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Sample records for tributyl phosphate-methyl-isobutyl-ketone metodos

  1. Solvent. I. Extraction systems applied to uranium analysis. I. Extraction studies with Tributyl phosphate-Methyl-isobutyl-ketone; Metodos de extraccion don disolventes aplicados al analisis quimico del uranio. I. Estudio de la extraccion con fosfato de tributilo-metilisobutilcetano

    Energy Technology Data Exchange (ETDEWEB)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement Eguiluz, J. C.

    1964-07-01

    A factorial study of the selective extraction of uranium with a mixture of TBP-MIC was carried out using 0,8 N nitric acid and different salting agents. We use the most suitable salting agent to develop new factorial experiments in order to get an equation involving the percent of extracted uranium, E, the concentration of the extraction agent in the organic phase, c, and the concentration of the slating agent in the aqueous phase, n. (Author) 3 refs.

  2. Solvent. I. Extraction systems applied to uranium analysis. I. Extraction studies with Tributyl phosphate-Methyl-isobutyl-ketone

    International Nuclear Information System (INIS)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement Eguiluz, J. C.

    1964-01-01

    A factorial study of the selective extraction of uranium with a mixture of TBP-MIC was carried out using 0,8 N nitric acid and different salting agents. We use the most suitable salting agent to develop new factorial experiments in order to get an equation involving the percent of extracted uranium, E, the concentration of the extraction agent in the organic phase, c, and the concentration of the slating agent in the aqueous phase, n. (Author) 3 refs

  3. Methods of Uranium Determination in solutions of Tributyl Phosphate and Kerosene; Metodos de determinacion de uranio en soluciones de fosfato de tributilo y queroseno

    Energy Technology Data Exchange (ETDEWEB)

    Petrement Eguiluz, J.; Palomares Delgado, F.

    1962-07-01

    A new analytical method for the determination of uranium in organic solutions of tributyl phosphate and kerosene is proposed. In this method the uranium is reectracted from the aqueous phase by reduction with cadmium in acid solution. The uranium can be determined in this solution by the usual methods. In case of very diluted solutions, a direct spectrophtometrical determination of uranium in the organic phase with dibenzoylmethane is proposed. (Author) 21 refs.

  4. Titrimetric determination of uranium in tributyl phosphate

    International Nuclear Information System (INIS)

    Sobkowska, A.

    1978-01-01

    The titrimetric method involving the reduction of U(VI) to uranium(IV) by iron(II) in phosphoric acid, selective oxidation of the excess of iron(II) and potentiometric titration with dichromate was directly used for the determination of uranium in tributyl phosphate mixtures. The procedure was applied to solutions containing more than 2 mg of uranium in the sample but the highest precision and accuracy were obtained in the range from 20 to 200 mg of uranium. Dibutyl phosphate and monobutyl phosphate as well as the other radiolysis products of TBP had no influence on the results of determinations. (author)

  5. Thermal Decomposition of Nitrated Tributyl Phosphate

    International Nuclear Information System (INIS)

    Paddleford, D.F.; Hou, Y.; Barefield, E.K.; Tedder, D.W.; Abdel-Khalik, S.I.

    1995-01-01

    Contact between tributyl phosphate and aqueous solutions of nitric acid and/or heavy metal nitrate salts at elevated temperatures can lead to exothermic reactions of explosive violence. Even though such operations have been routinely performed safely for decades as an intrinsic part of the Purex separation processes, several so-called ''red oil'' explosions are known to have occurred in the United States, Canada, and the former Soviet Union. The most recent red oil explosion occurred at the Tomsk-7 separations facility in Siberia, in April 1993. That explosion destroyed part of the unreinforced masonry walls of the canyon-type building in which the process was housed, and allowed the release of a significant quantity of radioactive material

  6. Investigation of tributyl phosphate hydrolysis in polymer matrix

    International Nuclear Information System (INIS)

    Sokal'skaya, L.I.; Yakshin, V.V.; Filippov, E.A.

    1978-01-01

    Hydrolytic stability of tributyl phosphate to 2 N nitric acid solutions at a temperature of 96 +- 0.5 deg C has been investigated. Tributyl phosphate has been put into a styrene - divinylbenzene matrix. By using the method of potentiometric titration in an anhydrous medium the following has been shown: the quantity of dibutylphosphoric acid that has been formed in the process of hydrolysis of tributylphosphate put into a polymeric matrix is two times smaller than that formed in the process of hydrolysis of pure tributylphosphate under the same conditions. The solubility of tributylphosphate put into a polymer matrix of 240 mg/l in distilled water and of 150 mg/l tributylphosphate in a sodaalkaline solution has been determined

  7. Study of the tributyl phosphate - 30% dodecane solvent

    International Nuclear Information System (INIS)

    Leroy, P.

    1967-01-01

    This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [fr

  8. Redox reactions of neptunium in tributyl phosphate-dodecane mixtures

    International Nuclear Information System (INIS)

    Wehrey, F.

    1989-01-01

    In relation with the reprocessing of irradiated fuels, disproportionation and oxidation by nitric acid of pentavalent neptunium in tributyl phosphate-dodecane mixtures have been studied. The experimental part of this work is based on spectrophotometric measurements. The disproportionation of pentavalent neptunium in organic perchloric medium is a second order reaction with respect to neptunium V. The reaction rate is strongly influenced by the perchloric acid concentration and has a higher value than in an aqueous medium. The reverse reaction in nitric media is a first order with respect to tetravalent and hexavalent ions. The reaction rate is a function of the reverse of the square of the nitric acid concentration. The energy of activation is the same than in aqueous medium. The oxidation rate of pentavalent neptunium by nitric acid is increased by nitrous acid. When no nitrous acid is added to the mixture, the reaction revealed to be autocatalytic, possesses an induction period. When nitrous and nitric acids are in excess to neptunium the reaction is first order with respect to neptunium. The reaction rate depends on the concentration of nitric acid and is a linear function of the concentration of nitrous acid. In tributyl phosphate dodecane mixtures the reaction occurs spontaneously. It is not the case in aqueous media. The values of thermodynamical and kinetical constants determined in this work could be used in a modelization of the behavior of neptunium in the reprocessing of irradiated fuels, which has to eliminate this element among its tasks [fr

  9. The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels

    International Nuclear Information System (INIS)

    Barney, G.S.; Cooper, T.D.

    1994-01-01

    Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125 degrees C and 250 degrees C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110 degrees C to 270 degrees C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252 degrees C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant

  10. The chemistry of tributyl phosphate at elevated temperatures in the Plutonium Finishing Plant Process Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Barney, G.S.; Cooper, T.D.

    1994-06-01

    Potentially violent chemical reactions of the tributyl phosphate solvent used by the Plutonium Finishing Plant at the Hanford Site were investigated. There is a small probability that a significant quantity of this solvent could be accidental transferred to heated process vessels and react there with nitric acid or plutonium nitrate also present in the solvent extraction process. The results of laboratory studies of the reactions show that exothermic oxidation of tributyl phosphate by either nitric acid or actinide nitrates is slow at temperatures expected in the heated vessels. Less than four percent of the tributyl phosphate will be oxidized in these vented vessels at temperatures between 125{degrees}C and 250{degrees}C because the oxidant will be lost from the vessels by vaporization or decomposition before the tributyl phosphate can be extensively oxidized. The net amounts of heat generated by oxidation with concentrated nitric acid and with thorium nitrate (a stand-in for plutonium nitrate) were determined to be about -150 and -220 joules per gram of tributyl phosphate initially present, respectively. This is not enough heat to cause violent reactions in the vessels. Pyrolysis of the tributyl phosphate occurred in these mixtures at temperatures of 110{degrees}C to 270{degrees}C and produced mainly 1-butene gas, water, and pyrophosphoric acid. Butene gas generation is slow at expected process vessel temperatures, but the rate is faster at higher temperatures. At 252{degrees}C the rate of butene gas generated was 0.33 g butene/min/g of tributyl phosphate present. The measured heat absorbed by the pyrolysis reaction was 228 J/g of tributyl phosphate initially present (or 14.5 kcal/mole of tributyl phosphate). Release of flammable butene gas into process areas where it could ignite appears to be the most serious safety consideration for the Plutonium Finishing Plant.

  11. Non-phosphate degradation products of tributyl phosphate

    International Nuclear Information System (INIS)

    Tashiro, Y.; Kodama, R.; Sugai, H.

    1995-01-01

    Tributyl phosphate(TBP) was compulsively degraded with nitric acid and/or uranium nitrate at elevated temperature around 105 degrees C. Experimental results indicates major non-phosphate degradation products are butyl nitrate (C 4 H 9 NO 3 ), propionic acid (C 2 H 5 COOH), acetic acid (CH 3 COOH), butyric acid (C 3 H 7 COOH) and butyl alcohol (C 4 H 9 OH) in ascending order of quantity. Degrading rate in uranium free system is less than that in uranium coexisting system. Carboxylic acids were not produced in uranium free system, and only acetic acid was identified in case of without supplying nitric acid from aqueous phase. Moreover, from the experimental study on the reactivity of each non-phosphate product with nitric acid, carboxylic acids were identified as byproducts of butyl alcohol and butyl nitrate, and each carboxylic acid was stable in these degrading conditions. Finally, butyl alcohol is considered as one of intermediate products to butyl nitrate and carboxylic acids. From this study, the non-phosphate degradation products of TBP is identified and the degrading reaction pass is proposed. Extraction behavior of each non-phosphate product and reactivity of degraded TBP are also elucidated

  12. Synthesis of tributyl citrate using SO 4 2- /Zr-MCM-41 as catalyst ...

    African Journals Online (AJOL)

    Zirconium-containing mesoporous molecular sieve SO42-/Zr-MCM-41 was synthesized for catalyst in synthesis of tributyl citrate. The structure was characterized by XRD, N2 Ad/De isotherms and FT-IR. The results indicated that the solid acids show good catalytic performance and are reusable. Under optimum conditions ...

  13. Synthesis of tributyl citrate using SO42-/Zr-MCM-41 as catalyst

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    Zheng Zhifeng

    2011-04-01

    Full Text Available Zirconium-containing mesoporous molecular sieve SO42-/Zr-MCM-41 was synthesized for catalyst in synthesis of tributyl citrate. The structure was characterized by XRD, N2 Ad/De isotherms and FT-IR. The results indicated that the solid acids show good catalytic performance and are reusable. Under optimum conditions and using SO42-/Zr-MCM-41 as catalyst, the conversion of citric acid was 95%. After easy separation of the products from the solid acid catalyst, it could be reused three times and gave a conversion of citric acid not less than 92%. The structure of tributyl citrate was characterized by FT-IR and 1H-NMR.

  14. Methods of Uranium Determination in solutions of Tributyl Phosphate and Kerosene

    International Nuclear Information System (INIS)

    Petrement Eguiluz, J.; Palomares Delgado, F.

    1962-01-01

    A new analytical method for the determination of uranium in organic solutions of tributyl phosphate and kerosene is proposed. In this method the uranium is reextracted from the aqueous phase by reduction with cadmium in acid solution. The uranium can be determined in this solution by the usual methods. In case of very diluted solutions, a direct spectrophtometrical determination of uranium in the organic phase with dibenzoylmethane is proposed. (Author) 21 refs

  15. Stima dell’effetto delle esternalità localizzative sui valori immobiliari tramite il metodo Delphi

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    Boaz Barzilay

    2012-12-01

    Full Text Available Il metodo Delphi è un metodo per raccogliere e strutturare indicazioni provenienti da un gruppo di esperti, utilizzando un questionario combinato con un feedback controllato delle opinioni. Il presente contributo esamina i principi fondamentali del metodo Delphi e tenta di convalidare i suoi risultati, utilizzando dati ottenuti mediante le normali tecniche econometriche di valutazione immobiliare, come, ad esempio, il metodo del prezzo edonico. Il metodo Delphi, come sosteniamo, può diventare uno strumento utile per la valutazione immobiliare in casi particolari, come i piccoli comuni con vendite di abitazioni relativamente scarse ed economie di transizione caratterizzate da mercati immobiliari in via di sviluppo.

  16. Experimental study on thermal hazard of tributyl phosphate-nitric acid mixtures using micro calorimeter technique

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qi; Jiang, Lin; Gong, Liang; Sun, Jin-Hua, E-mail: sunjh@ustc.edu.cn

    2016-08-15

    Highlights: • Heat flows after mixing TBP with nitric acid are of different orders of magnitude. • Thermodynamics and kinetics of tributyl phosphate-nitric acid mixtures are derived. • Tributyl phosphate directly reacts with nitric acid and form organic red oil. • Thermal runaway could occur at 79 °C with a high nitric acid concentration. - Abstract: During PUREX spent nuclear fuel reprocessing, mixture of tributyl phosphate (TBP) and hydrocarbon solvent are employed as organic solvent to extract uranium in consideration of radiation contaminated safety and resource recycling, meanwhile nitric acid is utilized to dissolve the spent fuel into small pieces. However, once TBP contacts with nitric acid or nitrates above 130 °C, a heavy “red oil” layer would occur accompanied by thermal runaway reactions, even caused several nuclear safety accident. Considering nitric acid volatility and weak exothermic detection, C80 micro calorimeter technique was used in this study to investigate thermal decomposition of TBP mixed with nitric acid. Results show that the concentration of nitric acid greatly influences thermal hazard of the system by direct reactions. Even with a low heating rate, if the concentration of nitric acid increases due to evaporation of water or improper operations, thermal runaway in the closed system could start at a low temperature.

  17. Chemistry of extractable nitrosyl ruthenium species in the system nitric acid-tributyl phosphate-dodecane

    International Nuclear Information System (INIS)

    Maya, L.

    1981-01-01

    Fission product ruthenium is present in solutions resulting from the dissolution of spent nuclear fuel in the form of nitro and nitrato complexes of nitrosyl ruthenium. A fraction of the ruthenium, mostly higher nitrato complexes, is extracted into the organic solvent phase in the Purex process. Stripping tests reveal a component in the solvent phase that cannot be readily transferred to the aqueous phase. Experiments were performed to determine whether the retained fraction is a highly extractable species originally present in the aqueous phase or if it is the product of a reaction between the extracted species and the solvent. A chromatographic procedure was developed to separate the species in the aqueous phase. This revealed a species more extractable than the tetranitrato complex; however, since the separation process involved TBP, the ambiguity regarding the origin of this species could not be resolved. On the other hand, in a separate series of experiments evidence was found showing that the retained species result from a reversible reaction in the solvent phase. The equilibrium concentration of this species is dependent on the temperature and the tributyl phosphate activity. This complex apparently results from the substitution of aquo ligands in the extracted species by tributyl phosphate. (author)

  18. Cleanup of 7.5% tributyl phosphate/n-paraffin solvent-extraction solvent

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-02-01

    The HM process at the Savannah River Plant uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials which influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands which hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM process first cycle solvent is discussed

  19. Uranium Rirang ore processing: extraction of uranium from Rirang ore digestion solution with tributyl phosphate

    International Nuclear Information System (INIS)

    Arief, E. R.; Zahardi; Susilaningtyas

    1998-01-01

    Uranium is extracted from Rirang ore acid digestion solution containing rare earths. A mixture of tributyl phosphate solvent and kerosene diluent is employed. Several parameters of solvent extraction have been studied included aqueous to organic phase ratio, H 2 O 2 reductor concentration and Tbp concentration in the solvent mixture, as well as the aqueous to organic phase ratio in the stripping process. The optimum conditions for the extraction step include the use of 25% H 2 O 2 (v/v), one to one aqueous to organic ratio, and 40% Tbp in kerosene. The extraction recovery for U, RE, Th, and PO 4 3 - are 99%, 4%, 70%, and 30%, respectively. The stripping step optimum conditions include the use of one to five organic to aqueous phase ratio 0.24 N HNO 3 . and the stripping recovery for U, RE, Th, and PO 4 3 - are 84%, 80%, 72%, and 83%, respectively

  20. Effect of alkaline earth metal and magnesium cations on cadmium extraction from chloride solutions by tributyl phosphate

    International Nuclear Information System (INIS)

    Prokuev, V.A.; Belousov, E.A.

    1985-01-01

    At 298 K thermodynamic constants of cadmium (2) extraction from chloride solutions of magnesium, calcium, strontium and barium by tributyl phosphate are calculated. It is established, that logarithm of the thermodynamic extraction constant is in a linear dependence from the change in the cation hydration enthalpy in agqueous solution. It is shown, that activity coefficient of neutral complex CdVCl 2 differs from one, and it is the higher the more stable the complex is in alkaline earth metal chloride solutions

  1. Criticality parameters for uranyl nitrate or plutonium nitrate systems in tributyl phosphate/kerosine and water

    International Nuclear Information System (INIS)

    Weber, W.

    1985-01-01

    This report presents the calculated values of smallest critical masses and volumina and neutron physical parameters for uranyl nitrate (3, 4, 5% U-235) or plutonium nitrate (5% Pu-240), each in a 30 per cent solution of tributyl phosphate (TBP)/kerosine. For the corresponding nitrate-water solutions, newly calculated results are presented together with a revised solution density model. A comparison of the data shows to what extent the criticality of nitrate-TBP/kerosine systems can be assessed on the basis of nitrate-water parameters, revealing that such data can be applied to uranyl nitrate/water systems, taking into account that the smallest critical mass of uranyl nitrate-TBP/kerosine systems, up to a 5 p.c. U-235 enrichment, is by 4.5 p.c. at the most smaller than that of UNH-water solutions. Plutonium nitrate (5% Pu-240) in the TBP/kerosine solution will have a smallest critical mass of up to 7 p.c. smaller, as compared with the water data. The suitability of the computing methods and cross-sections used is verified by recalculating experiments carried out to determine the lowest critical enrichment of uranyl nitrate. The calculated results are well in agreement with experimental data. The lowest critical enrichment is calculated to be 2.10 p.c. in the isotope U-235. (orig.) [de

  2. Characterization, Leaching, and Filtration Testing for Tributyl Phosphate (TBP, Group 7) Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Matthew K.; Billing, Justin M.; Blanchard, David L.; Buck, Edgar C.; Casella, Amanda J.; Casella, Andrew M.; Crum, J. V.; Daniel, Richard C.; Draper, Kathryn E.; Fiskum, Sandra K.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Snow, Lanee A.; Swoboda, Robert G.

    2009-03-09

    .A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. The tributyl phosphate sludge (TBP, Group 7) is the subject of this report. The Group 7 waste was anticipated to be high in phosphorus as well as aluminum in the form of gibbsite. Both are believed to exist in sufficient quantities in the Group 7 waste to address leaching behavior. Thus, the focus of the Group 7 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467.

  3. Emulsions stabilized by precipitates of zirconium and tributyl phosphate degradation products

    International Nuclear Information System (INIS)

    Sugai, H.; Munakata, K.; Miyachi, S.; Yasu, S.

    1992-01-01

    In the Purex process, a solvent extraction method of nuclear fuel reprocessing, a stable emulsion called crud forms at the interface between the oil and water phases. This paper reports that crud is an emulsion stabilized by finely dispersed solids. Insoluble residues and precipitates of zirconium and radiation-degraded products of tributyl phosphate (TBP) are key materials in crud formation. Cruds formed by precipitates of zirconium and TBP degradation products, such as di-n-butyl phosphate (HDBP), mono-n-butyl phosphate (H 2 MBP), and phosphoric acid (H 3 PO 4 ) are studied. Experimental results show that the precipitate of zirconium and HDBP is not effective in stabilizing emulsions. However, the refractory complex of zirconium and H 3 PO 4 is an important material for stabilizing an oil-in-water emulsion in a solution with or without uranium. Moreover, it is shown that the complex of zirconium and H 2 MBP has a significant role in stabilizing a water-in-oil emulsion, especially when uranium is also present

  4. Tributyl phosphate removal from reprocessing off-gas streams using a selected sorbent

    International Nuclear Information System (INIS)

    Parker, G.B.

    1980-01-01

    Laboratory experiments used small laboratory-scale columns packed with selected sorbent materials to remove tributyl phosphate (TBP) and iodine at conditions approaching those in actual reprocessing off-gas streams. The sorbent materials for TBP removal were placed upstream of iodine sorbent materials to protect the iodine sorbent from the deleterious effects of TBP. Methyl iodide in an airstream containing 30% TBP in normal paraffin hydrocarbons (NPH) and water vapor was metered to two packed columns of sorbents simultaneously (in parallel). One column contained a segment of 8-in. x 14-in. mesh alumina sorbent for TBP removal, the other did not. The measure of the effectiveness of TBP sorbent materials for TBP removal was determined by comparing the iodine retention of the iodine sorbent materials in the two parallel columns. Results from an 18 wt % Ag substituted mordenite iodine sorbent indicated that the iodine retention capacity of the sorbent was reduced 60% by the TBP and that the column containing iodine sorbent material protected by the alumina TBP sorbent retained 30 times more iodine than the column without TBP sorbent. TBP concentration was up to 500 mg/m 3 . Similar experiments using a 7 wt % Ag impregnated silica gel indicated that the TBP vapor had little effect on the iodine retention of the silica gel material. The stoichiometric maximum amount of iodine was retained by the silica gel material. Further experiments were conducted assessing the effects of NO 2 on iodine retention of this 7 wt % Ag sorbent. After the two columns were loaded with iodine in the presence of TBP (in NPH), one column was subjected to 2 vol % NO 2 in air. From visual comparison of the two columns, it appeared that the NO 2 regenerated the silica gel iodine sorbent and that iodine was washed off the silica gel iodine sorbent leaving the sorbent in the original state

  5. Extraction of lithium from salt lake brine using room temperature ionic liquid in tributyl phosphate

    International Nuclear Information System (INIS)

    Shi, Chenglong; Jia, Yongzhong; Zhang, Chao; Liu, Hong; Jing, Yan

    2015-01-01

    Highlights: • We proposed a new system for Li recovery from salt lake brine by extraction using an ionic liquid. • Cation exchange was proposed to be the mechanism of extraction followed in ionic liquid. • This ionic liquid system shown considerable extraction ability for lithium and the single extraction efficiency of lithium reached 87.28% under the optimal conditions. - Abstract: Lithium is known as the energy metal and it is a key raw material for preparing lithium isotopes which have important applications in nuclear energy source. In this work, a typical room temperature ionic liquid (RTILs), 1-butyl-3-methyl-imidazolium hexafluorophosphate ([C 4 mim][PF 6 ]), was used as an alternative solvent to study liquid/liquid extraction of lithium from salt lake brine. In this system, the ionic liquid, NaClO 4 and tributyl phosphate (TBP) were used as extraction medium, co-extraction reagent and extractant respectively. The effects of solution pH value, phase ratio, ClO 4 − amount and other factors on lithium extraction efficiency had been investigated. Optimal extraction conditions of this system include the ratio of TBP/IL at 4/1 (v/v), O/A at 2:1, n(ClO 4 − )/n(Li + ) at 2:1, the equilibration time of 10 min and unadjusted pH. Under the optimal conditions, the single extraction efficiency of lithium was 87.28% which was much higher than the conventional extraction system. Total extraction efficiency of 99.12% was obtained by triple-stage countercurrent extraction. Study on the mechanism revealed that the use of ionic liquid increased the extraction yield of lithium through cation exchange in this system. Preliminary results indicated that the use of [C 4 mim][PF 6 ] as an alternate solvent to replace traditional organic solvents (VOCs) in liquid/liquid extraction was very promising

  6. LE «SOTTIGLIEZZE DI CERTA DIDATTICA SUPERLATIVA» DELLA GRAMMATICA ELEMENTARE: STORIA (ATTESTATA DEL METODO RAFFORZISTA (1814-1914

    Directory of Open Access Journals (Sweden)

    Michela Dota

    2018-03-01

    Full Text Available Il contributo ripercorre la storia e le peculiarità del metodo rafforzista, metodo glottodidattico per l’insegnamento della lettura e della scrittura. Il metodo, nato in Italia nel primo Ottocento, nell’epoca postunitaria era praticato nelle scuole elementari soprattutto dell’Italia meridionale, nonché nelle scuole reggimentali e in alcuni istituti per sordomuti. Le sue fondamenta, aberranti rispetto alla norma ortografica e ortoepica tradizionale, lo resero obiettivo di un tenace ostracismo da parte del Ministero dell’Istruzione pubblica, sostenuto per questa occasione da due tra i più eminenti glottologi dell’epoca: Graziadio Isaia Ascoli e Francesco Lorenzo Pullè. Il metodo finì per estinguersi nel secondo decennio del Novecento.   The history of the “metodo rafforzista” for teaching Italian (1814-1914 This article retraces the history and peculiarities of the “metodo rafforzista”, a language teaching method developed in Italy during the first part of 1800s. In the post-Unitarian period, it was used in elementary schools, especially in Southern Italy, and also in military schools and in some institutes for the Deaf and Dumb. Orthographic and orthoepic models proposed by the “metodo rafforzista” diverged from rules of traditional Italian grammar. The method, supported by Graziadio Isaia Ascoli and Francesco Lorenzo Pullè, two of the most distinguished Italian linguists at that time, was subsequently rejected by the Ministry of Public Education, and it vanished during the second half of 1900s.

  7. Stratification in ternary liquid systems tetradecane - n-octanol (cyclohexanone) - solvates of lanthanide(III) nitrates with tributyl phosphate

    International Nuclear Information System (INIS)

    Pyartman, A.K.; Kudrova, A.V.; Keskinov, V.A.

    2001-01-01

    State diagrams of ternary liquid systems tetradecane - n-octanol (cyclohexanone) - solvates of lanthanide(III) nitrates with tributyl phosphate {[Ln(NO 3 ) 3 (TBP) 3 ], Ln=La, Ce, Pr, Sm} at 298.15 K are studied. State diagrams of ternary systems consist of homogeneous solution regions and region of stratification into two liquid phases (I, II). The phase I is enriched by tetradecane, the phase II is enriched by [Ln(NO 3 ) 3 (TBP) 3 ]. Distribution of components between I and II phases is studied in conditions of stratification. It is shown that in conditions of stratification of organic phase into two ones n-octanol (cyclohexanone) and [Ln(NO 3 ) 3 (TBP) 3 ] go mainly into phase II, and C 14 H 30 - into phase I [ru

  8. Thin-layer chromatographic separation and determination of dibutylphosphoric acid in a mixture of monobutylphosphoric acid and tributyl phosphate

    International Nuclear Information System (INIS)

    Tripathi, S.C.; Ramanujam, A.; Nadkarni, M.N.; Bandyopadhyay, C.

    1986-01-01

    A thin-layer chromatographic (TLC) technique using a silica gel-cellulose plate has been developed for the separation of a mixture of monobutylphosphoric acid (H 2 MBP), dibutylphosphoric acid (HDBP) and tributyl phosphate (TBP) and for the determination of HDBP. The technique involves initial separation on a TLC plate followed by the determination of isolated HDBP by an indirect spectrophotometric method whereby the concentration of HDBP is measured by its ability to reduce the colour intensity of a thorium-thoron complex at 545 nm. Less than 1 μg of H 2 MBP and HDBP can be detected on the TLC plate. The method is suitable for the determination of 40 to 260 μg of HDBP. (author)

  9. GIUSEPPE DE ROSA, Metodo per pianisti accompagnatori della danza, Milano, Suvini Zerboni, 2010

    Directory of Open Access Journals (Sweden)

    Chiara Sintoni

    2014-12-01

    Full Text Available Il volume di Giuseppe De Rosa è al contempo un agile metodo teorico-pratico per la formazione del pianista accompagnatore della danza classica e un sussidio didattico per la sua attività in situazione. Frutto dell’esperienza pluriennale dell’autore, colma un vuoto nella pubblicistica italiana dedicata all’argomento.

  10. Impact of a short-term exposure to tributyl phosphate on morphology, physiology and migratory behaviour of European eels during the transition from freshwater to the marine environment

    DEFF Research Database (Denmark)

    Privitera, Lucia; Aarestrup, Kim; Moore, Andy

    2013-01-01

    Migrating silver European eels were exposed for 5 days in a laboratory to an environmental level of tributyl phosphate (TBP), tagged with acoustic transmitters and released below the Tange hydropower station, on the River Gudenaa, Denmark. The subsequent movements of the eels were monitored as th...... predominantly at night. The results of the study are discussed in relation to the impact of diffuse pollution on the behaviour and physiology of European eels...

  11. Preparation and Characterization of Bioplastic-Based Green Renewable Composites from Tapioca with Acetyl Tributyl Citrate as a Plasticizer

    Directory of Open Access Journals (Sweden)

    Chi-Hui Tsou

    2014-08-01

    Full Text Available Granular tapioca was thermally blended with poly(lactic acid (PLA. All blends were prepared using a plasti-corder and characterized for tensile properties, thermal properties and morphology. Scanning electron micrographs showed that phase separation occurred, leading to poor tensile properties. Therefore, methylenediphenyl diisocyanate (MDI was used as an interfacial compatibilizer to improve the mechanical properties of PLA/tapioca blends. The addition of MDI could improve the tensile strength of the blend with 60 wt% tapioca, from 19.8 to 42.6 MPa. In addition, because PLA lacked toughness, acetyl tributyl citrate (ATBC was added as a plasticizer to improve the ductility of PLA. A significant decrease in the melting point and glass-transition temperature was observed on the basis of differential scanning calorimetry, which indicated that the PLA structure was not dense after ATBC was added. As such, the brittleness was improved, and the elongation at break was extended to several hundred percent. Therefore, mixing ATBC with PLA/tapioca/MDI blends did exhibit the effect of plasticization and biodegradation. The results also revealed that excessive plasticizer would cause the migration of ATBC and decrease the tensile properties.

  12. Investigation of air cleaning processes for removing tributyl phosphate vapors from fuel reprocessing off-gas streams

    International Nuclear Information System (INIS)

    Parker, G.B.; Schwendiman, L.C.

    1979-01-01

    Tributyl phosphate (TBP) is used as an extractant in combination with the solvent dodecane in the dissolution process in a conventional nuclear fuel reprocessing plant. When recycled acid is used in the process, the dissolver off-gas (DOG) may contain small amounts of TBP and dodecane vapor. The vessel off-gas (VOG) will also contain TBP vapors in even higher fractions. Under some conditions, TBP vapor in these gas streams adversely affects the performance of silver-loaded solid sorbent beds used in the treatment of these streams to remove iodine and organic iodide compounds. An investigation is reported of the use of inorganic solid sorbent beds located upstream of the silver-loaded sorbent beds to remove TBP and extend the useful life of the silver beds. Laboratory scale experiments have been conducted using selected inorganic solid sorbent materials which have specific properties indicating their effectiveness for removing TBP or similar organic compounds. Results indicated 4 inorganic materials would retain greater than 95% of inlet TBP over a 3-hour run time. These four materials are being tested in a small packed glass column arrangement using variations in TBP concentration, face velocity and column temperature. As a part of this work, a sensitive quantitative analysis technique was developed enabling continous real time analysis of TBP vapor concentrations, as low as 1 x 10 -7 g/l, so that breakthrough progression can be measured

  13. Measurement of tributyl phosphate (TBP) in groundwater at a legacy radioactive waste site and its possible role in contaminant mobilisation.

    Science.gov (United States)

    Rowling, Brett; Kinsela, Andrew S; Comarmond, M Josick; Hughes, Catherine E; Harrison, Jennifer J; Johansen, Mathew P; Payne, Timothy E

    2017-11-01

    At many legacy radioactive waste sites, organic compounds have been co-disposed, which may be a factor in mobilisation of radionuclides at these sites. Tri-butyl phosphate (TBP) is a component of waste streams from the nuclear fuel cycle, where it has been used in separating actinides during processing of nuclear fuels. Analyses of ground waters from the Little Forest Legacy Site (LFLS) in eastern Australia were undertaken using solid-phase extraction (SPE) followed by gas chromatographic mass spectrometry (GCMS). The results indicate the presence of TBP several decades after waste disposal, with TBP only being detected in the immediate vicinity of the main disposal area. TBP is generally considered to degrade in the environment relatively rapidly. Therefore, it is likely that its presence is due to relatively recent releases of TBP, possibly stemming from leakage due to container degradation. The ongoing presence and solubility of TBP has the potential to provide a mechanism for nuclide mobilisation, with implications for long term management of LFLS and similar legacy waste sites. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  14. The production of rare earth elements group via tributyl phosphate extraction and precipitation stripping using oxalic acid

    Directory of Open Access Journals (Sweden)

    Esmaeil Jorjani

    2016-11-01

    Full Text Available In this study, solvent extraction and precipitation stripping were used to produce rare earth elements (REEs. Tributyl phosphate (TBP was used to extract yttrium, lanthanum, cerium, and neodymium from an aqueous solution produced by nitric acid leaching of apatite concentrate. In the extraction stage, the effects of TBP concentration, pH, contact time, temperature, and phase ratio were investigated. The results show that about 95%, 90%, 87% and 80% of neodymium, cerium, lanthanum, and yttrium, respectively, can be extracted in optimum conditions of extraction. Hot, deionized water was used to scrub the impurities from the loaded organic phase. The results showed that three stages of scrubbing with a phase ratio (Va/Vo of five removed about 80%, 30%, 27%, and 15% of Ca, Mg, Fe, and P, respectively, from loaded TBP, while less than 9% of total REEs was lost. The effects on precipitation stripping of oxalic acid concentration, contact time, and phase ratio were investigated. The results showed that precipitation stripping is a viable alternative to traditional acid stripping in the REEs production process. Mixed REEs oxide with an assay of about 90% can be achieved as a final product.

  15. Comparison of 2-Octanol and Tributyl Phosphate in Recovery of Tungsten from Sulfuric-Phosphoric Acid Leach Solution of Scheelite

    Science.gov (United States)

    Liao, Yulong; Zhao, Zhongwei

    2018-04-01

    Tungsten was recovered from sulfuric-phosphoric acid leach solution of scheelite using 2-octanol and tributyl phosphate (TBP). Approximately 76% of the tungsten and less than 6.2% of the iron were extracted when using 70% 2-octanol, showing good selectivity for tungsten over iron; the tungsten extraction could not be significantly enhanced using a three-stage countercurrent simulation test. Moreover, more than 99.2% of the W and 91.0% of the Fe were extracted when using 70% TBP, showing poor selectivity, but after pretreating the leach solution with iron powder, less than 5.5% of the Fe was extracted. The loaded phases were stripped using deionized water and ammonia solution. The maximum stripping rate of tungsten from loaded 2-octanol was 45.6% when using water, compared with only 13.1% from loaded TBP. Tungsten was efficiently stripped from loaded phases using ammonia solution without formation of Fe(OH)3 precipitate. Finally, a flow sheet for recovery of tungsten with TBP is proposed.

  16. DOLOČITEV POVRŠINSKE NAPETOSTI Z METODO KAPILARNEGA DVIGA DVOFAZNIH SISTEMOV

    OpenAIRE

    Kravanja, Gregor

    2014-01-01

    Namen magistrske naloge je bil postavitev merilne naprave in razvoj nove metode merjenja površinske napetosti s kapilarnim dvigom dvofaznih sistemov v okolici kritične točke. Za pridobitev natančnih in primerljivih meritev je bilo potrebno poznati natančni notranji premer tankih kapilar. Določili smo ga z metodo laserskega tipanja na nemški koordinatni merilni napravi ZEISS tipa UMC-850 s pomočjo merilne programske opreme CALYPSO 5.1.4. Za merjenje ravnotežne višine smo uporabili računalniški...

