WorldWideScience

Sample records for bogota dc colombia

  1. Mobility, environment and heritage sites: A reflection about the sector of the Candelaria, Bogota DC, Colombia

    International Nuclear Information System (INIS)

    Martinez de V, Beatriz; Aguilar M, Maria del Pilar

    2008-01-01

    This article is part of the first bibliographic revision of the Sustainable mobility in historic centers in Colombia research, which proposes the inclusion of the concepts of technology, mobility,transport and environment, with emphasis on the impact of transport technologies on the built environment and the architectural heritage. The objective is to build a panoramic vision of the problem and so call attention to the important relationships that exist between technology, mobility, transport, environment and historic centers. Initially, a brief reference to the context and the sector of La Candelaria on the south Eastern part of Bogota DC, Colombia, with an extension of 188.12 Hectares and an altitude of 2,600 meters above sea level, declared a National Monument in 1963. Further on, aspects concerning aspects associated with mobility and transport in Bogota during the 19 th and 20 th centuries, and the effect of transport methods on the environment and architectural heritage. Finally, a brief description of some projects, plans and mobility and transport studies searching for solutions to the problems created in the historic center by transport technologies

  2. Fire incidence on vegetation in Cundinamarca and Bogota D.C. (Colombia) during the 2001 - 2010 period

    International Nuclear Information System (INIS)

    Amaya Villabona, Diego; Armenteras Pascual, Dolores

    2012-01-01

    This work aims to use remote sensing as a method for determining fire dynamics in the department of Cundinamarca and the city of Bogota D.C. in Colombia, by analyzing the temporal and spatial distribution of fires and the different types of vegetation affected in the 2001 - 2010 period. Based on modis fire hotspots, we found that the pattern fires in the study area are within the national standard, which includes increased number of events during the dry seasons (January - March and July-September). The fire incidence is caused by low rainfall that complements the root causes of ignition, which are mainly started by human intervention. The most affected populations are Caparrapi with 159 fires; Bogota with 152 fires and Guaduas with 101 fires. Bogota recorded most of their fires within protected areas in the south, in the area of Sumapaz. Sumapaz national park (84), followed by the district integrated management Cuchilla de San Antonio (21) and protective forest reserve Paramo Grande (9). Among the vegetation affected we can find grasses, shrubs, bushes and mosaics, emphasizing high values of impact on vegetation of paramo and subparamo. The central and northwestern parts, south and southeast parts of the department are those with more outbreaks, and most of them are between 0 to 1,000 masl and 3,000 to 4,000 masl. Finally active fires in the study area follow a pattern associated to the climate and in particular to the dry season but also show an altitudinal pattern. National and regional protected areas are effective against fires.

  3. Relationship Between Mycorrhizal Associations and Tree Phyto-Sanitary Conditions of Urban Woodlands of Bogota D.C., Colombia

    International Nuclear Information System (INIS)

    Ramos Montano, Carolina; Posada Almanza, Raul H; Ronderos Figueroa, Miguel A; Penagos Canon, Gustavo A

    2010-01-01

    Spore number and root infection by Arbuscular mycorrhizal fungi were evaluated in Eugenia myrtifolia, Ficus soatensis and Croton bogotensis, in parks and green zones of urban woodlands of Bogota D.C, Colombia. The aim was to investigate relations between mycorrhizal associations and tree phyto-sanitary conditions, and effects of two distinct climatic zones. It was demonstrated that plant species and climate are significant sources of variations in the general mycorrhizal state. Eugenia myrtifolia showed the highest degree of root colonization but the lowest number of spores, while C. bogotensis had the opposite response. In general, dry environments favored the mycorrhizal infection levels. By considering overall data, there was a positive relation between the general phytosanitary status of the urban trees and the mycorrhizal colonization. The evaluation of the relationship with the incidence of specific foliar symptoms showed that chlorosis, bight and herbivory maintained a negative relation with the mycorrhization in E. myrtifolia and C. bogotensis. Results suggest that association with AM fungi helps in any way for reducing

  4. Street-weary in Bogota. Voices of girls 3: Colombia.

    Science.gov (United States)

    Ross, T

    1998-01-01

    In Colombia, people displaced by rural violence have crowded Bogota's slums, where inhabitants are plagued by alcoholism, drug dependency, and violence. Violence against children is epidemic in Colombia, and education, which is supposed to be free, is in reality so expensive that over a third of children fail to complete primary school. Street culture beckons children, and one agency has identified 7454 girl prostitutes in Bogota and believes there are another 1000 who have not yet been contacted. Most of these girls are from low-income families residing in inner-city slums, and many were sexually abused at an early age by a male relative. Almost all start using drugs, and more than 80% are infected with sexually transmitted diseases, including 15% who have HIV/AIDS. Even efforts to help these children can go astray, as some learn deviant behavior from fellow residents of children's homes. The biggest danger faced by girls and boys alike on the street is rape, and some children report being raped by policemen. The Renacer Foundation is working to rehabilitate children in its residential units and has achieved success in some cases. In other cases, success is slow to achieve and hard to maintain because it is difficult, if not impossible, for the children to recover from early abuse. Colombia lacks a nationwide needs assessment or primary intervention program to prevent early abuse and to help vulnerable girls. The only programs available to help the children already in trouble use outdated methods and are severely overcrowded.

  5. A Sub-category Disaggregated Greenhouse Gas Emission Inventory for the Bogota Region, Colombia

    Science.gov (United States)

    Pulido-Guio, A. D.; Rojas, A. M.; Ossma, L. J.; Jimenez-Pizarro, R.

    2012-12-01

    Several international organizations, such as UNDP and UNEP, have recently recognized the importance of empowering sub-national decision levels on climatic governance according to the subsidiarity principle. Regional and municipal authorities are directly responsible for land use management and for regulating economic sectors that emit greenhouse gases (GHG) and are vulnerable to climate change. Sub-national authorities are also closer to the population, which make them better suited for educating the public and for achieving commitment among stakeholders. This investigation was developed within the frame of the Regional Integrated Program on Climate Change for the Cundinamarca-Bogota Region (PRICC), an initiative aimed at incorporating the climate dimension into the regional and local decision making. The region composed by Bogota and its nearest, semi-rural area of influence (Province of Cundinamarca) is the most important population and economic center of Colombia. Our investigation serves two purposes: a) to establish methodologies for estimating regional GHG emissions appropriate to the Colombian context, and b) to disaggregate GHG emissions by economic sector as a mitigation decision-making tool. GHG emissions were calculated using IPCC 1996 - Tier 1 methodologies, as there are no regional- or country-specific emission factors available for Colombia. Top-Down (TD) methodologies, based on national and regional energy use intensity, per capita consumption and fertilizer use, were developed and applied to estimate activities for following categories: fuel use in industrial, commercial and residential sectors (excepting NG and LPG), use of ozone depleting substances (ODS) and substitutes, and fertilizer use (for total emissions of agricultural soils). The emissions from the remaining 22 categories were calculated using Bottom-Up (BU) methodologies given the availability of regional information. The total GHG emissions in the Cundinamarca-Bogota Region on 2008 are

  6. Air Pollution alongside Bike-Paths in Bogota - Colombia

    Directory of Open Access Journals (Sweden)

    Juan Felipe Franco

    2016-11-01

    Full Text Available The study we present in this paper aims at characterizing the range of fine particulate matter (PM2.5 and black carbon (BC concentrations to which bike-path users in Bogotá are exposed to. Using a bike equipped with a DustTrak and a micro-aethalometer we measured PM2.5 and BC concentration levels along bike-paths corridors, during weekdays and weekends. Experiments were conducted in fours streets, representing four typical configurations of bike-paths in the city. Traffic data for workdays was also available from local mobility authority. Results indicate that bike-paths users in Bogota are exposed to air pollution levels far exceeding the threshold values established as potentially dangerous for human health. Average concentrations for PM2.5 ranged between 80 and 136 ug/m3 in workdays and between 30 and 72 ug/m3 in weekends. BC mean concentrations were between 16 and 38 µg/m3 during workdays and in the range 10 to 32 µg/m3 during weekends. A statistically significant difference exists in the levels of pollutants concentrations measured during workdays and weekends for all the considered bike paths. According to our results, both traffic volume and diffusions conditions, which are affected by many factors including street geometry, affect bike-path user’s exposure levels. Taking into account the important role that bicycling is playing as an alternative transport mode in Latin American cities, we consider these results provide useful insights to increase the appreciation of the excessive bikers´ exposure to air pollution in Bogotá. Moreover, these findings contribute with technical elements that should lead to the inclusion of air quality variable when designing and planning sustainable urban mobility infrastructures.

  7. Cryptosporidium, Giardia and Enterocytozoon bieneusi in cats from Bogota (Colombia) and genotyping of isolates.

    Science.gov (United States)

    Santín, Mónica; Trout, James M; Vecino, Jesús A Cortés; Dubey, J P; Fayer, Ronald

    2006-11-05

    The prevalence of Cryptosporidium, Giardia, and Enterocytozoon bieneusi in cats from Bogota (Colombia) was determined from fecal specimens and scrapings of duodenal and ileal mucosa screened by PCR. All PCR-positive specimens were sequenced to determine the genotype(s) present. Of 46 cats, 6 (13%) were positive for Cryptosporidium, 5 (11%) were infected with C. felis and one (2%) with C. muris. Three (6.5%) cats were infected with Giardia duodenalis Assemblage F. Eight (17%) cats were infected with four genotypes of E. bieneusi: genotype D-like (9%), K (4%), Peru 10 (2%), and Peru 5 (2%). This is the first report on the presence of zoonotic species/genotypes of Cryptosporidium and E. bieneusi in cats in Colombia.

  8. Mobility environment and urban centers: A reflection about the sector of the Candelaria, Bogota, Colombia

    International Nuclear Information System (INIS)

    Martinez de V, Beatriz; Aguilar, Maria del pilar

    2007-01-01

    This article is part of the first bibliographic revision of the Sustainable mobility in historic centers in Colombia research, which proposes the inclusion of the concepts of technology, mobility, transport and environment, with emphasis on the impact of transport technologies on the built environment and the architectural heritage. The objective is to build a panoramic vision of the problem and so call attention to the important relationships that exist between technology, mobility, transport, environment and historic centers. Initially, a brief reference to the context and the sector of La Candelaria on the south eastern part of Bogota, Colombia, with an extension of 188.12 Hectares and an altitude of 2,600 meters above sea level, declared a National Monument in 1963. Further on, aspects concerning aspects associated with mobility and transport in Bogota during the 19th and 20th centuries, and the effect of transport methods on the environment and architectural heritage. Finally, a brief description of some projects, plans and mobility and transport studies searching for solutions to the problems created in the historic center by transport technologies

  9. Clinical and Epidemiologic Description of Orofacial Clefts in Bogota and Cali, Colombia, 2001-2015.

    Science.gov (United States)

    Sarmiento, K; Valencia, S; Gracia, G; Hurtado-Villa, P; Zarante, I

    2018-04-01

    Among congenital craniofacial anomalies, orofacial clefts (OFCs) are the most common. Global prevalence is 2 in 1000 and in Colombia, 1 in 700. Our goal was to describe cleft palate (CP) prevalence and cleft lip with or without cleft palate (CL±P) from 2001 to 2015 in Bogota and Cali, Colombia. Using the ECLAMC case-control design method, information was obtained from the Congenital Anomalies Monitoring and Surveillance Programs in Bogota and Cali. We describe the prevalence of cases classified into the following groups: isolated, polymalformed, and syndromic. The proportion of cases and controls was 1:4. Data were analyzed using frequency distribution and Student t test to compare means and 95% confidence intervals (CIs). We identified 529 OFC cases and 2116 controls from 448,930 births: a rate of 11.8 per 10,000 (CI = 10.80-12.83). From the total cases, 73% were identified with CL/CP compared to 27% with CP. Males had higher CL±P (59%) prevalence, whereas the highest neonatal mortality was observed among polymalformed cases (7%). The most common anomaly identified among our cases was cleft lip without isolated cleft palate (58%). We found that OFCs are linked to birthweight, size, and gestational age and higher parity with statistically significant differences in all variables compared to controls. OFC is a highly prevalent anomaly in Colombia, with a range of maternal and infant differences across case subgroups. The identification of important OFC subgroups that follow certain patterns of prevalence may prove useful to primary and tertiary care facilities with the goal of reducing further disability.

  10. Energy assessment of peri-urban horticulture and its uncertainty: Case study for Bogota, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Bojaca, C.R. [Centro de Investigaciones y Asesorias Agroindustriales, Facultad de Ciencias Naturales, Universidad de Bogota Jorge Tadeo Lozano, P.O. Box: 140196, Chia (Colombia); Schrevens, E. [Department of Biosystems, Faculty of Applied Bioscience Engineering, Katholieke Universiteit Leuven, Geo-Institute, Celestijnenlaan 200 E, 3001 Heverlee (Belgium)

    2010-05-15

    Scarce information is available about the energy use pattern of horticultural commodities in general and more specifically for peri-urban horticulture. Peri-urban horticulture in the outskirts of Bogota is an important source of vegetables for Colombia's capital city. Based on detailed follow-ups and periodic field measurements an output-input energy balance was performed with the main objective to study the energy use efficiency of those systems. An uncertainty analysis on the input factors and on the energy equivalents was then applied. Over a measurement period of 18-month, the energy use for coriander, lettuce, radish and spinach was investigated, respectively 12.1, 18.8, 6.6 and 10.7 GJ ha{sup -1} were consumed in these cropping systems. Negative balances were observed for all species exception made for spinach where an output:input ratio of 1.16 was found. The two-way uncertainty analysis showed the highest uncertainty for N-based fertilization while no significant effect was observed for seeds in direct sowing crops. Sustainability of peri-urban horticulture around Bogota is compromised not only because of the city expansion but also due to its inefficient energy use. Technical improvements are required to ensure the environmental subsistence of this important sector for the metropolitan area of the city. (author)

  11. Urban air pollution in school-related microenvironments in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Juan Felipe Franco

    2013-05-01

    Full Text Available Particle-related pollution (PM10, PM2.5 and soot was measured in both indoor and outdoor microenvironments at four public elementary schools in Bogota, Colombia. Three of these schools were located alongside major urban roads in which different types of public transit systems are used (bus rapid transit system and conventional transit buses. The fourth school was located on a non-congested road (background school. Pollutant levels at schools situated on major-roads were higher than those found at the low-congestion-road school. Outdoor black carbon daily mean concentrations at the schools located near major roads were up to six times higher than those recorded at the background school. Mean particulate matter concentrations at schools near major roads were above international standards, suggesting that school-age children in Bogota are exposed to pollution levels that are considered to be harmful by environmental and public health authorities. Elevated indoor and outdoor pollutant concentrations documented in this study suggested that traffic has a direct impact on air quality regarding the schools’ characterised microenvironments.

  12. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia; Dosimetria personal TLD 110 en medicos ortopedistas expuestos a radiacion ionizante en Bogota - Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Sierra C, B. Y.; Jimenez, Y. [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Fisica Medica, Carrera 45 No. 26-85, Bogota (Colombia); Plazas, M. C. [Hospital Universitario Fundacion Santa Fe de Bogota, Instituto de Oncologia Carlos Ardila Lulle, Calle 119, No. 7-90, 220246 Bogota (Colombia); Eslava S, J. [Universidad Nacional de Colombia, Instituto de Investigaciones Clinicas, Grupo Equidad en Salud, Carrera 45 No. 26-85, Bogota (Colombia); Groot R, H., E-mail: brigith.sierra@gmail.com [Universidad de los Andes, Laboratorio de Genetica Humana, Carrera 1 No. 18A -12, Bogota (Colombia)

    2014-08-15

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  13. Trans-fatty acids in cooking oils in Bogota, Colombia: changes in the food supply from 2008 to 2013.

    Science.gov (United States)

    Moynihan, Meghan; Villamor, Eduardo; Marin, Constanza; Mora-Plazas, Mercedes; Campos, Hannia; Baylin, Ana

    2015-12-01

    Long-chain n-3 fatty acid intake in Colombia is low because fish consumption is limited. Vegetable oils with high n-3 fatty acid content are recommended, but their concentrations of trans fats were high in previous studies. Thus, regular monitoring of the fatty acid composition of vegetable oils is required. Our objective was to quantify the fatty acid composition in commercially available oils in Bogota, Colombia and determine if composition changed from 2008 to 2013. Cross-sectional study. We obtained samples of all commercially available oils reported in a survey of low- and middle-income families with a child participating in the Bogota School Children Cohort. Bogota, Colombia. Not applicable. Sunflower oil had the highest trans-fatty acid content (2.18%). Canola oil had the lowest proportion of trans-fatty acids (0.40%) and the highest n-3 fatty acid content (9.37%). In terms of percentage reduction from 2008 to 2013 in 18:1 and 18:2 trans-fatty acids, canola oil had 89% and 65% reduction, mixed oils had 44% and 48% reduction, and sunflower oil had 25% and 51 % reduction, respectively. Soyabean oil became widely available in 2013. The content of trans-fatty acids decreased in all oils from 2008 to 2013, suggesting a voluntary reduction by industry. We believe that regular monitoring of the fatty acid composition of oils is warranted.

  14. Young people in Bogota, Colombia develop their own strategies to prevent risky sexual behavior.

    Science.gov (United States)

    Saavedra, M

    1996-01-01

    Although the government of Colombia moved in 1993 to mandate sexuality education in primary and secondary schools, nongovernmental organizations have worked in this area for more than two decades. Notable has been the work of one such organization, the Colombian Human and Social Development Foundation, among youth from a marginal, underserved area of Bogota that houses approximately 27,000 adolescents. The project uses a peer approach to relate the values of responsibility, tolerance, and self-determination to the prevention of risky sexual behaviors. At the onset, 15 youth leaders from the local school identified strategies for raising the topic of sexuality to their peers: suggestion boxes, school radio programs, educational materials such as murals and pamphlets, workshops, board games with sexuality-related themes, and community involvement. Suggestion box submissions revealed that sixth and seventh graders wanted to know about puberty-related events, while older students were interested in the effects of masturbation on health and appearance and the association between premarital sexual activity and one's reputation. In an 18-month period, close to 9000 community residents were reached with program materials and 1798 adolescents participated in group meetings. Among the gains observed have been correction of misinformation, a broader view of sexuality, the capacity for independent thought, and self-pride.

  15. [Profile of children and adolescents with autism spectrum disorders in an institution in Bogota, Colombia].

    Science.gov (United States)

    Talero-Gutiérrez, C; Rodríguez, M; De La Rosa, D; Morales, G; Vélez-Van-Meerbeke, A

    2012-03-01

    To determine the profile of children and adolescents diagnosed with autism spectrum disorder (ASD) in a comprehensive care centre in Bogota, Colombia. A descriptive-correlational study with a sample of patients who had attended the institution from 2003 to 2009. Demographic and clinical aspects were evaluated and a correlation between the diagnosis and severity being analysed in search for risk factors. A total of 138 patients were studied. The average age of onset was 21 months, and diagnosis had been made at 45 months. There was a male predominance (6.15:1). The predominant diagnosis was autistic syndrome (83%), followed by pervasive developmental disorder not otherwise specified (17%). There was no pathological background in the family history, during pregnancy or during the neonatal period. Motor development during the first year was normal but acquisition of language skills was compromised. The specific signs of ASD as regards the disorder in itself, communication skills, spontaneous speech, verbal comprehension, attention, imitation, use of objects, self-care and symbolic play were significantly related to the severity of the disease. Diagnosis of ASD is still delayed in our population and usually after referral from someone other than a health professional. The most important problems were found in communication skills and relationships with peers. The study did not show significant associated risk factors. Copyright © 2010 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  16. Effect of socioeconomic status on the association between air pollution and mortality in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Luis Camilo Blanco-Becerra

    2014-07-01

    Full Text Available Objective. To evaluate the modification effect of socioeconomic status (SES on the association between acute exposure to particulate matter less than 10 microns in aerodynamic diameter (PM10 and mortality in Bogota, Colombia. Materials and methods. A time-series ecological study was conducted (1998-2006. The localities of the cities were stratified using principal components analysis, creating three levels of aggregation that allowed for the evaluation of the impact of SES on the relationship between mortality and air pollution. Results. For all ages, the change in the mortality risk for all causes was 0.76% (95%CI 0.27-1.26 for SES I (low, 0.58% (95%CI 0.16-1.00 for SES II (mid and -0.29% (95%CI -1.16-0.57 for SES III (high per 10μg/m3 increment in the daily average of PM10 on day of death. Conclusions. The results suggest that SES significantly modifies the effect of environmental exposure to PM10 on mortality from all causes and respiratory causes.

  17. Heaths and forests of the western hills of Chia, Bogota savanna, Colombia

    International Nuclear Information System (INIS)

    Cortes S, Sandra P.; Van der Hammen, Thomas; Rangel Ch, J Orlando

    2000-01-01

    The authors make a study of the heaths and forests of the western hills of the population of Chia, located in the savanna of Bogota and the presence or absences of these in the same Bogota savanna; the authors treat topics like their physiognomy and composition, distribution and ecology among other topics

  18. Notes of records about yellow-green vireo (vireo flavoviridis: vireonidae) at the Sabana de Bogota, Cundinamarca (Colombia)

    International Nuclear Information System (INIS)

    Acevedo Charry, Orlando A; Echeverri Mallarino, Laura

    2013-01-01

    The Yellow-green Vireo (Vireo flavoviridis) is migrant bird species, previously none reported to Cundinamarca Department. Distribution known in Colombia only includes localities below 1500 masl. Two individuals of the Yellow-green Vireo were observed at 2600 masl in the Universidad Nacional de Colombia Bogota Campus, at the Sabana de Bogota in Cundinamarca Department in 2011. In addition, we found 18 unpublished records for this species in the Cundinamarca Department above 2500 masl. Ten records were museum specimens (Instituto de Ciencias Naturales de la Universidad Nacional de Colombia, Vertebrate collection (Ornitology) Universidad de los Andes and Instituto de Investigacion en Recursos Biologicos Alexander von Humboldt Museum), and the other eight were birdwatching records. The oldest record was in 1964, but the great majority of records were collected between 2008 and 2013. We consider that the Yellow-green Vireo has been unnoticed in the Cundinamarca Department because of its morphological similarities with the Red-eye Vireo (V. olivaceus). Furthermore, the lack of review of scientific collections, and the deposition of specimens discontinuous there, make gap information about biodiversity distribution. Apparently, Yellow-green Vireo could be more common than expected above 1500 m during its migration, such as it was observed in at Cundinamarca Department.

  19. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia

    International Nuclear Information System (INIS)

    Sierra C, B. Y.; Jimenez, Y.; Plazas, M. C.; Eslava S, J.; Groot R, H.

    2014-08-01

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  20. Monotony, Isolation and Backward Agriculture. Travel Accounts of 19th Century and Agrarian History of Bogota Plateau (Colombia

    Directory of Open Access Journals (Sweden)

    Katherinne Giselle Mora Pacheco

    2015-07-01

    Full Text Available Different works of Agrarian History reproduce a similar description of Bogota Plateau (Colombia throughout the nineteenth century: agricultural use since colonial times; vast fields of wheat and barley; abrupt replacement of crops by cattle; agricultural crisis linked to the agro-export booms and the demand for tropical products that could not be obtained above 2000 meters. This paper discusses how this approach has perpetuated descriptions of travelers who visited the region during the nineteenth century and wrote up their notebooks based on their origins, objectives, political and economic interests, or from affirmations of their guides and informants. This article rebuilds a profile of travelers that are most often quoted by historians, their views about the Plateau landscape and its farming and ranching, and their influence on today reconstructions of the agrarian history of Bogota Plateau along nineteenth century. This text invites to contrast the travel accounts among themselves and with another sources, and also to incorporate the results of the research about the Colonial period and the biophysical conditions of the regions under study in the analysis.

  1. Latin American Clinical Epidemiology Network Series - Paper 5: Years of life lost due to premature death in traffic accidents in Bogota, Colombia.

    Science.gov (United States)

    Quitian-Reyes, Hoover; Gómez-Restrepo, Carlos; Gómez, Maria Juliana; Naranjo, Salome; Heredia, Patricia; Villegas, John

    2017-06-01

    This study aimed to quantify the number of years of life lost in traffic accidents in Bogota, Colombia. The years of life lost were calculated using the 'age-standardized expected years of life lost' method, the table of Japanese adjusted life expectancy and the database of the Institute of Legal Medicine and Forensic Science between September 2012 and August 2013. During a period of 1 year, 430 people died and 10,056.3 years of life were lost in Bogota due to traffic accidents. The mortality burden of traffic accidents in Bogota is high. Further studies are required in order to characterize the accidents and develop effective policy decisions. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Study of groundwater in the Chicu River basin, Sabana de Bogota, Colombia; Estudio de las aguas subterraneas de la cuenca del Rio Chicu, Sabana de Bogota, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Obando G, E; Jimenez B, G; Torres Q, E; Alayon C, E; Garavito B, F [Instituto de Ciencias Nucleares y Energias Alternativas, INEA, Bogota (Colombia)

    1995-10-01

    The Rio Chicu Valley aquifer system represents one of the many sub-systems constituting the hydrogeological system of the Sabana de Bogota. The valley has a structure of a graben, covered by a quaternary alluvial formation, which has a low permeability and therefore is an aquifer of poor characteristics. Due to the thickness of this aquifer (around 300 m), the tertiary aquifers are only exploited by few deep wells. The isotopic composition of water collected from the tertiary aquifer is depleted by 1 per mille in {delta}{sup 18}O and 8 per mille in {delta}D. This difference is due to the altitude effect of recharge, because the tertiary aquifers outcrop on the top of the surrounding hills. In some places, the stable isotope content of water sampled in wells tapping water from the quaternary aquifer is similar to the values found in the tertiary aquifer. This fact indicates the ascending leakage from deep horizons. A rather unique characteristics of the quaternary aquifer is that in the central part of the basin the dissolved inorganic carbon DIC is very high and shows a {delta}{sup 13}C values around +10 per mille vs PDB and {sup 14}C around 5-10 pmc. The positive values are probably related to decomposition of organic matter in anaerobic conditions. These values reflect a very low flow in the system and limited recharge. (author). 1 ref., 5 figs, 2 tabs.

  3. Spatial and temporal disaggregation of transport-related carbon dioxide emissions in Bogota - Colombia

    Science.gov (United States)

    Hernandez-Gonzalez, L. A.; Jimenez Pizarro, R.; Néstor Y. Rojas, N. Y.

    2011-12-01

    As a result of rapid urbanization during the last 60 years, 75% of the Colombian population now lives in cities. Urban areas are net sources of greenhouse gases (GHG) and contribute significantly to national GHG emission inventories. The development of scientifically-sound GHG mitigation strategies require accurate GHG source and sink estimations. Disaggregated inventories are effective mitigation decision-making tools. The disaggregation process renders detailed information on the distribution of emissions by transport mode, and the resulting a priori emissions map allows for optimal definition of sites for GHG flux monitoring, either by eddy covariance or inverse modeling techniques. Fossil fuel use in transportation is a major source of carbon dioxide (CO2) in Bogota. We present estimates of CO2 emissions from road traffic in Bogota using the Intergovernmental Panel on Climate Change (IPCC) reference method, and a spatial and temporal disaggregation method. Aggregated CO2 emissions from mobile sources were estimated from monthly and annual fossil fuel (gasoline, diesel and compressed natural gas - CNG) consumption statistics, and estimations of bio-ethanol and bio-diesel use. Although bio-fuel CO2 emissions are considered balanced over annual (or multi-annual) agricultural cycles, we included them since CO2 generated by their combustion would be measurable by a net flux monitoring system. For the disaggregation methodology, we used information on Bogota's road network classification, mean travel speed and trip length for each vehicle category and road type. The CO2 emission factors were taken from recent in-road measurements for gasoline- and CNG-powered vehicles and also estimated from COPERT IV. We estimated emission factors for diesel from surveys on average trip length and fuel consumption. Using IPCC's reference method, we estimate Bogota's total transport-related CO2 emissions for 2008 (reference year) at 4.8 Tg CO2. The disaggregation method estimation is

  4. [DIFFERENCES IN PHYSICAL ACTIVITY AND IN PHYSICAL CONDITION BETWEEN SCHOOL AGE STUDENTS OF TWO PUBLIC CURRICULUM PROGRAMS IN BOGOTA, COLOMBIA].

    Science.gov (United States)

    Carrillo Cubides, Raúl; Aldana Alarcón, Luis Gonzalo; Gutiérrez Galvis, Adriana Rocío

    2015-11-01

    During the past five decades there has been an increased in the prevalence of obesity and over weight, also in physical inactivity and /or low cardiorespiratory fitness within the population in school age from diverse regions of the planet, including Bogota-Colombia. The general objective of this study was to compare the physical condition and the levels of physical activity from students who belonged to two curriculum programs of the Public Schools Network from Bogota, one of which includes two sessions per week, each session of 90 minutes of physical activity. We developed a research of unlike cross-sectional groups. There were 178 children evaluated from the regular curriculum and 170 kids belonging to the program 40 x 40. The physical condition was evaluated applying the protocol of high priority from the ALPHA -Fitness test Battery. The weight, height, body mass index, the waist circumference, the standing long jump, the handgrip in both hands and the motor fitness 20 meter shuttle run test were developed under standardized conditions. The Global School Health Survey (GSHS) was used to evaluate the levels of AF. No significant statistical differences were founded between P-40x40 and the regular curriculum regarding: weight, height, the body mass index, the waist circumference, the handgrip in both hands and the explosive strength in lower limbs. Nevertheless the cardiorespiratory fitness was significantly lower within de P-40x40. In conclusion the participation in the curricular program 40 x 40 was not associated with better levels of physical condition. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  5. NW transverse fault system in Southern Bogota, Colombia: New seismologic and structural evidences derived from focal mechanisms and stress field determination

    Science.gov (United States)

    Angel Amaya, J.; Fierro Morales, J.; Ordoñez Potes, M.; Blanco, M.

    2012-12-01

    We present new seismological, morphotectonic and structural data of the Southern Bogota area. The goals of the study were to characterize the NW transverse fault system and to evaluate its effect on seismic wave's generation and propagation. The data set included epicenters of the RSNC (Red Sismologica Nacional de Colombia) catalog over the period 1993-2012, historical description of seismic events (period 1644-1921), structural field data (scale 1:100000) and remote sensors interpretation. The methodology included the structural analysis of over 476 faults having a known sense of offset by using a least squares iterative inversion outlined by Angelier (1984) to determinate the mean deviatoric principal stress tensor. Preliminary conclusions showed that both propagation medium and direction are determined by the structural and mechanic conditions of the Southern Bogota Shear Zone (SBSZ) defined by Fierro & Angel, (2008) as a NW-SE oblique-slip fault zone within sinistral and normal regimes. Based on both data sources (focal mechanism and field structural data) we attempted to reconstruct the stress field starting with a strike slip faulting stress regime (S2 vertical), the solution yielded a ENE-WSW orientation for horizontal principal stress (S1). It is hypothesized that the NW oblique-slip fault zone may generate and/or propagate seismic waves, as a local source, implying local hazard to Bogota the capital city of Colombia with over 8 million habitants.

  6. Findings on education in Bogota (Colombia based on a 2014 multipurpose survey

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Barragán Moreno

    2017-06-01

    Full Text Available This paper presents a study on education of the Multipurpose Survey of the year 2014, financed by the District Department of Planning of the city of Bogotá and developed by the National Statistics Department. This study focuses on determining the main reasons why people of school age did not do so at the time of the survey, and in characterizing the educational levels of household heads and their spouses or partners as referring adults in the households surveyed. The survey was applied to a sample of 61,725 people, who according to the sample design represent 7,794,463 inhabitants of urban areas in Bogota. Using descriptive and data mining techniques, it is stated that the two main reasons for not studying are the lack of money and the need to work. In addition, marital status is a more determinant predictor than sex or socioeconomic stratum. Single people are motivated to earn a college degree when they have had access to higher education at some point in their life. When studying the information of household heads, a similar behavior was observed, because the reasons for not studying were practically the same. Unplanned pregnancy and living with a partner are not outstanding reasons.

  7. [Evaluation of the National Vaccination Day in Bogota, D.C., 2001].

    Science.gov (United States)

    Prieto Alvarado, Franklyn E; de la Hoz Restrepo, Fernando P

    2003-01-01

    A national immunization day-NID, aimed at improving vaccination coverage, was carried out in Colombia in November 2001. The main objective of the study was to measure the proportion of children under 2 years either completing their immunization schedule or advancing through it by receiving doses during the NID. Besides, we also evaluated the proportion of lost opportunities for vaccination during the NID and the impact of the media (TV, ratio, newspapers, etc.) in advertising the NID. In order to evaluate the impact of immunization a cross sectional survey was carried out in Bogotá in the waiting rows of the 30 randomly selected vaccination posts; 623 participants were systematically chosen. The outcomes were analyzed by age, socioeconomic level and type of health insurance-SSS. Only children holding a vaccination card were considered eligible for the study. Most people become aware about NID through TV, 81%, followed by radio advertisements, 22%. After attending NID the proportion of fully vaccinated children, according to PAHO scheme, raised from 46% to 66%, a 43% increase. This increase was even higher among children aged less than 6 months (140% increment). There were no differences in the increment by social stratum or affiliation to the SSS. Among the children studied we identified a 24% of loss opportunities for vaccination that did not differ by socioeconomic level or SSS groups. Our results suggest that, despite its high costs, NID might be useful to transiently overcome barriers for adequate access to health services.

  8. Raising Awareness for Lung Cancer Prevention and Healthy Lifestyles in Female Scholars from a Low-Income Area in Bogota, Colombia: Evaluation of a National Framework.

    Science.gov (United States)

    Meneses-Echávez, J F; Alba-Ramírez, P A; Correa-Bautista, J E

    2017-07-06

    This study aims to determine the effects of an educational intervention, based on the Colombian guidelines for educational communication in the framework of cancer control, for raising lung cancer prevention-related awareness, and improving healthy lifestyles in female scholars from a low-income area in Bogota, Colombia. Uncontrolled trial conducted in 243 female scholars (mean age 14 years ± 1.5 SD). Two 90 min educational sessions were carried out in March 2015 according to the Colombian guidelines for educational communication in the framework of cancer control. Posters and other educational materials were created by scholars after the intervention. All participants completed a self-reported questionnaire-The Cancer Awareness Measure-at pre and post-intervention, as well as 1, 3, and 6 months after the intervention. Smoking prevalence (8.2% at baseline) was reduced by 3.7% at 6 months follow-up (p risk factors for lung cancer at baseline. These variables showed statistically significant improvements at 6 months follow-up (p communication in the framework of cancer control raised awareness towards lung cancer prevention, reduced smoking, and improved other healthy-lifestyle-related factors in a group of female scholars from a low-income area in Bogota, Colombia. Further randomized controlled studies are needed.

  9. Use of spermicide and impact of prophylactic condom use among sex workers in Santa Fe de Bogota, Colombia.

    Science.gov (United States)

    Farr, G; Acosta Castro, L A; DiSantostefano, R; Claassen, E; Olguin, F

    1996-01-01

    Condom use is one of the most important preventive measures sex workers can take to reduce the risk of becoming infected with a sexually transmitted disease. However, a client may refuse to use a condom when requested. Some sexually transmitted disease prevention programs are recommending that sex workers use spermicide as an alternative prophylaxis when a condom is refused, yet little is known about the effect of this recommendation on prophylactic condom use. To determine if using spermicide, either in conjunction with condoms or as a backup, influenced overall condom use among a group of sex workers at high risk of sexually transmitted diseases in Santa Fe de Bogota, Colombia. Participants were assigned randomly to one of three condom use groups: use of condoms only (Condoms Only), use of condoms and spermicides concurrently (Condom and Spermicide), or use of spermicide when condoms were refused (Spermicide as a Backup). A total of 199 sex workers entered the study and were asked to return for follow-up every 2 weeks for a period of 12 weeks. Women assigned to the Spermicide as a Backup group used a condom for an average of 78.1% of their reported acts of intercourse, compared with an average of 94.5% in the Condom Only and 92.3% in the Condom and Spermicide groups. However, women in the Spermicide as a Backup group used a condom or spermicide for an average of 96.9% of their acts of intercourse. Condoms were used for every intercourse act by less than 5% of the women in the Spermicide as a Backup groups, compared with 50.7% in the Condom Only group and 41.2% in the Condom and Spermicide group (P 0.001). When condoms were not used, client refusal was the primary reason reported. The incidence of sexually transmitted diseases and other urogenital inflammations in all groups was lower than expected. Among Colombian sex workers, condom use declined substantially when women were instructed to use spermicides if they were unable to persuade their partner to use a

  10. Where Latin Americans are physically active, and why does it matter? Findings from the IPEN-adult study in Bogota, Colombia; Cuernavaca, Mexico; and Curitiba, Brazil.

    Science.gov (United States)

    Salvo, Deborah; Sarmiento, Olga L; Reis, Rodrigo S; Hino, Adriano A F; Bolivar, Manuel A; Lemoine, Pablo D; Gonçalves, Priscilla B; Pratt, Michael

    2017-10-01

    Latin America (LA) has a unique structural, political, cultural and social environment. This study aimed to identify the places where Latin American adults are physically active; and to determine the association of using public- and restricted-access places with physical activity (PA). We used data from the International PA Environment Network study in Bogota, Colombia (n=1000, accelerometry=249); Cuernavaca, Mexico (n=677, accelerometry=652); and Curitiba, Brazil (n=697, accelerometry=331) (2010-2011). Walking and moderate-to-vigorous PA for leisure were measured with the International Physical Activity Questionnaire. Overall PA and PA within 10-minute bouts were measured with accelerometers. Participants reported use of public- and restricted-access places for PA. Mixed-effects regression models were used to determine the association of using public- and restricted-access places with PA. The streets were the most frequently-reported place for PA, and walking was the most common PA in the studied places. 'Informal', non-exercise-or-sports places (e.g., shopping malls) ranked high for use for PA in Bogota and Cuernavaca. In Curitiba, use of 'formal' places for sports/exercise (e.g., gyms) was more prevalent. Using public-access places was directly related to walking for leisure in all cities, and to additional PA outcomes in Bogota and Cuernavaca. In Cuernavaca and Curitiba, using restricted-access places was also associated with PA. Our study highlights the importance of public-access places for PA in LA. In some contexts, places for social interaction may be as important for PA as places for exercise/sport. Strategies increasing the availability, accessibility and quality of these places may effectively promote PA in LA. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Assessing the effect of physical activity classes in public spaces on leisure-time physical activity: "Al Ritmo de las Comunidades" A natural experiment in Bogota, Colombia.

    Science.gov (United States)

    Torres, Andrea; Díaz, María Paula; Hayat, Matthew J; Lyn, Rodney; Pratt, Michael; Salvo, Deborah; Sarmiento, Olga L

    2017-10-01

    The Recreovia program provides free physical activity (PA) classes in public spaces in Bogota, Colombia. The purpose of this study was to assess the effectiveness of the Recreovia program in increasing PA among users of nine parks in Bogota. This study was a natural experiment conducted between 2013 and 2015 in Bogota. Community members and park users living nearby three groups of parks were compared: Group 1 were parks implementing new Recreovias (n=3), Group 2 were control parks (n=3) without Recreovias, and Group 3 were parks with existing Recreovías. Individuals in the "intervention" group were exposed to newly implemented Recreovia programs in parks near their homes. Measurements were collected at baseline and 6-8months after the intervention started. A total of 1533 participants were enrolled in the study: 501 for the existing Recreovias (included in a cross-sectional assessment) and 1032 participants (from the new Recreovias and control parks) included in the cross-sectional and pre-post study. Most participants were low income females. Twenty-three percent of the intervention group started participating in the program. Users of existing Recreovias were significantly more active and less likely to be overweight/obese compared to new Recreovia users at baseline. No changes on PA were found when comparing the intervention and control groups. Recreovias may have potential for increasing PA at the population level in urban areas given their rapid scalability, the higher levels of PA observed among program users, and its potential to reach women, low-income, less educated populations, and the overweight and obese. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Normative reference values for the 20 m shuttle‐run test in a population‐based sample of school‐aged youth in Bogota, Colombia: the FUPRECOL study

    Science.gov (United States)

    Palacios‐López, Adalberto; Humberto Prieto‐Benavides, Daniel; Enrique Correa‐Bautista, Jorge; Izquierdo, Mikel; Alonso‐Martínez, Alicia; Lobelo, Felipe

    2016-01-01

    Abstract Objectives Our aim was to determine the normative reference values of cardiorespiratory fitness (CRF) and to establish the proportion of subjects with low CRF suggestive of future cardio‐metabolic risk. Methods A total of 7244 children and adolescents attending public schools in Bogota, Colombia (55.7% girls; age range of 9–17.9 years) participated in this study. We expressed CRF performance as the nearest stage (minute) completed and the estimated peak oxygen consumption (V˙O2peak). Smoothed percentile curves were calculated. In addition, we present the prevalence of low CRF after applying a correction factor to account for the impact of Bogota's altitude (2625 m over sea level) on CRF assessment, and we calculated the number of participants who fell below health‐related FITNESSGRAM cut‐points for low CRF. Results Shuttles and V˙O2peak were higher in boys than in girls in all age groups. In boys, there were higher levels of performance with increasing age, with most gains between the ages of 13 and 17. The proportion of subjects with a low CRF, suggestive of future cardio‐metabolic risk (health risk FITNESSGRAM category) was 31.5% (28.2% for boys and 34.1% for girls; X2 P = .001). After applying a 1.11 altitude correction factor, the overall prevalence of low CRF was 11.5% (9.6% for boys and 13.1% for girls; X2 P = .001). Conclusions Our results provide sex‐ and age‐specific normative reference standards for the 20 m shuttle‐run test and estimated V˙O2peak values in a large, population‐based sample of schoolchildren from a large Latin‐American city at high altitude. PMID:27500986

  13. Effect of size and vegetation cover in urban parks in the richness and diversity of bird life in Bogota, Colombia

    International Nuclear Information System (INIS)

    Berget, Carolina

    2006-01-01

    In one section of Bogota city some characteristics of urban recreational areas (size, distance to the east hills, coverage and diversity of vegetation) and their effects over the bird fauna diversity were studied between April and June of 2004. The samplings were made in 18 recreational areas of different sizes (100 m2 1 300000 m2), and at different distances (1.40 km -7.0 km) from two native vegetation patches to the east hills in Bogota, which were thought to be habitat sources. Lineal regression analysis showed that bird fauna diversity is affected by the size of the recreational area and, to a lesser extent, the vegetation cover, but not by other variables. These recreational areas are not considered fragments but human made islands and, therefore, they do not contain many relict forest bird species. I concluded that the east hills are not source habitat of bird species for the urban recreational areas studied. These habitats are suitable for the establishment of species associated to open areas

  14. Highlights from the first ecancer-Liga Colombiana contra el Cancer conference, 17-18 November 2016, Bogota, Colombia.

    Science.gov (United States)

    Castro, Carlos

    2017-01-01

    The first oncology conference organised by e cancer and the Liga Colombiana contra el Cancer took place on 17-18 November 2016 in Bogota. It was a highly successful event owing to the number of participants, the quality of the speakers, and the academic programme. Around 48 professors from 8 different countries came and shared their knowledge and experience of cancer management. They also talked about the most recent developments noted or achieved in this area. The keynote speech from Dr Nubia Muñoz was of great interest which was related to the safety of a HPV vaccine and the implications of a mass vaccination programme in developing countries. Geriatric oncology and palliative care were also topics that sparked great interest during the event.

  15. Effect of particulate matter less than 10μm (PM10 on mortality in Bogota, Colombia: a time-series analysis, 1998-2006

    Directory of Open Access Journals (Sweden)

    Luis Camilo Blanco-Becerra

    2014-07-01

    Full Text Available Objective. To analyze the association between daily mortality from different causes and acute exposure to particulate matter less than 10 microns in aerodynamic diameter (PM10, in Bogota, Colombia. Materials and methods. A time-series ecological study was conducted from 1998 to 2006. The association between mortality (due to different causes and exposure was analyzed using single and distributed lag models and adjusting for potential confounders. Results. For all ages, the cumulative effect of acute mortality from all causes and respiratory causes increased 0.71% (95%CI 0.46-0.96 and 1.43% (95%CI 0.85-2.00, respectively, per 10μg/m3 increment in daily average PM10 with a lag of three days before death. Cumulative effect of mortality from cardiovascular causes was -0.03% (95%CI -0.49-0.44% with the same lag. Conclusions. The results suggest an association between an increase in PM10 concentrations and acute mortality from all causes and respiratory causes.

  16. Medición e interpretación de vibraciones producidas por el tráfico en Bogotá D.C. Measurement and interpretation of vibrations produced by the traffic in Bogota D.C.

    Directory of Open Access Journals (Sweden)

    Hermes Vacca Gámez

    2011-01-01

    Full Text Available Debido al desarrollo de Bogotá (ciudad principal de Colombia y a su incremento de población, se han construido en la última década sistemas de transporte. A pesar de que estos sistemas incrementan el bienestar de los ciudadanos, el tráfico vehicular podría generar problemas de vibraciones. Estas vibraciones afectarían negativamente a las personas y a las edificaciones cercanas. Estos efectos pueden ser importantes si se presentan altos niveles de amplitud de las vibraciones. Estas vibraciones, dependen, entre otros aspectos, de las características mecánicas de los suelos. Teniendo en cuenta los planes futuros de construcción de sistemas transporte en Bogotá, se registraron vibraciones de tráfico vehicular y ferroviario en 6 sitios de Bogotá. En estos lugares se identificaron suelos típicos del estudio de microzonificación sísmica. Se hicieron mediciones para registrar las vibraciones debidas al tren de la sabana, Transmilenio (buses articulados y servicio público principalmente. Se determinaron curvas de atenuación en aceleración y velocidad. Se determinó que para las condiciones actuales las vibraciones pueden llegar a ser molestas para las personas pero no generan problemas a las estructuras. No obstante, estos valores deben tomarse como punto de referencia de mediciones futuras cuando se incremente el tráfico, el peso de los vehículos (metro y las velocidades de circulación.Due to the development of Bogota (main city of Colombia and to its increase of population, transport systems have been constructed in the last decade. Although these systems increase the well-being of the citizens, the traffic could generate vibrations problems. These vibrations could affect the people and the constructions near to highways. These effects can be important for high levels of vibrations. These vibrations, depend, among others aspects, of the mechanical characteristics of the soils. Considering the future plans of construction of

  17. The management of water providing strategic ecosystems. The case of the basins that supply Medellin and Bogota in Colombia

    International Nuclear Information System (INIS)

    Cardenas Agudelo, Maria Fernanda

    2013-01-01

    The population growth and the urban concentration involve a sustained increment in water demand, which requires an adequate effort and management of the ecosystems that provide the liquid to guarantee a plenty future offer. The performance of the entities in charge of the management of such ecosystems and the results obtained in the basins that supply drinkable water to two cities in Colombia are analyzed; financial topics and their relation with the local community are considered. Management is delegated to governmental entities, whose work is insufficient and unsatisfactory. Thus, application of economical, legal and social tools is proposed in order to improve ecosystem's conservation and life quality of farmers that inhabit in their influence areas, partially transferring management to the local community's orbit.

  18. Effects of an Educational Intervention on Breast Self-Examination, Breast Cancer Prevention-Related Knowledge, and Healthy Lifestyles in Scholars from a Low-Income Area in Bogota, Colombia.

    Science.gov (United States)

    Masso-Calderón, A M; Meneses-Echávez, J F; Correa-Bautista, J E; Tovar-Cifuentes, A; Alba-Ramírez, P A; Charry-Ángel, C E

    2016-11-04

    The aim of this study was to evaluate the effects of an educational intervention on breast self-examination, cancer prevention-related knowledge, practices, and behavior change in scholars from a low-income area in Bogota, Colombia. Uncontrolled trial was conducted in 155 scholars. Two educational sessions, 90 min each, were carried out in March 2015 according to the Colombian guidelines for educational communication in the framework of cancer control. All participants completed a self-reported questionnaire at pre- and post-intervention, as well as 1, 3, and 6 months after the intervention. Breast self-examination was practiced by 78.1% of the scholars, and the overall knowledge of breast cancer risk factors was poor. The educational intervention resulted in significant improvements on breast self-examination practice, the knowledge of the technique, and the knowledge of the main risk factors for breast cancer as well as the practice of physical activity and vegetable intake at 6 months follow-up. An educational intervention according to the Colombian guidelines for educational communication in the framework of cancer control improved the practice of breast self-examination, cancer prevention-related knowledge, as well as the practice of physical activity and vegetable consumption in scholars from a low-income area in Bogota, Colombia. Further randomized controlled studies are warranted.

  19. Uso de hierbas medicinales en mujeres gestantes y en lactancia en un hospital universitario de Bogotá (Colombia The use of herbal medicine among pregnant and lactating women attending a university hospital in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Gloria Paulina Pulido Acuña

    2012-12-01

    Full Text Available Las mujeres durante la gestación y lactancia utilizan diferentes hierbas y es escasa la información en el ámbito clínico en Colombia. Objetivo: Describir las prácticas relacionadas con el uso de hierbas en mujeres gestantes y en lactancia del Hospital de San José, Bogotá (Colombia. Metodología: Estudio de corte transversal. Con un cuestionario estructurado se indagó el uso, la frecuencia, el modo y razones de uso, de las hierbas medicinales y de quién se aprendió la práctica. Resultados: El uso de hierbas en mujeres gestantes y en lactancia fue de 33.6% (IC95%: 29.2% - 38% y 36.6% (IC95%: 30.8% - 42.3%, respectivamente. En el grupo de gestantes la hierba más usada fue la manzanilla (36.7% y en las mujeres en lactancia fue el hinojo (65%. Conclusión: Las mujeres gestantes y en lactancia, utilizan hierbas para las molestias del embarazo, acelerar el parto, disminuir el frío y promover la producción de leche.The use of herbal supplements is a common practice about pregnant and lactating women, however in Colombia there is limited data regarding the extent of women's use of herbal medicines during pregnancy and breastfeeding. The aim of this study was to describe the patterns of herbal medication use among pregnant and lactating women at the Hospital San Jose in Bogota, Colombia. Methods: Cross-sectional study. A questionnaire was designed to measure the frequency of herbal supplementation, why women took the herbal medicine, form of supplements, and who recommended the supplements or how did they learn about the herbal supplements. Results: The use of herbal supplements among pregnant and lactating women is 33.6% (CI 95%: 29.2%-38% and 36.6 (CI 95%: 30.8%-42.3%, respectively. The most common supplement used by pregnant women is Chamomile (36,7%, and among lactating women is Fennel (Foeniculum vulgare (65%. Conclusion: Pregnant and breastfeeding women use herbal supplements for specific pregnancy-related problems, to induce labor, to

  20. Rate Proposal for Remuneration of Air Pollutants Emissions From Stationary Sources Located in Bogota D.C.

    Directory of Open Access Journals (Sweden)

    Gabriel Herrera Torres

    2011-04-01

    Full Text Available The objective of this project is to develop a methodological proposal for the establishment of the retributive rate for the direct use of the atmosphere as the receptor of pollutant emissions that come from stationary resources on Bogotá D.C. By means of the emissions from stationary sources inventory and the air quality analysis, the pollutant that are emitted by the industries and the ones that are regulated by the network observations of the were identified selecting the particulated matter (PM10, sulfur oxides (SOx, and nitrogen oxides (NOx as the atmospheric pollutants that should be the object of payment in the retributive rate. Besides the selection of the pollutants that should be in the payment, the analysis of the retributive rate structure was made witch was based on the description or four key elements the generated fact, the tax base, the passive subject, and the fee of the rate. taking into account the social costs which are related to the investment being made by the district for the treatment of patients that present acute respiratory diseases ERA´s, associated and the costs of program control and monitoring of the air quality in Bogotá, the tariffs of the payment of the retributive rate were redefined in 281 $/Kg for the PM10, 2816 $/kg for the SOX and 2866 $/kg for NOX. Finally a new model of the payment was established, which is the result of the multiplication of the respective tariff for each of the pollutants that were selected as object of payment, expressed in ($/kg times, the charge of the pollutants emitted by the source expressed in (kg/ day.times the total number of days of the operation of the source emissions in a year.

