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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. Seasonal variations of volcanic eruption frequencies

    Science.gov (United States)

    Stothers, Richard B.

    1989-01-01

    Do volcanic eruptions have a tendency to occur more frequently in the months of May and June? Some past evidence suggests that they do. The present study, based on the new eruption catalog of Simkin et al.(1981), investigates the monthly statistics of the largest eruptions, grouped according to explosive magnitude, geographical latitude, and year. At the 2-delta level, no month-to-month variations in eruption frequency are found to be statistically significant. Examination of previously published month-to-month variations suggests that they, too, are not statistically significant. It is concluded that volcanism, at least averaged over large portions of the globe, is probably not periodic on a seasonal or annual time scale.

  6. EL AHORRO DE LOS HOGARES EN COLOMBIA

    OpenAIRE

    Ligia Melo B.; Héctor Zárate S.; Juana Tellez C.

    2006-01-01

    En este documento se presenta un análisis del comportamiento del ahorro de los hogares y sus determinantes, considerando una perspectiva de largo plazo para el periodo 1950-2004 y una de corto plazo a nivel microeconómico, utilizando la información de las encuestas de calidad de vida de 1997 y 2003. A nivel agregado, con base en un análisis de cointegración se encontró una relación de largo plazo entre la tasa de ahorro de los hogares, el PIB per-cápita, los impuestos directos y una medida de...

  7. On variation of word frequencies in Russian literary texts

    Science.gov (United States)

    Kargin, Vladislav

    2016-03-01

    We study the variation of word frequencies in Russian literary texts. Our findings indicate that the standard deviation of a word's frequency across texts depends on its average frequency according to a power law with exponent 1/2 volatility (that is, higher "burstiness"). A latent factor model has been estimated to investigate the structure of the word frequency distribution. The findings suggest that the dependence of a word's frequency volatility on its average frequency can be explained by the asymmetry in the distribution of latent factors.

  8. [Variation in mycoses frequency in Mexico].

    Science.gov (United States)

    Méndez Tovar, L J; López Martínez, R; Macotela Ruiz, E; Manzano Gayosso, P; Serrano Jaén, L; Carmona Castañón, A; Mondragón Gonźalez, R

    1999-01-01

    We show the records about diagnosed mycoses in a hospital in Mexico City in two periods of time: from 1967 to 1977 and from 1993 to 1997. In the former 15,429 patients were studied and in the latter, 5,998. Striking differences among frequency, etiological agents and clinical outcome, were observed. The most frequent infections in both lapses were the superficial ones, however the most recent scores showed a notorious increase in opportunistic infections. We diagnosed only one histoplasmosis case during the period from 1993 to 1997. Etiological agents have also changed, dermatophytes frequency like Trichophyton mentagrophytes and T. tonsurans have diminished while T. rubrum increased from 60% to 80% of the whole dermatophytoses cases. Even though Criptococcus neoformans used to be the only agent causing criptococosis, in the most recent report we found that C. laurentii, C. terreus and C. unigutulatus were also isolated. Another important difference was mortality in rhinocerebral mucormicosis: twenty years ago it was fairly 80%, nowadays it has decreased to 20%.

  9. 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

  10. Probabilistic frequency variations of structure-soil systems

    International Nuclear Information System (INIS)

    Hamilton, C.W.; Hadjian, A.H.

    1976-01-01

    During earthquakes, structure-soil systems act as filters greatly amplifying the response of equipment whose frequencies are at or near their natural frequencies. Thus, the estimation of these structure-soil system frequencies assumes significant importance both for safety and cost. Actual in-situ frequencies of structures differ from calculated frequencies due both to variations in mathematical modelling techniques and to variations of material properties. This paper studies the second source only. This variability is usually gauged by the 'worst case' analyses technique in which extreme high- and low- parameter values are assumed and the associated frequencies are used as upper and lower bounds. This approach is not entirely satisfactory because it does not provide any indication of the probability of these limits being exceeded, of the distribution between these limits, or of the level of conservation introduced into the design process. The present approach provides this additional information. The emphasis in this part is both on developing the methodology and on the results obtained. It covers both the fixed-base structure and the effects of soil-structure interaction. Empirical data on concrete proerties were obtained from previously published results. Much less is known about variability of soil properties, so the soil structure interaction coefficients are assumed to be normally distributed. As data on the variation of soil properties become available, they can be readily incorporated via the methodology developed here. (Auth.)

  11. Climatic variations, trends and drought frequency in Dejen District ...

    African Journals Online (AJOL)

    ... and expected to increase in the future. This implies that the country specifically the study area whose mainstay depends on agriculture must cope with further warming, low, and erratic rainfall, and frequent climatic extremes. Keywords: Climate change, drought frequency, standardized precipitation index, rainfall variations ...

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

    Science.gov (United States)

    Olson, P

    2007-12-18

    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.

  13. Frequency variations of discrete cranial traits in major human populations. I. Supernumerary ossicle variations.

    Science.gov (United States)

    Hanihara, T; Ishida, H

    2001-06-01

    Four supernumerary ossicle variations-the ossicle at the lambda, the parietal notch bone, the asterionic bone, and the occipitomastoid bone-were examined for laterality differences, intertrait correlations, sex differences, and between group variations in the samples from around the world. Significant laterality differences were not detected in almost all samples. In some pairs of traits, significant association of occurrence were found. Several geographic samples were sexually dimorphic with respect to the asterionic bone and to a lesser extent for the parietal notch bone. East/Northeast Asians including the Arctic populations in general had lower frequencies of the 4 accessory ossicles. Australians, Melanesians and the majority of the New World peoples, on the other hand, generally had high frequencies. In the western hemisphere of the Old World, Subsaharan Africans had relatively high frequencies. Except for the ossicle at the lambda, the distribution pattern in incidence showed clinal variation from south to north. Any identifiable adaptive value related to environmental or subsistence factors may be expressed in such clinal variation. This may allow us to hypothesise that not only mechanical factors but a founder effect, genetic drift, and population structure could have been the underlying causes for interregional variation and possible clines in the incidences of the accessory ossicles.

  14. Variation in female morph frequencies and mating frequencies : random, frequency-dependent harassment or male mimicry?

    NARCIS (Netherlands)

    Hammers, Martijn; Van Gossum, Hans

    2008-01-01

    Female-limited colour polymorphisms occur in a variety of species, where often one female morph (androchrome) resembles the body coloration of the conspecific male, whereas the other (gynochrome) does not. We tested predictions of two frequency-dependent hypotheses that are commonly invoked to

  15. Ahorro para el retiro en Colombia: patrones y determinantes

    OpenAIRE

    Guataquí, Juan; Rodríguez Acosta, Mauricio; Garcia-Suaza, Andres

    2009-01-01

    La decisión de los individuos acerca del ahorro para el retiro ha sido abordada teóricamente bajo la hipótesis de que el sistema de seguridad social se comporta como un sustituto de otros mecanismos de ahorro. Este documento presenta evidencia de los patrones y determinantes del ahorro para el retiro en Colombia a partir de la Gran Encuesta Integrada de Hogares de 2007. Los resultados muestran que el 63% de los ocupados declaran no ahorrar para su vejez. A partir de modelos de selección d...

  16. Cajas de ahorro, bancarización e inestabilidad financiera

    Directory of Open Access Journals (Sweden)

    Alicia Girón

    2012-01-01

    Full Text Available Las Cajas de Ahorro han sido instituciones financieras emblemáticas del sistema financiero español. A partir del impacto de la crisis en curso sobre las Cajas de Ahorro, el Banco de España las sometió a un proceso de intervención, lo que ha llevado a un proceso de concentración y centralización mediante fusiones para fortalecerse y mejorar sus estados contables, y, así, convertirse en entidades bancarias. La bancarización de las 45 Cajas de Ahorro ha sido la alternativa a la crisis financiera y económica en el sistema financiero español. Estas acciones han permitido una nueva reconfiguración del sector. Ante la profunda inestabilidad financiera por la que atraviesa el sistema financiero, y en particular las Cajas de Ahorro, la bancarización no resuelve el problema de origen.

  17. Circadian variation in dominant atrial fibrillation frequency in persistent atrial fibrillation

    International Nuclear Information System (INIS)

    Sandberg, Frida; Stridh, Martin; Sörnmo, Leif; Bollmann, Andreas; Husser, Daniela

    2010-01-01

    Circadian variation in atrial fibrillation (AF) frequency is explored in this paper by employing recent advances in signal processing. Once the AF frequency has been estimated and tracked by a hidden Markov model approach, the resulting trend is analyzed for the purpose of detecting and characterizing the presence of circadian variation. With cosinor analysis, the results show that the short-term variations in the AF frequency exceed the variation that may be attributed to circadian. Using the autocorrelation method, circadian variation was found in 13 of 18 ambulatory ECG recordings (Holter) acquired from patients with long-standing persistent AF. Using the ensemble correlation method, the highest AF frequency usually occurred during the afternoon, whereas the lowest usually occurred during late night. It is concluded that circadian variation is present in most patients with long-standing persistent AF though the short-term variation in the AF frequency is considerable and should be taken into account

  18. Frequency variations of discrete cranial traits in major human populations. III. Hyperostotic variations.

    Science.gov (United States)

    Hanihara, T; Ishida, H

    2001-09-01

    Seven discrete cranial traits usually categorised as hyperostotic characters, the medial palatine canal, hypoglossal canal bridging, precondylar tubercle, condylus tertius, jugular foramen bridging, auditory exostosis, and mylohyoid bridging were investigated in 81 major human population samples from around the world. Significant asymmetric occurrences of the bilateral traits were detected in the medial palatine canal and jugular foramen bridging in several samples. Significant intertrait associations were found between some pairs of the traits, but not consistently across the large geographical samples. The auditory exostosis showed a predominant occurrence in males. With the exception of the auditory exostosis and mylohyoid bridging in a few samples, significant sex differences were slight. The frequency distributions of the traits (except for the auditory exostosis) showed some interregional clinality and intraregional discontinuity, suggesting that genetic drift could have contributed to the observed pattern of variation.

  19. 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)

    1994-12-31

    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.

  20. 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.

  1. Electron collision frequency variations and electric fields in the lower ionosphere

    International Nuclear Information System (INIS)

    Gokov, A.M.; Martynenko, S.I.

    1997-01-01

    Distribution of relative variations of the electron effective collision frequency at the ionosphere lower boundary is determined on the basis of analysis of radio-signals partially reflected from the lower ionosphere. Technique to evaluate the strength of electrical fields at the ionosphere lower boundary using experimentally measured variations of the effective frequency of electron collisions is elaborated. 12 refs., 2 figs

  2. 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 bandwi...... verified by implementing in ALTERA cyclone II FPGA board....

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

    OpenAIRE

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    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 these amplifiers is self-oscillation. A parameter of key interest in self-oscillating amplifiers is the switching frequency, which is known 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 frequenc...

  4. Further environmental factors causing variations of SCE frequencies

    International Nuclear Information System (INIS)

    Tuschl, H.; Kovac, R.; Wottawa, A.

    1986-12-01

    The frequencies of spontaneously occurring sister chromatid exchanges (=SCE) were determined in control persons, persons exposed to very low doses of ionizing radiation and employees of a rubber factory. Besides smoking habits and the usage of oral contraceptives, background ultraviolet (=UV) radiation seems to exert the most pronounced effect on SCE levels in control persons. (Author)

  5. Transducer frequency response variations investigated by time reversal calibration

    Czech Academy of Sciences Publication Activity Database

    Kober, Jan; Převorovský, Zdeněk

    2016-01-01

    Roč. 26, č. 2 (2016), A16-A16 ISSN 1213-3825. [Europen Conference on Acoustic Emission Testing /32./. 07.09.2016-09.09.2016, Praha] Institutional support: RVO:61388998 Keywords : calibration * time reversal * transducer * frequency response Subject RIV: BI - Acoustics

  6. Silent (painless) thyroiditis. Evidence of a geographic variation in frequency

    International Nuclear Information System (INIS)

    Vitug, A.C.; Goldman, J.M.

    1985-01-01

    Recent reports suggest that 14% to 23% of thyrotoxic patients have silent (painless) thyroiditis, a newly described syndrome characterized by transient thyrotoxicosis with a low radioactive iodine uptake. A three-year review at a Brooklyn (NY) hospital showed only one definite and three possible cases of silent thyroiditis among 86 thyrotoxic patients. At most, 4% to 5% of thyrotoxic patients had silent thyroiditis. The authors suggest a geographic variation in this syndrome. Most cases and the largest series are from Japan and the Great Lakes area of North America. The latter may be related to increased iodine intake over many years in a previously endemic area of hypoiodidism and goiter, although other local factors may also be involved

  7. Silent (painless) thyroiditis. Evidence of a geographic variation in frequency

    Energy Technology Data Exchange (ETDEWEB)

    Vitug, A.C.; Goldman, J.M.

    1985-03-01

    Recent reports suggest that 14% to 23% of thyrotoxic patients have silent (painless) thyroiditis, a newly described syndrome characterized by transient thyrotoxicosis with a low radioactive iodine uptake. A three-year review at a Brooklyn (NY) hospital showed only one definite and three possible cases of silent thyroiditis among 86 thyrotoxic patients. At most, 4% to 5% of thyrotoxic patients had silent thyroiditis. The authors suggest a geographic variation in this syndrome. Most cases and the largest series are from Japan and the Great Lakes area of North America. The latter may be related to increased iodine intake over many years in a previously endemic area of hypoiodidism and goiter, although other local factors may also be involved.

  8. Impact of soil-structure interaction on the probabilistic frequency variation of concrete structures

    International Nuclear Information System (INIS)

    Hadjian, A.H.; Hamilton, C.W.

    1975-01-01

    Earthquake response of equipment in nuclear power plants is characterized by floor response spectra. Since these spectra peak at the natural frequencies of the structure, it is important, both from safety and cost standpoints, to determine the degree of the expected variability of the calculated structural frequencies. A previous work is extended on the variability of the natural frequencies of structures due to the variations of concrete properties and a rigorous approach is presented to evaluate frequency variations based on the probability distributions of both the structural and soil parameters and jointly determine the distributions of the natural frequencies. It is assumed that the soil-structure interaction coefficients are normally distributed. With the proper choice of coordinates, the simultaneous random variations of both the structural properties and the interaction coefficients can be incorporated in the eigenvalue problem. The key methodology problem is to obtain the probability distribution of eigenvalues of matrices with random variable elements. Since no analytic relation exists between the eigenvalues and the elements, a numerical procedure had to be designed. It was found that the desired accuracy can be best achieved by splitting the joint variation into two parts: the marginal distribution of soil variations and the conditional distribution of structural variations at specific soil fractiles. Then after calculating the actual eigenvalues at judiciously selected paired values of soil and structure parameters, this information is recombined to obtain the desired cumulative distribution of natural frequencies

  9. 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.

  10. Collective frequency variation in network synchronization and reverse PageRank.

    Science.gov (United States)

    Skardal, Per Sebastian; Taylor, Dane; Sun, Jie; Arenas, Alex

    2016-04-01

    A wide range of natural and engineered phenomena rely on large networks of interacting units to reach a dynamical consensus state where the system collectively operates. Here we study the dynamics of self-organizing systems and show that for generic directed networks the collective frequency of the ensemble is not the same as the mean of the individuals' natural frequencies. Specifically, we show that the collective frequency equals a weighted average of the natural frequencies, where the weights are given by an outflow centrality measure that is equivalent to a reverse PageRank centrality. Our findings uncover an intricate dependence of the collective frequency on both the structural directedness and dynamical heterogeneity of the network, and also reveal an unexplored connection between synchronization and PageRank, which opens the possibility of applying PageRank optimization to synchronization. Finally, we demonstrate the presence of collective frequency variation in real-world networks by considering the UK and Scandinavian power grids.

  11. Collective frequency variation in network synchronization and reverse PageRank

    Science.gov (United States)

    Skardal, Per Sebastian; Taylor, Dane; Sun, Jie; Arenas, Alex

    2016-04-01

    A wide range of natural and engineered phenomena rely on large networks of interacting units to reach a dynamical consensus state where the system collectively operates. Here we study the dynamics of self-organizing systems and show that for generic directed networks the collective frequency of the ensemble is not the same as the mean of the individuals' natural frequencies. Specifically, we show that the collective frequency equals a weighted average of the natural frequencies, where the weights are given by an outflow centrality measure that is equivalent to a reverse PageRank centrality. Our findings uncover an intricate dependence of the collective frequency on both the structural directedness and dynamical heterogeneity of the network, and also reveal an unexplored connection between synchronization and PageRank, which opens the possibility of applying PageRank optimization to synchronization. Finally, we demonstrate the presence of collective frequency variation in real-world networks by considering the UK and Scandinavian power grids.

  12. 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.

  13. 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.

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

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Verschuur, Jeroen W.J.; Boller, Klaus 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

  15. Low-frequency variations in the wake of a circular cylinder at Re = 3900

    International Nuclear Information System (INIS)

    Lehmkuhl, Oriol; Rodríguez, Ivette; Pérez-Segarra, Carlos D; Oliva, Assensi; Borrell, Ricard

    2011-01-01

    Flow around cylindrical structures is of relevance for many practical applications. Knowledge of flow-related unsteady loading of such structures is crucial for hydro - and aerodynamic control and design. In order to obtain a deeper knowledge of this kind of flow, a DNS have been performed at Re D = 3900 (Re D = U ref D/ν). The instantaneous velocity signals of probes located in the separated shear-layer and in the vortex formation region exhibit the presence of low-frequency variations. The statistical analysis of these signals suggest that low-frequency variations in the vortex formation length, suction base pressure and intermittencies in the shear layer are closely related. It is shown that these variations are the responsible of the large scattering of data obtained in different experimental and numerical results, as well as the U-shape and V-shape stream-wise velocity profiles observed in the very near wake of the cylinder.

  16. 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.

  17. 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.

  18. Frequency variations of gravity waves interacting with a time-varying tide

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C.M.; Zhang, S.D.; Yi, F.; Huang, K.M.; Gan, Q.; Gong, Y. [Wuhan Univ., Hubei (China). School of Electronic Information; Ministry of Education, Wuhan, Hubei (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan, Hubei (China); Zhang, Y.H. [Nanjing Univ. of Information Science and Technology (China). College of Hydrometeorolgy

    2013-11-01

    Using a nonlinear, 2-D time-dependent numerical model, we simulate the propagation of gravity waves (GWs) in a time-varying tide. Our simulations show that when aGW packet propagates in a time-varying tidal-wind environment, not only its intrinsic frequency but also its ground-based frequency would change significantly. The tidal horizontal-wind acceleration dominates the GW frequency variation. Positive (negative) accelerations induce frequency increases (decreases) with time. More interestingly, tidal-wind acceleration near the critical layers always causes the GW frequency to increase, which may partially explain the observations that high-frequency GW components are more dominant in the middle and upper atmosphere than in the lower atmosphere. The combination of the increased ground-based frequency of propagating GWs in a time-varying tidal-wind field and the transient nature of the critical layer induced by a time-varying tidal zonal wind creates favorable conditions for GWs to penetrate their originally expected critical layers. Consequently, GWs have an impact on the background atmosphere at much higher altitudes than expected, which indicates that the dynamical effects of tidal-GW interactions are more complicated than usually taken into account by GW parameterizations in global models.

  19. Effect of Temperature Variation on Modal Frequency of Reinforced Concrete Slab and Beam in Cold Regions

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-01-01

    Full Text Available Changes of modal frequencies induced by temperature variation can be more obvious than those caused by structural damage, which will lead to the false damage identification results. Therefore, quantifying the temperature effect on modal frequencies is a critical step to eliminate its interference in damage detection. Due to the nonuniform and time-dependent characteristics of temperature distribution, it is insufficient to obtain the reliable relationships between temperatures and modal frequencies using temperatures in air or at surface. In this paper, correlations between measured temperatures (air temperature, surface temperature, mean temperature, etc. and modal frequencies for the slab and beam are comparatively analyzed. And the quantitative models are constructed considering nonuniform temperature distribution. Firstly, the reinforced concrete slab and beam were constructed and placed outside the laboratory to be monitored. Secondly, the correlation coefficients between modal frequencies and three kinds of temperatures are calculated, respectively. Thirdly, simple linear regression models between mean temperature and modal frequencies are established for the slab and beam. Finally, five temperature variables are selected to construct the multiple linear regression models. Prediction results reveal that the proposed multiple linear regression models possess favorable accuracy to quantify the temperature effect on modal frequencies considering nonuniform temperature distribution.

  20. Variations of the ionization push frequency in the ASK-1 chamber

    International Nuclear Information System (INIS)

    Krivoshapkin, P.A.; Mamrukova, V.P.; Skripin, G.V.; Shafer, G.V.

    1997-01-01

    The data on frequency push in the ASK-1 chamber at the Yakutsk station for 1954-1994 are analyzed. The observed eleven-year and half-year push variations are related to the solar activity. The narrowly directed galactic anisotropy with 6-8 h direction, coinciding with the direction of the helio-magnetosphere tail, formed by the solar system motion relative to stars is identified in a daily motion by sidereal time. The great barometric and temperature coefficients of the frequency pushes are obtained. This indicates the prevailing role of the nuclear-active particles in formation of pushes

  1. High frequency variations of Earth Rotation Parameters from GPS and GLONASS observations.

    Science.gov (United States)

    Wei, Erhu; Jin, Shuanggen; Wan, Lihua; Liu, Wenjie; Yang, Yali; Hu, Zhenghong

    2015-01-28

    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.

  2. 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.

  3. 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.

  4. Variation of saturation effect in the ionospheric F2 critical frequency at low latitude

    Science.gov (United States)

    Ikubanni, S. O.; Adeniyi, J. O.

    2013-08-01

    Saturation in the dependence of foF2 on solar flux is a phenomenon more pronounced in the equatorial ionization anomaly region. The phenomenon was observed in the relationship between the F2 critical frequency (foF2) and any solar indices. Using a two-segmented regression fit on data from an African low latitude station (Geographical Latitude 12.4°N; Geomagnetic latitude 3.5°N), saturation features from the dependence of foF2 on solar radio flux (F10.7) was studied. Diurnal and seasonal variation were studied for the first time in this low latitude region of the African sector. Significant variations were observed, especially in the solstices. It was observed that saturation effect is closely related to the hourly F2 critical frequency and these results were compared with those from Asian, Australian and the American sectors. The diurnal and seasonal variations find their explanations in the photo-ionization process, the fountain effect, and the pre-reversal enhancement while the seasonal variation was attributed to both the ion drift and thermospheric circulation. Future work with larger volume of data is expected to validate the observations from this study.

  5. 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.

  6. Effect of pulse frequency variation in laser welding of stainless steel

    International Nuclear Information System (INIS)

    Ahmed, E.; Manzoor, T.; Hussain, N.

    2007-01-01

    A parametric investigation by variations of frequencies was conducted to evaluate their effect on microstructural changes in the fusion and heat affected zones. Ferrite plus martensite microstructure was developed in these regions with visible grain coarsening in the fusion zone. The grain coarsening possibly be due to poor heat conductivity in this region. The morphology and volume fraction of martensite was changed with an increase in the frequency. At lower frequency the martensite laths and grain boundary growth was progressively changed to a network, forming connectivity of martensite and decreasing its volume fraction. The restricted growth of martensite particles to the grain boundaries for connectivity of martensite is little effective in raising the hardness of the fusion zone. An increase in the hardness ratio of fusion to heat affected zones with connected martensite particles indicates that hardness loss due to grain coarsening is compensated to some extent. (author)

  7. 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...

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

    OpenAIRE

    Nava Bolaños, Isalia; Brown Grossman, Flor; Domínguez Villalobos, Lilia

    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 jefaturasfemenina 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 ...

  9. Fundamental Frequency Variation of Neonatal Spontaneous Crying Predicts Language Acquisition in Preterm and Term Infants.

    Science.gov (United States)

    Shinya, Yuta; Kawai, Masahiko; Niwa, Fusako; Imafuku, Masahiro; Myowa, Masako

    2017-01-01

    Spontaneous cries of infants exhibit rich melodic features (i.e., time variation of fundamental frequency [ F 0 ]) even during the neonatal period, and the development of these characteristics might provide an essential base for later expressive prosody in language. However, little is known about the melodic features of spontaneous cries in preterm infants, who have a higher risk of later language-related problems. Thus, the present study investigated how preterm birth influenced melodic features of spontaneous crying at term-equivalent age as well as how these melodic features related to language outcomes at 18 months of corrected age in preterm and term infants. At term, moderate-to-late preterm (MLP) infants showed spontaneous cries with significantly higher F 0 variation and melody complexity than term infants, while there were no significant differences between very preterm (VP) and term infants. Furthermore, larger F 0 variation within cry series at term was significantly related to better language and cognitive outcomes, particularly expressive language skills, at 18 months. On the other hand, no other melodic features at term predicted any developmental outcomes at 18 months. The present results suggest that the additional postnatal vocal experience of MLP preterm infants increased F 0 variation and the complexity of spontaneous cries at term. Additionally, the increases in F 0 variation may partly reflect the development of voluntary vocal control, which, in turn, contributes to expressive language in infancy.

  10. 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

  11. Low and high frequency Madden-Julian oscillations in austral summer: interannual variations

    Energy Technology Data Exchange (ETDEWEB)

    Izumo, Takeshi [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); LOCEAN, IRD-CNRS-UPMC, Paris (France); Masson, Sebastien; Vialard, Jerome; Madec, Gurvan [LOCEAN, IRD-CNRS-UPMC, Paris (France); Boyer Montegut, Clement de [IFREMER, Brest (France); Behera, Swadhin K. [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); Takahashi, Keiko [Earth Simulator Center (JAMSTEC), Yokohama (Japan); Yamagata, Toshio [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); University of Tokyo, Tokyo (Japan)

    2010-09-15

    The Madden-Julian oscillation (MJO) is the main component of intraseasonal variability of the tropical convection, with clear climatic impacts at an almost-global scale. Based on satellite observations, it is shown that there are two types of austral-summer MJO events (broadly defined as 30-120 days convective variability with eastward propagation of about 5 m/s). Equatorial MJO events have a period of 30-50 days and tend to be symmetric about the equator, whereas MJO events centered near 8 S tend to have a longer period of 55-100 days. The lower-frequency variability is associated with a strong upper-ocean response, having a clear signature in both sea surface temperature and its diurnal cycle. These two MJO types have different interannual variations, and are modulated by the Indian Ocean Dipole (IOD). Following a negative IOD event, the lower-frequency southern MJO variability increases, while the higher-frequency equatorial MJO strongly diminishes. We propose two possible explanations for this change in properties of the MJO. One possibility is that changes in the background atmospheric circulation after an IOD favour the development of the low-frequency MJO. The other possibility is that the shallower thermocline ridge and mixed layer depth, by enhancing SST intraseasonal variability and thus ocean-atmosphere coupling in the southwest Indian Ocean (the breeding ground of southern MJO onset), favour the lower-frequency southern MJO variability. (orig.)

  12. Genetic and environmental variation in rust frequency on mature mountain birch trees

    Energy Technology Data Exchange (ETDEWEB)

    Elamo, Pirjo; Saloniemi, Irma; Helander, M.L.; Neuvonen, Seppo [Turku Univ. (Finland). Dept. of Biology) and (Kevo Subarctic Research Inst., Turku (Finland)

    2000-07-01

    This study investigated genetic and environmental variation in the frequency of birch rust, the most important leaf disease of birch species, The same half-sib families of mature mountain birch trees were studied in two areas corresponding to their natural growing habitats over 3 yrs. The frequency of birch rust was examined both in the field and from detached leaves inoculated in the laboratory. The frequency of birch rust varied among the mountain birch families. However, the heritability of birch rust resistance was found to be fairly low, with the heritability of naturally occurring birch rust varying between 0.27 and 0.41. The frequency of birch rust varied highly between the two study areas and among study years. Nevertheless, the relative frequency of birch rust among tree individuals and tree families remained similar and as a result no notable genotype x environment interaction was observed. The field and in vitro results differed with respect to the ranking of birch families by birch rust resistance.

  13. Assessment of high to low frequency variations of isoprene emission rates using a neural network approach

    Science.gov (United States)

    Boissard, C.; Chervier, F.; Dutot, A. L.

    2007-08-01

    Using a statistical approach based on artificial neural networks, an emission algorithm (ISO_LF) accounting for high (instantaneous) to low (seasonal) frequency variations was developed for isoprene. ISO_LF was optimised using an isoprene emission data base (ISO-DB) specifically designed for this work. ISO-DB consists of 1321 emission rates collected in the literature, together with 34 environmental variables, measured or assessed using NCDC (National Climatic Data Center) or NCEP (National Centers for Environmental Predictions) meteorological databases. ISO-DB covers a large variety of emitters (25 species) and environmental conditions (10° S to 60° N). When only instantaneous environmental regressors (air temperature and photosynthetic active radiation, PAR) were used, a maximum of 60% of the overall isoprene variability was assessed and the highest emissions were underestimated. Considering a total of 9 high (instantaneous) to low (up to 3 weeks) frequency regressors, ISO_LF accounts for up to 91% of the isoprene emission variability, whatever the emission range, species or climate. Diurnal and seasonal variations are correctly reproduced for textit{Ulex europaeus} with a maximum factor of discrepancy of 4. ISO-LF was found to be mainly sensitive to air temperature cumulated over 3 weeks T21 and to instantaneous light L0 and air temperature T0 variations. T21, T0 and L0 only accounts for 76% of the overall variability. The use of ISO-LF for non stored monoterpene emissions was shown to give poor results.

  14. Low-frequency variations in the wake of a circular cylinder at Re = 3900

    Energy Technology Data Exchange (ETDEWEB)

    Lehmkuhl, Oriol; Rodriguez, Ivette; Perez-Segarra, Carlos D; Oliva, Assensi [Heat and Mass Transfer Technological Center, Politechnical University of Catalonia (Spain); Borrell, Ricard, E-mail: cttc@cttc.upc.edu [TermoFluids S.L. (Spain)

    2011-12-22

    Flow around cylindrical structures is of relevance for many practical applications. Knowledge of flow-related unsteady loading of such structures is crucial for hydro - and aerodynamic control and design. In order to obtain a deeper knowledge of this kind of flow, a DNS have been performed at Re{sub D} = 3900 (Re{sub D} = U{sub ref}D/{nu}). The instantaneous velocity signals of probes located in the separated shear-layer and in the vortex formation region exhibit the presence of low-frequency variations. The statistical analysis of these signals suggest that low-frequency variations in the vortex formation length, suction base pressure and intermittencies in the shear layer are closely related. It is shown that these variations are the responsible of the large scattering of data obtained in different experimental and numerical results, as well as the U-shape and V-shape stream-wise velocity profiles observed in the very near wake of the cylinder.

  15. Estrategias que permitan mejorar los productos de inversión y ahorro de las cooperativas de ahorro y crédito de la ciudad de Machala, caso: Cooperativa de Ahorro y Crédito Once de Junio Ltda.

    OpenAIRE

    Moran Molina, Germán Gracián

    2015-01-01

    El presente trabajo de investigación, titulado “Estrategias que permitan mejorar los productos de inversión y ahorro de las Cooperativas de ahorro y crédito de la ciudad de Machala, Caso: Cooperativa de Ahorro y Crédito Once de Junio Ltda.”, propone buscar un nuevo producto financiero que beneficie a una institución financiara netamente orense como lo es la cooperativa de ahorro y crédito “Once de Junio Ltda.” y obviamente a sus socios y clientes, con lo cual buscara afianzarse en el mercado ...

  16. Improved estimation of leak location of pipelines using frequency band variation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Sup [Embedded System Engineering Department, Incheon National University, Incheon (Korea, Republic of); Yoon, Dong Jin [Safety Measurement Center, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2014-02-15

    Leakage is an important factor to be considered for the management of underground water supply pipelines in a smart water grid system, especially if the pipelines are aged and buried under the pavement or various structures of a highly populated city. Because the exact detection of the location of such leaks in pipelines is essential for their efficient operation, a new methodology for leak location detection based on frequency band variation, windowing filters, and probability is proposed in this paper. Because the exact detection of the leak location depends on the precision of estimation of time delay between sensor signals due to leak noise, some window functions that offer weightings at significant frequencies are applied for calculating the improved cross-correlation function. Experimental results obtained by applying this methodology to an actual buried water supply pipeline, ∼ 253.9 m long and made of cast iron, revealed that the approach of frequency band variation with those windows and probability offers better performance for leak location detection.

