysis applies the k-means, hierarchical and self-organizing map clustering techniques to explore potential clusters or regions; statistical tests are then applied to identify homogeneous regions and appropriate probability distribution models. The result from the analysis is expected to provide essential knowledge about the areas with potential capacity of constructing wind power plants, which can also be readily extended to assist decisions on their daily operations.

  13. Parametrizing the time-variation of the "surface term" of stellar p-mode frequencies: application to helioseismic data

    CERN Document Server

    Howe, R; Davies, G R; Ball, W H; Chaplin, W J; Elsworth, Y; Komm, R

    2016-01-01

    The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic modes includes a significant frequency-dependent term known as the surface term that is also related to the inverse mode inertia. We parametrize both the surface term and the frequency variations for low-degree solar data from Birmingham Solar-Oscillations Network (BiSON) and medium-degree data from the Global Oscillations Network Group (GONG) using the mode inertia together with cubic and inverse frequency terms. We find that for the central frequency of rotationally split multiplets the cubic term dominates both the average surface term and the temporal variation, but for the medium-degree case the inverse term improves the fit to the temporal variation. We also examine the variation of the even-order splitting coefficients for the medium-degree data and find that, as for ...

  14. A thorough analysis of the short- and mid-term activity-related variations in the solar acoustic frequencies

    CERN Document Server

    Santos, A R G; Avelino, P P; Chaplin, W J; Campante, T L

    2016-01-01

    The frequencies of the solar acoustic oscillations vary over the activity cycle. The variations in other activity proxies are found to be well correlated with the variations in the acoustic frequencies. However, each proxy has a slightly different time behaviour. Our goal is to characterize the differences between the time behaviour of the frequency shifts and of two other activity proxies, namely, the area covered by sunspots and the 10.7cm flux. We define a new observable that is particularly sensitive to the short-term frequency variations. We then compare the observable when computed from model frequency shifts and from observed frequency shifts obtained with the Global Oscillation Network Group (GONG) for cycle 23. Our analysis shows that on the shortest time-scales the variations in the frequency shifts seen in the GONG observations are strongly correlated with the variations in the area covered by sunspots. However, a significant loss of correlation is still found. We verify that the times when the fre...

  15. The effect of diurnal variations of ionospheric parameters on Doppler frequency shift on the Boulder-Havana path

    Science.gov (United States)

    Laso, B.; Potapova, N. I.; Freizon, I. A.; Shapiro, B. S.

    1981-08-01

    An analysis of vertical-sounding and Doppler-shift data at 10 and 15 MHz obtained for the Boulder-Havana path indicates that the influence of critical frequencies is primarily manifested in variations of propagation modes and associated variations of Doppler shift. Variations of layer height are shown to have a considerable effect on the morning peak and to primarily determine the magnitude of Doppler shift during disturbed nighttime periods.

  16. Extreme recombination frequencies shape genome variation and evolution in the honeybee, Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Andreas Wallberg

    2015-04-01

    Full Text Available Meiotic recombination is a fundamental cellular process, with important consequences for evolution and genome integrity. However, we know little about how recombination rates vary across the genomes of most species and the molecular and evolutionary determinants of this variation. The honeybee, Apis mellifera, has extremely high rates of meiotic recombination, although the evolutionary causes and consequences of this are unclear. Here we use patterns of linkage disequilibrium in whole genome resequencing data from 30 diploid honeybees to construct a fine-scale map of rates of crossing over in the genome. We find that, in contrast to vertebrate genomes, the recombination landscape is not strongly punctate. Crossover rates strongly correlate with levels of genetic variation, but not divergence, which indicates a pervasive impact of selection on the genome. Germ-line methylated genes have reduced crossover rate, which could indicate a role of methylation in suppressing recombination. Controlling for the effects of methylation, we do not infer a strong association between gene expression patterns and recombination. The site frequency spectrum is strongly skewed from neutral expectations in honeybees: rare variants are dominated by AT-biased mutations, whereas GC-biased mutations are found at higher frequencies, indicative of a major influence of GC-biased gene conversion (gBGC, which we infer to generate an allele fixation bias 5 - 50 times the genomic average estimated in humans. We uncover further evidence that this repair bias specifically affects transitions and favours fixation of CpG sites. Recombination, via gBGC, therefore appears to have profound consequences on genome evolution in honeybees and interferes with the process of natural selection. These findings have important implications for our understanding of the forces driving molecular evolution.

  17. High-frequency Earth rotation variations deduced from altimetry-based ocean tides

    Science.gov (United States)

    Madzak, Matthias; Schindelegger, Michael; Böhm, Johannes; Bosch, Wolfgang; Hagedoorn, Jan

    2016-06-01

    A model of diurnal and semi-diurnal variations in Earth rotation parameters (ERP) is constructed based on altimetry-measured tidal heights from a multi-mission empirical ocean tide solution. Barotropic currents contributing to relative angular momentum changes are estimated for nine major tides in a global inversion algorithm that solves the two-dimensional momentum equations on a regular 0.5° grid with a heavily weighted continuity constraint. The influence of 19 minor tides is accounted for by linear admittance interpolation of ocean tidal angular momentum, although the assumption of smooth admittance variations with frequency appears to be a doubtful concept for semi-diurnal mass terms in particular. A validation of the newly derived model based on post-fit corrections to polar motion and universal time (Δ UT1) from the analysis of Very Long Baseline Interferometry (VLBI) observations shows a variance reduction for semi-diurnal Δ UT1 residuals that is significant at the 0.05 level with respect to the conventional ERP model. Improvements are also evident for the explicitly modeled K_1 , Q_1 , and K_2 tides in individual ERP components, but large residuals of more than 15 μ as remain at the principal lunar frequencies of O_1 and M_2 . We attribute these shortcomings to uncertainties in the inverted relative angular momentum changes and, to a minor extent, to violation of mass conservation in the empirical ocean tide solution. Further dedicated hydrodynamic modeling efforts of these anomalous constituents are required to meet the accuracy standards of modern space geodesy.

  18. High-frequency Earth rotation variations deduced from altimetry-based ocean tides

    Science.gov (United States)

    Madzak, Matthias; Schindelegger, Michael; Böhm, Johannes; Bosch, Wolfgang; Hagedoorn, Jan

    2016-11-01

    A model of diurnal and semi-diurnal variations in Earth rotation parameters (ERP) is constructed based on altimetry-measured tidal heights from a multi-mission empirical ocean tide solution. Barotropic currents contributing to relative angular momentum changes are estimated for nine major tides in a global inversion algorithm that solves the two-dimensional momentum equations on a regular 0.5° grid with a heavily weighted continuity constraint. The influence of 19 minor tides is accounted for by linear admittance interpolation of ocean tidal angular momentum, although the assumption of smooth admittance variations with frequency appears to be a doubtful concept for semi-diurnal mass terms in particular. A validation of the newly derived model based on post-fit corrections to polar motion and universal time (Δ UT1) from the analysis of Very Long Baseline Interferometry (VLBI) observations shows a variance reduction for semi-diurnal Δ UT1 residuals that is significant at the 0.05 level with respect to the conventional ERP model. Improvements are also evident for the explicitly modeled K_1, Q_1, and K_2 tides in individual ERP components, but large residuals of more than 15 μ as remain at the principal lunar frequencies of O_1 and M_2. We attribute these shortcomings to uncertainties in the inverted relative angular momentum changes and, to a minor extent, to violation of mass conservation in the empirical ocean tide solution. Further dedicated hydrodynamic modeling efforts of these anomalous constituents are required to meet the accuracy standards of modern space geodesy.

  19. Frequency of typhoid fever and its association with seasonal variations in Taxila, Pakistan

    Directory of Open Access Journals (Sweden)

    Naeem Bukhari

    2016-08-01

    Full Text Available Objective: To analyse seropositivity rates of salmonella with seasonal variations in the population of Taxila and the surrounding rural areas. Methods: The study was conducted among 760 suspected patients with symptoms of fever, headache, nausea and decreased white blood cells count screened for the typhoid fever. Blood samples collected from the suspected patients were tested for seropositivity by slide agglutination (Widal test and Immunochromatographic test, i.e. Typhidot. Results: From overall 760 suspected patients of typhoid fever only 192 (25.26% samples were positive for Widal and Typhidot test. The peak seropositivity rates were identified during the months of April–June, while decreased cases were observed from January to March. Age wise distribution of typhoid fever reflected that age groups of 10–15 years and 25–35 years were at higher risks of developing enteric fever with respect to age groups of 5–10 years and 61–70 years, respectively. On gender basis evaluation, females (24.49% were slightly at low risks of developing typhoid fever than males (25.9%. Conclusions: The present study highlights a higher burden of typhoid fever in Taxila and the surrounding areas population that directly reflects the poor hygienic condition and contamination of drinking water. The frequency of typhoid fever fluctuates with seasonal variations as higher rates found during the summer as compared to winter season.

  20. Demeter/ICE Experiment: Study of low frequency transmitter intensity variations

    Science.gov (United States)

    Boudjada, M. Y.; Moldovan, I.; Schwingenschuh, K.; Al-Haddad, E.; Biagi, P. F.; Parrot, M.

    2012-04-01

    We report on low frequency (LF) transmitter signal recorded by the 'Instrument Capteur Electrique' (ICE) experiment onboard the DEMETER micro-satellite. We mainly consider the signal emitted by the Brasov broadcasting station (25.60E, 45.75N) at frequency of about 153 kHz. We analyze the reception conditions of this transmitter several weeks before the occurrence of the Vrancea earthquakes, on October, 27th, 2004. Ground-based observations revealed the presence of sudden decrease of the Y-component of the magnetic field at Muntele Rosu Observatory (Romania), at about 68 km from the epicenter, as reported by Moldovan et al. (Rom. Journ. Phys., Vol. 54, Nos. 1-2, p. 249-261, Bucharest, 2009). In this contribution we attempt to check if the LF Brasov signal was also subject to similar disturbances as observed by the ground-station. We focus on the variation of the LF transmitter intensity levels, several weeks before and after the Vrancea earthquake occurrence. We discuss the physical parameters which may disturb the signal reception in particular the geomagnetic activity and the signal to noise ratios.

  1. Electric energy saving in the cellulose and paper industry; Ahorro de energia electrica en la industria de celulosa y papel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This paper delineates the results of the demonstration project for electric energy saving, which is one of the twenty four projects in which the Fideicomiso de Apoyo al Programa de Ahorro de Energia (FIDE) sponsors the diagnosis as well as the applied measures and the measures currently in application. Also the potential opportunity areas and the measures applied and in course of application, as well as the required investments and their recuperation periods. [Espanol] En este trabajo se describen los resultados del proyecto de demostracion de ahorro de energia electrica que es uno de los veinticuatro proyectos, en los que el Fideicomiso de Apoyo al Programa de Ahorro de Energia (FIDE) financia tanto el diagnostico como la aplicacion de medidas. Se presentan tanto las areas de oportunidad, potenciales y medidas aplicadas y en aplicacion, asi como las inversiones requeridas y los periodos de recuperacion de las mismas.

  2. Periodic Variations in the O - C Diagrams of Five Pulsation Frequencies of the DB White Dwarf EC 20058-5234

    Science.gov (United States)

    Dalessio, J.; Sullivan, D. J.; Provencal, J. L.; Shipman, H. L.; Sullivan, T.; Kilkenny, D.; Fraga, L.; Sefako, R.

    2013-03-01

    Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058-5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent when considered in unison. The pulsation frequencies vary periodically in a 12.9 year cycle and undergo secular changes that are inconsistent with simple neutrino plus photon-cooling models. The magnitude of the periodic and secular variations increases with the period of the pulsations, possibly hinting that the corresponding physical mechanism is located near the surface of the star. The phase of the periodic variations appears coupled to the sign of the secular variations. The standards for pulsation-timing-based detection of planetary companions around pulsating white dwarfs, and possibly other variables such as subdwarf B stars, should be re-evaluated. The physical mechanism responsible for this surprising result may involve a redistribution of angular momentum or a magnetic cycle. Additionally, variations in a supposed combination frequency are shown to match the sum of the variations of the parent frequencies to remarkable precision, an expected but unprecedented confirmation of theoretical predictions. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the US National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

  3. PERIODIC VARIATIONS IN THE O - C DIAGRAMS OF FIVE PULSATION FREQUENCIES OF THE DB WHITE DWARF EC 20058-5234

    Energy Technology Data Exchange (ETDEWEB)

    Dalessio, J.; Provencal, J. L.; Shipman, H. L. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Sullivan, D. J.; Sullivan, T. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Kilkenny, D. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Fraga, L. [Southern Observatory for Astrophysical Research, Casilla 603, La Serena (Chile); Sefako, R. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa)

    2013-03-01

    Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058-5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent when considered in unison. The pulsation frequencies vary periodically in a 12.9 year cycle and undergo secular changes that are inconsistent with simple neutrino plus photon-cooling models. The magnitude of the periodic and secular variations increases with the period of the pulsations, possibly hinting that the corresponding physical mechanism is located near the surface of the star. The phase of the periodic variations appears coupled to the sign of the secular variations. The standards for pulsation-timing-based detection of planetary companions around pulsating white dwarfs, and possibly other variables such as subdwarf B stars, should be re-evaluated. The physical mechanism responsible for this surprising result may involve a redistribution of angular momentum or a magnetic cycle. Additionally, variations in a supposed combination frequency are shown to match the sum of the variations of the parent frequencies to remarkable precision, an expected but unprecedented confirmation of theoretical predictions.

  4. Auditoría forense aplicada a cooperativas de ahorro y crédito

    OpenAIRE

    Almendáriz Romero, Silvia Margoth

    2008-01-01

    El propósito de este trabajo es presentar una propuesta, a los profesionales de la auditoria interna de las cooperativas de ahorro y crédito, sobre la aplicación de procedimientos de auditoria forense, como una alternativa para la detección, prevención y si cabe, la sanción de actos fraudulentos o dolosos cometidos por los directivos, administradores y empleados de este tipo de instituciones. El desarrollo de la tesis se realizó mediante el análisis, estudio y evaluación de la información ...

  5. Estructura del hogar y ahorro durante el ciclo de vida: Evidencia de las cohortes peruanas

    OpenAIRE

    Valdivia, Martín; Saavedra, Jaime

    2003-01-01

    Los cambios demográficos que ocurren en el Perú y en el resto de países en desarrollo tienen implicancias potenciales sobre un conjunto de sectores, en particular sobre el sistema de seguridad social para la vejez. La naturaleza de los efectos, sin embargo, depende del comportamiento de los individuos, y sus hogares, a lo largo del ciclo de vida; por ejemplo, en lo concerniente a sus decisiones laborales (momento de retiro) y de ahorro, las que a su vez están relacionadas con los arreglos int...

  6. Prospectiva del Programa de Ahorro Sistemático Integral en Mexicali, Baja California, México

    OpenAIRE

    José A. Suástegui Macías; Carlos Pérez Tello; H. Enrique Campbell; Hernán D. Magaña Almaguer

    2013-01-01

    El propósito de este trabajo es brindar información actualizada que permita elaborar una prospectiva del programa impulsado por el gobierno federal mexicano bajo el nombre de Programa de Ahorro Sistemático Integral (ASI) para el ahorro y uso eficiente de energía en el sector vivienda de Mexicali, Baja California. El presente estudio se realiza utilizando datos históricos del programa desde 1990 a la fecha e históricos de consumo de usuarios del servicio eléctrico. Se analiza la evolución del ...

  7. Process controls on regional flood frequency: Coefficient of variation and basin scale

    Science.gov (United States)

    BlöSchl, Günter; Sivapalan, Murugesu

    1997-12-01

    The coefficient of variation (CV) of maximum annual floods is examined to understand the effects of process controls and catchment size. A derived flood frequency model is used to interpret data from 489 catchments in Austria. At the core of process controls appears to be the interaction of catchment response time and storm duration, but the magnitude is not large, and often this interaction is hidden by other processes. The dependence of rainfall intensity and duration is clearly very important and reduces CV significantly. Increasing channel travel times with catchment scale tend to translate into decreasing CVs with area for small catchments while they tend to translate into increasing CVs with area for larger catchments. Nonlinear runoff processes, including threshold effects, is the main mechanism for increasing CV. They give rise to complex patterns in the relationship between CV and area. Base flow has been used as a surrogate for a number of processes, such as seasonality of streamflow. It always decreases CV and, in particular, leads to a significant decrease of CV with area. Both the observed tendency of CV to decrease with area and the scatter in the data are the result of a complex interplay of a number of processes which allows various alternative interpretations. Depending on which processes dominate under a particular hydrologic regime, different patterns arise. It appears that the explanations of the relationship between CV and catchment scale suggested in the literature are too simplistic. The case is made for using the concept of hydrologic regimes and process studies of the type presented here to help delineate homogeneous regions for regional flood frequency analyses in a physically consistent way.

  8. A Direct Assessment of the Role of Genetic Drift in Determining Allele Frequency Variation in Populations of EUPHYDRYAS EDITHA

    OpenAIRE

    Mueller, Laurence D.; Wilcox, Bruce A.; Ehrlich, Paul R.; David G Heckel; Murphy, Dennis D.

    1985-01-01

    Estimates of allele frequencies at six polymorphic loci were collected over eight generations in two populations of Euphydryas editha . We have estimated, in addition, the effective population size for each generation for both populations with results from mark-recapture and other field data. The variation in allele frequencies generated by random genetic drift was then studied using computer simulations and our direct estimates of effective population size. Substantial differences between ob...

  9. School-Based Racial and Gender Discrimination among African American Adolescents: Exploring Gender Variation in Frequency and Implications for Adjustment

    OpenAIRE

    Cogburn, Courtney D.; Chavous, Tabbye M.; Tiffany M. Griffin

    2011-01-01

    The present study examined school-based racial and gender discrimination experiences among African American adolescents in Grade 8 (n = 204 girls; n = 209 boys). A primary goal was exploring gender variation in frequency of both types of discrimination and associations of discrimination with academic and psychological functioning among girls and boys. Girls and boys did not vary in reported racial discrimination frequency, but boys reported more gender discrimination experiences. Multiple reg...

  10. Seasonal Variation and Frequency Distribution of Ectoparasites in Crossbreed Cattle in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Ferraz da Costa

    2014-01-01

    Full Text Available The aims of this study were to evaluate the seasonal variation and frequency distribution of Rhipicephalus (Boophilus microplus, Haematobia irritans, and Dermatobia hominis on crossbred heifers under field conditions in the northeast of Minas Gerais state, southeastern Brazil. From November 2007 to September 2009 (23 months, 40 heifers aged 16.6±2.4 months were divided into groups A (1/4 Holstein × 3/4 Gir and B (1/2 Holstein × 1/2 Gir and had the monthly infestation estimated along with the climatic conditions. The mean maximum and minimum temperatures were 28.5 and 19°C, respectively. The ectoparasites were present on animals in all months of the year. The levels of ticks on the animals were low (3.0±0.2 ticks/animal, with the highest density in midwinter. The temperature was the climatic factor that most influenced the tick levels. The population of H. irritans (13.9±0.3 flies/animal and D. hominis (1.5±0.2 larvae/animal on heifers was more influenced by rainfall and exhibited two population peaks during the year. 1/2 Holstein heifers harbored significantly more H. irritans and D. hominis than 1/4 Holstein heifers. The results are discussed considering the most appropriate periods to apply ectoparasiticides and the genetic make-up of the animals.

  11. EL AHORRO PARA EL RETIRO. Una reflexión para México

    Directory of Open Access Journals (Sweden)

    F. Alejandro Villagómez

    2014-01-01

    Full Text Available Desde hace tiempo existe una señalada preocupación entre académicos y autoridades en muchos países sobre si los individuos están realizando el ahorro necesario para su fase de retiro. La evidencia empírica muestra que en los países desarrollados no es así, y lo mismo indica la poca evidencia disponible para países en desarrollo. En este trabajo se hace una revisión de la literatura teórica sobre este tema, en particular del modelo de ciclo de vida, así como de otros planteamientos que contribuyen a explicar el fenómeno. Se hace hincapié en el caso mexicano y para ello se ofrece la escasa evidencia disponible sobre el ahorro para el retiro de su población y se muestra que éste no es adecuado en la mayoría de los casos. Se concluye con algunas reflexiones útiles para diseñar políticas públicas que permitan enfrentar este problema

  12. Effect of higher order non-linearity in frequency variation of self-phase modulation in optical fiber communication

    Institute of Scientific and Technical Information of China (English)

    Abhijit Sinha; Sourangshu Mukhopadhyay

    2004-01-01

    In optical soliton propagation through a single mode optical fiber,it is established that self-phase mod ulation is maintained by the third order non-linearity of the silica-based glass material of the fiber.In this paper we show that the fifth order non-linearity has also some contribution in frequency variation of self-phase modulation.

  13. Impact of atmospheric changes on the low-frequency variations of convective afternoon rainfall activity over Taiwan

    Science.gov (United States)

    Huang, Wan-Ru; Hsu, Huang-Hsiung; Wang, Shih-Yu; Chen, Jian-Pu

    2015-09-01

    This study examines the characteristics of low-frequency variations (defined as decadal-scale changes) in summer (June-August) convective afternoon rainfall (CAR) activity over Taiwan during 1961-2012. Using 3-hourly rain gauge data, it was found that (1) the CAR frequency exhibits a secular trend and the 10-20 decadal oscillation, (2) the trend in CAR frequency is positive in northern Taiwan but negative in central and southern Taiwan, and (3) the CAR rate increased over most of the lower plains but decreased over the mountain range of Taiwan. Diagnoses using the Japanese ReAnalysis (JRA-55) data and surface observations indicate that the low-frequency variations in CAR frequency are closely associated with the variations in monsoon southwesterly winds over the South China Sea and island-wide sea breeze convergence. The regional low-level circulation changes are linked to sea surface temperature anomalies over the Niño-4 region and its 10-20 year (quasi-decadal) oscillation. Regarding the processes that change the CAR rate in the trending patterns, it was found that increases in the moisture flux convergence and the moist (conditional) instability over the lower plains together explain the stronger CAR events in the long run.

  14. Evaluación del desempeño del plan de ahorro de la compañía Andes Petroleum

    OpenAIRE

    Egas Romero, José Luis

    2015-01-01

    El presente estudio está enfocado en evaluar el plan de ahorro de los empleados de la compañía Andes Petroleum Ecuador Ltd. como un beneficio de retención y capacidad de ahorro de los empleados mediante aportaciones mensuales personales y de la compañía.Se prevé analizar los resultados obtenidos por este plan de ahorros como un beneficio que apalanca la retención de personal en la compañía Andes Petroleum Ecuador Ltd. En vista de que siendo un beneficio adicional al salario de los empleados a...

  15. A mechanism for decadal variations in the frequency of extreme El Niño events

    Science.gov (United States)

    Wang, G.; Cai, W.

    2015-12-01

    The El Niño Southern Oscillation (ENSO), the largest source of Earth's climate variability on interannual time scales, has massive impacts on extreme weathers, agriculture and ecosystems, particularly during extreme El Niño events, such as the 1982/83 and 1997/98 episodes. However, the associated mechanism is not fully understood, hindering their forecasts, as attested by the false alarm of an extreme El Niño in 2014 predicted by many models. Recent studies have identified additional precursors beyond westerly wind anomalies and oceanic heat content along the equatorial Pacific, including the southwest Pacific southerly jets, which tend to occur strongly and concurrently with equatorial westerly anomalies during extreme El Niño, but NOT during weak El Niño events. Here we show that the concurrences of southwest Pacific southerlies, anomalous equatorial westerlies, and their relationship, are modulated by the Pacific Decadal Oscillation (PDO)/Interdecadal Pacific Oscillation (IPO), even on daily timescales. During a positive phase of the PDO/IPO, occurrences of westerly wind events (WWEs), in the region between the Maritime continent and the eastern Pacific Ocean, are reinforced by the southwest Pacific southerly surges (SPSSs) in austral winter. By contrast, during a negative phase of the PDO/IPO, such SPSSs are not reinforcing WWEs; instead stronger SPSSs are associated with weaker WWEs. This interdecadal contrast in the relationship between SPSSs and WWEs contributes to the decadal variations in the frequency of extreme El Niño events. The associated mechanism will be discussed.

  16. Complex permeability and permittivity variation of carbonyl iron rubber in the frequency range of 2 to 18 GHz

    Directory of Open Access Journals (Sweden)

    Adriana Medeiros Gama

    2010-04-01

    Full Text Available The complex dielectric permittivity (e and magnetic permeability (m of Radar Absorbing Materials (RAM based on metallic magnetic particles (carbonyl iron particles embedded in a dielectric matrix (silicon rubber have been studied in the frequency range of 2 to 18 GHz. The relative permeability and permittivity of carbonyl iron-silicon composites for various mass fractions are measured by the transmission/reflection method using a vector network analyzer. The concentration dependence of permittivity and permeability on the frequency is analyzed. In a general way, the results show that e´ parameter shows a more significant variation among the evaluated parameters (e”, m”, m’. The comparison of dielectric and magnetic loss tangents (e”/e” and m”/m’, respectively shows more clearly the variation of both parameters (e and m according to the frequency. It is also observed that higher carbonyl iron content fractions favor both dielectric and magnetic loss tangents.

  17. A Study of the Effect of Emotional State upon the Variation of the Fundamental Frequency of a Speaker

    Directory of Open Access Journals (Sweden)

    Marius Vasile GHIURCAU

    2010-01-01

    Full Text Available Telephone banking or brokering, building accesssystems or forensics are some of the areas in which speakerrecognition is continuously developing. Fundamental frequencyrepresents an important speech feature used in theseapplications. In this paper we present a study of the effect ofemotional state of a speaker upon the variation of thefundamental frequency of the speech signal. Human beings arequite frequently overwhelmed by various emotions and most ofthe time one can not really control these emotional states. Forthe purpose of our work we have used the Berlin emotionalspeech database which contains utterances of 10 speakers indifferent emotional situations: happy, angry, fearful, bored andneutral. The mean fundamental frequency and also the standarddeviation for every speaker in all the emotional states werecomputed. The results show a very strong influence of theemotional state upon frequency variation.

  18. Improved Frequency Control from Wind Power Plants Considering Wind Speed Variation

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Das, Kaushik; Altin, Müfit;

    2016-01-01

    A fast frequency controller (FFC) for wind power plants (WPPs), which produces a temporary overloading power reference based on frequency deviation and rate of change of frequency, is proposed in this paper. Contrary to standard controllers proposed in the literature, the gains of the FFC...

  19. Theoretical investigation of the variation of the radiation frequency of atmospheric-pressure CO/sub 2/ lasers in the course of a lasing pulse

    Energy Technology Data Exchange (ETDEWEB)

    Kuntsevich, B.F.; Maliuta, D.D.; Mezhevov, V.S.; Napartovich, A.P.; Strel' tsov, A.P.

    1987-02-01

    The variation of the radiation frequency during the emission pulse of atmospheric-pressure CO/sub 2/ lasers is studied for the case where the underlying mechanisms responsible for the frequency sweeping are the variation of the density of free electrons in the discharge and anomalous dispersion. The frequency variation can take on both a monotonic and nonmonotonic character. If the initial position of the resonator's longitudinal mode is fixed, then the frequency range within which the main fraction of the lasing energy luminesces changes with variations of the photon lifetime in the resonator and of the energy stored by the discharge. 17 references.

  20. SU-E-T-408: Evaluation of the Type and Frequency of Variations Discovered During Routine Secondary Patient Chart Review

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, M; Harrison, A; Lockamy, V; Li, J; Peng, C; Potrebko, P; Yu, Y; Doyle, L; Cao, J [Thomas Jefferson University, Philadelphia, PA (United States)

    2015-06-15

    Purpose: Desire to improve efficiency and throughput inspired a review of our physics chart check procedures. Departmental policy mandates plan checks pre-treatment, after first treatment and weekly every 3–5 days. This study examined the effectiveness of the “after first” check with respect to improving patient safety and clinical efficiency. Type and frequency of variations discovered during this redundant secondary review was examined over seven months. Methods: A community spreadsheet was created to record variations in care discovered during chart review following the first fraction of treatment and before the second fraction (each plan reviewed prior to treatment). Entries were recorded from August 2014 through February 2015, amounting to 43 recorded variations out of 906 reviewed charts. The variations were divided into categories and frequencies were assessed month-to-month. Results: Analysis of recorded variations indicates an overall variation rate of 4.7%. The initial rate was 13.5%; months 2–7 average 3.7%. The majority of variations related to discrepancies in documentation at 46.5%, followed by prescription, plan deficiency, and dose tracking related variations at 25.5%, 12.8%, and 12.8%, respectively. Minor variations (negligible consequence on patient treatment) outweighed major variations 3 to 1. Conclusion: This work indicates that this redundant secondary check is effective. The first month spike in rates could be due to the Hawthorne/observer effect, but the consistent 4% variation rate suggests the need for periodical re-training on variations noted as frequent to improve awareness and quality of the initial chart review process, which may lead to improved treatment quality, patient safety and increased clinical efficiency. Utilizing these results, a continuous quality improvement process following Deming’s Plan-Do-Study-Act (PDSA) methodology was generated. The first iteration of this PDSA was adding a specific dose tracking

  1. Carbon Bonds and the saving of energy; Bonos de carbono y el ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Ramirez, Alejandro [NovaEnergia (Mexico)

    2005-07-01

    This document deals with the development of the carbon bond project, the energy saving and the entry into force of the Kyoto Protocol at a world-wide level. In this project Mexico opts for a development model in which the economic growth brakes ties with the discharge of greenhouse effect gases and in which the progress does not mean more damages to our planet. [Spanish] Este documento trata sobre el desarrollo del proyecto de bonos de carbono, ahorro de energia y la entrada en vigor del Protocolo de Kyoto a nivel mundial, en el cual Mexico opta por un modelo de desarrollo en el que el crecimiento economico esta desvinculado de la emision de gases de efecto invernadero y en donde el progreso no signifique mas danos a nuestro planeta.

  2. Energy conservation in ice manufacturing; Ahorro de energia en la fabricacion de hielo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This paper shows the results of the energy diagnosis study for ice manufacturing industries. The identified opportunities for conservation and efficient use of energy have allowed the reduction of the electric bill, modernizing at the same time, its installations and addressing inherent aspects of the use of energy producing items; in which the estimated investments are recovered in its major part in a period of a year, the goodness of the investments propitiate the growth and competitiveness required in these days. [Espanol] En este documento se exponen los resultados del estudio del diagnostico energetico para industrias productoras de hielo. Las oportunidades de ahorro y uso eficiente de energia identificadas, han permitido reducir la facturacion energetica, a la par de modernizar sus instalaciones y atender aspectos inherentes al uso de energeticos; en lo cual las inversiones estimadas se recuperan en su mayoria en un ano, las bondades de las inversiones propician un crecimiento y competitividad requerida en estos dias.

  3. Energy saving in agricultural pumping equipment; Ahorro de energia en equipos de bombeo agricola

    Energy Technology Data Exchange (ETDEWEB)

    Acosta Torres, R. Aracely [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1993-12-31

    This paper analyses the current state of the pumping equipment for agricultural irrigation in Mexico. Because of being of the vertical centrifugal turbine type pumps, the most commonly utilized for this service, the study has been focussed into this equipment, obtaining efficiency and consumption scenarios, as well as the potential energy saving existing in this sector. [Espanol] En el presente articulo se analiza el estado actual de los equipos de bombeo para riego agricola en Mexico, al ser las bombas centrifugas verticales tipo turbina, las mas comunmente utilizadas para este servicio, el estudio ha sido enfocado a estos equipos, obteniendose los escenarios de eficiencias y consumos, asi como, el potencial de ahorro energetico existente en este sector.

  4. Compact fluorescent lamps, innovation for electricity saving; Lamparas fluorescentes compactas, innovacion para el ahorro de electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, Fernando [Fideicomiso para el Ahorro de Energia Electrica (Mexico); Camacho P, Wendolin E; Villalobos Alarcon, German [Phillips Lighting Mexico (Mexico)

    2007-01-15

    An extremely important resource is electricity because it has provided illumination for homes, buildings and cities in the absence of natural light. Therefore, the human being is considering to save this valuable resource by using sophisticated light bulbs. At the end of the 70's the compact fluorescent lamps appeared. In this article we can disclose the advantages and disadvantages of this technology, and how some years later of its invention, those lamps satisfied the client expectations, due to its cost, electricity saving, longer lifetime, use possibilities, and technological improvements. We can also know how Federal Electricity Commission (CFE) and The Trust Fund for Electric Energy Savings (FIDE) supported a project to favor these lamps to be in the Mexican market. [Spanish] La electricidad es un recurso de suma importancia porque ha contribuido a la iluminacion de casas, edificios y ciudades, ante la ausencia de luz natural, es por ello que se ha buscado ahorrar este recurso tan preciado con el uso de lamparas sofisticadas. Una tecnologia que aparecio a finales de los anos 70 fueron las lamparas fluorescentes compactas. En este articulo encontramos sus ventajas y desventajas, y como despues de algunos anos de su creacion comenzaron a llenar las expectativas del cliente gracias a su costo, ahorro de electricidad, mayor tiempo de vida, posibilidades de aplicacion y mejoras tecnologicas. Asi mismo podemos conocer, el proyecto que se hizo para que esta tecnologia entrara al mercado mexicano, con el apoyo de la Comision Federal de Electricidad (CFE) y del Fideicomiso para el Ahorro de Energia Electrica (FIDE).

  5. Energy saving and efficiency in building; Ahorro de energia y eficiencia en edificios

    Energy Technology Data Exchange (ETDEWEB)

    Perez Sanchez, Maria M. [Universidad Autonoma de Yucatan, Merida, Yucatan (Mexico); Pacheco Aguilar, Francisco [Comision Federal de Electricidad, (Mexico)

    2000-07-01

    High energy consumption is one of the serious problems in the world today. Newly, this question has taken on not only economic, but also social and ecological importance. In order to reduce the amount of fossil energy, energy diagnosis are one of the most useful tools for increasing the energy efficiency in buildings. In the Faculty of Engineering, dependency of the Universidad Autonoma de Yucatan, Mexico a program of energy diagnosis was developed under an ongoing project entitled energy savings program, which begun in 1996. This paper describes a methodology about diagnosis building energy consumption building shell and energy efficiency in a case study. No doubt future developments are likely to lead to changes in the estimates. We hope that, nevertheless, this study will contribute to increased energy efficiency in this Faculty. [Spanish] En el mundo actual, uno de los problemas mas serios que se tienen es el elevado consumo de energia, que no solamente representa un problema economico sino que tambien abarca aspectos de indole social y ecologica. Con el fin de reducir el alto costo de la energia fosil, el diagnostico de energia es una de las herramientas mas poderosas para promover la eficiencia de los edificios. En la Facultad de Ingenieria, dependencia de la Universidad Autonoma de Yucatan, Mexico se esta llevando a efecto un diagnostico energetico perteneciente al programa de ahorros de energia que comenzo en el ano de 1996. En este estudio se describe una metodologia de diagnostico de ahorro energetico y eficiencia energetica de la envolvente termica en un estudio del caso, aplicado a los edificios de la Facultad de Ingenieria (FIUADY).

  6. Saving of electrical energy in educative institutions; Ahorro de energia electrica en instituciones educativas

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Medina, Gabino [Instituto Tecnologico y de Estudios Superiores de Monterrey Campus Estado de Mexico, (Mexico)

    2003-07-01

    The present work looks for integrating the actions of energy saving that can be applied in educative institutions, not concerning the level or size of the same ones. The actions go from questions of making aware the student population until those involved in the change in the operation, migration and implementation of technology. Without overlooking the formative aspect that the educative institutions have and the social commitment of these last ones. It is important that the saving measures have as mission to achieve a culture focussed to make efficient use of the resources, of energy as well as material. This culture must be born from the classrooms and must transform the way to be and act of the student community that will permeate itself with the society. Let us remember that actions are worth more than words, so the educative institutions must preach with the example. [Spanish] El presente trabajo busca integrar las acciones de ahorro de energia que pueden ser aplicadas en instituciones educativas, no importando el nivel o tamano de las mismas. Las acciones van desde cuestiones de concienciar a la poblacion estudiantil hasta las que involucran el cambio en la operacion, migracion e implementacion de tecnologia. Sin perder de vista el aspecto formativo que tienen las instituciones educativas y el compromiso social de estas ultimas. Es importante que las medidas de ahorro tengan como mision lograr una cultura enfocada a hacer uso eficiente de los recursos, tanto energeticos como materiales. Dicha cultura debe nacer desde las aulas y debe transformar la manera de ser y actuar, de la comunidad estudiantil que se permeara con la sociedad. Recordemos que las acciones valen mas que las palabras, asi que las instituciones educativas deben predicar con el ejemplo.

  7. México: la economía de los sectores institucionales, distribución del ingreso, ahorro y crecimiento

    Directory of Open Access Journals (Sweden)

    Roberto Michel Padilla

    2003-01-01

    Full Text Available A partir del análisis de las cuentas nacionales de México por sector institucional se descubre una relación de sustitución perfecta entre el ahorro externo y el ahorro interno. Cambios en la disponibilidad de ahorro externo generan, mediante diferentes mecanismos, variaciones en el mismo sentido en la participación de los salarios y los dividendos en el producto y en sus propensiones al consumo; y en sentido opuesto en el ahorro interno de las empresas. La relación de causalidad es clara; a mayor disponibilidad de ahorro externo mayor ingreso de los hogares y mayor consumo, no al revés. Mediante una reformulación del modelo de N. Kaldor, (1955, para incluir el ahorro externo y diferenciando las ganancias entre dividendos y ganancias retenidas, se formalizan y estiman, econométricamente, las relaciones entre los coeficientes de inversión, ahorro externo y dividendos por un lado y la distribución del ingreso entre salarios y ganancias por otro. Se resalta la importancia estratégica que la conducta económica de los dirigentes empresariales, manifiesta en las decisiones de inversión y en la propensión a distribuir las ganancias , ejerce sobre el crecimiento económico la distribución del ingreso, el consumo, el ahorro y la balanza de pagos. Hasta hoy, México se ha endeudado con el exterior para aumentar su consumo no para ampliar su planta productiva.

  8. High frequency genetic variation of purine biosynthesis genes is a mechanism of success in Campylobacter jejuni

    Science.gov (United States)

    Phenotypic variation is prevalent among progeny of the zoonotic pathogen Campylobacter jejuni, the leading agent of enterocolitis in the developed world. Heterogeneity bestows increased survival to bacterial populations because variable phenotypes ensure some cells will be protected against future s...

  9. Investigation of switching frequency variations in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard

    2009-01-01

    Class D audio amplifiers have gained significant influence in sound reproduction due to their high efficiency. One of the most commonly used control methods in class D amplifiers is known as self-oscillation. An parameter of key interest in self-oscillating class D amplifiers is the switching...... frequency, which can be directly related to the performance of the amplifier. This paper will clearify the myth of the switching frequency through investigation of its dependency on modulation index and reference frequency. Validation is done using simulations and an 50 W amplifier providing 0...

  10. Variation.

    Science.gov (United States)

    Hamilton City Board of Education (Ontario).

    Suggestions for studying the topic of variation of individuals and objects (balls) to help develop elementary school students' measurement, comparison, classification, evaluation, and data collection and recording skills are made. General suggestions of variables that can be investigated are made for the study of human variation. Twelve specific…

  11. Time variation in the low frequency spectrum of Vela-like pulsar B1800-21

    CERN Document Server

    Basu, Rahul; Lewandowski, Wojciech; Kijak, Jarosław; Dembska, Marta

    2016-01-01

    We report the flux measurement of the Vela like pulsar B1800-21 at the low radio frequency regime over multiple epochs spanning several years. The spectrum shows a turnover around the GHz frequency range and represents a typical example of gigahertz-peaked spectrum (GPS) pulsar. Our observations revealed that the pulsar spectrum show a significant evolution during the observing period with the low frequency part of the spectrum becoming steeper, with a higher turnover frequency, for a period of several years before reverting back to the initial shape during the latest measurements. The spectral change over times spanning several years requires dense structures, with free electron densities around 1000--20000 cm$^{-3}$ and physical dimensions ~220 AU, in the interstellar medium (ISM) traversing across the pulsar line of sight. We look into the possible sites of such structures in the ISM and likely mechanisms particularly the thermal free-free absorption as possible explanations for the change.

  12. Geographic Variation in Festuca rubra L. Ploidy Levels and Systemic Fungal Endophyte Frequencies

    Science.gov (United States)

    Dirihan, Serdar; Helander, Marjo; Väre, Henry; Gundel, Pedro E.; Garibaldi, Lucas A.; Irisarri, J. Gonzalo N.; Saloniemi, Irma; Saikkonen, Kari

    2016-01-01

    Polyploidy and symbiotic Epichloë fungal endophytes are common and heritable characteristics that can facilitate environmental range expansion in grasses. Here we examined geographic patterns of polyploidy and the frequency of fungal endophyte colonized plants in 29 Festuca rubra L. populations from eight geographic sites across latitudes from Spain to northernmost Finland and Greenland. Ploidy seemed to be positively and negatively correlated with latitude and productivity, respectively. However, the correlations were nonlinear; 84% of the plants were hexaploids (2n = 6x = 42), and the positive correlation between ploidy level and latitude is the result of only four populations skewing the data. In the southernmost end of the gradient 86% of the plants were tetraploids (2n = 4x = 28), whereas in the northernmost end of the gradient one population had only octoploid plants (2n = 8x = 56). Endophytes were detected in 22 out of the 29 populations. Endophyte frequencies varied among geographic sites, and populations and habitats within geographic sites irrespective of ploidy, latitude or productivity. The highest overall endophyte frequencies were found in the southernmost end of the gradient, Spain, where 69% of plants harbored endophytes. In northern Finland, endophytes were detected in 30% of grasses but endophyte frequencies varied among populations from 0% to 75%, being higher in meadows compared to riverbanks. The endophytes were detected in 36%, 30% and 27% of the plants in Faroe Islands, Iceland and Switzerland, respectively. Practically all examined plants collected from southern Finland and Greenland were endophyte-free, whereas in other geographic sites endophyte frequencies were highly variable among populations. Common to all populations with high endophyte frequencies is heavy vertebrate grazing. We propose that the detected endophyte frequencies and ploidy levels mirror past distribution history of F. rubra after the last glaciation period, and local

  13. High-Frequency EEG Variations in Children with Autism Spectrum Disorder during Human Faces Visualization

    Directory of Open Access Journals (Sweden)

    Celina A. Reis Paula

    2017-01-01

    Full Text Available Autism spectrum disorder (ASD is a neuropsychiatric disorder characterized by the impairment in the social reciprocity, interaction/language, and behavior, with stereotypes and signs of sensory function deficits. Electroencephalography (EEG is a well-established and noninvasive tool for neurophysiological characterization and monitoring of the brain electrical activity, able to identify abnormalities related to frequency range, connectivity, and lateralization of brain functions. This research aims to evidence quantitative differences in the frequency spectrum pattern between EEG signals of children with and without ASD during visualization of human faces in three different expressions: neutral, happy, and angry. Quantitative clinical evaluations, neuropsychological evaluation, and EEG of children with and without ASD were analyzed paired by age and gender. The results showed stronger activation in higher frequencies (above 30 Hz in frontal, central, parietal, and occipital regions in the ASD group. This pattern of activation may correlate with developmental characteristics in the children with ASD.

  14. Searches for high frequency variations in the 8-B neutrino flux at the Sudbury neutrino observatory

    Energy Technology Data Exchange (ETDEWEB)

    Rielage, Keith [Los Alamos National Laboratory; Seibert, Stanley R [Los Alamos National Laboratory; Hime, Andrew [Los Alamos National Laboratory; Elliott, Steven R [Los Alamos National Laboratory; Stonehill, L C [Los Alamos National Laboratory; Wouters, J M [Los Alamos National Laboratory; Aharmim, B [LAURENTIAN UNIV; Ahmed, S N [QUEEN' S UNIV; Anthony, A E [UNIV OF TEXAS; Barros, N [PORTUGAL; Beier, E W [UNIV OF PA; Bellerive, A [CARLETON UNIV; Belttran, B [UNIV OF ALBERTA; Bergevin, M [LBNL; Biller, S D [UNIV OF OXFORD; Boudjemline, K [CARLETON UNIV; Burritt, T H [UNIV OF WASHINGTON; Cai, B [QUEEN' S UNIV; Chan, Y D [LBNL; Chauhan, D [LAURENTIAN UNIV; Chen, M [QUEEN' S UNIV; Cleveland, B T [UNIV OF OXFORD; Cox - Mobrand, G A [UNIV OF WASHINGTON; Dai, X [QUEEN' S UNIV; Deng, H [UNIV OF PA; Detwiler, J [LBNL; Dimarco, M [QUEEN' S UNIV; Doe, P J [UNIV OF WASHINGTON; Drouin, P - L [CARLTON UNIV; Duba, C A [UNIV OF WASHINGTON; Duncan, F A [SNOLAB, SUDBURY; Dunford, M [UNIV OF PA; Earle, E D [QUEEN' S UNIV; Evans, H C [QUEEN' S UNIV; Ewan, G T [QUEEN' S UNIV; Farine, J [LAURENTTIAN UNIV; Fergani, H [UNIV OF OXFORD; Fleurot, F [LAURENTIAN UNIV; Ford, R J [SNOLAB, SUDBURY; Formaggilo, J A [MASSACHUSETTS INST. OF TECH.; Gagnon, N [UNIV OF WASHINGTON; Goon, J Tm [LOUISIANA STATE UNIV; Guillian, E [QUEEN' S UNIV; Habib, S [UNIV OF ALBERTA; Hahn, R L [BNL; Hallin, A L [UNIV OF ALBERTA; Hallman, E D [LAURENTIAN UNIV; Harvey, P J [QUEEN' S UNIV; Hazama, R [UNIV OF WASHINGTON; Heintzelman, W J [UNIV OF PA; Heise, J [SNOLAB, SUDBURY; Helmer, R L [TRIUMF; Howard, C [UNIV OF ALBERTA; Howe, M A [UNIV OF WASHINGTON; Huang, M [UNIV OF TEXAS; Jamieson, B [UNIV OF BRITISH COLUMBIA; Jelley, N A [UNIV OF OXFORD; Keeter, K J [SNOLAB, SUDBURY; Klein, J R [UNIV OF TEXAS; Kos, M [QUEEN' S UNIV; Kraus, C [QUEEN' S UNIV; Krauss, C B [UNIV OF ALBERTA; Kutter, T [LOUISIANA STATE UNIV; Kyba, C C M [UNIV OF PA; Law, J [UNIV OF GUELPH; Lawson, I T [SNOLAB, SUDBURY; Lesko, K T [LBNL; Leslie, J R [QUEEN' S UNIV; Loach, J C [UNIV OF OXFORD; Maclellan, R [QUEEN' S UNIV; Majerus, S [UNIV OF OXFORD; Mak, H B [QUEEN' S UNIV; Maneira, J [PORTUGAL; Martin, R [QUEEN' S UNIV; Mccauley, N [UNIV OF PA; Mc Donald, A B [QUEEN' S UNIV; Mcgee, S [UNIV OF WASHINGTON; Miffin, C [CARLETON UNIV; Miller, M L [MASSACHUSETTS INST. OF TECH.; Monreal, B [MASSACHUSETTS INST. OF TECH.; Monroe, J [MASSACHUSETTS INST. OF TECH; Morissette, B [SNOLAB, SUDBURY; Nickel, B G [UNIV OF GUELPH; Noble, A J [QUEEN' S UNIV; O' Keeffe, H M [UNIV OF OXFORD; Oblath, N S [UNIV OF WASHINGTON; Orebi Gann, G D [UNIV OF OXFORD; Oser, S M [UNIV OF BRITISH COLUMBIA; Ott, R A [MASSACHUSETTS INST. OF TECH.; Peeters, S J M [UNIV OF OXFORD; Poon, A W P [LBNL; Prior, G [LBNL; Reitzner, S D [UNIV OF GUELPH; Robertson, B C [QUEEN' S UNIV; Robertson, R G H [UNIV OF WASHINGTON; Rollin, E [CARLETON UNIV; Schwendener, M H [LAURENTIAN UNIV; Secrest, J A [UNIV OF PA; Seibert, S R [UNIV OF TEXAS; Simard, O [CARLETON UNIV; Sinclair, D [CARLETON UNIV; Sinclair, L [CARLETON UNIV; Skensved, P [QUEEN' S UNIV; Sonley, T J [MASSACHUSETTS INST. OF TECH.; Tesic, G [CARLETON UNIV; Tolich, N [UNIV OF WASHINGTON; Tsui, T [UNIV OF BRITISH COLUMBIA; Tunnell, C D [UNIV OF TEXAS; Van Berg, R [UNIV OF PA; Van Devender, B A [UNIV OF WASHINGTON; Virtue, C J [LAURENTIAN UNIV; Wall, B L [UNIV OF WASHINGTON; Waller, D [CARLETON UNIV; Wan Chan Tseung, H [UNIV OF OXFORD; West, N [UNIV OF OXFORD; Wilkerson, J F [UNIV OF WASHINGTON; Wilson, J R [UNIV OF OXFORD; Wright, A [QUEEN' S UNIV; Yeh, M [BNL; Zhang, F [CARLETON UNIV; Zuber, K [UNIV OF OXFORD

    2009-01-01

    We have peformed three searches for high-frequency signals in the solar neutrino flux measured by the Sudbury Neutrino Observatory (SNO), motivated by the possibility that solar g-mode oscillations could affect the production or propagation of solar {sup 8}B neutrinos. The first search looked for any significant peak in the frequency range l/day to 144/day, with a sensitivity to sinusoidal signals with amplitudes of 12% or greater. The second search focused on regions in which g-mode signals have been claimed by experiments aboard the SoHO satellite, and was sensitive to signals with amplitudes of 10% or greater. The third search looked for extra power across the entire frequency band. No statistically significant signal was detected in any of the three searches.

  15. Quantitatively analyzing dielectrical properties of resins and mapping permittivity variations in CFRP with high-frequency eddy current device technology

    Science.gov (United States)

    Gäbler, Simone; Heuer, Henning; Heinrich, Gert; Kupke, Richard

    2015-03-01

    Eddy current testing is well-established for non-destructive characterization of electrical conductive materials. The development of high-frequency eddy current technology (with frequency ranges up to 100 MHz) made it even possible to extend the classical fields of application towards less conductive materials like CFRP. Maxwell's equations and recent research show that the use of high-frequency eddy current technology is also suitable for non-conductive materials. In that case the change of complex impedance of the probing coil contains information on sample permittivity. This paper shows that even a quantitative measurement of complex permittivity with high-frequency eddy current device technology is possible using an appropriate calibration. Measurement accuracy is comparable to commercial capacitive dielectric analyzers. If the sample material is electrically conductive, both, permittivity and conductivity influence the complex impedance measured with high-frequency eddy current devices. Depending on the measurement setup and the sheet resistance of the sample a parallel characterization of both parameters is possible on isotropic multi-layer materials. On CFRP the permittivity measurement is much more complex due to the capacitive effects between the carbon rovings. However, first results show that at least the local permittivity variations (like those caused by thermal damages) are detectable.

  16. Genome-Wide Analysis Shows Increased Frequency of Copy Number Variation Deletions in Dutch Schizophrenia Patients

    NARCIS (Netherlands)

    Buizer-Voskamp, Jacobine E.; Muntjewerff, Jan-Willem; Strengman, Eric; Sabatti, Chiara; Stefansson, Hreinn; Vorstman, Jacob A. S.; Ophoff, Roel A.; GROUP investigators, [No Value

    2011-01-01

    Background: Since 2008, multiple studies have reported on copy number variations (CNVs) in schizophrenia. However, many regions are unique events with minimal overlap between studies. This makes it difficult to gain a comprehensive overview of all CNVs involved in the etiology of schizophrenia. We p

  17. Active noise control using noise source having adaptive resonant frequency tuning through stress variation

    Science.gov (United States)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor); Renshaw, Anthony A. (Inventor); Hedeen, Robert A. (Inventor)

    1995-01-01

    A noise source for an aircraft engine active noise cancellation system in which the resonant frequency of a noise radiating element is tuned to permit noise cancellation over a wide range of frequencies. The resonant frequency of the noise radiating element is tuned by an expandable ring embedded in the noise radiating element. Excitation of the ring causes expansion or contraction of the ring, thereby varying the stress in the noise radiating element. The ring is actuated by a controller which receives input of a feedback signal proportional to displacement of the noise radiating element and a signal corresponding to the blade passage frequency of the engine's fan. In response, the controller determines a control signal which is sent to the ring, causing the ring to expand or contract. Instead of a single ring embedded in the noise radiating panel, a first expandable ring can be bonded to one side of the noise radiating element, and a second expandable ring can be bonded to the other side.

  18. Path loss variation of on-body UWB channel in the frequency bands of IEEE 802.15.6 standard.

    Science.gov (United States)

    Goswami, Dayananda; Sarma, Kanak C; Mahanta, Anil

    2016-06-01

    The wireless body area network (WBAN) has gaining tremendous attention among researchers and academicians for its envisioned applications in healthcare service. Ultra wideband (UWB) radio technology is considered as excellent air interface for communication among body area network devices. Characterisation and modelling of channel parameters are utmost prerequisite for the development of reliable communication system. The path loss of on-body UWB channel for each frequency band defined in IEEE 802.15.6 standard is experimentally determined. The parameters of path loss model are statistically determined by analysing measurement data. Both the line-of-sight and non-line-of-sight channel conditions are considered in the measurement. Variations of parameter values with the size of human body are analysed along with the variation of parameter values with the surrounding environments. It is observed that the parameters of the path loss model vary with the frequency band as well as with the body size and surrounding environment. The derived parameter values are specific to the particular frequency bands of IEEE 802.15.6 standard, which will be useful for the development of efficient UWB WBAN system.

  19. Application of active power sensitivity to frequency and voltage variations on load shedding

    Energy Technology Data Exchange (ETDEWEB)

    Girgis, Adly A. [Clemson University, 303 Riggs Hall, Clemson, SC 29634-0915 (United States); Mathure, Shruti [ITC Holdings, MI (United States)

    2010-03-15

    The occurrence of a large disturbance in a power system can lead to a decline in the system frequency and bus voltages due to a real and reactive power deficiency or due to the formation of islands with generation-load imbalance. Load shedding is an emergency control action that can prevent a blackout in the power system by relieving the overload in some parts of the system. This paper shows that rate of change of frequency can be utilized to determine the magnitude of generation-load imbalance, while the rate of change of voltage with respect to active power can be utilized to identify the sensitive bus for load shedding. The frequency, voltages and their rate of change can be obtained by means of measurements in real-time from various devices such as digital recorders or phasor measurement units or these parameters can be estimated from the voltage data by other means such as an optimal estimation method like Kalman filtering. The rate of change of system frequency, along with the equivalent system inertia may be used to estimate the magnitude of the disturbance prior to each load shedding step. The buses with a higher rate of change of voltage may be identified as the critical ones for load shedding and load can be first shed at these buses, depending on the change in the power flow at each bus. This application is tested on the IEEE 30 bus system and the preliminary results demonstrate that it is feasible to be used in load shedding to restore system voltage and frequency. (author)

  20. Seasonal and regional variations in extreme precipitation event frequency using CMIP5

    Science.gov (United States)

    Janssen, E.; Sriver, R. L.; Wuebbles, D. J.; Kunkel, K. E.

    2016-05-01

    Understanding how the frequency and intensity of extreme precipitation events are changing is important for regional risk assessments and adaptation planning. Here we use observational data and an ensemble of climate change model experiments (from the Coupled Model Intercomparison Project Phase 5 (CMIP5)) to examine past and potential future seasonal changes in extreme precipitation event frequency over the United States. Using the extreme precipitation index as a metric for extreme precipitation change, we find key differences between models and observations. In particular, the CMIP5 models tend to overestimate the number of spring events and underestimate the number of summer events. This seasonal shift in the models is amplified in projections. These results provide a basis for evaluating climate model skill in simulating observed seasonality and changes in regional extreme precipitation. Additionally, we highlight key sources of variability and uncertainty that can potentially inform regional impact analyses and adaptation planning.

