46 research outputs found
Lesiones en docentes de educaci贸n f铆sica en Catalu帽a: an谩lisis de la percepci贸n ergon贸mica en su puesto de trabajo
Los docentes de educaci贸n f铆sica (EF) se exponen a una serie de riesgos f铆sicos en su puesto de trabajo. Una correcta adecuaci贸n del entorno, m谩quinas y personas favorecer谩n su salud. Comprobar las lesiones que afectan a los docentes de EF de Catalu帽a en su puesto de trabajo, las zonas anat贸micas lesionadas, sus efectos en las bajas laborales, los factores de riesgo y c贸mo puede influenciar la ergonom铆a en el personal docente. Se emple贸 un estudio epidemiol贸gico descriptivo con 769 docentes (hombres: 431; mujeres: 337; 1 N/C), diferenciados por edad, servicio territorial o zona de trabajo de ense帽anza, etapa de ense帽anza, titulaci贸n y n煤mero de horas de dedicaci贸n al centro escolar (jornada laboral). La recogida de datos se hizo conun cuestionario autorellenado. El 43.86% de la muestra sufri贸 alguna vez una lesi贸n en el puesto de trabajo. Las lesiones m谩s comunes son musculares (31.6%) y articulares (21.1%). Las zonas anat贸micas m谩s afectadas fueron: rodilla (18.65%), espalda (18.35%) y tobillo (14.98%). La temperatura (12.8%) y el ruido (12.5%) eran los elementos peor valorados, junto con el reconocimiento del 谩rea de EF (12.5%). El 67.23% de los docentes de EF no ten铆a ninguna formaci贸n en prevenci贸n de lesiones, h谩bitos posturales y ergonom铆a en el puesto de trabajo y el 89.46% considerar铆a interesante una futura formaci贸n. Ser铆a interesante proponer cursos de rehabilitaci贸n para docentes de EF, como ya se hace en otros pa铆ses, y m谩s formaci贸n en prevenci贸n de lesiones, factores de riesgo y ergonom铆a en el puesto de trabajo para garantizar una mejor salud de estos docente
Lesions en docents d鈥檈ducaci贸 f铆sica a Catalunya: an脿lisi de la percepci贸 ergon貌mica al seu lloc de treball
Els docents d鈥檈ducaci贸 f铆sica (EF) s鈥檈xposen a una s猫rie de riscos f铆sics al seu lloc de treball. Una correcta adequaci贸 de l鈥檈ntorn, m脿quines i persones afavoriran la seva salut. Comprovar les lesions que afecten els docents d鈥橢F de Catalunya al seu lloc de treball, les zones anat貌miques lesionades, els seus efectes en les baixes laborals, els factors de risc i com l鈥檈rgonomia pot influir en el personal docent. Es va emprar un estudi epidemiol貌gic descriptiu amb 769 docents (homes = 431; dones = 337; 1 N/C), diferenciats per edat, servei territorial o zona de treball d鈥檈nsenyament, etapa d鈥檈nsenyament, titulaci贸 i nombre d鈥檋ores de dedicaci贸 al centre escolar (jornada laboral). La recollida de dades es va fer amb un q眉estionari autoemplenat. El 43.86% de la mostra va patir alguna vegada una lesi贸 al lloc de treball. Les lesions m茅s comunes s贸n musculars (31.6%) i articulars (21.1%). Les zones anat貌miques m茅s afectades van ser: genoll (18.65%), esquena (18.35%) i turmell (14.98%). La temperatura (12.8%) i el soroll (12.5%) eren els elements pitjor valorats, juntament amb el reconeixement de l鈥櫭爎ea d鈥橢F (12.5%). El 67.23% dels docents d鈥橢F no tenia cap formaci贸en prevenci贸 de lesions, h脿bits posturals i ergonomia al lloc de treball i el 89.46% consideraria interessant una formaci贸 futura. Seria interessant proposar cursos de rehabilitaci贸 per a docents d鈥橢F, com ja es fa en altres pa茂sos, i m茅s formaci贸 en prevenci贸 de lesions, factors de risc i ergonomia al lloc de treball per garantir una millor salut d鈥檃quests docents
Atmospheric correction algorithm for POLDER data. Case study: DAISEX 1999 campaign
RESUMEN Este art铆culo presenta un algoritmo para corregir los efectos de la atm贸sfera de la reflectividad multiangulare hiperespectral de POLDER, prestando especial atenci贸n al efecto de los aerosoles. Los datos fueron adquiridos durante la campa帽a DAISEX-99 de la Agencia Espacial Europea. El algoritmo est谩 basado en la inversi贸n de la reflectividad medida en dos pasos. Primero, se invierte la reflectividad de POLDER para determinar los tres par谩metros de la funci贸n de distribuci贸n de la reflectividad bidireccional de la superficie (BRDF). Estos valores son los datos de entrada de la superficie para el segundo paso. En este segundo paso, invertimos de nuevo la reflectividad para obtener tres par谩metros de la superficie y cuatro par谩metros de los aerosoles para localidades rurales y cinco en el resto. Los par谩metros de los aerosoles son la densidad de part铆culas de los componentes b谩sicos de los aerosoles: insoluble en agua, soluble en agua, holl铆n, sales marina es modo de acumulaci贸n y sales marinas en modo grueso. Por tanto, la salida del algoritmo es el contenido de varios componentes b谩sicos y los par谩metros del modelo de BRDF. Aplicando la teor铆a de dispersi贸n de Mie hemos obtenido el espesor 贸ptico de los aerosoles (AOD) y comparado el resultado con los valores determinados a partir de medidas de extinci贸n de la radiaci贸n solar a nivel del suelo. Se ha obtenido como condici贸n de contorno para la inversi贸n la informaci贸n disponible sobre los aerosoles obtenida a partir de las retrotrayectorias de las masas de aire. Utilizando esta informaci贸n mostramos que los valores del AOD est谩n m谩s pr贸ximos a la medida y que por tanto el funcionamiento del algoritmo es mejor. ABSTRACT This paper presents an algorithm to correct the effects of the atmosphere of POLDER hyperspectral and multiangular reflectance, paying particular emphasis to the aerosol effect. The data were acquired during the European Space Agency campaign DAISEX-99. The algorithm is based on the inversion of measured reflectance in two steps. First, we invert the POLDER reflectances to determine the three parameters of a bidirectional reflectance distribution function (BRDF) of the surface. These values are the first guess of the surface parameters for the second step. In the second step, we invert again the reflectance to obtain three surface parameters and four aerosol variables, in rural sites, and five variables in the rest. The aerosol variables are the particle density of the basic aerosol components: water-insoluble, water soluble and soot particles, sea-salt in accumulation mode and sea-salt in coarse mode. Thus, the algorithm output is the content of some aerosol basic components and the BRDF parameters of the surface. Applying the Mie scattering theory we have obtained the aerosol optical depth (AOD) of the retrieved aerosols and compared it with the values obtained from ground-based solar irradiance extinction measurements. The available information about the aerosols coming from airmass backtrajectories and isobaric maps provides a boundary condition for the inversion. Using this information we show that the AOD values are closer to the measured values and thus the performance of the algorithm is better. icon
A new approach for characterizing atmospheric aerosols from spectral values of their optical depth. A simulated case study.
