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[en] Lead aprons are used in medical facilities to protect workers and patients from unnecessary x-ray radiation exposure from diagnostic radiology procedures. A lead (or lead equivalent) apron is a protective garment which is designed to shield the body from harmful radiation, usually in the context of medical imaging. Both patients and medical personnel utilize lead aprons, which are customized for a wide range of usages. As is the case with many protective garments, it is important to remember that a lead apron is only effective when it is worn properly, matched with the appropriate radiation energy and is used in a safe and regularly inspected environment and also need stored properly. They should not be folded or thrown on the floor since it may produce creases that develop into breaks in the protective barrier. The integrity of lead aprons should be assessed annually. For reasons of weight, lead aprons generally have shielding equivalence equal to a 0.25 to 0.50 mm lead barrier and will only attenuate the radiation. Lead aprons absorb 90 % to 95 % of scattered radiation that reaches them. The main purpose of this study is to determine the radiation attenuation properties of different material lead apron against an X-ray beam in the diagnostic energy range (80 & 100 kVp) by employing an appropriate procedure. The shielding effectiveness of lead aprons was determined by performing simple transmission experiments. The results of evaluation of the effectiveness various type of lead apron with different energy range test will be presented in brief. (author)
[en] The research compares the degree to which four organizations use evaluations to identify outcomes and to improve their practice. The studied organizations (a nonprofit organization (NGO), a federal agency, a local government and a public university) implement natural resource management projects in a terrestrial biosphere reserve of Mexico. Framed in a case study, an analysis of institutional documents was combined with semi-structured interviews to gain access to the information. The NGO has the most appropriate evaluation system to identify compliance with conservation and development objectives. In contrast, the local government completely lacks evaluative procedures.
[en] Male Tettigoniidae emit sound to attract conspecific females. The sound is produced by stridulation. During stridulation the forewings open and close, but it is during the closing stroke that the scraper contacts the file teeth to generate the predominant sound components, which are amplified by adjacent wing cells specialized in sound radiation. The sounds usually exceed the sonic boundary and might occur above 40 kHz, reaching extreme ultrasonic frequencies of 150kHz in some species. Here we test the hypothesis that Tettigoniidae species should prefer microhabitats that favour efficient signal transmission, i.e. that there is a relationship of sound frequency with the vertical distribution of the species (from ground to canopy) at Gorgona National Natural Park, Colombia. We sampled 16 trees and four different altitudinal levels between 1 and 20m above the understory vegetation. We placed collecting blankets separated by vertical distances of 5m, and knocked insects down using the technique known as fogging. We found no correlation between vertical distribution and carrier frequency, but there was a preference for open spaces (below the canopy and above the understory) in species using extreme ultrasound. This is the first quantitative description of the vertical distribution in neotropical species of the family Tettigoniidae and its relationship to the calling song frequency. (author)
[en] The Fundamental Data Unit of the Laboratoire National Henri Becquerel (LNHB) – French national standards laboratory – performs a number of full decay scheme evaluations as part of the Decay Data Evaluation Project (DDEP). Particular attention is paid to the atomic data, with both conversion- and Auger-electron data included, as well as the emitted X-rays. Evaluated data from the LNHB are part of the DDEP, whose current working membership was listed along with the means of access to these data. Recommended DDEP datasets are currently available within seven hardcopy volumes of the Monographie-5 series published by the Bureau International de Poids et Mesures (BIPM), which can also be downloaded free of charge from: https://www.bipm.org/en/publications/scientific-output/monographie-ri-5.html along with volume 8 which was assembled and issued in 2016.