  1. Elaboration of a velocity model of the Bogota basin (Colombia) based on microtremors arrays measurements, gravity data, and geological information

    Science.gov (United States)

    Pulido Hernandez, N. E.; Senna, S.; Garcia, H. Mr; Montejo, S.; Reyes, J. C.

    2017-12-01

    Bogotá, a megacity with almost 8 million inhabitants is prone to a significant earthquake hazard due to nearby active faults as well as subduction megathrust earthquakes. The city has been severely affected by many historical earthquakes in the last 500 years, reaching MM intensities of 8 or more in Bogotá. The city is also located at a large lacustrine basin composed of extremely soft soils which may strongly amplify the ground shaking from earthquakes. The basin extends approximately 40 km from North to South, is bounded by the Andes range to the East and South, and sharply deepens towards the West of Bogotá. The city has been the subject of multiple microzonations studies which have contributed to gain a good knowledge on the geotechnical zonation of the city and tectonic setting of the region. To improve our knowledge on the seismic risk of the city as one of the topics, we started a 5 years project sponsored by SATREPS (a joint program of JICA and JST), entitled "Application of state of the art technologies to strengthen research and response to seismic, volcanic and tsunami events and enhance risk management in Colombia (2015-2019)". In this paper we will show our results for the elaboration of a velocity model of the city. To construct a velocity model of the basin we conducted multi-sized microtremors arrays measurements (radius from 60 cm up to 1000 m) at 41 sites within the city. We calculated dispersion curves and inferred velocity profiles at all the sites. We combine these results with gravity measurements as well as geological information to obtain the initial velocity model of the basin. Ackowledgments This research is funded by SATREPS (a joint program of JICA and JST).

  2. Norma categorial para el español de Bogotá, Colombia Category norm for the Spanish spoken in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Albeiro Migue Ángel Ramírez Sarmiento

    2010-07-01

    Full Text Available En este trabajo presentamos los resultados de un estudio elaborado en Bogotá con 210 estudiantes universitarios de 5 instituciones con diferentes características sociodemográficas, con el fin de establecer las normas categoriales léxicas. Se utilizaron las 56 categorías léxico-semánticas usadas en el clásico estudio de Battig y Motague (1969 y se recogieron más de 7800 palabras que fueron organizadas por rango y moda. En la revisión bibliográfica realizada no se encontraron trabajos de esta naturaleza para el español colombiano (o latinoamericano, y se espera que sus resultados sean usados en protocolos para el campo de la terapia del lenguaje y los estudios psicolingüísticos. Los datos recogidos fueron comparados con uno de los estudios de norma categorial realizados para el español ibérico.In this article, we present the results of a study carried out in Bogotá, Colombia with 210 university students from five different universities pertaining to diverse socio-demographic groups. The objective of the study was to establish the lexical category norms. 56 lexical-semantic categories used by Battig and Montague (1969 in their classic study were employed. More than 7800 words were collected and organized by range and mode. There are no other studies on this subject for Colombian or Latin American Spanish. We hope that the results presented here will be used both in psycholinguistic and language therapy studies. The collected data were compared to one of the category norm studies made for European Spanish.

  3. The biodiversity from Bogota

    International Nuclear Information System (INIS)

    Calvachi Zambrano, Byron

    2002-01-01

    It is about the flora biodiversity and fauna that it occupied the savannah of Bogota originally, about the flora and extinct fauna and of the flora and fauna that still persist in spite of the colonization

  4. Chemical composition and source apportionment of PM10 at an urban background site in a high-altitude Latin American megacity (Bogota, Colombia).

    Science.gov (United States)

    Ramírez, Omar; Sánchez de la Campa, A M; Amato, Fulvio; Catacolí, Ruth A; Rojas, Néstor Y; de la Rosa, Jesús

    2018-02-01

    Bogota registers frequent episodes of poor air quality from high PM 10 concentrations. It is one of the main Latin American megacities, located at 2600 m in the tropical Andes, but there is insufficient data on PM 10 source contribution. A characterization of the chemical composition and the source apportionment of PM 10 at an urban background site in Bogota was carried out in this study. Daily samples were collected from June 2015 to May 2016 (a total of 311 samples). Organic carbon (OC), elemental carbon (EC), water soluble compounds (SO 4 2- , Cl - , NO 3 - , NH 4 + ), major elements (Al, Fe, Mg, Ca, Na, K, P) and trace metals (V, Cd, Pb, Sr, Ba, among others) were analyzed. The results were interpreted in terms of their variability during the rainy season (RS) and the dry season (DS). The data obtained revealed that the carbonaceous fraction (∼51%) and mineral dust (23%) were the main PM 10 components, followed by others (15%), Secondary Inorganic Compounds (SIC) (11%) and sea salt (0.4%). The average concentrations of soil, SIC and OC were higher during RS than DS. However, peak values were observed during the DS due to photochemical activity and forest fires. Although trace metals represented <1% of PM 10 , high concentrations of toxic elements such as Pb and Sb on RS, and Cu on DS, were obtained. By using a PMF model, six factors were identified (∼96% PM 10 ) including fugitive dust, road dust, metal processing, secondary PM, vehicles exhaust and industrial emissions. Traffic (exhaust emissions + road dust) was the major PM 10 source, accounting for ∼50% of the PM 10 . The results provided novel data about PM 10 chemical composition, its sources and its seasonal variability during the year, which can help the local government to define control strategies for the main emission sources during the most critical periods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. A new case of alert about a possible menace to native fauna of amphibians in Colombia: first report of the bull frog (Lithobates catesbeianus) in the savanna of Bogota

    International Nuclear Information System (INIS)

    Mueses Cisneros, Jhon Jairo; Ballen, Gustavo

    2007-01-01

    Two specimens of bullfrog (Lithobates catesbeianus) in two different localities of Bogota are reported. Knowing the devastating effect that this species produces to the native populations of amphibians where it is introduced, we warn of the possible danger that the species of amphibians of the sabana of Bogota can suffer if no controls on the management and trade of this species are done

  6. Determination of Magnitude and Location of Earthquakes With Only Five Seconds of a Three Component Broadband Sensor Signal Located Near Bogota, Colombia Using Support Vector Machines

    Science.gov (United States)

    Ochoa Gutierrez, L. H.; Vargas Jiménez, C. A.; Niño Vasquez, L. F., Sr.

    2017-12-01

    Early warning generation for earthquakes that occur near the city of Bogotá-Colombia is extremely important. Using the information of a broadband and three component station, property of the Servicio Geológico Colombiano (SGC), called El Rosal, which is located very near the city, we developed a model based on support vector machines techniques (SVM), with a standardized polynomial kernel, using as descriptors or input data, seismic signal features, complemented by the hipocentral parameters calculated for each one of the reported events. The model was trained and evaluated by cross correlation and was used to predict, with only five seconds of signal, the magnitude and location of a seismic event. With the proposed model we calculated local magnitude with an accuracy of 0.19 units of magnitude, epicentral distance with an accuracy of about 11 k, depth with a precision of approximately 40 km and the azimuth of arrival with a precision of 45°. This research made a significant contribution for early warning generation for the country, in particular for the city of Bogotá. These models will be implemented in the future in the "Red Sismológica de la Sabana de Bogotá y sus Alrededores (RSSB)" which belongs to the Universidad Nacional de Colombia.

  7. Triceps and Subscapular Skinfold Thickness Percentiles and Cut-Offs for Overweight and Obesity in a Population-Based Sample of Schoolchildren and Adolescents in Bogota, Colombia

    Science.gov (United States)

    Ramírez-Vélez, Robinson; López-Cifuentes, Mario Ferney; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; González-Jiménez, Emilio; Córdoba-Rodríguez, Diana Paola; Vivas, Andrés; Triana-Reina, Hector Reynaldo; Schmidt-RioValle, Jacqueline

    2016-01-01

    The assessment of skinfold thickness is an objective measure of adiposity. The aims of this study were to establish Colombian smoothed centile charts and LMS L (Box–Cox transformation), M (median), and S (coefficient of variation) tables for triceps, subscapular, and triceps + subscapular skinfolds; appropriate cut-offs were selected using receiver operating characteristic (ROC) analysis based on a population-based sample of children and adolescents in Bogotá, Colombia. A cross-sectional study was conducted in 9618 children and adolescents (55.7% girls; age range of 9–17.9 years). Triceps and subscapular skinfold measurements were obtained using standardized methods. We calculated the triceps + subscapular skinfold (T + SS) sum. Smoothed percentile curves for triceps and subscapular skinfold thickness were derived using the LMS method. ROC curve analyses were used to evaluate the optimal cut-off point of skinfold thickness for overweight and obesity, based on the International Obesity Task Force definitions. Subscapular and triceps skinfolds and T + SS were significantly higher in girls than in boys (p < 0.001). The ROC analysis showed that subscapular and triceps skinfolds and T + SS have a high discriminatory power in the identification of overweight and obesity in the sample population in this study. Our results provide sex- and age-specific normative reference standards for skinfold thickness values from a population from Bogotá, Colombia. PMID:27669294

  8. Triceps and Subscapular Skinfold Thickness Percentiles and Cut-Offs for Overweight and Obesity in a Population-Based Sample of Schoolchildren and Adolescents in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Robinson Ramírez-Vélez

    2016-09-01

    Full Text Available The assessment of skinfold thickness is an objective measure of adiposity. The aims of this study were to establish Colombian smoothed centile charts and LMS L (Box–Cox transformation, M (median, and S (coefficient of variation tables for triceps, subscapular, and triceps + subscapular skinfolds; appropriate cut-offs were selected using receiver operating characteristic (ROC analysis based on a population-based sample of children and adolescents in Bogotá, Colombia. A cross-sectional study was conducted in 9618 children and adolescents (55.7% girls; age range of 9–17.9 years. Triceps and subscapular skinfold measurements were obtained using standardized methods. We calculated the triceps + subscapular skinfold (T + SS sum. Smoothed percentile curves for triceps and subscapular skinfold thickness were derived using the LMS method. ROC curve analyses were used to evaluate the optimal cut-off point of skinfold thickness for overweight and obesity, based on the International Obesity Task Force definitions. Subscapular and triceps skinfolds and T + SS were significantly higher in girls than in boys (p < 0.001. The ROC analysis showed that subscapular and triceps skinfolds and T + SS have a high discriminatory power in the identification of overweight and obesity in the sample population in this study. Our results provide sex- and age-specific normative reference standards for skinfold thickness values from a population from Bogotá, Colombia.

  9. Bogota - Urban Expansion Social Segregation and Land Degradation

    Science.gov (United States)

    Czerny, Mirosława; Czerny, Andrzej

    2016-01-01

    Colombia's capital city Bogota was founded in 1538 by Gonzalo Jiménez de Quesada, a Spanish Conquistador who came down from the north to reach the Sabana de Bogotá, i.e. the intermountain plateau (and "Savannah") around Bogota. The whole region was already well-developed by then, and inhabited by the Muisca people. Their settlements were dispersed across the plateau, though only rarely did these encompass flat areas suitable for crop-growing. Today's Bogota is the largest metropolitan area in the country, with more than 8 million residents currently, and occupying a considerable part of the extensive high plateau. Processes which have resulted in Bogota's present spatial form and its - in some ways - unique functional and spatial structure, are manifold, and highly complex. They include environmental, political, social and economic factors. Nevertheless, among all of these cause-and-effect processes, institutionalized segregation (called estratificación in Colombia) is the reason why rigid spatial structures are maintained, while the spontaneous and uncontrolled movement of groups of people within the city and from one social class to another is restricted.

  10. Large cell lymphoma in children and adolescents of the Instituto Nacional de Cancerologia E.S.E. (Bogota, Colombia): 1980-2001

    International Nuclear Information System (INIS)

    De los Reyes I; Martinez, T; Vizcaino M; Moreno C

    2005-01-01

    Objective: to characterize and establish the survival of pediatric patients with lymphoma treated at the National Cancer Institute of Colombia, the period 1980-2001. Methods: clinical records of nineteen patients were reviewed, diagnosis was confirmed by morphology, and immune-phenotype was established with CD20, CD30, CD43, CD45RB, CD45RO, CD68, CD3, ALK, tdt and S-100 antibodies. Associations were established by using Fisher's exact test, Kaplan-Meier's method for survival, and the log rank test to compare survival trends. Results: ten patients were girls; the age median was eleven years, with a range between three and sixteen years. Seven cases presented lymphoma at the neck, which was the most frequent localization, nine patients were at stage l; the most frequent immune-phenotype was that of T cells, with eleven cases. Thirteen patients presented complete remission. After two years, event-free survival was 47.3%, disease-free survival was 99.8%, and global survival 68%. After five years, event-free survival was 28,8%. Conclusion: a bigger number of patients must be studied in order to establish more precise estimations concerning clinical features and survival

  11. The marshes in Bogota

    International Nuclear Information System (INIS)

    Garcia Romero, Juan F; Moreno Gutierrez, Vanesa; Villalba Malaver, Juan Carlos

    1998-01-01

    A description is made, a diagnosis and some exits, to their preservation for each one of the 10 marshes that they still exist in Bogota. The marshes defines them the convention of Ramsar: As extensions of swamps, swamps or peat-bogs covered with water, be these of natural or artificial, permanent or temporary, stagnated regime or currents, sweet, salubrious or salted, included those of extensions of marine water whose depth in tide lowers don't exceed six meters. The marshes occupy the space that there are between the humid means and the dry means, and that they possess characteristic of both, for what they cannot be classified categorically as aquatic neither terrestrial. The characteristic of a marsh is the presence of water during sufficiently lingering periods as to alter the soils, their microorganisms and the flora and fauna communities

  12. Ácidos grasos, vitamina e y rotulado nutricional de margarinas y esparcibles comercializados en Bogotá, Colombia Fatty acids, vitamin E and nutritional labeling of margarines and spreads commercialized in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Lorena A Bolívar C

    2010-06-01

    Full Text Available INTRODUCCIÓN: en Colombia es escasa la información sobre el contenido de ácidos grasos y vitaminas en margarinas y esparcibles comercializados en el ámbito local. OBJETIVO: analizar el perfil de ácidos grasos y de vitamina E de las margarinas y esparcibles más comercializados en Bogotá, Colombia, y su situación actual de rotulado nutricional según la Resolución 0288 de 2008. MATERIALES Y MÉTODOS: en 2008 se realizó un conteo de caras de las margarinas y esparcibles más comercializados en supermercados de cadena de cinco localidades de Bogotá que incluyeron diferentes estratos socioeconómicos, y se escogieron las primeras diecisiete marcas comerciales y tres marcas propias para el estudio. De cada producto se tomaron y analizaron cinco repeticiones, una por localidad, entre agosto y noviembre de 2008. RESULTADOS: los ácidos grasos mayoritarios son palmítico, oleico y linoleico, y cuatro productos son fuente de ácidos grasos trans (4,4 g y 6,9 g/100 g. El contenido de vitamina E varía de 2,3 mg a 39,9 mg/100 g de producto. De 74,3% a 96,2% de los nutrientes de declaración obligatoria son efectivamente declarados en la etiqueta de los productos analizados. RESULTADOS: 91% de las margarinas y esparcibles más comercializados en cinco localidades de Bogotá en agosto de 2008 es libre de ácidos grasos trans (INTRODUCTION: information on the content of fatty acids and vitamins in margarines and spreads locally commercialized in Colombia is scarse. OBJECTIVE: analyze the fatty acids and vitamin E profile in margarines and spreads most commercialized in Bogotá, Colombia and its current nutritional labeling under Resolution 0288 of 2008. MATERIALS AND METHODS: a counting of labels of margarines and spreads most commercialized in chain supermarkets of five localities in Bogotá that included different socio-economical strata, was made. The first seventeen trademarks and three study brand marks were chosen for the study. Five samples

  13. MODELACIÓN HIDROLÓGICA DEL HUMEDAL DE JABOQUE – BOGOTÁ, D.C. (COLOMBIA

    Directory of Open Access Journals (Sweden)

    Beltrán Julio

    2013-07-01

    Full Text Available Se propone un modelo de simulación dinámico para explicar los procesos hidrológicosdel humedal Jaboque – Bogotá D.C., Colombia, en tres secciones con característicasfísicas y químicas particulares. El modelo incluye los caudales de entrada y salidade agua para cada una de las secciones del humedal. La modelación dinámica sebasó en ecuaciones diferenciales. Se utilizó el método Euler de integración con elprograma computacional Stella 9.1®. El comportamiento hidrológico del humedaltiene una alta dependencia de los aportes de la cuenca aferente que a su vez obedecenfundamentalmente a las condiciones climáticas de la cuenca. En el año 1992 (añoNiño la precipitación fue 432.7 mm/año con una descarga de agua estimada de lacuenca aferente de 905 225 m3/año, siendo el valor más bajo en los últimos 39 años.En el 2010 (año Niña la precipitación anual fue de 1251.3. mm, con una descargade la cuenca aferente de 2 471 634 m3/año, que corresponde al dato más alto para elmismo periodo. La comparación entre los caudales de entrada y salida del humedalJaboque muestran una diferencia bruta de 82 165 m3/mes para un total anual de 985980 m3/año. El tiempo hidráulico de retención modelado (THR se estimó en quincepara la primera sección, 36 y 42 días para la segunda y tercera sección. El promedioen el humedal fue de 93 días/año. El análisis de sensibilidad mostró que entre loslimites de 800 mm/año y 900 mm/año, valores entre los cuales oscila el promediomultianual de la precipitación, el comportamiento del THR es de 13 a 15 días/año enla primera sección, en la segunda de 32 a 36 días/año y la tercera de 38 a 43 días. Secorrobora así la relación que existe entre la precipitación y los factores morfométricosdel humedal.

  14. Description of the early stages of Eccopsis galapagana Razowski & Landry (Lepidoptera: Tortricidae), a defoliator of Prosopis juliflora (Sw.) DC (Fabaceae) in Colombia

    Science.gov (United States)

    The biology and early stages of Eccopsis galapagana Razowski & Landry are described and illustrated for the first time; details of the adults also are provided. Under outbreak conditions, the species has become a serious pest of algarrobo tree (Prosopis juliflora (Sw.) DC.; Fabaceae) in Colombia. Al...

  15. All projects related to Colombia | Page 3 | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Region: Argentina, Bolivia, Brazil, Colombia, Ecuador, Guatemala, Mexico, Peru, ... Violence in three Latin American cities: A comparative study between Bogota, Lima, ... Topic: Natural disasters, CLIMATOLOGY, Economic and social development, ... SOCIAL STRATIFICATION, CASE STUDIES, RESEARCH NETWORKS, ...

  16. Colombia.

    Science.gov (United States)

    1986-10-01

    This report of background notes for Colombia concentrates on political history, but also summarizes geography, people, economy, defense and foreign relations. Colombia, linking Panama to the northwest tip of South America, has 26.5 million people, growing at 1.3% per year, expected to be the third most populous nationon the continent soon. Infant mortality rate is 65/1000 and life expectancy is 62 years. Literacy is reported at 80% although less than 40% of children complete 2.5 years of school. Geographically, Colombia has flat coastal areas, several mountain ranges, highlands and hot eastern plains. 70% of the population live in cities. There are 2 major political parties, in existence since the early 19th century. Recently there have been violent inter-party differences, punctuated by even more contentious guerrilla attacks. Colombia possesses resources of oil, gas coal, nickel, gold, emeralds, platinum, iron. Agricultural products are dominated by coffee, but also include a wide variety of tropical and temperate grains, fruits, vegetables, dairy and meat products, timber and flowers.

  17. Plant succession patterns on residual open-pit gravel mines deposits Bogota

    OpenAIRE

    Ricardo A. Mora Goyes

    1999-01-01

    Based on both: the study of composition and structure of plant communities and the analysis of the physico-chemical characteristics of mining wastes, the initial patterns of primary succession were determined. These patterns were present in three deposits of waste material abandoned during 18, 36 and 120 months respectively. Sue materials were originated in open-pit gravel mines located to the south of Bogota (Colombia). This study pretends to contribute to the knowledge of the meehanlsms of ...

  18. Bio indication of water quality in the Bogota Sabane using fuzzy logic sagging and aquatic micro invertebrates

    International Nuclear Information System (INIS)

    Gutierrez, Juan David; Riss Wolfgang; Ospina Rodolfo

    2002-01-01

    An application of the Sagging-type fuzzy logic to calculate biological water quality in Bogota, Colombia is presented 28 sites corresponding to 9 watersheds in the Bogota area were used. The organisms selected were: Leptoceridae and Hidrobiosidae as indicators of clean waters, Planariidae and Amphipoda as indicators of polluted waters and Psychodida and Syrphidae as indicators of highly polluted waters Chironomids were also included. In order to prove the degree of reliability of Sugeno-type fuzzy logic, the results obtained were compared with values for the Cfq index, and a highly significant correlation was obtained

  19. Selección de una tecnología de banda ancha para la Universidad Nacional de Colombia — Sede Bogota, usando una técnica de decisión multicriterio

    Directory of Open Access Journals (Sweden)

    Félix Antonio Cortés Aldana

    2007-01-01

    Full Text Available La Universidad Nacional de Colombia Sede Bogotá (U.N. Bogotá ha planteado un proyecto para mejorar sus servicios de acceso a Internet mediante el empleo de una tecnología de banda ancha. En una fase inicial del proyecto se ha tenido que seleccionar la tecnología más adecuada entre las cuatro disponibles en Colombia: LMDS, ADSL, Cable Modem y Fibra óptica. Para adoptar esta decisión se ha aplicado el proceso analítico le- rárquico (AHP. Este método, basado en el análisis de decisiones multicriterio (MCDA, permite establecer los criterios de decisión, ponderarlos y valorar las alternativas en función de las prioridades que el decisor establezca para cada criterio. Como apoyo en todo el proceso de decisión se ha considerado la opinión de diferentes expertos. En la presente comunicación se expone el proceso seguido con el objetivo de mostrar que el empleo de métodos basados en el análisis de decisiones multicriterio (MCDA puede resultar útil a la hora de adoptar decisiones complejas.

  20. Plant succession patterns on residual open-pit gravel mines deposits Bogota

    Directory of Open Access Journals (Sweden)

    Ricardo A. Mora Goyes

    1999-07-01

    Full Text Available Based on both: the study of composition and structure of plant communities and the analysis of the physico-chemical characteristics of mining wastes, the initial patterns of primary succession were determined. These patterns were present in three deposits of waste material abandoned during 18, 36 and 120 months respectively. Sue materials were originated in open-pit gravel mines located to the south of Bogota (Colombia. This study pretends to contribute to the knowledge of the meehanlsms of natural restauration of tropical ecosystems subjected to man-borne degradation.

  1. Influences of the trees plantation in structures of Santa Fe of Bogota

    International Nuclear Information System (INIS)

    Acuna, John Fabio

    1999-01-01

    Through the project - Evaluation of damages caused by forest species planted in Santa Fe of Bogota and of the publication: Lungs for Santa Fe de Bogota; the Agricultural Engineering Department of the National University of Colombia, in collaboration with the Botanical Garden of Bogota Jose Celestino Mutis, offers to the capital a valuable contribution on trees plantation and its influence on the structures. Keeping in mind that trees are vital for any city, because they constitute a relating a fundamental for the appropriate use of the senses because forms behave, scents, colors and natural flavors in a means where the rest of the landscape is artificial. They contribute with the health when purifying the air; with the ecology and environment because they are hosts of many other forms of life, they are source of beauty, recreation and harmony, also giving a stamp of identity to the city; however, their implantation and handle, demands knowledge and cares, to assure a harmonious and lasting integration with the city

  2. History of the Oral and Maxillofacial Surgery Residency Program at Universidad el Bosque, Bogotá, Colombia.

    Science.gov (United States)

    Castro-Núñez, Jaime

    2012-01-01

    The formal training of oral and maxillofacial surgeons in Colombia started in 1958 at Hospital Sanjos6, thanks to the titanic work of Waldemar Wilhelm, a German-born surgeon who settled in BogotA in 1950. Today there are seven institutions in Colombia that offer residency programs in oral and maxillofacial surgery. The aim of this article is to describe the history of the Oral and Maxillofacial Surgery Residency Program at Universidad El Bosque in Bogota.

  3. El papel de los profesionales en centros de atención en drogas en ambulatorios de la ciudad de Bogotá, Colombia Papéis de profissionais, em centros de atenção ambulatorial em drogas, na cidade de Bogotá, Colômbia Roles of professionals in drug outpatient care centers, in the city of Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Luz Patricia Díaz Heredia

    2010-06-01

    ço dentro da equipe de atenção aos usuários de drogas.The aim of this descriptive, cross-sectional study, developed with 93 professionals, was to characterize the roles of the professionals who were working in the drug addiction outpatient centers of the city of Bogota, Colombia. The results showed that psychologists were the predominant professionals (38%, followed by occupational therapists (34%. Nurses corresponded to 8% of the professionals, with their roles predominantly in the aspects of health promotion and self care (100%, in the administrative area (43% and in prevention (57% and very little in rehabilitation and social rehabilitation (14%. The roles of the professionals agreed with the expected activities of the different professions, with the exception of the occupational therapists. It is considered that nurses need to gain more space within the team to focus on drug users.

  4. [Prostitution and poverty in Santafe de Bogota].

    Science.gov (United States)

    Cabrera Fadul, O

    1998-06-01

    The Chamber of Commerce of Bogota conducted a study of prostitution in the city with the participation of prostitutes themselves. In 1990, around 14,000 women were found to be working as prostitutes in the city's center, with 44% concentrated in the barrios of La Alameda, Las Nieves, and San Bernardo. Over 70% of the women were born outside of Bogota. 82% were aged 15-40 years; the age range was 9-60 years. 1200 minors were counted. A 1992 study in the sector of Chapinero revealed 3480 women working as prostitutes. 81% had migrated to the city and 96% were aged 15-40 years. Visible street prostitution was infrequent. A 1993 study of child prostitution in a smaller area than the 1990 center-city study revealed 2959 minors, suggesting that the number had nearly tripled. 60% were natives of the city. A 1994 study of 200 male prostitutes in the center-city found that 24% were natives of Bogota. 32% had left home before the age of 10. 89% had become prostitutes before their 16th birthday. 17% were HIV-seropositive; most of their clients were married men. In all cases, the factors leading to prostitution originated within the family and included physical mistreatment, sexual abuse by parents or stepparents, rejection and abandonment, as well as lack of income, unemployment, and lack of skills. Information on HIV infection was incomplete and ineffective. The number of indigent and homeless persons and that of drug addicts living on the streets of Bogota is not known. A large number of governmental and nongovernmental organizations attempt to provide help, but their efforts are not guided by any coherent plan of action.

  5. The Pact of Bogota: Cases and Practice

    Directory of Open Access Journals (Sweden)

    María Teresa Infante Caffi

    2017-03-01

    Full Text Available The jurisdiction of the International Court of Justice (ICJ under the Pact of Bogota (1948 is part of a system of norms attributing competenceto the referenced tribunal along with other means of settlement. The system sets out principles and general exceptions applicable to all the means of peaceful settlement embodied in the Pact. This study will topic relates to the theory of dispute settlement and treaty interpretation hemispheric politics and diplomacy.

  6. Uribe, M. (2013. La Nación Vetada. Estado, desarrollo y guerra civil en Colombia. Bogotá, D.C: Universidad Externado de Colombia, 343 pp.

    Directory of Open Access Journals (Sweden)

    Juan Carlos Villamizar

    2017-01-01

    Full Text Available El libro plantea una tesis sugestiva que será objeto de discusión en la futura historiografía acerca del proceso político colombiano en la segunda mitad del siglo XX: la explicación de las causas de la persistencia de la guerra civil en Colombia por cerca de sesenta años. Uribe explica cómo la sociedad colombiana ha mantenido una guerra civil prolongada desde 1964, la cual se ha configurado por la coexistencia del veto de las élites a la Nación, un estilo de desarrollo concentrador de la riqueza con sesgo anti-campesino y una adopción irrestricta de las élites a la política norteamericana. Los anteriores elementos se retroalimentan mutuamente generando una ruta, en la cual, la guerra civil es la marca distintiva.

  7. Awake at the wheel : Bogota's response to the transportation challenge

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, O.E.

    2001-03-01

    The domination of private automobiles in cities like Bogota, Colombia, has resulted in vehicle chaos and increasingly high levels of atmospheric pollution that will poison urban populations. Eighty per cent of the people of Bogota ota use public transportation on a daily basis, but private vehicles occupy 95 per cent of the roads. Local authorities have indicated that the solution to the excessive use of the private automobile is to curtail its use. Bogota City Hall is working on developing the Bogota Project, a sustainable system of urban mobility which takes into account both supply and demand factors. The project includes the development of mass and alternative means of transportation such as the TransMilenio high-capacity mass transportation system consisting of articulated buses. By 2015, TransMilenio will have 22 lines and 6000 articulated buses. In addition, a network of cycle paths is being developed to encourage the use of bicycles as a means of transportation. The construction of sidewalks and shaded walks is also advancing throughout the city. Several measures are being implemented in order to stimulate the demand for public transportation and to restrict private car use. These include fees for public parking, increased gasoline taxes, and tolls at the city entrances. The peak and licence plate program is a measure that restricts 40 per cent of vehicles from travelling during peak hours in the entire urban area. Cycleway is a program which leaves the city's highways clear for 7 hours on Sundays for cycling, skating or walking. A referendum was held in October 2000 in which a proposal was put forward to restrict the use of private vehicles during the six hours of major traffic congestion beginning January 1, 2015. The 51 per cent support for the proposal means that no private vehicles, except taxis, will be allowed to circulate during rush hours. Sixty three per cent of the people of Bogota also supported the annual celebration of a car-free day on

  8. Bogota bag in the treatment of abdominal wound dehiscence.

    Science.gov (United States)

    Sukumar, N; Shaharin, S; Razman, J; Jasmi, A Y

    2004-06-01

    A patient who underwent emergency laparotomy for rectal prolapse developed repeated abdominal wound dehiscence and subsequently an enteric fistula. The management of abdominal wound dehiscence is discussed, specifically with regards to the Bogota bag. Use of Bogota bag has been reported worldwide but this may be the first report here.

  9. La salud en Colombia. Marcela Vélez. Bogotá, D.C.: Penguin Random House Grupo Editorial; 2016

    Directory of Open Access Journals (Sweden)

    Omar Segura

    2016-04-01

    Full Text Available Colombia afronta una crisis en su sistema de seguridad social en salud prácticamente desde cuando fue promulgada la Ley 100 el 20 diciembre de 1993. Casi una generación después, Marcela Vélez quiere explicar en 207 páginas la crisis de un modelo de aseguramiento, prestación de servicios y salud pública que ha resultado inadecuado para el desarrollo social y económico del país. La autora también pretende mostrar cómo este conocimiento puede servir para argumentar su rechazo al sistema y proponer cambios, ya que nuevas componendas legales disfrazadas de reforma solo empeorarán las cosas.

  10. The paleobotanical record of Colombia: Implications for biogeography and biodiversity

    NARCIS (Netherlands)

    Hooghiemstra, H.; Wijninga, V.M.; Cleef, A.M.

    2006-01-01

    Plant microfossil and macrofossil associations obtained from six dated sections from the area of the basin of Bogota¿ (2550 m, Eastern Cordillera, Colombia) show the evolution of the late Neogene Andean montane forest, triggered by the Andean orogeny. Progressive adaptation of warm tropical taxa to

  11. Muertes por causas violentas y ciclo económico en Bogotá, Colombia: un estudio de series de tiempo, 1997-2006 Death from violent causes and economic cycles in Bogota, Colombia: a time-series study, 1997-2006

    Directory of Open Access Journals (Sweden)

    José Moreno Montoya

    2009-07-01

    Full Text Available OBJETIVOS: Caracterizar las tendencias temporales del número de muertes por causas violentas en la ciudad de Bogotá entre 1997 y 2006 y analizar su posible asociación con los ciclos económicos de la ciudad. MÉTODOS: Estudio ecológico a partir de las cifras absolutas de muertes violentas registradas entre enero de 1997 y septiembre de 2006 en Santa Fe de Bogotá, Colombia. Se utilizaron modelos ARIMA de series de tiempo trimestrales para caracterizar el comportamiento de las muertes violentas. Como variables explicativas del ciclo económico de la ciudad se utilizaron las series trimestrales del índice de precios al consumidor, la tasa de desempleo y el número total de personas ocupadas; se evaluó su asociación con las series de muertes mediante modelos de función de transferencia. RESULTADOS: Del total de 36575 muertes por causas violentas en Bogotá, 57,7% fueron por homicidios y 23,7% por accidentes de tránsito. Las series de homicidios, suicidios y muertes por accidentes de tránsito mostraron tendencias decrecientes, con un marcado comportamiento estacional en las series de muertes por accidentes de tránsito y suicidios, con picos en los dos últimos trimestres de cada año. Se hallaron asociaciones significativas entre todas las series de muertes por las diferentes causas con al menos una serie económica y en cada caso se identificó el modelo de función de transferencia respectivo. CONCLUSIONES: Los homicidios constituyen la mayor parte de las muertes por causas violentas y revelan la existencia de patrones temporales en este tipo de muertes. Se encontraron asociaciones significativas entre las muertes por causas violentas y algunas variables económicas que describen el ciclo de la actividad en la ciudad. Se confirmó que diferentes circunstancias socioeconómicas que afectan a una sociedad pueden influir en el nivel de violencia.OBJECTIVES: To determine seasonal trends in the number of deaths from violence in Bogot

  12. Correlación de protoporfirina zinc y plomo en sangre en trabajadores de fábricas de baterías, de Bogotá, Colombia Correlation of zinc protoporphyrin with blood lead levels in car battery industry workers in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Omayda Cárdenas-Bustamante

    2001-06-01

    Full Text Available Objetivo. Determinar la utilidad de la protoporfirina zinc en sangre (PPz como indicador de exposición a plomo en trabajadores de fábricas de baterías. Material y métodos. Se hizo un estudio transversal en 116 trabajadores de fábricas de baterías del sector informal en Bogotá, Colombia. La información sobre variables generales, ocupacionales y de salud fue obtenida por medio de una entrevista con los trabajadores. Se establecieron dos categorías para los valores de PPz: aquellos por debajo del valor límite de (70 µg/dl, y aquellos por arriba de este valor. Se empleó análisis de regresión lineal para medir la correlación entre los valores logarítmicos de PPz (>70 µg/dl y plomo en sangre (PbS (>38 µg/dl. Resultados. Se encontró un coeficiente de correlación semilogarítmica r=0.54, además de posibles asociaciones estadísticamente significativas entre los niveles elevados de PPz y el oficio actual de exposición directa (RM:3.35, IC 95% 1.02-11.91; p:0.02, emplear plomo como materia prima (RM:7.80, IC 95% 2.96-21.03; phttp://www.insp.mx/salud/index.htmlObjective. To determine the usefulness of zinc protoporphyrin in blood (PPz as an indicator of lead exposure in workers of the homemade car battery industry. Material and methods. A cross-sectional study was performed in 116 workers of the car battery industry in Bogotá, Colombia. Data on general, occupational, and health variables were collected by interview. Two categories of PPz values were established: Those below the cutoff value (70 µg/dL and those above it. A linear regression analysis was performed to measure the correlation between logarithm values of PPz (>70 µg/dL and lead in blood (PbB (>38 µg/dL. Results. A semi-logarithmic correlation coefficient of r=0.54 was found, and statistically significant associations between high levels of PPz and direct exposure to lead were observed (OR:3.35, 95% IC 1.02-11.91; p:0.02; for workers who often use lead as a raw material

  13. The boundaries of poverty in Bogota

    Directory of Open Access Journals (Sweden)

    Consuelo Uribe Mallarino

    2016-07-01

    Full Text Available The article proposes an analytical perspective on poverty with a multidimensional approach, not only as an aggregate of variables and indicators, but also using a probing strategy that considers the way in which it is perceived between the groups receiving programs to alleviate poverty or use subsidized public services, and those without. Based on tools for quantitative and qualitative analysis applied to data collected on a sample of residents of Bogota, the authors analyze how the boundaries of sense on poverty are related to both objective and subjective factors related to being or not users of these programs, socioeconomic and educational conditions, as well as political participation, degree of association and use of mechanisms to enforce civil rights.

  14. Internal displacement in Colombia: Fifteen distinguishing features.

    Science.gov (United States)

    Shultz, James M; Ceballos, Ángela Milena Gómez; Espinel, Zelde; Oliveros, Sofia Rios; Fonseca, Maria Fernanda; Florez, Luis Jorge Hernandez

    2014-01-01

    This commentary aims to delineate the distinguishing features of conflict-induced internal displacement in the nation of Colombia, South America. Even as Colombia is currently implementing a spectrum of legal, social, economic, and health programs for "victims of armed conflict," with particular focus on internally displaced persons (IDPs), the dynamics of forced migration on a mass scale within this country are little known beyond national borders.   The authors of this commentary are embarking on a global mental health research program in Bogota, Colombia to define best practices for reaching the displaced population and implementing sustainable, evidence-based screening and intervention for common mental disorders. Presenting the defining characteristics of internal displacement in Colombia provides the context for our work and, more importantly, conveys the compelling and complex nature of this humanitarian crisis. We attempt to demonstrate Colombia's unique position within the global patterning of internal displacement.

  15. Caracterización sociodemográfica del cuidador familiar de la persona mayor en una localidad de Bogotá-Colombia / Socio-demographic Characteristics of the Caregiver for Elderly People in a Location in Bogota-Colombia / Caracterização sociodemográfica do cuidador familiar da pessoa idosa numa região da cidade de Bogotá-Colômbia

    Directory of Open Access Journals (Sweden)

    Blanca Nieves Piratoba-Hernández, Enf., Esp., MSc.

    2015-07-01

    caregivers. [Piratoba-Hernández BN, Rozo-Gutiérrez JN. Socio-demographic characteristics of the caregiver for elderly people in a location in Bogota-Colombia. MedUNAB 2015; 18 (1: 51-57]. Introdução: O aumento da população idosa e das doenças crônicas não transmissíveis tem aumentado a procura de cuidados permanentes realizados por mulheres. O reconhecimento das características sociodemográficas permite identificar a situação vivida pelas cuidadoras. Objetivo: Caracterizar os familiares cuidadores das pessoas idosas em situação de dependência, para ajudar a desenvolver programas adaptáveis às necessidades das pessoas cuidadoras. Metodologia: Elaboração de um projeto quantitativo, descritivo e transversal de agosto de 2010 a março de 2011. A informação foi adquirida através de entrevistas domiciliares e das respostas ao questionário de caracterização sociodemográfica. A amostra intencional foi de 91 cuidadores. Para a análise estatística utilizou-se o programa SPSS em sua versão 15. Resultados: Foi evidente a faixa etária das pessoas familiares cuidadoras entre os 36 e 59 anos (53%; na sua maioria são mulheres (81%, com níveis de escolaridade fundamental ou ensino médio incompleto (45%, casados (36%, com total dedicação ao lar (53%, afiliadas ao seguro social subsidiado ou do Estado (87%. O trabalho de familiares cuidadores tem sido exercido por mais de 37 meses (87%; com uma dedicação diária de 24 horas (54% e a maioria é cuidado pelo filho (a. Estes cuidadores não têm os conhecimentos suficientes para lidar com situações negativas decorrentes da assistência às pessoas idosas. Conclusões: Características como idade, nível de escolaridade, tempo dedicado ao cuidado, rede de apoio, ocupação e status socioeconômico fazem urgente a procura de alternativas para os cuidadores que não têm os recursos para obter níveis ótimos de informação; estes resultados permitem que diferentes setores possam implementar ações e criar

  16. Terrorism in Colombia.

    Science.gov (United States)

    Paredes Zapata, Gabriel Darío

    2003-01-01

    Colombia is a poor country that has been plagued by ongoing violence for more than 120 years. During the 1940s, subversive terrorist groups emerged in rural areas of the country when criminal groups came under the influence of Communism, and were later transformed into contemporary groups, such as the Ejercito de Liberacion Nacional (ELN) or National Liberation Army and Fuerzas Armadas Revolucionares de Colombia (FARC) or Revolutionary Armed Forces of Colombia). Paramilitary terrorist groups emerged in response to subversive groups and were later transformed into contemporary groups, such as the Autodefensas Unidas de Colombia (AUC) or United Self-Defense Forces of Colombia. Terrorism has placed an enormous burden on modern Colombia. From 1995 to 2002, 9,435 people were killed by terrorism-related events, of which 5,864 were killed by subversive terrorist activities and 3,571 were killed by paramilitary terrorist activities. In 2002, at least nineteen attacks produced 10 or more casualties, of which 18 were bombings. In 2002, terrorists killed at least 12 mayors, 71 legislators, and internally displaced 300,000 persons from their homes. Since terrorist groups in Colombia are typically supported by drug manufacturing and trafficking, it has been difficult at times to distinguish violence due to terrorism from violence due to illicit drug trafficking. Terrorism has also had a major adverse effect on the economy, with restricted travel, loss of economic resources, and lack of economic investment. In addition to political, military, and commercial targets, terrorists have specifically targeted healthcare infrastructure and personnel. At the national and local levels, much emergency planning and preparedness has taken place for terrorism-related events. The Centro Regulador de Urgencias (CRU) or Emergency Regulation Center in Bogota plays a major role in coordinating local prehospital and hospital emergency response in the capital city and the national level where

  17. MODELACIÓN DEL ESTADO TRÓFICO DEL HUMEDAL DE JABOQUE, BOGOTÁ D.C., COLOMBIA

    Directory of Open Access Journals (Sweden)

    Julio Eduardo Beltrán Vargas

    2013-01-01

    Full Text Available Se construyó un modelo de simulación dinámica con la intención de explicar el comportamiento del fósforo total en el agua y su relación con el estado trófico del humedal de Jaboque, Bogotá D. C., Colombia. En el modelo se incluyen los flujos de entrada y salida del agua y los aportes de fósforo total en cada una de las tres secciones de la cubeta con características morfométricas y condiciones físicas y químicas del agua muy diferentes. La modelación dinámica se basó en ecuaciones diferenciales y para ella se utilizó el programa computacional Stella 9.1® . En los meses con mayores caudales (época de lluvias, la carga de fósforo disminuye en las tres secciones del humedal, mientras que en los meses con menores caudales (época de sequía, la misma se incrementa. En la sección uno (tercio alto el valor del índice de estado trófico fue de 45,09 mg/m3  y el tiempo de retención hidráulica de 14 días/año. En la segunda sección (tercio medio el valor del mencionado índice fue de 35,89 mg/m3  y el THR fue de 34 días/año. Finalmente, en la tercera sección (tercio bajo los valores fueron 19,5 mg/m3  y 40 días/año respectivamente. Estos valores indican que la primera y segunda sección se encuentran en condiciones de eutrofía y la tercera de mesotrofía. El análisis de sensibilidad permitió estimar que con una carga de 0,62 mg/m3  de fósforo total se podrían mantener las condiciones de mesotrofía en la tercera sección y que para las dos primeras secciones se debería reducir la carga hasta 0,2 mg/m3, para alcanzar un estado de mesotrofía.

  18. Lightning magnetic field measuring system in Bogota

    OpenAIRE

    Escobar Alvarado, Oscar Fernardo

    2013-01-01

    This thesis presents the configuration and performance of a lightning radiated electromagnetic field measuring system in Bogotá Colombia. The system is composed by both magnetic and electric field measuring systems working as separated sensors. The aim of the thesis is the design and construction of a Magnetic Field Measuring System and the implementation of a whole lightning measuring system in Bogotá. The theoretical background, design process, construction and implementation of the system ...

  19. Guerrilla Violence in Colombia: Examining Causes and Consequences

    Science.gov (United States)

    1994-06-01

    Ecuador’s Alfaro 27 Walker, Phyllis, "National Security", in Colombia a Country Study, Washington, 1990, p. 300. 28 Registraduria Nacional del Estado Civil...necessary to profoundly transform institutions. On several occasions, the old political 114 Informe Financiero Contraloria General de la Rep~blica, June...Societies, Princeton Press, 1988. Informe Financiero Contraloria General de la Repzblica, Bogota, 1988. Kalmanovitz, Salomon, Economia del

  20. Evaluation of the ''Sabana de Bogota'' aquifer using isotopes techniques

    International Nuclear Information System (INIS)

    Torres, E.; Jimenez, G.; Obando, E.; Sanchez, L.; Alayon, E.

    1987-01-01

    Groundwater from the Sabana de Bogota area was studied by means of isotopic techniques such as isotope analysis, injection of tracers for determination of hydrogeological parameters, velocity measurements using tracers. These results combined with the ones obtained by conventional techniques were used to determine recharge area, origin, equipotencial lines and direction of groundwater. The results show that a combined application of classical and nuclear methods may establish rather reasonable hydrogeological concepts without investing much time and money

  1. Assessment of environmental projects in official schools in the locality 18 in Bogota

    International Nuclear Information System (INIS)

    Herrera R, Juan Francisco; Reyes S, Lucia; Amaya, Hector Oswaldo T .Gerena Oscar Arturo

    2006-01-01

    It was investigated the current state of de School Environment Projects in the public educational institutions of de Town 18 Rafael Uribe Uribe in Bogota (Colombia). The participation grade was measured in the design o execution and evaluation of the environmental projects, the registration and systematising of experiences, the generation of reflection spaces and the structuring to the Institutional Educational Project. By means of the test pilot the variables were determined for the sample design and the validation of the mensuration instrument. Three populations study object were determined and for each was designed a for through which the information of the variable was gathered by means of the method of direct interview. The results show that the overwhelming majority of the considered population didn't participated in the design in the execution of the environmental projects. The registration and systematizing of experiences are minimum, as well as the reflection spaces and conceptualization. There is not articulation from the environmental project to the Institutional Educational Project. The little participation, systematizing of experiences and lack of reflection spaces and conceptualization limit the impact of the School Environmental Projects in the formation of favorable attitudes to the environment

  2. Nuclear Medicine week in Colombia

    International Nuclear Information System (INIS)

    Padhy, A.K.

    2003-01-01

    During the week of 6-12 October 2003 the IAEA organized a Research Coordination Meeting on 'Relationship between lower Respiratory Tract Infection, Gastroesophageal reflux and bronchial Asthma in children' at Hospital San Ignacio in Bogota. Besides there were four workshops in Bogota; workshops on Bone infection and Bone scan in Pediatric ortopaedics at Hospital Militar and Fundacion CardioInfantil, a workshop for Nuclear Medicine Technologists and a workshop on Sentinel Lymph Node mapping and Surgical Gamma Probe Application at Institute of Oncology. A nuclear cardiology workshop was organized in Medellin, and finally crowning them all was the 9th Congress of the Colombian Association of Nuclear Medicine at Cali from 10-12 October, 2003; probably the largest and best Colombian nuclear medicine congress every held in the country. A workshop was also organized in Cali for nuclear medicine technologists in conjunction with the Annual Convention. It was a mix of IAEA's Technical Cooperation and Regular Budget activities along with the activities of Colombian Association of Nuclear Medicine, bringing in absolute synergy to galvanize the entire nuclear medicine community of the country. The week saw nuclear medicine scientists from more than 20 IAEA Member States converging on Colombia to spread the message of nuclear medicine, share knowledge and to foster International understanding and friendship among the nuclear medicine people of the world

  3. 75 FR 54696 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2010-09-08

    ...., Bogota, Colombia; c/o DIRECCION COMERCIAL Y MARKETING CONSULTORIA EMPRESA UNIPERSONAL, Bogota, Colombia... COLOMBIA LTDA., Bogota, Colombia; c/o ASOCIACION TURISTICA INTERNACIONAL S.C.S., Bogota, Colombia; c/o...

  4. History of medical micology in Colombia, 1930-1970 = Historia de la micología médica en Colombia, 1930-1970

    OpenAIRE

    Galvis Pérez, Yeisson; Cano Restrepo, Luz Elena; Vásquez Valencia, María Fernanda

    2013-01-01

    The overall objective of this research was to understand the events that made possible the creation, diffusion and appropriation of medical mycology in Colombia between 1930 and 1970. It was based on the review of scientific journals and theses in different libraries, archives and documentation centers in Medellin and Bogota. The report includes the different problems faced by physicians and laboratory personnel concerning the classification of fungi, the relationship between dermatology and ...

  5. Advanced DC/DC converters

    CERN Document Server

    Luo, Fang Lin

    2003-01-01

    DC/DC conversion techniques have undergone rapid development in recent decades. With the pioneering work of these authors, DC/DC converters have now moved into their sixth generation. This book offers a concise, practical presentation of DC/DC converters, summarizing the spectrum of conversion tecnologies and presentingmany new ideas and more than 100 new topologies. Nowhere else in the literature are DC/DC converters so logically sorted and systematically introduced, and nowhere else can readers find detailed information on prototype topologies that represent a major contribution to modern power engineering. More than 320 figures, 60 tables, and 500 formulae facilitate understand and provide precise data.

  6. 77 FR 14593 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2012-03-12

    ..., Orlando, c/o ALFA PHARMA S.A., Bogota, Colombia; c/o LABORATORIOS GENERICOS VETERINARIOS, Bogota, Colombia; c/ o LABORATORIOS KRESSFOR, Bogota, Colombia; c/o PENTA PHARMA DE COLOMBIA S.A., Bogota, Colombia.../o DISTRIBUIDORA DE DROGAS CONDOR LTDA., Bogota, Colombia; c/o ALFA PHARMA S.A., Bogota, Colombia; c...

  7. ?Strange Attractors (chaos) in the hydro-climatology of Colombia?