  1. A synthesis approach for antennas with a quasi-linear gain variation over a wide frequency range

    Science.gov (United States)

    Deacu, Daniela; Tamas, Razvan; Petrescu, Teodor; Tasu, Sorin

    2016-12-01

    In this paper, we propose to extend the frequency-domain synthesis approach based on a variable slope profile for antennas with a linear variation over a fractional bandwidth in the order of 100%. In that case the inflection point on the resulting profile is no longer located at its half. Thus, the profile shape will no longer be folded at the half, but at a coordinate closer to the end, the resulting shape approaching to a bow-tie antenna than to a circular dipole antenna.

  2. Variations of the Magnetosphere Resonance Frequencies During Magnetic Storm of July 15——16, 2000

    Institute of Scientific and Technical Information of China (English)

    A. Potapov; A. Polyakov; T. Polyushkina; H. Zhao

    2005-01-01

    ULF observations at two mid-latitude sites during the large geomagnetic storm of July 15-16,2000 were used to trace variations of resonance frequencies of the field line resonators. A brief description of the geomagnetic disturbance as it was observed on the ground, at the geostationary orbit, and before the Earth's bow shock is given. Then a detailed study of ULF dynamic spectra from Borok and Mondy is performed for8 succesive 6-hour intervals of July 15 and 16. In conclusion some tasks for the future work are listed.

  3. Size-related variation in arm damage frequency in the crown-of-thorns sea star, Acanthaster planci

    Institute of Scientific and Technical Information of China (English)

    Jairo Rivera-Posada; Ciemon F Caballes; Morgan S Pratchett

    2014-01-01

    Objective: To examine variation in the frequency of arm damage in different sizes of Acanthasterplanci (A. planci), assess how this damage is inflicted by fish predators, and infer the potential role of predation in population regulation. Methods:and arm damage frequency and severity was assessed. Frequency of arm damage was compared between sizes. Feeding behavior of fish predators was also observed in the laboratory. Results:This study demonstrates that sublethal predation by triggerfishes on A. planci result inDiameters of A. planci collected from three sites in the Philippines were measured extensive arm damage. Overall, 60% of A. planci sampled across all sites had sublethal injuries. The frequency of individuals with missing or regenerating arms was highest in medium-sized young adults (11-20 cm), which coincides with the phase where A. planci shift from cryptic to exposed daytime feeding. Conclusions: The high incidence of arm damage within intermediate-sized sea stars indicates that predators exercise some level of regulation on A. planci populations at a local scale. Identification and protection of putative predators that target the most vulnerable life history stages of A. planci are essential in developing population control strategies and reverse sustained declines in coral cover.

  4. Genetic variation among the Mapuche Indians from the Patagonian region of Argentina: mitochondrial DNA sequence variation and allele frequencies of several nuclear genes.

    Science.gov (United States)

    Ginther, C; Corach, D; Penacino, G A; Rey, J A; Carnese, F R; Hutz, M H; Anderson, A; Just, J; Salzano, F M; King, M C

    1993-01-01

    DNA samples from 60 Mapuche Indians, representing 39 maternal lineages, were genetically characterized for (1) nucleotide sequences of the mtDNA control region; (2) presence or absence of a nine base duplication in mtDNA region V; (3) HLA loci DRB1 and DQA1; (4) variation at three nuclear genes with short tandem repeats; and (5) variation at the polymorphic marker D2S44. The genetic profile of the Mapuche population was compared to other Amerinds and to worldwide populations. Two highly polymorphic portions of the mtDNA control region, comprising 650 nucleotides, were amplified by the polymerase chain reaction (PCR) and directly sequenced. The 39 maternal lineages were defined by two or three generation families identified by the Mapuches. These 39 lineages included 19 different mtDNA sequences that could be grouped into four classes. The same classes of sequences appear in other Amerinds from North, Central, and South American populations separated by thousands of miles, suggesting that the origin of the mtDNA patterns predates the migration to the Americas. The mtDNA sequence similarity between Amerind populations suggests that the migration throughout the Americas occurred rapidly relative to the mtDNA mutation rate. HLA DRB1 alleles 1602 and 1402 were frequent among the Mapuches. These alleles also occur at high frequency among other Amerinds in North and South America, but not among Spanish, Chinese or African-American populations. The high frequency of these alleles throughout the Americas, and their specificity to the Americas, supports the hypothesis that Mapuches and other Amerind groups are closely related.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Ahorro energético mediante estrategias de iluminación natural optimizadas

    Directory of Open Access Journals (Sweden)

    Puigdomènech Franquesa, Joan

    1986-04-01

    Full Text Available Electrical charges in buildings and specially in those of commercial use, can be diminished by means of natural lighting strategies. Taking the climate features of our country into consideration, it is necessary to prevent the inconveniences caused by an en erg y excess in summer, so solar Controls are needed. The only practical way to achieve the suitable balance between thermal and light needs, so as to get a monthly or annual energetic balance optimization, is to operate with the computer. A programme with such characteristics is described here. Its application gives important sarings in non renouvable energy savings.Mediante estrategias de iluminación natural es posible disminuir las cargas eléctricas de los edificios y en especial los de uso comercial. Dadas las características climáticas de nuestro país es necesario prever los inconvenientes de un exceso de energía en verano, para lo cual es preciso disponer de controles solares. Encontrar el correcto equilibrio entre las necesidades térmicas y lumínicas en base a la optimización del balance energético mensual o anual es únicamente factible mediante el uso del ordenador. Un programa que responde a estas características es descrito en el presente trabajo, obteniéndose con su aplicación importantes ahorros en el consumo de energías no renovables.

  6. Cálculo del ahorro de energía por menor fricción

    Directory of Open Access Journals (Sweden)

    Pedro Albarracín Aguillón

    2004-01-01

    Full Text Available En este artículo se expone como disminuir costos de operación (menor consumo de energía, costos de mantenimiento y pérdidas de producción de equipos, mediante el control de los diferentes fenómenos de la fricción en mecanismos lubricados. Para hacer esto posible es necesario conocer las condiciones criticas de trabajo de los mismos, a que tipo de lubricación corresponden, y que clase lubricante requiere, para así calcular los valores de los coeficientes de fricción de los lubricantes que se están empleando y compararlos con los de otros lubricantes que pueden dar lugar a ahorros de energía y mantenimiento. Además se presentan algunos ejemplos tomados de casos reales, que confirman que con una buena implementación de un programa de tribologia se obtienen resultados satisfactorios desde el punto de vista económico.

  7. Project of energy saving in compressed air; Proyecto de ahorro de energia en aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Automatizacion, Productividad y Calidad S.A. de C.V. Puebla, (Mexico)

    2005-07-01

    The objective of this project is to reduce the operation costs by means of the energy saving through the use of the compressed air system. For this purpose the solenoid valves controlled per time and the manually acted valves of sphere must be replaced by pneumatic purges that remove from the system the condensed humidity without discharging air and which act automatically when the water reaches the level of unloading in its deposit. The pressure level is the reduction of the operation rank of pressure in the compressors, satisfying the operation requirements of the process equipment. [Spanish] El objetivo de este proyecto es reducir el costo de operacion mediante el ahorro de energia en la utilizacion del sistema de aire comprimido. Para ello se tienen que remplazar las valvulas solenoides controladas por tiempo y valvulas de esfera actuadas manualmente por purgas neumaticas que remueven del sistema la humedad condensada sin descargar aire y que actuan en forma automatica al alcanzar el agua el nivel de descarga en su deposito. El nivel de presion es la reduccion del rango de operacion de presion de los compresores, satisfaciendo los requerimientos de operacion de los equipos de proceso.

  8. Potential of energy saving with photovoltaic systems; Potencialidad de ahorro de energia con sistemas fotovoltaicos

    Energy Technology Data Exchange (ETDEWEB)

    Guzman S, Eusebio; Bratu S, Neagu [Universidad Autonoma Metropolitana, Mexico, D. F. (Mexico)

    1998-12-31

    This paper presents an approach on the application of photovoltaic systems in energy saving. The problem of the electric energy demand in the coming years is analyzed and its consequences on the environment and on the energy reserves of conventional sources. A model of the electric circuit equivalent to a photovoltaic cell illustrates the behavior of the photovoltaic cell in function of the climatological conditions. The former in order to show some of the limiting factors in this type of generator. Also, the evolution of the applications of the photovoltaic systems and its forecasting in the installed capacity in the next 20 years, is described. [Espanol] En este trabajo se presenta un enfoque de la aplicacion de los sistemas fotovoltaicos en el ahorro de energia. Se plantea el problema del crecimiento de la demanda energetica en los proximos anos y sus consecuencias sobre el medio ambiente y las reservas de energia por fuentes convencionales. Un modelo del circuito electrico equivalente de una celda fotovoltaica ilustra el comportamiento del generador fotovoltaico en funcion de las condiciones climatologicas. Lo anterior con el fin de mostrar algunas limitantes de este tipo de generador. Tambien se describe la evolucion de las aplicaciones de los sistemas fotovoltaicos y el pronostico de la potencia instalada en los proximos 20 anos.

  9. Remesas y Ahorro de los Migrantes Michoacanos radicados en EUA. Un Diagnóstico Preliminar

    Directory of Open Access Journals (Sweden)

    Jerjes Aguirre Ochoa

    2007-06-01

    Full Text Available El objetivo de este artículo es realizar un diagnostico del potencial productivo del ahorro migrante para el caso del estado de Michoacán. Los datos obtenidos muestran un perfil de Michoacano radicado en EUA con ingresos suficientes para enviar remesas familiares a México pero limitados para realizar inversiones mayores a 200 dólares mensuales en Michoacán. Dentro de esa limitación, de contar con capital, los michoacanos manifestaron una preferencia por invertir en México y específicamente en su comunidad de origen. La preferencia de inversión mas citada es la compra de una vivienda o reparación de la misma. Asimismo, la corrupción y la inseguridad son señaladas como obstáculos para la inversión en México. Finalmente, el alto porcentaje de migrantes indocumentados encontrados en la encuesta refleja los profundos impactos que una reforma migratoria en EUA puede tener en la dinámica económica del estado. La migración a EUA puede dejar de convertirse en la válvula de escape para la población michoacana que no encuentre oportunidades laborales en Michoacán sumiendo a la entidad en graves problemas económicos y sociales.

  10. Variations in dream recall frequency and dream theme diversity by age and sex

    Directory of Open Access Journals (Sweden)

    Tore eNielsen

    2012-07-01

    Full Text Available We assessed dream recall frequency and dream theme diversity with an internet questionnaire among a cohort of 28,888 male and female participants aged 10 to 79 years in a cross-sectional design. Dream recall frequency increased from adolescence (ages 10-19 to early adulthood (20-29 and then decreased again for the next 20 years. The nature of this decrease differed for males and females. For males, it began earlier (30-39, proceeded more gradually, and reached a nadir earlier (40-49 than it did for females. For females, it began later (40-49, dropped more abruptly, and reached nadir later (50-59. Marked sex differences were observed for age strata 10-19 through 40-49 and year-by-year analyses estimated the window for these differences to be more precisely from 14-44 yrs. Dream theme diversity decreased linearly with age for both sexes up to 50-59 and then dropped even more sharply for 60-79. There was a sex difference favouring males on this measure but only for ages 10-19. Findings replicate, in a single sample, those from several previous studies showing an increase in dream recall frequency from adolescence to early adulthood, a subsequent decrease in dream recall frequency—primarily in early and middle adulthood, and different patterns of age-related decrease in the two sexes. Age-related changes in sleep structure, such as decreasing %REM sleep, parallel the observed dream recall changes but are much smaller and more gradual in nature. Changes in the phase and amplitude of circadian rhythms of REM propensity and generational differences in life experiences may also account for some part of the findings. However, that decreases in dream theme diversity parallel known age-related decreases in episodic and autobiographical memory may signify that the diversity measure indexes an aspect of autobiographical memory that is specific to dream recall.

  11. The temporal and spatial variations of low frequency geomagnetic pulsations at polar cusp and cap latitudes

    Directory of Open Access Journals (Sweden)

    J. Bitterly

    1999-06-01

    Full Text Available Geomagnetic field measurements at two Antarctic stations are compared during two weeks in the local summer (January 1-15, 1992. Low frequency (0.6-6 mHz pulsations are observed at each station near local magnetic noon. The same wave packets appear in some cases also at the other station, although with a significant attenuation, more clearly in the morning sector; the waves show a near noon reversal of the polarization sense from counter-clockwise in the morning to clockwise in the afternoon indicating a westward and an eastward propagation, respectively.

  12. Improving Processes of Mechanized Pulsed Arc Welding of Low-Frequency Range Variation of Mode Parameters

    Science.gov (United States)

    Saraev, Yu N.; Solodskiy, S. A.; Ulyanova, O. V.

    2016-04-01

    A new technology of low-frequency modulation of the arc current in MAG and MIG welding is presented. The technology provides control of thermal and crystallization processes, stabilizes the time of formation and crystallization of the weld pool. Conducting theoretical studies allowed formulating the basic criteria for obtaining strong permanent joints for high-duty structures, providing conditions for more equilibrium structure of the deposited metal and the smaller width of the HAZ. The stabilization of time of the formation and crystallization of the weld pool improves the formation of the weld and increases productivity in welding thin sheet metal.

  13. Variation in low-frequency estimates of sound levels based on different units of analysis.

    Science.gov (United States)

    Hawkins, Russell S; Miksis-Olds, Jennifer L; Smith, Chad M

    2014-02-01

    The measurement and analysis of underwater sound is a complicated process because of the variable durations of contributing sources and constantly changing water column dynamics. Because the ambient sound distribution does not always follow a Gaussian structure and may be nonstationary in time, analysis over an extended period is required to accurately characterize the data. Utilizing recordings from the Indian Ocean, the temporal variation in ambient sound including transient signals was examined using multiple processing window lengths and subsampling intervals. Results illustrate the degree of uncertainty in sound levels based on different units of analysis. The average difference between sound level estimates in the 10-30 Hz band due to subsampling was 2 dB and as high as 4 dB. The difference in the full band (5-110 Hz) was as high as 6 dB. Longer averaging windows (200 vs 60 s) resulted in larger variations over different subsampling intervals. This work demonstrates how sampling protocols within a single dataset can influence results and acknowledges that comparative studies at the same location but with different sampling protocols can be substantial if signal processing parameters are not statistically accounted for to confirm interpretation of results and observed trends.

  14. Improving the accuracy: volatility modeling and forecasting using high-frequency data and the variational component

    Directory of Open Access Journals (Sweden)

    Manish Kumar

    2010-06-01

    Full Text Available In this study, we predict the daily volatility of the S&P CNX NIFTY market index of India using the basic ‘heterogeneous autoregressive’ (HAR and its variant. In doing so, we estimated several HAR and Log form of HAR models using different regressor. The different regressors were obtained by extracting the jump and continuous component and the threshold jump and continuous component from the realized volatility. We also tried to investigate whether dividing volatility into simple and threshold jumps and continuous variation yields a substantial improvement in volatility forecasting or not. The results provide the evidence that inclusion of realized bipower variance in the HAR models helps in predicting future volatility.

  15. Can the Tibetan Plateau snow cover influence the interannual variations of Eurasian heat wave frequency?

    Science.gov (United States)

    Wu, Zhiwei; Zhang, Peng; Chen, Hua; Li, Yun

    2016-06-01

    The Eurasian continent has experienced significant year-to-year variations of summer heat waves during the past decades. Several possible factors, such as ocean temperature, soil moisture, and changes in land use and greenhouse gases, have been identified in previous studies, but the mechanisms are still unclear. In this study, it is found that the Tibetan Plateau snow cover (TPSC) is closely linked to the interannual variations of summer heat waves over Eurasia. The TPSC variability explains more than 30 % of the total variances of heat wave variability in the southern Europe and northeastern Asia (SENA) region. A set of numerical experiments reveal that the reduced TPSC may induce a distinct teleconnection pattern across the Eurasian continent, with two anomalous high pressure centers in the upper troposphere over the SENA region, which may lead to a reduction of the cloud formation near the surface. The less cloud cover tends to increase the net shortwave radiation and favor a stronger surface sensible heat flux in the dry surface condition over the SENA region, resulting in a deeper, warmer and drier atmospheric boundary layer that would further inhibit the local cloud formation. Such a positive land-atmosphere feedback may dry the surface even further, heat the near-surface atmosphere and thereby intensify the local heat waves. The above dynamical processes also operate on interdecadal time scales. Given the reduction of the TPSC could become more pronounced with increasing levels of greenhouse gases in a warming climate, we infer that the TPSC may play an increasingly important role in shaping the summer heat waves over the SENA region in next decades.

  16. Catalogue of x-ray solar flare induced variations in sub-ionospheric very low frequency (VLF) waveguides

    Science.gov (United States)

    Eichelberger, Hans; Schwingenschuh, Konrad; Boudjada, Mohammed Y.; Besser, Bruno P.; Wolbang, Daniel; Rozhnoi, Alexander; Solovieva, Maria; Biagi, Pier F.; Stachel, Manfred; Prattes, Gustav; Aydogar, Özer; Muck, Cosima; Grill, Claudia; Jernej, Irmgard; Stachel, Thomas; Moro, Florian

    2017-04-01

    In this study we present a catalogue of solar flare induced very low frequency (VLF) variations along sub-ionospheric paths between several transmitters and the Graz seismo-electromagnetic UltraMSK receiving station. These measurements of non-seismic disturbances are important in order to carefully characterise the Earth-ionosphere VLF waveguide and disentangle possible earthquake related phenomena from natural and man-made ambient VLF amplitude and phase modifications. The period of investigation is from Jan. 2010 to April 2016, i.e. largely covers the sunspot cycle 24. In total we've 373 VLF amplitude and phase fluctuations related with C/M/X-class solar flare events (the data are from NOAA GOES x-ray flux measurements). We obtain the statistics (dependence on VLF signal vs. x-ray flux variations) for high signal-to-noise ratio VLF links under consideration of the zenith angle. We conclude, that with the mid-latitude Graz VLF knot, a part of the European receiver network, a reliable service for solar flare induced variations of the VLF waveguide can be established. In addition to complementary region-wide network multi-parameter observations this could be a crucial step towards a full characterisation of the behaviour of sub-ionospheric VLF paths including modifications related to seismic activity.

  17. Telomere length affects the frequency and mechanism of antigenic variation in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Galadriel A Hovel-Miner

    Full Text Available Trypanosoma brucei is a master of antigenic variation and immune response evasion. Utilizing a genomic repertoire of more than 1000 Variant Surface Glycoprotein-encoding genes (VSGs, T. brucei can change its protein coat by "switching" from the expression of one VSG to another. Each active VSG is monoallelically expressed from only one of approximately 15 subtelomeric sites. Switching VSG expression occurs by three predominant mechanisms, arguably the most significant of which is the non-reciprocal exchange of VSG containing DNA by duplicative gene conversion (GC. How T. brucei orchestrates its complex switching mechanisms remains to be elucidated. Recent work has demonstrated that an exogenous DNA break in the active site could initiate a GC based switch, yet the source of the switch-initiating DNA lesion under natural conditions is still unknown. Here we investigated the hypothesis that telomere length directly affects VSG switching. We demonstrate that telomerase deficient strains with short telomeres switch more frequently than genetically identical strains with long telomeres and that, when the telomere is short, switching preferentially occurs by GC. Our data supports the hypothesis that a short telomere at the active VSG expression site results in an increase in subtelomeric DNA breaks, which can initiate GC based switching. In addition to their significance for T. brucei and telomere biology, the findings presented here have implications for the many diverse pathogens that organize their antigenic genes in subtelomeric regions.

  18. The Variation of Photon Speed with Photon Frequency in Quantum Gravity

    CERN Document Server

    Dubey, Anuj Kumar; Nath, Sonarekha

    2016-01-01

    Einstein's special relativity is Lorentz invariance; the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon frequency. There is a fundamental scale the Planck scale, at which quantum effects are expected to strongly affect the nature of space-time. The commonly used ideas of space-time should break down at or before the Planck length is reached. It is then natural to question the exactness of the Lorentz invariance that is pervasive in all macroscopic theories. Quantum gravity effect could be seen from the dispersion relations violating Lorentz invariance, because the motivation for the Lorentz invariance violation is quantum gravity. Then it is expected that the energy-momentum dispersion relation could be modified to include the dependence on the ratio of the particle's energy and the quantum gravity energy. In the present work, we have derived an expression of Planck mass or Planck energy by equating the Compton wavelength with Kerr gravitational radius of...

  19. The relationship between surname frequency and Y chromosome variation in Spain

    Science.gov (United States)

    Martinez-Cadenas, Conrado; Blanco-Verea, Alejandro; Hernando, Barbara; Busby, George BJ; Brion, Maria; Carracedo, Angel; Salas, Antonio; Capelli, Cristian

    2016-01-01

    In most societies, surnames are passed down from fathers to sons, just like the Y chromosome. It follows that, theoretically, men sharing the same surnames would also be expected to share related Y chromosomes. Previous investigations have explored such relationships, but so far, the only detailed studies that have been conducted are on samples from the British Isles. In order to provide additional insights into the correlation between surnames and Y chromosomes, we focused on the Spanish population by analysing Y chromosomes from 2121 male volunteers representing 37 surnames. The results suggest that the degree of coancestry within Spanish surnames is highly dependent on surname frequency, in overall agreement with British but not Irish surname studies. Furthermore, a reanalysis of comparative data for all three populations showed that Irish surnames have much greater and older surname descent clusters than Spanish and British ones, suggesting that Irish surnames may have considerably earlier origins than Spanish or British ones. Overall, despite closer geographical ties between Ireland and Britain, our analysis points to substantial similarities in surname origin and development between Britain and Spain, while possibly hinting at unique demographic or social events shaping Irish surname foundation and development. PMID:25898922

  20. Natural variation in life history and aging phenotypes is associated with mitochondrial DNA deletion frequency in Caenorhabditis briggsae

    Directory of Open Access Journals (Sweden)

    Smith Samson W

    2011-01-01

    Full Text Available Abstract Background Mutations that impair mitochondrial functioning are associated with a variety of metabolic and age-related disorders. A barrier to rigorous tests of the role of mitochondrial dysfunction in aging processes has been the lack of model systems with relevant, naturally occurring mitochondrial genetic variation. Toward the goal of developing such a model system, we studied natural variation in life history, metabolic, and aging phenotypes as it relates to levels of a naturally-occurring heteroplasmic mitochondrial ND5 deletion recently discovered to segregate among wild populations of the soil nematode, Caenorhabditis briggsae. The normal product of ND5 is a central component of the mitochondrial electron transport chain and integral to cellular energy metabolism. Results We quantified significant variation among C. briggsae isolates for all phenotypes measured, only some of which was statistically associated with isolate-specific ND5 deletion frequency. We found that fecundity-related traits and pharyngeal pumping rate were strongly inversely related to ND5 deletion level and that C. briggsae isolates with high ND5 deletion levels experienced a tradeoff between early fecundity and lifespan. Conversely, oxidative stress resistance was only weakly associated with ND5 deletion level while ATP content was unrelated to deletion level. Finally, mean levels of reactive oxygen species measured in vivo showed a significant non-linear relationship with ND5 deletion level, a pattern that may be driven by among-isolate variation in antioxidant or other compensatory mechanisms. Conclusions Our findings suggest that the ND5 deletion may adversely affect fitness and mitochondrial functioning while promoting aging in natural populations, and help to further establish this species as a useful model for explicit tests of hypotheses in aging biology and mitochondrial genetics.

  1. Una aproximación al análisis financiero de las cajas de ahorros andaluzas mediante el método multicriterio PROMETHEE

    Directory of Open Access Journals (Sweden)

    Asunción Zapata Reina.

    2000-01-01

    Full Text Available En este trabajo se hace un análisis económico y financiero de las cajas de ahorros andaluzas. Se abordan los diferentes aspectos (estructura patrimonial, estructura de costes, rentabilidad, productividad y solvencia de las seis cajas que configuran el sistema andaluz de cajas de ahorros, agrupadas en la confederación andaluza de cajas de ahorros, por medio de un conjunto de ratios. El gran número y la diversidad de ratios disponibles en el problema, generalmente en conflictos unos con otros, confiere a éste una dimensión multicriterio que analizamos con el método PROMETHEE. Procedimiento que permite sintetizar la información disponible sobre el conjunto estudiado.

  2. Time variation in amplitude-frequency distribution of deep non-volcanic tremors in the Bungo Channel region, southwest Japan

    Science.gov (United States)

    Hanakawa, Y.; Suda, N.

    2009-12-01

    Magnitude-frequency distribution of earthquakes follows the Gutenberg-Richter law. The slope of this law, b value, represents the relative occurrence of large and small earthquakes. Since magnitude is defined as corrected logarithmic amplitude, amplitude-frequency distribution of earthquakes is linear on log-log graph. On the other hand, that of non-volcanic tremors is linear on semi-log graph, indicating that it follows the exponential distribution, not the power-law distribution [Hiramatsu et al., 2008]. Thus the slope of amplitude-frequency distribution for tremors is equivalent to b value for earthquakes. In this study, we investigated time variation in the slope of amplitude-frequency distribution from analyses of tremor activities in the Bungo Channel region, where long-term slow slip events occurred in 1997 and 2003. We analyzed vertical-component records from Hi-net and the seismic networks of Japan Meteorological Agency and universities for the five-year period between 2004 and 2008. We also used records from the temporal seismic station in Hiburi Island installed by us in the period after Sept. 2004. In the Bungo Channel region, tremor activity occurs with a recurrence interval of approximately two months. We observed a total of 35 activities including small ones in the analysis period. To detect tremors and determine their hypocenters, we used the same software as Automatic Tremor Monitoring System (ATMOS) [Suda et al., in press]. We obtained frequency distribution of reduced displacements (RDs) for each tremor activity. RD is RMS amplitude of ground displacement corrected with hypocentral distance [Aki and Koyanagi, 1981], and it is proportional to seismic moment rate. The observed slopes of RD-frequency distribution for active swarms were approximately constant in the period between 2004 and 2006, but they declined in 2007. At the end of 2008, the slopes decreased bellow half the values between 2004 and 2006. As well as b value, the slope represents

  3. Time-frequency analysis of beach bacteria variations and its implication for recreational water quality modeling.

    Science.gov (United States)

    Ge, Zhongfu; Frick, Walter E

    2009-02-15

    This paper exploited the potential of the wavelet analysis in resolving beach bacteria concentration and candidate explanatory variables across multiple time scales with temporal information preserved. The wavelet transform of E. coli concentration and its explanatory variables observed at Huntington Beach, Ohio in 2006 exhibited well-defined patterns of different time scales, phases, and durations, which cannot be clearly shown in conventional time-domain analyses. If linear regression modeling is to be used for the ease of implementation and interpretation,the wavelet-transformed regression model reveals that low model residual can be realized through matching major patterns and their phase angles between E. coli concentration and its explanatory variables. The property of pattern matching for linear regression models can be adopted as a criterion for choosing useful predictors, while phase matching further explains why intuitively good variables such as wave height and onshore wind speed were excluded from the optimal models by model selection processes in Frick et al. (Environ. Sci. Technol. 2008, 42,4818-4824). The phase angles defined by the wavelet analysis in the time-frequency domain can help identify the physical processes and interactions occurring between bacteria concentration and its explanatory variables. It was deduced, for this particular case, that wind events resulted in elevated E. coli concentration, wave height, and turbidity at the beach with a periodicity of 7-8 days. Wind events also brought about increased beach bacteria concentrations through large-scale current circulations in the lake with a period of 21 days. The time length for linear regression models with statistical robustness can also be deduced from the periods of the major patterns in bacteria concentration and explanatory variables, which explains and supplements the modeling efforts performed in (1).

  4. Variations in Dream Recall Frequency and Dream Theme Diversity by Age and Sex

    Science.gov (United States)

    Nielsen, Tore

    2012-01-01

    We assessed dream recall frequency (DRF) and dream theme diversity (DTD) with an internet questionnaire among a cohort of 28,888 male and female participants aged 10–79 years in a cross-sectional design. DRF increased from adolescence (ages 10–19) to early adulthood (20–29) and then decreased again for the next 20 years. The nature of this decrease differed for males and females. For males, it began earlier (30–39), proceeded more gradually, and reached a nadir earlier (40–49) than it did for females. For females, it began later (40–49), dropped more abruptly, and reached nadir later (50–59). Marked sex differences were observed for age strata 10–19 through 40–49 and year-by-year analyses estimated the window for these differences to be more precisely from 14 to 44 years. DTD decreased linearly with age for both sexes up to 50–59 and then dropped even more sharply for 60–79. There was a sex difference favoring males on this measure but only for ages 10–19. Findings replicate, in a single sample, those from several previous studies showing an increase in DRF from adolescence to early adulthood, a subsequent decrease primarily in early and middle adulthood, and different patterns of age-related decrease in the two sexes. Age-related changes in sleep structure, such as decreasing %REM sleep which parallel the observed dream recall changes, might help explain these findings, but these sleep changes are much smaller and more gradual in nature. Changes in the phase and amplitude of circadian rhythms of REM propensity and generational differences in life experiences may also account for some part of the findings. That decreases in DTD parallel known age-related decreases in episodic and autobiographical memory may signify that this new diversity measure indexes an aspect of autobiographical memory that also influences dream recall. PMID:22783222

  5. Energy saving in the sugar cane agroindustry; Ahorro de energia en la agroindustria azucarera canera

    Energy Technology Data Exchange (ETDEWEB)

    Zedillo Ponce de Leon, Luis [Grupo de paises Latinoamericanos y del Caribe exportadores de azucar (Mexico)

    1996-07-01

    The traditional sugar mill is inefficient from the energy point of view. Most of the sugar mills were designed to use all the available bagasse, due to the risk of spontaneous ignition and environmental pollution. Consequently, the steam generators, the turbines and other components were designed to work with low efficiencies. Each ton of sugar produced generates a power potential equivalent to four to six oil barrels (bagasse and residues). That is to say, a sugar mill is capable of producing 500 ton/day of sugar, equivalent to an oil well of 2000 to 3000 barrels/day and one thermoelectric power plant of 15,000 kW. Under this context an analysis is made of the sugar mills in Latin America and the Caribbean as one of the ways of increasing their efficiency and obtain great energy savings. As far as steam generation the appropriate use of energy is dictated by the boilers' efficiency. [Spanish] El ingenio azucarero tradicional es ineficiente desde el punto de vista energetico. La mayoria de los ingenios azucareros se disenaron para usar todo el bagazo disponible, debido al riesgo de ignicion espontanea y contaminacion. En consecuencia, los generadores de vapor, las turbinas y demas componentes fueron disenados para trabajar con bajas eficiencias. Cada tonelada de azucar producida genera una potencialidad energetica equivalente de cuatro a seis barriles de petroleo (bagazo y residuos). Es decir, un ingenio capaz de producir 500 ton/dia de azucar equivalente a un pozo de petroleo de 2000 a 3000 barriles/dia y una termoelectrica de 15000 kW. Bajo este contexto se hace un analisis del ingenio azucarero en Latinoamerica y el Caribe como una de las vias para incrementar su eficiencia y lograr grandes ahorros en la energia. En cuanto a generacion de vapor se refiere, el buen uso de la energia viene expresado por la eficiencia de las calderas.

  6. Modelo de gestión del riesgo crediticio en la cooperativa de ahorro y crédito Mirachina

    OpenAIRE

    2016-01-01

    1. Introducción. --2. Planteamiento de la Propuesta de Trabajo. --3. Marco Teórico. --4. Metodología. --5. Resultados La presente investigación tiene como objeto desarrollar un modelo de gestión del riesgo de crédito en la Cooperativa de Ahorro y Crédito Mirachina, para disminuir el índice de morosidad e incrementar los niveles de liquidez, alcanzando los parámetros exigidos por la entidad de control. Con esta mejora se reducirá a un dígito el riesgo de morosidad, mediante la aplicación de...

  7. Experiences of energy saving and co-generation projects; Experiencias de proyectos de ahorro de energia y cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Barajas, Alberto [Heat and Power Systems, S.A. de C.V., Mexico D.F. (Mexico)

    2005-07-01

    In this document are presented the successful projects of energy saving and co-generation that Heat and Power Systems, S.A. de C.V. has made in diverse industries. The investment recovery periods have been smaller to 18 months. The projects have been made for different companies within Mexican Republic. [Spanish] Se presentan los casos exitosos de proyectos de ahorro de energia y cogeneracion que Heat and Power Systems, S.A. de C.V. ha realizado en diversas industrias cuyo periodo de recuperacion de la inversion han sido menores a 18 meses. Los proyectos han sido realizados para distintas empresas dentro de la Republica Mexicana.

  8. Determinantes del isomorfismo institucional de las sociedades cooperativas de ahorro y préstamos en México

    OpenAIRE

    Graciela LARA GÓMEZ; Felipe A. Pérez Sosa

    2015-01-01

    El propósito del presente trabajo es establecer si las sociedades cooperativas de ahorro y préstamo se hacen isomorfas a la banca formal en México; debido a que tales entidades tradicionalmente han operado en un entorno de informalidad, pero últimamente han transitado hacia la formalización como consecuencia de las exigencias legales impuestas por entidades regulatorias. Para este fin, el presente estudio se llevó a cabo con una orientación metodológica mixta, en la que los resultados obtenid...

  9. Diseño bioclimático en Galicia : ahorro energético y confort

    OpenAIRE

    Pena Gayo, Katia

    2016-01-01

    El objeto de estudio de la presente disertación es la arquitectura bioclimática en Galicia, comunidad situada al noroeste de la península ibérica. La investigación surge fruto de una manera de entender la arquitectura como un elemento que debe relacionarse con el entorno en el que se ubica, aprovechando las condiciones del medio a su favor para generar ahorro energético y un mayor confort a sus ocupantes. El carácter limitado de recursos energéticos, junto con los problemas act...

  10. La Percepción Emocional del Dinero como Determinante de un Comportamiento de Ahorro o Endeudamiento

    Directory of Open Access Journals (Sweden)

    Mª Carmen Lozano Gutierrez

    2007-06-01

    Full Text Available En el presente artículo se realiza un análisis de afinidades en la percepción del dinero para las personas que ahorran o se endeudan, con la finalidad de establecer las consecuencias que en el comportamiento económico propio de cada grupo tienen las valoraciones subjetivas en relación al dinero. Las conclusiones a las que llegamos podrían servir para el desarrollo de estrategias de promoción del ahorro y contención del endeudamiento.

  11. La Percepción Emocional del Dinero como Determinante de un Comportamiento de Ahorro o Endeudamiento

    OpenAIRE

    Mª Carmen Lozano Gutierrez; Federico Fuentes Martín

    2007-01-01

    En el presente artículo se realiza un análisis de afinidades en la percepción del dinero para las personas que ahorran o se endeudan, con la finalidad de establecer las consecuencias que en el comportamiento económico propio de cada grupo tienen las valoraciones subjetivas en relación al dinero. Las conclusiones a las que llegamos podrían servir para el desarrollo de estrategias de promoción del ahorro y contención del endeudamiento.

  12. Variations in dust event frequency over the past century reflected by ice-core and lacustrine records in north China

    Institute of Scientific and Technical Information of China (English)

    WANG NingLian; YAO TanDong; YANG XiangDong; SHEN Ji; WANG Yong

    2007-01-01

    In this paper, we analyzed the variations of dust proxies in the Dunde, Malan and Chongce ice cores from the northern Tibetan Plateau and the Hongjiannao lacustrine sediment core from north Shaanxi Province, and found that they all showed a general decrease trend over the past century. Owing to the fact that all these ice cores and lacustrine core were retrieved from the margins and/or the leeward sides of the major areas of dust events in north China, their records could suggest that the dust event frequency in north China declined over the study period. This decrease trend might be attributed to increasing precipitation and weakening westerly. However, human activities have made the areal extent of desertification expand acceleratingly in north China. This status could make it possible that dust events would occur on a large spatial scale under the future climate change, which would be a big environmental issue we shall face.

  13. Autoregressive processes with anomalous scaling behavior: applications to high-frequency variations of a stock market index.

    Science.gov (United States)

    Dose, Christian; Porto, Markus; Roman, H Eduardo

    2003-06-01

    We employ autoregressive conditional heteroskedasticity processes to model the probability distribution function (PDF) of high-frequency relative variations of the Standard & Poors 500 market index data, obtained at the time horizon of 1 min. The model reproduces quantitatively the shape of the PDF, characterized by a Lévy-type power-law decay around its center, followed by a crossover to a faster decay at the tails. Furthermore, it is able to reproduce accurately the anomalous decay of the central part of the PDF at larger time horizons and, by the introduction of a short-range memory, also the crossover behavior of the corresponding standard deviations and the time scale of the exponentially decaying autocorrelation function of returns displayed by the empirical data.

  14. Aplicación de la Contabilidad de Costos en las Cajas Rurales de Ahorro y Crédito en el Perú, Arequipa - 2013

    OpenAIRE

    Pacheco Zegarra, Edward Víctor

    2017-01-01

    El presente trabajo de investigación busca determinar el grado de aplicación de la contabilidad de costos en las Cajas Rurales de Ahorro y Crédito en el Perú. ENUNCIADO “APLICACIÓN DE LA CONTABILIDAD DE COSTOS EN LA CAJAS RURALES DE AHORRO Y CRÉDITO EN EL PERÚ, AREQUIPA – 2013” La variable a investigar fue la aplicación de la contabilidad de costos cuyos indicadores son las generalidades de la aplicación de la contabilidad de costos, objetivos de la contabilidad de costos...

  15. Energy saving using solar filters with iron base in windows; Ahorro de energia usando filtros solares con base en hierro en ventanas

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Galan, Jesus

    2003-07-01

    For the high temperature seasons, the radiation emitted by the sun later introduced through the windows, provokes a great thermal gain in the buildings causing within them an excessive warming. For the cold seasons, the exterior is at low temperature and the window is the main element through which the building losses the heat generated in the interior. The former turns out into an elevated energy consumption (mainly electricity) to obtain the conditions of human thermal comfort; this altogether with the growing energy demand that the residential, commercial and public sector experiences in Mexico, constitutes a serious problem. As a proposal for the solution to the problem of thermal discomfort generated in the interior of the buildings because of the inadequate properties of the construction materials, in this work were developed solar filers with iron base by means of which it is obtained a selective control of the solar radiation that is transmitted through the windows. These solar filters consist in thin films of FeO deposited over subtracts of lime-soda glass (the most used in our country for buildings) of 600 x 300 x 3 mm, by means of the sputtering technique added with a radio frequency and flat magnetrons, starting from a pure iron target of 127 x 254 mm and using an argon plasma. To obtain the desired oxidation degree in the iron, small samples (45 x 22 mm) were subjected to a heating process in a reducing atmosphere constituted by 50% H{sub 2} + 50% N{sub 2} for a period of time of 10 minutes at a temperature of 400 centigrade. The solar filters with the FeO base present a transmissibility of 30.2 % for the visible interval of the electromagnetic spectrum (radiation with a wave length of 380-780 nm) and of 39.9 % for the near infrared (radiation with a wave length of 780-2500 nm); while the reflectivity is of 17.5 and 19% for the visible intervals and near infrared of electromagnetic spectrum respectively. A simulation was performed by means of the

  16. School-Based Racial and Gender Discrimination among African American Adolescents: Exploring Gender Variation in Frequency and Implications for Adjustment

    Science.gov (United States)

    Chavous, Tabbye M.; Griffin, Tiffany M.

    2012-01-01

    The present study examined school-based racial and gender discrimination experiences among African American adolescents in Grade 8 (n = 204 girls; n = 209 boys). A primary goal was exploring gender variation in frequency of both types of discrimination and associations of discrimination with academic and psychological functioning among girls and boys. Girls and boys did not vary in reported racial discrimination frequency, but boys reported more gender discrimination experiences. Multiple regression analyses within gender groups indicated that among girls and boys, racial discrimination and gender discrimination predicted higher depressive symptoms and school importance and racial discrimination predicted self-esteem. Racial and gender discrimination were also negatively associated with grade point average among boys but were not significantly associated in girls’ analyses. Significant gender discrimination X racial discrimination interactions resulted in the girls’ models predicting psychological outcomes and in boys’ models predicting academic achievement. Taken together, findings suggest the importance of considering gender- and race-related experiences in understanding academic and psychological adjustment among African American adolescents. PMID:22837794

  17. THE RELATIONSHIP BETWEEN GLOBAL WARMING AND THE VARIATION IN TROPICAL CYCLONE FREQUENCY OVER THE WESTERN NORTH PACIFIC

    Institute of Scientific and Technical Information of China (English)

    MA Li-ping; CHEN Lian-shou

    2009-01-01

    The relationship between global warming and the variation in tropical cyclone (TC) genesis frequency is analyzed using the data of the Tropical Cyclone Year Book by the China Meteorological Administration and the National Centers for Environmental Prediction (NCEP) reanalysis data from 1949 to 2007. The observational results indicate that the average sea surface temperature (SST) in the Intertropieal Convergence Zone (ITCZ) region (10°N - 20°N,100°E - 140°E) increases by 0.6°C against thc background of global warming,while the frequency of tropical cyclone geneses in this region decreases significantly. Generally,the rise of SSTs is favorable tbr the genesis of tropical cyclones,but it is now shown to be contrary to the normal cffect. Most of the tropical cyclones in the western North Pacific (WNP) are generated in the ITCZ. This is quite different from the case in the Atlantic basin in which the tropical cyclones are mostly generated from thc easterly wave. Our research results demonstrate that the ITCZ has a weakening trend in strength,and it has moved much more equatorward in the past 40 years; both are disadvantageous to the fbrmation of tropical cyclones. Furthermore,our study also found that the ridge of the subtropical high tends to shift slightly equatorward,which is another adverse mechanism for the formation of tropical cyclones.

  18. THE CHARACTERISTICS OF THUNDERSTORM FREQUENCY VARIATION AND THEIR POSSIBLE RELATION WITH THE ADJUSTMENT OF CROP DISTRIBUTION IN THE LEIZHOU PENINSULA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; NIU Sheng-jie

    2009-01-01

    In order to research possible influences of the adjustment of plant distribution on the development frequency of thunderstorms over the Leizhou Peninsula,mathematic statistic methods, including correlation analyses,11 kinds of fitting models and all-variable regression methods,were used for analyses and research. The results show that the average trend of the number of annual thunderstorm days is descending obviously,and there are thunderstorms in all seasons,in which warm post-midday thunderstorms have taken up the most part,and high frequency is found from May to September,and the starting and ending dates of thunderstorms have a great annual discrepancy. The vegetation structure has been improved along with the reduction of rice fields and the area increment of sugarcane and fruits planting,which results in the decrease of the number of thunderstorm days; the change in the characteristics of winter spare fields,which is caused by the planting of vegetables,limits the formation of thunderstorms in early winter and late spring. Meanwhile,the area adjustment of peanut planting has little influence on the variation of thunderstorm days. The adjustment of principal crop distribution,such as rice, sugarcane,fruits and vegetables,may have obvious influence on the formation of thunderstorms,and sugarcane has the largest effect,followed in turn by rice,vegetables and fruits,and the adjustment of crop distribution has little influence on the starting and ending dates of thunderstorms.

  19. Strategies for energy saving in warm climate dwellings; Estrategias de ahorro de energia para viviendas en clima calido

    Energy Technology Data Exchange (ETDEWEB)

    Pilatowsky, I [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico (Mexico); Ramos Niembro, Gaudencio [Comision Nacional para el Ahorro de Energia -CONAE (Mexico); Morillon, David [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico); Oskam, A. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico (Mexico)

    2008-04-15

    The domestic sector consumes almost one quarter of the national electrical energy. In order to reduce in an important manner the power consumption in dwellings there is an integral alternative based on three elements: the bio-climatic design, the saving and efficient use of the energy in equipment and apparatuses, and the use of centralized air conditioning systems. Besides saving the electrical and thermal power consumption, with this scheme, comfort conditions are pretended to be reached in dwellings and, contributing at the same time, to the diminution of polluting emissions. [Spanish] El sector domestico consume casi una cuarta parte de la energia electrica nacional. Con objeto de reducir de manera importante el consumo de energia en las viviendas, se presenta una alternativa integral, basada en tres elementos: el diseno bioclimatico, el ahorro y uso eficiente de la energia en equipos y aparatos, y la utilizacion de sistemas de climatizacion centralizados. Ademas del ahorro en el consumo de energia electrica y termica, con este esquema se pretende alcanzar condiciones de confort en las viviendas y, al mismo tiempo, contribuir a la disminucion de emisiones contaminantes.

  20. Daylight-saving time: Consumption and demand saving and pollutants emission reduction; El cambio de horario de verano: Ahorros en consumo y demanda, y reduccion de contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Gaudencio; Diaz, Rodrigo; Fiscal, Raul; Alquicira, Claudia; Martinez, Serafin; Maqueda, Martin [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    This paper presents some of the saving obtained in demand and in fuels with the daylight-saving time, as well as the main aspects considered to make an evaluation of it. [Espanol] Se presentan los ahorros obtenidos en consumo, demanda y combustibles con el cambio de horario de verano, asi como los principales aspectos considerados para efectuar la evaluacion de los mismos.

  1. Periodic Variations in the O-C Diagrams of Five Pulsation Frequencies of the DB White Dwarf EC 20058-5234

    CERN Document Server

    Dalessio, James; Provencal, Judi; Shipman, Harry; Sullivan, Tiri; Kilkenny, Dave; Fraga, Luciano; Sefako, Ramotholo; 10.1088/0004-637X/765/1/5

    2013-01-01

    Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058-5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent when considered in unison. The pulsation frequencies vary periodically in a 12.9 year cycle and undergo secular changes that are inconsistent with simple neutrino plus photon-cooling models. The magnitude of the periodic and secular variations increases with the period of the pulsations, possibly hinting that the corresponding physical mechanism is located near the surface of the star. The phase of the periodic variations appears coupled to the sign of the secular variations. The standards for pulsation-timing-based detection of planetary companions around pulsating white dwarfs, and possibly other variables such as subdwarf B stars, should be re-evaluated. The physical mechanism responsible for this surprising result may involve a redistribution of angular momentum or a magnetic cycle. Add...

  2. Evaluation of variation in ( m_p/m_e) from the frequency difference between the 15N2+ and 87Sr transitions

    Science.gov (United States)

    Kajita, Masatoshi

    2016-07-01

    The uncertainty of the 87Sr1 S0-3 P0 transition frequency (429 THz) has been reduced to the level of 10^{-18}. Also, the 15N2+ Q(0) vibrational transition frequency is expected to be measured with an uncertainty of 10^{-17} , and the v = 0-7 transition frequency (422 THz) is close to the 87Sr transition frequency. In this paper, we propose a test for the variation in the proton-to-electron mass ratio μ via precise measurement of the difference (f_d=7 THz) between these transition frequencies. By measuring f_d within the uncertainty of 10^{-16}, a variation in μ of 4 × 10^{-18} can be detected. The 15N2+ v =0 -7 Q(0) transition frequency is free from Zeeman and electric quadrupole shifts. The dc Stark coefficient is about 0.2 mHz/(V/cm)2, and the measurement of f_d with an uncertainty lower than 10^{-16} appears to be attainable using molecular ions in a string crystal. The 15N2+ transition frequency is observed via the two-photon excitation of a laser with a wavelength of 1422 nm (laser A). Another laser with a wavelength of 1396 nm (laser B) is used as a 87Sr clock laser after frequency doubling. The frequency difference between lasers A and B (3.5 THz) should be measured using a frequency comb. Lasers A and B can be transferred to another laboratory via an optical fiber. Therefore, a sensitive test of the variation in μ can be performed in cooperation between two distant laboratories.

  3. Yearly variation of spontaneous somatic mutation frequency in the stamen hairs of Tradescantia clone KU 9 grown outdoors, which showed a significant increase after the Chernobyl accident.

    Science.gov (United States)

    Ichikawa, S; Nakano, A; Kenmochi, M; Yamamoto, I; Murai, M; Takahashi, E; Yamaguchi, A; Watanabe, K; Tomiyama, M; Sugiyama, K; Yogo, A; Yazaki, T; Okumura, M; Shima, N; Satoh, M; Yoshimoto, M; Xiao, L Z

    1996-02-01

    Scoring of spontaneous somatic pink mutation frequency in the stamen hairs of Tradescantia clone KU 9, a heterozygote for flower color (blue/pink; the blue color being dominant), was carried out for 11 years on plants grown outdoors, during the period of May 11-31 (for 3 weeks) in every year from 1982 to 1992. Weekly and yearly variations of the spontaneous mutation frequency were observed, and such variations could mostly be correlated to the difference in temperature. That is, the mutation frequency was generally higher in the weeks and years when the temperature was relatively low, showing the strongest negative correlation with the average minimum temperature. The variations were also correlated to the diurnal temperature difference, the mutation frequency being higher with larger diurnal temperature difference in general. However, the mutation frequency observed in 1986 was exceptionally higher than that expected from the temperature for this year, and was very significantly higher than for other years. The scoring of mutation frequency was thus continued in 1986 for an additional 4 weeks (June 1-28), and it was confirmed that such higher mutation frequencies lasted for 6 weeks in total. The exceptionally high mutation frequency seemed to be related to the radioactive fallout which occurred in early to mid May of 1986, even in Japan, after the serious nuclear reactor accident at Chernobyl, and also to the biological concentrations of radioactive nuclides which subsequently occurred, although it was difficult to conclude this definitely. The mutation frequency in 1987 was second highest, and was also significantly higher than the lowest mutation frequency observed in 1990.

  4. The variations of ionosphere critical frequency of E layer over the equatorial geomagnetic region in Southeast Asia

    Science.gov (United States)

    Kenpankho, Prasert; Ishii, Mamoru; Supnithi, Pornchai

    2016-07-01

    We investigate the values of the critical frequency of the ionospheric E layer, foE, obtained at Chumphon ionospheric observatory station, Thailand. For a declining phase of the solar cycle 23 during the year 2005-2008 and an inclining phase of the solar cycle 24 during the year 2009-2013, the foE data have been used to investigate the foE variations over the equatorial geomagnetic region in Southeast Asia. A comparison between the observation data and International Reference Ionosphere (IRI) 2012 model has also been investigated and studied. The results show that the foE obtained from IRI 2012 model underestimates foE from Chumphon station especially during the period of 7-11 am and after 6 pm for each day and all seasons. As the results combining with the previous investigations, we suggest that the underestimation of ionospheric foE by IRI 2012 model is helpful for the correction and improvement of IRI model in an equatorial Asia region.

  5. Profitability Variations of a Solar System with an Evacuated Tube Collector According to Schedules and Frequency of Hot Water Demand

    Directory of Open Access Journals (Sweden)

    Carlos J. Porras-Prieto

    2016-12-01

    Full Text Available The use of solar water heating systems with evacuated tube collectors has been experiencing a rapid growth in recent years. Times when there is demand for hot water, the days of use and the volumes demanded may determine the profitability of these systems, even within the same city. Therefore, this paper characterizes the behavior of a solar system with active circulation with the objective of determining the profitability variations according to the timing and schedule of demand. Through a simplified methodology based on regression equations, calculated for each hour of the day based on data from an experimental facility, the useful energy is estimated from the time and frequency of the demand for hot water at 60 °C. The analysis of the potential profitability of the system in more than 1000 scenarios analyzed shows huge differences depending on the number of days when the water is demanded, the time when demand occurs, the irradiation and the average price of energy. In cities with high irradiation and high energy prices, the system could be profitable even in homes where it is used only on weekends. The study of profitability in a building of 10 homes shows that by applying an average European household’s profile for hot water demand, levels close to full potential would be reached; for this, it is necessary to optimize the collection surface.

  6. Possible association of the western Tibetan Plateau snow cover with the decadal to interdecadal variations of northern China heatwave frequency

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiwei [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China); Jiang, Zhihong; Zhong, Shanshan; Wang, Lijuan [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Li, Jianping [Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China)

    2012-11-15

    Northern China has been subject to increased heatwave frequency (HWF) in recent decades, which deteriorates the local droughts and desertification. More than half a billion people face drinking water shortages and worsening ecological environment. In this study, the variability in the western Tibetan Plateau snow cover (TPSC) is observed to have an intimate linkage with the first empirical orthogonal function mode of the summer HWF across China. This distinct leading mode is dominated by the decadal to inter-decadal variability and features a mono-sign pattern with the extreme value center prevailing over northern China and high pressure anomalies at mid- and upper troposphere over Mongolia and the adjacent regions. A simplified general circulation model is utilized to examine the possible physical mechanism. A reduced TPSC anomaly can induce a positive geopotential height anomaly at the mid- and upper troposphere and subsequently enhance the climatological high pressure ridge over Mongolia and the adjacent regions. The subsidence associated with the high pressure anomalies tends to suppress the local cloud formation, which increases the net radiation budget, heats the surface, and favors more heatwaves. On the other hand, the surface heating can excite high pressure anomalies at mid- and upper troposphere. The latter further strengthens the upper troposphere high pressure anomalies over Mongolia and the adjacent regions. Through such positive feedback effect, the TPSC is tied to the interdecadal variations of the northern China HWF. (orig.)

  7. Sensitive search for the temporal variation of the fine structure constant using radio-frequency E1 transitions in atomic dysprosium

    CERN Document Server

    Nguyen, A T; Lamoreaux, S K; Torgerson, J R

    2003-01-01

    It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant ($\\alpha$) [V. A. Dzuba, V. V. Flambaum, and J. K. Webb, Phys. Rev. A {\\bf 59}, 230 (1999)]. We discuss here an experimental realization of the proposed search, which involves monitoring the E1 transition frequency over a period of time using direct frequency counting techniques. We estimate that a statistical sensitivity of $|\\adota| \\sim 10^{-18}$/yr may be achieved and discuss possible systematic effects in such a measurement.

  8. Energy saving in illumination using sensorial presence devices; Ahorro de energia en iluminacion utilizando sensores de presencia

    Energy Technology Data Exchange (ETDEWEB)

    Cortes Eslava, Alejandro [Universidad Nacional Autonoma de Mexico (Mexico)

    2001-03-01

    This is an analysis and evaluation of electrical energy saving that a system of illumination controlled by presence sensors provides in an enclosure with low transit within the Universidad Nacional Autonoma de Mexico (UNAM) that is one of the libraries of the Institute of Anthropological Investigations. The data on which the analysis is sustained and the results deducted come from a time counter located at the site. [Spanish] Este es un analisis y evaluacion de los ahorros de energia electrica que suministra un sistema de iluminacion controlado por sensores de presencia en un recinto con bajo transito dentro de la Universidad Nacional Autonoma de Mexico (UNAM) que es una de las bibliotecas del Instituto de Investigaciones Antropologicas. Los datos de donde se sustenta el analisis y se deducen los resultados provienen de un contador de tiempo de uso localizado en el sitio.

  9. Learning to be different: Acquired skills, social learning, frequency dependence, and environmental variation can cause behaviourally mediated foraging specializations

    Science.gov (United States)

    Tinker, M.T.; Mangel, M.; Estes, J.A.