  17. Tritium distribution ratios between the 30 % tributyl phosphate(TBP)-normal dodecane(nDD) organic phase and uranyl nitrate-nitric acid aqueous phase

    International Nuclear Information System (INIS)

    Fujine, Sachio; Uchiyama, Gunzou; Sugikawa, Susumu; Maeda, Mitsuru; Tsujino, Takeshi.

    1989-10-01

    Tritium distribution ratios between the organic and aqueous phases were measured for the system of 30 % tributyl phosphate(TBP)-normal dodecane(nDD)/uranyl nitrate-nitric acid water. It was confirmed that tritium is extracted by TBP into the organic phase in both chemical forms of tritiated water (HTO) and tritiated nitric acid (TNO 3 ). The value of tritium distribution ratio ranged from 0.002 to 0.005 for the conditions of 0-6 mol/L nitric acid, 0.5-800 mCi/L tritium in aqueous phase, and 0-125 g-U/L uranium in organic phase. Isotopic distribution coefficient of tritium between the organic and aqueous phases was observed to be about 0.95. (author)

  18. The distribution of Th(NO3)4, UO2(NO3)2 and HNO3 between an aqueous phase and an organic tributyl phosphate phase

    International Nuclear Information System (INIS)

    Nakashima, T.; Zimmer, E.

    1984-05-01

    The distribution of Th(NO 3 ) 4 , UO 2 (NO 3 ) 2 and HNO 3 between an aqueous phase and an organic phase, consisting of 30 Vol.% tributyl phosphate in dodecane, has been experimentally investigated. About 120 distribution data have been determined in the concentration ranges that can be seen in the THOREX process for reprocessing spent thorium bearing fuel. Based on the experimental data, two computer programs have been developed which make possible interpolations and, to some extent, extrapolations. With model 1, concentrations in the organic phase can be calculated if that in the aqueous phase are known. With model 2, concentrations in the aqueous phase can be calculated vice versa. Besides the description of the calculation models, a large body of calculated data can be found in this report. In a addition, a calculation mode is presented that makes possible the calculation of distribution data for very low thorium concentrations. (orig.) [de

  19. Correlacion entre metodos de analisis de Zn disponible en cuatro ordenes de suelos de Costa Rica

    Directory of Open Access Journals (Sweden)

    Eloy Molina

    2001-01-01

    Full Text Available Se realizo una comparación entre métodos analisis del Zn disponible en 4 ordenes de sue- Analytilos de Costa Rica (Ultisoles, Vertisoles, Andisoles Inceptisoles, 25 de c/u, utilizando las siguientes soluciones extractoras: Olsen Modificado, Meh- lich 3, Morgan Modificado, DTPA y HC1. Las cantidades de Zn extrafdas dependieron de la natu- raleza qufmica de la solucion extractora. El HCl presento los contenidos mas altos de Zn en los chasuelos, excepto en Vertisoles. Las soluciones que hicontienen el agente quelante EDTA (Olsen Modi- ficado y Mehlich`3, extrajeron niveles interme- Modidios de Zn, en tanto que los metodos que contie- Den el quelato DTPA (Morgan Modificado y DT - PA, obtuvieron los valores mas bajos. Las corre- laciones de Zn extrafble entre los 5 metodos fue- signifirOD significativas en la mayona de los casos, tanto nivel de orden de suelos como en el conjunto de indivilos 100 suelos analizados. Los coeficientes de co- rrelacion mas altos, se presentaron entre Mehlich Morgan Modificado y DTPA. Las correlaciones Modifueron consistentes en los 4 ordenes, 10 que indica que estas soluciones poseen un amplio margen de adaptacion a diferentes tipos de suelo, siendo una caractenstica ventajosa para la selección de un metodo de analisis. El Olsen Modificado fue mas slighteficiente para la extraccion de Zn en suelos de pH ligeramente acido 0 neutro (Vertisoles e Inceptiso- les, que en suelos acidos (Ultisoles y Andisoles. EI HCI extrajo cantidades muy aItas de Zn que Moraparentementestan relacionadas con formas no disponibles para lag plantas. Se concluye que lag soluciones Mehlich 3, Morgan Modificado y DT - PA son semejantes en la forma de extraer Zn dispo- Dible, y podrian seT una altemativa para sustituir el metoda tradicional de Olsen Modificado utilizado en Costa Rica. Sin embargo,la eficiencia de ellas no puede seT establecida sino a traves de log estudios de correlacion contra rendimiento en invernadero y campo.

  20. Reactivity and transfer of tributyl-tin and mercury in aquatic environments; Etude de la reactivite et du transfert du tributyletain et du mercure dans les environnements aquatiques

    Energy Technology Data Exchange (ETDEWEB)

    Tessier, E.

    2004-12-15

    Aquatic ecosystems are particularly affected by tributyl-tin (TBT) and mercury (Hg) chronic contamination. These micro-pollutants are ubiquitous and persistent and occurred at trace level, likely to drastically impair aquatic environments. TBT and Hg biogeochemical cycles are driven by transformation and transfer mechanisms between the different environmental compartments. These natural processes have been studied in details by using novel analytical methods and environmental design to improve the risk assessment. The first part of this work focus on the mechanistic study of TBT and Hg reactivity and transfer in reconstituted aquatic ecosystems. These experiments involve both state-of-the-art analytical speciation techniques, partly based on quantification by isotopic dilution and experimental tools simulating the environmental conditions. Kinetics of TBT and Hg distribution (adsorption, bioaccumulation, biodegradation, clearance) have been simultaneously characterized in all compartments of the microcosms presenting a simple biological organization. In a second step, volatilization kinetics of TBT at real interfaces have been studied to assess the potential remobilization and elimination pathways of butyl-tin compounds. Finally, in a third part, stable isotopic tracers of Hg have been employed to discriminate and quantify the coupled methylation and demethylation kinetics in estuarine sediments, by forcing different environmental factors (oxygenation, microbial activity). (author)

  1. The synthesis and characterization of tributyl phosphate grafted carbon nano-tubes by the floating catalytic chemical vapor deposition method and their sorption behavior towards uranium

    International Nuclear Information System (INIS)

    Shruti Mishra; Jaya Dwivedi; Amar Kumar; Nalini Sankararamakrishnan

    2016-01-01

    Carbon nano-tubes (CNTs) were synthesized by the floating catalytic chemical vapor deposition technique using ferrocene in benzene as the hydrocarbon source. The functionalization of CNTs was carried out by oxidation (CNT-OX) and grafting with a tributyl phosphate (TBP) ligand (CNT-TBP). Various spectroscopic techniques including scanning electron microscopy (SEM), Fourier Transform Infra Red Spectroscopy (FTIR), BET surface area and X-ray photoelectron spectroscopy (XPS) were used to characterize the adsorbents. FTIR and XPS studies revealed the efficient grafting of the TBP ligand on the CNT surface. The effect of the initial pH and the contact time for the maximum adsorption of U(VI) with CNT-plain, CNT-OX and CNT-TBP was studied. The spontaneity of the sorption was confirmed by thermodynamic data. A pseudo second order model with a regression coefficient of ≥0.978 was obtained for CNT-TBP and equilibrium was reached within 3 h. The Langmuir maximum adsorption capacity of U(VI) at pH 5 for CNT, CNT-OX and CNT-TBP was found to be 66.6, 100.0 and 166.6 mg.g -1 respectively. Using 0.1 M HCl as a de-sorbent, recyclability studies were carried out for three cycles. The probable mechanism of adsorption between U(VI) and CNT-TBP could be understood through FTIR and XPS techniques. (authors)

  2. Estudio numerico y experimental del proceso de soldeo MIG sobre la aleacion 6063--T5 utilizando el metodo de Taguchi

    Science.gov (United States)

    Meseguer Valdenebro, Jose Luis

    improvement on mechanical properties in aluminum metal joint. Los procesos de soldadura por arco electrico representan unas de las tecnicas mas utilizadas en los procesos de fabricacion de componentes mecanicos en la industria moderna. Los procesos de soldeo por arco se han adaptado a las necesidades actuales, haciendose un modo de fabricacion flexible y versatil. Los resultados obtenidos numericamente en el proceso de soldadura son validados experimentalmente. Los principales metodos numericos mas empleados en la actualidad son tres, metodo por diferencias finitas, metodos por elementos finitos y metodo por volumenes finitos. El metodo numerico mas empleado para el modelado de uniones soldadas, es el metodo por elementos finitos, debido a que presenta una buena adaptacion a las condiciones geometricas y de contorno ademas de que existe una diversidad de programas comerciales que utilizan el metodo por elementos finitos como base de calculo. Este trabajo de investigacion presenta un estudio experimental de una union soldada mediante el proceso MIG de la aleacion de aluminio 6063-T5. El metodo numerico se valida experimentalmente aplicando el metodo de los elementos finitos con el programa de calculo ANSYS. Los resultados experimentales obtenidos son: las curvas de enfriamiento, el tiempo critico de enfriamiento t4/3, geometria del cordon, microdurezas obtenidas en la union soldada, zona afectada termicamente y metal base, dilucion del proceso, areas criticas intersecadas entre las curvas de enfriamiento y la curva TTP. Los resultados numericos son: las curvas del ciclo termico, que representan tanto el calentamiento hasta alcanzar la temperatura maxima y un posterior enfriamiento. Se calculan el tiempo critico de enfriamiento t4/3, el rendimiento termico y se representa la geometria del cordon obtenida experimentalmente. La zona afectada termicamente se obtiene diferenciando las zonas que se encuentran a diferentes temperaturas, las areas criticas intersecadas entre las

  3. Solvent Extraction of Rare Earth Elements from a Nitric Acid Leach Solution of Apatite by Mixtures of Tributyl Phosphate and Di-(2-ethylhexyl) Phosphoric Acid

    Science.gov (United States)

    Ferdowsi, Ali; Yoozbashizadeh, Hossein

    2017-12-01

    Solvent extraction of rare earths from nitrate leach liquor of apatite using mixtures of tributyl phosphate (TBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was studied. The effects of nitrate and hydrogen ion concentration of the aqueous phase as well as the composition and concentration of extractants in the organic phase on the extraction behavior of lanthanum, cerium, neodymium, and yttrium were investigated. The distribution ratio of REEs increases by increasing the nitrate concentration in aqueous phase and concentration of extractants in organic phase, but the hydrogen ion concentration in aqueous phase has a decreasing effect. Yttrium as a heavy rare earth is more sensitive to these parameters than light rare earth elements. Although the composition of organic phase has a minor effect on the extraction of light rare earths, the percent of extraction of yttrium decreases dramatically by increasing the TBP content of organic phase. Mixtures of TBP and D2EHPA can show either synergism or antagonism extraction depending on the concentration and composition of extractants in organic phase. The best condition for separating rare earth elements in groups of heavy and light REEs can be achieved at high nitrate concentration, low H+ concentration, and high concentration of D2EHPA in organic phase. Separation of Ce and La by TBP and D2EHPA is practically impossible in the studied conditions; however, low nitrate concentration and high hydrogen ion concentration in aqueous phase and low concentration of extractants in organic phase favor the separation of Nd from other light rare earth elements.

  4. Extraction studies of uranium into a third-phase of thorium nitrate employing tributyl phosphate and N,N-dihexyl octanamide as extractants in different diluents

    International Nuclear Information System (INIS)

    Neelam Kumari; Prabhu, D.R.; Pathak, P.N.; Kanekar, A.S.; Manchanda, V.K.

    2011-01-01

    Extraction behavior of 1 x 10 -2 - 0.1 M U(VI) from aqueous phases containing 0.86 M Th(IV) at 4 M HNO 3 in 1.1 M tributyl phosphate (TBP) and 1.1 M N,N-dihexyl octanamide (DHOA) solutions in different diluents viz. n-dodecane, 10% 1-octanol + n-dodecane, and decahydronaphthalene (decalin) was studied. Third-phase formation was observed in both the extractants using n-dodecane as diluent. There was a gradual decrease in Th(IV) concentration in the third-phase (heavy organic phase, HOP) with increased aqueous U(VI) concentration [0.71 M (no U(VI)) - 0.61 M (0.1 M U(VI)) for TBP; 0.27 M (no U(VI)) - 0.22 M (0.1 M U(VI)) for DHOA]. The HOP volume in case of DHOA was ∼ 2.2 times of that of TBP. Uranium concentration in HOP increased with its initial concentration in the aqueous phase [from 1.8 x 10 -2 M (0.01 M U(VI)) - 0.162 M (0.1 M U(VI)) for TBP; from 1.4 x 10 -2 M (0.01 M U(VI)) - 0.14 M (0.1 M U(VI)) for DHOA] suggesting that Th(IV) was being replaced by U(VI). An empirical correlation was developed for predicting the concentrations of uranium and thorium in HOP for both the extractants. No third-phase appeared during the extraction of uranium and thorium from the aqueous phases employing 10% 1-octanol + n-dodecane, or decalin as diluents, and therefore, were better choices as diluent for alleviating the third-phase formation during the reprocessing of spent thorium based fuels, and for the recovery of thorium from high-level waste solutions. (author)

  5. Atlas de aves: Un metodo para documentar distribucion y seguir poblaciones

    Science.gov (United States)

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.; Alvarez-Lopez, Humberto; Kattan, Gustavo; Murcia, Carolina

    1988-01-01

    Los Atlas de Aves son proyectos nacionales o regionalies para trazar en mapas la distribucion en reproduccion de cada especie de ave. Ese procedimiento se esta usando en Europa, Australia, Nueva Zelanda, Norteamerica, y partes de Africa. El tama?o de los cuadrados varia de medio grado de latitud y Iongitud hasta 5 x 5 km. El trabajo de campo de cada proyecto exige aproxlmadamente cinco a?os, pero los aficionados pueden llevar a cabo la mayor parte del trabajo. Es posible almacenar los resultados en un computador personal. Hay muchos beneficios: (I) se presenta la distribucion corriente de las aves de la nacion, del estado, o de la Iocalidad; (2) se desarrolla nueva informacion especialmente sobre especies raras o en peligro; (3) se descubren areas que tienen una avlfauna sobresaliente o habitats raros y ayuda a su proteccion, (4) se documentan cambios de dlstribucion; (5) se pueden usar para documentar cambios de poblacion, especialmente en los tropicos donde otros metodos son mas dificiles de usar porque hay muchas especies y no hay muchos observadores calificados en la identificacion de sonidos de las aves; (6) son proyectos buenos de investigacion para estudiantes graduados; (7) los turistas y los jefes de excursiones de historia natural pueden contribuir con muchas informaciones

  6. Subsurface microbial ecology. Epi fluorescence direct counts; Ecologia microbica del sottosuolo: metodo di conta diretta in epifluorescenza

    Energy Technology Data Exchange (ETDEWEB)

    Barra Caracciolo, A.; Silvestri, C.; Creo, C.; Izzo, G. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1998-07-01

    To the aim of recognize the importance of microorganisms in affecting or even determining the fate of xenobiotics in the subsurface environment evaluating bacteria concentration in a subsurface ecosystem, the report discusses a soil sample treatment method which has been developed for epi fluorescence direct counting with DAPI. [Italian] Lo studio discute un metodo di trattamento del campione per la conta diretta in epifluorescenza con un marcatore selettivo per il DNA, il DAPI, al fine di quantificare la concentrazione batterica del sottosuolo e studiare il ruolo dei microrganismi nella biodegradazione delle molecole esogene, ancora poco indagato.

  7. Lingua per se notata. Una annotazione sul metodo Ørberg alla luce dell’Ipotesi del Noticing di Schmidt

    Directory of Open Access Journals (Sweden)

    Marco Ricucci

    2017-10-01

    Full Text Available L’istruzione classica sta attraversando una crisi mondiale per molteplici motivi:, mentre il greco antico e il latino sono stati eliminati dalle scuole superiori, persino in Italia. Questo articolo è un breve esame in cui la modalità di apprendimento della grammatica nel metodo induttivo-contestuale, approntato da Hans Ørberg, viene analizzata alla luce dell’ Ipotesi del Noticing di Richard Schmidt, linguista applicato statunitense: essa è una teoria cognitiva che spiega l’acquisizione di una lingua seconda.

  8. Method to allow the estimation of heat transfer coefficients in solar stills; Metodo para determinar coeficientes locales de transferencia de calor en destiladores solares

    Energy Technology Data Exchange (ETDEWEB)

    Rubio Cerda, Eduardo; Porta Gandara, Miguel A [CIBNOR, Mexico D.F (Mexico); Fernandez Zayas, Jose Luis [UNAM Mexico, D.F. (Mexico)

    2000-07-01

    This work reports an experimental method that allows to estimate the heat transfer coefficients in the neighborhood of walls or flat plates subject to convective transport phenomena. This method can be applied to a great variety of thermal systems since it is based on the knowledge of the border condition for the temperature at the surface of the plate, and the temperature profile that characterize the dimensionless coefficient of heat transfer in the fluid, according to its definition given by the Nusselt number. The approach of this work are the foundations of the method and the system that has been developed to apply it, that incorporates automatic acquisition equipment for continuos monitoring of the information and elements to control the parameters of interest. In addition, the experimental cavities on which the method will be evaluated are discussed, considering two different scales, as well as experiments in cavities filled with air, and with a mixture of air and steam water, as is the case for solar distillation. [Spanish] En este trabajo se presenta un metodo que permite determinar de manera experimental coeficientes de transferencia de calor por conveccion. Este metodo puede ser aplicado a una gran variedad de sistemas termicos ya que se fundamenta en el conocimiento de la condicion de frontera para la temperatura en la superficie de la placa, y del perfil de temperaturas que caracteriza el coeficiente adimensional de transferencia de calor en el fluido, de acuerdo a la definicion de este, dada por el numero de Nusselt. El trabajo que aqui se reporta esta enfocado a la fundamentacion del metodo y al equipamiento que se ha desarrollado para instrumentarlo, que incorpora equipos automaticos de adquisicion continua de informacion y elementos de control para los parametros de interes. Se presentan ademas, las cavidades experimentales sobre las que sera evaluado el metodo, que considera dos escalas diferentes, asi como experimentos en cavidades llenas de aire

  9. Končni rezultat zdravljenja starostnika z zlomom vratu stegnenice je povezan z metodo operacije

    Directory of Open Access Journals (Sweden)

    Drago Brilej

    2007-12-01

    Full Text Available Izhodišča: Prebivalstvo Slovenije se stara. Med starostniki so zlomi kolkov pomemben vzrok umrljivosti in invalidnosti. Incidenca zlomov vratu stegnenice dosega 25–30 na 100.000 prebivalcev letno. Mnenja o načinu zdravljenja starostnikov z zlomom vratu stegnenice si nasprotujejo. Kar 94 % dislociranih zlomov vratu stegnenice pri starostnikih na Nizozemskem zdravijo s hemiartroplastiko, v Švedski pa praktično vse primarno oskrbijo z osteosintezo. V SUB Celje so do leta 1994 večino dislociranih zlomov vratu stegnenice oskrbeli z osteo sintezo s tremi vijaki. Leta 1995 so spremenili protokol zdravljenja. Poškodovance, starejše od 65 let z dislociranim zlomom vratu stegnenice so oskrbeli z delno cementirano bipolarno protezo. Obe skupini so primerjali med sabo, da bi ugotovili upravičenost menjave metode zdravljenja. Hipoteza je bila, da vstavitev delno cementirane bipolarne endoproteze izboljša preživetje starostnikov z dislociranim zlomom vratu stegnenice in da preživelim omogoči uspešnejšo rehabilitacijo.Bolniki in metode: V SUB Celje so od januarja 1993 do decembra 1996 zaradi svežega dislociranega zloma vratu stegnenice (Garden 3,4 zdravili 164 poškodovancev, starejših od 65 let. Praviloma so v letih 1993 in 94 zdravili te zlome z osteosintezo s tremi vijaki, v letih 1995 in 96 z vstavitvijo delne bipolarne endoproteze. 131 (80 % poškodovancev so spremljali 1 leto. Glede na način oskrbe zloma so jih razdelili v dve skupini. V letih 1993 in 94 so zdravili 52 starostnikov zaradi dislociranega zloma vratu stegnenice z osteosintezo s tremi vijaki. V letih 1995 in 96 so zdravili 81 starostnikov zaradi dislociranega zloma vratu stegnenice z delno cementirano bipolarno protezo. Pred operativnim posegom so ocenili zdravstveno stanje poškodovanca po ASA lestvici. Ugotavljali so zaplete med zdravljenjem in trajanje hospitalizacije. Ob koncu zdravljenja in po enem letu so ocenili samostojnost poškodovancev pri hoji. Z metodo po

  10. Microscale adaptation of the potentiometric method with ion-selective electrode for the quantification of fluoride; Adaptacion a microescala del metodo potenciometrico con electrodo ion selectivo para la cuantificacion de fluoruro

    Energy Technology Data Exchange (ETDEWEB)

    Guevara Ruiz, Paulina; Ortiz Perez, Maria Deogracias [Laboratorio de Bioquimica, Facultad de de Medicina, Universidad Autonoma de San Luis Potosi, San Luis Potosi, San Luis Potosi, (Mexico)]. E-mail: mdortiz@uaslp.mx

    2009-05-15

    Similarly to other countries, ground water from Mexico is naturally polluted by fluoride. The main effects of fluoride at typical ground water concentrations are dental fluorosis, neurological deficits and reproductive disorders. In order to verify that the fluoride concentration is within the allowed guideline in Mexico (NOM 127 and 201), it is important to monitor fluoride levels in water and commercial beverages. The aim of this work is to develop a modification of the standard potentiometric method for fluoride determination in water, in order to reduce costs and amount of potentially toxic waste substances. Both methods were validated, the standard potentiometric method with the ion selective electrode and the microscale modification proposed in this paper. The methods were compared using statistic tests and graphics, followed by the comparison of 125 samples of commercial bottled water sold in the city of San Luis Potosi. Optimal results were obtained for the validation of both methods, and the microscale modification showed statistically identical results to those obtained with the standard method in all samples of bottled water. The microscale modification is a good alternative for fluoride assessment in water and beverages, and it represents a 95 % reduction of costs and chemical waste. [Spanish] En varios paises, incluido Mexico se presenta una contaminacion natural con fluoruro en agua subterranea; los principales efectos en la salud observados en poblacion expuesta a concentraciones mayores al valor permisible (que en Mexico es de 1.5 mg/L) son la fluorosis dental y esqueletica, asi como dano reproductivo y neurologico. En varios estados de la republica Mexicana, este problema es aun desconocido, de ahi la necesidad de evaluar las concentraciones de fluoruro en agua de consumo en varias comunidades. Asi, el objetivo de este trabajo es desarrollar un metodo a microescala para la determinacion de fluoruro en agua, que al reducir la cantidad de reactivo y

  11. Torque calculation in the induction motor with the finite element method; Calculo del par en el motor de induccion con el metodo del elemento finito

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Diaz, Ramon

    2002-06-15

    In this work the method of the finite element is applied to the bi-dimensional analysis of the induction motor in operation in steady state, excited by sine sources of laminar currents and sine sources of voltage. The analysis is focused mainly in the calculation of the electromagnetic torque. The topics of electromagnetic theory are covered and in an idealized model of the induction motor, analytically and numerically with the method of the finite element, in the variant method of Galerkin, the vectorial potential and the torque are calculated. The results obtained with the analytical and numerical methods are compared. Three formulations are developed to calculate the torque with the method of the finite element, using triangular elements of first order, based in the equation of force of Lorentz, the Maxwell tensor and the principle of the virtual work. Finally, a motor of induction of real characteristics is simulated, assuming it is connected to a three-phase voltage source. In this motor it is analyzed the convergence and the evolution in the results obtained of the torque with different discretions, and the torque-velocity performance curve is calculated. [Spanish] En este trabajo se aplica el metodo del elemento finito al analisis bidimensional del motor de induccion en operacion en estado estable, excitado por fuentes de corriente laminar senoidales y fuentes de voltaje senoidales. El analisis se enfoca principalmente en el calculo del par electromagnetico. Se tratan los topicos de teoria electromagnetica involucrados y en un modelo idealizado del motor de induccion, se calculan analitica y numericamente con el metodo del elemento finito, en la variante metodo de Galerkin, el potencial vectorial y el par. Se comparan resultados obtenidos con los metodos analiticos y numericos. Se desarrollan tres formulaciones para calcular el par con el metodo del elemento finito, utilizando elementos triangulares de primer orden, basadas en la ecuacion de fuerza de

  12. Flow measurement in a 170-MW hydraulic turbine using the Gibson method; Medicion del flujo de una turbina hidraulica de 170 MW utilizando el metodo Gibson

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza, Gustavo [Universidad Autonoma del Estado de Morelos (Mexico); Adamkowski, Adam [The Szewalski Institute of Fluid-Flow Machinery (Poland); Kubiak, Janusz; Sierra, Fernando [Universidad Autonoma del Estado de Morelos (Mexico); Janicki, Waldemar [The Szewalski Institute of Fluid-Flow Machinery (Poland); Fernandez, J. Manuel [Comision Federal de Electricidad (Mexico)

    2007-07-15

    This paper describes the methodology applied for measuring water flow through a 170-MW hydraulic turbine. The flow rate was measured using the pressure-time method, also known as the Gibson method. This method uses the well-known water hammer phenomenon in pipelines; in turbine penstocks, for instance. The version of this method used here is based on measuring, during total stop of the water stream, the time-history of pressure change in one section of the turbine penstock and relate it to the pressure in the upper reservoir to which the penstock is connected. The volumetric flow rate is determined from the relevant integration of the measured temporary pressure rise. Flow measurement was possible this way because the influence of the penstock inlet was negligible as far as an error of the measurement is concerned. The length of the penstock was 300 m. Previous experience and a standard IEC-41-1991 were the criteria adopted and applied. A fast and efficient acquisition system, including a 16 bit card, was used. The flow rate was calculated using a computer program developed and tested on several cases. The results obtained with the Gibson method were used for calibration of the on-line flow measuring system based on the Winter-Kennedy method as one of the index methods. This method is very often used for continuous monitoring of the flow rate through hydraulic turbines, when the calibration has been done on site by using the results of measurements obtained by the absolute method. Having measured the flow rate and output power, the efficiency was calculated for any operating conditions. A curve showing the best operating conditions based on the highest efficiency is presented and discussed. The details of the instrumentation, its installation, and the results obtained are discussed in the paper. [Spanish] Este articulo describe la metodologia aplicada para la medicion del flujo en una turbina hidraulica de 170 MW. El flujo se midio utilizando el metodo de presion

  13. Flow in potential cascades by means of the finite element method; Flujo en cascadas potenciales mediante el metodo del elemento finito

    Energy Technology Data Exchange (ETDEWEB)

    Sosa Cordero, Rodolfo; Fernandez Valencia, Gonzalo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    This article presents a mathematical model and its solution by means of the finite element method with approximate Garlekin formulation, for the flow analysis in a circular cascade, in a surface of revolution current of a turbo- machine, that can be axial, mixed or radial. To the revolution surface an agreed transformation is applied to obtain a plane, eliminating in this form one term in the equation succeeding in avoiding an iterative solution. Likewise, the finite element method allows to solve the equation in partial derivatives of the elliptical type in its quasi-harmonic form. Additionally, the method followed to introduce the contour conditions is presented; specially, the Kutta-Joukowsky conditions and the one of periodicity, which distinguishes this problem from the classical problems of ideal flows evaluated in the contour. [Espanol] En este articulo se presenta un modelo matematico y su solucion mediante el empleo del metodo del elemento finito con formulacion aproximada de Galerkin, para el analisis del flujo en una cascada circular, en una superficie de corriente de revolucion de una turbomaquina, que puede ser axial, mixta o radial. A la superficie de revolucion se le aplica una transformacion conforme para obtener un plano, eliminando de esta forma un termino en la ecuacion logrando evitar la solucion iterativa. Asimismo, el metodo del elemento finito permite resolver la ecuacion en derivadas parciales del tipo eliptico en su forma cuasiarmonica. Se presenta, ademas, el metodo seguido para introducir las condiciones de contorno; en especial, las condiciones de Kutta-Joukowsky y la de periodicidad, que distinguen a este problema de los problemas clasicos de flujos ideales valuados en el contorno.

  14. Method of identifying the friction of rotors using the wavelet transform; Metodo para identificar el rozamiento de rotores utilizado la transformada wavelet

    Energy Technology Data Exchange (ETDEWEB)

    Jauregui Correa, Juan Carlos; Rubio Cerda, Eduardo; Gonzalez Brambila, Oscar [CIATEQ, A.C., Queretaro (Mexico)

    2007-11-15

    The modern processes of signal analysis that measure mechanical vibrations are based on the fast transform of Fourier (FFT), nevertheless, this method is not able to identify transient phenomena nor of nonlinear nature. Although many efforts have been made to try to identify these phenomena in the frequency spectra, it is not possible to correlate the spectra with the physical characteristics of this type of phenomena. Within these phenomena on the rubbing of a rotor against the housing or trunnion of a bearing, this phenomenon has a nonlinear behavior, as it is demonstrated in this paper. In the first part a method based on the of signal analysis type wavelets is presented and how this technique can be used to predict transient and nonlinear phenomena. Once defined the method, its application in the identification of the friction of rotors is demonstrated. With this, one demonstrates that the method presented in this paper allows to also identifying in real time the rubbing phenomenon and also that it can be used as an of analysis technique in the preventive maintenance systems. [Spanish] Los procesos modernos de analisis de senales que miden vibraciones mecanicas se basan en la transformada rapida de Fourier (FFT por sus siglas en ingles), sin embargo, este metodo no es capaz de identificar fenomenos transitorios ni de naturaleza no lineal. A pesar de que se han hecho muchos esfuerzos para tratar de identificar estos fenomenos en los espectros de frecuencia, no es posible correlacionar el espectro con las caracteristicas fisicas de este tipo de fenomenos. Dentro de estos fenomenos sobre el rozamiento de un rotor contra la carcasa o munon de una chumacera, este fenomeno tiene un comportamiento no lineal, como se demuestra en este trabajo. En la primera parte se presenta un metodo basado en el analisis de senales tipo wavelets y como esta tecnica puede utilizarse para predecir fenomenos transitorios y no lineales. Una vez definido el metodo, se demuestra su

  15. Synthesis of xLiMnPO4·yLi3V2(PO43/C Nanocomposites for Lithium Ion Batteries Using Tributyl Phosphate as Phosphor Source

    Directory of Open Access Journals (Sweden)

    Yanming Wang

    2017-01-01

    Full Text Available The xLiMnPO4·yLi3V2(PO43/C (x/y = 1 : 0, 12 : 1, 8 : 1, 6 : 1, 4 : 1, 0 : 1 composite cathode materials are synthesized using tributyl phosphate as a novel organic phosphor source via a solid-state reaction process. All obtained xLiMnPO4·yLi3V2(PO43/C composites present similar particles morphology with an average size of ca. 100 nm and low extent agglomeration. The electrochemical performance of pristine LiMnPO4/C can be effectively improved by adding small amounts of Li3V2(PO43 additives. The 4LiMnPO4·Li3V2(PO43/C has a high discharge capacity of 143 mAh g−1 at 0.1 C and keeps its 94% at the end of 100 cycles.

  16. Calculation of concentration profiles and their experimental verification with a pulsed sieve-plate column and the reactive material system of uranyl nitrate, nitric acid/tributyl phosphate, kerosine

    International Nuclear Information System (INIS)

    Ihle, E.

    1985-01-01

    The present study is concerned with the calculation of stationary and non-stationary concentration profiles as well as with the starting and disturbance behaviour of a pulsed sieve-plate extraction column. It investigates into the material system HNO 3 /uranyl nitrate in water with 30 per cent by volume of tributyl phosphate in kerosine. During the measurements of the concentration profiles for HNO 3 transition, which were effected in the direction of extraction and reextraction, it was shown that the concentration profiles measured in the mixer-settler range, in spite of a sixfold enlargement of the specific heat transfer area, do not differ essentially from those measured in the dispersion range. During the measurements of concentration profiles for HNO 3 /uranium transition, which were effected in the direction of coextraction and co-reextraction only for mixer-settler range, it was discovered that with increasing phase ratios, there is a depletion of the uranium concentration in the aqueous phase. If the phase ratio is further raised, it is the nitric acid, and not the uranium, that is depleted. (orig./PW) [de

  17. An analytical method for determination of mercury by cold vapor atomic absorption spectroscopy; Determinazione di mercurio. Metodo per spettrometria di assorbimento atomico a vapori freddi (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Campanella, L. [Rome Univ. La Sapienza, Rome (Italy); Mastroianni, D.; Capri, S.; Pettine, M. [CNR, Rome (Italy). Ist. di Ricerca sulle Acque; Spezia, S.; Bettinelli, M. [ENEL, Unified Modelling Language, Piacenza (Italy)

    1999-09-01

    An analytical procedure for the determination of total mercury in wastewaters and natural waters is described. Aqueous samples are fast digested with nitric acid by using the microwave-oven technique; the analysis of mercury is then performed by cold vapor atomic absorption spectrometry (CV-AAS) using two possible instrumental apparatus (batch system or flow injection). Sodium borohydride is used as the reducing agent for mercury in solution (Method A). The use of amalgamation traps on gold for the preconcentration of mercury lowers the detection limit of the analyte (Method B). [Italian] Viene descritta una procedura analitica per la determinazione del mercurio totale in acque di scarico e naturali. Il campione acquoso viene sottoposto a mineralizzazione con acido nitrico in forno a microonde e analizzato mediante spettroscopia di assorbimento atomico a vapori freddi (CV-AAS) in due possibili configurazioni strumentali (sistema batch oppure flow injection), utilizzando sodio boro idruro come agente riducente del mercurio (metodo A). L'impiego della trappola di oro per la preconcentrazione del mercurio mediante amalgama consente di determinare l'analita a livelli di pochi ng/L (metodo B).

  18. Croissance prolongée de la diatomée marine Phaeodactylum tricornutum en milieu contaminé par le chlorure de tributylétain : conséquence sur le biotransfert du polluant

    Directory of Open Access Journals (Sweden)

    MARSOT P.

    1996-04-01

    Full Text Available Cette étude consiste à évaluer le biotransfert du tributylétain (TBT par le filtreur bivalve Mya arenaria, à partir d'une culture semi-continue de la diatomée Phaeodactylum tricornutum exposée à un niveau de contamination n'arrêtant pas sa croissance à long terme. La dose du contaminant employée (100 ng I-1 est de l'ordre de grandeur de celles décelées dans certaines régions contaminées, telles les marinas et les régions portuaires. Dans ces conditions, la culture de P tricornutum a maintenu son équilibre de croissance durant plus de 50 jours. Sa productivité était légèrement inférieure (de 4 % à celle de la culture témoin (sans contaminant. L'ingestion des diatomées contaminées, sur une période de 90 jours, a entraîné une bioaccumulation de TBT et DBT (dibutylétain dans la chair du mollusque, atteignant des concentrations respectives de 133 et 128 ng g-1 (poids humide. L'étude suggère que le biotransfert du TBT et du DBT associés à des micro-algues en croissance continue ou semi-continue pourrait constituer un facteur de bioamplification important du biocide en milieu naturel.