    International Nuclear Information System (INIS)

    Poveda Jaramillo, German

    1997-01-01

    Inter annual hydro-climatology of Colombia is strongly influenced by extreme phases of ENSO, a phenomenon exhibiting many features of chaotic non-linear system. The possible chaotic nature of Colombian hydrology is examined by using time series of monthly precipitation at Bogota (1866-1992) and Medellin (1908-1995), and average stream flows of the Magdalena River at Puerto Berrio. The power spectrum, the Haussdorf-Besikovich (fractal) dimension, the correlation dimension, and the largest Lyapunov exponent are estimated for the time series. Ideas of hydrologic forecasting and predictability are discussed in the context of nonlinear dynamical systems exhibit chaotic behavior

  8. Analysis of the existing correlations of effective friction angle for eastern piedmont soils of Bogota from in situ tests

    Directory of Open Access Journals (Sweden)

    July E. Carmona-Álvarez

    2015-07-01

    Full Text Available To estimate the effective friction angle of soil from in situ test is a complicated job, due to high rates of strain existing in this kind of tests, which tend to be too invasive and disturb the vicinities of test depth, even the sample that eventually is taken at the site. Likewise, the most of the correlations found in the current bibliography to obtain the effective friction angle using field tests, have been developed for soils from different regions. For that reason when are implemented on tropical soils present high scatter, to compare the field parameter values with real results obtained at the lab. This research aims to use in situ tests define through of analysis of different correlations, which fits adequately to the specific conditions of the piedmont soils of Bogota. For the present study will be utilized data from SPT (widely used in Colombia and SPT-T (never before conducted in the country, carried out considering the appropriated norms to each test, taking in account to SPT-T, doesn’t exist local standard governing such tests. The correlations for field procedures of the tests implemented were for effective confining and energy transference of the SPT hammer, since the state-of-the-art mentions it as the most affect the reliability of the final results. The final results show the tendency of the methodologies used to obtain the correlation, in relation with the real value of effective friction angle from of lab tests.

  9. Mumps in a district primary school at the locality of Santa Fe, Bogota (Colombia 2010.

    Directory of Open Access Journals (Sweden)

    Oneida Castañeda

    2010-12-01

    Full Text Available Background. Epidemic parotitis (“mumps” is a human viral infection which affects mainly the salivary glands; its peak incidence afflicts children 5 to 9-year. At epidemiologic week (EW 40/2010, the Centro Oriente II Level Hospital received a community report about a mumps outbreak in a District Primary School (DPS, eastwards of the locality of Santa Fe (Bogotá. The hospital’s epidemiology office sent a response team to investigate the situation and to guide prevention & control actions. Methods. The team made an outbreak descriptive study; field investigation included description time-place-person; case-definition as patient with active clinical condition of parotitis; Active Institutional Search (AIS and house visitations; study variables matched those of the official individual notification report. Data were registered and analyzed using Epi -Info 3.5.1® with frequency, central trend and association measurements. Results. 14 mumps cases were identified: 1 adult and 13(93% children; 5(35,7% were girls; median age was 11,9 year (range 7-40. Four cases (28,6% were confirmed by clinical signs, 10(71,4% by epidemiologic link; no one was hospitalized. 12 patients (86% had unknown vaccination status; 11 cases (78% produced neither the vaccination card nor any additional information. Index case occurred at EW30/2010 and the epidemic peak occurred at EW34/2010; attack rate was 8.1%. Conclusions. Epidemiology office confirmed mumps outbreak, delayed notification and impossibility to verify vaccination records. The response team recommended the DPS to strengthen biosafety measures; and advised local health institution to increase epidemiologic surveillance & control activities, adherence to national mumps protocol, school vaccination and to promote information, communication, education strategies on importance of vaccination and cards right use.

  10. Citibikes de Colombia. La bicicleta publica: sistema alternativo de transporte para Santafe de Bogota

    Directory of Open Access Journals (Sweden)

    Javier Enrique Ramos

    2000-12-01

    Full Text Available EI objetivo del presente artículo es presentar una nueva propuesta en materia de transporte urbano, teniendo en cuenta el cada vez más restringido uso del automóvil particular y la ineficiencia de los actuales médicos de transporte público. En la primera parte del trabajo se presenta un panorama general de la importancia de los sistemas de transporte en las ciudades y cómo afectan la vida de sus habitantes. También se muestra la situación actual del transite en Bogotá y la necesidad de implantar sistemas alternativos de transporte. En la segunda parte, se propone el diseño de un sistema en línea de alquiler de bicicletas denominado Bicicleta Publica, que sea parte integral del Sistema integrado de transporte para Santafé de Bogotá. Para cumplir con este propósito se presentan los lineamientos generales mediante un plan de negocios, que conduzca a la creación de una empresa que administre el sistema y los servicios conexos. EI plan de negocios pretende cubrir la mayor parte de la ciudad, ubicando estaciones de bicicleta publica en diferentes lugares, principalmente en las áreas de influencia de las universidades, parques, centros comerciales y, en un futuro, en las estaciones de Transmilenio y el Metro. Esto le brinda al usuario la posibilidad de tomar una bicicleta en un punto determinado y retornarla en otra estación diferente a donde la alquiló inicialmente. Las ventajas de este mecanismo son apreciables, ya que no representa complicación alguna para el usuario debido a que puede usar la bicicleta el tiempo deseado sin preocuparse por aspectos tales como el estacionamiento, el clima o las diferentes actividades, para lo cual la bicicleta propia sería un completo inconveniente.

  11. Colombia: Emerging Labor Movement and the State Colombian Drug Problem: Effect on the Peace Process between the M19 and the State

    Science.gov (United States)

    1990-05-01

    de la Energia en Colombia. 1537-1930 (Bogota,1985), 1. 39 Steam navigation in the inland rivers, Magdalena and Cauca Rivers, used wood as a fuel to...Cartagena, 325. 72 Table 5. Cartagena-Oil Refining Co. 1912 Prod Rates (Monthly) ° Product Octane Amount Gasoline 72 Kerosene "Luz Solar " 110 Kerosene "Luz...1987. De La Pedraja, Ren6. Energy Politics in Colombia, San Francisco : Westview Press, 1989. De La Pedraja, Ren6. Historia de la Energia en Colombia

  12. Factores de riesgo para el desarrollo de infección de vías urinarias por microorganismos productores de betalactamasas de espectro extendido adquiridos en la comunidad, en dos hospitales de Bogotá D.C., Colombia

    Directory of Open Access Journals (Sweden)

    Mariana Pineda-Posada

    Full Text Available Abstract Objetivo: Determinar factores de riesgo para infección urinaria por microorganismos productores de betalactamasas de espectro extendido (BLEE adquirida en la comunidad en pacientes adultos. Material y método: Estudio de casos y controles, en el período comprendido entre enero de 2012 a mayo de 2015, en dos hospitales de Bogotá D.C., Colombia. Pareo por edad, año del aislamiento, microorganismo y género. Se excluyeron pacientes con antecedente de infección por un microorganismo productor de BLEE en el último mes e infección urinaria asociada al cuidado de la salud. Resultados: Se analizaron 555 pacientes: 185 casos y 370 controles. 462 pacientes (83,2% de la Fundación Clínica Shaio y 93 (16,8% del Hospital Santa Clara. Factores de riesgo identificados: Infección urinaria recurrente (OR 2,13 con IC de 1,48 a 3,07, enfermedad renal crónica (OR 1,56, IC del 95% de 1,07 a 2,27, uso previo de antibióticos (OR 3,46, IC del 95% de 2,48 a 5,35, hospitalización reciente (OR 3,0, IC del 95% de 1,96 a 2,45, diabetes mellitus (OR 1,61 con IC del 95% de 1,06 a 2,45 e infección urinaria alta (OR 2,64 con IC del 95% de 1,61 a 4,32. Conclusiones: Los factores de riesgo para microorganismos productores de BLEE adquiridos en la comunidad fueron en orden de frecuencia: antecedente de antibioticoterapia reciente, hospitalización previa, presencia de infección urinaria alta, así como los antecedentes de infección urinaria recurrente, enfermedad renal crónica y diabetes mellitus, lo que concuerda con los principales hallazgos descritos en la literatura mundial.

  13. Male-only clinics: a success story in Colombia.

    Science.gov (United States)

    Goldman, R

    1987-04-01

    2 male-only reproductive health clinics in Colombia are refuting the stereotype that Latin American men reject vasectomy as a threat to their machismo image and consider birth control to be a woman's responsibility. Over 1000 vasectomies were performed in the 2 clinics in Bogota and Medellin in 1986. The clinics are operated by PROFAMILIA and supported by the Association for Voluntary Surgical Contraception. Information about these male-only clinics is dispersed through radio announcements, magazine advertisements, and newspaper articles. The cost of services at these clinics is 50% less than services provided at other family facilities. These clinics demonstrate that Colombian men are willing to share family planning responsibilities if services are offered in a manner respectful of their needs. 3 additional male-only clinics are scheduled to open in Colombia in 1987.

  14. Colombia: A Country Under Constant Threat of Disasters

    Science.gov (United States)

    2014-05-22

    Hydrological Map Source: El Clima Colombiano, “El Clima Colombiano, Ciclo Anual de Lluvias,” http://pwp.supercabletv.net.co/garcru/colombia/Colombia...a Global Risk Analysis. Washington, DC: World Bank Publications, 2005. El Clima Colombiano. “El Clima Colombiano, Ciclo Anual de Lluvias.” http

  15. 75 FR 65557 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2010-10-25

    .../o PENTA PHARMA DE COLOMBIA S.A., Bogota, Colombia; c/o LABORATORIOS KRESSFOR DE COLOMBIA S.A... PHARMA DE COLOMBIA S.A., Bogota, Colombia; c/o DECAFARMA S.A., Bogota, Colombia; c/o DROCARD S.A., Bogota...) [SDNT]. 11. MORAN GUERRERO, Mario Fernando, c/o PENTACOOP LTDA., Bogota, Colombia; c/o PENTA PHARMA DE...

  16. Milliwatt dc/dc Inverter

    Science.gov (United States)

    Mclyman, C. W.

    1983-01-01

    Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.

  17. History of medical micology in Colombia, 1930-1970 = Historia de la micología médica en Colombia, 1930-1970

    Directory of Open Access Journals (Sweden)

    Galvis Pérez, Yeisson

    2013-04-01

    Full Text Available The overall objective of this research was to understand the events that made possible the creation, diffusion and appropriation of medical mycology in Colombia between 1930 and 1970. It was based on the review of scientific journals and theses in different libraries, archives and documentation centers in Medellin and Bogota. The report includes the different problems faced by physicians and laboratory personnel concerning the classification of fungi, the relationship between dermatology and mycology, the development of the study of systemic mycoses and the role played by some persons in the institutionalization of medical mycology.

  18. Colombia: crusading efforts bring signs of progress.

    Science.gov (United States)

    Kendall, S

    1989-01-01

    Colombia, like many developing countries, has not committed resources to fight the AIDS problem. They have used the media for condom promotion and other sexually transmitted diseases. There have been 151 deaths caused by AIDS by the end of 1988; 344 cases are known, and 130 additional have tested positive to the virus. Health officials were reluctant to recognize the problem, thinking it was outside their country and that they would not be affected by it. Since then, they have tried to target high risk groups and educate them and assist with testing and counseling. There is a move to make the new drug zidovudine available, but few could afford its high price. The authorities have put transvestite prostitutes in jail and kept them for AIDS testing, but few woman prostitutes have been tested. Up until 1986, only 30% of the Red Cross blood bank supplies were being tested; now 80% are, although it comprises only about 40% of the total supply. Drugs are used heavily, but mostly smoked, in Colombia, yet there is some concern about increased use of needles. The majority of cases in Columbia have been homosexual and bisexual men, but prostitution among men and women is prevalent in large cities such as Bogota. Health officials state that education is the best deterrent, but must be perpetuated so people will be constantly reminded.

  19. Strategies for the implementation of an environmental mining plan of the construction materials in Bogota. Phase 1 Diagnostic

    International Nuclear Information System (INIS)

    Gonzalez Oviedo, Leopoldo; Parrado L, Guillermo; Cardenas, John Fernan

    1995-01-01

    The study contains the geologic aspects, miners and environmental of 10 areas selected in Bogota where construction materials exist, like they are sands, clays, and gravels, in each area a definition is made, the productive units are described, reserves, mining production and environmental impacts are given generated by the material exploitation; a prioritizing of potential areas is included to implement a miner-environmental plan of this industry in Bogota

  20. Genetic architecture of male sterility and segregation distortion in Drosophila pseudoobscura Bogota-USA hybrids.

    Science.gov (United States)

    Phadnis, Nitin

    2011-11-01

    Understanding the genetic basis of reproductive isolation between recently diverged species is a central problem in evolutionary genetics. Here, I present analyses of the genetic architecture underlying hybrid male sterility and segregation distortion between the Bogota and USA subspecies of Drosophila pseudoobscura. Previously, a single gene, Overdrive (Ovd), was shown to be necessary but not sufficient for both male sterility and segregation distortion in F(1) hybrids between these subspecies, requiring several interacting partner loci for full manifestation of hybrid phenomena. I map these partner loci separately on the Bogota X chromosome and USA autosomes using a combination of different mapping strategies. I find that hybrid sterility involves a single hybrid incompatibility of at least seven interacting partner genes that includes three large-effect loci. Segregation distortion involves three loci on the Bogota X chromosome and one locus on the autosomes. The genetic bases of hybrid sterility and segregation distortion are at least partially--but not completely--overlapping. My results lay the foundation for fine-mapping experiments to identify the complete set of genes that interact with Overdrive. While individual genes that cause hybrid sterility or inviability have been identified in a few cases, my analysis provides a comprehensive look at the genetic architecture of all components of a hybrid incompatibility underlying F(1) hybrid sterility. Such an analysis would likely be unfeasible for most species pairs due to their divergence time and emphasizes the importance of young species pairs such as the D. pseudoobscura subspecies studied here.

  1. 75 FR 10557 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Science.gov (United States)

    2010-03-08

    ... BUSTOS ARIZA Y CIA. S.C.S., Bogota, Colombia; c/o MODERNA EXPRESS TRANSPORTE DE CARGA LTDA., Bogota..., Colombia; c/o LOGISTICA Y TRANSPORTE NORVAL LTDA., Bogota, Colombia; Calle 135 No. 17-25 apto. 503, Bogota.... LOGISTICA Y TRANSPORTE NORVAL LTDA., Avenida Boyaca No. 68-24, Bogota, Colombia; NIT 900224846-0 (Colombia...

  2. A Unidirectional DC-DC Autotransformer for DC Grid Application

    Directory of Open Access Journals (Sweden)

    Meng Zhou

    2018-03-01

    Full Text Available Conventional unidirectional DC-DC converters for DC grid application employ DC-AC-DC two-stage conversion technology and suffer from high converter cost and power loss. To solve these issues, a unidirectional step-up DC-DC autotransformer (UUDAT and a unidirectional step-down DC-DC autotransformer (DUDAT are studied. The UUDAT and DUDAT are composed of a series connection of diode bridges and voltage source converters. Topologies of UUDAT and DUDAT are detailed. The harmonic and un-controllability issues are discussed. Control and possible application scenarios for UUDAT and DUDAT are depicted. DC fault isolation mechanism and the methods of dimensioning the voltage and power ratings of the components in UUDAT and DUDAT are studied. Extensive simulations on power system level and experiments on a UUDAT and DUDAT prototype verified their technical feasibility.

  3. Towards a radiation safety culture at Universidad Nacional de Colombia

    International Nuclear Information System (INIS)

    Poveda, Jairo F.; Munera, Hector A.

    2008-01-01

    Full text: During the 20th century, nuclear and radiation techniques for research, teaching, and medical and engineering practice slowly appeared at the National University of Colombia, mainly at the Bogota, Medellin and Manizales branches. Each individual laboratory or researcher obtained the license for the use of the radioactive source, or radiation emitting apparatus. However, the University as a whole does not have as yet a Radiation Safety Manual, nor an inventory of laboratories using radiation. From the viewpoint of radiation safety and culture, this situation is undesirable, and may easily lead to inappropriate waste management practices, including the possibility of orphan sources (one such source has been already found). As part of the program of environmental management of dangerous wastes promoted by the National Division of Laboratories of our University, an office of radiation safety was created in the year 2006. This paper describes the situation that was found, the activities that have been carried out, some of the difficulties that we have met, and the plans that we have to help shape a safety culture at our institution. Currently we are pursuing an inventory of laboratories using radioactive sources and radiation emitting apparatuses, starting with the branches in Bogota and Manizales which are perceived as the most urgent to deal with. Fortunately, the branch in Medellin has been for about a decade under the care of a former radiation safety officer of our national Institute of Nuclear Affairs, who presently teaches there. During 2006 and 2007, 13 laboratories using radioactive sources were visited in the Bogota branch. Safety procedures and waste handling protocols were checked, safety manuals prepared and/or revised, and recommendations for safety culture provided. During 2008 we will visit Manizales, and will continue visiting a number of X-ray machines used in the Bogota branch for engineering, veterinary, and diagnostic, and surgery medical

  4. Latin American Clinical Epidemiology Network Series - Paper 6: The influence of alcohol in traffic accidents and health care costs of it in Bogotá-Colombia.

    Science.gov (United States)

    Gómez-Restrepo, Carlos; Naranjo-Lujan, Salomé; Rondón, Martín; Acosta, Andrés; Maldonado, Patricia; Arango Villegas, Carlos; Hurtado, Jaime; Hernández, Juan Carlos; Angarita, María Del Pilar; Peña, Marcela; Saavedra, Miguel Ángel; Quitian, Hoover

    2017-06-01

    In Colombia, some studies have estimated medical costs associated to traffic accidents. It is required to assess results by city or region and determine the influence of variables such as alcohol consumption. The main objective of this study was to identify health care costs associated to traffic accidents in Bogota and determine whether alcohol consumption can increase them. Cross-sectional costs study conducted in patients over 18 years treated in the emergency rooms of six different hospitals in Bogota, Colombia. The average total cost of medical care per patient was 628 USD, in Bogota-Colombia. The average cost per accident was estimated at 1,349 USD. On average, the total cost for health care for patients with positive blood alcohol level was 1.8 times higher than those who did not consume alcohol. The indirect costs were on average 115.3 USD per injured person. Numbers are expressed in 2011 U.S. dollars. Alcohol consumption increases the risk of traffic accidents and direct medical health costs. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. REDESCUBRIMIENTO DE MYRRHINIUM ATROPURPUREUM VAR. OCTANDRUM (MYRTACEAE: MYRTINAE EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    PARRA-O. CARLOS

    2003-12-01

    Full Text Available Se documenta el redescubrimiento de Myrrhinium atropurpureum var. octandrum(Myrteae DC., Myrtaceae, taxón prácticamente desconocido en Colombia. Se presentala descripción del taxón, así como notas sobre su distribución en Colombia, elhábitat en que se desarrolla y su posible estatus dentro de las categorías de la ListaRoja de la UICN.

  6. Step-Up DC-DC converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

    2017-01-01

    on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage...

  7. Plan Colombia

    Directory of Open Access Journals (Sweden)

    Noam Chomsky

    2000-12-01

    Full Text Available Colombia recibe más ayuda militar de Estados Unidos que el resto de América Latina y el Caribe unidos, y esta situación puede profundizarse con la ejecución del Plan Colombia, fundamentado en la lucha antidrogas. Sin embargo, el pais ha sido calificado con el récord en violación de derechos humanos. En este contexto se aplica la reforma económica más significativa en la década de los noventa, generando condicionantes en los procesos de integración con sus vecinos. En concordancia con el secretario de Defensa, Henry Stimson, desde los años 60 Estados Unidos estaba autorizado para controlar su propio sistema regional, mientras todos los demás intenlos serian desmantelados. La presentación ambigua de esta política del gobierno estadounidense en Colombia es cómo disociar esta guerra contra la droga y la lucha irregular contrainsurgente En Estados Unidos hay otra opinión que debe conocerse para comprender las divergencias en e! interior de dicho país. Este artículo del prestigioso profesor universitario del MU, Noam Chomsky, es un referente obligado en términos de opinión pública y académica de dimensión internacional, por el inmenso respeto que infunde tanto en América como en Europa

  8. Contamination with Cadmium and Arsenic in soils and vegetables of a sector of the Bogota River Basin

    International Nuclear Information System (INIS)

    Gonzalez G, Saul; Mejia, Leonidas

    1995-01-01

    Soils of six different horticultural sites of the Savanna of Bogota (Cundinamarca) traditionally watered with the highly polluted waters of the Bogota River, were sampled to quantify Cd and As accumulated with irrigation. Soil of site six representatives of Rio Bogota series (fine clay, mixed, isothermic family of Fluventic tropaquepts) was selected for greenhouse experiments directed to show: a) Actual content of Cd and As in one of the most representative horticultural soil sites of the plain savanna. b) The accumulation level of Cd and As in the edible parts of three different vegetables (lettuce, cucumber and carrots) watered with polluted waters with know and variable Cd and As concentrations. c) The effects of Cd and As on vegetable's yields

  9. 77 FR 41479 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2012-07-13

    ..., Maria Teresa), c/o INVERSIONES MPS S.A., Bogota, Colombia; c/o PROYECTOS Y SOLUCIONES INMOBILIARIA LTDA., Bogota, Colombia; c/o GERENCIA DE PROYECTOS Y SOLUCIONES LTDA., Bogota, Colombia; DOB 3 Aug 1957; POB...

  10. DC Home Appliances for DC Distribution System

    Directory of Open Access Journals (Sweden)

    MUHAMMAD KAMRAN

    2017-10-01

    Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance

  11. Spatiotemporal variability and meteorological control of particulate matter pollution in a large open-pit coal mining region in Colombia

    Science.gov (United States)

    Morales Rincon, L. A.; Jimenez-Pizarro, R.; Porras-Diaz, H.

    2012-12-01

    Luis Morales-Rincon (1), Hernan Porras-Diaz (1), Rodrigo Jiménez (2,*) (1) Geomatic Research Group, Department of Civil Engineering, Universidad Industrial de Santander, Bucaramanga, Santander 680002, Colombia; (2) Air Quality Research Group, Department of Chemical and Environmental Engineering, Universidad Nacional de Colombia, Bogota, DC 111321, Colombia *Corresponding author: phone +57-1-316-5000 ext. 14099, fax +57-1-316-5334, e-mail rjimenezp@unal.edu.co The semi-desertic area of Central Cesar, Colombia, produced approximately 44 million tons of coal in 2011. This mining activity has been intensively developed since 2005. There are currently 7 large-scale mining projects in that area. The coal industry has strongly impacted not only the ecosystems, but also the neighboring communities around the coal mines. The main goal of the research work was to characterize spatial and temporal variations of particulate matter (total suspended particulates - TSP - and particulate matter below 10 μm - PM10) as measured at various air quality monitoring stations in Cesar's coal industry region as well as to study the relationship between these variability and meteorological factors. The analysis of the meteorological time series of revealed a complex atmospheric circulation in the region. No clear repetitive diurnal circulation patterns were observed, i.e. statistical mean patterns do not physically represent the actual atmospheric circulation. We attribute this complexity to the interdependence between local and synoptic phenomena over a low altitude, relatively flat area. On the other hand, a comparison of air quality in the mining area with a perimeter station indicates that coal industry in central Cesar has a mayor effect on the levels of particulate matter in the region. Particulate matter concentration is highly variable throughout the year. The strong correlation between TSP and PM10 indicates that secondary aerosols are of minor importance. Furthermore, particle

  12. Incidence of public expenditure on the human development index in Bogota, 1995-2010

    Directory of Open Access Journals (Sweden)

    Mónica Consuelo Rodríguez Torres

    2012-01-01

    Full Text Available This paper seeks to test the hypothesis that social public expenditure per capita invested in Bogota has had a significant influence on the improvement of the city’s human development. For this purpose, the Human Development Index (HDI for the capital between 1995-2010 is estimated, using the new methodology proposed by the UNDP in 2010. Thus, a retrospective estimation of the life expectancy, salaries, and educational achievement rates is carried out, the last as a combination between the average years of education and expected years of instruction. A qualitative analysis is then presented, between the HDI components and the social public expenditure invested through politics, programs, projects carried out in the city, according to the District Development Plan “Bogotá positiva, para vivir mejor (Positive Bogota, to Live Better”. Finally, a quantitative analysis of this relation is made and it is concluded that social public spending per capita is significant to explain the HDI, since there is a long-term and stable relation between the two variables.

  13. Breast Cancer Screening Coverage with clinical examination and Mammography Among insured women in Bogota

    International Nuclear Information System (INIS)

    Arboleda, Walter; Murillo Raul; Pinero, Marion

    2009-01-01

    The objective is to determine the coverage of clinical breast examination (CBE) and mammography for screening of breast cancer among a group of insured women in Bogota. Methods: A telephone survey was carried out with 4,526 women between the ages of 50 and 69, residing in Bogota or its suburbs, who were insured by one of three commercial health plans. Women with a history of breast cancer were excluded. Screening coverage was estimated as the proportion of women who had had a mammography or CBE. Estimates were established for lifetime frequency, two years prior the survey, and one year prior the survey. Factors associated with screening procedures were analyzed with calculations based on adjusted OR. Results: Lifetime frequency of CBE was 59.3% and 79.8% for mammography; and 49.7% and 65.6% of women respectively underwent the tests for screening purposes; the remainder, for diagnostic purposes (breast symptoms). CBE reported a 34.2% one year coverage and mammography reported a 54% two years coverage. Screening was associated to cancer education and family history of breast cancer. Conclusion: Coverage of CBE for screening purposes is low. Mammography coverage is above that required by the Colombian Health Ministry, but below that reported by developed countries.

  14. Step-Up DC-DC converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam P.; Gorji, Saman A.

    2017-01-01

    on the general law and framework of the development of next-generation step-up dc-dc converters, this paper aims to comprehensively review and classify various step-up dc-dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage......DC-DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which......-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc-dc converters are presented and summarized with comparative study of different voltage-boosting techniques....

  15. Tratamiento de la sifilis gestacional y prevencion de la sifilis congenita en un hospital de iii nivel. bogota, colombia.

    OpenAIRE

    Rubio Romero, Jorge Andrés

    2013-01-01

    RESUMENObjetivo: evaluar el cumplimiento de las recomendaciones del Centro de Control de Enfermedades (CDC) para el tratamiento en casos intrahospitalarios de sífilis gestacional y congénita. Metodología: estudio retrospectivo basado en registros de notificación e historias clínicas de gestantes y neonatos de un hospital terciario público de Bogotá entre  enero 1 y Octubre 31 de 2010. Se describen las variables demográficas de las mujeres con diagnóstico de sífilis gestacional y sus hijos, el...

  16. [CONSISTENCY OF MINI NUTRITIONAL ASSESSMENT TO IDENTIFY SARCOPENIA IN OLDER ADULTS IN NURSING HOMES IN BOGOTA, COLOMBIA].

    Science.gov (United States)

    Díaz Muñoz, Gustavo Alfonso; Cárdenas Zuluaga, Diana María; Mesa Jimenez, Alfonso

    2015-07-01

    malnutrition and sarcopenia, which have similar physiological mechanisms and are both responsible for adverse health outcomes, are highly prevalent in the elderly. to measure the consistency of the MNA with the diagnosis of sarcopenia in older adults. cross-sectional study of consistency in four nursing homes in Bogotá. The nutritional screening and nutritional assessment were made with the Mini Nutritional Assessment in its long form; the diagnosis of sarcopenia was done with the algorithm and the breakpoints of the European Consensus (EWGSOP). Pearson Chi2, Mann-Whitney and consistency by Cohen's kappa coefficient. we included 108 patients, 62% women, mean age 80.4 years (SD 7.7). The prevalence of sarcopenia, malnutrition and risk of malnutrition were 38.9%, 33.3% and 2.8% respectively. The concordance of the MNA with the diagnosis of sarcopenia was slight (kappa 0.1908 95% CI 0.0025 to 0.3791, p sarcopenia, suggesting that it is not an appropriate tool for the diagnosis of sarcopenia in older institutionalized adults. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  17. Spatial and temporal distribution of dragonflies naiads in wetlands La Vaca and Santa Maria del Lago, Bogota, Colombia

    International Nuclear Information System (INIS)

    Moreno Pallares, Maria Ines; Guillot Monroy, Gabriel Hernando

    2012-01-01

    We evaluated the spatial and temporal variation in communities of dragonfly's naiads and their association to the habitat rehabilitation status in La Vaca and Santa Maria del Lago wetlands. Four samplings were carried out in several sites of each during a year. Macroinvertebrates were collected at the entry and exit flow, and in open waters of the wetlands using standard techniques. We found a gradient in the distribution of the abundance of nymphs in both wetlands, where naiads community had the highest number of individuals in the places located farther from the dumping sites. Comparing the community s composition between wetlands La Vaca and Santa Maria del Lago through the beta diversity, heterogeneity was found in both ecosystems. The gradient in the distribution of the abundance of naiads observed in both wetlands fits with to a response of the species in terms of tolerance to the environmental variables.

  18. CARACTERIZACIÓN DEL CONOCIMIENTO DE PROFESORES DE BOGOTA COLOMBIA SOBRE EDUCACIÓN AMBIENTAL. PROBLEMA DE INVESTIGACION

    Directory of Open Access Journals (Sweden)

    Jenny Johanna Duarte Diaz

    2015-12-01

    Full Text Available Uno de los retos que se le ha impuesto a la educación actual está dado en la educación ambiental, por lo que las naciones han modificado sus políticas incluyendo la presencia de la dimensión ambiental y la formación en educación ambiental desde la escuela. Sin embargo a pesar del importante rol que desempeñan los profesores de todas las disciplinas en los procesos de enseñanza aprendizaje, se tiene poco en cuenta su conocimiento profesional en este ámbito, dejando la tarea de la educación ambiental como un campo exclusivo de formación para los docentes de Ciencias Naturales y especialmente  en los licenciados en biología.   Desde allí, resulta necesario avanzar en lo referente a la caracterización de los componentes del conocimiento profesional de profesor en la enseñanza de la educación ambiental, desde sus prácticas pedagógicas en este campo, identificando las concepciones de educación ambiental que poseen docentes de diferentes áreas del conocimiento y estableciendo las corrientes que se conciben en los procesos ambientales que lideran junto a los enfoques en los que direccionan sus prácticas pedagógicas, a fin de propiciar la apropiación de discursos que repercutan en la realidad inmediata de los contextos escolares.

  19. Mediating Pathways in the Socio-Economic Gradient of Child Development: Evidence from Children 6-42 Months in Bogota

    Science.gov (United States)

    Rubio-Codina, Marta; Attanasio, Orazio; Grantham-McGregor, Sally

    2016-01-01

    Research has previously shown a gap of near 0.5 of a standard deviation (SD) in cognition and language development between the top and bottom household wealth quartile in children aged 6-42 months in a large representative sample of low- and middle-income families in Bogota, using the Bayley Scales of Infant and Toddler Development. The gaps in…

  20. DC electric springs with DC/DC converters

    DEFF Research Database (Denmark)

    Wang, Qingsong; Cheng, Ming; Jiang, Yunlei

    2016-01-01

    The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi-directio......The concept of DC electric spring (DCES) was recently proposed to solve the stability issue caused by integrating intermittent renewable energy sources (RESs) to DC microgrids. In this paper, a new topology of DCES is proposed based on DC/DC converters. The proposed DCES consists of a bi...... and/or constant discharging for batteries is adopted and four operating modes are analyzed as charging-positive, charging-negative, discharging-positive and discharging-negative modes. An additional mechanism for fast charging or fast discharging is also designed to secure normal operation...... of batteries. With the proposed DCES, the power fluctuations due to intermittent RESs can be passed to non-critical loads (NCLs) and batteries while power on critical loads (CLs) is kept stable. This is possibly the first attempt to design a DCES with only DC/DC converters. The performances of the proposed...

  1. A resonant dc-dc power converter assembly

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the s......The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...

  2. VENTAQUEMADA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Sergio D. Fonseca

    2017-01-01

    Full Text Available Con el objetivo de someter los residuos de maíz al proceso termoquímico llamado gasificación, en este trabajo se muestran resultados de diferentes análisis para conocer algunas propiedades físico-químicas que son de gran importancia antes de realizar este proceso. Se determinó el contenido de lignina la cual registro un valor de 14,7%, se determinó el poder calorífico de esta biomasa obteniendo un valor de 17,965 MJ kg-1, análisis TGA con tres velocidades de calentamiento diferentes, se realiza un análisis ultimo para revelar la composición química de la biomasa; estos resultados fueron comparados con estudios realizados en otros países. Los resultados obtenidos contribuyen a la investigación de este tipo de biomasa en Colombia, ya que no se registra información bibliográfica de la caracterización de esta; se debe aprovechar su uso en la utilización en el proceso de gasificación, ya que poseen las características necesarias para obtener un producto como el “syngas”.

  3. Retardo del crecimiento intrauterino asociado con el consumo de pasta básica de cocaína por mujeres gestantes de Bogotá, D.C., Colombia

    Directory of Open Access Journals (Sweden)

    Oscar Ramírez

    2000-12-01

    Full Text Available El objetivo de este estudio fue identificar una posible asociación entre el consumo de pasta ásica de cocaína o 'basuco' entre mujeres embarazadas y el crecimiento intrauterino de sus productos vivos en dos hospitales de tercer nivel en Bogotá, Colombia. Con un diseño de cohorte retrospectiva, se encuestaron 1.878 mujeres en el puerperio mediato para indagar, entre otras variables, la historia sobre el consumo de drogas ilicitas. Tanto a las madres como a sus recién nacidos se les realizaron mediciones antropométricas estandarizadas. Se comparó la prevalencia de bajo peso al nacer (BPN, parto prematuro (PP y retardo del crecimiento intrauterino (RCIU con la historia de consumo de drogas ilicitas durante el embarazo por medio de modelos de regresión lineal múltiple y regresión logística múltiple, para ajustar el efecto de posibles confusores como edad materna, estado nutricional y patologias maternas, nivel socioeconómico, escolaridad y tabaquismo, entre otros. Los resultados mostraron que una de cada 189 mujeres consumió sustancias ilegales durante el embarazo, comúnmente Cannabis safiva o pasta básica de cocaina. Las consumidoras de ostos productos tipicamente tenían menor escolaridad, eran de nivel socioeconomico más bajo. eran más delgadas, con una historia de control prenatal inadecuado, primigestantes o multigestantes y, con frecuencia, también fumaban tabaco y bebían alcohol. Se halló una asociación entre el consumo de las sustancias ilegales con RCIU (cociente de suertes de prevalencias de 5.24, IC95%: 1,3-21.0, y un déficit de 0.7 desvios estándares del peso para la edad gestacional (p=0.03. Además, se encontró un cociente de suertes ajustado de 7,78 con IC95%: 1,O-62, entre el consumo de pasta básica de cocaina y RCIU. Aunque es probable que a través de entrevistas se subestime la prevalencia de consumo de drogas y a pesar del limitado poder del estudio, éste fue capaz de identificar un efecto importante

  4. Heat island and spatio-temporal changes of temperature in the city of Bogota

    International Nuclear Information System (INIS)

    Angel, L; Ramirez, A; Dominguez, E.

    2010-01-01

    The planet Earth, as a whole, has experienced a warming process caused principally by the accumulation of atmospheric greenhouse gases. Otherwise, it has been well demonstrated that thermic islands exist inside of cities, essentially as a result of the replacement of forest areas with urban materials such as asphalt, concrete, bricks, etc. Based on this foundation, this research evaluated the minimum, median and maximum temperature changes that occurred in the city of Bogota over the last 40 years. This research makes evident the presence of a heat island 3o Cover the periphery median temperature in most of the city. There were also periods with increases and decreases in city temperatures, not affected in its main tendency by the Nino Phenomena which in contrast affected the periphery.

  5. Social responsability of the Bogota companies and their relation to employement and poverty

    Directory of Open Access Journals (Sweden)

    Adriana Patricia López Velázquez

    2006-07-01

    Full Text Available This article shows the main results , conclusions and recommendations from two researches about Entrepreneurial Social Responsibility (RSE, and its relation to poverty and employment in the specific case of Bogotá. These results were obtained from a field work and literature revision about RSE, both nationally and internationally. It is worth noting that most of the Bogota companies do not know or do not have any interest in RSE, for them RSE implies high costs and little economic revenue. Out of the total of companies, only 1,3% have participated in programs to reduce poverly applied by district administration, where the common points of public and private investmetl have been education, nutrition and housing programs. The companies that include RSE programs for their workers consider it positive, because the work environment improved and the employees' productivity increased, which contributed for the welfare of both parties.

  6. Study of the mobilization of pollutants in soils of the Bogota Savanna - phase 1, Heavy Metals

    International Nuclear Information System (INIS)

    Gonzalez, Luz Myrian; Vargas Zarate, Orlando

    1997-01-01

    In this study the soils contamination of the Bogota Savanna was evaluated by heavy metals, that they have importance to be this the area of population's of the country bigger density, where the use of the soils has suffered changes in the last years that have affected its properties, as consequence of the not controlled growth of the urban area, of the industrialization and of the agricultural use not planned. As a first stage toward the risk evaluation for the presence of metals weighed in the soils of the Bogota Savanna, the concentrations of cadmium, cobalt, chromium, copper, manganese, nickel, lead, zinc, molybdenum, arsenic and mercury were measured. It was also measured the movilizable fraction and the mobile fraction, that is to say, the quantity of metals that can be taken by the roots of the plants or that it can be leached toward the water bodies. Equally, the soils of the Savanna were characterized in an area of the plane part that covers 800 km 2 , as for the physical and chemical properties that can affect the retention and mobilization of heavy metals. The results obtained shows elements, that will allow in a future to develop mobilization and transport models, adapted for our specific conditions and to make an risks evaluation for the population's health, foods consumption on these soils or for the possibility of contamination of the underground waters. The obtained data of levels of heavy metals and other properties of the soils will serve as base for future studies of the conditions of the Savanna soils and for the establishment of standard of quality in our country. During 1997 it plans to enlarge the study area to 1200 km 2 and to begin the sampling and analysis of the soils. In the first phase of the study were found levels of heavy metals that overcome the world averages especially cadmium, cobalt, nickel, lead and zinc and in some cases chromium and mercury, levels that put in evidence the existence an ecological risk and for the population

  7. en Colombia?

    Directory of Open Access Journals (Sweden)

    William Andrés Ocampo Duque

    2006-01-01

    Full Text Available El Ministerio de Minas y Energía aprobó la comercialización de biogasolina en Colombia a partir del día 1.º de noviembre de 2005. La biogasolina (gasohol o mezcla E10 es una mezcla que contiene 90% de gasolina y 10% de etanol en volumen. El etanol se origina a partir de la fermentación natural, luego de extraer los jugos de cultivos como la caña de azúcar, el maíz, el trigo o la yuca. Tanto el Gobierno nacional como los productores interesados han manifestado que la biogasolina se presenta como una alternativa para reducir los efectos negativos sobre el medio ambiente que producen las grandes ciudades debido a la quema de combustibles fósiles en el sector del transporte. Sin embargo, en la literatura científica especializada la evidencia de efectos ambientales favorables por el uso de gasolina oxigenada con un 10% de etanol es escasa. Por el contrario, hay gran controversia a nivel mundial acerca del uso de este combustible modificado. En este trabajo se hace una extensa revisión científica en la que se muestra que la mezcla etanol-gasolina presenta cuestionables beneficios ambientales ya que puede incrementar la producción de contaminantes altamente tóxicos y smog fotoquímico, ofrece pocos beneficios en cuanto a reducciones de gases de efecto invernadero y sostenibilidad ambiental, además de incrementar el riesgo de la contaminación de las aguas subterráneas.

  8. A methodology of design for a one-variable neural network model to forecast the minimum temperature on the Mosquera zone, Cundimarca, Colombia

    International Nuclear Information System (INIS)

    Bonilla, Jose Ebert; Ramirez, Jairo; Ramirez, Oscar; Leon, Gloria and others

    2006-01-01

    The meteorological phenomena are factors that affect the economy, especially on a country like Colombia, which sustainability is based highly on agricultural products like corns, potato and flowers, plants of a paramour landscape like Bogota savannah. Among this phenomenon is the extreme minimum temperature (frost damage) it is a result of the non-lineal interactions of many atmospheric phenomena, for all that, frost damage forecast is very hard to accomplish with traditional methods. The approach of the project is to process this time series with an artificial neural network; it generals a now casting forecast on the zone of Mosquera

  9. IGBT Based DC/DC Converter

    Directory of Open Access Journals (Sweden)

    M. Akherraz

    1997-12-01

    Full Text Available This paper presents an in-depth analytical and experimental investigation of an indirect DC-DC converter. The DC-AC conversion is a full bridge based on IGBT power modules, and the AC-DC conversion is done via a high  frequency AC link and a first diode bridge. The AC link, which consists of snubbing capacitors and a variable air-gap transformer, is analytically designed to fulfill Zero Voltage commutation requirement. The proposed converter is simulated using PSPICE and a prototype is designed built and tested in the laboratory. PSPICE simulation and experimental results are presented and compared.

  10. ESTUDIO DE LAS VISITAS DE LAS MOSCAS DE LAS FLORES (DIPTERA: SYRPHIDAE EN Salvia bogotensis (LAMIACEAE EN EL JARDÍN BOTÁNICO JOSÉ CELESTINO MUTIS (BOGOTÁ D.C., COLOMBIA

    Directory of Open Access Journals (Sweden)

    Zamora Monica

    2011-12-01

    Full Text Available El objetivo de esta investigación fue describir la interacción entre Salvia bogotensis (Lamiaceae y las moscas de las flores (Diptera: Syrphidae en un ambiente urbano, el jardín botánico "José Celestino Mutis" (Bogotá D.C.. Una vez comprobada la existencia del síndrome de entomofilia, se caracterizó la morfología floral, la composición taxonómica, la riqueza y la abundancia de las especies de sírfidos identificadas como visitantes florales, así como la morfometría cefálica y bucal. S. bogotensis presenta el síndrome de la entomofilia con ausencia de autofecundación. La comunidad de sírfidos asociada con esta comprende nueve especies, agrupadas en cinco géneros. Las especies son Allograpta neotropica Curran, 1936, Allograpta exotica Wiedermann, 1830, Allograpta annulipes Macquart, 1850, Allograpta aenea Hull, 1937, Lejops mexicana Macquart, 1842, Platycheirus ecuadoriensis Fluke, 1945, Platycheirus fenestrata Macquart, 1842, Syrphus shoree Fluke, 1950 y Toxomerus sp. 1. Las especies de moscas identificadas presentan en su conjunto características conductuales y morfológicas asociadas a polinizadores de baja eficiencia, con una baja tasa de visitas, incapacidad de activación de los balancines y un mínimo contacto corporal del insecto con las anteras y el estigma de la flor. Adicionalmente, las moscas presentan una carga muy baja de granos de polen de S. bogotensis sobre el cuerpo y alta inversión de tiempo en la limpieza de su cuerpo (acicalamiento. Las flores visitadas por estos insectos no dieron origen a frutos. Todo lo anterior permite concluir que dichas moscas no son polinizadores efectivos de S. bogotensis. Además de dípteros, se observaron varias especies de insectos visitantes florales de S. bogotensis pertenecientes a las familias Apidae, Halictidae y Megachilidae. Los sírfidos se benefician por el consumo de polen de S. bogotensis, pero no interfieren en el crecimiento y el desarrollo de la planta, por lo cual

  11. Molecular Epidemiology of Epidemic Severe Malaria Caused by Plasmodium vivax in the State of Amazonas, Brazil

    Science.gov (United States)

    2005-01-01

    Suarez, C.F., Florez, C., del Portillo, H.A.; Andrade, L.E. Direct Submission to NCBI gene bank. Submitted 03-JAN-1997. Laboratorio de Biologia Molecular...Departamento de Biologia , Universidad Nacional de Colombia, Ciudad Universitaria, Santa Fe de Bogota, D.C., Colombia. Nardin, E.H.; Zavala, F

  12. (Colombia 2010

    Directory of Open Access Journals (Sweden)

    Sandra Constanza Cañón

    2011-01-01

    Full Text Available El presente estudio pretende indagar sobre las prácticas y comportamientos sexuales en una población universitaria, ya que comportamientos positivos pueden desarrollar mejores habilidades para la prevención de conductas de alto riesgo, mayor satisfacción sexual y, por ende, vivir más plenamente. La presente investigación es de tipo transversal y en ella participaron estudiantes de todas las facultades de la Universidad de Manizales (Caldas, Colombia, que estaban cursando entre primero y noveno semestre. La muestra de esta investigación la constituyeron 267 personas sobre una población de 3600 estudiantes regulares; se obtuvo mediante un muestreo probabilístico estratificado por género y facultad. La edad media fue de 21.69 años; la mayor proporción fue de mujeres en un 58.8%; 1.5% eran homosexuales y un 5%, bisexuales, el método de anticoncepción más usado fueron los métodos de barrera en un 41.3%; el 15.2% habían tenido alguna infección de transmisión sexual. En lo que se refiere a las prácticas sexuales el 22.8% realizan todas las prácticas (masturbación, sexo oral, sexo anal, sexo vaginal; en cuanto al promedio de edad de inicio de relaciones sexuales fue de 16.09 años; están de acuerdo con la despenalización total del aborto en un 53.1%; el 73.2% adoptan una posición de aceptación y tolerancia hacia la homosexualidad. El estudio permitió ver la influencia de varias variables como género, familia, religión y formación educativa sobre el comportamiento y la práctica sexual responsable.

  13. A resonant dc-dc power converter assembly

    OpenAIRE

    Madsen, Mickey Pierre

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or fo...

  14. Environmental quality evaluation for towns in Bogota; An approach to the construction of indexes of environmental quality

    International Nuclear Information System (INIS)

    Escobar, Luis; Bermudez, Tatiana

    2004-01-01

    This paper is a conceptual and methodological estimate for the construction of a synthetic indicator that allows one to come a step closer to the diagnosis of the environmental conditions of the nineteen administrative units of Bogota known as localidades. Here the contained information is synthesized in eight simple selected indicators, the index is constructed by applying analysis of principal components, of which the alignment of the localidades is derived in accordance with the value that it takes in the environmental quality index. Once the method of calculation is applied, the results indicate that the conditions of environmental quality if Bogota are not homogeneous, clearly existing environmental differences between localidades in the north and south. Also prioritization and analysis index of environmental qualities per localidades introduced, of which the principal determinants of the index of each localidad are introduced, thus providing the decision makers with important input, in order to define the base line as a stating point of the urban environmental management

  15. Counterterrorism policy in Colombia

    OpenAIRE

    Self, Kevin A.

    2007-01-01

    The purpose of this thesis is to suggest a coherent, credible, and long-term counterterrorism policy in Colombia. The events of September 11, 2001 heightened U.S. awareness of Colombian terrorist organizations, the most powerful being the Revolutionary Armed Forces of Colombia (FARC). The U.S. counterterror approach in Colombia appears fragmented, with only minor changes to its previous drug control policies. In contrast, the Colombian government has developed and implemented a policy to ...

  16. Colombia: Issues for Congress

    National Research Council Canada - National Science Library

    Veillette, Connie

    2005-01-01

    ... into sharper focus after the attacks of September 11, 2001. The United States has made a significant commitment of funds and material support to help Colombia and the Andean region fight drug trafficking since the development of Plan Colombia in 1999...

  17. Arms Trafficking and Colombia

    Science.gov (United States)

    2003-01-01

    chronology of the intensification of violence in the area, see Noche Y Niebla: Panorama De Derechos Humanos Y Violencia Politica En Colombia, Bogotá...Arms, London, UK: Zed Books, 2000, pp. 155–178. Noche Y Niebla: Panorama De Derechos Humanos Y Violencia Politica En Colombia, Bogotá: Cinep & Justicia

  18. Implementation of a WRF-CMAQ Air Quality Modeling System in Bogotá, Colombia

    Science.gov (United States)

    Nedbor-Gross, R.; Henderson, B. H.; Pachon, J. E.; Davis, J. R.; Baublitz, C. B.; Rincón, A.

    2014-12-01

    Due to a continuous economic growth Bogotá, Colombia has experienced air pollution issues in recent years. The local environmental authority has implemented several strategies to curb air pollution that have resulted in the decrease of PM10 concentrations since 2010. However, more activities are necessary in order to meet international air quality standards in the city. The University of Florida Air Quality and Climate group is collaborating with the Universidad de La Salle to prioritize regulatory strategies for Bogotá using air pollution simulations. To simulate pollution, we developed a modeling platform that combines the Weather Research and Forecasting Model (WRF), local emissions, and the Community Multi-scale Air Quality model (CMAQ). This platform is the first of its kind to be implemented in the megacity of Bogota, Colombia. The presentation will discuss development and evaluation of the air quality modeling system, highlight initial results characterizing photochemical conditions in Bogotá, and characterize air pollution under proposed regulatory strategies. The WRF model has been configured and applied to Bogotá, which resides in a tropical climate with complex mountainous topography. Developing the configuration included incorporation of local topography and land-use data, a physics sensitivity analysis, review, and systematic evaluation. The threshold, however, was set based on synthesis of model performance under less mountainous conditions. We will evaluate the impact that differences in autocorrelation contribute to the non-ideal performance. Air pollution predictions are currently under way. CMAQ has been configured with WRF meteorology, global boundary conditions from GEOS-Chem, and a locally produced emission inventory. Preliminary results from simulations show promising performance of CMAQ in Bogota. Anticipated results include a systematic performance evaluation of ozone and PM10, characterization of photochemical sensitivity, and air

  19. Strategies for the implementation of an environmental mining plan of the construction materials in Bogota. Phase 1 Diagnostic; Estrategias para la implementacion de un plan integral de gestion minero-ambiental de la industria extractiva de materiales de la construccion en la Sabana de Bogota. Fase I Diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Oviedo, Leopoldo; Parrado L, Guillermo; Cardenas, John Fernan

    1995-07-01

    The study contains the geologic aspects, miners and environmental of 10 areas selected in Bogota where construction materials exist, like they are sands, clays, and gravels, in each area a definition is made, the productive units are described, reserves, mining production and environmental impacts are given generated by the material exploitation; a prioritizing of potential areas is included to implement a miner-environmental plan of this industry in Bogota.

  20. Full range ZVS DC-DC converter

    International Nuclear Information System (INIS)

    Upadhyay, Rinki; Badapanda, M.K.; Hannurkar, P.R.

    2011-01-01

    A 500 V, 24 Amp DC-DC converter with digital signal processor (DSP) based control and protection has been designed, fabricated and tested. Its power circuit consists of IGBT based single phase inverter bridge, ferrite transformer and diode rectifier. All IGBTs in the inverter bridge are operated in zero voltage switching (ZVS) mode to minimize switching losses thereby increasing the efficiency of the converter significantly. The efficiency of this converter is measured to be greater than 97% at full load. In a conventional full bridge inverter, typically ZVS is achieved under full load condition while at light load ZVS is lost. An auxiliary LC circuit has been intentionally incorporated in this converter to achieve ZVS even at light loaded conditions. Detailed simulation of the converter circuit is carried out and crucial waveforms have been presented in this paper. Microchip make dsPIC30F2020 DSP is employed to provide phase shifted PWMs to IGBTs in the inverter bridge. All the crucial parameters are also monitored by this DSP and in case of any unfavorable conditions, the converter is tripped off. Suitable experiments were carried out in this DC-DC converter under different loaded conditions and a close match between the simulated and experimental results were obtained. Such DC-DC converters can be connected in series or parallel for the development of solid state modular power supplies for various applications. (author)

  1. [Case study: school meals' management in Santiago de Cali and Bogota].