    2009-01-01

    ) Offspring can learn foraging skills from their mothers (matrilineal social learning). (6) Food abundance is limited, such that average individual energy reserves are low Additionally, the following factors increase the likelihood of alternative specializations co-occurring in a predator population: (1) The predator exerts effective top-down control of prey abundance, resulting in frequency-dependent dynamics. (2) There is stochastic Variation in prey population dynamics, but this Variation is neither too extreme in magnitude nor too 'slow' with respect to the time required for an individual forager to learn new foraging skills. For a given predator population, we deduce that the degree of specialization will be highest for those prey types requiring complex capture or handling skills, while prey species that are both profitable and easy to capture and handle will be included in the diet of all individuals. Frequency-dependent benefits of selecting alternative prey types, combined with the ability of foragers to improve their foraging skills by learning, and transmit learned skills to offspring, can result in behaviourally mediated foraging specialization, and also lead to the co-existence of alternative specializations. The extent of such specialization is predicted to be a variable trait, increasing in locations or years when intra-specific competition is high relative to inter-specific competition. ?? 2009 M. Tim Tinker.

  10. Variation of Seismic Frequency in the Yunnan Region After the Indonesia Earthquake With Ms 8.7

    Institute of Scientific and Technical Information of China (English)

    Guo Tieshuan; Liu Jie; Zheng Dalin; Peng Keyin

    2007-01-01

    The seismic frequency increased significantly in the Yunnan region after the Indonesia earthquake with MS 8.7 on December 26,2004.This was estimated by analyzing the seismic frequency ratio between the influenced and normal times, the spatial distribution characteristics of the increased seismic frequency, the temporal-spatial distribution and types of seismic swarms.Seismic frequency increased at 71.3% of the statistical sites in the Yunnan area.The maximal increase ratio is 18.2.

  11. 瓦块固有频率对可倾瓦轴承频变刚度的影响%Effect of Pad Natural Frequency on Frequency-variation Stiffness of Tilting Pad Bearings

    Institute of Scientific and Technical Information of China (English)

    洪红伦; 许吉敏; 陈润霖; 张帆; 吴立明; 袁小阳

    2016-01-01

    为研究轻载工况下可倾瓦块固有频率和振动频率对轴承刚度的影响,基于长轴承理论建立求解可倾瓦推力轴承瓦块固有频率和频变刚度的润滑和动力学耦合模型,推导润滑模型的解析解和频变动力学特性的表达式,并通过实例计算分析载荷、支点系数(瓦进油边到支点的距离与瓦长的比值)、瓦块转动惯量等结构参数对瓦块固有频率和频变刚度的影响。结果表明:瓦块的惯性、油膜的刚度和阻尼共同决定瓦块振动的固有频率,瓦块在固有频率附近振动可以使轴承的频变刚度出现负值,甚至正负无穷大;小载荷的瓦(如非承载瓦)容易出现瓦块振动频率接近其固有频率的状况,使瓦发生共振;可倾瓦轴承设计中有必要考虑瓦块的固有频率和频变刚度来设计非承载瓦的支点系数和转动惯量,使瓦块的振动频率跨过固有频率而产生大的刚度。%In order to research the effect of natural frequency and vibration frequency of pad on stiffness of tilting⁃pad bearing,lubrication and dynamic coupling model based on long bearing theory was established to solve natural frequency and frequency⁃variation stiffness of pad in tilting pad thrust bearing.Analytical solution of this lubrication model and formulae of frequency⁃variation dynamic characteristics were deduced,and the influence of load,pivot coefficient ( Ratio of the distance between oil inlet and pivot to the pad length) ,rotational inertia and other structural parameters on natural frequency and fre⁃quency⁃variation stiffness were analyzed through example calculation.The results show that vibration natural frequency of tilt⁃ing pad is codetermined by inertia,stiffness and damping of oil film.When the vibration frequency of pad is close to its natu⁃ral frequency,frequency⁃variation stiffness of bearing presents negative value even with positive and negative infinite.The sit

  12. Electric energy saving and its impact in the mining industry; El ahorro de energia electrica y su impacto en la industria minera

    Energy Technology Data Exchange (ETDEWEB)

    Urteaga Dufour, Jose Antonio [Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE), Mexico, D. F. (Mexico)

    1993-12-31

    In this paper are shown the most important results of the energy diagnosis performed in some representative industries of the mining industry, where opportunity areas were detected in electric energy saving, starting from those measures that do not require investment up to the ones that require medium investment, recoverable in less than two years terms as a maximum and with electric energy saving ranging from 10% to 25%. [Espanol] En este trabajo, se presentan los resultados mas importantes, obtenidos en el diagnostico energetico realizado en algunas empresas representativas de la rama de la mineria, en donde se detectaron areas de oportunidad de ahorro de energia electrica que van desde aquellas medidas que no requieren inversiones hasta las que requieren medianas inversiones, recuperables en menos de dos anos como maximo y con ahorros de energia que van desde un 10% hasta un 25%.

  13. Modelo de Gestión Gerencial para disminuir los riesgos en la cooperativa de Ahorro y Crédito Tulcán.

    OpenAIRE

    Mora Grijalva, Ney Fernando

    2012-01-01

    Realizar un diagnóstico de la gestión en la Cooperativa de Ahorro y Crédito “Tulcán”, con los diferentes responsables de las áreas y de las oficinas operativas, a fin de determinar el papel de los procesos de participación, de la interpretación de los indicadores financieros y gestión enfocados a mitigar los diferentes riesgos. En el presente estudio: Modelo de Gestión Gerencial para disminuir los riesgos en la Cooperativa de Ahorro y Crédito ¿Tulcán¿ qué es una entidad financiera r...

  14. Investigación industrial sobre ahorro de energía en la fabricación de nuevos cementos compuestos españoles

    Directory of Open Access Journals (Sweden)

    Puig, J.

    1981-09-01

    Full Text Available Not available

    Se exponen en este trabajo los resultados de un estudio consistente en la preparación de varios cementos nuevos, en diversas fábricas de diferentes zonas del país, basada en la utilización de materiales de adición, tanto activos como fillers calizos, con objeto de contribuir al ahorro energético en la fabricación de cemento. Los nuevos cementos fabricados se comparan con los producidos en la actualidad y se llega a la conclusión de que muchos de ellos permitirán sustanciales ahorros de fuel-oil, sin merma sensible, en la mayoría de los casos —y con mejora en otros— de la calidad y del comportamiento de los cementos nuevos.

  15. Variation of CH Stretch Frequencies with CH_4 Orientation in the CH_4 - F^- Complex: Multiple Resonances as Vibrational Conical Intersections

    Science.gov (United States)

    Thapaliya, Bishnu P.; Perry, David S.

    2016-06-01

    In the CH_4 - F^- complex, an adiabatic separation of the CH stretch frequencies from the CH_4 orientational coordinates allows the calculation of the four adiabatic CH stretch surfaces. These ab initio calculations reveal (i) a large variation of CH stretch frequencies (> 100 wn) in the orientational space and (ii) the existence of four symmetrically equivalent sets of vibrational conical intersections (CIs). Two sets of symmetry-allowed CIs are identified in addition to the symmetry-required CIs at the front- and back-side C3v geometries. These results have implications for the evolution of excited CH vibrations in methane during its approach to a potentially reactive surface.

  16. A new multi-frequency approach based on Padé approximants for the treatment of transient dynamics problems with the variational theory of complex rays

    Science.gov (United States)

    Rouzaud, C.; Gatuingt, F.; Hervé, G.; Dorival, O.

    2017-03-01

    Frequency-based methods were set up in order to circumvent the limits of classical finite element methods in fast dynamic simulations due to discretizations. In this approach the dynamic loading was shifted in the frequency domain by FFT, then treated by the Variational Theory of Complex Rays, and then the time response was reconstructed through an IFFT. This strategy proved to be very efficient due to the CPU VTCR very low cost. However in the case of a large loading spectrum this frequency-by-frequency approach could seriously degrade the computational performances of the strategy. This paper addresses this point by proposing the use of Padé approximants in order to limit the number of frequencies at which the response should be calculated. Padé approximation is applied to the overall VTCR system based on its frequency dependency. Finally, as simulations on a simple academic case and on a civil engineering structure show, this method is found to be very efficient for interpolating the frequency response functions of a complex structure. This is a key point to preserve the efficiency of the complete VTCR strategy for transient dynamic problems.

  17. Utilization of the computational technic for the promotion and diffusion of the energy conservation practice; Utilizacion de tecnicas computacionales para promocionar y difundir el ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Kemper Valverde, N. [Laboratorio de Inteligencia Artificial, Instituto de Ingenieria, UNAM, Mexico D. F. (Mexico)

    1995-12-31

    In this paper are presented the developments obtained through the application of the new computational technologies in the diffusion and promotion tasks of energy efficient use and conservation. The most relevant aspects are described of three multimedia courses that were designed in order to increase the possibilities of offering personal training in efficient energy technic, as well as to have on hand totally open consulting and interactive tools. The courses that are described are: ``Design of Energy Conservation Programs for the Industry``, ``Energy Conservation in Combustion Equipment`` and ``Energy Cogeneration Technologies.`` On another subject, an analysis is also made of the possibilities for the development and application of expert systems that advise and give support to the work of technicians and engineers dedicated to energy conservation. The main characteristics of an expert system to give support to the energy analysis of lighting industrial systems, malls, buildings and hotels are also described. [Espanol] En este trabajo se presentan los desarrollos obtenidos por la aplicacion de las tareas de difusion y promocion del uso eficiente y ahorro de energia. Se describen los aspectos mas relevantes de tres cursos multimedia que fueron disenados con el objeto de incrementar las posibilidades de brindar capacitacion individualizada en tecnicas energeticas eficientes, asi como de contar con herramientas de consulta totalmente abiertas e interactivas. Los cursos que se describen son: ``Diseno de Programas de Ahorro de Energia en la Industria,`` ``Ahorro de Energia en Equipos de Combustion`` y ``Tecnologias de Cogeneracion de Energia.`` Por otro lado, tambien se hace un analisis de las posibilidades para el desarrollo y aplicacion de sistemas expertos que asesoren y apoyen el trabajo de tecnicos e ingenieros dedicados al ahorro de energia. Se describen las caracteristicas principales de un sistema experto disenado para brindar apoyo en analisis energeticos

  18. Integral programs of energy conservation (exergy) in the petroleum industry; Programas integrales de ahorro de energia (exergia) en la industria petrolera

    Energy Technology Data Exchange (ETDEWEB)

    Rivero Rodriguez, R. [Instituto Mexicano del Petroleo (IMP), Mexico, D. F. (Mexico)

    1995-12-31

    This paper presents some of the fundamental issues related to energy conservation programs in general and to the petroleum industry in particular with the purpose of integrating them both, that is, considering not only the energy issues, but also the ecological and economical aspects. This is achieved by using the two fundamental laws of thermodynamics (the science that studies energy, its characteristics, and its transformations) through the use of the exergy concept, which is a measure of the energy quality and of its withdrawal with respect to the environment. The origins of the present-day technologies, regarding energy conservation, the short, medium and long term general strategies and the implementation stages of the integral programs of energy conservation are presented, and it concludes with a series of general policies aimed at making the energy conservation programs more congruent with the maintenance of a sustainable development. [Espanol] En este trabajo se presentan algunos aspectos fundamentales relacionados con los programas de ahorro de energia en general, y en la industria petrolera en particular, con objeto de lograr que los mismos sean integrales, es decir que consideren no solo los aspectos puramente energeticos, sino tambien los aspectos ecologicos y economicos. Esto se logra utilizando conjuntamente las dos leyes fundamentales de la termodinamica (la ciencia que estudia la energia, sus caracteristicas y sus transformaciones), mediante la utilizacion del concepto de exergia, que es una medida de la calidad de la energia y de su alejamiento con respecto al medio ambiente. Se presentan los origenes de las tendencias tecnologicas actuales en materia de ahorro de energia, las estrategias generales a corto, mediano y largo plazos y las etapas en la implementacion de programas integrales de ahorro de energia, para concluir con una serie de politicas generales tendientes a lograr que los programas de ahorro de energia sean congruentes con el

  19. Ahorro de agua y materia prima en los procesos de pelambre y curtido del cuero mediante precipitación y recirculación de aguas

    Directory of Open Access Journals (Sweden)

    SANDRA AGUDELO A.

    2007-01-01

    Full Text Available El principio del proceso de recuperación de cromo, consiste en precipitar el cromo contenido en el licor residual como hidróxido utilizando un álcali; este precipitado se separa por sedimentación y se disuelve nuevamente con ácido sulfúrico. De los resultados obtenidos, se observaron porcentajes de remoción superiores al 99%. Con la recirculación directa de aguas de pelambre fue posible obtener ahorros de agua del 64% y ahorros en materia prima del 32 %, además, con una adecuada selección del tamizador es posible recircular el agua un número máximo de tres veces, sin afectar la calidad del producto final. Así mismo, se comprobó la viabilidad de la recirculación directa de aguas de curtido, con ahorros de materia prima del 17%. Con medidas de este tipo, prácticas y fáciles de implementar, la industria del curtido del cuero podría disminuir considerablemente la contaminación, operar de una forma mas segura y con mayor eficiencia de producción.

  20. Energy saving in the management of the BIMBO group distribution fleet; Ahorro de energia en la operacion de la flotilla de distribucion del grupo BIMBO

    Energy Technology Data Exchange (ETDEWEB)

    BIMBO Mexico

    2005-07-01

    In this work BIMBO demonstrates that in order to save energy it is necessary to invest in equipment, parts, research and people. This is why they got involved in the task of developing the projects of fuel cells participating with universities, associations, Secretaria de Energia, Comision Nacional de Ahorro de Energia (National Commission for Energy Saving) (CONAE) and the National Council for Science and Tecnologia (CONACYT), through financial supports with projects of mechanisms of clean development (Kyoto Protocol). For doing it they had to prove different types of fuels: biodiesel, hydrogen, alcohol and hybrids; for them to determine the most profitable and practical thus reducing the energy consumption. With the saving of fuels and lubricants in our vehicles, a greater yield in the company is obtained. [Spanish] En este trabajo BIMBO demuestra que para ahorrar energia hay que invertir en equipo, partes, investigacion y gente. Es por eso que se dieron a la tarea de desarrollar los proyectos de celdas de combustible, participando con universidades, asociaciones, la Secretaria de Energia, la Comision Nacional para el Ahorro de Energia (CONAE) y el Consejo Nacional para la Ciencia y Tecnologia (CONACYT), a traves de apoyos financieros con proyectos de mecanismos de desarrollo limpio (protocolo de Kyoto). Para ello tuvieron que probar diferentes tipos de combustibles: biodiesel, hidrogeno, alcohol e hibridos, para determinar los mas rentables y practicos y asi reducir el consumo de energia; con el ahorro de combustibles y lubricantes en nuestros vehiculos, logrando una mayor rentabilidad en la empresa.

  1. Análisis de ahorro energético en iluminación LED industrial: Un estudio de caso

    Directory of Open Access Journals (Sweden)

    Ana Serrano-Tierz

    2015-01-01

    Full Text Available El presente estudio muestra el ahorro económico y las ventajas medioambientales que supone la iluminación industrial con tecnología LED. Se ha planteado un estudio de caso en el que luminarias de halogenuros metálicos han sido sustituidas por luminarias LED. Para validar la sustitución de luminarias con halogenuros metálicos de 400W por LED de 200W, se han efectuado las simulaciones luminotécnicas y mediciones de campo mediante luxómetro. Los resultados obtenidos indican que ambas luminarias son equiparables obteniendo un importante ahorro energético cercano al 50%. Esta investigación demuestra que la tecnología LED ofrece soluciones de iluminación de alto rendimiento que optimizan el ahorro energético reduciendo a su vez costes de mantenimiento con un coste total de propiedad significativamente menor, incrementando la esperanza de vida útil de las luminarias. Desde el punto de vista medioambiental supone una importante reducción en emisiones de CO2 y eliminación de residuos tóxicos como el mercurio.

  2. Photographic Records Showing the Variations of the Virtual Height of Reflection as a Function of the Radio Frequency

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standard (analog) ionosonde produces photographic records known as ionograms, which show the variations of the virtual height of reflection as a function of the...

  3. Las puzolanas y el ahorro energético en los materiales de construcción

    Directory of Open Access Journals (Sweden)

    Soria Santamaría, Francisco

    1983-09-01

    Full Text Available This discussion commences with some general comments on the energy crisis and its impact on the cement industry, with the corresponding coal reconversion problems. Three factors are highlighted where saving has been centered: technological process, raw materials and finished product, emphasizing the interest of latter which includes incorporating active additions in Portland cement. A quick review then follows about pozzolanas, their origin, definitions and classification. Their chemical composition is underlined, and the concept of pozzolanic activity is described. Later on, pozzolanic cements, their most significant properties and the advantages of using pozzolana are explained. After a lengthy description about possible applications of pozzolanas and pozzolanic cements, the conclusion reviews current trends in international standards for such cements and possible evolution in consumption of additions by the year 2000, with a view to saving more energy, without impairing the essential properties of the cement.

    Comienza esta exposición con unas consideraciones generales sobre la crisis energética y su impacto en la industria cementera, con los correspondientes problemas de reconversión al carbón. Se mencionan los tres aspectos en que se ha centrado el ahorro energético: proceso tecnológico, materias primas y producto acabado, destacando el interés de este último que incluye la incorporación de adiciones activas al cemento portland. Se hace a continuación un rápido comentario sobre puzolanas, su origen, definiciones y clasificación. Se destaca la composición química de las mismas y se desarrolla el concepto de actividad puzolánica. Más tarde se hace una exposición sobre cementos puzolánicos, sus propiedades más destacadas y las ventajas que supone el empleo de la puzolana. Tras una exposición amplia de las posibles aplicaciones de las puzolanas y cementos puzolánicos, se concluye comentando las tendencias

  4. National potential of saving of electricity in domestic refrigeration; Potencial nacional de ahorro de electricidad en refrigeracion domestica

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo C, Fernando [Universidad Nacional Autonoma de Mexico (Mexico); Ambriz G, Juan Jose; Romero P, Hernando [Universidad Autonoma Metropolitana, (Mexico)

    2003-07-01

    In the present paper the evaluation of the potential of saving of electrical energy in Mexico is presented, by means of the substitution of old refrigerators of low efficiency by modern high efficiency ones. This potential is very ample, since the replacement of the old models by new follows a very slow curve, if the economic difficulties of the Mexican families are considered and that, on the other hand, the technology of the domestic refrigerators is so reliable that they have a very long life and they are not easily rejected. In field work have been found refrigerators operating with ages of more than 30 years and still 40. In Mexico, it is estimated that the refrigeration is responsible for around 29% of the of electricity consumption in homes settled in tempered climate and of 14 % in those of warm climate in which air conditioning is used. The proposal of this work is the organization of a governmental program of accelerated substitution of refrigerators that helps to acquire an efficient refrigerator and to reject the old ones. The results indicate that if a total renovation of the park of domestic refrigerators is made, the saving of electrical energy would reach the 5.2 TWh/a which represents the 44.5% of the total consumption of 11.7 TWh in a year. [Spanish] En el presente trabajo se presenta la evaluacion del potencial de ahorro de energia electrica en Mexico, mediante la substitucion de refrigeradores antiguos de baja eficiencia por modernos de alta eficiencia. Este potencial es muy amplio, ya que el reemplazo de los modelos viejos por nuevos sigue una curva muy lenta, si se consideran las dificultades economicas de las familias mexicanas y que, por otro lado, la tecnologia de los refrigeradores domesticos es tan confiable que tienen una vida muy larga y no se desechan facilmente. En trabajos de campo se han encontrado refrigeradores operando con edades de mas de 30 anos y aun 40. En Mexico, se estima que la refrigeracion es responsable de alrededor del

  5. Cost-benefit of energy saving in bioclimatic designs; Costo-beneficio del ahorro de energia en los disenos bioclimatios

    Energy Technology Data Exchange (ETDEWEB)

    Lopez P, J. Manuel A. [Doble dos soluciones de Negocios (Mexico); Morillon G, David; Rdriguez V, Luis [Universidad Autonoma de Mexico (Mexico)

    2001-06-01

    Tools and criteria for Cost-Benefit Analysis (ACB) of energy saving in bioclimatic designs (DB) are presented, for which a reference project is established. Based on the traditional design of air conditioning of a building and with the support of this one, the estimation of costs and benefits of the same building is made; but with passive systems. The tools used consider related resources such as time and money. Criteria are used such as: Present value (VP), Equivalent Annual Cost (EAC) and the Cost of the conserved Energy (CEC). The costs related to the construction, maintenance and operation of the design are taken into consideration. The differences between the design of reference and the Bioclimatic Design, established from the application of these criteria, allow evaluating the economic margin as far as operation and maintenance. Finally, the cost of the conserved energy of the bioclimatic measures is evaluated as an initiative for energy saving and calculates the present value from them in all of the period of useful life of the bioclimatic design. [Spanish] Se presentan herramientas y criterios para el analisis Costo-Beneficio (ACB) del ahorro de energia en los disenos bioclimaticos (DB), para lo cual se establece un proyecto de referencia. Basado en el diseno tradicional de la climatizacion de un edificio y con apoyo en este, se realiza la estimacion de costos y beneficios del mismo edificio; pero con sistema pasivos. Las herramientas usadas consideran recursos relacionados como son tiempo y dinero. Se usan criterios tales como: Valor Presente (VP), Costo Anual Equivalente (CAE) y el Costo de la Energia conservada (CEC). Se toman en consideracion los costos relacionados con la construccion, mantenimiento y operacion del diseno. Las diferencias entre el diseno de referencia y el Diseno Bioclimatico, establecidas a partir de la aplicacion de estos criterios, permiten evaluar el margen economico en cuanto a la operacion y el mantenimiento. Finalmente, se

  6. Projects of electrical energy saving in Costa Rica; Proyectos de ahorro de energia electrica en Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Henry Chinchilla [Compania Nacional de Luz y Fuerza, S.A., San Jose (Costa Rica)

    1999-07-01

    Costa Rica, located in Central America, is a highly electrified country, more of the 93.6% of the population, has access to the electricity, and its load curve presents two important demand peaks, one of them near noon and another one at sundown, additionally, the growth of this service is important, reason why it has been oriented to the establishment of actions focussed to the better use of the energy, in special of the electricity. The following notes are intended to show briefly the origin of the actions oriented to the energy saving, identifying the main projects that marked an important track in the national development in this sense, as well as a sample of some of the projects which have permitted to maintain throughout the last decade of this century a permanent attitude on the promotion and education of the saving and handling of the energy demand, specially of electricity, of such a way as to a suitable contribution is achieved towards the industrial competitiveness, human comfort and environmental protection. [Spanish] Costa Rica, ubicado en la America Central, es un pais altamente electrificado, mas del 93.6% de la poblacion, tiene acceso a la electricidad, y su curva de carga presenta dos importantes picos de demanda uno cercano al medio dia y otro al ocultarse el sol, junto a ello el crecimiento este servicio es importante, por lo que se ha abocado a establecer acciones que se orientan al mejor uso de la energia, en especial de la electricidad. En las siguientes notas se trata de mostrar en forma breve el origen de las acciones orientadas al ahorro de energia, identificando los principales proyectos que marcaron una huella importante en el rumbo nacional en este sentido, asi como una muestra de algunos de los proyectos que han permitido mantener a lo largo de la ultima decada de este siglo una permanente actitud de la promocion y ensenanza del ahorro y manejo de la demanda de energia, en especial de la electricidad, de tal forma que se logre con ello

  7. Performance Analysis of Variation in Power Consumption and Frequency on Different Topologies of Ring VCO in 70 nm CMOS Technology

    Directory of Open Access Journals (Sweden)

    Sumant Katiyal

    2012-07-01

    Full Text Available The proposed work describes the performance evaluation ofdifferent types of ring oscillator Voltage Controlled Oscillatortopologies on the basis of two characteristic parameters powerand frequency in 70 nm CMOS technology. The varioustopologies analyzed include Current Starved VCO, VCO withGates of PMOS Transistor Grounded, VCO with PMOS DiodeConnected, VCO with NMOS Diode Connected, VCO withvoltage applied to both PMOS and NMOS Transistor.Simulation of different parameters of ring oscillator VCO iscarried out on Tanner tool Version 13. VCO topologies areevaluated on the basis of frequency and power consumption bytaking lower supply voltage of 1.2 V. Performance evaluationand comparison of different topologies results in minimumpower consumption of 0.57 uW by Current Starved VCOtopology and maximum operating frequency of 0.57 MHz byVCO with Gates of PMOS Transistor Grounded.

  8. Switching Operation Simulations in a Large Offshore Wind Farm with Use of Parametric Variation and Frequency Domain Severity Factor

    DEFF Research Database (Denmark)

    Holdyk, Andrzej; Holbøll, Joachim; Arana, Ivan;

    2012-01-01

    Transient voltages resulting from switching operations depend on an interaction between the breaker, the transformer, cables and a neighbourhood grid and imply a risk for the transformer and other components. In this paper the Frequency Domain Severity Factor (FDSF) is used to assess the severity...... implemented in ATP-EMTP using standard component models and further validated against measurements. The results show the range of overvoltages on the transformer terminals as well as the corresponding FSDF for all turbines under a number of varying parameters. The maximum FDSF of 1.235 and frequency of 445 k...

  9. Oportunidad de ahorro energético en sistema para la climatización de unidades quirúrgicas

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Mora Aguilera

    2010-01-01

    Full Text Available Se presentó una valoración del autor acerca de la oportunidad de ahorro de energía eléctrica en el sistema para la climatización del Hospital Pediátrico de Holguín a partir de la recuperación de energía del volumen de aire que se expulsa al exterior en los quirófanos. En los resultados del trabajo se describió el procedimiento empleado para la cuantificación de la incidencia del volumen de aire para la ventilación de los quirófanos en el deterioro del consumo energético del sistema para la climatización y se enunció una propuesta que logra ahorrar energía eléctrica en el mismo mediante la elevación de su eficiencia energética sin comprometer los requerimientos de limpieza del aire que se maneja.

  10. CAJAS DE AHORROS: UN MODELO DE COMPROMISO CON LA SOCIEDAD / SAVINGS BANKS AND SOCIETY: A MODEL OF COMMITMENT TO SOCIETY

    Directory of Open Access Journals (Sweden)

    Antoni SEGUÍ ALCARAZ

    2012-01-01

    Full Text Available Las entidades de crédito tienen cada vez mayor interés en las cuestiones sociales, como reflejo de un compromiso empresarial para satisfacer la demanda de la sociedad, en general, funcionando de una forma eficiente a medio plazo. El trabajo de campo se realizó a través de una encuesta contestada por 57 entidades de crédito españolas. En las Cajas de ahorros por lo que se refiere al tipo de inversión, se observan correlaciones significativas positivas entre el porcentaje del presupuesto destinado a inversiones en la comunidad y en proyectos medioambientales. Por lo tanto, vemos que cuantas más inversiones se realizan en la comunidad, mayor cantidad se destina a proyectos medioambientales. Por el contrario, se observa una relación negativa entre el porcentaje del presupuesto destinado a inversiones para la comunidad y la materialización de las aportaciones en metálico / The field work was conducted through a questionnaire answered by 57 Spanish institutions. In savings banks as regards the type of investment, there are significant positive correlations between the percentage of the budget for investment in community and environmental projects. Therefore, we see that the more investments are made in the community, the greater amount is allocated to environmental projects. On the contrary, there is a negative relationship between the percentage of the budget for investment in the community and the realization of cash contributions.

  11. Edificio de oficinas del Monte de Piedad y Caja de Ahorros de Sevilla-España

    Directory of Open Access Journals (Sweden)

    Población Knappe, Eleuterio

    1981-03-01

    Full Text Available Architect The essential feature of the new building of the Pawnshop and Savings Bank in Seville, built on a site in an «L» form and affected in the course of the planning and building by successive changes of Ordenances, its attempt to harmonize with the surrounding architecture, respecting its traditional characteristics. The building, which has seven stories on a slope and two basements, broadcasts its different private and public missions by the volumes, forms and different exterior treatments, presenting particular attention to its functionality in accordance with the initial programme proposed by the organisation.

    La característica esencial de la nueva sede del Monte de Piedad y Caja de Ahorros de Sevilla, levantada sobre un solar en forma de «L» y afectada en el transcurso del proyecto y construcción por sucesivos cambios de Ordenanzas, armoniza con la arquitectura circundante, respetando sus características tradicionales. La edificación, de siete plantas sobre rasante y dos sótanos, patentiza su distinta misión privada y de cara al público a través de los volúmenes, formas y diferentes tratamientos exteriores, presentando una especial atención a su funcionalidad de acuerdo con el programa inicial planteado por la entidad.

  12. Potential of bioclimatic architecture for energy saving in buildings; Potencial de la arquitectura bioclimatica para ahorro de energia en edificios

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Chavez, Jose Roberto [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D. F. (Mexico)

    1994-12-31

    The design and construction of current buildings has been characterized, most of all, in the last 30 years, for the lack of consideration in the design process of aspects that nowadays represent a fundamental importance. These aspects are related to energy conservation and environmental protection, with man as the main center of attention for the optimum satisfaction of its physiological as well as psychological needs. In this paper are presented the causes for the lack of consideration of the mentioned aspects and guidelines to follow are set forth for their integration in the design process. Also the architecture potential with a bioclimatic approach is analyzed, for energy saving in buildings. [Espanol] El diseno y construccion de edificios contemporaneos se ha caracterizado, sobre todo en los ultimos treinta anos, por la falta de consideracion en el proceso de diseno, de aspectos que hoy en dia revisten una importancia primordial. Estos aspectos se relacionan con la preservacion de la energia y del medio ambiente, teniendo al hombre como principal centro de atencion, para la satisfaccion optima de sus necesidades, tanto fisiologicas como psicologicas. En este trabajo, se presentan las causas de la falta de consideracion de los aspectos antes citados y se plantean las pautas a seguir para su integracion en el proceso de diseno. Asi mismo, se analiza el potencial de la arquitectura con un enfoque bioclimatico, para ahorro de energia en los edificios.

  13. Energy saving by the use of polystyrene in construction; Ahorro de energia por la utilizacion de poliestireno en la construccion

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Raul [Polioles S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    In the past last years, the building industry has been faced with requirements in the rational energy use and environmental preservation. The polystyrene foam is a material that for more than forty years has demonstrated its attributes all over the world in its application in the construction industry as well as in the packing and crating industries, becoming a synonym of economic construction in regard to energy saving and a synonym also of a rational and safe packing. In this paper a short description is made of the manufacturing process of the expandable polystyrene foam, its properties and applications in the construction industry. [Espanol] En los ultimos anos, la industria de la construccion se ha enfrentado a exigencias en el uso racional de la energia y en la preservacion del medio ambiente. La espuma de poliestireno expansible es un material que por mas de cuarenta anos, ha demostrado sus cualidades a nivel mundial en su aplicacion tanto en la industria de la construccion como en la del empaque y embalaje, llegando a convertirse en sinonimo de una construccion economica en cuanto a ahorro de energia y sinonimo tambien de un embalaje racional y seguro. En este trabajo se hace una breve descripcion del proceso de fabricacion de la espuma de poliestireno expandible, sus propiedades y aplicaciones dentro de la industria de la construccion.

  14. Variations in apolipoprotein e frequency with age in a pooled analysis of a large group of older people

    NARCIS (Netherlands)

    G.J. McKay (Gareth); G. Silvestri (Giuliana); U. Chakravarthy (Usha); S. Dasari (Shilpa); L.G. Fritsche (Lars); B.H.F. Weber (Bernhard); P.J. Francis (Peter); C.N. Keilhauer (Claudia); M.L. Klein (Michael); C.C.W. Klaver (Caroline); J.R. Vingerling (Hans); L. Ho (Lintje); P.T.V.M. de Jong (Paulus); M. Dean (Michael Emmans); J. Sawitzke (Julie); P.N. Baird (Paul); R.H. Guymer (Robyn); D.E. Stambolian (Dwight); A. Orlin (Anton); J.M. Seddon (Johanna); I. Peter (Inga); A.F. Wright (Alan); C. Hayward (Caroline); A.J. Lotery (Andrew); S. Ennis (Sarah); M.B. Gorin (Michael); C.-L. Kuo; A. Hingorani (Aroon); R. Sofat (Reecha); F. Cipriani (Francesco); A. Swaroop (Anand); M.I. Othman (Mohammad); A. Kanda (Atsuhiro); W. Chen (Wei); G.R. Abecasis (Gonçalo); J.R. Yates (John); A.R. Webster (Andrew); A.T. Moore (Anthony); J.H. Seland (Johan ); M. Rahu (Mati); G. Soubrane (Gisele); L. Tomazzoli (Laura); F. Topouzis (Fotis); J. Vioque (Jesus); I.S. Young (Ian); A.E. Fletcher (Astrid E.); C.C. Patterson (Chris); D.E. Weeks (Daniel)

    2011-01-01

    textabstractVariation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (

  15. Variations in apolipoprotein e frequency with age in a pooled analysis of a large group of older people

    NARCIS (Netherlands)

    G.J. McKay (Gareth); G. Silvestri (Giuliana); U. Chakravarthy (Usha); S. Dasari (Shilpa); L.G. Fritsche (Lars); B.H.F. Weber (Bernhard); P.J. Francis (Peter); C.N. Keilhauer (Claudia); M.L. Klein (Michael); C.C.W. Klaver (Caroline); J.R. Vingerling (Hans); L. Ho (Lintje); P.T.V.M. de Jong (Paulus); M. Dean (Michael Emmans); J. Sawitzke (Julie); P.N. Baird (Paul); R.H. Guymer (Robyn); D.E. Stambolian (Dwight); A. Orlin (Anton); J.M. Seddon (Johanna); I. Peter (Inga); A.F. Wright (Alan); C. Hayward (Caroline); A.J. Lotery (Andrew); S. Ennis (Sarah); M.B. Gorin (Michael); C.-L. Kuo; A. Hingorani (Aroon); R. Sofat (Reecha); F. Cipriani (Francesco); A. Swaroop (Anand); M.I. Othman (Mohammad); A. Kanda (Atsuhiro); W. Chen (Wei); G.R. Abecasis (Gonçalo); J.R. Yates (John); A.R. Webster (Andrew); A.T. Moore (Anthony); J.H. Seland (Johan ); M. Rahu (Mati); G. Soubrane (Gisele); L. Tomazzoli (Laura); F. Topouzis (Fotis); J. Vioque (Jesus); I.S. Young (Ian); A.E. Fletcher (Astrid E.); C.C. Patterson (Chris); D.E. Weeks (Daniel)

    2011-01-01

    textabstractVariation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (

  16. Modelling of human low frequency sound localization acuity demonstrates dominance of spatial variation of interaural time difference and suggests uniform just-noticeable differences in interaural time difference.

    Directory of Open Access Journals (Sweden)

    Rosanna C G Smith

    Full Text Available Sound source localization is critical to animal survival and for identification of auditory objects. We investigated the acuity with which humans localize low frequency, pure tone sounds using timing differences between the ears. These small differences in time, known as interaural time differences or ITDs, are identified in a manner that allows localization acuity of around 1° at the midline. Acuity, a relative measure of localization ability, displays a non-linear variation as sound sources are positioned more laterally. All species studied localize sounds best at the midline and progressively worse as the sound is located out towards the side. To understand why sound localization displays this variation with azimuthal angle, we took a first-principles, systemic, analytical approach to model localization acuity. We calculated how ITDs vary with sound frequency, head size and sound source location for humans. This allowed us to model ITD variation for previously published experimental acuity data and determine the distribution of just-noticeable differences in ITD. Our results suggest that the best-fit model is one whereby just-noticeable differences in ITDs are identified with uniform or close to uniform sensitivity across the physiological range. We discuss how our results have several implications for neural ITD processing in different species as well as development of the auditory system.

  17. Restoration of Normal Frequency Affected by Small Load Variations Through HVDC link Using Neuro-Fuzzy Approach

    Directory of Open Access Journals (Sweden)

    Anil Kumar Sharma,

    2011-03-01

    Full Text Available HVDC power transmission is coming up with merits to replace the EHV-AC system. The controller inverter operation can successfully regulate the power in HVDC link leading to fulfillment ofpower demand in A.C. networks caused by sudden rise in loading. Since overloading and unloading both lead to the departure of operating frequency below or above normal, its control for normalization isexercised through control of power flow in HVDC Link. Also the same is achieved by adjusting firing delay angle intelligently. This paper aims at providing automation to frequency normalization after it hasundergone changes from normal value of 50 Hz, due to sudden and sustained increase in load or due to working of generations at increased loads in H.V.D.C transmission systems. It is planned to automate the restoration of departed frequency to normal value by arranging the change in firing delay angle i.e. α of the converter of H.V.D.C. link till the increased load demand is met with. An adaptive control system has been devised which controls the firing delay angle on the basis of decisions given by a fuzzy controller. Also the fuzzy controls are decided by the departure in frequency from normal. The results have been found to be encouraging.

  18. Genetic control of mammalian meiotic recombination. I. Variation in exchange frequencies among males from inbred mouse strains.

    Science.gov (United States)

    Koehler, Kara E; Cherry, Jonathan P; Lynn, Audrey; Hunt, Patricia A; Hassold, Terry J

    2002-09-01

    Genetic background effects on the frequency of meiotic recombination have long been suspected in mice but never demonstrated in a systematic manner, especially in inbred strains. We used a recently described immunostaining technique to assess meiotic exchange patterns in male mice. We found that among four different inbred strains--CAST/Ei, A/J, C57BL/6, and SPRET/Ei--the mean number of meiotic exchanges per cell and, thus, the recombination rates in these genetic backgrounds were significantly different. These frequencies ranged from a low of 21.5 exchanges in CAST/Ei to a high of 24.9 in SPRET/Ei. We also found that, as expected, these crossover events were nonrandomly distributed and displayed positive interference. However, we found no evidence for significant differences in the patterns of crossover positioning between strains with different exchange frequencies. From our observations of >10,000 autosomal synaptonemal complexes, we conclude that achiasmate bivalents arise in the male mouse at a frequency of 0.1%. Thus, special mechanisms that segregate achiasmate chromosomes are unlikely to be an important component of mammalian male meiosis.

  19. Compact cascadable gm-C all-pass true time delay cell with reduced delay variation over frequency

    NARCIS (Netherlands)

    Garakoui, Seyed Kasra; Klumperink, Eric A.M.; Nauta, Bram; Vliet, van Frank E.

    2015-01-01

    At low-GHz frequencies, analog time-delay cells realized by LC delay lines or transmission lines are unpractical in CMOS, due to their large size. As an alternative, delays can be approximated by all-pass filters exploiting transconductors and capacitors (g m -C filters). This paper presents an easi

  20. A CDI Study of Bilingual English-Hebrew Children--Frequency of Exposure as a Major Source of Variation

    Science.gov (United States)

    Armon-Lotem, Sharon; Ohana, Odelya

    2017-01-01

    The present study explores the vocabulary development of bilingual children when neither of their languages has a minority language status. With both languages having high relative prestige, it is possible to address the impact of exposure variables: age of onset, length of exposure, and frequency of exposure (FoE) to both languages. Parents of 40…

  1. A CDI Study of Bilingual English-Hebrew Children--Frequency of Exposure as a Major Source of Variation

    Science.gov (United States)

    Armon-Lotem, Sharon; Ohana, Odelya

    2017-01-01

    The present study explores the vocabulary development of bilingual children when neither of their languages has a minority language status. With both languages having high relative prestige, it is possible to address the impact of exposure variables: age of onset, length of exposure, and frequency of exposure (FoE) to both languages. Parents of 40…

  2. Variation in the gene frequencies of three generations of humans from Monterrey, Nuevo León, Mexico.

    Science.gov (United States)

    Cerda-Flores, R M; Garza-Chapa, R

    1989-04-01

    Allele frequencies for the ABO, Rh, MNSs, Duffy, Kidd, Lutheran, P and Lewis blood group systems in 207 persons whose 4 grandparents were born in the Monterrey Metropolitan area (MMA), grouped into 3 generations, were ascertained along with other related population from the MMA, Mestizos from Saltillo, Coahuila and Tlaxcala, and from the populations thought to have contributed to their genetic constitution (native Mexican Indians and Spanish). Genetic admixture and distance estimates were calculated. Gene frequencies of the three generations from MMA are intermediate to those of the ancestral populations, indicating that they are Mestizo but with a genetic structure different from Mestizos of Saltillo and Tlaxcala. Both genetic admixture and distance estimates indicate that the oldest generation exhibits the greatest Spanish influence which decreases in the youngest generation and in the other MMA populations as a result of the immigration from the central states of Mexico.

  3. Designing 2D Phononic Crystal Slabs with Transmission Gaps for Solid Angle as well as Frequency Variation

    Directory of Open Access Journals (Sweden)

    Sven M. Ivansson

    2009-01-01

    Full Text Available Phononic crystals (PCs can be used as acoustic frequency selective insulators and filters. In a two-dimensional (2D PC, cylindrical scatterers with a common axis direction are located periodically in a host medium. In the present paper, the layer multiple-scattering (LMS computational method for wave propagation through 2D PC slabs is formulated and implemented for general 3D incident-wave directions and polarizations. Extensions are made to slabs with cylindrical scatterers of different types within each layer. As an application, the problem is considered to design such a slab with small sound transmittance within a given frequency band and solid angle region for the direction of the incident plane wave. The design problem, with variable parameters characterizing the scatterer geometry and material, is solved by differential evolution, a global optimization algorithm for efficiently navigating parameter landscapes. The efficacy of the procedure is illustrated by comparison to a direct Monte Carlo method.

  4. Restoration of Normal Frequency Affected by Small Load Variations Through HVDC link Using Neuro-Fuzzy Approach

    OpenAIRE

    Anil Kumar Sharma,; Dr. G. K. Joshi,; Tarun Kumar De; Shyam Krishan Joshi

    2011-01-01

    HVDC power transmission is coming up with merits to replace the EHV-AC system. The controller inverter operation can successfully regulate the power in HVDC link leading to fulfillment ofpower demand in A.C. networks caused by sudden rise in loading. Since overloading and unloading both lead to the departure of operating frequency below or above normal, its control for normalization isexercised through control of power flow in HVDC Link. Also the same is achieved by adjusting firing delay ang...

  5. Influence of wave frequency variation on anomalous cyclotron resonance interaction of energetic electrons with finite amplitutude ducted whistler-mode wave

    CERN Document Server

    Erokhin, N S; Rycroft, M J; Nunn, D G

    1996-01-01

    The influence of wave frequency variation on the anomalous cyclotron resonance $\\omega=\\omega_{Be}+kv_{\\|}$ interaction (ACRI) of energetic electrons with a ducted finite amplitude whistler-mode wave propagating through the so-called transient plasma layer (TPL) in the magnetosphere or in the ionosphere is studied both analytically and numerically. The anomalous cyclotron resonance interaction takes place in the case when the whistler-mode wave amplitude $B_{W}$ is consistent with the gradient of magnetic field interacting energetic electrons (synchronous particles) is determined. The efficiencies of both the pitch-angle scattering of resonant electrons and their transverse acceleration are studied and the efficiencies dependence on the magnitude and sign of the wave frequency drift is considered. It has been shown that in the case of ACRI occuring under conditions relevant to VLF-emission in the magnetosphere, the energy and pitch-angle changes of synchronous electrons may be enchanced by a factor $10^2 \\div...

  6. HLA class II variation in the Gila River Indian Community of Arizona: alleles, haplotypes, and a high frequency epitope at the HLA-DR locus.

    Science.gov (United States)

    Williams, R C; McAuley, J E

    1992-01-01

    A genetic distribution for the HLA class II loci is described for 349 "full-blooded" Pima and Tohono O'odham Indians (Pimans) in the Gila River Indian Community. A high frequency epitope in the *DRw52 family was defined by reactions with 31 alloantisera, which we have designated *DR3X6. It segregates as a codominant allele at HLA-DR with alleles *DR2, *DR4, and *DRw8, and has the highest frequency yet reported for an HLA-DR specificity, 0.735. It forms a common haplotype with *DRw52 and *DQw3 that is a valuable marker for genetic admixture and anthropological studies. Phenotype and allele frequencies, and haplotype frequencies for two and three loci, are presented. Variation at these loci is highly restricted, the mean heterozygosity for HLA-DR and HLA-DQ being 0.361. The Pimans represent a contemporary model for the Paleo-Indians who first entered North America 20,000 to 40,000 years ago.

  7. High frequency variations of the main magnetic field: convergence of observations and theory (Petrus Peregrinus Medal Lecture)

    Science.gov (United States)

    Jault, Dominique

    2013-04-01

    Understanding the main magnetic field variations has been hindered by the discrepancy between the periods (from months to years) of the simplest linear wave phenomena and the relatively long time intervals (10 to 100 years) over which magnetic field changes can be confidently monitored. A theoretical description of short-period waves within the Earth's fluid core is at hand. Quasi-geostrophic inertial waves (akin to Rossby waves in the atmosphere) are slightly modified in the presence of magnetic fields and torsional oscillations consist of differential motion between coaxial rigid cylindrical annuli. Torsional oscillations are sensitive to the whole magnetic field that they shear in the course of their propagation. From their modelling, we have thus gained an estimate for the magnetic field strength in the core interior. There is now ongoing work to extend the theoretical framework to longer times. Furthermore, data collected from the Swarm constellation of three satellites to be launched this year by ESA will permit to better separate the internal and external magnetic signals. We may thus dream to detect quasi-geostrophic inertial waves. As the spectral ranges of theoretical models and observations begin to overlap, we can now go beyond the understanding of the magnetic field variations as the juxtaposition of partial models, arranged as a set of nested Matryoshka dolls. This talk will give illustrations for this statement, among which the question of induction in the lower mantle.

  8. Variation of Dielectric and Electrical Properties of Zr-Substituted Lead Calcium Iron Niobate with Temperature and Frequency

    Science.gov (United States)

    Puri, Maalti; Bahel, Shalini; Narang, Sukhleen Bindra

    2016-10-01

    The purpose of the present study is to improve the dielectric properties of lead calcium iron niobate with Zr substitution, and to make it suitable for multilayer capacitor applications in resonant circuits. (Pb0.45Ca0.55)(Fe0.5Nb0.5)1- y Zr y O3 dielectric ceramics where y varies from 0.00 to 0.15 in steps of 0.03, that have been synthesized by the columbite precursor method. Dielectric and electrical properties were measured as a function of frequency (10 kHz to 1 MHz) and temperature. Two frequency dependent anomalies were observed in relative permittivity ( ɛ r) versus temperature ( T) plots around 375 K and between 500 K and 575 K. The temperature coefficient of relative permittivity, ( τ ɛ ) has been improved with the substitution of (Fe0.5Nb0.5)4+ ions by Zr4+ ions at B-sites. The single semicircle, observed in Nyquist plots at different temperatures, suggests a single relaxation process in the synthesized samples. The activation energies obtained from different dependences are found to be approximately comparable.

  9. High-frequency sea level variations and implications for coastal flooding: A case study of the Solent, UK

    Science.gov (United States)

    Ozsoy, Ozgun; Haigh, Ivan D.; Wadey, Matthew P.; Nicholls, Robert J.; Wells, Neil C.

    2016-07-01

    This study examines the occurrence and characteristics of high-frequency (energy events have a mean amplitude of approximately 0.6 m and a dominant period of around 4 h. These events correspond with periods of enhanced meteorological activity, namely a marked reduction in air pressure and onset of strong southwesterly-southeasterly winds. Sea level observations from tide gauges around the Solent and the wider English Channel region (23 in total) were used to assess the spatial characteristics of these events. Analysis of time series and phase information indicates the occurrence of standing waves oscillating across the English Channel between southern England and northern France. This study provides a unique example of standing waves generated by extra-tropical cyclones over a large basin (the English Channel) with implications for flood inundation. The event of 28th October 2013 - the highest-amplitude (1.16 m) event in the record - was associated with minor coastal flooding at Yarmouth, Isle of Wight. This flood occurred during a neap tide, when such events are widely thought to be impossible. Hence, our findings emphasize the relevance of high-frequency sea level variability for regional sea level forecasting and flood risk management.

  10. Microsatellite frequencies vary with body mass and body temperature in mammals, suggesting correlated variation in mutation rate

    Directory of Open Access Journals (Sweden)

    William Amos

    2014-11-01

    Full Text Available Substitution rate is often found to correlate with life history traits such as body mass, a predictor of population size and longevity, and body temperature. The underlying mechanism is unclear but most models invoke either natural selection or factors such as generation length that change the number of mutation opportunities per unit time. Here we use published genome sequences from 69 mammals to ask whether life history traits impact another form of genetic mutation, the high rates of predominantly neutral slippage in microsatellites. We find that the length-frequency distributions of three common dinucleotide motifs differ greatly between even closely related species. These frequency differences correlate with body mass and body temperature and can be used to predict the phenotype of an unknown species. Importantly, different length microsatellites show complicated patterns of excess and deficit that cannot be explained by a simple model where species with short generation lengths have experienced more mutations. Instead, the patterns probably require changes in mutation rate that impact alleles of different length to different extents. Body temperature plausibly influences mutation rate by modulating the propensity for slippage. Existing hypotheses struggle to account for a link between body mass and mutation rate. However, body mass correlates inversely with population size, which in turn predicts heterozygosity. We suggest that heterozygote instability, HI, the idea that heterozygous sites show increased mutability, could provide a plausible link between body mass and mutation rate.

  11. Determination of natural frequencies by coupled method of homotopy perturbation and variational method for strongly nonlinear oscillators

    Science.gov (United States)

    Akbarzade, M.; Langari, J.

    2011-02-01

    In this paper a new approach combining the features of the homotopy concept with variational approach is proposed to find accurate analytical solutions for nonlinear oscillators with and without a fractional power restoring force. Since the first-order approximation leads to very accurate results, comparisons with other results are presented to show the effectiveness of this method. The validity of the method is independent of whether or not there exist small or large parameters in the considered nonlinear equations; the obtained results prove the validity and efficiency of the method, which can be easily extended to other strongly nonlinear problems. At the end we compare our procedure with the optimal homotopy perturbation method.

  12. El capital social y su tratamiento en las entidades en las entidades de ahorro y crédito popular sobre la base de la normativa contable internacional

    Directory of Open Access Journals (Sweden)

    Luis Carlos Gámez Adame

    2013-03-01

    Full Text Available Las Entidades de Ahorro y Crédito Popular (Cooperativas constituyen un segmento importante dentro de los servicios financieros que se prestan en diferentes países y que han tenido un desarrollo vertiginoso al satisfacer demandas y necesidades de numerosas masas poblacionales.Se presentan algunas consideraciones asociadas al tratamiento del capital social en estas entidades sobre la base de la normatividad contable internacional vigente y donde a criterio de los autores existen una serie de incongruencias a las que hay que darles solución.

  13. Cost-Benefit of the energy saving in the bioclimatic designs; Costo-Beneficio del ahorro de energia en los disenos bioclimaticos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez P, J. Manuel A. [Doble Dos Soluciones de Negocios, S.A. de C.V., Mexico, D.F. (Mexico); Morillon G, David; Rodriguez V, Luis [Instituto de Ingenieria de la UNAM, Mexico, D.F. (Mexico)

    1999-07-01

    Tools and criteria for the Cost-Benefit analysis from the energy saving in bioclimatic designs (BD) are presented, for which, a reference project is established and the costs and benefits of energy saving in BD with base in that project are evaluated. A case study is presented taking as reference the traditional design of the air conditioning of a building and with this base the estimation of cost-benefit of the same building is made, but with passive systems. The tools used are those that allow to consider related resources such as time and money; in that sense, are used criteria such as: Present value (PV), Equivalent Annual Cost (EAC) and the Cost of the Conserved Energy (CCE). The costs related to the construction, maintenance and operation of the design are taken into account. The differences between the reference design and the BD, established from the application of these criteria, allow to evaluate the economic margin of the BD as far as operation and maintenance is concerned. Finally the CCE of the bioclimatic measures is evaluated as an initiative of energy saving and the present value is calculated of the energy saving in the entire useful life of a bioclimatic design. [Spanish] Se presentan herramientas y criterios para el analisis Costo-Beneficio del ahorro de energia en disenos bioclimaticos (DB), para lo cual, se establece un proyecto de referencia y se evaluan los costos y beneficios del ahorro de energia en DB con base en ese proyecto. Se presenta el estudio de un caso tomando como referencia el dise tradicional de la climatizacion de un edificio y con base en este, se realiza la estimacion de costos y beneficios del mismo edificio, pero con sistemas pasivos. Las herramientas usadas, son aquellas que permiten considerar recursos relacionados como son tiempo y dinero; en ese sentido, se usan criterios como: Valor Presente (VP), Costo Anual Equivalente (CAE) y el Costo de la Energia Conservada (CEC). Se toman en consideracion los costos relacionados

  14. Evaluation of energy saving in large scale projects in domestic lighting; Evaluacion del ahorro de energia en proyectos de gran escala en alumbrado domestico

    Energy Technology Data Exchange (ETDEWEB)

    Valera Negrete, Adrian [Comision Federal de Electricidad, Mexico, D.F. (Mexico)

    2001-07-01

    The present work shows the methodology and the necessary parameters are indicated to evaluate the energy saving and the reduction of power demand obtained, by the large scale projects of substitution of incandescent lamps by compact, circular fluorescent and globe type lamps in the domestic sector. [Spanish] El presente trabajo muestra la metodologia y se indican los parametros necesarios para evaluar el ahorro de energia y reduccion de la demanda de potencia obtenidos, por los proyectos de gran escala de sustitucion de focos incandescentes por lamparas fluorescentes compactas, circulares y tipo globo en el sector domestico.

  15. Diseño inmotico para ahorro energético, seguridad y control de instalaciones para el nuevo edificio de la fiec

    OpenAIRE

    Cobos Franco, Ma. Jose; Loayza Intriago, Andrea A.; Garay Contreras, Francisco; Leyton, Edgar

    2009-01-01

    Este proyecto tiene como propósito asegurar a los usuarios de la edificación un aumento del confort, de la seguridad, del ahorro energético y de las facilidades de comunicación mediante la automatización de la gestión y la información de la misma. Se explican los principios teóricos empleados en este proyecto. Se detallan conceptos básicos de Edificio Inteligente así como la definición y diferencias entre los diferentes conceptos que encierra la Domótica. Además se realiza un estudio ...

  16. Parametric variation of gamma frequency and power with luminance contrast: A comparative study of human MEG and monkey LFP and spike responses.

    Science.gov (United States)

    Hadjipapas, A; Lowet, E; Roberts, M J; Peter, A; De Weerd, P

    2015-05-15

    Gamma oscillations contribute significantly to the manner in which neural activity is bound into functional assemblies. The mechanisms that underlie the human gamma response, however, are poorly understood. Previous computational models of gamma rely heavily on the results of invasive recordings in animals, and it is difficult to assess whether these models hold in humans. Computational models of gamma predict specific changes in gamma spectral response with increased excitatory drive. Hence, differences and commonalities between spikes, LFPs and MEG in the spectral responses to changes in excitatory drive can lead to a refinement of existing gamma models. We compared gamma spectral responses to varying contrasts in a monkey dataset acquired previously (Roberts et al., 2013) with spectral responses to similar contrast variations in a new human MEG dataset. We found parametric frequency shifts with increasing contrast in human MEG at the single-subject and the single-trial level, analogous to those observed in the monkey. Additionally, we observed parametric modulations of spectral asymmetry, consistent across spikes, LFP and MEG. However, while gamma power scaled linearly with contrast in MEG, it saturated at high contrasts in both the LFP and spiking data. Thus, while gamma frequency changes to varying contrasts were comparable across spikes, LFP and MEG, gamma power changes were not. This indicates that gamma frequency may be a more stable parameter across scales of measurements and species than gamma power. The comparative approach undertaken here represents a fruitful path towards a better understanding of gamma oscillations in the human brain.

  17. High frequency of HMW-GS sequence variation through somatic hybridization between Agropyron elongatum and common wheat.