  19. A reverse method to estimate initial temperatures in geothermal reservoirs; Un metodo inverso para estimacion de la temperatura inicial de yacimientos geotermicos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx; Ramos Alcantara, Jose R. [Centro Nacional de Investigacion y Desarrollo Tecnologico, Departamento de Ingenieria Mecanica, Cuernavaca, Morelos (Mexico); Arellano Gomez, Victor M. [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)

    2010-01-15

    A method is presented for estimating the initial temperature in geothermal-reservoir formations. The method is based on control theory where the measured temperatures or temperature logs are compared with corresponding simulated temperatures for different times with the well closed. The comparison is made using a control algorithm that makes changes to the originally assumed reservoir temperatures and performs iterations until the best fit between the temperature logs and the simulated temperatures is obtained. The simulation of fluid transport and heat in the well includes the processes of circulation and stop in the presence of circulation losses, modeled on macroscopic balances of momentum and energy. The transport processes in the formation regard the reservoir as an isotropic porous medium and fluid flow is described by Darcy's law. This model generates the fields of temperatures, pressures and speeds as a function of time and space. The method was tested with data from well LV-3 in Las Tres Virgenes geothermal field, Baja California Sur, Mexico. The estimated temperatures of the undisturbed formation-or initial temperatures-are compared within {+-}15 degrees Celsius with the measured temperatures, which is an acceptable outcome from an engineering point of view. [Spanish] Se presenta un metodo para la estimacion de la temperatura inicial en las formaciones de yacimientos geotermicos. El metodo se basa en la teoria de control donde las temperaturas medidas o registros de temperatura se comparan con las correspondientes temperaturas simuladas a diferentes tiempos con el pozo cerrado. La comparacion se hace usando un algoritmo de control el cual hace cambios a las temperaturas de yacimiento originalmente supuestas y realiza iteraciones hasta que se obtiene el mejor ajuste entre los registros de temperatura y las temperaturas simuladas. La simulacion del transporte de fluidos y calor en el pozo incluye los procesos de circulacion y paro en presencia de

  20. Spores of anaerobic clostridia for a quantitative chemical analysis methodology; Metodo per la determinazione delle spore di clostridi solfito-riduttori in campioni di sedimenti, fanghi di depurazione, suolo e prodotti di compostaggio

    Energy Technology Data Exchange (ETDEWEB)

    Bonadonna, L.; Marini, R. [Istituto Superiore di Sanita' , Rome (Italy)

    2001-02-01

    The described analytical procedure allows the quantitative enumeration of the parameter Spores of Anaerobic Clostridia in solid matrixes, such as sediment, sludge, soil and compost. The present technique should be an useful reference method for all the laboratories working on the hygienic quality control of the environment. [Italian] Viene descritto il metodo analitico per la determinazione quantitativa delle Spore di Clostridi solfito-riduttori. Il parametro viene generalmente ancora quantificato con metodiche piu' adatte per l'analisi delle acque. Il metodo qui riportato, modifica invece la procedura di rilevamento per adeguarla all'analisi di materiale solido, quali sedimento, fango di depurazione, suolo e prodotti di compostaggio e vuole essere uno strumento applicativo di riferimento utile alla pianificazione e all'unificazione delle procedure analitiche per le strutture che operano nel settore del controllo della qualita' igienico-sanitaria ed ambientale di specifiche matrici ambientali.

  1. Method to estimate the convective mixing height from atmospheric sounding data; Un metodo para estimar la altura de la capa de mezcla a partir de datos de radiosondeo atmosferico

    Energy Technology Data Exchange (ETDEWEB)

    Salcido, Alejandro [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Castro, Telma [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-07-01

    A simple method to estimate the convective mixing height from atmospheric sounding data is presented in this paper. The proposed method is based on the slab model of the atmospheric boundary layer, which assumes that virtual potential temperature remains constant in the mixed layer, increases linearly with height in the free atmosphere, and has a discontinuity at the entrainment layer (in fact, the entrainment layer is assumed to be infinitesimal in depth). The proposed method was applied in Mexico City in order to estimate the mixing height values for 5:00 and 17:00 hours (local time) from January to May of 1993 and 1994. [Spanish] En este trabajo se presenta un metodo para estimar la altura de la capa de mezcla a partir de los datos de radiosondeo atmosferico. El metodo esta basado en un modelo de la capa limite atmosferica donde la temperatura potencial virtual se mantiene constante en la capa de mezclado, sufre una discontinuidad en la zona de entrainment (el espesor de la cual se supone infinitesimal), y crece linealmente con la altura en la atmosfera libre. El metodo desarrollado se utilizo para la determinacion de la altura de la capa de mezcla de la Ciudad de Mexico para las 11:00z y 23:00z de los dias de los meses de enero a mayo de los anos de 1993 y 1994.

  2. SHORT COMMUNICATION SYNTHESIS OF TRIBUTYL CITRATE ...

    African Journals Online (AJOL)

    Preferred Customer

    It is a plasticizer permitted in the field of food additives, food contact materials and medical products and is widely used in cosmetics [2] and biodegradable polymers [3]. Moreover, TBC is an environmentally, friendly plasticizer because the materials used for synthesis are available from renewable resources by fermentation.

  3. 40 CFR 799.4360 - Tributyl phosphate.

    Science.gov (United States)

    2010-07-01

    ... substance shall be applied to the intact clipped skin (approximately 2 cm2 for rats, 40 cm2 for mini-pigs... cells from the test solution shall be done using an ultrafiltration (e.g., 0.45 micrometer pore size...

  4. Action Research in the Library: Method, Experiences, and a Significant Case La ricerca-azione in biblioteca: il metodo, le esperienze e un caso significativo

    Directory of Open Access Journals (Sweden)

    Ilaria Moroni

    2011-12-01

    Full Text Available This article aims to promoting action research in library contexts by illustrating the method and its applications in library, and by presenting a meaningful case.
    Action research, devised in 1950s, was spread in information sciences since 1990s, with results that have been interesting in promoting change of involved people and organizations. The method is based on engaging a group coordinated by a researcher. Problem analysis is functional to realizing improvement interventions, in a recursive process of reflection, action, evaluation, and result sharing.
    The action research case at the University Milano Bicocca Library is meaningful under various aspects: increase of motivation and awareness in the working group that was responsible of improving the perception of library services; complementary use of quantitative and qualitative research methods in order to analyze users' service utilization and satisfaction; realization of many interventions, coherent with research results, aimed to enhance service usage and perceived quality; self-reflection and reflection on the organizational context, benchmarking with other libraries and assessment of the realized activities in the perspective of continuing improvement; internal sharing and external diffusion of the project to the advantage of librarians, users, and researchers.

    L’articolo si propone di diffondere l’utilizzo della ricerca-azione nel contesto bibliotecario, illustrando il metodo e le sue applicazioni nelle biblioteche e presentando un caso significativo.

    La ricerca-azione, ideata negli anni Cinquanta, si è diffusa nell’ambito delle scienze dell’informazione a partire dagli anni Novanta con risultati interessanti per i cambiamenti promossi nelle persone e nelle organizzazioni coinvolte. Il metodo prevede il coinvolgimento di un gruppo di persone coordinate da un ricercatore e l’analisi del problema è funzionale alla realizzazione di interventi migliorativi, in

  5. Fundamentos del metodo cientifico

    Directory of Open Access Journals (Sweden)

    Badii, M. H.

    2004-01-01

    Full Text Available El objetivo de esta obra no radica en realizar una búsqueda exhaustiva de la literatura en el tema, sino, sentar las bases del método científico, notando los aspectos filosóficos e éticos de la ciencia. Se presentan los conceptos y definiciones fundamentales relacionados con la metodología de la investigación científica. Se maneja el concepto de la toma de los datos válidos como un requisito básico en cualquier trabajo científico. Se pone a disposición del lector un modelo denominado el ECOEE que es una herramienta poderosa para establecer puntos de comparación e discusión entre los resultados de diferentes trabajos científicos. Finalmente, ofrece unas sugerencias de que hacer o no hacer en cuanto a realizar un trabajo de investigación.

  6. Development of an analytic method for arsenic's determination in lime and tortilla; Desarrollo de un metodo analitico para determinacion de arsenico en cal y tortilla

    Energy Technology Data Exchange (ETDEWEB)

    Huato Soberanis, Julio; Ogura, Tetsuya [Universidad Autonoma de Guadalajara, Guadalajara, Jalisco (Mexico)

    1995-02-01

    A spectrophotometric method to determine As in tortilla and lime has been optimized, modifying the AsH{sub 3} generator. The reaction between arsin (AsH{sub 3}){sub 4} and diethyldithiocarbamate of Ag (AgDDC); was followed spectrophotometrically. The conditions under which the As remains in the ash during the calcination of the tortillas were studied. It was found that when they were heated in a quartz tube with a careful control of the air flow and oxygen, as well as the heating temperature, the arsenic loss in minimized. [Spanish] Se ha optimizado el metodo para determinar As en la tortilla y cal mediante espectrometria en el visible del color producido en la reaccion entre Arsina (AsH{sub 3}){sub 4} y dietilditiocarbamato de plata (AgDDC); modificando el generador de AsH{sub 3}. Se han buscado las condiciones en las que el arsenico permanece en las cenizas de la calcinacion de las tortillas; encontrandose que las tortillas deben calentarse en un tubo de cuarzo con control del flujo de aire y oxigeno asi como de la temperatura de calentamiento.

  7. Application of the identification methods from Hilbert and Prony to the study of oscillatory phenomena in electrical power systems; Aplicacion de los metodos de identificacion de Hilbert y Prony al estudio de fenomenos oscilatorios en sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Soto, Manuel Antonio

    2002-10-15

    In the present thesis work the application of identification techniques is investigated based on methods of spectral analysis to the study of the instantaneous characteristics of signals obtained by means of digital simulation of the dynamic behavior of the power system. The study focuses on the perspectives developed from two different approaches of analysis: the use of lineal methods of spectral analysis and the use of methods of non-lineal analysis, based on the concept of an analytical signal. The developed tools are applied to the study of two phenomena of electromechanical origin of different characteristics in complex power systems. A comparison between the results obtained is performed for these techniques and the possibility of its application is discussed for the problem of on-line identification in power systems. [Spanish] En el presente trabajo de tesis se investiga la aplicacion de tecnicas de identificacion basadas en metodos de analisis espectral al estudio de las caracteristicas instantaneas de senales obtenidas mediante simulacion digital del comportamiento dinamico del sistema de potencia. El estudio se centra en las aproximaciones desarrolladas desde dos enfoques distintos de analisis: la utilizacion de metodos lineales de analisis espectral y la utilizacion de metodos de analisis no lineal, basados en el concepto de una senal analitica. Las herramientas desarrolladas se aplican al estudio de dos fenomenos de origen electromecanico de caracteristicas distintas en sistemas complejos de potencia. Se hace una comparacion entre los resultados obtenidos por estas tecnicas y se discute la posibilidad de su aplicacion al problema de identificacion en linea en sistemas de potencia.

  8. Validation of Hiriart equation to compute steam production by the lip pressure method; Validacion de la ecuacion de Hiriart para calculo de gasto de vapor por el metodo de presion de labio

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-09-01

    Mainly in new geothermal wells, it is necessary to evaluate the production in a very fast, simple and not expensive way, to know the convenience to install surface equipment, such as silencers and separators, to drive the steam to the commercial gathering system. In practice, one of the most known methods is the lip pressure one, which requires a simple set of installations. The objective of this paper is to validate the steam flow rate calculated by the lip pressure method, with respect to the ASME method. The ASME method is known for its accuracy, and is done by measuring the steam and liquid after a high pressure separator, by an orifice plate of known diameter and a triangular weir. Results of the validation show up the feasibility of application of the lip pressure method by using a simple adjustment equation. Percentage of mistake results less than 1%, without any notable influence of the production enthalpy. That equation to be applied in a general case, is as follows: Q{nu} =(20642)(F*P*D{sup 2}/{radical}h-2000). For the particular case of the Los Azufres geothermal field, the equation is: Q{nu}= 810*P*D{sup 2} [Espanol] En los pozos geotermicos, principalmente en los nuevos, es necesario evaluar su produccion de manera rapida, sencilla y economica, para determinar la conveniencia de instalar equipo superficial, como separadores, silenciadores, etc., que permita la integracion del vapor al sistema comercial de generacion electrica. Para fines practicos uno de los metodos mas conocidos es el de presion de labio, que solo requiere un arreglo sencillo de instalaciones superficiales. En este documento se validan y ajustan los calculos de produccion de vapor por ese metodo de presion de labio, con respecto a las mediciones exactas efectuadas con el metodo ASME. Este ultimo es reconocido internacionalmente por su precision, y se lleva a cabo separando la mezcla obtenida en superficie en un recipiente a presion para medir el vapor a traves de una placa de orificio

  9. Factors application of MW-mile method and participation in the allocation of charges by the drills use in electricity markets; Aplicacion de los factores de participacion y del metodo de MW-milla en la asignacion de cargos por uso de redes de transmision en mercados de electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Alba-Gomez, L; Tovar-Hernandez, J. H; Gutierrez-Alcaraz, G [Instituto Tecnologico de Morelia, Michoacan (Mexico)]. E-mail: horaciotovar@mexico.com; ggutier@itmorelia.edu.mx

    2007-04-15

    Use of network allocation costs by shift factors and MW-Mile method is reported in this paper. Conventional shift factors are computed based on DC power flow. DC power flow requires to selecting a slack bus in order to avoid matrix singularity. Therefore, shift factors are slack bus dependent. In order to evade slack bus dependency, two approaches are considered. [Spanish] Este trabajo presenta la asignacion de costos por uso de red mediante la aplicacion de Factores de Participacion (FP) y el metodo de MW-Milla. Los FP clasicos son calculados a partir del modelo lineal de flujos de potencia para lo que se requiere de establecer un nodo de referencia a fin de eliminar la singularidad de la matriz de coeficientes. Por lo tanto, los FP son dependientes de la asignacion del nodo de referencia. Dos metodos alternativos para evitar la dependencia del nodo compensador en la obtencion de los factores de participacion son presentados.

  10. Benzyl-tributyl-ammonium 7-hydroxy-naphthalene-1-sulfonate.

    Science.gov (United States)

    Sato, Yohei; Uta, Kazuya; Mizuguchi, Jin

    2009-01-17

    The title compound, C(19)H(34)N(+)·C(10)H(7)O(4)S(-), is a charge-control agent used for toners in electrophotography. The anions form one-dimensional chains by O-H⋯O hydrogen bonds in a zigzag fashion along the c axis between the OH group of one anion and the sulfonate O atom of a neighboring anion. One of the n-butyl chains of the cation is disordered over two sites in a 0.77:0.23 ratio.

  11. Benzyl-tributyl-ammonium 6-hydroxy-naphthalene-2-sulfonate.

    Science.gov (United States)

    Uta, Kazuya; Sato, Yohei; Mizuguchi, Jin

    2009-01-17

    The title compound, C(19)H(34)N(+)·C(10)H(7)O(4)S(-), is a charge-control agent for toners used in electrophotography. Inter-moleclar O-H⋯O hydrogen bonding between the OH group of one anion and the sulfonate O atom of a neighboring anion leads to the formation of one-dimensional chains along the b axis. In addition, C-H⋯O hydrogen bonds are observed. One of the n-butyl chains of the cation is disordered over two sites in a 0.88:0.12 ratio.

  12. Benzyl-tributyl-ammonium 4-hydroxy-naphthalene-2-sulfonate.

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-17

    The title compound, C(19)H(34)N(+)·C(10)H(7)O(4)S(-), is a charge-control agent used for toners in electrophotography. In the crystal structure, centrosymmetric anions associate through O-H⋯O hydrogen bonds formed between the O-H group of one anion and the sulfonate O atom of a neighbor. The components of the dimer are offset with respect to each other so that the separation between the two parallel naphthalene skeletons is about 1.6 Å. The ethyl residues of two of the butyl groups are disordered and were modelled over two postions (site occupancies = 0.33/0.67 and 0.34/0.66).

  13. Treatment of organic waste solutions containing tributyl phosphate

    International Nuclear Information System (INIS)

    Drobnik, S.

    The two processes developed in the laboratory for treating waste solutions containing TBP, namely TBP separation with phosphoric acid and saponification were tested on a semi-industrial scale. A waste solution from the first phase of the Karlsruhe reprocessing plant was used

  14. Recovery of acid-degraded tributyl phosphate by solvent extraction

    International Nuclear Information System (INIS)

    Young, G.C.; Holladay, D.W.

    1981-01-01

    During nuclear fuel reprocessing the organic solvent becomes loaded with various acidic degradation products, which can be effectively removed through solvent extraction. Studies have been made with a small bench-scale solvent extraction system to optimize such parameters as pH of aqueous phase, phase ratio, residence time, flow rates, and temperature. The necessary decontamination factors have been obtained for various degradation products during continuous solvent extraction in one stage, with the aqueous phase being recycled. The aqueous phase contains compounds that can be degraded to gases to minimize waste disposal problems

  15. Nonaqueous chlorination of uranium metal in tributyl phosphate

    International Nuclear Information System (INIS)

    Buchikhin, E.P.; Kuznetsov, A.Yu.; Shatalov, V.V.; Vidanov, V.L.; Chekmarev, A.M.

    2005-01-01

    Low-temperature (30-50 deg C) chlorination of uranium metal in the TBP-TCE-Cl 2 system (TCE = tetrachloroethylene) was studied. Dissolution of uranium in the dipolar aprotic solvent proceeds with formation of U(IV) compounds. The activation energy of this process is 31.24 kJ mol -1 , and relative reaction order with respect to Cl 2 is 2. The effect of TBP concentration on chlorination was examined. The chlorination rate sharply increases at a water content in the TBP-TCE system of 0.2- 0.6 vol % [ru

  16. Development of a chromatographic method for the study of the stability and compatibility of Mexican fuel oils; Desarrollo de un metodo cromatografico para el estudio de estabilidad y compatibilidad de combustoleos mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Blass Amador, Georgina; Panama Tirado, Luz Angelica [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-11-01

    compatibility of fuel oil mixes. [Espanol] En Mexico, la mayoria de la energia electrica producida proviene del uso de combustibles residuales pesados conocidos como combustoleos los cuales han sufrido disminuciones en la calidad debido a una combinacion de factores, entre los que destaca el de los cambios en el proceso de refinacion. Es necesario desarrollar metodos que sean capaces de indicar la inestabilidad (formacion de sedimento o incremento en viscosidad durante el almacenamiento o calentamiento) o incompatibilidad (formacion de sedimento al mezclar dos o mas) de los combustoleos utilizados en las centrales termoelectricas. El objetivo de este trabajo fue el desarrollar una prueba alternativa para el estudio de la compatibilidad y/o estabilidad de combustoleos mexicanos empleando cromatografia de liquidos de alta resolucion (CLAR) y asi poder determinar aspectos estructurales del combustoleo que determinan su estabilidad. Dado que la formacion de sedimentos ocurre cuando el poder disolvente del combustible es inadecuado para mantener los asfaltenos en solucion, es importante conocer la medida del poder disolvente o aromaticidad del diluyente; asi pues, la primera parte de este trabajo se centro en la determinacion del perfil de compuestos aromaticos de los diluyentes de los combustoleos, la otra parte se dedico a la determinacion del perfil de distribucion de los pesos moleculares de los asfaltenos presentes en los combustoleos. Los perfiles de la fraccion aromatica, asi como los de distribucion de pesos moleculares se determinaron empleando cromatografia de liquidos, en la que se empleo una variedad de columnas y de disolventes. Se efectuo una combinacion de pruebas de rutina tales como contenido de asfaltenos, equivalencia de tolueno, viscosidad, etcetera con el fin de obtener correlaciones con el metodo cromatografico desarrollado. En este articulo se discute solo la seccion correspondiente a la obtencion del perfil de contenidos de aromaticos de los combustoleos. Se

  17. Sizing an isolated wind-solar-fuel cell generation system based on the particle swarm optimization method; Dimensionamiento de un sistema de generacion aislado eolico-solar-celda de combustible basado en el metodo de optimizacion de enjambre de particulas

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Huerta, V; Ramirez-Arredondo, Juan M. [Universidad de Quintana Roo, Chetumal, Quintana Roo (Mexico)]. E-mail: vsanchez@gdl.cinvestav.mx; Arriaga-Hurtado, L. G. [CIDETEQ, Queretaro (Mexico)

    2009-09-15

    Sizing an electric energy system requires an analysis of investment, maintenance and operating costs. In the case of a generation system that uses renewable sources, optimal capacity becomes more complex compared to a conventional system, because of the randomness of renewable resources (wind, solar) and the still high costs of wind and photovoltage generator modules. This work presents the optimal sizing of a wind-solar-fuel cell generation system, minimizing the costs of the system while satisfying the energy demands of an isolated charge. The optimization method used is based on an evolutionary programming technique known as particle swarms (PSO-particle swarm optimization). The generation of energy with a hybrid system is discussed, based on the profile of insolation and wind availability at the site, with the objective of satisfying a specific electric demand. [Spanish] El dimensionamiento de un sistema de generacion de energia electrica requiere un analisis de los costos de inversion, mantenimiento y operacion. En el caso de un sistema de generacion que utiliza fuentes renovables la capacidad optima resulta mas compleja con respecto a un sistema convencional, debido a la aleatoriedad de los recursos renovables (eolico, solar), y a los aun altos costos de generadores eolicos y modulos fotovoltaicos. En este trabajo se presenta el dimensionamiento optimo de un sistema de generacion eolico-solar-celda de combustible minimizando los costos del sistema que satisfaga la energia demandada por una carga aislada. El metodo de optimizacion utilizado esta basado en una tecnica de programacion evolutiva conocida como enjambre de particulas (PSO por sus siglas en ingles: particle swarm optimization). Se plantea la generacion de energia del sistema hibrido con base a la insolacion y el perfil del viento disponible en sitio, con objeto de satisfacer una demanda electrica determinada.

  18. L’INFLUENZA DELLE DIFFERENZE CULTURALI NELL’APPRENDIMENTO DELL’ITALIANO L2 DA PARTE DEGLI APPRENDENTI SINOFONI: IL METODO DI STUDIO E L’INSEGNAMENTO DELLA LINGUA STRANIERA IN CINA

    Directory of Open Access Journals (Sweden)

    Gilda Consalvo

    2012-07-01

    Full Text Available Spesso la grande differenza tra la cultura italiana e quella cinese rende il percorso di apprendimento del discente sinofono particolarmente lento e difficile. Come dimostrato da diversi studi, infatti, la cultura di appartenenza ricopre un ruolo fondamentale nell’apprendimento linguistico.Il presente articolo, dopo una breve comparazione tra le peculiarità delle due culture in questione secondo le categorie di Geert Hofstede (1991, illustra il metodo di insegnamento utilizzato nelle suole cinesi, il ruolo dell’insegnante all’interno della classe e della società, il rapporto tra insegnante e studente, approfondendo in modo particolare lo stile di apprendimento dei discenti sinofoni e le loro strategie messe in atto per apprendere la lingua straniera.Lo scopo è fornire informazioni che consentano di comprendere cosa accade quando i discenti sinofoni si trovano in una classe di lingua straniera o seconda con insegnanti madrelingua di culture così differenti e in un contesto di apprendimento diverso da quello già sperimentato nel loro paese e di poter rispondere alle loro esigenze con un intervento didattico adeguato.THE INFLUENCE OF CULTURAL DIFFERENCES IN ITALIAN L2 LEARNING BY CHINESE-SPEAKERS: METHOD OF STUDY AND FOREIGN LANGUAGE TEACHING IN CHINAOften the huge difference between Italian and Chinese cultures makes the learning process for Chinese-speaking students particularly hard and slow. As many studies have shown, in fact, the home culture plays a fundamental role in language learning.This article, after a brief comparison between the two cultures according to the categories defined by Geert Hofstede (1991, illustrates teaching methods used in Chinese schools, the teacher’s role in the classroom and in society and the relationship between teacher and student, investigating the learning style of Chinese-speaking students and the strategies they implement when learning a foreign language.The aim is to offer information which

  19. Uses and updating of the Benders method in the integer-mixed programming in the planning of the electric power systems expansion; Usos y actualizacion del metodo de Benders en la programacion entera-mixta y en la planeacion de la expansion de los sistemas electricos de potencia

    Energy Technology Data Exchange (ETDEWEB)

    De la Torre Vega, Eli

    1997-04-01

    of some potential improvements that the proposed method has. [Espanol] En el primer capitulo se presenta la deduccion de los cortes de Benders partiendo de las propiedades de la dualidad. Tambien se presentan las propiedades de los cortes de Benders asi como el algoritmo inicial de Benders para resolver cualquier problema de programacion lineal entera-mixta. En el segundo capitulo, se presenta el problema de la planeacion de la expansion de los medios de generacion y transmision en un sistema electrico de potencia, las distintas estructuras de la programacion matematica a que da lugar y como se puede adaptar el metodo de Benders a estas. En el tercer capitulo se presentan las aportaciones teoricas de este trabajo: a) Como inicializar el problema maestro para aprovechar la experiencia adquirida despues de haber resuelto un problema similar, de modo que se pueda resolver mas eficientemente, la sucesion de problemas de programacion lineal entero-mixtos que surgen al resolver el problema de la planeacion de la expansion de los medios de generacion y transmision en un sistema electrico de potencia. b) Como generar un problema maestro cuya solucion optima continua corresponda al optimo continuo del problema entero-mixto, de modo que la busqueda de soluciones enteras se realice en la vecindad del optimo continuo. c) Como generar una solucion entera, cercana al optimo continuo del problema entero-mixto, que tenga mucha probabilidad de ser factible, y que quizas sea la solucion optima entera, en un tiempo menor al que se requiere para resolverlo en forma exacta. Ademas, se presentan otras ideas que se le pueden incorporar al metodo de Benders. A fin de mostrar la efectividad de las ideas propuestas, en el capitulo 4 se presentan los resultados obtenidos al resolver varios problemas usando: 1. El metodo de Benders in actualizacion, 2. El metodo de Ramificacion y Acotamiento, 3. La actualizacion de Benders al agregar restricciones y 4. La actualizacion de Benders al considerar

  20. A radiochemical procedure for a low-level measurement of ''241Am in environmental samples using a supported functional organo phosphorus extractant; Metodo analitico para la determinacion de ''241Am en muestras biologicas y sedimentos marinos mediante uso de una columna con extractante organico

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Anton, M. P.; Alvarez, A.; Navarro, N.; Salvador, S.

    1994-07-01

    The transuranides analysis in environmental samples is carried out by CIEMAT using standardized methods based on sequential separation with ionic-exchange resins. The americium fraction is purified through a two-layer ion exchange column and lately in an anion-exchange column in nitric acid methanol medium. The technique is time consuming and the results are not completely satisfactory (low recovery and loss of a-resolution) for some samples. The chemical compound CMPO (octyl(phenyl)-N,N-diisobutyl carbomoylmethyiphosphine oxide) dissolved in TPB (tributyl phosphate) and supported on an inert substrate has been tested directly for ''241Am analysis by a large number of laboratories. A new method that combines both procedures has been developed. The details of the improved procedure are described in this paper. The advantages of its application to environmental samples (urine, faeces and sediments) are discussed. The utilization of standard samples, with americium certified concentrations confirms the reliability of our measurements. (Author) 8 refs.

  1. Proposed method for the hydraulic design of ski-jump energy dissipators in dam spillways considering the occurrence of scour holes downstream of the structure; Metodo propuesto para el diseno hidraulico de trampolines empleados como disipadores de energia en aliviaderos para presas, considerando la ocurrencia del cono de socavacion al pie del mismo

    Energy Technology Data Exchange (ETDEWEB)

    Pardo-Gomez, Rafael [Centro de Investigaciones Hidraulicas (Cuba)

    2008-04-15

    Ski-jump energy dissipators are widely used in hydraulic engineering because of their well-known effectiveness. Nevertheless, some uncertainty exits associated with the dimensions of the scour hole appearing downstream of the structure. This paper presents a new method for solving this problem. This method includes spillway stability checking as part of the design process and also stability checking of any other construction near the energy dissipation zone. [Spanish] Los disipadores de energia tipo trampolin tienen amplia utilizacion en la practica de la ingenieria hidraulica por su probada eficacia; sin embargo, su diseno esta sujeto a cierto grado de incertidumbre en cuanto a la prediccion de las dimensiones del cono de socavacion que habra de producirse aguas abajo de la estructura. En el presente trabajo se muestra un metodo novedoso, mediante el cual el autor soluciona el aspecto antes referido, toda vez que se incluye como parte del proceso de diseno la comprobacion de la estabilidad del propio aliviadero o de cualquier otra obra cercana a la zona de disipacion de energia.

  2. Benzyl­tributyl­ammonium 4-hydroxy­naphthalene-2-sulfonate

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-01

    The title compound, C19H34N+·C10H7O4S−, is a charge-control agent used for toners in electrophotography. In the crystal structure, centrosymmetric anions associate through O—H⋯O hydrogen bonds formed between the O—H group of one anion and the sulfonate O atom of a neighbor. The components of the dimer are offset with respect to each other so that the separation between the two parallel naphthalene skeletons is about 1.6 Å. The ethyl residues of two of the butyl groups are disordered and were modelled over two postions (site occupancies = 0.33/0.67 and 0.34/0.66). PMID:21581925

  3. Benzyl­tributyl­ammonium 4,6-dihydroxy­naphthalene-2-sulfonate

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-01

    The title mol­ecular salt, C19H34N+·C10H7O5S−, is a charge-control agent used for toners in electrophotography with a high melting point of 508 K. In the crystal structure, the anions form inversion dimers, linked by pairs of O—H⋯O hydrogen bonds. Further O—H⋯O links between dimers generate anionic sheets propagating in (010). One of the n-butyl chains of the cation is disordered over two sets of sites in a 0.53:0.47 ratio. PMID:21581927

  4. Benzyl­tributyl­ammonium 6,7-dihydroxy­naphthalene-2-sulfonate

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-01

    The title mol­ecular salt, C19H34N+·C10H7O5S−, is a charge-control agent used for toners in electrophotography. There are two formula units in the asymmetric unit. Both anions form inversion dimers connected by pairs of O—H⋯O hydrogen bonds between the –OH group of one anion and a sulfonic O atom of the neighboring one. The two dimers A and B are characterized by a step between the least-squares planes of the naphthalene atoms of 0.85 and 2.30 Å. Further O—H⋯O bonds link the dimers into a two-dimensional network propagating in (110) such that dimer A is hydrogen-bonded to four B units and vice versa. One of the tert-butyl chains in one of the cations is disordered over two sets of sites in a 0.56:0.44 ratio. PMID:21581928

  5. Benzyl-tributyl-ammonium 4,6-dihydroxy-naphthalene-2-sulfonate.

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-17

    The title mol-ecular salt, C(19)H(34)N(+)·C(10)H(7)O(5)S(-), is a charge-control agent used for toners in electrophotography with a high melting point of 508 K. In the crystal structure, the anions form inversion dimers, linked by pairs of O-H⋯O hydrogen bonds. Further O-H⋯O links between dimers generate anionic sheets propagating in (010). One of the n-butyl chains of the cation is disordered over two sets of sites in a 0.53:0.47 ratio.

  6. Benzyl­tributyl­ammonium 7-hydroxy­naphthalene-1-sulfonate

    Science.gov (United States)

    Sato, Yohei; Uta, Kazuya; Mizuguchi, Jin

    2009-01-01

    The title compound, C19H34N+·C10H7O4S−, is a charge-control agent used for toners in electrophotography. The anions form one-dimensional chains by O—H⋯O hydrogen bonds in a zigzag fashion along the c axis between the OH group of one anion and the sulfonate O atom of a neighboring anion. One of the n-butyl chains of the cation is disordered over two sites in a 0.77:0.23 ratio. PMID:21581926

  7. Benzyl-tributyl-ammonium 6,7-dihydroxy-naphthalene-2-sulfonate.

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-17

    The title mol-ecular salt, C(19)H(34)N(+)·C(10)H(7)O(5)S(-), is a charge-control agent used for toners in electrophotography. There are two formula units in the asymmetric unit. Both anions form inversion dimers connected by pairs of O-H⋯O hydrogen bonds between the -OH group of one anion and a sulfonic O atom of the neighboring one. The two dimers A and B are characterized by a step between the least-squares planes of the naphthalene atoms of 0.85 and 2.30 Å. Further O-H⋯O bonds link the dimers into a two-dimensional network propagating in (110) such that dimer A is hydrogen-bonded to four B units and vice versa. One of the tert-butyl chains in one of the cations is disordered over two sets of sites in a 0.56:0.44 ratio.

  8. Radiation Stability of Benzyl Tributyl Ammonium Chloride Towards Technetium-99 Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Jared Horkley; Audrey Roman; Keri Campbell; Ana Nunez; Amparo Espartero

    2013-02-01

    A closed nuclear fuel cycle combining new separation technologies along with generation III and generation IV reactors is a promising way to achieve a sustainable energy supply. But it is important to keep in mind that future recycling processes of used nuclear fuel (UNF) must minimize wastes, improve partitioning process, and integrate waste considerations into processes. New separation processes are being developed worldwide to complement the actual industrialized PUREX process which selectively separates U(VI) and Pu(IV) from the raffinate. As an example, low nitric acid concentration in the aqueous phase of a UREX based process will co-extract U(VI) and Tc(VII) by tri-n-butyl phosphate (TBP). Technetium (Tc-99) is recognized to be one of the most abundant, long-lived radiotoxic isotopes in UNF (half-life, t1/2 = 2.13 × 105 years), and as such, it is targeted in UNF separation strategies for isolation and encapsulation in solid waste forms for final disposal in a nuclear waste repository. Immobilization of Tc-99 by a durable solid waste form is a challenge, and its fate in new advanced technology processes is of importance. It is essential to be able to quantify and locate 1) its occurrence in any new developed flow sheets, 2) its chemical form in the individual phases of a process, 3) its potential quantitative transfer in any waste streams, and consequently, 4) its quantitative separation for either potential transmutation to Ru-100 or isolation and encapsulation in solid waste forms for ultimate disposal. Furthermore, as a result of an U(VI)-Tc(VII) co-extraction in a UREX-based process, Tc(VII) could be found in low level waste (LLW) streams. There is a need for the development of new extraction systems that would selectively extract Tc-99 from LLW streams and concentrate it for feed into high level waste (HLW) for either Tc-99 immobilization in metallic waste forms (Tc-Zr alloys), and/or borosilicate-based waste glass. Studies have been launched to investigate the suitability of new macrocompounds such as crown-ethers, aza-crown ethers, and resorcinarenes for the selective extraction of Tc-99 from nitric acid solutions. The selectivity of the ligand is important in evaluating potential separation processes and also the radiation stability of the molecule is essential for minimization of waste and radiolysis products. In this paper, we are reporting the extraction of TcO4- by benzyltributyl ammonium chloride (BTBA). Experimental efforts were focused on determining the best extraction conditions by varying the ligand’s matrix conditions and concentration, as well as varying the organic phase composition (i.e., diluent variation). Furthermore, the ligand has been investigated for radiation stability. The ?-irradiation was performed on the neat organic phases containing the ligand at different absorbed doses to a maximum of 200 kGy using external Co-60 source. Post-irradiation solvent extraction measurements will be discussed.