    Science.gov (United States)

    Díaz, Mónica del Pilar; Montoya, Iván A; Montoya, Luz A

    2011-10-01

    This research was aimed at ascertaining the state's role regarding hunger and how it manages to combat this matter; a food security program in two Colombian cities was thus assessed (i.e. school meals' provision in Cali and Bogota). A qualitative approach was adopted; documentary analysis, participant observation and in-depth interviews with various actors for both selected cases were used as data collection techniques. It was found that several measures taken in this area were not covered by regulatory principles aimed at covering all the dimensions of food security. Serious weaknesses in school meals' management in Cali were associated with a weak environment regarding the fight against hunger. School meals' management in Bogotá was aimed at recognizing the right to food as being supported by an institutional process where the issue of reducing hunger has become a firm purpose. School meals' program management was associated with the characteristics of its product, thereby affecting the program and the population's food and nutritional status; state management thus becomes another dimension of food security.

  2. Estimating of precursors and behavior of acid precipitation wet and dry, in the north of Bogota

    International Nuclear Information System (INIS)

    Garcia Lozada, Hector; Natal, Angelica; Esquivel, Antolinez; Diaz Alvarez, Cristian Julian

    2004-01-01

    Measurements of pH of the wet deposition were made in the north sector of Bogota, in two manual stations located to the East (Sans Facon) and to the West (Agustiniano Norte) of the northern highway, which served as the axis of the studied area, with an approximated extension of 54 km 2 . By means of an algorithm based on the model CORINAIR, the emissions of the precursors of acid rain were obtained: NOx (7665 T/y) and SO 2 (109 T/y). Between December 2002 and April 2003, 35 rain events were evaluated and it was found that 70% of the 17 rain water samples in the eastern sector and 83% of the 18 ones in the western sector, as viewed from the northern highway, show a pH smaller than 5.6, considered to be the natural value of the pH in rain. In the settled dust, to the west of the highway, the pH reached a value of 7.47, that to the east reached 7.78, while along monitoring lines the pH ranged between 5.71 and 6.70

  3. Critical revision of the technical aspects of sanitation of the Bogota river 1994 project

    International Nuclear Information System (INIS)

    Giraldo Eugenio

    1996-01-01

    A moral obligation exists on the part of the human societies of having designed to remove the contamination the environment that has been commended to manage and that it represents the inheritance that guarantees the survival of the species in the earth planet. It exists a growing recognition of this imperious necessity at the present time on the part of all the societies in the world that immediately opens the roads for the political exploitation of so praiseworthy feelings. Paradoxically, the environmentalist feelings don't always redound in a better protection for the nature and the environment, natural or urban. The reparation plan to continue for the Decontamination of the Bogot River; hired by the concession system the first stage of the same one, it is summarized in making three plants of treatment of located residual waters, each one of them in the outlets on the Bogota river of the main basins of drainage of the sanitary sewer system of the city. The treatment plants are of a conventional technology, mud activated that basically are designed to remove 90% of the contamination for organic matter that takes the sanitary sewer system of the respective basin. This level of achieved treatment is denominated in the technical literature as secondary treatment

  4. A pollen diagram from “Laguna de la Herrera” (Sabana de Bogota)

    NARCIS (Netherlands)

    Hammen, van der T.; Gonzalez, E.

    1965-01-01

    The Laguna de La Herrera (alt. ca 2550 m) is a lake situated on the western border of the Sabana de Bogotá, near Mosquera (dept. of Cundinamarca, Colombia) (fig. 2). This part of the Sabana has a relatively dry climate (appr. 600—700 mm rainfall), as it lies in the rain-shadow of the hills that

  5. High voltage dc cables

    Energy Technology Data Exchange (ETDEWEB)

    Bjustrom, B

    1965-12-01

    How stress distribution in dc cables varies with temperature and stress level, influence of polarity reversals and space charges, and different types of overvoltage to which dc cable may be subjected are discussed. Design problems, especially as related to corrosion protection and to mechanical stress caused by wire armoring during manufacturing and laying, accessories and work done on test methods, and the possibility of designing 400 to 600 kV dc cables for transmitting 2000 to 4000 MW are described.

  6. [Colombia 2015 National Mental Health Survey. Study Protocol].

    Science.gov (United States)

    Gómez-Restrepo, Carlos; de Santacruz, Cecilia; Rodriguez, María Nelcy; Rodriguez, Viviana; Tamayo Martínez, Nathalie; Matallana, Diana; Gonzalez, Lina M

    2016-12-01

    The 2015 National Mental Health Survey (NMHS) is the fourth mental survey conducted in Colombia, and is part of the National System of Surveys and Population Studies for health. A narrative description is used to explain the background, references, the preparation, and characteristics of the 2015 NMHS. The 2015 NMHS and its protocol emerge from the requirements that support the national and international policies related to mental health. Together with the Ministry of Health and Social Protection, the objectives, the collection tools, the sample, and the operational plan are defined. The main objective was to obtain updated information about the mental health, mental problems and disorders, accessibility to health services, and an evaluation of health conditions. Participants were inhabitants from both urban and rural areas, over 7 years old, and in whom the comprehension of social determinants and equity were privileged. An observational cross-sectional design with national, regional and age group representativity, was used. The age groups selected were 7-11, 12-17, and over 18 years old. The regions considered were Central, Orient, Atlantic, Pacific, and Bogota. The calculated sample had a minimum of 12,080 and a maximum of 14,496 participants. A brief summary of the protocol of the 2015 NMHS is presented. The full document with all the collection tools can be consulted on the Health Ministry webpage. Copyright © 2016. Publicado por Elsevier España.

  7. Family of multiport bidirectional DC-DC converters

    NARCIS (Netherlands)

    Tao, H.; Kotsopoulos, A.; Duarte, J.L.; Hendrix, M.A.M.

    2006-01-01

    Multiport DC-DC converters are of potential interest in applications such as generation systems utilising multiple sustainable energy sources. A family of multiport bidirectional DC-DC converters derived from a general topology is presented. The topology shows a combination of DC-link and magnetic

  8. Impact of payroll taxes for small shoe manufacturing enterprises profit generation in Bogota city 15th district

    Directory of Open Access Journals (Sweden)

    José Armando Hernández Bernal

    2016-04-01

    Full Text Available In this paper we illustrate the financial difficulties that payroll taxes would impose on small shoe manufacturing enterprises in Bogota City 15th district and how this would impose some restrictions for firms profit generation, when such contributions turns out to be a fixed cost. We present a brief on the legal framework as well as an econometric exercise that shows the relations between labor costs and profit generation for the footwear industry in the 15th urban district of Bogotá city.

  9. Strategic ecosystems of Colombia

    International Nuclear Information System (INIS)

    Marquez Calle German

    2002-01-01

    The author relates the ecosystems in Colombia, he makes a relationship between ecosystems and population, utility of the ecosystems, transformation of the ecosystems and poverty and he shows a methodology of identification of strategic ecosystems

  10. Contribución al conocimiento de los Machiloidea de Colombia (Archaeognatha: Insecta Contribución al conocimiento de los Machiloidea de Colombia (Archaeognatha: Insecta

    Directory of Open Access Journals (Sweden)

    Sturm Helmut

    1983-09-01

    Full Text Available Se describen cuatro nuevas especies y una subespecie de Meinertellidae recolectadas en Colombia y en un bosque pluvial cerca de Manaos, Brasil. Son las siguientes: Meinertellus adisi, M. bogotensis santaemartae, Neomachilellus aboucbaari, N. amazonicus y N. rangeli. Se discute la posición sistemática de los ejemplares recolectados cerca de Bogotá, en el valle del río Magdalena y en la Cordillera Oriental cerca de Neiva. Se da una clave para los géneros suramericanos de la familia.Four new species and one new subspecies of Meinertellidae occurring respectively in Colombia and in the rain forest near Manaus, Brazil, are described:  Meinertellus adisi, M. bogotensis santaemartae , Neomachilellus abouchaari, N. amazonicus and N. rangeli. The systematical position of specimens collected near Bogota, in the Magdalena Valley and in the Eastern Andes near Neiva is discussed. A key for the South American genera of the family is given.

  11. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  12. Shadow Toll in Colombia

    OpenAIRE

    González Ruiz, Juan David; Botero Botero, Sergio; Arboleda, Carlos Alejandro; Duque Grisales, Eduardo Alexander

    2015-01-01

    The growing development in infrastructure projects in Colombia has been linked to legal adjustments and capital markets. These two last factors have provided important elements for project developers to design funding strategies. Based on the shadow toll scheme, this paper proposes a new financing strategy for funding highway projects. This strategy may be implemented in Colombia. Finally, the paper proposes future research on shadow toll schemes as a financial mechanism.

  13. Multilevel DC link inverter

    Science.gov (United States)

    Su, Gui-Jia

    2003-06-10

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  14. Characteristics of the technical parameters in the realization of computed tomography studies in pediatric patients in Bogota

    International Nuclear Information System (INIS)

    Triana, Gustavo; Romero, Javier; Rivero, Oscar; Sosa, Daniel; Patarroyo, Edith

    2005-01-01

    The use of Computed Tomography (CT) examinations for the diagnosis of common pathologies in pediatric patients has increase. This implies an increase in the radiation doses that pediatric patients received, therefore increasing the risk of secondary mortality due to cancer throughout life. In recent papers, the recommended radiation doses for pediatric patients in agreement with the concept ALARA (As Low As Reasonably Achievable) has settled down. This study evaluates the CT technical parameters of pediatric examinations in Bogota city, and review if they have been fitted with parameters recommended according to age and body weight. Materials and methods: A non-probabilistic sampling of 46 scanning tests were applied to children in six different institutions in Bogota; the technical parameters of kv and second mAs were checked of studies in abdomen, thorax and skeletal muscle system. Results: It was found that the technical parameters used in TC in children are higher of the recommended; the group of 4-year-old is the most affected by dos e of unnecessary radiation. Discussion and conclusions: The information from the protection of the radiation must be spread to the whole radiology personnel of the institutions that fulfill scanning tests of pediatric patients. ar zones that influences the wetland

  15. Bidirectional dc-to-dc Power Converter

    Science.gov (United States)

    Griesbach, C. R.

    1986-01-01

    Solid-state, series-resonant converter uses high-voltage thyristors. Converter used either to convert high-voltage, low-current dc power to lowvoltage, high current power or reverse. Taking advantage of newly-available high-voltage thyristors to provide better reliability and efficiency than traditional converters that use vacuum tubes as power switches. New converter essentially maintenance free and provides greatly increased mean time between failures. Attractive in industrial applications whether or not bidirectional capability is required.

  16. A DC Transformer

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of the project was to demonstrate a true direct current (DC) transformer, a new electro-mechanical component with potentially high power applications; in...

  17. Chemical speciation of Pb, Ni Cr, Cu, Co and V in two natural soils and in an antropic agricultural soil contaminated by irrigation with the polluted Rio Bogota waters in its High Basin

    International Nuclear Information System (INIS)

    Matamoros, Adriana; Vargas, O; Mejia, L

    1999-01-01

    Traditional and continuous irrigation with the highly polluted waters of Rio Bogota in its upper basin has induced in soils, grasses and crops grown next to the river, a gradually increasing accumulation of highly toxic elements like Pb, Ni, Cr, Cu, Cd, Co, V and some others, which represents a real and very high risk for public health whenever grasses and edible crops growing on them absorb these elements above critical or permissible limits. To evaluate the magnitude of this problem three different soils of the Sabana were subjected to the chemical speciation procedure proposed by Tessier (1979) in order to determine: 1) the total content of essential and/or structural elements like Al, Fe, Ca, K, P, Mn and Ti, and the trace elements Pb, Ni, Cr, Cu, Cd, Co and V accumulated through time in the soils; 2) the relative proportion on which each one of them are linked to the different components or fractions of soils (ex. exchangeable, CO 3 , Fe/Mn oxides, O.M. and sulfides, and residual fraction) and 3) the bioavailability or amount of each that could be really absorbed by plants or able to go down to the underground water. Results showed in general for all soils normal values for the essential and/or structural elements and high to very high levels of Pb, Ni, Cu, Cd, Cr, Co y V, higher in Jardines de Colombia and Las Parcelas farms soils than in el Recreo farm soils. This situation is aggravated by the relatively high mobility and high concentration and bioavailability of some of these elements, which increase the risk for public health and the possibility of its migration down to the underground waters

  18. Asociacion de leveduras del genero Cryptococcus con especies de Eucalyptus en Santafe de Bogota Isolation of Cryptococcus sp. associated with Eucalyptus trees in Santafé de Bogota

    Directory of Open Access Journals (Sweden)

    A. Duarte

    1994-04-01

    Full Text Available El aislamiento de Cryptococcus neoformans var. gattii, serotipo B, a partir del medio ambiente se estableció inicialmente en Australia en 1989, en asocio con el Eucalyptus camaldulensis y posteriormente con E. tereticornis. Con estos hallazgos se postuló que desde allí, el hongo se ha podido exportar, por medio de las semillas contaminadas, a otras regiones geográficas, incluyendo Colombia. El objetivo de éste estudio fue identificar las levaduras del género Cryptococcus asociadas con especies de Eucalyptus sp., como primera evaluación en la ecología de C. neoformans var. gattii en nuestro país. Se realizó en Santafé de Bogotá, con una población de 100 árboles ubicados al centro, nororiente, oriente y occidente de la ciudad, recolectando de cada uno de ellos flores, frutos, hojas, cortezas y detritos; el procesamiento de las muestras incluyó extracción del material con una solución salina con antibióticos, siembra en medios selectivos e identificación de las especies con base en las características morfológicas, macro y microscópicas y bioquímicas. Se aislaron 27 cepas de Cryptococcus pertenecientes a 9 especies de Cryptococcus, a partir de 21 árboles ubicados en 5 zonas diferentes de la ciudad. Se aisló C. neoformans y se identificó como C. neoformans var. neoformans serotipo A. Estos datos iniciales son importantes como primera evaluación de la asociación de Cryptococcus sp. con los Eucalyptus en nuestro país.Environmental isolation of Cryptococcus neoformans var. gattii was first made in Australia in 1989 by ELLIS. He established a specific association with the tree species Eucalyptus camaldulensis and E. tereticornis. Based on his findings, ELLIS proposed that the fungus could be exported from Australia to others regions, including Colombia, by means of infected seeds. The purpose of this study was to isolate and identify Cryptococcus sp., associated with Eucalyptus trees; this is the first ecological evaluation

  19. [PHYSICAL ACTIVITY LEVELS, PHYSICAL FITNESS AND SCREE TIME AMONG CHILDREN AND ADOLESCENTS FROM BOGOTÁ, COLOMBIA].

    Science.gov (United States)

    Prieto-Benavides, Daniel Humberto; Correa-Bautista, Jorge Enrique; Ramírez-Vélez, Robinson

    2015-11-01

    to investigate the association between objective measures of physical activity levels, physical fitness and screen time in Colombia children and adolescents from Bogota, Colombia. a sample of 149 healthy Colombian youth, children and adolescents (9-17.9 years old) participated in the study. Physical activity level was assessed over 7 days using an accelerometer. Weight, height, waist circumference, hip waist, subscapular/ triceps skinfold thicknesses and self-reported screen time (television/internet and videogame-viewing time) were measured. Aerobic capacity, handgrip strength, standing broad jump, vertical jump, speed/agility and flexibility were used as indicators of physical fitness. in girls with a high level of physical activity had favorable aerobic capacity (r = 0.366) and inverse relationship with subscapular/triceps skinfold thicknesses (r = -0.257) and (r = -0,237) p < 0.05, respectively. In boys, vigorous physical activity were associated with higher values of flexibility (r = 0.277) and aerobic capacity (r = 0.347), p < 0.05. Finally, the participants who watched 2 h or less of television per day showed 1.81 times (95%CI 1.401 to 2.672) that met physical activity guidelines. the healthy Colombian youth who reported moderate to vigorous objective measures of physical activity levels, presented higher levels in physical fitness especially in aerobic capacity and flexibility and lower values in subscapular/triceps skinfold thicknesses. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  20. Pesticide Flow Analysis to Assess Human Exposure in Greenhouse Flower Production in Colombia

    Directory of Open Access Journals (Sweden)

    Claudia R. Binder

    2013-03-01

    Full Text Available Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.

  1. Three new DC-to-DC Single-Switch Converters

    Directory of Open Access Journals (Sweden)

    Barry W. Williams

    2017-06-01

    Full Text Available This paper presents a new family of three previously unidentified dc-to-dc converters, buck, boost, and buck-boost voltage-transfer-function topologies, which offer advantageous transformer coupling features and low capacitor dc voltage stressing. The three single-switch, single-diode, converters offer the same features as basic dc-to-dc converters, such as the buck function with continuous output current and the boost function with continuous input current. Converter time-domain simulations and experimental results (including transformer coupling support and extol the dc-to-dc converter concepts and analysis presented.

  2. Proyecto Ensamblando en Colombia

    OpenAIRE

    Kreime, Pablo; Gómez Morales, Yuri Jack; Ashmore, Malcolm; Miranda Canal, Néstor; Pérez Bustos, Tania; Vinck, Dominique; Amaya, José Antonio; Carvajal Marín, Luz Mery; Castro-Gómez, Santiago; Camargo Uribe, Juan Arturo; Dávila Dávila, Juan Manuel; Sebastián, Díaz Ángel; Duque Muñoz, Lucía; Durán-Sánchez, María Fernanda; García Álvarez, Claudia María

    2013-01-01

    Los dos volúmenes de esta obra reúnen los resultados del proyecto ganador de la «Convocatoria nacional de proyectos bicentenario 1810-2010 “Historia social de la ciencia, la tecnología y la innovación en Colombia: ciudadanía, saberes y nación”», lanzada por Colciencias en el 2009. El proyecto, titulado «Ensamblado en Colombia: producción de saberes y construcción de ciudadanías» se propuso estudiar la manera como se constituyen en el presente y se han constituido en el pasado «asuntos de inte...

  3. 78 FR 62947 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to the Foreign...

    Science.gov (United States)

    2013-10-22

    ...., Bogota, Colombia; c/o FERTILIZANTES LIQUIDOS DE LA SABANA LTDA., Bogota, Colombia; Calle 109 No. 21-41... 800099351-8 (Colombia) [SDNTK]. 3. FERTILIZANTES LIQUIDOS DE LA SABANA LTDA. (a.k.a. FERTILISA LTDA.), Calle...

  4. Three-port DC-DC converter with new integrated transformer for DC Distribution Systems

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Andersen, Michael A. E.

    2014-01-01

    A new integrated transformer for three-port dc-dc converter is proposed to overcome the power coupling effect existed in some known multiple inputs dc-dc converters. Orthogonal primary windings arrangement and in series connection of diagonal secondary Windings enables a fully power decoupling...

  5. 75 FR 23571 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-05-04

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... amends Sec. 39.13 by adding the following new AD: 2010-09-12 McDonnell Douglas Corporation: Amendment 39... to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

  6. Design and Testing of Boost Type DC/DC Converter for DC Motor Control Applications

    OpenAIRE

    Samman, Faizal Arya; Akil, Yusri Syam; Noor, Nirwan A.

    2017-01-01

    in The Proceeding of The 2nd International Symposium on Smart Material and Mechatronics 2015 This paper presents the design and testing of a boost type DC/DC converter circuit, which can be used for DC motor control applications. The Boost converter is designed using DC chopper and DC chopper cascade configurations. The experimental setup was made by connecting the boost converter circuit with four types of DC motor, i.e. self-excited DC motor shunt, series, compound and separately exci...

  7. IDRC in Colombia

    International Development Research Centre (IDRC) Digital Library (Canada)

    oceans, wastewater from poor urban com- munities could be treated and used to gener- ate energy. Mexican researchers lead the testing of wastewater treatment systems in Brazil, Colombia, Chile, Honduras, and. Mexico to identify the most appropriate technologies. Alternative energy (through biogas) could eventually ...

  8. El IDRC en Colombia

    International Development Research Centre (IDRC) Digital Library (Canada)

    gación de Colombia en salud, agri- ... y desarrollar una base nacional de datos ... apoyada por el IDRC mostró caminos para .... conocimiento con los formuladores de políticas, con otros investigadores y comunidades en todo el mundo.

  9. Control of improved full-bridge three-level DC/DC converter for wind turbines in a DC grid

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    transformer in the IFBTL dc/dc converter. A modulation strategy, including two operation modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the control of the wind turbine based on the IFBTL dc/dc converter......This paper presents an improved full-bridge three-level (IFBTL) dc/dc converter for a wind turbine in a dc grid by inserting a passive filter into the dc/dc converter to improve the performance of the converter. The passive filter can effectively reduce the voltage stress of the medium frequency...

  10. Overview of Multi-DC-Bus Solutions for DC Microgrids

    DEFF Research Database (Denmark)

    Ricchiuto, D.; Mastromauro, R.A.; Liserre, Marco

    2013-01-01

    DC Microgrids have recently received a lot of attention in the last years due to high penetration of renewable energy sources as well as distributed energy storage systems. In the future DC microgrids could be preferable respect to AC microgrids in terms of redundancy since multi-DC-Bus solutions...... could provide a continuative power supply to the loads. An overview of Multi-DC-Bus solutions is presented in this paper. The performances are compared on the basis of possible DC microgrid configurations, redundancy, different DC voltage levels....

  11. The process of Ethno-Racialization and Resistance in the Multicultural Age: Being Black in Bogota

    Directory of Open Access Journals (Sweden)

    Klára Hellebrandová

    2014-01-01

    Full Text Available This article is about the process of ethno-racialization in the multicultural era specifically in the context of Colombia nowadays. A wide comprehensive theoretical framework is taken as the basis (racialization, structural racism, multiculturalism, intersectionality, everyday racism. The analysis of primary sources and in-depth interviews to young African descents from Bogotá are used to argue that multiculturalism, as it has been developed on a legislative level and in the colombian public policies, is not a challenge for the racialized foundations of power and social relations and that there is a variety of mechanisms that seek to defend the privileges of the white-mestizo. However and simultaneously, we suggest that multiculturalism provides a number of opportunities to question the racialized social and political system and to develop strategies of resistance.

  12. [Cooperative learning for improving healthy housing conditions in Bogota: a case study].

    Science.gov (United States)

    Torres-Parra, Camilo A; García-Ubaque, Juan C; García-Ubaque, César A

    2014-01-01

    This was a community-based effort at constructing an educational proposal orientated towards self-empowerment aimed at improving the target population's sanitary, housing and living conditions through cooperative learning. A constructivist approach was adopted based on a programme called "Habitat community manger". The project involved working with fifteen families living in the Mochuelo Bajo barrio in Ciudad Bolívar in Bogotá, Colombia, for identifying the most relevant sanitary aspects for improving their homes and proposing a methodology and organisation for an educational proposal. Twenty-one poor housing-related epidemiological indicators were identified which formed the basis for defining specific problems and establishing a methodology for designing an educational proposal. The course which emerged from the cooperative learning experience was designed to promote the community's skills and education regarding health aimed at improving households' living conditions and ensuring a healthy environment which would allow them to develop an immediate habitat ensuring their own welfare and dignity.

  13. Promoción de la salud en la primera infancia: estrategia jardines infantiles promotores de la salud para la localidad de Santa Fe - Bogota D.C.

    OpenAIRE

    Camargo, Ramos; Tique, Zubieta

    2012-01-01

    La primera infancia ha sido considerada la fase de desarrollo más importante de todo el ciclo vital. Es un período fundamental en la constitución del ser humano, de sus competencias, habilidades y de su manera de relacionarse con el mundo. Durante la niñez se llevan a cabo importantes procesos de maduración y aprendizaje que son los que permiten interactuar, integrarse y desarrollar al máximo las potencialidades como persona. El sano desarrollo infantil, se ha relacionado con la disminución d...

  14. Multi Bus DC-DC Converter in Electric Hybrid Vehicles

    Science.gov (United States)

    Krithika, V.; Subramaniam, C.; Sridharan, R.; Geetha, A.

    2018-04-01

    This paper is cotncerned with the design, simulation and fabrication of the prototype of a Multi bus DC- DC converter operating from 42V DC and delivering 14V DC and 260V DC. As a result, three DC buses are interconnected through a single power electronic circuitry. Such a requirement is energized in the development of a hybrid electric automobile which uses the technology of fuel cell. This is implemented by using a Bidirectional DC-DC converter configuration which is ideally suitable for multiple outputs with mutual electrical isolation. For the sake of reduced size and cost of step-up transformer, selection of a high frequency switching cycle at 10 KHz was done.

  15. dc Arc Fault Effect on Hybrid ac/dc Microgrid

    Science.gov (United States)

    Fatima, Zahra

    The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

  16. Loodushariduse mammutkongress Colombias / Aarne Tõldsepp

    Index Scriptorium Estoniae

    Tõldsepp, Aarne

    2009-01-01

    Sel suvel toimunud rahvusvahelisest matemaatika- ja loodushariduse kongressist Colombia ajaloolises sadamalinnas Cartagenas, mille peakorraldajaks oli 19 aastat tagasi Valgevenest Colombiasse emigreerunud professor Juri Orlik

  17. Early Oscillation Detection for DC/DC Converter Fault Diagnosis

    Science.gov (United States)

    Wang, Bright L.

    2011-01-01

    The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.

  18. The caves of Cunday (Colombia, South America)

    NARCIS (Netherlands)

    Hammen, van der Th.; Nelson, H.W.

    1955-01-01

    A short time ago rumors reached Bogota that a big cavesystem had been discovered by some farmers in the southwest of the department of Tolima, between the villages of Cunday and Purificación. This region belongs morphologically and geologically to the Eastern Cordillera, and forms the westernmost

  19. Colombia vista desde afuera

    Directory of Open Access Journals (Sweden)

    Boletín Cultural y Bibliográfico Banco de la República

    1984-06-01

    Full Text Available Mucha de la bibliografía sobre Colombia no se conoce en el país. Cada año se realizan centenares de trabajos acerca de diferentes aspectos de las ciencias naturales, sociales, o sobre literatura, que a la postre quedan archivadas en bibliotecas europeas o estadounidenses, como ocurre de manera específica con los trabajos presentados como tesis de grado en universidades extranjeras.

  20. An estimation of Iodine 131 intakes for occupational workers of nuclear medicine group at the Instituto Nacional de Cancerologia, Bogota, Colombia

    International Nuclear Information System (INIS)

    Nino, Nelcy Yasmin; Lagares, Luis Carlos; Veloza, Luz Stella; Martinez, Maria Cristina; Reyes, Amelia de los

    2008-01-01

    Full text: In nuclear medicine, unsealed radioactive substances are administered to patients for diagnosis, treatment or research. The manipulation of these radionuclides, particularly those volatile, like iodine 131 (I-131), generates a risk of internal contamination by ingestion and inhalation. The inhaled radioactive particles are retained in the lungs or uptake by the thyroid tissue and could produce health effects. The IAEA provides regulatory practices in handling radioactive material to reduce internal contamination in the staff, based on the radiation protection principle to achieve occupational doses as low as reasonably achievable (ALARA). A quality assurance program in radioprotection should include the monitoring of occupational intakes. This paper describes a pilot study which determined quantitative methods to monitoring the nuclear medicine staff. The estimates of intakes and doses of I-131 were derived from the review and interpretation of urine monitoring data, using a Ludlum model 203 Shielded Well Scintillator (2 inches diameter x 1.8 inches thick), with a ratemeter model 2200. This study included workers occupationally exposed to I-131: physicians, technicians, radio pharmacists and physicists. The initial tests of the activity levels of I-131 in urine showed an average MPBB (Maximum Permissible Body Burden) of 0.035%, i.e. 0.025 μCi. Comparing with the maximum value of whole body 0.7μCi, the percentages of I-131 MPBB indicate the presence of small activities of I-131 in the urine, suggesting low-level chronic exposures from occupational workers in Nuclear Medicine. The higher values are the medical personnel who perform treatments for thyroid disorders. Conclusion: To do statistically significant the sampling and to protect individuals in each area it should be considered the daily urinary excretion, which is due to implement a protocol for regular assessment of the levels of incorporation of iodine 131 for jobs and activities, personnel in nuclear medicine. The training of the workers in safety principles and good practice in handling iodine should be continuously reinforced. The Instituto Nacional de Cancerologia will have a Thyroid Uptake Systems Captus 3000 Capintec for direct measurements of internal contamination. (author)

  1. Comparison of Lactic Acid, Peracetic Acid and Sodium Hypochlorite in Disinfection of Bovine Carcasses at a Meat Processing Plant in Bogota, Colombia

    OpenAIRE

    Valencia Montero, Verónica; Acero Plazas, Víctor

    2013-01-01

    Disinfection systems play an important role in reducing microbiological hazards in cattle carcasses. Disinfection is used in processing plants to decrease the number of pathogenic microorganisms present in the surface of the product. This study evaluated the efficacy of three disinfectants: lactic acid (0.9 ± 2%), peroxyacetic acid (100 ± 20 ppm) and sodium hypochlorite (100 ± 20 ppm) in reducing Escherichia coli and Salmonella spp. in the surface of bovine carcasses within the premises of a ...

  2. REPRESENTACIONES SOCIALES DE AMBIENTE Y EDUCACIÓN AMBIENTAL EN EL C.E.D. LA CONCEPCIÓN (BOGOTA-COLOMBIA

    Directory of Open Access Journals (Sweden)

    Jenny Johanna Duarte Díaz

    2014-05-01

    Full Text Available En la actualidad en las instituciones educativas existe dificultad por construir prácticas relacionadas con temas ambientales, a consecuencia de que no hay suficiente claridad en la forma de diseñar e implementar propuestas, propiciando que lo abordado desde los proyectos ambientales no tenga el impacto esperado. Razón que genera la necesidad de iniciar procesos investigativos que establezcan coherencia en las posturas curriculares, políticas nacionales y los contextos escolares en los que está inmersa la educación ambiental.   Por lo cual, el presente estudio se planteó con el objetivo de identificar las representaciones sociales frente al ambiente y la educación ambiental que poseían algunos miembros de una institución educativa de carácter público en Bogotá. Con el fin de iniciar procesos formativos que lleven a trabajar la educación ambiental de manera interdisciplinar en la escuela desde miradas reflexivas, que nos permitan construir una visión global del ambiente.   Para lo cual se utilizó un enfoque metodológico cualitativo apoyado en la técnica de entrevistas y como instrumento el cuestionario.   Concluyendo que el grupo de participantes no presentan una única representación social de ambiente definiéndolo desde tres miradas: como el medio de vida, los recursos a utilizar y la naturaleza. Y la educación ambiental desde las visiones naturalista, conservacionista - recursista y humanista. Evidenciando la importancia de generar más que actividades puntuales, procesos formativos en educación ambiental que vinculen a los diversos sujetos de las comunidades educativas.

  3. Thyristors for dc transmission

    Energy Technology Data Exchange (ETDEWEB)

    1966-05-06

    As a first stage towards determining the feasibility of applying thyristors to hvdc converter terminals, the Westinghouse Electric Corporation has built a converter laboratory capable of testing thyristors under conditions similar to those which would have to be met in a 200 kV dc system. The equipment has been designed to test a 5 kV 600 A group of thyrisotrs, elevated 200 kV above earth. This rating has been chosen so that there would be a sufficient number of thyristors in series to enable the gating and voltage division characteristics to be investigated and at the same time the group could be operated at a potential equivalent to a complete 200 kV dc bridge.

  4. Aproximación inicial de un modelo eficiente y sostenible de gestión de los residuos de la construcción y demolición RCD en la ciudad de Bogotá DC-Colombia

    OpenAIRE

    Cubillos Rojas, Néstor Raúl

    2017-01-01

    La construcción es uno de los ejes estructurales de las economías mundiales, por lo tanto se constituye en sector determinante para el desarrollo y evolución continua de las ciudades, por esta razón, para generar un cambio en los hábitos y adaptabilidad de los ocupantes de las urbes obligatoriamente se debe intervenir el territorio; intervención que trae consigo múltiples afectaciones en su mayoría medio ambientales. En Bogotá, siendo la capital de Colombia, es la ciudad de mayor crecimien...

  5. TOPOLOGICAL REVIEW AND ANALYSIS OF DC-DC BOOST CONVERTERS

    Directory of Open Access Journals (Sweden)

    V. INDRA GANDHI

    2017-06-01

    Full Text Available DC voltage boost up is essential in numerous applications; especially considering Photovoltaic (PV based renewable power generation system. The conventional DC-DC boost converter is the most admired configuration for this scheme, even if the converter efficiency is restricted at duty cycle near to maximum value. In order to find solution to the problem and improve its conversion capability, many converter configurations have been implemented so far. With this circumstance, this research work proposes to give overview of a few most imperative research works related to DC-DC boost converters. Some configurations are covered and classified basically based on the application. The major benefits and disadvantages related to the available techniques are also briefly conveyed. At last, a proper evaluation is recognized among the important types of DC-DC boost converters in terms of efficiency, number of components, and stability.

  6. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    OpenAIRE

    Liwen Pan; Chengning Zhang

    2016-01-01

    This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs). The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for m...

  7. 78 FR 47492 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2013-08-05

    ... PROYECTOS Y SOLUCIONES S.A., Bogota, Colombia; c/ o PROYECTOS Y SOLUCIONES INMOBILIARIA LTDA., Bogota, Colombia; c/o GERENCIA DE PROYECTOS Y SOLUCIONES LTDA., Bogota, Colombia; c/o ACUICOLA SANTA CATALINA S.A...; NIT 805027303-4 (Colombia) [SDNT]. 7. PROYECTOS J.A.M. LTDA. Y CIA. S. EN C., Calle 74 No. 53-23 of...

  8. Non - Vegetated Standard Bioretention Structure Hydrodynamic Soil Characterization For Ponding - Layer Optimum Thickness Determination With A Distinctive Urban - Region Rainfall Event In Bogota

    Science.gov (United States)

    Velasco Ávila, Frank; Acero Rivero, Germán Eduardo; Angulo Jaramillo, Rafael

    2017-04-01

    Aiming to propose a system, in accordance with Best Management Practices (BMP) kind of structures, specifically a standard bioretention system in Bogota city, and in order to apply the inverse solution methodology on Hydrus - 1D, it is mandatory to determine each θ_s; θ_r; α;n and ks parameters in van Genuchten - Mualem function, without considering the hysteresis phenomenon, for a standard bioretention system composing soils, as well as required components and dimensions to implement the bioretention structure in Bogota. First, a bioretention structure general dimensioning was carried out based on current urban landscaping regulations and recommendations given by the sewage - system service provider in Bogota city. Soil composing and design were performed after information gathering and previous investigation on bioretention systems dimensioning from different sources such as manuals. To give an adequate interpretation of the vadose zone, a soil column experimental prototype was built to be able to control and measure the intervening parameters in the subsoil unidimensional flow description, such as capillary pressure, soil water saturation, inflow and outflow. Thirteen sensor - based devices were built to measure the inverse model required parameters. It is important to underline that all the designed instrumentation was based on low cost electronic development. In addition, the whole instrumentation system is controlled by an Arduino Mega PLC and was designed and built as a personal initiative by the author of this work. For signal processing and data capturing, a commercial Lab View version intuitive program was designed, to be able to create a user-friendly interface to make real-time sensor visualisation and control. Finally, all the hydrodynamic characterisation for the studied soils was made through a Hydrus-1D inverse model and laboratory experimenting and obtained results. In addition, several direct models were run in order to determinate both

  9. The decision of the International Court of Justice related to preliminary exceptions in the Nicaragua v. Colombia case

    Directory of Open Access Journals (Sweden)

    Rafael Nieto Navia

    2010-05-01

    Full Text Available This article is divided into three main parts. The fi rst part presents the precedents in the case relating to delimiting the Caribbean Sea boundary between Nicaragua and Colombia. It analyzes the competence of the International Court of Justice – ICJ (the Court in accordance with Article 36 of the Statute of the Court; consequently, it studies the Declaration of the acceptance of the Competence of the Court presented by Colombia to the Permanent Court of International Justice in 1937 as well as the Bogota Pact of 1948 as to its applicability and breadth as regards the 1928 EsguerraBárcenas Treaty. The second part presents a detailed analysis of the decision of the Court on the preliminary exceptions in which it was determined that the sovereignty of the islands of San Andres, Providencia, and Santa Catalina was Colombian, that the Esguerra-Bárcenas Treaty was not treaty delimiting maritime boundaries and that it (the Court was competent to get to the foundation of the matter. The third part sets out the actions which still must be completed relative to the foundation of the case.

  10. Modeling of primary production of phytoplankton in the wetland Jaboque, Bogotá D.C.

    Directory of Open Access Journals (Sweden)

    Julio Eduardo Beltrán Vargas

    2016-02-01

    Full Text Available A dynamic simulation model is presented to explain the general behavior of the  primary production of phytoplankton in the wetland Jaboque - Bogota, Colombia, in three sections with differential physical and chemical characteristics. The model takes into account the physicochemical variables, the basin area, depth, annual rainfall, water temperature, pH and concentration of chlorophyll _a. The dynamic modeling is based on differential equations and the Euler integration method is used, the modeling was developed using Stella 9.1® computer program. The model allows quantifying the primary production of phytoplankton in wetland Jaboque from chlorophyll _a monthly average concentration for each section. The results of the Ppf modeling show that Ppf concentration variations  in each section of the wetland follow a reverse pattern to the bimodal behavior of precipitation. A high degree of correspondence between the values of chlorophyll_a Ppf field and modeled in the following manner r2 = 0.86 for the first section and r2 = 0.86 and r2 = 0.79 for the remaining sections was found. Error determination was 0,57 relative to the first section and 0,35; 0,46, indicating that the results are not overstated. The model shows in general terms the functional aspects of behavior Ppf and its relation to the process of eutrophication, and it allows recommendations for the management and restoration of wetlands.

  11. Colombia science without future

    Directory of Open Access Journals (Sweden)

    Alexander Pérez-Cordero

    2017-12-01

    Full Text Available Colombia no será nada hasta que no se eduque su gente, es un país que está retrasado intelectualmente; un país que no valora la ciencia es porque nadie les ha enseñado a sus ciudadanos su valor y sus dirigentes no lo entienden, es porque no les interesa, según lo comentó GINAS, (2004. “El futuro de Colombia va a estar profunda y directamente relacionado con la capacidad que los colombianos tengamos de organizar la educación; la hija de la educación: la ciencia; y la hija de la ciencia: la tecnología-GINAS, 1993” (CORREA, 2017, hoy la ciencia en Colombia no tiene futuro; la inversión pública para ciencia disminuirá para el año 2018 en 41.5 %. El punto de inversión más alto fue de $430.150 millones para el año 2013; para 2014 bajó a $376.768 millones, en 2015 pasó a $332.197 y en 2016 perdió otra porción y se redujo a $304.516 millones. Este año bajó hasta $299.177 millones y para el 2018 se prevé será el más bajo en una década, con apenas $220.506 millones (CORREA, 2017. Las mayores repercusiones se reflejarán en el congelamiento de nuevas becas para programas doctorados y en el presupuesto para convocatorias de proyectos de investigación (EL ESPECTADOR, 2017.

  12. Energetic Planning in Colombia

    International Nuclear Information System (INIS)

    Lombana V, Jorge E

    1998-01-01

    In the country one of the most dynamic sectors in the last years, it has been the mining - energy sector that has had rates of increase superiors to 5%. The most critical situation corresponds to the sector of hydrocarbons, where the exploration in Colombia has arrived at its lower historical levels as they are those of 22 and 30 perforated wells, and 2148 and 2300 acquired kilometers of seismic 2d, in the years of 1996 and 1997, that which doesn't agree with the National Energy Plan NEP that inclined to perforate 100 exploratory wells per year, for the period 1997 - 2010, with the purpose of maintaining the production of 1.0 mbd starting from the year 2000 and this way to avoid that Colombia loses its self-sufficiency and be importer in the 2004 again. The oil politics in charge of the Ecopetrol, will have to be revised with different approaches if one wants a reactivation, because from 1989, year in that included the escalation clause, not alone it has not been possible to increase the exploration, but rather it has fallen at the mentioned levels. In the electric sector; the Regulation of Energy and Gas Commission - REGC, has been a supremely difficult to put priorities, because measures and immediate and urgent changes are needed. To medium term, Colombia should solve its institutional, normative problems and of infrastructure, to be able to have a true integral planning, that takes us to receive the next millennium with true energy self-sufficiency and a consolidation of the country in the export of coal and petroleum, if they take the necessary measures and avoid the lost of the self-sufficiency in hydrocarbons

  13. On and off controlled resonant dc-dc power converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter comprising an input side circuit comprising a positive and a negative input terminal for receipt of an input voltage or current and an output side circuit comprising positive and negative output terminals for supply of a converter...... output voltage and connection to a converter load. The resonant DC-DC power converter further comprises a rectification circuit connected between an output of a resonant network and the output side circuit. The resonant network is configured for alternatingly being charged from the input voltage...... or current and discharged through the rectification circuit by a first controllable switch arrangement in accordance with a first switch control signal. A second controllable switch arrangement of the resonant DC-DC power converter is configured to select a first impedance characteristic of the resonant...

  14. Las serpientes en colombia

    OpenAIRE

    Daniel, H.

    2012-01-01

    El estudio de las serpientes en Colombia no deja de tener su particular interés; existe una inmensa variedad de especies que se escalonan desde los valles ardientes hasta alturas relativamente considerables; en estos últimos puntos disminuye notablemente la variedad de formas y de modo especial las especies provistas de veneno. Hacer una distinción entre las especies venenosas y las inofensivas, resulta un tanto difícil; en algunos textos se dan unas cuántas reglas, pero la mayor parte d...

  15. Serpientes de colombia

    OpenAIRE

    M., Rodrigo Ángel

    2013-01-01

    En este libro es una guía práctica sobre las serpientes de Colombia en cuanto a su clasificación y tratamiento del envenenamiento causado por sus mordeduras. Contiene los siguientes capítulos: 1. Características generales, 2. Serpiente Colombianas, 3. Aparato venenoso, 4. Clasificación fisiopatología de los efectos del veneno, 5. Mordedura por serpientes venenosas en Antioquía, listas de nombres populares y científicos, la bibliografía. Esta es una introducción a esta práctica guí...

  16. Aging in Colombia

    Directory of Open Access Journals (Sweden)

    María Lourdes SANTOS PÉREZ

    2015-12-01

    Full Text Available Using data from statistical sources and official reports, we propose a critical approach to aging in Colombia, specifically from the point of view of public policy in progress or in planning. Our main hypothesis is that these measures refuse comprehensive treatment of the ageing in terms of needs and rights promoting a pure welfare system which, instead, contributes to reinforce a collective imagination of a dependent and impoverished old age, with «fatal» consequences that sustain and reproduce the socioeconomic system.

  17. DC Cable for Railway

    Science.gov (United States)

    Tomita, Masaru

    The development of a superconducting cable for railways has commenced, assuming that a DC transmission cable will be used for electric trains. The cable has been fabricated based on the results of current testing of a superconducting wire, and various evaluation tests have been performed to determine the characteristics of the cable. A superconducting transmission cable having zero electrical resistance and suitable for railway use is expected to enhance regeneration efficiency, reduce power losses, achieve load leveling and integration of sub-stations, and reduce rail potential.

  18. Three-Dimensional Mantle Flow Near an Oceanic Paleotransform Fault System: Geological Constraints From the Bogota Peninsula, New Caledonia

    Science.gov (United States)

    Chatzaras, V.; Kruckenberg, S. C.; Titus, S.; Tikoff, B.; Teyssier, C. P.; Drury, M. R.

    2016-12-01

    We provide geological constraints on mantle deformation across a system of two oceanic paleotransform faults exposed in the Bogota Peninsula area, New Caledonia. Mantle deformation occurred at depths corresponding to temperatures of 900 oC and is highly heterogeneous. The paleotransform faults consist of mylonitic shear zones ( 1 km wide), and are surrounded by broader areas in which rotation of both the shape fabric (foliation and lineation) and olivine crystallographic preferred orientation (CPO) takes place. Outside the plaeotransform faults, mantle flows oblique to the strike of the mylonitic zones and is characterized by lateral variations in the flow direction. To further constrain the kinematics and type of deformation, we determine the orientation of the crystallographic vorticity axes as an independent tool for constraining deformation geometry (e.g., simple shear, transpression, transtension). The observed mantle flow is associated to lateral variations in: 1) the geometry and degree of anisotropy of spinel shape fabric; 2) olivine CPO type; 3) amount of stretching; and 4) the orientation of the crystallographic vorticity axes. Upper mantle in the vicinity of oceanic transform faults may be characterized by complex, three-dimensional flow patterns and deformation geometries deviating from simple shear.

  19. Drugs of abuse consumption in health professionals (physicians and nurses from two outpatient services of first level attention in Bogota

    Directory of Open Access Journals (Sweden)

    Lara-Hidalgo Catalina

    2012-03-01

    Full Text Available We conducted a study to establish the prevalence of drugs of abuse consumption in physiciansand nurses in two health institutions in Bogota outpatient identify the frequency of consumption,to establish the prevalence of alcoholism using the CAGE questionnaire and explore the interestparticipate in prevention or reduction of consumption in the workplace. Materials and methods: Across-sectional study by applying an anonymous survey. Results: There were 58 questionnaires (38in physicians and 20 nurses. The substances most consumed in both groups were alcohol, cigarettesand energy drinks, followed on medical by marijuana in nursing followed by barbiturates, antidepressants,amphetamines and opiates. The prevalence of alcoholism was greater than 8% in bothgroups. 58% of physicians and 70% of nurses would participate in the design of occupational healthprograms to reduce the consumption of psychoactive substances. Conclusions: The use of drugs ofabuse is higher that found in the literature for most of the substances in the general population andis similar to the revised health personnel. It recommends the formulation and implementation ofcorporate policy within the framework of occupational health work of these institutions, aimed atreducing and preventing the consumption of psychoactive substances.

  20. Auxiliary resonant DC tank converter

    Science.gov (United States)

    Peng, Fang Z.

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  1. PENGGUNAAN FUZZY LOGIC UNTUK KONTROL PARALLEL CONVERTER DC-DC

    Directory of Open Access Journals (Sweden)

    Bambang Prio Hartono

    2012-09-01

    Full Text Available Abstract: Using system fuzzy logic as control  technology have been used on low load dc-dc converter with combined parallel compiled  dc-dc converter can  obtain big load.   With existence of differrence of component parameter and each parallel compiled converter can obtained different current  and voltage output.  Function of controller  for to do adjustment, so that current which is applied  to  load by each converter  can be obtained  difference error as small as possible or same. The object of research is developing design of large signal dc-dc converter which is  combined with using  FLC so that  obtain  better performance.  To get better performance have been made plant model and simulation with CDE method.  The more systematic  system and design is needed to overcome bigger load  on dc-dc converter, so that parallel  compiled current master slave control system on dc-dc converter with using fuzzy logic  controller is used. Result of  research showed that error or difference of  current  which is applied to load can handled by fuzzy logic  controller.  Technic of current and voltage controller co to do adjustment current and voltage distribution  equally to load.  Distribution of iL1,iL2 and  output voltage Vo on dc-dc  converter with load 2,25 until  7,875 and voltage  100  until 120 volt,  load current beetwen  12 until 48, % relatif  error  Vo  0,4% until  0,9%.

  2. Step-Up DC-DC Power Converter

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a step-up DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage and an input...... being charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier in accordance with a switch control signal to produce the converter output voltage. The step-up DC-DC power converter comprises an electrical short-circuit connection across the galvanic...

  3. DC Distribution Systems and Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Anvari-Moghaddam, Amjad; Quintero, Juan Carlos Vasquez

    2017-01-01

    summarized. Due to its attractive characteristics in terms of compliance with modern generation, storage and electronic load technologies, high reliability and current carrying capacity, as well as simple control, DC systems are already an indispensable part of power systems. Moreover, the existing......A qualitative overview of different hardware topologies and control systems for DC MGs has been presented in this chapter. Some challenges and design considerations of DC protections systems have also been discussed. Finally, applications of DC MGs in emerging smart grid applications have been...... challenges such as protection issues will be effectively resolved in the near future due to fast progress of semiconductor technology which is a key enabler cheap and reliable future DC solid-state protection systems. Therefore, it is the view of the author that more and more DC systems will appear...

  4. Observatorio de Política Internacional I. COLOMBIA - Colombia. Crónica de un proceso de paz fracasado

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  5. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  6. SCM Handbooks for dc-to-dc Converters

    Science.gov (United States)

    Lee, F.; Mohmoud, M.; Yu, Y.

    1984-01-01

    Two documents aid in design of control modules for dc-to-dc converters. Features of SCM include: Adaptive stability, power component stress limiting, implementation of various control laws, unified design approach. Analysis and quidelines contained in handbooks enable engineer to design SCM circuit and confidently predict resulting overall performance.

  7. Sheppard-Taylor Isolated High Boost DC-DC Converter

    DEFF Research Database (Denmark)

    Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri

    2017-01-01

    This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can...

  8. Dc-To-Dc Converter Uses Reverse Conduction Of MOSFET's

    Science.gov (United States)

    Gruber, Robert P.; Gott, Robert W.

    1991-01-01

    In modified high-power, phase-controlled, full-bridge, pulse-width-modulated dc-to-dc converters, switching devices power metal oxide/semiconductor field-effect transistors (MOSFET's). Decreases dissipation of power during switching by eliminating approximately 0.7-V forward voltage drop in anti-parallel diodes. Energy-conversion efficiency increased.

  9. A Current-Fed Isolated Bidirectional DC-DC Converter

    DEFF Research Database (Denmark)

    Sun, Xiaofeng; Wu, Xiaoying; Shen, Yanfeng

    2017-01-01

    This paper proposes a current-fed isolated bidirectional DC-DC converter (CF-IBDC) which has the advantages of wide input voltage range, low input current ripple, low conduction losses, and soft switching over the full operating range. Compared with conventional CF-IBDCs, the voltage spikes...

  10. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  11. A propósito de la introducción de aislamientos de Phytophthora infestans para investigación en Colombia Sorne thoughts concerning the import of the mating type A2 of Phytophthora infestans into Colombia

    Directory of Open Access Journals (Sweden)

    García Dominguez Celsa

    1997-12-01

    Full Text Available Phitophthora infestans es un patógeno heterotálico que requiere dos tipos de apareamiento, A 1 y A2, para que haya reproducción sexual. El tipo A 1 se encontraba distribuido en todas las zonas productoras de papa del mundo; pero, al final de los años 1970s el tipo A2 salió de México (su centro de origen, hacia Europa y al resto del mundo. Como en Colombia no se conocía la composición de las poblaciones de este patógeno, dos grupos de investigación de la Universidad Nacional iniciaron su estudio. El grupo de la Sede Bogotá optó por la importación del tipo A2 para realizar los trabajos de investigación. El presente comunicado es una reflexión sobre los riesgos y los cuidados que se deben tener al importar un patógeno que no está
    presente en el país.Phytophthora infestans is an heterothallic pathogen that requires the presence oftwo mating types, A1 and A2, for sexual reproduction. The A1 type had a worldwide distribution, but at the end of the 70s the A2 migrated from Mexico (the center of origin to Europe and from there to the rest of the world. Since in Colombia there was no information conceming the composition of the population of this pathogen, two research groups from the Universidad Nacional de Colombia initiated studies to determine the composition of the population of this pathogen. The group from Bogota imported the A2 type. The present work contains some thoughts on the risk involved when importing alien and exotic pathogens.