    Science.gov (United States)

    Gao, Xin; Liu, Shu Wei; Sun, Qun; Xia, Guang Min

    2010-01-01

    A symmetric somatic hybridization was performed to combine the protoplasts of tall wheatgrass (Agropyron elongatum) and bread wheat (Triticum aestivum). Fertile regenerants were obtained which were morphologically similar to tall wheatgrass, but which contained some introgression segments from wheat. An SDS-PAGE analysis showed that a number of non-parental high-molecular weight glutenin subunits (HMW-GS) were present in the symmetric somatic hybridization derivatives. These sequences were amplified, cloned and sequenced, to deliver 14 distinct HMW-GS coding sequences, eight of which were of the y-type (Hy1-Hy8) and six x-type (Hx1-Hx6). Five of the cloned HMW-GS sequences were successfully expressed in E. coli. The analysis of their deduced peptide sequences showed that they all possessed the typical HMW-GS primary structure. Sequence alignments indicated that Hx5 and Hy1 were probably derived from the tall wheatgrass genes Aex5 and Aey6, while Hy2, Hy3, Hx1 and Hy6 may have resulted from slippage in the replication of a related biparental gene. We found that both symmetric and asymmetric somatic hybridization could promote the emergence of novel alleles. We discussed the origination of allelic variation of HMW-GS genes in somatic hybridization, which might be the result from the response to genomic shock triggered by the merger and interaction of biparent genomes.

  18. Higher frequency of social learning in China than in the West shows cultural variation in the dynamics of cultural evolution.

    Science.gov (United States)

    Mesoudi, Alex; Chang, Lei; Murray, Keelin; Lu, Hui Jing

    2015-01-07

    Cultural evolutionary models have identified a range of conditions under which social learning (copying others) is predicted to be adaptive relative to asocial learning (learning on one's own), particularly in humans where socially learned information can accumulate over successive generations. However, cultural evolution and behavioural economics experiments have consistently shown apparently maladaptive under-utilization of social information in Western populations. Here we provide experimental evidence of cultural variation in people's use of social learning, potentially explaining this mismatch. People in mainland China showed significantly more social learning than British people in an artefact-design task designed to assess the adaptiveness of social information use. People in Hong Kong, and Chinese immigrants in the UK, resembled British people in their social information use, suggesting a recent shift in these groups from social to asocial learning due to exposure to Western culture. Finally, Chinese mainland participants responded less than other participants to increased environmental change within the task. Our results suggest that learning strategies in humans are culturally variable and not genetically fixed, necessitating the study of the 'social learning of social learning strategies' whereby the dynamics of cultural evolution are responsive to social processes, such as migration, education and globalization.

  19. Assessment of periodic sub-diurnal Earth rotation variations at tidal frequencies through transformation of VLBI normal equation systems

    Science.gov (United States)

    Artz, Thomas; Tesmer Née Böckmann, Sarah; Nothnagel, Axel

    2011-09-01

    We present an empirical model for periodic variations of diurnal and sub-diurnal Earth rotation parameters (ERPs) that was derived based on the transformation of normal equation (NEQ) systems of Very Long Baseline Interferometry (VLBI) observing sessions. NEQ systems that contain highly resolved polar motion and UT1-TAI with a temporal resolution of 15 min were generated and then transformed to the coefficients of the tidal ERP model to be solved for. To investigate the quality of this model, comparisons with empirical models from the Global Positioning System (GPS), another VLBI model and the model adopted by the conventions of the International Earth Rotation and Reference Systems Service (IERS) were performed. The absolute coefficients of these models agree almost completely within 7.5 μ as in polar motion and 0.5 μ s in UT1-TAI. Several bigger differences exist, which are discussed in this paper. To be able to compare the model estimates with results of the continuous VLBI campaigns, where signals with periods of 8 and 6 h were detected, terms in the ter- and quarter-diurnal band were included in the tidal ERP model. Unfortunately, almost no common features with the results of continuous VLBI campaigns or ERP predictions in these tidal bands can be seen.

  20. Free-ranging male koalas use size-related variation in formant frequencies to assess rival males.

    Directory of Open Access Journals (Sweden)

    Benjamin D Charlton

    Full Text Available Although the use of formant frequencies in nonhuman animal vocal communication systems has received considerable recent interest, only a few studies have examined the importance of these acoustic cues to body size during intra-sexual competition between males. Here we used playback experiments to present free-ranging male koalas with re-synthesised bellow vocalisations in which the formants were shifted to simulate either a large or a small adult male. We found that male looking responses did not differ according to the size variant condition played back. In contrast, male koalas produced longer bellows and spent more time bellowing when they were presented with playbacks simulating larger rivals. In addition, males were significantly slower to respond to this class of playback stimuli than they were to bellows simulating small males. Our results indicate that male koalas invest more effort into their vocal responses when they are presented with bellows that have lower formants indicative of larger rivals, but also show that males are slower to engage in vocal exchanges with larger males that represent more dangerous rivals. By demonstrating that male koalas use formants to assess rivals during the breeding season we have provided evidence that male-male competition constitutes an important selection pressure for broadcasting and attending to size-related formant information in this species. Further empirical studies should investigate the extent to which the use of formants during intra-sexual competition is widespread throughout mammals.

  1. Free-ranging male koalas use size-related variation in formant frequencies to assess rival males.

    Science.gov (United States)

    Charlton, Benjamin D; Whisson, Desley A; Reby, David

    2013-01-01

    Although the use of formant frequencies in nonhuman animal vocal communication systems has received considerable recent interest, only a few studies have examined the importance of these acoustic cues to body size during intra-sexual competition between males. Here we used playback experiments to present free-ranging male koalas with re-synthesised bellow vocalisations in which the formants were shifted to simulate either a large or a small adult male. We found that male looking responses did not differ according to the size variant condition played back. In contrast, male koalas produced longer bellows and spent more time bellowing when they were presented with playbacks simulating larger rivals. In addition, males were significantly slower to respond to this class of playback stimuli than they were to bellows simulating small males. Our results indicate that male koalas invest more effort into their vocal responses when they are presented with bellows that have lower formants indicative of larger rivals, but also show that males are slower to engage in vocal exchanges with larger males that represent more dangerous rivals. By demonstrating that male koalas use formants to assess rivals during the breeding season we have provided evidence that male-male competition constitutes an important selection pressure for broadcasting and attending to size-related formant information in this species. Further empirical studies should investigate the extent to which the use of formants during intra-sexual competition is widespread throughout mammals.

  2. High frequency (hourly) variation in vertical distribution and abundance of meroplanktonic larvae in nearshore waters during strong internal tidal forcing

    Science.gov (United States)

    Liévana MacTavish, A.; Ladah, L. B.; Lavín, M. F.; Filonov, A.; Tapia, Fabian J.; Leichter, J.

    2016-04-01

    We related the vertical distribution and abundance of nearshore meroplankton at hourly time scales with internal tidal wave events. We proposed that significant changes in plankter abundance would occur across internal tidal fronts, and that surface and bottom strata would respond in opposite fashions. First-mode internal tidal bores propagating in the alongshore direction were detected in water-column currents and baroclinic temperature changes. Surface and bottom currents always flowed in opposite directions, and abrupt flow reversals coincided with large temperature changes during arrival of bores. Crab zoeae and barnacle cyprids were more abundant in the bottom strata, whereas barnacle nauplii showed the opposite pattern. Significant changes in vertical distribution and abundance of target meroplankters occurred across internal tidal fronts, especially for crabs at depth, with surface and bottom organisms responding in opposite fashions. Changes in plankter abundance were significantly correlated with current flows in the strata where they were most abundant. The manner in which plankters were affected (increasing or decreasing abundance) appeared to be modulated by their vertical position within the water column. The significant differences found at the high frequencies of this study, maintained across sampling days, suggest that nearshore meroplankton populations may have greater and more consistent temporal and vertical variability than previously considered.

  3. Spontaneous low frequency BOLD signal variations from resting-state fMRI are decreased in Alzheimer disease.

    Science.gov (United States)

    Kazemifar, Samaneh; Manning, Kathryn Y; Rajakumar, Nagalingam; Gómez, Francisco A; Soddu, Andrea; Borrie, Michael J; Menon, Ravi S; Bartha, Robert

    2017-01-01

    Previous studies have demonstrated altered brain activity in Alzheimer's disease using task based functional MRI (fMRI), network based resting-state fMRI, and glucose metabolism from 18F fluorodeoxyglucose-PET (FDG-PET). Our goal was to define a novel indicator of neuronal activity based on a first-order textural feature of the resting state functional MRI (RS-fMRI) signal. Furthermore, we examined the association between this neuronal activity metric and glucose metabolism from 18F FDG-PET. We studied 15 normal elderly controls (NEC) and 15 probable Alzheimer disease (AD) subjects from the AD Neuroimaging Initiative. An independent component analysis was applied to the RS-fMRI, followed by template matching to identify neuronal components (NC). A regional brain activity measurement was constructed based on the variation of the RS-fMRI signal of these NC. The standardized glucose uptake values of several brain regions relative to the cerebellum (SUVR) were measured from partial volume corrected FDG-PET images. Comparing the AD and NEC groups, the mean brain activity metric was significantly lower in the accumbens, while the glucose SUVR was significantly lower in the amygdala and hippocampus. The RS-fMRI brain activity metric was positively correlated with cognitive measures and amyloid β1-42 cerebral spinal fluid levels; however, these did not remain significant following Bonferroni correction. There was a significant linear correlation between the brain activity metric and the glucose SUVR measurements. This proof of concept study demonstrates that this novel and easy to implement RS-fMRI brain activity metric can differentiate a group of healthy elderly controls from a group of people with AD.

  4. Spatial variation in the frequency-magnitude distribution of earthquakes under the tectonic framework in the Middle East

    Science.gov (United States)

    Mousavi, S. Mostafa

    2017-10-01

    Spatial variations of seismic energy released and b-value over the Middle East region are investigated based on a seismicity catalog from 1995 to 2007. The goal is to use these seismic parameters and based on other geodetic and geophysical observations, such as GPS measurements, strain rate model, fault distribution, focal mechanism, crustal model, Q model, and gravity measurements, etc., to uncover spatial patterns that seem anomalous. Areas of high energy released (cumulative) seem to correspond to the areas of relatively high b-values. Areas of high energy released and high b-values seem to correspond very well with the location of continental collision where earthquake activities are high. The divergent boundary between Arabia and African plates and subduction zone at Makran seem to correspond to low to moderate energy release. Northern Pamir, Azerbaijan-Caucasus, the lower part of Zagros Mountains, eastern Turkey, Owen Fracture Zone, Strait of Bob-el-Mandeb, and south of the Sulaiman Shear Zone seem to correspond to high cumulative energy-released, high strain rate, high b-values, and high fault density. While, the central and eastern Iran, southern Zagros, northern Pakistan, Gulf of Aden, Alborz, southwest of the Caspian Sea, western Caucasus and Kopeh-Dagh seem to correspond with lower b-values. The cross-section map for Hindu-Kush shows general decreasing of the b-values with depth, however, a region of high b-value is observed underneath Pamir at depths from 170 to 230 km. This anomaly region can be due to dehydration of Pamir crustal slab at depth.

  5. Proposal for energy saving in air conditioning equipment; Propuesta para ahorro energetico en acondicionadores de aire

    Energy Technology Data Exchange (ETDEWEB)

    Solis Recendez, Daniel H [Division de Ingenieria Electrica, Universidad Nacional Autonoma de Mexico (Mexico)

    2008-10-15

    In the last decades, the air conditioning systems have become a crucial part in the search from comfort in extreme climates. Nevertheless, they have also become one of the greatest energy consumers. In this article it is proposed that the final conditions that the air conditioning equipment looks for not to be fixed, but variable in respect to a certain comfort zone. This zone is a variation of the used one in the bio-climatic chart of Olgyay that considers the rapidity whereupon the reached conditions tend to leave the comfort zone. It is analyzed how to choose the point on the zone that costs less energy in arriving to it. [Spanish] En las ultimas decadas, los sistemas de aire acondicionado se han vuelto una parte crucial en la busqueda de confort en climas extremosos. Sin embargo, tambien se han vuelto de los mayores consumidores de energia. En este articulo se propone que las condiciones finales que busquen lograr los acondicionadores no sean fijas, si no variables respecto a una determinada zona de confort. Dicha zona es una variacion de la utilizada en la carta bioclimatica de Olgyay, que considera la rapidez con que las condiciones alcanzadas tienden a abandonar la zona de confort. Se discute como elegir el punto sobre la zona que cueste menos energia en llegara el.

  6. Molecular spectrum of somatic EGFR and KRAS gene mutations in non small cell lung carcinoma: determination of frequency, distribution pattern and identification of novel variations in Indian patients.

    Science.gov (United States)

    Das, Bibhu Ranjan; Bhaumik, Sangeet; Ahmad, Firoz; Mandsaurwala, Aziz; Satam, Heena

    2015-07-01

    Somatic mutations of EGFR and KRAS gene represent the most common alterations currently known in NSCLC patients. This study explored the frequency, distribution pattern of EGFR and KRAS mutations in Indian patients. The frequencies of EGFR and KRAS mutations were 29 % (116/400) and 4.5 % (6/132) respectively. Both EGFR and KRAS mutations were prevalent in females, and a trend towards higher mutation frequency was seen in patients under ≥ 60 years age. The presence of EGFR and KRAS mutations were higher in adenocarcinomas in comparison to other histological subtype. Sequencing analysis of EGFR exon 18 revealed Inframe deletion (G709_T710 > A) and missense mutation (K713R). Among exon 19 positive cases, 49.3 % (37/75) were in-frame deletions, of which E746_A750del was frequent. Similarly, ~47 % (35/75) cases showed complex mutation involving indel. Among mutations in exon 20 (N = 9), 8 were substitutions, one showed duplication, while all exon 21 mutations were of the missense types with L858R as the most recurrent type. Sequencing analysis of KRAS exon 1 revealed three different types codon 12 substitutions resulting in c34G > T (G12C) (n = 4), c.35G > A (G12D) (n = 1), and c.35G > T (G12V) (n = 1). In conclusion, the present study is an example of molecular diversity of EGFR and KRAS gene in Indian patients and further confirms that the frequency of EGFR and KRAS mutations varies considerably globally. To the best of our knowledge, this is the first Indian study to evaluate KRAS mutation. The current study also served to identify novel variations that added new insights into the genetic heterogeneity of NSCLC.

  7. Celiac disease T-cell epitopes from gamma-gliadins: immunoreactivity depends on the genome of origin, transcript frequency, and flanking protein variation

    Directory of Open Access Journals (Sweden)

    Salentijn Elma MJ

    2012-06-01

    Full Text Available Abstract Background Celiac disease (CD is caused by an uncontrolled immune response to gluten, a heterogeneous mixture of wheat storage proteins. The CD-toxicity of these proteins and their derived peptides is depending on the presence of specific T-cell epitopes (9-mer peptides; CD epitopes that mediate the stimulation of HLA-DQ2/8 restricted T-cells. Next to the thoroughly characterized major T-cell epitopes derived from the α-gliadin fraction of gluten, γ-gliadin peptides are also known to stimulate T-cells of celiac disease patients. To pinpoint CD-toxic γ-gliadins in hexaploid bread wheat, we examined the variation of T-cell epitopes involved in CD in γ-gliadin transcripts of developing bread wheat grains. Results A detailed analysis of the genetic variation present in γ-gliadin transcripts of bread wheat (T. aestivum, allo-hexaploid, carrying the A, B and D genome, together with genomic γ-gliadin sequences from ancestrally related diploid wheat species, enabled the assignment of sequence variants to one of the three genomic γ-gliadin loci, Gli-A1, Gli-B1 or Gli-D1. Almost half of the γ-gliadin transcripts of bread wheat (49% was assigned to locus Gli-D1. Transcripts from each locus differed in CD epitope content and composition. The Gli-D1 transcripts contained the highest frequency of canonical CD epitope cores (on average 10.1 per transcript followed by the Gli-A1 transcripts (8.6 and the Gli-B1 transcripts (5.4. The natural variants of the major CD epitope from γ-gliadins, DQ2-γ-I, showed variation in their capacity to induce in vitro proliferation of a DQ2-γ-I specific and HLA-DQ2 restricted T-cell clone. Conclusions Evaluating the CD epitopes derived from γ-gliadins in their natural context of flanking protein variation, genome specificity and transcript frequency is a significant step towards accurate quantification of the CD toxicity of bread wheat. This approach can be used to predict relative levels of CD toxicity of

  8. Antigenic topology of the P29 surface lipoprotein of Mycoplasma fermentans: differential display of epitopes results in high-frequency phase variation.

    Science.gov (United States)

    Theiss, P; Karpas, A; Wise, K S

    1996-05-01

    Antibodies to P29, a major lipid-modified surface protein of Mycoplasma fermentans, reveal phase variation of surface epitopes occurring with high frequency in clonal lineages of the organism. This occurs despite continuous expression of the entire epitope-bearing P29 product (detected by Western immunoblotting) and contrasts with phase variation of other surface antigens mediated by differential expression of proteins. To understand the structure and antigenic topology of P29, the single-copy p29 gene from strain PG18 was cloned and sequenced. The gene encodes a prolipoprotein containing a signal sequence predicted to be modified with lipid and cleaved at the N-terminal Cys-1 residue of the mature P29 lipoprotein. The remaining 218-residue hydrophilic sequence of P29 is predicted to be located external to the single plasma membrane. Additional Cys residues at positions 91 and 128 in the mature protein were shown to form a 36-residue disulfide loop by selectively labeling sulfhydryl groups that were liberated only after chemical reduction of monomeric P29. Two nearly identical charged amino acid sequences occurred in P29, within the disulfide loop and upstream of this structure. Two distinct epitopes binding different monoclonal antibodies were associated with opposite ends of the P29 protein, by mapping products expressed in Escherichia coli from PCR-generated 3' deletion mutations of the p29 gene. Each monoclonal antibody detected high-frequency and noncoordinate changes in accessibility of the corresponding epitopes in colony immunoblots of clonal variants, yet sequencing of the p29 gene from these variants and analysis of disulfide bonds revealed no associated changes in the primary sequence or disulfide loop structure of P29. These results suggest that P29 surface epitope variation may involve masking of selected regions of P29, possibly by other surface components undergoing phase variation by differential expression. Differential masking may be an important

  9. Electric power saving potential due to domestic refrigerators replacement; Potencial de ahorro de energia electrica por el reemplazo de refrigeradores domesticos

    Energy Technology Data Exchange (ETDEWEB)

    Peralta Solorio, Jose Luis [Fideicomiso para el Ahorro de Energia Electrica (Mexico)]. E-mail: jose.peralta@cfe.gob.mx

    2006-04-15

    In Mexico the second most used electrical appliance is: refrigerator. Owing to its use, it would be a promising option for electric power saving. In Guadalajara, Reynosa and Tampico it was performed a study with the aim of launching a project to replace the old refrigerators with new ones which are more effective and less expensive. Since the refrigerators cost and the electrical invoicing saving, the electric appliance change is profitable. To expect with this replacement more than eight million of refrigerators manufactured before 1997 will be changed. [Spanish] El refrigerador es el segundo electrodomestico mas utilizado a nivel nacional, esto permite que debido a su uso sea una opcion prometedora para el ahorro de energia electrica. Se hizo un estudio en Guadalajara, Reynosa y Tampico con el fin de lanzar un proyecto para sustituir los refrigeradores viejos por unos nuevos que sean mas eficaces y menos costosos. Por el costo de los refrigeradores y el ahorro en la facturacion electrica, el cambio de electrodomestico es rentable, de esta manera se espera que los mas de ocho millones de refrigeradores fabricados antes de 1997 que existen en el pais sean cambiados.

  10. An analysis of intrinsic variations of low-frequency shear wave speed in a stochastic tissue model: the first application for staging liver fibrosis

    Science.gov (United States)

    Wang, Yu; Wang, Min; Jiang, Jingfeng

    2017-02-01

    Shear wave elastography is increasingly being used to non-invasively stage liver fibrosis by measuring shear wave speed (SWS). This study quantitatively investigates intrinsic variations among SWS measurements obtained from heterogeneous media such as fibrotic livers. More specifically, it aims to demonstrate that intrinsic variations in SWS measurements, in general, follow a non-Gaussian distribution and are related to the heterogeneous nature of the medium being measured. Using the principle of maximum entropy (ME), our primary objective is to derive a probability density function (PDF) of the SWS distribution in conjunction with a lossless stochastic tissue model. Our secondary objective is to evaluate the performance of the proposed PDF using Monte Carlo (MC)-simulated shear wave (SW) data against three other commonly used PDFs. Based on statistical evaluation criteria, initial results showed that the derived PDF fits better to MC-simulated SWS data than the other three PDFs. It was also found that SW fronts stabilized after a short (compared with the SW wavelength) travel distance in lossless media. Furthermore, in lossless media, the distance required to stabilize the SW propagation was not correlated to the SW wavelength at the low frequencies investigated (i.e. 50, 100 and 150 Hz). Examination of the MC simulation data suggests that elastic (shear) wave scattering became more pronounced when the volume fraction of hard inclusions increased from 10 to 30%. In conclusion, using the principle of ME, we theoretically demonstrated for the first time that SWS measurements in this model follow a non-Gaussian distribution. Preliminary data indicated that the proposed PDF can quantitatively represent intrinsic variations in SWS measurements simulated using a two-phase random medium model. The advantages of the proposed PDF are its physically meaningful parameters and solid theoretical basis.

  11. Modeling the variations of reflection coefficient of Earth's lower ionosphere using very low frequency radio wave data by artificial neural network

    Science.gov (United States)

    Ghanbari, Keyvan; Khakian Ghomi, Mehdi; Mohammadi, Mohammad; Marbouti, Marjan; Tan, Le Minh

    2016-08-01

    The ionized atmosphere lying from 50 to 600 km above surface, known as ionosphere, contains high amount of electrons and ions. Very Low Frequency (VLF) radio waves with frequencies between 3 and 30 kHz are reflected from the lower ionosphere specifically D-region. A lot of applications in long range communications and navigation systems have been inspired by this characteristic of ionosphere. There are several factors which affect the ionization rate in this region, such as: time of day (presence of sun in the sky), solar zenith angle (seasons) and solar activities. Due to nonlinear response of ionospheric reflection coefficient to these factors, finding an accurate relation between these parameters and reflection coefficient is an arduous task. In order to model these kinds of nonlinear functionalities, some numerical methods are employed. One of these methods is artificial neural network (ANN). In this paper, the VLF radio wave data of 4 sudden ionospheric disturbance (SID) stations are given to a multi-layer perceptron ANN in order to simulate the variations of reflection coefficient of D region ionosphere. After training, validation and testing the ANN, outputs of ANN and observed values are plotted together for 2 random cases of each station. By evaluating the results using 2 parameters of pearson correlation coefficient and root mean square error, a satisfying agreement was found between ANN outputs and real observed data.

  12. Estimated potential of energy saving and reduction of the demand commercial buildings illumination; Potencial estimado de ahorro de energia y reduccion de la demanda en iluminacion de edificios comerciales

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Gomez, Victor Hugo; Morillon Galvez, David [Posgrado en Energetica de la DEPFI-UNAM, Mexico, D. F. (Mexico)

    1999-07-01

    In this paper the estimated energy saving potential in illumination, the energy end use and the technology used in commercial buildings of different use is analyzed. Estimation that departs from information of the Fideicomiso para el Ahorro de Energia (FIDE) demonstrative cases, presents the energy saving and the demand reduction in a sample of 29 buildings, among which are shopping malls, hospitals, schools, hotels, restaurants and public buildings in which energy saving programs have been carried out, with measures such as the cleaning of the luminaries and its replacement for more efficient ones. The average saving obtained is of 21.81%, in the following areas: illumination, air conditioning and others. In addition, in a sample of 4 buildings, it was observed that before applying the energy saving programs, two of them did not fulfill with the norm NOM-007-1995 (electric power density in interior lighting systems W/m{sup 2}) and later did fulfill the values and criteria of the norm. [Spanish] En el presente trabajo se analiza el potencial estimado de ahorro de energia en iluminacion, el uso final de la energia y la tecnologia empleada en edificios comerciales de uso distinto. Estimacion que parte de la informacion de los casos demostrativos del Fideicomiso para el Ahorro de Energia (FIDE), se presenta el ahorro y reduccion de la demanda en una muestra de 29 edificios, entre los que se tienen centros comerciales, hospitales, escuelas, hoteles, restaurantes y edificios publicos en los cuales se ha llevado a cabo programas de ahorro de energia, con medidas como la limpieza de las luminarias y su remplazo por otros mas eficientes. El ahorro promedio obtenido es de 21.81%, en las siguientes areas: iluminacion, aire acondicionado y otros. Ademas, en una muestra de 4 edificios, se observo que antes de aplicar los programas de ahorro de energia, dos no cumplian con la norma NOM-007-ENER-1995 (densidad de potencia electrica en alumbrado interior W/m{sup 2}) y

  13. Análisis del impacto económico y financiero de un programa de ahorro de agua en los dispositivos de descarga en sanitarios de una institución de educación básica

    OpenAIRE

    2006-01-01

    Uno de los temas centrales del IV Foro Mundial del Agua, realizado en la Ciudad de México en marzo de 2006 fueron el ahorro y cuidado del agua en el mundo. Para lograr dichos ahorros se requieren cambios radicales en los que el proceso de toma de decisiones se torna muy importante, debido a los costos que por lo regular implican dichos cambios. Esta Tesis pretende demostrar que los programas de ahorro y cuidado del agua no brindan solamente beneficios ambientales o sustenta...

  14. Nissan Mexicana. First place in national prize of electrical energy saving 1998; Nissan Mexicana. Primer lugar en premio nacional de ahorro de energia electrica 1998

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez S, Enrique [Nissan Mexicana, S.A. de C.V., Planta Civac, Cuernavaca, Mor. (Mexico)

    1999-07-01

    For Plant CIVAC of Nissan Mexicana, the energy saving began in the year of 1990. From then, different programs have been developed using different strategies for energy saving until arriving at the Benchmarking with other Plants of Japan, which represents a new challenge, since it opened up an area of opportunity of saving in processes that generally were known in detail as far as to its main function (to make vehicles with quality, cost and opportunity of delivery), but the parameter of energy consumption of by unit and its benefits in relation to the cost was unknown. This was endorsed by the high Direction and began with the optimization of training for the operation of each equipment with the involvement of the user (Production), the engineering area (that establishes the process) and the maintenance area. We designed a general program where the basic activities were included, such as the general and special activities. Each one of them fulfilled its objective, but the special activities took us to the optimization of the processes, finding excess of energy in the design conditions. [Spanish] Para Planta CIVAC de Nissan Mexicana, el ahorro de energia se inicio en el ano de 1990. A partir de entonces se han desarrollado programas de ahorro de energia usando estrategias diferentes hasta llegar al Benchmarking con otras Plantas de Japon, el cual representa un reto nuevo, ya que puso al descubierto una area de oportunidad de ahorro en los procesos que por lo general se conocian a detalle en cuanto a la funcion principal (hacer vehiculos con calidad, costo y oportunidad de entrega), pero se desconocia el parametro de consumo de energia por unidad y sus beneficios en relacion con el costo. Esto fue avalado por la alta Direccion y se inicio con la capacitacion de la optimizacion de la operacion de cada equipo y se involucro al usuario (Produccion), al area de ingenieria (que establece el proceso) y al area de mantenimiento. Elaboramos un programa general donde se

  15. Temperature variation of ultralow frequency modes and mean square displacements in solid lasamide (diuretic drug) studied by 35Cl-NQR, X-ray and DFT/QTAIM.

    Science.gov (United States)

    Latosińska, Jolanta Natalia; Latosińska, Magdalena; Kasprzak, Jerzy; Tomczak, Magdalena; Maurin, Jan Krzysztof

    2012-10-25

    The application of combined (35)Cl-NQR/X-ray/DFT/QTAIM methods to study the temperature variation of anisotropic displacement parameters and ultralow frequency modes of anharmonic torsional vibrations in the solid state is illustrated on the example of 2,4-dichloro-5-sulfamolybenzoic acid (lasamide, DSBA) which is a diuretic and an intermediate in the synthesis of furosemide and thus its common impurity. The crystallographic structure of lasamide is solved by X-ray diffraction and refined to a final R-factor of 3.06% at room temperature. Lasamide is found to crystallize in the triclinic space group P-1, with two equivalent molecules in the unit cell a = 7.5984(3) Å, b = 8.3158(3) Å, c = 8.6892(3) Å; α = 81.212(3)°, β = 73.799(3)°, γ = 67.599(3)°. Its molecules form symmetric dimers linked by two short and linear intermolecular hydrogen bonds O-H···O (O-H···O = 2.648 Å and ∠OHO = 171.5°), which are further linked by weaker and longer intermolecular hydrogen bonds N-H···O (N-H···O = 2.965 Å and ∠NHO = 166.4°). Two (35)Cl-NQR resonance frequencies, 36.899 and 37.129 MHz, revealed at room temperature are assigned to chlorine sites at the ortho and para positions, relative to the carboxyl functional group, respectively. The difference in C-Cl(1) and C-Cl(2) bond lengths only slightly affects the value of (35)Cl-NQR frequencies, which results mainly from chemical inequivalence of chlorine atoms but also involvement in different intermolecular interactions pattern. The smooth decrease in both (35)Cl-NQR frequencies with increasing temperature in the range of 77-300 K testifies to the averaging of EFG tensor at each chlorine site due to anharmonic torsional vibrations. Lasamide is thermally stable; no temperature-induced release of chlorine or decomposition of this compound is detected. The temperature dependence of ultralow frequency modes of anharmonic small-angle internal torsional vibrations averaging EFG tensor and mean square angle

  16. Economía y sociedad en Burgos (1890-1936): la Caja de Ahorros del Círculo Católico

    OpenAIRE

    Chicote Ureta, María Felicidad

    2016-01-01

    El objetivo que pretende alcanzar esta investigación y la metodología que se va a utilizar conducen a un propósito: realizar un análisis de la Caja de Ahorros y Monte de Piedad del Círculo Católico de Obreros de Burgos –a lo largo de sesenta años– que ponga de relieve su impacto real sobre la sociedad en la que se instala y ayude a explicar su contribución en el devenir de la historia burgalesa de la segunda mitad del siglo XX. Aspira a presentar a la Institución como un síntoma, como la resp...

  17. Evaluation of the energy saving potential in illumination using presence sensors; Evaluacion del potencial de ahorro de energia en iluminacion utilizando sensores de presencia

    Energy Technology Data Exchange (ETDEWEB)

    Cortes Eslava, Alejandro [Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D. F. (Mexico)

    1999-07-01

    The analysis and the evaluation of the energy saving that would provide a system of illumination controlled by sensors of presence in an enclosure with low transit, evaluating the economic profitability of the system is presented. The data, from which the analysis is sustained and the results are deducted, coming from the use and installation of a timer in the area. [Spanish] Se presenta el analisis y la evaluacion de los ahorros de energia que suministraria un sistema de iluminacion controlado por sensores de presencia en un recinto con bajo transito, evaluando la rentabilidad economica del sistema. Los datos, a partir de los cuales se sustenta el analisis y se deducen los resultados, provienen de la utilizacion e instalacion de un contador de tiempo de uso en el recinto.

  18. Design aspects and conservation of roads in the saving of energy; Aspectos de diseno y conservacion de carreteras en el ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Cajun, Carlos S.; Aguerrebere Salido, Roberto [Instituto Mexicano del Transporte, Queretaro (Mexico)

    1992-12-31

    In this paper the effects that on the fuel consumption the roads have for their slopes and roughness are presented. A mathematical model is presented which shows the relationship between the slope, the roughness coefficient and the required power to overcome the corresponding resistance; the former in order to predict the fuel consumption and therefore, the potential level of energy saving corresponding to this item. [Espanol] En este trabajo se presentan los efectos que sobre consumo de combustible se tienen, debido a las pendientes y rugosidades de las carreteras. Se presenta un modelo matematico que muestra la relacion entre la pendiente, el coeficiente de rodamiento y la potencia requerida para vencer las resistencias correspondientes; lo anterior con el fin de predecir el consumo de combustible y, por lo tanto, los niveles potenciales de ahorro de energia correspondientes a este rubro.

  19. Energy saving in Bellota Mexico S.A. de C.V.; Ahorro de energia en Bellota Mexico S.A de C.V.

    Energy Technology Data Exchange (ETDEWEB)

    Salazar Lopez, Jose Albeiro [Bellota Mexico S.A. de C.V. (Mexico)

    2003-07-01

    The present article intends to make a general description of the different activities that were developed in Bellota Mexico S.A. de C.V. during year 2001 and which lead to obtaining the national prize of energy saving granted by the Comision Federal de Electricidad (CFE) and the Fideicomiso para el Ahorro de Energia Electrica (FIDE). In the executed actions stands out an entirely coordinated program that includes: lighting systems, motors, refrigeration systems, transformers, special projects (settling tanks), capacitors, compressed air pipeline, induction furnaces, machinery in general, maximum demand control, preventive maintenance, measuring systems, operational and organizational systems. In all these subjects a fast description is made of the performed actions and the obtained results. It is mentioned in addition the importance of making a power diagnosis and the use of historical data for the planning of the strategies to follow. Also reference is made of the use of appropriate technology that considers the use of high-energy efficiency equipment, such as motors, lamps, compressors, etc. Finally an evaluation is made of the obtained results where the improvement of the electrical parameters stands out such as: reduction of the power index in 35.06%, reduction of the maximum demand in 11.94%, increase of the power factor from 93.53% in 98.21%. The obtained results demonstrate that investing in energy saving it is a good business. [Spanish] El presente trabajo tiene por objeto hacer una descripcion general de las diferentes actividades que se desarrollaron en Bellota Mexico S.A. de C.V. durante el ano 2001 y que condujeron a la obtencion del premio nacional de ahorro de energia otorgado por la Comision Federal de Electricidad (CFE) y el Fideicomiso para el Ahorro de Energia Electrica (FIDE). En las acciones ejecutadas se destaca todo un programa coordinado que abarca: sistemas de iluminacion, motores, sistemas de refrigeracion, transformadores, proyectos

  20. Ahorro infantil: “Chispitas”-Estrategia para combatir la pobreza, Fundación Ayú, Oaxaca, México

    OpenAIRE

    Guadalupe Arcos-Medina*; Emma Zapata-Martelo; Oliverio Hernández-Romero

    2016-01-01

    En esta investigación analizamos cómo la estrategia de combate a la pobreza de la Fundación Ayú, influye en el hábito del ahorro de los niños y niñas mixtecos de Oaxaca -los “Chispitas”-, con datos obtenidos de noviembre de 2013 a julio de 2014. Realizamos un taller participativo y entrevistas semiestructuradas, aplicando un cuestionario a 42 niños y niñas de diez años de edad promedio, y antigüedad como ahorradores de entre tres y siete años. El perfil socioeconómico familiar corresponde may...

  1. Implementacion del modelo Lean Service en el proceso de recaudo de la Cooperativa de Ahorro y Crédito Fincomercio ltda

    Directory of Open Access Journals (Sweden)

    Jonny Gavilán

    2016-12-01

    Full Text Available El presente trabajo forma parte de la tesis de maestría, para optar al título de Magister en Ingeniería Industrial de la Universidad Distrital Francisco José de Caldas. El cual se basó fundamentalmente en el diseño e implementación del modelo Lean Service para el proceso de recaudo de la Cooperativa de Ahorro y Crédito Fincomercio Ltda. En este marco de referencia, la presente investigación de tipo Descriptivo – Explicativo consistirá en la aplicación de la metodología Lean Service para el mejoramiento del proceso de recaudo de la Cooperativa.

  2. Las cajas de ahorro en el sistema financiero español. Trayectoria histórica y realidad histórica actual.

    OpenAIRE

    Cals, Joan,

    2002-01-01

    La OCDE (1971) calificaba al sistema financiero español, a comienzos de los años setenta, como uno de los más rígidos y reglamentados de los países que integraban la organización. A su vez, la cajas de ahorros españolas figuraban entre las que de forma más restrictiva debían desarrollar sus actividades (Ros, 1967). Por ello, era lógico que a partir de 1973-74 y, especialmente, 1977, se iniciara un proceso de reforma y liberalización que operaría en diversos frentes y daría paso a la equiparac...

  3. Ahorro energético y cogeneración en el sector hotelero de Cozumel y la Riviera Maya (México)

    OpenAIRE

    Mendoza Vizcaino, Fco. Javier

    2013-01-01

    En este trabajo se desarrollará un ejercicio de ahorro energético y cogeneración en un hotel de Cozumel (Riviera Maya) México. Para esto, se requiere de la implementación de un sistema de conversión de los residuos orgánicos en biogás, el cual alimente a un equipo de cogeneración y así, la producción y una mejor gestión de la energía, sean una solución viable para disminuir el costo de operación y la emisión de gases de efecto invernadero (GEI) buscando obtener una bonificación...

  4. Evaluation of saving measurements and energetic efficiency in air-conditioning systems; Evaluacion de medidas de ahorro y eficiencia energetica en sistemas de climatizacion

    Energy Technology Data Exchange (ETDEWEB)

    Perez Lombard, L [Asociacion de Investigacion y Cooperacion de Andalucia (Spain); Ortiz, J [Building Research Establishment (United Kingdom); Riviere, P [Armines-ecole des mines de Paris (France)

    2006-04-15

    Buildings require an adequate air conditioning to offer workers a labor environment where there is thermal comfort. A study was performed in three different European places which count on several climates. The conclusion was the following: in order to analyze the energy efficiency in edifications it is fundamental the simulation tools use with the purpose of calculating the consumption and evaluating the saving measurements. [Spanish] Los edificios requieren de una climatizacion adecuada para que los que ahi operan puedan hacerlo dentro de un ambiente laboral donde exista el confort termico. Se llevo a cabo un estudio en tres lugares de Europa poseedores de diferentes climas y se concluyo que para poder analizar la eficiencia energetica de climatizacion en las edificaciones es imprescindible el uso de herramientas de simulacion con el proposito de calcular el consumo y evaluar las medidas de ahorro.

  5. Strategies for energy saving in buildings by means of automatic control; Estrategias de ahorro de energia en inmuebles mediante el control automatico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Trujillo, Oscar [Johnson Controls de Mexico S. A. de C. V., Mexico, D. F. (Mexico)

    1998-12-31

    In this paper some of the measures and strategies for energy saving that can be applied in different types of buildings, mainly in hotels and office buildings, are presented. The proposed actions are accomplished with the aid of the automatic control equipment and the operation and/or maintenance personnel that supervises and establishes the control parameters of each one of the strategies than are focused to the appropriate utilization of the electric energy. [Espanol] En este documento se presentan algunas de las medidas y estrategias de ahorro de energia que pueden ser aplicadas en diferentes tipos de inmuebles, principalmente en hoteles y en edificios de oficinas. Las acciones propuestas son realizadas con la ayuda del equipo de control automatico y del personal de operacion y/o mantenimiento quien supervisa y establece los parametros de control de cada una de las estrategias que son destinadas a la buena utilizacion de la energia electrica.

  6. Experiences on energy saving in Comision Federal Electricidad (CFE) buildings; Experiencias de ahorro de energia en edificios de la Comision Federal de Electricidad (CFE)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Velasco, Jorge E. [Comision Federal de Electricidad (CFE) (Mexico)

    2005-07-01

    This document describes the developed saving projects in buildings and generating power stations in 2004 by the Comision Federal de Electricidad (CFE). The projects considered are: buildings of the oficinas nacionales, Divisions of distribution office buildings, office buildings of production regions, construction deputy manager's office building, buildings of transmission and transformation, generating power stations, investments and savings of the projects in oficinas nacionales, divisions of distribution and construction subdivision buildings. From these projects the ones concluded in the 2004 were: Distribution Divisions, Gulf-Center Division, Center-West Distribution Division. The developing projects of 2005: oficinas nacionales, distribution divisions, Construction Subdivision, Generating Power Stations, Transmission Areas and office buildings. And finally, the projects concluded in the 2005 are the distribution divisions, the construction subdivision, the generating power stations, the office buildings, the minisplit units and their advantages with respect to the air conditioning window units. [Spanish] Este documento describe los proyectos de ahorro desarrollados en inmuebles y centrales generadoras en el ano 2004 por la Comision Federal de Electricidad (CFE), los proyectos tratados son: inmuebles de oficinas nacionales, inmuebles de divisiones de distribucion, inmuebles de regiones de produccion, inmuebles de la subdireccion de construccion, inmuebles de transmision y transformacion, centrales generadoras, inversiones y ahorros de los proyectos en inmuebles de oficinas nacionales y divisiones de distribucion y subdireccion de construccion. De dichos proyectos se tiene que los proyectos concluidos en el 2004 fueron: Divisiones de Distribucion, Division Golfo Centro, Division de Distribucion Centro Occidente. Los proyectos en desarrollo del 2005: oficinas nacionales, divisiones de distribucion, Subdireccion de Construccion, Centrales Generadoras, Areas

  7. Energy conservation programs of Pemex exploration and production, south region; Programas de ahorro de energia en Pemex exploracion y produccion, region sur

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Milla, Guillermo; Garcia Juarez, Francisco; Alarcon Aleman, Jose Mauricio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The technological developments of energy economizing equipment constitute a powerful tool for the conservation and saving of the electric energy in new or existing installations. Petroleos Mexicanos (PEMEX) Exploration and Production initiated in 1997 a program for energy economizing in the South region, for which the Instituto de Investigaciones Electricas, through its Unit for the Use of Energy, collaborated performing energy assessments in 115 buildings of the above mentioned region. This paper describes the employed methodology to carry on the energy assessment, which consisted in an analysis of each building and different options for energy economizing were presented, which was accompanied with cost-benefit studies. The results obtained show that the air conditioning equipment and lighting represent the most important loads permanently connected, therefore the study was concentrated in these two loads [Espanol] Los desarrollos tecnologicos de equipos ahorradores de energia constituyen una poderosa herramienta para la conservacion y el ahorro de energia electrica en instalaciones nuevas o existentes. Petroleos Mexicanos (PEMEX) Exploracion y Produccion inicio en 1997 un programa para el ahorro de energia en la region sur, para lo cual el Instituto de Investigaciones Electricas, a traves de la Unidad de Uso de Energia, colaboro realizando diagnosticos energeticos en 115 edificios de dicha region. En este documento se describe la metodologia utilizada para realizar el diagnostico energetico, el cual consistio en un analisis de cada edificio y se presentaron diversas opciones para ahorrar energia, lo cual se acompano de estudios de costo-beneficio. Los resultados obtenidos muestran que los equipos de aire acondicionado e iluminacion representan la parte mas importante de las cargas conectadas permanentemente, por lo que el estudio se concentro en estas dos cargas

  8. Valoración de la garantía de pensión en las cuentas de ahorro individual en colombia

    Directory of Open Access Journals (Sweden)

    José V. Restrepo

    2011-09-01

    Full Text Available El comportamiento del individuo como persona que aporta, y futuro beneficiario de una pensión, es determinante para cuantificar los efectos que su densidad de aportes tiene sobre el sistema de ahorro individual y la exigibilidad de las diferentes garantías. Por esta razón, en el presente trabajo se intenta buscar desde las finanzas personales una visión alterna a lo expuesto en diferentes estudios que sobre la materia se han realizado, no solo en Colombia sino a nivel internacional, y brindar una aproximación a la solución del problema de sostenibilidad en el retiro. Para calcular la magnitud de las garantías, se desarrolló un procedimiento que combina metodologías de modelos estocásticos con modelos de lógica difusa y con el cálculo actuarial. de esta forma, y soportado en resultados de otros estudios, se logró determinar el ahorro individual potencial alcanzable por cada individuo en función de su género y su cohorte salarial, y el posible déficit existente para conseguir una pensión mínima de retiro. los resultados encontrados indican que en las condiciones de baja densidad de aportes es muy difícil para las cohortes de bajo y medio ingreso asegurar una pensión mínima sin el agotamiento de las garantías existentes y la participación del gobierno.

  9. Application of frequency converters in industry; Aplicacion de convertidores de frecuencia en la industria

    Energy Technology Data Exchange (ETDEWEB)

    Adame Gonzalez, A.; Aguilar Galvan, A. [Ingenieria Energetica Integral, S.A. de C.V. (Mexico)

    1997-12-31

    Some of the applications of the frequency converters will be analyzed, as well as the parameters to be considered for the feasibility of its application evaluation. It is also described how an energy evaluation is accomplished and finally a series of actions are enlisted conducting to the energy savings. [Espanol] Se presentaran algunas de las aplicaciones de los convertidores de frecuencia. Ademas se indicaran los parametros a registrar para evaluar la factibilidad de aplicacion de los mismos, se describe como ejecutar la evaluacion energetica y finalmente se listan una serie de acciones que conducen a lograr ahorros de energia.

  10. The methodology for the evaluation of the energy saving by the daylight saving time in Mexico; Metodologia para la evaluacion del ahorro de energia debido al cambio de horario durante la epoca del verano

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Niembro, Gaudencio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    A description is made of the methodology for the evaluation of energy saving by the daylight saving time in Mexico. A mathematical model was developed that would allow the quantitative evaluation of the energy saving by the daylight saving time, through measurements of the consumption of different users from the domestic commercial and industrial sector, considering the various variables that impact the consumption [Espanol] Se describe la metodologia para la evalucion del ahorro de energia por el cambio de horario de verano en Mexico. Se desarrollo un modelo matematico que permitiera evaluar cuantitativamente el ahorro de energia debido al cambio de horario durante la epoca de verano, atraves de mediciones de consumos de los diferentes usuarios de los sectores domestico, comercial e industrial, considerando las diversas variables que impactan en el consumo

  11. Ahorro de energía eléctrica por implementación de filtros desecantes en sistemas de acondicionamiento de aire por compresión de vapor

    Directory of Open Access Journals (Sweden)

    Antonio José Bula Silvera

    2004-01-01

    Full Text Available Una serie de experimentos exploratorios han sido llevados a cabo para determinar cómo se afecta el desempeño energético de un sistema de aire acondicionado por compresión de vapor al trabajar con un filtro deshumidificador instalado en la línea de retorno del aire hacia el evaporador. Los experimentos se realizaron considerando sistemas con alta y baja carga latente, y se observo cómo variaba el consumo de energía del equipo. Se encontró que al estar sometido el sistema de aire acondicionado a altas cargas latentes, el ahorro de energía al instalar estos filtros desecantes puede llegar a 14,5% mientras que al estar sometido el sistema a bajas cargas latentes, el ahorro sólo llega a 2%.

  12. Introduction criteria and concepts on energy saving in the technical standards for electric installations; Introduccion de criterios y conceptos de ahorro de energia en las normas tecnicas para instalaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Rincon Nader, Jorge A. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-12-31

    The project Introduction Criteria and Concepts on Energy Saving in the Technical Standards for electric installations, is described, whose immediate objective is to recommend and in some cases regulate the use of energy saving equipment and devices and the adoption of attitudes and procedures that convey into saving, and the rational and efficient use of the electric energy. [Espanol] Se describe el proyecto Introduccion de Criterios y Conceptos de Ahorro de Energia en las Normas Tecnicas para instalaciones electricas, que tiene como objetivo inmediato recomendar, y en algunos casos reglamentar el uso de equipos y dispositivos ahorradores y la adopcion de actitudes y procedimientos que conduzcan a un ahorro y uso racional y eficiente de la energia electrica.

  13. Estimating variation in stomatal frequency at intra-individual, intra-site, and inter-taxonomic levels in populations of the Leonardoxa africana (Fabaceae) complex over environmental gradients in Cameroon

    Science.gov (United States)

    Finsinger, Walter; Dos Santos, Thibaut; McKey, Doyle

    2013-07-01

    Variation of stomatal frequency (stomatal density and stomatal index) includes genetically-based, potentially-adaptive variation, and variation due to phenotypic plasticity, the degree of which may be fundamental to the ability to maintain high water-use efficiency and thus to deal with environmental change. We analysed stomatal frequency and morphology (pore length, pore width) in leaves from several individuals from nine populations of four sub-species of the Leonardoxa africana complex. The dataset represents a hierarchical sampling wherein factors are nested within each level (leaves in individuals, individuals in sites, etc.), allowing estimation of the contribution of different levels to overall variation, using variance-component analysis. SI showed significant variation among sites ("site" is largely confounded with "sub-species"), being highest in the sub-species localized in the highest-elevation site. However, most of the observed variance was accounted for at intra-site and intra-individual levels. This variance could reflect great phenotypic plasticity, presumably in response to highly local variation in micro-environmental conditions.

  14. UV frequency metrology on CO (a3Pi); isotope effects and sensitivity to a variation of the proton-to-electron mass ratio

    CERN Document Server

    de Nijs, Adrian J; Eikema, Kjeld S E; Ubachs, Wim; Bethlem, Hendrick L

    2011-01-01

    UV frequency metrology has been performed on the a3Pi - X1Sigma+ (0,0) band of various isotopologues of CO using a frequency-quadrupled injection-seeded narrow-band pulsed Titanium:Sapphire laser referenced to a frequency comb laser. The band origin is determined with an accuracy of 5 MHz (delta \

  15. Análisis de costes y ahorros potenciales relacionados con la utilización de pruebas preoperatorias en los hospitales de Canarias

    Directory of Open Access Journals (Sweden)

    López-Bastida J.

    2003-01-01

    Full Text Available Objetivos: Estimar el ahorro potencial que podría tener lugar en el Servicio Canario de Salud (SCS, a partir de una utilización apropiada científica de las pruebas preoperatorias, haciendo uso de la información obtenida de los 5 hospitales universitarios de la red pública. Métodos: Un total de 55 anestesiólogos (60% del SCS cumplimentaron un cuestionario. En éste se prestó especial atención a las pruebas preoperatorias más frecuentemente utilizadas, como la radiografía de tórax, el electrocardiograma, las pruebas de laboratorio y la espirometría. Los costes unitarios medios para las diferentes pruebas preoperatorias se obtuvieron de 2 hospitales participantes en el estudio. Para calcular los ahorros potenciales derivados del uso apropiado de las pruebas preoperatorias se han considerado varios escenarios caracterizados por diferentes hipótesis o grados de cumplimiento de un protocolo basado en el conocimiento científico, considerado como parámetro de referencia. Resultados: En el caso ideal de que se cumpliera el protocolo científico recomendado en el 100% de los 16.179 pacientes considerados ASA I y II, la repercusión económica sería notable, pues supondría una liberación de recursos sensible que podría ser utilizada para otros programas de salud. Estas cifras podrían alcanzar aproximadamente los 1,02 millones de euros, sin considerar el coste de la estancia preoperatoria. Esta cifra podría incrementarse hasta, aproximadamente, los 2,13 millones de euros si incluimos un día de estancia preoperatoria, y hasta los 3,24 millones de euros incluyendo 2 días de estancia preoperatoria. Conclusiones: La revisión reciente de la literatura científica y los resultados proporcionados por el cuestionario aplicado en el SCS indican que las pruebas preoperatorias alcanzan los mayores beneficios para los pacientes y para la sociedad si se guían por el conocimiento científico. Es posible, además, liberar recursos a partir de una

  16. Scenarios simulation for the conservation and efficient use of energy, using passive control measures; Simulacion de escenarios de ahorro y uso eficiente de energia, utilizando medidas de control pasivo

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, G.; Heard, Ch.; Sanchez Viveros, A. [Instituto de Investigaciones Electricas,Cuernavaca (Mexico)

    1997-12-31

    Every one involved with the conservation and efficient use of electric energy, has listened in reiterative occasions to the causes that changed the conventional mentality at the beginning of the seventies. Nevertheless, there are many persons that still ignore that by using the energy rationally, their costs are significantly reduced, their comfort is enhanced and the environmental problems are minimized. Specifically, in the domestic sector, from the figures reported by the Comision Federal de Electricidad (CFE) in 1996, the electric energy sold was 28,410 Gwh, that is, 23.4% of the total consumption (121,579 Gwh). Table 1 presents the average by tariff in the national domestic sector, which shows that 20% of the electricity consumed was required for environmental conditioning (air conditioning, evaporative coolers and electric fans). The above figures quantitatively show that there is a strong impact in the consumption of electric energy due to weather conditions. For this reason, currently the Comision Nacional de Ahorro de Energia (CONAE) and the Fideicomiso para el Ahorro de Energia (FIDE) are promoting standards and projects to propitiate the rationalization in the use of energy, besides of achieving the improvement of thermal comfort conditions. One more case would be the Fideicomiso para el Aislamiento Termico de la Vivienda en Mexicali (FIPATERM), which promotes the financing of saving measures and efficient energy use in cities with extreme climate. This paper describes the strategy that was followed by the Instituto de Investigaciones Electricas (IIE), for the development of the human and material infrastructure, that has allowed the sustainment of several projects in the saving and efficient use of energy in CFE, CONAE, FIDE, FIPATERM and the Lawrence Berkeley National Laboratory (LBNL), concretely in relationship with the thermal analysis of dwellings. [Espanol] Todos aquellos relacionados con el ahorro y el uso eficiente de la energia electrica, han

  17. Influence of frequency variation in the load behaviour in electric power systems; Influencia da variacao da frequencia no comportamento da carga dos sistemas eletricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Sobrinho, Mauro de

    1994-11-01

    This work presents several models for the representation of load-frequency control systems and describes the main characteristics of the load. The composition of the load is described in details, divided by sectors. Finally, simulations of the load-frequency control system is performed. Conclusions are presented.

  18. Actions and results of the management of energy saving of the CONDUMEX group; Acciones y resultados de la gerencia de ahorro de energia de grupo CONDUMEX

    Energy Technology Data Exchange (ETDEWEB)

    Sashida Key, Carlos; Jimenez Huerta, Arturo; Alavez Alcazar, Moises [Grupo Condumex, Industrias IEM, S.A. de C.V., Mexico, D.F. (Mexico)

    1999-07-01

    The purpose of this paper is to expose some practical cases that have been developed through the Energy Saving Management of GRUPO CONDUMEX, in different areas such as systems related to water, steam, electricity and compressed air. This experience has been compiled of diagnoses and actions that have been carried out in the companies inside and outside GRUPO CONDUMEX, and of systems with the purpose of making efficient the use of fuels and getting close to the energy indexes that are handled in other International companies of the same manufacture branch. [Spanish] Este trabajo tiene por objeto exponer algunos casos practicos que se han desarrollado a traves de la Gerencia de Ahorro de Energia de GRUPO CONDUMEX, en distintas areas tales como sistemas relacionados con agua, vapor, electricidad y aire comprimido. Esta experiencia ha sido recopilada de diagnosticos y acciones que se han llevado a cabo en las empresas dentro y fuera de GRUPO CONDUMEX, y de sistemas con la finalidad de eficientar el uso de los energeticos y acercarnos a los indices energeticos que se manejan en otras empresas internacionales del mismo ramo de fabricacion.

  19. Energy saving in buildings through the elimination of typical problems; Ahorro de energia electrica en edificios a traves de la eliminacion de problemas tipicos

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Rivero, Alex G. [Genertek, S. A. de C. V., Mexico, D. F. (Mexico)

    1993-12-31

    The enormous electric energy consumption in buildings represents an important area of saving opportunities. The design of installations without advanced technical illumination criteria, the absence of standardization over energy efficiency, the lack of observation of the existing standards and guides, the continuous load growth in existing installations and the lack of appropriate maintenance, are some of the causes of the inefficient use of electric energy in buildings. Although the problems, and consequently the solutions, are exclusive for each unit, some of the former are frequently repeated. In this paper the problems found along more than 40 audits conducted in large buildings of different types in Mexico city are commented. [Espanol] El enorme consumo de energia electrica en edificios representa una importante area de oportunidad para ahorro. El diseno de instalaciones sin criterios luminotecnicos avanzados, la ausencia de normalizacion sobre eficiencia energetica, la falta de observancia de las normas y recomendaciones vigentes, el continuo crecimiento de carga en instalaciones existentes y la falta de mantenimiento adecuado son algunas de las causas del uso ineficiente de la energia electrica en inmuebles. Aunque los problemas y por tanto las soluciones son particulares para cada unidad, algunos de los primeros se repiten frecuentemente. En este trabajo se comentan los problemas encontrados a lo largo de mas de 40 auditorias realizadas a inmuebles grandes de diversos tipos en la ciudad de Mexico.