We are developing a new method to determine the spectral contribution to the aerosol optical depth due to each aerosol type. An aerosol type depends directly on the procedence of the particles (marine, continental, artic, etc) and it is formed by some different pure components (mineral, soot, soluble and insoluble particles, sulphate, etc). In order to separate these contributions it is necessary to have the spectral aerosol optical thickness and aerosol size distribution. We use this distribution function to identify the different components of aerosols allowing us to reconstruct the aerosol optical depth taking into account the contribution of each type of aerosol. The validation of the method will be carried out by verifying that the spectral aerosol optical depth corresponds to the sum of the optical depths obtained for each identified aerosol type
Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range
An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectroradiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330-1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth
A comparison of Microtops II and satellite ozone measurements in the period 2001-2011
Daily average total ozone Microtops measurements obtained during several campaigns conducted from 2001 to 2011 at latitudes from 31 to 68掳N and in different seasons are compared with satellite observations. The Microtops ozone is derived using different wavelength combinations (Channel I, 305.5/312.5 nm; Channel II, 312.5/320 nm; and Channel III, 305.5/312.5/320 nm). Satellite data from TOMS, OMI, GOME, and GOME-2 are used in the comparison. The three Microtops channels show a high correlation with the satellite retrievals. Channel I shows the best results and produces a mean bias deviation (MBD) less than 2.14% with respect to TOMS, OMI and GOME. The MBD increases to 3% in the comparison against GOME-2, due to the small number of available data. In addition, the total ozone content provided by Channel I displays the more stable behavior during the ten-year period. The Channel III total ozone shows MBD values smaller than those observed for Channel I. However the Channels II and III present a larger variability and show a larger spread of the data. Consequently, Channel I appears as the best option for long term measurements with Microtops
Synthesis and structure of complexes of acyl N-aminides with zinc(II) salts
The structures of complexes obtained by reacting acyl N-aminides and ZnCl2 were ascertained by X-ray analysis and were show to incorporate one Zn atom and two molecules of the N-aminide in a distorted tetrahedral geometry. Bis-aminides act as bidentate ligands forming ZnLCl2 complexes.The authors acknowledge the Comisi贸 lnterdepartamental de Recer蟼a i lnnovaci贸 Tecnologica (CIRIT, project QFN94-4619) for financial support and the Ministerio de Educaci贸n y Ciencia for a studentship (MAH.
1-(Benzoylamino)-3-methylimidazolium chlorochromate (BAMICC), a new selective and mild reagent for the oxidation of allylic and benzylic alcohols
A new mild chromium(VI) oxidizing reagent, the 1-(benzoylamino)-3-methylimidazolium chlorochromate (BAMICC) has been prepared as a stable yellow-orange solid which selectively oxidizes allylic and benzylic alcohols, including those bearing basic nitrogens, to carbonyl compounds.The authors are grateful for a grant (MAH) received from Ministerio de Educaci贸n y Ciencia and for financial support from Comisi贸n lnterministerial de Ciencia y Tecnolog铆a (CICYT, project PB90-0284
Operational considerations to improve total ozone measurements with a Microtops II ozone monitor
A Microtops II 'ozone monitor' with UV channels centered at 305.5, 312.5, and 320 nm has been used routinely in six experimental campaigns carried out in several geographic locations and seasons, covering latitudes from 35 to 68掳 N during the last ten years (2001-2011). The total ozone content is retrieved by Microtops II by using different combinations (Channel I, 305.5/312.5 nm; Channel II, 312.5/320 nm; and Channel III, 305.5/312.5/320 nm) of the signals at the three ultraviolet wavelengths. The long-term performance of the total ozone content determination has been studied taking into account the sensitivities to the calibration, airmass, temperature and aerosols. When a calibration was used and the airmass limit was fixed to 3, the root mean square deviations of the relative differences produced by Microtops II with respect to several Brewers are 0.9, 2, and 2% respectively for the Channel I, Channel II, and Channel III retrieval. The performance of the Microtops retrieval has been stable during the last ten years. Channel I represents the best option to determine the instantaneous total ozone content. Channels II and III values appear weakly sensitive to temperature, ozone content, and aerosols. Channel II is more stable than Channel I for airmasses larger than 2.6. The conclusions do not show any dependence on latitude and season