  12. A DC Transformer

    Science.gov (United States)

    Youngquist, Robert C.; Ihlefeld, Curtis M.; Starr, Stanley O.

    2013-01-01

    A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply can be stepped up (or down) with a corresponding step down (or up) in current. The basic theory for this device is developed, performance predictions are made, and the results from a small prototype are presented. Based on demonstrated technology in the literature, this de transformer should be scalable to low megawatt levels, but it is more suited to high current than high voltage applications. Significant development would be required before it could achieve the kilovolt levels needed for de power transmission.

  13. PLAN COLOMBIA: Some Differing Perspectives

    National Research Council Canada - National Science Library

    Marcella, Gabriel

    2001-01-01

    This monograph, with an introduction by Dr. Gabriel Marcella, includes four short, but interesting and important papers presented at a conference on Plan Colombia, sponsored by the Strategic Studies Institute of the U.S...

  14. Gravity Data For Colombia 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (9,050 records), were observed and processed by the Instituto Geografico Agustin Codazzi(IGAC), in Colombia from 1958 to 1996. This data...

  15. The performance of the DC motor by the PID controlling PWM DC-DC boost converter

    OpenAIRE

    Can, Erol; Sayan, Hasan Hüseyin

    2017-01-01

    This paper presents the PID controlling direct current (DC) to the direct current boost converter feds DC motor which has a 3.68 kW and 240 V of DC voltage input on its characteristics. What is first formed is the boost converter mathematical model at the design stage. Secondly, a mathematical model of the DC motor is created so that the boost converter with the machine can be established and modeled at the Matlab Simulink. The PID controller is considered for arranging a pulse width modulati...

  16. Contamination of rice (Oryza sativa L) with Cadmium and Arsenic by irrigation with the Bogota River water in rice soils of the Lower Basin

    International Nuclear Information System (INIS)

    Montenegro, Omar; Mejia L

    2001-01-01

    In this study, field and greenhouse experiments were simultaneously carried out with rice (oryza sativa l., variedad oryzica-1) in soils of the Bogota River lower basin (Los Manueles Series, a member of the clayed, mixed, isohipertermic family of the Fluventic Vertic Haplustepts) to evaluate the effect of Cd and As content of the irrigation waters (of the Bogota River and greenhouse) on soils and: 1) rice growth physiological parameters; 2) Cd and As accumulated in different parts of rice plants; 3) yields and other aspects and properties of rice crop. The results lead to the following conclusions: 1) The Cd and As content of the Bogota River water, increased during the driest months and was minimum in those with the highest precipitation; Cd and As concentrations in both seasons surpassed the maximum permissible limits. 2) Rice height was highest when irrigation water does have neither Cd nor As. Effects of both elements showed an inverse lineal tendency. 3) The gradual increase of Cd in irrigation water reduced in 12.5% the number of grains per panicle; the increase of As induced a 10% reduction. 4) The highest concentration of Cd and As in irrigation waters significantly reduced yields; maximum yields l were obtained when Cd and As were absent from irrigation waters. 5) For any concentration of As in irrigation water the highest concentration of Cd was accumulated in rice leafs when concentration of Cd 2 was 2mg/l; above this value Cd accumulation in leafs el decreased with the gradual increase of As concentration. 6) Cd and As accumulated in rice grains increased with the gradual increment of both elements in the irrigation waters; Cd and As accumulated were respectively 50 and 15 times higher than the maximum critical levels proposed for rice grains. 7) Cd and As accumulated progressively on soils with gradual increase of both elements in irrigation waters 8) Cd and As concentration in irrigation waters apparently does not affect the rice mill behavior

  17. LAS MIGRACIONES INTERNACIONALES EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Maguemati Wabgou

    2012-01-01

    Full Text Available El artículo expone los resultados de una investigación sobre los flujos migratorios internacionales que han estado llegando a Colombia desde el siglo XVI hasta la actualidad. La metodología investigativa se fundamenta en la recolección y el análisis de datos derivados de investigaciones anteriores. Los resultados son significativos en lamedida que presentan el estado de las migraciones en Colombia entre los siglos XVI y XIX y desde la primera mitad del siglo XX hasta la actualidad. Por un lado, engloban a la inmigración británica, jamaiquina y africana en las islas de San Andrés y Providencia; junto con la inmigración árabe, judía, alemana, francesa, italiana y gitana en Colombia continental. Por otro, aluden a las migraciones japonesas, suramericanas, junto con los crecientes asentamientos de migrantes norteamericanos, europeos y las nuevas oleadas de migraciones asiáticas y africanas en Colombia. Todo ello lleva a aprehender la envergadura del papel jugado por Colombia como un país de destino de las migraciones internacionales, lo que contrasta con la imagen más conocida de Colombia como un país expulsor de emigrantes.

  18. Sertula Florae Colombiae, II

    Directory of Open Access Journals (Sweden)

    Uribe Uribe Lorenzo

    1955-08-01

    Full Text Available En el presente artículo el autor registra como nuevas para Colombia varias especies pertenecientes a las Familias botánicas Aristolochiaceae, Passifloraceae y Solanaceae; provee de una diagnosis latina a Aristolochia argyroneura con el fin de revalidar ese binomio empleado irreglamentariamente desde hace medio siglo por carecer de la debida descripción; y discute brevemente el problema suscitado en torno al género Dilkea (de las Pasifloráceas, al cual se han atribuido varias especies por algunos botánicos, mientras otros sospechan que se trata de simples formas de una misma entidad específica por lo cual el genero debe ser considerado como monotípico.

  19. Marine biodiversity in Colombia

    International Nuclear Information System (INIS)

    Diaz, Juan Manuel

    2002-01-01

    One decade ago, the seas and oceans were considered biologically less diverse that the terrestrial environment. Now it is known that it is on the contrary; 33 of the 34 categories of animals (phylum), they are represented in the sea, compared with those solely 15 that exist in earth. The investigation about the diversity of life in the sea has been relatively scorned, but there are big benefits that we can wait if this is protected. The captures of fish depend on it; the species captured by the fisheries are sustained of the biodiversity of their trophic chains and habitats. The marine species are probably the biggest reservoir of chemical substances that can be used in pharmaceutical products. The genetic material of some species can be useful in biotechnical applications. The paper treats topics like the current state of the knowledge in marine biodiversity and it is done a diagnostic of the marine biodiversity in Colombia

  20. Derecho Electoral en Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Ariel Sanchez-Torres

    2010-03-01

    Full Text Available El artículo quiere demostrar que la afirmación y profundización de las normas electorales, en orden a la democracia y su progreso, han constituido en Colombia una forma institucional de cambio.  Si bien es cierto que no puede desconocerse el paréntesis del Frente Nacional que limitó el libre juego de las fuentes políticas, la legislación en temas como financiación política, publicidad y encuestas de opinión actualmente vigentes, son vitales para  que la democracia  y las normas electorales sean el camino Institucional  del cambio.

  1. Mucormicosis (ficomicosis en Colombia

    Directory of Open Access Journals (Sweden)

    Carlos E. Peña

    1965-10-01

    Full Text Available Se presentan dos casos de mucormicosis (ficomicosis, entidad que ha sido muy raramente encontrada en Colombia. El primer caso se refiere a un prematuro con deshidratación consecutiva a vómito y diarrea. A la autopsia se encontró una mucormicosis del intestino delgado con necrosis del mismo e invasión al bazo, a la vez que una candidiasis esofágica. El segundo caso es el de un niño de 5 meses de edad, con diarreas, vómito, acidosis y signos de trombosis del seno cavernoso derecho y de meningitis. La autopsia reveló una mucormicosis ocular y meningo-encefálica acompañada de trombosis de la arteria cerebral media derecha y del seno cavernoso del mismo lado.

  2. Las Serpientes en Colombia

    Directory of Open Access Journals (Sweden)

    Daniel H.

    1949-12-01

    Full Text Available El estudio de las serpientes en Colombia no deja de tener su particular interés; existe una inmensa variedad de especies que se escalonan desde los valles ardientes hasta alturas relativamente considerables; en estos últimos puntos disminuye notablemente la variedad de formas y de modo especial las especies provistas de veneno. Hacer una distinción entre las especies venenosas y las inofensivas, resulta un tanto difícil; en algunos textos se dan unas cuántas reglas, pero la mayor parte de ellas sólo tienen aplicación con especies exóticas ya que la mayor parte de esas distinciones se han tomado de obras que hacen referencia a la fauna europea.

  3. 75 FR 61989 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-8-31, DC-8-32, DC-8-33, DC-8-41...

    Science.gov (United States)

    2010-10-07

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and... to all of the McDonnell Douglas Corporation airplanes identified above. The existing AD currently... the following new airworthiness directive (AD): 2010-21-03 McDonnell Douglas Corporation: Amendment 39...

  4. Triple voltage dc-to-dc converter and method

    Science.gov (United States)

    Su, Gui-Jia

    2008-08-05

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  5. Bi-Directional DC-DC Converter for PHEV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Abas Goodarzi

    2011-01-31

    Plug-In Hybrid Electric Vehicles (PHEV) require high power density energy storage system (ESS) for hybrid operation and high energy density ESS for Electric Vehicle (EV) mode range. However, ESS technologies to maximize power density and energy density simultaneously are not commercially feasible. The use of bi-directional DC-DC converter allows use of multiple energy storage, and the flexible DC-link voltages can enhance the system efficiency and reduce component sizing. This will improve fuel consumption, increase the EV mode range, reduce the total weight, reduce battery initial and life cycle cost, and provide flexibility in system design.

  6. Land Reform and Conflict Resolution in Colombia

    National Research Council Canada - National Science Library

    Nieswiadomy, Mark

    2003-01-01

    One of the leading arguments explaining the current rural conflict in Colombia is that it stems from deeply rooted peasant grievances over lack of land, As is true in much of Latin America, Colombia...

  7. United States Strategy in Colombia: New Opportunities

    National Research Council Canada - National Science Library

    Roberts, Lee C

    2003-01-01

    .... Despite decades of U.S. support to the Government of Colombia, the troika of guerrilla insurgency, civil disorder by paramilitaries, and illegal drug activities has brought Colombia close to becoming a failed State. U.S...

  8. Economic geology of the Zipaquira quadrangle and adjoining area, Department of Cundinamarca, Colombia

    Science.gov (United States)

    McLaughlin, Donald H.; Arce Herrera, Marino

    1970-01-01

    At least four evaporite sequences are interbedded with Cretaceous strata in the Bogotga area of the Cordillera Oriental of Colombia. The easternmost and oldest evaporite interval is of probable Berriasian-Valanglnian age; the next oldest is of probable late Barremian-early Aptian age, and is followed by a possible late Aptian sequence. The westernmost and best known sequence is Turonian-early Coniacian in age, in the Sabana de Bogota. This youngest sequence contains the thickest known salt deposits and is probably the most widespread geographically. Three gypsum deposits of probable Barremian-Valanginian age are in the eastern part of the area under investigation. These deposits may have been leached from former salt accumulations. No other evaporites are exposed, but numerous brine springs are known, That the sources of these brines are neither deep not distant is suggested by the generally high concentrations, of the brines, the local presence of rute (leached salt residue), and the commonly significant amounts of H2S gas emitted at these springs. The rock salt exposed in three accessible mines commonly has a characteristic lamination caused by alternating layers of relatively pure halite and very argillaceous halite. Ubiquitously scattered throughout all salt deposits are small clasts of black, commonly pyritic, marly claystone. This lithology is also present as large claystone bodies conformably interbedded in the salt strata. Anhydrite is rare and is apparently more abundant at the Zipaquira mine that at the Nemocon and Upin mine. Paleontologic evidence in the Sabana de Bogota demonstrates that the salt-claystone series, hematite impregnated strata, and carbonaceous to locally coaly claystone are coeval. The salt-claystone facies may have been deposited in shallow evaporite pans that were separated within the overall evaporite interval by barriers on which the locally hematitic strata were deposited. The carbonaceous facies may also have formed in barrier

  9. RESONANT STEP-DOWN DC-DC POWER CONVERTERS

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant step-down DC-DC power converter which comprises a primary side circuit and a secondary side circuit coupled through a galvanic isolation barrier. The primary side circuit comprises a positive and a negative input terminal for receipt of an input voltage...... charged from the input voltage and discharged to the output capacitor through the galvanic isolation barrier by a semiconductor switch arrangement in accordance with a switch control signal to produce the converter output voltage. The resonant step-down DC-DC power converter comprises an electrical short......-circuit connection across the galvanic isolation barrier connecting, in a first case, the second negative electrode of the output capacitor to the positive input terminal of the primary side circuit or, in a second case, connecting the second positive electrode of the output capacitor to the negative input terminal...

  10. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sinha, Mohit [University of Minnesota; Dhople, Sairaj [University of Minnesota; Poon, Jason [University of California at Berkeley

    2017-09-01

    We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.

  11. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-05-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  12. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Yong, X.

    2000-01-01

    in a method for real-time developments. An operational semantics with behavior is specified for TRSL. It is defined what its means for a TRSL process to satisfy a DC requirement, and a method for verifying whether the satisfaction relation holds or not is provided. Our contribution also demonstrates a general......Duration Calculus (DC) is an interval-based real-time logic, which can be used in capturing and eliciting users' real-time requirements. The Timed RAISE Specification Language (TRSL) is an extension of the RAISE Specification Language with real-time features. This paper links DC and TRSL together...

  13. DC Microgrids—Part II

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Lu, Xiaonan; Quintero, Juan Carlos Vasquez

    2016-01-01

    distribution applications such as traction, telecom, vehicular and distributed power systems can be classified under DC MG framework and ongoing development and expansion of the field is largely influenced by concepts used over there. This paper aims firstly to shed light on the practical design aspects of DC...... MG technology concerning typical power hardware topologies and their suitability for different emerging smart grid applications. Then, an overview of the state of the art in DC MG protection and grounding is provided. Owing to the fact that there is no zero current crossing, an arc that appears upon...

  14. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-20

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

  15. Interaction of the heavy metals (Cr +6, Cd, Pb, Ni) between the silt and the water column in the case study of Bogota River

    International Nuclear Information System (INIS)

    Pinzon U, L.F.; Rodriguez, J.A.; Giraldo, E.

    1993-01-01

    For the present study the Bogota River it uses as framework, this river has a course of 255 km., in it pathway through 26 municipalities, including the Western area of the District Capital (Bogota). In the District Capital area, some significant sampling points were founded, due to their localization on the bed and that industrial activities of grateful polluting function are developed. Silt samples were extracted and it dilutes for chemical-physical analysis and study to scale; these samples were implanted in columns or reactors; one of characteristic totally anaerobic and another of characteristic aerobic. Of equal forms it procedure is repeated, but replacing the river water for dilution water; every third day the extracted samples are been about agreement with the metal to analyze Chromium IV for the waters, Total Chromium for the silts, Cadmium, Lead and Total Nickel in the column of water and silts to be analyzed by means of Absorption Atomic Spectrophotometry. The object is the one of establishing that exchange type is presented between the polluted water and the water free of contaminants

  16. The Colombia Seismological Network

    Science.gov (United States)

    Blanco Chia, J. F.; Poveda, E.; Pedraza, P.

    2013-05-01

    The latest seismological equipment and data processing instrumentation installed at the Colombia Seismological Network (RSNC) are described. System configuration, network operation, and data management are discussed. The data quality and the new seismological products are analyzed. The main purpose of the network is to monitor local seismicity with a special emphasis on seismic activity surrounding the Colombian Pacific and Caribbean oceans, for early warning in case a Tsunami is produced by an earthquake. The Colombian territory is located at the South America northwestern corner, here three tectonic plates converge: Nazca, Caribbean and the South American. The dynamics of these plates, when resulting in earthquakes, is continuously monitored by the network. In 2012, the RSNC registered in 2012 an average of 67 events per day; from this number, a mean of 36 earthquakes were possible to be located well. In 2010 the network was also able to register an average of 67 events, but it was only possible to locate a mean of 28 earthquakes daily. This difference is due to the expansion of the network. The network is made up of 84 stations equipped with different kind of broadband 40s, 120s seismometers, accelerometers and short period 1s sensors. The signal is transmitted continuously in real-time to the Central Recording Center located at Bogotá, using satellite, telemetry, and Internet. Moreover, there are some other stations which are required to collect the information in situ. Data is recorded and processed digitally using two different systems, EARTHWORM and SEISAN, which are able to process and share the information between them. The RSNC has designed and implemented a web system to share the seismological data. This innovative system uses tools like Java Script, Oracle and programming languages like PHP to allow the users to access the seismicity registered by the network almost in real time as well as to download the waveform and technical details. The coverage

  17. DC injection into low voltage AC networks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report summarises the results of a study investigating the impact of levels of injected DC current injections on a low voltage AC distribution network systems in order to recommend acceptable limits of DC from microgeneration. Relevant literature is reviewed, and the impact of DC levels in distribution transformers, transformer modelling, and instrumental transformers are discussed. The impact of DC in residual current devices (RCD) and in domestic electricity watt hour meters is examined along with DC enhanced corrosion, corrosion failure, and the measurement of DC current injection. Sources of DC injection outlined include DC from computer power supplies, network faults, geomagnetic phenomena, lighting circuits/dimmers, and embedded generators.

  18. Isolated step-down DC -DC converter for electric vehicles

    Science.gov (United States)

    Kukovinets, O. V.; Sidorov, K. M.; Yutt, V. E.

    2018-02-01

    Modern motor-vehicle industrial sector is moving rapidly now towards the electricity-driving cars production, improving their range and efficiency of components, and in particular the step-down DC/DC converter to supply the onboard circuit 12/24V of electric vehicle from the high-voltage battery. The purpose of this article - to identify the best circuitry topology to design an advanced step-down DC/DC converters with the smallest mass, volume, highest efficiency and power. And this will have a positive effect on driving distance of electric vehicle (EV). On the basis of computational research of existing and implemented circuit topologies of step-down DC/DC converters (serial resonant converter, full bridge with phase-shifting converter, LLC resonant converter) a comprehensive analysis was carried out on the following characteristics: specific volume, specific weight, power, efficiency. The data obtained was the basis for the best technical option - LLC resonant converter. The results can serve as a guide material in the process of components design of the traction equipment for electric vehicles, providing for the best technical solutions in the design and manufacturing of converting equipment, self-contained power supply systems and advanced driver assistance systems.

  19. Enfermedad cerebrovascular en Colombia Cerebrovascular disease in Colombia

    Directory of Open Access Journals (Sweden)

    Federico A Silva

    2006-10-01

    Full Text Available Introducción: la enfermedad cerebrovascular constituye un problema de salud pública mundial. En Colombia es la cuarta causa de muerte en la población adulta y genera una alta discapacidad en estos pacientes. Objetivo: describir algunos resultados obtenidos por el grupo de Ciencias Neurovasculares de la Fundación Cardiovascular de Colombia. Desarrollo y conclusiones: la enfermedad cerebrovascular es una entidad con una alta prevalencia en la población colombiana y genera discapacidad mental, motora y del lenguaje. Es necesaria la implementación de unidades de cuidado neurovascular con personal entrenado, protocolos definidos, tratamientos adecuados y tecnología de punta. En Colombia deben imponerse este tipo de unidades dentro del cuidado básico de los pacientes para disminuir la morbilidad, mortalidad y discapacidad generada en estos pacientes. La Fundación Cardiovascular de Colombia es pionera en la implementación de este tipo de cuidados.Introduction: cerebrovascular disease constitutes a worldwide public health problem. In Colombia, it is the fourth leading cause of death in the adult population and generates high disability in these patients. Objective: to describe some results obtained by the Neurovascular Sciences group from the Colombian Cardiovascular Foundation. Development and conclusions: cerebrovascular disease has a high prevalence in the Colombian population and generates mental, motor, and language disabilities. The implementation of neurovascular care units with trained personnel, defined protocols, adequate treatments and high technology, are necessary. This kind of units must be imposed in Colombia as a basic care for these patients in order to decrease morbidity, mortality and disability. The Colombian Cardiovascular Foundation is pioneer in the implementation of these care units.

  20. Street youth in Colombia: lifestyle, attitudes and knowledge.

    Science.gov (United States)

    Ruiz, J

    1994-01-01

    Gamines in Bogota, Colombia, are youths who live on the streets sometimes keeping loose family ties. They belong to informal gangs, use drugs, and survive by doing itinerant informal sector work, begging, and stealing. The New Life Program (NLP) of the Corporacion SOS Aldea de Ninos worked with three other agencies to investigate the lifestyle, attitudes, and knowledge of gamines about HIV/STDs for the purpose of designing AIDS/STD educational activities for the population. Focus group discussions and educational activities were conducted with 12 girls and 18 boys aged 14-25 years who had started living in NLP's shelter while working on the streets. Participants had spent an average of 7 years on the street typically from age 10. Concentrating primarily upon daily survival, these youths act on the basis of intuition and emotions. Verbal communication is essential to gain and maintain their trust. Although their sexual lives are influenced by the family of origin, institutions in which they have resided, and peers, and their daily lifestyles have much influence. Steady partners are sought for affection and romance, while sexual intercourse is had for pleasure and to satisfy biological need. Some homosexuality and prostitution are tolerated. Gangs also gang-rape and expel members thought to be traitors. The idea of birth control exists among the girls, but the boys overwhelmingly reject condom use. The boys got information on sex from prostitutes, erotic magazines, and adults, but girls rarely talk about sex. Many have had STDs and are generally aware about AIDS, but misinformed about transmission modes, symptoms, and treatment. The boys were especially negative about meeting a person with AIDS. Overall, the youths did not perceive themselves as being at risk for HIV infection. Participants also strongly distrusted the health system because many had been turned away for being dirty or received only callous treatment. The author concludes that we must acknowledge that

  1. de Cali, Colombia

    Directory of Open Access Journals (Sweden)

    Mauricio Jaramillo Ayerbe

    2007-01-01

    Full Text Available En este trabajo se presentan los resultados de la modelación para la predicción a corto plazo de la concentración de ozono troposférico en la zona urbana de la ciudad de Cali, Colombia, mediante el análisis univariante de series de tiempo. El método se aplicó a una serie de 2.496 datos horarios de concentración de ozono, obtenida en una de las estaciones de la Red de Monitoreo de Calidad del Aire (RMCA de Cali, correspondiente a 104 días consecutivos durante el período abril a julio de 2003. Los datos de los primeros 93 días se utilizaron para la estimación del modelo, y los de los 11 días restantes para la validación del mismo. El modelo propuesto podría ser utilizado por las autoridades ambientales de la región para predecir y alertar a la población sobre posibles episodios de altas concentraciones de ozono que puedan poner en riesgo la salud pública con hasta 8 horas de anticipación.

  2. Environmental information in Colombia

    International Nuclear Information System (INIS)

    Velez S, Andres

    2005-01-01

    This article is a chapter from the paper, Elements for the description of an environmental information system, which was written by the author as a requirement for the degree of specialist on environment and Geoinformatics at the school of engineering. Universidad de Antioquia. The original paper attempted a description of the context and development of a particular environmental information system, built at the eastern region of Antioquia by CORNARE (a regional autonomous corporation for the environment and the natural resources). This article refers to the Colombian institutional context for environmental information. With particular emphasis laid on the strategic character that must be conceded to the administration of information. Towards the construction of equitable and sustainable development models under autonomous orientation an efficient and transparent environmental administration as is needed by such models is only attainable through the design and application of environmental information systems committed to the pursuit of collective interests. Here a balance is sought between accomplishments and failures reached during the long standing discussion held in Colombia around the formulation of public policies that acknowledge and strengthen the role of information as a cornerstone of environmental administration, and a contribution towards the goal of human sustainable development

  3. de barranquilla (Colombia

    Directory of Open Access Journals (Sweden)

    Pamela Flores

    2006-01-01

    Full Text Available Esta investigación aborda algunas de las variables que, en las periferias de las ciudades del Tercer Mundo, inciden en la ausencia de una identidad urbana y de una cultura política democrática, tomando como ejemplo el municipio de Soledad, en el departamento del Atlántico, Colombia. La investigación tuvo como primer objetivo indagar por los sentidos de lo público que construyen los habitantes y para ello se realizó un inventario de los espacios públicos y unos diarios de campo sobre los usos dados a estos espacios. En segundo lugar, nos preguntamos sobre los modos de inserción en las dinámicas urbanas. Las encuestas realizadas confirmaron la ausencia de canales de expresión y participación, con lo cual formas no institucionalizadas de identidad social se convierten en la alternativa para los ciudadanos, en particular, para los jóvenes. De ahí que el estudio centrara sus conclusiones en las demandas que estas realidades presentan al Estado y en los peligros que, para la consolidación de la democracia, implican estas ciudadanías inconclusas..

  4. Borehole DC-12 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-12. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

  5. Borehole DC-14 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-14. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

  6. Borehole DC-15 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-15. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

  7. El Patentamiento Universitario en Colombia

    Directory of Open Access Journals (Sweden)

    Diana Milena González Gélvez

    2013-04-01

    Full Text Available El artículo presenta un panorama general del patentamiento que realizan las Universidades en Colombia. Para ello, se realiza un análisis de la información de la base de datos de patentes de la Superintendencia de Industria y Comercio de Colombia desde 1970 hasta 2010. Los resultados permiten observar el estado real del patentamiento Universitario en Colombia, así como identificar las Universidades más exitosas en el proceso de patentamiento y los tiempos reales requeridos para proteger las nuevas creaciones. Así mismo, los resultados son un insumo importante en la determinación de la estrategia de protección que adopten las Universidades Colombianas en cuanto a la protección de sus creaciones.

  8. Natalidad y fecundidad, Colombia, 2001

    OpenAIRE

    León A, Alba Luz; Ocampo A, Leidy Johanna; Spath P, Doris Estella; Agudelo G, Héctor Byron; Grisales R, Hugo

    2006-01-01

    Se presenta la natalidad, la fecundidad y los nacimientos vivos en Colombia en el año 2001 con base en la totalidad de los registros de nacidos vivos del Departamento Administrativo Nacional de Estadísticas (dane) (724.236). La población de Colombia, calculada a mitad de período, se dividió en ocho categorías de municipios de acuerdo con el tamaño poblacional, según la Ley 617/2001. No se presentaron diferencias importantes entre las variables afines a las características del recién nacido po...

  9. Descubrir el universo desde Colombia

    OpenAIRE

    Duque Escobar, Gonzalo

    2009-01-01

    Los dos hechos científicos más relevantes en la corta historia de Colombia, son la Real Expedición Botánica del Nuevo Reino de Granada y la Misión Corográfica. Hoy cuando los astrónomos, entre otros asuntos que se ubican en la frontera del conocimiento, intentan conocer la geometría del espacio, la naturaleza de la materia oscura y los misterios del tiempo, en Colombia nuestros científicos tienen pendiente entre otros aportes para la construcción de la Nación, apoyar tareas fundamentales y es...

  10. Five-Level Active-Neutral-Point-Clamped DC/DC Converter for Medium-Voltage DC Grids

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Chen, Zhe

    2017-01-01

    This paper proposes a five-level active-neutralpoint- clamped (5L-ANPC) dc/dc converter for applications in medium voltage dc (MVDC) grids. A modulation strategy is proposed for the 5L-ANPC dc/dc converter to generate multilevel voltage waveforms, which can effectively reduce voltage change rate dv...... effectively eliminate high voltage leaps caused by the dead time effect. In addition, a capacitor voltage control strategy is proposed for the 5L-ANPC dc/dc converter to ensure the balanced flying capacitor voltage and desired five-level voltage waveforms. Finally, simulation and experimental studies...

  11. Serpientes de Colombia

    Directory of Open Access Journals (Sweden)

    M. Rodrigo Ángel

    1983-06-01

    Full Text Available En este libro es una guía práctica sobre las serpientes de Colombia en cuanto a su clasificación y tratamiento del envenenamiento causado por sus mordeduras. Contiene los siguientes capítulos: 1. Características generales, 2. Serpiente Colombianas, 3. Aparato venenoso, 4. Clasificación fisiopatología de los efectos del veneno, 5. Mordedura por serpientes venenosas en Antioquía, listas de nombres populares y científicos, la bibliografía. Esta es una introducción a esta práctica guía sobre las serpientes Colombianas: Desde el origen del hombre, a través de la evolución de las distintas culturas y aún en la época actual en un amplio sector sociocultural, la serpiente ha sido considerada como un animal dotado de ciertos poderes sobrenaturales, bien sea como fuente de mal, de beneficio, de poder, de sabiduría o de salud. Considerada por su aspecto tóxico, la influencia en la patología humana es evidente y de gran importancia como causa de morbilidad sobre todo en aquellos países donde se le considera animal sagrado. En el aspecto simbólico, el folklor es abundante en creencias y tradiciones, que generalmente coinciden en la mayoría de los pueblos. En un país tropical como Colombia, con diversidad de climas y bosques, las serpientes venenosas de gran poder tóxico son también abundantes y significan un peligro real para nuestra población campesina en lucha abierta con la naturaleza. Los envenenamientos causados por sus mordeduras, graves de por sí, empeoran frecuentemente debido a diversos factores tales como la escasez y alto costo del suero antiofídico y la demora en la atención médica, condicionada esta última no sólo por la deficiencias de nuestras vías de comunicación, sino por la influencia nefasta del curandero. Sobre tema tan importante de nuestra patología, es entonces necesario que nuestras instituciones educativas y las encargadas de velar por la salud, se preocupen no sólo por su

  12. Dengue en Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Boshell

    1986-12-01

    Full Text Available El Gobierno Colombiano estableció una campaña que erradicó el Aedes aegypti de su territorio en atención a las recomendaciones que hizo la Oficina Sanitaria Panamericana en 1947. Esta campaña consiguió desaparecer el dengue endémico durante aproximadamente 20 años, apareciendo de nuevo en forma explosiva con la epidemia de dengue 2 en la Costa Atlántica (1971-1972, seguida de dos epidemias bien documentadas de dengue 3 (1975-1977 y dengue 1 en 1978. Se hace un resumen de las actividades que desarrolla el Laboratorio de Virología del Instituto Nacional de Salud para apoyar el diagnóstico de esta enfermedad en el país incluyendo el primer aislamiento de dengue 4 en 1982, la actividad de los virus dengue 1, 2 y 4 detectada hasta la fecha, los hallazgos clínicos y virológicos en un caso fatal de enfermedad hemorrágica asociada a infección por virus del dengue y un breve recuento de la epidemia de Tumaco en la Costa Pacífica en la cual se comprobó actividad simultánea de dengue 1 y 2. Finalmente se informa sobre el estado de infestación que tiene el país actualmente con el Aedes aegypti y sobre la actividad del virus de fiebre amarilla en focos selváticos vecinos a ciudades altamente infestadas, detectada en el mes de enero de 1987 en Colombia.

  13. de Manizales, Colombia

    Directory of Open Access Journals (Sweden)

    Hernán Humberto Vargas López

    2007-01-01

    Full Text Available El presente artículo se deriva de una investigación realizada con 29 jóvenes escolarizados de la ciudad de Manizales, Colombia, en la cual se indagó por los sentidos y significados de la ciudadanía. Para la recolección de información se utilizó el taller pedagógico, en tanto permitió combinar diversas técnicas e instrumentos tales como la entrevista semiestructurada, la entrevista a profundidad y la discusión. El estudio concluye que las y los jóvenes significan y comprenden la ciudadanía desde cuatro referentes: el lugar del sujeto en la sociedad y la cultura, el sentido del derecho y la ley en la organización y la convivencia, las percepciones del actuar moral y político de los líderes y de los políticos, y las percepciones y consumos de ciudad que hacen los ciudadanos. Se concluye que las y los jóvenes sitúan la ciudadanía desde un referente de la acción, manifestado fundamentalmente en la participación, el enjuiciamiento político y la posibilidad de ser representados por otros. Igualmente, se plantea que las y los jóvenes orientan la ciudadanía desde los principios y marcos de significación cultural de ciudad, expresados en los vínculos y compromisos que adquieren los ciudadanos con su ciudad y viceversa. Finalmente, se afirma que se trata de una ciudadanía significada en el respeto, la libertad, la justicia social y el reconocimiento del potencial humano universal

  14. 75 FR 63040 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

    Science.gov (United States)

    2010-10-14

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10... following new airworthiness directive (AD): 2010-21-13 McDonnell Douglas Corporation: Amendment 39-16473... November 18, 2010. Affected ADs (b) None. Applicability (c) This AD applies to McDonnell Douglas...

  15. 75 FR 68246 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-11-05

    ...-1044; Directorate Identifier 2010-NM-033-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas..., 2007) and adding the following new AD: McDonnell Douglas Corporation: Docket No. FAA-2010-1044.... Applicability (c) This AD applies to all McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

  16. Pulsewidth modulated DC-to-DC power conversion circuits, dynamics, and control designs

    CERN Document Server

    Choi, Byungcho

    2013-01-01

    This is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to

  17. Atmel Microcontroller Based Soft Switched PWM ZVS Full Bridge DC to DC Converter

    Directory of Open Access Journals (Sweden)

    DEEPAK KUMAR NAYAK

    2010-12-01

    Full Text Available This paper deals with the simulation and implementation of soft switched PWM ZVS full bridge DC to DC converter. The 48V DC is efficiently reduced to 12V DC using a DC to DC converter. This converter has advantages like reduced switching losses, stresses and EMI. Input DC is converted into high frequency AC and it is stepped down to 12V level. Later it is rectified using a full wave rectifier. Laboratory model of microcontroller based DC to DC converter is fabricated and tested. The experimental results are compared with the simulation results.

  18. 75 FR 60602 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-10-01

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10... adding the following new AD: 2010-20-14 McDonnell Douglas Corporation: Amendment 39-16449. Docket No. FAA... the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD. (1) McDonnell Douglas Corporation...

  19. 75 FR 6160 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-15, DC...

    Science.gov (United States)

    2010-02-08

    ...-0032; Directorate Identifier 2009-NM-213-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0032; Directorate Identifier 2009-NM-213-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A...

  20. 75 FR 38943 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, DC-10-30, DC...

    Science.gov (United States)

    2010-07-07

    ...-0672; Directorate Identifier 2010-NM-047-AD] RIN 2120-AA64 Airworthiness Directives; McDonnell Douglas...: McDonnell Douglas Corporation: Docket No. FAA-2010-0672; Directorate Identifier 2010-NM-047-AD. Comments Due... applies to McDonnell Douglas Corporation Model DC- 10-10, DC-10-10F, DC-10-30, DC-10-30F (KDC-10), DC-10...

  1. Solving Colombia’s Problems

    Science.gov (United States)

    2003-04-07

    parties for political control during the period from 1948 to 1953.15 “During this period, referred to as ‘La Violencia ,’ groups of armed men paid by...surprise to those familiar with the Colombia government history of mishandling foreign aid in the war against drugs and in their parallel inability to

  2. Rocky Mountain spotted fever, Colombia.

    Science.gov (United States)

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

    2007-07-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

  3. Colombia extends its exploration horizon

    International Nuclear Information System (INIS)

    Carta Petrolera

    1997-01-01

    The Return 1 Contract, currently being awarded under the tender system, faithfully reflects Colombia's new approach to hydrocarbon exploration and exploitation. This policy aims to increase reserves and has Ecopetrol assume a more aggressive role in its direct activities by sharing the exploration risks with private partners

  4. Pseudotectites from Colombia and Peru

    NARCIS (Netherlands)

    Martin, R.; Sitter-Koomans, de C.

    1955-01-01

    In a previous note on “Americanites” (Martin, 1934) from Colombia and Peru, the writer came to the conclusion, on the basis solely of published data, that it was very likely that these so-called tectites are in reality obsidian of terrestrial origin. He stated, however, that “before it is possible

  5. Light-weight DC to very high voltage DC converter

    Science.gov (United States)

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  6. Light-weight DC to very high voltage DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

    1998-01-01

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

  7. Radiated electromagnetic emissions of DC-DC converters

    International Nuclear Information System (INIS)

    Feld, L; Jussen, R; Karpinski, W; Klein, K; Sammet, J; Wlochal, M

    2010-01-01

    For the CMS tracker at SLHC a new powering scheme is considered to be mandatory to allow the detector to provide at least the same performance as today at the LHC. The baseline solution of CMS foresees the use of DC-DC converters to provide larger currents with smaller losses. An important component of most converters are inductors which, however, tend to radiate the switching noise generated by the converter. The emissions of different inductors have been measured and simulated, the coil design has been optimized and noise susceptibility measurements, with present CMS hardware, have been performed. This article summarizes the results.

  8. Pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2008-01-01

    This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system. With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters,

  9. DESIGN OPTIMIZATION OF RESONANT DC-DC CONVERTERS

    OpenAIRE

    Belqasem Aljafari

    2016-01-01

    Resonant DC/DC converters are the class of converters, which have L-C resonant tank serving as a major part of the power conversion process. The fundamental concept of the resonant converter is that the circulating energy in an L-C resonant circuit is manageable by changing the operating frequency, and therefore the converter can condition the input power to the desired output voltage. The development in power conversion technology is steady demand for high power efficiency and high power den...

  10. DC grid for home applications

    Science.gov (United States)

    Elangovan, D.; Archana, R.; Jayadeep, V. J.; Nithin, M.; Arunkumar, G.

    2017-11-01

    More than fifty percent Indian population do not have access to electricity in daily lives. The distance between the power generating stations and the distribution centers forms one of the main reasons for lack of electrification in rural and remote areas. Here lies the importance of decentralization of power generation through renewable energy resources. In the present world, electricity is predominantly powered by alternating current, but most day to day devices like LED lamps, computers and electrical vehicles, all run on DC power. By directly supplying DC to these loads, the number of power conversion stages was reduced, and overall system efficiency increases. Replacing existing AC network with DC is a humongous task, but with power electronic techniques, this project intends to implement DC grid at a household level in remote and rural areas. Proposed work was designed and simulated successfully for various loads amounting to 250 W through appropriate power electronic convertors. Maximum utilization of the renewable sources for domestic and commercial application was achieved with the proposed DC topology.

  11. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne; Yong, Xia

    1999-01-01

    In this talk we present a method for linking the Duration Calculus together with the Timed RAISE Specification Language. Duration Calculus (DC) [ZHR91] is an interval-based real time logic, which can be used naturally in capturing and eliciting users' real time requirements in the form of constra......In this talk we present a method for linking the Duration Calculus together with the Timed RAISE Specification Language. Duration Calculus (DC) [ZHR91] is an interval-based real time logic, which can be used naturally in capturing and eliciting users' real time requirements in the form.......TRSL is a real-time extension of the RAISE Specification Language (RSL) [Rlg92] which together with its associated method [Rmg95]and tools has shown to be very useful in the industrial development of software systems. Therefore, a promising approach for the development of real-time systemscould be to use DC...... for high-level specifications of real-time requirementsand TRSL for specifying real-time implementations in the form of timed communicating concurrent processes.In order to link DC and TRSL together in a well-founded way, we formally define what it means for a TRSL process to satisfy a DC requirement...

  12. CANCER DE MAMA EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Mario A. González Mariño

    2014-12-01

    Full Text Available OBJETIVO: Conocer la situación del cáncer de mama en Colombia mediante la revisión de publicaciones epidemiológicas y clínicas. MATERIALES Y MÉTODOS: Evaluación de estudios publicados en revistas científicas seriadas sobre cáncer de mama en Colombia mediante búsqueda en las bases de datos Medline con los términos neoplasm and breast and Colombia y Lilacs con neoplasia y mama y Colombia. Se seleccionaron los estudios con aplicación epidemiológica o clínica con muestreo o datos de mujeres residentes en Colombia, ubicando sus resultados en la sección de introducción y en la de discusión de acuerdo con los enfoques de promoción, prevención y tratamiento. RESULTADOS: Se encontraron 62 referencias en Medline de las que se seleccionaron 23 y en Lilacs de 16 se escogieron 4. Las referencias se descartaron en Medline por las siguientes razones: 15 por el diseño de estudio (revisión de tema, presentación de casos clínicos, 7 por tratarse de investigación básica, 10 por tema diferente al cáncer de mama en Colombia y 7 por datos pertenecientes a otro país. En Lilacs se excluyeron por: 7 artículos también presentes en Medline, 3 por diseño, 1 de investigación básica y 1 de un tema diferente. CONCLUSIONES: Los artículos revisados permiten tener una visión integral sobre el cáncer de mama en Colombia. En ellos se puede verificar que hay limitaciones en la prestación del servicio de atención en salud para esta enfermedad, y se identifican factores de riesgo con significancia estadística como la nuliparidad, niveles altos de inactividad física y exposición a DDE (diclorodifenildicloroeteno y para el cáncer genético se encontraron mutaciones fundadoras. La consulta se hace principalmente por síntomas, no sobre resultados de cribado como sería lo deseable. Existen también contribuciones sobre el manejo quirúrgico y adyuvante extrapolables a las condiciones del país.

  13. Preliminary methodological proposal for estimating environmental flows in projects approved by the ministry of environment and sustainable development (MADS), Colombia

    International Nuclear Information System (INIS)

    Pinilla Agudelo, Gabriel A; Rodriguez Sandoval, Erasmo A; Camacho Botero, Luis A

    2014-01-01

    A methodological proposal for estimating environmental flows in large projects approved by Agencia Nacional de Licencias Ambientales (ANLA) in Colombian rivers was developed. The project is the result of an agreement between the MADS and the Universidad Nacional de Colombia, Bogota (UNC). The proposed method begins with an evaluation of hydrological criteria, continues with a hydraulic and water quality validation, and follows with the determination of habitat integrity. This is an iterative process that compares conditions before and after the project construction and allows to obtain the magnitude of a monthly flow that, besides preserving the ecological functions of the river, guarantees the water uses downstream. Regarding to the biotic component, the proposal includes the establishment and monitoring of biotic integrity indices for four aquatic communities (periphyton, macro invertebrates, riparian vegetation, and fish). The effects that flow reduction may produce in the medium and long term can be assessed by these indices. We present the results of applying the methodology to several projects licensed by the MADS.

  14. Mining Taxation in Colombia

    Directory of Open Access Journals (Sweden)

    Duanjie Chen

    2015-02-01

    Full Text Available This paper first assesses the current Colombian mining tax-and-royalty regime in comparison with other countries from the points of view of efficiency, competitiveness and revenue performance. It then discusses the theoretical convenience of introducing alternative designs for a resource rent tax (RRT to be applied to new mining projects, together with a reduced common royalty rate for all minerals, and simulates their potential efficiency, competitiveness and revenue-performance effects. In particular, it examines alternative interactions between the RRT, the royalty regime and the corporate income tax (royalties creditable against the RRT or deductible from its tax base; accepting or not corporate income tax deductibility from the RRT tax base, under alternative RRT tax rates. It also discusses alternative capital return allowances and the pros and cons of project-by-project versus sectorial ring fencing, and sharing RRT revenues between the national and sub-national governments. It concludes with a detailed blueprint for reform based on these discussions, assessments and simulations, as well as political economy and administrative considerations for the specific case of Colombia. Este trabajo evalúa la eficiencia, competitividad y capacidad de recaudo del régimen tributario y de regalías colombiano en comparación con el de otros países mineros relevantes. Posteriormente, propone la implementación de un “Resource Rent Tax” (RRT para proyectos mineros futuros (junto con una reducción y unificación de la tasa de regalías entre minerales y modela el impacto que tendría éste sobre la eficiencia y el recaudo. Se examinan la interacción entre el RRT, las regalías y el impuesto de renta bajo distintos diseños y tasas de RRT y costo de oportunidad del capital. También se analiza si es preferible tener “ringfencing” a nivel de proyecto o a nivel sectorial. El trabajo concluye con una propuesta de reforma junto con consideraciones

  15. Phytochemical research of leaves and flowers of Smallanthus pyramidalis (Triana) H. Rob. (Arboloco) and its use in the recovery of wetlands in Bogota

    International Nuclear Information System (INIS)

    Guzman Avendano, Antonio J; Barrera Adame, Diana A.

    2011-01-01

    This research focused on the phytochemical characterization of the species Smallanthus pyramidalis (Triana) H. Rob. in order to identify the secondary metabolites of flowers and leaves. This is due to the importance these trees on the sustainable development of the wetlands in the Sabana de Bogota, and its possible application as a promising species in the use and conservation of these ecosystems. We performed preliminary chemical tests, fractionation using conventional techniques, identification of physical and chemical properties, and structural analysis using spectroscopic and spectrometric techniques, such as UV, 1H-RMN, 13C-RMN and GC-MS. We identified alkane-type compounds, steroids, terpenoids and flavonoids mainly, and their role in the plant and the ecosystem.

  16. Modeling and analysis of fractional order DC-DC converter.

    Science.gov (United States)

    Radwan, Ahmed G; Emira, Ahmed A; AbdelAty, Amr M; Azar, Ahmad Taher

    2017-07-11

    Due to the non-idealities of commercial inductors, the demand for a better model that accurately describe their dynamic response is elevated. So, the fractional order models of Buck, Boost and Buck-Boost DC-DC converters are presented in this paper. The detailed analysis is made for the two most common modes of converter operation: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). Closed form time domain expressions are derived for inductor currents, voltage gain, average current, conduction time and power efficiency where the effect of the fractional order inductor is found to be strongly present. For example, the peak inductor current at steady state increases with decreasing the inductor order. Advanced Design Systems (ADS) circuit simulations are used to verify the derived formulas, where the fractional order inductor is simulated using Valsa Constant Phase Element (CPE) approximation and Generalized Impedance Converter (GIC). Different simulation results are introduced with good matching to the theoretical formulas for the three DC-DC converter topologies under different fractional orders. A comprehensive comparison with the recently published literature is presented to show the advantages and disadvantages of each approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. An Integrated Multifunctional Bidirectional AC/DC and DC/DC Converter for Electric Vehicles Applications

    Directory of Open Access Journals (Sweden)

    Liwen Pan

    2016-06-01

    Full Text Available This paper presents an on-board vehicular battery charger that integrates bidirectional AC/DC converter and DC/DC converter to achieve high power density for application in electric vehicles (EVs. The integrated charger is able to transfer electrical energy between the battery pack and the electric traction system and to function as an AC/DC battery charger. The integrated charger topology is presented and the design of passive components is discussed. The control schemes are developed for motor drive system and battery-charging system with a power pulsation reduction circuit. Simulation results in MATLAB/Simulink and experiments on a 30-kW motor drive and 3.3-kW AC/DC charging prototype validate the performance of the proposed technology. In addition, power losses, efficiency comparison and thermal stress for the integrated charger are illustrated. The results of the analyses show the validity of the advanced integrated charger for electric vehicles.

  18. Pasteur en Colombia

    Directory of Open Access Journals (Sweden)

    Alfredo Bárcenas lsaacs

    1986-08-01

    Full Text Available

    Simposio Internacional sobre Inmunización y Producción de Vacunas, Bogotá, 29 de Septiembre de 1985.

    La Sociedad Colombiana de Historia de la Medicina recibió del Comité Organizador de la reunión que hoy nos congrega, la solicitud de presentar el tema de la influencia de Luís Pasteur en la América Latina. La Sociedad mencionada tuvo a bien encargarme de tan honroso cometido; sin embargo, habida cuenta de la vastedad de nuestro continente, del largo tiempo que se requiere para consultar responsable y juiciosamente archivos y bibliotecas en los diferentes países, además de los viajes que hubiera sido necesario realizar, decliné tan atractiva y desafiante tarea, pero propuse, en cambio, que se me permitiera abordar el tema circunscribiéndolo a Colombia.

    Me doy cuenta cabal de que lo que diga pudiera parecer estrecho o parroquial a este distinguido concurso de personalidades provenientes de tan diversas latitudes. No obstante, me atrevo a creer que lo que aconteció en Colombia al advenimiento de las ideas y de los descubrimientos de Pasteur, no debe diferir demasiado de lo sucedido en otras naciones, a las cuales Bolívar agrupó en una sola cuando dijo “para nosotros la patria es América”.

    Con la salvedad expresada, trataré de cumplir con la generosa designación que he recibido de la Sociedad Colombiana de Historia de la Medicina, a la cual me complazco en pertenecer y a cuyo presidente y Junta Directiva agradezco la distinción que me hacen.

    En este año de 1985 se cumplen y se celebran cien de la primera aplicación humana de la vacuna antirrábica debida a Pasteur. Se conmemora también el centenario de la muerte de Víctor Hugo, uno de los más grandes escritores y poetas de la humanidad. Siempre he creído que estos dos hijos insignes de la Francia del Siglo XIX, se distinguieron por el respeto, el afecto y la admiración que les profesaron sus contemporáneos y entre

  19. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    Science.gov (United States)

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  20. Application of Distributed DC/DC Electronics in Photovoltaic Systems

    Science.gov (United States)

    Kabala, Michael

    In a typical residential, commercial or utility grade photovoltaic (PV) system, PV modules are connected in series and in parallel to form an array that is connected to a standard DC/AC inverter, which is then connected directly to the grid. This type of standard installation; however, does very little to maximize the energy output of the solar array if certain conditions exist. These conditions could include age, temperature, irradiance and other factors that can cause mismatch between PV modules in an array that severely cripple the output power of the system. Since PV modules are typically connected in series to form a string, the output of the entire string is limited by the efficiency of the weakest module. With PV module efficiencies already relatively low, it is critical to extract the maximum power out of each module in order to make solar energy an economically viable competitor to oil and gas. Module level DC/DC electronics with maximum power point (MPP) tracking solves this issue by decoupling each module from the string in order for the module to operate independently of the geometry and complexity of the surrounding system. This allows each PV module to work at its maximum power point by transferring the maximum power the module is able to deliver directly to the load by either boosting (stepping up) the voltage or bucking (stepping down) the voltage. The goal of this thesis is to discuss the development of a per-module DC/DC converter in order to maximize the energy output of a PV module and reduce the overall cost of the system by increasing the energy harvest.

  1. [Burnout Syndrome, Family and Work Related Variables on General Practitioners in Bogota. A Strategy of Work Quality].