  20. The satisfaction of developing a project of electrical energy saving; La satisfaccion de desarrollar un proyecto de ahorro de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Arreola Suarez, Alejandro [Hotel Club Marival, Nuevo Vallarta, Nayarit (Mexico)

    2002-09-01

    The projects for the energy saving in hotels represent a great opportunity to reduce the operation costs in the demand and consumption of electrical energy, since the existing facilities can take advantage of new technologies in illumination, air conditioning, refrigeration and heating. By their constitution, the hotels work the year around uninterruptedly and must provide all type of services to the guests and working personnel, which originates that they consume great amounts of energy in air conditioning, lightning, laundry, etc., since the prestige of the installation depends on it. [Spanish] Los proyectos para el ahorro de energia en hoteles representan una gran oportunidad para reducir costos de operacion en la demanda y consumo de energia electrica, ya que las instalaciones existentes pueden aprovechar nuevas tecnologias en iluminacion, aire acondicionado, refrigeracion y calefaccion. Por su constitucion, los hoteles trabajan ininterrumpidamente todo el ano y deben proporcionar toda clase de servicios a los huespedes y personal que labora, lo cual origina que consuman grandes cantidades de energia en aire acondicionado, iluminacion, lavanderia, etc., pues de ello depende el prestigio de la instalacion.

  1. Energy saving: optimal use of air conditioning equipment by means of the solar control; Ahorro de energia: uso optimo de los acondicionadores de aire mediante el control solar

    Energy Technology Data Exchange (ETDEWEB)

    Mejia D, David; Morillon G, David; Rodriguez V, Luis [Universidad Nacional Autonoma de Mexico (Mexico)

    2001-09-01

    In this article the evaluation of the solar heat gains through the transparent parts of a building (houses of social interest) is presented; with the purpose of determining the heat gains through windows during summer time and under the following conditions: without solar protection, with the use of eaves, solar breakers and, finally, with the use of both elements. With the determined percentage of the diminution of heat gains, the considered potential of energy saving in air conditioning was obtained that would be available if the houses were constructed with solar control. [Spanish] En este articulo se presenta la evaluacion de las ganancias de calor solar a traves de las partes transparentes de un edificio (viviendas de interes social); con el objeto de determinar las ganancias de calor a traves de ventanas para la epoca de verano y bajo las siguientes condiciones: sin proteccion solar, con el empleo de aleros, con quiebrasoles y, finalmente, con el empleo de ambos elementos. Con el porcentaje determinado de la disminucion de ganancias de calor, se obtuvo el potencial estimado de ahorro de energia en aire acondicionado que se tendria si las viviendas se construyen con control solar.

  2. Ahorro infantil: “Chispitas”-Estrategia para combatir la pobreza, Fundación Ayú, Oaxaca, México

    Directory of Open Access Journals (Sweden)

    Guadalupe Arcos-Medina*

    2016-02-01

    Full Text Available En esta investigación analizamos cómo la estrategia de combate a la pobreza de la Fundación Ayú, influye en el hábito del ahorro de los niños y niñas mixtecos de Oaxaca -los “Chispitas”-, con datos obtenidos de noviembre de 2013 a julio de 2014. Realizamos un taller participativo y entrevistas semiestructuradas, aplicando un cuestionario a 42 niños y niñas de diez años de edad promedio, y antigüedad como ahorradores de entre tres y siete años. El perfil socioeconómico familiar corresponde mayormente a hogares campesinos; las razones para ahorrar son la educación, el futuro y las emergencias, siendo las madres quienes mayor influencia tienen en este hábito. Participar en las cajas visibiliza a los niños y niñas en la localidad y los inicia en la inclusión social y financiera.

  3. Composición quimicomineralógica de las materias primas y ahorro de energía en la industria del cemento

    Directory of Open Access Journals (Sweden)

    Soria Santamaría, Francisco

    1982-06-01

    Full Text Available In the field of energy saving, mainly thermic, in the cement industry, not only should we consider the possibilities in the technological process or the finished product, but also the influence of the chemical-mineral composition of the raw materials. The distinct parameters which fall into the reactivity of the crudes are analyzed, such as the size of the grain (fineness, chemical and mineral composition of the principal components. There follows an exposition of the importance of the minority components as smelting and mineralizers, finally emphasizing the interest and practical behaviour of some of them.

    En el campo del ahorro de energía, principalmente térmica, en la industria cementera, no sólo deben contemplarse las posibilidades en cuanto al proceso tecnológico o el producto acabado, sino también la influencia de la composición quimicomineralógica de las materias primas. Se analizan los distintos parámetros que inciden en la reactividad de los crudos, tales como tamaño de grano (finura, composición química y mineralogía de los componentes principales. A continuación se hace una exposición de la importancia de los componentes minoritarios como fundentes y mineralizadores, destacando finalmente el interés y comportamiento práctico de alguno de ellos.

  4. Variation of Fractional Electron Density Fluctuations Near 0.1 AU From the Sun Observed by Ulysses Dual-Frequency Ranging Measurements

    Science.gov (United States)

    Woo, R.; Armstrong, J. W.; Bird, M. K.; Patzold, M.

    1994-01-01

    This paper presents the results of determining fractional density fluctuations, which requires the measurement of absolute electron density as provided by dual-frequency observations of time delay or ranging conducted by the Ulysses Solar Corona Experiment.

  5. On Data and Parameter Estimation Using the Variational Bayesian EM-algorithm for Block-fading Frequency-selective MIMO Channels

    DEFF Research Database (Denmark)

    Christensen, Lars P.B.; Larsen, Jan

    2006-01-01

    A general Variational Bayesian framework for iterative data and parameter estimation for coherent detection is introduced as a generalization of the EM-algorithm. Explicit solutions are given for MIMO channel estimation with Gaussian prior and noise covariance estimation with inverse-Wishart prio...

  6. Introduction to natural disturbances and historic range of variation: type, frequency, severity, and post-disturbance structure in central hardwood forests

    Science.gov (United States)

    Katie Greenberg; Beverly S. Collins; Henry McNab; Douglas K. Miller; Gary R. Wein

    2015-01-01

    EXCERPT FROM: Natural Disturbances and Historic Range Variation 2015. Throughout the history of upland hardwood forests of the Central Hardwood Region, natural disturbances have been integral to shaping forest structure and composition, and essential in maintaining diverse biotic...

  7. Variation in adult sex ratio alters the association between courtship, mating frequency and paternity in the lek-forming fruitfly Ceratitis capitata.

    Science.gov (United States)

    Leftwich, P T; Edward, D A; Alphey, L; Gage, M J G; Chapman, T

    2012-09-01

    The intensity with which males deliver courtship and the frequency with which they mate are key components of male reproductive success. However, we expect the strength of the relationship between these traits and a male's overall paternity to be strongly context dependent, for example to be altered significantly by the extent of post-mating competition. We tested this prediction in a lekking insect, Ceratitis capitata (medfly). We examined the effect of manipulating the sex ratio from male- to female-biased (high and low male competition, respectively) on courtship behaviour, mating frequency and paternity of focal males. Under high male competition, focal males delivered significantly more courtship but gained lower paternity than under lower competition. Paternity was positively associated with mating frequency and small residual testes size. However, the association between mating frequency and paternity was significantly stronger under low competition. We conclude that manipulation of sex ratio significantly altered the predictors of mating success and paternity. The relationship between pre- and post-mating success is therefore plastic and alters according to the prevailing level of competition. The results highlight the importance of post-copulatory processes in lekking species and illuminate selection pressures placed on insects such as medflies that are mass reared for pest control. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  8. The technical-economic potential of thermal energy saving in hospitals; El potencial tecnico-economico de ahorro de energia termica en hospitales

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, A. [Universidad Nacional Autonoma de Mexico (Mexico); Islas, J [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Arriola, A. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    cantidad representa un porcentaje importante de los gastos totales del hospital (29.367 millones de dolares) es importante determinar posibilidades tecnico - economicas de ahorro de energia termica del hospital. El HGZ N 1 - IMSS Ags. Esta ubicado en un conjunto mas amplio en donde se localizan las unidades del IMSS, tales como, la lavanderia regional, la unidad deportiva, el centro de seguridad social, la unidad de medicina familiar N 1 y el hospital. Sin embargo a partir de las instalaciones electricas y de suministro de vapor y agua caliente del hospital se distribuyen los fluidos electricos y termicos de todo este conjunto. Debido a esta situacion, en este trabajo nos referiremos al consumo global del conjunto del IMSS de Aguascalientes en donde el hospital es el principal consumidor de energia termica. En el presente trabajo calcularemos el potencial tecnico - economico de ahorro de energia termica del conjunto del IMSS a traves de la tecnica termodinamica de punto de pliegue o tecnica pinch.

  9. Variations of high frequency parameter of heart rate variability following osteopathic manipulative treatment in healthy subjects compared to control group and sham therapy: randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Nuria eRuffini

    2015-08-01

    Full Text Available Context: Heart Rate Variability (HRV indicates how heart rate changes in response to inner and external stimuli. HRV is linked to health status and it is an indirect marker of the autonomic nervous system (ANS function. Objective: To investigate the influence of osteopathic manipulative treatment (OMT on ANS activity through changes of High Frequency, a heart rate variability index indicating the parasympathetic activity, in healthy subjects, compared with sham therapy and control group.Methods: Sixty-six healthy subjects, both male and female, were included in the present 3-armed randomized placebo controlled within subject cross-over single blinded study. Participants were asymptomatic adults, both smokers and non-smokers and not on medications. At enrollment subjects were randomized in 3 groups: A, B, C. Standardized structural evaluation followed by a patient need-based osteopathic treatment was performed in the first session of group A and in the second session of group B. Standardized evaluation followed by a protocoled sham treatment was provided in the second session of group A and in the first session of group B. No intervention was performed in the two sessions of group C, acting as a time-control. The trial was registered on clinicaltrials.gov identifier: NCT01908920.Main Outcomes Measures: HRV was calculated from electrocardiography before, during and after the intervention, for a total amount time of 25 minutes.Results: OMT engendered a statistically significant increase of parasympathetic activity, as shown by High Frequency rate (p<0.001, and decrease of sympathetic activity, as revealed by Low Frequency rate (p<0.01; results also showed a reduction of Low Frequency/High Frequency ratio (p<0.001 and Detrended fluctuation scaling exponent (p<0.05. Conclusions: Findings suggested that OMT can influence ANS activity increasing parasympathetic function and decreasing sympathetic activity, compared to sham therapy and control group.

  10. Energy saving program in an operating potable water and sanitation organism; Programa de ahorro de energia en un organismo operador de agua potable y saneamiento

    Energy Technology Data Exchange (ETDEWEB)

    Flores Cruz, Juan Jose [Fideicomiso para el Ahorro de la Energia Electrica, (Mexico)

    2001-03-01

    For the achievement of the objectives it was decided to use, among others, the following strategies: Personnel training, increase of the efficiency of the electromechanical equipment, study of Comision Federal de Electricidad (CFE) tariffs, correction of low power factors, increase of load factors, operation automate, regulation of the operation times, preventive maintenance of the equipment, establishment of technical standards, rational and efficient use of air conditioning equipment and illumination. So that these actions were applied in an easy and opportune form, it was established that within the structure of the General Coordination of Foreign Municipalities, the Program of Energy Saving depended directly of the Technical Management of CFE. In this way, the recommendations are first put under consideration of high-level officers, and then are lowered to the operative departments. [Spanish] Para el logro de los objetivos se acordo utilizar, entre otras, las siguientes estrategias: capacitacion del personal; aumentar la eficiencia de los equipos electromecanicos; estudio de tarifas de la Comision Federal de Electricidad (CFE); correccion de bajos factores de potencia; aumento de los factores de carga; automatizar la operacion; regular de los tiempos de operacion; mantenimiento preventivo a los equipos; establecimiento de normas tecnicas; uso racional y eficiente de aire acondicionado e iluminacion. Para que estas acciones se aplicaran en forma agil y oportuna, se establecio que dentro de la estructura de la Coordinacion General de Municipios Foraneos, el Programa de Ahorro de Energia dependiera directamente de la Gerencia Tecnica de la CRE. De esta forma, las recomendaciones primero se someten a consideracion de los funcionarios de alto nivel, y luego bajan a los departamentos operativos.

  11. La Función de la Auditoría Interna en las Cajas de Ahorros Españolas

    Directory of Open Access Journals (Sweden)

    Horacio Molina Sánchez

    2007-06-01

    Full Text Available Hoy día la función de auditoría interna es clave en el esquema de gobierno corporativo de las entidades financieras. Esta investigación tiene dos objetivos. En primer lugar, pretendemos describir el grado de cumplimiento de las recomendaciones del Comité de Basilea por parte de las cajas de ahorros españolas en un momento anterior a la regulación de aspectos sustanciales del gobierno de estas entidades (como por ejemplo, la figura del comité de auditoría por parte de la Ley Financiera. En segundo lugar, identificamos las diferencias existentes entre las entidades atendiendo a su dimensión. El método empleado ha sido una encuesta a las entidades, obteniéndose respuesta de 42 de las 47 entidades. Los resultados obtenidos presentan la situación de los departamentos de auditoría interna y confirman que, en un número significativo de aspectos, la dimensión de las entidades influye en el grado de implantación de los estándares emitidos por el Comité de Basilea.Nowadays, the internal audit function is critical in the corporate governance framework of financial institutions. Our research’s objective has to objectives. First, we try to describe the implementation level of Basle Committee’s recommendations in the Spanish saving banks before an important regulation over corporate governance has been issued in Spain (for instance, the figure of audit committee through the Financial Law. Second, we assess the differences between entities considering their dimmension. We have carried out a survey to saving banks, obtaining a response from 42 out of 47 entities. Our results show the situation of internal audit departments and confirm that, in a significative number of cases, entities’ dimmension affects the level of implementation of the Basel Committee’s standards.

  12. Energy saving avoiding the centrifugal motor-compressors air vents discharge to the surrounding atmosphere; Ahorro de energia evitando venteo de aire a la atmosfera en motocompresores centrifugos

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Alex [Compressor Controls Corporation, Houston, TX (United States)

    1996-12-31

    The motor-compressors are a key part of the industrial processes. The reliability and efficient operation of a compressor is critical. The surge phenomenon is a threat in the reliability of a compressor and therefore for the process. Surge, in a centrifugal compressor is defined as a dramatic flow and pressure drop, including back-flow. This is always a significant process disturbance. Continuous surge results into costly process shutdowns and mechanical damages. To prevent surge, and control the discharge pressure with simple or obsolete controls it is needed to vent air to the surrounding atmosphere. This form of control is very inefficient and costly. An advanced control with leading technology, besides providing an economical value preventing surge damages, offers substantial energy saving reducing or eliminating the venting of air to the atmosphere. [Espanol] Los motocompresores son un aparte clave de los procesos industriales. La confiable y eficiente operacion de un compresor es critica. El fenomeno de surge es una amenaza a la confiabilidad de un compresor y por lo tanto del proceso. El surge en un compresor centrifugo es definido como una dramatica caida de flujo y presion, incluyendo flujo inverso. Esto es siempre un significante disturbio del proceso. El surge continuo resulta en costosos paros de proceso y danos mecanicos. Para prevenir el surge y controlar la presion de descarga con controles simples u obsoletos, es necesario ventear aire a la atmosfera. Esta forma de control es muy ineficiente y costosa. Un control avanzado con tecnologia de punta ademas de proveer valor economico previniendo danos por surge, provee sustanciales ahorros de energia reduciendo o eliminando el venteo de aire a la atmosfera.

  13. Energy saving in hotels by means of heat pumps application; Ahorro de energia en hoteles mediante la aplicacion de bombas de calor

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana, Unidad Iztapalapa (Mexico)

    2005-07-15

    The thermal energy is presented as an alternate saving technology for utilities by means of the acute implementation of heat pumps. The objective is to demonstrate the technical and economical feasibility of the application of commercial heat pumps to installations where the handling of opposite temperatures for the conditioning of a space and/or of a fluid is required. In this article it is described the functioning of a heat pump, its different operation principles or types as well as the large diversity of applications they can have in industry, utilities and residential buildings. As an application example the substitution of an electric boiler by a heat pump is presented in a hotel installation and its differences in performance regarding the environmental conditioning of a nearby area and the heating of swimming pool water are analyzed. [Spanish] Se presenta la energia termica como una tecnologia de ahorro alterna para empresas de servicios valiendose de la implementacion agudizada de bombas de calor. El objetivo es demostrar la factibilidad tecnica y economica de la aplicacion de bombas de calor comerciales a instalaciones donde se requiere la manipulacion de temperaturas opuestas para el acondicionamiento de un espacio y/o un fluido. Se describe el funcionamiento de una bomba de calor, sus diferentes principios de operacion o tipos, asi como la gran diversidad de aplicaciones que pueden tener en la industria, empresas de servicios y edificios residenciales. Como ejemplo de aplicacion se presenta la sustitucion de una caldera electrica por una bomba de calor en una instalacion hotelera y sus diferencias de rendimiento en el calentamiento de agua de alberca y el acondicionamiento ambiental de un area cercana.

  14. Los Sistemas de Transferencia Interna de Fondos: Su Aplicación en las Cajas de Ahorros y en las Cajas Rurales españolas

    Directory of Open Access Journals (Sweden)

    Pilar Ibarrondo Dávila

    2004-12-01

    Full Text Available El entorno competitivo de las entidades de depósito ha sufrido fuertes cambios durante las dos últimas décadas, y en la actualidad se caracteriza por una fuerte rivalidad entre las empresas del sector. En este contexto, las entidades bancarias deben dotarse de sistemas de información ágiles y flexibles que les permitan dar respuesta a las nuevas necesidades gerenciales y a las actuales exigencias de la dirección estratégica. Desde esta perspectiva, en el presente trabajo se estudian las características de los distintos sistemas de transferencia interna de fondos aplicables en las entidades bancarias, procediendo a un análisis comparativo de los mismos, y, posteriormente, se presentan los principales rasgos que caracterizan a los sistemas de transferencia de fondos correspondientes a las cajas de ahorros y a las cajas rurales, a partir de los resultados obtenidos de una encuesta realizada en dichas entidades. The competitive environment of monetary financial institutions has undergone great changes over the last two decades, and at present is characterized by strong competition among the companies of the sector. In this context, the monetory financial institutions should be endowed with agile and flexible information systems that allow them to respond to the new managerial necessities and the current demands of Strategic Management. Thus, in this paper, first we analyse the characteristics of the different funds-tranfer- pricing methods applicable in the banks and go on to carry out a comparative analysis of the former. Secondly, we present the main features that characterize the funds-transfer-pricing methods in Spanish Savings Banks and Spanish Rural Banks, based on the results obtained from a survey carried out among these companies.

  15. Aplicación electrónica para el ahorro de energía eléctrica utilizando una energía alternativa

    Directory of Open Access Journals (Sweden)

    Juan Carlos Cruz-Ardila

    2013-01-01

    Full Text Available El artículo presenta un trabajo orientado a disminuir el consumo de energía eléctrica entregada por la red eléctrica convencional, a través del aprovechamiento de la energía solar fotovoltaica. Se propone el diseño de un sistema de transferencia electrónica que facilita el uso de la energía eléctrica DC proveniente del panel solar, suprimiendo de esta manera, la utilización del inversor de voltaje, comúnmente usado en este tipo de aplicaciones y que eleva el costo de utilización de la energía solar. Se da a conocer inicialmente una revisión del estado del arte, que permite contextualizar el problema resuelto a partir de una energía renovable como la fotovoltaica, destacándose que actualmente España es el país con mayor desarrollo en este tema. Luego, se muestra el desarrollo secuencial del sistema de alimentación y la transferencia electrónica, haciendo una descripción de las variables identificadas y explicación, con el uso de diagramas de flujo, del sistema embebido implementado. También se da una descripción de los dispositivos usados tal como el sensor de corriente, la regulación y la rectificación. Se muestra el esquemático de la transferencia implementada. Finalmente, se revelan los resultados y las pruebas operacionales realizadas al sistema para demostrar la funcionalidad de la aplicación electrónica en el ahorro de la energía eléctrica utilizando una energía alternativa.

  16. Evaluation of energy saving in pilot projects of window type air conditioning equipment in the domestic sector; Evaluacion del ahorro de energia en proyectos pilotos en equipos de aire acondicionado tipo ventana en el sector domestico

    Energy Technology Data Exchange (ETDEWEB)

    Duran Ramirez, Ricardo [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

    2001-07-01

    The present work shows the energy saving when replacing low efficiency window type air conditioning equipment, for higher efficiency equipment, as well as the necessary parameters to identify the results obtained by the pilot projects of substitution of conventional equipment for other more efficient in the domestic sector. [Spanish] El presente trabajo muestra los ahorros de energia al sustituir equipos de aire acondicionado tipo ventana de baja eficiencia, por equipos de mayor eficiencia, asi como los parametros necesarios para identificar los resultados obtenidos, por los proyectos pilotos de sustitucion de equipos convencionales por otros mas eficientes en el sector domestico.

  17. Diseño de un modelo de gestión basado en responsabilidad social para el manejo de riesgos en cooperativas de ahorro y crédito

    OpenAIRE

    Proaño Castillo, Jenny Catalina

    2015-01-01

    1. Introducción.-- 2. Planteamiento de la Propuesta de Trabajo.-- 3. Marco Teórico.-- 4. Metodología.-- 5. Resultados.-- 6. Conclusiones y Recomendaciones El presente trabajo es el diseño de un modelo de gestión basado en responsabilidad social para el manejo de riesgos para uso de Cooperativas de Ahorro y Crédito, apoyado en la necesidad de que las Cooperativas gestionen su accionar administrativo financiero fundamentado en principios éticos y socialmente responsables e implementen mecani...

  18. Bancos Cooperativos y Sociedades de Ahorro y Crédito en El Salvador: modelo de supervisión prudencial y análisis empírico del coeficiente de solvencia

    OpenAIRE

    Hernández, Ana Verónica

    2013-01-01

    Estudio bibliográfico empírico, con el que se presenta una propuesta de supervisión para la superintendencia financiera de El Salvador, que incluye requisitos mínimos a considerar por el auditor, tomando como base Basilea II, III y siguiendo el Modelo OSFI de Canadá. Además se presenta un estudio empírico sobre los determinantes del coeficiente patrimonial en bancos cooperativos y sociedades de ahorro y crédito de El Salvador. Economía Financiera y Contabilidad Máster en Investigación ...

  19. Conclusiones de las Ponencias y Debates del Coloquio Internacional sobre Ahorro de Energía celebrado en Budapest, organizado por la Sección Húngara de la Europrefab

    Directory of Open Access Journals (Sweden)

    Aguirre de Iraola, Fernando

    1980-03-01

    Full Text Available Durante los días 10 y 11 de abril, el doctor Arquitecto F. Aguirre, director del ITEcc, estvuo en Budapest para presidir el Coloquio Internacional sobre «Ahorro de energía en la edificación», que había sido organizado por la sociedad europea para la promoción de la industrialización de la construcción, (EUROPREFAB, de la cual el profesor Aguirre es presidente.

  20. The use of reflecting paints on building`s roofs for energy saving; Uso de pinturas reflejantes en los techos de las edificaciones para el ahorro de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Valera Negrete, Jose Adrian [Programa de Ahorro de Energia del Sector Electrico (PAESE), Comision Federal de Electricidad, Mexico, D. F. (Mexico); Sanchez Soto, Ramon [Facultad de Ingenieria, Departamento de Termoenergia de la UNAM, Mexico, D. F. (Mexico)

    1998-12-31

    This paper shows the effects of the use of reflecting paints in different colors on the buildings roofs and the results in energy saving obtained in a field test carried on in Monterrey, Nuevo Leon State of Mexico using aluminum paint. [Espanol] El presente trabajo muestra los efectos del uso de pinturas reflejantes de diferentes colores en los techos de edificaciones, y los resultados de ahorro de energia electrica obtenidos en una prueba de campo efectuada en Monterrey, Nuevo Leon, Mexico, utilizando pintura de aluminio.

  1. Examen de auditoría integral al área de Recursos Humanos de la Cooperativa de Ahorro y Crédito El Sagrario Ltda. , correspondiente al periódo 01 de enero al 31 de diciembre 2012

    OpenAIRE

    2014-01-01

    El presente trabajo, se desarrolla en la Cooperativa de Ahorro y Crédito El Sagrario Ltda., específicamente en el proceso de Talento Humano que involucra: actividades de selección, administración de nómina, capacitación y desvinculación. El objetivo principal, será el realizar un examen de auditoría integral al proceso de Talento Humano de la Cooperativa de Ahorro y Crédito El Sagrario Ltda., correspondiente al periodo 01 de Enero al 31 de Diciembre 2012. Para el desarrollo del examen ...

  2. Galactosemia in the Turkish population with a high frequency of Q188R mutation and distribution of Duarte-1 and Duarte-2 variations.

    Science.gov (United States)

    Özgül, Rıza Köksal; Güzel-Ozantürk, Ayşegül; Dündar, Halil; Yücel-Yılmaz, Didem; Coşkun, Turgay; Sivri, Serap; Aydoǧdu, Sultan; Tokatlı, Ayşegül; Dursun, Ali

    2013-10-01

    Classical galactosemia is an inherited recessive disorder of galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase (GALT), which is caused by mutations in the GALT gene. In this study, 56 Turkish patients diagnosed with galactosemia were screened for GALT gene mutations using Affymetrix resequencing microarrays. Eleven types of mutations were detected in these patients, including two novel mutations (R258G and G310fsX49) and nine recurrent mutations. We detected six patients who were homozygous for the E340* mutation and for N314D, L218L silent substitutions (Duarte-1 variant) in this study. The haplotype E340*, N314D and L218L has been reported only in Turkish patients, which suggests that the E340* mutation is specific for our population and might be spread by a Turk ancestor. In patients, the Duarte-1 allele was found with a frequency of 10.71%, whereas the Duarte-2 allele was not detected. Duarte-1 and Duarte-2 alleles were found to be present at a frequency of 2.3% and 1.4%, respectively, in the screening of 105 healthy individuals. Considering all detected mutations, it is a very important finding that exons 6 and 10 of the GALT gene account for 79% of all mutant alleles in the Turkish population. The most common mutation is Q188R, with a frequency of 55.35%.

  3. Measurement of respiratory mechanics in a mechanically ventilated infant lung simulator: effects of variations in the frequency response of the flow measurement system.

    Science.gov (United States)

    Turner, M J; MacLeod, I M; Rothberg, A D

    1994-01-01

    The frequency responses of systems used to measure flow and pressure in ventilated infants may differ, and hence affect estimates of resistance and compliance. We estimated resistance and compliance in 16 ventilated mechanical lung models using linear regression while varying the frequency response of the flow measurement system. Lung models comprised combinations of four sections of tubing and four bottles filled with steel wool. The cut-off frequencies of a filter in the flow measurement system were chosen to yield time delays of 0, +/-3, +/-6, and +/-9 ms relative to the pressure signal. When the phase lags in the measurement systems were not equal at 10 Hz, a bias in resistance approximately (relative delay) x (elastance) ensued. The bias in the resistance estimate when resistance is 5 Pa ml-1 s and compliance is 2 ml kPa-1 is approximately 28% per ms of delay mismatch. Time-shifting the flow data to eliminate the phase discrepancy reduced the resistance bias by 85%. The residual resistance bias was assumed to be due to inappropriate amplitude response. Compliance measurements were affected by less than 8% and less than 2% after time correction of the flow data. Pressure and flow signals must be synchronized to within 1 ms at 10 Hz and the amplitude responses of the measurement systems must be adequate for reliable resistance measurement.

  4. Robust Two Degrees-of-freedom Single-current Control Strategy for LCL-type Grid-Connected DG System under Grid-Frequency Fluctuation and Grid-impedance Variation

    DEFF Research Database (Denmark)

    Zhou, Leming; Chen, Yandong; Luo, An

    2016-01-01

    For LCL-type grid-connected distributed generation(DG) system, the grid-frequency fluctuation and grid-impedance variation affect the active/reactive power control accuracy and resonance peak suppression respectively, which would reduce the system robustness. In this paper, a robust two degrees-of-freedom......-state performances. The stability margin and dynamic response of the overall system are analyzed in detail, and the proper parameters are selected without complicated trial. Finally, Simulation and experimental results verify the proposed control and design strategies....

  5. Multi-scale harmonic model for solar and climate cyclical variation throughout the Holocene based on Jupiter-Saturn tidal frequencies plus the 11-year solar dynamo cycle

    CERN Document Server

    Scafetta, Nicola

    2012-01-01

    The sunspot record since 1749 is made of three major cycles (9.98, 10.9 and 11.86 yr). The side frequencies are related to the spring tidal period of Jupiter and Saturn (9.93 yr) and to the tidal sidereal period of Jupiter (11.86 yr). A simplified harmonic constituent model based on the above two planetary tidal frequencies and on the exact dates of Jupiter and Saturn planetary tidal phases, plus a theoretically deduced 10.87-year central cycle reveals complex quasi-periodic interference/beat patterns at about 115, 61 and 130 years, plus a quasi-millennial large beat cycle around 983 years. We show that equivalent synchronized cycles are found in cosmogenic records used to reconstruct solar activity and in proxy climate records throughout the Holocene. The quasi-secular beat oscillations hindcast reasonably well the known prolonged periods of low solar activity during the last millennium known as Oort, Wolf, Sporer, Maunder and Dalton minima, as well as 17 115-year long oscillations found in temperature recon...

  6. Bioeffects of extremely low-frequency electromagnetic fields: variation with intensity, waveform, and individual or combined electric and magnetic fields. [Effects on mitosis and respiration in Physarium polycephalum

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, E.M.; Greenebaum, B.; Marron, M.T.

    1979-06-01

    Prolonged exposure of the myxomycete Physarum polycephalum to either continuous wave (75 Hz) or frequency modulated wave (76 Hz) electromagnetic fields (EMF) (0.1 to 2.0 G and 0.035 to 0.7 V/m) lengthens the mitotic cycle and depresses the respiration rate. Once induced, these effects persist indefinately in the presence of EMF without increasing or decreasing in magnitude beyond that due to normal variability of the organism. Similar effects are observed when either individual electric fields (0.7 V/m) or magnetic fields (2.0 G) are applied; however, the magnitude of the response is less than that observed with simultaneous fields. The individual field effects appear to be additive for respiration but not for nuclear division rate. For fields applied simultaneously at levels below 0.14 V/m and 0.4 G the response was independent of field intensity. No threshold was observed for simultaneously applied electric and magnetic fields; however, indirect evidence is presented that suggests either the electric or magnetic field is below threshold at levels of 0.14 V/m and 0.4 G, respectively. Frequency modulation of the fields seems to have no major effect o the response induced in P. polycephalum.

  7. La financiación de las oligarquías provinciales en el apogeo y crisis del negocio inmobiliario en España: una reflexión sociológica sobre las cajas de ahorros

    Directory of Open Access Journals (Sweden)

    José Manuel Rodríguez Acevedo

    2011-10-01

    Full Text Available El hundimiento, en el contexto de la crisis internacional del capitalismo, del modelo económico basado en el “ladrillo” y la especulación urbanística −además de en el turismo− ha puesto sobre la mesa el problema de las cajas de ahorros. En este artículo se repasa el papel destacado que estas peculiares entidades financieras han venido jugado en la financiación del boom inmobiliario de las últimas décadas en España. Creemos que no se puede llegar al fondo del asunto sin comprender la naturaleza histórica de unas fragmentadas oligarquías económicas y políticas de ámbito provincial y local, lideradas por promotores y grandes propietarios del suelo rústico y urbano, que han encontrado en las cajas de ahorros una privilegiada forma de financiación para los turbios y particulares negocios en los que se ha basado el tan alabado milagro económico español.

  8. Análisis de la relación entre los resultados sociales y económicos de las cajas de ahorros españolas: un caso de responsabilidad social corporativa

    Directory of Open Access Journals (Sweden)

    Laura Cabeza-García

    2010-10-01

    Full Text Available La obra social constituye uno de los ámbitos de aplicación de la responsabilidad social corporativa (RSC en el contexto de las cajas de ahorros. Por ello, a partir del marco teórico que explica la naturaleza de la relación entre la realización de actividades de índole social y los resultados financieros, el objetivo de este trabajo es analizar el efecto de la inversión en obra social sobre la performance de las cajas españolas. Tras aplicar un modelo dinámico de datos de panel (GMM los hallazgos encontrados sugieren, una vez controlado el problema de endogeneidad, una influencia negativa y significativa sobre el nivel de rentabilidad, tanto económica como financiera. Por tanto, nuestros resultados avalan la hipótesis del trade off en el sub-sector financiero de las cajas de ahorros españolas

  9. Electric power saving in the drinkable water, sewage and sanitation system, La Piedad; Ahorro de energia electrica en el sistema de agua potable, alcantarillado y saneamiento de La Piedad

    Energy Technology Data Exchange (ETDEWEB)

    Sistema de Agua Potable, Alcantarillado y Saneamiento de la Piedad (Mexico). E-mail: sapaslapiedad@prodigy.net.mx

    2006-04-15

    In Michoacan, Mexico, a project who seeks to benefice the Municipal public resources was crated in 1994. It would be achieved trough the electric power saving in the public lighting system, and drinkable water pumping and black water, since those activities required the budget biggest part. The program could be developed recently and the saving was significant. In addition the electromechanical efficiency increased in the equipment installation. This work is an example for other States to do something similar that can improve their conditions. [Spanish] En el estado de Michoacan, Mexico se creo un proyecto en el ano de 1994, el cual buscaba beneficiar los recursos publicos municipales, a traves del ahorro de la energia electrica en los sistemas de alumbrado publico y bombeo de agua potable y aguas negras, ya que estas actividades son las que requieren la mayor parte del presupuesto. El programa pudo llevarse a cabo en anos recientes y el ahorro fue significativo, ademas de que aumento la eficiencia electromecanica en los equipos que se instalaron, y esta obra ha servido de ejemplo a otros estados para que realicen algo similar que pueda mejorar su situacion.

  10. Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study

    DEFF Research Database (Denmark)

    Bouserhal, Rachel E.; MacDonald, Ewen; Falk, Tiago H.;

    2016-01-01

    concern for people wearing hearing protection devices (HPD). Although practical, radio communication is cumbersome, as it does not distinguish designated receivers. A smarter radio communication protocol must be developed to alleviate this problem. Thus, it is necessary to model speech production in noise...... while wearing HPDs. Such a model opens the door to radio communication systems that distinguish receivers and offer more efficient communication between persons wearing HPDs. Design: This paper presents the results of a pilot study aimed to investigate the effects of occluding the ear on changes...... in voice level and fundamental frequency in noise and with varying talker-to-listener distance. Study sample: Twelve participants with a mean age of 28 participated in this study. Results: Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded...

  11. Catalysis as a tool for energy conservation in the refinery industry; Catalisis como herramienta de ahorro de energia en la industria de la refinacion

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, S.; Moran-Pineda, M. [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico); Bazan, G.; Gonzalez, L.; Barrios, H. [Pemex-Refinacion, Mexico, D. F. (Mexico)

    1996-12-31

    The catalysis, defined by the alchemists since its appearance, as that something or Philosophical Stone, with a special power to transform matter by means of the energy, has always represented a challenge to mankind, even more now, when most of the goods needed for its survival are related to a chemical process and nowadays, when they can not be imagined without the presence of a catalyzer. In the reciprocity between the chemical change and the catalyzer, the energy utilized represents the critical point. Once stated the above, it becomes interesting the study of the impact and the consequence of the binomial catalysis-energy in relation to the fuel recovery processes and the emission control processes, originated by its combustion, where the main objective is in establishing an analysis criterion for energy conservation with different trends; the first one, on the impact of the application of optimum catalytic systems in the fuel recovery processes and the second one on the optimum catalytic processes for emissions control. [Espanol] La catalisis desde su aparicion definida por los alquimistas como ese algo o piedra filosofal, con una fuerza especial para la transformacion de la materia mediante la energia, siempre ha representado un reto para el hombre, mas aun en la actualidad donde la mayoria de los bienes necesarios para su supervivencia estan relacionados con un proceso quimico y que hoy en dia no se conciben estos sin la presencia de un catalizador. En la reciprocidad entre el cambio quimico y el catalizador, la energia utilizada representa el punto critico. Dado lo anterior, resulta interesante el estudio del impacto y trascendencia del binomio catalisis-energia en relacion con los procesos para la obtencion de los combustibles y de los procesos para el control de emisiones, producto de la combustion de los mismos, donde el objetivo primordial esta en establecer un criterio de analisis de ahorro de energia con diferentes directrices; la primera, el impacto

  12. Importance of the harmonics in the lighting systems for the electric energy saving; Importancia de las armonicas en el sistema de iluminacion para el ahorro de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Garibay Mendoza, V. [Lumisistemas, departamento de aseguramineto de calidad, Naucalpan (Mexico); Hernandez Bernal, J. M. [UNICORP, Mexico, D. F. (Mexico)

    1995-12-31

    In a lighting system the discharge lamps (fluorescent and high intensity discharge (HID)), ballast and controls are generating elements of harmonics. As a consequence of the tendency of saving energy, the use of electronic ballasts and controls that integrate dimmers, daylight and present sensors has increased in order to optimize the energy use. This paper presents the harmonics generation resulting from the fluorescent lamps operating different electronic ballasts as well as their electronic controls. Likewise, are also shown the effects caused by generation of harmonics components by the lighting system in the electric system that go from the voltage and current distortion, the presence of currents in the neutral conductor in balanced systems to the repercussions in the metering equipment such as watthour meters and the effects the lighting equipment suffer due to the presence of harmonics, such as the power factor decrease in ballasts that are of high power factor and the temperature increment in the magnetic type ballasts. [Espanol] Dentro de un sistema de iluminacion, las lamparas de descarga (fluorescentes y alta intensidad de descarga {sup H}ID{sup )}, balastros y los controles son elementos generadores de armonicas. A consecuencia de la tendencia al ahorro de energia se ha incrementado el uso de balastros electronicos y controles que integran atenuadores de luz (dimmers), sensores de luz natural y de presencia con el fin de optimizar el uso de la energia. Este trabajo presenta los resultados de generacion de armonicas para lamparas fluorescentes, operando diferentes balastros electronicos asi como con controles electronicos. Asi mismo son presentados los efectos causados por la generacion de componentes armonicas por el sistema de iluminacion dentro del sistema electrico que van desde la distorsion en voltaje y corriente, la presencia de corrientes dentro del conductor neutro en sistemas balanceados, asi como la repercusion en los equipos de medicion tales

  13. Cuestiones actuales del régimen jurídico-administrativo de las Cajas de ahorros españolas

    Directory of Open Access Journals (Sweden)

    Ana Belén Casares Marcos

    2005-12-01

    Full Text Available Las reformas legislativas que han afectado en los últimos tiempos a la organización y el funcionamiento del sistema financiero español han tenido una especial repercusión en el ámbito de las cajas de ahorros. La tramitación parlamentaria de la Ley 44/2002, de 22 de noviembre, de Medidas de Reforma del Sistema Fianciero, reavivó el debate sobre su régimen jurídico y la necesidad de acotar la intervención pública en su seno. Ahonda en ello la Ley 26/2003 , de 17 de julio, de Transparencia, que extiende al ámbito de las cajas la preocupación por el corporate governance. Ambas normas responden a la necesidad de dar respuesta a algunos de los problemas más inmediatos a que se enfrentan estas entidades, si bien adolecen de un defecto fundamental por cuanto no abordan de forma exhaustiva la regulación de la institución. Se perpetúa así la trayectoria tradicional de "parcheo" del régimen jurídico aplicable a las mismas, evitando entrar en la cuestión esencial de la definición de su naturaleza jurídica y abocando a las cajas, en consecuencia, al díficil reto de acompasar su vocación social tradicional a las nuevas exigencias legales en pro de una mayor eficiencia, racionalidad y neutralidad de su acitividad económica.Recent legal changes pertaining to the organization and performance of the Spanish financial system have had significant repercussions on the savings banks sector. The law on financial market reform passed in 2002, Ley Financiera, raised once again the debate on their legal situation and the urge to cut down public influence on their management. The 2003 Transparency Law, Ley de Transparencia, follows this reform and extends corporate governance to Spanish savings banks. Both Laws seek to confront some of the most important issues raised by these credit institutions, but they also share the flaw of not regulating its legal framework and status completely. They continue, therefore, to add "patches" to the savings

  14. Variation within categories.

    NARCIS (Netherlands)

    Das-Smaal, E.A.; Swart, de J.H.

    1984-01-01

    Two aspects of variation within categories, relating to different models of categorization, were investigated - frequency of dimensional values and typicality differences within values. The influence of range of typicality experienced during learning and of informational value of feedback was also

  15. Along-strike variations in fault frictional properties along the San Andreas Fault near Cholame, California from joint earthquake and low-frequency earthquake relocations

    Science.gov (United States)

    Harrington, R.M; Cochran, Elizabeth S.; Griffiths, E.M.; Zeng, X.; Thurber, C.

    2016-01-01

    Recent observations of low‐frequency earthquakes (LFEs) and tectonic tremor along the Parkfield–Cholame segment of the San Andreas fault suggest slow‐slip earthquakes occur in a transition zone between the shallow fault, which accommodates slip by a combination of aseismic creep and earthquakes (35  km depth). However, the spatial relationship between shallow earthquakes and LFEs remains unclear. Here, we present precise relocations of 34 earthquakes and 34 LFEs recorded during a temporary deployment of 13 broadband seismic stations from May 2010 to July 2011. We use the temporary array waveform data, along with data from permanent seismic stations and a new high‐resolution 3D velocity model, to illuminate the fine‐scale details of the seismicity distribution near Cholame and the relation to the distribution of LFEs. The depth of the boundary between earthquakes and LFE hypocenters changes along strike and roughly follows the 350°C isotherm, suggesting frictional behavior may be, in part, thermally controlled. We observe no overlap in the depth of earthquakes and LFEs, with an ∼5  km separation between the deepest earthquakes and shallowest LFEs. In addition, clustering in the relocated seismicity near the 2004 Mw 6.0 Parkfield earthquake hypocenter and near the northern boundary of the 1857 Mw 7.8 Fort Tejon rupture may highlight areas of frictional heterogeneities on the fault where earthquakes tend to nucleate.

  16. Along-strike variations in fault frictional properties along the San Andreas Fault near Cholame, California from joint earthquake and low-frequency earthquake relocations

    Science.gov (United States)

    Harrington, Rebecca M.; Cochran, Elizabeth S.; Griffiths, Emily M.; Zeng, Xiangfang; Thurber, Clifford H.

    2016-01-01

    Recent observations of low‐frequency earthquakes (LFEs) and tectonic tremor along the Parkfield–Cholame segment of the San Andreas fault suggest slow‐slip earthquakes occur in a transition zone between the shallow fault, which accommodates slip by a combination of aseismic creep and earthquakes (fault, which accommodates slip by stable sliding (>35  km depth). However, the spatial relationship between shallow earthquakes and LFEs remains unclear. Here, we present precise relocations of 34 earthquakes and 34 LFEs recorded during a temporary deployment of 13 broadband seismic stations from May 2010 to July 2011. We use the temporary array waveform data, along with data from permanent seismic stations and a new high‐resolution 3D velocity model, to illuminate the fine‐scale details of the seismicity distribution near Cholame and the relation to the distribution of LFEs. The depth of the boundary between earthquakes and LFE hypocenters changes along strike and roughly follows the 350°C isotherm, suggesting frictional behavior may be, in part, thermally controlled. We observe no overlap in the depth of earthquakes and LFEs, with an ∼5  km separation between the deepest earthquakes and shallowest LFEs. In addition, clustering in the relocated seismicity near the 2004 Mw 6.0 Parkfield earthquake hypocenter and near the northern boundary of the 1857 Mw 7.8 Fort Tejon rupture may highlight areas of frictional heterogeneities on the fault where earthquakes tend to nucleate.

  17. Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study.

    Science.gov (United States)

    Bouserhal, Rachel E; Macdonald, Ewen N; Falk, Tiago H; Voix, Jérémie

    2016-01-01

    Speech production in noise with varying talker-to-listener distance has been well studied for the open ear condition. However, occluding the ear canal can affect the auditory feedback and cause deviations from the models presented for the open-ear condition. Communication is a main concern for people wearing hearing protection devices (HPD). Although practical, radio communication is cumbersome, as it does not distinguish designated receivers. A smarter radio communication protocol must be developed to alleviate this problem. Thus, it is necessary to model speech production in noise while wearing HPDs. Such a model opens the door to radio communication systems that distinguish receivers and offer more efficient communication between persons wearing HPDs. This paper presents the results of a pilot study aimed to investigate the effects of occluding the ear on changes in voice level and fundamental frequency in noise and with varying talker-to-listener distance. Twelve participants with a mean age of 28 participated in this study. Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded quiet condition. This implies that a model can be developed to better understand speech production for the occluded ear.

  18. Dosimetry of infant exposure to power-frequency magnetic fields: variation of 99th percentile induced electric field value by posture and skin-to-skin contact.

    Science.gov (United States)

    Li, Congsheng; Wu, Tongning

    2015-04-01

    Infant exposure to 50 Hz magnetic fields from power lines was numerically analyzed in this study. Dosimetric variability due to posture and skin-to-skin contact was evaluated using human anatomical models including a recently developed model of a 12-months-old infant. As proposed by the International Commission on Non-Ionizing Radiation Protection, the induced E-field strength (99th percentile value, E99 ) for the central nerve systems (E99_CNS ) and peripheral nerve system (E99_PNS ), were used as metrics. Results showed that the single (free of contact with others) infant model has lower E99 (E99_CNS and E99_PNS inclusive) compared with single adult and child models when exposed to the same power-frequency magnetic field. Also, studied postures of sitting, standing, or arm-up, would not change E99 _PNS . However, skin-to-skin contact with other models could significantly raise induced E-field strength in the infant (e.g., contact on 0.93% of the infant's total surface increased E99_PNS by 213%). Simulations with canonical models were conducted to assess different factors contributing to the E99 enhancement. Results indicated the importance of thoroughly investigating the conservativeness of current safety guidelines in the case of skin-to-skin contact, especially with infants.

  19. Determination of the sputter rate variation pattern of a silicon carbide target for radio frequency magnetron sputtering using optical transmission measurements

    Energy Technology Data Exchange (ETDEWEB)

    Galvez de la Puente, G. [Departamento de Ciencias, Seccion Fisica, Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, Apartado Postal 1761, Lima 32 (Peru); Department of Materials Science 6, University of Erlangen, Martensstrasse 7, 91058-Erlangen (Germany); Guerra Torres, J.A. [Departamento de Ciencias, Seccion Fisica, Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, Apartado Postal 1761, Lima 32 (Peru); Erlenbach, O. [Departamento de Ciencias, Seccion Fisica, Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, Apartado Postal 1761, Lima 32 (Peru); Department of Materials Science 6, University of Erlangen, Martensstrasse 7, 91058-Erlangen (Germany); Steidl, M. [Department of Materials Science 6, University of Erlangen, Martensstrasse 7, 91058-Erlangen (Germany); Weingaertner, R., E-mail: rolandw@fisica.pucp.edu.pe [Departamento de Ciencias, Seccion Fisica, Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, Apartado Postal 1761, Lima 32 (Peru); Department of Materials Science 6, University of Erlangen, Martensstrasse 7, 91058-Erlangen (Germany); De Zela, F. [Departamento de Ciencias, Seccion Fisica, Pontificia Universidad Catolica del Peru, Av. Universitaria 1801, Apartado Postal 1761, Lima 32 (Peru); Winnacker, A. [Department of Materials Science 6, University of Erlangen, Martensstrasse 7, 91058-Erlangen (Germany)

    2010-10-25

    We produce amorphous silicon carbide thin films (a-SiC) by radio frequency (rf) magnetron sputtering from SiC bulk target. We present the emission pattern of the rf magnetron with SiC target as a function of process parameters, like target sample distance, rf power, sputtering rate and process gas pressure. The emission pattern is determined by means of thickness distribution of the deposited a-SiC films obtained from optical transmission measurements using a slightly improved method of Swanepoel concerning the determination of construction of the envelopes in the interference pattern of the transmission spectra. A calibration curve is presented which allows the conversion of integrated transmission to film thickness. Holding constant a set of process parameters and only varying the target sample distance the emission pattern of the rf magnetron with SiC target was determined, which allowed us to predict the deposition rate distribution for a wide range of process parameters and target geometry. In addition, we have found that the transmission spectra of the a-SiC films change with time and saturate after approximately 10 days. Within this process no change in thickness is involved, so that the determination of thickness using transmission data is justified.

  20. Spatial and temporal variations of new particle formation in East Asia using an NPF-explicit WRF-chem model: North-south contrast in new particle formation frequency

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, H.; Koike, Makoto; Takegawa, Nobuyuki; Kondo, Yutaka; Takami, A.; Takamura, T.; Yoon, Soh-joung; Kim, S. W.; Lim, Hyuntae; Fast, Jerome D.

    2013-10-27

    The new particle formation (NPF)-explicit version of the WRF-chem model, which we developed recently, can calculate the growth and sink of nucleated clusters explicitly with 20 aerosol size bins from 1 nm to 10 μm. In this study, the model is used to understand spatial and temporal variations of the frequency of NPF events and the concentrations of aerosols (condensation nuclei, CN) and cloud condensation nuclei (CCN) within the boundary layer in East Asia in spring 2009. Model simulations show distinct north-south contrast in the frequency and mechanism of NPF in East Asia. NPF mostly occurred over limited periods and regions between 30° and 45°N, such as northeast China, Korea, and Japan, including regions around active volcanoes (Miyakejima and Sakurajima). At these latitudes, NPF was considerably suppressed by high concentrations of preexisting particles under stagnant air conditions associated with high-pressure systems, while nucleation occurred more extensively on most days during the simulation period. Conversely, neither nucleation nor NPF occurred frequently south of 30°N because of lower SO2 emissions and H2SO4 concentrations. The period-averaged NPF frequency was 3 times higher at latitudes of 30° - 45°N than at latitudes of 20° - 30°N. The north-south contrast of NPF frequency is validated by surface measurements in outflow regions in East Asia. The period- and domain-averaged contribution of secondary particles is estimated to be 44% for CN (> 10 nm) and 26% for CCN at a supersaturation of 1.0% in our simulation, though the contribution is highly sensitive to the magnitudes and size distributions of primary aerosol emissions and the coefficients in the nucleation parameterizations.

  1. Spatial and temporal variations of new particle formation in East Asia using an NPF-explicit WRF-chem model: North-south contrast in new particle formation frequency

    Science.gov (United States)

    Matsui, H.; Koike, M.; Takegawa, N.; Kondo, Y.; Takami, A.; Takamura, T.; Yoon, S.; Kim, S.-W.; Lim, H.-C.; Fast, J. D.

    2013-10-01

    recently developed new particle formation (NPF)-explicit version of the Weather Research and Forecasting Chemistry (WRF-chem) model can explicitly calculate the growth and sink of nucleated clusters with 20 aerosol size bins from 1 nm to 10 µm in diameter. In this study, the model was used to investigate spatial and temporal variations in NPF event frequency and the concentrations of aerosols (condensation nuclei, CN) and cloud condensation nuclei (CCN) within the boundary layer in East Asia in spring 2009. We found a distinct north-south contrast in the NPF frequency and mechanism in East Asia. NPF occurred mainly during limited periods over certain regions between 30° and 45°N (northeast China, Korea, and Japan, including regions around the active volcanoes Miyakejima and Sakurajima). In these latitudes, NPF was suppressed by high concentrations of preexisting particles under stagnant air conditions associated with high-pressure systems, although nucleation occurred more extensively during most of the simulation period. In contrast, south of 30°N, nucleation and NPF were both infrequent because of low SO2 emissions and H2SO4 concentrations. The period-averaged NPF frequency at 30°-45°N was three times that at 20°-30°N. This north-south contrast in NPF frequency was validated by surface measurements in outflow regions of East Asia. The simulated period- and domain-averaged contribution of secondary particles was estimated to be 44% for CN (>10 nm) and 26% for CCN at a supersaturation of 1.0%, though the contribution was highly sensitive to the amount and size distribution of primary aerosol emissions and the rate coefficient of the nucleation parameterization.

  2. Quantifying the climate change-induced variations in Saskatoon's Intensity-Duration-Frequency curves using stochastic rainfall generators and K-nearest neighbors

    Science.gov (United States)

    Shahabul Alam, Md.; Nazemi, Alireza; Elshorbagy, Amin

    2014-05-01

    Intensity-Duration-Frequency (IDF) curves are among standard design criteria for various engineering applications, such as storm water management systems. Warming climate, however, changes the extreme rainfall quantiles represented by the IDF curves. This study attempts to construct the future IDF curves under possible climate change scenarios. For this purpose, a stochastic rainfall generator is used to spatially downscale the daily projections of Global Climate Models (GCMs) from coarse grid resolution to the point scale. The stochastically downscaled daily rainfall realizations can be further disaggregated to hourly and sub-hourly rainfall series using a deterministic disaggregation scheme developed based on the K-Nearest Neighbor (K-NN) method. We applied this framework for constructing the future IDF curves in the city of Saskatoon, Canada. As a model development step, the sensitivity of the K-NN disaggregation model to the number of nearest neighbors (i.e. window size) is evaluated during the baseline periods. The optimum window size is assigned based on the performance in reproducing the historical IDF curves. The optimum windows identified for 1-hour and 5-min temporal resolutions are then used to produce the future hourly and consequently, 5-min resolution rainfall based on the K-NN simulations. By using the simulated hourly and sub-hourly rainfall series and the Generalized Extreme Value (GEV) distribution future changes in IDF curves and associated uncertainties are quantified using a large ensemble of projections obtained for the CGCM3.1 and HadCM3 based on A1B, A2 and B1 emission scenarios in case of CMIP3 and RCP2.6, RCP4.5, and RCP8.5 in case of CMIP5 datasets. The constructed IDF curves for the city of Saskatoon are then compared with corresponding historical relationships at various durations and/or return periods and are discussed based on different models, emission scenarios and/or simulation release (i.e. CMIP3 vs. CMIP5).