  17. 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.

  18. Improved estimation of leak location of pipelines using frequency band variation

    International Nuclear Information System (INIS)

    Lee, Young Sup; Yoon, Dong Jin

    2014-01-01

    Leakage is an important factor to be considered for the management of underground water supply pipelines in a smart water grid system, especially if the pipelines are aged and buried under the pavement or various structures of a highly populated city. Because the exact detection of the location of such leaks in pipelines is essential for their efficient operation, a new methodology for leak location detection based on frequency band variation, windowing filters, and probability is proposed in this paper. Because the exact detection of the leak location depends on the precision of estimation of time delay between sensor signals due to leak noise, some window functions that offer weightings at significant frequencies are applied for calculating the improved cross-correlation function. Experimental results obtained by applying this methodology to an actual buried water supply pipeline, ∼ 253.9 m long and made of cast iron, revealed that the approach of frequency band variation with those windows and probability offers better performance for leak location detection.

  19. Ecological drivers of variation in tool-use frequency across sea otter populations

    Science.gov (United States)

    Fujii, Jessica; Ralls, Katherine; Tinker, M. Tim

    2015-01-01

    Sea otters are well-known tool users, employing objects such as rocks or shells to break open hard-shelled invertebrate prey. However, little is known about how the frequency of tool use varies among sea otter populations and the factors that drive these differences. We examined 17 years of observational data on prey capture and tool use from 8 sea otter populations ranging from southern California to the Aleutian Islands in Alaska. There were significant differences in the diets of these populations as well as variation in the frequency of tool use. Sea otters at Amchitka Island, Alaska, used tools on less than 1% of dives that resulted in the capture of prey compared with approximately 16% in Monterey, California. The percentage of individuals in the population that used tools ranged from 10% to 93%. In all populations, marine snails and thick-shelled bivalves were most likely to be associated with tool use, whereas soft-bodied prey items such as worms and sea stars were the least likely. The probability that a tool would be used on a given prey type varied across populations. The morphology of the prey item being handled and the prevalence of various types of prey in local diets were major ecological drivers of tool use: together they accounted for about 64% of the variation in tool-use frequency among populations. The remaining variation may be related to changes in the relative costs and benefits to an individual otter of learning to use tools effectively under differing ecological circumstances.

  20. Power variation and frequency regulation. Adaptation of PWR plant possibilities to the network needs

    International Nuclear Information System (INIS)

    Baboulin, J.P.; Burger, M.

    1980-01-01

    When the PWR are an important part of the power installed on a network, and that will be the case of the EDF network in the coming years, the participation of those plants to the power regulating becomes a necessity for the operating staff. This load regulating includes: daily variations of high amplitude; a permanent frequency - power regulating. The first part of the communication shows the network exploitation principles, and the resulting power variations concerning the existing nuclear power plants. Such transients are leading to stresses on fuel. The second part of the communication reports about the test program engaged by EDF in collaboration with the CEA and FRAMATOME, in order to study the fuel behaviour in real power conditions and power cycles, and that, just to the operational burn up of this fuel. (author)

  1. Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans.

    Directory of Open Access Journals (Sweden)

    Arbel Harpak

    2016-12-01

    Full Text Available The site frequency spectrum (SFS has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the "phylogenetically-conditioned SFS" or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC, combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans.

  2. 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.

  3. 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

  4. Radio-frequency characteristic variation of interdigital capacitor having multilayer graphene of various widths

    Science.gov (United States)

    Lee, Hee-Jo; Hong, Young-Pyo

    2018-03-01

    In this paper, a radio-frequency circuit model of an interdigital capacitor (IDC) with a multilayer graphene (MLG) width variation is proposed. The circuit model with three sample configurations, i.e., a bare IDC, IDC-MLG with a width of 5 μm, and IDC-MLG with a width of 20 μm, is constructed via a fitted method based on the measured samples. The simulated results of the circuit model are validated through the RF characteristics, e.g., the capacitance and the self-resonance frequency, of the measured samples. From the circuit model, all samples show not only a similar capacitance behavior but also an identical self-resonance frequency of 10 GHz. Moreover, the R, L, and C values of MLG with a 5 μm width (MLG with a 20 μm width) alone are approximately 0.8 kΩ (0.5 kΩ), 0.5 nH (0.9 nH), and 0.3 pF (0.1 pF), respectively. As a result, we find that the simulated results are in good agreement with RF characteristics of the measured samples. In the future, we expect that the proposed circuit model of an IDC with MLG will offer assistance with performance predictions of diverse IDC-based 2D material applications, such as biosensors and gas sensors, as well as supercapacitors.

  5. Determining Time Variation of Cable Tension Forces in Suspended Bridges Using Time-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Gannon Stromquist-LeVoir

    2018-01-01

    Full Text Available A feasibility study was conducted to develop a novel method to determine the temporal changes of tensile forces in bridge suspender cables using time-frequency analysis of ambient vibration measurements. An analytical model of the suspender cables was developed to evaluate the power spectral density (PSD function of a cable with consideration of cable flexural stiffness. Discrete-time, short-time Fourier transform (STFT was utilized to analyze the recorded acceleration histories in both time and frequency domains. A mathematical convolution of the analytical PSD function and time-frequency data was completed to evaluate changes in cable tension force over time. The method was implemented using acceleration measurements collected from an in-service steel arch bridge with a suspended deck to calculate the temporal variation in cable forces from the vibration measurements. The observations served as proof of concept that the proposed method may be used for cable fatigue life calculations and bridge weigh-in-motion studies.

  6. 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.

  7. 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.

  8. 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)

    1999-12-31

    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.

  9. Frequency of mononuclear diploid cardiomyocytes underlies natural variation in heart regeneration.

    Science.gov (United States)

    Patterson, Michaela; Barske, Lindsey; Van Handel, Ben; Rau, Christoph D; Gan, Peiheng; Sharma, Avneesh; Parikh, Shan; Denholtz, Matt; Huang, Ying; Yamaguchi, Yukiko; Shen, Hua; Allayee, Hooman; Crump, J Gage; Force, Thomas I; Lien, Ching-Ling; Makita, Takako; Lusis, Aldons J; Kumar, S Ram; Sucov, Henry M

    2017-09-01

    Adult mammalian cardiomyocyte regeneration after injury is thought to be minimal. Mononuclear diploid cardiomyocytes (MNDCMs), a relatively small subpopulation in the adult heart, may account for the observed degree of regeneration, but this has not been tested. We surveyed 120 inbred mouse strains and found that the frequency of adult mononuclear cardiomyocytes was surprisingly variable (>7-fold). Cardiomyocyte proliferation and heart functional recovery after coronary artery ligation both correlated with pre-injury MNDCM content. Using genome-wide association, we identified Tnni3k as one gene that influences variation in this composition and demonstrated that Tnni3k knockout resulted in elevated MNDCM content and increased cardiomyocyte proliferation after injury. Reciprocally, overexpression of Tnni3k in zebrafish promoted cardiomyocyte polyploidization and compromised heart regeneration. Our results corroborate the relevance of MNDCMs in heart regeneration. Moreover, they imply that intrinsic heart regeneration is not limited nor uniform in all individuals, but rather is a variable trait influenced by multiple genes.

  10. Extreme Recombination Frequencies Shape Genome Variation and Evolution in the Honeybee, Apis mellifera

    Science.gov (United States)

    Wallberg, Andreas; Glémin, Sylvain; Webster, Matthew T.

    2015-01-01

    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. PMID:25902173

  11. 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.

  12. Low-frequency variation of a zonally localized jet stream: Observation and theory

    International Nuclear Information System (INIS)

    Cai, M.

    1994-01-01

    The climatological mean circulation in the extratropics of the Northern Hemisphere is characterized by two zonally localized jet streams over the east coasts of the two major continents. The zonal inhomogeneity of the climatological mean circulation is believed to be a primary factor determining the geographical locations of the maximum activity centers of the atmospheric transients, such as storm tracks over the east coasts of the two major continents and frequent blocking episodes occurring over the central regions of the two oceans. The impact of the transients on the zonally localized jet streams is studied mostly in the linear dynamics framework in terms of so-called open-quotes feedbackclose quotes diagnosis. This study investigates nonlinear instability of a zonally localized jet stream. The emphasis is on the nonlinear adjustment of a zonally localized jet stream associated with the development of the transients via local instability. The adjustment of a zonally localized jet stream would naturally consists of two parts: One is the time-invariant part and the other is the transient part (temporal variation of the adjustment). In conjunction with the observation, the time-mean adjustment is part of the climatological mean flow and hence is open-quotes invisible.close quotes The transient part of the adjustment is evidenced by the changes of the jet streams in terms of both location and intensity. In this study, we tend to relate the transient part of the adjustment of the jet stream to the maximum activity centers of low-frequency variability. The underlying mechanisms that are responsible for the temporal variation of the adjustment will be investigated. The time-mean adjustment will be also studied to better understand the temporal variation of the adjustment

  13. Effects of variations of stage and flux at different frequencies on the estimates using river stage tomography

    Science.gov (United States)

    Wang, Y. L.; Yeh, T. C. J.; Wen, J. C.

    2017-12-01

    This study is to investigate the ability of river stage tomography to estimate the spatial distribution of hydraulic transmissivity (T), storage coefficient (S), and diffusivity (D) in groundwater basins using information of groundwater level variations induced by periodic variations of stream stage, and infiltrated flux from the stream boundary. In order to accomplish this objective, the sensitivity and correlation of groundwater heads with respect to the hydraulic properties is first conducted to investigate the spatial characteristics of groundwater level in response to the stream variations at different frequencies. Results of the analysis show that the spatial distributions of the sensitivity of heads at an observation well in response to periodic river stage variations are highly correlated despite different frequencies. On the other hand, the spatial patterns of the sensitivity of the observed head to river flux boundaries at different frequencies are different. Specifically, the observed head is highly correlated with T at the region between the stream and observation well when the high-frequency periodic flux is considered. On the other hand, it is highly correlated with T at the region between monitoring well and the boundary opposite to the stream when the low-frequency periodic flux is prescribed to the stream. We also find that the spatial distributions of the sensitivity of observed head to S variation are highly correlated with all frequencies in spite of heads or fluxes stream boundary. Subsequently, the differences of the spatial correlations of the observed heads to the hydraulic properties under the head and flux boundary conditions are further investigated by an inverse model (i.e., successive stochastic linear estimator). This investigation uses noise-free groundwater and stream data of a synthetic aquifer, where aquifer heterogeneity is known exactly. The ability of river stage tomography is then tested with these synthetic data sets to

  14. Dielectric properties of porcine cerebrospinal tissues at microwave frequencies: in vivo, in vitro and systematic variation with age

    International Nuclear Information System (INIS)

    Peyman, A; Holden, S J; Watts, S; Perrott, R; Gabriel, C

    2007-01-01

    The dielectric properties of pig cerebrospinal tissues were measured in vivo and in vitro, in the frequency range of 50 MHz-20 GHz. The total combined measurement uncertainty was calculated at each frequency point and is reported over representative frequency regions. Comparisons were made for each tissue between the two sets of data and with the literature of the past decade. The in vitro study was extended to include tissue from pigs weighing approximately 10, 50 and 250 kg to re-visit the question of the variation of dielectric properties with age. White matter and spinal chord showed significant variation as function of animal age, no age-related variations were recorded for grey matter

  15. Distortion of the activation energy of high temperature internal friction background due to temperature dependence frequency variations

    International Nuclear Information System (INIS)

    Lambri, O.; Povolo, F.; Molinas, B.

    1991-01-01

    In this work, a study is made of how the variation of frequency with temperature affects an activation enthalpy. This effect is usually neglected, but in some cases like Cu-Au or Zry-4 (an alloy of nuclear interest base or Zr alloyed with Sn, Fe and Cr) such variation can rise up to as much as 16%/4/ and 37%/5/. (Author) [es

  16. 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.; Griffin, Tiffany M.

    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...

  17. frequency and seasonal variation of plasmodium species in southern districts of Khyber pakhtunkhwa

    International Nuclear Information System (INIS)

    Khan, N.U.

    2014-01-01

    To determine the frequency of malaria and seasonal variation of Plasmodium species in southern districts of Khyber Pakhtunkhwa. Study Design: Descriptive study. Place and Duration of study: Department of Pathology Combined Military Hospital (CMH), Bannu, from 1st January 2010 to 31st December 2011. Patients and Methods: Five thousand eight hundred and seventy eight (5878) patients with symptoms of fever, nausea, malaise and body aches irrespective of age and gender were included in the study. Samples were collected, thin and thick smears of the samples were prepared and stained with Giemsa's stain. Thick film was used for screening for malaria parasites and species identification was done on thin smears. Results: Out of 5878 patients, 1962 (28.8%) were found to be positive for malaria. Of them 1524 (90%) had plasmodium vivax infection, while 119 (7.0%) patients were infected with plasmodium falciparum, 49 (3.0%) of the patients were infected with both Plasmodium vivax and Plasmodium falciparum. Plasmodium vivax was most common in the months of August 203 (12.3%) patients, September 235 (14.3%) patients and October 317 (20%), whereas plasmodium falciparum infection was most common in the months of October 34 (28.6%) patients, November 19 (16%) patients and December 30 (25.2%) patients. Conclusion: Malaria is an endemic infectious disease in Pakistan, in the Southern districts of Khyber Pakhtunkhaw and tribal areas of North and South Waziristan. It is prevalent throughout the year and most noticeably from May to November. (author)

  18. 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.

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

    Science.gov (United States)

    Ferraz da Costa, Maria do Socorro; Guimarães, Marcos Pezzi; Lima, Walter dos Santos; Ferraz da Costa, Ana Julia; Facury Filho, Elias Jorge; Araujo, Ricardo Nascimento

    2014-01-01

    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. PMID:26464941

  20. Testing the Sensory Drive Hypothesis: Geographic variation in echolocation frequencies of Geoffroy's horseshoe bat (Rhinolophidae: Rhinolophus clivosus).

    Science.gov (United States)

    Jacobs, David S; Catto, Sarah; Mutumi, Gregory L; Finger, Nikita; Webala, Paul W

    2017-01-01

    Geographic variation in sensory traits is usually influenced by adaptive processes because these traits are involved in crucial life-history aspects including orientation, communication, lineage recognition and mate choice. Studying this variation can therefore provide insights into lineage diversification. According to the Sensory Drive Hypothesis, lineage diversification may be driven by adaptation of sensory systems to local environments. It predicts that acoustic signals vary in association with local climatic conditions so that atmospheric attenuation is minimized and transmission of the signals maximized. To test this prediction, we investigated the influence of climatic factors (specifically relative humidity and temperature) on geographic variation in the resting frequencies of the echolocation pulses of Geoffroy's horseshoe bat, Rhinolophus clivosus. If the evolution of phenotypic variation in this lineage tracks climate variation, human induced climate change may lead to decreases in detection volumes and a reduction in foraging efficiency. A complex non-linear interaction between relative humidity and temperature affects atmospheric attenuation of sound and principal components composed of these correlated variables were, therefore, used in a linear mixed effects model to assess their contribution to observed variation in resting frequencies. A principal component composed predominantly of mean annual temperature (factor loading of -0.8455) significantly explained a proportion of the variation in resting frequency across sites (P < 0.05). Specifically, at higher relative humidity (around 60%) prevalent across the distribution of R. clivosus, increasing temperature had a strong negative effect on resting frequency. Climatic factors thus strongly influence acoustic signal divergence in this lineage, supporting the prediction of the Sensory Drive Hypothesis. The predicted future increase in temperature due to climate change is likely to decrease the

  1. Testing the Sensory Drive Hypothesis: Geographic variation in echolocation frequencies of Geoffroy's horseshoe bat (Rhinolophidae: Rhinolophus clivosus.

    Directory of Open Access Journals (Sweden)

    David S Jacobs

    Full Text Available Geographic variation in sensory traits is usually influenced by adaptive processes because these traits are involved in crucial life-history aspects including orientation, communication, lineage recognition and mate choice. Studying this variation can therefore provide insights into lineage diversification. According to the Sensory Drive Hypothesis, lineage diversification may be driven by adaptation of sensory systems to local environments. It predicts that acoustic signals vary in association with local climatic conditions so that atmospheric attenuation is minimized and transmission of the signals maximized. To test this prediction, we investigated the influence of climatic factors (specifically relative humidity and temperature on geographic variation in the resting frequencies of the echolocation pulses of Geoffroy's horseshoe bat, Rhinolophus clivosus. If the evolution of phenotypic variation in this lineage tracks climate variation, human induced climate change may lead to decreases in detection volumes and a reduction in foraging efficiency. A complex non-linear interaction between relative humidity and temperature affects atmospheric attenuation of sound and principal components composed of these correlated variables were, therefore, used in a linear mixed effects model to assess their contribution to observed variation in resting frequencies. A principal component composed predominantly of mean annual temperature (factor loading of -0.8455 significantly explained a proportion of the variation in resting frequency across sites (P < 0.05. Specifically, at higher relative humidity (around 60% prevalent across the distribution of R. clivosus, increasing temperature had a strong negative effect on resting frequency. Climatic factors thus strongly influence acoustic signal divergence in this lineage, supporting the prediction of the Sensory Drive Hypothesis. The predicted future increase in temperature due to climate change is likely to

  2. Ulysses: accurate detection of low-frequency structural variations in large insert-size sequencing libraries.

    Science.gov (United States)

    Gillet-Markowska, Alexandre; Richard, Hugues; Fischer, Gilles; Lafontaine, Ingrid

    2015-03-15

    The detection of structural variations (SVs) in short-range Paired-End (PE) libraries remains challenging because SV breakpoints can involve large dispersed repeated sequences, or carry inherent complexity, hardly resolvable with classical PE sequencing data. In contrast, large insert-size sequencing libraries (Mate-Pair libraries) provide higher physical coverage of the genome and give access to repeat-containing regions. They can thus theoretically overcome previous limitations as they are becoming routinely accessible. Nevertheless, broad insert size distributions and high rates of chimerical sequences are usually associated to this type of libraries, which makes the accurate annotation of SV challenging. Here, we present Ulysses, a tool that achieves drastically higher detection accuracy than existing tools, both on simulated and real mate-pair sequencing datasets from the 1000 Human Genome project. Ulysses achieves high specificity over the complete spectrum of variants by assessing, in a principled manner, the statistical significance of each possible variant (duplications, deletions, translocations, insertions and inversions) against an explicit model for the generation of experimental noise. This statistical model proves particularly useful for the detection of low frequency variants. SV detection performed on a large insert Mate-Pair library from a breast cancer sample revealed a high level of somatic duplications in the tumor and, to a lesser extent, in the blood sample as well. Altogether, these results show that Ulysses is a valuable tool for the characterization of somatic mosaicism in human tissues and in cancer genomes. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. 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.

  4. 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.

  5. Variations in frequency content of acoustic emission during extension of HF-1 steel

    International Nuclear Information System (INIS)

    Hartman, W.F.; Kline, R.A.

    1977-01-01

    Acoustic emissions resulting from continuous, dead-weight, tensile loading of quenched and tempered HF-1 steel were analyzed for frequency content. Three distinct frequency spectra were observed. These correspond to microplasticity, plasticity and deformation after recovery. It is shown that frequency analysis of acoustic emission can be a sensitive evaluation technique for assessing structural integrity

  6. Correlation analysis of extremely low-frequency variations of the natural electromagnetic Earth field and the problem of detecting periodical gravitational radiation

    International Nuclear Information System (INIS)

    Balakin, A.B.; Murzakhanov, Z.G.; Grunskaya, L.V.

    1994-01-01

    A proposal on the experimental detection of extremely low-frequency variations of the electromagnetic Earth field at the gravitational-wave frequency and method for correlation processing results of the experiments are described. 14 refs

  7. Low-frequency pulse profile variation in PSR B2217+47: evidence for echoes from the interstellar medium

    Science.gov (United States)

    Michilli, D.; Hessels, J. W. T.; Donner, J. Y.; Grießmeier, J.-M.; Serylak, M.; Shaw, B.; Stappers, B. W.; Verbiest, J. P. W.; Deller, A. T.; Driessen, L. N.; Stinebring, D. R.; Bondonneau, L.; Geyer, M.; Hoeft, M.; Karastergiou, A.; Kramer, M.; Osłowski, S.; Pilia, M.; Sanidas, S.; Weltevrede, P.

    2018-05-01

    We have observed a complex and continuous change in the integrated pulse profile of PSR B2217+47, manifested as additional components trailing the main peak. These transient components are detected over 6 yr at 150 MHz using the LOw Frequency ARray (LOFAR), but they are not seen in contemporaneous Lovell observations at 1.5 GHz. We argue that propagation effects in the ionized interstellar medium (IISM) are the most likely cause. The putative structures in the IISM causing the profile variation are roughly half-way between the pulsar and the Earth and have transverse radii R ˜ 30 au. We consider different models for the structures. Under the assumption of spherical symmetry, their implied average electron density is \\overline{n}_e ˜ 100 cm-3. Since PSR B2217+47 is more than an order of magnitude brighter than the average pulsar population visible to LOFAR, similar profile variations would not have been identified in most pulsars, suggesting that subtle profile variations in low-frequency profiles might be more common than we have observed to date. Systematic studies of these variations at low frequencies can provide a new tool to investigate the proprieties of the IISM and the limits to the precision of pulsar timing.

  8. Coordinated frequency control from offshore wind power plants connected to multi terminal DC system considering wind speed variation

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Altin, Müfit; Hansen, Anca Daniela

    2017-01-01

    A coordinated fast primary frequency control scheme from offshore wind power plants (OWPPs) integrated to a three terminal high voltage DC (HVDC) system is proposed in this study. The impact of wind speed variation on the OWPP active power output and thus on the AC grid frequency and DC grid...... the active power support from OWPP with a ramp rate limiter and (iii) An alternative method for the wind turbine overloading considering rotor speed. The effectiveness of the proposed control scheme is demonstrated on a wind power plant integrated into a three terminal HVDC system developed in DIg......SILIENT PowerFactory. The results show that the proposed coordinated frequency control method performs effectively at different wind speeds and minimises the secondary effects on frequency and DC voltage....

  9. 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.

  10. 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.

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

    International Nuclear Information System (INIS)

    Hardin, M; Harrison, A; Lockamy, V; Li, J; Peng, C; Potrebko, P; Yu, Y; Doyle, L; Cao, J

    2015-01-01

    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

  12. 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

  13. 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...

  14. Effects of feeding frequency variation on the growth and survival of ...

    African Journals Online (AJOL)

    Highest survival rate of 73.3% was recorded in fingerlings fed once in two days. The study showed that body composition of C. gariepinus fingerlings was influenced by the different feeding frequencies. Based on the growth performance recorded in this research, once in a day feeding frequency was the best to obtain the ...

  15. Low-frequency and common genetic variation in ischemic stroke: The METASTROKE collaboration.

    Science.gov (United States)

    Malik, Rainer; Traylor, Matthew; Pulit, Sara L; Bevan, Steve; Hopewell, Jemma C; Holliday, Elizabeth G; Zhao, Wei; Abrantes, Patricia; Amouyel, Philippe; Attia, John R; Battey, Thomas W K; Berger, Klaus; Boncoraglio, Giorgio B; Chauhan, Ganesh; Cheng, Yu-Ching; Chen, Wei-Min; Clarke, Robert; Cotlarciuc, Ioana; Debette, Stephanie; Falcone, Guido J; Ferro, Jose M; Gamble, Dale M; Ilinca, Andreea; Kittner, Steven J; Kourkoulis, Christina E; Lemmens, Robin; Levi, Christopher R; Lichtner, Peter; Lindgren, Arne; Liu, Jingmin; Meschia, James F; Mitchell, Braxton D; Oliveira, Sofia A; Pera, Joana; Reiner, Alex P; Rothwell, Peter M; Sharma, Pankaj; Slowik, Agnieszka; Sudlow, Cathie L M; Tatlisumak, Turgut; Thijs, Vincent; Vicente, Astrid M; Woo, Daniel; Seshadri, Sudha; Saleheen, Danish; Rosand, Jonathan; Markus, Hugh S; Worrall, Bradford B; Dichgans, Martin

    2016-03-29

    To investigate the influence of common and low-frequency genetic variants on the risk of ischemic stroke (all IS) and etiologic stroke subtypes. We meta-analyzed 12 individual genome-wide association studies comprising 10,307 cases and 19,326 controls imputed to the 1000 Genomes (1 KG) phase I reference panel. We selected variants showing the highest degree of association (p frequencies for all IS and stroke subtypes. We showed genome-wide significance for 4 loci: ABO for all IS, HDAC9 for large vessel disease (LVD), and both PITX2 and ZFHX3 for cardioembolic stroke (CE). We further refined the association peaks for ABO and PITX2. Analyzing different allele frequency bins, we showed significant enrichment in low-frequency variants (allele frequency frequency variants (allele frequency 10% and 30%) for CE (all p low-frequency and rare variants. Larger sample sizes are needed to identify the variants associated with all IS and stroke subtypes. © 2016 American Academy of Neurology.

  16. Frequency response variation of two offshore wind park transformers with different tap changer positions

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holbøll, Joachim; Sørensen, T

    2010-01-01

    This paper presents the results of several sweep frequency response analysis (SFRA) measurements performed on two identical offshore wind farm transformers. A comparison is made between the transformers based on different recommended measurements and procedures, different measurement systems...

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

    OpenAIRE

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

    2015-01-01

    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 selecti...

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

    OpenAIRE

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    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 ...

  19. Variation in recombination frequency and distribution across eukaryotes: patterns and processes

    Science.gov (United States)

    Feulner, Philine G. D.; Johnston, Susan E.; Santure, Anna W.; Smadja, Carole M.

    2017-01-01

    Recombination, the exchange of DNA between maternal and paternal chromosomes during meiosis, is an essential feature of sexual reproduction in nearly all multicellular organisms. While the role of recombination in the evolution of sex has received theoretical and empirical attention, less is known about how recombination rate itself evolves and what influence this has on evolutionary processes within sexually reproducing organisms. Here, we explore the patterns of, and processes governing recombination in eukaryotes. We summarize patterns of variation, integrating current knowledge with an analysis of linkage map data in 353 organisms. We then discuss proximate and ultimate processes governing recombination rate variation and consider how these influence evolutionary processes. Genome-wide recombination rates (cM/Mb) can vary more than tenfold across eukaryotes, and there is large variation in the distribution of recombination events across closely related taxa, populations and individuals. We discuss how variation in rate and distribution relates to genome architecture, genetic and epigenetic mechanisms, sex, environmental perturbations and variable selective pressures. There has been great progress in determining the molecular mechanisms governing recombination, and with the continued development of new modelling and empirical approaches, there is now also great opportunity to further our understanding of how and why recombination rate varies. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109219

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

    Directory of Open Access Journals (Sweden)

    Serdar Dirihan

    Full Text Available 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

  1. Space Shuttle Redesigned Solid Rocket Motor nozzle natural frequency variations with burn time

    Science.gov (United States)

    Lui, C. Y.; Mason, D. R.

    1991-01-01

    The effects of erosion and thermal degradation on the Space Shuttle Redesigned Solid Rocket Motor (RSRM) nozzle's structural dynamic characteristics were analytically evaluated. Also considered was stiffening of the structure due to internal pressurization. A detailed NASTRAN finite element model of the nozzle was developed and used to evaluate the influence of these effects at several discrete times during motor burn. Methods were developed for treating erosion and thermal degradation, and a procedure was developed to account for internal pressure stiffening using differential stiffness matrix techniques. Results were verified using static firing test accelerometer data. Fast Fourier Transform and Maximum Entropy Method techniques were applied to the data to generate waterfall plots which track modal frequencies with burn time. Results indicate that the lower frequency nozzle 'vectoring' modes are only slightly affected by erosion, thermal effects and internal pressurization. The higher frequency shell modes of the nozzle are, however, significantly reduced.

  2. 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.

  3. 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.

  4. Infraspecific variation of C-banded karyotype and chiasma frequency in Cucumis sativus (Cucurbitaceae)

    NARCIS (Netherlands)

    Ramachandran, C.; Brandenburg, W.A.; Nijs, de S.A.P.M.

    1985-01-01

    Infraspecific cytogenetical variation was studied in a diverse collection of five non-cultivated and cultivatedCucumis sativus accessions. The individual chromosomes of different accessions could be identified by the C-banding pattern and chromosome measurements. About 40–50% of the genomic area are

  5. Ethnic variations in UK asthma frequency, morbidity, and health-service use: a systematic review and meta-analysis.

    Science.gov (United States)

    Netuveli, Gopalakrishnan; Hurwitz, Brian; Levy, Mark; Fletcher, Monica; Barnes, Greta; Durham, Stephen R; Sheikh, Aziz

    The frequency of asthma varies between countries, and may also vary between ethnic groups in more geographically confined areas. We sought evidence of such ethnic variations in the UK for asthma frequency, morbidity, and health-services use, and to understand possible reasons for any differences. We searched MEDLINE, EMBASE, CINAHL, PSYCHInfo, PREMEDLINE, HEALTHSTAR, Cambridge Register of Conference Abstracts, the Dissertation and Thesis Database, and the National Registry of Research. Additionally, we searched the bibliographies of reports identified and websites of health authorities, and contacted experts in this discipline. Our main outcomes were comparisons of asthma rate, morbidity, and health-services use. We did meta-analyses using random-effects models. 13 studies contained relevant data. All prevalence studies were of children and showed that south Asian children had a lower frequency of symptoms suggestive of asthma compared with black and white children (pooled rate of history of wheeze in the previous 12 months: south Asians 9.6% [95%CI 8.0-11.2%], black people 16.2% [12.8-19.6%], white people 14.6% [11.5-17.8%]). The pooled frequency of clinician-diagnosed asthma in children followed a similar pattern (south Asians 7.6% [3.7-11.4%], black people 15.0% [3.5-26.5%], white people 10.6% [4.6-16.7%]. However, relative to white people, the risk of admission for asthma in children and adults was higher for south Asians (odds ratio 2.9 [2.4-3.4]) and black people (2.1 [1.8-2.5]). The differences in admission are not explained by differences in asthma frequency between groups; they could relate to ethnic variations in asthma severity, differences in health-seeking behaviour, or difficulties in accessing high-quality primary care services.

  6. 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

    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 these amplifiers is self-oscillation. A parameter of key interest in self-oscillating amplifiers is the switching frequency, which is kno...

  7. Variation in sister chromatid exchange frequencies between human and pig whole blood, plasma leukocyte, and mononuclear leukocyte cultures

    International Nuclear Information System (INIS)

    Larramendy, M.L.; Reigosa, M.A.

    1986-01-01

    Sister chromatid exchange (SCE) induction by ultraviolet (UV) light was studied in both human and pig whole blood cultures (WBC) and plasma leukocyte cultures (PLC). No variation in SCE frequency was observed between pig WBC and PLC in control as well as in treated cells. Conversely, SCE frequencies of human PLC were consistently higher than those of WBC in control and UV-exposed cells. Thus, red blood cells (RBCs) do not influence the sensitivity of lymphocytes to UV LIGHT exposure, and there must be some different culture condition(s) in the inducation of SCEs between human WBC and PLC but not in swine lymphocyte cultures. Since the BrdUrd/lymphocyte ratio of WBC was halved in PLC, the effect of BrdUrd concentration in inducing the SCE baseline frequency of PLC may be ruled out. Neither the cell separation technique nor polymorphonuclear leukocytes had a significant role in the elevated SCE frequency of human PLC or MLC. Experiments where human RBCs were titrated into human PLC showed that the induction of an elevated SCE frequency of PLC was suppressed in a dose-dependent manner by the presence of RBCs in the culture medium. Since the incorporation of pig or human RBCs into human PLC as well as into MLC reduced the SCE frequency to that of WBC, a common component and/or function existing in these cells is suggested. Analysis of different RBC components showed that RBCs, specifically RBC ghosts, release a diffusible but not dialyzable corrective factor into culture medium that is able to reduce the SCE frequencies of PLC

  8. 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.