    Science.gov (United States)

    Aguirre Roldán, Adriana María; Quijano Barriga, Ana María

    2015-01-01

    The burnout syndrome is a set of work-related symptoms related to weariness and exhaustion, in response to the emotional stress at work and its consequences. The aim of the study was to measure the frequency of burnout in General Practitioners (GPs) from 3 private institutions in Bogotá, Colombia and to determine the associated factors according to the variables taken into account. It is a descriptive cross-sectional study which was used to analyse the Questionnaire for Burnout Syndrome (CESQT). The population was 106 GPs. The level of burnout was at a critical level in 6.6% of the GP population. The variables showed that having a stable partner and children are a protective factor. By contrast, work in emergency rooms is a risk factor. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  2. VENTAJAS ARANCELARIAS OTORGADAS POR ESTADOS UNIDOS POR MEDIO DEL ATPDEA, APROVECHABLES PARA LAS PyMES DE BOGOTA Y CUNDINAMARCA

    Directory of Open Access Journals (Sweden)

    Mario Ernesto

    2003-07-01

    Full Text Available En medio de la crisis de desempleo, pobreza y desigualdad que afronta Colombia, las pequeñas y medianas empresas se han convertido en una alternativa importante de generación de trabajo y valor agregado. Sin embargo, éstas deben aprovechar las ventajas que se otorgaron al país en el marco del ATPDEA, por medio del cual los Estados Unidos concedió preferencias arancelarias a más de cinco mil seiscientos productos que estuvieron vigentes durante más de diez años, y que luego, a partir de septiembre del 2002, se ampliaron en más de seiscientos productos. En este trabajo se presentan los rubros de la lista adicional, que presentan posibilidades de exportación a los Estados Unidos por parte de las PyMES de Bogotá y Cundinamarca.

  3. 77 FR 25536 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2012-04-30

    ... (Colombia) (individual) [SDNT]. 6. RODRIGUEZ CONRADO, Elmer Martin, c/o COPSERVIR LTDA., Bogota, Colombia; c... MIGUEL RODRIGUEZ E HIJO, Cali, Colombia; c/o RADIO UNIDAS FM S.A., Cali, Colombia; c/o REVISTA DEL...

  4. Voltage Weak DC Distribution Grids

    NARCIS (Netherlands)

    Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.

    2017-01-01

    This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of

  5. Compact integrated dc SQUID gradiometer

    Science.gov (United States)

    de Waal, V. J.; Klapwijk, T. M.

    1982-10-01

    An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17×12 mm and a sensitivity of 3.5×10-12 T m-1 Hz-1/2.

  6. Compact integrated dc SQUID gradiometer

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, V.J.; Klapwijk, T.M.

    1982-10-01

    An all-niobium integrated system of first-order gradiometer and dc suprconducting quantum interference device (SQUID) has been developed. It is relatively simple to fabricate, has an overall size of 17 x 12 mm and a sensitivity of 3.5 x 10/sup -12/ T m/sup -1/ Hz/sup -1/2/.

  7. Experiments with a DC Motor

    Science.gov (United States)

    Kraftmakher, Yaakov

    2010-01-01

    Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the…

  8. Borehole DC-6 hydrostratigraphic chart

    International Nuclear Information System (INIS)

    Gephart, R.E.

    1981-09-01

    This hydrostratigraphic chart for Borehole DC-6 identifies the basic stratigraphy and preliminary hydrologic test results. This borehole was cored for obtaining stratigraphic data and only that portion within the Grande Ronde formation remains open for hydrologic testing. The upper two formations were cased and cemented off

  9. Outlook of the process of storage of oncology drugs from the logistic operator in Colombia

    Directory of Open Access Journals (Sweden)

    Pedro Vicente Sánchez-Calvera

    2014-05-01

    Full Text Available This article mainly on the problem of  storage of oncology drugs, which is an important element in the supply chain, applied in the context of warehouse management of oncology drugs, in the logistics operator and providers of health services institutions (IPS for its acronym in Spanish of Bogotá DC and in the contex of a macro project "Methodological proposal for the definition of policies , rules of negotation and coordination in supply management of oncology drugs in Colombia," funded by Colciencias and the Universidad Nacional of Colombia. This article presents the current situation of oncology drugs, marking a characterization, diagnosis and identification and startegies evaluated under different scenarios. Finally, it is presented a proposal of improvement applied tranversely to storage processes including labels such as just in Time and the application of information and communication technologies (ICT.

  10. Notas sobre la Flora de Colombia y países vecinos, III

    Directory of Open Access Journals (Sweden)

    Dugand Armando

    1969-06-01

    Full Text Available Continuación (parte III de la nueva serie de notas botánicas iniciada hace tres años en Phytologia (vol. 13, no. 6: 379-400. 1966, y cuya segunda parte se publicó recientemente en Caldasia (vol, 10, no. 47: 173-213. 1968, relativas en su mayor parte a la flora xerófila y subxerófila de la región costera del Caribe en Colombia y países vecinos, particularmente Venezuela.  En ellas se hacen observaciones sobre la taxonomía, nomenclatura, morfología, distribución geográfica, hábitat, y otras varias, de las siguientes plantas: ASCLEPIADACEAE Matelea albiflra (Karst. Dugand. BIGNONIACEAE Anemopaegma chrysoleucum. (Kth. in H. & B. Sandw. # Arrabidaea candicans (L. C. Rich. DC. Arrabidaea conjugata (VeIl. Mart. ex DC. Arrabidaea florida DC. # Arrabidaea pleei DC. Clytostoma cuneatum Dugand. Clytostoma pterocalyx Spr. ex Urb. # Onohualcoa helicocalyx (O. Kze. Sandw. Phryganocydia uliginosa Dugand. Romeroa verticillata Dugand. # Roseodendron chryseum. (Blake Miranda. Tabebuia dugandii StandI. BOMBACACEAE Pseudobombax maximum A. Robyns. LEGUMINOSAE·FABOIDEAE Uribea tamarindoides Dugand & Romero. RUBIACEAE Guettarda eliadis StandI. Sickingia klugei StandI. Tal vez con la sola excepción de Arrabidaea florida DC., de cuya existencia en Colombia no hay -que yo sepa- ninguna información anterior (a menos que la colección original sea realmente del Caquetá colombiano como bien pudiera serlo, véase nota al pie de la página respectiva en este trabajo , todas las especies enumeradas arriba ya han sido catalogadas antes en la flora de este pais, ora con el mismo nombre con que figuran en la Iista, ora con otro que ha caido en desuso necesario o se considera sinonimo del que se da aqui. Las de este ultimo grupo se seiialan con el signo #.

  11. Assessing the deep drilling potential of Lago de Tota, Colombia, with a seismic survey

    Science.gov (United States)

    Bird, B. W.; Wattrus, N. J.; Fonseca, H.; Velasco, F.; Escobar, J.

    2015-12-01

    Reconciling orbital-scale patterns of inter-hemispheric South American climate during the Quaternary requires continuous, high-resolution paleoclimate records that span multiple glacial cycles from both hemispheres. Southern Andean Quaternary climates are represented by multi-proxy results from Lake Titicaca (Peru-Bolivia) spanning the last 400 ka and by pending results from the Lago Junin Drilling Project (Peru). Although Northern Andean sediment records spanning the last few million years have been retrieved from the Bogota and Fúquene Basins in the Eastern Cordillera of the Colombian Andes, climatic reconstructions based on these cores have thus far been limited to pollen-based investigations. When viewed together with the Southern Hemisphere results, these records suggest an anti-phased hemispheric climatic response during glacial cycles. In order to better assess orbital-scale climate responses, however, independent temperature and hydroclimate proxies from the Northern Hemisphere are needed in addition to vegetation histories. As part of this objective, an effort is underway to develop a paleoclimate record from Lago de Tota (3030 m asl), the largest lake in Colombia and the third largest lake in the Andes. One of 17 highland tectonic basins in Eastern Cordillera, Lago de Tota formed during Tertiary uplift that deformed pre-foreland megasequences, synrift and back-arc megasequences. The precise age and thickness of sediments in the Lago de Tota basin has not previously been established. Here, we present results from a recent single-channel seismic reflection survey collected with a small (5 cubic inch) air gun and high-resolution CHIRP sub-bottom data. With these data, we examine the depositional history and sequence stratigraphy of Lago de Tota and assess its potential as a deep drilling target.

  12. The consequences of hospital autonomization in Colombia: a transaction cost economics analysis.

    Science.gov (United States)

    Castano, Ramon; Mills, Anne

    2013-03-01

    Granting autonomy to public hospitals in developing countries has been common over recent decades, and implies a shift from hierarchical to contract-based relationships with health authorities. Theory on transactions costs in contractual relationships suggests they stem from relationship-specific investments and contract incompleteness. Transaction cost economics argues that the parties involved in exchanges seek to reduce transaction costs. The objective of this research was to analyse the relationships observed between purchasers and the 22 public hospitals of the city of Bogota, Colombia, in order to understand the role of relationship-specific investments and contract incompleteness as sources of transaction costs, through a largely qualitative study. We found that contract-based relationships showed relevant transaction costs associated mainly with contract incompleteness, not with relationship-specific investments. Regarding relationships between insurers and local hospitals for primary care services, compulsory contracting regulations locked-in the parties to the contracts. For high-complexity services (e.g. inpatient care), no restrictions applied and relationships suggested transaction-cost minimizing behaviour. Contract incompleteness was found to be a source of transaction costs on its own. We conclude that transaction costs seemed to play a key role in contract-based relationships, and contract incompleteness by itself appeared to be a source of transaction costs. The same findings are likely in other contexts because of difficulties in defining, observing and verifying the contracted products and the underlying information asymmetries. The role of compulsory contracting might be context-specific, although it is likely to emerge in other settings due to the safety-net role of public hospitals.

  13. DC motor operation controlled from a DC/DC power converter in pulse mode with low duty cycle

    OpenAIRE

    Stefanov, Goce; Kukuseva, Maja; Citkuseva Dimitrovska, Biljana

    2016-01-01

    In this paper pulse mode of operation of DC motor controlled by DC/DC power converter is analyzed. DC motor operation with time intervals in which the motor operates without output load is of interest. In this mode it is possible the motor to restore energy. Also, in the paper are represented calculations for the amount of the restored energy in the pulse mode operation of the motor for different duty cycles.

  14. DC to DC power converters and methods of controlling the same

    Science.gov (United States)

    Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

    2012-12-11

    A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

  15. Violencia y salud en Colombia

    Directory of Open Access Journals (Sweden)

    Saúl Franco Agudelo

    1997-02-01

    Full Text Available La violencia en Colombia parece incontenible. A las masacres y asesinatos colectivos, de una crueldad desconcertante, se suman los secuestros y desapariciones, el maltrato de niños y ancianos y las violaciones de adolescentes. Cada día, sin tregua, los colombianos son espectadores o víctimas de atracos callejeros y de discriminación racial, sexual y socioeconómica. Sin quererlo, se convierten en agentes de agresiones en el transporte urbano, el hogar, la escuela y el trabajo. Colombia tiene las tasas de mortalidad por homicidio más altas del mundo. Independientemente de la enorme sobrecarga institucional que impone a los servicios de salud y medicina legal, la violencia constituye actualmente en Colombia el principal problema de salud pública. Para hacerle frente, el sector de la salud debe elaborar políticas y financiar acciones; crear nuevos procesos de formación de personal, poner en marcha procesos de educación pública, y dedicar mayor esfuerzo y creatividad al campo de la investigación, que hasta ahora ha dado respuestas importantes pero aún insuficientes. Al reflexionar sobre la violencia, que es la sustitución de toda argumentación por la fuerza, es necesario ubicarla en el contexto de la vida y la salud. No se pretende solo racionalizarla, y menos aún sustituir la acción por la palabra o por las reflexiones, sino tratar de comprenderla a fondo con el objeto de buscarle alternativas. En el presente artículo se analiza, con esta finalidad, el tema de la violencia en Colombia, principalmente desde el punto de vista de su efecto en la salud de los colombianos y de sus implicaciones para el sector sanitario. El autor expone sus puntos de vista con plena conciencia de su subjetividad y limitaciones.

  16. La industria maltera en colombia

    OpenAIRE

    Parra Restrepo, Bernardo

    2011-01-01

    Este artículo estudia la industria maltera de Colombia, su origen, evolución y el estado en que se encuentra. Presenta cifras respecto al comportamiento de la producción y ventas. Muestra las relaciones de propiedad y describe la importancia relativa de la empresa con las otras subsidiarias del grupo económico al que pertenece. De otra parte analiza las relaciones obrero/patronales en el contexto actual y las relaciones con la agroindustria colombiana.

  17. Violence and health in Colombia Violencia y salud en Colombia

    Directory of Open Access Journals (Sweden)

    Saúl Franco Agudelo

    1997-09-01

    Full Text Available In Colombia, violence seems uncontrollable. Along with massacres and group killings of astonishing cruelty, there are also kidnappings and disappearances, abuse of children and the elderly, and rape of young adolescents. Every day, without respite, Colombians are witnesses or victims of street crimes as well as racial, sexual, and socioeconomic discrimination. Unwillingly, they become agents of aggression in public transport, at home, at school, and at work. Colombia has the highest rates of mortality from homicide in the world. Apart from the enormous institutional burden that violence imposes on the health services and forensic medicine, it now constitutes the principal public health problem in the country. To confront it, the health sector must develop policies and finance actions, develop innovative ways to train personnel, implement public education processes, and devote more effort and greater creativity to research, which up to now has provided some important, albeit insufficient, responses. Violence, which is the substitution of force for any type of dialogue, must be considered within the context of life and health. Doing so is not an attempt to rationalize violence, much less to substitute words or reflection for action, but rather an attempt to understand it in depth in order to search for alternatives. With that goal, this article analyzes the subject of violence in Colombia, principally from the perspective of its effect on the health of the citizens and its implications for the health sector. The author fully recognizes the subjectivity and limitations of the views he expresses herein.La violencia en Colombia parece incontenible. A las masacres y asesinatos colectivos, de una crueldad desconcertante, se suman los secuestros y desapariciones, el maltrato de niños y ancianos y las violaciones de adolescentes. Cada día, sin tregua, los colombianos son espectadores o víctimas de atracos callejeros y de discriminación racial, sexual

  18. Violencia y salud en Colombia Violence and health in Colombia

    Directory of Open Access Journals (Sweden)

    Saúl Franco Agudelo

    1997-02-01

    Full Text Available La violencia en Colombia parece incontenible. A las masacres y asesinatos colectivos, de una crueldad desconcertante, se suman los secuestros y desapariciones, el maltrato de niños y ancianos y las violaciones de adolescentes. Cada día, sin tregua, los colombianos son espectadores o víctimas de atracos callejeros y de discriminación racial, sexual y socioeconómica. Sin quererlo, se convierten en agentes de agresiones en el transporte urbano, el hogar, la escuela y el trabajo. Colombia tiene las tasas de mortalidad por homicidio más altas del mundo. Independientemente de la enorme sobrecarga institucional que impone a los servicios de salud y medicina legal, la violencia constituye actualmente en Colombia el principal problema de salud pública. Para hacerle frente, el sector de la salud debe elaborar políticas y financiar acciones; crear nuevos procesos de formación de personal, poner en marcha procesos de educación pública, y dedicar mayor esfuerzo y creatividad al campo de la investigación, que hasta ahora ha dado respuestas importantes pero aún insuficientes. Al reflexionar sobre la violencia, que es la sustitución de toda argumentación por la fuerza, es necesario ubicarla en el contexto de la vida y la salud. No se pretende solo racionalizarla, y menos aún sustituir la acción por la palabra o por las reflexiones, sino tratar de comprenderla a fondo con el objeto de buscarle alternativas. En el presente artículo se analiza, con esta finalidad, el tema de la violencia en Colombia, principalmente desde el punto de vista de su efecto en la salud de los colombianos y de sus implicaciones para el sector sanitario. El autor expone sus puntos de vista con plena conciencia de su subjetividad y limitaciones.In Colombia, violence seems uncontrollable. Along with massacres and group killings of astonishing cruelty, there are also kidnappings and disappearances, abuse of children and the elderly, and rape of young adolescents. Every day

  19. Prediabetes in Colombia: Expert Consensus

    Science.gov (United States)

    Calderón, Carlos; Castillo, Jorge; Escobar, Iván Darío; Melgarejo, Enrique; Parra, Gustavo Adolfo

    2017-01-01

    Abstract The prevalence of Prediabetes in Colombia is high, and despite being recognized and categorized in the main Medical Guidelines and included in the International Classification of Diseases in Colombia, knowledge and awareness of it is limited amongst healthcare professionals and in the community. Our expert group recommends that educational programs emphasize a global approach to risk which includes a recognition of the importance of prediabetes and its evaluation along with and other risk factors such as a family history of DM2, overweight and obesity, dislipidemia and hypertension. Studies conducted in Colombia demonstrate the value of the FINDRIS questionnaire as a tool to identify subjects at risk of prediabetes and DM2, and we recommend that it should be systematic applied throughout the country as part of government policy. Prediabetes progresses to DM2 at an annual rate of 10%, but it has also been shown that prediabetes is an independent risk factor for cardiovascular outcomes. On this basis, the Committee recommends that once prediabetes is detected and diagnosed, immediate management of the disease begins through lifestyle changes, with follow up assessments performed at 3 and 6 months. If the patient does not respond with a weight loss of at least 5% and if the HbA1C values ​​are not normalized, pharmacological management should be initiated with a metformin dose of 500 mg / day, increasing up to 1,500 - 1,700 mg / day, according to tolerance. PMID:29662261

  20. Violence and health in Colombia

    Directory of Open Access Journals (Sweden)

    Saúl Franco Agudelo

    1997-09-01

    Full Text Available In Colombia, violence seems uncontrollable. Along with massacres and group killings of astonishing cruelty, there are also kidnappings and disappearances, abuse of children and the elderly, and rape of young adolescents. Every day, without respite, Colombians are witnesses or victims of street crimes as well as racial, sexual, and socioeconomic discrimination. Unwillingly, they become agents of aggression in public transport, at home, at school, and at work. Colombia has the highest rates of mortality from homicide in the world. Apart from the enormous institutional burden that violence imposes on the health services and forensic medicine, it now constitutes the principal public health problem in the country. To confront it, the health sector must develop policies and finance actions, develop innovative ways to train personnel, implement public education processes, and devote more effort and greater creativity to research, which up to now has provided some important, albeit insufficient, responses. Violence, which is the substitution of force for any type of dialogue, must be considered within the context of life and health. Doing so is not an attempt to rationalize violence, much less to substitute words or reflection for action, but rather an attempt to understand it in depth in order to search for alternatives. With that goal, this article analyzes the subject of violence in Colombia, principally from the perspective of its effect on the health of the citizens and its implications for the health sector. The author fully recognizes the subjectivity and limitations of the views he expresses herein.

  1. Prediabetes in Colombia: Expert Consensus.

    Science.gov (United States)

    López-Jaramillo, Patricio; Calderón, Carlos; Castillo, Jorge; Escobar, Iván Darío; Melgarejo, Enrique; Parra, Gustavo Adolfo

    2017-12-30

    The prevalence of Prediabetes in Colombia is high, and despite being recognized and categorized in the main Medical Guidelines and included in the International Classification of Diseases in Colombia, knowledge and awareness of it is limited amongst healthcare professionals and in the community. Our expert group recommends that educational programs emphasize a global approach to risk which includes a recognition of the importance of prediabetes and its evaluation along with and other risk factors such as a family history of DM2, overweight and obesity, dislipidemia and hypertension. Studies conducted in Colombia demonstrate the value of the FINDRIS questionnaire as a tool to identify subjects at risk of prediabetes and DM2, and we recommend that it should be systematic applied throughout the country as part of government policy. Prediabetes progresses to DM2 at an annual rate of 10%, but it has also been shown that prediabetes is an independent risk factor for cardiovascular outcomes. On this basis, the Committee recommends that once prediabetes is detected and diagnosed, immediate management of the disease begins through lifestyle changes, with follow up assessments performed at 3 and 6 months. If the patient does not respond with a weight loss of at least 5% and if the HbA1C values ​​are not normalized, pharmacological management should be initiated with a metformin dose of 500 mg / day, increasing up to 1,500 - 1,700 mg / day, according to tolerance.

  2. Analysis of a high power, resonant DC-DC converter for DC wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2018-01-01

    This paper is introducing a new method of operation for a series resonant converter, with intended application in megawatt high-voltage DC wind turbines. Compared to a frequency controlled series resonant converter operated in sub resonant mode, the method (entitled pulse removal technique) allows...

  3. Dilation and Curettage (D&C)

    Science.gov (United States)

    ... For Patients About ACOG Dilation and Curettage (D&C) Home For Patients Search FAQs Dilation and Curettage ( ... February 2016 PDF Format Dilation and Curettage (D&C) Special Procedures What is dilation and curettage (D& ...

  4. Seismological observations at the Northern Andean region of Colombia: Evidence for a shallowly subducting Caribbean Slab and an extensional regime in the upper plate

    Science.gov (United States)

    Monsalve, G.; Cardona, A.; Yarce, J.; Alvira, D.; Poveda, E.

    2013-05-01

    A number of seismological observations, among which we can mention teleseismic travel time residuals, P to S receiver functions and Pn velocity quantification, suggest a clear distinction between the seismic structure of the crust and uppermost mantle between the plains on the Caribbean coast of Colombia and the mountains at the Northern Andean region. Absolute and relative travel time residuals indicate the presence of a seismically fast material in the upper mantle beneath northern Colombia; preliminary results of Pn studies show a region of relatively slow Pn velocities (between 7.8 and 7.9 km/s) underneath the Caribbean coast, contrasting with values greater than 8 km/s beneath the Central and Western cordilleras of Colombia, and the Pacific coast; receiver functions suggest a significantly thinner crust beneath the Caribbean coast, with a crustal thickness between 25 and 30 km, than beneath the Northern Andean zone at the cordilleras of Colombia, where it exceeds 40 km and reaches about 57 km at the location of Bogota. Besides the obviuos discrepancies that appear in response to different topography, we think that the seismological observations are a consequence of the presence of two very distinct slab segments beneath Colombia and contrasting behaviors of the upper plate, which correspond to Caribbean and Nazca subductions. Our seismic observations can be explained by a shallowly subducting Caribbean Plate, in the absence of an asthenospheric wedge, that steepens at about the location of the Bucaramanga nest, and a thinned continental crust that reflects an extensional component linked to oblique convergence of the Caribbean, which contrasts with the crustal thickening in the Andean Cordillera linked to crustal shortening and Nazca plate subuction. These new data are consistent with the idea of of a relatively warm Nazca slab of Neogene age which seems to have a relatively frontal convergence, and a colder, more buoyant Caribbean slab which represents an

  5. Hierarchical Power Sharing Control in DC Microgrids

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

    2016-01-01

    Because of the advances in power electronics, DC-based power systems, have been used in industrial applications such as data centers [18], space applications [10], aircraft [12], offshore wind farms, electric vehicles [56], DC home systems [5, 20], and high-voltage DC transmission systems...

  6. Characterising and modelling extended conducted electromagnetic interference in densely packed DC-DC converter

    CSIR Research Space (South Africa)

    Grobler, Inus

    2013-09-01

    Full Text Available . The military specified DC-DC converters are applicable, spanning from 100 W handheld power managers up to 2 kW DC-DC battery chargers. Circuit layout high frequency effects as well as high frequency impedances of the power components were characterised...

  7. Full wave dc-to-dc converter using energy storage transformers

    Science.gov (United States)

    Moore, E. T.; Wilson, T. G.

    1969-01-01

    Full wave dc-to-dc converter, for an ion thrustor, uses energy storage transformers to provide a method of dc-to-dc conversion and regulation. The converter has a high degree of physical simplicity, is lightweight and has high efficiency.

  8. A DC-DC Conversion Powering Scheme for the CMS Phase-1 Pixel Upgrade

    CERN Document Server

    Feld, Lutz Werner; Marcel Friedrichs; Richard Hensch; Karpinski, Waclaw; Klein, Katja; Sammet, Jan Domenik; Wlochal, Michael

    2012-01-01

    The powering scheme of the CMS pixel detector will be described, and the performance of prototype DC-DC buck converters will be presented, including power efficiency, system tests with DC-DC converters and pixel modules, thermal management, reliability at low temperature, and studies of potential frequency locking betwe...

  9. Plan Colombia or development as security

    Directory of Open Access Journals (Sweden)

    Juan Pablo Guevara Latorre

    2015-01-01

    the most relevant policy for the construction of the State in 21st-century Colombia from a critical standpoint. The document makes it possible to show that Plan Colombia is a privatized form of development, interpreted in terms of security based on an incomplete understanding of the Colombian conflict that prevails into our present

  10. Transformerless dc-Isolated Converter

    Science.gov (United States)

    Rippel, Wally E.

    1987-01-01

    Efficient voltage converter employs capacitive instead of transformer coupling to provide dc isolation. Offers buck/boost operation, minimal filtering, and low parts count, with possible application in photovoltaic power inverters, power supplies and battery charges. In photovoltaic inverter circuit with transformerless converter, Q2, Q3, Q4, and Q5 form line-commutated inverter. Switching losses and stresses nil because switching performed when current is zero.

  11. AC-DC PFC Converter Using Combination of Flyback Converter and Full-bridge DC-DC Converter

    Directory of Open Access Journals (Sweden)

    Moh. Zaenal Efendi

    2014-06-01

    Full Text Available This paper presents a combination of power factor correction converter using Flyback converter and Full-bridge dc-dc converter in series connection. Flyback converter is operated in discontinuous conduction mode so that it can serve as a power factor correction converter and meanwhile Full-bridge dc-dc converter is used for dc regulator. This converter system is designed to produce a 86 Volt of output voltage and 2 A of output current. Both simulation and experiment results show that the power factor of this converter achieves up to 0.99 and meets harmonic standard of IEC61000-3-2. Keywords: Flyback Converter, Full-bridge DC-DC Converter, Power Factor Correction.

  12. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    Directory of Open Access Journals (Sweden)

    Haojie Wang

    2016-07-01

    Full Text Available It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC is proposed for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control.

  13. A Feed-Forward Control Realizing Fast Response for Three-Branch Interleaved DC-DC Converter in DC Microgrid

    DEFF Research Database (Denmark)

    Wang, Haojie; Han, Minxiao; Yan, Wenli

    2016-01-01

    It is a common practice for storage batteries to be connected to DC microgrid buses through DC-DC converters for voltage support on islanded operation mode. A feed-forward control based dual-loop constant voltage PI control for three-branch interleaved DC-DC converters (TIDC) is proposed...... for storage batteries in DC microgrids. The working principle of TIDC is analyzed, and the factors influencing the response rate based on the dual-loop constant voltage control for TIDC are discussed, and then the method of feed-forward control for TIDC is studied to improve the response rate for load...... changing. A prototype of the TIDC is developed and an experimental platform is built. The experiment results show that DC bus voltage sags or swells caused by load changing can be reduced and the time for voltage recovery can be decreased significantly with the proposed feed-forward control....

  14. FLYWHEEL AND A DC MACHINE

    Directory of Open Access Journals (Sweden)

    IVAN ALCALÁ

    2014-01-01

    Full Text Available Este artículo describe el análisis, modelado y simulación de un vehículo eléctrico (EV enfocado al desarrollo de un banco de pruebas para reproducir la dinámica del EV. El banco está formado por un drive de motor de inducción (IM acoplado directamente a una máquina de DC y a un volante de inercia a través de una transmisión. El volante de inercia y la máquina de DC reproducen la dinámica y las fuerzas que actúan en el vehículo. Se propone una metodología para diseñar un banco de pruebas de EV para estudiar el comportamiento de vehículos eléctricos cercano a las condiciones de operación reales. El análisis de las fuerzas en el EV en conjunto con la máquina DC define las condiciones de operación del EV. El modelado y la simulación son desarrollados en MATLAB/Simulink, el banco de pruebas implementado es controlado por un DSP. Finalmente, los resultados de simulación y experimentales obtenidos validan el funcionamiento del banco de prueba.

  15. 50 Years of the Aesthetic Research Institute, Nowadays Carlos Arbelaez Camacho Institute for the architectural and urban heritage in Bogota

    Directory of Open Access Journals (Sweden)

    Olimpia Niglio

    2014-01-01

    Full Text Available Con los primeros 50 años del Instituto de Investigaciones Estéticas, hoy Instituto Carlos Arbeláez Camacho para el patrimonio arquitectónico y urbano en Bogotá, este artículo tiene como finalidad recorrer las etapas fundamentales del desarrollo de la cultura de la restauración en Colombia gracias a la obra del profesor Carlos Arbeláez Camacho.Su obra se desarolló en un contexto cultural muy complejo donde la práctica de la conservación del patrimonio cultural no era de interés para la comunidad más interesada a la modernización del país. Sin embargo el trabajo de sensibilización desarrollado por Carlos Arbeláez Camacho con sus alumnos ha puesto las bases por una cultura de la restauración, hoy con más de cincuenta años de historia y de experiencias muy interesantes. 

  16. Caracterización de la gestión de residuos hospitalarios y similares en cami vista hermosa, Bogota

    Directory of Open Access Journals (Sweden)

    Juan Carlos Hernández-Criado

    2016-01-01

    Full Text Available Background. The environmental management of residues is defined within the public policy, which involves the hazardous waste from a general standpoint. Only until 2000, the mandatory guidelines were established for the comprehensive management of hospital waste and similar in Colombia. Objective. To characterize the management of hospitaland similar waste in CAMI VISTA HERMOSA, Bogotá. Methods. Research was performed at the first level healthcare provider CAMI VISTA HERMOSA, a public social company. A cross – section type study was performed, where the daily-base generated waste was characterized qualitatively and quantitatively, through the consolidation of the information in the RH1 form, established by the Manual for the Comprehensive Management of Hospital Solid Waste and Similar. Results. Biosanitary, sharps, drug, heavy metal, ordinary, recyclable and anatomic-pathological wastes were identified by using the RH1 form; similarly, they were quantified in each of the areas involved in the service providing process, showing the fluctuation in the behavior related to weights and each of their classes, determined by several factors including: the increasing number of medical appointments regarding respiratory diseases associated with raining seasons and the inappropriate waste disposal in different areas. Conclusions. Data collection was a tool that allowed to identify critical points such as the inappropriate waste disposal. Besides, the information was useful as a strategy to reorganize processes of change according to the Plan of Management of Hospital Waste and Similar.

  17. Quasi-Z-Source Half-Bridge DC-DC Converter for Photovoltaic Applications

    OpenAIRE

    Vinnikov, D; Chub, A; Husev, O; Zaķis, J

    2015-01-01

    This paper presents a novel quasi-Z-source halfbridge galvanically isolated DC-DC converter intended for the photovoltaic applications. The topology could be envisioned as an alternative to the boost half-bridge DC-DC converter but the benefit of its symmetric structure reduces the threat of transformer saturation due to the dc flux. The proposed converter features the continuous input current and could be used either with one or two input voltage sources.

  18. Control of the DC-DC Converter used into Energy Generation System

    International Nuclear Information System (INIS)

    Bizon, Nicu; Oproescu, Mihai

    2006-01-01

    This paper presents an investigation of the DC-DC Converter controller used into Energy Generation System. The full bridge is used into an Energy Generation System (EGS) as second power interface between the energy source and the high DC bus. The simulation results show that the DC-DC Converter behavior can be improved using a well designed PI control surface. The used Simulink models for the EGS blocks and some design considerations are presented, too. (authors)

  19. The FARC and Hugo Chavez: Is Contemporary Venezuela a Threat to Colombia?

    Science.gov (United States)

    2010-12-01

    Smith, The Emergence of Liberation Theology: Radical Religion and the Social Movement Theory (Chicago: Chicago University Press, 1991), 59. 16...Socialismo del Siglo XXI (Bogota: Fundacion para la Investigacion y la Cultura, 2007), 50. 146 Cristóbal Valencia Ramírez, “Venezuela’s Bolivarian... Siglo XXI. Bogota: Fundacion para la Investigacion y la Cultura, 2007. Discovery en Español. “Fuga de las FARC.” http://www.tudiscovery.com/web

  20. ZVS Operating Region of Multiresonant DC/DC Boost Conveter

    Directory of Open Access Journals (Sweden)

    Elzbieta Szychta

    2007-01-01

    Full Text Available Electromagnetic phenomena that occur during stable operation in resonant circuits of multiresonant ZVS boost converter are described, which can be applied in many fields of the needs of DC voltage electricity. The operating region of the converter is defined which assures the circuit’s operation in which semiconductor elements are switched at zero voltage (ZVS. Conditions delimiting the ZVS operating region are provided. Analysis of the circuit’s operation is based on results of simulation testing by means of Simplorer software.

  1. A Feedback Passivation Design for DC Microgrid and Its DC/DC Converters

    Directory of Open Access Journals (Sweden)

    Feifan Ji

    2016-12-01

    Full Text Available There are difficulties in analyzing the stability of microgrids since they are located on various network structures. However, considering that the network often consists of passive elements, the passivity theory is applied in this paper to solve the above-mentioned problem. It has been formerly shown that when the network is weakly strictly positive real (WSPR, the DC microgrid is stable if all interfaces between the microgrid and converters are made to be passive, which is called interface passivity. Then, the feedback passivation method is proposed for the controller design of various DC–DC converters to achieve the interface passivity. The interface passivity is different from the passivity of closed-loop systems on which the passivity based control (PBC concentrates. The feedback passivation design is detailed for typical buck converters and boost converters in terms of conditions that the controller parameters should satisfy. The theoretical results are verified by a hardware-in-loop real-time labotray (RTLab simulation of a DC microgrid with four generators.

  2. Enfermedad de Chagas en Colombia

    Directory of Open Access Journals (Sweden)

    Fernando Serpa Florez

    1985-12-01

    Full Text Available

    Generalidades.

    La tripanosomiasis americana o enfermedad de Chagas se halla ampliamente distribuida en Centro y Sur América. La Organización Mundial de la Salud considera que pueden haber doce millones de casos de esta dolencia en el continente (1, estudiados principalmente en Argentina, Brasil y Venezuela. Se calcula que en Colombia tendríamos una incidencia muy alta de casos, (Marinkelle (2 estima que 7.140/0 de la población podría estar infectada o sea cerca de dos millones de personas, distribuidos en las zonas rurales del nordeste del país (cuenca del Catatumbo Magdalena Medio y Llanos Orientales (Piedemonte, Macarena y Meta cercano (3 (4 (5 Y que seis millones de nuestros compatriotas -22.30/0 de la población total- (2 corren el riesgo de adquirir la enfermedad pues habitan en regiones donde se dan las condiciones para que ésta se propague.


    RESEÑA HISTORICA DE LA ENFERMEDAD EN COLOMBIA
    La existencia de casos de tripanosomiasis americana y de sus vectores fue comprobada en Colombia desde 1929 cuando César Uribe Piedrahita (6 encontró en Prado, Tolima, vectores del mal infectados con T.

    cruzi e Ignacio Moreno Pérez observó dicho hemoflagelado en sangre de seres humanos en Cali (4. En los años siguientes Hernando Ucrós, Benjamín Otálora, Hernando Groot, Santiago Renjifo, Hernando Osorno, Carlos Duarte Rangel, C.J. Marinkelle, Augusto Corredor, Ernesto Suescún y varios otros investigadores colomb iano s describieron diversos focos de la enfermedad en Colombia y estudiaron la distribución de sus vectores y huéspedes intermediarios. En 1947 1. Caicedo y C. Hernández publicaron su informe sobre los primeros casos crónicos de enfermedad de Chagas comprobados en nuestro país, procedentes de la región de Fusagasugá, Cundinamarca (7 en tanto que, en 1961, Marcos Duque inicia los estudios sobre cardiopatía chagásica (8 y Hernando Rocha, en 1971, comunica

  3. Historia del paramilitarismo en Colombia

    OpenAIRE

    Rivera,Edgar de Jesús Velásquez

    2007-01-01

    En Colombia, desde la década de los años ochenta del siglo XX tomó fuerza el paramilitarismo como estrategia contrainsurgente, política que no ha sido reconocida como tal por parte de los distintos gobiernos y se expresa como terrorismo de Estado. Incidió en el surgimiento de tal fenómeno, la ideología anticomunista que profesan la mayoría de miembros de las fuerzas armadas, la cultura política derivada de la violencia, la corrupción y el clientelismo, así como el narcotráfico, al igual que l...

  4. Colombia competente para la paz

    Directory of Open Access Journals (Sweden)

    Norma Sofía Vanegas Torres

    2013-07-01

    Full Text Available La paz y la convivencia en Colombia demandan el desarrollo de un enfoque humanístico, una competencia particular que como las restantes competencias implican un saber y un saber hacer dentro de un contexto, pero que en este caso se relacionan más concretamente con el saber vivir. Este artículo analiza el desarrollo de una posible de competencia para la paz y analiza la importancia de la academia como medio para su desarrollo e instrumentalización. Se analizan al mismo tiempo las connotaciones de esta competencia en el marco de la sociedad posmoderna contemporánea.

  5. MICROCRÉDITO EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Bernardo Barona Z

    2004-01-01

    Full Text Available El artículo tiene como propósitos: proporcionar una visión general de la forma en que el financiamiento de los microempresarios y los estratos más vulnerables de la población ha sido abocada en Colombia; resumir los grandes retos que enfrenta en la actualidad el programa de microfinanzas en el mundo, presentar el programa de investigación que están adelantando las Universidades Icesi y del Valle en Colombia en asocio con la Universidad de Laval en Canadá y con algunos centros de Investigación de Filipinas, Marruecos y Benin y algunos resultados parciales de este esfuerzo investigativo; y, presentar algunas recomendaciones tendientes a fortalecer a las organizaciones microfinancieras en el país. Una revisión de la historia y el estado actual del microcrédito en Colombia indica que los esfuerzos hasta ahora realizados parecen haberse quedado muy cortos frente a las necesidades de financiación de los microempresarios: la cobertura de microemepresarios alcanzada por instituciones gubernamentales, ONG y la banca convencional ha sido muy baja. En cuanto a los retos que afronta el movimiento microfinanciero en el mundo dos muy importantes son (i, clarificar el efecto de los diferentes esfuerzos de microcrédito realizados en la reducción de la pobreza de la población del país y, (ii, identificar mecanismos para lograr un aumento significativo de la cobertura mediante un balance adecuado entre regulación, supervisión y disciplina de mercado. Los principales resultados (parciales obtenidos en la línea de investigación descrita en este artículo son (i, contrario a lo que con frecuencia se asume, a medida que una organización cooperativa crece en tamaño no necesariamente se torna más eficiente: los posibles beneficios de la mayor escala fueron más que compensados en las empresas estudiadas por nosotros por la propensión al gasto excesivo que exhiben los gerentes en caso de instituciones de mayor tamaño (ii, las cooperativas

  6. Food Innocuousness: Prospect In Colombia

    Directory of Open Access Journals (Sweden)

    Ana Elvira Ortiz Amaya

    2011-12-01

    Full Text Available Food innocuousness, on all over the world, is receiving more attention due to the increment in the incidence of food borne diseases (ETAs, the worry about emergent known dangers and the globalization of trade. Consequently, this literature review shows the progress in relation to this thematic, in Colombia. It covers topics as the relation between food innocuousness and safety, the international and national organizations involved, the developments, in legislation, the system of epidemiological surveillance of ETAs and their perspectives, as cornerstones to ensure food quality

  7. La industria maltera en Colombia

    Directory of Open Access Journals (Sweden)

    Bernardo Parra Restrepo

    2002-06-01

    Full Text Available Este artículo estudia la industria maltera de Colombia, su origen, evolución y el estado en que se encuentra. Presenta cifras respecto al comportamiento de la producción y ventas. Muestra las relaciones de propiedad y describe la importancia relativa de la empresa con las otras subsidiarias del grupo económico al que pertenece. De otra parte analiza las relaciones obrero/patronales en el contexto actual y las relaciones con la agroindustria colombiana.

  8. Los desequilibrios territoriales en Colombia

    OpenAIRE

    Alfonso Roa, Óscar A.; A. Alfonso R., Óscar; Revéiz Roldán, Édgar

    2016-01-01

    Colombia es un país de regiones metropolitanas. Si a cada región que es habitada por una población le es inmanente un gobierno, las formas de ocupación territorial por la población y las actividades humanas deberían contar con la forma de gobierno más pertinente. Por tanto, un nuevo modelo territorial de Estado tendrá que organizarse en torno a gobiernos metropolitanos cuyas funciones de alcance supralocal se construirían con base en las que ya poseen las jurisdicciones involucradas en el pol...

  9. Artificial neural network control of sab dc/dc converter

    International Nuclear Information System (INIS)

    Mahar, M.A.; Abro, M.R.; Larik, A.S.

    2009-01-01

    The latest development of power semiconductor devices enable the modern power electronic converters to withstand high voltage and high power applications. Power electronic converters are mostly periodic variable structure systems due to their switched operations. The main drawback of these converters is the generation of oscillations which are developed during the operation of the converters under nonlinear situations. To handle these nonlinearities, various researchers have proposed different control techniques. Power electronic designers are devoting in the further development of converter topologies and their control techniques. SAB (Single Active Bridge) DC/DC converter is a new topology recently introduced by Demetriades. This topology is used in high voltage and high power applications. Because of its smart features, SAB converter has recently drawn attention of many researchers. However, during the operation of SAB converter severe oscillations are generated. In this research work, a novel NNC (Neural Network Controller) model is developed for SAB converter to minimize oscillations generated during its operation. NNC is believed to be an advanced nonlinear and robust controller which has the ability to map the nonlinear behaviour in a negligible response time. The performance of SAB converter with NNC is tested under dynamic region by considering the reference voltage variation and duty ratio variation. The SAB converter is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)

  10. Experiments with a dc motor

    International Nuclear Information System (INIS)

    Kraftmakher, Yaakov

    2010-01-01

    Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the mechanical and electrical parameters of the motor is clearly seen. The measurements are carried out with the ScienceWorkshop data-acquisition system and the DataStudio software from PASCO scientific. The experiments are well related to university courses of electricity and magnetism and can be used in undergraduate laboratories or for lecture demonstrations.

  11. Using PBL to Improve Educational Outcomes and Student Satisfaction in the Teaching of DC/DC and DC/AC Converters

    Science.gov (United States)

    Martinez-Rodrigo, Fernando; Herrero-De Lucas, Luis Carlos; de Pablo, Santiago; Rey-Boue, Alexis B.

    2017-01-01

    This paper examines the question of how to use project-based learning to increase student performance and satisfaction in a power electronics course addressing the topics of dc/dc and dc/ac converters, the assembly of a dc/dc converter, and the use of a commercial speed drive. A detailed presentation of the methodology is shown, and the results…

  12. The south territory; the city limits as recognition in new ways of urban-regional growth between Bogota and the Municipality of Soacha

    International Nuclear Information System (INIS)

    Acebedo R, Luis Fernando

    2002-01-01

    The purpose of this paper is to study the context of the great urban developments occurring in the south of Bogota and Soacha, as two towns that form an extremely complex urban, continuum, emerging from the spread of residential areas and diverse productive activities, during five decades. The Tunjuelito River basin-being part of the Savanna's main ecological structure became the foundation for these settlements. To acknowledge the process of urban expansion, taking the river as a natural borderline, allowed us to identify certain social and functionally homogeneous areas that we named the South Territory. Advances in the understanding of the of Colombian cities we the passing and coming into operation of the first generation of the territorial ordering plans, have allowed us to identify, at least, two shortcomings. The first one has to do with an inherent weakness in regional analyses, which to the present day has hindered progress towards a rational distribution of metropolitan territories; the second one has to do with the lack of adequate tools to interpret the so-called peripheral spaces; spaces which, actually, constitute a complex urban and rural system having extraordinary regional impact. The study of the South Territory helps to prove the truth of this hypothesis and suggests new interpretations and ways to approach the problem

  13. [Respiratory disease risk factors in the 5-14 year-old population in an area of Bogota, 2012-2013].

    Science.gov (United States)

    Rodríguez-Moreno, Natalia; Martínez-Morales, Viviana; Sarmiento-Suarez, Rodrigo; Medina-Palacios, Katalina; Hernández, Luis J

    2013-01-01

    Establishing the prevalence of respiratory symptoms, asthma and rhinitis, possibly associated with air pollution, in 5- to 14-year-old children in Bosa (a conurbation of Bogota), between 2012 and 2013. A sample was taken of 553 children living in the conurbation. The results indicated that when a child lives with people who smoke there was a 1.5 times risk of coughing at night (compared to living in a non-smoking home) such night-time coughing being different to that produced by respiratory infections such as colds, bronchitis and pneumonia. Children living in homes having fireplaces/open cooking areas located less than 100 m apart had 1.6 times greater probability of presenting symptoms. Children attending schools having greater PM10 exposure and living near buildings being constructed or having roads in a poor state of repair less than 100 meters from their homes were 2.5 times more likely to suffer respiratory disease. Children living in damp rooms were 4 times more likely to have wheezed during the past year. The risk of wheezing became increased by 80 % when a child lived within 100 meters of buildings being constructed or near unpaved roads and attended a school having greater exposure. Government intervention is critical for changing respiratory disease-associated extramural risk factors, such as improvements benefitting children which should be carried out in urban areas.

  14. Hierarchical Velocity Control Based on Differential Flatness for a DC/DC Buck Converter-DC Motor System

    Directory of Open Access Journals (Sweden)

    R. Silva-Ortigoza

    2014-01-01

    Full Text Available This paper presents a hierarchical controller that carries out the angular velocity trajectory tracking task for a DC motor driven by a DC/DC Buck converter. The high level control is related to the DC motor and the low level control is dedicated to the DC/DC Buck converter; both controls are designed via differential flatness. The high level control provides a desired voltage profile for the DC motor to achieve the tracking of a desired angular velocity trajectory. Then, a low level control is designed to ensure that the output voltage of the DC/DC Buck converter tracks the voltage profile imposed by the high level control. In order to experimentally verify the hierarchical controller performance, a DS1104 electronic board from dSPACE and Matlab-Simulink are used. The switched implementation of the hierarchical average controller is accomplished by means of pulse width modulation. Experimental results of the hierarchical controller for the velocity trajectory tracking task show good performance and robustness against the uncertainties associated with different system parameters.

  15. The Topologies Research of a Soft Switching Bidirectional DC/DC Converter

    DEFF Research Database (Denmark)

    Zhang, Qi; Zhang, Yongping; Sun, Xiangdong

    2017-01-01

    A soft-switching solution implemented to the traditional bidirectional DC/DC converter is developed. The soft-switching cell, which composed of three auxiliary switches, one resonant capacitor and one resonant inductor, is equipped in the traditional bidirectional DC/DC converter to realize circuit...... circle. And the proposed topology of bidirectional soft-switching dc-dc converter(TASBC) performs ideal soft switching at boost operations. The characteristics of the proposed converter has been verified by MATLAB simulations and experimental results....

  16. Elimination of output voltage oscillations in DC-DC converter using PWM with PI controller

    Directory of Open Access Journals (Sweden)

    Sreenivasappa Veeranna Bhupasandra

    2010-01-01

    Full Text Available In this paper the SIMULINK model of a PWM controlled DC-DC converter is modeled using switching function concept to control the speed of the DC motor. The presence of the voltage oscillation cycles due to higher switching frequency in the DC-DC converter is identified. The effect of these oscillations on the output voltage of the converter, Armature current, Developed torque and Speed of the DC motor is analyzed. In order to minimize the oscillation cycles the PI controller is proposed in the PWM controller.

  17. Chaos analysis and chaotic EMI suppression of DC-DC converters

    CERN Document Server

    Zhang, Bo

    2014-01-01

    Introduces chaos theory, its analytical methods and the means to apply chaos to the switching power supply design DC-DC converters are typical switching systems which have plenty of nonlinear behaviors, such as bifurcation and chaos. The nonlinear behaviors of DC-DC converters have been studied heavily over the past 20 years, yet researchers are still unsure of the practical application of bifurcations and chaos in switching converters. The electromagnetic interference (EMI), which resulted from the high rates of changes of voltage and current, has become a major design criterion in DC-DC co

  18. Observatorio de Política Internacional I. COLOMBIA - Una paz esquiva

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  19. Observatorio de Política Internacional I. COLOMBIA - Una nueva estrategia de paz

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  20. Observatorio de Política Internacional I. COLOMBIA - Una paz secuestrada

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  1. Observatorio de Política Internacional I. COLOMBIA - Los momentos de la paz

    OpenAIRE

    Neira Fernández, Enrique

    2012-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  2. Observatorio de Política Internacional I. COLOMBIA - Siempre es tarde para la paz

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  3. Observatorio de Política Internacional I. COLOMBIA - Viraje en el proceso de paz

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  4. ConstitutionalJustice: Cases of Protection of Freedom and Personal Security in Colombia

    Directory of Open Access Journals (Sweden)

    Viridiana Molinares Hassan

    2014-07-01

    Full Text Available In this paper we present the results of an investigation about judicial protection of freedom and personal security granted by the Constitutional Court (cc of Colombia, with a comparative analysis between the period 1992-2001, to which governments have appointed period of postconstitucionales, which coincides with the issuance of the 1991 Constitution, and the creation of constitutional jurisdiction, and the period 2002-2010, during which it ran the Democratic Security Policy (dsp as a government policy proposal by former president Álvaro Uribe, whose aim was to achieve peace through the declaration of war to the guerrilla group Revolutionary Armed Forces of Colombia (farc. Our interest is to show that the protection of freedom and personal security as the basis of the Constitutional (ec finds in the cc his greatest guarantor, even against closing courts in other jurisdictions that are still rooted in the failed legal positivist paradigm, ignoring the postulates of neoconstitutionalism dc sufficiently developed from a process of creative interpretation and decision-making. This coupled with the importance for the branches of power and knowledge associated scope of freedom and personal security developed by the cc in the difficult context of irregular warfare that exists in Colombia, yet it is, for universal constitutionalism, an example of the development of legal guarantor in the context of current constitutionalism.

  5. COMERCIO DE FAUNA SILVESTRE EN COLOMBIA WILDLIFE TRADE IN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Néstor Javier Mancera Rodríguez

    2008-12-01

    Full Text Available Este trabajo ofrece un panorama sobre las actividades relacionadas con el comercio de bienes derivados de las especies de fauna silvestre en Colombia, abordando el tema desde el desarrollo que ha tenido su actividad productiva, el aprovechamiento extractivo, así como la dinámica de su comercio legal e ilegal en el país y el desarrollo y promoción de alternativas productivas sustentadas en su aprovechamiento. Se analizó la información secundaria de entidades como el Ministerio de Ambiente, Vivienda y Desarrollo Territorial, las Corporaciones Autónomas Regionales y Autoridades Ambientales Urbanas, el Instituto Colombiano de Desarrollo Rural-INCODER, las Autoridades Policiales, los Institutos de Investigación, el Departamento Administrativo Nacional de Estadística, la Dirección de Impuestos y Aduanas Nacionales-DIAN, el Ministerio de Comercio, Industria y Turismo, y PROEXPORT. entre otras. En Colombia, el comercio de especies de fauna silvestre está centrado principalmente en la extracción de ejemplares de forma ilegal, lo cual ha generado desequilibrios en las poblaciones naturales y ha repercutido en el deterioro de la dinámica de los ecosistemas. El comercio legal de fauna silvestre se basa en la producción de unas pocas especies entre las que se destacan la babilla (Caiman crocodilus, el chigüiro (Hydrochaeris hydrochaeris, cerca de 200 especies de peces ornamentales y en menor medida el lobo pollero (Tupinambis nigropunctatus, la iguana (Iguana iguana, la boa (Boa constrictor, escarabajos (Dynastes hercules y mariposas. En el país no se tiene información exacta sobre el número de incautaciones realizadas en los operativos de control al tráfico ilegal de fauna, y no existe un conocimiento de la dinámica de este comercio ilegal.This work offers a current view on the activities related to the trade of derived from the wildlife species in Colombia, approaching the topic from the development that has had its productive activity

  6. Generation and evaluation of an indicator of the health system's performance in maternal and reproductive health in Colombia: An ecological study.