  3. Technical and economical assessment of the options for energy saving in the library of the Universidad Autonoma Metropolitana-Azcapotzalco; Evaluacion tecnico economica de opciones para el ahorro de energia en la biblioteca de la Universidad Autonoma Metropolitana-Azcapotzalco

    Energy Technology Data Exchange (ETDEWEB)

    Bratu, N.; Campero, E.; Dorantes, R.; Fuentes, V.; Figueroa, A.; Garcia, R.; Zekkour, A. [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D. F. (Mexico)

    1993-12-31

    This paper presents a diagnosis of the electrical energy consumption in the library of the Azcapotzalco Unit of the Universidad Autonoma Metropolitana, to determine the actions that can be implemented for energy conservation. This without disturbing the lighting and thermal comfort. The analysis showed that, by changing the reflecting surfaces of the lighting lamps, the number of units can be reduced, without lowering the illumination level below the recommended values. The saving was estimated for replacement of the fluorescent lamps for others of metallic halogenides in the areas where the ceiling is high; for the installation of switches to improve the selectivity in turning on and turning off the lamps, achieving this way a better usage of the natural light; for the reduction of the electric load of the air conditioning units which will be obtained in incorporating induced draft shafts; and for an improvement in the electric and ballast installation. For the actions that turned out to be redeemable in three years the assistance of the Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE) of the Comision Federal de Electricidad (CFE) has been available. It is expected that the execution of the modifications will be carried out in the November and December months of 1993, and the results will be evaluated in 1994. [Espanol] En este trabajo se presenta un diagnostico del consumo de energia electrica en la biblioteca de la Unidad Azcapotzalco de la Universidad Autonoma Metropolitana para determinar las acciones que se pueden llevar a cabo para ahorrar energia electrica. Esto sin deteriorar el confort luminico y termico. El analisis mostro que, cambiando las superficies reflectoras de las luminarias, se puede reducir el numero de lamparas, sin que el nivel de iluminacion quede debajo de los valores recomendados. Se estimaron ahorros: por la sustitucion de las lamparas fluorescentes por otras de halogenuros metalicos en las partes donde el

  4. Las Cajas de Ahorros en España durante el Régimen de Franco y la Transición Democrática : Su importancia en la economía regional

    Directory of Open Access Journals (Sweden)

    Luis Javier Coronas Vida

    2010-06-01

    Full Text Available En este artículo analizaremos las conexiones entre el desarrollo regional y la evolución de las cajas de ahorros, a partir del PIB regional per cápita y los depósitos en las cajas de ahorros, agrupados por regiones. El PIB real per cápita creció rápidamente en todas las regiones desde 1959 (el segundo franquismo. Aunque el crecimiento de las regiones pobres fue más fuerte que el de las ricas, en 1980 el PIB per cápita de las pobres no alcanzaba el 59% del correspondiente a las ricas (pero en 1945 era sólo el 43%. Los depósitos per cápita en las cajas de ahorros de las regiones pobres eran extremadamente reducidos en 1945 (sólo el 8% del dato correspondiente a las ricas; sin embargo en 1980 había alcanzado el 40%. El crecimiento de los depósitos en las regiones pobres fue acompañado por un crecimiento de la población débil (11% entre 1945 y 1980; por otra parte, el crecimiento demográfico en las regiones ricas alcanzó el 127%.In this paper we will analyse connections between regional development and the Savings Banks evolution in Spain, attending to regional GDP, per capita, and Savings Banks deposits accounts, gathered together by regions. Real GDP per capita, in all Spanish regions, increased quickly since 1959 (the 2nd Franco's era. Although, poor regions growth was stronger than that of the rich ones, in 1980, GDP per capita in poor regions didn't reach up to 59% of rich ones (even though in 1945 was only 43%.Savings Banks deposits per capita in poor regions were extremely short in 1945 (only 8% of the rich ones; nevertheless, in 1980 they reached 40%. Deposit increase in poor regions was also accompanied by a short population growth (11% between 1945 and 1980; on the other hand, demographic development in rich regions reached 127%.

  5. 1957-2004年影响我国的强热带气旋频数和强度变化%Variations in Frequency and Intensity of Strong Tropical Cyclones Affecting China During 1957-2004

    Institute of Scientific and Technical Information of China (English)

    王小玲; 任福民

    2008-01-01

    Based on tropical cyclone track dataset in the western North Pacific from China Meteorological Administration(CMA),variations in frequency and intensity of tropical cyclones(TCs)in the western North Pacific,affecting-China TCs(ACTCs)and landfall TCs(LTCs)achieving a typhoon intensity during 1957-2004 were studied.Frequencies of strong tropical cyclones showed significant decreasing trends from 1957 to 2004 and the linear trend was much greater when the intensity was stronger.There was no linear trend in the portion of strong tropical cyclones achieving a typhoon(TY)intensity,while those reaching a strong typhoon(STY)and a super typhoon(SuperTY)intensity showed decreasing trends during 1957-2004.The maximum intensities of TCs,ACTCs and LTCs all decreased during the period of 1957-2004.The mean intensities of TCs and ACTCs displayed decreasing trends and the mean intensity of LTCs achieving a TY intensity also showed a decreasing trend.

  6. High frequency of the IVS2-2A>G DNA sequence variation in SLC26A5, encoding the cochlear motor protein prestin, precludes its involvement in hereditary hearing loss

    Directory of Open Access Journals (Sweden)

    Pereira Fred A

    2005-08-01

    Full Text Available Abstract Background Cochlear outer hair cells change their length in response to variations in membrane potential. This capability, called electromotility, is believed to enable the sensitivity and frequency selectivity of the mammalian cochlea. Prestin is a transmembrane protein required for electromotility. Homozygous prestin knockout mice are profoundly hearing impaired. In humans, a single nucleotide change in SLC26A5, encoding prestin, has been reported in association with hearing loss. This DNA sequence variation, IVS2-2A>G, occurs in the exon 3 splice acceptor site and is expected to abolish splicing of exon 3. Methods To further explore the relationship between hearing loss and the IVS2-2A>G transition, and assess allele frequency, genomic DNA from hearing impaired and control subjects was analyzed by DNA sequencing. SLC26A5 genomic DNA sequences from human, chimp, rat, mouse, zebrafish and fruit fly were aligned and compared for evolutionary conservation of the exon 3 splice acceptor site. Alternative splice acceptor sites within intron 2 of human SLC26A5 were sought using a splice site prediction program from the Berkeley Drosophila Genome Project. Results The IVS2-2A>G variant was found in a heterozygous state in 4 of 74 hearing impaired subjects of Hispanic, Caucasian or uncertain ethnicity and 4 of 150 Hispanic or Caucasian controls (p = 0.45. The IVS2-2A>G variant was not found in 106 subjects of Asian or African American descent. No homozygous subjects were identified (n = 330. Sequence alignment of SLC26A5 orthologs demonstrated that the A nucleotide at position IVS2-2 is invariant among several eukaryotic species. Sequence analysis also revealed five potential alternative splice acceptor sites in intron 2 of human SLC26A5. Conclusion These data suggest that the IVS2-2A>G variant may not occur more frequently in hearing impaired subjects than in controls. The identification of five potential alternative splice acceptor sites in

  7. Energy saving in the auxiliaries consumption for circulation water pumps optimizing the thermal regime; Ahorro en el consumo de auxiliares por bombas de agua de circulacion optimando el regimen termico

    Energy Technology Data Exchange (ETDEWEB)

    Orozco Martinez, Roni [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    A methodology is proposed that should be followed in any thermal electric power plant to determine the load value at which a unit requires a second circulation water pump without affecting the thermal regime and avoiding an excessive auxiliaries consumption in partial loads. In applying this method the power plant would have an energy saving equivalent to the auxiliaries consumption during an hour, when the unit as operating at full load. [Espanol] Se propone una metodologia que debe seguirse en cualquier central termoelectrica para determinar el valor de la carga en la cual una unidad requiere de la segunda bomba de agua de circulacion sin afectar el regimen termico y evitadose un excesivo consumo de auxiliares en cargas parciales. Al aplicar este metodo la central tendria un ahorro de energia equivalente al consumo de auxiliares durante una hora cuando la unidad esta generando su maxima carga.

  8. Opportunities for energy conservation detected in a diagnosis made for the smelting industry; Oportunidades de ahorro de energia detectadas en un diagnostico efectuado en la industria de la fundicion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Bautista, Rolando; Magana Castro, Rogelio [Fideicomiso de Apoyo al Programa de Ahorro de Energia del Sector Electrico (FIDE), Mexico, D. F. (Mexico)

    1993-12-31

    The smelting industry is one of the main industrial branches in the utilization of electric power at national level, for this reason an energy diagnosis was made in representative industries of this process in which excellent results were obtained regarding opportunity areas, with potentials ranging from 15% up to 40% of energy saving in relation to the energy consumption, with actions recoverable in less than 15 months. [Espanol] La industria de la fundicion es una de las principales ramas industriales en la utilizacion de la energia electrica a nivel nacional, por esta razon se realizo un diagnostico energetico en empresas representativas de este proceso y en las cuales se obtuvieron excelentes resultados en cuanto a areas de oportunidad, teniendo potenciales que van desde un 15% hasta un 40% de ahorro con relacion al consumo de energia, con medidas que se recuperan en menos de 15 meses.

  9. Método integral para mejorar el diseño de columnas de destilación, a partir de conceptos de ahorro de energía

    Directory of Open Access Journals (Sweden)

    Marco Antonio Ponce Guerrero

    2001-01-01

    Full Text Available Se presenta una metodología para analizar esquemas de destilación y proponer modificaciones que signifiquen ahorros de energía, mediante el uso de curvas de entalpía-temperatura que relacionan la operación simulada con el caso de una operación ideal reversible, tal como lo proponen Dhole y Linhoff. Se hace una aplicación a una columna de destilación atmosférica de crudo, que presenta un arreglo complejo con pumparounds y extracciones laterales. El resultado de adicionar un pumparound muestra una reducción en los consumos de energía, del orden de 400 millones de BTU/día, comprobando la utilidad de los métodos de análisis de procesos que utilizan la simulación.

  10. Energy saving by means of air conditioning equipment replacement and the household application of thermal insulation; Ahorro de energia electrica por reemplazo de equipos de aire acondicionado y aplicacion de aislamiento termico en viviendas

    Energy Technology Data Exchange (ETDEWEB)

    Peralta Solorio, Jose Luis [Fideicomiso para el Ahorro de la Energia (Mexico)

    2005-07-15

    An extension study of the Financing Program for Energy Saving looked for the evaluation of the electric energy saving potential obtained by the replacement of air conditioning equipment and the application of thermal insulation in 30 houses of two Mexican cities with warmth climate. In a joint effort with Comision Federal de Electricidad the consumption files of the users were analyzed and field measurements of electric demand and of refrigeration were made. As a following step the change of the refrigeration necessities derived from the application of thermal insulation were evaluated as well as the energy efficiency improvement obtained by the substitution of the air conditioning equipment and the favorable results obtained by the implementation of both measures - thermal insulation and change of air conditioning equipment in a joint form. This way, as a conclusion, the optimum sequence of application of these measures is revealed. [Spanish] Un estudio extension del Programa de Financiamiento para el Ahorro de Energia Electrica busco evaluar el potencial de ahorro de energia electrica alcanzado por el reemplazo de equipos de aire acondicionado y la aplicacion de aislamiento termico en 30 viviendas de dos ciudades mexicanas con clima calido. En un esfuerzo conjunto con la Comision Federal de Electricidad se analizaron los historiales de consumo de los usuarios y se efectuaron las mediciones de campo de demanda electrica y de refrigeracion. Como paso siguiente se valoro el cambio en las necesidades de refrigeracion derivado de la aplicacion de aislamiento termico al igual que la mejora en eficiencia energetica obtenida por la sustitucion de aire acondicionado y se identificaron los resultados favorecedores arrojados por la implementacion de ambas medidas -aislamiento termico y cambio de equipo de aire acondicionado- en forma conjunta. De esta manera, como conclusion, se devela la mas optima secuencia de aplicacion de estas medidas.

  11. Disponer las prácticas: consumo, crédito y ahorro en un asentamiento del gran Buenos Aires = Arranging practice: consumption, credit and saving on a settlement in the metropolitan area of Buenos Aires

    Directory of Open Access Journals (Sweden)

    Figueiro, Pablo

    2010-01-01

    Full Text Available El presente artículo se propone indagar sobre las especificidades que adopta el uso del dinero en sectores subalternos a partir de un trabajo de campo realizado en un asentamiento de la localidad de José León Suárez, provincia de Buenos Aires. Se sostiene que en el cruce entre, por un lado, las modalidades que asume la percepción del ingreso en dicha población y, por el otro, los mecanismos formales e informales que regulan la relación con el dinero, se generan prácticas específicas de consumo, crédito y ahorro que tienden a profundizar las desigualdades existentes en dichos sectores. En este sentido, el trabajo plantea que las prácticas de consumo son estructuradas en torno a las condiciones de percepción del ingreso, es decir, a partir del trabajo del que se disponga – formal o informal –, la regularidad del pago – fijo o no y, en el primer caso, con que frecuencia temporal se percibe – y la forma del mismo – si se halla bancarizado o no –. Vinculado a esto, se desprenden distintas posibilidades de acceso a créditos – en bancos, en casas de venta de bienes para el hogar, de “confianza” entre parientes y vecinos y/o en comercios del lugar – que suponen otras tantas formas de relación con el tiempo y de la vivencia y calculabilidad del mismo. Estas cuestiones, entrecruzadas por reglamentaciones, exclusiones y controles que operan modelando las formas que adopta el gasto, encuadran formas diferenciales del manejo del dinero y del ahorro

  12. Propuesta de un sistema de aprovechamiento de agua lluvia como alternativa para el ahorro de agua potable, en la institución educativa María Auxiliadora de Caldas, Antioquia

    Directory of Open Access Journals (Sweden)

    Palacio Castañeda Natalia

    2011-11-01

    Full Text Available El aprovechamiento del agua lluvia es una práctica interesante, tanto ambiental como económicamente, si se tiene en cuenta la gran demanda del recurso sobre las cuencas hidrográficas, el alto grado de contaminación de las fuentes superficiales y los elevados costos por el consumo de agua potable en una institución educativa. Este proyecto presenta la ingeniería conceptual de una propuesta de diseño de un si stema de aprovechamiento de agua lluvia como alternativa para el ahorro de agua potable en usos tales como la descarga de sanitarios, el lavado de zonas comunes, entre otros. Se presenta, adicionalmente, un análisis aproximado de la viabilidad técnica y económica de dicho aprovechamiento en una institución educativa del municipio de Caldas, Antioquia. Se desarrollan en este documento tres aspectos principales: el cálculo de los volúmenes disponibles de agua lluvia en la zona, la evaluación del volumen de agua potable ahorrado con el aprovechamiento del agua lluvia, la estimación del presupuesto para la construcción del sistema y la proyección del ahorro generado al utilizarlo. Los resultados sugieren que el aprovechamiento de agua lluvia es una opción técnicamente viable, pero financieramente no, pues la inversión inicial es alta, por lo que es importante buscar financiación externa para desarrollar este tipo de proyectos que representan una solución interesante para contribuir al desarrollo sostenible de la institución educativa.

  13. Variation Characteristics and Time-frequency Analysisof NO2 in Zhanjiang%湛江市空气NO_2浓度变化特征及时频分析

    Institute of Scientific and Technical Information of China (English)

    张羽; 牛生杰

    2009-01-01

    为了探究湛江市空气NO_2浓度的变化特征及时频特性,以达到有效防治空气污染,利用数理统计方法和时频分析技术的短时傅立叶变换、小波分解分析、平滑伪Wigner-Ville分布分析、重排谱图及Hough变换等方法进行了分析和研究.结果表明,湛江市空气NO_2浓度较全国大多数城市偏低,逐日差异明显,变化辐度波动大,资料离散度高.分布形态属正偏(右偏)分布,偏斜程度较大,分布陡峭,为尖峰分布.湛江市空气NO_2浓度的变化逐年呈明显减少趋势,年内跨度也明显减少,波动变小,同时NO_2逐日资料的年分布形态偏斜程度明显减少,尖峰分布逐年变得更为平缓.NO_2季节变化比较明显,年周期性清楚.NO_2年内变化具有冬春季节值大,夏秋季节值小,变化相对平缓的年趋势变化特性;冬春季节振辐大,夏秋季节振辐小,小波分解变化信号的频率从低层至高层细节系数逐层降低的年振荡波动特性.湛江市空气NO_2浓度的重排谱图与平滑伪Wigner-Ville分布趋势相近,但没有交叉项,时频聚集性好,可解释性强.平滑伪Wigner-Ville分布的Hough变换可发现湛江市空气NO_2浓度年内的辐值变化峰值.%In order to control air pollution effectively, variations characteristics of NO_2 in Zhanjiang were analyzed by means of Numerical Statistic method and time-frequency analysis, including short time discrete Fourier transform, wavelet composition, smoothing pseudorange Wigner-Ville distribution、recomposition spectrogram and Hough Transform method. The results showed that: the NO_2 concentration in Zhanjiang was lower than that in most cities in China. It changed obviously day by day and wave motion of the Variations peak type was wide,which indicated a right asymmetric distribution shape with great decline. Distributional pattern classified forward bias (right avertence) distribution,decline level was comparatively large, distributional

  14. Proceedings of the 24. National seminar on the rational use of energy and exposition of equipment and services and 7. Binational seminar on energy saving [Selected Papers]; 24. Seminario nacional sobre el uso racional de energia y exposicion de equipos y servicios y 7. Seminario binacional de ahorro de energia. Memoria Tecnica. [Ponencias seleccionadas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document contains the technical briefings of the 24. National Seminar on the rational use of energy, and exhibition of the equipment and services and the 7. Binational seminar on energy saving, organized by the Asociacion de Profesionistas y Tecnicos en Aplicacion Energetica (ATPAE), in Ciudad Juarez, Chihuahua, Mexico, from November 9 to 11, 2005. This seminar dealt with subjects such as: electrical energy saving, energy distribution, solar energy, energy saving in compressed air, biomass, administration and control of the demand of the electrical energy, bioclimatic architecture, use of the compressed natural gas, renewable energy, co-generation, qualification and consultancy for the intelligent use of the energy in PyMES. [Spanish] Este documento contiene la memoria tecnica del 24 Seminario Nacional sobre el uso racional de energia, y exposicion de los equipos y servicios y el 7 Seminario binacional de ahorro de energia, organizado por la Asociacion de Tecnicos y Profesionistas en Aplicacion Energetica (ATPAE), en Ciudad Juarez, Chihuahua, Mexico, del 9 al 11 de noviembre del 2005. Este seminario trato temas tales como: ahorro de energia electrica, distribucion de la energia, energia solar, ahorro de energia en aire comprimido, biomasa, administracion y control de la demanda de la energia electrica, arquitectura bioclimatica, uso del gas natural comprimido, energia renovable, cogeneracion, capacitacion y consultoria para el uso inteligente de la energia en las Pymes.

  15. Program of actions for energy conservation in the equipment for the urban public transportation; Programa de acciones para el ahorro de la energia en los equipos de transporte publico urbanos

    Energy Technology Data Exchange (ETDEWEB)

    Sanhez Arellano, L.I. [Facultad de Ingenieria, Universidad Autonoma del Estado de Mexico, Toluca (Mexico)

    1995-12-31

    las redes de transporte y su explotacion, asi como la del ahorro y uso eficiente de la energia utilizada para su funcionamiento. El trabajo aqui presentado se inscribe dentro de las lineas de interes de este programa. Las caracteristicas propias de operacion y de consumo de energia de los diferentes tipos de vehiculos utilizados en el servicio de transporte publico urbano, dependen principalmente de las aplicaciones para las que se hayan previsto. Sin embargo un punto importante es el conocer de manera mas concreta y especifica la naturaleza y otras opciones de utilizacion posibles de los diversos sistemas de transporte urbano, asi como su impacto energetico y la posibilidad de ahorros bien canalizados. El objetivo de este trabajo es la de presentar de manera concreta los diferentes equipos utilizados en el transporte publico urbano, haciendo una comparacion energetica, ademas de plantear un programa de acciones tendientes al ahorro de energia para los vehiculos que operan actualmente en las principales ciudades del pais. Se indican las principales acciones y sus caracteristicas basicas para su puesta en marcha, las cuales se pueden resumir en tres grandes rubros: -acciones dentro de las mismas empresas y sobre el parque vehicular existente. -acciones sobre la administracion y explotacion de los sistemas de transporte. -acciones para la utilizacion de nuevos equipos y vehiculos mas eficientes. Una explicacion detallada de cada una de estas acciones y su impacto en el consumo de energeticos son el proposito final de este estudio.

  16. GOBERNANZA MULTIFIDUCIARIA DE STAKEHOLDERS: ANÁLISIS COMPARADO DE LA EFICIENCIA DE BANCOS Y CAJAS DE AHORROS. / MULTIFIDUCIARY GOVERNANCE OF STAKEHOLDERS: A COMPARATIVE ANALYSIS OF THE EFFICIENCY OF BANKS AND SAVING BANKS.

    Directory of Open Access Journals (Sweden)

    Jose Luis RETOLAZA

    2012-05-01

    Full Text Available Las cajas de ahorros Españolas son posiblemente el caso más significativo a nivel mundial de entidades multistakeholders, no sólo por su misión, sino también en su gobernanza. La teoría multifiduciaria de los stakeholders plantea, al menos de forma teórica lo que en las cajas de ahorros ha sido una realidad por más de un siglo. Así, las cajas se convierten en un “caso de laboratorio” para analizar la viabilidad e idoneidad de una gobernanza participada por el conjunto de stakeholders de la organización. Nuestra hipótesis es que la gobernanza multistakeholder, así como la orientación hacia los stakeholders, generan un planteamiento estratégico diferente, no centrado en los beneficios. Por tanto, la gobernanza multifiduciaria puede perfectamente ser más ineficiente en relación con indicadores económico-financieros referidos a los shareholders de una entidad. Sin embargo, estas entidades deberían ser más eficientes si se tienen en cuenta indicadores relacionados con la generación de valor social. Con el fin de contrastar la eficiencia relativa hemos utilizando la población de bancos y cajas de España y los datos de 2009, utilizando la técnica de Análisis Envolvente de Datos con objeto de comparar la eficiencia económica, social y global de ambos tipos de entidades. Los resultados indican una diferenciación significativa entre estos dos grupos de entidades financieras en relación con la eficiencia social y económica, si bien no ocurre lo mismo cuando se utiliza la eficiencia global –económica más social-. Por lo que podemos concluir que la eficiencia en la gestión entre inputs y outputs en cajas de ahorros y bancos es similar. / Probably, Spanish savings banks are the most significant worldwide multistakeholders entities, not only because of their mission, but also in their governance. The stakeholder multifiduciary theory, establishes at least theoretically what the saving banks has been a reality for more than

  17. Optical frequency combs generated mechanically

    CERN Document Server

    Sumetsky, M

    2016-01-01

    It is shown that a highly equidistant optical frequency comb can be generated by the parametric excitation of an optical bottle microresonator with nanoscale effective radius variation by its natural mechanical vibrations.

  18. FET frequency discriminator

    Science.gov (United States)

    Mawhinney, F. D.

    1982-03-01

    The FET Frequency Discriminator is an experimental microwave frequency discriminator developed for use in a specialized set-on VCO frequency memory system. Additional development and evaluation work has been done during this program to more fully determine the applicability of the FET frequency discriminator as a low-cost, expendable receiver front-end for both surveillance and ECM systems. Various methods for adjusting the frequency-to-voltage characteristic of the discriminator as well as the effects of detector characteristics and ambient temperature changes were evaluated. A number of discriminators for use in the 7- to 11-GHz and the 11to 18-GHz bands were fabricated and tested. Interim breadboard and final packaged models were either delivered or installed in developmental frequency systems. The major limitations and deficiencies of the FET frequency discriminator that were reviewed during the program include the effects of temperature, input power level variations, nonlinearity, and component repeatability. Additional effort will be required to advance the developmental status of the FET frequency discriminator to the level necessary for inclusion in low-cost receiver systems, but the basic simplicity of the approach continues to show much promise.

  19. 带锯条掉齿前后横向振动位移及主频率变化规律%Horizontal Vibration Displacement and Main Frequency Variation of Band Saw Blade before and after Dropping Tooth

    Institute of Scientific and Technical Information of China (English)

    高金贵; 张健; 李辉; 吴俊华; 赵洪刚; 齐华春; 姜兆方

    2016-01-01

    Based on MJ345A woodworking band saw machine as the research object, the transverse vibration displacement of the saw blade was tested by using vibration analyzer under no-load and vibration signal acquisition, processing, analysis software. The vibration displacement and main modal frequency of different blades under the different conditions were found out through transverse vibration displacement of the saw blade and analysis of the power spectrum. The orthogonal experiment analysis showed that saw wheel spindle speed is the most significant factor impacting on the saw blade transverse vibration displacement,followed by the tension of saw blade,belt tension is not obvious. Analysis of band saw blade before and after dropping teeth showed that if the measuring range of transverse vibration displacement of band saw blade is in 0. 56~0. 68μm microns,and the vibration in 450~465 Hz frequency range,the saw blade had at least two teeth,new band saw blade need to be replaced in a timely manner in order to ensure the safety and cutting sawing quality;Then horizontal vibration displacement and frequency variation of band saw blade before and after dropping tooth have been clear. Research results can provide preliminary research and criterion of preliminary basis for sufficient and reasonable using band saw blade in the process of production,processing quality serious decline and the occurrence of the phenomenon such as endangering the personal safety accident,timely replacement blade.%以MJ345A型木工带锯机为研究对象,在空载下利用振动分析仪和振动信号采集、处理、分析软件对带锯条的横向振动进行测试及信号采集,通过锯条横向振动位移、自功率谱分析,找出不同条件下锯条振动位移和主振型频率的变化规律.通过正交试验分析可知:锯轮主轴转速是对锯条横向振动位移影响最为显著的因素,其次为锯条张紧力,皮带张紧力为不明显因素.对带

  20. Ahorro de dinero y de energía mediante la instalación de una conducción termoplástica en una refinería, EE.UU.

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1979-11-01

    Full Text Available This article describes the method used by and oil refinery to save some two hundred thousand dollars in the replacement of a seriously damaged stretch of a pipeline carrying salt water refrigerant. This substantial saving was obtained by installing high density polyethylene pressure pipe as a cover around the damaged pipe section. The same type of piping can be used in other industries (pulp and paper mills, Chemical processes pollution control, mining, textile mills, etc. where worm or abrasion corrosion damaged pipes can be found.

    Este artículo describe el método por el cual una refinería pudo ahorrarse unos doce millones de pesetas en la operación de repuesto de un tramo muy deteriorado de una conducción que transporta agua salada refrigerante. Este ahorro substancial se obtuvo gracias al uso de futras de presión de polietileno, de alta densidad, como revestimiento de la sección deteriorada de la tutoría. El mismo tipo de tubería se puede emplear también en otras industrias (pastas, papel, procesos químicos, control de polución, minería, textil, etcétera donde existan conducciones desgastadas o deterioradas por corrosión o abrasión.

  1. Estimated saving potential and efficient use of energy in air conditioning by means of the solar protection; Potencial estimado de ahorro y uso eficiente de energia en aires acondicionados mediante la proteccion solar

    Energy Technology Data Exchange (ETDEWEB)

    Mejia D, David; Morillon G, David; Rodriguez V, Luis [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2001-07-01

    In here it is presented the analysis of the impact of the solar gains through the transparent parts of a prototype house of social interest, located in a dry warm climate. This analysis was made to determine the gains through windows for the summer time and under the following conditions: without outside solar protections, with the use of eaves, solar breakers and finally with the use of both systems of solar protection. The results were compared to obtain the considered potential of energy saving in cooling equipment, that could be obtained in future houses to build. [Spanish] Se presenta el analisis del impacto de las ganancias solares a traves de las partes transparentes de un prototipo de vivienda de interes social, ubicado en un clima calido seco. Dicho analisis se realizo para determinar las ganancias a traves de ventanas para la epoca de verano y bajo las siguientes condiciones: sin protecciones solares exteriores, con el empleo de aleros, con quiebrasoles y finalmente con el empleo de ambos sistemas de proteccion solar. Se compararon los resultados para obtener el potencial estimado de ahorro de energia en equipo de enfriamiento, que se tendria en las futuras viviendas por construir.

  2. Frequency standards

    CERN Document Server

    Riehle, Fritz

    2006-01-01

    Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards

  3. Frequency synthesiser

    NARCIS (Netherlands)

    Drago, Salvatore; Sebastiano, Fabio; Leenaerts, Dominicus Martinus Wilhelmus; Breems, Lucien Johannes; Nauta, Bram

    2016-01-01

    A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an

  4. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  5. Energy conservation and contribution to the sustained development through action in the bioclimate design; Ahorro de energia y contribucion al desarrollo sustentable a partir de acciones de diseno bioclimatico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Chavez, J. R.; Dorantes Rodriguez, R. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1995-12-31

    , construction and monitoring of the functioning of cooling passive systems. The results obtained to date point out that the energy consumption has diminished and improved the environmental comfort conditions for the library building users. [Espanol] La crisis mundial de energia de 1973, ademas de los problemas de abastecimiento y elevacion de precios, propicio tambien diversos paises, una reaccion orientada al uso eficiente y conservacion de la energia, y a la aplicacion de una arquitectura con sentido comun: la ARQUITECTURA BIOCLIMATICA, misma que se basa en la utilizacion en las edificaciones de las energias alternativas, tales como la solar eolica, etc. Obtencion de condiciones de confort natural ambiental y ahorro y uso eficiente de la energia en los edificios, son los objetivos fundamentales de la ARQUITECTURA BIOCLIMATICA. Bajo estas consideraciones, se han planteado diversos sistemas pasivos para control termico de edificios, los cuales se han aplicado en diferentes regiones climaticas del planeta. En el presente trabajo, se presenta y analiza el potencial de medidas para ahorro de energia, tales como sistemas de iluminacion artificial de alta eficiencia y sistemas pasivos de enfriamiento para el control termico de un edificio educativo, la biblioteca central de la Universidad Autonoma Metropolitana, Unidad Azcapotzalco, ubicada en la ciudad de Mexico. El objetivo de este estudio se orienta a la reduccion del consumo de energia en la biblioteca, y a la obtencion de condiciones de confort ambiental higrotermico para sus ocupantes. Estudios realizados durante la primera etapa de investigacion, han permitido identificar un excesivo consumo de energia y condiciones de falta de confort higrotermico y de la necesaria calidad del aire interior en la biblioteca. Estas acciones se han enfocado en dos aspectos. El primero se refiere al mejoramiento de la operacion de la instalacion electrica y el alumbrado de la biblioteca. Estas acciones se basaron en la sustitucion de lamparas

  6. The relation between preventive maintenance and energy saving, planning and production control; La relacion entre el mantenimiento preventivo y el ahorro de energia planeacion y control de la produccion

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Cazarez, Mario [Coorporacion de ingenieros en aire acondicionado y mantenimiento en general (Mexico)

    2003-07-01

    In this paper the importance that the preventive maintenance has as an important ingredient of the internal policies of the companies for the promotion of the energy saving is discussed. It considers that the department of planning and production control must take into account very seriously the importance of programmed preventive maintenance in order to maintain the continuity of the production process and with this eliminate the bottle necks that adversely affect it and consequently the the company's image before the clients, besides contributing positively the promotion of energy saving. The faults that stop the production process inflict losses of income and adversely affect the yield of the company, in addition, they increase the production cost or the plant expenses associated to the repair of the damaged equipment, in the worst of the cases, important penalties will have to be paid for the delayed delivery of the product to the client. By keeping the correct operation of the equipment, increasing its availability and assuring that all the safeties of these operate correctly we will be contributing to the optimal operation of the enterprise system and avoiding the additional consumption of energy associated to the failure of an equipment and interruption of the production line. The preventive maintenance also promotes, the order and the cleanliness, the safety and hygiene in the work centers and the protection to the environment. Once the prevention has won the battle to the correction, one enters the field of diagnosis, handling the service periods in an optimal way in benefit of the production line. In this stage it can be spoken of entering the application of Total Productive Maintenance. [Spanish] En este trabajo se discute la importancia que tiene el mantenimiento preventivo como un ingrediente importante de las politicas internas de las empresas para la promocion del ahorro de energia. Considera que el departamento de planeacion y control de la

  7. Analysis of passive systems as a tool for energy saving in buildings: solar control; Analisis de sistemas pasivos como herramienta para el ahorro de energia en edificaciones: Control solar

    Energy Technology Data Exchange (ETDEWEB)

    Saravia, Maricela; Morillon Galvez, David [Instituto de Ingenieria, UNAM, Mexico, D. F. (Mexico)

    1999-07-01

    A bioclimatic study of El Salvador is presented, with the purpose of using window eaves as elements of passive solar control and to determine the optimal angles of orientation, in order to diminish the thermal gains by direct solar radiation and to manage to get close to the comfort conditions. The former with the intention of integrating measures that help to obtain energy efficiency and comfortable buildings, for the conditions of warm humid climate, characteristic of a Central American country like El Salvador. Besides offering a document of consultation among the professionals dedicated to the design and as base of bioclimatic considerations that must have the construction regulations. As a conclusion the optimal angles of eaves for each orientation are presented and a quantitative estimation of the savings that would imply not to consume electrical energy in cooling systems using these elements as a protection to the direct solar radiation. [Spanish] Se presenta un estudio del bioclima de El Salvador, con el fin de utilizar aleros de ventana como elementos de control solar pasivo y determinar los angulos optimos por orientacion, para disminuir las ganancias termicas por radiacion solar directa y lograr acercar a las condiciones de confort. Lo anterior con el objeto de integrar medidas que coadyuven a lograr edificios energeticamente eficientes y confortables, para las condiciones de clima calido humedo, caracteristico de un pais centroamericano como El Salvador. Ademas de brindar un documento de consulta entre los profesionales dedicados al dise y como base de consideraciones bioclimaticas que debe tener el reglamento de construcciones. Como conclusion se presentan los angulos optimos de alero por cada orientacion y una estimacion cuantitativa del ahorro que implicaria el no consumir energia electrica en sistemas de enfriamiento utilizando estos elementos como una proteccion a la radiacion solar directa.

  8. Energy saving in the pumping of drinking water, Municipality of San Felipe, Guanajuato; Ahorro de energia electrica en bombeo de agua potable, en el municipio de San Felipe, Gto.

    Energy Technology Data Exchange (ETDEWEB)

    Gamiz Sanchez, Lorenzo [Applied Technology Center de Mexico, S.A. de C.V. (Mexico)

    2006-01-15

    This paper shows the results attained in energy saving through a project of potable water pumping, which took an investment of $433,043.00 and an internal rate of return of 126%. This project puts into evidence that it is possible to reduce between 15 and 30% of the total invoicing for energy consumption in potable water pumping if an equipment of poor efficiency is replaced by another of high efficiency. The project was requested by the Guanajuato's State Water Comision and the Municipal Bureau of Sewage and Potable Water, with the double intention of reducing the energy consumption along with the corresponding invoicing and incrementing the output of the wells in order to improve the potable water supply. In the site two high efficiency submersible motor-pumps were installed previously to the energy diagnosis that triggered profitable operation results and a convenient invoicing. [Spanish] Se documentan los resultados obtenidos en un proyecto de ahorro de energia en el bombeo de agua potable realizado con una inversion de $433,043.00 y con una tasa interna de retorno de 126%. Este proyecto pone en evidencia que es posible reducir entre el 15 y 30% de la facturacion total por consumo de energia electrica en el bombeo de agua potable si se sustituye un equipo poco eficiente por otro de alta eficiencia. El proyecto fue solicitado por la Comision Estatal del Agua de Guanajuato y la Junta Municipal de Agua Potable y Alcantarillado del municipio, con un doble proposito, reducir el consumo de energia junto con la facturacion correspondiente e incrementar la capacidad de produccion de los pozos con la intencion de mejorar el abasto de agua potable. En el lugar se instalaron dos motobombas sumergibles de alta eficiencia previo diagnostico energetico que desencadenaron rentables resultados operativos y de facturacion.

  9. 飞行学员高频听力损失的变化跟踪及评价%Evaluation of high frequency hearing loss variation in enrolled student pilots

    Institute of Scientific and Technical Information of China (English)

    郭睿; 王广云; 陈同欣; 马晓丽; 马中立

    2011-01-01

    Objective To follow up the hearing of newly enrolled students, inquire into the impact of high frequency hearing loss on linguistic frequency hearing and predict the change of hearing. Methods Newly enrolled student pilots from an Air Force flying college underwent estimation of hearing. The change of hearing among 16 student pilots with high frequency hearing loss on entrance was observed for 2 years. Results There was no significant change in the high frequency hearing loss among these students( H = 0). High frequency hearing loss had no impact on linguistic frequency hearing. Conclusions There are no significant changes in high frequency hearing loss over two years. There is no impact on linguistic frequency hearing.%目的 探讨一定程度高频听力损失的学员其听力变化情况及分析其对语频听力的影响,预判其变化趋势.方法 对某年入某航校的全部飞行学员2年后转校体检时进行听力学检测,对其中16名入校时即有高频听力损失学员的听力水平进行统计学分析.结果 入校时有高频听力损失的学员在2年后所有频率的听力改变差异均不具有统计学意义(H=0).结论 一定程度的高频听力损失2年后无明显进展趋势,对语频听力影响不显著.

  10. FODA financiero de las Cooperativas de Ahorro y Crédito pertenecientes al Segmento 4 de la Zonal 6-SEPS, basado en un análisis financiero con la metodología CAMEL en los períodos 2010, 2011 y 2012

    OpenAIRE

    García Vidal, Karina Elizabeth

    2014-01-01

    El documento consiste en un análisis financiero CAMEL de las Cooperativas de Ahorro y Crédito del Segmento 4 de la Superintendencia de Economía Popular y Solidaria de Ecuador en la Zona 6. Los resultados se presentan en una Matriz FODA que permite conocer la situación de las Instituciones financieras analizadas y el Segmento. The document consists of a CAMEL financial analysis of Savings and Credit Cooperatives in segment 4 of the Superintendencia de Economía Popular y Solidaria of Ecuador...

  11. Frequency discrimination of brief tonal steps as a function of frequency in the lesser bulldog bat.

    Science.gov (United States)

    Roverud, R C

    1999-09-01

    In a two-alternative, forced-choice task lesser bulldog bats were trained to distinguish between a pure tone pulse and a pulse composed of a series of brief tonal steps oscillating between two different frequencies. The tone-step pulse gradually approximates the pure tone pulse as the frequency difference between the steps becomes progressively smaller. Frequency difference limens for the brief tonal frequency steps were determined for a broad range of ultrasonic frequencies. The variation in tone-step difference limens with frequency appears to be correlated to the frequency structure of the bat's short-constant-frequency/frequency-modulated echolocation sound. There was a marked decline in the value of the relative frequency difference limens (Weber ratio) over a fairly narrow range of frequencies above the constant frequency and a sharp increase in threshold above this range. The relative thresholds for frequency discrimination were small and uniform over the frequency range of the frequency-modulated sweep and increased for frequencies below the frequency-modulated sweep. Thus, the most accurate frequency-discrimination abilities occur over a narrow frequency range around the frequency of the constant-frequency component of returning echoes. Frequency discrimination over the range of frequencies of the frequency-modulated component is relatively good.

  12. Experiencing variation

    DEFF Research Database (Denmark)

    Kobayashi, Sofie; Berge, Maria; Grout, Brian William Wilson

    2017-01-01

    This study contributes towards a better understanding of learning dynamics in doctoral supervision by analysing how learning opportunities are created in the interaction between supervisors and PhD students, using the notion of experiencing variation as a key to learning. Empirically, we have based...... were discussed, created more complex patterns of variation. Both PhD students and supervisors can learn from this. Understanding of this mechanism that creates learning opportunities can help supervisors develop their competences in supervisory pedagogy....

  13. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  14. Pumping systems characterization; Caracterizacion de los sistemas de bombeo

    Energy Technology Data Exchange (ETDEWEB)

    Torres Gutierrez, R. [Eficiencia Energetica, S.A. de C.V., Mexico, D. F. (Mexico)

    1995-12-31

    In this paper the characterization of the pumping systems is discussed, and an explanation is given of the need of evaluating in detail the possibility of implementing the frequency variators as an option for energy conservation, explaining how the simple use of the similarity or affinity laws lead to over-estimate the saving. [Espanol] En este articulo se describe la caracterizacion de los sistemas de bombeo y se explica la necesidad de evaluar en detalle la posibilidad de implementacion de variadores de frecuencia, como una alternativa para el ahorro de energia, explicando como el simple uso de las leyes de semejanza o afinidad llevan a sobre-evaluar los ahorros.

  15. Las Unidades Básicas de Análisis para la Gestión de las Cajas de Ahorros y las Cajas Rurales Españolas: Un Análisis Comparativo

    Directory of Open Access Journals (Sweden)

    Pilar Ibarrondo Dávila

    2002-06-01

    Full Text Available Las unidades básicas de análisis para la gestión de las entidades de depósito representan los ejes centrales en tomo a los cuales se debe generar la información que suministra el sistema de contabilidad de gestión y, por consiguiente, se configuran como un instrumento esencial para apoyar las decisiones gerenciales. En este artículo, tras delimitar las unidades de análisis básicas para los sistemas de información de las cajas rurales y las cajas de ahorros, presentamos los resultados obtenidos a través de una encuesta realizada en dichas entidades, al objeto de contrastar la importancia que ostentan dichas unidades de análisis en sus sistemas de información. El estudio empírico llevado a cabo ha puesto de manifiesto que la unidad de análisis por excelencia en ambas categorías de entidades es la oficina, seguida por las direcciones regionales o de zona. Los productos y los clientes presentan un menor grado de implantación en sus sistemas de información, en especial en las cajas rurales. The basic units of analysis for managing Depository Financial Institutions are the central axes where management accounting information should be generated and, consequently, are also formed as an essential instrument to support the managerial decisions. Once the basic analysis units for information systems in the rural and savings banks are defined, we offer the results obtained by means of a survey carried out in the aforementioned institutions. So the relevance of this analysis unit in their information systems may be known. The empirical study carried out has shown that the main analysis unit in both categories of entities is the branch office, followed by regional management. Products and customers have a minor relevance in their information systems, particularly in the rural banks.

  16. LA CONTRIBUCIÓN DE LAS COOPERATIVAS DE AHORRO Y CRÉDITO AL DESARROLLO LOCAL EN QUERETARO, MÉXICO / THE CREDIT SAVING COOPERATIVE´S CONTRIBUTION TO THE MEXICAN LOCAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Graciela LARA GÓMEZ

    2011-09-01

    Full Text Available A partir de una aproximación teórica y empírica a las empresas sociales y su rol en el desarrollo local, se buscó establecer cómo las cooperativas de ahorro y crédito constituyen una estrategia pertinente para el avance social y económico de las comunidades mexicanas. Para tal efecto se recurrió al método cualitativo recurriendo a la estrategia de estudio de caso, seleccionando cuatro organizaciones ubicadas en zonas clasificadas como de alta marginación de acuerdo con indicadores oficiales en México. Los casos corresponden a cooperativas fundadas con la participación de miembros de la iglesia católica y cuya actividad financiera ha sido fundamental en el ámbito local en el que funcionan. Los resultados muestran que la organización de cooperativas, la acción voluntaria de sus miembros y en algunos casos el apoyo del Estado, constituyen instrumentos eficaces en la promoción del desarrollo local. Los principales beneficios en favor de los asociados se traducen en el otorgamiento de créditos y de servicios adicionales como becas educacionales y servicios de salud. Pudo constatarse, que con la práctica de los principios y valores del cooperativismo se facilita el trabajo en equipo y los asociados desarrollan habilidades emprendedoras y directivas que los benefician individual y colectivamente mejorando su calidad de vida. / From an empiric and theoretical approach to the social enterprises and its role at the local development, it was sought to establish how the credit and saving cooperatives are a pertinent strategy for the economic and social advance from the Mexican communities. For this purpose the qualitative method was used to utilize the study case strategy; it were selected four organizations located in classified areas as high marginalization according to the official Mexican indicators. The cases are cooperatives founded with the participation from members of the Catholic Church and whose financial activity has being

  17. Automatic oscillator frequency control system

    Science.gov (United States)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  18. A new device for step-down inhibitory avoidance task--effects of low and high frequency in a novel device for passive inhibitory avoidance task that avoids bioimpedance variations.

    Directory of Open Access Journals (Sweden)

    Gilvan Luiz Borba Filho

    Full Text Available Step-down inhibitory avoidance task has been widely used to evaluate aversive memory, but crucial parameters inherent to traditional devices that may influence the behavior analysis (as stimulus frequency, animal's bioimpedance are frequently neglected.We developed a new device for step-down inhibitory avoidance task by modifying the shape and distribution of the stainless steel bars in the box floor where the stimuli are applied. The bars are 2 mm wide, with rectangular shape, arranged in pairs at intervals of 1cm from the next pairs. Each pair makes an electrical dipole where the polarity inverts after each pulse. This device also presents a component that acquires and records the exact current received by the animal foot and precisely controls the frequency of stimulus applied during the entire experiment.Different from conventional devices, this new apparatus increases the contact surface with bars and animal's paws, allowing the electric current pass through the animal's paws only, drastically reducing the influence of animal's bioimpedance. The analysis of recorded data showed that the current received by the animal was practically the same as applied, independent of the animal's body composition. Importantly, the aversive memory was observed at specific stimuli intensity and frequency (0.35 or 0.5 mA at 62 and 125 Hz but not at 0.20 mA or 20 Hz. Moreover, with this device it was possible to observe the well-known step-down inhibitory avoidance task memory impairment induced by guanosine.This new device offers a substantial improvement for behavioral analysis in step-down inhibitory avoidance task and allows us to precisely compare data from different animals with distinct body composition.

  19. Energy conservation and contribution to the sustained development through action in the bioclimate design; Ahorro de energia y contribucion al desarrollo sustentable a partir de acciones de diseno bioclimatico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Chavez, J. R.; Dorantes Rodriguez, R. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D. F. (Mexico)

    1995-12-31

    , construction and monitoring of the functioning of cooling passive systems. The results obtained to date point out that the energy consumption has diminished and improved the environmental comfort conditions for the library building users. [Espanol] La crisis mundial de energia de 1973, ademas de los problemas de abastecimiento y elevacion de precios, propicio tambien diversos paises, una reaccion orientada al uso eficiente y conservacion de la energia, y a la aplicacion de una arquitectura con sentido comun: la ARQUITECTURA BIOCLIMATICA, misma que se basa en la utilizacion en las edificaciones de las energias alternativas, tales como la solar eolica, etc. Obtencion de condiciones de confort natural ambiental y ahorro y uso eficiente de la energia en los edificios, son los objetivos fundamentales de la ARQUITECTURA BIOCLIMATICA. Bajo estas consideraciones, se han planteado diversos sistemas pasivos para control termico de edificios, los cuales se han aplicado en diferentes regiones climaticas del planeta. En el presente trabajo, se presenta y analiza el potencial de medidas para ahorro de energia, tales como sistemas de iluminacion artificial de alta eficiencia y sistemas pasivos de enfriamiento para el control termico de un edificio educativo, la biblioteca central de la Universidad Autonoma Metropolitana, Unidad Azcapotzalco, ubicada en la ciudad de Mexico. El objetivo de este estudio se orienta a la reduccion del consumo de energia en la biblioteca, y a la obtencion de condiciones de confort ambiental higrotermico para sus ocupantes. Estudios realizados durante la primera etapa de investigacion, han permitido identificar un excesivo consumo de energia y condiciones de falta de confort higrotermico y de la necesaria calidad del aire interior en la biblioteca. Estas acciones se han enfocado en dos aspectos. El primero se refiere al mejoramiento de la operacion de la instalacion electrica y el alumbrado de la biblioteca. Estas acciones se basaron en la sustitucion de lamparas

  20. Windows with selective covering to the solar radiation based in copper for saving energy; Ventanas con recubrimiento selectivo a la radiacion solar basado en cobre que permiten el ahorro de energia

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Genaro; Almanza, Rafael [Instituto de Ingenieria UNAM, Mexico, D.F. (Mexico)

    2000-07-01

    savings and the necessary strategies for such aim, based on the geographic region. [Spanish] Se presentan los resultados de un esfuerzo por contribuir al desarrollo de nuevos elementos constructivos acordes a las necesidades bioclimaticas de las edificaciones en Mexico que propicien el ahorro de energia. Se desarrollaron ventanas con dos tipos de recubrimientos, uno exclusivamente de oxido cuproso (Cu{sub 2}O), y otro resultado del deposito sucesivo de una pelicula de sulfuro cuprico (CuS) sobre otra de oxido cuproso. El segundo tipo de ventanas presento un adecuado control al paso de la radiacion infrarroja, lo que permite reducir aun mas la cantidad de radiacion calorifica que pasa a traves de la ventana. Durante las condiciones de calentamiento, estas ventanas dejan pasar en el peor de los casos, la mitad del calor, reduciendo la carga termica al interior de la habitacion o del edificio. Durante condiciones de enfriamiento, la ventana permite la salida del calor a la mitad de la velocidad, manteniendo durante mas tiempo la temperatura de confort del interior. Los recubrimientos de los mencionados compuestos de cobre fueron fabricados en los laboratorios de los Institutos de Ingenieria y Fisica de la Universidad Nacional Autonoma de Mexico (UNAM). Se utilizo la tecnica de erosion ionica o sputtering de un blanco de cobre 99.999% con ayuda de un plasma compuesto de argon (70%) y oxigeno (30%), que posibilita la oxidacion del cobre y el deposito del Cu{sub 2}O. Se utilizo un sustrato de vidrio flotado comercial de 600x400 mm., este tamano del vidrio estuvo determinado por las limitaciones de espacio de nuestra camara de deposito. La ventana asi obtenida presenta una agradable coloracion amarillenta y gran luminosidad, sin embargo, en el infrarrojo cercano, unicamente bloquea el 50%. Para las propiedades deseadas de control termico era necesario reducir aun mas el paso del calor. Para ello se incorporo una pelicula de sulfuro cuprico con la cual fue posible alcanzar

  1. Frequency Standards and Metrology

    Science.gov (United States)

    Maleki, Lute

    2009-04-01

    Preface / Lute Maleki -- Symposium history / Jacques Vanier -- Symposium photos -- pt. I. Fundamental physics. Variation of fundamental constants from the big bang to atomic clocks: theory and observations (Invited) / V. V. Flambaum and J. C. Berengut. Alpha-dot or not: comparison of two single atom optical clocks (Invited) / T. Rosenband ... [et al.]. Variation of the fine-structure constant and laser cooling of atomic dysprosium (Invited) / N. A. Leefer ... [et al.]. Measurement of short range forces using cold atoms (Invited) / F. Pereira Dos Santos ... [et al.]. Atom interferometry experiments in fundamental physics (Invited) / S. W. Chiow ... [et al.]. Space science applications of frequency standards and metrology (Invited) / M. Tinto -- pt. II. Frequency & metrology. Quantum metrology with lattice-confined ultracold Sr atoms (Invited) / A. D. Ludlow ... [et al.]. LNE-SYRTE clock ensemble: new [symbol]Rb hyperfine frequency measurement - spectroscopy of [symbol]Hg optical clock transition (Invited) / M. Petersen ... [et al.]. Precise measurements of S-wave scattering phase shifts with a juggling atomic clock (Invited) / S. Gensemer ... [et al.]. Absolute frequency measurement of the [symbol] clock transition (Invited) / M. Chwalla ... [et al.]. The semiclassical stochastic-field/atom interaction problem (Invited) / J. Camparo. Phase and frequency noise metrology (Invited) / E. Rubiola ... [et al.]. Optical spectroscopy of atomic hydrogen for an improved determination of the Rydberg constant / J. L. Flowers ... [et al.] -- pt. III. Clock applications in space. Recent progress on the ACES mission (Invited) / L. Cacciapuoti and C. Salomon. The SAGAS mission (Invited) / P. Wolf. Small mercury microwave ion clock for navigation and radioScience (Invited) / J. D. Prestage ... [et al.]. Astro-comb: revolutionizing precision spectroscopy in astrophysics (Invited) / C. E. Kramer ... [et al.]. High frequency very long baseline interferometry: frequency standards and

  2. Voltage, Temperature, Frequency Margin Test Report

    DEFF Research Database (Denmark)

    Denver, Troelz

    1999-01-01

    The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation......The purpose of the tests is to establish the camera functionality when it is exposed to an extreme environment for prolonged periods, thus simulating the end of life performance. This environment covers temperature, input clock frequency and supply voltage variation...

  3. Temporal variation of accumulation rates on a natural salt marsh in the 20th century determined by 137Cs chronologies – the impact of sea level rise and increased inundation frequency

    DEFF Research Database (Denmark)

    Andersen, Thorbjørn Joest; Svinth, Steffen; Pejrup, Morten

    2011-01-01

    Salt marshes are potentially threatened by sea level rise if sediment supply is unable to balance the rising sea. A rapid sea level rise is one of the pronounced effects of global warming and global sea level is at present rising at an elevated rate of about 3.4 mm y-1 on average. This increasing...... rate of sea level rise should make it possible to study the effect of rapidly rising sea level on salt marsh accumulation. However, such an understanding is generally hampered by lack of available data with sufficient precision. Here we present a high-precision dataset based on detailed radiometric...... accretion has generally kept pace with sea level rise since 1963 but comparison of the accumulation rates of minerogenic material in the period 1963–1986 and 1986–2003 revealed a slight decrease in accumulation with time in spite of an observed increase in inundation frequency. The observed decrease...

  4. 用李萨如图形变化的快慢测多普勒效应中的频率差(测速)%Measuring frequency shift (speed) in Doppler effect through the variation of Lissajous figures

    Institute of Scientific and Technical Information of China (English)

    周珺; 王婷; 郭鹏

    2013-01-01

    The measurement of frequency shift was difficult in speedometer system based on Doppler effect .The application of Lissajous figures in the system was introduced .The experiment was more practical because a remote controlled toy car was used to simulate real vehicle .%针对当前利用多普勒效应测速实验中的测量频率差难的问题,通过实验发现利用李萨如图形变化的快慢测多普勒效应中的频率差,效果很好。实验中设计了使用遥控赛车模拟现实中的车辆,实验更具现实性。

  5. Evolution of the Field Entropy and Preparation of Quantum States in the Control of Atomic Motion and Field-frequency Variation%原子运动与场频率变化操控下的场熵演化及量子态制备

    Institute of Scientific and Technical Information of China (English)

    刘小娟; 文一曼; 刘敏

    2011-01-01

    In the rotating-wave approximation,the evolution of the field quantum entropy in the system that consists of a two-level atom interacting with a single-mode field was studied,considering the atomic motion and the field frequency varying with the time in the form of sine-function at the same time. In two cases of neglecting atomic motion and considering atomic motion,figures of the time evolutions of the field entropy were plotted respectively using numerical calculations. Influences of the atomic motion, the field-model structure parameter, amplitude and angular frequency of the field-frequency variation on the field entropy were also discussed. The atom-field entangled states, field rock states and atomic high fidelity states were prepared by analytic method according to the decomposition theorem of Schmidt,and the related system parameters of these quantum states operation were acquired. The results show that: the time evolution behavior of the field entropy is modulated by the frequency variation of field; the interaction between the field and atom will weaken with the increase of the amplitude of variation of the field frequency; the period of the field entropy agrees with the period of field-frequency variation; the atomic motion will result in the period of the field entropy doubled; the evolution of the field entropy is related to the parity of field-mode structure parameter; the approximate EPR states of field-atom can be prepared periodically whether the atom moves or not.%在旋波近似下,同时考虑原子运动和光场频率随时间作正弦函数变化,研究了二能级原子与单模辐射场相互作用系统中场的量子约化熵的演化规律.运用数值计算的方法分别给出了在不考虑原子的运动和考虑原子的运动的情况下场熵随时间的演化曲线,讨论了原子运动、场模结构、场频率的幅值和角频率变化对场熵的影响.根据Schmidt分解定理,解析制备了光场与原子

  6. Energy saving in the house of social interest by means of the application of the power efficiency standard:NOM-020; Ahorro de energia en la vivienda de interes social mediante la aplicacion de la norma de eficiencia energetica: NOM-020

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Jimenez, Rodolfo; Morillon Galvez, David [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2001-07-01

    In face of the urgent necessity of saving and of using in an efficient way the energy, the Secretariat of Energy (Sener) through the Comision Nacional para el Ahorro de Energia, (CONAE) (National Commission for Energy Saving) has promoted the design and application of different measures and programs of energy efficiency. The elaboration of standards of energy efficiency has been a subject of great importance to foment the adequate use of the energy resources. For the residential sector the standard first draft exists: NOM-020-ENER-1998 energy efficiency in constructions: Standard for the covering of buildings for housing up to three floors. In this study the thermal analysis of the cover of one of the house models more used in the construction of houses of social interest in Mexico. By applying the methodology proposed by the first draft of the Standard the thermal gains by conduction in roof and walls, and by radiation in windows were determined. The analysis was performed for several cities of the country with different climates, the results were compared with the values proposed in the Standard, the viability of application of this Standard in the sector of the house of social interest was analyzed and finally the energy saving in ceasing using air conditioning systems for interiors. [Spanish] Ante la imperiosa necesidad de ahorrar y usar de forma eficiente la energia, la Secretaria de Energia (Sener) a traves de la Comision Nacional para el Ahorro de Energia, (CONAE) ha promovido el diseno y aplicacion de diferentes medidas y programas de eficiencia energetica. La elaboracion de normas de eficiencia energetica ha sido un rubro de gran importancia para fomentar el uso adecuado de los recursos energeticos. Para el sector residencial existe el anteproyecto de norma: NOM-020-ENER-1998 ficiencia energetica en edificaciones: Norma para la envolvente de los edificios para uso habitacional hasta de tres pisos. En este estudio se presenta el analisis termico de la

  7. Estrategias para el ahorro de aire comprimido

    OpenAIRE

    2009-01-01

    El titular dels drets d'autor de l'article només permet la seva visualització en pantalla. Abordar el objetivo de mejorar el rendimiento de una instalación neumática pasa por minorizar el consumo y reducir las pérdidas de energía. Minorizar el consumo incluye tomar medidas encaminadas a consumir sólo cuando es necesario y a no producir en exceso. Las pérdidas de energía básicas se producen en las fugas y en los escapes libres, que ocurren en toda instalación neumática por su...