  9. Determination of tributyl phosphate (TBP) by precision densimetry : TBP-varsol-HNO3 system

    International Nuclear Information System (INIS)

    Matsuda, H.T.; Araujo, B.F. de; Araujo, J.A. de

    1980-01-01

    A simple and rapid method for TBP direct determination is presented, based on precision densimetry, aiming to control solvent concentration in the TBP-Varsol system during the reprocessing of irradiated uranium. The method comprises the determination of the density of liquids or gases by electronic measurement of the variation in the frequency (f) or period (T = 1/f) of a glass oscillator containing the liquid or the gas. (C.L.B.) [pt

  10. Intensification of separation of extraction emulsions in systems with tributyl phosphate in ultrasonic field

    International Nuclear Information System (INIS)

    Khavskij, N.N.; Kagerman'yan, V.S.; Kanevskij, I.N.; Kim, S.P.

    1976-01-01

    The fundamental principles have been studied determining the separation of extraction emulsions appearing in the course of the aqueous and ammonia reextraction of molybdenum from tributylphosphate (TBP) in the ultrasonic field. Piezoelectric radiators with a frequency of 0.8 to 1,0 MHz are used as ultrasonic generators. The organic extract contains 7 g/1 Mo within the hydrosolvate complex. Acceleration of the separation process has been established to take place in the ultrasound region 0.25 to 1.25 W/cm 2 for the aqueous and ammonia systems. The optimal conditions for the separation process exist within 0.5 to 0.65 W/cm 2 , they being 18 minutes for the aqueous and 16 minutes for the ammonia emulsion. It is demonstrated that as a result of the superposition of the ultrasound over the emulsions being formed by TBP with water and ammonia, the separation of the aqueous emulsions increases by a factor of 5 to 6 and of the ammonia emulsions - by a factor of 50 to 80. It is advisable that the ultrasound emulsion treatment for 5 to 10 minutes be coupled with a subsequent settling. As this takes place, the total period of the phase separation will be 18 to 20 minutes. The separation rate increases with temperature. The maximum emulsion separation acceleration is observed within 25 to 30 deg C. The possibility has been revealed to realize the process of the ultrasound intensification of the emulsion separation process by using small-sized extraction equipment

  11. Mechanism of extraction emulsion separation with tributyl phosphate in ultrasonic field

    International Nuclear Information System (INIS)

    Khavskij, N.N.; Kagerman'yan, V.S.; Kanevskij, I.N.; Kim, S.P.; Smirnov, Yu.R.

    1977-01-01

    The main specific features of separating extraction emulsions with the help of ultrasound, accelerating the separation process 5-6 times, have been studied. The emulsions prepared from TBP containing 7 g/m of Mo and 3 g/l of W, water, aqueous solution of sodium oleate, and NH 4 OH have been investigated. The process of emulsion separation can be divided into two stages: a fast stage where coagulation proceeds due to a radiation pressure and orthokinetic collisions, and a slow stage proceeding because of hydrodynamic forces. For qualitative and fast separation of the emulsions it is necessary to apply ultrasound from the beginning of separation when concentration of large particles is noticeable

  12. Extraction and determination of molybdenum with tributyl phosphate Application to analysis of copper-molybdenum ores.

    Science.gov (United States)

    Caiozzi, M; Zunino, H; Sepúlveda, L

    1969-12-01

    A differential spectrophotometric method is described for the determination of molybdenum by means of solvent extraction with tributylphosphate of the peroxymolybdate complex formed with H(2)O(2) in 3.5N H(2)SO(4). The extraction parameters are studied, and the behaviour of some other ions is reported. The method is used for ore analysis.

  13. Avaliação da composição corporal em adolescentes obesos: o uso de dois diferentes métodos Evaluación de la composición corporal en adolescentes obesos: uso de dos metodos diferentes Body composition evaluation in obese adolescents: the use of two different methods

    Directory of Open Access Journals (Sweden)

    Marco Túlio de Mello

    2005-10-01

    Full Text Available A pletismografia é um método rápido e fácil para determinação da composição corporal que utiliza a relação inversa entre pressão e volume. O objetivo do presente estudo foi o de comparar os valores obtidos com o método pletismografia com os valores observados com o DEXA em uma população de adolescentes obesos. Participaram da amostra 88 adolescentes pós-púberes de ambos os sexos, com idades entre 15 e 19 anos (17,01 ± 1,6 ingressantes de um programa de atividade física multidisciplinar. Os voluntários foram submetidos a uma avaliação da composição corporal em dias distintos dentro da mesma semana, pelo método de pletismografia e outra avaliação pelo método DEXA. Quando os métodos foram comparados, não se observaram diferenças significativas entre eles; além disso, foram observadas correlações significativas entre os parâmetros comuns dos dois métodos (massa magra, massa gorda (kg e massa gorda (%, r = 0,88 p La pletismografía es un método rápido y fácil para la determinación de la composición corporal que utiliza la relación inversa entre la presión y el volumen. El objetivo del presente estudio fué el de comparar los valores obtenidos con el metodo pletismografia con los valores observados con el DEXA en una población de adolescentes obesos. Participaron de la muestra 80 adolescentes post púberes de ambos sexos, con edades entre los 15 y los 19 años (17,01±1,6 iniciantes en un programa de actividad física multidisciplinar. Los voluntarios fueron sometidos a una evaluación de la composición corporal en días distintos dentro de la misma semana, por el método de pletismografia y otra evaluación por el método DEXA. Cuando se compararon los métodos, no fueron observadas diferencias significativas entre ellos, además de ello, fueron observadas correlaciones entre los parámetros comunes a los dos métodos (masa magra, masa grasa (kg y masa gorda (%, r = 0,88 p Plethysmography is an easy and

  14. Electrochemical performance in the hydrogen evolution reaction of Ni-TR (TR= La, Ce) materials synthesized using the solid state reaction method; Desempeno electroquimico en la reaccion de evolucion de hidrogeno de materiales de electrodo Ni-TR (TR = La, Ce) sintetizados por el metodo de reaccion de estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Huerta, A. M.; Dominguez-Crespo, M. A.; Ramirez-Meneses, E.; Yanez-Zamora, C. [CICATA, IPN, Altamira, Tamaulipas (Mexico); Avila-Garcia, I. [IPN, ESIQIE, UPALM, Mexico, D.F. (Mexico)]. E-mail: mdominguezc@ipn.mx; adcrespo2000@yahoo.com.mx

    2009-09-15

    relacionados con su operacion. El material de electrodo con mayor electroactividad es el Pt, pero debido a su costo elevado se han tenido que buscar electrocatalizadores alternativos con un balance entre costo y actividad. Uno de los materiales que mas se ha utilizado es el Niquel en conjunto con algunas de sus aleaciones. Este material ha demostrado un buen desempeno utilizando bajos sobrepotenciales en reacciones tradicionales como las reacciones de evolucion de hidrogeno (REH) y oxigeno (REO), asi como una alta resistencia a la corrosion y bajo costo. Particularmente, aleaciones binarias y ternarias han demostrado un incremento importante en la actividad de la REH al compararla con los materiales en su estado puro o masivo. Por esta razon, en la busqueda de nuevas alternativas con una aceptable eficiencia al compararla con los materiales a bajo costo, en este trabajo se obtuvieron materiales Ni-TR (TR = La, Ce) por el metodo de reaccion de estado solido, a partir de: a) acetilacetonatos metalicos y b) polvos metalicos. Estos materiales se sinterizaron durante 3 h a diferentes temperaturas (795 o 920 , 1000 y 1200 grados centigrados) a fin de evaluar su efecto en el desempeno electroquimico de los electrocatalizadores. La caracterizacion estructural y morfologica de materiales se realizo por las tecnicas de DRX y MEB, respectivamente. Asimismo, el desempeno electroquimico de los materiales de electrodo se evaluo en la REH utilizando voltametria ciclica (VC) y curvas potenciodinamicas. Los resultados obtenidos muestran que a bajas temperaturas se obtiene una mezcla de oxidos (NiO, CeO{sub 2} y LaNiO{sub 3}); sin embargo a medida que la temperatura de sinterizado se incrementa, se alcanza la formacion de las aleaciones NiO-CeO{sub 2} y NiO-LaNiO{sub 3}, respectivamente. Al mismo tiempo se observo una clara dependencia de la actividad electrocatalitica con la fuente obtencion de estos materiales (Ni-TR).

  15. SPECULAZIONI E TESTABILITÀ IN COSMOLOGIA: IN DIFESA DEL METODO

    Directory of Open Access Journals (Sweden)

    Giovanni Covone

    2017-12-01

    Full Text Available SPECULATION AND TESTABILITY IN COSMOLOGY: IN DEFENSE OF THE METHOD The direct detection of the gravitational waves offers new means for the exploration of the cosmos: we can investigate the centre of supernovae, the physics of black holes and gamma flashes, and even push (in the future our gaze at the early stages of life of the Universe. Cosmological research has allowed us to establish a robust framework of the structure and evolution of the Universe. However, some of his foundations are still mysterious as they were twenty years ago: the nature of dark matter or the value of the fundamental physical constants. Some theoretical proposals for solving these problems are based on theoretical entities beyond any possible verification, perhaps even in principle, fueling the controversy about the state of scientificness of part of contemporary theoretical physics. After briefly presenting the state of current knowledge in cosmology, we will introduce the problems of philosophical interest discussed in the community of physicists and cosmologists. Finally, we discuss the possibilities offered by the forthcoming gravitational wave observations. In this contribution, therefore, we focus our attention on the general picture of the universe provided by cosmology, the short-term prospects and the discussion of the epistemological value of some theoretical attempt.

  16. Il metodo della fisica e le problematiche della biologia

    Directory of Open Access Journals (Sweden)

    Tripodi, G

    2007-07-01

    Full Text Available Following the ancient Hermetic aphorism solve et coagula, we investigate the nature of the interface between physics and biology by moving up and down the different temporal and spatial scales which enter the description of natural phenomena. Various indications seem to support both the existence of such an interface and the possibility of finding methods, languages, and targets shared by such two disciplines. However, this possibility becomes remote if one moves further and further from the microscopic level of atoms and molecules (and, correspondingly, of molecular biology. We conclude that the biologically founded epistemology proposed by Maturana and Varela as well as cultural anthropology and sociology cannot yet be treated with the methodology of physics.

  17. El Metodo Llamado Proyecto (The Project Approach). ERIC Digest.

    Science.gov (United States)

    Katz, Lilian G.

    A project is an in-depth investigation of a topic worth learning more about, usually undertaken by a group of children within a class. The goal of a project is to learn more about a topic rather than to find answers to questions posed by a teacher. Project work is complementary to the systematic parts of a curriculum. Whereas systematic…

  18. Vico e il problema del metodo tra sperimentalismo e retorica

    Directory of Open Access Journals (Sweden)

    Giulio Gisondi

    2016-12-01

    Full Text Available [Vico and the Problem of Method between Rhetoric and Experimentalism]. This paper analyses some of the major issues discussed by Vico in his De nostri temporis studiorum ratione. Focusing especially on books VII and X, the author examines Vico’s comparison between the method of the “ancients” – or “topica”– and the one of the “moderns” – or critica. In this perspective, the study retraces the question of method exposed by Vico, starting from the discussions within the Accademia of Investiganti and from the heritage of humanistic rhetoric. The solution proposed by Vico to the problem of education and learning showshow it ispossible to conciliate the “ratio critica” and the “ratiotopica”. The study underlines how Vico can recovery the rhetorical method of “topica” in the context of the Cartesian debate in Naples.

  19. Ensenanza de la Astronomia a Traves de Metodos no Tradicionales

    Science.gov (United States)

    Tignanelli, H. L.

    1990-11-01

    REUMEN: Se presentan los aspects pri nc ipales de a ense? anza de la astronor:. a para -; s. En esta cc .unicaci #n, 5 ha especial mfasis em Ia descripci':"n de las caracteristicas y las posibi lidades peda gicas de los no tradicionales de aprendiZaje. E' : In the following the principal aspects of teaching of astrono ..y for children) are oresented. In this paper, special emphasis has been given to desc rib the characteristics and pedagogical possibilities of the non traditional methods of learning. : TEACHING

  20. Il metodo di Aristarco à solo un modello?

    Science.gov (United States)

    Sigismondi, Costantino; Agolini, Giorgia

    2017-06-01

    The method of Aristarchus of Samo to measure the distance Earth-Sun is well known as the first step in the cosmological distance ladder. Our task is to understand if it is worth to repeat it also experimentally, with positive conclusions, especially with respect to the experimental design.

  1. A {beta} - {gamma} coincidence; Metodo de coincidencias {beta} - {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Agullo, F.

    1960-07-01

    A {beta} - {gamma} coincidence method for absolute counting is given. The fundamental principles are revised and the experimental part is detailed. The results from {sup 1}98 Au irradiated in the JEN 1 Swimming pool reactor are given. The maximal accuracy is 1 per cent. (Author) 11 refs.

  2. Impacto orcamentario da utilizacao do Metodo Canguru no cuidado neonatal

    Directory of Open Access Journals (Sweden)

    Aline Piovezan Entringer

    2013-10-01

    Full Text Available OBJETIVO Estimar o impacto orçamentário da utilização do Método Canguru na rede municipal de saúde. MÉTODOS Um modelo de decisão analítico foi desenvolvido para simular os custos do Método Canguru e Unidade Intermediária Neonatal no Rio de Janeiro, RJ, em 2011. A população de referência foi constituída pelos recém-nascidos estáveis clinicamente, que podem receber assistência nas duas modalidades de cuidado. O impacto orçamentário foi estimado para uma coorte hipotética de 1.000 recém-nascidos elegíveis em um ano. A proporção de recém-nascidos elegíveis que recebem assistência nas duas modalidades foi obtida por coleta de dados nas maternidades incluídas no estudo. As probabilidades dos eventos e o consumo de recursos de saúde, no período da assistência, foram incorporados ao modelo. Cenários foram desenvolvidos para refletir a adoção do método Canguru em maior ou menor escala. RESULTADOS A utilização do Método Canguru significou redução de gastos equivalente a 16% em um ano, se todos os recém-nascidos elegíveis fossem assistidos por esse método. CONCLUSÕES A opção Método Canguru é de menor custo comparado com a da Unidade Intermediária Neonatal. A análise de impacto orçamentário da utilização desse método no Sistema Único de Saúde indicou economia importante para o período de um ano.

  3. Volatile organic compounds determination in the atmosphere of Mexico City by the use of optical systems and non conventional methods; Determinacion de compuestos organicos volatiles en la atmosfera de la Ciudad de Mexico mediante el uso de sistemas opticos y metodos convencionales

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Maria Esther; Arriaga, Jose Luis; Garcia, Isidoro [Gerencia de Ciencias de Ambiente, Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    1996-04-01

    results presented here were obtained through collaboration of the Environmental Sciences group of the Mexican Petroleum Institute (GCA-IMP) with different people and groups. [Spanish] Desde 1991, se han determinado las concentraciones de los componentes orgaicos volatiles (COV) presentes en la atmosfera de la Zona Metropolitana de la Ciudad de Mexico (ZMCM) mediante diferentes metodos de muestreo y analisis. Las muestras recolectadas en cartuchos y canisteres se analizan por cromatografia de gases o de liquidos. Tambien se ha iniciado el monitoreo continuo de la atmosfera mediante un analizador de la absorcion diferencial en trayectorias largas conocido como DOAS. El Instituto Mexicano del Petroleo junto con la Agencia de Proteccion al Ambiente de los Estados Unidos (EPA) y las autoridades ambientales en Mexico han llevado a cabo cuatro campans de muestreo y analisis de aire del ambiente en canisteres, siguiendo la metodologia TO-14 de la EPA. Las campans se han llevado a cabo en el mes de marzo, porque es en este mes cuando han sucedido los peores episodios de ozono. Se han hecho muestreos adicionales durante el mes de noviembre con objeto de comparar los resultados entre las diferentes estaciones del ano. En marzo de 1993, se recolectaron muestras en tres diferentes tipos de cartuchos que absorben selectivamente a los componentes carbonilo, los hidrocarburos ligeros (C{sub 2}-C{sub 4}) y los hidrocarburos pesados (C{sub 5}-C{sub 1}5). Las tres tenicas de muestreo, canisteres, cartuchos y DOAS revelan concentraciones atmosfericas altas de compuestos organicos y volatiles, especies precursoras del ozono, estas altas concentraciones explican las excedencias a las normas observadas frecuentemente en la ZMCM. La cinetica del conjunto de reacciones indica entonces, que la formacion de ozono en esta atmosfera estara limitada por los oxidos de nitrogeno que en este caso son los precursores en menor concentracion relativa y por lo tanto, la especie limitante de las reacciones

  4. Histopathology of kidney induced by LICAM (C) therapy in baboons after inhalation of plutonium-tributyl phosphate complex

    International Nuclear Information System (INIS)

    Fritsch, P.; Lepage, M.; Duserre, C.; Metivier, H.; Gerasimo, P.

    1989-01-01

    The histological changes induced in baboon kidneys after administration of LICAM C and/or DTPA to remove Pu after inhalation of large doses of 239 Pu-TBP have been characterised. Treatment with LICAM C alone was most effective at removing Pu from the body but increased its retention in the kidneys. It also induced specific kidney lesions confined to the proximal tubules, i.e. vacuole formation in the basal part of the tubular cells. No vacuolar lesions were observed after treatment with DTPA alone. Combined treatment with LICAM C and DTPA was less effective than with LICAM C alone but more effective than with DTPA alone. After this combined treatment, in which the smallest cumulated dose of LICAM C was used, the kidney Pu burden decreased compared to the burden after treatment with LICAM C alone, but the specific lesions in the proximal tubules were still sometimes observed. The vacuole formation induced by LICAM C seemed to be reversible and the number of vacuoles was closely correlated with the dose of LICAM C administered. (author)

  5. Determination of halogens, silicon, phosphorus, carbon, sulfur, tributyl phosphate and of free acid in uranyl nitrate solutions

    International Nuclear Information System (INIS)

    Chu Van Vinh

    2003-01-01

    High-purity uranium compounds are widely used in nuclear field in the form of uranyl nitrate or uranium oxides. In production of uranium material the estimation and the control of products quality is necessary and very important. Halogens was separated from uranium compounds by steam distillation and they were later determined by high performance liquid chromatography (HPLC) for Cl - , Br - , I - ions. Br - was also determined by spectrophotometric and iodide by the individual pulse polarography. Silicon and phosphorus in uranyl nitrate solutions were determined by the photometric method. Sulfur was determined as sulfate form by the measurement of turbidity by the titrimetry. TBP in kerosene and free acid in aqueous solution were determined by the titration. (author)

  6. Studies on the Conditioning Methods of Spent Tri-butyl Phosphate/Kerosene and its Degradation Product in Different Matrices

    International Nuclear Information System (INIS)

    El-Dessouky, M.I.; El-sourougy, M.R.; Abed El-Aziz, M.M.; Aly, H.F.

    1999-01-01

    The destruction of spent TBP/Kerosene (odourless Kerosene (OK)) with potassium permanganate have been investigated. Comparative studies on the immobilization of spent TBP/Kerosene and its degradation product into different matrices have been carried out. The matrices used include, ordinary Portland cement, silica fume, treated fly ash, epoxy resin and cement mixed with epoxy resin.The different factors affecting solidified waste forms such as, compressive strength, water resistance, thermal stability, chemical resistance, radiological stability and leachability have been investigated. It was found that, epoxy resin and cement mixed with 5,10,20, and 50% of epoxy resin enhance the compressive strength of the solidified waste forms with spent TBP/OK more than that obtained from degradation products. The leaching rates of 152 and 154 Eu and 181 Hf from waste forms containing TBP/OK was found lower than that with degradation product

  7. Investigation on the formation of a third phase in the extraction of Pu(IV) nitrate with tributyl phosphate

    International Nuclear Information System (INIS)

    Yu Enjiang; Liu Liming; Huang Huaian

    1986-01-01

    The formation of a third phase is studied in the system Pu(IV) nitratenitric acid-TBP-alkane diluent (or kerosine). The maximum concentration (solubility, S Pu ) of Pu(IV) in the equilibrium organic phase at which still no third phase is formed is measured as a function of the nitric acid concentration in the equilibrium aqueous phase C H , the temperature, and the molecular size of n-alkane duluent. Results show that maxima of S Pu at 6 to 7 M nitric acid are observed at 17 deg C, 26 deg C and 35 deg C while not at 40 deg C. Minima on the S Pu vs. C H curves at 0.5 to 2 M mitric acid have been observed at 17 deg C and 26 deg C. It is found that the molecular size of n-alkane diluents has a very pronounced effect on S Pu . The effect of aqueous equilibrium Pu(IV) concentration on the formation of a third phase is investigated, when the equilibrium HNO 3 concentration is 3.5 M. It is shown that the plutonium concentration of the third phase is increased with increasing aqueous equilibrium Pu(IV) concentration. The effect of the addition of lauryl alcohol on the S Pu is preliminarily studied

  8. Studies on the conditioning methods of spent tri-butyl phosphate/kerosene and its degradation product in different matrices

    International Nuclear Information System (INIS)

    El-Dessouky, M.I.; El-Sourougy, M.R.; Abed El-Aziz, M.M.; Aly, H.F.

    2001-01-01

    The destruction of spent TBP/Kerosene (odourless kerosene (OK)) with potassium permanganate has been investigated. Comparative studies on the immobilization of spent TBP/Kerosene and its degradation product into different matrices have been carried out. The matrices used include, ordinary portland cement, silica fume, treated fly ash, epoxy resin and cement mixed with epoxy resin. The different factors affecting solidified waste forms, such as compressive strength, water resistance, thermal stability, chemical resistance, radiological stability and leachability, have been investigated. It was found that epoxy resin and cement mixed with 5, 10, 20, and 50% of epoxy resin enhance the compressive strength of the solidified waste forms with spent TBP/OK more than that obtained from degradation products. The leaching rates of 152,154 Eu and 181 Hf from waste forms containing TBP/OK was found lower than that with degradation product. (author)

  9. Application of the gyroscopic method in subterranean orientation. Comparison with conventional methods. Aplicacion del metodo gyroscopic en la orientacion subterranea. Comparacion con los metodos convencionales

    Energy Technology Data Exchange (ETDEWEB)

    Saez Garcia, E.; Fuente Martin, P.L. (HUNOSA, Madrid (Spain))

    1988-01-01

    This entry tries to revise the most used method for the direction transition what with exterior and interior using plumbs in connected with vertical shaft coalmines. A technical and economic cooperation was also realized between the indicated method and the gyroscope.

  10. COMPARACIÓN DEL ESTADIO FETAL OBTENIDO POSTMORTEM MEDIANTE DOS METODOS ANTROPOMETRICOS. Comparación del estadio fetal obtenido postmortem mediante dos metodos antropometricos

    Directory of Open Access Journals (Sweden)

    Mirta M Aliendo

    2016-03-01

    Full Text Available En la etapa fetal se observa un rápido incremento de la masa corporal y de todas las dimensiones. La literatura evidencia discrepancias sobre los criterios para determinar el estadio fetal post-mortem, en relación a los parámetros morfométricos utilizados, por lo que nuestro objetivo fue comparar la medición morfológica directa (vertex-coxis, tabla de Hansmann con la ultrasonografía (medición del fémur, para establecer el grado de confiabilidad en la determinación post-mortem del estadío fetal. Se utilizaron 120 fetos: 1 grupo A (60 fetos estadificado ecográficamente y 2 grupo B (60 fetos estadificado por tabla de Hansmann. A ambos grupos se le realizaron múltiples mediciones siguiendo parámetros probados según la literatura internacional. Se utilizó calibre de precisión. Parámetros evaluados: longitud vertex-coxis, circunferencia cefálica, diámetro cefálico occipito-frontal, biparietal, longitud mentón-vertex, perímetro toráxico-transverso, circunferencia abdomi-nal y longitudes de brazo, antebrazo, mano, muslo, pierna y pie. Estos valores fueron agrupados por semanas, obteniéndose la media y aplicándose la prueba t de Student. Los resultados demostraron que la diferencia entre los parámetros medidos en el grupo A y en el grupo B eran significativas en todas las semanas, por lo que se observa disparidad en la determinación del estadio fetal por ecografía y los registros correspondientes a la medición vertex-coxis (tabla de Hansmann postmortem. Concluímos que los resultados obtenidos por ambas modalidades de medición son diferentes para una misma edad gestacional y, por ende, resultaría más apropiado referirse a fetos con ciertas dimensiones según alguno de estos parámetros que a “edad gestacional”.In fetal stage, body mass and measurements quickly increase. Scientific literature shows differences on the criteria to determine the post-mortem fetal stage, depending on morphometric parameters. Our objective was to compare both methods, direct morphologic measures (crown-rump length, Hansmann table and ultrasonography (femur measurement, to establish their reliability on post-mortem determination of fetal age. One hundred and twenty fetuses were studied: 1 group A (60 fetuses sonographically staged and 2 group B (60 fetuses staged according to Hansmann table. Many measurements were performed on both groups, following internationally determined parameters. We used a precision gauge. Considered parameters were: crown-rump length, head circumference, occipito-frontal diameter, bi-parietal length, chin-vertex length, thoracic transverse perimeter, abdominal circumference, arm, forearm, hand, thigh, leg and foot lengths. Obtained information was grouped by weeks. We calculated the data mean and significant difference was managed by Student t-test. Results demonstrated significant difference in the considered parameters between group A and B, and then, to determine the fetal age.We conclude that results obtained by both measuring modalities were different for the same gestational age, and therefore, it should be more appropriate to consider fetuses by measures obtained following certain parameters than by “gestational age”.

  11. A spanish mineral of zirconium and hafnium. Separation of the two elements by liquid-liquid extraction, using tributyl phosphate as chelating agent

    International Nuclear Information System (INIS)

    Ruiz Sanchez, F.; Cruz Castillo, F. de la; Fernandez Cellini, R.

    1962-01-01

    The zirconium and Hafnium oxides are obtained from a Spanish mineral of zircon with an average contest of 55% in ZrO 2 -HfO 2 . An alkaline fusion to open the mineral, followed by a purification by crystallization as (Zr O-Hf O)Cl 2 H 2 O or as (Zr-Hf) (SO 4 ) 2 . 4H 2 O, is used. A discussion of the best experimental conditions for opening the mineral and of the purification method is made. (Author) 45 refs

  12. Characterisation of aggregation of tributylphosphate molecules in organic solvent; Caracterisation de l'auto-organisation du phosphate de tributyle en solvant organique

    Energy Technology Data Exchange (ETDEWEB)

    Mandin, C.; Martinet, L.; Zemb, Th.; Berthon, L.; Madic, Ch

    2000-07-01

    This report presents a structural study of the aggregates formed with the organic phases of the extractant tri-n-butyl phosphate, used in the industrial PUREX process (Plutonium and Uranium Extraction; liquid-liquid solvent extraction) for the treatment of high radioactive waste. Combined Small Angle X-ray Scattering and Small Angle Neutron Scattering show that organic TBP solutions (in equilibrium with acid solutions) are organised in oligomeric aggregates. The influence of various parameters such as HNO{sub 3} or TBP concentrations, diluent or acid natures, does not seem to modify the aggregate shape and size, whereas the interactions are modified. Moreover the aggregates disappear under high temperatures, whereas the attractive interactions between them increase at low temperatures. The 'drop weight' method gives the critical micellar concentration values of TBP in case of H{sub 2}O or HNO{sub 3} extractions (H{sub 2}O: 0.48 M; HNO{sub 3} 2M: 0.65 M; at 21 deg C). Furthermore, the measures at different acid concentrations show that the c.m.c. varies with the acidity. The more acid the aqueous phase is, the smaller is the entropy in the system because of the numerous negative charges, i.e. the harder the micellization occurs, so the higher the c.m.c. value is. The sticky sphere model proposed by Baxter, can be used to model successfully small reverse micelles of the organic TBP phases. The aggregation number would be 4{+-}1 (water extraction) and 5{+-}1(HNO{sub 3}2M extraction). These values are also given by vapor pressure measurements. (authors)

  13. Use of Monte Carlo Methods in brachytherapy; Uso del metodo de Monte Carlo en braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Granero Cabanero, D.

    2015-07-01

    The Monte Carlo method has become a fundamental tool for brachytherapy dosimetry mainly because no difficulties associated with experimental dosimetry. In brachytherapy the main handicap of experimental dosimetry is the high dose gradient near the present sources making small uncertainties in the positioning of the detectors lead to large uncertainties in the dose. This presentation will review mainly the procedure for calculating dose distributions around a fountain using the Monte Carlo method showing the difficulties inherent in these calculations. In addition we will briefly review other applications of the method of Monte Carlo in brachytherapy dosimetry, as its use in advanced calculation algorithms, calculating barriers or obtaining dose applicators around. (Author)

  14. Edgar Allan Poe y su metodo de creación romántico

    OpenAIRE

    Gómez Mejias, Loriet

    2012-01-01

    Edgar Allan Poe es una de las más grandes figuras de la literatura norteamericana y universal, considerado, además, padre del relato policial moderno. Por la trascendencia y vitalidad de su obra, se pretende un acercamiento, desde los planos ideotemático, estilístico y compositivo, a tres de los cuentos más conocidos: El corazón delator, El gato negro y El tonel de amontillado. Asimismo, enfatizaremos en las características de su método de creación, matizado por las peripeci...

  15. Methods of selective protection against electric arcs; Metodos de protecao seletiva contra arcos eletricos

    Energy Technology Data Exchange (ETDEWEB)

    Kumpulainen, Lauri; Dahl, Samuel [Vamp Ltd. (Finland)

    2010-12-15

    The faults with electric arcs can cause serious accidents and endanger the safety of people and equipment, which necessitates effective methods to reduce the impact of these incidents. This article discusses ways to mitigate electric arcs and encourages the use of technology based on light detection, with its benefits and practical applications.

  16. General method of quantitative spectrographic analysis; Estudio de un metodo general de analisis espectrografico cuantitativo

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.; Roca, M.

    1966-07-01

    A spectrographic method was developed to determine 23 elements in a wide range of concentrations; the method can be applied to metallic or refractory samples. Previous melting with lithium tetraborate and germanium oxide is done in order to avoid the influence of matrix composition and crystalline structure. Germanium oxide is also employed as internal standard. The resulting beads ar mixed with graphite powder (1:1) and excited in a 10 amperes direct current arc. (Author) 12 refs.

  17. Metodo para montaje permanente de huevos de helmintos enteroparasitos Definitive preservation of helminthic eggs

    Directory of Open Access Journals (Sweden)

    Victor Muñoz

    1990-04-01

    Full Text Available Se comunican resultados obtenidos empleando Medio de Hoyer para el montaje de huevos de helmintos enteroparásitos, destinado a preparaciones para colecciones docentes y/o de investigación. La utilización de esta técnica en muestras fecales conteniendo huevos de A. lumbricoides, T. trichiura, Uncinaria sp., Taenia sp., Diphyllobothrium sp., H. nana, H. diminuta y F. hepática, permitió la correcta observación de ellos en lecturas iniciadas a las 24 horas y mantenidas hasta 180 días después.The results using the Hoyer method for examining eggs of helminths enteroparasites are presented. This method is particularly swited for teaching and on research purposes. Using this technique in fecal sample containing eggs of A.lumbricoides, T. trichiura, Uncinaria sp., Taenia sp., Diphyllobothrium sp., H. nana, H. diminuta and F. hepática allowed the correct identification of then after 24 hours up to 180 days after the samples were obtained.

  18. Gastroesophageal reflux - correlation between diagnostic methods; Refluxo gastroesofagico - correlacao entre metodos diagnosticos

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Maria das Gracas de Almeida; Penas, Maria Exposito; Fonseca, Lea Mirian Barbosa [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia-Medicina Nuclear; Lemme, Eponina Maria O. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Clinia Medica-Gastroenterologia; Martinho, Maria Jose Ribeiro [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear

    1999-02-01

    A group of 97 individuals with typical symptoms of gastroesophageal reflux disease (GERD) was submitted to gastroesophageal reflux scintigraphy (GES) and compared to the results obtained from endoscopy, histopathology and 24 hours pHmetry. Twenty-four healthy individuals were used as a control group and they have done only the GERS. The results obtained showed that: (a) the difference in the reflux index (RI) for the control group and the sick individuals was statistically significant (p < 0.0001); (b) the correlation between GERS and the other methods showed the following results: sensitivity, 84%; specificity, 95%; positive predictive value, 98%; negative predictive value, 67%; accuracy, 87%. We have concluded that the scintigraphic method should be used to confirm the diagnosis of GERD and also recommended as initial investiative procedure. (author)

  19. Proteinas do liquido cefalorraqueano: I. Estudo comparativo entre metodos de concentração

    Directory of Open Access Journals (Sweden)

    Lucia M. Singer Vermes

    1983-03-01

    Full Text Available No intuito de escolher entre métodos de concentração, aplicáveis ao LCR, aquele que, não provocando desnaturação de proteínas, seja o mais exato, preciso e de fácil aplicação em laboratórios de rotina, foram estudados quatro procedimentos: diálise contra solução de goma-arábica, centrífugo-ultrafiltração, absorção de substâncias de baixo peso molecular por gel seco de poliacrilamida e ultrafiltração sob pressão positiva. Concluiu-se que a diálise contra solução de goma-arábica, por ser preciso, relativamente exato, simples e pouco oneroso, é o mais satisfatório dentre os métodos estudados.

  20. Geostatistical methods for the integrated information; Metodos geoestadisticos para la integracion de informacion

    Energy Technology Data Exchange (ETDEWEB)

    Cassiraga, E.F.; Gomez-Hernandez, J.J. [Departamento de Ingenieria Hidraulica y Medio Ambiente, Universidad Politecnica de Valencia, Valencia (Spain)

    1996-10-01

    The main objective of this report is to describe the different geostatistical techniques to use the geophysical and hydrological parameters. We analyze the characteristics of estimation methods used in others studies.

  1. ESTUDIO CONFORMACIONAL EN ALGUNAS 1,3-OXAZINAS Y 1,3-BENZOXAZINAS EMPLEANDO METODOS TEORICOS.

    OpenAIRE

    HURTADO OCAMPO, SANDRA MARCELA; HURTADO OCAMPO, SANDRA MARCELA

    2007-01-01

    En la década del cincuenta, resultados experimentales entregados por Urbanski y colaboradores [1] pusieron en evidencia propiedades antituberculósicas y antitumorales en compuestos del tipo 5-nitro-R-N-1 ,3- oxazínicos. Como resultado de un proceso relati 187p.

  2. Methods in nuclear reactors calculations; Metodos de calculo en reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Velarde, G.