  9. Generalized expressions for variations in critical frequencies, electron densities and altitudes of the ionospheric layers

    International Nuclear Information System (INIS)

    Njau, E.C.

    1990-12-01

    We develop generalized mathematical expressions for time and space variations of peak electron densities of the ionospheric D, E, F1 and F2 layers as well as corresponding variations in the altitudes of the electron density peaks in each of these layers. On the basis of the Chapman characteristics of the E and F1 layers and other techniques, a generalized expression is developed for the electron density height profile of each of the four ionospheric layers. Consequently a generalized mathematical expression is developed for the entire electron density height profile of the whole ionosphere as a function of time, latitude and longitude. The latter mathematical expression may be used to compute or predict ionospheric parameters associated with ratio and satellite communications. Finally we show that some well documented equations on ionospheric parameters are simplified (or approximated) versions of some of our mathematical expressions. (author). 29 refs

  10. 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

    1993-12-31

    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.

  11. 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.

  12. Frequency of palmaris longus absence and its association with other anatomical variations in the Egyptian population.

    Science.gov (United States)

    Raouf, Hoda Abdel; Kader, Ghada Abdel; Jaradat, Ahmed; Dharap, Amol; Fadel, Raouf; Salem, Abdel Halim

    2013-07-01

    The palmaris longus (PL) is one of the most variable muscles in the human body. Racial differences in its variation have been documented. Several studies have attempted to correlate PL absence with other anatomical variations. This study was conducted to determine the prevalence of absence of PL, correlate it with gender and body side and to determine its association with other anatomical variations in the Egyptian population. The presence of PL was clinically determined in 386 Egyptians using the standard technique. All subjects were examined for the presence of the flexor digitorum superficialis (FDS) to the fifth finger. Allen's test was done to assess the completeness of the superficial palmar arch (SPA). The overall prevalence of absence of the PL in Egyptian subjects was 50.8%. There was no significant difference in PL absence with regard to the body side but a significant difference was seen as regards gender and when bilateral absence of PL was compared to its unilateral absence. Absence of FDS tendon to the fifth finger was seen in 1.3% subjects. There was no association between the absence of the FDS tendon to the fifth finger and either presence or absence of PL and also between the absence of PL and the incompleteness of SPA in both genders. In conclusion, the prevalence of absence of PL in the Egyptian population represents one of the highest rates of absence to be reported for this muscle, which is significantly different from that in other ethnic groups. Copyright © 2013 Wiley Periodicals, Inc.

  13. Advanced impedance matching system for ICRF heating using innovative twin stub tuner and frequency variation

    International Nuclear Information System (INIS)

    Kumazawa, R.; Saito, K.; Kasahara, H.; Seki, T.; Mutoh, T.; Shimpo, F.; Nomura, G.; Kato, A.; Okada, H.; Zhao, Y.; Kwak, J.G.; Yoon, J.S.

    2008-01-01

    Ion cyclotron range of frequency (ICRF) heating has been a reliable tool for steady-state plasma heating with high RF power of several tens of megawatts. However, a sudden increase in the reflected RF power during ICRF heating experiments with ELMy H-mode plasmas is an issue which must be solved for future fusion experimental devices or fusion reactors. This paper describes an innovative ICRF heating system using a frequency feedback control to reduce the reflected power in response to the rapid change in the plasma impedance in the ELMy H-mode plasma. A twin stub tuner has been newly invented for this purpose. The feasibility of keeping the reflected RF power fraction at a low level, e.g. 1%, is demonstrated even with a large change in plasma resistance, e.g. 2 ∼ 8Ω. Calculated and experimental results are presented for the conventional double stub tuner impedance matching system equipped with the twin stub tuner.

  14. Investigation of common, low-frequency and rare genome-wide variation in anorexia nervosa

    Science.gov (United States)

    Huckins, L M; Hatzikotoulas, K; Southam, L; Thornton, L M; Steinberg, J; Aguilera-McKay, F; Treasure, J; Schmidt, U; Gunasinghe, C; Romero, A; Curtis, C; Rhodes, D; Moens, J; Kalsi, G; Dempster, D; Leung, R; Keohane, A; Burghardt, R; Ehrlich, S; Hebebrand, J; Hinney, A; Ludolph, A; Walton, E; Deloukas, P; Hofman, A; Palotie, A; Palta, P; van Rooij, F J A; Stirrups, K; Adan, R; Boni, C; Cone, R; Dedoussis, G; van Furth, E; Gonidakis, F; Gorwood, P; Hudson, J; Kaprio, J; Kas, M; Keski-Rahonen, A; Kiezebrink, K; Knudsen, G-P; Slof-Op 't Landt, M C T; Maj, M; Monteleone, A M; Monteleone, P; Raevuori, A H; Reichborn-Kjennerud, T; Tozzi, F; Tsitsika, A; van Elburg, A; Adan, R A H; Alfredsson, L; Ando, T; Andreassen, O A; Aschauer, H; Baker, J H; Barrett, J C; Bencko, V; Bergen, A W; Berrettini, W H; Birgegard, A; Boni, C; Boraska Perica, V; Brandt, H; Breen, G; Bulik, C M; Carlberg, L; Cassina, M; Cichon, S; Clementi, M; Cohen-Woods, S; Coleman, J; Cone, R D; Courtet, P; Crawford, S; Crow, S; Crowley, J; Danner, U N; Davis, O S P; de Zwaan, M; Dedoussis, G; Degortes, D; DeSocio, J E; Dick, D M; Dikeos, D; Dina, C; Ding, B; Dmitrzak-Weglarz, M; Docampo, E; Duncan, L; Egberts, K; Ehrlich, S; Escaramís, G; Esko, T; Espeseth, T; Estivill, X; Favaro, A; Fernández-Aranda, F; Fichter, M M; Finan, C; Fischer, K; Floyd, J A B; Foretova, L; Forzan, M; Franklin, C S; Gallinger, S; Gambaro, G; Gaspar, H A; Giegling, I; Gonidakis, F; Gorwood, P; Gratacos, M; Guillaume, S; Guo, Y; Hakonarson, H; Halmi, K A; Hatzikotoulas, K; Hauser, J; Hebebrand, J; Helder, S; Herms, S; Herpertz-Dahlmann, B; Herzog, W; Hilliard, C E; Hinney, A; Hübel, C; Huckins, L M; Hudson, J I; Huemer, J; Inoko, H; Janout, V; Jiménez-Murcia, S; Johnson, C; Julià, A; Juréus, A; Kalsi, G; Kaminska, D; Kaplan, A S; Kaprio, J; Karhunen, L; Karwautz, A; Kas, M J H; Kaye, W; Kennedy, J L; Keski-Rahkonen, A; Kiezebrink, K; Klareskog, L; Klump, K L; Knudsen, G P S; Koeleman, B P C; Koubek, D; La Via, M C; Landén, M; Le Hellard, S; Levitan, R D; Li, D; Lichtenstein, P; Lilenfeld, L; Lissowska, J; Lundervold, A; Magistretti, P; Maj, M; Mannik, K; Marsal, S; Martin, N; Mattingsdal, M; McDevitt, S; McGuffin, P; Merl, E; Metspalu, A; Meulenbelt, I; Micali, N; Mitchell, J; Mitchell, K; Monteleone, P; Monteleone, A M; Mortensen, P; Munn-Chernoff, M A; Navratilova, M; Nilsson, I; Norring, C; Ntalla, I; Ophoff, R A; O'Toole, J K; Palotie, A; Pante, J; Papezova, H; Pinto, D; Rabionet, R; Raevuori, A; Rajewski, A; Ramoz, N; Rayner, N W; Reichborn-Kjennerud, T; Ripatti, S; Roberts, M; Rotondo, A; Rujescu, D; Rybakowski, F; Santonastaso, P; Scherag, A; Scherer, S W; Schmidt, U; Schork, N J; Schosser, A; Slachtova, L; Sladek, R; Slagboom, P E; Slof-Op 't Landt, M C T; Slopien, A; Soranzo, N; Southam, L; Steen, V M; Strengman, E; Strober, M; Sullivan, P F; Szatkiewicz, J P; Szeszenia-Dabrowska, N; Tachmazidou, I; Tenconi, E; Thornton, L M; Tortorella, A; Tozzi, F; Treasure, J; Tsitsika, A; Tziouvas, K; van Elburg, A A; van Furth, E F; Wagner, G; Walton, E; Watson, H; Wichmann, H-E; Widen, E; Woodside, D B; Yanovski, J; Yao, S; Yilmaz, Z; Zeggini, E; Zerwas, S; Zipfel, S; Collier, D A; Sullivan, P F; Breen, G; Bulik, C M; Zeggini, E

    2018-01-01

    Anorexia nervosa (AN) is a complex neuropsychiatric disorder presenting with dangerously low body weight, and a deep and persistent fear of gaining weight. To date, only one genome-wide significant locus associated with AN has been identified. We performed an exome-chip based genome-wide association studies (GWAS) in 2158 cases from nine populations of European origin and 15 485 ancestrally matched controls. Unlike previous studies, this GWAS also probed association in low-frequency and rare variants. Sixteen independent variants were taken forward for in silico and de novo replication (11 common and 5 rare). No findings reached genome-wide significance. Two notable common variants were identified: rs10791286, an intronic variant in OPCML (P=9.89 × 10−6), and rs7700147, an intergenic variant (P=2.93 × 10−5). No low-frequency variant associations were identified at genome-wide significance, although the study was well-powered to detect low-frequency variants with large effect sizes, suggesting that there may be no AN loci in this genomic search space with large effect sizes. PMID:29155802

  15. Caracterización del sector cooperativo de ahorro y crédito en el Valle del Cauca

    Directory of Open Access Journals (Sweden)

    Ximena Sánchez Mayorga

    2008-01-01

    Full Text Available El artículo presenta una caracterización del sector cooperativo de ahorro y crédito en el Valle del Cauca, el cual es uno de los objetivos a desarrollar en el proyecto de investigación "Análisis del sector cooperativo de ahorro y crédito en el Valle del Cauca y propuesta de estrategia. Caso Cooperativa de Ahorro del Valle", del Grupo de Investigación Gestión y Productividad Contable. El estudio muestra la dinámica de crecimiento que ha tenido el sector cooperativo de ahorro y crédito en el Valle del Cauca en los últimos cinco años, aportando a la bancarización en Colombia; también se revisa el sector de economía solidaria en Colombia, presentando estadísticas que permiten visualizar lo que representa este sector en la economía del país. Se identifican en el Valle del Cauca las entidades dedicadas a la actividad de ahorro y crédito, planteándose las diferencias entre estas entidades y los establecimientos bancarios del sector financiero tradicional, resaltando el aporte de las cooperativas de ahorro y crédito a la estrategia del Gobierno Nacional definida como la banca de oportunidades1; puesto que en estas entidades hay igualdad social para sus asociados, logrando que un mayor número de personas accedan a los servicios financieros, aportando al desarrollo económico de las localidades donde funcionan.

  16. Natural time analysis on the ultra-low frequency magnetic field variations prior to the 2016 Kumamoto (Japan) earthquakes

    Science.gov (United States)

    Potirakis, Stelios M.; Schekotov, Alexander; Asano, Tomokazu; Hayakawa, Masashi

    2018-04-01

    On 15 April 2016 a very strong and shallow earthquake (EQ) (MW = 7.0 , depth ∼ 10 km) occurred in Southwest Japan under the city of Kumamoto, while two very strong foreshocks (MW = 6.2 and MW = 6.0) preceded by about one day. The Kumamoto EQs being very catastrophic, have already attracted much attention among the scientific community in a quest for understanding the generation mechanism, as well as for reporting any preseismic anomalies in various observables and assessing the effectivity of the current early warning systems. In the present article we report precursory behavior of the ground-based observed ultra-low frequency (ULF) magnetic field variations before the Kumamoto EQs. By analyzing specific ULF magnetic field characteristics in terms of the recently introduced natural time (NT) analysis method, we identified that ULF magnetic field variations presented critical features from 2 weeks up to 1 month before the Kumamoto EQs. Specifically, the ULF magnetic field characteristics Fh , Fz , Dh and δDep were analyzed. The first two represent variations of the horizontal and vertical components of the geomagnetic field. The third and fourth characteristics correspond to the depression (decrease) and a relative depression of the horizontal magnetic field variations, respectively. The latter depends on the degree of ionospheric disturbance. All of them were found to reach criticality before the Kumamoto EQs; however, in different time periods for each characteristic.

  17. 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...... of electrical stress imposed on wind turbine transformers by voltage waveforms produced during switching operations. The method is implemented in Matlab together with automatic and systematic variation of parameters. Simulations of a radial energization are performed on a 90MVA offshore wind farm model...

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

    Directory of Open Access Journals (Sweden)

    Jairo Rivera-Posada

    2014-03-01

    Full Text Available Objective: To examine variation in the frequency of arm damage in different sizes of Acanthaster planci (A. planci, assess how this damage is inflicted by fish predators, and infer the potential role of predation in population regulation. Methods: Diameters of A. planci collected from three sites in the Philippines were measured 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 in 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.

  19. Process Inference from High Frequency Temporal Variations in Dissolved Organic Carbon (DOC) Dynamics Across Nested Spatial Scales

    Science.gov (United States)

    Tunaley, C.; Tetzlaff, D.; Lessels, J. S.; Soulsby, C.

    2014-12-01

    In order to understand aquatic ecosystem functioning it is critical to understand the processes that control the spatial and temporal variations in DOC. DOC concentrations are highly dynamic, however, our understanding at short, high frequency timescales is still limited. Optical sensors which act as a proxy for DOC provide the opportunity to investigate near-continuous DOC variations in order to understand the hydrological and biogeochemical processes that control concentrations at short temporal scales. Here we present inferred 15 minute stream water DOC data for a 12 month period at three nested scales (1km2, 3km2 and 31km2) for the Bruntland Burn, a headwater catchment in NE Scotland. High frequency data were measured using FDOM and CDOM probes which work by measuring the fluorescent component and coloured component, respectively, of DOC when exposed to ultraviolet light. Both FDOM and CDOM were strongly correlated (r2 >0.8) with DOC allowing high frequency estimations. Results show the close coupling of DOC with discharge throughout the sampling period at all three spatial scales. However, analysis at the event scale highlights anticlockwise hysteresis relationships between DOC and discharge due to the delay in DOC being flushed from the increasingly large areas of peaty soils as saturation zones expand and increase hydrological connectivity. Lag times vary between events dependent on antecedent conditions. During a 10 year drought period in late summer 2013 it was apparent that very small changes in discharge on a 15 minute timescale result in high increases in DOC. This suggests transport limitation during this period where DOC builds up in the soil and is not flushed regularly, therefore any subsequent increase in discharge results in large DOC peaks. The high frequency sensors also reveal diurnal variability during summer months related to the photo-oxidation, evaporative and biological influences of DOC during the day. This relationship is less

  20. 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)

  1. Genomic variation in CYP3A4: type, frequencies and potential implications for pharmacogenetic understanding.

    OpenAIRE

    Creemer, O.

    2012-01-01

    The human cytochrome P450 3A subfamily metabolises endogenous substances and approximately half of all currently available drugs. There is marked inter-individual variation in hepatic expression of the major adult isoform, CYP3A4; the genetic component of this variability is estimated at 60-90% and, as yet, remains largely uncharacterised. Elucidation of genetic factors determining CYP3A4 activity would permit personalised dose-adjustment in therapies with CYP3A4 drug substrates. CYP3A4 genom...

  2. Determinantes del perfil de ahorro en Colombia : una estimación para hogares e individuos

    OpenAIRE

    Daza Báez, Nancy Aireth

    2011-01-01

    En este documento se presenta un análisis de los determinantes del perfil de ahorro para hogares e individuos con el objetivo de contrastar la Hipótesis de Ciclo de Vida, utilizando la metodología expuesta en Deaton y Paxson (2000a y 2000b) con datos de la Encuesta Nacional de Ingresos y Gastos (ENIG) para los periodos 1984-1985, 1994-1995 y 2006-2007. Se encontró que para el análisis por hogar no hay evidencia que determine el cumplimiento de la Hipótesis del Ciclo de Vida, mientras que para...

  3. El ahorro fiscal de las cooperativas en el impuesto sobre Sociedades en España

    OpenAIRE

    Herrero Blasco, Aurelio

    2015-01-01

    [ES] El objeto de este artículo es medir el ahorro fiscal que procede del Impuesto sobre Sociedades de las cooperativas en España para el período 1999-2009. La metodología utilizada ha sido un estudio longitudinal en el cual se ha analizado la recaudación total en España por tipos impositivos. Se ha analizado el Impuesto sobre Sociedades en general y posteriormente el Tipo Impositivo Efectivo (TIE) de las Sociedades Cooperativas. Los resultados más importantes son la constatación de diferenc...

  4. 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.

  5. Gain variation of phototube in the frequency domain at very short term

    Energy Technology Data Exchange (ETDEWEB)

    Celani, F; Codino, A; Cora, U; Falcioni, R; Felici, G; Levy, G [Istituto Nazionale di Fisica Nucleare, Frascati (Italy); D' Ettorre Piazzoli, B; Mannocchi, G [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Bologna, G; Picchi, P [Turin Univ. (Italy). Ist. di Fisica

    1981-11-15

    A new very fast pulse generator with injected charge control is used to drive a LED-phototube configuration, reproducing the working conditions of many experiments in high energy physics which make use of fast plastic scintillators. We have studied the behavior of the Phillips XP 2008 phototube operated under such experimental conditions. We find a gain shift vs. frequency that is a function of intensity of the light incident on the PM. For an output ranging between 83 and 450 pC the gain shift at about 33 kHz varies in the range 15-33%.

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

    International Nuclear Information System (INIS)

    Kleimenova, N.; Kozyreva, O.V.; Francia, P.; Villante, U.

    1999-01-01

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

  7. 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.

  8. Calculation of vibrational frequencies through a variational reduced-coupling approach.

    Science.gov (United States)

    Scribano, Yohann; Benoit, David M

    2007-10-28

    In this study, we present a new method to perform accurate and efficient vibrational configuration interaction computations for large molecular systems. We use the vibrational self-consistent field (VSCF) method to compute an initial description of the vibrational wave function of the system, combined with the single-to-all approach to compute a sparse potential energy surface at the chosen ab initio level of theory. A Davidson scheme is then used to diagonalize the Hamiltonian matrix built on the VSCF virtual basis. Our method is applied to the computation of the OH-stretch frequency of formic acid and benzoic acid to demonstrate the efficiency and accuracy of this new technique.

  9. Experimental investigation on the effects of non-cyclical frequency and amplitude variation on dynamic stall

    Science.gov (United States)

    Heintz, Kyle C.

    An experimental study of a cambered airfoil undergoing non-cyclical, transient pitch trajectories and the resulting effects on the dynamic stall phenomenon is presented. Surface pressure measurements and airfoil incidence angle are acquired simultaneously to resolve instantaneous aerodynamic load coefficients at Mach numbers ranging from 0.2 to 0.4. Derived from these coefficients are various formulations of the aerodynamic damping factor, referred to copiously throughout. Using a two-motor mechanism, each providing independent frequency and amplitude input to the airfoil, unique pitch motions can be implemented by actively controlling the phase between inputs. This work primarily focuses on three pitch motion schemas, the first of which is a "chirp" style trajectory featuring concurrent exponential frequency growth and amplitude decay. Second, these parameters are tested separately to determine their individual contributions. Lastly, a novel dual harmonic pitch motion is devised which rapidly traverses dynamic stall regimes on an inter-cycle basis by modulating the static-stall penetration angle. Throughout all results presented, there is evidence that for consecutive pitch-cycles, the process of dynamic stall is affected when prior oscillations prior have undergone deeper stall-penetration angles. In other words when stall-penetration is descending, retreating from a regime of light or deep stall, statistics of load coefficients, such as damping coefficient, maximum lift, minimum quarter-chord moment, and their phase relationships, do not match the values seen when stall-penetration was growing. The outcomes herein suggest that the airfoil retains some memory of previous flow separation which has the potential to change the influence of the dynamic stall vortex.

  10. Development of a new medium frequency EM device: Mapping soil water content variations using electrical conductivity and dielectric permittivity

    Science.gov (United States)

    Kessouri, P.; Buvat, S.; Tabbagh, A.

    2012-12-01

    Both electrical conductivity and dielectric permittivity of soil are influenced by its water content. Dielectric permittivity is usually measured in the high frequency range, using GPR or TDR, where the sensitivity to water content is high. However, its evaluation is limited by a low investigation depth, especially for clay rich soils. Electrical conductivity is closely related not only to soil water content, but also to clay content and soil structure. A simultaneous estimation of these electrical parameters can allow the mapping of soil water content variations for an investigation depth close to 1m. In order to estimate simultaneously both soil electrical conductivity and dielectric permittivity, an electromagnetic device working in the medium frequency range (between 100 kHz and 10 MHz) has been designed. We adopted Slingram geometry for the EM prototype: its PERP configuration (vertical transmission loop Tx and horizontal measuring loop Rx) was defined using 1D ground models. As the required investigation depth is around 1m, the coil spacing was fixed to 1.2m. This prototype works in a frequency range between 1 and 5 MHz. After calibration, we tested the response of prototype to objects with known properties. The first in situ measurements were led on experimental sites with different types of soils and different water content variations (artificially created or natural): sandy alluvium on a plot of INRA (French National Institute for Agricultural Research) in Orléans (Centre, France), a clay-loam soil on an experimental site in Estrée-Mons (Picardie, France) and fractured limestone at the vicinity of Grand (Vosges, France). In the case of the sandy alluvium, the values of dielectric permittivity measured are close to those of HF permittivity and allow the use of existing theoretical models to determine the soil water content. For soils containing higher amount of clay, the coupled information brought by the electrical conductivity and the dielectric

  11. Modeling of temporal variation of very low frequency radio waves over long paths as observed from Indian Antarctic stations

    Science.gov (United States)

    Sasmal, Sudipta; Basak, Tamal; Chakraborty, Suman; Palit, Sourav; Chakrabarti, Sandip K.

    2017-07-01

    Characteristics of very low frequency (VLF) signal depends on solar illumination across the propagation path. For a long path, solar zenith angle varies widely over the path and this has a significant influence on the propagation characteristics. To study the effect, Indian Centre for Space Physics participated in the 27th and 35th Scientific Expedition to Antarctica. VLF signals transmitted from the transmitters, namely, VTX (18.2 kHz), Vijayanarayanam, India, and NWC (19.8 kHz), North West Cape, Australia, were recorded simultaneously at Indian permanent stations Maitri and Bharati having respective geographic coordinates 70.75°S, 11.67°E, and 69.4°S, 76.17°E. A very stable diurnal variation of the signal has been obtained from both the stations. We reproduced the signal variations of VLF signal using solar zenith angle model coupled with long wavelength propagation capability (LWPC) code. We divided the whole path into several segments and computed the solar zenith angle (χ) profile. We assumed a linear relationship between the Wait's exponential model parameters effective reflection height (h'), steepness parameter (β), and solar zenith angle. The h' and β values were later used in the LWPC code to obtain the VLF signal amplitude at a particular time. The same procedure was repeated to obtain the whole day signal. Nature of the whole day signal variation from the theoretical modeling is also found to match with our observation to some extent.

  12. Impact of blood processing variations on Natural Killer cell frequency, activation, chemokine receptor expression and function

    Science.gov (United States)

    Naranbhai, Vivek; Bartman, Pat; Ndlovu, Dudu; Ramkalawon, Pamela; Ndung’u, Thumbi; Wilson, Douglas; Altfeld, Marcus; Carr, William H

    2011-01-01

    Understanding the role of natural killer (NK) cells in human disease pathogenesis is crucial and necessitates study of patient samples directly ex vivo. Manipulation of whole blood by density gradient centrifugation or delays in sample processing due to shipping, however, may lead to artifactual changes in immune response measures. Here, we assessed the impact of density gradient centrifugation and delayed processing of both whole blood and peripheral blood mononuclear cells (PBMC) at multiple timepoints (2–24 hrs) on flow cytometric measures of NK cell frequency, activation status, chemokine receptor expression, and effector functions. We found that density gradient centrifugation activated NK cells and modified chemokine receptor expression. Delays in processing beyond 8 hours activated NK cells in PBMC but not in whole blood. Likewise, processing delays decreased chemokine receptor (CCR4 and CCR7) expression in both PBMC and whole blood. Finally, delays in processing PBMC were associated with a decreased ability of NK cells to degranulate (as measured by CD107a expression) or secrete cytokines (IFN-γ and TNF-α). In summary, our findings suggest that density gradient centrifugation and delayed processing of PBMC can alter measures of clinically relevant NK cell characteristics including effector functions; and therefore should be taken into account in designing clinical research studies. PMID:21255578

  13. Spatial-temporal variation of low-frequency earthquake bursts near Parkfield, California

    Science.gov (United States)

    Wu, Chunquan; Guyer, Robert; Shelly, David R.; Trugman, D.; Frank, William; Gomberg, Joan S.; Johnson, P.

    2015-01-01

    Tectonic tremor (TT) and low-frequency earthquakes (LFEs) have been found in the deeper crust of various tectonic environments globally in the last decade. The spatial-temporal behaviour of LFEs provides insight into deep fault zone processes. In this study, we examine recurrence times from a 12-yr catalogue of 88 LFE families with ∼730 000 LFEs in the vicinity of the Parkfield section of the San Andreas Fault (SAF) in central California. We apply an automatic burst detection algorithm to the LFE recurrence times to identify the clustering behaviour of LFEs (LFE bursts) in each family. We find that the burst behaviours in the northern and southern LFE groups differ. Generally, the northern group has longer burst duration but fewer LFEs per burst, while the southern group has shorter burst duration but more LFEs per burst. The southern group LFE bursts are generally more correlated than the northern group, suggesting more coherent deep fault slip and relatively simpler deep fault structure beneath the locked section of SAF. We also found that the 2004 Parkfield earthquake clearly increased the number of LFEs per burst and average burst duration for both the northern and the southern groups, with a relatively larger effect on the northern group. This could be due to the weakness of northern part of the fault, or the northwesterly rupture direction of the Parkfield earthquake.

  14. 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.

  15. Comparing the accuracy of perturbative and variational calculations for predicting fundamental vibrational frequencies of dihalomethanes

    Science.gov (United States)

    Krasnoshchekov, Sergey V.; Schutski, Roman S.; Craig, Norman C.; Sibaev, Marat; Crittenden, Deborah L.

    2018-02-01

    Three dihalogenated methane derivatives (CH2F2, CH2FCl, and CH2Cl2) were used as model systems to compare and assess the accuracy of two different approaches for predicting observed fundamental frequencies: canonical operator Van Vleck vibrational perturbation theory (CVPT) and vibrational configuration interaction (VCI). For convenience and consistency, both methods employ the Watson Hamiltonian in rectilinear normal coordinates, expanding the potential energy surface (PES) as a Taylor series about equilibrium and constructing the wavefunction from a harmonic oscillator product basis. At the highest levels of theory considered here, fourth-order CVPT and VCI in a harmonic oscillator basis with up to 10 quanta of vibrational excitation in conjunction with a 4-mode representation sextic force field (SFF-4MR) computed at MP2/cc-pVTZ with replacement CCSD(T)/aug-cc-pVQZ harmonic force constants, the agreement between computed fundamentals is closer to 0.3 cm-1 on average, with a maximum difference of 1.7 cm-1. The major remaining accuracy-limiting factors are the accuracy of the underlying electronic structure model, followed by the incompleteness of the PES expansion. Nonetheless, computed and experimental fundamentals agree to within 5 cm-1, with an average difference of 2 cm-1, confirming the utility and accuracy of both theoretical models. One exception to this rule is the formally IR-inactive but weakly allowed through Coriolis-coupling H-C-H out-of-plane twisting mode of dichloromethane, whose spectrum we therefore revisit and reassign. We also investigate convergence with respect to order of CVPT, VCI excitation level, and order of PES expansion, concluding that premature truncation substantially decreases accuracy, although VCI(6)/SFF-4MR results are still of acceptable accuracy, and some error cancellation is observed with CVPT2 using a quartic force field.

  16. 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

  17. Las cooperativas de ahorro y crédito y la economía popular y solidaria, ante el derecho la veeduría ciudadana

    OpenAIRE

    Cisneros Bayas, Manuel Enrique

    2016-01-01

    En el año 2015 varias cooperativas de ahorro y crédito han entrado en liquidación, aproximadamente 75.000 clientes podrían ser perjudicados. La Superintendencia de Economía Popular y Solidaria (SEPS) anunció la liquidación de cinco cooperativas de ahorro y crédito, una en Riobamba (Chimborazo) y cuatro en Ambato (Tungurahua). La liquidación de la primera, la Cooperativa de Ahorro y Crédito Acción Rural con sede en Riobamba se dio debido a "pérdidas, incapacidad de cumplir sus obligaciones con...

  18. Variational calculation of the limit cycle and its frequency in a two-neuron model with delay

    International Nuclear Information System (INIS)

    Brandt, Sebastian F.; Wessel, Ralf; Pelster, Axel

    2006-01-01

    We consider a model system of two coupled Hopfield neurons, which is described by delay differential equations taking into account the finite signal propagation and processing times. When the delay exceeds a critical value, a limit cycle emerges via a supercritical Hopf bifurcation. First, we calculate its frequency and trajectory perturbatively by applying the Poincare-Lindstedt method. Then, the perturbation series are resummed by means of the Shohat expansion in good agreement with numerical values. However, with increasing delay, the accuracy of the results from the Shohat expansion worsens. We thus apply variational perturbation theory (VPT) to the perturbation expansions to obtain more accurate results, which moreover hold even in the limit of large delays

  19. Genetic Variation and Its Reflection on Posttranslational Modifications in Frequency Clock and Mating Type a-1 Proteins in Sordaria fimicola

    Directory of Open Access Journals (Sweden)

    Rabia Arif

    2017-01-01

    Full Text Available Posttranslational modifications (PTMs occur in all essential proteins taking command of their functions. There are many domains inside proteins where modifications take place on side-chains of amino acids through various enzymes to generate different species of proteins. In this manuscript we have, for the first time, predicted posttranslational modifications of frequency clock and mating type a-1 proteins in Sordaria fimicola collected from different sites to see the effect of environment on proteins or various amino acids pickings and their ultimate impact on consensus sequences present in mating type proteins using bioinformatics tools. Furthermore, we have also measured and walked through genomic DNA of various Sordaria strains to determine genetic diversity by genotyping the short sequence repeats (SSRs of wild strains of S. fimicola collected from contrasting environments of two opposing slopes (harsh and xeric south facing slope and mild north facing slope of Evolution Canyon (EC, Israel. Based on the whole genome sequence of S. macrospora, we targeted 20 genomic regions in S. fimicola which contain short sequence repeats (SSRs. Our data revealed genetic variations in strains from south facing slope and these findings assist in the hypothesis that genetic variations caused by stressful environments lead to evolution.

  20. Genetic Variation and Its Reflection on Posttranslational Modifications in Frequency Clock and Mating Type a-1 Proteins in Sordaria fimicola.

    Science.gov (United States)

    Arif, Rabia; Akram, Faiza; Jamil, Tazeen; Mukhtar, Hamid; Lee, Siu Fai; Saleem, Muhammad

    2017-01-01

    Posttranslational modifications (PTMs) occur in all essential proteins taking command of their functions. There are many domains inside proteins where modifications take place on side-chains of amino acids through various enzymes to generate different species of proteins. In this manuscript we have, for the first time, predicted posttranslational modifications of frequency clock and mating type a-1 proteins in Sordaria fimicola collected from different sites to see the effect of environment on proteins or various amino acids pickings and their ultimate impact on consensus sequences present in mating type proteins using bioinformatics tools. Furthermore, we have also measured and walked through genomic DNA of various Sordaria strains to determine genetic diversity by genotyping the short sequence repeats (SSRs) of wild strains of S. fimicola collected from contrasting environments of two opposing slopes (harsh and xeric south facing slope and mild north facing slope) of Evolution Canyon (EC), Israel. Based on the whole genome sequence of S. macrospora , we targeted 20 genomic regions in S. fimicola which contain short sequence repeats (SSRs). Our data revealed genetic variations in strains from south facing slope and these findings assist in the hypothesis that genetic variations caused by stressful environments lead to evolution.