  8. Application of frequency converters in industry; Aplicacion de convertidores de frecuencia en la industria

    Energy Technology Data Exchange (ETDEWEB)

    Delmar Saavedra, Alejandro [Eficiencia Energetica, S.A. de C.V., Mexico, D. F. (Mexico)

    1999-07-01

    Next an analysis methodology for the application of a frequency converter in equipment that handles flows, as they can be pumps, fans, blowers and extractors is presented. Measurements of some practical cases that we have had in the industry are shown. Some of the types of applications in which the control of speed with the frequency converter is used, are the following ones: pumps, fans, mills, crushing machines, extruders, Banbury mixers, spinning machines, conveyors, mixers, electrical vehicles, lime furnaces, injection machines, blowers and extractors. The purpose of a frequency converter is of controlling the speed and/or torque of an electrical motor. The reasons for which a frequency converter is used can be classified, in two large fields: the necessary and those that provide energy saving. [Spanish] A continuacion se presenta una metodologia de analisis para la aplicacion de un convertidor de frecuencia en equipos que manejan flujos, como pueden ser bombas, ventiladores, sopladores y extractores. Se muestran mediciones de algunos casos practicos que hemos tenido en la industria. Algunos de los tipos de aplicaciones en donde se usa el control de velocidad con el convertidor de frecuencia, son los siguientes: bombas, ventiladores, molinos, trituradoras, extrusoras, mezcladoras banbury, maquinas de hilado, transportadoras, mezcladoras, vehiculos electricos, horno de cal, maquinas de inyeccion, sopladores y extractores. El proposito de un convertidor de frecuencia es el de controlar la velocidad y/o par en un motor electrico. Se pueden, clasificar las razones por las que se usa un convertidor de frecuencia, en dos grandes campos: las necesarias y las que proporcionan ahorros de energia.

  9. LAS CAJAS DE AHORRO Y LAS COOPERATIVAS DE CRÉDITO ANTE LA CRISIS: EVOLUCIÓN EN SU PRESENCIA TERRITORIAL Y EN SU OPERATIVA / SAVING BANKS AND CREDIT CO-OPERATIVES FACED WITH THE CRISIS: THE CHANGES IN THEIR LOCALIZATION AND PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Jesús PAÚL GUTIÉRREZ

    2010-01-01

    Full Text Available El artículo estudia el impacto que la crisis económica y financiera está teniendo en las entidades bancarias de carácter social, en especial en sus estrategias de financiación y de localización territorial. En primer lugar, se analizan las crecientes necesidades de financiación de la economía española durante el pasado ciclo expansivo y el decisivo papel de las instituciones financieras en la canalización del ahorro externo. Posteriormente, se analiza la evolución de la presencia territorial de las cajas de ahorro y de las cooperativas de crédito, así como la distribución de sus operaciones activas y pasivas. El análisis se realiza diferenciando dos períodos, uno desde el inicio de los noventa hasta el verano de 2007, momento en el que se inicia la crisis, y un segundo período, desde el cuarto trimestre de 2007 hasta la actualidad. / This paper examines the impact that the international economic and financial crisis is having on the behaviour of Spanish social banking institutions, particularly in their funding and localization strategies. First of all, we analyse the growing net borrowing of the Spanish economy in the former economic expansion cycle and how the national financial institutions were the primary source of foreign financing. Secondly, we analyse the evolution of territorial localization of saving banks and credit co-operatives, and of their lending and borrowing transactions. In this analysis we are going to difference two periods: since the beginning of nineties until August 2007, the start of the international financial, and a second period since the fourth quarter 2007 until now.

  10. Study on Somaclonal Variation of Spring Wheat

    Institute of Scientific and Technical Information of China (English)

    JIANG Shu-mei; HU Shang-lian; LI Wen-xiong

    2004-01-01

    Somaclonal variation of calli and regenerated plants of spring wheat ware detected by using technique RAPD in the study. Calli at different culture stages and regenerated plants derived from young spikes and immature embryos were used as materials. Molecular variation could be reflected from electrophoresis patternof RAPD fragments at different culture stage in calli, and in regenerated plants derived from different explants, even no phenotype variations were found. Somaclonal variation in calli and in regenerated plants appeared regularly: A higher frequency of variation in hybrids F2 was detected than that of the cultivar that is stable genetically. High variation frequency of RAPD fragments appeared in calli when cultured 75 days. The identical variations of RAPD fragments were observed in calli and in the regenerated plants induced from different genotype or explants. The variation frequency detected is higher in regenerated plants than that of in calli. RAPD could be applied easily and simply to determine variation in level of DNA at each stage cultured in vitro.

  11. Variations on tremor parameters

    Science.gov (United States)

    Boose, A.; Jentgens, Ch.; Spieker, S.; Dichgans, J.

    1995-03-01

    This paper describes our analysis procedure for long-term tremor EMG recordings, as well as three examples of applications. The description of the method focuses on how characteristics of the tremor (e.g. frequency, intensity, agonist-antagonist interaction) can be defined and calculated based on surface EMG data. The resulting quantitative characteristics are called ``tremor parameters.'' We discuss sinusoidally modulated, band-limited white noise as a model for pathological tremor-EMG, and show how the basic parameters can be extracted from this class of signals. The method is then applied to (1) estimate tremor severity in clinical studies, (2) quantify agonist-antagonist interaction, and (3) investigate the variations of the tremor parameters using simple methods from time-series analysis.

  12. Partnership concurrency and coital frequency.

    Science.gov (United States)

    Gaydosh, Lauren; Reniers, Georges; Helleringer, Stéphane

    2013-09-01

    National HIV prevalence estimates across sub-Saharan Africa range from less than 1 percent to over 25 percent. Recent research proposes several explanations for the observed variation, including prevalence of male circumcision, levels of condom use, presence of other sexually transmitted infections, and practice of multiple concurrent partnerships. However, the importance of partnership concurrency for HIV transmission may depend on how it affects coital frequency with each partner. The coital dilution hypothesis suggests that coital frequency within a partnership declines with the addition of concurrent partners. Using sexual behavior data from rural Malawi and urban Kenya, we investigate the relationship between partnership concurrency and coital frequency, and find partial support for the coital dilution hypothesis. We conclude the paper with a discussion of our findings in light of the current literature on concurrency.

  13. Frequency noise in frequency swept fiber laser

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-01-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto...

  14. Frequency noise in frequency swept fiber laser.

    Science.gov (United States)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-04-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto- optical modulators and forward propagating Brillouin scattering appear in the spectrum.

  15. Variational integrators for electric circuits

    Energy Technology Data Exchange (ETDEWEB)

    Ober-Blöbaum, Sina, E-mail: sinaob@math.upb.de [Computational Dynamics and Optimal Control, University of Paderborn (Germany); Tao, Molei [Courant Institute of Mathematical Sciences, New York University (United States); Cheng, Mulin [Applied and Computational Mathematics, California Institute of Technology (United States); Owhadi, Houman; Marsden, Jerrold E. [Control and Dynamical Systems, California Institute of Technology (United States); Applied and Computational Mathematics, California Institute of Technology (United States)

    2013-06-01

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator.

  16. Modulation of ionization on laser frequency in ultra-short pulse intense laser-gas-target

    Institute of Scientific and Technical Information of China (English)

    Hu Qiang-Lin; Liu Shi-Bing

    2006-01-01

    Based on the dispersion relation of intense laser pulse propagating in gradually ionized plasma, this paper discusses the frequency modulation induced by ionization of an ultra-short intense laser pulse interacting with a gas target.The relationship between the frequency modulation and the ionization rate, the plasmas frequency variation, and the polarization of atoms (ions) is analysed. The numerical results indicate that, at high frequency, the polarization of atoms (ions) plays a more important role than plasma frequency variation in modulating the laser frequency, and the laser frequency variation is different at different positions of the laser pulse.

  17. The effect of vibrational molecular excitation on the chirping of the pulsed single-frequency CO2 laser radiation frequency

    Energy Technology Data Exchange (ETDEWEB)

    Kozolupenko, V.P.; Kuntsevich, B.F.; Maliuta, D.D.; Mezhevov, V.S.; Strel' tsov, A.P. (Institut Atomnoi Energii, Moscow (USSR))

    1989-03-01

    The dependence of the nonresonant part of the refractive index on vibrational molecular excitation is shown to be one of the possible mechanisms responsible for the chirping of the radiation frequency of pulsed single-frequency CO{sub 2} lasers. A heterodyning method was used to record the radiation frequency variation with two receivers utilizing HgCdTe. 12 refs.

  18. Cluster analysis of word frequency dynamics

    Science.gov (United States)

    Maslennikova, Yu S.; Bochkarev, V. V.; Belashova, I. A.

    2015-01-01

    This paper describes the analysis and modelling of word usage frequency time series. During one of previous studies, an assumption was put forward that all word usage frequencies have uniform dynamics approaching the shape of a Gaussian function. This assumption can be checked using the frequency dictionaries of the Google Books Ngram database. This database includes 5.2 million books published between 1500 and 2008. The corpus contains over 500 billion words in American English, British English, French, German, Spanish, Russian, Hebrew, and Chinese. We clustered time series of word usage frequencies using a Kohonen neural network. The similarity between input vectors was estimated using several algorithms. As a result of the neural network training procedure, more than ten different forms of time series were found. They describe the dynamics of word usage frequencies from birth to death of individual words. Different groups of word forms were found to have different dynamics of word usage frequency variations.

  19. Demand as frequency controlled reserve

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z.; Togeby, M.; OEstergaard, J.

    2008-09-15

    Using demand as frequency controlled reserve (DFR) is an emerging technology which allow demand to participate actively in maintaining the system operation without reducing the energy service delivered to the customer and without need of user interaction. The basic premise is that traditional frequency controlled reserves from power plants and interconnections with neighbouring systems can be costly, slow and not fulfil the need for future power grids with a high share of wind power and fewer central power plants, and an intention to perform flexible operation such as is landing. Electricity demands, on the other hand, have advantages as frequency reserve including fast activation speed, smooth linear activation, low expected costs, and well-dispersed in the distribution grid. The main challenge of DFR is new methods for monitoring the available capacity. This project has investigated the technology of using electricity demands for providing frequency reserve to power systems. Within the project the potential and economy of DFR compatible loads in Denmark has been investigated, control logic has been designed, power system impact has been investigated, potential business models has been evaluated and an implementation strategy has been suggested. The tasks and goals of the project have been successfully accomplished based on which the conclusion and future recommendation are made. This project has developed the DFR technology that enables electricity demands to autonomously disconnect or reconnect to the grid in response to system frequency variations. The developed DFR technology is proved to be a promising technology from several perspectives. Technically, using DFR is feasible to provide reserves and enhance power system frequency control, while fulfilling technical requirements such as linear activation (or reconnection) according to frequency (or time). Environmentally, the DFR technology is pollution free in contrast to traditional reserves from generation

  20. Digital repetitive control under varying frequency conditions

    CERN Document Server

    Ramos, Germán A; Olm, Josep M

    2013-01-01

    The tracking/rejection of periodic signals constitutes a wide field of research in the control theory and applications area. Repetitive Control has proven to be an efficient way to face this topic. However, in some applications the frequency of the reference/disturbance signal is time-varying or uncertain. This causes an important performance degradation in the standard Repetitive Control scheme. This book presents some solutions to apply Repetitive Control in varying frequency conditions without loosing steady-state performance. It also includes a complete theoretical development and experimental results in two representative systems. The presented solutions are organized in two complementary branches: varying sampling period Repetitive Control and High Order Repetitive Control. The first approach allows dealing with large range frequency variations while the second allows dealing with small range frequency variations. The book also presents applications of the described techniques to a Roto-magnet plant and...

  1. Frequency dependence of lung volume changes during superimposed high-frequency jet ventilation and high-frequency jet ventilation.

    Science.gov (United States)

    Sütterlin, R; Priori, R; Larsson, A; LoMauro, A; Frykholm, P; Aliverti, A

    2014-01-01

    Superimposed high-frequency jet ventilation (SHFJV) has proved to be safe and effective in clinical practice. However, it is unclear which frequency range optimizes ventilation and gas exchange. The aim of this study was to systematically compare high-frequency jet ventilation (HFJV) with HFJV by assessing chest wall volume variations (ΔEEV(CW)) and gas exchange in relation to variable high frequency. SHFJV or HFJV were used alternatively to ventilate the lungs of 10 anaesthetized pigs (21-25 kg). The low-frequency component was kept at 16 min(-1) in SHFJV. In both modes, high frequencies ranging from 100 to 1000 min(-1) were applied in random order and ventilation was maintained for 5 min in all modalities. Chest wall volume variations were obtained using opto-electronic plethysmography. Airway pressures and arterial blood gases were measured repeatedly. SHFJV increased ΔEEV(CW) compared with HFJV; the difference ranged from 43 to 68 ml. Tidal volume (V(T)) was always >240 ml during SHFJV whereas during HFJV ranged from 92 ml at the ventilation frequency of 100 min(-1) to negligible values at frequencies >300 min(-1). We observed similar patterns for Pa(O₂) and Pa(CO₂). SHFJV provided generally higher, frequency-independent oxygenation (Pa(O₂) at least 32.0 kPa) and CO₂ removal (Pa(CO₂) ∼5.5 kPa), whereas HFJV led to hypoxia and hypercarbia at higher rates (Pa(O₂) 10 kPa at f(HF)>300 min(-1)). In a porcine model, SHFJV was more effective in increasing end-expiratory volume than single-frequency HFJV, but both modes may provide adequate ventilation in the absence of airway obstruction and respiratory disease, except for HFJV at frequencies ≥300 min(-1).

  2. Multi-frequency excitation

    KAUST Repository

    Younis, Mohammad I.

    2016-03-10

    Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi- frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

  3. Frequency selectivity at very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten

    2010-01-01

    A significant factor in the decrease of sensitivity to low-frequency sound is the helicotrema shunt effect. In humans, it causes a slope increase of the middle-ear transfer function (METF) from 6 dB/oct to 12 dB/oct below approximately 50 Hz [Marquardt et al., J.Acoust. Soc. Am. 121, 3628......-3638 (2007)]. Recent experiments showed that the exact frequency varies from individual to individual. Besides, the helicotrema region in the METF has been found to highly influence frequency selectivity for centre frequencies (CFs) below 80 Hz (Jurado and Moore in prep). By using individual METF...... in the shape of the METFs, thought to be affected by the helicotrema impedance. Preliminary analysis indicates that individual differences in the METFs might underlay the observed individual differences in frequency selectivity. Main effects predicted by the calculations are a pronounced flattening off...

  4. Variational Bayesian Inference of Line Spectra

    DEFF Research Database (Denmark)

    Badiu, Mihai Alin; Hansen, Thomas Lundgaard; Fleury, Bernard Henri

    2017-01-01

    In this paper, we address the fundamental problem of line spectral estimation in a Bayesian framework. We target model order and parameter estimation via variational inference in a probabilistic model in which the frequencies are continuous-valued, i.e., not restricted to a grid; and the coeffici......In this paper, we address the fundamental problem of line spectral estimation in a Bayesian framework. We target model order and parameter estimation via variational inference in a probabilistic model in which the frequencies are continuous-valued, i.e., not restricted to a grid...

  5. Calculus of variations

    CERN Document Server

    Elsgolc, L E; Stark, M

    1961-01-01

    Calculus of Variations aims to provide an understanding of the basic notions and standard methods of the calculus of variations, including the direct methods of solution of the variational problems. The wide variety of applications of variational methods to different fields of mechanics and technology has made it essential for engineers to learn the fundamentals of the calculus of variations. The book begins with a discussion of the method of variation in problems with fixed boundaries. Subsequent chapters cover variational problems with movable boundaries and some other problems; sufficiency

  6. Low frequency signal in the GOLF measurements

    Energy Technology Data Exchange (ETDEWEB)

    Grec, G; Provost, J; Renaud, C, E-mail: grec@obs-nice.fr [Universite de Nice-Sophia Antipolis, CNRS UMR 6202 Cassiopee, OCA (France)

    2011-01-01

    This paper shows the results obtained using a revisited method to normalize the velocity evaluation extracted from the measurements, for roughly 14 years of GOLF data. For the search of g modes, we calculate the low frequency power spectrum of the signal with 2 different approaches: - . The classical calculation of the power spectrum of the velocity signal. - . An alternative calculation, extracting first the variations along the time of the p-mode; frequencies, then calculating the power spectrum of those frequency modulation. Both spectra are compared to the g-mode frequency spectrum calculated for a solar model. Several observed frequencies are in close agreement with the calculated g modes. A careful statistical analysis of this result should now follow.

  7. External cavity diode laser with very-low frequency drift

    Science.gov (United States)

    Takamizawa, Akifumi; Yanagimachi, Shinya; Ikegami, Takeshi

    2016-03-01

    An external cavity diode laser with significant mechanical robustness was installed in a housing that was sealed from outside for eliminating variations in the refractive index of air. Using the feedback signal for a frequency lock, it was found that the variation in the laser frequency under free running was suppressed to 275 MHz over one month and depended on the room temperature. Moreover, the upper limit of the linear frequency drift rate was evaluated as intrinsically 40 Hz/s. The frequency lock is expected to be sustainable for more than 110 days with temperature-controlled housing.

  8. Heat pumping using the thermal earth gradient to produce air conditioned and hot water with savings of up to 70%; Bombeo de calor utilizando el gradiente termico de la tierra para producir aire acondicionado y agua caliente con ahorros de hasta un 70%

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Ramirez, Alejandro [Novaenergia de Mexico S.A. de C.V. (Mexico)

    2003-07-01

    The pumping of heat using the Earth heat as partial energy source bases its principle on which the energy of the ground is constant and the energy efficiency to produce air conditioning and hot water simultaneously is important, obtaining savings up to 70%, comparing itself with the traditional equipment and what these operate of separated way to produce each one of them the cold air and the hot water. The use of this technology presents an opportunity to reduce the energy costs of and the demand of the company. [Spanish] El bombeo de calor utilizando el calor de la tierra como fuente parcial de energia basa su principio en que la energia del suelo es constante y el rendimiento energetico para producir simultaneamente aire acondicionado y agua caliente es importante, obteniendose ahorros hasta de un 70%, comparandose con los equipos tradicionales y que estos operan de manera separada para producir cada uno de ellos el aire frio y el agua caliente. El uso de esta tecnologia presenta una oportunidad para reducir los costos de energia y demanda de la empresa.

  9. Hyperfine phononic frequency comb

    CERN Document Server

    Ganesan, Adarsh; Seshia, Ashwin A

    2016-01-01

    Optical frequency combs [1-8] have resulted in significant advances in optical frequency metrology and found wide application to precise physical measurements [1-4, 9] and molecular fingerprinting [8]. A direct analogue of frequency combs in the phononic or acoustic domain has not been reported to date. In this letter, we report the first clear experimental evidence for a phononic frequency comb. In contrast to the Kerr nonlinearity [10] in optical frequency comb formation, the phononic frequency comb is generated through the intrinsic coupling of a driven phonon mode with an auto-parametrically excited sub-harmonic mode [16]. Through systematic experiments at different drive frequencies and amplitudes, we portray the well-connected process of phononic frequency comb formation and define attributes to control the features [17-18] associated with comb formation in such a system. Further, the interplay between these nonlinear resonances and the well-known Duffing phenomenon [12-14] is also observed. The present...

  10. Seasonal variation in dust events and the causes of the variation in the Tarim Basin,China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    We analyzed dust event occurrence and its seasonal distribution at 16 sites in the Tarim Basin,China.Although the overall frequency of dust events was the highest in spring in this region,its variation in other seasons could be classified into three patterns:(1) frequency of dust events in autumn > that in summer > that in winter(at the Kashi and Kuche sites);(2) frequency in summer > that in winter > that in autumn(at the Ruoqiang site);and(3) frequency in summer > that in autumn > that in winter(at all other areas of the Tarim Basin).The frequency of dust events and their seasonal variations in the Tarim Basin were mainly controlled by wind speed and locally available dust sources;the former was the key control when dust sources did not differ significantly.The seasonal variation in evaporation had a smaller,but still significant effect on the frequency of dust events.

  11. Static electromagnetic frequency changers

    CERN Document Server

    Rozhanskii, L L

    1963-01-01

    Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work

  12. Modeling Frequency Comb Sources

    Directory of Open Access Journals (Sweden)

    Li Feng

    2016-06-01

    Full Text Available Frequency comb sources have revolutionized metrology and spectroscopy and found applications in many fields. Stable, low-cost, high-quality frequency comb sources are important to these applications. Modeling of the frequency comb sources will help the understanding of the operation mechanism and optimization of the design of such sources. In this paper,we review the theoretical models used and recent progress of the modeling of frequency comb sources.

  13. Eastern Frequency Response Study

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

    2013-05-01

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  14. A global reference for human genetic variation

    DEFF Research Database (Denmark)

    Auton, Adam; Abecasis, Goncalo R.; M. Altshuler, David;

    2015-01-01

    insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. This resource includes >99% of SNP variants with a frequency of >1% for a variety of ancestries. We describe the distribution of genetic variation across the global sample, and discuss the implications...

  15. Frequency selective infrared sensors

    Science.gov (United States)

    Davids, Paul; Peters, David W

    2013-05-28

    A frequency selective infrared (IR) photodetector having a predetermined frequency band. The exemplary frequency selective photodetector includes: a dielectric IR absorber having a first surface and a second surface substantially parallel to the first surface; an electrode electrically coupled to the first surface of the dielectric IR absorber; and a frequency selective surface plasmonic (FSSP) structure formed on the second surface of the dielectric IR absorber. The FSSP structure is designed to selectively transmit radiation in the predetermined frequency band that is incident on the FSSP structure substantially independent of the angle of incidence of the incident radiation on the FSSP structure.

  16. Functions of bounded variation

    OpenAIRE

    Lind, Martin

    2006-01-01

    The paper begins with a short survey of monotone functions. The functions of bounded variation are introduced and some basic properties of these functions are given. Finally the jump function of a function of bounded variation is defined.

  17. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  18. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  19. Variational Bayesian Inference of Line Spectra

    DEFF Research Database (Denmark)

    Badiu, Mihai Alin; Hansen, Thomas Lundgaard; Fleury, Bernard Henri

    2016-01-01

    In this paper, we address the fundamental problem of line spectral estimation in a Bayesian framework. We target model order and parameter estimation via variational inference in a probabilistic model in which the frequencies are continuous-valued, i.e., not restricted to a grid; and the coeffici......In this paper, we address the fundamental problem of line spectral estimation in a Bayesian framework. We target model order and parameter estimation via variational inference in a probabilistic model in which the frequencies are continuous-valued, i.e., not restricted to a grid......; and the coefficients are governed by a Bernoulli-Gaussian prior model turning model order selection into binary sequence detection. Unlike earlier works which retain only point estimates of the frequencies, we undertake a more complete Bayesian treatment by estimating the posterior probability density functions (pdfs...

  20. Frequency correlates in grapheme-color synaesthesia.

    Science.gov (United States)

    Beeli, Gian; Esslen, Michaela; Jäncke, Lutz

    2007-09-01

    Individuals with synaesthesia experience certain stimuli in more than one sensory modality. Most common is the linkage of letters and digits (graphemes) to colors. Whereas synaesthesia might be partly genetically determined, the linkages to specific colors are assumed to be learned. We present a systematic statistical analysis of synaesthetic color perception based on subjects' reproduction of individual colors for each grapheme, instead of simple verbal categorizations. The statistical analysis revealed that the color perceptions, measured with the HSL (hue, saturation, and luminance) scale, varied systematically among the different digits and letters. The frequencies of the digits and letters (in the German language) partly explained these systematic variations. However, digit frequency was more strongly related to color perception in the synaesthetes than was letter frequency. The results for digit and letter frequency indicate that experience with graphemes may shape synaesthetic color perception.

  1. Radio frequency detection assembly and method for detecting radio frequencies

    Science.gov (United States)

    Cown, Steven H.; Derr, Kurt Warren

    2010-03-16

    A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.

  2. Observer variations in short period spectral analysis of heart rate variability.

    Science.gov (United States)

    van Schelven, L J; Oey, P L; Klein, I H; Barnas, M G; Blankestijn, P J; Wieneke, G H

    2000-03-15

    25% of the corresponding mean LF/HF ratio. The smallest interobserver variations were found for the 'fixed frequency' method. The data showed that it is advantageous to select the 3-min ECG periods but not to select the frequency regions. Selection of the latter led to an increase in interobserver variation. The results of this study give a realistic impression of the intrasubject and interobserver variation to be expected when measuring the LF/HF ratio. This variation is considerable.

  3. Waveform frequency notching

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W.; Andrews, John

    2017-05-09

    The various technologies presented herein relate to incorporating one or more notches into a radar spectrum, whereby the notches relate to one or more frequencies for which no radar transmission is to occur. An instantaneous frequency is monitored and if the frequency is determined to be of a restricted frequency, then a radar signal can be modified. Modification can include replacing the signal with a signal having a different instantaneous amplitude, a different instantaneous phase, etc. The modification can occur in a WFS prior to a DAC, as well as prior to a sin ROM component and/or a cos ROM component. Further, the notch can be dithered to enable formation of a deep notch. The notch can also undergo signal transitioning to enable formation of a deep notch. The restricted frequencies can be stored in a LUT against which an instantaneous frequency can be compared.

  4. Universal Optical Frequency Comb

    CERN Document Server

    Savchenkov, A A; Liang, W; Ilchenko, V S; Seidel, D; Maleki, L

    2010-01-01

    We demonstrate that whispering gallery mode resonators can be utilized to generate optical frequency combs based on four wave mixing process at virtually any frequency that lies in the transparency window of the resonator host material. We show theoretically how the morphology of the resonator can be engineered to produce a family of spectrally equidistant modes with anomalous group velocity dispersion appropriate for the comb generation. We present experimental results for a frequency comb centered at 794 nm to support our theoretical findings.

  5. Probability and Relative Frequency

    Science.gov (United States)

    Drieschner, Michael

    2016-01-01

    The concept of probability seems to have been inexplicable since its invention in the seventeenth century. In its use in science, probability is closely related with relative frequency. So the task seems to be interpreting that relation. In this paper, we start with predicted relative frequency and show that its structure is the same as that of probability. I propose to call that the `prediction interpretation' of probability. The consequences of that definition are discussed. The "ladder"-structure of the probability calculus is analyzed. The expectation of the relative frequency is shown to be equal to the predicted relative frequency. Probability is shown to be the most general empirically testable prediction.

  6. Frequency Response Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Etingov, Pavel V.; Kosterev, Dmitry; Dai, T.

    2014-12-31

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  7. Frequency Response Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

  8. Optimization of frequency quantization

    CERN Document Server

    Tibabishev, V N

    2011-01-01

    We obtain the functional defining the price and quality of sample readings of the generalized velocities. It is shown that the optimal sampling frequency, in the sense of minimizing the functional quality and price depends on the sampling of the upper cutoff frequency of the analog signal of the order of the generalized velocities measured by the generalized coordinates, the frequency properties of the analog input filter and a maximum sampling rate for analog-digital converter (ADC). An example of calculating the frequency quantization for two-tier ADC with an input RC filter.

  9. On the contribution of sunspots to the observed frequency shifts of solar acoustic modes

    CERN Document Server

    Santos, A R G; Avelino, P P; Chaplin, W J; Campante, T L

    2016-01-01

    Activity-related variations in the solar oscillation properties have been known for 30 years. However, the relative importance of the different contributions to the observed variations is not yet fully understood. Our goal is to estimate the relative contribution from sunspots to the observed activity-related variations in the frequencies of the acoustic modes. We use a variational principle to relate the phase differences induced by sunspots on the acoustic waves to the corresponding changes in the frequencies of the global acoustic oscillations. From the sunspot properties (area and latitude as a function of time), we are able to estimate the spot-induced frequency shifts. These are then combined with a smooth frequency shift component, associated with long-term solar-cycle variations, and the results compared with the frequency shifts derived from the Global Oscillation Network Group (GONG) data. The result of this comparison is consistent with a sunspot contribution to the observed frequency shifts of rou...

  10. Dual-Frequency Operation of Bow-Tie Microstrip Antenna

    Institute of Scientific and Technical Information of China (English)

    钟顺时; 张需溥

    2005-01-01

    Characteristics of a single-feed dual-frequency bow-tie microstrip antenna are studied. By using the variation method, simple formulas for resonant frequencies of the bow-tie microstrip antenna are derived. It is shown that the dual-frequency ratio can be controlled easily by choosing the parameters of the antenna. This design gives compact antenna size and simple antenna structure. Experimental results are presented, verifying the validity of the design.

  11. Absolute distance measurement using frequency-sweeping heterodyne interferometer calibrated by an optical frequency comb.

    Science.gov (United States)

    Wu, Xuejian; Wei, Haoyun; Zhang, Hongyuan; Ren, Libing; Li, Yan; Zhang, Jitao

    2013-04-01

    We present a frequency-sweeping heterodyne interferometer to measure an absolute distance based on a frequency-tunable diode laser calibrated by an optical frequency comb (OFC) and an interferometric phase measurement system. The laser frequency-sweeping process is calibrated by the OFC within a range of 200 GHz and an accuracy of 1.3 kHz, which brings about a precise temporal synthetic wavelength of 1.499 mm. The interferometric phase measurement system consisting of the analog signal processing circuit and the digital phase meter achieves a phase difference resolution better than 0.1 deg. As the laser frequency is sweeping, the absolute distance can be determined by measuring the phase difference variation of the interference signals. In the laboratory condition, our experimental scheme realizes micrometer accuracy over meter distance.

  12. LA EXPANSIÓN TERRITORIAL COMO FACTOR MOTIVADOR DE LA REESTRUCTURACIÓN DEL SISTEMA FINANCIERO ESPAÑOL: EL CASO DE LAS CAJAS DE AHORROS Y LAS COOPERATIVAS DE CRÉDITO / THE TERRITORIAL EXPANSION AS A MOTIVATING FACTOR OF THE RESTRUCTURING OF THE SPANISH FINANCIAL SYSTEM: THE CASE OF SAVING BANKS AND CREDIT COOPERATIVES

    Directory of Open Access Journals (Sweden)

    Milagros GUTIÉRREZ FERNÁNDEZ

    2012-01-01

    Full Text Available La actual crisis financiera internacional está actuando como catalizador de un profundo proceso de cambio en el sector bancario español que está afectando también a las entidades de crédito de la Economía Social: cajas de ahorros y cooperativas de crédito. Su modelo de banca “minorista”, centrada en la cercanía al cliente, se ha visto acompañado en los últimos años de un fuerte proceso de expansión geográfica que ha supuesto un sobredimensionamiento de su red de sucursales. Sin embargo, como consecuencia de las actuales circunstancias de la economía española en general, y del sistema bancario en particular, dicha estrategia de desarrollo interno no parece sostenible, siendo necesario que se produzca un redimensionamiento del sector, para ver recuperada la confianza en el sistema y para que éste vuelva a ser considerado como uno de los más solventes del mundo. Bajo este enfoque, el objetivo de este trabajo es analizar las distintas estrategias de expansión territorial desarrolladas por dichas entidades con el objetivo de plasmar su situación actual y comprender por qué es necesaria la reestructuración del sector. Para ello se ha empleado tanto el análisis descriptivo como el econométrico, utilizando en todo momento los datos que presentan la Confederación Española de Cajas de Ahorros (CECA y la Unión Nacional de Cooperativas de Crédito (UNACC en sus anuarios estadísticos. / The current financial international crisis is acting as catalyst of a deep process of change in the Spanish banking sector which is affecting also the credit institutions of the Social Economy: saving banks and credit cooperatives. These entities share a model of "retail" banking, centered on the nearness to the client, that has been accompanied in the last years of a strong process of geographical expansion which has supposed an oversizing of its network of branches. Nevertheless, as a consequence of the current circumstances of the Spanish

  13. Reducción del Consumo Eléctrico y C0(2 mediante Sistemas de Ahorro y de Aislamiento Térmico aplicados a Viviendas en Zonas Áridas de México Electrical Consumption and C0(2 Reduction using Saving Systems and Thermal Insulation applied to Dwellings in Arid Lands of México

    Directory of Open Access Journals (Sweden)

    Roberto Calderón

    2011-01-01

    Full Text Available Se compara los consumos de energía de dos tipos de vivienda, eficiente e ineficiente, determinando su consumo eléctrico y reducción de C0(2, utilizando aislamiento térmico y sistemas de ahorro de energía. El estudio realizado mediante simulación se aplica a tres ciudades áridas de México: Mexicali, Ciudad Obregón y Hermosillo. De la vivienda ineficiente evaluada en las tres ciudades, Mexicali, registró los índices más altos con 7.014 kWh/año, impactando directamente sobre el ingreso familiar, los rangos de confort y la calidad de vida del usuario, además de aportar una cantidad de 4.88 toneladas de emisiones de C0(2 por vivienda al año. Estos indicadores pueden llegar a reducirse en entre el 40 y 50% si la vivienda es eficiente.The energy consumption of two types of dwellings, efficient and inefficient, are analyzed and compared, determining the electrical consumption and C0(2 reduction, utilizing thermal insulation and saving-energy options. The study done by simulation was applied in three arid áreas in México: Mexicali, Baja Obregón and Hermosillo. The results indícate that Mexicali presented the highest consumptions rates with 7.104 kWh/year, affecting directly the family household income, thermal comfort and life quality, besides providing 4.88 tons of C0(2 emission per house per year. These indexes can be reduced by 40 and 50% if the house is efficient.

  14. Energy saving based on the reduction of losses in the transmission and distribution of the power generated incrementing the transmission capacities by means of the use of direct current; Ahorro de energia basado en la reduccion de perdidas en la transmision y redistribucion de la generacion al ampliar las capacidades de transmision por medio del empleo de la transmision en corriente directa

    Energy Technology Data Exchange (ETDEWEB)

    Meraz Ateca, E.; Alanis Rodriguez, J.P.; Salinas Barrera, H.; Arechiga Rodriguez, L.D.; Guerrero Garza, J.J. [Comision Federal de Electricidad (CFE) (Mexico)

    1995-12-31

    alternating current terminal is recovered from the power lines and there will not be generation restrictions because of the unavailability of alternating current power lines; the achieved reliability is not evaluated, but it will be another benefit. The other option proposed for the project of utilization of power lines with direct current, consists in modifying or using the tie that will be constructed for the Rio Escondido Thermal Electric Station to the Northern Zone and that will operate in parallel with the alternating current network. This project provides the benefits of saving losses of about 20 MW. It is also achieved the increase in effective transmission capacity towards the Northern Zone, due to the fact that it will be Also available a controlled power mean, which facilitates the dispatch functions and re-distribution of power flows in the alternating current network. This tie is proposed of 500 MW operating in bi-polar form at least of 400 KV and reaching up to the Chihuahua Zone, allowing besides the re-dispatching of units to the Northern Zone in counting with greater capacity of effective transmission. The saving in re-dispatching could be significative; additionally, this tie will free transmission capacity from the Coal Power Stations towards the Monterrey Zone. This paper does not get deeper into the advantages regarding the dynamic behavior of the electric system in operating these ties in direct current, but they are not less important, since they can contribute with great benefits to the system during disturbance or emergency conditions. [Espanol] El presenta trabajo propone el empleo de la tecnologia de transmision en corriente directa, que proporciona un ahorro de perdidas de orden del 50% al transmitir la misma cantidad de potencia que la linea energizada en corriente alterna, asi como el contar con una mayor capacidad de transmision, dado que la limitante en la linea trabajando en corriente directa esta dada por su capacidad termica. El aspecto del

  15. Program integration at JVC Industrial de Mexico, S.A. de C.V./Electric energy saving/Environmental management system /ISO 14001 standard; Integracion de programas en JVC Industrial de Mexico, S.A. de C.V. Ahorro de energia electrica/Sistema de administracion ambiental/Estandar ISO 14001

    Energy Technology Data Exchange (ETDEWEB)

    Argote Molina, Martin [JVC Industrial de Mexico S. A. de C. V., Tijuana (Mexico)

    1998-12-31

    It is possible, and besides logic, the integration of programs such as the electric energy saving and an environmental management system. In managing the consumption and the demand of the electric service, there is an effect on the pollutants emitted for the generation. It is clear that the user in not, and can not be, responsible for the type of fuel used but its importance in project planning is out of question. In its turn the central point of the environmental management system, consists in identifying the main effects on the environment caused by its activities, services and products, as well as the current or potential control level of the enterprise on them. Such identification and further evaluation took us at JVC Industrial de Mexico, to integrate conceptually and operationally such programs. The commitment with the Management was concentrated and strengthened resulting in a fuller consciousness of resource administration. [Espanol] Es posible, ademas de logica, la integracion de programas tales como el ahorro de energia electrica y un sistema de administracion ambiental. Al administrar el consumo y la demanda del servicio electrico tenemos un efecto en los contaminantes emitidos para la generacion. Es claro que el usuario no es, ni puede ser, responsable del tipo de combustible utilizado pero su importancia en la planeacion de proyectos es indiscutible. A su vez el punto central del sistema de administracion ambiental, consiste en identificar los principales efectos en el medio ambiente causados por sus actividades, servicios o productos, asi como el nivel de control actual o potencial de la empresa sobre ellos. Dicha identificacion y la posterior evaluacion nos llevo, en JVC Industrial de Mexico, a integrar tanto conceptual como operacionalmente dichos programas. El compromiso de la Gerencia se vio concentrado y fortalecido dando como resultado una conciencia mas plena de la administracion de recursos.

  16. Variation of fundamental constants

    CERN Document Server

    Flambaum, V V

    2006-01-01

    We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

  17. Microfabricated ion frequency standard

    Science.gov (United States)

    Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.

    2010-12-28

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  18. Breakfast frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Damsgaard, Mogens Trab

    2016-01-01

    , quality of family communication and family support. Further, analyses suggested that the associations were more pronounced among girls, immigrants and adolescents from other family structure than traditional. The study highlights the importance of the family setting in promoting regular breakfast......OBJECTIVE: To investigate (i) associations between adolescents' frequency of breakfast and family functioning (close relations to parents, quality of family communication and family support) and (ii) if any observed associations between breakfast frequency and family functioning vary...... (n 3054) from a random sample of forty-one schools. RESULTS: Nearly one-quarter of the adolescents had low breakfast frequency. Low breakfast frequency was associated with low family functioning measured by three dimensions. The OR (95 % CI) of low breakfast frequency was 1·81 (1·40, 2...

  19. Coordinated Fast Primary Frequency Control from Offshore Wind Power Plants in MTDC System

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio

    2016-01-01

    In this paper, coordinated fast primary frequency control (FPFC) from offshore wind power plants (OWPPs) integrated to surrounding onshore AC power system through a three terminal VSC HVDC system is presented. The onshore AC grid frequency variations are emulated at offshore AC grid through...... and the dynamics of wind turbine are also discussed. The corresponding impact of OWPPs active power output variation at different wind speeds on the power system frequency control and DC grid voltage is also presented. The results show that the proposed coordinated fast primary frequency control from OWPPs...... improves the power system frequency while relieving the stress on the other AC grid participating in frequency control....

  20. Calculus of variations

    CERN Document Server

    Gelfand, I M

    2000-01-01

    Based on a series of lectures given by I. M. Gelfand at Moscow State University, this book actually goes considerably beyond the material presented in the lectures. The aim is to give a treatment of the elements of the calculus of variations in a form both easily understandable and sufficiently modern. Considerable attention is devoted to physical applications of variational methods, e.g., canonical equations, variational principles of mechanics, and conservation laws.The reader who merely wishes to become familiar with the most basic concepts and methods of the calculus of variations need on

  1. Anatomic variation and orgasm: Could variations in anatomy explain differences in orgasmic success?

    Science.gov (United States)

    Emhardt, E; Siegel, J; Hoffman, L

    2016-07-01

    Though the public consciousness is typically focused on factors such as psychology, penis size, and the presence of the "G-spot," there are other anatomical and neuro-anatomic differences that could play an equal, or more important, role in the frequency and intensity of orgasms. Discovering these variations could direct further medical or procedural management to improve sexual satisfaction. The aim of this study is to review the available literature of anatomical sexual variation and to explain why this variation may predispose some patients toward a particular sexual experience. In this review, we explored the available literature on sexual anatomy and neuro-anatomy. We used PubMed and OVID Medline for search terms, including orgasm, penile size variation, clitoral variation, Grafenberg spot, and benefits of orgasm. First we review the basic anatomy and innervation of the reproductive organs. Then we describe several anatomical variations that likely play a superior role to popular known variation (penis size, presence of g-spot, etc). For males, the delicate play between the parasympathetic and sympathetic nervous systems is vital to achieve orgasm. For females, the autonomic component is more complex. The clitoris is the primary anatomical feature for female orgasm, including its migration toward the anterior vaginal wall. In conclusions, orgasms are complex phenomena involving psychological, physiological, and anatomic variation. While these variations predispose people to certain sexual function, future research should explore how to surgically or medically alter these. Clin. Anat. 29:665-672, 2016. © 2016 Wiley Periodicals, Inc.

  2. Seismic noise level variation in South Korea

    Science.gov (United States)

    Sheen, D.; Shin, J.

    2008-12-01

    The variations of seismic background noise in South Korea have been investigated by means of power spectral analysis. The Korea Institute of Geoscience and Mineral Resources (KIGAM) and the Korea Meteorological Administation (KMA) have national wide seismic networks in South Korea, and, in the end of 2007, there are 30 broadband stations which have been operating for more than a year. In this study, we have estimated the power spectral density of seismic noise for 30 broadband stations from 2005 to 2007. Since we estimate PSDs from a large dataset of continuous waveform in this study, a robust PSD estimate of McNamara and Buland (2004) is used. In the frequency range 1-5 Hz, the diurnal variations of noise are observed at most of stations, which are especially larger at coastal stations and at insular than at inland. Some stations shows daily difference of diurnal variations, which represents that cultural activities contribute to the noise level of a station. The variation of number of triggered stations, however, shows that cultural noise has little influence on the detection capability of seismic network in South Korea. Seasonal variations are observed well in the range 0.1-0.5 Hz, while much less found in the frequency range 1-5 Hz. We observed that strong peaks in the range 0.1-0.5 Hz occur at the summer when Pacific typhoons are close to the Korean Peninsula.

  3. GENERALIZED VARIATIONAL OPTIMAZATION ANALYSIS FOR 2-D FLOW FIELD

    Institute of Scientific and Technical Information of China (English)

    HUANG Si-xun; XU Ding-hua; LAN Wei-ren; TENG Jia-jun

    2005-01-01

    The Variational Optimization Analysis Method (VOAM) for 2-D flow field suggested by Sasaki was reviewed first. It is known that the VOAM can be used efficiently in most cases. However, in the cases where there are high frequency noises in 2-D flow field, it appears to be inefficient. In the present paper, based on Sasaki's VOAM, a Generalized Variational Optimization Analysis Method (GVOAM) was proposed with regularization ideas, which could deal well with flow fields containing high frequency noises. A numerical test shows that observational data can be both variationally optimized and filtered, and therefore the GVOAM is an efficient method.

  4. Frequency comb swept lasers.

    Science.gov (United States)

    Tsai, Tsung-Han; Zhou, Chao; Adler, Desmond C; Fujimoto, James G

    2009-11-09

    We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep rate of 1kHz and 120kHz, respectively over a 135nm tuning range centered at 1310nm with average output powers of 50mW. A 25GHz free spectral range frequency comb filter in the swept lasers causes the lasers to generate a series of well defined frequency steps. The narrow bandwidth (0.015nm) of the frequency comb filter enables a approximately -1.2dB sensitivity roll off over approximately 3mm range, compared to conventional swept source and FDML lasers which have -10dB and -5dB roll offs, respectively. Measurements at very long ranges are possible with minimal sensitivity loss, however reflections from outside the principal measurement range of 0-3mm appear aliased back into the principal range. In addition, the frequency comb output from the lasers are equally spaced in frequency (linear in k-space). The filtered laser output can be used to self-clock the OCT interference signal sampling, enabling direct fast Fourier transformation of the fringe signals, without the need for fringe recalibration procedures. The design and operation principles of FC swept lasers are discussed and designs for short cavity lasers for OCT and interferometric measurement applications are proposed.

  5. Copernicus observations of Iota Herculis velocity variations

    Science.gov (United States)

    Rogerson, J. B., Jr.

    1984-01-01

    Observations of Iota Her at 109.61-109.67 nm obtained with the U1 channel of the Copernicus spectrophotometer at resolution 5 pm during 3.6 days in May, 1979, are reported. Radial-velocity variations are detected and analyzed as the sum of two sinusoids with frequencies 0.660 and 0.618 cycles/day and amplitudes 9.18 and 8.11 km/s, respectively. Weak evidence supporting the 13.9-h periodicity seen in line-profile variations by Smith (1978) is found.

  6. Broadband frequency conversion

    DEFF Research Database (Denmark)

    Sanders, Nicolai Højer; Jensen, Ole Bjarlin; Dam, Jeppe Seidelin;

    that ensures phase matching over a broad spectral range in the BBO crystal. Since the tuning mechanism relies on all-passive components with extremely short response times the proposed method is well suited for short pulse, broad bandwidth laser sources like mode-locked lasers or super-continuum sources......We demonstrate a method for frequency conversion of broadly tunable or broad bandwidth light in a static, passive setup. Using simple optical components like lenses, mirrors and gratings and a BiBO crystal as the nonlinear material, we are able to frequency double a single-frequency, tunable...

  7. Quantum frequency downconversion experiment

    CERN Document Server

    Takesue, Hiroki

    2010-01-01

    We report the first quantum frequency downconversion experiment. Using the difference frequency generation process in a periodically poled lithium niobate waveguide, we successfully observed the phase-preserved frequency downconversion of a coherent pulse train with an average photon number per pulse of $<$1, from the 0.7-$\\mu$m visible wavelength band to the 1.3-$\\mu$m telecom band. We expect this technology to become an important tool for flexible photonic quantum networking, including the realization of quantum repeater systems over optical fiber using atom-photon entanglement sources for the visible wavelength bands.

  8. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  9. Ladder Variational Autoencoder

    DEFF Research Database (Denmark)

    Sønderby, Casper Kaae; Raiko, Tapani; Maaløe, Lars

    2016-01-01

    Variational autoencoders are powerful models for unsupervised learning. However deep models with several layers of dependent stochastic variables are difficult to train which limits the improvements obtained using these highly expressive models. We propose a new inference model, the Ladder Variat...

  10. Variation of Fundamental Constants

    Science.gov (United States)

    Flambaum, V. V.

    2006-11-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra. Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance.

  11. Genetic variation in variability

    NARCIS (Netherlands)

    Mulder, Herman; Gienapp, Phillip; Visser, Marcel E.

    2016-01-01

    Variation in traits is essential for natural selection to operate and genetic and environmental effects can contribute to this phenotypic variation. From domesticated populations, we know that families can differ in their level of within-family variance, which leads to the intriguing situation th

  12. Physiology of biological variation

    NARCIS (Netherlands)

    Schouten, R.E.

    2004-01-01

    In agricultural products, variation exists in quality attributes between batches. Examples of this biological variation are well known and the general response is trying to suppress it as much as possible; to create uniformity using pre- andpostharvestmethods. This thesis

  13. Natural transformation and phase variation modulation in Neisseria meningitidis.

    Science.gov (United States)

    Alexander, Heather L; Richardson, Anthony R; Stojiljkovic, Igor

    2004-05-01

    Neisseria meningitidis has evolved the ability to control the expression-state of numerous genes by phase variation. It has been proposed that the process aids this human pathogen in coping with the diversity of microenvironments and host immune systems. Therefore, increased frequencies of phase variation may augment the organism's adaptability and virulence. In this study, we found that DNA derived from various neisserial co-colonizers of the human nasopharynx increased N. meningitidis switching frequencies, indicating that heterologous neisserial DNA modulates phase variation in a transformation-dependent manner. In order to determine whether the effect of heterologous DNA was specific to the Hb receptor, HmbR, we constructed a Universal Rates of Switching cassette (UROS). With this cassette, we demonstrated that heterologous DNA positively affects phase variation throughout the meningococcal genome, as UROS phase variation frequencies were also increased in the presence of neisserial DNA. Overexpressing components of the neisserial mismatch repair system partially alleviated DNA-induced changes in phase variation frequencies, thus implicating mismatch repair titration as a cause of these transformation-dependent increases in switching. The DNA-dependent effect on phase variation was transient and may serve as a mechanism for meningococcal genetic variability that avoids the fitness costs encountered by global mutators.

  14. Total variation regularization with bounded linear variations

    Science.gov (United States)

    Makovetskii, Artyom; Voronin, Sergei; Kober, Vitaly

    2016-09-01

    One of the most known techniques for signal denoising is based on total variation regularization (TV regularization). A better understanding of TV regularization is necessary to provide a stronger mathematical justification for using TV minimization in signal processing. In this work, we deal with an intermediate case between one- and two-dimensional cases; that is, a discrete function to be processed is two-dimensional radially symmetric piecewise constant. For this case, the exact solution to the problem can be obtained as follows: first, calculate the average values over rings of the noisy function; second, calculate the shift values and their directions using closed formulae depending on a regularization parameter and structure of rings. Despite the TV regularization is effective for noise removal; it often destroys fine details and thin structures of images. In order to overcome this drawback, we use the TV regularization for signal denoising subject to linear signal variations are bounded.

  15. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  16. Microwave Radiometer - high frequency

    Data.gov (United States)

    Oak Ridge National Laboratory — The Microwave Radiometer-High Frequency (MWRHF) provides time-series measurements of brightness temperatures from two channels centered at 90 and 150 GHz. These two...

  17. FPGA IMPLEMENTATION OF LOW POWER DIGITAL FREQUENCY

    Directory of Open Access Journals (Sweden)

    K. R. Rekha,

    2010-10-01

    Full Text Available In this Paper we are presenting a new FPGA approach to design an optimized use a Digital Frequency Synthesizer (DDFS in our system to generate a sampled sinusoidal wave of frequency. The major advantage of Digital Frequency Synthesizer (DFS is that its output frequency, phase and amplitude can be precisely and rapidly manipulated under the control of a DSP. Other inherent DFS attributes include the ability to tune with extremely fine frequency and phase resolution and to rapidly “hop” between the frequencies. These combined characteristics have made this technology popular in military, radar and communications systems. The digital circuits used to implementsignal processing functions do not suffer the effects of thermal drifts, aging and component variations associated with their analog counterparts. The implementation of digital functional blocks makes it possible to achieve a high degree of system integration. Recent advances in IC fabrication technology, particularly the CMOS technology coupled with advanced DSP algorithms and architectures provide possible single chip solutions to complex communication and signal processing sub-systems such as modulators, demodulators, local oscillators, and programmable clock generators, cellular base stations, up converters, down converters, power line communication,wireless local loop base stations etc .

  18. Variation tolerant SoC design

    Science.gov (United States)

    Kozhikkottu, Vivek J.

    The scaling of integrated circuits into the nanometer regime has led to variations emerging as a primary concern for designers of integrated circuits. Variations are an inevitable consequence of the semiconductor manufacturing process, and also arise due to the side-effects of operation of integrated circuits (voltage, temperature, and aging). Conventional design approaches, which are based on design corners or worst-case scenarios, leave designers with an undesirable choice between the considerable overheads associated with over-design and significantly reduced manufacturing yield. Techniques for variation-tolerant design at the logic, circuit and layout levels of the design process have been developed and are in commercial use. However, with the incessant increase in variations due to technology scaling and design trends such as near-threshold computing, these techniques are no longer sufficient to contain the effects of variations, and there is a need to address variations at all stages of design. This thesis addresses the problem of variation-tolerant design at the earliest stages of the design process, where the system-level design decisions that are made can have a very significant impact. There are two key aspects to making system-level design variation-aware. First, analysis techniques must be developed to project the impact of variations on system-level metrics such as application performance and energy. Second, variation-tolerant design techniques need to be developed to absorb the residual impact of variations (that cannot be contained through lower-level techniques). In this thesis, we address both these facets by developing robust and scalable variation-aware analysis and variation mitigation techniques at the system level. The first contribution of this thesis is a variation-aware system-level performance analysis framework. We address the key challenge of translating the per-component clock frequency distributions into a system-level application

  19. Estimating quadratic variation using realized variance

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    This paper looks at some recent work on estimating quadratic variation using realized variance (RV) - that is, sums of M squared returns. This econometrics has been motivated by the advent of the common availability of high-frequency financial return data. When the underlying process is a semimar......This paper looks at some recent work on estimating quadratic variation using realized variance (RV) - that is, sums of M squared returns. This econometrics has been motivated by the advent of the common availability of high-frequency financial return data. When the underlying process...... have to impose some weak regularity assumptions. We illustrate the use of the limit theory on some exchange rate data and some stock data. We show that even with large values of M the RV is sometimes a quite noisy estimator of integrated variance. Copyright © 2002 John Wiley & Sons, Ltd....

  20. Frequency Bandwidth Optimization of Left-Handed Metamaterial

    Science.gov (United States)

    Chevalier, Christine T.; Wilson, Jeffrey D.

    2004-01-01

    Recently, left-handed metamaterials (LHM s) have been demonstrated with an effective negative index of refraction and with antiparallel group and phase velocities for microwave radiation over a narrow frequency bandwidth. In order to take advantage of these characteristics for practical applications, it will be beneficial to develop LHM s with increased frequency bandwidth response and lower losses. In this paper a commercial three-dimensional electromagnetic simulation code is used to explore the effects of geometry parameter variations on the frequency bandwidth of a LHM at microwave frequencies. Utilizing an optimizing routine in the code, a geometry was generated with a bandwidth more than twice as large as the original geometry.

  1. SEMICONDUCTOR INTEGRATED CIRCUITS: A low power fast-settling frequency-presetting PLL frequency synthesizer

    Science.gov (United States)

    Zhiqing, Geng; Xiaozhou, Yan; Wenfeng, Lou; Peng, Feng; Nanjian, Wu

    2010-08-01

    This work presents the design and implementation of a 2.4 GHz low power fast-settling frequency-presetting PLL frequency synthesizer in the 0.18 μm CMOS process. A low power mixed-signal LC VCO, a low power dual mode prescaler and a digital processor with non-volatile memory are developed to greatly reduce the power consumption and the setting time. The digital processor can automatically calibrate the presetting frequency and accurately preset the frequency of the VCO under process variations. The experimental results demonstrate that the power consumption of the synthesizer is about 4 mA @ 1.8 V and that the typical setting time of the synthesizer is less than 3 μs.