    1966-07-01

    Studies are made of the neutron transport equation corresponding to the the real and virtual reactors, as well as the starting hypotheses. Methods are developed to solve the transport equation in slab geometry, and P{sub l}; B{sub l}; M{sub l}; S{sub n} and discrete ordinates approximations. (Author)

  3. Microbicidas Metodo de Prevencion en VIH/SIDA Controlado por Mujeres.

    Science.gov (United States)

    Ruiz, Cindy; Torres, Viviana; Cianelli, Rosina; Ferrer, Lilian

    2009-03-01

    HIV/AIDS continues to expand throughout the world, and in recent times has had a severe impact on the number of women living with HIV. Access to methods of prevention for HIV/AIDS around the world is limited and for many women may not be feasible. Examples of such methods are sexual abstinence, which though recognized as an effective method of prevention is difficult for many women to achieve. Mutual fidelity is another option, but many women cannot control the sexual behavior of their partners. Finally, the male condom continues to be an available method of HIV prevention for sexually active people. However, in many places, gender inequality, social norms, and economic disparities severely limit women's capacity to negotiate the use of a condom with their partner. For this reason, an urgent need exists to develop a product for the prevention of HIV/AIDS that can be handled by women. Microbicides, products that can reduce HIV risk when applied intravaginally, hold promise for stopping the advance of HIV/AIDS, especially when considering that women can make their own decisions about whether to use them when other methods of prevention are not available. The objective of the current literature review was to understand the scientific advances related to microbicides in the prevention of HIV/AIDS in women through the analysis of available literature in this area. Interest in this topic emerged from the need to contribute to women's health and HIV/AIDS prevention. To achieve this review's objective, a search was carried out in multiple databases, including OVID, PUBMED, PROQUEST, and CINAHL, as well as published materials from organizations related to this area such as UNAIDS and CONASIDA, and literature available from the Internet. Upon completion of the literature review, it was concluded that microbicides are an effective method for preventing HIV/AIDS for women as well as their partners. Although they have a high level of acceptance among the female population, the majority of microbicides are still in clinical studies, requiring further evaluation for their safe use in humans. There are 3 microbicides in the final phases of clinical studies that will soon be available on the market. One of these was found to be 60% effective in protecting against the transmission of HIV and was used by women in 50% of their sexual activity, which resulted in avoiding approximately 2.5 million new HIV infections in men, women, and children over a 3-year period.

  4. Metodos no convencionales para el tratamiento de aguas contaminadas con productos farmaceuticos

    OpenAIRE

    Quesada-Peñate, Isariebel

    2009-01-01

    Des solutions modèles de lévodopa et de paracétamol, représentatives d'effluents pharmaceutiques, ont été traitées par adsorption et par des techniques non conventionnelles comme les ultrasons, l'oxydation en voie humide catalytique et le procédé séquentiel adsorption-oxydation ADOX, en utilisant des charbons actifs comme adsorbants et/ou catalyseurs. Les isothermes d'adsorption des deux composés sur trois charbons actifs ont été caractérisées, puis en oxydation, la puissance et la fréquence ...

  5. Estudios de cordinación de las protecciones por metodos computarizados

    OpenAIRE

    Mendoza Miño, José; Paredes Aguilar, Fabricio; Peralta Moarry, Dario

    2009-01-01

    This project presents in a very detailed way the study of adjustment and coordination when using Digital Relays to protect interconnection of barges such as Power Barge I and II with the SNI (National Interconnected System) at voltage levels of 69KV and 13,8KV, using characteristics of the protection elements’ curves along with Microsoft Excel 2007. In the making of this project several aspects have been taken into account, such as the study of electrical charge flow and the study of short...

  6. La Società Umanitaria e la diffusione del Metodo Montessori (1908-1923

    Directory of Open Access Journals (Sweden)

    Irene Pozzi

    2015-07-01

    Full Text Available The Società Umanitaria ofMilan, between 1918 and 1923, played an essential role in spreading and developing the Montessori Method. Studying in the Historical Archive of Società Umanitaria the numerous documents there collected, the author reconstructed the crucial moments of the extremely significant collaboration between Maria Montessori and Augusto Osimo, General Secretary of the Società Umanitaria.This complex and in-depth investigation was guided by the analysis, in specific, of the training courses for Montessori teachers organised by Società Umanitaria, essentially unexamined before this study, that allowed the researcher to have a deep insight into the action of Società Umanitaria aimed to promote and implement the Montessori Method in Italy and all around the world.

  7. Um metodo para modelagem de exceções em desenvolvimento baseado em componentes

    OpenAIRE

    Patrick Henrique da Silva Brito

    2005-01-01

    Resumo: Devido a grande popularização do Desenvolvimento Baseado em Componentes (DBC), ele vem sendo empregado inclusive no desenvolvimento de sistemas computacionais críticos. O emprego do DBC na construção de sistemas confiáveis evidencia a necessidade de se desenvolver componentes de software que sejam robustos e que possuam uma garantia maior do seu funcionamento correto. Tratamento de exceções é uma técnica bastante conhecida para a verificação e tratamento de erros em sistemas de softwa...

  8. ARTE E FENOMENOLOGIA BRANCUSIANA: “IL METODO PURAMENTE SCULTORIO DI PENSARE IL MONDO”

    Directory of Open Access Journals (Sweden)

    MANUELA TEODORA BALAŞCA-MIHOCI

    2010-11-01

    Full Text Available The entailing creative labour reveals works that imply the whole human thinking and sensitivity aiming to comprehend them. Thus, we can reach the great Brancusian art in understanding that, beyond the glance and the material, we find the spiritual; the last is not something untouchable, but it is a sort of co-partner of the creative life experience. Fear, love, pain, happiness, and ecstazy, all the human affinities and the substance of beingness are created by art and by philosophy alike. Merely their expression is different as concerning the material and the word. We find sameness between the capacity of communication using and feeling life through wood or rock, for example, on one hand; and the gift of putting in act and writing words, of interpreting verse, on the other. Such a similarity belongs to the unique creative agent, finally, that is varying only by the material and the expressive shape.

  9. Conocimiento y uso de metodos anticonceptivos por la poblacion femenina de una zona de salud

    Directory of Open Access Journals (Sweden)

    Maroto de Agustín Alicia

    1998-01-01

    Full Text Available FUNDAMENTO: El uso de métodos anticonceptivos está en relación, entre otros, con factores demográficos, sociales, económicos, educativos e ideológicos. El objetivo de este trabajo es conocer qué métodos anticonceptivos conocen las mujeres en edad fértil, así como la prevalencia de su uso. MÉTODOS: A partir del listado de tarjeta sanitaria se seleccionaron mediante muestreo sistemático 389 de las 5800 mujeres en edad fértil (15-45 años asignadas a un centro de salud. Previo envío de una carta, comunicando el motivo del estudio, se contactó telefónicamente con ellas para la realización de una encuesta, la cual incluía preguntas acerca del conocimiento y uso de métodos anticonceptivos, características socioculturales y actividad sexual. Las mujeres que no tenían teléfono fueron citadas en el centro de salud. RESULTADOS: Se contactó con 178 mujeres, de las que participaron 166 (tasa de respuesta de 42,7%. De ellas utilizaban algún método anticonceptivo 86 (51,8%; IC:44,2-59,4%. Sin embargo, entre mujeres con riesgo de embarazo no deseado, la prevalencia de uso era del 70,5% (IC: 62,4-78,6%, destacando el hecho de que en el grupo de mujeres de 40 a 45 años sólo utilizaran anticonceptivos el 45,4%, con una frecuencia significativamente inferior a los otros grupos de edad. Los métodos más conocidos eran el preservativo (90,4%, los contraceptivos orales (89,2% y el dispositivo intrauterino (78,3%, siendo escaso el conocimiento de otros métodos. CONCLUSIONES: La tasa de utilización de métodos anticonceptivos en mujeres con riesgo de embarazo no deseado es aceptable, si bien entre 40 y 45 años es llamativamente baja. Los métodos más conocidos son el preservativo, los contraceptivos orales y el dispositivo intrauterino.

  10. Imperfect twinning - evaluation by imaging methods; Gemelidade imperfeita - avaliacao pelos metodos de imagem

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Arildo Correa; Julio, Hamilton [Parana Univ., Curitiba, PR (Brazil). Hospital das Clinicas. Disciplina de Ginecologia e Obstetricia; Mazer, Sergio; Urban, Linei Augusta Brolini Delle [Parana Univ., Curitiba, PR (Brazil). Hospital das Clinicas. Servico de Radiologia]. E-mail: lineiurban@hotmail.com

    2003-02-01

    Conjoined twins are rare malformations and a challenge for both radiologists and pediatric surgeons. Antenatal evaluation is essential for the identification of anatomic fusions and other associated abnormalities, which will enable an adequate surgical planning and the assessment of fetal prognosis. The authors present the clinical and imaging findings of thoracopagus twins, joined by the anterior portion of the thorax, sharing the heart and the liver. Diagnosis was made by ultrasonography and confirmed with fetal magnetic resonance imaging. (author)

  11. Dose estimation by biological methods; Estimacion de dosis por metodos biologicos

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; David C, L.; Serment G, J.; Brena V, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The human being is exposed to strong artificial radiation sources, mainly of two forms: the first is referred to the occupationally exposed personnel (POE) and the second, to the persons that require radiological treatment. A third form less common is by accidents. In all these conditions it is very important to estimate the absorbed dose. The classical biological dosimetry is based in the dicentric analysis. The present work is part of researches to the process to validate the In situ Fluorescent hybridation (FISH) technique which allows to analyse the aberrations on the chromosomes. (Author)

  12. POLIMEROS COMO METODOS PARA RECUPERAÇÃO AVANÇADA DE PETRÓLEO

    OpenAIRE

    Marques, Landson S.; UFBA; Quintella, Cristina M.; UFBA; Neto, Guilherme João Musse; UFBA; Cavalcanti, David Falcão; UFBA; Santos, Lauro Tiago Souza; UFBA

    2014-01-01

    A recuperação terciária ou avançada de petróleo (EOR) com a injeção de soluções diluídas de um polímero nos reservatórios ajuda a deslocar o óleo dos poros atuando na viscosidade do fluido injetado e na molhabilidade. EOR é utilizada especialmente quando aumenta a demanda por petróleo e seus derivados. EOR com polímeros tem sido patenteada desde 1967 e continua até aos dias de hoje em pequenas ondas. Os EUA têm o maior número de patentes. A grandes depositantes são as maiores empresas de p...

  13. MODELADO DE EQUILIBRIO LIQUIDO-LIQUIDO DE SISTEMAS QUE CONTIENEN LIQUIDOS IONICOS USANDO EL METODO ASOG

    OpenAIRE

    ROBLES VASQUEZ, PEDRO ADRIAN

    2012-01-01

    Modelos termodinámicos capaces de predecir datos de equilibrio son indispensables en la elaboración de proyectos de plantas de procesos químicos. Los datos del equilibrio líquido - líquido (ELL) para los sistemas incluyendo líquidos iónicos, son esenciales para el diseño y operación de los procesos de separación, pero aún son escasos. En este sentido, objetivo de esta Tesis es aplicar el método de contribución de grupos ASOG para el cálculo del coeficiente de actividad capaz de pr...

  14. Metodo a variazione di frequenza per la misurazione della suscettività magnetica delle rocce

    Directory of Open Access Journals (Sweden)

    P. DOMINICI

    1968-06-01

    Full Text Available method is described for the measurement of the isotropic
    and anisotropic susceptibility of rocks in a weak alternating field
    (0,5 Oe; frequency 500 c/sec, based on the frequency variation of an oscillator
    in whose inductor the specimen is placed; the frequency variation is
    measured by means of an electronic frequency meter.

  15. Synovial chondromatosis of the shoulder: imaging findings; Osteocondromatose sinovial no ombro: achados por metodos de imagem

    Energy Technology Data Exchange (ETDEWEB)

    Terazaki, Carlos Renato Ticianelli; Trippia, Carlos Henrique; Caboclo, Maria Fernanda Sales Ferreira; Medaglia, Carla Regina Miranda, E-mail: reticianelli@hotmail.com [Hospital Sao Vicente (FUNEF), Curitiba, PR (Brazil). Servico de Radiologia e Diagnostico por Imagem; Trippia, Cesar Rodrigo [Hospital Sao Vicente (FUNEF), Curitiba, PR (Brazil)

    2014-01-15

    Synovial chondromatosis is a benign condition characterized by synovial proliferation and metaplasia, with development of cartilaginous or osteocartilaginous nodules within a joint, bursa or tendon sheath. In the shoulder, synovial osteochondromatosis may occur within the glenohumeral joint and its recesses (including the tendon sheath of the biceps long head), and in the subacromial-deltoid bursa. Such condition can be identified either by radiography, ultrasonography or magnetic resonance imaging, showing typical features according to each method. Radiography commonly shows ring-shaped calcified cartilages and periarticular soft tissues swelling with erosion of joint margins. Ultrasonography demonstrates hypoechogenic cartilaginous nodules with progressive increase in echogenicity as they become calcified, with development of posterior acoustic shadow in case of ossification. Besides identifying cartilaginous nodules, magnetic resonance imaging can also demonstrate the degree of synovial proliferation. The present study is aimed at describing the imaging findings of this entity in the shoulder. (author)

  16. Peripezie di immagini: il metodo-Warburg e la Divina Commedia

    Directory of Open Access Journals (Sweden)

    Gioachino Chiarini

    2012-05-01

    Full Text Available The paper is part of a ‘work in progress’ on the influence of oriental cultures and religions on Western ancient literature (The Seven Gates. After a short history of use and symbolic role of the “planetary ladder” from Sumerians to Islamic literatures and cultures via Greece, Rome and Jewish mysticism, the essai tries to show that the early Christians writers preferred to avoid employing the planetary ladder as a cipher of an itinerary to God. It was only Dante, in his Divina Commedia, who resumed to use with high perfection the planetary ladder: he re-elaboreted the circular Islamic hell in the Inferno, the Islamic heaven in the Paradiso and the Islamic paradise in the Purgatorio (his source was the Latin translation of The book of the ladder of Mahomet.

  17. Tratamento quimico de colmos de bambu pelo metodo de Boucherie modificado

    OpenAIRE

    Jean Claudio Chiozzini Espelho

    2007-01-01

    Resumo: O bambu é uma matéria-prima com múltiplas aplicações, principalmente no setor da construção. Seu desenvolvimento e seu desempenho mecânico são obtidos após um curto intervalo de tempo, quando comparado com as árvores. O bambu é um material renovável e encontrado em abundância em regiões tropicais e subtropicais, nas quais é considerado um material de baixo custo. No entanto, a maior parte das espécies de bambu é altamente susceptível ao ataque de fungos e insetos. Basicamente, pode-se...

  18. Obsidian dating by fission track method; Datacao de obsidianas com o metodo dos tracos de fissao

    Energy Technology Data Exchange (ETDEWEB)

    Araya, A.M.O.

    1990-12-01

    The fission track method was employed to obtain the age of twelve obsidian sample from Ecuador. By using the plateau-age correction method, we obtained the true age of each sample and were able to identify four groups of ages in the studied area. Thereafter we studied the fading of fission tracks in two obsidian samples with different origins: Yanaurcu, Ecuador and Monte Arci, Italy. We constructed Arrhenius plots and calculated activation energies for both samples. The results from thermal annealing experiments were compared with theoretical curves obtained by integrating an equation proposed by Shukolyukov et al (1965). (author). 43 refs, 20 figs, 10 tabs.

  19. Atresia of the gastrointestinal tract: imaging evaluation; Atresia do trato gastrintestinal: avaliacao por metodos de imagem

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Sizenildo da Silva; Nobrega, Bruno Barcelos da; Ribeiro, Luiza Helena Vilela; Costa, Marlos Augusto Bittencourt; Monteiro, Soraya Silveira; Lederman, Henrique Manoel [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: brunoradiol@hotmail.com; Oliveira, Galba Leite [Irmandade Santa Casa de Misericordia de Sao Paulo, SP (Brazil). Dept. de Diagnostico por Imagem; Esteves, Edward [Goias Univ., Goiania, GO (Brazil). Faculdade de Medicina. Dept. de Cirurgia e Urologia Pediatrica

    2005-04-01

    A wide spectrum of congenital anomalies may affect the gastrointestinal tract at any level from the esophagus to the anus. Atresia is an important cause of gastrointestinal obstruction with high morbidity rate in neonates. Different pathogenetic mechanisms could cause this malformation and the two classical explanations are: a defect of recanalization of the intestinal tube or an interruption of blood supply during intrauterine life. The authors present a literature review with an iconographic essay of imaging findings in children with gastrointestinal atresia. (author)

  20. Problemi e di Fisica e Astronomia ed il metodo di Gerberto docente

    Science.gov (United States)

    Sigismondi, Costantino

    2015-04-01

    Teaching Physics and Astronomy to pupils of 14-19 years old requires nowadays a continuous upgrade of knowledge as well as a capacity of selecting topics. The art of presenting arguments made Gerbert the teacher Rogatus a Pluribus in the end of X century and it is still actual; the proposed series of problems wants to link everyday experiences with the mathematical models of the phenomena, to allow the prediction and explanation of the experimental data. These problems of Physics and Astronomy are “observation oriented”, as the method of Gerbert was to start from the experience to get the theory, and not viceversa. Physics is much more than an “applied Algebra”. In the dispute of Ravenna (980) between Gerbert and Otric from Magdeburg, the primacy of Physics with respect to Mathematics was discussed. In the Italian secondary technical schools there are laboratory activities, while there is nothing similar for Lyceums and for the Astronomy teaching which is limited to a series of notions to be learned without any kind of observation; considered too difficult in polluted skyes.

  1. La pronunciacion espanola y los metodos de investigacion. (Spanish Pronunciation and Methods of Investigation.)

    Science.gov (United States)

    Torreblanca, Maximo

    1988-01-01

    Discusses the validity of studies of Spanish pronunciation in terms of research methods employed. Topics include data collection in the laboratory vs. in a natural setting; recorded vs. non-recorded data; quality of the recording; aural analysis vs. spectrographic analysis; and transcriber reliability. Suggestions for improving data collection are…

  2. FOTOGRAFIA DI STRUMENTI MUSICALI METODO DI DOCUMENTAZIONE QUOTIDIANO E PROVE ELEMENTARI DI FILOLOGIA DIGITALE

    Directory of Open Access Journals (Sweden)

    Emanuele Marconi

    2012-04-01

    Full Text Available

    Il restauro virtuale, inteso come manipolazione 2d di un’immagine attraversoprogrammi di grafi ca o elaborazione digitale, può essere, in alcuni casi, unvalido aiuto per la ricerca ontologica per ottenere una visione di insieme diun'opera prima di un intervento di restauro o per ricostruire parti che non sonopervenute. In alcuni casi la manipolazione dell’immagine diviene un supporto perla ricerca organologica.

     

    Digital photo of musical instruments

    Digital photography is a great support in musical instruments conservation forms filling. Video documentation, still not much used, contributes a great amount of details that doesn’t written text or still images. Digital image manipulation,or virtual restoration (defined as the manipulation of 2D image through digital imaging processing, in some cases can be a great help to get a fi rst overview of a restoration, or to reconstruct parts of an artwork that are missed. Some case studies are presented, showing differents application ofsimple techniques to on the field activities regarding musical instruments.

  3. Acrilamida em alimentos : ocorrencia, metodos analiticos e estimativas de ingestão.

    OpenAIRE

    Adriana Pavesi Arisseto

    2007-01-01

    Resumo: Uma importante descoberta de pesquisadores suecos em abril de 2002 mostrou que acrilamida, uma substância provavelmente carcinogênica a seres humanos, pode ser formada em determinados alimentos que são submetidos a tratamento térmico em altas temperaturas. No presente estudo, 111 amostras de diferentes categorias de alimentos foram coletadas em supermercados, lojas de "fast-foods" e restaurantes da cidade de Campinas-SP, entre os meses de setembro de 2004 e abril de 2006, e analisadas...

  4. Alternate method for to realize image fusion; Metodo alterno para realizar fusion de imagenes

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, L.; Hernandez, F.; Fernandez, R. [Departamento de Medicina Nuclear, Imagenologia Diagnostica. Centro Medico de Xalapa, Veracruz (Mexico)

    2005-07-01

    At the present time the image departments have the necessity of carrying out image fusion obtained of diverse apparatuses. Conventionally its fuse resonance or tomography images by X-rays with functional images as the gammagrams and PET images. The fusion technology is for sale with the modern image equipment and not all the cabinets of nuclear medicine have access to it. By this reason we analyze, study and we find a solution so that all the cabinets of nuclear medicine can benefit of the image fusion. The first indispensable requirement is to have a personal computer with capacity to put up image digitizer cards. It is also possible, if one has a gamma camera that can export images in JPG, GIF, TIFF or BMP formats, to do without of the digitizer card and to record the images in a disk to be able to use them in the personal computer. It is required of one of the following commercially available graph design programs: Corel Draw, Photo Shop, FreeHand, Illustrator or Macromedia Flash that are those that we evaluate and that its allow to make the images fusion. Anyone of them works well and a short training is required to be able to manage them. It is necessary a photographic digital camera with a resolution of at least 3.0 mega pixel. The procedure consists on taking photographic images of the radiological studies that the patient already has, selecting those demonstrative images of the pathology in study and that its can also be concordant with the images that we have created in the gammagraphic studies, whether for planar or tomographic. We transfer the images to the personal computer and we read them with the graph design program. To continuation also reads the gammagraphic images. We use those digital tools to make transparent the images, to clip them, to adjust the sizes and to create the fused images. The process is manual and it is requires of ability and experience to choose the images, the cuts, those sizes and the transparency grade. (Author)

  5. Persistent hyperplastic primary vitreous: imaging evaluation; Persistencia hiperplastica do vitreo primitivo: avaliacao por metodos de imagem

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Beatriz Mahmud; Teixeira, Kim-Ir-Sen Santos; Figueiredo, Sizenildo da Silva; Nobrega, Bruno Barcelos da [Universidade Federal de Goias, Goiania (Brazil). Hospital das Clinicas. Dept. de Diagnostico por Imagem]. E-mail: biamjacob@hotmail.com

    2003-06-01

    Persistent hyperplastic primary vitreous (PHPV) is a congenital developmental anomaly of the eye that primarily affects premature infants. PHPV results from failure of regression of the embryogenic primary vitreous and hyaloid vasculature, and proliferation of connective tissue. Three types of PHPV may be found: anterior, posterior and a combination of anterior and posterior. The clinical findings include leukocoria (white pupillary reflex) and microphthalmic eye. This anomaly is usually unilateral and unassociated with other systemic findings. The differential diagnosis between PHPV and other ocular diseases may be difficult due to similar features such as leukocoria, detached retina, retinal folds and cataract. Other diseases with similar features include retinoblastoma, isolated congenital cataract, retinopathy of prematurity and pseudo gliomas or leukocorias. Direct visualization of the remnants of the fetal hyaloid vascular system offers the best evidence of PHPV. However, diagnosis using the ophthalmoscope is sometimes impossible because of opaque tissues. In this circumstance an indirect visualization by ultrasound, computed tomography or magnetic resonance imaging may be useful. These imaging methods provide valuable information for the differentiation from other diseases, particularly retinoblastoma. The authors present a review of the literature and an iconographic study of the imaging findings in patients with PHPV. (author)

  6. Porous oxides synthesized by the combustion method; Oxidos porosos sintetizados por el metodo de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lugo L, V

    2005-07-01

    The result of this work, seeks to be a contribution for the treatment of radioactive wastes, with base to the sorption properties that present those porous oxides, synthesized by a method that allows to increase the sorption capacity. The main objective of the present investigation has been the modification of the structural characteristics of the oxides of Fe, Mg and Zn to increase its capacity of sorption of {sup 60} Co in particular. It was studied the effect of the synthesis method by combustion in the inorganic oxides; the obtained solids were characterized using the following techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), semiquantitative elementary analysis by Dispersive energy spectroscopy (EDS) and determination of surface area by the Brunauner-Emmett-Teller method (BET). Also was carried out batch type experiments for the sorption of Co{sup 2+}, with the purpose of studying the sorption capacity of each one of the prepared oxides. In accordance with that previously exposed, the working plan that was carried out in this investigation is summarized in the following stages: 1. Preparation of inorganic oxides by two different methods, studying the effect of the temperature in the synthesis process. 2. Characterization of the inorganic oxides by XRD, by means of which those were chosen the solids with better properties. 3. Characterization of the inorganic oxides by SEM and EDS where it was studied the morphology of the synthesized materials and the semiquantitative elemental composition. 4. Realization of a sorption experiment type Batch with non radioactive Co{sup 2+} to simulate the sorption of {sup 60} Co and determination of the sorption capacity by means of neutron activation of the non radioactive cobalt. 5. Determination of the surface area by the (BET) technique of the inorganic oxides with better sorption properties. (Author)

  7. Metodos construtivos para edificações utilizando componentes derivados da madeira de reflorestamento

    OpenAIRE

    Devanir Cabral Lima Morikawa

    2006-01-01

    Resumo: : No Brasil, a facilidade na obtenção de madeiras nativas a baixo custo, ocasionou algumas conseqüências, entre elas, o atraso tecnológico na indústria de processamento mecânico da madeira. A atual escassez de madeira nativa, aliada às pressões ecológicas e de legislação mais rigorosa, ajudam na busca de alternativas que se direcionem no desenvolvimento de plantios silviculturais, provocando assim uma revolução industrial na indústria madeireira, em particular, na de painéis de madeir...

  8. Investigando il suono dei cieli: tra metodo scientifico e pensiero magico-simbolico

    Directory of Open Access Journals (Sweden)

    Stefano A.E. Leoni

    2012-11-01

    Full Text Available In the sixteenth and seventeenth centuries European scholars of natural philosophy often attempted to formalize music in apparently very different contexts. It is fascinating to follow the influence of magic and the symbolic on high culture, often resulting in controversies, and the fruitful critical reflections about the method of scientific inquiry. It is in this context that musicology becomes important, starting from the interdisciplinary musical treatises which were fashionable until the end of the seventeenth century. With regard to this specific issue, one can focus on points that link the history of scientific thought and the history of world-views to the field of music and to the possibilities of mythopoeic speculation of music, both used as a formalization of magicsymbolic universes, and as a dismantling of methodological (and ethical rational models. This essay discusses, amongst others, Kepler, Mersenne, Fludd as writers that make extensive use of the meta-language of music to give shape to their, at times controversial, ideas.

  9. Controle de reatores de batelada exotermicos pelo metodo da linearização global

    OpenAIRE

    Luis Emilio Vasconcelos de Andrade

    1993-01-01

    Resumo: Os reatores em batelada representam um tipo de processo de grande importância na indústria química, visto que estão associados à produção de uma variada quantidade de produtos, tais como as especialidades químicas e fármacos o satisfatório controle deste processo, visando assegurar a qualidade do produto final, põe-se como uma questão bastante particular.Como muitas das reações promovidas em reatores em batelada envolvem 1iberação de calor, tem-se configurado, para efeito de controle,...

  10. La scrittura è terapeutica? Il metodo autobiografico e la composizione del sé

    Directory of Open Access Journals (Sweden)

    Nicola Ghezzani

    2010-02-01

    Full Text Available Far da sé il proprio ritratto biografico significa, in rapporto a queste alienazioni, sfidare i demoni della compiacenza e della connivenza con l’altro, quindi porre il rifiuto, l’opposizione e quindi il vuoto, il nulla, l’assenza come base sulla quale veder apparire le proprie scene e le proprie passioni. Solo se non devo rispondere di me stesso a nessun altro che a me stesso, io sono nella condizione di cogliermi nella mia delusione fondamentale, nell’opposizione frontale che ho verso il mondo o verso i valori recepiti, nella mia protesta di riscatto dalla soggezione, nelle mie istanze di vendetta, di cui avverto insieme la violenza apocalittica e la colpa morale, quindi posso valutare quanto sono trascinato da passioni, reso nemico agli altri e a me stesso, e quanto posso riequilibrare il mio essere sulla base di una valutazione intima, sentita, ponderata di ogni lato contrapposto della mia identità.

  11. Study of parametric methods for identification of mathematical models and Sundaresam method application in a steam boiler; Estudo dos metodos parametricos de identificacao de modelos matematicos e aplicacao do metodo de Sundaresam em uma caldeira a vapor

    Energy Technology Data Exchange (ETDEWEB)

    Schuttenberg, Rose Mary Cosso [Pontificia Univ. Catolica de Minas Gerais, Belo Horizonte, MG (Brazil). Nucleo de Controle de Processos

    1999-12-01

    Some identification techniques are discussed and the required data for application to the Sundaresam's identification method are obtained by connecting a microcomputer to the Spiraflo, an instrument available at the CEFET/MG - Federal Center for Technological Education of Minas Gerais, Brazil - steam boiler. All the graphical output, by an specified test, for the temperature, steam's flow and pressure are shown and analyzed. Through picked up data and Sundaresan's method, the transfer function between the pressure of the CEFET-MG's steam boiler and the flow is identified. (author)

  12. Wielandt method applied to the diffusion equations discretized by finite element nodal methods; Metodo de Wielandt aplicado a las ecuaciones de difusion discretizadas por metodos nodales de elemento finito

    Energy Technology Data Exchange (ETDEWEB)

    Mugica R, A.; Valle G, E. del [IPN, ESFM, 07738 Mexico D.F. (Mexico)]. e-mail: mugica@esfm.ipn.mx

    2003-07-01

    Nowadays the numerical methods of solution to the diffusion equation by means of algorithms and computer programs result so extensive due to the great number of routines and calculations that should carry out, this rebounds directly in the execution times of this programs, being obtained results in relatively long times. This work shows the application of an acceleration method of the convergence of the classic method of those powers that it reduces notably the number of necessary iterations for to obtain reliable results, what means that the compute times they see reduced in great measure. This method is known in the literature like Wielandt method and it has incorporated to a computer program that is based on the discretization of the neutron diffusion equations in plate geometry and stationary state by polynomial nodal methods. In this work the neutron diffusion equations are described for several energy groups and their discretization by means of those called physical nodal methods, being illustrated in particular the quadratic case. It is described a model problem widely described in the literature which is solved for the physical nodal grade schemes 1, 2, 3 and 4 in three different ways: to) with the classic method of the powers, b) method of the powers with the Wielandt acceleration and c) method of the powers with the Wielandt modified acceleration. The results for the model problem as well as for two additional problems known as benchmark problems are reported. Such acceleration method can also be implemented to problems of different geometry to the proposal in this work, besides being possible to extend their application to problems in 2 or 3 dimensions. (Author)

  13. An alternative method study for determining the content oils and greases derived from spectrophotometric; Estudo de um metodo alternativo para determinacao de oleos e graxas derivado do metodo espectrofotometrico

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Leila Rose Benevides; Bezerra, Magna Angelica dos Santos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Recursos Humanos da ANP, PRH-14; Melo, Josette Lourdes de Sousa; Melo, Henio Normando de Sousa [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Gomes, Andrea Karla Martins [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia Quimica

    2004-07-01

    The determination of the Text of Oils and Greases (TOG) it can be done by several methods - gravimetrical or spectrophotometric. That work seeks to study a method alternative spectrophotometric, being compared this with the method used by Curbelo (2002). The modifications were: the reason solvent/sample, and the procedure in which the solvent the sample was mixed. For the method of Curbelo (2002) 100 mL of the sample was mixed to 10 chloroform mL and separated in separation funnel. In the proposed method, adapted denominated Chloroform, the reason was of 20 sample mL for 20 chloroform mL, being this mixture, after manual agitation, taken directly for centrifuge. The medium results were of 81,36 mg/L and 150,44 mg/L for the methods of the Chloroform and Adapted Chloroform, respectively. In spite of the medium values they present differences of almost 50%, it can be verified that the methods demonstrated certain uniformity when evaluated separately, being obtained a minimum deviation of 5,88%. With base in those preliminary results, it can be verified that the developed alternative method gets to remove more oil, mainly for more concentrated samples - exception done to the results of the pattern - and that the two methods present viability of substitution of the gravimetrical methods. (author)

  14. Application of numerical analysis methods to thermoluminescence dosimetry; Aplicacion de metodos de analisis numerico a la dosimetria por termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Ros, J. M.; Delgado, A.

    1989-07-01

    This report presents the application of numerical methods to thermoluminescence dosimetry (TLD), showing the advantages obtained over conventional evaluation systems. Different configurations of the analysis method are presented to operate in specific dosimetric applications of TLD, such as environmental monitoring and mailed dosimetry systems for quality assurance in radiotherapy facilities. (Author) 10 refs.

  15. Experimental method for calculation of effective doses in interventional radiology; Metodo experimental para calculo de dosis efectivas en radiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz Lblanca, M. D.; Diaz Romero, F.; Casares Magaz, O.; Garrido Breton, C.; Catalan Acosta, A.; Hernandez Armas, J.

    2013-07-01

    This paper proposes a method that allows you to calculate the effective dose in any interventional radiology procedure using an anthropomorphic mannequin Alderson RANDO and dosimeters TLD 100 chip. This method has been applied to an angio Radiology procedure: the biliary drainage. The objectives that have been proposed are: to) put together a method that, on an experimental basis, allows to know dosis en organs to calculate effective dose in complex procedures and b) apply the method to the calculation of the effective dose of biliary drainage. (Author)

  16. LA INVESTIGACION COMO CONTENIDO, METODO, ENFOQUE Y CONTEXTO EN LA FORMACIÓN DE LOS PROFESIONALES EN LA UNIVERSIDAD CONTEMPORANEA.

    Directory of Open Access Journals (Sweden)

    Alina Martínez

    2016-04-01

    La universidad, tiene un papel fundamental en el proceso respectivo y potencia las competencias de sus educandos, y entre las funciones principales la creacion de cultura a partir de los procesos de investigacion que en ella se genera y, consecuentemente, participa de manera activa en la solucion de los problemas del entorno, lo que tambien constituye su encargo social; siendo este fundamental en el proceso y la prioridad en la formacion para la investigacion de los estudiantes y al desarrollo de habilidades formativas como parte de sus competencias profesionales, ademas de la autopreparacion y cpacitacion permanente del docente vínculo clave en los procesos de desarrollo. La capacidad laboral mediad a través de las competencias, que el educando recibe en su proceso de formacion, es la búsqueda de los elementos necesarios que constituyen habilidades, destrezas, comportamientos debidamente organizados a fin de lograr metas y objetivos concretos, estos deben ser medidos y cualificados con eficacia, dentro de los niveles de rendimiento exigidos en el trabajo; se logra con la adquisicion y desarrollo de conocimientos, expresados en el desempeño a través de la integracion del saber, el saber hacer y saber ser.