  1. 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

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

    Science.gov (United States)

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

    2011-01-03

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    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.

  4. 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)

    1994-12-31

    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.

  5. 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.

  6. 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.

  7. 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.

  8. 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).

  9. 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.

  10. Spatial distribution and temporal variations of occurrence frequency of lightning whistlers observed by VLF/WBA onboard Akebono

    Science.gov (United States)

    Oike, Yuta; Kasahara, Yoshiya; Goto, Yoshitaka

    2014-09-01

    We statistically analyzed lightning whistlers detected from the analog waveform data below 15 kHz observed by the VLF instruments onboard Akebono. We examined the large amount of data obtained at Uchinoura Space Center in Japan for 22 years from 1989 to 2010. The lightning whistlers were mainly observed inside the L shell region below 2. Seasonal dependence of the occurrence frequency of lightning whistlers has two peaks around July to August and December to January. As lightning is most active in summer, in general, these two peaks correspond to summer in the Northern and Southern Hemispheres, respectively. Diurnal variation of the occurrence frequency showed that lightning whistlers begin to increase in the early evening and remain at a high-occurrence level through the night with a peak around 21 in magnetic local time (MLT). This peak shifts toward nightside compared with lightning activity, which begins to rise around noon and peaks in the late afternoon. This trend is supposed to be caused by attenuation of VLF wave in the ionosphere in the daytime. Comparison study with the ground-based observation revealed consistent results, except that the peak of the ground-based observation appeared after midnight while our measurements obtained by Akebono was around 21 in MLT. This difference is explained qualitatively in terms that lightning whistlers measured at the ground station passed through the ionosphere twice above both source region and the ground station. These facts provide an important clue to evaluate quantitatively the absorption effect of lightning whistler in the ionosphere.

  11. 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.)

  12. Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean.

    Science.gov (United States)

    Grimsditch, G; Pisapia, C; Huck, M; Karisa, J; Obura, D; Sweet, M

    2017-10-01

    This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as 'stress tolerant' showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of 'competitive' corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for 'competitive' corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of 'stress tolerant' and 'generalist' coral genera. Copyright © 2017. Published by Elsevier Ltd.

  13. Evaluación del punto de conmutación unicast- multicast para ahorro de potencia de transmisión en redes MBMS

    Directory of Open Access Journals (Sweden)

    Raúl Tamayo Fernández

    2014-01-01

    Full Text Available La oferta de aplicaciones y servicios multimedia para terminales móviles se hace principalmente a través de las redes celulares de tercera y cuarta generación (3G/4G existentes. El envío de los datos en este tipo de redes se realiza en modo unicast, es decir, a cada usuario se le dedican recursos de radio (ancho de banda y potencia de transmisión durante toda la sesión. Esto presenta algunos inconvenientes, tales como agotamiento rápido del ancho de banda del operador móvil, alto consumo de potencia de transmisión, incremento de la interferencia, y costos altos del servicio. Los operadores móviles requieren de nuevas tecnologías que optimicen el uso de sus recursos de radio y así lograr un mayor índice de penetración de los servicios. De ahí la necesidad de cambiar de paradigma hacia un modo de transmisión en multicast o broadcast, en el que una misma señal pueda recibirse por varios usuarios simultáneamente, de tal forma que los recursos de radio se puedan compartir. Para ello, la solución técnica sobre redes celulares LTE (Long Term Evolution se dio en la especificación 3GPP Release 6, llamada Servicio Multimedia por Broadcast/Multicast (MBMS, Multimedia Broadcast Multicast Service. La especificación de MBMS permite que una transmisión cambie de modo unicast a modo multicast a partir de un “punto de conmutación”, que determina el momento de hacer el cambio para obtener un ahorro tanto en ancho de banda como en potencia de transmisión. Este artículo presenta una evaluación para determinar los puntos de conmutación de modo de transmisión óptimos en el estándar MBMS para diferentes ambientes de propagación inalámbrica. Además, dado que MBMS se puede utilizar en topologías de Red de Frecuencia Única (SFN, Single Frequency Networks, que tienen la propiedad de “ganancia de red”, también se determina el ahorro de potencia de transmisión adicional que se obtiene en esta configuración.

  14. 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.

  15. Three-dimensional polarization characteristics of magnetic variations in the Pc 5 frequency range at conjugate areas near L=4

    International Nuclear Information System (INIS)

    Fukunishi, H.; Lanzerotti, L.J.; MaClennan, C.G.

    1975-01-01

    By using magnetic data measured at a network of stations extending from L approx. 3.2 to L approx. 4.4 and at a station in the conjugate area, ellipticities in the three orthogonal planes (H-D, H-Z, and D-Z) for the frequency range 2-5 mHz were computed continuously by the cross-spectral matrix method over 10 days with various levels of magnetic activity. The ellipticity diagrams in the H-D plane show that, except for the time interval during the main phase of a major magnetic storm, the sense of polarization reverses every day across local noon, with a left-hand polarization observed during local morning hours and a right-hand polarization observed during local evening hours, regardless of the level of magnetic activity. The second reversal of the sense of polarization occurs generally around approx. 2000 LT. The ellipticity diagrams in the H-Z plane show a predominantly clockwise polarization throughout the day, while the diurnal variation of the ellipticity in the D-Z plane tends to be confused. As to the latitude dependence of the wave phase, it is found that the D component oscillations are almost in phase at all latitudes, while the H component oscillations have advanced phase shifts at the lower-latitude stations. As to the conjugate dependence of wave phase, it is found that the D component oscillations are almost out of phase, while the H component oscillations are almost in phase atthe conjugate pair stations. These polarization characteristics are discussed in terms of external driving sources coupling to the shear Alfven waves of the local resonant field lines. Possible energy sources of Pc 5 waves are also discussed on the basis of the local time dependence of the sense of polarization

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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)

    1999-12-31

    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.

  2. Drought Conditions Maximize the Impact of High-Frequency Flow Variations on Thermal Regimes and Biogeochemical Function in the Hyporheic Zone.

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-03-01

    Anthropogenic activities, such as dam operations, often induce larger and more frequent stage fluctuations than those occurring in natural rivers. However, the long-term impact of such flow variations on thermal and biogeochemical dynamics of the associated hyporheic zone (HZ) is poorly understood. A heterogeneous, two-dimensional thermo-hydro-biogeochemical model revealed an important interaction between high-frequency flow variations and watershed-scale hydrology. High-frequency stage fluctuations had their strongest thermal and biogeochemical impacts when the mean river stage was low during fall and winter. An abnormally thin snowpack in 2015, however, created a low river stage during summer and early fall, whereby high frequency stage fluctuations caused the HZ to be warmer than usual. This study provided the scientific basis to assess the potential ecological consequences of the high-frequency flow variations in a regulated river, as well as guidance on how to maximize the potential benefits—or minimize the drawbacks—of river regulation to river ecosystems.

  3. Variation in the human lymphocyte sister chromatid exchange frequency as a function of time: results of daily and twice-weekly sampling

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, J.D.; Christensen, M.L.; Strout, C.L.; McGee, K.A.; Carrano, A.V.

    1987-01-01

    The variation in lymphocyte sister chromatid exchange (SCE) frequency was investigated in healthy nonsmokers who were not taking any medication. Two separate studies were undertaken. In the first, blood was drawn from four women twice a week for 8 weeks. These donors recorded the onset and termination of menstruation and times of illness. In the second study, blood was obtained from two women and two men for 5 consecutive days on two separate occasions initiated 14 days apart. Analysis of the mean SCE frequencies in each study indicated that significant temporal variation occurred in each donor, and that more variation occurred in the longer study. Some of the variation was found to be associated with the menstrual cycle. In the daily study, most of the variation appeared to be random, but occasional day-to-day changes occurred that were greater than those expected by chance. To determine how well a single SCE sample estimated the pooled mean for each donor in each study, the authors calculated the number of samples that encompassed that donor's pooled mean within 1 or more standard errors. For both studies, about 75% of the samples encompassed the pooled mean within 2 standard errors. An analysis of high-frequency cells (HFCs) was also undertaken. The results for each study indicate that the proportion of HFCs, compared with the use of Fisher's Exact test, is significantly more constant than the means, which were compared by using the t-test. These results coupled with our previous work suggest that HFC analysis may be the method of choice when analyzing data from human population studies.

  4. 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...

  5. 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...

  6. 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.

  7. Social responsibility and social security: The foundation of caja de pensiones para la vejez y de ahorros

    OpenAIRE

    Argandoña, Antonio; Moreno, Carlos M.; Sola, Joan M.

    2009-01-01

    The concept of Corporate Social Responsibility (CSR) is not new. Over the course of time, many entrepreneurs have created and developed companies, with a strong sense of ethical and social responsibility. This paper presents an example of how CSR was conceived and put into practice when Caja de Pensiones para la Vejez y de Ahorros was created in Barcelona in 1905, following the life and ideas of its founder, Francesc Moragas, a lawyer with a deep commitment to social action and a successful c...

  8. Ahorro de consumo de agua, aplicando técnicas de riego en jardines de la UNAC

    OpenAIRE

    Sánchez Hernández, Jaime Eloy

    2013-01-01

    La implementación del Proyecto "AHORRO DE CONSUMO DE AGUA, APLICANDO TECNICAS DE RIEGO EN JARDINES DE LA UNAC, con un sistema tecnificado de riego, específicamente por aspersión, se lograría ahorrar agua aproximadamente en un 50%. Además de personal de jardinería provista de mangueras (sistema de inundación) se dedicarían a otras labores que mejoren los jardines de la UNAC. Como corolario se tiene que no solo se ahorraría agua (pago de consumo a la empresa SEDAPAL), sino que al personal se...

  9. El Ahorro de los hogares colombianos: un análisis a partir de las encuestas de ingresos y gastos

    OpenAIRE

    Castañeda Cordy, Alberto

    2004-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada En Colombia el seguimiento a la evolución del ahorro privado y de las variables que lo determinan se ha realizado a partir de la información agregada de las cuentas nacionales. No existe aproximación alguna a partir de datos individuales que consideren el influjo de las características socioeconómicas de las familias sobre esa variable. Esto obedece, en gran parte, a la ausencia de datos de encuestas que sigan la evoluci...

  10. El ahorro de los hogares colombianos: un analisis a partir de las encuestas de ingresos y gastos

    OpenAIRE

    Castañeda Cordy, Alberto

    2003-01-01

    En Colombia el seguimiento a la evolución del ahorro privado y de las variables que lo determinan se ha realizado a partir de la información agregada de las cuentas nacionales. No existe aproximación alguna a partir de datos individuales que consideren el influjo de las características socioeconómicas de las familias sobre esa variable. Esto obedece, en gran parte, a la ausencia de datos de encuestas que sigan la evolución de los ingresos y los consumos de los hogares.Mientras la información ...

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

    OpenAIRE

    Lara Gómez, Graciela; Pérez Sosa, Felipe A.

    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...

  12. 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.

  13. 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

  14. Regional variations in frequency of glycosylated hemoglobin (HbA1c) monitoring in Korea: A multilevel analysis of nationwide data.

    Science.gov (United States)

    Yoo, Kyoung-Hun; Shin, Dong-Wook; Cho, Mi-Hee; Kim, Sang-Hyuck; Bahk, Hyun-Jung; Kim, Shin-Hye; Jeong, Su-Min; Yun, Jae-Moon; Park, Jin-Ho; Kim, Heesun; Cho, BeLong

    2017-09-01

    Suboptimal frequency of glycosylated hemoglobin (HbA1c) monitoring is associated with poor diabetes control. We aimed to analyze compliance to HbA1c testing guidelines and explore associated individual and area-level determinants, focusing on regional variation. This cross-sectional study between the period of 2012-2013 was conducted by using the Korean National Health Insurance Research Database, and included 45,634 patients diagnosed with diabetes mellitus, who were prescribed any anti-diabetic medications, including insulin. We calculated the proportion of each HbA1c testing frequency (≥1, ≥2, or ≥4 times per year) stratified by 17 administrative regions. Multilevel and multivariate logistic analyses were performed with regional (proportion of farmer population) and individual characteristics (age, sex, income level, duration of diabetes, and most visited medical institution). Overall, 67.3% of the patients received≥1 HbA1c test per year; 37.8% and 6.1% received ≥2 and ≥4 tests per year, respectively. Those managed in secondary-level hospitals or clinics and those living in rural areas were less likely to receive HbA1c testing. Even after adjusting for individual and regional level characteristics, significant area level variation was observed (variance participant coefficients were 7.91%, 9.58%, and 14.43% for testing frequencies of ≥1, ≥2, and ≥4 times a year, respectively). The frequency of HbA1c monitoring is suboptimal in Korea, especially in rural areas. Moreover, significant regional variation was observed, implying a contextual effect. This suggests the need for developing policy actions to improve HbA1c monitoring. In particular, access to HbA1c testing in rural primary care clinics must be improved. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Theoretical Calculations of the Seasonal and Solar Activity Variations for Ionospheric Collision Frequency and Debye Length over Baghdad City

    Directory of Open Access Journals (Sweden)

    Ali Hussein Ni'ma

    2017-03-01

    Full Text Available In this study, two important ionospheric factors have been calculated, the collision frequency of electron and Deby length for a height range from 80 Km to a height approaching the maximum height of the F2 region of the ionosphere above the Earth's surface. Both above factors have been calculated for two different levels of solar activity and for two seasons (winter and summer. Also, six months were adopted for every level of solar activity and season. The estimation of collision frequency of electron is depends on the contribution of neutral constituents and ions. Three neutral atmospheric gases have been adopted to calculate the collision frequency, Molecular and atomic oxygen O2 and O respectively and molecular nitrogen N2, as well as the singly charged ions were taken into account in calculation.

  16. 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…

  17. Variation in style morph frequencies in tristylous Lythrum salicaria in the Iberian Peninsula: the role of geographical and demographic factors

    Science.gov (United States)

    Costa, Joana; Castro, Sílvia; Loureiro, João; Barrett, Spencer C. H.

    2016-01-01

    Background and Aims The balance between stochastic forces and negative frequency-dependent selection largely determines style morph frequencies in heterostylous populations. Investigation of morph frequencies at geographical range limits can provide insights into the forces maintaining the floral polymorphism, and the factors causing biased morph ratios. Here, we investigate style morph frequencies in populations at the south-western European range limit of tristylous Lythrum salicaria, to explore the role of demographic and geographical factors influencing morph ratios in its native range. Methods We measured morph composition and evenness, and the size of 96 populations, along a north to south latitudinal transect from Galicia to Andalucia, Iberian Peninsula, traversing a steep climatic gradient. To examine the potential influence of morph-specific fitness components on morph ratios, we examined reproductive traits in 19 populations. Key Results Most populations of L. salicaria were trimorphic (94·79 %), the majority exhibiting 1 : 1 : 1 morph ratios (68·75 %). Populations with biased morph ratios had a deficiency of the short-styled morph. Population size and morph evenness were positively associated with latitude, with smaller populations and those with less even morph ratios occurring towards the south. Greater variance in morph evenness was evident at the southern range margin. There were no consistent differences in components of reproductive fitness among style morphs, but southern populations produced less fruit and seed than more northerly populations. Conclusions Our results demonstrate the influence of finite population size on morph frequencies in L. salicaria. However, they also illustrate the resilience of Iberian populations to the factors causing deviations from isoplethy and morph loss, especially at the southern range limit where populations are smaller. The maintenance of tristyly in small populations of L. salicaria may be aided

  18. 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.

  19. Data-driven approach to detect common copy-number variations and frequency profiles in a population-based Korean cohort.

    Science.gov (United States)

    Moon, Sanghoon; Kim, Young Jin; Hong, Chang Bum; Kim, Dong-Joon; Lee, Jong-Young; Kim, Bong-Jo

    2011-11-01

    To date, hundreds of thousands of copy-number variation (CNV) data have been reported using various platforms. The proportion of Asians in these data is, however, relatively small as compared with that of other ethnic groups, such as Caucasians and Yorubas. Because of limitations in platform resolution and the high noise level in signal intensity, in most CNV studies (particularly those using single nucleotide polymorphism arrays), the average number of CNVs in an individual is less than the number of known CNVs. In this study, we ascertained reliable, common CNV regions (CNVRs) and identified actual frequency rates in the Korean population to provide more CNV information. We performed two-stage analyses for detecting structural variations with two platforms. We discovered 576 common CNVRs (88 CNV segments on average in an individual), and 87% (501 of 576) of these CNVRs overlapped by ≥1 bp with previously validated CNV events. Interestingly, from the frequency analysis of CNV profiles, 52 of 576 CNVRs had a frequency rate of population.

  20. 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.

  1. 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.

  2. 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)

    1998-12-31

    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.

  3. Píldora de Crecimiento Económico: Modelos de crecimiento económico con tasas de ahorro constantes

    OpenAIRE

    López Díaz, Julio

    2015-01-01

    Claves para obtener, con carácter genérico, la ecuación fundamental de crecimiento en un modelo con tasa de ahorro constante. Departamento de Fundamentos del Análisis Económico e Historia e Instituciones Económicas

  4. Genetic Variation and Its Reflection on Posttranslational Modifications in Frequency Clock and Mating Type a-1 Proteins in Sordaria fimicola

    OpenAIRE

    Arif, Rabia; Akram, Faiza; Jamil, Tazeen; Mukhtar, Hamid; Lee, Siu Fai; Saleem, Muhammad

    2017-01-01

    Posttranslational modifications (PTMs) occur in all essential proteins taking command of their functions. There are many domains inside proteins where modifications take place on side-chains of amino acids through various enzymes to generate different species of proteins. In this manuscript we have, for the first time, predicted posttranslational modifications of frequency clock and mating type a-1 proteins in Sordaria fimicola collected from different sites to see the effect of environment o...

  5. Genetic variation of the angiotensin-converting enzyme gene: increased frequency of the insertion allele in Koreans.

    Science.gov (United States)

    Hong, S H; Kang, B Y; Park, W H; Kim, J Q; Lee, C C

    1997-01-01

    In view of the clinical importance of angiotensin-converting enzyme (ACE) as a major marker for cardiovascular diseases, we investigated insertion/deletion (I/D) polymorphism of the ACE gene in Koreans. Genotype frequencies were examined by polymerase chain reaction in 171 patients with coronary artery disease (CAD) and 120 healthy subjects. Allele frequencies of ACE polymorphism in Koreans were not significantly different between patient and control groups. In addition, association between ACE genotypes and the number of stenosed coronary arteries was not detected. ACE genotypes in the CAD group were not associated with body mass index and plasma lipid levels. Thus, our results suggest that, at least in Koreans, I/D polymorphism of the gene is unlikely to be a useful marker for CAD subjects. However, the I allele frequency of Koreans (0.58) was higher than that of Caucasian populations (0.47) but lower than that of Samoan (0.91) and Yanomami (0.85) populations. Here, we discuss the clinical and ethnic importance of ACE polymorphism.

  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. The Source of Variation in Policies around the World: The Case of Protection of Human Health from Extremely Low Frequency Electromagnetic Fields

    International Nuclear Information System (INIS)

    Kandel, S.

    2006-01-01

    Scientific evidence supposedly plays a dominant role in environmental and public health regulation. This paper uses the example of Extremely Low Frequency Electromagnetic Fields regulation to test whether this is indeed the case. The paper first shows that there exists a significant variation in health protection policies for Extremely Low Frequencies Extremely Low Frequency Electromagnetic Fields around the world. Some countries adopt the international scientific-based guidelines while other countries choose to apply additional precautionary regulations of varying severity. Electromagnetic Fields policy makers around the world indicate that the Cost Benefit Analysis is one of the parameters considered for their choice among various policy options. A simple Cost Benefit Analysis framework is presented, utilizing scientific evidence on health risks from Extremely Low Frequencies as well as parameter values used in the Cost Benefit Analysis studies from California, Netherlands, Israel, and the United Kingdom to determine the justification of using several mitigation techniques. This Cost Benefit Analysis using data from the different countries leads to a clear conclusion: under all parameter values considered, only the low cost intervention measures, such as re-phasing and compacting lines, are justified. Re-routing lines, except in cases of very close proximity to residences, and under grounding existing lines cannot be justified due to the high costs involved and the small health benefits that are projected. Since the stringent policies cannot be accomplished with the low-cost measures, this suggests that if the Cost Benefit Analysis were indeed the basis for the policies implemented in different countries, one would expect a smaller variation in the worldwide policies observed today. The divergence between the policies that are implemented and those that can be supported by the Cost Benefit Analysis suggests that the Cost Benefit Analysis is either not used to

  8. Frequency of rare mutations and common genetic variations in severe hypertriglyceridemia in the general population of Spain.

    Science.gov (United States)

    Lamiquiz-Moneo, Itziar; Blanco-Torrecilla, Cristian; Bea, Ana M; Mateo-Gallego, Rocío; Pérez-Calahorra, Sofía; Baila-Rueda, Lucía; Cenarro, Ana; Civeira, Fernando; de Castro-Orós, Isabel

    2016-04-23

    Hypertriglyceridemia (HTG) is a common complex metabolic trait that results of the accumulation of relatively common genetic variants in combination with other modifier genes and environmental factors resulting in increased plasma triglyceride (TG) levels. The majority of severe primary hypertriglyceridemias is diagnosed in adulthood and their molecular bases have not been fully defined yet. The prevalence of HTG is highly variable among populations, possibly caused by differences in environmental factors and genetic background. However, the prevalence of very high TG and the frequency of rare mutations causing HTG in a whole non-selected population have not been previously studied. The total of 23,310 subjects over 18 years from a primary care-district in a middle-class area of Zaragoza (Spain) with TG >500 mg/dL were selected to establish HTG prevalence. Those affected of primary HTG were considered for further genetic analysis. The promoters, coding regions and exon-intron boundaries of LPL, LMF1, APOC2, APOA5, APOE and GPIHBP1 genes were sequenced. The frequency of rare variants identified was studied in 90 controls. One hundred ninety-four subjects (1.04%) had HTG and 90 subjects (46.4%) met the inclusion criteria for primary HTG. In this subgroup, nine patients (12.3%) were carriers of 7 rare variants in LPL, LMF1, APOA5, GPIHBP1 or APOE genes. Three of these mutations are described for the first time in this work. The presence of a rare pathogenic mutation did not confer a differential phenotype or a higher family history of HTG. The prevalence of rare mutations in candidate genes in subjects with primary HTG is low. The low frequency of rare mutations, the absence of a more severe phenotype or the dominant transmission of the HTG would not suggest the use of genetic analysis in the clinical practice in this population.

  9. Assessing variation in skeletal production from surface death assemblages on the basis of age-frequency distributions

    Science.gov (United States)

    Tomasovych, Adam; Kidwell, Susan M.; Foygel Barber, Rina

    2015-04-01

    Age-frequency distributions of dead skeletal material that capture information on the elapsed time since death of individuals on the landscape or seabed provide decadal- to millennial-scale windows into the history of production and on the processes that lead to skeletal disintegration and burial. However, models quantifying the dynamics of skeletal loss assumed that skeletal production has been constant during accumulation of death assemblages. Here, we assess the joint effects of temporally-variable production and skeletal loss on the shape of postmortem age-frequency distributions. We show that the modes of such distributions will tend to be shifted to younger age cohorts relative to the true timing of past production pulses. This shift in the timing of a past production will be higher where loss rates are high and/or the rate of decline in production is slow. We apply the models combining the dynamic of loss and production to death assemblages with the deposit-feeding bivalve Nuculana taphria from the Southern California continental shelf, finding that (1) an onshore-offshore gradient in time averaging is dominated by a gradient in the timing of production, corresponding to the tracking of shallow-water habitats under a sea-level rise, and (2) model estimates of the timing of past production are in good agreement with an independent sea-level curve.

  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. Spontaneous micronucleus frequencies in human peripheral blood lymphocytes as a screening test for an individual variation in a different population and radiation-induced micronucleus induction

    International Nuclear Information System (INIS)

    Kang, Chang-Mo; Jeon, Hye-Jeong; Cho, Chul-Koo

    2004-01-01

    Our studies were to evaluate the role of epigenetic factors in the variation of radiosensitivity on human peripheral blood lymphocytes by measuring the frequencies of micronucleus (MN) from 293 healthy subjects of different population for assessing the radiation health risk in Korea. We analyzed the frequencies of both spontaneous and in vitro 60 Co γ-rays or 50MeV neutron-induced MNs. The frequencies of spontaneous NMs not only vary greatly between individuals, but also working or living areas. The increased levels of cells with spontaneous MNs were observed with an increasing age. The frequencies of spontaneous MNs were significantly higher in females than in males. For both sexes, MN frequency was significantly and positively correlated with age. Age and gender are the most important demographic variables impacting on the MN index. Donors who had ever smoked showed significantly increased frequencies of MNs compared to nonsmokers. The main lifestyle factors influencing the MN index in the subjects are correlated significantly and positively with smoke while measuring the spontaneous frequencies of micronuclei. Therefore, it is evident that with regard to the application of MN assay all future studies to evaluate the association between radiosensitivity and susceptibility for radiation health risks in different populations should take into account the effect of age, gender and lifestyle. For the dose-response study, the induced MNs were observed at all doses, and the numerical changes according to doses. The dose-response curves were fitted with a linear-quadratic forms of the dose, and the results were different for γ-rays and neutrons significantly. Neutrons were more effective than γ-rays in producing MN with a dose-dependent manner. The frequency of MN varies with dose. The RBE for a micronuclei was 2.37 ± 0.17. The results suggested that the MN assay have a high potential to ensure appropriate quality control and a standard documentation protocol, which

  12. High frequency modes of YBa2Cu3O6+x and their variation with the oxygen content x

    International Nuclear Information System (INIS)

    Ruan Jinghui; Niu Shiwen; Cheng Zhixu; Cheng Yufen; Zeng Xiangxin; Gou Cheng; Wang Jun; Guo Liping; Lin Jun; Yu Ansun; Shen Zhigong; Zhang Panlin; Chai Zhang

    1994-01-01

    Neutron inelastic scattering spectra of YBa 2 Cu 3 O 6+x samples with various oxygen contents x have been measured in the range from 10 to 150 meV with a new type of Be-filter detector spectrometer at the CIAE, Beijing. In semiconducting samples with x=0 and x=0.2, some strong high frequency modes (HFMs) are observed in the range from 60 to 150 meV. However, HFMs are not present in superconducting samples with x=0.78 and 0.97. An anomalous inelastic scattering intensity of the sample with x ≤ 0.2 is about two to three times stronger than that obtained with x=0.78 and 0.97 in the measured energy range from 10 to 150 meV. (orig.)

  13. Length-Weight Realtionship and Seasonal Distrubition of Magalaspis cordyla (Linnaeus 1758 fish Size frequency Variation from Karachi Coast

    Directory of Open Access Journals (Sweden)

    Quratulan AHMED

    2013-09-01

    Full Text Available The study of seasonal variation in distribution of 167 fishes of magalaspis cordyla from the Karachi fish harbour collected seasonally (pre-monsoon, mon-soon, post-monsoon between September 2011-August 2012. The highest catch of fish (68 was recorded in pre-monsoon season and the lowest catch of fish (47 was recorded in monsoon season. The highest mean length (38.6+ 0.746 and weight (288+ 21.90 was measured during pre-monsoon season and lowest mean length (22.5+ 0.671 and weight (120.5+ 2.73 was measured during mon-soon season. The highest mean condition factor (1.192+ 0.817 and minimum (0.500+ 0.038 was recorded in pre-monsoon season. Fish estimated negative and positive allometric growth because b values larger and less then 3 in pre-monsoon and monsoon season but post-monsoon season showed positive allometric growth because b value larger then 3 in all size classes

  14. 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.

  15. 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.

  16. Spatial variations in the frequency-magnitude distribution of earthquakes at Soufriere Hills Volcano, Montserrat, West Indies

    Science.gov (United States)

    Power, J.A.; Wyss, M.; Latchman, J.L.

    1998-01-01

    The frequency-magnitude distribution of earthquakes measured by the b-value is determined as a function of space beneath Soufriere Hills Volcano, Montserrat, from data recorded between August 1, 1995 and March 31, 1996. A volume of anomalously high b-values (b > 3.0) with a 1.5 km radius is imaged at depths of 0 and 1.5 km beneath English's Crater and Chance's Peak. This high b-value anomaly extends southwest to Gage's Soufriere. At depths greater than 2.5 km volumes of comparatively low b-values (b-1) are found beneath St. George's Hill, Windy Hill, and below 2.5 km depth and to the south of English's Crater. We speculate the depth of high b-value anomalies under volcanoes may be a function of silica content, modified by some additional factors, with the most siliceous having these volumes that are highly fractured or contain high pore pressure at the shallowest depths. Copyright 1998 by the American Geophysical Union.

  17. Variation in type and frequency of diagnostic imaging during trauma care across multiple time points by patient insurance type

    International Nuclear Information System (INIS)

    Bell, Nathaniel; Repáraz, Laura; Fry, William R.; Smith, R. Stephen; Luis, Alejandro

    2016-01-01

    Research has shown that uninsured patients receive fewer radiographic studies during trauma care, but less is known as to whether differences in care are present among other insurance groups or across different time points during hospitalization. Our objective was to examine the number of radiographic studies administered to a cohort of trauma patients over the entire hospital stay as well as during the first 24-hours of care. Patient data were obtained from an American College of Surgeons (ACS) verified Level I Trauma Center between January 1, 2011 and December 31, 2012. We used negative binomial regression to construct relative risk (RR) ratios for type and frequency of radiographic imaging received among persons with Medicare, Medicaid, no insurance, or government insurance plans in reference to those with commercial indemnity plans. The analysis was adjusted for patient age, sex, race/ethnicity, injury severity score, injury mechanism, comorbidities, complications, hospital length of stay, and Intensive Care Unit (ICU) admission. A total of 3621 records from surviving patients age > =18 years were assessed. After adjustment for potential confounders, the expected number of radiographic studies decreased by 15 % among Medicare recipients (RR 0.85, 95 % CI 0.78–0.93), 11 % among Medicaid recipients (0.89, 0.81–0.99), 10 % among the uninsured (0.90, 0.85–0.96) and 19 % among government insurance groups (0.81, 0.72–0.90), compared with the reference group. This disparity was observed during the first 24-hours of care among patients with Medicare (0.78, 0.71–0.86) and government insurance plans (0.83, 0.74–0.94). Overall, there were no differences in the number of radiographic studies among the uninsured or among Medicaid patients during the first 24-hours of care compared with the reference group, but differences were observed among the uninsured in a sub-analysis of severely injured patients (ISS > 15). Both uninsured and insured patients treated at a

  18. Modulation of the atmospheric quasi-biweekly oscillation on the diurnal variation of the occurrence frequency of the Tibetan Plateau vortices

    Science.gov (United States)

    Li, Lun; Zhang, Renhe; Wen, Min

    2018-06-01

    In this study, modulation of the atmospheric quasi-biweekly oscillation (QBWO) on diurnal variation of the occurrence frequency of Tibetan Plateau vortices (TPVs) during May-August of 2000-2009 was investigated. The diurnal variations of the occurrence frequency of the TPVs (OFTPVs) and the related dynamic and thermodynamic features in the positive and negative phases of QBWO were compared. In both the positive and negative phases, the OFTPVs reaches the maximum from evening to midnight (18-00 LT, LT indicates the local time), and minimum from early morning to noon (06-12 LT). At 18 LT, there is strongest convergence at 500 hPa and ascending motion, as well as the most abundant net water vapor budget over the Tibetan Plateau, which is in favor of the precipitation and the related condensation latent heat release, corresponding to the maximum of OFTPVs in 18-00 LT. On the contrary, in the early morning at 06 LT, the conditions are most unfavorable for genesis of TPVs in 06-12 LT. QBWO leads to stronger convergence at 500 hPa, ascending motion as well as more massive water vapor in the positive phases than those in the negative phases, resulting in larger numbers of TPVs occur in all of the four periods of a day (00-06 LT, 06-12 LT, 12-18 LT, and 18-00 LT) in the former. The TPVs generating from the early morning to noon (06-12 LT) are weaker and more sensitive and fragile to the disadvantageous background, while the TPVs occurring from evening to midnight (18-00 LT) are stronger and seem to be well tolerated, leading to more remarkable contrast between the OFTPVs in the negative and positive phases in 06-12 LT than in 18-00 LT.