  2. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  3. Porosity variation in chalk

    DEFF Research Database (Denmark)

    Lind, Ida; Grøn, Peter

    1996-01-01

    Vertical porosity variations in chalk are generally assumed to result from either a vaguely defined combination of primary sedimentary and diagenetic processes or solely to diagenetic processes. In this study, image analysis of backscatter electron images of polished samples and geochemical...... microprobe mapping were applied to measure the porosity variation in a limited number of chalk samples. Microscope data indicate that in all cases the chalk has been subjected to diagenetic processes, but our data suggest that the variations in porosity originate in primary sedimentary differences....

  4. Adaptive introgression in animals: examples and comparison to new mutation and standing variation as sources of adaptive variation.

    Science.gov (United States)

    Hedrick, Philip W

    2013-09-01

    Adaptive genetic variation has been thought to originate primarily from either new mutation or standing variation. Another potential source of adaptive variation is adaptive variants from other (donor) species that are introgressed into the (recipient) species, termed adaptive introgression. Here, the various attributes of these three potential sources of adaptive variation are compared. For example, the rate of adaptive change is generally thought to be faster from standing variation, slower from mutation and potentially intermediate from adaptive introgression. Additionally, the higher initial frequency of adaptive variation from standing variation and lower initial frequency from mutation might result in a higher probability of fixation of the adaptive variants for standing variation. Adaptive variation from introgression might have higher initial frequency than new adaptive mutations but lower than that from standing variation, again making the impact of adaptive introgression variation potentially intermediate. Adaptive introgressive variants might have multiple changes within a gene and affect multiple loci, an advantage also potentially found for adaptive standing variation but not for new adaptive mutants. The processes that might produce a common variant in two taxa, convergence, trans-species polymorphism from incomplete lineage sorting or from balancing selection and adaptive introgression, are also compared. Finally, potential examples of adaptive introgression in animals, including balancing selection for multiple alleles for major histocompatibility complex (MHC), S and csd genes, pesticide resistance in mice, black colour in wolves and white colour in coyotes, Neanderthal or Denisovan ancestry in humans, mimicry genes in Heliconius butterflies, beak traits in Darwin's finches, yellow skin in chickens and non-native ancestry in an endangered native salamander, are examined.

  5. Term frequency inverse document frequency (TF-IDF) technique and ...

    African Journals Online (AJOL)

    Term frequency inverse document frequency (TF-IDF) technique and artificial neural ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL ... Electronic mail contents are extracted and Term Frequency Inverse ...

  6. A global reference for human genetic variation

    DEFF Research Database (Denmark)

    Auton, Adam; Abecasis, Goncalo R.; M. Altshuler, David

    2015-01-01

    The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole-genome sequencing to a diverse set of individuals from multiple populations. Here we report completion of the project, having reconstructed the genomes of 2,504 individuals...... from 26 populations using a combination of low-coverage whole-genome sequencing, deep exome sequencing, and dense microarray genotyping. We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide polymorphisms (SNPs), 3.6 million short...... insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. This resource includes >99% of SNP variants with a frequency of >1% for a variety of ancestries. We describe the distribution of genetic variation across the global sample, and discuss the implications...

  7. Saturn chorus latitudinal variations

    National Research Council Canada - National Science Library

    Menietti, J. D; Hospodarsky, G. B; Shprits, Y. Y; Gurnett, D. A

    2014-01-01

    The variation of propagation properties of whistler mode chorus as a function of latitude is not well known at Saturn but is important for the calculation of pitch angle diffusion and nonlinear growth of chorus...

  8. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  9. A mechanism for frequency modulation in songbirds shared with humans.

    Science.gov (United States)

    Amador, Ana; Margoliash, Daniel

    2013-07-03

    In most animals that vocalize, control of fundamental frequency is a key element for effective communication. In humans, subglottal pressure controls vocal intensity but also influences fundamental frequency during phonation. Given the underlying similarities in the biomechanical mechanisms of vocalization in humans and songbirds, songbirds offer an attractive opportunity to study frequency modulation by pressure. Here, we present a novel technique for dynamic control of subsyringeal pressure in zebra finches. By regulating the opening of a custom-built fast valve connected to the air sac system, we achieved partial or total silencing of specific syllables, and could modify syllabic acoustics through more complex manipulations of air sac pressure. We also observed that more nuanced pressure variations over a limited interval during production of a syllable concomitantly affected the frequency of that syllable segment. These results can be explained in terms of a mathematical model for phonation that incorporates a nonlinear description for the vocal source capable of generating the observed frequency modulations induced by pressure variations. We conclude that the observed interaction between pressure and frequency was a feature of the source, not a result of feedback control. Our results indicate that, beyond regulating phonation or its absence, regulation of pressure is important for control of fundamental frequencies of vocalizations. Thus, although there are separate brainstem pathways for syringeal and respiratory control of song production, both can affect airflow and frequency. We hypothesize that the control of pressure and frequency is combined holistically at higher levels of the vocalization pathways.

  10. The Schwinger Variational Method

    Science.gov (United States)

    Huo, Winifred M.

    1995-01-01

    Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions.

  11. Generalized quasi variational inequalities

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  12. Variation in Metaphor Variation in Metaphor

    Directory of Open Access Journals (Sweden)

    Zóltan Kövecses

    2010-05-01

    Full Text Available

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

     

    Cognitive linguists have so far paid a great deal of attention to the emarkable universality of many conceptual metaphors. However, their theories fail to account for the equally impressive diversity of metaphorical conceptualization both across and within cultures. The present paper is an attempt to lay down the foundations of a theory of metaphor that is capable of simultaneously accounting for both universality and variation in metaphor.

  13. Single frequency intracavity SRO

    DEFF Research Database (Denmark)

    Abitan, Haim; Buchhave, Preben

    2000-01-01

    Summary form only given. A single resonance optical parametric oscillator (SRO) is inserted intracavity to a CW high power, single frequency, and ring Nd:YVO4 laser. We obtain a stable single frequency CW SRO with output at 1.7-1.9 μm (idler) and a resonating signal at 2.3-2.6 μm. The behavior...... of the two coupled resonators is simulated and the output power from the SRO is described as a function of the diode pumping power supplied to the Nd:YVO4 laser....

  14. Mid-frequency readers

    OpenAIRE

    Nation, Ian Stephen Paul; Anthony, Laurence

    2013-01-01

    This article describes a new free extensive reading resource for learning the mid-frequency words of English and for reading well known texts with minor vocabulary adaptation. A gap exists between the end of graded readers at around 3,000 word families and the vocabulary size needed to read unsimplified texts at around 8,000 word families. Mid-frequency readers are designed to fill this gap. They consist of texts from Project Gutenberg adapted for learners with a vocabulary size of 4,000 word...

  15. Prestress Force Identification for Externally Prestressed Concrete Beam Based on Frequency Equation and Measured Frequencies

    Directory of Open Access Journals (Sweden)

    Luning Shi

    2014-01-01

    Full Text Available A prestress force identification method for externally prestressed concrete uniform beam based on the frequency equation and the measured frequencies is developed. For the purpose of the prestress force identification accuracy, we first look for the appropriate method to solve the free vibration equation of externally prestressed concrete beam and then combine the measured frequencies with frequency equation to identify the prestress force. To obtain the exact solution of the free vibration equation of multispan externally prestressed concrete beam, an analytical model of externally prestressed concrete beam is set up based on the Bernoulli-Euler beam theory and the function relation between prestress variation and vibration displacement is built. The multispan externally prestressed concrete beam is taken as the multiple single-span beams which must meet the bending moment and rotation angle boundary conditions, the free vibration equation is solved using sublevel simultaneous method and the semi-analytical solution of the free vibration equation which considered the influence of prestress on section rigidity and beam length is obtained. Taking simply supported concrete beam and two-span concrete beam with external tendons as examples, frequency function curves are obtained with the measured frequencies into it and the prestress force can be identified using the abscissa of the crosspoint of frequency functions. Identification value of the prestress force is in good agreement with the test results. The method can accurately identify prestress force of externally prestressed concrete beam and trace the trend of effective prestress force.

  16. Analysis of the potencial of natural illumination for the savings and efficient use of the energy in buildings located in hot climates; Analisis del potencial de la iluminacion natural para ahorro y uso eficiente de la energia en las edificaciones en climas calidos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Chavez, J. R. [Universidad Autonoma Metropolitana-Azcapotzalco, Division de Ciencias y Artes para el Diseno, Departamento de Medio Ambiente, (Mexico)

    1997-12-31

    consumos de energia electrica para alumbrado de espacios interiores son muy cuantiosas, sobre todo en edificios no habitacionales. En este trabajo se exploran y presentan las posibilidades de la luz natural diurna para lograr ahorro de energia y confort visual termolumnico en las edificaciones.

  17. Ahorro energético en tándem de molinos de caña de azúcar mediante regulación de presiones hidráulicas//Energy saving in tandem of sugar cane mills by means regulation of hydraulic pressures

    Directory of Open Access Journals (Sweden)

    Jorge Michel Corrales‐Suárez

    2013-09-01

    Full Text Available Entre las áreas de mayor consumo de energía en un central azucarero se encuentra el tándem de molinos. Una de las variables que influye sobre este consumo es la presión hidráulica aplicada a la maza superior. La investigación tuvo como objetivo determinar las posibilidades de reducir este consumo regulandoapropiadamente las presiones hidráulicas sin disminuir la eficiencia del proceso de extracción, se llevó a cabo en un tándem de seis molinos donde solo se varió las presiones en los molinos intermedios según un diseño estadístico factorial completo 24. Las variables independientes fueron: las presiones hidráulicasen los molinos intermedios; las dependientes: la demanda de potencia, el % pol y % humedad. Se concluyó que en las condiciones del experimento, el empleo de presiones hidráulicas de trabajo menores en 3,45 MPa en los molinos intermedios, no afectó el proceso de extracción de la sacarosa, pero disminuyó en un 8,12% la demanda de potencia.Palabras claves: presión hidráulica, molino de caña de azúcar, ahorro de energía, tándem.______________________________________________________________________________AbstractAmong the areas of more energy consumption in a sugar power station is the tandem of mills. One of the variables that influences on this consumption is the hydraulic pressure applied to the superior mass. The investigation had as objective to determine the possibilities to reduce this consumption regulating the hydraulic pressures appropriately without diminishing the efficiency of the extraction process, it was carried out in a tandem of six mills where alone it was varied the pressures in the intermediate mills according to a complete factorial statistical design 24. The independent variables were: the hydraulic pressures in the intermediate mills; the dependents: the demand of power, the %pol and %humidity. You concluded thatunder the conditions of the experiment, the employment of hydraulic pressures

  18. Estimado de la reducción de la emisión de co2 por accione de ahorro de electricidad en las condiciones de Cuba;Estimation of reduction of CO2 emission by electric power saving project in the Cuba conditions

    Directory of Open Access Journals (Sweden)

    Irina Salazar - Fonseca et all.

    2010-11-01

    Full Text Available Este trabajo expone los resultados del estudio realizado a las numerosas vías que existen para el cálculo del factor de emisión de CO2 a nivel mundial. A partir de una amplia búsqueda de información, se obtuvo la metodología propuesta para el cálculo del factor de emisión de CO2 para proyectos de ahorro de energía eléctrica, teniendo en cuenta las particularidades de la matriz energética del país en cuestión. La metodología propuesta es el resultado de las modificaciones realizadas a la metodología ACM 0002, que es la aprobada por la Junta Ejecutiva del Mecanismo de Desarrollo Limpio (MDL. A partir de los datos reales del consumo de combustible para la electricidad en Cuba en los años 2007 y 2008, se calcula el factor de emisión de CO2, obteniéndose un valor igual a 0,795 y 0,794 t CO2/MWh, respectivamente. Estos resultados evidencian el paulatino desarrollo hacia fuentes de energía mas limpias que se ha realizado en ese periodo en el país, caracterizado por la entrada en funcionamiento de varios emplazamientos de Fuel-oil.This work exposes result of accomplished study to the many manners that exist for the calculation of CO2 emission factor in the world. Latter a ample quest of information, the proposed methodology was obtained for calculation of CO2 emission factor for electric power saving project, taking the particularities of electrical systems into account country. The proposed methodology is results of modifications realized to the methodology ACM 0002, this are the approved in Executive Board of the Clean Development Mechanism (CDM. Whit the real data of fuel consumption for the electricity in Cuba in the years 2007 and 2008, CO2 emission factor is calculated, obtained an equal value to 0.795 and 0.794 tCO2/MWh, respectively. These aftermath evidence the gradual development to cleaning sources of energy that success in period at the country, characterized for the entrance in functioning of several Fuel

  19. Human genetic variation database, a reference database of genetic variations in the Japanese population

    Science.gov (United States)

    Higasa, Koichiro; Miyake, Noriko; Yoshimura, Jun; Okamura, Kohji; Niihori, Tetsuya; Saitsu, Hirotomo; Doi, Koichiro; Shimizu, Masakazu; Nakabayashi, Kazuhiko; Aoki, Yoko; Tsurusaki, Yoshinori; Morishita, Shinichi; Kawaguchi, Takahisa; Migita, Osuke; Nakayama, Keiko; Nakashima, Mitsuko; Mitsui, Jun; Narahara, Maiko; Hayashi, Keiko; Funayama, Ryo; Yamaguchi, Daisuke; Ishiura, Hiroyuki; Ko, Wen-Ya; Hata, Kenichiro; Nagashima, Takeshi; Yamada, Ryo; Matsubara, Yoichi; Umezawa, Akihiro; Tsuji, Shoji; Matsumoto, Naomichi; Matsuda, Fumihiko

    2016-01-01

    Whole-genome and -exome resequencing using next-generation sequencers is a powerful approach for identifying genomic variations that are associated with diseases. However, systematic strategies for prioritizing causative variants from many candidates to explain the disease phenotype are still far from being established, because the population-specific frequency spectrum of genetic variation has not been characterized. Here, we have collected exomic genetic variation from 1208 Japanese individuals through a collaborative effort, and aggregated the data into a prevailing catalog. In total, we identified 156 622 previously unreported variants. The allele frequencies for the majority (88.8%) were lower than 0.5% in allele frequency and predicted to be functionally deleterious. In addition, we have constructed a Japanese-specific major allele reference genome by which the number of unique mapping of the short reads in our data has increased 0.045% on average. Our results illustrate the importance of constructing an ethnicity-specific reference genome for identifying rare variants. All the collected data were centralized to a newly developed database to serve as useful resources for exploring pathogenic variations. Public access to the database is available at http://www.genome.med.kyoto-u.ac.jp/SnpDB/. PMID:26911352

  20. Variation in the vocabulary of Russian literary texts

    CERN Document Server

    Kargin, Vladislav

    2015-01-01

    In this paper, the data from a large online collection is used to study variation in the vocabulary of Russian literary texts. First, we find that variation in the vocabulary size of different authors is in a good agreement with Heaps' law with parameter $\\lambda=0.5$, consistent with previous studies. The overall distribution of word frequencies has lighter tails than both the Zipf and lognormal laws predict. Next, we focus on the variation of word frequencies across texts. We confirm statistically that word frequencies vary significantly across texts, and find that the variance of the cross-text frequency distribution is in general higher for more frequent words. The dependence of the variance on the average word frequency follows a power law with exponent $\\alpha=1.25.$ The factor models applied to the data suggest that the most of the cross-text variation is concentrated in less than $100$ most frequent words and can be explained by about $10$ factors. For less-frequent words, the frequency data is more s...

  1. Low-power variable frequency PFC converters

    Energy Technology Data Exchange (ETDEWEB)

    Li Yani; Yang Yintang; Zhu Zhangming, E-mail: yanili@mail.xidian.edu.c [Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of the Ministry of Education, Institute of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-01-15

    Based on the SinoMOS 1 {mu}m 40 V CMOS process, a novel power factor contention (PFC) converter with a low-power variable frequency function is presented. The circuit introduces a multi-vector error amplifier and a programmable oscillator to achieve frequency modulation, which provides a rapid dynamic response and precise output voltage clamping with low power in the entire load. According to the external load variation, the system can modulate the circuit operating frequency linearly, thereby ensuring that the PFC converter can work in frequency conversion-mode. Measured results show that the normal operating frequency of the PFC converter is 5-6 kHz, the start-up current is 36 {mu}A, the stable operating current is only 2.43 mA, the efficiency is 97.3%, the power factor (PF) is 0.988, THD is 3.8%, the load adjust rate is 3%, and the linear adjust rate is less than 1%. Both theoretical and practical results reveal that the power consumption of the whole supply system is reduced efficiently, especially when the load varies. The active die area of the PFC converter chip is 1.61 x 1.52 mm{sup 2}. (semiconductor integrated circuits)

  2. Multiband frequency selective surface

    Science.gov (United States)

    Wu, Te-Kao

    1998-10-01

    This paper addresses the similarity of microwave/millimeter wave frequency selective surfaces (FSS) to optical filters. Specifically, the design approaches of the 4-band FSSs developed for NASA's CASSINI high gain antenna are described in detail. Representative RF test results are given to demonstrate the validity of these designs. These design approaches are very general and can be applied to multiband optical filters.

  3. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  4. Frequency scanning microstrip antennas

    DEFF Research Database (Denmark)

    Danielsen, Magnus; Jørgensen, Rolf

    1979-01-01

    The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase...

  5. Frequency of orthodontic extraction

    Directory of Open Access Journals (Sweden)

    Camila de S. Dardengo

    2016-02-01

    Full Text Available Introduction: The option of dental extraction for orthodontic purposes has been debated for more than 100 years, including periods when it was widely used in treatment, including the present, during which other methods are used to avoid dental extractions. The objective was to analyze the frequency of tooth extraction treatment performed between 1980 and 2011 at the Orthodontic Clinic of Universidade Estadual do Rio de Janeiro (UERJ. Material and Methods: The clinical records of 1484 patients undergoing orthodontic treatment were evaluated. The frequency of extractions was evaluated with regard to sex, Angle's classification, the different combinations of extractions and the period when orthodontic treatment began. Chi-square test was used to determine correlations between variables, while the chi-square test for trends was used to assess the frequency of extractions over the years. Results: There was a reduction of approximately 20% in the frequency of cases treated with tooth extraction over the last 32 years. The most frequently extracted teeth were first premolars. Patients with Class I malocclusion showed fewer extractions, while Class II patients underwent a higher number of extraction treatment. There were no statistically significant differences with regard to sex. Conclusion: New features introduced into the orthodontic clinic and new esthetic concepts contributed to reducing the number of cases treated with dental extractions. However, dental extractions for orthodontic purposes are still well indicated in certain cases.

  6. All-frequency reflectionlessness

    CERN Document Server

    Philbin, T G

    2016-01-01

    We derive planar permittivity profiles that do not reflect perpendicularly exiting radiation of any frequency. The materials obey the Kramers-Kronig relations and have no regions of gain. Reduction of the Casimir force by means of such materials is also discussed.

  7. Multiple Frequency Parametric Sonar

    Science.gov (United States)

    2015-09-28

    300003 1 MULTIPLE FREQUENCY PARAMETRIC SONAR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...beams. However, the multiple nonlinear interactions are not taken advantage of in order to generate additional efficiencies, bandwidth, and SNR...array. [0050] It will be understood that many additional changes in details, materials , steps, and arrangements of parts which have been described

  8. HIGHER FREQUENCY ULTRASONIC LIGHT MODULATORS.

    Science.gov (United States)

    LIGHT), (* MODULATORS , (*ULTRASONIC RADIATION, MODULATORS ), OPTICAL COMMUNICATIONS, BANDWIDTH, TRANSDUCERS, HIGH FREQUENCY, VERY HIGH FREQUENCY, ATTENUATION, DATA PROCESSING, OPTICAL EQUIPMENT, ANALOG COMPUTERS, THEORY.

  9. Structural variations in pig genomes

    NARCIS (Netherlands)

    Paudel, Y.

    2015-01-01

    Abstract Paudel, Y. (2015). Structural variations in pig genomes. PhD thesis, Wageningen University, the Netherlands Structural variations are chromosomal rearrangements such as insertions-deletions (INDELs), duplications, inversions, translocations, and copy number variations (CNVs

  10. Research on a Micro-Grid Frequency Modulation Strategy Based on Optimal Utilization of Air Conditioners

    Directory of Open Access Journals (Sweden)

    Qingzhu Wan

    2016-12-01

    Full Text Available With the proportion of air conditioners increasing gradually, they can provide a certain amount of frequency-controlled reserves for a micro-grid. Optimizing utilization of air conditioners and considering load response characteristics and customer comfort, the frequency adjustment model is a quadratic function model between the trigger temperature of the air conditioner compressor, and frequency variation is provided, which can be used to regulate the trigger temperature of the air conditioner when the micro-grid frequency rises and falls. This frequency adjustment model combines a primary frequency modulation method and a secondary frequency modulation method of the energy storage system, in order to optimize the frequency of a micro-grid. The simulation results show that the frequency modulation strategy for air conditioners can effectively improve the frequency modulation ability of air conditioners and frequency modulation effects of a micro-grid in coordination with an energy storage system.

  11. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

    High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing

  12. Discrete Variational Optimal Control

    CERN Document Server

    Jimenez, Fernando; de Diego, David Martin

    2012-01-01

    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher-dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical and a practical examples, e.g. the control of an underwater vehicle, will illustrate the application of the proposed approach.

  13. Discrete Variational Optimal Control

    Science.gov (United States)

    Jiménez, Fernando; Kobilarov, Marin; Martín de Diego, David

    2013-06-01

    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, and underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical examples and a practical one, the control of an underwater vehicle, illustrate the application of the proposed approach.

  14. Variation and Synthetic Speech

    CERN Document Server

    Miller, C; Massey, N; Miller, Corey; Karaali, Orhan; Massey, Noel

    1997-01-01

    We describe the approach to linguistic variation taken by the Motorola speech synthesizer. A pan-dialectal pronunciation dictionary is described, which serves as the training data for a neural network based letter-to-sound converter. Subsequent to dictionary retrieval or letter-to-sound generation, pronunciations are submitted a neural network based postlexical module. The postlexical module has been trained on aligned dictionary pronunciations and hand-labeled narrow phonetic transcriptions. This architecture permits the learning of individual postlexical variation, and can be retrained for each speaker whose voice is being modeled for synthesis. Learning variation in this way can result in greater naturalness for the synthetic speech that is produced by the system.

  15. Variational electrodynamics of Atoms

    CERN Document Server

    De Luca, Jayme

    2013-01-01

    We study extrema with velocity discontinuities for the variational electromagnetic two-body problem. Along $C^2$ segments, these broken extrema satisfy the Euler-Lagrange equations of the variational principle, which are neutral differential delay equations with state-dependent deviating arguments. At points where accelerations are not defined and velocities are discontinuous, broken extrema satisfy Weierstrass-Erdmann corner conditions that energies and momenta are continuous. Here we construct periodic broken extrema near the $C^{\\infty}$ two-body circular orbits, using piecewise-defined $C^2$ solutions of the neutral differential delay equations along regular segments and a variational approximation for the boundary-layer segments. Broken periodic extrema with an integer number of corner points bifurcate from a discrete set of circular orbits, with scales defined by the Weierstrass-Erdmann corner conditions. We consider the three cases of hydrogen, muonium and positronium atoms. In each case the broken ext...

  16. Fimbrial phase variation

    DEFF Research Database (Denmark)

    Khandige, Surabhi; Møller-Jensen, Jakob

    2016-01-01

    Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question if the fimb......Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question...... if the fimbrial diversity seen at the population level is the product of random stochasticity or a concerted effort based on active communication. Here we discuss the possibility of a mechanism alternative to a stochastic fimbrial phase variation model affecting the dynamics of a heterogeneous population....

  17. Natural frequency of beams with embedded piezoelectric sensors and actuators

    OpenAIRE

    Della, Christian N.; Shu, Dongwei

    2007-01-01

    A mathematical model is developed to study the natural frequency of beams with embedded piezoelectric sensors and actuators. The piezoelectric sensors/actuators in a non-piezoelectric matrix (host beam) are analyzed as two inhomogeneity problems by using Eshelby’s equivalent inclusion method. The natural frequency of the beam is determined from the variational principle in Rayleigh quotient form, which is expressed as functions of the elastic strain energy and dielectric energy of the piezoel...

  18. Multiple window correlation analysis of HRV power and respiratory frequency.

    Science.gov (United States)

    Hansson-Sandsten, Maria; Jönsson, Peter

    2007-10-01

    In this paper, we evaluate the correlation estimate, based on multiple window spectrum analysis, between the respiratory center frequency and the high-frequency band of the heartrate variability (HRV) power. One aim is to examine whether a more restricted frequency range would better capture respiratory related HR variation, especially when the HR variation is changing rapidly. The respiratory peak is detected and a narrow-banded measure of the high-frequency (HF) band of the HRV is defined as the respiratory frequency +/-0.05 Hz. We compare the mean square error of the correlation estimate between the frequency of the respiratory peak and the power of the HRV with the power in the usual 0.12-0.4 Hz frequency band. Different multiple window spectrum techniques are used for the estimation of the respiratory frequency as well as for the power of the HRV. We compare the peak-matched multiple windows with the Welch method while evaluating the two different HF-power estimates mentioned above. The results show that using a more narrow band for the power estimation gives stronger correlation which indicates that the estimate of the power is more robust.

  19. High Frequency Linacs for Hadrontherapy

    Science.gov (United States)

    Amaldi, Ugo; Braccini, Saverio; Puggioni, Paolo

    The use of radiofrequency linacs for hadrontherapy was proposed about 20 years ago, but only recently has it been understood that the high repetition rate together with the possibility of very rapid energy variations offers an optimal solution to the present challenge of hadrontherapy: "paint" a moving tumor target in three dimensions with a pencil beam. Moreover, the fact that the energy, and thus the particle range, can be electronically adjusted implies that no absorber-based energy selection system is needed, which, in the case of cyclotron-based centers, is the cause of material activation. On the other side, a linac consumes less power than a synchrotron. The first part of this article describes the main advantages of high frequency linacs in hadrontherapy, the early design studies, and the construction and test of the first high-gradient prototype which accelerated protons. The second part illustrates some technical issues relevant to the design of copper standing wave accelerators, the present developments, and two designs of linac-based proton and carbon ion facilities. Superconductive linacs are not discussed, since nanoampere currents are sufficient for therapy. In the last two sections, a comparison with circular accelerators and an overview of future projects are presented.

  20. Análisis de costes y ahorros potenciales relacionados con la utilización de pruebas preoperatorias en los hospitales de Canarias Cost analysis and potential savings related to the use of preoperative tests in the hospitals of the Canary Islands [Spain

    Directory of Open Access Journals (Sweden)

    J. López-Bastida

    2003-04-01

    Full Text Available Objetivos: Estimar el ahorro potencial que podría tener lugar en el Servicio Canario de Salud (SCS, a partir de una utilización apropiada científica de las pruebas preoperatorias, haciendo uso de la información obtenida de los 5 hospitales universitarios de la red pública. Métodos: Un total de 55 anestesiólogos (60% del SCS cumplimentaron un cuestionario. En éste se prestó especial atención a las pruebas preoperatorias más frecuentemente utilizadas, como la radiografía de tórax, el electrocardiograma, las pruebas de laboratorio y la espirometría. Los costes unitarios medios para las diferentes pruebas preoperatorias se obtuvieron de 2 hospitales participantes en el estudio. Para calcular los ahorros potenciales derivados del uso apropiado de las pruebas preoperatorias se han considerado varios escenarios caracterizados por diferentes hipótesis o grados de cumplimiento de un protocolo basado en el conocimiento científico, considerado como parámetro de referencia. Resultados: En el caso ideal de que se cumpliera el protocolo científico recomendado en el 100% de los 16.179 pacientes considerados ASA I y II, la repercusión económica sería notable, pues supondría una liberación de recursos sensible que podría ser utilizada para otros programas de salud. Estas cifras podrían alcanzar aproximadamente los 1,02 millones de euros, sin considerar el coste de la estancia preoperatoria. Esta cifra podría incrementarse hasta, aproximadamente, los 2,13 millones de euros si incluimos un día de estancia preoperatoria, y hasta los 3,24 millones de euros incluyendo 2 días de estancia preoperatoria. Conclusiones: La revisión reciente de la literatura científica y los resultados proporcionados por el cuestionario aplicado en el SCS indican que las pruebas preoperatorias alcanzan los mayores beneficios para los pacientes y para la sociedad si se guían por el conocimiento científico. Es posible, además, liberar recursos a partir de una

  1. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  2. [Frequency dependance of compliance].

    Science.gov (United States)

    Gayrard, P

    1975-01-01

    Resistance of peripheral or "small" airways is only a small part of the total pulmonary resistance (Raw). Even considerable obstruction in these airways will have little effect on total resistance. Conversely this will lead to inequality in the time constants of units in parallel, and dynamic lung compliance (C dyn) shall fall as respiratory frequence increases. C dyn is measured from simultaneous recordings of transpulmonary pressure (esophageal balloon) and volume obtained from a volume displacement plethysmograph. If Raw and static compliance are found to be normal, the frequency dependance of compliance will result from peripheral airway obstruction only. Early stages of chronic airway obstruction can be established by this method. However this appear not suitable for wide-scale studies.

  3. Direct Observations of PMC Local Time Variations by Aura OMI

    Science.gov (United States)

    DeLand, Matthew T.; Shettle, Eric P.; Thomas, Gary E.; Olivero, John J.

    2010-01-01

    The Ozone Monitoring Instrument (OMI) on the Aura satellite obtains unique measurements for polar mesospheric cloud (PMC) analysis. Its wide cross-track viewing swath and high along-track spatial resolution makes it possible to directly evaluate PMC occurrence frequency and brightness variations between 6S" and 8S' latitude as a function of local time over a 12-14 h continuous period. OMI PMC local time variations are closely coupled to concurrent variations in measurement scattering angle, so that ice phase function effects must be considered when interpreting the observations. Two different phase functions corresponding to bright and faint clouds are examined in this analysis. OMI observations show maximum frequency and albedo values at 8-10 h local time in the Northern Hemisphere, with decreasing amplitude at higher latitudes. Southern Hemisphere values reach a minimum at 18-20 h LT. Larger variations are seen in Northern Hemisphere data. No statistically significant longitudinal dependence was seen.

  4. Direct Observations of PMC Local Time Variations by Aura OMI

    Science.gov (United States)

    DeLand, Matthew T.; Shettle, Eric P.; Thomas, Gary E.; Olivero, John J.

    2010-01-01

    The Ozone Monitoring Instrument (OMI) on the Aura satellite obtains unique measurements for polar mesospheric cloud (PMC) analysis. Its wide cross-track viewing swath and high along-track spatial resolution makes it possible to directly evaluate PMC occurrence frequency and brightness variations between 6S" and 8S' latitude as a function of local time over a 12-14 h continuous period. OMI PMC local time variations are closely coupled to concurrent variations in measurement scattering angle, so that ice phase function effects must be considered when interpreting the observations. Two different phase functions corresponding to bright and faint clouds are examined in this analysis. OMI observations show maximum frequency and albedo values at 8-10 h local time in the Northern Hemisphere, with decreasing amplitude at higher latitudes. Southern Hemisphere values reach a minimum at 18-20 h LT. Larger variations are seen in Northern Hemisphere data. No statistically significant longitudinal dependence was seen.

  5. Radio frequency ion source

    CERN Document Server

    Shen Guan Ren; Gao Fu; LiuNaiYi

    2001-01-01

    The study on Radio Frequency Ion Source is mainly introduced, which is used for CIAE 600kV ns Pulse Neutron Generator; and obtained result is also presented. The RF ion source consists of a diameter phi 25 mm, length 200 mm, coefficient of expansion =3.5 mA, beam current on target >=1.5 mA, beam spot =100 h.

  6. Frequency steerable acoustic transducers

    Science.gov (United States)

    Senesi, Matteo

    Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing

  7. Variational methods for field theories

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Menahem, S.

    1986-09-01

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions.

  8. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  9. Variational transition state theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

  10. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  11. Progress in variational methods

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The International Conference on Variational Methods (ICVAM) was held from May 20th to 26th in 2007 at the Chern Institute of Mathematics, Nankai University, Tianjin, China. Twenty eight invited speakers from ten countries and areas worldwide gave their lectures at the conference.

  12. Variation and Linguistic Theory.

    Science.gov (United States)

    Bailey, Charles-James N.

    This volume presents principles and models for describing language variation, and introduces a time-based, dynamic framework for linguistic description. The book first summarizes some of the problems of grammatical description encountered from Saussure through the present and then outlines possibilities for new descriptions of language which take…

  13. Operation of the CAPRICE electron cyclotron resonance ion source applying frequency tuning and double frequency heating.

    Science.gov (United States)

    Maimone, F; Tinschert, K; Celona, L; Lang, R; Mäder, J; Rossbach, J; Spädtke, P

    2012-02-01

    The properties of the electromagnetic waves heating the electrons of the ECR ion sources (ECRIS) plasma affect the features of the extracted ion beams such as the emittance, the shape, and the current, in particular for higher charge states. The electron heating methods such as the frequency tuning effect and the double frequency heating are widely used for enhancing the performances of ECRIS or even for the routine operation during the beam production. In order to better investigate these effects the CAPRICE ECRIS has been operated using these techniques. The ion beam properties for highly charged ions have been measured with beam diagnostic tools. The reason of the observed variations of this performance can be related to the different electromagnetic field patterns, which are changing inside the plasma chamber when the frequency is varying.

  14. Orthogonal Frequency Division Multiplexing System with Frequency Offset Estimation

    Directory of Open Access Journals (Sweden)

    Meghashree D.Nimje

    2013-03-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM system, use a large number of parallel narrowband subcarriers instead of a single wide-band carrier to transport information. Orthogonal frequency division multiplexing is the modulation technique use in digital communication systems . Carrier frequency offset occurs due to Doppler effect or noise. Carrier frequency offsets (CFOs is the Offset between the transmitter and the receiver oscillators .CFO damages the orthogonality of the carries ,resulting in degradation of the systems performance. Carrier frequency offset estimation method is discussed in this paper. In this paper one complex training sequence use, which can effectively estimate carrier frequency offset in the time domain and frequency domain. Here fine and coarse frequency is estimated to improve the improve the system performance. This paper shows the estimation range for frequency offset can be improve to large extent..

  15. Estimation of luminescence lifetime in frequency domain

    Institute of Scientific and Technical Information of China (English)

    Zhang Fu-Jun; Xu Zheng; Zhao Su-Ling; Lou Zhi-Dong; Yang Sheng-Yi; Xu Xu-Rong

    2006-01-01

    Absorption is the origin of luminescence. But it must be noticed that the lifetime of luminescence might reversely influence the rate of absorption. In this paper, it is reported that the luminescence intensity of copper and manganese changes with the driving frequency at constant voltage. The variation of luminescent intensity depends only on the lifetime of luminescence but not on the type of quenching or other factors. Generally the rate of absorption is dominantly determined by the material property and the lifetime of luminescence centres, the absorption of shorter lifetime centre will be larger than that of the longer lifetime centre at the same excited condition.

  16. A high frequency resonance gravity gradiometer

    Energy Technology Data Exchange (ETDEWEB)

    Bagaev, S. N.; Kvashnin, N. L.; Skvortsov, M. N. [Laser Physics Institute SB RAS, Novosibirsc (Russian Federation); Bezrukov, L. B.; Krysanov, V. A. [Institute of Nuclear Physics RAS, Moscow (Russian Federation); Oreshkin, S. I.; Motylev, A. M.; Popov, S. M.; Samoilenko, A. A.; Yudin, I. S. [Lomonosov MSU, Sternberg Astronomical Institute, Moscow (Russian Federation); Rudenko, V. N. [Institute of Nuclear Physics RAS, Moscow (Russian Federation); Lomonosov MSU, Sternberg Astronomical Institute, Moscow (Russian Federation)

    2014-06-15

    A new setup OGRAN—the large scale opto-acoustical gravitational detector is described. As distinguished from known gravitational bar detectors it uses the optical interferometrical readout for registering weak variations of gravity gradient at the kilohetz frequency region. At room temperature, its sensitivity is limited only by the bar Brownian noise at the bandwidth close to 100 Hz. It is destined for a search for rare events—gravitational pulses coincident with signals of neutrino scintillator (BUST) in the deep underground of Baksan Neutrino Observatory of INR RAS.

  17. Effect of off-frequency sampling in magnetic resonance elastography.

    Science.gov (United States)

    Johnson, Curtis L; Chen, Danchin D; Olivero, William C; Sutton, Bradley P; Georgiadis, John G

    2012-02-01

    In magnetic resonance elastography (MRE), shear waves at a certain frequency are encoded through bipolar gradients that switch polarity at a controlled encoding frequency and are offset in time to capture wave propagation using a controlled sampling frequency. In brain MRE, there is a possibility that the mechanical actuation frequency is different from the vibration frequency, leading to a mismatch with encoding and sampling frequencies. This mismatch can occur in brain MRE from causes both extrinsic and intrinsic to the brain, such as scanner bed vibrations or active damping in the head. The purpose of this work was to investigate how frequency mismatch can affect MRE shear stiffness measurements. Experiments were performed on a dual-medium agarose gel phantom, and the results were compared with numerical simulations to quantify these effects. It is known that off-frequency encoding alone results in a scaling of wave amplitude, and it is shown here that off-frequency sampling can result in two main effects: (1) errors in the overall shear stiffness estimate of the material on the global scale and (2) local variations appearing as stiffer and softer structures in the material. For small differences in frequency, it was found that measured global stiffness of the brain could theoretically vary by up to 12.5% relative to actual stiffness with local variations of up to 3.7% of the mean stiffness. It was demonstrated that performing MRE experiments at a frequency other than that of tissue vibration can lead to artifacts in the MRE stiffness images, and this mismatch could explain some of the large-scale scatter of stiffness data or lack of repeatability reported in the brain MRE literature.

  18. Genetic analysis of environmental variation

    NARCIS (Netherlands)

    Hill, W.G.; Mulder, H.A.

    2010-01-01

    Environmental variation (VE) in a quantitative trait – variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences – can be regarded as being under some degree of genetic control. Such variation may be either between repeated expressions of the same trait

  19. Genetic analysis of environmental variation

    NARCIS (Netherlands)

    Hill, W.G.; Mulder, H.A.

    2010-01-01

    Environmental variation (VE) in a quantitative trait – variation in phenotype that cannot be explained by genetic variation or identifiable genetic differences – can be regarded as being under some degree of genetic control. Such variation may be either between repeated expressions of the same trait

  20. Precision spectroscopy of hydrogen and femtosecond laser frequency combs.

    Science.gov (United States)

    Hänsch, T W; Alnis, J; Fendel, P; Fischer, M; Gohle, C; Herrmann, M; Holzwarth, R; Kolachevsky, N; Udem, Th; Zimmermann, M

    2005-09-15

    Precision spectroscopy of the simple hydrogen atom has inspired dramatic advances in optical frequency metrology: femtosecond laser optical frequency comb synthesizers have revolutionized the precise measurement of optical frequencies, and they provide a reliable clock mechanism for optical atomic clocks. Precision spectroscopy of the hydrogen 1S-2S two-photon resonance has reached an accuracy of 1.4 parts in 10(14), and considerable future improvements are envisioned. Such laboratory experiments are setting new limits for possible slow variations of the fine structure constant alpha and the magnetic moment of the caesium nucleus mu(Cs) in units of the Bohr magneton mu(B).

  1. DEMODULATION OF FREQUENCY OR SPACE MODULATED LIGHT.

    Science.gov (United States)

    LIGHT , DEMODULATION), (*OPTICAL COMMUNICATIONS, FREQUENCY MODULATION), (*FREQUENCY MODULATION, LIGHT ), OPTICAL TRACKING, BEAMS(ELECTROMAGNETIC), DEFLECTION, MICROWAVE FREQUENCY, ELECTRON BEAMS, PHOTOCATHODES

  2. Resonance frequency analysis

    Directory of Open Access Journals (Sweden)

    Rajiv K Gupta

    2011-01-01

    Full Text Available Initial stability at the placement and development of osseointegration are two major issues for implant survival. Implant stability is a mechanical phenomenon which is related to the local bone quality and quantity, type of implant, and placement technique used. The application of a simple, clinically applicable, non-invasive test to assess implant stability and osseointegration is considered highly desirable. Resonance frequency analysis (RFA is one of such techniques which is most frequently used now days. The aim of this paper was to review and analyze critically the current available literature in the field of RFA, and to also discuss based on scientific evidence, the prognostic value of RFA to detect implants at risk of failure. A search was made using the PubMed database to find all the literature published on "Resonance frequency analysis for implant stability" till date. Articles discussed in vivo or in vitro studies comparing RFA with other methods of implant stability measurement and articles discussing its reliability were thoroughly reviewed and discussed. A limited number of clinical reports were found. Various studies have demonstrated the feasibility and predictability of the technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are based on short-term results and long-term follow up are still scarce in this field. Nonetheless, from available literature, it may be concluded that RFA technique evaluates implant stability as a function of stiffness of the implant bone interface and is influenced by factors such as bone type, exposed implant height above the alveolar crest. Resonance frequency analysis could serve as a non-invasive diagnostic tool for detecting the implant stability of dental implants during the healing stages and in subsequent routine follow up care after treatment. Future studies, preferably randomized

  3. Microwave Frequency Polarizers

    Science.gov (United States)

    Ha, Vien The; Mirel, Paul; Kogut, Alan J.

    2013-01-01

    This article describes the fabrication and analysis of microwave frequency polarizing grids. The grids are designed to measure polarization from the cosmic microwave background. It is effective in the range of 500 to 1500 micron wavelength. It is cryogenic compatible and highly robust to high load impacts. Each grid is fabricated using an array of different assembly processes which vary in the types of tension mechanisms to the shape and size of the grids. We provide a comprehensive study on the analysis of the grids' wire heights, diameters, and spacing.

  4. Frequency Dependent Attenuation Revisited

    CERN Document Server

    Richard, Kowar; Xavier, Bonnefond

    2009-01-01

    The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we study causal equations describing propagation of attenuated pressure waves. We review standard models like frequency power laws and and the thermo-viscous equation. The lack of causality of standard models in the parameter range relevant for photoacoustic imaging requires to derive novel equations. The main ingredients for deriving causal equations are the Kramers-Kronig relation and the mathematical concept of linear system theory. The theoretical results of this work are underpined by numerical experiments.

  5. High frequency electromagnetic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Daily, W.; Ramirez, A.; Ueng, T.; Latorre, R.

    1989-09-01

    An experiment was conducted in G Tunnel at the Nevada Test Site to evaluate high frequency electromagnetic tomography as a candidate for in situ monitoring of hydrology in the near field of a heater placed in densely welded tuff. Tomographs of 200 MHz electromagnetic permittivity were made for several planes between boreholes. Data were taken before the heater was turned on, during heating and during cooldown of the rockmass. This data is interpreted to yield maps of changes in water content of the rockmass as a function of time. This interpretation is based on laboratory measurement of electromagnetic permittivity as a function of water content for densely welded tuff. 8 refs., 6 figs.

  6. Lunch frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Krølner, Rikke

    2016-01-01

    frequency was most common among students who were boys, 13- and 15-year-olds, from medium and low family social class, descendants of immigrants, living in a single-parent family and in a reconstructed family. School-level analyses suggested that having access to a canteen at school was associated with low...... students appears to be largely influenced by sociodemographic factors. Additionally, the presence of an adult during lunch breaks promotes frequent lunch consumption while availability of a canteen may discourage frequent lunch consumption. These findings vary between older and younger students....

  7. Radio Frequency Identification

    Indian Academy of Sciences (India)

    V Rajaraman

    2017-06-01

    Radio Frequency Identification (RFID) has been around sinceearly 2000. Its use has currently become commonplace as thecost of RFID tags has rapidly decreased. RFID tags have alsobecome more ‘intelligent’ with the incorporation of processorsand sensors in them. They are widely used now in manyinnovative ways. RFIDs are an integral part of Internet ofThings (IOT) and IT systems of smart cities. In this article,we introduce the technology used by RFID systems, illustratetheir use in several applications, and discuss problems of privacyand security when they are used.

  8. On functions of bounded variation

    OpenAIRE

    Aistleitner, Christoph; Pausinger, Florian; Svane, Anne Marie; Tichy, Robert F.

    2015-01-01

    The recently introduced concept of $\\mathcal{D}$-variation unifies previous concepts of variation of multivariate functions. In this paper, we give an affirmative answer to the open question from Pausinger \\& Svane (J. Complexity, 2014) whether every function of bounded Hardy--Krause variation is Borel measurable and has bounded $\\mathcal{D}$-variation. Moreover, we show that the space of functions of bounded $\\mathcal{D}$-variation can be turned into a commutative Banach algebra.

  9. Face Recognition Is Affected by Similarity in Spatial Frequency Range to a Greater Degree Than Within-Category Object Recognition

    Science.gov (United States)

    Collin, Charles A.; Liu, Chang Hong; Troje, Nikolaus F.; McMullen, Patricia A.; Chaudhuri, Avi

    2004-01-01

    Previous studies have suggested that face identification is more sensitive to variations in spatial frequency content than object recognition, but none have compared how sensitive the 2 processes are to variations in spatial frequency overlap (SFO). The authors tested face and object matching accuracy under varying SFO conditions. Their results…

  10. Time frequency analyses of vibrations of wind turbine towers

    Science.gov (United States)

    Chiang, Chih-Hung; Huang, Chi-Luen; Hsu, Keng-Tseng; Cheng, Chia-Chi; Yu, Chih-Peng; Lai, Jiunnren

    2015-04-01

    Transient vibrations of the tower supporting a horizontal-axis wind turbine were recorded using a microwave interferometer. Variations in dominant frequencies have been reported in the previous study. Signal analyses aiming to uncouple different frequency components were performed using reassigned spectrogram, a time-frequency representation based on time-corrected short time Fourier transform. Optimal resolutions in both time and frequency domains were first investigated using synthetic signals. The goal was to seek out the favorable combinations of window size and overlapping portions of adjacent windows for a data sequence at a given sampling rate. The dominant frequency found in reassigned spectrogram agrees with that obtained using Fourier spectrum of the same transient measurements of the wind turbine tower under investigation.

  11. A CMOS frequency generation module for 60-GHz applications

    Institute of Scientific and Technical Information of China (English)

    Zhou Chunyuan; Zhang Lei; Wang Hongrui; Qian He

    2012-01-01

    A frequency generation module for 60-GHz transceivers and phased array systems is presented in this paper.It is composed of a divide-by-2 current mode logic divider (CM L) and a doubler in push-push configuration.Benefiting from the CML structure and push-push configuration,the proposed frequency generation module has a wide operating frequency range to cover process,voltage,and temperature variation.It is implemented in a 90-nm CMOS process,and occupies a chip area of 0.64 × 0.65 mm2 including pads.The measurement results show that the designed frequency generation module functions properly with input frequency over 15 GHz to 25 GHz.The whole chip dissipates 12.1 mW from a 1.2-V supply excluding the output buffers.

  12. Human immune system variation.

    Science.gov (United States)

    Brodin, Petter; Davis, Mark M

    2017-01-01

    The human immune system is highly variable between individuals but relatively stable over time within a given person. Recent conceptual and technological advances have enabled systems immunology analyses, which reveal the composition of immune cells and proteins in populations of healthy individuals. The range of variation and some specific influences that shape an individual's immune system is now becoming clearer. Human immune systems vary as a consequence of heritable and non-heritable influences, but symbiotic and pathogenic microbes and other non-heritable influences explain most of this variation. Understanding when and how such influences shape the human immune system is key for defining metrics of immunological health and understanding the risk of immune-mediated and infectious diseases.

  13. High Frequency Chandler Wobble Excitation

    Science.gov (United States)

    Seitz, F.; Stuck, J.; Thomas, M.

    2003-04-01

    Variations of Earth rotation on sub-daily to secular timescales are caused by mass redistributions in the Earth system as a consequence of geophysical processes and gravitational influences. Forced oscillations of polar motion are superposed by free oscillations of the Earth, i.e. the Chandler wobble and the free core nutation. In order to study the interactions between externally induced polar motion and the Earth's free oscillations, a non-linear gyroscopic model has been developed. In most of the former investigations on polar motion, the Chandler wobble is introduced as a damped oscillation with predetermined frequency and amplitude. However, as the effect of rotational deformation is a backcoupling mechanism of polar motion on the Earth's rotational dynamics, both period and amplitude of the Chandler wobble are time-dependent when regarding additional excitations from, e.g., atmospheric or oceanic mass redistributions. The gyroscopic model is free of any explicit information concerning amplitude, phase, and period of free oscillations. The characteristics of the Earth's free oscillation is reproduced by the model from rheological and geometrical parameters and rotational deformation is taken into account. This enables to study the time variable Chandler oscillation when the gyro is forced with atmospheric and oceanic angular momentum from the global atmospheric ECHAM3-T21 general circulation model together with the ocean model for circulation and tides OMCT driven by ECHAM including surface pressure. Besides, mass redistributions in the Earth's body due to gravitational and loading deformations are regarded and external torques exerted by Moon and Sun are considered. The numerical results of the gyro are significantly related with the geodetically observed time series of polar motion published by the IERS. It is shown that the consistent excitation is capable to counteract the damping and thus to maintain the Chandler amplitude. Spectral analyses of the ECHAM

  14. NONLINEAR NATURAL FREQUENCY OF SHALLOW CONICAL SHELLS WITH VARIABLE THICKNESS

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-zhi; HAN Ming-jun; ZHAO Yong-gang; YEH Kai-yuan

    2005-01-01

    The nonlinear dynamical variation equation and compatible equation of the shallow conical shell with variable thickness are obtained by the theory of nonlinear dynamical variation equation and compatible equation of the circular thin plate with variable thickness. Assuming the thin film tension is composed of two items. The compatible equation is transformed into two independent equations. Selecting the maximum amplitude in the center of the shallow conical shells with variable thickness as the perturbation parameter,the variation equation and the differential equation are transformed into linear expression by theory of perturbation variation method. The nonlinear natural frequency of shallow conical shells with circular bottom and variable thickness under the fixed boundary conditions is solved. In the first approximate equation, the linear natural frequency of shallow conical shells with variable thickness is obtained. In the third approximate equation, the nonlinear uatural frequency of it is obtained. The figures of the characteristic curves of the natural frequency varying with stationary loads, large amplitude, and variable thickness coefficient are plotted. A valuable reference is given for dynamic engineering.

  15. Shoaling and shoreline dissipation of low‐frequency waves

    NARCIS (Netherlands)

    Van Dongeren, A.; Battjes, J.A.; Janssen, T.; Van Noorloos, J.; Steenhauer, K.; Steenbergen, G.; Reniers, A.

    2007-01-01

    The growth rate, shoreline reflection, and dissipation of low‐frequency waves are investigated using data obtained from physical experiments in the Delft University of Technology research flume and by parameter variation using the numerical model Delft3D‐SurfBeat. The growth rate of the shoaling inc

  16. Fact or friction: jumps at ultra high frequency

    NARCIS (Netherlands)

    K. Christensen; R. Oomen; M. Podolskij

    2011-01-01

    In this paper, we demonstrate that jumps in financial asset prices are not nearly as common as generally thought, and that they account for only a very small proportion of total return variation. We base our investigation on an extensive set of ultra high-frequency equity and foreign exchange rate d

  17. Multiple frequency atmospheric radar techniques

    Science.gov (United States)

    Stitt, Gary Richard

    The use of multiple frequency coding to improve the vertical resolution of pulsed-Doppler very high frequency atmospheric radars, especially with regards to the two-frequency techniques known as frequency domain interferometry (FDI), is presented. This technique consists of transmitting alternate pulses on two distinct carrier frequencies. The two resulting time series are used to evaluate the normalized cross-correlation function, whose magnitude and phase are related to the thickness and position of a scattering layer. These same time series are also used to evaluate cross-spectra, which yield magnitude and phase values for each Doppler frequency component of the return signal.

  18. Frequency Population Growth Rate

    Directory of Open Access Journals (Sweden)

    Nouralah Salehi Asfiji

    2012-10-01

    Full Text Available The Solow growth model assumes that labor force grows exponentially. That is not a realistic assumption. In generalized logistic equations that describes more accurately population growth. Economic growth is not a smooth process. Real GDP has fluctuations in the growth rate. We call these fluctuations business cycles. Business cycle theory came about from the failures of classical economics in being able to illuminate on the causes of the Great Depression. The logistic growth model to explain changes in population growth rates are not. In this paper a new analysis of the population growth rate in the frequency space is described with mathematical logic and economic reasoning, so that, firstly, to a higher level of capital per capita, or at least equal to the Solow growth model reaches Second, the limits of saturation (Carrying-Capacity is not, and ultimately, population growth rates have an impact on long-term per capita amounts. The initial classic assumption is changed in this article based on the available frequencies in the population growth equation.

  19. Malaria haplotype frequency estimation.

    Science.gov (United States)

    Wigger, Leonore; Vogt, Julia E; Roth, Volker

    2013-09-20

    We present a Bayesian approach for estimating the relative frequencies of multi-single nucleotide polymorphism (SNP) haplotypes in populations of the malaria parasite Plasmodium falciparum by using microarray SNP data from human blood samples. Each sample comes from a malaria patient and contains one or several parasite clones that may genetically differ. Samples containing multiple parasite clones with different genetic markers pose a special challenge. The situation is comparable with a polyploid organism. The data from each blood sample indicates whether the parasites in the blood carry a mutant or a wildtype allele at various selected genomic positions. If both mutant and wildtype alleles are detected at a given position in a multiply infected sample, the data indicates the presence of both alleles, but the ratio is unknown. Thus, the data only partially reveals which specific combinations of genetic markers (i.e. haplotypes across the examined SNPs) occur in distinct parasite clones. In addition, SNP data may contain errors at non-negligible rates. We use a multinomial mixture model with partially missing observations to represent this data and a Markov chain Monte Carlo method to estimate the haplotype frequencies in a population. Our approach addresses both challenges, multiple infections and data errors.

  20. High-frequency ECG

    Science.gov (United States)

    Tragardh, Elin; Schlegel, Todd T.

    2006-01-01

    The standard ECG is by convention limited to 0.05-150 Hz, but higher frequencies are also present in the ECG signal. With high-resolution technology, it is possible to record and analyze these higher frequencies. The highest amplitudes of the high-frequency components are found within the QRS complex. In past years, the term "high frequency", "high fidelity", and "wideband electrocardiography" have been used by several investigators to refer to the process of recording ECGs with an extended bandwidth of up to 1000 Hz. Several investigators have tried to analyze HF-QRS with the hope that additional features seen in the QRS complex would provide information enhancing the diagnostic value of the ECG. The development of computerized ECG-recording devices that made it possible to record ECG signals with high resolution in both time and amplitude, as well as better possibilities to store and process the signals digitally, offered new methods for analysis. Different techniques to extract the HF-QRS have been described. Several bandwidths and filter types have been applied for the extraction as well as different signal-averaging techniques for noise reduction. There is no standard method for acquiring and quantifying HF-QRS. The physiological mechanisms underlying HF-QRS are still not fully understood. One theory is that HF-QRS are related to the conduction velocity and the fragmentation of the depolarization wave in the myocardium. In a three-dimensional model of the ventricles with a fractal conduction system it was shown that high numbers of splitting branches are associated with HF-QRS. In this experiment, it was also shown that the changes seen in HF-QRS in patients with myocardial ischemia might be due to the slowing of the conduction velocity in the region of ischemia. This mechanism has been tested by Watanabe et al by infusing sodium channel blockers into the left anterior descending artery in dogs. In their study, 60 unipolar ECGs were recorded from the entire