  17. Pipeline integrity management using Monte Carlo simulation; A aplicacao do metodo de Monte Carlo no gerenciamento da integridade de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Claudio; Costa, Artur; Bittencourt, Euclides [TRANSPETRO - PETROBRAS Transporte, Rio de Janeiro, RJ (Brazil)

    2005-07-01

    Due to the growing relevance of safety and environmental protection policies in PETROBRAS and its subsidiaries, as well as official regulatory agencies and population requirements, integrity management of oil and gas pipelines became a priority activity in TRANSPETRO, involving several sectors of the company's Support Management Department. Inspection activities using intelligent PIGs, field correlations and replacement of pipeline segments are known as high cost operations and request complex logistics. Thus, it is imperative the adoption of management tools that optimize the available resources. This study presents Monte Carlo simulation method as an additional tool for evaluation and management of pipeline structural integrity. The method consists in foreseeing future physical conditions of most significant defects found in intelligent PIG In Line Inspections based on a probabilistic approach. Through Monte Carlo simulation, probability functions of failure for each defect are produced, helping managers to decide which repairs should be executed in order to reach the desired or accepted risk level. The case that illustrates this study refers to the reconditioning of ORSOL 14'' (35,56 mm) pipeline. This pipeline was constructed to transfer petroleum from Urucu's production fields to Solimoes port, in Coari, city in Brazilian Amazon Region. The result of this analysis indicated critical points for repair, in addition to the results obtained by the conventional evaluation (deterministic ASME B-31G method). Due to the difficulties to mobilize staff and execute necessary repairs in remote areas like Amazon forest, the probabilistic tool was extremely useful, improving pipeline integrity level and avoiding future additional costs. (author)

  18. Thermochemical method for the treatment of oil contaminated sand; Metodo termoquimico para tratamento de areia contaminada por oleo

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Rosana C.G.M. [Fundacao Gorceix, Ouro Preto, MG (Brazil)]|[PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Khalil, Carlos N. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    In January 2000 there was a major oil spill in Guanabara Bay, Rio de Janeiro, which contaminated 2400 tons of sand. This work, based on NGS (Nitrogen Generating System) technology, was adapted for cleaning contaminated sand and recovering of spilled oil. NGS is a thermochemical method first developed for removal of paraffin deposits in production and export pipelines. The method is based on a strongly exothermic redox chemical reaction between two salts catalyzed in acidic pH. The reaction products are harmless to the environment and consist of nitrogen, sodium chloride, water and heat. By combining simultaneous effects of the treatment such as heating, turbulence and floatation, one can remove, within 98% of efficiency, spilling oil from contaminated sand. After treatment, removed oil can be securely returned to refining process. The method has proved to be efficient, fast, low cost and ecologically correct method for cleaning contaminated sand and can be applied in place right after a contamination event. (author)

  19. Carbon/Clay nanostructured composite obtained by hydrothermal method; Compositos nanoestruturados carbono/argila obtidos por metodo hidotermico

    Energy Technology Data Exchange (ETDEWEB)

    Barin, G.B.; Bispo, T.S.; Gimenez, I.F.; Barreto, L.S., E-mail: gabriela.borin@gmail.co [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Souza Filho, A.G. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica

    2010-07-01

    The development of strategies for converting biomass into useful materials, more efficient energy carrier and / or hydrogen storage is shown a key issue for the present and future. Carbon nanostructure can be obtained by severe processing techniques such as arc discharge, chemical deposition and catalyzed pyrolysis of organic compounds. In this study we used hydrothermal methods for obtaining nanostructured composites of carbon / clay. To this end, we used coir dust and special clays. The samples were characterized by infrared spectroscopy, X-ray diffraction and Raman. The presence of the D band at 1350 cm{sup -1} in the Raman spectrum shows the formation of amorphous carbon with particle size of about 8.85 nm. (author)

  20. Non invasive scintigraphic method for biodistribution study of radiopharmaceuticals; Metodo cintilografico nao invasivo para estudo de biodistribuicao de radiofarmacos

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Erika V.; Silva, Natanael G.; Freire, Antonio C.; Monteiro, Elisiane de G.; Benedetti, Stella; Muramoto, Emiko; Fukumori, Neuza T.O.; Matsuda, Margareth M.N., E-mail: erikavieira@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Diretoria de Radiofarmacia; Vasconcellos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisa

    2011-07-01

    Biodistribution studies can be done by invasive or noninvasive methods. The aim of this study was to evaluate the percentage of retained dose (RD) in the organs of interest in noninvasive and invasive study of biodistribution of {sup 99m}Tc-DMSA (dimercaptosuccinic acid), {sup 99m}Tc-MAA (macro aggregated human serum albumin) and {sup 99m}Tc-MDP (methylene diphosphonate) and to compare with the invasive method described in the United States Pharmacopoeia (USP). Lyophilized reagents (DMSA, MAA and MDP) and sodium pertechnetate was obtained from IPEN-CNEN/SP. The radioactive concentration was 123 MBq mL{sup -1} ({sup 99m}Tc-DMSA and {sup 99m}Tc-MAA) and 617 MBq mL{sup -1} ({sup 99m}Tc-MDP). {sup 99m}Tc-DMSA and {sup 99m}Tc-MDP were injected via the tail vein and {sup 99m}Tc-MAA in the penile vein of rats. The scintigraphic images were obtained in a Nucline TH/22 Mediso gamma camera. The animals were sacrificed after the acquisition of images. The organs were removed and the activity of each organ of interest was measured in an ionization chamber. The renal uptake of {sup 99m}Tc-DMSA by noninvasive method was (47,02 +- 2,87)% up to (49,37 +- 3,41)%. By the invasive method it was observed RD (49.27 +- 1.88)%. The %RD of {sup 99m}Tc-MAA in the lungs by non-invasive method varied from (94,22 +- 0,17)% to (94,67 +- 0,25)%. Bone scintigraphy with {sup 99m}Tc-MDP showed significant uptake in the skeleton. The method proposed for noninvasive scintigraphic study biodistribution of radiopharmaceuticals was feasible, with results comparable to those obtained by invasive method described in USP. (author)

  1. A proactive method for safety management in nuclear facilities; Um metodo proativo para gerenciamento da seguranca em instalacoes nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Grecco, Claudio Henrique dos Santos; Carvalho, Paulo Victor Rodrigues de; Santos, Isaac Antonio Luquetti dos, E-mail: grecco@ien.gov.br, E-mail: paulov@ien.gov.br, E-mail: luquetti@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN/RJ), Rio de Janeiro, RJ (Brazil). Div. de Instrumentacao e Confiabilidade Humana

    2014-07-01

    Due to the modern approach to address the safety of nuclear facilities which highlights that these organizations must be able to assess and proactively manage their activities becomes increasingly important the need for instruments to evaluate working conditions. In this context, this work presents a proactive method of managing organizational safety, which has three innovative features: 1) the use of predictive indicators that provide current information on the performance of activities, allowing preventive actions and not just reactive in safety management, different from safety indicators traditionally used (reactive indicators) that are obtained after the occurrence of undesired events; 2) the adoption of resilience engineering approach in the development of indicators - indicators are based on six principles of resilience engineering: top management commitment, learning, flexibility, awareness, culture of justice and preparation for the problems; 3) the adoption of the concepts and properties of fuzzy set theory to deal with subjectivity and consistency of human trials in the evaluation of the indicators. The fuzzy theory is used primarily to map qualitative models of decision-making, and inaccurate representation methods. The results of this study aim an improvement in performance and safety in organizations. The method was applied in a radiopharmaceutical shipping sector of a nuclear facility. The results showed that the method is a good monitoring tool objectively and proactively of the working conditions of an organizational domain.

  2. Diagnostic methods in ischemic necrosis of the femoral head. Metodos de diagnostico en la necrosis isquemica de la cabeza femoral

    Energy Technology Data Exchange (ETDEWEB)

    Parra Blanco, J.A.; Pagola Serrano, M.A.; Delgado Macias, M.T. (Hospital Universitario Marques de Valdecilla, Santander (Spain))

    1994-01-01

    Ischemic necrosis of the femoral head (INFH) must be diagnosed at an early stage of development, when therapeutic approaches such as forage biopsy or osteotomy can prevent or slow the normal progression of the disease to arthrosis. In this article, on the basis of the pathological changes that characterize process, we review the advantages and limitations of the principal diagnostic techniques (table I) currently employed in the study of INFH. (Author)

  3. Rigid inclusions-Comparison between analytical and numerical methods; Inclusiones rigidas-Analisis comparativo de los metodos analiticos y numericos

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Perez, R.; Melentijevic, S.

    2014-07-01

    This paper compares different analytical methods for analysis of rigid inclusions with finite element modeling. First of all, the load transfer in the distribution layer is analyzed for its different thicknesses and different inclusion grids to define the range between results obtained by analytical and numerical methods. The interaction between the soft soil and the inclusion in the estimation of settlements is studied as well. Considering different stiffness of the soft soil, settlements obtained analytical and numerically are compared. The influence of the soft soil modulus of elasticity on the neutral point depth was also performed by finite elements. This depth has a great importance for the definition of the total length of rigid inclusion. (Author)

  4. Evaluation of methods for wax determination in crude oil; Avaliacao de metodos de determinacao de parafinas em petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Julio Cesar M.; Silva, Maria do Socorro A.J. da; Vasconcellos, Rosa C.U. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Tamanqueira, Juliana B. [Fundacao Gorceix, Ouro Preto, MG (Brazil)

    2008-07-01

    Determining the wax content of crude oil is of great importance for petroleum industry, especially for production, storage and transportation of crude oils. Many different methodologies of wax determining are available in the technical literature. However, the selection of the most suitable method must be in accordance with the aim of the analysis and observing the specificities of each technique. The purpose of this work was to determine the performance of different techniques of wax determining applied to characterization of precipitation properties of waxy compounds in crude oils. Twelve samples of crude oils proceeding from the main Brazilian oil producing sedimentary basins were selected for this study. These samples were analyzed by three important analytical techniques of wax determining: precipitation by cooled solvent; liquid chromatography with precipitation by cooled solvent; and liquid chromatography followed by gas chromatography. Differential scanning calorimetry data related to the wax crystallization in these oils were used as parameters of validation. The results obtained in this study indicate that the liquid chromatography followed by gas chromatography method has the best performance for wax determining in crude oils. (author)

  5. Implementation of statistical analysis methods for medical physics data; Implementacao de metodos de analise estatistica para dados de fisica medica

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Marilia S.; Pinto, Nivia G.P.; Barroso, Regina C.; Oliveira, Luis F., E-mail: mariliasilvat@gmail.co, E-mail: lfolive@oi.com.b, E-mail: cely_barroso@hotmail.co, E-mail: nitatag@gmail.co [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2009-07-01

    The objective of biomedical research with different radiation natures is to contribute for the understanding of the basic physics and biochemistry of the biological systems, the disease diagnostic and the development of the therapeutic techniques. The main benefits are: the cure of tumors through the therapy, the anticipated detection of diseases through the diagnostic, the using as prophylactic mean for blood transfusion, etc. Therefore, for the better understanding of the biological interactions occurring after exposure to radiation, it is necessary for the optimization of therapeutic procedures and strategies for reduction of radioinduced effects. The group pf applied physics of the Physics Institute of UERJ have been working in the characterization of biological samples (human tissues, teeth, saliva, soil, plants, sediments, air, water, organic matrixes, ceramics, fossil material, among others) using X-rays diffraction and X-ray fluorescence. The application of these techniques for measurement, analysis and interpretation of the biological tissues characteristics are experimenting considerable interest in the Medical and Environmental Physics. All quantitative data analysis must be initiated with descriptive statistic calculation (means and standard deviations) in order to obtain a previous notion on what the analysis will reveal. It is well known que o high values of standard deviation found in experimental measurements of biologicals samples can be attributed to biological factors, due to the specific characteristics of each individual (age, gender, environment, alimentary habits, etc). This work has the main objective the development of a program for the use of specific statistic methods for the optimization of experimental data an analysis. The specialized programs for this analysis are proprietary, another objective of this work is the implementation of a code which is free and can be shared by the other research groups. As the program developed since the method modeling through his implementation, this fact will allows that modifications and adaptations be accomplished any time at null cost

  6. Metodos estadisticos empleados en los articulos originales publicados sobre tabaquismo en cuatro revistas medicas espanõlas (1985-1996

    Directory of Open Access Journals (Sweden)

    García López José Antonio

    2000-01-01

    Full Text Available Fundamento: Siendo el tabaquismo un tema prioritario de investigación y habiéndose incrementado el uso de técnicas estadísticas en las publicaciones biomédicas, se describen las técnicas estadísticas utilizadas y se cuantifica la accesibilidad estadística en los artículos originales sobre tabaquismo publicados en cuatro revistas médicas españolas. Métodos: Estudio descriptivo retrospectivo de los 154 artículos originales sobre tabaquismo publicados en las revistas Atención Primaria, Medicina Clínica (Barcelona, Revista Española de Salud Pública y Revista Clínica Española, en el período de 1985 a 1996. Un único observador codificó las técnicas estadísticas en 14 categorías de acuerdo con la clasificación elaborada por Carré et al (1995 a partir de la clasificación establecida por Emerson y Colditz (1983. Para el estudio de la accesibilidad estadística se estableció como referencia el conocimiento de técnicas bivariables, hasta regresión lineal simple. Resultados: El 81,8% de los originales utilizaron la estadística inferencial. Las categorías estadísticas más frecuentemente utilizadas fueron las "Tablas de contingencia" (37,0%, "Estadística descriptiva" (18,2% y "Tablas de vida y análisis de supervivencia" (9,7%. Un lector familiarizado con técnicas bivariables tuvo acceso estadístico al 96,0% de los originales de Revista Española de Salud Pública, al 86,2% de Atención Primaria, al 66,7% de Medicina Clínica (Barcelona y al 33,3% de Revista Clínica Española. Este mismo lector tuvo acceso al 100% de los originales publicados en el trienio 1985-87 y al 68,1% en el 1994-96. Conclusiones: La utilización de técnicas estadísticas varía en función del tema y diseño de investigación, de la revista y del año de publicación. La disminución de la accesibilidad estadística hace necesario identificar el perfil del lector estándar en nuestro país para adaptar sus conocimientos a las exigencias de la literatura biomédica actual.

  7. Desulfurization of fuel oils using an advanced oxidation method; Desulfuracion de combustibles usando un metodo de oxidacion avanzada

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    In the present work, the oxidative desulfurization of fuel oils assisted by ultrasound was analyzed. It was studied the effect of hydrogen peroxide concentration, the fuel oil to aqueous solution volumetric ratio, and type of catalyst. The Fenton-like catalysts studied were ferric chloride and copper sulfate. [Spanish] En esta investigacion se analiza la desulfuracion oxidativa de combustoleo asistida con ultrasonido. Tambien se estudia el efecto de la concentracion de peroxido de hidrogeno (H{sub 2}O{sub 2}), la relacion volumetrica combustoleo/solucion acuosa y el tipo de catalizador. Los catalizadores tipo Fenton que se estudiaron fueron el cloruro ferrico (FeCl{sub 3}) y el sulfato de cobre (CuSO{sub 4}).

  8. Methods of calculus for neutron spectrometry in proportional counters; Metodos de calculo para espectrometria de neutrones en contadores proporcionales

    Energy Technology Data Exchange (ETDEWEB)

    Butragueno, J. L.; Blazquez, J. B.; Barrado, J. M.

    1976-07-01

    Response functions for cylindrical proportional counters with hydrogenated gases have been determined, taking in account only wall effect, by means of two independent calculus methods. One of them is a Monte Carlo application and the other one analytica at all. Results of both methods have been compared. (Author)

  9. Probabilistic method for geotechnical design. Application to cohesive soils; Metodo probabilista de diseno geotecnico. Aplicacion en Suelos Cohesivos

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Rodriguez, A. J.; Quevedo Sotolongo, G.

    2012-07-01

    A methodology to carry out a process of stochastic modelling in the calculation of the bearing capacity of a strip footing, on a purely cohesive soil, is proposed. the mentioned modelling is based on the application of Monte Carlo Simulation, which is more efficient, in terms of results, than classic procedures using deterministic models. These results will be the base for the application of a probabilistic design method, specifically the safety theory, starting by a statistical characterization of every random variables the impact in the problem, and it defines as a final result, a safety level for the structure, whose value will be the nearest to required safety in first limit state design or stability limit state, which is equivalent to 0.98. By this way it is established the design point of the structure according to safety design condition. (Author) 9 refs.

  10. A new method for the coefficients of the characteristic polynomial; Un metodo nuevo para los coeficientes del polinomio caracteristico

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, H.E. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    In linear algebra, one can associate an equation to each square matrix: its characteristic equation or secular equation. Starting from this equation, the one characteristic polynomial that codes several important properties of the matrix is obtained: its own values, it determinant and it appearance. The first method to calculate those coefficients of this polynomial were proposed by the french astronomer Urbain Jean Joseph Le Verrier (1811-1877), from then on, many methods have intended to calculate these coefficients. In this work the author proposes a new one method and a bibliographical citation is given where the calculations with others methods that know each other for it, taking like reference the matrix used by Le Verrier are explained. It was concluded that it here proposed, besides being the only mexican method that is knew, has the advantage of being very easy of understanding and of calculating well, in the operations that it carries out, it doesn't use the division and it avoids fractions in matrices whose entrances are whole. This has a great importance for their use in the classroom for their great didactic value and in nuclear reactors and Genetic Engineering. (Author)

  11. Chemical analysis of superconductor material by Rietveld method; Analise quimica de material superconductor atraves do metodo de Rietveld

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Junior, E.S.; Gomes Junior, G.G.; Ogasawara, T., E-mail: georges@metalmat.ufrj.b [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Dept. de Eng. Metalurgica e Materiais; Bispo, E.R.; Polasek, A. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil); Amorim, H.S. [Universidade Federal do Rio de Janeiro (IF/UFRJ), RJ (Brazil). Inst. de Fisica

    2010-07-01

    Among the main superconducting systems, the system Bi-Sr-Ca-Cu-O is extremely important because it presents two stages of high superconducting critical temperature. To manufacture samples of the superconducting phase (Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}Ox (Bi-2223) were used oxides and carbonates of high purity. The mixture was calcined and sintered for 100-200h in air. To characterize the material we used X-ray diffraction, SEM / EDS and measurement of critical temperature (Tc). The Rietveld method was used for structure refinement, and quantification of phases and to estimate the chemical composition of samples in order to obtain greater control of chemical composition using only the data of X-ray diffraction. The results were compared with the refinement results of X-ray fluorescence and was observed a discrepancy of about 8%. This result indicates that the Rietveld method can be an interesting alternative to perform chemical analysis. (author)

  12. Dalla riqualificazione energetica al recupero sostenibile. Un metodo di analisi energetica dei tessuti della città compatta

    Directory of Open Access Journals (Sweden)

    Carlo Cecere

    2012-12-01

    Full Text Available A dispetto della sempre maggiore “insostenibilità” della città odierna, recenti statistiche ne hanno confermato il crescente potere attrattivo; una circostanza che vede il continente europeo presentare un’assoluta prevalenza del costruito esistente sul nuovo. Per tentare di raggiungere quel complesso stato di equilibrio, che in molti fanno ricadere sotto il nome di sostenibilità, appare dunque necessario confrontarsi con il patrimonio edilizio dei tessuti storici, piuttosto che realizzarne di nuovi ad alta efficienza. Si presentano qui i risultati di uno studio comparativo condotto su diversi tessuti urbani alla ricerca di relazioni tra densità urbana e performance energetiche. Tale metodologia può rappresentare una base di conoscenza che conduca a trasformazioni consapevoli verso condizioni a maggiore efficienza.

  13. Comparação e desenvolvimento de metodos analiticos para acidos benzoico e sorbico em alimentos

    OpenAIRE

    Heloisa Mascia Cecchi

    1988-01-01

    Resumo: O controle dos aditivos nos alimentos processados deve ser abordado tanto em relação aos níveis máximos permitidos como aos mínimos necessários para exercerem a sua função. Para que este controle seja efetivamente colocado em funcionamento, é necessária a disponibilidade de métodos analíticos simples, rápidos, econômicos e ao mesmo tempo exatos e precisos. Neste trabalho foram comparados três métodos de análise, utilizando absorção na região ultra-violeta (UV), cromatografia em camada...

  14. Hydroxyapatite coating on stainless steel by biomimetic method; Recobrimento de hidroxiapatita em acos inoxidaveis austeniticos pelo metodo biomimetico

    Energy Technology Data Exchange (ETDEWEB)

    Dias, V.M.; Maia Filho, A.L.M.; Silva, G.; Sousa, E. de; Cardoso, K.R., E-mail: katiarc@univap.b [Universidade do Vale do Paraiba (IPD/UNIVAP), Sao Jose dos Campos, SP (Brazil). Inst. de Pesquisa e Desenvolvimento

    2010-07-01

    Austenitic stainless steels are widely used in implants due to their high mechanical strength and corrosion, however, are not able to connect to bone tissue and were classified as bioinert. The calcium phosphate ceramics such as hydroxyapatite (HA) are bioactive materials and create strong chemical bonds with bone tissue, but its brittleness and low fracture toughness render its use in conditions of high mechanical stress. The coating of steel with the bioactive ceramics such as HA, combines the properties of interest of both materials, accelerating bone formation around the implant. In this study, austenitic stainless steel samples were coated with apatite using the biomimetic method. The effect of three different surface conditions of steel and the immersion time in the SBF solution on the coating was evaluated. The samples were characterized by SEM, EDS and X-ray diffraction. (author)

  15. Metodo de ensino integral da dança : um estudo do desenvolvimento dos exercicios tecnicos centrado no aluno

    OpenAIRE

    Eusebio Lobo da Silva

    1993-01-01

    Resumo: O objetivo deste trabalho: "Método de Ensino Integral da Dança. Um Estudo do Desenvolvimento dos Exercícios Técnicos Centrado no Aluno" é criar instrumentos que possibilitem o desenvolvimento de uma habilidade motora específica para o dançarino, a partir do potencial de cada indivíduo, sem que este desenvolvimento esteja desvinculado da sua pessoa. Adotamos os conceitos de: a) Tendência Atualizante definido por ROGERS, b) de Ser Integral da filosofia oriental, principalmente exposto p...

  16. Precise magnetostatic field using the finite element method; Calculo de campos magnetostaticos com precisao utilizando o metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Francisco Rogerio Teixeira do

    2013-07-01

    The main objective of this work is to simulate electromagnetic fields using the Finite Element Method. Even in the easiest case of electrostatic and magnetostatic numerical simulation some problems appear when the nodal finite element is used. It is difficult to model vector fields with scalar functions mainly in non-homogeneous materials. With the aim to solve these problems two types of techniques are tried: the adaptive remeshing using nodal elements and the edge finite element that ensure the continuity of tangential components. Some numerical analysis of simple electromagnetic problems with homogeneous and non-homogeneous materials are performed using first, the adaptive remeshing based in various error indicators and second, the numerical solution of waveguides using edge finite element. (author)

  17. Reconstruction of the limit cycles by the delays method; Reconstruccion de ciclos limite por el metodo de los retardos

    Energy Technology Data Exchange (ETDEWEB)

    Castillo D, R.; Ortiz V, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Calleros M, G. [CFE, CNLV, Alto Lucero, Veracruz (Mexico)]. e-mail: rcd@nuclear.inin.mx

    2003-07-01

    The boiling water reactors (BWRs) are designed for usually to operate in a stable-lineal regime. In a limit cycle the behavior of the one system is no lineal-stable. In a BWR, instabilities of nuclear- thermohydraulics nature can take the reactor to a limit cycle. The limit cycles should to be avoided since the oscillations of power can cause thermal fatigue to the fuel and/or shroud. In this work the employment of the delays method is analyzed for its application in the detection of limit cycles in a nuclear power plant. The foundations of the method and it application to power signals to different operation conditions are presented. The analyzed signals are: to steady state, nuclear-thermohydraulic instability, a non linear transitory and, finally, failure of a controller plant . Among the main results it was found that the delays method can be applied to detect limit cycles in the power monitors of the BWR reactors. It was also found that the first zero of the autocorrelation function is an appropriate approach to select the delay in the detection of limit cycles, for the analyzed cases. (Author)

  18. Organic facies applied to petroleum exploration; Facies organica: conceitos, metodos e estudos de casos na industria do petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Taissa Rego; Araujo, Carla Viviane; Souza, Igor Viegas Alves F. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). Gerencia de Geoquimica,]. E-mail: taissamenezes@petrobras.com.br; Mendonca Filho, Joao Graciano; Mendonca, Joalice de Oliveira [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Geologia

    2008-06-15

    The concept of organic facies, as well as the definitions and means of the different facies became a very important tool to petroleum exploration. The application of this concept is the best way to integrate microscopy and geochemical techniques to study kerogen contained in sedimentary rocks. Thus, palynofacies analysis and bulk geochemical methods are used to characterize the total particulate organic matter. Palynofacies analysis involves the integrated study of all aspects of the kerogen assemblage: identification of the individual particulate components, assessment of their absolute and relative proportions and preservation states. The correlation between palynofacies and geochemical data provides the organic facies models that point out the depositional environmental conditions and hydrocarbon source rock potential. (author)

  19. Eficacia do metodo Meir Schneider de autocuidado em pessoas com distrofias musculares progressivas : ensaio clinico fase II

    OpenAIRE

    Lea Beatriz Teixeira Soares

    1999-01-01

    Resumo: As pessoas com distrofias musculares progressivas vivem o limite do conhecimento médico e aguardam resultados de pesquisa da prevenção, reabilitação e mesmo a cura dos indivíduos portadores. Nesse contexto discute-se a eficácia do método Meir Schneider de autocuidado (self-healing) baseado em ensaio clínico fase II em 12 pessoas com distrofias musculares progressivas, sob tratamento ambulatorial intensivo e não intensivo. Foram atendidos 7 portadores de Distrofia Muscular Duchenne- DM...

  20. Thermochemical methods for the treatment of oil contaminated sand; Metodo termoquimico para tratamento de areia contaminada por oleo

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Rosana C.G.M. [Fundacao Jose Bonifacio, Rio de Janeiro, RJ (Brazil); Khalil, Carlos N. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    The Nitrogen Generating System (SGN in Portuguese) is a thermochemical method first developed for cleaning and removal of paraffin deposits in production and export pipelines. SGN is based on a redox chemical reaction between two salts which is catalyzed in acidic pH. The reaction is strongly exothermic and its products are nitrogen, sodium chloride, water and heat. All reaction products are harmless to the environment. In January 2000 there was a major oil spill in Guanabara Bay, Rio de Janeiro, which contaminated 2400 tons of sand. This work, developed at PETROBRAS Research Center (CENPES), was based on SGN technology which has been adapted for cleaning contaminated sand and recovering of spilled oil. By combining simultaneous effects of the SGN treatment such as heating, turbulence and floatation, one can remove, within 98% of efficiency, spilling oil from contaminated sand and removed oil can be securely returned to refining process. SGN technology has proved to be efficient, fast, low cost and ecologically correct method for cleaning contaminated sand and can be applied in loco right after a contamination event. (author)

  1. Automation of the method gamma of comparison dosimetry images; Automatizacion del metodo gamma de comparacion de imagenes dosimetricas

    Energy Technology Data Exchange (ETDEWEB)

    Moreno Reyes, J. C.; Macias Jaen, J.; Arrans Lara, R.

    2013-07-01

    The objective of this work was the development of JJGAMMA application analysis software, which enables this task systematically, minimizing intervention specialist and therefore the variability due to the observer. Both benefits, allow comparison of images is done in practice with the required frequency and objectivity. (Author)

  2. Silicon dioxide obtained by Polymeric Precursor Method; Obtencao de dioxido de silicio pelo Metodo dos Precursores Polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.T.; Granado, S.R.; Lopes, S.A.; Cavalheiro, A.A., E-mail: cinthia_quimica@hotmail.com [Universidade Estadual de Mato Grosso do Sul (CPTREN/UEMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    The Polymeric Precursor Method is able for obtaining several oxide material types with high surface area even obtained in particle form. Several MO{sub 2} oxide types such as titanium, silicon and zirconium ones can be obtained by this methodology. In this work, the synthesis of silicon oxide was monitored by thermal analysis, XRD and surface area analysis in order to demonstrate the influence of the several synthesis and calcining parameters. Surface area values as higher as 370m2/g and increasing in the micropore volume nm were obtained when the material was synthesized by using ethylene glycol as polymerizing agent. XRD analysis showed that the material is amorphous when calcinated at 600°C in despite of the time of calcining, but the material morphology is strongly influenced by the polymeric resin composition. Using Glycerol as polymerizing agent, the pore size increase and the surface area goes down with the increasing in decomposition time, when compared to ethylene glycol. (author)

  3. Approximation of the Doppler broadening function by Frobenius method; Aproximacao da funcao de alargamento doppler atraves do metodo de Frobenius

    Energy Technology Data Exchange (ETDEWEB)

    Palma, Daniel A.P. [Centro Federal de Educacao Tecnologica de Quimica de Nilopolis/RJ (CEFET), RJ (Brazil)]. E-mail: dpalma@cefeteq.br; Martinez, Aquilino S.; Silva, Fernando C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: aquilino@lmp.ufrj.br; fernando@lmn.con.ufrj.br

    2005-07-01

    An analytical approximation of the Doppler broadening function {psi}(x,{xi}) is proposed. This approximation is based on the solution of the differential equation for {psi}(x,{xi}) using the methods of Frobenius and the parameters variation. The analytical form derived for {psi}(x,{xi}) in terms of elementary functions is very simple and precise. It can be useful for applications related to the treatment of nuclear resonances mainly for the calculations of multigroup parameters and self-protection factors of the resonances, being the last used to correct microscopic cross-sections measurements by the activation technique. (author)

  4. Preparation methods, reactivity and biological importance of 4-thiazolidinones; Metodos de obtencao, reatividade e importancia biologica de 4-tiazolidinonas

    Energy Technology Data Exchange (ETDEWEB)

    Liesen, Andre P.; Aquino, Thiago M. de; Goes, Alexandre J.S. [Universidade Federal de Pernambuco (UFPE)e, PE (Brazil). Dept. de Antibioticos]. E-mail: ajsg@ufpe.br; Lima, Jose G. de; Faria, Antonio R. de; Alves, Antonio J. [Universidade Federal de Pernambuco (UFPE)e, PE (Brazil). Dept. de Ciencias Farmaceuticas

    2008-07-01

    Molecules containing the 4-thiazolidinone ring are known to possess a wide range of biological properties including antimicrobial and antiinflammatory activities among others. These compounds can be synthesized by cyclization reactions involving alpha-haloacetic acid or alpha-mercaptoacetic acid and employed in several chemoselective reactions. Comprehensive reviews have been written on 4-thiazolidinones in 1961 by Brown and in 1980 by Singh et al. In the recent literature, some new synthesis methods for 4-thiazolidinone derivatives and several reactions have been reported. These advances warrant to review the chemical and biological properties of compounds with this important heterocycle employed in synthetic organic chemistry and medicinal chemistry (author)

  5. Thiosemicarbazones: preparation methods, synthetic applications and biological importance; Tiossemicarbazonas: metodos de obtencao, aplicacoes sinteticas e importancia biologica

    Energy Technology Data Exchange (ETDEWEB)

    Tenorio, Romulo P.; Goes, Alexandre J.S. [Universidade Federal de Pernambuco, Recife, PE (Brazil). Dept. de Antibioticos]. E-mail: ajsg@ufpe.br; Lima, Jose G. de; Faria, Antonio R. de; Alves, Antonio J.; Aquino, Thiago M. de [Universidade Federal de Pernambuco, Recife, PE (Brazil). Dept. de Ciencias Farmaceuticas

    2005-11-15

    Thiosemicarbazones are a class of compounds known by their chemical and biological properties, such as antitumor, antibacterial, antiviral and antiprotozoal activity. Their ability to form chelates with metals has great importance in their biological activities. Their synthesis is very simple, versatile and clean, usually giving high yields. They are largely employed as intermediates, in the synthesis of others compounds. This article is a survey of some of these characteristics showing their great importance to organic and medicinal chemistry. (author)

  6. Elaboration of groundwater quality maps using Kriging methods; Creacion de mapas de calidad de aguas subterraneas mediante metodos de Krigeaje

    Energy Technology Data Exchange (ETDEWEB)

    Chica-Olmo, M.; Luque-Espinar, J. A.

    2003-07-01

    Two different geostatistical approaches for the elaboration of groundwater quality maps are presented. Firstly, the main theoretical aspects concerning to the two estimation methods used, ordinary kriging and indicator kriging, are described. They share a common theoretical basis but focus their estimations in different terms. The former gives the most probable value of a groundwater quality parameter in the aquifer, e. g. nitrate contents, so that is applied to map it spatial distribution. Whereas the latter estimates is applied to estimate the spatial probability distribution function of surpassing a given threshold or alert value for the experimental parameter. A case study regarding the Vega of Granada aquifer is also presented. The comparative advantages offered by each of these methods are discussed, taking into account the random behaviour shown by the studied variable. It is concluded that maps created by both methods provide value information of great interest for decision-making with regards to water quality control. (Author) 10 refs.