    Science.gov (United States)

    Pinzón-Flórez, Carlos Eduardo; Fernandez-Niño, Julian Alfredo; Cardenas-Cardenas, Luz Mery; Díaz-Quijano, Diana Marcela; Ruiz-Rodriguez, Myriam; Reveiz, Ludovic; Arredondo-López, Armando

    2017-01-01

    To generate and evaluate an indicator of the health system's performance in the area of maternal and reproductive health in Colombia. An indicator was constructed based on variables related to the coverage and utilization of healthcare services for pregnant and reproductive-age women. A factor analysis was performed using a polychoric correlation matrix and the states were classified according to the indicator's score. A path analysis was used to evaluate the relationship between the indicator and social determinants, with the maternal mortality ratio as the response variable. The factor analysis indicates that only one principal factor exists, namely "coverage and utilization of maternal healthcare services" (eigenvalue 4.35). The indicator performed best in the states of Atlantic, Bogota, Boyaca, Cundinamarca, Huila, Risaralda and Santander (Q4). The poorest performance (Q1) occurred in Caqueta, Choco, La Guajira, Vichada, Guainia, Amazonas and Vaupes. The indicator's behavior was found to have an association with the unsatisfied basic needs index and women's education (β = -0.021; 95%CI -0031 to -0.01 and β 0.554; 95%CI 0.39 to 0.72, respectively). According to the path analysis, an inverse relationship exists between the proposed indicator and the behavior of the maternal mortality ratio (β = -49.34; 95%CI -77.7 to -20.9); performance was a mediating variable. The performance of the health system with respect to its management of access and coverage for maternal and reproductive health appears to function as a mediating variable between social determinants and maternal mortality in Colombia.

  7. Generation and evaluation of an indicator of the health system's performance in maternal and reproductive health in Colombia: An ecological study.

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Pinzón-Flórez

    Full Text Available To generate and evaluate an indicator of the health system's performance in the area of maternal and reproductive health in Colombia.An indicator was constructed based on variables related to the coverage and utilization of healthcare services for pregnant and reproductive-age women. A factor analysis was performed using a polychoric correlation matrix and the states were classified according to the indicator's score. A path analysis was used to evaluate the relationship between the indicator and social determinants, with the maternal mortality ratio as the response variable.The factor analysis indicates that only one principal factor exists, namely "coverage and utilization of maternal healthcare services" (eigenvalue 4.35. The indicator performed best in the states of Atlantic, Bogota, Boyaca, Cundinamarca, Huila, Risaralda and Santander (Q4. The poorest performance (Q1 occurred in Caqueta, Choco, La Guajira, Vichada, Guainia, Amazonas and Vaupes. The indicator's behavior was found to have an association with the unsatisfied basic needs index and women's education (β = -0.021; 95%CI -0031 to -0.01 and β 0.554; 95%CI 0.39 to 0.72, respectively. According to the path analysis, an inverse relationship exists between the proposed indicator and the behavior of the maternal mortality ratio (β = -49.34; 95%CI -77.7 to -20.9; performance was a mediating variable.The performance of the health system with respect to its management of access and coverage for maternal and reproductive health appears to function as a mediating variable between social determinants and maternal mortality in Colombia.

  8. Simultaneous distribution of AC and DC power

    Science.gov (United States)

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  9. Drilling history core hole DC-8

    International Nuclear Information System (INIS)

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored

  10. Drilling history core hole DC-8

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored.

  11. Médicos, prostitución y enfermedades venéreas en Colombia (1886-1951 Physicians, prostitution, and venereal disease in Colombia (1886-1951

    Directory of Open Access Journals (Sweden)

    Diana Obregón

    2002-01-01

    Full Text Available Este trabajo examina la lucha del cuerpo médico colombiano contra las enfermedades 'venéreas' entre 1886 y 1951. En este período, Colombia sufrió procesos de urbanización, crecimiento de población, nacimiento de la industria y aparición de una clase media y de un proletariado urbano. Los médicos encontraron una conexión estrecha entre la difusión del contagio de la sífilis y la gonorrea, y el aumento del ejercicio de la prostitución en las ciudades. A finales del siglo XIX, los médicos y los organismos de higiene asumieron la prostitución como inevitable; en 1907 consiguieron reglamentarla y fundaron dispensarios para aplicar los tratamientos de mercurio y compuestos arsenicales. Hacia los años 1930 y 1940, la curación de las enfermedades venéreas se asumió como un deber estatal de defensa de la raza y a favor de la civilización y del progreso. Hacia 1950, el uso eficaz de la penicilina hizo que la cuestión de la prostitución se volviera a plantear en términos más morales y estéticos, y se impuso la abolición de las normas que regulaban su ejercicio, por lo menos en Bogotá.The article examines the Colombian medical field's fight against so-called venereal diseases between 1886 and 1951, a period when the country was undergoing processes of urbanization, population growth, and the emergence both of industry as well as of a middle class and an urban proletariat. Physicians found a close connection between the spread of syphilis and gonorrhea and the rise of prostitution in cities. At the close of the 19th century, doctors and public health bodies assumed prostitution was inevitable. In 1907 they managed to have it legalized and they opened clinics to dispense mercury therapy and treatment with arsenic compounds. Starting in the 1930s and 1940s, treatment of venereal diseases was viewed as the State's duty, necessary to protect "la raza" and safeguard progress and civilization. As of 1950, the efficient use of penicillin

  12. Plan Colombia, Consequences for Venezuelan Natonal Security

    National Research Council Canada - National Science Library

    Arroyo, Alfredo

    2002-01-01

    ...% reduction in cocaine production), and narcotics trafficking groups move into Venezuela, the government will have to commit its Armed Forces but, under unequal military and technological conditions when compared to Colombia...

  13. Bartoneliasis: fiebre verrucosa del guaitara en colombia

    OpenAIRE

    Patiño Camargo, Luis

    2011-01-01

    En Colombia, al descubrirla, diósele (1) a esta dolencia los siguientes nombres: Bartonellosis, Fiebre verrucosa del Guaitara y Verruga, análoga a la enfermedad de Carrión, Fiebre de Oroya y Verruga Peruana.

  14. Colombia: More Than Just a Drug Problem

    National Research Council Canada - National Science Library

    Wynne, Charles E

    2003-01-01

    ... of $45 billion in the year 2000. While estimates vary, most experts agree between 80-90 percent of the cocaine and more than 50 percent of the heroin used in the United States comes from Colombia...

  15. Wide Temperature Range DC-DC Boost Converters for Command/Control/Drive Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We shall develop wide temperature range DC-DC boost converters that can be fabricated using commercial CMOS foundries. The boost converters will increase the low...

  16. Modular Power System Configured with Standard Product Hybrid DC-DC Converters, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — VPT proposes an innovative concept whereby complex NASA space power electronic systems can be configured using a small number of qualified hybrid DC-DC converter and...

  17. Development of a DC-DC conversion powering scheme for the CMS Phase-1 pixel upgrade

    CERN Document Server

    Feld, Lutz Werner; Karpinski, Waclaw; Klein, Katja; Lipinski, Martin; Preuten, Marius; Max Rauch; Rittich, David Michael; Sammet, Jan Domenik; Wlochal, Michael

    2014-01-01

    A novel powering scheme based on the DC-DC conversion technique will be exploited to power the CMS Phase-1 pixel detector. DC-DC buck converters for the CMS pixel project have been developed, based on the AMIS5 ASIC designed by CERN. The powering system of the Phase-1 pixel detector is described and the performance of the converter prototypes is detailed, including power efficiency, stability of the output voltage, shielding, and thermal management. Results from a test of the magnetic field tolerance of the DC-DC converters are reported. System tests with pixel modules using many components of the future pixel barrel system are summarized. Finally first impressions from a pre-series of 200 DC-DC converters are presented.

  18. DIAGNOSTIC/PROGNOSTIC EXPERIMENTS FOR CAPACITOR DEGRADATION AND HEALTH MONITORING IN DC-DC CONVERTERS

    Data.gov (United States)

    National Aeronautics and Space Administration — Studying and analyzing the ageing mechanisms of electronic components avionics in systems such as the GPS and INAV are of critical importance. In DC-DC power...

  19. Digitally intensive DC-DC converter for extreme space environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro –Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  20. Digitally intensive DC-DC converter for extreme space environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Micro-Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

  1. 75 FR 61352 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-30, DC-10-30F, DC-10-30F (KC...

    Science.gov (United States)

    2010-10-05

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A and KDC-10...-13 McDonnell Douglas Corporation: Amendment 39-16448; Docket No. FAA-2010-0553; Directorate.... Applicability (c) This AD applies to McDonnell Douglas Corporation Model DC- 10-30, DC-10-30F, DC-10-30F (KC-10A...

  2. 75 FR 27401 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

    Science.gov (United States)

    2010-05-17

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes... airworthiness directive (AD) for certain Model DC-9-30, DC-9-40, and DC-9-50 series airplanes. This AD requires... this AD to detect and correct the potential for an arc/spark condition to occur within the fuel boost...

  3. Barriers to combating human trafficking in Colombia

    OpenAIRE

    Wilcox, Daniel Joseph

    2015-01-01

    Approved for public release; distribution is unlimited Despite international and domestic policies and programs intended to combat human trafficking, Colombia remains one of the countries with the highest instances of human trafficking in the Western Hemisphere. Factors contributing to human trafficking in Colombia, such as internal violence and displacement, drug trafficking, a weak central government, and widespread corruption, have overpowered what energies the government marshaled agai...

  4. EVALUACIÓN DEL IMPACTO PRESUPUESTAL DE UNA NUEVA TÉCNICA DIAGNÓSTICA PARA LA VIGILANCIA EPIDEMIOLÓGICA DE LA ENFERMEDAD RESPIRATORIA AGUDA EN UN LABORATORIO DE REFERENCIA EN BOGOTÁ, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Liliana Patricia Díaz Cuevas

    2016-04-01

    Full Text Available

    Objetivo: Evaluar el impacto presupuestal de introducir una nueva técnica diagnóstica para la vigilancia epidemiológica en la enfermedad respiratoria aguda en un laboratorio de referencia en Bogotá, Colombia.

    Materiales y métodos: Estudio de impacto presupuestario desde la perspectiva del tercero pagador, para la patología de ERA con criterios de Infección respiratoria aguda grave (IRAG, con un horizonte temporal de cinco años (2013-2017, determinando los costos directos de las pruebas y su impacto en la población.

    Resultados: Al introducir la nueva técnica en forma progresiva hasta llegar al 75%, a los cinco años, el impacto fue un incremento del presupuesto en un 27% ($203.463.717 más que con el costo de las pruebas actuales. El análisis de sensibilidad univariado, modificando la variable porcentaje de introducción de la nueva prueba, permitió establecer que a un menor porcentaje de inversión de las pruebas actuales y un porcentaje mayor de introducción de la nueva prueba, el impacto en el costo del presupuesto al término de los cinco años será mayor.

    Conclusiones: La introducción de la nueva técnica diagnóstica hasta el 75% en el horizonte temporal de cinco años, tendrá un impacto del 27% en el presupuesto, comparado con la utilización de las pruebas actuales. La ampliación del perfil viral y el acercamiento a la realidad, permitirá formular nuevas políticas públicas en el tratamiento y pronóstico de la ERA en la población de Bogotá.

    BUDGET IMPACT ASSESSMENT OF A NEW DIAGNOSTIC TECHNIQUE FOR SURVEILLANCE OF ACUTE RESPIRATORY DESEASE IN A LABORATORY REFERENCE IN BOGOTA-COLOMBIA

    ABSTRACT

    Objective: To evaluate the budget impact of the introduction of a new diagnostic test for epidemiological surveillance for acute respiratory illness in a reference

  5. Novel composite resonance DC-DC converter with voltage doubler rectifier

    OpenAIRE

    Kato, Hisatsugu; Matsuo, Hirohumi; Eguchi, Masaki; Sakamoto, Yukitaka; Nakaishi, Masaki

    2009-01-01

    This paper deals with a novel composite resonance DC-DC converter with the voltage doubler rectifier, which is developed to be applied to the power conditioner of the photovoltaic generation system. The proposed DC-DC converter has the current and voltage resonance functions. Therefore, the output voltage regulation can be achieved for the large variations of the input voltage and load. Also, this converter has the high power efficiency. The maximum power efficiency 96.1% can be realized.

  6. Regulation of DC development and DC-mediated T-cell immunity via CISH

    OpenAIRE

    Miah, Mohammad Alam; Bae, Yong-Soo

    2013-01-01

    Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

  7. Regulation of DC development and DC-mediated T-cell immunity via CISH.

    Science.gov (United States)

    Miah, Mohammad Alam; Bae, Yong-Soo

    2013-03-01

    Cytokine inducible SH2-containing protein (CISH) plays a crucial role in type 1 dendritic cell (DC) development as well as in the DC-mediated activation of cytotoxic T lymphocytes (CTLs). CISH expression at late DC developmental stages shuts down the proliferation of DC progenitors by negatively regulating signal transducer and activator of transcription 5 (STAT5) and facilitates the differentiation of DCs into potent stimulators of CTLs.

  8. Design and Analysis of Two-Phase Boost DC-DC Converter

    OpenAIRE

    Taufik Taufik; Tadeus Gunawan; Dale Dolan; Makbul Anwari

    2010-01-01

    Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results fr...

  9. A Fixed-Frequency Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Blaabjerg, Frede

    2017-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant DC-DC converters, and meanwhile achieves high efficiency...... and characteristics of the proposed converter are analyzed. Finally, a 1-kW converter prototype is built and the experimental results verify the theoretical analyses....

  10. Development of a green mode DC/DC converter available to portable nuclear instrument

    International Nuclear Information System (INIS)

    Gao Feiyan; Wu Longxiong; Tan Wei; Tang Yaogeng

    2010-01-01

    A green mode DC/DC converter was developed which suitable to the portable nuclear instrument which is powered by battery and is sometime at stand-by mode. Some updated control approaches such as pseudo-resonant type power supply control and synchronous rectification were adopted to makethe DC/DC converter operate with low power consumption and high efficiency. The test results the battery can be prolonged with this converter. (authors)

  11. Superconducting dc fault current limiter

    International Nuclear Information System (INIS)

    Cointe, Y.

    2007-12-01

    Within the framework of the electric power market liberalization, DC networks have many interests compared to alternative ones, but their protections need to use new systems. Superconducting fault current limiters enable by an overstepping of the critical current to limit the fault current to a preset value, lower than the theoretical short-circuit current. For these applications, coated conductors offer excellent opportunities. We worked on the implementation of these materials and built a test bench. We carried out limiting experiments to estimate the quench homogeneity at various short-circuit parameters. An important point is the temperature measurement by deposited sensors on the ribbon, results are in good correlation with the theoretical models. Improved quench behaviours for temperatures close to the critical temperature have been confirmed. Our results enable to better understand the limitation mechanisms of coated conductors. (author)

  12. The possibility of detecting DC

    International Nuclear Information System (INIS)

    Witte, N.S.; Brown, R.D.

    1977-01-01

    IRC + 10216, a bright infrared late type carbon star, is observed to have millimetre range line emission of the species 12 CO, 13 CO, CS, C 2 H, HC 3 N, CN, HCN, SiS and SiO in an extended envelope around the central infrared sources. A model explaining the line emission in terms of infrared pumping between the two lowest vibrational levels, first proposed for IRC + 10216, was used to calculate antenna temperatures for various rotational transitions of HC 3 N; since there is a prima facie agreement between the calculated and observed values for HC 3 N we have attempted the same calculation for DC 3 N. (J.R.)

  13. The dual burden of malnutrition in Colombia.

    Science.gov (United States)

    Sarmiento, Olga L; Parra, Diana C; González, Silvia A; González-Casanova, Inés; Forero, Ana Y; Garcia, Johnattan

    2014-12-01

    Almost all nutrition policies in Colombia currently focus on either undernutrition or obesity, with the predominant emphasis on undernutrition. It is crucial to assess the prevalence of the dual burden of malnutrition in Colombia to better target programs and policies. The aim was to estimate the national prevalence of the dual burden of malnutrition in Colombia at the individual and household levels in children aged malnutrition was defined as the coexistence of overweight and stunting or anemia in the same person or household. In Colombia, low to high prevalences of overweight and obesity (3.4-51.2%) coexist with moderate to high prevalences of anemia (8.1-27.5%) and stunting (13.2%). The observed prevalence of the dual burden was lower than expected. Approximately 5% of households had at least one stunted child aged malnutrition in Colombia are lower than expected. Despite the independence of the occurrence of these conditions, the fact that the dual burden coexists at the national, household, and intraindividual levels suggests that public policies should address both conditions through multiple strategies. It is imperative to evaluate the current nutrition policies to inform malnutrition prevention efforts in Colombia and to share lessons with other countries at a similar stage of nutritional transition. © 2014 American Society for Nutrition.

  14. Helmintiasis y protozoasis en Colombia

    Directory of Open Access Journals (Sweden)

    Luis Patiño Camargo

    1940-02-01

    Full Text Available Sabre un territorio de más de un millón de kilómetres cuadrados caracrerizado por la multiplicidad de climas y la variedad topográfica de su relieve, habita el pueblo de Colombia de cerca de nueve millones de personas de un tipo humano con caracteres propios en via de eetabilización. El parasitismo intestinal por helmintos y protozoarios es una pandemia de todos los climas colombianos, pera alcanza su intensidad maxima en las zonas extendidas del nivel del mar a 2.000 metros de elevación con temperaturas medias de 32° a 16° grados oentígrados.

  15. Known uraniferous occurrences in Colombia

    International Nuclear Information System (INIS)

    Rodriguez, H.; Aluja, J.A.; Pfeiffer, J.; Cortes, L.A.

    1981-01-01

    On the basis of an internal report entitled 'Possibilities of Uranium in Colombia' compiled by the author in 1973, and as a result of work done by the foreign companies TOTAL-MINATOME (France) and ENUSA (Spain) using carborne radiometric techniques, ground surveys (plus occasional aerial prospecting) and geochemical methods (sediments and waters), approximately 260 uranium anomalies (in 1973 the figure was 106) have been discovered after covering 30% of the areas considered under priorities I, II and III (321,000 km 2 ), together with 16,000 km of the national road network (+-44,000 km). In addition to supporting the original selection, these results indicate considerable variation in the geological conditions and metallogenic associations, which IAN, MINATOME and ENUSA have now begun to evaluate in the hope of obtaining specific data by the end of 1980. (author)

  16. Las marcas propias en Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Felipe Payán Rodríguez

    2013-11-01

    Full Text Available El artículo analiza la situación actual de las marcas propias en Colombia, teniendo en cuenta su creciente auge al interior de las grandes superficies. Mediante este tipo de marcas el mismo distribuidor vende productos y servicios con su nombre o recurriendo a una marca de su propiedad, compitiendo con las marcas ya posicionadas en el mercado de los fabricantes. El texto se articula, primero, en una contextualización con base en doctrina comparada respecto de las marcas propias. Luego, se aplican las reglas de dichos conceptos doctrinales a la situación actual colombiana. Por último, se plantean dos problemas jurídicos respecto de las marcas propias, uno, analizado desde la propiedad industrial, y el otro, desde las reglas del Estatuto del Consumidor.

  17. Superconducting energy stabilizer with charging and discharging DC-DC converters

    International Nuclear Information System (INIS)

    Kim, S.H.; Kostecki, E.L.; DeWinkel, C.C.

    1992-01-01

    This patent describes a superconducting energy stabilizer having multiple load connections and employing DC-DC conversion for storing energy in a superconducting inductive energy storage device having a first end and a second end, and for releasing the stored energy from the superconducting inductive energy storage device to a load or loads or to a utility or an industrial electrical distribution system, the superconducting energy stabilizer having multiple load connections and employing DC-DC conversion. It comprises: energy storage cell means for supplying energy to the load, discharging DC-DC converter means for releasing energy from the superconducting inductive energy storage device to the energy storage cell means, the discharging DC-DC converter means having input terminals, output terminals, and a discharging control line means for carrying signals controlling the operation of the discharging DC-DC converter means, one of the input terminals of the discharging DC-DC converter means coupled to the first end of the superconducting energy storage device

  18. Colombia - The Quality of Education in Colombia : An Analysis and Options for a Policy Agenda

    OpenAIRE

    World Bank

    2008-01-01

    The main objective of this report is to analyze student learning in Colombia in order to foster policies to improve education quality that are grounded in research and the Colombian context. In 2006, Colombia participated for the first time in the Programme for International Student Assessment (PISA) of the Organization for Economic Cooperation and Development (OECD), which provides an imp...

  19. Dual wound dc brush motor gearhead

    Science.gov (United States)

    Henson, Barrie W.

    1986-01-01

    The design requirements, the design, development tests and problems, the qualification and life test and the findings of the strip examination of a dual wound DC brushed motor gearhead are described. It is the only space qualified dual wound dc brushed motor gearhead in Europe.

  20. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  1. DC/DC converters for integration of double-layer condensers in onboard power supply; DC/DC-Wandler zur Einbindung von Doppelschichtkondensatoren in das Fahrzeugenergiebordnetz

    Energy Technology Data Exchange (ETDEWEB)

    Polenov, Dieter

    2010-01-15

    The paper discusses DC/DC converters for integration of double layer condensers into the onboard power system. First, requirements on DC/DC converters are listed and compared on the basis of three exemplary applications. A DC/DC converter concept is developed for decoupling transient high-power loads like electric steering systems. Three different topologies are compared using a specially developed method in order to find the best solution for the given application. In order to establish adequate criteria for selecting the switching frequency and inductivities of storage throttles, the influence of the trottle power change on the switching characteristics of the MOSFETs and on certain ranges of EMP interference emissions is investigated. As methods of optimising the operation of the synchronous rectifiers, parallel connection of Schottky diodes and synchronous rectifiers as well as the variation of the shut-off dead times of synchronous rectifiers were investigated. Further, a concept for converter control was developed in consideration of the intended application and topology. Finally, selected aspects for implementation of the DC/DC converter concept are presented as well as the results of experimental investigations.

  2. Modelling of flow phenomena during DC casting

    NARCIS (Netherlands)

    Zuidema, J.

    2005-01-01

    Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an

  3. DC KIDS COUNT e-Databook Indicators

    Science.gov (United States)

    DC Action for Children, 2012

    2012-01-01

    This report presents indicators that are included in DC Action for Children's 2012 KIDS COUNT e-databook, their definitions and sources and the rationale for their selection. The indicators for DC KIDS COUNT represent a mix of traditional KIDS COUNT indicators of child well-being, such as the number of children living in poverty, and indicators of…

  4. Role of sleep duration and sleep-related problems in the metabolic syndrome among children and adolescents

    OpenAIRE

    Pulido-Arjona, Leonardo; Correa-Bautista, Jorge Enrique; Agostinis-Sobrinho, Cesar; Mota, Jorge; Santos, Rute; Correa-Rodríguez, María; Garcia-Hermoso, Antonio; Ramírez-Vélez, Robinson

    2018-01-01

    Background There is increasing recognition that sleep is a risk factor for metabolic syndrome (MetS). The aim of the present study was to analyze the relationship between self-reported sleep duration, sleep-related problems and the presence of MetS in children and adolescents from Bogotá, D.C., Colombia. Methods This is a cross-sectional analysis from the FUPRECOL study (2014–15). Participants included 2779 (54.2% girls) youth from Bogota (Colombia). MetS was defined as the presence of ≥3 of ...

  5. A Component-Reduced Zero-Voltage Switching Three-Level DC-DC Converter

    DEFF Research Database (Denmark)

    Qin, Zian; Pang, Ying; Wang, Huai

    2016-01-01

    The basic Zero-Voltage Switching (ZVS) three-level DC-DC converter has one clamping capacitor to realize the ZVS of the switches, and two clamping diodes to clamp the voltage of the clamping capacitor. In order to reduce the reverse recovery loss of the diode as well as its cost, this paper...... proposes to remove one of the clamping diodes in basic ZVS three-level DC-DC converter. With less components, the proposed converter can still have a stable clamping capacitor voltage, which is clamped at half of the dc link voltage. Moreover, the ZVS performance will be influenced by removing the clamping...

  6. Improved Control Strategy for T-type Isolated DC/DC Converters

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Wang, Yanbo

    2017-01-01

    T-type isolated DC/DC converters have recently attracted attention due to their numerous advantages, including few components, low cost, and symmetrical operation of transformers. This study proposes an improved control strategy for increasing the efficiency of T-type isolated DC/DC converters....... Under the proposed strategy, the primary circulating current flows through the auxiliary switches (metal–oxide–semiconductor field-effect transistors) instead of their body diodes in free-wheeling periods. Such feature can reduce conduction losses, thereby improving the efficiency of T-type isolated DC...

  7. DC Voltage Droop Control Implementation in the AC/DC Power Flow Algorithm: Combinational Approach

    DEFF Research Database (Denmark)

    Akhter, F.; Macpherson, D.E.; Harrison, G.P.

    2015-01-01

    of operational flexibility, as more than one VSC station controls the DC link voltage of the MTDC system. This model enables the study of the effects of DC droop control on the power flows of the combined AC/DC system for steady state studies after VSC station outages or transient conditions without needing...... to use its complete dynamic model. Further, the proposed approach can be extended to include multiple AC and DC grids for combined AC/DC power flow analysis. The algorithm is implemented by modifying the MATPOWER based MATACDC program and the results shows that the algorithm works efficiently....

  8. Design of PI Controlled Non Isolated Bidirectional DC to DC Converter for Electric Vehicle Application

    Science.gov (United States)

    Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.

    2018-04-01

    Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.

  9. Evaluation of the contamination for Hg and Pb in horticultural soils of the Bogota Savanna and of the effect of the Hg and Pb of the watering water and of the soils in several vegetables

    International Nuclear Information System (INIS)

    Vargas Zarate, Orlando; Mejia C, Leonidas

    1998-01-01

    Soils of six different horticultural zones of the Sabanna of Bogota were studied to quantify Hg and Pb accumulation in soils and crops caused by traditional and continuous irrigation with the highly polluted waters of Bogota River and its effluents. Soils of site No.6 representative of Rio Bogota is series (a fine clayed, mixed, isothermic family of aeric fluventic tropaquepts) was selected for greenhouse experiments conducted to show: a) The amounts of Hg and Pb absorbed by 3 different vegetables (lettuce, cucumber and carrots) grown under greenhouse conditions, irrigated with waters with variable Hg and Pb concentrations; b) the effects of increased levels of Hg and Pb in irrigation water on the accumulation level of both metals in soils at the harvest; and c) the individual effect and interactions of Hg and Pb on yields of each one vegetable. Results afforded this conclusions: 1) soils of all six sites have average Hg and Pb concentrations (0.5 and 110 ppm respectively) which exceed normal levels for soils (who, 1976); site 6 has the highest level of Hg and Pb accumulation (1.6 and 3.36 ppm); 2) for all three vegetables Hg and Pb accumulation level was almost proportional to Hg and Pb concentration in irrigation water; 3) Hg and Pb concentration in edible parts was different for each vegetable. Average contents of Hg and Pb were respectively 33 ppb and 172 ppm in lettuce; 24 ppb and 10 ppm in cucumber and 36 ppb and 48 ppm in carrots. Average absorption of Pb in lettuce was 17 times higher than in cucumber and 3.5 times higher than in carrots; Pb absorption levels widely surpass those recommended as permissible by WHO (1976) 4) high correlation coefficients were found between Hg and Pb absorption by lettuce (R=0.94 and 0.97 respectively), cucumber (R=0.89 and R=0.80 respectively) and carrots (R=0.99 y R=0.85 respectively) and the corresponding Hg and Pb accumulation levels in soils at harvest; 5) Effects of Hg and Pb levels in irrigation water on yields was

  10. Estudio piloto de detecci?n de par?sitos en frutas y hortalizas expendidas en los mercados p?blicos y privados de la ciudad de Bogota D.C.

    OpenAIRE

    Camargo Castillo, Nelsi Andrea; Campuzano, Silvia

    2006-01-01

    Las enfermedades transmitidas por los alimentos contaminados, representan un grave problema de salud p?blica, muchos microorganismos son capaces de sobrevivir a condiciones adversas para su desarrollo, por esta raz?n pueden encontrarse en las frutas y vegetales crudos. Se pretende con este trabajo, exaltar la importancia de validar e implementar los m?todos para detectar par?sitos en frutas y hortalizas durante el proceso de las buenas pr?cticas agr?colas, ya que algunos de estos pr...

  11. U.S. Support to Plan Colombia: A Heading Check

    National Research Council Canada - National Science Library

    Buckley, Kevin

    2004-01-01

    .... For some Latin American countries like Colombia these ideals fall quite short of reality. Colombia is plagued by internal problems which restrict its ability to adequately govern its population and territory...

  12. Urban Violence Reduction and Citizen Security in Brazil, Colombia ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Urban Violence Reduction and Citizen Security in Brazil, Colombia, Mexico, and ... The work will be conducted in Brazil, Colombia, Mexico, and South Africa, which are ... Minister Bibeau announces appointments of IDRC's President and new ...

  13. Drilling history core hole DC-4

    International Nuclear Information System (INIS)

    1978-12-01

    Core hole DC-4 was completed at a depth of 3998 feet in December, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Sicsson, Inc. furnished the engineering, daily supervision of the cable tool and core drilling activities, and geological core logging for DC-4. Core hole DC-4 is located on the Hanford Site about 3 miles east of the Yakima Barricade and approximately 103 feet southwest of rotary hole DC-5, which was completed to 3990 feet in February, 1978. Hanford Site coordinates reported for hole DC-4 are north 49,385.62 feet and west 85,207.63 feet, and Washington State coordinates are north 454,468.73 feet and east 2,209,990.87 feet. No elevation survey is available for hole DC-4, but it is approximately 745 feet above mean sea level based upon the survey of hole DC-5, which has a reported elevation of 745.16 feet on the top of the 3-inch flange. The purpose of core hole DC-4 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing, cross-hole seismic shear, and pressure wave velocity studies with rotary hole DC-5. Hole DC-4 was drilled through the overburden into basalt bedrock by cable tool methods (0-623 feet) and continuously cored through the final interval (623 to 3998 feet).Core recovery was 95.8 percent of the total footage cored

  14. Controlling DC-DC converters by chaos-based pulse width modulation to reduce EMI

    International Nuclear Information System (INIS)

    Li Hong; Zhang Bo; Li Zhong; Halang, Wolfgang A.; Chen Guanrong

    2009-01-01

    In this paper, periodic and chaotic behaviors of DC-DC converters under certain parametric conditions are simulated, experimentally verified, and analyzed. Motivated by the work of J.H.B. Deane and D.C. Hamill in 1996, where chaotic phenomena are useful in suppressing electromagnetic interference (EMI) by adjusting the parameters of the DC-DC converter and making it operate in chaos, a chaos-based pulse width modulation (CPWM) is proposed to distribute the harmonics of the DC-DC converters continuously and evenly over a wide frequency range, thereby reducing the EMI. The output waves and spectral properties of the EMI are simulated and analyzed as the carrier frequency or amplitude changes with regard to different chaotic maps. Simulation and experimental results are given to illustrate the effectiveness of the proposed CPWM, which provides a good example of applying chaos theory in engineering practice.

  15. A Dual-Buck–Boost AC/DC Converter for DC Nanogrid With Three Terminal Outputs

    DEFF Research Database (Denmark)

    Wu, Weimin; Wang, Houqing; Liu, Yuan

    2017-01-01

    Due to the widely used dc characterized loads and more distributed power generation sources, the dc nanogrid becomes more and more popular, and it is seen as an alternative to the ac grid. For safety considerations, the dc nanogrid should provide reliable grounding for the residential loads...... such as the low-voltage ac power system. There are three typical grounding configurations for a dc nanogrid: the united grounding, the unidirectional grounding, and the virtual isolated grounding. Each grounding configuration has its own specifications to ac/dc converters. In this paper, a dual-buck-boost ac/dc...... converter for use in the united-grounding-configuration-based dc nanogrid with three terminal outputs is proposed. The working principle of this converter is presented in detail through analyzing the equivalent circuits. Experiments are carried out to verify the theoretical analysis....

  16. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    Science.gov (United States)

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  17. A comparative analysis of costs of single and dual rapid HIV and syphilis diagnostics: results from a randomised controlled trial in Colombia.

    Science.gov (United States)

    Obure, Carol Dayo; Gaitan-Duarte, Hernando; Losada Saenz, Ricardo; Gonzalez, Lina; Angel-Muller, Edith; Laverty, Maura; Perez, Freddy

    2017-11-01

    HIV and congenital syphilis are major public health burdens contributing to substantial perinatal morbidity and mortality globally. Although studies have reported on the costs and cost-effectiveness of rapid diagnostic tests (RDTs) for syphilis screening within antenatal care in a number of resource-constrained settings, empirical evidence on country-specific cost and estimates of single RDTs compared with dual RDTs for HIV and syphilis are limited. A cluster randomised controlled study design was used to compare the incremental costs of two testing algorithms: (1) single RDTs for HIV and syphilis and (2) dual RDTs for HIV and syphilis, in 12 health facilities in Bogota and Cali, Colombia. The costs of single HIV and syphilis RDTs and dual HIV and syphilis RDTs were collected from each of the health facilities. The economic costs per woman tested for HIV and syphilis and costs per woman treated for syphilis defined as the total costs required to test and treat one woman for syphilis were estimated. A total of 2214 women were tested in the study facilities. Cost per pregnant woman tested and cost per woman treated for syphilis were US$10.26 and US$607.99, respectively in the single RDT arm. For the dual RDTs, the cost per pregnant woman tested for HIV and syphilis and cost per woman treated for syphilis were US$15.89 and US$1859.26, respectively. Overall costs per woman tested for HIV and syphilis and cost per woman treated for syphilis were lower in Cali compared with Bogota across both intervention arms. Staff costs accounted for the largest proportion of costs while treatment costs comprised <1% of the preventive programme. Findings show lower average costs for single RDTs compared with dual RDTs with costs sensitive to personnel costs and the scale of output at the health facilities. NCT02454816; results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. Environmental information in Colombia; La informacion ambiental en Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Velez S, Andres

    2005-07-01

    This article is a chapter from the paper, Elements for the description of an environmental information system, which was written by the author as a requirement for the degree of specialist on environment and Geoinformatics at the school of engineering. Universidad de Antioquia. The original paper attempted a description of the context and development of a particular environmental information system, built at the eastern region of Antioquia by CORNARE (a regional autonomous corporation for the environment and the natural resources). This article refers to the Colombian institutional context for environmental information. With particular emphasis laid on the strategic character that must be conceded to the administration of information. Towards the construction of equitable and sustainable development models under autonomous orientation an efficient and transparent environmental administration as is needed by such models is only attainable through the design and application of environmental information systems committed to the pursuit of collective interests. Here a balance is sought between accomplishments and failures reached during the long standing discussion held in Colombia around the formulation of public policies that acknowledge and strengthen the role of information as a cornerstone of environmental administration, and a contribution towards the goal of human sustainable development.

  19. 77 FR 59064 - United States-Colombia Trade Promotion Agreement

    Science.gov (United States)

    2012-09-26

    ...-Colombia Trade Promotion Agreement AGENCY: U.S. Customs and Border Protection, Department of Homeland... Trade Promotion Agreement entered into by the United States and the Republic of Colombia. DATES: Interim...-Colombia Trade Promotion Agreement (``CTPA'' or ``Agreement''), and on June 28, 2007, the Parties signed a...

  20. 75 FR 22207 - Importation of Papayas From Colombia and Ecuador

    Science.gov (United States)

    2010-04-28

    .... APHIS-2008-0050] RIN 0579-AC95 Importation of Papayas From Colombia and Ecuador AGENCY: Animal and Plant... Colombia and Ecuador into the continental United States. The conditions for the importation of papayas from Colombia and Ecuador include requirements for field sanitation, hot water treatment, and fruit fly trapping...

  1. Improved DC Gun Insulator Assembly

    International Nuclear Information System (INIS)

    Neubauer, M.L.; Dudas, A.; Sah, R.; Poelker, M.; Surles-Law, K.E.L.

    2010-01-01

    Many user facilities such as synchrotron radiation light sources and free electron lasers require accelerating structures that support electric fields of 10-100 MV/m, especially at the start of the accelerator chain where ceramic insulators are used for very high gradient DC guns. These insulators are difficult to manufacture, require long commissioning times, and often exhibit poor reliability. Two technical approaches to solving this problem will be investigated. Firstly, inverted ceramics offer solutions for reduced gradients between the electrodes and ground. An inverted design will be presented for 350 kV, with maximum gradients in the range of 5-10 MV/m. Secondly, novel ceramic manufacturing processes will be studied, in order to protect triple junction locations from emission, by applying a coating with a bulk resistivity. The processes for creating this coating will be optimized to provide protection as well as be used to coat a ceramic with an appropriate gradient in bulk resistivity from the vacuum side to the air side of an HV standoff ceramic cylinder. Example insulator designs are being computer modelled, and insulator samples are being manufactured and tested

  2. Investigations of dc breakdown fields

    CERN Document Server

    Ramsvik, Trond; Reginelli, Alessandra; Taborelli, Mauro

    2006-01-01

    The need for high accelerating gradients for the future 30 GHz multi-TeV e+e- Compact Linear Collider (CLIC) at CERN has triggered a comprehensive study of DC breakdown fields of metals in UHV. The study shows that molybdenum (Mo), tungsten (W), titanium (Ti) and TiVAl reach high breakdown fields, and are thus good candidates for the iris material of CLIC structures. A significant decrease in the saturated breakdown field (Esat) is observed for molybdenum and tungsten when exposed to air. Specifically, at air pressures of 10-5 mbar, the decrease in Esat is found to be 50% and 30% for molybdenum and tungsten, respectively. In addition, a 30% decrease is found when molybdenum is conditioned with a CO pressure of ~1-10-5 mbar. Surface analysis measurements and breakdown conditioning in O2 ambience imply that the origin of the decrease in Esat is closely linked to oxide formation on the cathode surface. "Ex-situ" treatments by ion bombardment of molybdenum effectively reduce the oxide layers, and improve the brea...

  3. A THREE-PHASE BOOST DC-AC CONVERTER

    African Journals Online (AJOL)

    dc-ac converter (inverter) based on the dc-dc boost converters. ... Sliding mode controllers are designed to perform a robust control for the ... Computer simulations and spectral analysis demon- ... the conventional three-phase buck inverter,.

  4. 75 FR 75872 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-30, DC-9-40, and DC-9-50...

    Science.gov (United States)

    2010-12-07

    ... Airworthiness Directives; McDonnell Douglas Corporation Model DC- 9-30, DC-9-40, and DC-9-50 Series Airplanes...: We are adopting a new airworthiness directive (AD) for the McDonnell Douglas Corporation airplanes... to include an airworthiness directive (AD) that would apply to certain McDonnell Douglas Model DC-9...

  5. The Revolutionary Armed Forces of Colombia - People’s Army (FARC-EP): Marxist-Leninist Insurgency or Criminal Enterprise

    Science.gov (United States)

    2005-12-01

    Landazábal’s public defiance of civil authority, the general was relieved of his position and subsequently retired. 32 Socorro Ramírez, “El proceso de...Bogotá D.C., 2003), 273. 33 Socorro Ramírez, “El proceso de paz de Belisario Betancur”, in Tiempos de Paz: Acuerdos en Colombia, 1902-1994, eds...José Miguel Narvaéz Martínez, Deputy Director of the Departamento Administrativo de Seguridad (Colombian equivalent of U.S. FBI), interview by author

  6. 77 FR 63420 - Unblocking of Specially Designated Nationals and Blocked Persons Pursuant to Executive Order 12978

    Science.gov (United States)

    2012-10-16

    ...., Bogota, Colombia; c/o DROGAS LA REBAJA, Cali, Colombia; c/o VALORES MOBILIARIOS DE OCCIDENTE S.A., Bogota... VARIOS CALIMA S.A., Cali, Colombia; c/o CHAMARTIN S.A., Cali, Colombia; c/o SERVICIOS DE LA SABANA E.U... VALLE S.A., Cali, Colombia; c/o CONCRETOS CALI S.A., Cali, Colombia; c/o ADMINISTRACION INMOBILIARIA...

  7. Strategi Counterinsurgency Kolombia terhadap Farc (Fuerzas Armadas Revolucionarias De Colombia) 2010-2012

    OpenAIRE

    Olivia, Yessi; Miranda, Dea

    2014-01-01

    This paper is analysing about counterinsurgency Colombia to against paramilitary group in Colombia to help address the humanitarian crisis that occurred because of civil conflict in Colombia. Conflict in Colombia involving the Fuerzas Armadas Revolucionaries de Colombia (FARC) and the Government of Colombia is one example of a threat to human security in this case is a citizen of Colombia. Thousands of people confirmed dead, and hundreds more injured and displaced into the surrounding area. C...

  8. Pulsed-DC selfsputtering of copper

    International Nuclear Information System (INIS)

    Wiatrowski, A; Posadowski, W M; Radzimski, Z J

    2008-01-01

    At standard magnetron sputtering conditions (argon pressure ∼0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (∼550W/cm 2 ). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%

  9. Pulsed-DC selfsputtering of copper

    Science.gov (United States)

    Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

    2008-03-01

    At standard magnetron sputtering conditions (argon pressure ~0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (~550W/cm2). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%.

  10. Contribución al estudio de la biología y capacidad de control de Encarsia Formosa Gahan en la Sabana de Bogotá Biology ano control activity ,of Encarsia formosa Gahan in Bogota (Colombia

    Directory of Open Access Journals (Sweden)

    Español Jeannette Amparo

    1988-12-01

    Full Text Available Con la introducción de Encarsia formosa Ganan.(Hvrnenóptero-Aphelinidae, parásito espec ífico de la mosca blanca Trisleurodes vaporariorum (Westwood Ouaintance
    & Baker, se realizó un estudio de biología, comportamiento y adaptación del parásito en condiciones de laboratorio e invernadero a nivel de la Sabana de Bogotá, A partir de las primeras liberaciones de Encsrsie, se observó una buena capacidad de búsqueda, dispersión, adaptación y eficiencia
    de control sobre la mayoría de hospederos vegetales muestreados, En condiciones de la boratorio sobre plantas de tomate, se obtuvo una fecundidad promedia de 63 huevos/
    hembra/20 días, una longevidad promedia de 41,4 días, una relación de sexos de 361: 1 Hembras/macho, una duración del ciclo de vida de 22,1 días cuando parasitó ninfas en tercer instar y de 12,7 días cuando parasitó ninfas de mosca blanca en cuarto instar, En la evaluación del control ejercido sobre las ninfas de mosca blanca en plantas de tomate se determinó un mayor porcentaje de parasitismo en los folíolos medios y apicales y un mayor porcentaje de predación en los folíolos basales, En cuanto al control ejercido por Encarsia formosa sobre plantas de tomate y tabaco en laboratorio y tomate,  milflores y alstroemeria bajo condiciones de
    invernadero y sometidas a libre infestación de la plaga y el parásito se determinó un buen control expresado en un alto porcentaje de parasitismo superior al 70% y un bajo
    porcentaje de predación.
    Some preliminary studies on behavior and adaptation of the newly introduced Encarsia formosa Gahan as a parasite of the greenhouse whitefly Trisleurodes vaporariorum (Westwood under laboratory and greenhouse conditions were determined. Different plant hosts of T. vaporariorum were considered. Using tomato as a host for the greenhouse whitefly it was found that E. formosa showed and average
    fecundity of 63 eggs per female in 20 days, an adult longevity of 41,4 days, a sexual ratio of 361 females to 1 male and alife
    cycle of 22,1 days when paresitation occurred on the third instar of T. vaporariorum and 12,7 days when parasitation was on the fourth instar. Greater rate of parasitism was found on the middle and upper third of the tomato plant and a greater rate of predation was observed on the lower third of the tomato plant. E. formosa showed a parásitation rate higher than 70% on the total number of greenhouse whitefly nymhs when measured on tomato and tobbaco under
    laboratory conditions and on alstroemeria under greenhouse conditions.

  11. Current state of uranium exploration in central Colombia: Regional perspective and selected case studies

    International Nuclear Information System (INIS)

    Moreno, G.; Perez, A.

    2014-01-01

    The Colombian Geological Survey has been working in a regional exploration program focus on the ancients massifs of the Eastern Cordillera. The general geology distribution in these massifs (Santander and Quetame) includes a core of meta sedimentary to medium grade metamorphic rocks of pellitic origin presumed to be of Cambro – Ordovician age, intruded by Ordovician age plutons that grade from granodiorite to quartz diorite. This igneous – metamorphic core is unconformable overlain by a Devonian age sedimentary cover that includes conglomerates of continental origin, black mudstone of marine origin and red sandstones of deltaic environments with some calcareous intervals. In the Santander Massif a sequence of continental red beds of Jurasic age is present and in the Zapatoca (Santander) area contains uranium. In the Santander Massif, mineral exploration in an area on 1300 km"2 with 1235 sample locations, gives average uranium values of 5.44 ppm, an a maximum of 20 ppm, located in Ordovician plutonic rocks. In the Quetame Massif, mineral exploration in an area on 1000 km"2 with 1274 samples locations, gives average uranium values of 6.13 ppm, and a maximum of 2763 ppm, located in Devonian to Carboniferous sedimentary rocks. In the Paipa area, 140 kilometers from Bogota, the Colombian Geological Survey has undertaken exploratory drilling. As a result there is an anomalous area of 500 m"2 with values of 2000 ppm uranium and rare earth associations has been identified. The volcanic system has been studied by several authors and is important for its location and extention. In recent years, exploration by private companies was reactivated. In early 2000 several junior companies such as KPS/Energentia Resources Inc., Mega Uranium, U3O8 Corp, Energentia Resources Inc., Blue Sky Uranium Corp, Sprott Resource Corp. and UrAmericaLtd and began exploratory work in Colombia. The Berlin project, located in the central mountain range, is perhaps the most developed in the

  12. Superconducting DC homopolar motors for ship propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Heiberger, M.; Reed, M.R.; Creedon, W.P.; O' Hea, B.J. [General Atomic (United States)

    2000-07-01

    Superconducting DC homopolar motors have undergone recent advances in technology, warranting serious consideration of their use for ship propulsion. Homopolar motor propulsion is now practical because of two key technology developments: cryogen-free superconducting refrigeration and high performance motor fiber brushes. These compact motors are ideal for podded applications, where reduced drag and fuel consumption are predicted. In addition, the simple DC motor controller is more efficient and reliable compared with AC motor controllers. Military ships also benefit from increased stealth implicit in homopolar DC excitation, which also allows the option for direct hull or pod mounting. (authors)

  13. DC-Compensated Current Transformer †

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

  14. High power density dc/dc converter: Selection of converter topology

    Science.gov (United States)

    Divan, Deepakraj M.

    1990-01-01

    The work involved in the identification and selection of a suitable converter topology is described. Three new dc/dc converter topologies are proposed: Phase-Shifted Single Active Bridge DC/DC Converter; Single Phase Dual Active Bridges DC/DC Converter; and Three Phase Dual Active Bridges DC/DC Converter (Topology C). The salient features of these topologies are: (1) All are minimal in structure, i.e., each consists of an input and output bridge, input and output filter and a transformer, all components essential for a high power dc/dc conversion process; (2) All devices of both the bridges can operate under near zero-voltage conditions, making possible a reduction of device switching losses and hence, an increase in switching frequency; (3) All circuits operate at a constant frequency, thus simplifying the task of the magnetic and filter elements; (4) Since, the leakage inductance of the transformer is used as the main current transfer element, problems associated with the diode reverse recovery are eliminated. Also, this mode of operation allows easy paralleling of multiple modules for extending the power capacity of the system; (5) All circuits are least sensitive to parasitic impedances, infact the parasitics are efficently utilized; and (6) The soft switching transitions, result in low electromagnetic interference. A detailed analysis of each topology was carried out. Based on the analysis, the various device and component ratings for each topology operating at an optimum point, and under the given specifications, are tabulated and discussed.

  15. CISH is induced during DC development and regulates DC-mediated CTL activation.

    Science.gov (United States)

    Miah, Mohammad Alam; Yoon, Cheol-Hee; Kim, Joonoh; Jang, Jinah; Seong, Young-Rim; Bae, Yong-Soo

    2012-01-01

    The cytokine inducible SH2-domain protein (CISH) is a well-known STAT5 target gene, but its role in the immune system remains uncertain. In this study, we found that CISH is predominantly induced during dendritic cell (DC) development from mouse bone marrow (BM) cells and plays a crucial role in type 1 DC development and DC-mediated CTL activation. CISH knockdown reduced the expression of MHC class I, co-stimulatory molecules and pro-inflammatory cytokines in BMDCs. Meanwhile, the DC yield was markedly enhanced by CISH knockdown via cell-cycle activation and reduction of cell apoptosis. Down-regulation of cell proliferation at the later stage of DC development was found to be associated with CISH-mediated negative feedback regulation of STAT5 activation. In T-cell immunity, OT-1 T-cell proliferation was significantly reduced by CISH knockdown in DCs, whereas OT-2 T-cell proliferation was not affected by CISH knockdown. CTLs generated by DC vaccination were also markedly reduced by CISH knockdown, followed by significant impairment of DC-based tumor immunotherapy. Taken together, our data suggest that CISH expression at the later stage of DC development triggers the shutdown of DC progenitor cell proliferation and facilitates DC differentiation into a potent stimulator of CTLs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Changhao Piao

    2014-01-01

    Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.

  17. Studi Komparasi Fungsi Keanggotaan Fuzzy sebagai Kontroler Bidirectional DC-DC Converter pada Sistem Penyimpan Energi

    Directory of Open Access Journals (Sweden)

    Eka Prasetyono

    2015-09-01

    Full Text Available Bidirectional DC-DC converter is needed in the energy storage system. The converter topology used in this paper was a non-isolated bidirectional DC-DC buck-boost converter. This converter worked in two ways, which the charging mode stored energy into battery when load current was less than nominal main DC current (set point and discharging mode transferred energy from battery to the load when its current exceeded set point value. Both of these modes worked automatically according to the load current. The charging and discharging currents were controlled by fuzzy logic controller which was implemented on microcontroller ARM Cortex-M4F STM32F407VG. This paper compares two types of fuzzy membership function (triangular and sigmoid in controlling bidirectional DC-DC converter. The results showed that fuzzy logic controller with triangle membership function and sigmoid as control bidirectional DC-DC converter had no significant different response, both had an average error for charging and discharging process under 4% with ripple current on the main DC bus around 0.5%. The computing time of program for fuzzy logic controller with triangular membership functions had 19.01% faster than sigmoid, and fuzzy logic computation time on a microcontroller with hardware floating point was 60% faster than software floating point.