  19. Variations of the critical foE-frequency of the ionosphere connected with earthquakes. Evaluation of observations of the vertical sounding station "Tokyo"

    Science.gov (United States)

    Liperovskaya, Elena V.; Meister, Claudia-Veronika; Hoffmann, Dieter H. H.; Silina, Alexandra S.

    2016-04-01

    In the present work the critical frequencies foE and foF2 of the ionosphere are considered as possible earthquake precursors. The statistical analysis of the critical frequencies is carried out based on the data of the vertical sounding station (VSS) "Kokubunji" ("Tokyo") (ϕ = 35.7o N, λ = 139.5o E, 1957-1988) obtained every hour. Disturbances are considered on the background of seasonal, geomagnetic as well as 11-years and 27-days Solar variations. Special normalized parameters E and F are introduced, which represent the almost seasonal-independent parts of foE and foF2. Days with high Solar (Wolf number > 100) and geomagnetic (ΣKp > 25) activities are excluded from the analysis. For all data (observed every hour) analysed, no correlations of the normalized parameters E and F are found. One day before the seismic shock, a positive correlation is observed. The superimposed epochs method is used to determine the temporal behaviour of E and F. It is found that E and F decrease one day before the earthquakes provided that the seismic shocks occur at distances 600 5.5 is situated at depths smaller than 60 km. The reliability of the effect is larger than 98 %. Possible physical mechanisms of the phenomenon are discussed.

  20. 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)

    1994-12-31

    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%.

  1. 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%.

  2. 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

  3. 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

  4. 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)

    1996-12-31

    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

  5. 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)

    1996-12-31

    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

  6. 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)

    Mexico, BIMBO

    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.

  7. 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.

  8. Decadal-scale variation in dune erosion and accretion rates: An investigation of the significance of changing storm tide frequency and magnitude on the Sefton coast, UK

    Science.gov (United States)

    Pye, K.; Blott, S. J.

    2008-12-01

    Monitoring of frontal dune erosion and accretion on the Sefton coast in northwest England over the past 50 years has revealed significant spatial and temporal variations. Previous work has shown that the spatial variations primarily reflect longshore differences in beach and nearshore morphology, energy regime and sediment budget, but the causes of temporal variations have not previously been studied in detail. This paper presents the results of work carried out to test the hypothesis that a major cause of temporal variation is changes in the frequency and magnitude of storms, surges and resulting high tides. Dune toe erosion/accretion records dating from 1958 have been compared with tide gauge records at Liverpool and Heysham. Relatively high dune erosion rates at Formby Point 1958-1968 were associated with a relatively large number of storm tides. Slower erosion at Formby, and relatively rapid accretion in areas to the north and south, occurred during the 1970's and 1980's when there were relatively few major storm tides. After 1990 rates of dune erosion at Formby increased again, and dunes to the north and south experienced slower accretion. During this period high storm tides have been more frequent, and the annual number of hours with water levels above the critical level for dune erosion has increased significantly. An increase in the rate of mean sea-level rise at both Liverpool and Heysham is evident since 1990, but we conclude that this factor is of less importance than the occurrence of extreme high tides and wave action associated with storms. The incidence of extreme high tides shows an identifiable relationship with the lunar nodal tidal cycle, but the evidence indicates that meteorological forcing has also had a significant effect. Storms and surges in the eastern Irish Sea are associated with Atlantic depressions whose direction and rate of movement have a strong influence on wind speeds, wave energy and the height of surge tides. However

  9. Correlated inter-regional variations in low frequency local field potentials and resting state BOLD signals within S1 cortex of monkeys.

    Science.gov (United States)

    Wilson, George H; Yang, Pai-Feng; Gore, John C; Chen, Li Min

    2016-08-01

    The hypothesis that specific frequency components of the spontaneous local field potentials (LFPs) underlie low frequency fluctuations of resting state fMRI (rsfMRI) signals was tested. The previous analyses of rsfMRI signals revealed differential inter-regional correlations among areas 3a, 3b, and 1 of primary somatosensory cortex (S1) in anesthetized monkeys (Wang et al. [2013]: Neuron 78:1116-1126). Here LFP band(s) which correlated between S1 regions, and how these inter-regional correlation differences covaried with rsfMRI signals were examined. LFP signals were filtered into seven bands (delta, theta, alpha, beta, gamma low, gamma high, and gamma very high), and then a Hilbert transformation was applied to obtain measures of instantaneous amplitudes and temporal lags between regions of interest (ROI) digit-digit pairs (areas 3b-area 1, area 3a-area 1, area 3a-area 3b) and digit-face pairs (area 3b-face, area 1-face, and area 3a-face). It was found that variations in the inter-regional correlation strengths between digit-digit and digit-face pairs in the delta (1-4 Hz), alpha (9-14 Hz), beta (15-30 Hz), and gamma (31-50 Hz) bands parallel those of rsfMRI signals to varying degrees. Temporal lags between digit-digit area pairs varied across LFP bands, with area 3a mostly leading areas 1/2 and 3b. In summary, the data demonstrates that the low and middle frequency range (1-50 Hz) of spontaneous LFP signals similarly covary with the low frequency fluctuations of rsfMRI signals within local circuits of S1, supporting a neuronal electrophysiological basis of rsfMRI signals. Inter-areal LFP temporal lag differences provided novel insights into the directionality of information flow among S1 areas at rest. Hum Brain Mapp 37:2755-2766, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. 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

  11. 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

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Chinchilla, Henry [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

  14. Characterizing and understanding the climatic determinism of high- to low-frequency variations in precipitation in northwestern France using a coupled wavelet multiresolution/statistical downscaling approach

    Science.gov (United States)

    Massei, Nicolas; Dieppois, Bastien; Hannah, David; Lavers, David; Fossa, Manuel; Laignel, Benoit; Debret, Maxime

    2017-04-01

    Geophysical signals oscillate over several time-scales that explain different amount of their overall variability and may be related to different physical processes. Characterizing and understanding such variabilities in hydrological variations and investigating their determinism is one important issue in a context of climate change, as these variabilities can be occasionally superimposed to long-term trend possibly due to climate change. It is also important to refine our understanding of time-scale dependent linkages between large-scale climatic variations and hydrological responses on the regional or local-scale. Here we investigate such links by conducting a wavelet multiresolution statistical dowscaling approach of precipitation in northwestern France (Seine river catchment) over 1950-2016 using sea level pressure (SLP) and sea surface temperature (SST) as indicators of atmospheric and oceanic circulations, respectively. Previous results demonstrated that including multiresolution decomposition in a statistical downscaling model (within a so-called multiresolution ESD model) using SLP as large-scale predictor greatly improved simulation of low-frequency, i.e. interannual to interdecadal, fluctuations observed in precipitation. Building on these results, continuous wavelet transform of simulated precipiation using multiresolution ESD confirmed the good performance of the model to better explain variability at all time-scales. A sensitivity analysis of the model to the choice of the scale and wavelet function used was also tested. It appeared that whatever the wavelet used, the model performed similarly. The spatial patterns of SLP found as the best predictors for all time-scales, which resulted from the wavelet decomposition, revealed different structures according to time-scale, showing possible different determinisms. More particularly, some low-frequency components ( 3.2-yr and 19.3-yr) showed a much wide-spread spatial extentsion across the Atlantic

  15. Testing local Lorentz and position invariance and variation of fundamental constants by searching the derivative of the comparison frequency between a cryogenic sapphire oscillator and hydrogen maser

    International Nuclear Information System (INIS)

    Tobar, Michael Edmund; Wolf, Peter; Bize, Sebastien; Santarelli, Giorgio; Flambaum, Victor

    2010-01-01

    The cryogenic sapphire oscillator at the Paris Observatory has been continuously compared to various hydrogen masers since 2001. The early data sets were used to test local Lorentz invariance in the Robertson-Mansouri-Sexl (RMS) framework by searching for sidereal modulations with respect to the cosmic microwave background, and represent the best Kennedy-Thorndike experiment to date. In this work, we present continuous operation over a period of greater than six years from September 2002 to December 2008 and present a more precise way to analyze the data by searching the time derivative of the comparison frequency. Because of the long-term operation we are able to search both sidereal and annual modulations. The results give P KT =β RMS -α RMS -1=-1.7(4.0)x10 -8 for the sidereal and -23(10)x10 -8 for the annual term, with a weighted mean of -4.8(3.7)x10 -8 , a factor of 8 better than previous. Also, we analyze the data with respect to a change in gravitational potential for both diurnal and annual variations. The result gives β H-Maser -β CSO =-2.7(1.4)x10 -4 for the annual and -6.9(4.0)x10 -4 for the diurnal terms, with a weighted mean of -3.2(1.3)x10 -4 . This result is 2 orders of magnitude better than other tests that use electromagnetic resonators. With respect to fundamental constants a limit can be provided on the variation with ambient gravitational potential and boost of a combination of the fine structure constant (α), the normalized quark mass (m q ), and the electron to proton mass ratio (m e /m p ), setting the first limit on boost dependence of order 10 -10 .

  16. 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.

  17. 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)

    1993-12-31

    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.

  18. 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.

  19. 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.

  20. Propuesta de incorporación del Segmento Pymes en las operaciones de crédito de la Cooperativa de Ahorro y Crédito 29 de Octubre

    OpenAIRE

    Ríos Páliz, Cristina Araceli

    2015-01-01

    En el proyecto que se presenta a continuación permite aplicar una metodología de análisis que brinde a la Cooperativismo de Ahorro y Crédito “29 de Octubre”, incorporar operaciones de crédito del segmento Comercial Pymes a su cartera de crédito cumpliendo lo establecido por la Superintendencia de Bancos, normativa que será transitoria para la Superintendencia de Economía Popular y Solidaria hasta que defina sus políticas de control y seguimiento para las Cooperativas de Ahorro y Crédito por ...

  1. Incidencia del modelo de otorgamiento de cartera en la gestión del riesgo de crédito de la cooperativa de ahorro y crédito Bola Amarilla de la ciudad de Ibarra

    OpenAIRE

    Ayala Pupiales, Sandra Maribel

    2017-01-01

    Evaluar la incidencia del modelo de otorgamiento de cartera en la gestión del riesgo de crédito de la cooperativa de ahorro y crédito Bola Amarilla de la ciudad de Ibarra. El presente trabajo proporciona estrategias, políticas y procedimientos con el fin de dar cumplimiento a las resoluciones emitidas por el órgano de supervisión y control para las cooperativas de ahorro y crédito Superintendencia de Economía Popular y Solidaria del Ecuador y la Junta Política de Regulación Financiera y Mo...

  2. Diseño de un sistema de gestión de seguridad de la información para Cooperativas de Ahorro y Crédito en base a la norma ISO 27001

    OpenAIRE

    Mantilla Guerra, Aníbal Rubén

    2009-01-01

    209 hojas : ilustraciones, 29 x 21 cm + CD-ROM 2254 En esta Tesis se diseñó un Sistema de Gestión de Seguridad de la Información para Cooperativas de Ahorro y Crédito, en base a la norma ISO 27001, la Ley de la Superintendencia de Bancos y Seguros, la Ley de Cooperativas de Ahorro y Crédito, considerando además, su evolución y problemática en el Sistema Financiero Nacional. De manera metodológica, científica y objetiva, se muestra como identificar, evaluar y gestionar el riesgo, en Coopera...

  3. Aplicación del impuesto a las transacciones financieras ITF y su incidencia en el servicio de ahorro del Banco de la Nación Región Puno 2004 - 2007.

    OpenAIRE

    Caceres Quispe, Hector Omar

    2010-01-01

    El presente trabajo de investigación titulado "APLICACIÓN DEL IMPUESTO A LAS TRANSACCIONES FINANCIERAS ITF Y SU INCIDENCIA EN EL SERVICIO DE AHORRO DEL BANCO DE LA NACIÓN REGION PUNO 2004-2007". Tiene como objetivo general determinar la incidencia del Impuesto a las Transacciones Financieras- ITF, en el servicio de ahorro del Banco de la Nación Región Puno. Los impuestos se obtienen de los ingresos generados en la economía, tanto por la interacción de las personas como por las empresas (en ac...

  4. Use of a novel cell adhesion method and digital measurement to show stimulus-dependent variation in somatic and oral ciliary beat frequency in Paramecium.

    Science.gov (United States)

    Bell, Wade E; Hallworth, Richard; Wyatt, Todd A; Sisson, Joseph H

    2015-01-01

    When Paramecium encounters positive stimuli, the membrane hyperpolarizes and ciliary beat frequency increases. We adapted an established immobilization protocol using a biological adhesive and a novel digital analysis system to quantify beat frequency in immobilized Paramecium. Cells showed low mortality and demonstrated beat frequencies consistent with previous studies. Chemoattractant molecules, reduction in external potassium, and posterior stimulation all increased somatic beat frequency. In all cases, the oral groove cilia maintained a higher beat frequency than mid-body cilia, but only oral cilia from cells stimulated with chemoattactants showed an increase from basal levels. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

  5. Desarrollo de un manual de auditoría informática aplicado a Cooperativas de Ahorro y Crédito

    OpenAIRE

    Sarango Ontaneda, Carlos Alberto

    2013-01-01

    La auditoría informática es una función (en ocasiones un servicio) que apoya al trabajo de las unidades de auditoría interna de las Cooperativas de Ahorro y Crédito. Sin embargo, el trabajo a realizarse exige que los profesionales en auditoría informática cumplan con ciertas normas y requerimientos tanto legales como profesionales. El uso de marcos de buenas prácticas, análisis de riesgos y la observación de las normas de auditoría son fundamentales para el desarrollo de las evaluaciones de ...

  6. Propuesta de un plan estratégico de marketing para la Cooperativa de Ahorro y Crédito Artesanal de la ciudad de Cuenca

    OpenAIRE

    Salazar Centeno, Sandra Elizabeth; Toledo Solano, Miriam Alexandra

    2008-01-01

    La presente tesina, constituye un Plan Estratégico de Marketing para la Cooperativa de Ahorro y Crédito "Artesanal", orientado a contribuir con el desarrollo y bienestar para sus socios. Hoy en día las empresas deben ser proactivas y adelantarse a las necesidades del mercado, esto ayudará a mejorar su imagen, pero para esto, es importante contar con la filosofía empresarial, es decir el tener establecido cual es el norte de le entidad financiera, determinar las metas, objetivos institucion...

  7. Diagnóstico al sistema de control interno del área contable Cooperativa Nacional Educativa de Ahorro y Crédito "COONFIE"

    OpenAIRE

    Quesada Sánchez, Iván Darío; Calderón Gómez, Ramsés Camilo; Saavedra Pinzón, Miguel Antonio

    2013-01-01

    Presenta el resultado del estudio de evaluación sobre la aplicación y el desarrollo del sistema de control interno, en el área Contable de la Cooperativa Nacional Educativa de Ahorro y Crédito “COONFIE”. Así mismo se busca medir la utilización que ha hecho dicha entidad de la metodología empleada para inspección y vigilancia, el cual ha proporcionado herramientas y acciones complementarias en las entidades aportando desarrollo y crecimiento

  8. Análisis de un plan de ahorro energético implementando sistemas fotovoltaicos para los modelos de vivienda propuestos por el gobierno nacional

    OpenAIRE

    Quinto Ayovi, Marlon Jamil; Cadena Avila, Diego Alberto

    2016-01-01

    En el siguiente artículo se muestran los diseños de los sistemas fotovoltaicos que se desean implementar a las viviendas modelos propuestas por el gobierno nacional con la finalidad de obtener un ahorro energético a mediano o largo plazo utilizando fuentes de energías renovables como lo es el sol. Se procede a realizar dos escenarios, en el primero escenario se consideran todas las cargas de la vivienda modelo y en el segundo escenario se considera como carga solo a la cocina de inducción, en...

  9. 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.

  10. 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

  11. Planeamiento estratégico de las cajas municipales de ahorro y crédito de la Región Junín

    OpenAIRE

    Corilla Ruiz, Mariella; Julcarima Iñigo, Gilmar; Meneses Galindez, Carolina; Rodríguez Rivera, Franchesca

    2017-01-01

    La presente tesis desarrolla un planeamiento estratégico, con el propósito de que las Cajas Municipales de Ahorro y Crédito de la región Junín, se mantengan para el año 2022 como líderes del sector microfinanciero dentro de esta región, mediante la generación de soluciones financieras eficientes y eficaces basadas en incrementar la inclusión y educación financiera, la responsabilidad social y el cuidado del medio ambiente. Así mismo, el presente trabajo tiene por finalidad aume...

  12. Administración estratégica y gobernabilidad en las cooperativas de ahorro y crédito del cantón Portoviejo

    OpenAIRE

    Dianexy Viviana Carreño

    2014-01-01

    Las Cooperativas de Ahorro y Crédito (CAC’s) tienen una activa participación en el crecimiento y desarrollo económico del Ecuador, lo que permite desarrollar un estudio en la provincia de Manabí, tomando una muestra deliberada en el cantón Portoviejo, que concentra el 40% de las cooperativas que operan en la provincia; se utilizó la encuesta como técnica de recolección de datos, y se aplicó a los gerentes, presidentes de los Consejos de Administración y de vigilancia de diez CAC’s; A modo de ...

  13. De Cajas de Ahorro a sociedades capitalistas y Fundaciones un nuevo enfoque en la gestión y aplicación de la Obra Social

    OpenAIRE

    Aranda Ruiviejo, Antonio Carlos; Sotomayor Morales, Eva

    2017-01-01

    El presente trabajo se ha desarrollado con la finalidad de analizar las estrategias emprendidas por las nuevas Fundaciones surgidas tras el proceso de reestructuración del sector de las Cajas de Ahorro para garantizar la sostenibilidad de la Obra Social que anteriormente venían realizando estas entidades. Para ello se realiza un estudio de carácter descriptivo y explorativo que comprende un horizonte temporal de diez años y en el que se contrastan planteamientos anteriores y posteriores a los...

  14. Propuesta para la Incorporación del Concepto y la Estructuración del Área de Sostenibilidad en el Fondo Nacional del Ahorro

    OpenAIRE

    Diazgranados Muñoz, Ana María; Merlano Uribe, María Paula; Zamora Ramírez, Judith Andrea

    2014-01-01

    En el contexto actual en el que las organizaciones buscan generar acciones que respondan por el impacto que tienen sus actividades y decisiones en su entorno más próximo, se realiza un propuesta de incorporación del concepto de la Responsabilidad Social Empresarial (RSE) para el Fondo Nacional del Ahorro (FNA) con el fin de que la entidad involucre dentro de sus procesos acciones socialmente responsables y a su vez contribuya con el desarrollo sostenible. El documento Propuesta Para La ...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

    1998-12-31

    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.

  1. 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

  2. Frequency spirals

    International Nuclear Information System (INIS)

    Ottino-Löffler, Bertrand; Strogatz, Steven H.

    2016-01-01

    We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “frequency spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous frequencies, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, frequency spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest frequency spiral and characterize its properties using analytical and numerical methods. Simulations show that frequency spirals in large lattices behave much like this simple prototype.

  3. Frequency spirals

    Energy Technology Data Exchange (ETDEWEB)

    Ottino-Löffler, Bertrand; Strogatz, Steven H., E-mail: strogatz@cornell.edu [Center for Applied Mathematics, Cornell University, Ithaca, New York 14853 (United States)

    2016-09-15

    We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “frequency spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous frequencies, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, frequency spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest frequency spiral and characterize its properties using analytical and numerical methods. Simulations show that frequency spirals in large lattices behave much like this simple prototype.

  4. 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

  5. Dielectric Properties of Marsh Vegetation in a Frequency Range of 0.1-18 GHz Under Variation of Temperature and Moisture

    Science.gov (United States)

    Romanov, A. N.; Kochetkova, T. D.; Suslyaev, V. I.; Shcheglova, A. S.

    2017-09-01

    Dielectric characteristics of some species of marsh vegetation: lichen Cladonia stellaris (Opiz) Pouzar, moss Sphagnum, and a representative of Bryidae mosses - Dicranum polysetum are studied in the frequency range from 100 MHz to 18 GHz. At a frequency of 1.41 GHz, the influence of temperature in the range from -12 to +20°C on the behavior of dielectric characteristics of mosses, lichens, and peat is studied. The dependences of the dielectric characteristics of vegetation on the volumetric wetness are established.

  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. 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

    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...

  8. Low-Frequency Synonymous Coding Variation in CYP2R1 Has Large Effects on Vitamin D Levels and Risk of Multiple Sclerosis

    NARCIS (Netherlands)

    Manousaki, Despoina; Dudding, Tom; Haworth, Simon; Hsu, Yi Hsiang; Liu, Ching Ti; Medina-Gómez, Carolina; Voortman, Trudy; Velde, Van Der Nathalie; Melhus, Håkan; Vandenput, Liesbeth; Noordam, Raymond; Forgetta, Vincenzo; Greenwood, Celia M.T.; Biggs, Mary L.; Psaty, Bruce M.; Rotter, Jerome I.; Zemel, Babette S.; Mitchell, Jonathan A.; Taylor, Bruce; Lorentzon, Mattias; Karlsson, Magnus; Jaddoe, Vincent W.V.; Tiemeier, Henning; Campos-Obando, Natalia; Franco, Oscar H.; Utterlinden, Andre G.; Broer, Linda; Schoor, van Natasja M.; Ham, Annelies C.; Ikram, Arfan M.A.; Karasik, David; Mutsert, De Renée; Rosendaal, Frits R.; Heijer, den Martin; Wang, Thomas J.; Lind, Lars; Orwoll, Eric S.; Mook-Kanamori, Dennis O.; Michaëlsson, Karl; Kestenbaum, Bryan; Ohlsson, Claes; Mellström, Dan; Groot, de Lisette C.P.G.M.; Grant, Struan F.A.; Kiel, Douglas P.; Zillikens, M.C.; Rivadeneira, Fernando; Sawcer, Stephen; Timpson, Nicholas J.; Richards, J.B.

    2017-01-01

    Vitamin D insufficiency is common, correctable, and influenced by genetic factors, and it has been associated with risk of several diseases. We sought to identify low-frequency genetic variants that strongly increase the risk of vitamin D insufficiency and tested their effect on risk of multiple

  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. 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)

    1993-12-31

    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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

    1999-12-31

    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.

  18. Creación de un marco de control para la administración del riesgo operativo relacionado con la tecnologias de la información como modelo para las cooperativas de ahorro y crédito del Ecuador

    OpenAIRE

    Brito Domínguez, Jimmy Arturo; Echeverria Briones, Pedro Fabricio

    2009-01-01

    Creación de un marco de control para la administración del riesgo operativo relacionado con la tecnologías de la informacion como modelo para las cooperativas de ahorro y credito del Ecuador Creación de un marco de control para la administración del riesgo operativo relacionado con la tecnologías de la informacion como modelo para las cooperativas de ahorro y credito del Ecuador

  19. 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)

    1999-12-31

    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

  20. 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

  1. 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 de

  2. 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

  3. Familia: Consumo y ahorro

    OpenAIRE

    Navarro López, Manuel

    2003-01-01

    Es obvio que el contenido de este trabajo deberá moverse entre la sociología de la familia y la del consumo, aunque solo sea como referentes teóricos. Sin embargo, tales vínculos deberán ser solo puntos de apoyo para analizar sin ataduras académicas una visión de los comportamientos económicos que tienen su localización primaria en la familia. Consecuentemente, tendremos que hacer una descripción de esos comportamientos y sus contenidos, su evolución y su diversificación, retomando los motivo...

  4. Familia: Consumo y ahorro

    Directory of Open Access Journals (Sweden)

    Navarro López, Manuel

    2003-01-01

    Full Text Available Es obvio que el contenido de este trabajo deberá moverse entre la sociología de la familia y la del consumo, aunque solo sea como referentes teóricos. Sin embargo, tales vínculos deberán ser solo puntos de apoyo para analizar sin ataduras académicas una visión de los comportamientos económicos que tienen su localización primaria en la familia. Consecuentemente, tendremos que hacer una descripción de esos comportamientos y sus contenidos, su evolución y su diversificación, retomando los motivos más recurrentes al uso, pero con la orientación hacia la familia como institución y como grupo en las sociedades avanzadas actuales…

  5. Induced micro-mutations in rice - the frequency and spectrum of gamma ray induced height variations in rice variety-Jaya

    International Nuclear Information System (INIS)

    Nair, N.K.; Ninan, C.A.

    1975-01-01

    Seeds of rice variety, Jaya, treated with moderate doses of (10, 20 and 30 kR) gamma rays were subjected to study the relative magnitude of induced variability and the type of mutations induced for height of plant in M 2 and M 3 generations. Progenies of 3352 M 1 spikes, totalling to 35691 M 2 plants and their subsequent progenies in M 3 were analysed. To get wider variability, very large populations in all the generations were studied. The mean value, genetic variance and phenotypic frequency distribution with and between generations were studied. The treated population showed no significant shift in mean values from that of control. The variance was greater in the irradiated material compared to control. The variability was found to shift in both plus and minus direction from that of control with a higher frequency in the minus direction in M 2 . A high frequency of dwarf mutants was observed in 20 kR treated population in the M 2 generation. The segregation ratio was higher in M 2 compared to M 3 generation. (author)

  6. Low-Frequency Synonymous Coding Variation in CYP2R1 Has Large Effects on Vitamin D Levels and Risk of Multiple Sclerosis.

    Science.gov (United States)

    Manousaki, Despoina; Dudding, Tom; Haworth, Simon; Hsu, Yi-Hsiang; Liu, Ching-Ti; Medina-Gómez, Carolina; Voortman, Trudy; van der Velde, Nathalie; Melhus, Håkan; Robinson-Cohen, Cassianne; Cousminer, Diana L; Nethander, Maria; Vandenput, Liesbeth; Noordam, Raymond; Forgetta, Vincenzo; Greenwood, Celia M T; Biggs, Mary L; Psaty, Bruce M; Rotter, Jerome I; Zemel, Babette S; Mitchell, Jonathan A; Taylor, Bruce; Lorentzon, Mattias; Karlsson, Magnus; Jaddoe, Vincent V W; Tiemeier, Henning; Campos-Obando, Natalia; Franco, Oscar H; Utterlinden, Andre G; Broer, Linda; van Schoor, Natasja M; Ham, Annelies C; Ikram, M Arfan; Karasik, David; de Mutsert, Renée; Rosendaal, Frits R; den Heijer, Martin; Wang, Thomas J; Lind, Lars; Orwoll, Eric S; Mook-Kanamori, Dennis O; Michaëlsson, Karl; Kestenbaum, Bryan; Ohlsson, Claes; Mellström, Dan; de Groot, Lisette C P G M; Grant, Struan F A; Kiel, Douglas P; Zillikens, M Carola; Rivadeneira, Fernando; Sawcer, Stephen; Timpson, Nicholas J; Richards, J Brent

    2017-08-03

    Vitamin D insufficiency is common, correctable, and influenced by genetic factors, and it has been associated with risk of several diseases. We sought to identify low-frequency genetic variants that strongly increase the risk of vitamin D insufficiency and tested their effect on risk of multiple sclerosis, a disease influenced by low vitamin D concentrations. We used whole-genome sequencing data from 2,619 individuals through the UK10K program and deep-imputation data from 39,655 individuals genotyped genome-wide. Meta-analysis of the summary statistics from 19 cohorts identified in CYP2R1 the low-frequency (minor allele frequency = 2.5%) synonymous coding variant g.14900931G>A (p.Asp120Asp) (rs117913124[A]), which conferred a large effect on 25-hydroxyvitamin D (25OHD) levels (-0.43 SD of standardized natural log-transformed 25OHD per A allele; p value = 1.5 × 10 -88 ). The effect on 25OHD was four times larger and independent of the effect of a previously described common variant near CYP2R1. By analyzing 8,711 individuals, we showed that heterozygote carriers of this low-frequency variant have an increased risk of vitamin D insufficiency (odds ratio [OR] = 2.2, 95% confidence interval [CI] = 1.78-2.78, p = 1.26 × 10 -12 ). Individuals carrying one copy of this variant also had increased odds of multiple sclerosis (OR = 1.4, 95% CI = 1.19-1.64, p = 2.63 × 10 -5 ) in a sample of 5,927 case and 5,599 control subjects. In conclusion, we describe a low-frequency CYP2R1 coding variant that exerts the largest effect upon 25OHD levels identified to date in the general European population and implicates vitamin D in the etiology of multiple sclerosis. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  7. 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

    -of-freedom single-current control (RTDOF-SCC) strategy is proposed, which mainly includes the synchronous reference frame quasi-proportional-integral (SRFQPI) control and robust grid-current-feedback active damping (RGCFAD) control. The proposed SRFQPI control can compensate the local-loads reactive power......, and regulate the instantaneous grid current without steady-state error regardless of the fundamental frequency fluctuation. Simultaneously, the proposed RGCFAD control effectively damps the LCL-resonance peak regardless of the grid-impedance variation, and further improves both transient and steady...

  8. 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 prior....... Simulation of a GSM-like system provides empirical proof that the VBEM-algorithm is able to provide better performance than the EM-algorithm. However, if the posterior distribution is highly peaked, the VBEM-algorithm approaches the EM-algorithm and the gain disappears. The potential gain is therefore...

  9. The evolution of polyandry: patterns of genotypic variation in female mating frequency, male fertilization success and a test of the sexy-sperm hypothesis.

    Science.gov (United States)

    Simmons, L W

    2003-07-01

    The sexy-sperm hypothesis predicts that females obtain indirect benefits for their offspring via polyandy, in the form of increased fertilization success for their sons. I use a quantitative genetic approach to test the sexy-sperm hypothesis using the field cricket Teleogryllus oceanicus. Previous studies of this species have shown considerable phenotypic variation in fertilization success when two or more males compete. There were high broad-sense heritabilities for both paternity and polyandry. Patterns of genotypic variance were consistent with X-linked inheritance and/or maternal effects on these traits. The genetic architecture therefore precludes the evolution of polyandry via a sexy-sperm process. Thus the positive genetic correlation between paternity in sons and polyandry in daughters predicted by the sexy-sperm hypothesis was absent. There was significant heritable variation in the investment by females in ovaries and by males in the accessory gland. Surprisingly there was a very strong genetic correlation between these two traits. The significance of this genetic correlation for the coevolution of male seminal products and polyandry is discussed.

  10. 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)

    1993-12-31

    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.

  11. 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

  12. 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)

    1997-12-31

    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

  13. 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.

  14. Prefrontal activity during working memory is modulated by the interaction of variation in CB1 and COX2 coding genes and correlates with frequency of cannabis use.