  7. In service inspection of pipes based on risk methods; Inspeccion en servicio de tuberias basada en metodos de riesgo

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza G, G.; Viais J, J.; Carmona C, M. [ININ, Centro Nuclear ' Dr. Nabor Carrillo Flores' , Carretera Mexico Toluca, S/N. La Marquesa, Ocoyoacac, Mexico, C. P. 52750 (Mexico)]. e-mail: gmg@nuclear.inin.mx

    2006-07-01

    The politics of the Nuclear Regulatory Commission (by its initials in English NRC) of the United States of America on the use of the Probabilistic Safety Analysis (PSA) in activities of nuclear regulation it foments the use of this analysis technique to improve the decisions making, to reduce the unnecessary work in maintenance aspects, inspection and tests and to improve the regulatory efficiency. The inspection programs in service (ISI by its initials in English) developed by the American Society of Mechanical Engineers (by its initials in English ASME) it has been the one primary mechanism to prove the mechanical equipment in plants of nuclear energy, these programs indeed have been carried out in plants of nuclear energy by more of two decades. Their purpose is to identify the conditions, such as indications of cracks that are precursory of flights and ruptures which violate the integrity principles of the pressure frontier. The inspection in service activities include ultrasonic tests, surface tests and penetrating liquids test, also activities that include the scaffolds construction, removal of insulations and welding polishing. The inspections in service every 18 months during the times outside of service are executed. One of the objectives is to lower the costs of the inspections during the times outside of service and to reduce the exposure to the radiation by part of the personnel during these times out for inspections, while it is increased or it maintains the personnel's safety and the reliability. As part of the methodology a pipe segment is selected for which a fault in any point has the same consequences, being calculated the fault probability of the tube using the dimensions of the segment. In this work the inspection in service methodology is applied based on risk to an aspersion system of low pressure of the Laguna Verde Nucleo electric Central. For this system a reduction in the number of welding to inspect of 103 to only 15 is obtained, recommending only flight monitoring and pressure and flight tests for 13 considered segments of low risk. With the above-mentioned a substantial saving is obtained in the costs by inspection for the plant, avoiding the potential personnel's lesions by means of the reduction of the construction of scaffolds, removal of asbestos, removal of insulations and welding polishing. (Author)

  8. Fuel cell design using a new heuristic method; Diseno de celdas de combustible mediante un nuevo metodo heuristico

    Energy Technology Data Exchange (ETDEWEB)

    Perusquia, R.; Montes T, J. L.; Ortiz S, J. J.; Castillo M, A., E-mail: joseluis.montes@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    In this paper a new method for the pre-design of a typical fuel cell with a structural array of 10 x 10 fuel elements for a BWR is presented. The method is based on principles of maximum dispersion and minimum peaks of local power within the array of fuel elements. The pre-design of the fuel cells is made by simulation in two dimensions (2-D) through the cells physics code CASMO-4. For this purpose of pre-design the search process is guided by an objective function which is a combination of the main neutronic parameters of the fuel cell. The results show that the method is a promising tool that could be used for the design of fuel cells for use in a nuclear plant BWR. (Author)

  9. Modern analytic methods applied to the art and archaeology; Metodos analiticos modernos aplicados al arte y la arqueologia

    Energy Technology Data Exchange (ETDEWEB)

    Tenorio C, M. D.; Longoria G, L. C., E-mail: dolores.tenorio@inin.gob.m [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    The interaction of diverse areas as the analytic chemistry, the history of the art and the archaeology has allowed the development of a variety of techniques used in archaeology, in conservation and restoration. These methods have been used to date objects, to determine the origin of the old materials and to reconstruct their use and to identify the degradation processes that affect the integrity of the art works. The objective of this chapter is to offer a general vision on the researches that have been realized in the Instituto Nacional de Investigaciones Nucleares (ININ) in the field of cultural goods. A series of researches carried out in collaboration with national investigators and of the foreigner is described shortly, as well as with the great support of degree students and master in archaeology of the National School of Anthropology and History, since one of the goals that have is to diffuse the knowledge of the existence of these techniques among the young archaeologists, so that they have a wider vision of what they could use in an in mediate future and they can check hypothesis with scientific methods. (Author)

  10. Method to calculate failure rate of submarine flexible pipes; Metodo para calculo da taxa de falha de dutos flexiveis submarinos

    Energy Technology Data Exchange (ETDEWEB)

    Simoes Filho, Salvador [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This report presents calculation method for failure rate of submarine flexible pipes in PETROBRAS using the distribution of Weibull in comparison with the traditional method of PARLOC that uses the exponential distribution. PARLOC - Pipeline and Riser Loss of Containment Study - Pipeline Offshore Reliability Data - database of pipes of the North Sea. (author)

  11. Modificação do metodo "kindling" para obtenção de status epilepticus experimental em ratos

    Directory of Open Access Journals (Sweden)

    Carlos J. Reis de Campos

    1980-03-01

    Full Text Available Foi utilizada em nova espécie animal (ratos, uma modificação do método "kindling", introduzida por Taber e col. (1977 para obtenção de status epilepticus experimental. Para isso foram implantados mediante cirurgia estereotáxica, eletrodos duplos, torcidos no hipocampo dorsal de 12 ratos machos albinos. Esses animais foram submetidos, após uma semana de pós-operatório, a 1 segundo de estimulação elétrica de baixa intensidade em forma intermitente, um estímulo por minuto durante 2 horas, desenvolvendo-se em prazo de 30 minutos um estado de epilepsia eletrográfica e comportamental duradoura. Vários padrões de descargas epilépticas eletrográficas foram observados bem como manifestações convulsivas tônico-clônicas. Os animais que foram submetidos a novas sessões de estimulação após 7 e 14 dias mostraram aumento de atividade epiléptica demonstrando uma modificação plástica do hipocampo do rato submetido a estimulação elétrica a qual perdura no tempo. O método permite a obtenção de "kindling" em tempo bem mais curto (horas, comparativamente às técnicas anteriormente descritas (dias, tornando-se um promissor modelo de epilepsia para testes de drogas anticonvulsivantes e para o estudo dos mecanismos fisiopatológicos e bioquímicos envolvidos na descarga epiléptica.

  12. Manual method for dose calculation in gynecologic brachytherapy; Metodo manual para o calculo de doses em braquiterapia ginecologica

    Energy Technology Data Exchange (ETDEWEB)

    Vianello, Elizabeth A.; Almeida, Carlos E. de [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil); Biaggio, Maria F. de [Universidade do Estado, Rio de Janeiro, RJ (Brazil)

    1998-09-01

    This paper describes a manual method for dose calculation in brachytherapy of gynecological tumors, which allows the calculation of the doses at any plane or point of clinical interest. This method uses basic principles of vectorial algebra and the simulating orthogonal films taken from the patient with the applicators and dummy sources in place. The results obtained with method were compared with the values calculated with the values calculated with the treatment planning system model Theraplan and the agreement was better than 5% in most cases. The critical points associated with the final accuracy of the proposed method is related to the quality of the image and the appropriate selection of the magnification factors. This method is strongly recommended to the radiation oncology centers where are no treatment planning systems available and the dose calculations are manually done. (author) 10 refs., 5 figs.

  13. Influence of the drying method in chitosans purification step; Influencia do metodo de secagem na etapa de purificacao de quitosanas

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Ana C.M.; Batista, Jorge G.S.; Bettega, Antonio; Lima, Nelson B. de, E-mail: acmfonseca.acf@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Currently, the study of extracellular biopolymers properties has received prominence for being easy extraction and purification. Chitosan has been an attractive proposition for applications in various fields such as engineering, biotechnology, medicine and pharmacology. For such applications, it is necessary purification of chitosan to obtain a product more concentrated and free of undesirable impurities. However, at this stage of the process of obtaining the biopolymer may occur morphological and physicochemical changes. This study evaluated the influence of the drying process after purification of a commercial chitosan sample and the importance of this step and its cost/benefit in applications requiring a high degree of purity. The method of drying influenced in the organoleptic properties and in the main characteristics of material. Analysis of the crystal structure by X-ray diffraction showed that the degree of crystallinity, X (%), in the purified chitosan samples was lower when compared with the unpurified sample. The degree of acetylation, DA (%), was analyzed by spectroscopy infrared with no significant changes on the three drying methods assessed, unlike the viscosimetric molecular weight, M{sub v}, determined by capillary viscometry. (author)

  14. Obtaining hydroxyapatite coatings on titanium by the biomimetic method; Obtencion de recubrimientos de hidroxiapatita sobre titanio mediante el metodo biomimetico

    Energy Technology Data Exchange (ETDEWEB)

    Paz, A.; Martin, Y.; Pazos, L. M.; Parodi, M. B.; Ybarra, G. O.; Gonzalez, J. E.

    2011-07-01

    In this work, a study about the deposition of hydroxyapatite on a titanium substrate employing the biomimetic method is presented. A solution with high content of calcium and phosphorus (SCS) was used. In addition, activation of titanium with hydrogen peroxide and hydrochloric acid and a subsequent heat treatment was performed. The characterization of materials used and the coating obtained was carried out by Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). As a result of the activation processes a hydrated titanium oxide was formed. On the active surface, a coating of hydroxyapatite was obtained after a period of 24 h, which has a thickness of about 2-4 {mu}m. (Author) 21 refs.

  15. A new method for dosimetry with films radiochromic; Un nuevo metodo para la dosimetria con peliculas radiocromica

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Carot, I.

    2013-07-01

    in this paper a new method is presented and the results of the comparison between the calibration is summarized based on a planning reference and calibration obtained from the irradiated fragments measure different dose levels multichannel compare dosimetry based on the weighted average dosimetry described by Micke et al.(present in the FilmQAPro software) and, finally, show different results obtained with the method proposed in several applications clinics. (Author)

  16. Applications of the pseudo-harmonics to the multidimensional kinetics; Aplicacao do metodo dos pseudo-harmonicos a cinetica multidimensional

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Zelmo Rodrigues de; Silva, Fernando Carvalho da; Alvim, Antonio C. Marques [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: zelmo@con.ufrj.br; fernando@con.ufrj.br; alvim@con.ufrj.br

    2005-07-01

    In this work we propose the application of the pseudo-harmonics in modal methods of spatial kinetics. The pseudo-harmonics, or the pseudo-modes, are the eigenfunctions associated to the leakage+removal operator in each group of energy of the steady-state diffusion equation. This operator is self-adjoint and it is not necessary to calculate the adjoints eigenfunctions. In the present work the pseudo-harmonics will be obtained starting from the equation of diffusion discretized by the coarse-mesh finite difference (CMFD). The modal methods approximate the time-dependent flux for an expansion in functions predetermined, that include the spatial dependence, with unknown expansion coefficients, that include the whole dependent part of the time. The obtaining of the system whose solution they are the coefficients of the modal expansion is done with aid of a function weight. Using the pseudomodes obtained in the steady state calculations, in the modal expansion as been the dependent functions of the space, we will show that the function weight can be chosen as being the own adjoint pseudo-modes. This calculation leads to a linear system of ordinary differential equations with the defined dimension for the number of pseudo-harmonics employed. The solution of the equations is built through the analytical integration of the equations of the precursor of delayed neutron. The proposed method was tested and it present good results, when compared with the direct method. (author)

  17. Determination of polycyclic aromatic hydrocarbons (PAHs). gas chromatographic method; Determinazione degli idrocarburi policiclici aromatici (IPA). Metodo gascaromatografico

    Energy Technology Data Exchange (ETDEWEB)

    Menichini, E.; Viviano, G. [Istituto Superiore di Sanita`, Rome (Italy). Lab. di Igiene Ambientale

    1997-12-01

    The method enables the determination of 4- to 6- ring PAHs and particularly of carcinogenic PAHs regulated in Italy. This revision is based on the results of a national collaborative study. Sample extract, obtained by a method described in a previous report (Rapporto ISTISAN: 90/33) is cleaned up by thin layer chromatography and analysed by gas chromatography; identification is confirmed by mass spectrometry. An intralaboratory quality control program is described.

  18. Tools for building Breast Cancer CAD methods; Herramientas para elaborar metodos de CAD del cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Herrero, G.; Franco-Valiente, J. M.; Suarez-Ortega, C.; Rubio del Solar, M.; Ramos-Pollam, R.; Guevara-Lopez, M. A.; Gonzalez de Posada, N.; Ramos, I.; Loureiro, J.

    2011-07-01

    This paper describes the main results of the collaboration currently ongoing between CETA-CIEMAT and the Faculty of Engineering at the University of Porto. It introduces the Mammography image Workstation for Analysis and Diagnosis (MIWAD) and the data analysis processes through which Grid infrastructures are used to develop Breast Cancer Computer-Aided Diagnosis (CAD) methods.MIWAD is a novel integrated software framework that integrates a specialized graphical user interface combining digital image processing, pattern recognition and artificial intelligence techniques. This paper describes its successful application in a pilot experience, on the first Portuguese Breast Cancer Digital Repository. (Author)

  19. The Brazilian dilution method for ballast water exchange; O metodo de diluicao brasileiro para troca de agua de lastro

    Energy Technology Data Exchange (ETDEWEB)

    Mauro, Celso Alleluia [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Avaliacao e Monitoramento Ambiental]. E-mail: celso@cenpes.petrobras.com.br; Land, Claudio Goncalves [PETROBRAS, Rio de Janeiro, RJ (Brazil). Abastecimento, Logistica e Planejamento]. E-mail: cgland@petrobras.com.br; Pimenta, Jose Maria Hollanda Alvares; Barreto, Francisco Carlos Peixoto [PETROBRAS, Rio de Janeiro, RJ (Brazil). Engenharia; Brandao, Marcus Vinicius Lisboa; Marroig, Nilton Lemos [Transpetro, Rio de Janeiro, RJ (Brazil). Frota Nacional de Petroleiros. Inspetoria Geral; Tristao, Maria Luiza Braganca [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Quimica; Fadel, Andre Luiz da Fonseca [PETROBRAS, Rio de Janeiro, RJ (Brazil). Financas Corporativa e Tesouraria; Villac, Maria Celia; Fernandes, Lohengrin; Paranhos, Rodolfo; Dias, Cristina; Bonecker, Sergio; Denise Tenenbaum [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Biologia; Persich, Graziela; Garcia, Virginia; Odebrecht, Clarisse [Fundacao Universidade do Rio Grande, RS (Brazil). Dept. de Oceanografia

    2002-12-01

    In a precautionary approach and dealing with the coming International Maritime Organization (IMO) regulations on ballast water, PETROBRAS developed a new method for ballast water exchange in tankers. Differently from ordinary methods PETROBRAS method which have been called Brazilian Dilution Method (BDM) or Dilution Method involves ballast loading through the top with simultaneous unloading from the bottom of the tanks. The method proposal was firstly presented to IMO, which encouraged PETROBRAS to carry out a field trial. PETROBRAS in June 1998 carried out a trial in the product carrier M/V Lavras. A simulation study was useful to plan the trial assessing the theoretical efficiency of the method, establishing the best sampling points and comparing the BDM with the Tank Overfilling Method (TOM). Simulation showed that for the same tank shape, the water renewal in BDM is more effective than in TOM and that 90 % of water renewal could be obtained by BDM. A dye concentration variation monitoring and a biological assessment were performed and the results confirmed that over than 90 % of the ballast water was renewed after three exchanges. The method was proved safe, practical, economical and suitable to minimize the risk of exotic species transport between ports. (author)

  20. Trends in the analytical methods for water analysis; Tendencias de los metodos analiticos para el analisis del agua

    Energy Technology Data Exchange (ETDEWEB)

    Tortajada-Genero, L. A.; Campins-Falco, P. [Universidad de Valencia (Spain)

    2003-07-01

    The technological and methodological advances have provided and evolution of analytical chemistry, specially in the area of water analysis. There area wide variety of problems for this kind of analysis, as result of the high number of possible objectives. They involve from complex environmental studies to routine control of a physical-chemical parameter. Additionally, the variety of analysis to analyse is increasing as in total number as in complexity terms. The response has been the appearance of a high number of analytical methods. Some guidelines and recommendations have been described together with different strategies for quality assurance. In this paper, a review of the last analytical methods described in the scientific references for determinations in water was realised. The evolution and future perspectives were also studied. (Author) 16 refs.

  1. Y-method for subsea equipment installation; Metodo Y de instalacao de equipamentos 'subsea'

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Melquisedec F.; Neves, Cassiano R. [SUBSIN - Subsea Integrity Engenharia e Projetos Ltda., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The paper presents a new design of equipment to fall to the seabed, and the results of preliminary calculations to validate the concept. The goals to be achieved consider the current reality of offshore production demands the increasing use of equipment background with large mass and dimensions at increasing depths. The increase of the depths brings necessarily, independent of the mass value, the appearance of a 'zone of resonance' in which pick of tensions arise in values often exceed the capacity of the traction cables designed with all the factors of safety required in standard. This phenomenon necessitates the use of equipment that create the 'spring effect', damping equipment installed in the line of tension involving the use of cranes and ferries or compensating for 'heave' trying to minimize the effects of the balance of the sea in the operation involving where the use of vessels of large size and high cost. By splitting the vector of the load in two, by two different boats, six variables are introduced make it easy to control. The variables are: relative positions and lengths of the cable of witch vessel and the speed of descent of these cables. This development emphasized the cost factor to meet technical and operational characteristics of this type of work, including the same way all the safety requirements and operational speed. As a result of the additional method, we were able to introduce a new parameter in the coupling of equipment in the background since the method also brings the possibility of total control of the speed of approach and touch a tool in its 'slot' even it in a sea adverse. (author)

  2. Nuclear method applied in archaeological sites at the Amazon basin; Metodo nuclear aplicado em sitios arqueologicos na bacia amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Nicoli, Ieda Gomes [Comissao Nacional de Energia Nuclear (CNEN), Brasilia, DF (Brazil). Distrito do Planalto Central; Bernedo, Alfredo Victor Bellido; Latini, Rose Mary [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Fisico-Quimica

    2002-07-01

    The aim of this work was to use the nuclear methodology to character pottery discovered inside archaeological sites recognized with circular earth structure in Acre State - Brazil which may contribute to the research in the reconstruction of part of the pre-history of the Amazonic Basin. The sites are located mainly in the Hydrographic Basin of High Purus River. Three of them were strategic chosen to collect the ceramics: Lobao, in Sena Madureira County at north; Alto Alegre in Rio Branco County at east and Xipamanu I, in Xapuri County at south. Neutron Activation Analysis in conjunction with multivariate statistical methods were used for the ceramic characterization and classification. An homogeneous group was established by all the sherds collected from Alto Alegre and was distinct from the other two groups analyzed. Some of the sherds collected from Xipamunu I appeared in Lobao's urns, probably because they had the same fabrication process. (author)

  3. Synthesis of barium titanate crystalline nanoparticles using hydrothermal microwave method; Obtencao de nanoparticulas cristalinas de titanato de bario usando metodo hidrotermal assistido por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, A.E.; Silva, R.A.; Teixeira, S.R. [Universidade Estadual Paulista (DFQB/FCT/UNESP), Presidente Prudente, SP (Brazil). Dept. de Fisica, Quimica e Biologia. Lab. de Compositos e Ceramicas Funcionais; Moreira, M.L. [Universidade Federal de Sao Carlos (LiEC/UFSCAR), SP (Brazil). Lab. Interdisciplinar de Eletroquimica e Ceramica; Volanti, D.P.; Longo, E. [Universidade Estadual Paulista (LiEC/UNESP), Araraquara, SP (Brazil). Lab. Interdisciplinar de Eletroquimica e Ceramica

    2009-07-01

    The hydrothermal microwave method (HTMW) was used in the synthesis of barium titanate (BaTiO{sub 3}) nanoparticles. The solution was prepared in deionized water by using titanium (IV) isopropoxide (C{sub 12}H{sub 28}O{sub 4}Ti), barium chloride (BaCl{sub 2}.2H{sub 2}O) and potassium hydroxide (KOH). Afterwards it was heated in an adapted conventional microwave oven. The system is composed of a temperature controller with thermocouple, a hermetic camera of reaction made of teflon, a manometer and a safety valve. The solution was heated to 140 deg C, at a 140 deg C/min heating rate, and maintained at this temperature for 40 minutes. The obtained ceramic powder was characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The XRD data confirms the formation of a high crystalline ceramic material with perovskite structure. The FE-SEM images reveal morphologies with dimensions varying from 27 to 54 nm. (author)

  4. Sintering kinetics and mass transport in ceramic engobes; Cinetica de sinterizacion y transporte de masa en engobes ceramicos por el metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Dal Bo, M.; Boschi, A. O.; Hotza, D.

    2013-10-01

    This work is concerned to study the sintering rate and mass transport mechanism in ceramic engobes. Specimens of engobes were prepared from a determined formulation by slip casting. Sintering was carried in two steps: (i) at constant heating rate of 7.5 degree centigrade/min and (ii) with an isothermal treatment, during 120 min. According to the dilatometric curves obtained with the engobe sintering during isothermal treatment, the dominant sintering mechanism and the rate of reactions, between the 775 and 975 degree centigrade, were determined. The results showed that between 775 and 800 degree centigrade, the sintering rate can be described by ln[d({Delta}L/L{sub 0})/dt] = -5.64 + 1.77.E10{sup -}3T. At higher temperatures, from 850 to 975 degree centigrade, this rate can be expressed by ln[d({Delta}L/L{sub 0})/ dt] = -30.73 + 3.E10{sup -}2T. The dominant transport mass mechanisms were the grain rearrangement, solution-precipitation and grain boundaries reaction. (Author)

  5. Methods for the control of NOx and particles in the combustion; Metodos para el control de NOx y particulas en la combustion

    Energy Technology Data Exchange (ETDEWEB)

    Romo Millares, Cesar A. [Instituto de Investigaciones Electrica, Cuernavaca (Mexico)

    1996-12-31

    This present the techniques and equipment of control of transmissions for thermoelectric power stations appear that have mayor possibilities of being considered in the future immediate within the national energetic panorama and the frame established by the environmental normative. The subject polluting compounds to overhaul are oxides of nonburned nitrogen and particles [Espanol] Se presentan las tecnicas y equipos de control de emisiones para centrales termoelectricas que tienen mayores posibilidades de ser consideradas en el futuro inmediato dentro del panorama energetico nacional y el marco establecido por la normatividad ambiental. Los compuestos contaminantes sujetos a revision son los oxidos de nitrogeno y las particulas inquemadas

  6. Risk assessment methods in radiotherapy: Probabilistic safety assessment (PSA); Los metodos de analisis de riesgo en radioterapia: Analisis Probabilistico de seguridad (APS)

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Vera, M. L.; Perez Mulas, A.; Delgado, J. M.; Barrientos Ontero, M.; Somoano, F.; Alvarez Garcia, C.; Rodriguez Marti, M.

    2011-07-01

    The understanding of accidents that have occurred in radiotherapy and the lessons learned from them are very useful to prevent repetition, but there are other risks that have not been detected to date. With a view to identifying and preventing such risks, proactive methods successfully applied in other fields, such as probabilistic safety assessment (PSA), have been developed. (Author)

  7. Metodo de Archivar las Observaciones del Comportamiento del Nino, Como Guia para Entenderlo Mejor (Methods of Recording Observations of Children's Behavior, A Guide for Better Understanding)

    Science.gov (United States)

    Stamp, Isla M.

    1971-01-01

    Copies of the Behaviour Study Technique described in this article may be obtained in English from the Australian Council for Educational Research, Frederick St., Hawthorn, Victoria, Australia 3122. (RY)

  8. Application of foresight methods in applications for patents and trademarks in Spain; Aplicacion de metodos de prevision en las solicitudes de patentes y marcas en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo Nuchera, A.; Glabaly Marquez, S.

    2011-07-01

    Patent and trademark offices which run according to principles of new management have an inherent need for dependable forecasting data in planning capacity and service levels. The predictive approach adopted for the time series of Spanish patents and trademarks applications (1979-2009) has been the use of different techniques of time series prediction in a short-term time horizon. The methods used can be grouped into two specifics areas: regression models of trends and time series models advanced. The results of this study show that it is possible to model the series of patents and trademarks applications with different models, especially ARIMA, with satisfactory model adjustment and relatively low error. (Author) 33 refs.

  9. Metodo de gestão em sistema de produção animal Management method in animal production system

    Directory of Open Access Journals (Sweden)

    Paulo Fernando Machado

    2009-07-01

    Full Text Available O sistema MDA de gerenciamento de explorações leiteiras teve origem em um conjunto de práticas gerenciais desenvolvidas e utilizadas eficientemente pelo setor industrial desde o início da década de 90. Foi desenvolvido aplicando-se os cinco princípios administrativos básicos para se atingir o sucesso nas empresas. Estes princípios, somados aos princípios de sobrevivência na atividade nortearam as características do Sistema MDA. Ele pode ser caracterizado como um sistema de gestão estratégica que se inicia com os fins em mente, ou seja, é condição básica para a realização de qualquer tarefa a definição, a priori, de metas e prazos. Com isso infere-se que há necessidade de se medir coisas. Se os resultados não forem alcançados, devem-se procurar as causas no treinamento dos funcionários ou nos métodos utilizados e nunca nas pessoas. Também, deve-se satisfazer a todos os interessados no negócio - os acionistas, os clientes, os funcionários e a sociedade.The MDA (Master Dairy Administration system was created as a result of management practices developed by and effectively utilized in the industrial sector since the early 1990's. It was designed by applying the five basic management principles to reach success in business. These principles, along with survival principles in the activity, delineated the features of the MDA System. It can be characterized as a strategic system which targets the ends from start, that is, the definition, a prior, of targets and deadlines is a primary condition to carry out any task. Therefore, there is a need to measure and follow up procedures. If results are not reached, questions must be placed on the training offered to employees or on the methods utilized, but never on the people. Moreover, all people interested in the business must have their expectations met - shareholders, customers, employees and the society.

  10. De-complessificazione della vita e "costruzione" del metodo tra condizioni fisico-chimiche e manifestazioni vitali. Alcune note sulla fisiologia di Claude Bernard

    Directory of Open Access Journals (Sweden)

    Delio Salottolo

    2014-12-01

    Full Text Available In this paper we intend to analyze the devices and conceptual strategies fielded by Claude Bernard, trying to figure out what was the contribution of the physiologist to the life sciences and vitalistic metaphysics of our time. The basic idea is that the originality and importance of his work consists not so much in the experimental method applied to living organisms, but rather in having inserted old and new concepts within an epistemological framework expertly re‐determined. The analysis will focus on a few key points – the re‐ positioning of the dichotomy vitalism/mechanism, the question of heredity and individual variation, the analysis of the level of “latent life” and the relationship between physiology and morphology – and the horizon within which will be included will be that of the dialectic between conditions and expressions.

  11. Calculation methods of reactivity using derivatives of nuclear power and Filter fir; Metodos para o calculo da reatividade usando derivadas da potencia nuclear e o filtro FIR

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Daniel Suescun

    2007-07-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  12. Stime della biomassa marina attraverso il metodo acustico: discernimento delle specie e gestione delle risorse ittiche - Acoustical estimation of fish biomass: species identification and stocks management

    Directory of Open Access Journals (Sweden)

    Víctor Espinosa

    2015-09-01

    Full Text Available L’acustica è alla base delle più importanti tecnologie nelle telecomunicazioni subacquee, nonché nel rilevamento e nella determinazione dei target acustici nei mezzi acquatici. Le misure a multi-frequenza sono lo strumento principale per l’identificazione selettiva delle specie marine e per la pesca sostenibile. Lo sviluppo di sistemi a larga banda larga e le tecniche basate su sonar multi-beam costituiscono l'attuale sfida per gli scienziati e gli sviluppatori. Al contempo, sistemi più semplici ed economicamente efficienti, come boe satellitari, sono in grado di offrire informazioni per il monitoraggio degli ecosistemi o l’individuazione di specie bersaglio nella pesca marittima. ------ Acoustics is the basics of the most important technologies for underwater telecommunication, as well as for target detection and identification in the aquatic media. Multiple frequency measurements are the key for species discrimination and open the door for sustainable fisheries. The development of wider broadband systems and quantitative multi-beam sonars and processing techniques constitute the present challenge for scientists and developers. In parallel, simpler and cost-efficient systems like satellite buoys can offer clue information for marine ecosystem monitoring or target species fisheries.

  13. Method of transient identification based on a possibilistic approach, optimized by genetic algorithm; Metodo de identificacao de transientes com abordagem possibilistica, otimizado por algoritmo genetico

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Jose Carlos Soares de

    2001-02-01

    This work develops a method for transient identification based on a possible approach, optimized by Genetic Algorithm to optimize the number of the centroids of the classes that represent the transients. The basic idea of the proposed method is to optimize the partition of the search space, generating subsets in the classes within a partition, defined as subclasses, whose centroids are able to distinguish the classes with the maximum correct classifications. The interpretation of the subclasses as fuzzy sets and the possible approach provided a heuristic to establish influence zones of the centroids, allowing to achieve the 'don't know' answer for unknown transients, that is, outside the training set. (author)

  14. Protocolo Nacional para la Evaluacion de Disturbios en Suelos Forestales; Volumen II: Metodos complementarios, estadística y recoleccion de datos

    Science.gov (United States)

    Deborah S. Page-Dumroese; Ann M. Abbott; Thomas M. Rice

    2013-01-01

    Este documento-El Volumen II: Métodos complementarios, estadística y recolección de datos- define las bases, los métodos estadísticos y de almacenamiento de datos de un Protocolo Nacional para la Evaluación de Disturbios en Suelos Forestales. Esta guía técnica proporciona las bases de un método consistente, con definiciones comunes, para generar datos de alta calidad,...

  15. Planetary method to measure the neutrons spectrum in lineal accelerators of medical use; Metodo planetario para medir el espectro de neutrones en aceleradores lineales de uso medico

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Benites R, J. L., E-mail: fermineutron@yahoo.com [Centro Estatal de Cancerologia de Nayarit, Servicio de Seguridad Radiologica, Calzada de la Cruz 118 Sur, 63000 Tepic, Nayarit (Mexico)

    2014-08-15

    A novel procedure to measure the neutrons spectrum originated in a lineal accelerator of medical use has been developed. The method uses a passive spectrometer of Bonner spheres. The main advantage of the method is that only requires of a single shot of the accelerator. When this is used around a lineal accelerator is necessary to operate it under the same conditions so many times like the spheres that contain the spectrometer, activity that consumes enough time. The developed procedure consists on situating all the spheres of the spectrometer at the same time and to realize the reading making a single shot. With this method the photo neutrons spectrum produced by a lineal accelerator Varian ix of 15 MV to 100 cm of the isocenter was determined, with the spectrum is determined the total flow and the ambient dose equivalent. (Author)

  16. Three dimensional simulation of compressible and incompressible flows through the finite element method; Simulacao tridimensional de escoamentos compressiveis e incompressiveis atraves do metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Gustavo Koury

    2004-11-15

    Although incompressible fluid flows can be regarded as a particular case of a general problem, numerical methods and the mathematical formulation aimed to solve compressible and incompressible flows have their own peculiarities, in such a way, that it is generally not possible to attain both regimes with a single approach. In this work, we start from a typically compressible formulation, slightly modified to make use of pressure variables and, through augmenting the stabilising parameters, we end up with a simplified model which is able to deal with a wide range of flow regimes, from supersonic to low speed gas flows. The resulting methodology is flexible enough to allow for the simulation of liquid flows as well. Examples using conservative and pressure variables are shown and the results are compared to those published in the literature, in order to validate the method. (author)

  17. Comparison between calculation methods of dose rates in gynecologic brachytherapy; Comparacion entre metodos de calculo de tasa de dosis en braquiterapia ginecologica8

    Energy Technology Data Exchange (ETDEWEB)

    Vianello, E.A.; Biaggio, M.F.; Dr, M.F.; Almeida, C.E. de [Laboratorio de Ciencias Radiologicas- (L.C.R.)-D.B.B.- UERJ- R. Sao Francisco Xavier, 524- Pav. HLC- sala 136- CEP 20550-013 Rio de Janeiro (Brazil)

    1998-12-31

    In treatments with radiations for gynecologic tumors is necessary to evaluate the quality of the results obtained by different calculation methods for the dose rates on the points of clinical interest (A, rectal, vesicle). The present work compares the results obtained by two methods. The Manual Calibration Method (MCM) tri dimensional (Vianello E., et.al. 1998), using orthogonal radiographs for each patient in treatment, and the Theraplan/T P-11 planning system (Thratonics International Limited 1990) this last one verified experimentally (Vianello et.al. 1996). The results show that MCM can be used in the physical-clinical practice with a percentile difference comparable at the computerized programs. (Author)

  18. El uso del metodo MICMAC y MACTOR analisis prospectivo en un area operativa para la busqueda de la excelencia operativa a traves del Lean Manufacturing

    Directory of Open Access Journals (Sweden)

    Juan Baldemar Garza Villegas

    2011-07-01

    Full Text Available Presents the MICMAC and MACTOR prospective analysis study in an operational area which looks for world-class management with reference to the concepts of lean manufacturing. The results of a qualitative analysis and his conclusions are presented.

  19. Development of method to chemical separation of gallium-67 by thermal diffusion technique; Desenvolvimento de metodo para separacao quimica de galio-67 pela tecnica de difusao termica

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Patricia de Andrade

    2012-07-01

    Radioisotopes of gallium have been studied and evaluated for medical applications since 1949. Over the past 50 years {sup 67}Ga has been widely used in the diagnosis of various diseases, including acute and chronic inflammatory lesions, bacterial or sterile and several types of tumors. In Brazil 30% of clinics that provide services for Nuclear Medicine use {sup 67}Ga citrate and the demand for 67{sup G}a at IPEN-CNEN/SP is 37 GBq (1 Ci)/week. The {sup 67}Ga presents physical half-life of 3.26 days (78 hours) and decays 100% by electron capture to stable {sup 67}Zn. Its decay includes the emission of {gamma} rays with energies of 93.3 keV (37%), 184.6 keV (20.4%), 300.2 keV (16.6%) and 888 keV (26%). In the past {sup 67}Ga was produced by the reaction {sup 68}Zn (p, 2n) {sup 67}Ga at IPEN-CNEN/SP. After irradiation, the target was dissolved in concentrated HCl and the solution percolated through a cationic resin DOWEX 50W-X8, 200-400 mesh, conditioned with 10 mol L{sup -1} HCl. Zinc, nickel and copper were eluted in 10 mol L{sup -1} HCl and {sup 67}Ga 3.5 mol L{sup -1} HCl. The final product was obtained as {sup 67}Ga citrate. This work presents a new, fast, direct and efficient method for the chemical separation of 67{sup G}a by thermal diffusion (heating of the target) combined with concentrated acetic acid extraction. Purification was performed by ion exchange chromatography. Natural zinc electrodeposition was performed on nickel/copper plates as substrate and the zinc deposits were adherent to the substrate, slightly shiny and uniform. The targets were irradiated with 26 MeV protons and integrated current of 10 {mu}A.h. After irradiation, the targets were heated at 300 deg C for 2 hours and placed in contact with concentrated acetic acid for 1 hour. The average yield of extraction of {sup 67}Ga was (72 {+-} 10)%. This solution was evaporated and the residue was taken up in 0.5 mol L{sup -1} NH{sub 4}OH. The 67{sup G}a was purified on cationic resin Dowex 50WX8 in NH{sub 4}OH medium. The {sup 67}Ga recovery was (98 {+-} 2)%. This solution was evaporated and taken up in 0.1 mol L{sup -1} HCl. The chemical purity was evaluated by ICP-OES that resulted in (2 {+-} 1) {mu}g mL{sup -1} of zinc. The concentration of iron, copper and nickel was lower than the detection limits and also than the utilization limits for {sup 67}Ga. The radionuclidic purity was greater than (99.9%). This method showed to be suitable to obtain high purity {sup 67}Ga in less aggressive chemical conditions than before. (author)

  20. Photoluminescence evaluation of TiO{sub 2} synthesized by Pechini method; Avaliacao da fotoluminescencia do TiO{sub 2} sintetizado pelo metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, D.S.; Diniz, V.C.S.; Dantas, J.; Araujo, P.M.A.G.; Costa, A.C.F.M., E-mail: dagobertoufcg@gmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Viana, R.S.; Junior, S.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. Quimica Fundamental; Torquato, R.A. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Engenharia de Materiais

    2017-07-15

    Titanium dioxide (TiO{sub 2}) stands out for use in various applications mainly due to its properties of thermal and chemical stability and its excellent optical properties. However, these properties are dependent on the type and phase morphology, which is related to the TiO{sub 2} processing method. Thus, this paper proposed to synthesize TiO{sub 2} nanoparticles by polymeric precursor method with different polymorphs, and evaluate the influence of these phases in the photoluminescent properties. For this, the stoichiometric molar proportions of citric acid:metallic cations of 1:1, 2:1, 3:1, 4:1 and 5:1 were investigated. The nanoparticles were characterized by X-ray diffraction (XRD), infrared spectroscopy, textural analysis, scanning electron microscopy (SEM), excitation and emission spectroscopy and determination of the band gap by UV-Vis diffuse reflectance spectroscopy. The presence of anatase and rutile was confirmed by XRD in different proportions for each sample. The agglomerate size increased with the citric acid/metal cations ratio as observed by SEM. Concerning photoluminescence, the maximum intensity in the emission spectrum occurred at the wavelength of 533 nm for the 3:1 sample and the maximum intensity in the excitation spectrum occurred for the 2:1 sample at the wavelength of 451 nm. (author)

  1. Accreditation of a system of extremity dosimetry: validation and uncertainty of method; Acreditacion de un sistema de dosimetria de extremidades: validacion e incertidumbre del metodo

    Energy Technology Data Exchange (ETDEWEB)

    Romero Gutierrez, A. M.; Rodriguez Jimenez, R.; Lopez Moyano, J. L.

    2013-07-01

    The authors' goal is to spread the practical experience gained during the accreditation process paying special attention to the process of method validation and estimation uncertainty of the dosimetry system. (Author)

  2. Accreditation of environmental TLD dosimetry system: validation and uncertainty of the method; Acreditacion de sistema de dosimetria ambiental TLD: validacion e incertumbre del metodo

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Jimenez, R.; Romero Gutierrez, A. M.; Lopez Moyano, J. L.