  18. los pobres de barranquilla (Colombia

    Directory of Open Access Journals (Sweden)

    José Luis Ramos R.

    2007-01-01

    Full Text Available En esta investigación se analizan las características socioeconómicas relevantes que tiene la población pobre del distrito de Barranquilla (Colombia, y se destacan en el análisis las aspiraciones y la percepción que estas personas tienen sobre las instituciones de carácter público que se dedican a atender las demandas sociales. El estudio examina la relación entre los ciudadanos menos favorecidos y la institucionalidad social en sus múltiples manifestaciones y dimensiones, siguiendo los preceptos de la teoría institucional. Metodológicamente el estudio responde a un diseño cualitativocuantitativo, de carácter descriptivo-analítico. Para la interpretación de la información recogida a través de las encuestas se realizó un análisis de correspondencias múltiples.

  19. Isotopic meteoric line for Colombia

    International Nuclear Information System (INIS)

    Rodriguez N, Cesar O

    2004-01-01

    Isotope analyses from representative rainfall samples taken from different areas in Colombia were processed to yield the meteoric line. Stable isotope composition in precipitation reflects the effects of temperature, altitude and of the continental site, being affected by different sources of atmospheric humidity over the Colombian territory. There is a seasonal variation in isotopic composition of precipitation with grater σ deviation during the rainy season and lower values in the dry season. In coastal areas the variation is smaller and is more pronounced than at continental stations. Correlation between altitude and isotope content led to equations, which indicate, on a regional level, a change in isotopic composition with altitude, of about 0.5 σ units per 200 m, for O 18 and 4 σ units per 200 m for H 2 . Such equations may be used to identify the original altitude of precipitation water, in hydrological surface and groundwater studies. Meteoric line and the concepts derived from the resulting equations presented in this paper may be applied to the interpretation of isotope analysis in future hydrological studies, particularly in areas without available data

  20. Timeline: environmental education in Colombia

    Directory of Open Access Journals (Sweden)

    Luz Adriana Pita-Morales

    2016-12-01

    Full Text Available The environmental education is a process that allows the individual to understand the relations of interdependence with the environment in the one that develops, is like that, since the reality bears biophysics in mind, social, political, economic in this respect it is necessary to generate in the company activities of valuation and respect for the environment. The environmental education is a dynamic and participative process orientated to the formation of critical and reflexive persons with aptitude to understand the environmental problematics of the local, regional and national context. In this frame the need is born of contextualized the labor that has become national in the construction of instruments that allow him the condition to look at the environmental education as a fundamental tool for the care of the natural resources and not as an isolated concept foreign to the community. In the present review their approaches the historical frame of the environmental education in Colombia his challenges, challenges and the way like are opening formative spaces and of projection for the suitable managing of the environment. In conclusion environmental education is a participatory process that must be born of the group in order to give management the natural resources of a region and community where professionals to do is oriental these processes in society.

  1. The century of the Petroleum in Colombia

    International Nuclear Information System (INIS)

    Carta Petrolera

    1999-01-01

    A recount of the big changes is made with hydrocarbons in Colombia during the X X century. The X X century it meant everything for Colombia in oil matter. In this century it took off and it consolidated their industry of the hydrocarbons and with her great part of the industrialization process and development of the country. It is undeniable that the petroleum was one of the big main characters of the century X X and Colombia has not been unaware to the sways of a highly changing industry. The creation of the OPEC, the warlike conflicts, the times of high and low prices, the technological advances, the processes of energy integration and the mega coalitions are hardly some of the ingredients that seasoned the Oil Industry in the years 1900

  2. Sistema de salud de Colombia The health system of Colombia

    Directory of Open Access Journals (Sweden)

    Ramiro Guerrero

    2011-01-01

    Full Text Available En este trabajo se presenta una breve descripción de las condiciones de salud de Colombia y una descripción detallada del sistema colombiano de salud. Esta última incluye una descripción de su estructura y cobertura, sus fuentes de financiamiento, el gasto en salud, los recursos con los que cuenta, quién vigila y evalúa al sector salud y qué herramientas de participación tienen los usuarios. Dentro de las innovaciones más recientes del sistema se incluyen las modificaciones al Plan Obligatorio de Salud y a los montos de la unidad de pago por capitación, la integración vertical entre empresas promotoras de salud y las instituciones prestadoras de servicios, así como el establecimiento de nuevas fuentes de recursos para lograr la universalidad e igualar los planes de beneficios entre los distintos regímenes.This document briefly describes the health conditions of the Colombian population and, in more detail, the characteristics of the Colombian health system. The description of the system includes its structure and coverage; financing sources; expenditure in health; physical material and human resources available; monitoring and evaluation procedures; and mechanisms through which the population participates in the evaluation of the system. Salient among the most recent innovations implemented in the Colombian health system are the modification of the Compulsory Health Plan and the capitation payment unit, the vertical integration of the health promotion enterprises and the institutions in charge of the provision of services and the mobilization of additional resources to meet the objectives of universal coverage and the homologation of health benefits among health regimes.

  3. NAMMA DC-8 DROPSONDE V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The DC-8 dropsonde system uses an integrated, highly accurate, GPS-located atmospheric profiling dropsonde, which measures and records current atmospheric conditions...

  4. dc power system for deuteron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Creek, K.O.; Liska, D.J.

    1981-01-01

    The Fusion Materials Irradiation Test (FMIT) Facility dc power system provides excitation current for all linac and High-Energy Beam Transport (HEBT) quadrupole and bending magnets, excitation for horizontal and vertical beam steering, and current-bypass shunts.

  5. Determination of input/output characteristics of full-bridge AC/DC/DC converter for arc welding

    OpenAIRE

    Stefanov, Goce; Karadzinov, Ljupco; Sarac, Vasilija; Cingoski, Vlatko; Gelev, Saso

    2016-01-01

    This paper describes the design and practical implementation of AC/DC/DC converter in mode of arc welding. An analysis of the operation of AC/DC/DC converter and its input/output characteristics are determined with computer simulations. The practical part is consisted of AC/DC/DC converter prototype for arc welding with output power of 3 kW and switching frequency of 64 kHz. The operation of AC/DC/DC converter is validated with experimental measurements.

  6. Ultra-high Efficiency DC-DC Converter using GaN Devices

    DEFF Research Database (Denmark)

    Ramachandran, Rakesh

    2016-01-01

    properties of GaN devices can be utilized in power converters to make them more compact and highly efficient. This thesis entitled “Ultra-high Efficiency DC-DC Converter using GaN devices” focuses on achieving ultra-high conversion efficiency in an isolated dc-dc converter by the optimal utilization of Ga...... for many decades. However, the rate of improvement slowed as the silicon power materials asymptotically approached its theoretical bounds. Compared to Si, wideband gap materials such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are promising semiconductors for power devices due to their superior...... in this thesis. Efficiency measurements from the hardware prototype of both the topologies are also presented in this thesis. Finally, the bidirectional operation of an optimized isolated dc-dc converter is presented. The optimized converter has achieved an ultra-high efficiency of 98.8% in both directions...

  7. Modeling, Analysis and Control of Different DC-DC Converter Topologies for Photo Voltaic Emulator

    Directory of Open Access Journals (Sweden)

    Mohammad Tauquir Iqbal

    2016-05-01

    Full Text Available This paper presents the modeling, analysis and control of different DC-DC converter topologies to emulate the photovoltaic (PV system. A PV emulator is basically a DC-DC converter having same electrical characteristics that of solar PV panel.  The emulator helps to achieve real characteristics of PV system in a better way in an environment where using actual PV systems can produce inconsistent results due to variation in weather conditions. The paper describes different types of DC-DC converters like buck, Resonant and Quasi Resonant Converter. The complete system is modelled in MATLAB® Simulink SimPowerSystem software package. The Simulation results obtained from the MATLAB® Simulink SimPowerSystem software package for different topologies under steady and dynamic conditions are analyzed and presented. An evaluation table is also presented at the end of the paper, presenting the effectiveness of each topology.

  8. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-01-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  9. Application handbook for a Standardized Control Module (SCM) for DC-DC converters, volume 1

    Science.gov (United States)

    Lee, F. C.; Mahmoud, M. F.; Yu, Y.

    1980-04-01

    The standardized control module (SCM) was developed for application in the buck, boost and buck/boost DC-DC converters. The SCM used multiple feedback loops to provide improved input line and output load regulation, stable feedback control system, good dynamic transient response and adaptive compensation of the control loop for changes in open loop gain and output filter time constraints. The necessary modeling and analysis tools to aid the design engineer in the application of the SCM to DC-DC Converters were developed. The SCM functional block diagram and the different analysis techniques were examined. The average time domain analysis technique was chosen as the basic analytical tool. The power stage transfer functions were developed for the buck, boost and buck/boost converters. The analog signal and digital signal processor transfer functions were developed for the three DC-DC Converter types using the constant on time, constant off time and constant frequency control laws.

  10. Test Results of Selected Commercial DC/DC Converters under Cryogenic Temperatures - A Digest

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad

    2010-01-01

    DC/DC converters are widely used in space power systems in the areas of power management and distribution, signal conditioning, and motor control. Design of DC/DC converters to survive cryogenic temperatures will improve the power system performance, simplify design, and reduce development and launch costs. In this work, the performance of nine COTS modular, low-tomedium power DC/DC converters was investigated under cryogenic temperatures. The converters were evaluated in terms of their output regulation, efficiency, and input and output currents. At a given temperature, these properties were obtained at various input voltages and at different load levels. A summary on the performance of the tested converters was given. More comprehensive testing and in-depth analysis of performance under long-term exposure to extreme temperatures are deemed necessary to establish the suitability of these and other devices for use in the harsh environment of space exploration missions.

  11. Precharge strategies for isolated modular DC-DC converters under two different start-up conditions

    DEFF Research Database (Denmark)

    Zhang, Yi; Wang, Huai; Li, Binbin

    2017-01-01

    The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value of capaci......The isolated modular DC-DC converter (IMDCC) is a new topology designed to connect high-voltage direct current (HVDC) lines with different voltage levels, which ties two DC grids by using two modular multilevel converters (MMCs) via a medium-frequency transformer. Due to the large value...... of capacitance in the IMDCC, proper precharge strategies before the start-up are significant for the safety and reliability of the whole system. This paper presents two closed-loop precharge control strategies to fully charge the sub-module (SM) capacitors of the IMDCC, considering two different start...

  12. Kingsnorth-London dc transmission link

    Energy Technology Data Exchange (ETDEWEB)

    1966-03-11

    The hvdc transmission link between one of the 500 MW generators at Kingsnorth Power Station and two receiving stations in London will use a three-wire dc cable system rated to carry 1200 A at +- 266 kV. This 51-mile system will be the first dc link in the world to be used as an integral part of a complex interconnected ac network.

  13. Hole history, rotary hole DC-3

    International Nuclear Information System (INIS)

    1977-10-01

    Purpose of hole DC-3 was to drill into the Umtanum basalt flow using both conventional rotary and core drilling methods. The borehole is to be utilized for geophysical logging, future hydrological testing, and the future installation of a borehole laboratory for long-term pressure, seismic, and moisture migration or accumulation recording in the Umtanum basalt flow in support of the Basalt Waste Isolation Program. Hole DC-3 is located east of the 200 West barricaded area on the Hanford reservation

  14. DC-8 MTP calibration for SOLVE-2

    Science.gov (United States)

    Mahoney, M. J.

    2003-01-01

    The Jet Propulsion Laboratory (JPL) Microwave Temperature Profiler (MTP) was the only instrument making temperature measurements at and below flight level on the DC-8 during the SOLVE-2 campaign. Many years of careful comparison of MTP measurements with radiosondes near the DC-8 flight track have shown that the flight level temperature can be determined to an accuracy of 0.2K relative to radiosondes.

  15. dc illusion and its experimental verification

    Science.gov (United States)

    Liu, Min; Lei Mei, Zhong; Ma, Xiang; Cui, Tie Jun

    2012-07-01

    Based on the transformation optics method, we propose a dc illusion device, which can transform a metallic object into a magnified dielectric object using anisotropic conducting materials. Utilizing the analogy between electric conductivities and resistor networks, we design and fabricate the device using metal film resistors. The practical measurement data agree very well with simulation results. The proposed dc illusion device is easy to process and measure, and thus has potential applications in various sectors.

  16. Problematic of mining environmental liabilities in Colombia

    International Nuclear Information System (INIS)

    Arango Aramburo, Marcela; Olaya, Yris

    2012-01-01

    Mining environmental liabilities (PAM from its acronym in Spanish) are areas where there is a need for restoration, mitigation or compensation for environmental damage or unmanaged impact, produced by inactive or abandoned mining that threatens health, quality of life or public or private property. In Colombia the environmental liabilities from mining have not been regulated, but given the age and the prevalence of informality in mining, there is increasing interest in defining, regulating and managing these obligations. In this paper we approach the problem of valuing mining environmental liabilities by examining different management approaches for such liabilities around the world. We also identify key information requirements to manage mining environmental liabilities in Colombia.

  17. Plan para control de Malaria en Colombia

    Directory of Open Access Journals (Sweden)

    Hernando Rey

    1943-02-01

    Full Text Available Con motivo de la colaboración de la Oficina de Relaciones Interamericanas en la solución de algunos problemas de Higiene pública en Colombia, el Secretario del Ministerio de Trabajo, Higiene y Previsión Social, doctor Alfonso Orozco, me pidió la elaboración de un breve plan para control de Paludismo en Colombia. El Plan fué presentado al Ministerio por una parte y por otra enviado al doctor Mark F. Boyd de la International Health Division de la Fundación Rockefeller.

  18. Solar energy, architecture and climate in Colombia

    International Nuclear Information System (INIS)

    Carrillo B, J.

    1983-01-01

    In Colombia, the climatological conditions are such that with a possible serious appropriate technology to use the solar energy in the cities when the electricity rationing increases, for the illumination, the refrigeration, the electricity production, the heating, etc. The use of the solar energy is also been worth to look for a better adaptation between climate and architecture. In this sense, the article exposes some of the existent possibilities of application of the solar energy for the comfort of the habitat, possibilities of high efficiency and low cost that can be easily applicable in Colombia

  19. Characterization of diode valve in medium voltage dc/dc converter for wind turbines

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne

    2016-01-01

    This paper proposes a methodology for characterization of medium voltage (MV), medium frequency (MF) rectifier diode valve. The intended application is for 10MW dc/dc converters used in DC offshore wind turbines. Sensitivity to semiconductor component parameter variation, snubber component tolera...... tolerance, influence of temperature and stray capacitance are analyzed. It is concluded that the largest impact on sensitivity is given by reverse recovery charge variation and differences of temperature between adjacent devices....

  20. Computer Simulation of Phase Shifted Series Resonant DC to DC Converter

    Directory of Open Access Journals (Sweden)

    P. PARVATHY

    2016-01-01

    Full Text Available This paper deals with digital simulation of phase shifted series resonant DC to DC converter using Matlab Simulink. The Simulink models for open loop and closed loop systems are developed and they are used for simulation studies. This converter is capable of producing ripple free DC output. Switching losses and switching stresses are reduced by using soft switching. This converter has advantages like high power density and low switching losses. Theoretical predictions are well supported by the simulation results.

  1. DC-Link Compensation Method for Slim DC Link Drives Fed by Soft Grid

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Rosendahl Andersen, Henrik; Lazar, Radu

    2010-01-01

    Slim DC-link PWM (AC) drives for lowperformance applications are emerging on the market. Such drives equipped with a small DC-link capacitance exhibit instability tendencies, if installed on a soft line, giving a degraded performance. The total harmonic distortion (THD) and the partially weighted...... harmonic distortion (PWHD) of the line current are degraded, if resonance between the line impedance and the DC-link capacitance occurs. Likewise, the motor performance is affected negatively giving extra torque ripple, vibration and acoustic-noise emission. This paper proposes a novel DC-link compensation...

  2. Egr2 induced during DC development acts as an intrinsic negative regulator of DC immunogenicity.

    Science.gov (United States)

    Miah, Mohammad Alam; Byeon, Se Eun; Ahmed, Md Selim; Yoon, Cheol-Hee; Ha, Sang-Jun; Bae, Yong-Soo

    2013-09-01

    Early growth response gene 2 (Egr2), which encodes a zinc finger transcription factor, is rapidly and transiently induced in various cell types independently of de novo protein synthesis. Although a role for Egr2 is well established in T-cell development, Egr2 expression and its biological function in dendritic cells (DCs) have not yet been described. Here, we demonstrate Egr2 expression during DC development, and its role in DC-mediated immune responses. Egr2 is expressed in the later stage of DC development from BM precursor cells. Even at steady state, Egr2 is highly expressed in mouse splenic DCs. Egr2-knockdown (Egr2-KD) DCs showed increased levels of major histocompatability complex (MHC) class I and II and co-stimulatory molecules, and enhanced antigen uptake and migratory capacities. Furthermore, Egr2-KD abolished SOCS1 expression and signal transducer and activator of transcription 5 (STAT5) activation during DC development, probably resulting in the enhancement of IL-12 expression and Th1 immunogenicity of a DC vaccine. DC-mediated cytotoxic T lymphocyte (CTL) activation and antitumor immunity were significantly enhanced by Egr2-KD, and impaired by Egr2 overexpression in antigen-pulsed DC vaccines. These data suggest that Egr2 acts as an intrinsic negative regulator of DC immunogenicity and can be an attractive molecular target for DC vaccine development. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Analysis of high voltage step-up nonisolated DC-DC boost converters

    Science.gov (United States)

    Alisson Alencar Freitas, Antônio; Lessa Tofoli, Fernando; Junior, Edilson Mineiro Sá; Daher, Sergio; Antunes, Fernando Luiz Marcelo

    2016-05-01

    A high voltage step-up nonisolated DC-DC converter based on coupled inductors suitable to photovoltaic (PV) systems applications is proposed in this paper. Considering that numerous approaches exist to extend the voltage conversion ratio of DC-DC converters that do not use transformers, a detailed comparison is also presented among the proposed converter and other popular topologies such as the conventional boost converter and the quadratic boost converter. The qualitative analysis of the coupled-inductor-based topology is developed so that a design procedure can be obtained, from which an experimental prototype is implemented to validate the theoretical assumptions.

  4. High-Voltage DC-DC Converter Topology for PV Energy Utilization - Investigation and Implementation

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Blaabjerg, Frede; Wheeler, Patrick

    2017-01-01

    This paper exploited the utilization of photovoltaic (PV) energy system with high-voltage (HV) output DC-DC converter. Classical boost converters are used for both renewable energy integration and HV applications, but limited by reducing output/efficiency in performance. Moreover, as parasitic...... elements suppress the power transfer ratio, converter needs to maximize the PV energy utilization. This investigation study focused to include additional parasitic elements (voltage-lift technique) to a standard DC-DC buck converter and to overcome all the above drawbacks to maximize the PV power...

  5. Digital peak current mode control with adaptive slope compensation for DC-DC converters

    DEFF Research Database (Denmark)

    Andersen, Karsten Holm; Nymand, Morten

    2017-01-01

    performance and stability of current mode control. The presented method adapt to DC-DC converter operating conditions by estimating the rising and falling inductor current slopes, to apply a current slope compensation value to obtain a constant quality factor. The experimental results verifies the theoretical......This paper presents an adaptive slope compensation method for peak current mode control of digital controlled DC-DC converters, which controls the quality factor of the complex conjugated poles at half the switching frequency. Using quality factor control enables optimization of the dynamic...

  6. A Novel PPFHB Bidirectional DC-DC Converter for Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase-shift modula......This paper presents a novel bidirectional DC-DC converter for the supercapacitor application. In the proposed converter, push-pull forward with half bridge (PPFHB) voltage doubler structure is used to reduce the number of the power switches and get higher voltage gain. Based on phase...

  7. The application of standardized control and interface circuits to three dc to dc power converters.

    Science.gov (United States)

    Yu, Y.; Biess, J. J.; Schoenfeld, A. D.; Lalli, V. R.

    1973-01-01

    Standardized control and interface circuits were applied to the three most commonly used dc to dc converters: the buck-boost converter, the series-switching buck regulator, and the pulse-modulated parallel inverter. The two-loop ASDTIC regulation control concept was implemented by using a common analog control signal processor and a novel digital control signal processor. This resulted in control circuit standardization and superior static and dynamic performance of the three dc-to-dc converters. Power components stress control, through active peak current limiting and recovery of switching losses, was applied to enhance reliability and converter efficiency.

  8. Laboratory manual for pulse-width modulated DC-DC power converters

    CERN Document Server

    Kazimierczuk, Marian K

    2015-01-01

    Designed to complement a range of power electronics study resources, this unique lab manual helps students to gain a deep understanding of the operation, modeling, analysis, design, and performance of pulse-width modulated (PWM) DC-DC power converters.  Exercises focus on three essential areas of power electronics: open-loop power stages; small-signal modeling, design of feedback loops and PWM DC-DC converter control schemes; and semiconductor devices such as silicon, silicon carbide and gallium nitride. Meeting the standards required by industrial employers, the lab manual combines program

  9. A Bidirectional Multi-Port DC-DC Converter Integrating Voltage Equalizer

    DEFF Research Database (Denmark)

    Chen, Jianfei; Hou, Shiying; Deng, Fujin

    2015-01-01

    A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalize...... battery modules with different voltages. Simulation results has shown the feasibility of the proposed converter.......A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized...

  10. A Bidirectional Resonant DC-DC Converter Suitable for Wide Voltage Gain Range

    DEFF Research Database (Denmark)

    Shen, Yanfeng; Wang, Huai; Al-Durra, Ahmed

    2018-01-01

    This paper proposes a new bidirectional resonant dc-dc converter suitable for wide voltage gain range applications (e.g., energy storage systems). The proposed converter overcomes the narrow voltage gain range of conventional resonant dc-dc converters, and meanwhile achieves high efficiency...... losses. The operation principles and characteristics of the proposed converter are firstly analyzed in this paper. Then the analytical solutions for the voltage gain, soft-switching, and rms currents are derived, which facilitates the parameters design and optimization. Finally, the proposed topology...... and analysis are verified with experimental results obtained from a 1-kW converter prototype....

  11. Design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters

    CERN Document Server

    Cravero, Jean-Marc

    2013-01-01

    This technical report presents the design of the DC-DC power stage of the capacitor charger for MAXIDISCAP power converters. The power stage is based on a half bridge series resonant converter in Discontinuous Conduction Mode (DCM). This simple and robust topology allows obtaining a current source behavior with a low switching losses power stage. The associated control stage is implemented using a commercial controller which has differenti nternal circuits that allows a high integration of the converter control system. The report presents the design and tuning criteria for the DC-DC converter, including the power stage and the control system.

  12. Analysis and Design of Bi-Directional DC-DC Converter in the Extended Run Time DC UPS System Based on Fuel Cell and Supercapacitor

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes. The deli......Abstract-In this paper, an extended run time DC UPS system structure with fuel cell and supercapacitor is investigated. A wide input range bi-directional dc-dc converter is described along with the phase-shift modulation scheme and phase-shift with duty cycle control, in different modes...

  13. Impact of Faults and Protection Methods on DC Microgrids Operation

    DEFF Research Database (Denmark)

    Bayati, Navid; Hajizadeh, Amin; N. Soltani, Mohsen

    2018-01-01

    with the DC Microgrid. This paper evaluates and presents a comprehensive review on the most recent studies in the DC Microgrids protection. Moreover, the fault behavior and characteristics of DC Microgrids, the effect of Constant Power Load (CPL) , and recent DC Microgrid protection methods are reviewed. Also...

  14. Sustainable Colombia : A Comprehensive Colombian Footprint Review

    OpenAIRE

    Brad Ewing

    2010-01-01

    During the past several months, the Ministry of Environment, Housing and Territorial Development of Colombia has been researching potential indicators that would be useful to assess and possibly adopt among which included the ecological footprint. This work was commissioned in order to provide the Ministry with a deeper understanding of the ecological footprint and to train a number of its...

  15. Colombia's Libraries: Modernizing amidst a Drug War.

    Science.gov (United States)

    Chepesiuk, Ron

    1991-01-01

    Describes the impact that the war on drugs in Colombia has had on their library services and on the lives of professional librarians. Topics discussed include political, staffing, budget, resource, and physical plant problems; the serious shortage of professional librarians; and extending library service to rural areas. (LRW)

  16. Prevalence of urticaria in Cartagena, Colombia

    Directory of Open Access Journals (Sweden)

    Pablo Andrés Miranda-Machado

    2017-06-01

    Full Text Available Background: In Colombia, there have been studies on the prevalence of allergic diseases such as asthma, allergic rhinitis and atopic dermatitis. Prevalence studies of urticaria in Colombia are scarce. Objective: Our objective of this study was to estimate the prevalence of urticaria in Cartagena (Colombia in order to contribute to national epidemiological estimates of disease. Methods: A multicenter cross-sectional study in the city of Cartagena was conducted and 547 patients aged 1-58 years treated at the Allergy specialist consultation in care centers selected for this study between April and July 2015 were included, through non-probabilistic sampling. Results: The prevalence of urticaria in the care centers selected of city of Cartagena (Colombia was 7.1 % (4 % children and adults 3.1 %. 3.4 % prevalence of acute urticaria and 3.6 % of chronic urticaria was estimated. Conclusion: 46.1 % reported having a poor quality of life associated with urticaria.

  17. Sequencing: Targeting Insurgents and Drugs in Colombia

    Science.gov (United States)

    2007-03-01

    p. 73. 24 initiated by previous administrations coupled with declining prices in the late 1990s for coffee and oil—two of Colombia’s major...whose involvement in the illicit drug industry gained them notoriety in the 1970s with the production of cannabis . In the 1980s, Colombia became the

  18. Lifelong Learning in Colombia and Denmark

    DEFF Research Database (Denmark)

    Olesen, Henning Salling

    2004-01-01

    The article examines education and learning opportunities in Colombia against the backdrop of Danish modernisation and reform experiences from second half of 20th Century. The article discusses possibilities to learn from Danish experiences in the development of a Colombian lifelong learning policy...

  19. Characterization of cigarrete smuggling distribution in Colombia

    Directory of Open Access Journals (Sweden)

    Blanca Llorente

    2018-03-01

    Changes along the distribution chain are bringing new risks and opportunities for an effective control of illicit trade flows. It is necessary to explore interventions that address institutional weaknesses, and the circumstances of vulnerable actors to develop sustainable policies to eliminate illicit trade in Colombia.

  20. Astroparticle physics at the Eastern Colombia region

    Science.gov (United States)

    Asorey, Hernán; Núñez, Luis A.

    2015-12-01

    We present the emerging panorama of Astroparticle Physics at the Eastern Colombia region, and describe several ongoing projects, most of them related to the Latin American Giant Observatory (LAGO) Project. This research work is carried out at the Grupo de Investigaciones en Relatividad y Gravitacin of Universidad Industrial de Santander.

  1. Rice peasants and rice research in Colombia

    NARCIS (Netherlands)

    Spijkers, P.A.N.M.

    1983-01-01

    Rice has been grown as a food crop in Latin America from early colonial times. In Colombia rice became a prominent subsistence crop especially on the north coast where it has been grown since the 17th century, sometimes also as a commercial crop. During the last twenty years there has been a sharp

  2. Observatorio de Política Internacional I. COLOMBIA - El proceso de paz en sala de emergencia

    OpenAIRE

    Neira Fernández, Enrique

    2007-01-01

    Observatorio de Política Internacional I. COLOMBIA (Neira Fernández, Enrique) RECIENTES Año 2008 Colombia. Cerca el fin del paramilitarismo Colombia. Cerca el fin de las Farc Colombia. Conflicto armado y desarrollo humano Colombia. Política exterior Colombia. Inicia el 2008 con buen pie Año 2007 Colombia. Tras las pasadas elecciones Colombia. El espectro de las próximas elecciones Colombia. La garrocha de Uribe Colombia. III Parapolíticos Colombia. II...

  3. Zero-voltage DC/DC converter with asymmetric pulse-width modulation for DC micro-grid system

    Science.gov (United States)

    Lin, Bor-Ren

    2018-04-01

    This paper presents a zero-voltage switching DC/DC converter for DC micro-grid system applications. The proposed circuit includes three half-bridge circuit cells connected in primary-series and secondary-parallel in order to lessen the voltage rating of power switches and current rating of rectifier diodes. Thus, low voltage stress of power MOSFETs can be adopted for high-voltage input applications with high switching frequency operation. In order to achieve low switching losses and high circuit efficiency, asymmetric pulse-width modulation is used to turn on power switches at zero voltage. Flying capacitors are used between each circuit cell to automatically balance input split voltages. Therefore, the voltage stress of each power switch is limited at Vin/3. Finally, a prototype is constructed and experiments are provided to demonstrate the circuit performance.

  4. Ultrahigh-density trench cpacitors in silicon and their application to integrated DC-DC conversion

    NARCIS (Netherlands)

    Roozeboom, F.; Bergveld, H.J.; Nowak, K.; Le Cornec, F.; Guiraud, L.; Bunel, C.; Iochem, S.; Ferreira, J.; Ledain, S.; Pieraerts, E.; Pommier, M.

    2009-01-01

    This paper addresses silicon-based integration of passive components applied to 3D integration with dies of other technologies within one package. Particularly, the development of high-density trench capacitors has enabled the realization of small-formfactor DC-DC converters. As illustration, an

  5. Reliability study of high gain DC-DC converters based on RRPP I-IIA ...

    Indian Academy of Sciences (India)

    J DIVYA NAVAMANI

    2018-05-10

    May 10, 2018 ... Energy Storage Modules (ESM), Propulsion Motor Mod- ules (PMM) and ... All Electric Ship (AES) is the best way to power all the loads in the ship ... also used to derive quadratic step down DC-DC converters. [6]. The attractive ...... Exhibition on Ecological Vehicles and Renewable Energies,. TamilNadu ...

  6. Investigation of DC-DC Boost Converter for Reliability of Operational Planning

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Ashouri, Mani; Silva, Filipe Miguel Faria da

    2018-01-01

    of the interests related to reliability is the power semiconductor switches, which are the most vulnerable elements. The failure of one-power switches can reduce the system reliability. Interleaved technique for DC-DC converters is a redundant strategy to improve the reliability, but at the cost of increasing...

  7. A New Sliding Mode Controller for DC/DC Converters in Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    M. Sarvi

    2013-01-01

    Full Text Available DC/DC converters are widely used in many industrial and electrical systems. As DC/DC converters are nonlinear and time-variant systems, the application of linear control techniques for the control of these converters is not suitable. In this paper, a new sliding mode controller is proposed as the indirect control method and compared to a simple direct control method in order to control a buck converter in photovoltaic applications. The solar arrays are dependent power sources with nonlinear voltage-current characteristics under different environmental conditions (insolation and temperature. From this point of view, the DC/DC converter is particularly suitable for the application of the sliding mode control in photovoltaic application, because of its controllable states. Simulations are performed in Matlab/Simulink software. The simulation results are presented for a step change in reference voltage and input voltage as well as step load variations. The simulations results of proposed method are compared with the conventional PID controller. The results show the good performance of the proposed sliding mode controller. The proposed method can be used for the other DC/DC converter.

  8. Switched capacitor DC-DC converter with switch conductance modulation and Pesudo-fixed frequency control

    DEFF Research Database (Denmark)

    Larsen, Dennis Øland; Vinter, Martin; Jørgensen, Ivan Harald Holger

    A switched capacitor dc-dc converter with frequency-planned control is presented. By splitting the output stage switches in eight segments the output voltage can be regulated with a combination of switching frequency and switch conductance. This allows for switching at predetermined frequencies, 31...

  9. Spectral shaping of a randomized PWM DC-DC converter using maximum entropy probability distributions

    CSIR Research Space (South Africa)

    Dove, Albert

    2017-01-01

    Full Text Available maintaining constraints in a DC-DC converter is investigated. A probability distribution whose aim is to ensure maximal harmonic spreading and yet mainaint constraints is presented. The PDFs are determined from a direct application of the method of Maximum...

  10. Common mode noise in three-level DC-DC converters

    CSIR Research Space (South Africa)

    Grobler, Inus

    2009-09-01

    Full Text Available that three-level buck DC-DC converters in general generate much lower common mode currents than conventional two-level buck converters. Further, reductions in common mode currents are achieved by using the improved three-level topologies that have been...

  11. Y-Source Boost DC/DC Converter for Distributed Generation

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    This paper introduces a versatile Y-source boost dc/dc converter intended for distributed power generation, where high gain is often demanded. The proposed converter uses a Y-source impedance network realized with a tightly coupled three-winding inductor for high voltage boosting that is presently...

  12. Experimental study of dynamic behaviors and routes to chaos in DC-DC boost converters

    International Nuclear Information System (INIS)

    Cafagna, D.; Grassi, G.

    2005-01-01

    This paper illustrates an experimental study of a current-programmed DC-DC boost converter, with the aim of investigating possible pathways through which the converter may enter chaos. In particular, based on experimental measurements, it is shown that variations of input voltage and reference current can generate periodic, subharmonic, quasi-periodic and chaotic behaviors

  13. Magnetically integrated high step-up resonant DC-DC converter for distributed photovoltaic systems

    DEFF Research Database (Denmark)

    Vinnikov, Dmitri; Chub, Andrii; Liivik, Elizaveta

    2017-01-01

    In this paper magnetically integrated resonant single-switch quasi-Z-source DC-DC converter is evaluated as a candidate topology for the low-cost photovoltaic microconverter. The derivation of the topology and its basic operation principle are explained. Generalized design guidelines...

  14. Quasiperiodicity and Torus Breakdown in a Power Electronic DC/DC Converter

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai; Soukhoterin, Evgeniy; Mosekilde, Erik

    2007-01-01

    This paper discusses the mechanisms of torus formation and torus destruction in a dc/dc converter with relay control and hysteresis. We establish a chart of the dynamical modes in the input voltage versus load resistance parameter plane. This chart displays several different torus bifurcations...

  15. A DC-DC Converter with Wide Input Voltage Range for Fuel Cell and Supercapacitor Application

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael Andreas E.

    2009-01-01

    This paper proposes a novel phase-shift plus duty cycle controlled hybrid bi-directional DC-DC converter based on fuel cells and supercapacitors. The described converter employs two high frequency transformers to couple the half-bridge and full-bridge circuits together in the primary side...

  16. Modelling, Simulation and Construction of a DC/DC Boost Power Converter: A School Experimental System

    Science.gov (United States)

    Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernandez-Guzman, V. M.; Saldana-Gonzalez, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders…

  17. High-power three-port three-phase bidirectional DC-DC converter

    NARCIS (Netherlands)

    Tao, H.; Duarte, J.L.; Hendrix, M.A.M.

    2007-01-01

    This paper proposes a three-port three-phase bidirectional dc-dc converter suitable for high-power applications. The converter combines a slow primary source and a fast storage to power a common load (e.g., an inverter). Since this type of system is gaining popularity in sustainable energy

  18. Floating high step-down stacked dc-dc converter based on buck-boost cells

    NARCIS (Netherlands)

    Tibola, G.; Duarte, J.L.; Blinov, A.

    2015-01-01

    In some high power dc-dc applications, where high voltage is present, a converter with high step-down ratio is required in order to provide an isolated low power auxiliary supply. This requirement represents a challenge and many topologies are currently being researched. The analysis of a

  19. Magnetically coupled high-gain Y-source isolated DC/DC converter

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...

  20. Modelling, simulation and construction of a dc/dc boost power converter: a school experimental system

    International Nuclear Information System (INIS)

    Silva-Ortigoza, R; Marciano-Melchor, M; Silva-Ortigoza, G; Hernández-Guzmán, V M; Saldaña-González, G; Marcelino-Aranda, M

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories. (paper)

  1. Comparative evaluation of bidirectional dual active bridge DC-DC converter variants

    NARCIS (Netherlands)

    Sfakianakis, G.; Everts, J.; Huisman, H.; Lomonova, E.A.

    2016-01-01

    For the realization of DC-DC converters in automotive industry, the Dual Active Bridge (DAB) converter seems to be a promising choice because of its soft-switching and high-power-density capability. Contrary to the traditional 3 level - 3 level (3-3L) DAB, a 3 level - 5 level (3-5L) DAB can operate

  2. A Novel Single Switch Transformerless Quadratic DC/DC Buck-Boost Converter

    DEFF Research Database (Denmark)

    Mostaan, Ali; A. Gorji, Saman; N. Soltani, Mohsen

    2017-01-01

    A novel quadratic buck-boost DC/DC converter is presented in this study. The proposed converter utilizes only one active switch and can step-up/down the input voltage, while the existing single switch quadratic buck/boost converters can only work in step-up or step-down mode. First, the proposed ...

  3. Single Event Burnout in DC-DC Converters for the LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Claudio H. Rivetta et al.

    2001-09-24

    High voltage transistors in DC-DC converters are prone to catastrophic Single Event Burnout in the LHC radiation environment. This paper presents a systematic methodology to analyze single event effects sensitivity in converters and proposes solutions based on de-rating input voltage and output current or voltage.

  4. Design and Implementation of Digital Current Mode Controller for DC-DC Converters

    DEFF Research Database (Denmark)

    Taeed, Fazel

    to be regulated by a closed-loop controller. The Peak Current Mode Control (PCMC) is one of the most promising control methods for dc-dc converters. It has been known for high bandwidth (speed), and inherent current protection. Increasing the controller bandwidth decreases the output filter size and cost. Analog...

  5. Selection of DC/DC converter for offshore wind farms with MVDC power collection

    DEFF Research Database (Denmark)

    Dincan, Catalin Gabriel; Kjær, Philip Carne; Chen, Yu-Hsing

    2017-01-01

    Four DC/DC converters are analyzed and compared with respects to availability, efficiency, ratings, repair costs and power density. Intended application is offshore wind farms with MVDC power collection. The selected topology is a new series resonant converter, which offers 99% efficiency across...

  6. Area-Efficiency Trade-Offs in Integrated Switched-Capacitor DC-DC Converters

    DEFF Research Database (Denmark)

    Spliid, Frederik Monrad; Larsen, Dennis Øland; Knott, Arnold

    2016-01-01

    This paper analyzes the relationship between efficiency and chip area in a fully integrated switched capacitor voltage divider dc-dc converter implemented in 180nm-technology and a 1/2 topology. A numerical algorithm for choosing the optimal sizes of individual components, in terms of power loss...

  7. Research on Two-channel Interleaved Two-stage Paralleled Buck DC-DC Converter for Plasma Cutting Power Supply

    DEFF Research Database (Denmark)

    Yang, Xi-jun; Qu, Hao; Yao, Chen

    2014-01-01

    As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...

  8. Pulsed dc self-sustained magnetron sputtering

    International Nuclear Information System (INIS)

    Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

    2008-01-01

    The magnetron sputtering has become one of the commonly used techniques for industrial deposition of thin films and coatings due to its simplicity and reliability. At standard magnetron sputtering conditions (argon pressure of ∼0.5 Pa) inert gas particles (necessary to sustain discharge) are often entrapped in the deposited films. Inert gas contamination can be eliminated during the self-sustained magnetron sputtering (SSS) process, where the presence of the inert gas is not a necessary requirement. Moreover the SSS process that is possible due to the high degree of ionization of the sputtered material also gives a unique condition during the transport of sputtered particles to the substrate. So far it has been shown that the self-sustained mode of magnetron operation can be obtained using dc powering (dc-SSS) only. The main disadvantage of the dc-SSS process is its instability related to random arc formation. In such case the discharge has to be temporarily extinguished to prevent damaging both the magnetron source and power supply. The authors postulate that pulsed powering could protect the SSS process against arcs, similarly to reactive pulsed magnetron deposition processes of insulating thin films. To put this concept into practice, (i) the high enough plasma density has to be achieved and (ii) the type of pulsed powering has to be chosen taking plasma dynamics into account. In this article results of pulsed dc self-sustained magnetron sputtering (pulsed dc-SSS) are presented. The planar magnetron equipped with a 50 mm diameter and 6 mm thick copper target was used during the experiments. The maximum target power was about 11 kW, which corresponded to the target power density of ∼560 W/cm 2 . The magnetron operation was investigated as a function of pulse frequency (20-100 kHz) and pulse duty factor (50%-90%). The discharge (argon) extinction pressure level was determined for these conditions. The plasma emission spectra (400-410 nm range) and deposition

  9. Modeling, Control and Protection of Low-Voltage DC Microgrids

    OpenAIRE

    Salomonsson, Daniel

    2008-01-01

    Current trends in electric power consumption indicate an increasing use of dc in end-user equipment, such as computers and other electronic appliances used in households and offices. With a dc power system, ac/dc conversion within these loads can be avoided, and losses reduced. AC/DC conversion is instead centralized, and by using efficient, fully controllable power-electronic interfaces, high power quality for both ac and dc systems during steady state and ac grid disturbances can be obtaine...

  10. CSM: Profamilia's approach in Colombia.

    Science.gov (United States)

    Samuel, S

    1982-03-01

    Colombia's PROFAMILIA has successfully operated a contraceptive social marketing (CSM) program since 1973. Beginning with 1 salesperson distributing primarily to Cajas de Subsideio, the CSM program is now distributed through 70-80% of the 6000 registered pharmacies in the country, as well as pharmacy counters of several supermakets in urban areas. During 1981, PROFAMILIA's 5 salespersons accountd for commerical sales of oral contraceptives (OCs) to 225,000 couples and sales of barrier methods to another 75,000. Program sales of contraceptives and other products generated approximately US $1.7 million in revenue for the same year. PROFAMILIA's marketing approach is unique in its product and promotinal characteristics. Supplies are obtained directly from local and foreign manufacturers and are resold without any repackaging. While it is generally believed that CSM programs expand the market for contraceptives, data analysis and analysis of PROFAMILIA's distribution system suggests that the PROFAMILIA CSM program has simply absorbed some of the previously existing commerical market. Total commerical market sales of oral contraceptives (OCs) have grown at an annual rate of 3-4% since 1975. During the same period, direct sales of Schering, Wyeth, and other competitors have declined. PROFAMILIA's community-based program operates mainly among urban and semi-rural lower income populations. It sells products through established retail outlets rather than through institutional or non-retail outlets. PROFAMILIA's community-based program in all respects but its use of a staff of 112 salaried "instructoras" is as much a marketing program as PROFAMILIA's sales through pharmacies. Taken together, the 2 program expanded the commerical makert by about 1/2 since 1975. The contraceptive social marketing or pharmacy sales program appears to excel at generation of revenue and delivery of products to higher income clients. The community-based program excels at delivery of information

  11. Operation and control of a DC-grid offshore wind farm under DC transmission system faults

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    . Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....

  12. A suitable model plant for control of the set fuel cell-DC/DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Andujar, J.M.; Segura, F.; Vasallo, M.J. [Departamento de Ingenieria Electronica, Sistemas Informaticos y Automatica, E.P.S. La Rabida, Universidad de Huelva, Ctra. Huelva - Palos de la Frontera, S/N, 21819 La Rabida - Palos de la Frontera Huelva (Spain)

    2008-04-15

    In this work a state and transfer function model of the set made up of a proton exchange membrane (PEM) fuel cell and a DC/DC converter is developed. The set is modelled as a plant controlled by the converter duty cycle. In addition to allow setting the plant operating point at any point of its characteristic curve (two interesting points are maximum efficiency and maximum power points), this approach also allows the connection of the fuel cell to other energy generation and storage devices, given that, as they all usually share a single DC bus, a thorough control of the interconnected devices is required. First, the state and transfer function models of the fuel cell and the converter are obtained. Then, both models are related in order to achieve the fuel cell+DC/DC converter set (plant) model. The results of the theoretical developments are validated by simulation on a real fuel cell model. (author)

  13. Analysis of DC/DC Converter Efficiency for Energy Storage System Based on Bidirectional Fuel Cells

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    interface to the grid. In power electronics, the converter efficiency is characterized at fixed operating voltage for various output power. This type of characterization is not suitable for fuel cells, since as the power from the fuel cell increases, the cell voltage decreases. This paper analyses how......Renewable energy sources are fluctuating depending on the availability of the energy source. For this reason, energy storage is becoming more important and bidirectional fuel cells represent an attractive technology. Fuel cells require highcurrent low-voltage dc-dc or dc-ac converters as power...... the fuel cell I-V characteristics influences the power electronics converter efficiency and their consequence on the overall system. A loaddependent efficiency curve is presented based on experimental results from a 6 kW dc-dc converter prototype including the most suitable control strategy which maximizes...

  14. Research borehole drilling activity for boreholes DH-18, DH-19, DC-12, DC-13, DC-14, DC-15, and deepening of existing borehole DC-7

    International Nuclear Information System (INIS)

    1979-09-01

    This report is an environmental evaluation of the impacts of proposed borehole drilling activities at the Hanford Site, northwest of Richland, Washington. The proposed action is to drill six research boreholes ranging in depth from 137 to 1372 meters (m) [250 to 4500 +- feet (ft)]. In addition, an existing borehole (DC-7) will be extended from 1249 to 1524 m (4099 to 5000 +- ft). The purpose of the US Department of Energy's (DOE) borehole drilling activities is to collect data on in situ rock formations that are considered potentialy suitable for nuclear waste repositories. The technical program efforts necessary to identify and qualify specific underground waste facility sites in candidate rock formations include geologic and hydrologic studies (seismicity and tectonics, rock structure and stratigraphy, lithology, etc.). Borehole drilling is an integral part of the geological studies and is essential to a thorough understanding of potentially suitable geologic formations. The purpose of the proposed drilling activities is to obtain data for evaluating Columbia River basalts that are being evaluated by the National Waste Terminal Storage (NWTS) Program to determine their suitability potential for nuclear waste repositories. Unavoidable impact to the environment is limited primarily to the clearing of land needed for access and drilling operations. Considerations exercised during site preparation, drilling, and subsequent site restoration will limit modification of the natural environment to the minimum required for accomplishment of test objectives

  15. 76 FR 11561 - Additional Designations, Foreign Narcotics Kingpin Designation Act

    Science.gov (United States)

    2011-03-02

    ....A., Cali, Colombia; c/o INVERSIONES CIFUENTES Y CIA. S. EN C., Medellin, Colombia; c/o PARQUES... Federal, Mexico; c/o LINEA AEREA PUEBLOS AMAZONICOS S.A.S., Bogota, Colombia; c/o PARQUES TEMATICOS S.A... HOTELES Y BIENES S.A., Bogota, Colombia; c/o INVERPUNTO DEL VALLE S.A., Cali, Colombia; c/o PARQUES...

  16. Medidas de control de tuberculosis en una institución de salud de Bogotá D.C

    Directory of Open Access Journals (Sweden)

    Alba I. Muñoz-Sánchez

    2016-02-01

    Full Text Available Resumen Objetivo: evaluar la implementación de medidas de control, de tipo administrativo, ambiental y de protección respiratoria, de la infección de tuberculosis en un hospital de III nivel de atención en la ciudad de Bogotá D.C. Metodología: estudio de tipo descriptivo, transversal. Para la recolección de datos se aplicó una herramienta de autorreporte a 158 trabajadores de la salud del hospital, se realizó una entrevista estructurada al responsable del programa institucional de control de tuberculosis y una visita de observación de un experto en salud y seguridad laboral a las diferentes áreas de trabajo, para indagar por la implementación de medidas de control de infección de tuberculosis en la institución. Resultados: el responsable del programa institucional de control de tuberculosis y 158 trabajadores de la salud del hospital objeto de estudio reportaron una deficiente implementación de medidas de control de tuberculosis, de tipo administrativo, ambiental y de protección respiratoria en la institución, lo cual fue corroborado por el experto. Conclusiones: la deficiente implementación de medidas de control de infección de tuberculosis en instituciones de la salud, y algunas condiciones de trabajo presentes pueden favorecer la exposición ocupacional de los trabajadores de la salud al Mycobacterium Tuberculosis. Abstract Objective: to evaluate the implementation of tuberculosis infection control measures in administrative, environmental and respiratory protection equipment in a third level hospital in Bogota D.C. Methodology: a descriptive, cross-sectional study. Data were collected through a self-reporting instrument applied on 158 health care workers. The chief officer of the institutional program for tuberculosis control participated in a structured interview. In addition, an expert in occupational health and safety conducted an observational visit to the different workplaces in order to inquire on the implementation

  17. Three phase full wave dc motor decoder

    Science.gov (United States)

    Studer, P. A. (Inventor)

    1977-01-01

    A three phase decoder for dc motors is disclosed which employs an extremely simple six transistor circuit to derive six properly phased output signals for fullwave operation of dc motors. Six decoding transistors are coupled at their base-emitter junctions across a resistor network arranged in a delta configuration. Each point of the delta configuration is coupled to one of three position sensors which sense the rotational position of the motor. A second embodiment of the invention is disclosed in which photo-optical isolators are used in place of the decoding transistors.

  18. DCMF: DC & Microformats, a good marriage

    OpenAIRE

    Méndez Rodríguez, Eva María; Siches, Arnau; López, Leandro M.; Bravo, Alejandro G.

    2008-01-01

    This report introduces the Dublin Core Microformats (DCMF) project, a new way to use the DC element set within X/HTML. The DC microformats encode explicit semantic expressions in an X/HTML webpage, by using a specific list of terms for values of the attributes “rev” and “rel” for and elements, and “class” and “id” of other elements. Microformats can be easily processed by user agents and software, enabling a high level of interoperability. These characteristics are crucial for the growing n...

  19. Implementation of hierarchical control in DC microgrids

    DEFF Research Database (Denmark)

    Jin, Chi; Wang, Peng; Xiao, Jianfang

    2014-01-01

    of Technology, Singapore. The coordination control among multiple dc sources and energy storages is implemented using a novel hierarchical control technique. The bus voltage essentially acts as an indicator of supply-demand balance. A wireless control is implemented for the reliable operation of the grid....... A reasonable compromise between the maximum power harvest and effective battery management is further enhanced using the coordination control based on a central energy management system. The feasibility and effectiveness of the proposed control strategies have been tested by a dc microgrid in WERL....

  20. RF and dc desensitized electroexplosive device

    Science.gov (United States)

    Krainiak, John W.; Speaks, Paul D.; Cornett, Michael S.

    1989-07-01

    This patent application relates to electroexplosive devices (EEDs) such as detonators, blasting caps and squibs, in particular to a method and device for desensitizing EEDs to electromagnetic radiation and electrostatic charges with the added ability to desensitize the device to essentially dc currents. An insensitive electroexplosive device to electrically ignite explosive is disclosed. This device is inherently immune to radio frequency (RF) radiation, and also provides protection against dc or very low frequency RF induced by arcing. A central feature is use of zeners and capacitors to form a reactively balanced bridge circuit. When constructed in semiconductor form, as described in this application, the device is capable of incorporation in small caliber ordnance.