    Science.gov (United States)

    Taurisano, Paolo; Antonucci, Linda A; Fazio, Leonardo; Rampino, Antonio; Romano, Raffaella; Porcelli, Annamaria; Masellis, Rita; Colizzi, Marco; Quarto, Tiziana; Torretta, Silvia; Di Giorgio, Annabella; Pergola, Giulio; Bertolino, Alessandro; Blasi, Giuseppe

    2016-08-01

    The CB1 cannabinoid receptor is targeted in the brain by endocannabinoids under physiological conditions as well as by delta9-tetrahydrocannabinol under cannabis use. Furthermore, its signaling appears to affect brain cognitive processing. Recent findings highlight a crucial role of cyclooxygenase-2 (COX-2) in the mechanism of intraneuronal CB1 signaling transduction, while others indicate that two single nucleotide polymorphisms (SNPs) (rs1406977 and rs20417) modulate expression of CB1 (CNR1) and COX-2 (PTGS2) coding genes, respectively. Here, our aim was to use fMRI to investigate in healthy humans whether these SNPs interact in modulating prefrontal activity during working memory processing and if this modulation is linked with cannabis use. We recruited 242 healthy subjects genotyped for CNR1 rs1406977 and PTGS2 rs20417 that performed the N-back working memory task during fMRI and were interviewed using the Cannabis Experience Questionnaire (CEQ). We found that the interaction between CNR1 rs1406977 and PTGS2 rs20417 is associated with dorsolateral prefrontal cortex (DLPFC) activity such that specific genotype configurations (CNR1 C carriers/PTGS2 C carriers and CNR1 TT/PTGS2 GG) predict lower cortical response versus others in spite of similar behavioral accuracy. Furthermore, DLPFC activity in the cluster associated with the CNR1 by PTGS2 interaction was negatively correlated with behavioral efficiency and positively correlated with frequency of cannabis use in cannabis users. These results suggest that a genetically modulated balancing of signaling within the CB1-COX-2 pathway may reflect on more or less efficient patterns of prefrontal activity during working memory. Frequency of cannabis use may be a factor for further modulation of CNR1/PTGS2-mediated cortical processing associated with this cognitive process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The existence of Th22, pure Th17 and Th1 cells in CIN and Cervical Cancer along with their frequency variation in different stages of cervical cancer

    International Nuclear Information System (INIS)

    Zhang, Wenjing; Tian, Xinli; Mumtahana, Fidia; Jiao, Jun; Zhang, Teng; Croce, Kimiko Della; Ma, Daoxin; Kong, Beihua; Cui, Baoxia

    2015-01-01

    Recently, it is found that T-helper (Th) 22 cells are involved in different types of autoimmune and tumor diseases. But, till now, no study has been carried out to understand the involvement of these cells in cervical cancer (CC). Flow cytometry was used to determine the expression of interferon gamma (IFN-γ), Interleukin-22 (IL-22), IL-17 in the peripheral blood of healthy controls (HC), CIN and cervical cancer patients. From peripheral blood mononuclear cells (PBMCs), mRNA expression levels of Aryl hydrocarbon receptor (AHR), RAR-related orphan receptor C (RORC), TNF-α and IL-6 were respectively determined. Using the method of ELISA, plasma concentrations of IL-22, IL-17 and TNF-α were examined. Th22 and Th17 cells were elevated in CC and CIN patients. Th1 cells and the plasma concentrations of IL-22 in CC patients were significantly increased compared with HC. In CC patients, an increased prevalence of Th22 cells was associated with lymph node metastases. There was a positive correlation between Th22 and Th17 cells, but an approximately negative correlation between Th22 and Th1 cells in CC patients. The mRNA expression of RORC, TNF-α and IL-6 was significantly high in CC patients. Our results indicate that there is a higher circulatory frequency of Th22, Th17 and Th1 cells in CC which may conjointly participate in the pathogenesis and growth of CC

  16. 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.

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

    International Nuclear Information System (INIS)

    Galvez de la Puente, G.; Guerra Torres, J.A.; Erlenbach, O.; Steidl, M.; Weingaertner, R.; De Zela, F.; Winnacker, A.

    2010-01-01

    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.

  18. 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.

  19. 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

  20. 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

  1. 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)

    1998-12-31

    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

  2. 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.

  3. 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)

    1994-12-31

    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.

  4. 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.

  5. 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.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Guadalupe Arcos-Medina

    2016-01-01

    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.

  8. Administración estratégica y gobernabilidad en las cooperativas de ahorro y crédito del cantón Portoviejo

    Directory of Open Access Journals (Sweden)

    Dianexy Viviana Carreño

    2014-12-01

    Full Text Available Las Cooperativas de Ahorro y Crédito (CAC’s tienen una activa participación en el crecimiento y desarrollo económico del Ecuador, lo que permite desarrollar un estudio en la provincia de Manabí, tomando una muestra deliberada en el cantón Portoviejo, que concentra el 40% de las cooperativas que operan en la provincia; se utilizó la encuesta como técnica de recolección de datos, y se aplicó a los gerentes, presidentes de los Consejos de Administración y de vigilancia de diez CAC’s; A modo de conclusión es necesario recomendar promover el fortalecimiento y expansión con carácter holístico, a través de capacitación permanente y puesta en práctica de la Administración Estratégica, para alcanzar una mejor posición en el mercado, ganar la lealtad de los socios y atraer nuevos miembros.

  9. 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.

  10. 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.

  11. 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

  12. Ahorros en los consumos para enfriamiento de espacios interiores mediante la evaluación de sistemas de protección solar en edificios residenciales en altura. El caso de la "ciudad-oasis" de Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Julieta Balter

    2016-06-01

    Full Text Available El presente trabajo estudia el comportamiento térmico y energético de edificios residenciales en altura, en el contexto particular de una “ciudad-oasis”. Se plantea como objetivo la definición de sistemas de control solar adecuados en la envolvente para cada tipología material de edificio -másica y liviana- y para cada estrato en altura de las viviendas: debajo y sobre de la copa de los árboles. El monitoreo de viviendas en uso permite validar modelos geométricos (software Energy Plus y simular propuestas de aplicación de elementos de protección solar. Se analizan los ahorros en los consumos para enfriamiento en departamentos en niveles bajos, medios y altos. Los resultados muestran que en el edificio másico, en las viviendas ubicadas debajo de la copa de los árboles, es posible anular las cargas energéticas para enfriamiento mediante el uso de elementos exteriores de protección solar. Mientras que en las viviendas sobre la copa de los árboles, los ahorros energéticos se encuentran entre el 32% y 42%. En el edificio liviano, la aplicación de sistemas de control en departamentos bajo la copa de los árboles alcanza ahorros del orden del 53% y en las viviendas sobre la copa, las reducciones energéticas se encuentran entre el 46% y 54%. Las dimensiones adecuadas de tales elementos pueden generar propuestas posibles de ser transferidas a las normativas locales de edificación. 

  13. El back office de capital humano y su impacto en la optimización de procesos y generación de ahorros en costos de servicios en Arca Continental, sucursal Salta, durante el segundo semestre del año 2016

    OpenAIRE

    Giménez Perri, Solana

    2017-01-01

    248 p. il. El tema de la presente investigación fue el back office de capital humano y su impacto en la optimización de procesos y generación de ahorros en costos de servicios en Arca Continental, sucursal Salta, durante el segundo semestre del año 2016. Se trata de un estudio de tipo descriptivo que buscó establecer asociaciones entre tres dimensiones de análisis: back office de capital humano, optimización de procesos y generación de ahorros. En el trabajo de campo se entrevistó a inf...

  14. Diagnóstico y propuesta de plan de mejoramiento en el área financiera para el Sistema de Cooperativas de Ahorro y Crédito del Segmento Uno, reguladas por la Superintendencia de Economía Popular y Solidaria, durante el período 2011- 2014

    OpenAIRE

    Pacheco Guevara, Ximena Patricia

    2016-01-01

    La presente investigación se enfoca en una propuesta de mejora en el área financiera para el sistema de cooperativas de ahorro y crédito del segmento uno, reguladas por la Superintendencia de Economía Popular y Solidaria, durante el período 2011-2014. Bajo este contexto, se revisaron una serie de metodologías aplicadas a nivel internacional, definiendo la creada por el Consejo Mundial de Cooperativas de Ahorro y Crédito WOCCU como la más apropiada, al analizar específicamente cooperativas de ...

  15. Análisis de la eficiencia en las cooperativas de ahorro y crédito en Colombia, mediante la utilización de la técnica de Análisis de Datos Envolvente DEA, periodo 2008-2011

    OpenAIRE

    Moreno Sierra, Vivian Carolina; Rey Huertas, Luis Eduardo

    2015-01-01

    La presente estudio pretende analizar la eficiencia en las cooperativas de ahorro y crédito en Colombia, mediante la utilización de la técnica de análisis de datos envolvente (DEA); el trabajo investigativo es importante analizar al subsector cooperativo de ahorro y crédito para el periodo 2008-2011 debido a que este subsector es el más dinámico del sector cooperativo. La identificación de las cooperativas eficientes requiere de la aplicación de una técnica no paramétrica mediante el análisis...

  16. 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.

  17. Marketing estratégico para incrementar la cartera de socios de la Cooperativa de Ahorro y Crédito ?Uniblock? ubicada en la ciudad de Latacunga en el período 2013

    OpenAIRE

    Borja Brazales, Yadira Paola

    2015-01-01

    1. Fundamentos Teóricos.-- 2. Metodología.-- 3.Resultados.-- 4. Propuesta.-- 5. Conclusiones y Recomendaciones El desarrollo del presente trabajo tiene como objetivo diseñar estrategias de marketing para incrementar la cartera de socios de la Cooperativa de Ahorro y Crédito ?Uniblock?. Está investigación consiste en realizar un análisis situacional de la cooperativa, por lo cual primero se elaboró el marco teórico que abarca cada una de las variables objeto de estudio incluidas sus respect...

  18. Descripción y análisis de la aplicación de la teoría general de las organizaciones en el modelo de gestión del Fondo Nacional de Ahorro, FNA

    OpenAIRE

    Isairías Mora, José Edgar; Lozada Angarita, Carlos Eduardo

    2011-01-01

    La tesis que a continuación se presenta corresponde a la Maestría en Dirección y Gerencia de Empresas de la Universidad del Rosario. En ella se revisan y analizan múltiples factores mediante los cuales se determina o no la aplicación de aplicación de la Teoría General de las organizaciones en la gestión del Fondo Nacional de Ahorro, FNA. de la ciudad de Bogotá. En ella se plantean los aspectos que se aplican de cada una de las siguientes teorías organizacionales o administrativas: Administrac...

  19. Levantamiento del proceso de crédito e identificación de eventos de riesgo operativo en la Cooperativa de Ahorro y Crédito OSCUS Ltda.

    OpenAIRE

    Ibarra Licto, Carmen Jacqueline

    2008-01-01

    La Cooperativas de ahorro y crédito, como entidades financieras, actúan, se desarrollan y crecen en busca de beneficios mutuos, servicios financieros con rentabilidad y calidad social, y este negocio genérico, que tiene el dinero como vehículo requiere un adecuado manejo y administración de costos operativos, con el objeto de identificar y eliminar costos superfluos, y reducir al óptimo los necesarios, sin dejar de lado que en la actualidad la calidad, innovación y servicio ...

  20. Sistema de control de gestión de riesgo para la prevención del lavado de activos en la cooperativa de ahorro y crédito Sumak Samy Ltda. de la ciudad de Ambato.

    OpenAIRE

    Carrillo Sarabia, Patricia de las Mercedes

    2017-01-01

    1. Introducción. --2. Planteamiento de la Propuesta de Trabajo. --3. Marco Teórico. --4. Metodología. --5. Resultados. --6. Conclusiones y Recomendaciones. El presente trabajo tiene como objetivo fundamental el desarrollo de un Sistema de control de gestión de riesgo para la prevención del lavado de activos en la Cooperativa de Ahorro y Crédito Sumak Samy Ltda. en la ciudad de Ambato, el cual le permitirá a la cooperativa contar con el Nivel de riesgo de sus socios/clientes y aplicar polít...

  1. Diseño de un modelo de Administración de Riesgo Operativo aplicado al proceso de crédito en la Cooperativa de Ahorro y Crédito "Santa Ana de Nayón"

    OpenAIRE

    Sandoval Zambrano, Emma Patricia

    2016-01-01

    Este trabajo pretende aportar con un modelo de Riesgo Operativo en el Proceso de Crédito, a la Cooperativa de Ahorro y Crédito Santa Ana de Nayón, con el objetivo de disponer de una herramienta que permita mitigar posibles riesgos operativos a los que está expuesta. Intenta también motivar y concientizar a los directivos y a la gerencia de la importancia de la implementación de la Administración Integral de Riesgos, como estrategia institucional y de forma especial la gestión de riesgo operat...

  2. Análisis de la estructura financiera para la toma de decisiones gerenciales en la Junta Administradora del Fondo de Ahorro y Préstamo de la Universidad de Costa Rica

    OpenAIRE

    Rojas González, Catalina

    2012-01-01

    Tesis de maestría -- Universidad de Costa Rica. Posgrado en Administración y Dirección de Empresas. Maestría Profesional en Administración y Dirección de Empresas con énfasis en Finanzas, 2012 El objetivo general del trabajo es elaborar un análisis detallado de los estados financieros de la Junta Administradora del Fondo de Ahorro y Préstamo (JAFAP) de la Universidad de Costa Rica para el período comprendido entre el 31 de diciembre de 2009 y el 31 de diciembre de 2010, con el objetivo de ...

  3. Propuesta de nuevas opciones de inversión y gestión de la cartera de inversiones de la Junta Administradora de Ahorro y Préstamo de la Universidad de Costa Rica

    OpenAIRE

    López Bogantes, Randy Alberto

    2014-01-01

    Tesis de maestría -- Universidad de Costa Rica. Posgrado en Administración y Dirección de Empresas. Maestría Profesional en Administración y Dirección de Empresas con énfasis en Finanzas, 2014 El objetivo general del proyecto es proponer alternativas adicionales de inversión más rentables que permitan a la Junta Administradora de Ahorro y Préstamo de la Universidad de Costa Rica una estructura óptima del portafolio de acuerdo con la normativa interna, al lograr el mejor rendimiento posible...

  4. 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.

  5. 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.

  6. Reparto de utilidades en las sociedades cooperativas de ahorro y préstamo ¿por qué son gravadas? un análisis sobre la aplicación de la carga fiscal

    OpenAIRE

    Ramos Andrade, Zahyra del Rocío

    2015-01-01

    En síntesis en la presente investigación se realizó un minucioso análisis en torno a las sociedades cooperativas de ahorro y préstamo, basándose la autora en una entidad denominada caja popular San Rafael. Llegando a la conclusión de que dichas empresas son personas morales lucrativas pues obtienen un beneficio económico a cambio de los servicios que presta, son generadoras de riqueza y obtienen utilidades; sin embargo, dichas utilidades no son gravadas debido a que la legislación determina q...

  7. 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 ...

  8. Modelo de auditoría informática basada en riesgos en ámbitos financieros. Aplicación de un caso de estudio a una cooperativa de ahorro y crédito

    OpenAIRE

    Quishpe Goyes, Bety Elizabeth; Vargas Cisneros, Marjori Silvana

    2013-01-01

    184 hojas : ilustraciones, 29 x 21 cm + CD-ROM 4848 El presente documento tiene como objetivo presentar un modelo que permite efectuar auditorías informáticas basadas en riesgos en ámbitos financieros, el cual fue aplicado a una Cooperativa de Ahorro y Crédito. El modelo propuesto se basa en normas y estándares nacionales e internacionales relacionados con la auditoría informática basada en riesgos, que permiten al auditor informático obtener las referencias necesarias para efectuar el exa...

  9. 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)

    1999-12-31

    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.

  10. 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.

  11. 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.

  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 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)

    1997-12-31

    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.

  14. 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.

  15. Frequency and turmoil

    African Journals Online (AJOL)

    level of popular unrest focused on 'service delivery protests', but in recent years the broader conception of ... Drawing on the Centre for Social Change's archive of media reports, the largest database of its kind, and by comparing its data with .... impact on frequencies. The variation evident in the table is not accidental but is ...

  16. Desarrollo de la capacidad de prevención estratégica en la Cooperativa de Ahorro y Crédito de la Universidad Técnica de Manabí

    Directory of Open Access Journals (Sweden)

    Ángel Emilio Mendoza Mero

    2017-07-01

    Full Text Available En este trabajo se presenta un procedimiento que integra cinco pasos para el diagnóstico de la Capacidad de Prevención Estratégica (CAPE a través de la evaluación de los comportamientos prácticos de las 11 variables de la CAPE. La aplicación del procedimiento en la Cooperativa de Ahorro y Crédito de Profesores, Empleados y Trabajadores de la Universidad Técnica de Manabí logró demostrar un bajo desarrollo de la CAPE, limitado por la insuficiente aplicación de la administración de riesgos en el proceso de dirección estratégica. Las mejoras desarrolladas en la cooperativa permitieron aumentar la CAPE así como el diseño e implementación de un programa estratégico de acciones con la reducción de los principales riesgos y un impacto positivo en los indicadores de desempeño financiero de la cooperativa. Se considera un aporte teórico la determinación de la situación problemática a partir de la matriz de relaciones de riesgos.    Palabras clave: capacidad de prevención estratégica, administración de riesgos, cooperativa de ahorro y crédito.

  17. 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.

  18. 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

  19. 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)

    1996-12-31

    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

  20. 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

  1. 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

  2. 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)

    1997-12-31

    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

  3. Estimado de la reducción de la emisión de co2 por accione de ahorro de electricidad en las condiciones de Cuba,

    Directory of Open Access Journals (Sweden)

    Irina Salazar Fonseca

    2011-05-01

    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

  4. 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

  5. Frequency Synthesiser

    NARCIS (Netherlands)

    Drago, Salvatore; Sebastiano, Fabio; Leenaerts, Dominicus M.W.; Breems, Lucien J.; 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

  6. Frequency synthesiser

    NARCIS (Netherlands)

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

    2010-01-01

    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

  7. 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)

    1994-12-31

    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

  8. 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

  9. 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)

    1994-12-31

    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.

  10. 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)

    1999-12-31

    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.

  11. 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.

  12. Modelo de gestión de crédito y cobranza para recuperar cartera vencida en la Cooperativa de ahorro y crédito San Miguel de Los Bancos y sus tres agencias que la integran

    OpenAIRE

    Armijos Loaiza, Alex David; Oña Muñoz, Julio César

    2015-01-01

    El presente trabajo de grado se elaboró con el fin de brindar una solución a la problemática que enfrenta la Cooperativa de Ahorro y Crédito San Miguel de los Bancos al momento de recuperar sus créditos emitidos a sus clientes, por lo tanto, se propuso modelo de gestión de crédito y cobranza para mejorar las deficiencias en los procesos que actualmente se llevan a cabo dentro área de crédito. Dentro del primer capítulo se hizo referencia a las fuentes bibliográficas y referenciales que permit...

  13. 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.

  14. 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.

  15. 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.

  16. CAMAC programmable-control frequency synthesizer

    International Nuclear Information System (INIS)

    Yumaguzin, T.Kh.; Vyazovkin, D.E.; Nazirov, Eh.P.; Tuktarov, R.F.

    1989-01-01

    Synthesizer allows to set frequency with 0.015% accuracy and to scan it with variable step. Frequency controlled divider with further summing-up of divided frequency with fundamental one is used in synthesizer, and it has allowed to use digit of the input code and to obtain 3-4 MHz frequency range. Variation of operation flowsheet in the other frequency range is possible. K-155 and K-531 series microcircuits were used during development

  17. 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.

  18. 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.

  19. Hg(+) Frequency Standards

    Science.gov (United States)

    Prestage, John D.; Tjoelker, Robert L.; Maleki, Lute

    2000-01-01

    In this paper we review the development of Hg(+) microwave frequency standards for use in high reliability and continuous operation applications. In recent work we have demonstrated short-term frequency stability of 3 x 10(exp -14)/nu(sub tau) when a cryogenic oscillator of stability 2-3 x 10(exp 15) was used a the local oscillator. The trapped ion frequency standard employs a Hg-202 discharge lamp to optically pump the trapped Hg(+)-199 clock ions and a helium buffer gas to cool the ions to near room temperature. We describe a small Hg(+) ion trap based frequency standard with an extended linear ion trap (LITE) architecture which separates the optical state selection region from the clock resonance region. This separation allows the use of novel trap configurations in the resonance region since no optical pumping is carried out there. A method for measuring the size of an ion cloud inside a linear trap with a 12-rod trap is currently being investigated. At approx. 10(exp -12), the 2nd order Doppler shift for trapped mercury ion frequency standards is one of the largest frequency offsets and its measurement to the 1% level would represent an advance in insuring the very long-term stability of these standards to the 10(exp -14) or better level. Finally, we describe atomic clock comparison experiments that can probe for a time variation of the fine structure constant, alpha = e(exp 2)/2(pi)hc, at the level of 10(exp -20)/year as predicted in some Grand Unified String Theories.

  20. 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

  1. 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

  2. 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.

  3. 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)

    1996-12-31

    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.

  4. 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.

  5. Los determinantes a largo plazo y su contribución a la tasa de ahorro de los hogares españoles en el período 1985-2016 || Long-term determinants and its contribution to Spanish household saving rate during the period 1985-2016

    Directory of Open Access Journals (Sweden)

    de Andrés Mosquera, Andrés

    2017-12-01

    Full Text Available El trabajo estudia el comportamiento de la tasa de ahorro de los hogares en el período de 1985 a 2016. Se examinan las variables que la literatura considera que determinan la tasa de ahorro a largo plazo: renta, riqueza, desempleo, crédito y endeudamiento, ahorro público, estructura de la población, prestaciones sociales, tipos de interés y precios. Tras revisar la cointegración de las variables elegidas, proponemos cuatro especificaciones de la tasa de ahorro en función de sus determinantes a largo plazo: la renta permanente, la riqueza, el desempleo, el crédito, la tasa de dependencia y las prestaciones sociales. En el marco del modelo de corrección de error, contrastamos complementariamente la cointegración de las variables que confirman la validez del modelo. Los resultados muestran la especial relevancia a largo plazo de la tasa de dependencia que, como variable demográfica estructural, permite prever en cierta medida la evolución de la tasa de ahorro. Las prestaciones sociales, que muestran la importancia a largo plazo del sistema de prestaciones público, junto con el crédito y el desempleo, determinan la tasa de ahorro a largo plazo en consonancia con la fase del ciclo económico. La renta laboral-permanente incide sobre la tasa de ahorro especialmente en los cambios profundos de ciclo. La repercusión a largo plazo de la riqueza es de menor magnitud. || The paper studies the behavior of the household saving rate during the period from 1985 to 2016. We examine the variables considered by the literature to determine the long-term saving rate: Income, wealth, unemployment, credit and indebtedness, public savings, population structure, social benefits, interest rates and prices. In the framework of the error correction model, we contrast the cointegration of the variables by means of four specifications for the saving rate according to its long-term determinants: Permanent income, wealth, unemployment, credit, dependency rate

  6. Frequency primary regulation (FPR). Implications of the down stream flow variations. Operation methodology; Regulacion primaria de frecuencia (RPF). Implicancia por las variaciones del caudal aguas abajo. Metodologia de operacion

    Energy Technology Data Exchange (ETDEWEB)

    Morandi, Hector Enrique; Martelli, Jose Francisco [Ente Ejecutivo Presa Embalse Casa de Piedra, Buenos Aires (Argentina)]. E-mail: cdpba@impsat1.com.br

    1998-07-01

    This paper describes the Frequency Primary Regulation - FPR, determining that the operator running of a hydroelectric power plant must observe a set of norms, actions, etc, aiming to reduce as much as possible the environmental impact following the important modifications introduced. The regulation of the water flux downstream is one of the priority imposed to the project of a hydroelectric power plant. The regulation also allows other benefits as follows: the use of potentially or effectively flooded increasing the productive area; the efficient operation of water influx for various uses; the elimination of crop losses due to lack of irrigation water during certain seasons.

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. A short regression during the last interglacial (5e) sea level high-stand, along the reef coast of Egypt: a possible evidence for high-frequency glacio-eustatic variations during pleistocene times?

    International Nuclear Information System (INIS)

    Plaziat, J.C.; Orszag-sperber, F.; Baltzer, F.; Purser, B.H.; Reyss, J.L.; Choukri, A.

    1998-01-01

    In the most stable localities of the NW Red Sea-Gulf of Suez, the Last Interglacial shore deposits have been dated (α Th/U) and give evidence of a two-stages 5.5 (5e) + 8/5 m transgression subdivided by a 10 m (at least) relative sea-level fall. The respective ages of the initial reef and beach unit and about 3 m lower bay-lagoon-gypsum salina deposits are not discriminable with the available dating method. This high-frequency oscillation during 5.5 high stand would be tentatively interpreted as a glacio-eustatic sea-level coinciding with the 5.52 event of δ 18 O isotopic terminology. (authors)

  12. Metaleptic Variations

    OpenAIRE

    Pernot, Dominique

    2014-01-01

    Les derniers romans de Gabriel Josipovici offrent beaucoup de variété, allant de la parodie, de la fiction comique légère, dans Only Joking et Making Mistakes, à des sujets plus graves, plus personnels, ontologiques. Dans un court roman, Everything Passes, et dans un roman majeur, Goldberg: Variations, le lecteur est amené à se poser des questions sur la nature mystérieuse de la réalité, qui est, trop souvent, acceptée sans conteste par de nombreux roma...

  13. Periodic weather and climate variations

    International Nuclear Information System (INIS)

    Ivanov, Vladimir V

    2002-01-01

    Variations in meteorological parameters are largely due to periodic processes and can be forecast for several years. Many such processes are related to astronomical factors such as the gravitational influences of the Moon and the Sun, and the modulation of solar irradiance by lunar and planetary motion. The Moon, Jupiter, and Venus have the strongest effect. These influences produce lines in the spectra of meteorological variations, which are combinations of the harmonics of the frequencies of revolution of the planets, the Earth, and the Moon around the Sun with the harmonics of the lunar revolution around the Earth. Due to frequency differences between the orbital and radial motions, fine spectral features of three types appear: line splitting, line-profile complications due to radial oscillations, and additional lines due to the combination of radial-oscillation frequencies with perturbation harmonics. (reviews of topical problems)

  14. 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...... the study on four video-recorded sessions, with four different PhD students and their supervisors, all from life sciences. Our analysis revealed that learning opportunities in the supervision sessions concerned either the content matter of research (for instance, understanding soil structure......), or the research methods— more specifically how to produce valid results. Our results illustrate how supervisors and PhD students create a space of learning together in their particular discipline by varying critical aspects of their research in their discussions. Situations where more openended research issues...

  15. 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......-shift. Experimental results inX-band, in good agreement with the theory, show that it is possible to scan the main lobe an angle ofpm30degby a variation of the frequencypm300MHz, and where the 3 dB beamwidth is less than10deg. The directivity was 14.7 dB, while the gain was 8.1 dB. The efficiency might be improved...

  16. Genetic variation between ecotypic populations of Chloris ...

    African Journals Online (AJOL)

    Genetic variation between ecotypic populations of Chloris roxburghiana grass detected through RAPD analysis. ... frequency indicated that the four populations of C. roxburghiana were genetically distinct, probably as a result of variation in soil fertility, geographical isolation and socio-ecological history of the study sites.

  17. 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

  18. 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

  19. Diseño de la propuesta del modelo de procesos para la unidad de desarrollo de software del área de servicios informáticos y redes de comunicación de la Cooperativa de ahorro y crédito Jardín Azuayo

    OpenAIRE

    Montero Arévalo, María Eugenia

    2012-01-01

    La aplicación de modelos de procesos de desarrollo de software en nuestro medio, no es un tema importante para muchas organizaciones. El resultado, pérdida de tiempo, dinero y esfuerzos en proyectos fracasados. La Cooperativa de Ahorro y Crédito Jardín Azuayo, es una institución financiera que por su crecimiento acelerado necesita ordenar y redefinir muchos de sus procesos y entre ellos está el de desarrollo de software. Por esta razón se consideró importante, dar a conocer una breve historia...

  20. Las mejores prácticas aplicadas a un análisis de riesgos de seguridad de la información para las entidades financieras controladas por la Superintendencia de Economía Popular y Solidaria (Cooperativas de Ahorro y Crédito) que conforman el grupo de asistencia tecnológica Cooperativa (Asistecooper). Propuesta alternativa

    OpenAIRE

    Cevallos Guerra, Diego Fernando

    2015-01-01

    En el Ecuador, el sector financiero, como principal usuario de las tecnologías de la información y conocedor de las amenazas a las que se encuentran expuestos los diferentes servicios financieros, algunas instituciones han tenido iniciativas muy particulares para proteger la integridad, disponibilidad y confidencialidad de la información, sin embargo, se puede afirmar que estas iniciativas no han sido muy generalizadas especialmente en las cooperativas de ahorro y crédito, ante esta situación...

  1. Diseño e implementación de un modelo de gestión administrativo para la cooperativa de ahorro y crédito educadores de Chimborazo Ltda., y su incidencia en los indicadores de gestión. Periodo marzo 2013-abril 2014.

    OpenAIRE

    Castillo Fiallos, Mariela Paulina

    2015-01-01

    El presente trabajo de investigación se realizó en la Cooperativa de Ahorro y Crédito Educadores de Chimborazo Ltda., de la Ciudad de Riobamba, Provincia de Chimborazo, ubicada en las calles Veloz 22-11 y Espejo (esquina), con el propósito de dotar a la Institución de una herramienta idónea, capaz de analizar la gestión administrativa de manera cuantitativa y cualitativa. La gestión administrativa, es una herramienta que brindara parámetros para facilitar la toma de decisiones mejorando...

  2. 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.

  3. 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)

    1996-12-31

    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.

  4. 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.

  5. 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.

  6. 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......- optical modulators and forward propagating Brillouin scattering appear in the spectrum. © 2013 Optical Society of America....

  7. 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.

  8. Direct excitation of a high frequency wave by a low frequency wave in a plasma

    International Nuclear Information System (INIS)

    Tanaka, Takayasu

    1993-01-01

    A new mechanism is presented of an excitation of a high frequency wave by a low frequency wave in a plasma. This mechanism works when the low frequency wave varies in time in a manner deviated from a usual periodic motion with a constant amplitude. The conversion rate is usually not large but the conversion is done without time delay after the variation of the low frequency wave. The Manley Rowe relation in the usual sense does not hold in this mechanism. This mechanism can excite also waves with same or lower frequencies. (author)

  9. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Morgan, T.

    1985-01-01

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  10. Variational integrators for electric circuits

    International Nuclear Information System (INIS)

    Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

    2013-01-01

    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

  11. Multi-frequency excitation

    KAUST Repository

    Younis, Mohammad I.

    2016-01-01

    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

  12. Climatic Variations, Trends and Drought Frequency in Dejen District ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... from December to February, and 5 to 10% declined rainfall amount from ... district loses 50,555 quintals of crops, which has the potential to feed .... different scenarios, income per hectare will decrease by. 9.71% - 303.27% by ...

  13. Clutter Height Variation Effects on Frequency Dependen Path Loss ...

    African Journals Online (AJOL)

    http://dx.doi.org/10.4314/star.v4i4.21 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL · News. OTHER RESOURCES... for Researchers · for Journals · for Authors · for Policy Makers ...

  14. 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

  15. 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.

  16. Cluster analysis of word frequency dynamics

    International Nuclear Information System (INIS)

    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

  17. Frequency spectrum of Calder Hall reactor noise

    International Nuclear Information System (INIS)

    Cummins, J.D.

    1960-01-01

    The frequency spectrum of the noise power of Calder Hall reactor No. 1 has been obtained by analysing a tape recording of the backed off power. The root mean square noise power due to all frequencies above 0.001 cycles per second was found to be 0.13%. The noise power for this reactor, is due mainly to modulations of the power level by reactivity variations caused in turn by gas temperature changes. These gas temperature changes are caused by a Cyclic variation in the feedwater regulator to the heat exchanger. The apparatus and method used to determine the noise power are described in this memorandum. It is shown that for frequencies in the range 0.001 to 0.030 cycles per second the noise spectrum falls at 60 decibels per decade of frequency. (author)

  18. 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.

  19. 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.

  20. Frequency selectivity at very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten

    2010-01-01

    measurements based on OAE suppression techniques and notched-noise masking data psychophysically measured for centre frequencies in the range 50-125 Hz, this study examines how individual differences in frequency selectivity, as well as in masking, may occur at very low CFs due to individual differences...

  1. 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

  2. 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)

    1996-12-31

    , 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

  3. 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

  4. Rotavirus diarrhea disease burden in Peru: the need for a rotavirus vaccine and its potential cost savings Carga de morbilidad de la diarrea por rotavirus en Perú: la necesidad de una vacuna y su potencial de ahorro

    Directory of Open Access Journals (Sweden)

    Peter Ehrenkranz

    2001-10-01

    Full Text Available Objective. To assess the disease burden of rotavirus diarrhea in Peru as well the need for and the potential cost savings with a rotavirus vaccine in that country. Methods. To assess the burden of rotavirus diarrhea in Peru, we reviewed published and unpublished reports where rotavirus was sought as the etiologic agent of diarrhea in children. Rotavirus detection rates obtained from these studies were combined with diarrhea incidence rates from a number of national surveys in order to estimate both the burden of rotavirus diarrhea in the country and its associated medical costs. Results. Rotavirus is a significant cause of morbidity and mortality in Peruvian children. In their first 5 years of life, an estimated 1 in 1.6 children will experience an episode of rotavirus diarrhea, 1 in 9.4 will seek medical care, 1 in 19.7 will require hospitalization, and 1 in 375 will die of the disease. Per year, this represents approximately 384 000 cases, 64 000 clinic visits, 30 000 hospitalizations, and 1 600 deaths. The annual cost of medical care alone for these children is approximately US$ 2.6 million--and that does not take into account the indirect or societal costs of the illness and the deaths. Conclusions. Rotavirus immunization provides the prospect of decreasing the morbidity and mortality from diarrhea in Peru, but a vaccine regimen would have to be relatively inexpensive, a few dollars or less per child. Future cost-effectiveness analyses should explore the total costs (medical as well as indirect or societal associated with rotavirus diarrhea. Newly licensed vaccines should be tested according to both their ability to avert deaths and their efficacy with fewer than three doses. All three of these factors could increase the cost savings associated with a rotavirus vaccine.Objetivos. Evaluar la carga de morbilidad de la diarrea por rotavirus en Perú, la necesidad de una vacuna y el ahorro que esta podría proporcionar en este país. M

  5. Variational principles for locally variational forms

    International Nuclear Information System (INIS)

    Brajercik, J.; Krupka, D.