[en] Evaluation of radiation protection shield of X-ray inspection room in a company was carried out, because one new X-ray flaw detection apparatus will be put in. The thickness of all around protecting wall, lead door and inspection window of inspection room was got by flaw detection room shield calculation. Result of contrastive analysis of calculation and physical truth shows that radiation protection safeguard of inspection room conforms to related national regulations and meets addition of one new X-ray flaw detection apparatus radiation protection demand. (authors)
[en] Five approximate models were developed for the mean intraparticle concentration during adsorption and/or diffusion with negligible external resistance (Bi→∞); all of them are more accurate that the reference model of Do and Mayfield (1987). Their simplicity makes them applicable for the design of batch and fixed-bed adsorbers. Three of the models are based on a n-order profile for the intraparticle concentration with a time-dependent exponent n. Other two new models were obtained by analysis and algebraic manipulation of the A (τ) data. Graphical visualization and numerical optimization were used to develop the models and to assess their quality. The selection of a particular model will depend of the required accuracy. The approach described in this work can be applied to more complex models, such as non-linear isotherms, multicomponent adsorption and branched pore structure. (author)
[en] The qualitative analysis of typical image quality assessment images in routine QC tests is subjective and dependent on the type of monitor and viewing conditions. In this study, an image of a phantom of spatial resolution was evaluated by 11 medical physicists of the EBSERH network to determine the variation of results between observers and to compare with a quantitative method of determination of the MTF curve from the phantom bar standards. The results show that the variation between the observers was of up to 5 groups visualized (16 to 21), resulting in values of 2.8 to 4.5 pl / mm. The quantitative method resulted in an MTF value (5%) equal to 3.6 pl / mm. The results show that a quantitative method can be useful to compare with previous results performed by other people or when it is desired to compare responses of similar equipment in different institutions. (author)
[en] Determination of gold sample is something that is quite difficult to deliver in the gold trading market. One of the most popular methods in use is the XRF technique, but this method is only limited to surface testing. Since there are metals like tungsten that are gold-plated and are said to be pure gold, then this fake gold issue must be addressed. The purpose of these studies is to determine the capability of gamma transmission techniques in identifying different purity of gold plate which is very significant in developing a method to investigate counterfeiting. The studies involve irradiation of gold plate through a field of gamma-ray from Ba-133. The intensity of gamma-ray is transmitted through the gold plate and been detected by HPGe detector for analysis and evaluation at different spectrum of gamma energies. The preliminary studies which accomplished in the laboratory employed series of different purity of gold plate and the result of measurements are explained and discussed. (author)
[en] The contaminant attenuation in soils is a complex physical, chemical and biological process, which requires an experimental approach for its understanding. Batch experiments were carried out on samples of andisols taken between August and September 2016 from a coffee plantation in Poas de Alajuela to obtain the kF (mg/L) Freundlich constant and the kFoc normalized constant by 0,12 (mode of the existent organic matter fraction), for the substances (kF-kFoc): ametryn 62 - 517; atrazine 18 - 150; bromacil 5.3 - 44; carbaryl 36 - 300; chlorothalonil 45 - 375; hexazinone 3.2 - 27; simazine 5.2 - 43; and terbutryn 60 - 500. The results indicated that between 75 % and 95 % of the mass of the substances is withdrawn from the supernatant aqueous solution and suggest that these soils could reduce a pollutant mass that drags the recharge water by preventing it from reaching the groundwater. (author)
[es]La atenuacion de contaminantes en suelos es un proceso fisico, quimico y biologico complejo, que requiere un enfoque experimental para su entendimiento. Se hicieron ensayos en lote de muestras de andisoles tomadas entre agosto y septiembre del 2016 en una finca cafetalera en Poas de Alajuela. De ellos se obtuvo la kF constante de Freundlich (mg/L) y la kFoc constante de Freundlich normalizada por 0,12 (moda de la fraccion presente de materia organica), para las sustancias (kF-kFoc): ametrina 62 – 517; atrazina 18 – 150; bromacil 5,3 – 44; carbaril 36 – 300; clorotalonil 45 – 375; hexazinona 3,2 – 27; simazina 5,2 – 43; y terbutrina 60 – 500. Los resultados obtenidos indicaron que entre el 75 % y el 95 % de la masa de las sustancias es retirada de la disolucion acuosa sobrenadante y sugieren que estos suelos podrian reducir una masa contaminante que arrastre el agua de recarga y asi evitar que alcance la zona saturada. (author)
[en] Among the peer review activities accepted by nuclear power plants, there are two types: international peer review and domestic peer review. Internationally, NPPs receive OSART by the IAEA. Interiorly, NPPs receive Peer Review (PR) organized by the China Nuclear Energy Association (CNEA), etc. What similarities and differences between CNEA PR and IAEA OSART, this article carries on the comparative analysis from the CNEA PR and the IAEA OSART evaluation purpose, evaluation scope, evaluation criteria, etc., make two kinds of peer review can play its proper role. (authors)