    2005-01-01

    We present the theory of higher order local variational principles in fibered manifolds, in which the fundamental global concept is a locally variational dynamical form. Any two Lepage forms, defining a local variational principle for this form, differ on intersection of their domains, by a variationally trivial form. In this sense, but in a different geometric setting, the local variational principles satisfy analogous properties as the variational functionals of the Chern-Simons type. The resulting theory of extremals and symmetries extends the first order theories of the Lagrange-Souriau form, presented by Grigore and Popp, and closed equivalents of the first order Euler-Lagrange forms of Hakova and Krupkova. Conceptually, our approach differs from Prieto, who uses the Poincare-Cartan forms, which do not have higher order global analogues

  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. AUTOMATIC FREQUENCY CONTROL SYSTEM

    Science.gov (United States)

    Hansen, C.F.; Salisbury, J.D.

    1961-01-10

    A control is described for automatically matching the frequency of a resonant cavity to that of a driving oscillator. The driving oscillator is disconnected from the cavity and a secondary oscillator is actuated in which the cavity is the frequency determining element. A low frequency is mixed with the output of the driving oscillator and the resultant lower and upper sidebands are separately derived. The frequencies of the sidebands are compared with the secondary oscillator frequency. deriving a servo control signal to adjust a tuning element in the cavity and matching the cavity frequency to that of the driving oscillator. The driving oscillator may then be connected to the cavity.

  8. Frequency dependence and frequency control of microbubble streaming flows

    Science.gov (United States)

    Wang, Cheng; Rallabandi, Bhargav; Hilgenfeldt, Sascha

    2013-02-01

    Steady streaming from oscillating microbubbles is a powerful actuating mechanism in microfluidics, enjoying increased use due to its simplicity of manufacture, ease of integration, low heat generation, and unprecedented control over the flow field and particle transport. As the streaming flow patterns are caused by oscillations of microbubbles in contact with walls of the set-up, an understanding of the bubble dynamics is crucial. Here we experimentally characterize the oscillation modes and the frequency response spectrum of such cylindrical bubbles, driven by a pressure variation resulting from ultrasound in the range of 1 kHz raisebox {-.9ex{stackrel{textstyle <}{˜ }} }f raisebox {-.9ex{stackrel{textstyle <}{˜ }} } 100 kHz. We find that (i) the appearance of 2D streaming flow patterns is governed by the relative amplitudes of bubble azimuthal surface modes (normalized by the volume response), (ii) distinct, robust resonance patterns occur independent of details of the set-up, and (iii) the position and width of the resonance peaks can be understood using an asymptotic theory approach. This theory describes, for the first time, the shape oscillations of a pinned cylindrical bubble at a wall and gives insight into necessary mode couplings that shape the response spectrum. Having thus correlated relative mode strengths and observed flow patterns, we demonstrate that the performance of a bubble micromixer can be optimized by making use of such flow variations when modulating the driving frequency.

  9. Variation and Mathematics Pedagogy

    Science.gov (United States)

    Leung, Allen

    2012-01-01

    This discussion paper put forwards variation as a theme to structure mathematical experience and mathematics pedagogy. Patterns of variation from Marton's Theory of Variation are understood and developed as types of variation interaction that enhance mathematical understanding. An idea of a discernment unit comprising mutually supporting variation…

  10. Y-STR frequency surveying method

    DEFF Research Database (Denmark)

    Willuweit, Sascha; Caliebe, Amke; Andersen, Mikkel Meyer

    2011-01-01

    Reasonable formalized methods to estimate the frequencies of DNA profiles generated from lineage markers have been proposed in the past years and were discussed in the forensic community. Recently, collections of population data on the frequencies of variations in Y chromosomal STR profiles have...... reached a new quality with the establishment of the comprehensive neatly quality-controlled reference database YHRD. Grounded on such unrivalled empirical material from hundreds of populations studies the core assumption of the Haplotype Frequency Surveying Method originally described 10 years ago can...... be tested and improved. Here we provide new approaches to calculate the parameters used in the frequency surveying method: a maximum likelihood estimation of the regression parameters (r1, r2, s1 and s2) and a revised Frequency Surveying framework with variable binning and a database preprocessing to take...

  11. 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

  12. 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

  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. DDC Descriptor Frequencies.

    Science.gov (United States)

    Klingbiel, Paul H.; Jacobs, Charles R.

    This report summarizes the frequency of use of the 7144 descriptors used for indexing technical reports in the Defense Documentation Center (DDC) collection. The descriptors are arranged alphabetically in the first section and by frequency in the second section. The frequency data cover about 427,000 AD documents spanning the interval from March…

  15. Tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.

    1981-01-01

    The periodic variations of the earths' rotation resulting from the tidal deformation of the earth by the sun and moon were rederived including terms with amplitudes of 0.002 millisec and greater. The series applies to the mantle, crust, and oceans which rotate together for characteristic tidal periods; the scaling parameter is the ratio of the fraction of the Love number producing tidal variations in the moment of inertia of the coupled mantle and oceans (k) to the dimensionless polar moment of inertia of the coupled moments (C). The lunar laser ranging data shows that k/C at monthly and fortnightly frequencies equals 0.99 + or - 0.15 and 0.99 + or - 0.20 as compared to the theoretical value of 0.94 + or - 0.04.

  16. Investigación de los índices de gestión de las cooperativas de ahorro y crédito del cantón Ambato, y propuesta de mejora en los procesos internos de la satisfacción del cliente para el año 2012.

    OpenAIRE

    Guerrero López, Juliana Lissette; Manobanda Pinto, Christian Fernando

    2013-01-01

    Las cooperativas de ahorro y crédito reguladas por la Superintendencia de Bancos y Seguros de la ciudad de Ambato tienen como objetivo primordial el servir a la comunidad a través de la prestación de servicios financieros de los más altos estándares de calidad; comprometidos con el desarrollo socio económico del país. La presente investigación se realizó durante el año 2012 cuyo propósito fue investigar los índices de gestión y diseñar una propuesta de mejora en los procesos internos de la sa...

  17. Gestión de riesgo operativo: diseño de una metodología para su identificación y propuesta de planes de acción en cooperativas de ahorro y crédito no reguladas, miembros de una organización representativa

    OpenAIRE

    Sarango Tene, María Nancy

    2015-01-01

    La decisión de abordar como tema de tesis la “Gestión de riesgo operativo: diseño de una metodología para su identificación y propuesta de planes de acción en cooperativas de ahorro y crédito no reguladas miembros de una organización representativa”, responde a la preocupación, cada vez más acuciante, de que las cooperativas dispongan de una metodología de identificación de riesgo operativo para reducir posibles pérdidas resultantes de una mala gestión en factores de riesgo, tales como: proce...

  18. Strain Dependence of the Frequencies and the Thermal Expansion of the Hexagonal Close-Packed Lattice; Variations, en Fonction de la Deformation, des Frequences et de la Dilatation Thermique du Reseau a Structure Hexagonale Compacte; Zavisimost' chastot i teplovogo rasshireniya geksagonal'noj reshetki s plotnoj upakovkoj ot napryazheniya; Variacion de las Frecuencias y de la Dilatacion Termica de la Red Hexagonal Compacta en Funcion de la Deformacion

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, R.; Ramji Rao, R. [Physics Department, Indian Institute of Technology, Madras (India)

    1965-04-15

    The anisotropic thermal expansion of some hexagonal metals have been measured recently. To work out the theory of anisotropic thermal expansion of hexagonal close-packed (hcp) lattices, it is necessary to investigate the strain dependence of the frequencies of the hcp lattice. The hcp lattice with nearest-neighbour central interaction of the form Empty-Set = -a/{gamma}{sup m} + b/{gamma}{sup n} has been considered. The strains employed are (1) a longitudinal expansion {zeta} along the z-axis; and (2) a uniform areal expansion #Greek Lunate Epsilon Symbol#' in the basal plane. These are the relevant strains in the theory of thermal expansion and they have the advantage that they do not involve inter lattice displacements. The Grueneisen parameters {gamma}'{sub i} = -{partial_derivative}log{omega}{sub i}/{partial_derivative}#Greek Lunate Epsilon Symbol#' and {gamma}'{sub i}' = -{partial_derivative}log{omega}{sub i}/{partial_derivative}{zeta} have been worked out for wave-vectors lying along certain symmetry directions. These parameters for the acoustic branches are found to be strongly direction-dependent and to exhibit a wide variation. One of the transverse acoustic branches in the basal plane has a negative value of {gamma}'', whatever the values of m and n are. The dependence of the moments {mu}{sub 2}, {mu}{sub 4} and {mu}{sub 6} on the above strains has been worked out. The high and low temperature limits of the equivalent Grueneisen parameters {gamma}{sup +} and {gamma}{sup -} have been worked out for three pairs of values of m and n. It is found that {gamma}' = {gamma}'' and the high temperature limit {gamma}'{sub {infinity}} is greater than the low temperature limit {gamma}{sub 0} by about 0.3. The magnitude of this difference appears to be independent of the values of m and n. Taking farther-neighbour interaction into account, one may expect to reduce this difference. These theoretical results are compared with the experimental results in magnesium. (author

  19. Diode-pumped dual-frequency microchip Nd : YAG laser with tunable frequency difference

    Energy Technology Data Exchange (ETDEWEB)

    Ren Cheng; Zhang Shulian, E-mail: ren-c06@mails.tsinghua.edu.c [State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084 (China)

    2009-08-07

    The diode-pumped dual-frequency microchip Nd : YAG laser with tunable frequency difference is presented. The gain medium used is a microchip 2 mm in thickness for miniaturized and integrated design. Two quarter-wave plates are placed into the laser cavity and the intra-cavity birefringence produces two orthogonally linearly polarized modes. The rotation of one of the two quarter-wave plates introduces a controlled and variable cavity birefringence which causes a variable frequency difference between the two orthogonally polarized modes. The frequency difference can be tuned through the whole cavity free spectral range. The obtained frequency difference ranges from 14 MHz to 1.5 GHz. The variation of the beat frequency over a period of 10 min is less than 10 kHz. The lock-in between modes is not found. Experimental results are presented, which match well with the theoretical analysis based on Jones matrices.

  20. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...... microstructure noise in a general framework where little is assumed about the noise. For the practical implementation, we adopt the dis- crete Markov chain model that is well suited for the analysis of financial high-frequency prices. The Markov chain framework facilitates simple expressions and elegant analyti...

  1. Induced leaf variations in faba bean

    International Nuclear Information System (INIS)

    Yasin, M.

    1996-01-01

    The frequency and spectrum of M2 chlorophyll and other leaf mutations after gamma ray, ethyl methane sulfonate (EMS) and nitrous oxide (N2O) seed treatment in two varieties of faba bean were studied. In general, cv JV1 was more sensitive and EMS treatment was most effective. The frequency of chlorina-type mutations was higher than that of xantha and chlorotica type chlorophyll mutations. The highest frequency of variations was observed in leaflet texture, followed by arrangement, shape and size in both varieties. The use of these leaf mutations in formulating an ideotype of Vicia faba L. are discussed

  2. 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.

  3. Calculus of variations

    CERN Document Server

    Elsgolc, Lev D

    2007-01-01

    This concise text offers both professionals and students an introduction to the fundamentals and standard methods of the calculus of variations. In addition to surveys of problems with fixed and movable boundaries, it explores highly practical direct methods for the solution of variational problems.Topics include the method of variation in problems with fixed boundaries; variational problems with movable boundaries and other problems; sufficiency conditions for an extremum; variational problems of constrained extrema; and direct methods of solving variational problems. Each chapter features nu

  4. Quantum Variational Calculus

    OpenAIRE

    Malinowska , Agnieszka B.; Torres , Delfim

    2014-01-01

    International audience; Introduces readers to the treatment of the calculus of variations with q-differences and Hahn difference operators Provides the reader with the first extended treatment of quantum variational calculus Shows how the techniques described can be applied to economic models as well as other mathematical systems This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of it...

  5. Bilateral renal artery variation

    OpenAIRE

    Üçerler, Hülya; Üzüm, Yusuf; İkiz, Z. Aslı Aktan

    2014-01-01

    Each kidney is supplied by a single renal artery, although renal artery variations are common. Variations of the renal arteryhave become important with the increasing number of renal transplantations. Numerous studies describe variations in renalartery anatomy. Especially the left renal artery is among the most critical arterial variations, because it is the referred side forresecting the donor kidney. During routine dissection in a formalin fixed male cadaver, we have found a bilateral renal...

  6. Genetics and variation

    Science.gov (United States)

    John R. Jones; Norbert V. DeByle

    1985-01-01

    The broad genotypic variability in quaking aspen (Populus tremuloides Michx.), that results in equally broad phenotypic variability among clones is important to the ecology and management of this species. This chapter considers principles of aspen genetics and variation, variation in aspen over its range, and local variation among clones. For a more...

  7. 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

  8. La gestión de la calidad crediticia como alternativa de solución a los problemas de morosidad de la cartera de la micro y pequeña empresa y su efecto en los resultados económicos y financieros de la caja municipal de ahorro y crédito del santa - años 2014 y 2015.

    OpenAIRE

    Jiménez López, Nancy Raquel

    2016-01-01

    El presente trabajo de investigación ha sido realizado para entender que el problema de morosidad de la cartera de la micro y pequeña empresa genera resultados económicos financieros negativos en la Caja Municipal de Ahorro y Crédito del Santa, y que se requiere de una Gestión de Calidad para revertir esta situación para el mediano y largo plazo. Probablemente se puedan mencionar varios factores determinantes que influyen en la morosidad de las CMACS como consolidada y a la CMAC Santa en part...

  9. Breakfast frequency among adolescents

    DEFF Research Database (Denmark)

    Pedersen, Trine Pagh; Holstein, Bjørn E; Damsgaard, Mogens Trab

    2016-01-01

    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......·33) for adolescents who reported no close relations to parents, 2·28 (1·61, 3·22) for adolescents who reported low level of quality of family communication and 2·09 (1·39, 3·15) for adolescents who reported low level of family support. Joint effect analyses suggested that the odds of low breakfast frequency among...

  10. LOW FREQUENCY DAMPER

    Directory of Open Access Journals (Sweden)

    Radu BOGATEANU

    2009-09-01

    Full Text Available The low frequency damper is an autonomous equipment for damping vibrations with the 1-20Hz range.Its autonomy enables the equipment to be located in various mechanical systems, without requiring special hydraulic installations.The low frequency damper was designed for damping the low frequency oscillations occurring in the circuit controls of the upgraded IAR-99 Aircraft.The low frequency damper is a novelty in the aerospace field ,with applicability in several areas as it can be built up in an appropriate range of dimensions meeting the requirements of different beneficiaries. On this line an equipment able to damp an extended frequency range was performed for damping oscillations in the pipes of the nuclear power plants.This damper, tested in INCAS laboratories matched the requirements of the beneficiary.The low frequency damper is patented – the patent no. 114583C1/2000 is held by INCAS.

  11. Low frequency temperature forcing of chemical oscillations.

    Science.gov (United States)

    Novak, Jan; Thompson, Barnaby W; Wilson, Mark C T; Taylor, Annette F; Britton, Melanie M

    2011-07-14

    The low frequency forcing of chemical oscillations by temperature is investigated experimentally in the Belousov-Zhabotinsky (BZ) reaction and in simulations of the Oregonator model with Arrhenius temperature dependence of the rate constants. Forcing with temperature leads to modulation of the chemical frequency. The number of response cycles per forcing cycle is given by the ratio of the natural frequency to the forcing frequency and phase locking is only observed in simulations when this ratio is a whole number and the forcing amplitude is small. The global temperature forcing of flow-distributed oscillations in a tubular reactor is also investigated and synchronisation is observed in the variation of band position with the external signal, reflecting the periodic modulation of chemical oscillations by temperature.

  12. Frequency Hopping Transceiver Multiplexer

    Science.gov (United States)

    1983-03-01

    ATC 17 ULR IHQ OCLI CPCTR ULTRA HIGH "OQS" UP TO 4X HIGHER THAN BEST INDUS- TRY STANDARD (ATC 100). MICROWAVE POWER, CURRENT. AND 0 RATINGS5...Q"W were assigned to element (FigC-2); which will be modelled into the transformer previously ment td . The center frequencies, "Q", frequency range...of the TD 1288 system. Temperature stability, change with time or storage. Flexure Frequency, or non-linear change over bandwidth. * Humidity

  13. 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.

  14. Modeling of Perpendicularly Driven Dual-Frequency Capacitively Coupled Plasma

    International Nuclear Information System (INIS)

    Wang Hongyu; Sun Peng; Zhao Shuangyun; Li Yang; Jiang Wei

    2016-01-01

    We analyzed perpendicularly configured dual-frequency (DF) capacitively coupled plasmas (CCP). In this configuration, two pairs of electrodes are arranged oppositely, and the discharging is perpendicularly driven by two radio frequency (RF) sources. Particle-in-cell/Monte Carlo (PIC/MC) simulation showed that the configuration had some advantages as this configuration eliminated some dual frequency coupling effects. Some variation and potential application of the discharging configuration is discussed briefly. (paper)

  15. Variational principle for nonlinear gyrokinetic Vlasov--Maxwell equations

    International Nuclear Information System (INIS)

    Brizard, Alain J.

    2000-01-01

    A new variational principle for the nonlinear gyrokinetic Vlasov--Maxwell equations is presented. This Eulerian variational principle uses constrained variations for the gyrocenter Vlasov distribution in eight-dimensional extended phase space and turns out to be simpler than the Lagrangian variational principle recently presented by H. Sugama [Phys. Plasmas 7, 466 (2000)]. A local energy conservation law is then derived explicitly by the Noether method. In future work, this new variational principle will be used to derive self-consistent, nonlinear, low-frequency Vlasov--Maxwell bounce-gyrokinetic equations, in which the fast gyromotion and bounce-motion time scales have been eliminated

  16. Electrothermal frequency reference

    NARCIS (Netherlands)

    Makinwa, K.A.A.; Kashmiri, S.M.

    2011-01-01

    An electrothermal frequency-locked loop (EFLL) circuit is described. This EFLL circuit includes an oscillator in a feedback loop. A drive circuit in the EFLL circuit generates a first signal having a fundamental frequency, and an electrothermal filter (ETF) in the EFLL circuit provides a second

  17. Low frequency noise study.

    Science.gov (United States)

    2007-04-01

    This report documents a study to investigate human response to the low-frequency : content of aviation noise, or low-frequency noise (LFN). The study comprised field : measurements and laboratory studies. The major findings were: : 1. Start-of-takeof...

  18. 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...

  19. Fast fundamental frequency estimation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom

    2017-01-01

    Modelling signals as being periodic is common in many applications. Such periodic signals can be represented by a weighted sum of sinusoids with frequencies being an integer multiple of the fundamental frequency. Due to its widespread use, numerous methods have been proposed to estimate the funda...

  20. Frequency control modelling - basics

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Sørensen, Poul Ejnar; Zeni, Lorenzo

    2016-01-01

    The purpose of this report is to provide an introduction on how the system balance in an island system can be maintained by controlling the frequency. The power balance differential equation, which is fundamental in understanding the effect on the system frequency of the unbalance between...

  1. Impact of frequency control on PWR

    International Nuclear Information System (INIS)

    Constantieux, Thierry; Gautier, Alain; Deat, Max.

    1979-01-01

    This paper deals with experimental data that were recorded at TIHANGE 1, a Belgo-French nuclear power reactor, while the plant was performing frequency control with no load regulation. Frequency control induces quasi-permanent reactor power variations, whose effects on the following equipment must be analyzed carefully: rod mechanisms, fuel cladding and pressurizer components. A comparison of the experimental data with calculations performed on a hybrid computer is presented, together with a brief description of the hybrid program, DELTA, which was developed by FRAMATOME

  2. Low Frequency Space Array

    International Nuclear Information System (INIS)

    Dennison, B.; Weiler, K.W.; Johnston, K.J.

    1987-01-01

    The Low Frequency Space Array (LFSA) is a conceptual mission to survey the entire sky and to image individual sources at frequencies between 1.5 and 26 MHz, a frequency range over which the earth's ionosphere transmits poorly or not at all. With high resolution, high sensitivity observations, a new window will be opened in the electromagnetic spectrum for astronomical investigation. Also, extending observations down to such low frequencies will bring astronomy to the fundamental limit below which the galaxy becomes optically thick due to free-free absorption. A number of major scientific goals can be pursued with such a mission, including mapping galactic emission and absorption, studies of individual source spectra in a frequency range where a number of important processes may play a role, high resolution imaging of extended sources, localization of the impulsive emission from Jupiter, and a search for coherent emission processes. 19 references

  3. Variational Bayesian Inference of Line Spectra

    DEFF Research Database (Denmark)

    Badiu, Mihai Alin; Hansen, Thomas Lundgaard; Fleury, Bernard Henri

    2017-01-01

    parameters. We propose an accurate representation of the pdfs of the frequencies by mixtures of von Mises pdfs, which yields closed-form expectations. We define the algorithm VALSE in which the estimates of the pdfs and parameters are iteratively updated. VALSE is a gridless, convergent method, does......; 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......) of the frequencies and computing expectations over them. Thus, we additionally capture and operate with the uncertainty of the frequency estimates. Aiming to maximize the model evidence, variational optimization provides analytic approximations of the posterior pdfs and also gives estimates of the additional...

  4. Long-period and short-period variations of ionospheric parameters studied from complex observations performed on Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Laso, B; Lobachevskii, L A; Potapova, N I; Freizon, I A; Shapiro, B S

    1980-09-01

    Cuban data from 1978 are used to study long-period (i.e., diurnal) variations of Doppler shift on a 3000 km path at frequencies of 10 and 15 MHz these variations are related to variations of parameters on the ionospheric path. Short-period variations were also studied on the basis of Doppler shift data and vertical sounding data in the 0.000111-0.00113 Hz frequency range. The relation between the observed variations and internal gravity waves are discussed.

  5. Time and frequency applications.

    Science.gov (United States)

    Hellwig, H

    1993-01-01

    An overview is given of the capabilities of atomic clocks and quartz crystal oscillators in terms of available precision of time and frequency signals. The generation, comparison, and dissemination of time and frequency is then discussed. The principal focus is to survey uses of time and frequency in navigation, communication, and science. The examples given include the Global Positioning System, a satellite-based global navigation system, and general and dedicated communication networks, as well as experiments in general relativity and radioastronomy. The number of atomic clocks and crystal oscillators that are in actual use worldwide is estimated.

  6. 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.

  7. Characterization and comprehension of corona partial discharge in air under power frequency to very low frequency voltage

    Science.gov (United States)

    Yuanxiang, ZHOU; Zhongliu, ZHOU; Ling, ZHANG; Yunxiao, ZHANG; Yajun, MO; Jiantao, SUN

    2018-05-01

    For the partial discharge test of electrical equipment with large capacitance, the use of low-frequency voltage instead of power frequency voltage can effectively reduce the capacity requirements of test power supply. However, the validity of PD test under low frequency voltage needs to be evaluated. In order to investigate the influence of voltage frequency on corona discharge in the air, the discharge test of the tip-plate electrode under the frequency from 50 to 0.1 Hz is carried out based on the impulse current method. The results show that some of the main features of corona under low frequency do not change. The magnitude of discharge in a positive half cycle is obviously larger than that in a negative cycle. The magnitude of discharge and interval in positive cycle are random, while that in negative cycle are regular. With the decrease of frequency, the inception voltage increases. The variation trend of maximum and average magnitude and repetition rate of the discharge in positive and negative half cycle with the variation of voltage frequency and magnitude is demonstrated, with discussion and interpretation from the aspects of space charge transportation, effective discharge time and transition of discharge modes. There is an obvious difference in the phase resolved pattern of partial discharge and characteristic parameters of discharge patterns between power and low frequency. The experimental results can be the reference for mode identification of partial discharge under low frequency tests. The trend of the measured parameters with the variation of frequency provides more information about the insulation defect than traditional measurements under a single frequency (usually 50 Hz). Also it helps to understand the mechanism of corona discharge with an explanation of the characteristics under different frequencies.

  8. 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.

  9. Electric current - frequency converter

    International Nuclear Information System (INIS)

    Kumahara, Tadashi; Kinbana, Setsuro.

    1967-01-01

    Herein disclosed is an improved simple electric current-frequency converter, the input current and output frequency linearity of which is widened to a range of four to five figures while compensating, for temperature. The converter may be used for computor processing and for telemetering the output signals from a nuclear reactor. The converter is an astable multivibrator which includes charging circuits comprising emitter-voltage compensated NPN transistors, a charged voltage detecting circuit of temperature compensated field effect transistors, and a transistor switching circuit for generating switching pulses independent of temperature. The converter exhibited a 0.7% frequency change within a range of 5 - 45 0 C and less than a 0.1% frequency drift after six hours of operation when the input current was maintained constant. (Yamaguchi, T.)

  10. Frequency band adjustment match filtering based on variable frequency GPR antennas pairing scheme for shallow subsurface investigations

    Science.gov (United States)

    Shaikh, Shahid Ali; Tian, Gang; Shi, Zhanjie; Zhao, Wenke; Junejo, S. A.

    2018-02-01

    Ground penetrating Radar (GPR) is an efficient tool for subsurface geophysical investigations, particularly at shallow depths. The non-destructiveness, cost efficiency, and data reliability are the important factors that make it an ideal tool for the shallow subsurface investigations. Present study encompasses; variations in central frequency of transmitting and receiving GPR antennas (Tx-Rx) have been analyzed and frequency band adjustment match filters are fabricated and tested accordingly. Normally, the frequency of both the antennas remains similar to each other whereas in this study we have experimentally changed the frequencies of Tx-Rx and deduce the response. Instead of normally adopted three pairs, a total of nine Tx-Rx pairs were made from 50 MHz, 100 MHz, and 200 MHz antennas. The experimental data was acquired at the designated near surface geophysics test site of the Zhejiang University, Hangzhou, China. After the impulse response analysis of acquired data through conventional as well as varied Tx-Rx pairs, different swap effects were observed. The frequency band and exploration depth are influenced by transmitting frequencies rather than the receiving frequencies. The impact of receiving frequencies was noticed on the resolution; the more noises were observed using the combination of high frequency transmitting with respect to low frequency receiving. On the basis of above said variable results we have fabricated two frequency band adjustment match filters, the constant frequency transmitting (CFT) and the variable frequency transmitting (VFT) frequency band adjustment match filters. By the principle, the lower and higher frequency components were matched and then incorporated with intermediate one. Therefore, this study reveals that a Tx-Rx combination of low frequency transmitting with high frequency receiving is a better choice. Moreover, both the filters provide better radargram than raw one, the result of VFT frequency band adjustment filter is

  11. High frequency breakdown voltage

    International Nuclear Information System (INIS)

    Chu, Thanh Duy.

    1992-03-01

    This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O degrees C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f c , the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f ce , is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions' concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance

  12. 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.

  13. ALMA High Frequency Techniques

    Science.gov (United States)

    Meyer, J. D.; Mason, B.; Impellizzeri, V.; Kameno, S.; Fomalont, E.; Chibueze, J.; Takahashi, S.; Remijan, A.; Wilson, C.; ALMA Science Team

    2015-12-01

    The purpose of the ALMA High Frequency Campaign is to improve the quality and efficiency of science observing in Bands 8, 9, and 10 (385-950 GHz), the highest frequencies available to the ALMA project. To this end, we outline observing modes which we have demonstrated to improve high frequency calibration for the 12m array and the ACA, and we present the calibration of the total power antennas at these frequencies. Band-to-band (B2B) transfer and bandwidth switching (BWSW), techniques which improve the speed and accuracy of calibration at the highest frequencies, are most necessary in Bands 8, 9, and 10 due to the rarity of strong calibrators. These techniques successfully enable increased signal-to-noise on the calibrator sources (and better calibration solutions) by measuring the calibrators at lower frequencies (B2B) or in wider bandwidths (BWSW) compared to the science target. We have also demonstrated the stability of the bandpass shape to better than 2.4% for 1 hour, hidden behind random noise, in Band 9. Finally, total power observing using the dual sideband receivers in Bands 9 and 10 requires the separation of the two sidebands; this procedure has been demonstrated in Band 9 and is undergoing further testing in Band 10.

  14. Reproducibility of frequency-dependent low frequency fluctuations in reaction time over time and across tasks.

    Science.gov (United States)

    Liu, Zan-Zan; Qu, Hui-Jie; Tian, Zhuo-Ling; Han, Meng-Jian; Fan, Yi; Ge, Lie-Zhong; Zang, Yu-Feng; Zhang, Hang

    2017-01-01

    Increased levels of reaction time variability (RTV) are characteristics of sustained attention deficits. The clinical significance of RTV has been widely recognized. However, the reliability of RTV measurements has not been widely studied. The present study aimed to assess the test-retest reliability of RTV conventional measurements, e.g., the standard deviation (SD), the coefficient of variation (CV), and a new measurement called the amplitude of low frequency fluctuation (ALFF) of RT. In addition, we aimed to assess differences and similarities of these measurements between different tasks. Thirty-seven healthy college students participated in 2 tasks, i.e., an Eriksen flanker task (EFT) and a simple reaction task (SRT), twice over a mean interval of 56 days. Conventional measurements of RTV including RT-SD and RT-CV were assessed first. Then the RT time series were converted into frequency domains, and RT-ALFF was further calculated for the whole frequency band (0.0023-0.167 Hz) and for a few sub-frequency bands including Slow-6 (frequency bands (Slow-3), but SRT RT-ALFF values showed slightly higher ICC values than EFT values in lower frequency bands (Slow-5 and Slow-4). 2) RT-ALFF magnitudes in each sub-frequency band were greater for the SRT than those for the EFT. 3) The RT-ALFF in the Slow-4 of the EFT was found to be correlated with the RT-ALFF in the Slow-5 of the SRT for both two visits, but no consistently significant correlation was found between the same frequency bands. These findings reveal good test-retest reliability for conventional measurements and for the RT-ALFF of RTV. The RT-ALFF presented frequency-dependent similarities across tasks. All of our results reveal the presence of different frequency structures between the two tasks, and thus the frequency-dependent characteristics of different tasks deserve more attention in future studies.

  15. 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

  16. Frequency and temperature dependence of high damping elastomers

    International Nuclear Information System (INIS)

    Kulak, R.F.; Hughes, T.H.

    1993-01-01

    High damping steel-laminated elastomeric seismic isolation bearings are one of the preferred devices for isolating large buildings and structures. In the US, the current reference design for the Advanced Liquid Metal Reactor (ALMR) uses laminated bearings for seismic isolation. These bearings are constructed from alternating layers of high damping rubber and steel plates. They are typically designed for shear strains between 50 and 100% and are expected to sustain two to three times these levels for beyond design basis loading conditions. Elastomeric bearings are currently designed to provide a system frequency between 0.4 and 0.8 Hz and expected to operate between -20 and 40 degrees Centigrade. To assure proper performance of isolation bearings, it is necessary to characterize the elastomer's response under expected variations of frequency and temperature. The dynamic response of the elastomer must be characterized within the frequency range that spans the bearing acceptance test frequency, which may be as low as 0.005 Hz, and the design frequency. Similarly, the variation in mechanical characteristics of the elastomer must be determined over the design temperature range, which is between -20 and 40 degrees Centigrade. This paper reports on (1) the capabilities of a testing facility at ANL for testing candidate elastomers, (2) the variation with frequency and temperature of the stiffness and damping of one candidate elastomer, and (3) the effect of these variations on bearing acceptance testing criteria and on the choice of bearing design values for stiffness and damping

  17. 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.

  18. High frequency energy measurements

    International Nuclear Information System (INIS)

    Stotlar, S.C.

    1981-01-01

    High-frequency (> 100 MHz) energy measurements present special problems to the experimenter. Environment or available electronics often limit the applicability of a given detector type. The physical properties of many detectors are frequency dependent and in some cases, the physical effect employed can be frequency dependent. State-of-the-art measurements generally involve a detection scheme in association with high-speed electronics and a method of data recording. Events can be single or repetitive shot requiring real time, sampling, or digitizing data recording. Potential modification of the pulse by the detector and the associated electronics should not be overlooked. This presentation will review typical applications, methods of choosing a detector, and high-speed detectors. Special considerations and limitations of some applications and devices will be described

  19. Initiating events frequency determination

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Vukovic, I.

    2004-01-01

    The paper describes work performed for the Nuclear Power Station (NPS). Work is related to the periodic initiating events frequency update for the Probabilistic Safety Assessment (PSA). Data for all relevant NPS initiating events (IE) were reviewed. The main focus was on events occurring during most recent operating history (i.e., last four years). The final IE frequencies were estimated by incorporating both NPS experience and nuclear industry experience. Each event was categorized according to NPS individual plant examination (IPE) initiating events grouping approach. For the majority of the IE groups, few, or no events have occurred at the NPS. For those IE groups with few or no NPS events, the final estimate was made by means of a Bayesian update with general nuclear industry values. Exceptions are rare loss-of-coolant-accidents (LOCA) events, where evaluation of engineering aspects is used in order to determine frequency.(author)

  20. 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.

  1. Quantum variational calculus

    CERN Document Server

    Malinowska, Agnieszka B

    2014-01-01

    This Brief puts together two subjects, quantum and variational calculi by considering variational problems involving Hahn quantum operators. The main advantage of its results is that they are able to deal with nondifferentiable (even discontinuous) functions, which are important in applications. Possible applications in economics are discussed. Economists model time as continuous or discrete. Although individual economic decisions are generally made at discrete time intervals, they may well be less than perfectly synchronized in ways discrete models postulate. On the other hand, the usual assumption that economic activity takes place continuously, is nothing else than a convenient abstraction that in many applications is far from reality. The Hahn quantum calculus helps to bridge the gap between the two families of models: continuous and discrete. Quantum Variational Calculus is self-contained and unified in presentation. It provides an opportunity for an introduction to the quantum calculus of variations fo...

  2. Variational Monte Carlo Technique

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 8. Variational Monte Carlo Technique: Ground State Energies of Quantum Mechanical Systems. Sukanta Deb. General Article Volume 19 Issue 8 August 2014 pp 713-739 ...

  3. 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...

  4. Total variation-based neutron computed tomography

    Science.gov (United States)

    Barnard, Richard C.; Bilheux, Hassina; Toops, Todd; Nafziger, Eric; Finney, Charles; Splitter, Derek; Archibald, Rick

    2018-05-01

    We perform the neutron computed tomography reconstruction problem via an inverse problem formulation with a total variation penalty. In the case of highly under-resolved angular measurements, the total variation penalty suppresses high-frequency artifacts which appear in filtered back projections. In order to efficiently compute solutions for this problem, we implement a variation of the split Bregman algorithm; due to the error-forgetting nature of the algorithm, the computational cost of updating can be significantly reduced via very inexact approximate linear solvers. We present the effectiveness of the algorithm in the significantly low-angular sampling case using synthetic test problems as well as data obtained from a high flux neutron source. The algorithm removes artifacts and can even roughly capture small features when an extremely low number of angles are used.

  5. General quantum variational calculus

    Directory of Open Access Journals (Sweden)

    Artur M. C. Brito da Cruz

    2018-02-01

    Full Text Available We develop a new variational calculus based in the general quantum difference operator recently introduced by Hamza et al. In particular, we obtain optimality conditions for generalized variational problems where the Lagrangian may depend on the endpoints conditions and a real parameter, for the basic and isoperimetric problems, with and without fixed boundary conditions. Our results provide a generalization to previous results obtained for the $q$- and Hahn-calculus.

  6. 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.

  7. 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.

  8. Coordination of Voltage and Frequency Feedback in Load-Frequency Control Capability of Wind Turbine

    DEFF Research Database (Denmark)

    Hoseinzadeh, Bakhtyar; Silva, Filipe Faria Da; Bak, Claus Leth

    2014-01-01

    In close future, with high Wind Energy (WE) penetration in the power system, the burden of Load-Frequency Control (LFC) is gradually shifted to Variable Speed Wind Turbines (VSWTs). In order to equip the VSWT with LFC capability to support the grid during sudden variation in generation or load...... regulation. The proposed scheme demonstrates remarkable improvement transient state of both voltage and frequency profiles in comparison with conventional LFC designs provided by Central Power Plants (CPP) or Wind Power Plants (WPP). Numerical simulations carried out in DigSilent Power- Factory confirm...

  9. LOFAR - low frequency array

    NARCIS (Netherlands)

    Bentum, Marinus Jan; Gunst, André

    Nog een paar maanden en dan wordt de grootste radiotelescoop ter wereld officieel geopend: LOFAR, de ‘Low Frequency Arraÿ'.LOFAR is een nieuwe radiotelescoop die in Nederland gebouwd wordt door ASTRON, de Stichting Astronomisch Onderzoek in Nederland. Met LOFAR heeft Nederland er straks een uniek

  10. 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...

  11. 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.

  12. Low frequency radioastronomy

    International Nuclear Information System (INIS)

    Zarka, Philippe; Cecconi, Baptiste; Tagger, Michel; Torchinsky, Steve; Picard, Philippe; Pezzani, Jacques; Cognard, Ismael; Boone, Frederic; Woan, Graham; Weber, Rodolphe; Gousset, Thierry; Lautridou, Pascal; Dallier, Richard

    2011-07-01

    Low frequency radioastronomy deals with the direct detection (below 100 MHz) and heterodyne detection (up to few GHz) of electromagnetic waves (phase and amplitude) followed by a time or spectral analysis. The 30. Goutelas school covered several aspects of radioastronomy involving various aspects of physics: non-thermal phenomena in plasmas and physics of magnetized plasmas, atomic and molecular physics, and particle physics. These proceedings comprise 17 lectures dealing with: 1 - Low-Frequency Radioastronomy Basics (P. Zarka); 2 - Radioastronomy Historical Highlights (S. A. Torchinsky); 3 - Antennas (P. Picard, J. Pezzani); 4 - Receptors (P. Picard, J. Pezzani); 5 - Pulsars chronometry: metrology in radioastronomy (I. Cognard); 6 - Interferometry as imaging technique (F. Boone); 7 - Radio propagation and scintillation (G. Woan); 8 - Square Kilometer Array (S. A. Torchinsky); 9 - Techniques against radio-electrical interferences in low-frequency radioastronomy (R. Weber); 10 - Introduction to poly-phase filtering (R. Weber); 11 - Three decades of Jupiter's radio-emission studies: from the Nancay deca-meter network to LOFAR (P. Zarka); 12 - Atmospheric showers and their radio counterpart (T. Gousset); 13 - From cosmic rays radio-detection to pulse radioastronomy (P. Lautridou, R. Dallier); 14 - The CODALEMA project (R. Dallier, P. Lautridou); 15 - Space-based radio measurements: Gonio-polarimetry (B. Cecconi); 16 - Radio astronomy from space (G. Woan); 17 - LOFAR: the Low Frequency Array and the French FLOW consortium (M. Tagger, P. Zarka)

  13. Radio Frequency Identification

    Indian Academy of Sciences (India)

    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.

  14. 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.

  15. Food frequency questionnaires.

    Science.gov (United States)

    Pérez Rodrigo, Carmen; Aranceta, Javier; Salvador, Gemma; Varela-Moreiras, Gregorio

    2015-02-26

    Food Frequency Questionnaires are dietary assessment tools widely used in epidemiological studies investigating the relationship between dietary intake and disease or risk factors since the early '90s. The three main components of these questionnaires are the list of foods, frequency of consumption and the portion size consumed. The food list should reflect the food habits of the study population at the time the data is collected. The frequency of consumption may be asked by open ended questions or by presenting frequency categories. Qualitative Food Frequency Questionnaires do not ask about the consumed portions; semi-quantitative include standard portions and quantitative questionnaires ask respondents to estimate the portion size consumed either in household measures or grams. The latter implies a greater participant burden. Some versions include only close-ended questions in a standardized format, while others add an open section with questions about some specific food habits and practices and admit additions to the food list for foods and beverages consumed which are not included. The method can be self-administered, on paper or web-based, or interview administered either face-to-face or by telephone. Due to the standard format, especially closed-ended versions, and method of administration, FFQs are highly cost-effective thus encouraging its widespread use in large scale epidemiological cohort studies and also in other study designs. Coding and processing data collected is also less costly and requires less nutrition expertise compared to other dietary intake assessment methods. However, the main limitations are systematic errors and biases in estimates. Important efforts are being developed to improve the quality of the information. It has been recommended the use of FFQs with other methods thus enabling the adjustments required. Copyright AULA MEDICA EDICIONES 2015. Published by AULA MEDICA. All rights reserved.

  16. Accurate frequency measurements on gyrotrons using a ''gyro-radiometer''

    International Nuclear Information System (INIS)

    Rebuffi, L.

    1986-08-01

    Using an heterodyne system, called ''Gyro-radiometer'', accurated frequency measurements have been carried out on VARIAN 60 GHz gyrotrons. Changing the principal tuning parameters of a gyrotron, we have detected frequency variations up to 100 MHz, ∼ 40 MHz frequency jumps and smaller jumps (∼ 10 MHz) when mismatches in the transmission line were present. FWHM bandwidth of 300 KHz, parasitic frequencies and frequency drift during 100 msec pulses have also been observed. An efficient method to find a stable-, high power-, long pulse-working point of a gyrotron loaded by a transmission line, has been derived. In general, for any power value it is possible to find stable working conditions tuning the principal parameters of the tube in correspondance of a maximum of the emitted frequency

  17. 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

  18. Low frequency phase signal measurement with high frequency squeezing

    OpenAIRE

    Zhai, Zehui; Gao, Jiangrui

    2011-01-01

    We calculate the utility of high-frequency squeezed-state enhanced two-frequency interferometry for low-frequency phase measurement. To use the high-frequency sidebands of the squeezed light, a two-frequency intense laser is used in the interferometry instead of a single-frequency laser as usual. We find that the readout signal can be contaminated by the high-frequency phase vibration, but this is easy to check and avoid. A proof-of-principle experiment is in the reach of modern quantum optic...

  19. 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.

  20. 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....

  1. Variation, structure and norms

    DEFF Research Database (Denmark)

    Harder, Peter

    2014-01-01

    in linguistics: those that see linguistic norms as antithetical to a descriptive and variational linguistics. Once such a re-evaluation has taken place, however, the social recontextualization of cognition will enable linguistics (including sociolinguistics as an integral part), to eliminate the cracks...... that an evolutionary account can reintegrate the opposed fragments into a whole picture that puts each of them in their ‘ecological position’ with respect to each other. Empirical usage facts should be seen in the context of operational norms in relation to which actual linguistic choices represent adaptations....... Variational patterns should be seen in the context of structural categories without which there would be only ‘differences’ rather than variation. And emergence, individual choice, and flux should be seen in the context of the individual’s dependence on lineages of community practice sustained by collective...

  2. Ladder variational autoencoders

    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...... Variational Autoencoder, that recursively corrects the generative distribution by a data dependent approximate likelihood in a process resembling the recently proposed Ladder Network. We show that this model provides state of the art predictive log-likelihood and tighter log-likelihood lower bound compared...

  3. 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...... Variational Autoencoder, that recursively corrects the generative distribution by a data dependent approximate likelihood in a process resembling the recently proposed Ladder Network. We show that this model provides state of the art predictive log-likelihood and tighter log-likelihood lower bound compared...

  4. 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

  5. Cosmological constants and variations

    International Nuclear Information System (INIS)

    Barrow, John D

    2005-01-01

    We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that is consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying alpha cosmologies is outlined in the light of all the observational constraints. We also discuss some of the consequences of varying 'constants' for oscillating universes and show by means of exact solutions that they appear to evolve monotonically in time even though the scale factor of the universe oscillates

  6. 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.

  7. Power system frequency estimation based on an orthogonal decomposition method

    Science.gov (United States)

    Lee, Chih-Hung; Tsai, Men-Shen

    2018-06-01

    In recent years, several frequency estimation techniques have been proposed by which to estimate the frequency variations in power systems. In order to properly identify power quality issues under asynchronously-sampled signals that are contaminated with noise, flicker, and harmonic and inter-harmonic components, a good frequency estimator that is able to estimate the frequency as well as the rate of frequency changes precisely is needed. However, accurately estimating the fundamental frequency becomes a very difficult task without a priori information about the sampling frequency. In this paper, a better frequency evaluation scheme for power systems is proposed. This method employs a reconstruction technique in combination with orthogonal filters, which may maintain the required frequency characteristics of the orthogonal filters and improve the overall efficiency of power system monitoring through two-stage sliding discrete Fourier transforms. The results showed that this method can accurately estimate the power system frequency under different conditions, including asynchronously sampled signals contaminated by noise, flicker, and harmonic and inter-harmonic components. The proposed approach also provides high computational efficiency.

  8. 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…

  9. On exterior variational calculus

    International Nuclear Information System (INIS)

    Aldrovandi, R.; Kraenkel, R.A.

    1987-01-01

    Exterior variational calculus is introduced through examples in field theory. It provides a very simple technique to decide on the existence of Lagrangians for given equations of motions and, in the case, to find them. Only local aspects are discussed but the analogy to exterior calculus on finite dimensional manifolds is complete, strongly suggesting its suitability to the study of topological aspects. (Author) [pt

  10. Variational transition state theory

    International Nuclear Information System (INIS)

    Truhlar, D.G.

    1986-01-01

    This project is concerned with the development and applications of generalized transition state theory and multidimensional tunneling approximations to chemical reaction rates. They have developed and implemented several practical versions of variational transition state theory (VTST), namely canonical variational theory (CVT), improved canonical variational theory (ICVT), and microcanonical variational theory (μVT). They have also developed and implemented several accurate multidimensional semiclassical tunneling approximations, the most accurate of which are the small-curvature semiclassical adiabatic (SCSA), large-curvature version-3 (LC3), and least-action (LA) approximations. They have applied the methods to thermal rate constants, using transmission coefficients based on ground-state tunneling, and they have also presented and applied adiabatic and diabatic extensions to calculated rate constants for vibrationally excited reactants. Their general goal is to develop accurate methods for calculating chemical reaction rate constants that remain practical even for reasonably complicated molecules. The approximations mentioned above yield rate constants for systems whose potential energy surface is known or assumed. Thus a second, equally important aspect of their work is the determination or modeling, semi-empirically and/or from electronic structure calculations, of potential energy surfaces

  11. Variation in decision making

    NARCIS (Netherlands)

    Dall, Sasha R. X.; Gosling, Samuel; Gordon D.A., Brown,; Dingemanse, Niels; Ido, Erev,; Martin, Kocher,; Laura, Schulz,; Todd, Peter M; Weissing, Franz; Wolf, Max; Hammerstein, Peter; Stevens, Jeffrey R.

    2012-01-01

    Variation in how organisms allocate their behavior over their lifetimes is key to determining Darwinian fitness., and thus the evolution of human and nonhuman decision making. This chapter explores how decision making varies across biologically and societally significant scales and what role such

  12. 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…

  13. The variational spiked oscillator

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Ullah, N.

    1992-08-01

    A variational analysis of the spiked harmonic oscillator Hamiltonian -d 2 / d x 2 + x 2 + δ/ x 5/2 , δ > 0, is reported in this work. A trial function satisfying Dirichlet boundary conditions is suggested. The results are excellent for a large range of values of the coupling parameter. (author)

  14. 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.

  15. 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

  16. 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. © 2016 Wiley Periodicals, Inc.

  17. The nonholonomic variational principle

    Energy Technology Data Exchange (ETDEWEB)

    Krupkova, Olga [Department of Algebra and Geometry, Faculty of Science, Palacky University, Tomkova 40, 779 00 Olomouc (Czech Republic); Department of Mathematics, La Trobe University, Bundoora, Victoria 3086 (Australia)], E-mail: krupkova@inf.upol.cz

    2009-05-08

    A variational principle for mechanical systems and fields subject to nonholonomic constraints is found, providing Chetaev-reduced equations as equations for extremals. Investigating nonholonomic variations of the Chetaev type and their properties, we develop foundations of the calculus of variations on constraint manifolds, modelled as fibred submanifolds in jet bundles. This setting is appropriate to study general first-order 'nonlinear nonitegrable constraints' that locally are given by a system of first-order ordinary or partial differential equations. We obtain an invariant constrained first variation formula and constrained Euler-Lagrange equations both in intrinsic and coordinate forms, and show that the equations are the same as Chetaev equations 'without Lagrange multipliers', introduced recently by other methods. We pay attention to two possible settings: first, when the constrained system arises from an unconstrained Lagrangian system defined in a neighbourhood of the constraint, and second, more generally, when an 'internal' constrained system on the constraint manifold is given. In the latter case a corresponding unconstrained system need not be a Lagrangian, nor even exist. We also study in detail an important particular case: nonholonomic constraints that can be alternatively modelled by means of (co)distributions in the total space of the fibred manifold; in nonholonomic mechanics this happens whenever constraints affine in velocities are considered. It becomes clear that (and why) if the distribution is completely integrable (= the constraints are semiholonomic), the principle of virtual displacements holds and can be used to obtain the constrained first variational formula by a more or less standard procedure, traditionally used when unconstrained or holonomic systems are concerned. If, however, the constraint is nonintegrable, no significant simplifications are available. Among others, some properties of nonholonomic

  18. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  19. High frequency asymptotic methods

    International Nuclear Information System (INIS)

    Bouche, D.; Dessarce, R.; Gay, J.; Vermersch, S.

    1991-01-01

    The asymptotic methods allow us to compute the interaction of high frequency electromagnetic waves with structures. After an outline of their foundations with emphasis on the geometrical theory of diffraction, it is shown how to use these methods to evaluate the radar cross section (RCS) of complex tri-dimensional objects of great size compared to the wave-length. The different stages in simulating phenomena which contribute to the RCS are reviewed: physical theory of diffraction, multiple interactions computed by shooting rays, research for creeping rays. (author). 7 refs., 6 figs., 3 insets

  20. Frequency selective bolometers

    DEFF Research Database (Denmark)

    Kowitt, M.S.; Fixsen, D.J.; Goldin, A.

    1996-01-01

    We propose a concept for radiometry in the millimeter, the submillimeter, and the far-IR spectral regions, the frequency selective bolometer (FSB). This system uses a bolometer as a coupled element of a tuned quasi-optical interference filter in which the absorption, the transmission......-dimensional transmission-line model. Instruments based on FSB technology should have several advantages over current multiband bolometric radiometers including smaller and more compact cryogenic optics; reduced demands on cryostat size and weight, high coupling efficiency, minimum constraints on the geometry in the focal...

  1. Some considerations about frequency tuning effects in ECRIS plasmas

    International Nuclear Information System (INIS)

    Mascali, D.; Gammino, S.; Celona, L.; Ciavola, G.; Neri, L.; Miracoli, R.; Gambino, N.; Castro, G.; Maimone, F.

    2012-01-01

    In the recent past many experiments demonstrated that slight variations of the microwave frequency used for the ignition of ECRIS plasmas strongly influence their performances (frequency tuning effect) either in terms of extracted current, of mean charge state and of beam emittance. According with theoretical investigations, this phenomenon can be explained by assuming that the plasma chamber works as a resonant cavity: the excited standing waves, whose spatial structure considerably changes with the pumping frequency, globally influences either the energy absorption rate and the plasma spatial structure. The paper is followed by the slides of the presentation. (authors)

  2. ON THE INFLUENCE OF GLOBAL WARMING ON ATLANTIC HURRICANE FREQUENCY

    Directory of Open Access Journals (Sweden)

    S. R. Hosseini

    2018-04-01

    Full Text Available In this paper, the possible connection between the frequency of Atlantic hurricanes to the climate change, mainly the variation in the Atlantic Ocean surface temperature has been investigated. The correlation between the observed hurricane frequency for different categories of hurricane’s intensity and Sea Surface Temperature (SST has been examined over the Atlantic Tropical Cyclogenesis Regions (ACR. The results suggest that in general, the frequency of hurricanes have a high correlation with SST. In particular, the frequency of extreme hurricanes with Category 5 intensity has the highest correlation coefficient (R = 0.82. In overall, the analyses in this work demonstrates the influence of the climate change condition on the Atlantic hurricanes and suggest a strong correlation between the frequency of extreme hurricanes and SST in the ACR.

  3. On the Influence of Global Warming on Atlantic Hurricane Frequency

    Science.gov (United States)

    Hosseini, S. R.; Scaioni, M.; Marani, M.

    2018-04-01

    In this paper, the possible connection between the frequency of Atlantic hurricanes to the climate change, mainly the variation in the Atlantic Ocean surface temperature has been investigated. The correlation between the observed hurricane frequency for different categories of hurricane's intensity and Sea Surface Temperature (SST) has been examined over the Atlantic Tropical Cyclogenesis Regions (ACR). The results suggest that in general, the frequency of hurricanes have a high correlation with SST. In particular, the frequency of extreme hurricanes with Category 5 intensity has the highest correlation coefficient (R = 0.82). In overall, the analyses in this work demonstrates the influence of the climate change condition on the Atlantic hurricanes and suggest a strong correlation between the frequency of extreme hurricanes and SST in the ACR.

  4. A CMOS frequency generation module for 60-GHz applications

    International Nuclear Information System (INIS)

    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 (CML) 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 mm 2 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. (semiconductor integrated circuits)

  5. 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…

  6. Conformable variational iteration method

    Directory of Open Access Journals (Sweden)

    Omer Acan

    2017-02-01

    Full Text Available In this study, we introduce the conformable variational iteration method based on new defined fractional derivative called conformable fractional derivative. This new method is applied two fractional order ordinary differential equations. To see how the solutions of this method, linear homogeneous and non-linear non-homogeneous fractional ordinary differential equations are selected. Obtained results are compared the exact solutions and their graphics are plotted to demonstrate efficiency and accuracy of the method.

  7. 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

  8. Somaclonal variation in rice

    International Nuclear Information System (INIS)

    Kucherenko, L.

    1990-01-01

    Full text: 32 varieties of Oryza sativa L. ssp. japonica were used as donors for callus induction from somatic tissues. In some cases, the callus was treated before regeneration with the chemical mutagen MNU. Some of the regenerated plants demonstrated heritable alterations, among them chlorophyll deficiencies, variation in plant height, awness, glume colouring and fertility. Along with these, a number of lines with agronomically valuable alterations concerning maturity time, panicle structure, plant productivity and grain quality were found. The spectrum of variability was very wide. Vivipary was noticed. Superdwarfs with plant height of about 15 cm were found. Plants with no visible distinctions could be variants too, for example, with increased protein content or disease resistance. The rate and the spectrum of the somaclonal variation were not influenced by the culture media but depended on the donor's genotype. On the basis of somaclonal variation a variety 'Bioryza' was developed. It is an early maturing (about 95-100 days), long grain variety, with grain yield up to 8 t/ha. (author)

  9. Canonical variate regression.

    Science.gov (United States)

    Luo, Chongliang; Liu, Jin; Dey, Dipak K; Chen, Kun

    2016-07-01

    In many fields, multi-view datasets, measuring multiple distinct but interrelated sets of characteristics on the same set of subjects, together with data on certain outcomes or phenotypes, are routinely collected. The objective in such a problem is often two-fold: both to explore the association structures of multiple sets of measurements and to develop a parsimonious model for predicting the future outcomes. We study a unified canonical variate regression framework to tackle the two problems simultaneously. The proposed criterion integrates multiple canonical correlation analysis with predictive modeling, balancing between the association strength of the canonical variates and their joint predictive power on the outcomes. Moreover, the proposed criterion seeks multiple sets of canonical variates simultaneously to enable the examination of their joint effects on the outcomes, and is able to handle multivariate and non-Gaussian outcomes. An efficient algorithm based on variable splitting and Lagrangian multipliers is proposed. Simulation studies show the superior performance of the proposed approach. We demonstrate the effectiveness of the proposed approach in an [Formula: see text] intercross mice study and an alcohol dependence study. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Firewater system inadvertent actuation frequencies

    International Nuclear Information System (INIS)

    Schroeder, J.A.; Eide, S.A.

    1993-01-01

    This paper presents some recommended generic values for fire protection system inadvertent actuation frequencies. The frequencies are based on actual data from Department of Energy and commercial reactor plant facilities

  11. High Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    AC Bryan

    1996-01-01

    Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

  12. Frequency agile solar radiotelescope

    Science.gov (United States)

    Bastian, Tim S.

    2003-02-01

    The Frequency Agile Solar Radiotelescope (FASR) is a solar-dedicated, ground based, interferometric array optimized to perform broadband imaging spectroscopy from ~ 0.1-30+ GHz. It will do so with the angular, spectral, and temporal resolution required to exploit radio emission from the Sun as a diagnostic of the wide variety of astrophysical processes that occur there. FASR represents a major advance over existing radioheliographs, and is expected to remain the world's premier solar radio instrument for two decades or more after completion. FASR will be a versatile and powerful instrument, providing unique data to a broad users community. Solar, solar-terrestrial, and space physicists will exploit FASR to attack a broad science program, including problems of fundamental interest: coronal magnetography, solar flares and particle acceleration, drivers of space weather, and the thermal structure and dynamics of the solar atmosphere. A design study and implementation planning are underway. Recent progress is reviewed here.

  13. Radio frequency picosecond phototube

    International Nuclear Information System (INIS)

    Margaryan, A.; Carlini, R.; Ent, R.; Grigoryan, N.; Gyunashyan, K.; Hashimoto, O.; Hovater, K.; Ispiryan, M.; Knyazyan, S.; Kross, B.; Majewski, S.; Marikyan, G.; Mkrtchyan, M.; Parlakyan, L.; Popov, V.; Tang, L.; Vardanyan, H.; Yan, C.; Zhamkochyan, S.; Zorn, C.

    2006-01-01

    We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation

  14. Radio frequency picosecond phototube

    Energy Technology Data Exchange (ETDEWEB)

    Margaryan, A. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia)]. E-mail: mat@mail.yerphi.am; Carlini, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ent, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Grigoryan, N. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Gyunashyan, K. [Yerevan State University of Architecture and Construction, Yerevan (Armenia); Hashimoto, O. [Tohoku University, Sendai 98-77 (Japan); Hovater, K. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ispiryan, M. [University of Houston, 4800 Calhoun Rd, Houston TX 77204 (United States); Knyazyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Kross, B. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Majewski, S. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Marikyan, G. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Mkrtchyan, M. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Parlakyan, L. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Tang, L. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Vardanyan, H. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Yan, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Zhamkochyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States)

    2006-10-15

    We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation.

  15. Seasonally adjusted birth frequencies follow the Poisson distribution.

    Science.gov (United States)

    Barra, Mathias; Lindstrøm, Jonas C; Adams, Samantha S; Augestad, Liv A

    2015-12-15

    Variations in birth frequencies have an impact on activity planning in maternity wards. Previous studies of this phenomenon have commonly included elective births. A Danish study of spontaneous births found that birth frequencies were well modelled by a Poisson process. Somewhat unexpectedly, there were also weekly variations in the frequency of spontaneous births. Another study claimed that birth frequencies follow the Benford distribution. Our objective was to test these results. We analysed 50,017 spontaneous births at Akershus University Hospital in the period 1999-2014. To investigate the Poisson distribution of these births, we plotted their variance over a sliding average. We specified various Poisson regression models, with the number of births on a given day as the outcome variable. The explanatory variables included various combinations of years, months, days of the week and the digit sum of the date. The relationship between the variance and the average fits well with an underlying Poisson process. A Benford distribution was disproved by a goodness-of-fit test (p Poisson process when monthly and day-of-the-week variation is included. The frequency is highest in summer towards June and July, Friday and Tuesday stand out as particularly busy days, and the activity level is at its lowest during weekends.

  16. Radio Frequency Interference Mitigation

    Science.gov (United States)

    An, T.; Chen, X.; Mohan, P.; Lao, B. Q.

    2017-09-01

    The observational facilities of radio astronomy keep constant upgrades and developments to achieve better capabilities including increasing the time of the data recording and frequency resolutions, and increasing the receiving and recording bandwidth. However in contrast, only a limited spectrum resource has been allocated to radio astronomy by the International Telecommunication Union, resulting in that the radio observational instrumentations are inevitably exposed to undesirable radio frequency interference (RFI) signals which originate mainly from the terrestrial human activity and are becoming stronger with time. RFIs degrade the quality of data and even lead to invalid data. The impact of RFIs on scientific outcome becomes more and more serious. In this article, the requirement for RFI mitigation is motivated, and the RFI characteristics, mitigation techniques, and strategies are reviewed. The mitigation strategies adopted at some representative observatories, telescopes, and arrays are also introduced. The advantages and shortcomings of the four classes of RFI mitigation strategies are discussed and presented, applicable at the connected causal stages: preventive, pre-detection, pre-correlation, and post-correlation. The proper identification and flagging of RFI is the key to the reduction of data loss and improvement in data quality, and is also the ultimate goal of developing RFI mitigation technique. This can be achieved through a strategy involving a combination of the discussed techniques in stages. The recent advances in the high speed digital signal processing and high performance computing allow for performing RFI excision of the large data volumes generated from large telescopes or arrays in both real time and offline modes, aiding the proposed strategy.

  17. 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

  18. 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)

    1996-12-31

    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

  19. 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.

  20. Economic, environmental and social impacts of geothermal development, and energy savings and efficient use of power in Baja California, Mexico; Impactos economicos, ambientales y sociales del desarrollo geotermico y del ahorro y uso eficiente de la electricidad en Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Campbell R, Hector E.; Montero A, Gisela [Universidad Autonoma de Baja California, Instituto de Ingenieria, Mexicali, Baja California (Mexico)]. E-mail: hecr@iing.mxl.uabc.mx; Lambert A., Alejandro A. [Universidad Autonoma de Baja California, Facultad de Ingenieria, Mexicali, Baja California (Mexico)

    2011-01-15

    remain at 2200 tons per year (t/a), emitted mainly from geothermal-electric units. NO{sub x} emissions will increase from 6000 t/a in 2005 to 24,000 t/a in 2025, and CO{sub x} will rise from 3.4 million t/a in 2005 to 12.7 million t/a in 2025. The cost of generation will be affected by changes in the energy matrix, and the use of natural gas will predominate. In absolute values it will increase from $648 million USD in 2005 to $2273 million USD in 2025. The cost will depend on an use up to 70% of natural gas. The proposed goals of the Systemic Planning focused on: a) reduce own uses of electricity during generation, b) reduce electric own uses and electric losses during transmission and distribution, c) reducing the growth of electric consumption in the industrial sector, and d) increasing the share of geothermal energy. In a comparison of the Systemic Planning System with the Prospective, increasing in 500 MW the geothermal installed capacity will increase the investment cost, but the balance of net exports, carbon credits and reduced consumption of natural gas indicates a total savings of $11 billion USD and a decrease of 2.3 million tons of CO{sub x}. The geothermal growth combined with the saving and efficient electrical use was rated the best plan, with a total savings of $13.5 billion USD and a decrease in emissions of 8.5 million tons of CO{sub x}. [Spanish] Se presenta un ensayo de Planeacion Electrica para Baja California, Mexico, que incluye el diagnostico de produccion y consumo electrico 1994-2005, la prospectiva al ano 2025 manteniendo las tendencias historicas, y la planeacion sistemica al incidir en la prospectiva mediante acciones de ahorro y uso eficiente de la electricidad y el incremento de la participacion de la geotermia. El diagnostico indica que en 1998 la capacidad geotermoelectrica representaba el 57%, y para 2004 el 73% estaba basado en gas natural, aumentando la dependencia energetica. La generacion cambio de una relacion de 2 a 1 de vapor