    2013-07-01

    he work shows the results obtained in the validation of the method used, and the calculation of uncertainty. The authors' goal is to spread the practical experience gained during the accreditation process, paying special attention to the process of validation of the method and the estimation of the uncertainty of the dosimetric systems. (Author)

  3. Applied methods for mitigation of damage by stress corrosion in BWR type reactors; Metodos aplicados para la mitigacion del dano por corrosion bajo esfuerzo en reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez C, R.; Diaz S, A.; Gachuz M, M.; Arganis J, C. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencia de Materiales, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    The Boiling Water nuclear Reactors (BWR) have presented stress corrosion problems, mainly in components and pipes of the primary system, provoking negative impacts in the performance of energy generator plants, as well as the increasing in the radiation exposure to personnel involucred. This problem has caused development of research programs, which are guided to find solution alternatives for the phenomena control. Among results of greater relevance the control for the reactor water chemistry stands out particularly in the impurities concentration and oxidation of radiolysis products; as well as the supervision in the materials selection and the stresses levels reduction. The present work presents the methods which can be applied to diminish the problems of stress corrosion in BWR reactors. (Author)

  4. Use of Lagrange interpolating numerical method to correct solar databases; Utilizacao do metodo numerico interpolador de Lagrange para correcao de bases de dados de radiometria solar

    Energy Technology Data Exchange (ETDEWEB)

    Penteado, Miguel Suarez Xavier [Pos-Graduacao em Agronomia - Energia na Agricultura, FCA UNESP - Botucatu, SP (Brazil), Dept. de Recursos Naturais], e-mail: miguel_penteado@fca.unesp.br; Escobedo, Joao Francisco [Dept. de Recursos Naturais, FCA/UNESP, Botucatu, SP (Brazil)], e-mail: escobedo@fca.unesp.br; Dal Pai, Alexandre [Faculdade de Tecnologia de Botucatu - FATEC, Botucatu, SP (Brazil)], e-mail: adalpai@fatecbt.edu.br

    2011-07-01

    This work explores the suitability of the Lagrange interpolating polynomial as a tool to estimate and correct solar databases. From the knowledge of the irradiance distribution over a day, portion of it was removed for applying Lagrange interpolation polynomial. After generation of the estimates by interpolation, the assessment was made by MBE and Rms statistical indicators. The application of Lagrange interpolating generated the following results: underestimation of 0.27% (MBE = -1.83 W/m{sup 2}) and scattering of 0.51% (Rms = 3.48 W/m{sup 2}). (author)

  5. Parametric identification of an asynchronous machine by the reactive power method; Identificacao parametrica de uma maquina assincrona pelo metodo da potencia reativa

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandre Alves Sampaio e

    1996-07-01

    The obtention of the electrical and mechanical parameters of a squirrel-cage induction motor is investigated. Two methods of identification are studied: the reactive power method, used to determine the electrical parameters and an acceleration method on a startup test used to to find the mechanical ones. The method of reactive power is developed by analysing the machine steady state operation. In this analysis, a relationship between the electrical parameters and the reactive power is obtained. A minimization algorithm is used to determine the parameters based on this relationship. The acceleration method uses an acquisition of the transient variables, which is used in a recursive least square method furnishing the mechanical parameters. Both of methods are implemented on a special hardware and software system, consisting of sensors and A/D boards that make a digital acquisition of voltage, current and speed values. The validation procedures for the method and parameters are based on comparing between the real and simulated evaluation of the dynamical behavior of the motor in a startup test. The skin-effect influence over some of the motor parameters was also discussed. (author)

  6. Development of computer programme for the use of empirical calculation of mining subsidence; Desarrollo informatico para utilizacion de los metodos empiricos de calculo de subsidencia minera

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    The fundamental objective of the project is the elaboration of a user friendly computer programme which allows to mining technicians an easy application of the empirical calculation methods of mining subsidence. As is well known these methods use, together with a suitable theoretical support, the experimental data obtained during a long period of mining activities in areas of different geological and geomechanical nature. Thus they can incorporate to the calculus the local parameters that hardly could be taken into account by using pure theoretical methods. In general, as basic calculation method, it has been followed the procedure development by the VNIMI Institute of Leningrad, a particularly suitable method for application to the most various conditions that may occur in the mining of flat or steep seams. The computer programme has been worked out on the basis of MicroStation System (5.0 version) of INTERGRAPH which allows the development of new applications related to the basic aims of the project. An important feature, of the programme that may be quoted is the easy adaptation to local conditions by adjustment of the geomechanical or mining parameters according to the values obtained from the own working experience. (Author)

  7. An Optimised Method to Determine PAHs in a Contaminated Soil; Metodo Optimizado para la Determinacion de PAHs en un Suelo Contaminado

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Sevillano castano, M. L.; Escolano Segovia, O.; Garcia Frutos, F. J.

    2007-07-20

    An analytical study is presented based on an optimised method to determine selected polycyclic aromatic hydrocarbons (PAHs) by High Performance Liquid Chromatography (HPLC) with fluorescence detection. The work was focused to obtain reliable measurements of PAH in a gas work contaminated soil and was performed in the frame of the project 'Assessment of natural remediation technologies for PAHs in contaminated soils' (Spanish Plan Nacional l+D+i, CTM 2004-05832-CO2-01): First assays were focused to evaluate an initial proposed procedure by sonication extraction in the contaminated soil. Afterwards to extend the efficiency and reduce solvent and time consuming of extraction procedures, the more relevant parameters that affect the extraction step were investigated. A comparison between sonication and microwave procedures was done, and the influence of sample grinding was studied. In general, both extraction techniques led on comparable results, although sonication procedure needs to be more carefully optimised. Finally, as a final application of the optimised method, the effect of particle size on relative distribution of selected PAHs in the contaminated soil was investigated. Relative abundance of more volatile PAHs showed a decreasing according to lower grain size, while relative abundance of less volatile compounds indicated an increasing of concentration levels for lower grain size. (Author) 10 refs.

  8. Desarrollo de composites de base de nanoparticulas de FeNi obtenidas por el metodo de explosion de hilo para alas aplicaciones de altas frecuencias

    OpenAIRE

    Madinabeitia Terrones, Iñaki

    2014-01-01

    Actualmente ningún área científica es ajena a la revolución de la nanociencia; las nanopartículas atraen el interés de muchos investigadores desde el punto de vista de la ciencia fundamental y para sus aplicaciones tecnológicas. Las nanopartículas ofrecen la posibilidad de fabricar sensores que sean capaces de detectar desde un virus hasta concentraciones de substancias patógenas que no pueden ser detectadas por los métodos convencionales. Hoy en día existes 82 tratamientos contra el cáncer b...

  9. Estudo comparativo de tres metodos de classificação de ulcera em pe diabetico em população brasileira

    OpenAIRE

    Maria Candida Ribeiro Parisi

    2009-01-01

    Resumo: O objetivo deste estudo foi comparar três sistemas de classificação de úlceras em pé diabético avaliando a capacidade de predição de cicatrização em 6 meses de tratamento e seguimento: o sistema de Wagner, o da Universidade do Texas (UT) e o sistema S(AD)SAD (área-profundidade, sepsis, arteriopatia e denervação). Estudamos e classificamos de acordo com cada sistema 94 portadores de Diabetes Mellitus tipo 2 e úlcera em pés. Analisamos a área da úlcera, profundidade, aspecto, presença d...

  10. Development method for measuring thickness of nuclei and coating of fuel plates; Desenvolvimento de metodo de medicao das espessuras de nucleos e revestimentos de placas combustiveis

    Energy Technology Data Exchange (ETDEWEB)

    Borges Junior, Reinaldo

    2013-07-01

    One of the most important components of a nuclear reactor is the Nuclear Fuel. Currently, the most advanced commercial fuel, whose applicability in Brazilian reactors has been developed by IPEN since 1985, is the silicide U{sub 3}Si{sub 2}. This is formed by fuel plates with nuclei dispersion (where the fissile material (U{sub 3}Si{sub 2}) is homogeneously dispersed in a matrix of aluminum) coated aluminum. This fuel is produced in Brazil with developed technology, the result of the efforts made by the group of manufacturing nuclear fuel (CCN - Center of Nuclear Fuel) of IPEN. Considering the necessity of increasing the power of the IEA- R1 and Brazilian Multipurpose Reactor Building (RMB), for the production of radioisotopes - mainly for the area of medicine - there will be significant increase in the production of nuclear fuel at IPEN. Given this situation, if necessary, make the development of more modern and automated classification techniques. Aiming at this goal, this work developed a new computational method for measuring thickness of core and cladding of fuel plates, which are able to perform such measurements in less time and with more meaningful statistical data when compared with the current method of measurement. (author)

  11. Evaluation of plate type fuel elements by eddy current test method; Avaliacao de combustiveis nucleares tipo placa pelo metodo de correntes parasitas

    Energy Technology Data Exchange (ETDEWEB)

    Frade, Rangel Teixeira

    2015-07-01

    Plate type fuel elements are used in MTR research nuclear reactors. The fuel plates are manufactured by assembling a briquette containing the fissile material inserted in a frame, with metal plates in both sides of the set, to act as a cladding. This set is rolled under controlled conditions in order to obtain the fuel plate. In Brazil, this type of fuel is manufactured by IPEN and used in the IEA-R1 reactor. After fabrication of three batches of fuel plates, 24 plates, one of them is taken, in order to verify the thickness of the cladding. For this purpose, the plate is sectioned and the thickness measurements are carried out by using optical microscopy. This procedure implies in damage of the plate, with the consequent cost. Besides, the process of sample preparation for optical microscopy analysis is time consuming, it is necessary an infrastructure for handling radioactive materials and there is a generation of radioactive residues during the process. The objective of this study was verify the applicability of eddy current test method for nondestructive measurement of cladding thickness in plate type nuclear fuels, enabling the inspection of all manufactured fuel plates. For this purpose, reference standards, representative of the cladding of the fuel plates, were manufactured using thermomechanical processing conditions similar to those used for plates manufacturing. Due to no availability of fuel plates for performing the experiments, the presence of the plate’s core was simulated using materials with different electrical conductivities, fixed to the thickness reference standards. Probes of eddy current testing were designed and manufactured. They showed high sensitivity to thickness variations, being able to separate small thickness changes. The sensitivity was higher in tests performed on the reference standards and samples without the presence of the materials simulating the core. For examination of the cladding with influence of materials simulating the presence of core, in the thickness ranges of interest, it was found that the eddy current testing can be applied. (author)

  12. Advanced methods of analysis variance on scenarios of nuclear prospective; Metodos avanzados de analisis de varianza en escenarios de prospectiva nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez, J.; Montalvo, C.; Balbas, M.; Garcia-Berrocal, A.

    2011-07-01

    Traditional techniques of propagation of variance are not very reliable, because there are uncertainties of 100% relative value, for this so use less conventional methods, such as Beta distribution, Fuzzy Logic and the Monte Carlo Method.

  13. Torpedo Base - a new method for installation of a conductor casing; Base Torpedo - um novo metodo para instalacao do revestimento condutor

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Emmanuel Franco; Borges, Alexandre Thomaz [PETROBRAS. E and P Engenharia de Producao. Gerencia de Perfuracao e Operacoes Especiais (Brazil)], e-mails: efranco@petrobras.com.br, atborges@petrobras.com.br; Medeiros Junior, Cipriano Jose de [PETROBRAS. Engenharia. Gerencia de Geociencias (Brazil)], e-mail: cipri.intec@petrobras.com.br; Machado, Rogerio Diniz; Souza, Ebenezer Viana de [PETROBRAS. E and P - SERV. Gerencia de Ancoragem (Brazil)], e-mail: rogeriodm@petrobras.com.br, ebnezer_souza@petrobras.com.br

    2008-12-15

    In the last years, PETROBRAS has been optimizing and reducing the cost of the mooring systems through the use of torpedo anchors. It consists of a tubular pile with heavy weight ballast, installed by a process that uses the energy generated by the free fall of the pile from a supply vessel. It is a low cost anchoring concept, with simple fabrication and installation. More than two hundred torpedo anchors were installed offshore Brazil in the last four years. Based on the success of the torpedo anchors for mooring purposes PETROBRAS Exploration and Production department decided to employ the same idea for installing the conductor casing. The benefit was that this installation could be accomplished from an anchor-handling vessel saving important rig time. Another advantage with this installation method is a better foundation provided since no soil is removed during this process. The paper will provide an overview of PETROBRAS Torpedo Base experience in the Albacora Leste field as well as a few other applications of this technology for the production side. After the final installation of two prototypes in the Albacora Leste Field, in Campos Basin, at the end of 2004, the Torpedo Base project was approved by the clients and by PETROBRAS's technological area, having its acquisition requested by five assets (management areas responsible for oil fields located in that basin), in a total of 18 Torpedo Base. The difficulties related to the hiring of services and logistics faced in order to make the installation of the equipment feasible made the E and P technological area to choose to monitor the acquisition and installation of these 18 bases, so as to ensure a smooth transition between the project authors and the technicians in charge of operation of the equipment, ensuring, therefore, the consolidation of the technology. This paper reports PETROBRAS's experience with Torpedo Bases during the installation of these 18 bases in several fields in Campos Basin, throughout almost two years. There shall be presented the problems faced, solutions for them and improvements implemented aiming at optimizing not only the equipment but also its installation process. (author)

  14. Characterization of an absorbed dose standard in water through ionometric methods; Caracterizacion de un patron de dosis absorbida en agua mediante metodos ionometricos

    Energy Technology Data Exchange (ETDEWEB)

    Vargas V, M.X

    2003-07-01

    In this work the unit of absorbed dose at the Secondary Standard Dosimetry Laboratory (SSDL) of Mexico, is characterized by means of the development of a primary standard of absorbed dose to water, D{sub agua}. The main purpose is to diminish the uncertainty in the service of dosimetric calibration of ionization chambers (employed in radiotherapy of extemal beams) that offers this laboratory. This thesis is composed of seven chapters: In Chapter 1 the position and justification of the problem is described, as well as the general and specific objectives. In Chapter 2, a presentation of the main quantities and units used in dosimetry is made, in accordance with the recommendations of the International Commission on Radiation Units and Measurements (ICRU) that establish the necessity to have a coherent system with the international system of units and dosimetric quantities. The concepts of equilibrium and transient equilibrium of charged particles (TCPE) are also presented, which are used later in the quantitative determination of D{sub agua}. Finally, since the proposed standard of D{sub agua} is of ionometric type, an explanation of the Bragg-Gray and Spencer-Attix cavity theories is made. These theories are the foundation of this type of standards. On the other hand, to guarantee the complete validity of the conditions demanded by these theories it is necessary to introduce correction factors. These factors are determined in Chapters 5 and 6. Since for the calculation of the correction factors Monte Carlo (MC) method is used in an important way, in Chapter 3 the fundamental concepts of this method are presented; in particular the principles of the code MCNP4C [Briesmeister 2000] are detailed, making emphasis on the basis of electron transport and variance reduction techniques used in this thesis. Because a phenomenological approach is carried out in the development of the standard of D{sub agua}, in Chapter 4 the characteristics of the Picker C/9 unit, the ionization chamber type CC01, series 131, built by Osterreichisches Forschungszentrum Seibersdorf, and the experimental conditions are shown. The characteristics of the complementary instrumentation employed in the experimental part of the work, are also presented. In Chapter 5, two ionometric methods for the calculation of the correction factors are presented: that of the Bureau International des Poids et Mesures (BIPM) and that of the International Atomic Energy Agency (IAEA). In the BIPM method emphasis is made in the MC simulation of the spectral fluence of the photons that emits the unit (using a realistic geometry and an equivalent one) as well as its validation by means of the air-kerma output factors and the percent depth doses in water, with the aid of the condition of TCPE that apply to the CC01-131 chamber. In particular, it is presented how the factor k{sub cav} is determined, employing MC simulation of two positions of the chamber (with the chamber axis parallel or perpendicular to the beam axis), and by means of a semi-analytic approach that uses the energy dissipation functions of Spencer for the parallel position. Finally the factor k{sub p} is determined for both orientations. In the case of the IAEA method, the expressions of the correction factors in the protocols TRS-277 and TRS-398 are shown. Chapter 6 presents results and discussion, and Chapter 7 presents conclusions and recommendations. In Chapter 6, the protocol of the BIPM/ISO/TAG [ISO 1992] for the calculation of the uncertainties is detailed, later the results and its discussion is made. The main conclusion obtained of these results is that the value of the D{sub agua} and its U for the BIPM method is bigger than that for the IAEA method. This conclusion has at least three meanings: First: The correction factors calculated using the BIPM method are overestimated, regarding the IAEA method. Second: The possible overestimation is consistent with the order of uncertainty with which are calculated, that is with the infrastructure that at the moment the SSDL-Mexico possesses to carry out the unit of absorbed dose to water (instrumentation, traceability of the electrometers, barometers, thermometers, calculation algorithms, time of machine, etc). Third: In this work it was shown the necessity to solve, if it exists, the ambiguity [Alvarez et al. 2002] of the models of the IAEA and the BIPM methods, when applying them to the design of the CC01-131 chamber. It was determined that, within the order of uncertainty with which the correction factors and the D{sub agua} were obtained, none of the two models presents the problem of ambiguity. (Author)

  15. Upheaval buckling of heated pipelines: a comparative study of three analytical methods; Flambagem vertical de dutos aquecidos: um estudo comparativo de tres metodos analiticos

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Divino J.S.; Benjamin, Adilson C. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2005-07-01

    Three analytical methods frequently used for analyzing upheaval buckling are presented and compared in this work: the Hobbs' method which is applied to straight pipelines, the Pedersen-Jensen's method and the JIP-Shell's method, both applied to pipelines containing initial imperfections. The basic equations of the three methods are outlined and its differences are appointed. Also it is studied the sensitivity of the response of the last two methods to the cover of soil and to the amplitude of the initial imperfection. (author)

  16. An experimental-numerical method for comparative analysis of joint prosthesis; Un metodo numerico-experimental para el analisis comparativo de protesis articulares

    Energy Technology Data Exchange (ETDEWEB)

    Claramunt, R.; Rincon, E.; Zubizarreta, V.; Ros, A.

    2001-07-01

    The difficulty that exists in the analysis of mechanical stresses in bones is high due to its complex mechanical and morphological characteristics. This complexity makes generalists modelling and conclusions derived from prototype tests very questionable. In this article a relatively simple comparative analysis systematic method that allow us to establish some behaviour differences in different kind of prosthesis is presented. The method, applicable in principle to any joint problem, is based on analysing perturbations produced in natural stress states of a bone after insertion of a joint prosthesis and combines numerical analysis using a 3-D finite element model and experimental studies based on photoelastic coating and electric extensometry. The experimental method is applied to compare two total hip prosthesis cement-free femoral stems of different philosophy. One anatomic of new generation, being of oblique setting over cancellous bone and the other madreporique of trochantero-diaphyseal support over cortical bone. (Author) 4 refs.

  17. Determination of bacterial endotoxin (pyrogen) in radiopharmaceuticals by the gel clot method. Validation; Determinacao de endotoxina bacteriana (pirogenio) em radiofarmacos pelo metodo de formacao de gel. Validacao

    Energy Technology Data Exchange (ETDEWEB)

    Fukumori, Neuza Taeko Okasaki

    2008-07-01

    Before the Limulus amebocyte lysate (LAL) test, the only available means of pirogenicity testing for parenteral drugs and medical devices was the United States Pharmacopoeia (USP) rabbit pyrogen test. Especially for radiopharmaceuticals, the LAL assay is the elective way to determine bacterial endotoxin. The aim of this work was to validate the gel clot method for some radiopharmaceuticals without measurable interference. The FDA's LALTest guideline defines interference as a condition that causes a significant difference between the endpoints of a positive water control and positive product control series using a standard endotoxin. Experiments were performed in accordance to the USP bacterial endotoxins test in the {sup 131}I- m-iodobenzylguanidine; the radioisotopes Gallium-67 and Thallium-201; the lyophilized reagents DTPA, Phytate, GHA, HSA and Colloidal Tin. The Maximum Valid Dilution (MVD) was calculated for each product based upon the clinical dose of the material and a twofold serial dilution below the MVD was performed in duplicate to detect interferences. The labeled sensitivity of the used LAL reagent was 0.125 EU mL{sup -1} (Endotoxin Units per milliliter). For validation, a dilution series was performed, a twofold dilution of control standard endotoxin (CSE) from 0.5 to 0.03 EU mL{sup -1}, to confirm the labeled sensitivity of the LAL reagent being tested in sterile and non pyrogenic water, in quadruplicate. The same dilution series was performed with the CSE and the product in the 1:100 dilution factor, in three consecutive batches of each radiopharmaceutical. The products {sup 131}I-m-iodobenzylguanidine, Gallium-67, Thallium-201, DTPA, HSA and Colloidal Tin were found compatible with the LAL test at a 1:100 dilution factor. Phytate and GHA showed some interference in the gel clot test. Other techniques to determine endotoxins as the chromogenic (color development) and the turbidimetric test (turbidity development), were also assessed to get valuable quantitative and qualitative information about the endotoxin concentration in samples. (author)

  18. The Sterile Insect Technique as a method of pest control; La Tecnica del Insecto Esteril como metodo de lucha contra plagas

    Energy Technology Data Exchange (ETDEWEB)

    Argiles Herrero, R.

    2011-07-01

    In the Valencia community is doing one of the most ambitious project in the field of plant protection at European level: the fight against fruit fly, one of the most damaging pests of citrus and fruit; by Insect Technique Sterile. This technique consists of laboratory breeding and release into the fields of huge quantities of insects of the pest species that have previously been sterilized. Sterile insect looking for wild individuals of the same species to mate with them and the result is a clutch of viable eggs, causing a decrease in pest populations. After three years of application of the technique on an area of 150,000 hectares, the pest populations have been reduced by 90%. Other benefits have been the reduced used of insecticides and improved the quality of exported fruit. (Author)

  19. Analysis of mercury and selenium in biological samples by neutron activation analysis; Analise de mercurio e selenio em materiais biologicos pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Catharino, Marilia Gabriela Miranda

    2002-07-01

    In the present work, hair samples from populations suspected of contamination by mercury, in the localities of Serra do Navio, Vila Nova and Tartarugalzinho, in the State of Amapa, were analyzed. Hair samples of children under odontopediatric treatment were also analyzed for mercury, in order to study the possibility of transfer of mercury from the dental amalgam and also to obtain data of hair mercury in a control population of children. Another step of the work was the development of a method for the determination of selenium, by using the short-lived radioisotope {sup 77}mSe. After the certification of the method it was applied to the analysis of hair, nails and a vitamin supplement. A comparison was made with the results obtain ed by using the long-lived radioisotope of selenium, {sup 75}Se. The results obtained for mercury in the hair samples of populations living in the State of Amapa have shown that the mercury concentrations in these populations are much higher than in the controls. As for the hair samples of children under treatment with mercury amalgam, no significant differences were found in the concentrations of mercury after the treatment. On the other hand, these data were important to obtain data for a control population of children. The results obtained by using the radioisotope {sup 77}mSe showed that the method developed was suitable for the analyzed matrixes and the results were similar to the ones obtained by employing the usual AANI method, with the radioisotope {sup 75}Se. (author)

  20. Determination of the biodiesel acidity index by potentiometric titration by using different methods; Determinacao do indice de acidez de biodiesel por titulacao potenciometrica utilizando-se diferentes metodos

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Mary Ane; Sobral, Sidney Pereira; Borges, Paulo Paschoal [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (DIMCI/INMETRO), Duque de Caxias, RJ (Brazil). Diretoria de Metrologia Cientifica e Industrial], E-mail: magoncalves@inmetro.gov.br

    2009-07-01

    This work determined the index of the soybean/fat bio diesel through the potentiometric titration. Four different methods were used with variation of solvent and electrodes. The results were compared by F and t (Student) and it was verified that they were agreed in a 95% confidence interval.

  1. The Marine Magnetotelluric Method (MMT) applied of hydrocarbons exploration in Brazilian waters; Aplicacao do Metodo Magnetotelurico Marinho (MMT) na exploracao de hidrocarbonetos em aguas brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Vinicius R.; Flexor, Jean M.; La Terra, Emanuele F.; Fontes, Sergio L. [Observatorio Nacional do Brasil, Rio de Janeiro, RJ (Brazil); Lugao, Patricia P. [Schlumberger, Rio de Janeiro, RJ (Brazil). Western-Geco

    2008-07-01

    Magnetotellurics (MT) is a natural-source, electromagnetic geophysical method of imaging structures below the earth's surface. It is used to map the subsurface Earth's resistivity by measuring the naturally occurring electric and magnetic fields at the Earth's surface. These natural EM fields are generated in the Earth's atmosphere mainly by lightning strokes and by interactions between the solar wind and the ionosphere. Natural variations in the earth's magnetic field induce electric currents (or telluric currents) under the earth's surface. Concurrent measurements of orthogonal components of the electric and magnetic fields allow for the calculation of the impedance tensor, which is complex and frequency-dependent and from which it is possible to gain insight into the resistivity structure of the surrounding material. The marine magnetotelluric method (MMT) is the application of MT method to investigate the sea-floor resistivity's distribution. A MMT sounding with 96 stations was realized in the region of Santos Basin on a subsalt section to assist the interpretation of seismic data in order to estimate the depth of base of the salt (subsalt) since this imaging in general is problematic. The high contrast of the electrical resistivity between the salt and the surrounding sediments is an excellent objective and it constitutes a great opportunity to test the applicability of the MMT method in oil exploration studies. The geological interpretation of the seismic profile of the studied area shows the existence of several bodies of salt with depths of the base that could vary more from 7000 m to more than 9000 m. The top of the body of more important salt of the profile begins to the 3500 m and your base is not solved by the seismic sign that it reaches a maximum depth of 9000 m. The MMT data of the central profile were submitted an inversion procedure - 2D by using the non linear conjugate gradients that produces smooth models for the resistivity structure. The TE and TM modes were used simultaneously for the inversion, with admitted errors of 6%, for the resistivity and the phase. The inversions produced resistivity anomalies well delimited with a correct estimate of the position and of the depth reached by the bodies of salt. (author)

  2. In-situ gamma spectrometry method for determination of environmental gamma dose; Metodo de espectrometria gamma in situ para determinacao de dose gama ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Conti, Claudio de Carvalho

    1995-07-15

    This work tries to establish a methodology for germanium detectors calibration, normally used for in situ gamma ray spectrometry, for determining the environmental exposure rate in function of the energy of the incident photons. For this purpose a computer code has been developed, based on the stripping method, for the computational spectra analysis to calculate the contribution of the partial absorption of the gamma rays (Compton effect) in the active and nonactive parts of the detector. The resulting total absorption spectrum is then converted to fluence distribution in function of the energy for the photons reaching the detector, which is then used to calculate the exposure rate or kerma in air. The unfolding and fluency convention parameters are determined by detector calibration using point gamma sources. The method is validated by comparison of the results against the calculated exposure rate at a point of interest for the standards. This method is used for the direct measurement of the exposure rate distribution in function of the energy at the site, in situ measurement technic, leading to rapid results during an emergency situation and also used for indoor measurements. (author)

  3. The use of numerical methods in the solution of academic problems of classic mechanics; Empleo de metodos numericos en la solucion de problemas academicos de Mecanica Clasica

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Gonzalez, A.; Rubayo Soneira, J.; Portuondo Campa, E.

    2001-07-01

    In this work the use of numerical methods in the solution of physics academic problems is discussed, particularly those on classical mechanics. Frequently the solution of academic problems is limited to finding a differential equation which is left unsolved for having no analytical solution. However, by means of numerical methods we can solve these equations and enrich the physical analysis of the problem. This approach also makes the academic process a little closer to modern physical research, where numerical methods have increasingly been used in almost every field. In the present paper we discuss a classical mechanics problem using these methods. We start from both Newton's and Lagrange's formulations and apply different numerical algorithms in the solution of the obtained equations. During last academic semester, recently concluded, we tested the ideas of this work with students of Nuclear Physics career of the Higher Institute of Nuclear Sciences and technologies, at Havana, cuba. The results were encouraging. (Author) 7 refs.

  4. A Hybrid Method of medical Image Restoration with Gaussian and Impulsive Noise; Un Metodo Hibrido de Restauracion de Images Medidas con Ruido Gausino e Impulsivo

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, M. G.; Vidal, V.; Verdu, G.; Mayo, P.; Rodenas, F.

    2011-07-01

    The noise removal techniques to restore noisy images is currently an important issue, for example, medical images obtained by X-ray computed tomography in noise due to the use of a small number of projections present noise of different types. In this paper we analyze and evaluate two techniques that separately each behaves efficiently for the removal of Gaussian and impulsive noise respectively, and combined to form a hybrid approach obtains very good performance with respect to quality in most different types of noise.

  5. Obtaining of BNKT-KNN ceramic powders by the Pechini Method; Obtencion de polvos ceramicos de BNKT-KNN por el metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Yasno, J. P.; Tirado-Mejia, L.; Kiminamp, R. H. G. A.; Gaona, J. S.; Raigoza, C. E. V.

    2013-10-01

    Pechini method was used in order to obtain fine ceramic and single-phase powders for a lead-free ferroelectric system 0,97[(Bi{sub 1}/2Na{sub 1}/2){sub 1}-x(Bi{sub 1}/2K{sub 1}/2)xTiO{sub 3}]-0,03[(Na{sub 1}/2K{sub 1}/2)NbO{sub 3}] or BNKT-KNN (x = 0.00, 0.18, 0.21, 0.24, 0.27). This method allowed obtaining powders with 100 % perovskite phase, which was confirmed by X-ray diffraction, for this particular system in all the studied stoichiometries using temperature as low as 600 degree centigrade. The effects on the bonds present in the structure due to variation of the stoichiometry, Na-K, were determined using infrared spectroscopy, FT-IR. Irregular nanoparticles were observed by scanning electron microscopy. (Author)

  6. Obtaining of BNKT-KNN ceramic powders by the Pechini Method; Obtencion de polvos ceramicos de BNKT-KNN por el metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Yasno, J. P.; Tirado-Mejia, L.; Kiminami, R.; Gaona, J.; Raigoza, C. F. V.

    2013-09-01

    Pechini method was used in order to obtain fine ceramic and single-phase powders for a lead-free ferroelectric system 0,97[(Bi{sub 1}/2Na{sub 1}/2)1-x(Bi{sub 1}/2K{sub 1}/2)xTiO{sub 3}]-0,03[(Na{sub 1}/2K{sub 1}/2)NbO{sub 3}] or BNKT-KNN (x = 0.00, 0.18, 0.21, 0.24, 0.27). This method allowed obtaining powders with 100 % perovskite phase, which was confirmed by X-ray diffraction, for this particular system in all the studied stoichiometries using temperature as low as 600 degree centigrade. The effects on the bonds present in the structure due to variation of the stoichiometry, Na-K, were determined using infrared spectroscopy, FT-IR. Irregular nanoparticles were observed by scanning electron microscopy.

  7. Obtaining ZnO nanocrystalline through methods of combustion and precipitation; Obtencao de ZnO nanocristalino atraves dos metodos de combustao e de precipitacao

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.P.; Guaglianoni, W.C.; Cunha, M.A.; Basegio, T.M.; Bergmann, C.P., E-mail: anapquimica@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Lab. de Materiais Ceramicos

    2012-07-01

    Zinc oxide is important technological applications in rubber and industrial paints. The chemical properties and microstructure of ZnO powder depends on the synthesis method employed. In this work, it was obtained nanosized ZnO using different synthesis processes, such as solution combustion and precipitation, varying the concentrations of reactants and the working temperature. The obtained powders were characterized by SEM, BET, XRD, crystallite size determination and thermal analysis (TGA and DTA). It was possible to obtain nanosized ZnO with the methods used. (author)

  8. Comparative analysis of solution methods of the punctual kinetic equations; Analisis comparativo de metodos de solucion de las ecuaciones de cinetica puntual

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez S, A. [UNAM-LAIRN, Jiutepec, Morelos (Mexico)] e-mail: augusto_vib@yahoo.com.mx

    2003-07-01

    The following one written it presents a comparative analysis among different analytical solutions for the punctual kinetics equation, which present two variables of interest: a) the temporary behavior of the neutronic population, and b) The temporary behavior of the different groups of precursors of delayed neutrons. The first solution is based on a method that solves the transfer function of the differential equation for the neutronic population, in which intends to obtain the different poles that give the stability of this transfer function. In this section it is demonstrated that the temporary variation of the reactivity of the system can be managed as it is required, since the integration time for this method doesn't affect the result. However, the second solution is based on an iterative method like that of Runge-Kutta or the Euler method where the algorithm was only used to solve first order differential equations giving this way solution to each differential equation that conforms the equations of punctual kinetics. In this section it is demonstrated that only it can obtain a correct temporary behavior of the neutronic population when it is integrated on an interval of very short time, forcing to the temporary variation of the reactivity to change very quick way without one has some control about the time. In both methods the same change is used so much in the reactivity of the system like in the integration times, giving validity to the results graph the one the temporary behavior of the neutronic population vs. time. (Author)

  9. Metodo integrado para la gestion de Universidades basado en el Balanced Scorecard (bsc y el modelo europeo de calidad (efqm: caso U.C.S.M.

    Directory of Open Access Journals (Sweden)

    Horacio Vicente Barreda Tamayo

    2010-12-01

    Full Text Available El presente Trabajo realiza la propuesta de un Método Integrado que permite mejorar la competitividad en la Gestión de las Universidades, este método se basa: En una herramienta de Gestión Estratégica: el Balanced Scorecard (BSC, que fue creada por Kaplan y Norton en 1992; y En el Modelo Europeo de Calidad (EFQM, que fue desarrollado como un Modelo de Excelencia en 1991. La metodología utilizada consiste en analizar las características, ventajas y limitaciones del BSC y el EFQM para aplicarlos simultáneamente en la gestión de Tomando como base los 9 criterios del EFQM, se desarrolla un Mapa Estratégico del BSC, para que se alineen todas las perspectivas hacia el logro de los Objetivos Estratégicos de la Organización. El método integrado planteado se aplica en el caso de la Universidad Católica de Santa María (Arequipa- Perú, donde se analiza las ventajas que implicaría la implementación del mismo.

  10. Metodo integrado para la gestion de Universidades basado en el Balanced Scorecard (bsc y el modelo europeo de calidad (efqm: caso U.C.S.M.

    Directory of Open Access Journals (Sweden)

    Edwing Jesús Ticse Villanueva

    2010-06-01

    Full Text Available http://dx.doi.org/10.5007/1983-4535.2010v3n1p01   El presente Trabajo realiza la propuesta de un Método Integrado  que permite mejorar la competitividad en la Gestión de las Universidades, este método se basa: En una herramienta de Gestión Estratégica: el Balanced Scorecard (BSC, que fue creada por Kaplan y Norton en 1992; y En el Modelo  Europeo de Calidad (EFQM, que fue desarrollado como un Modelo de Excelencia en 1991. La metodología utilizada consiste en analizar las características, ventajas y limitaciones del BSC y el EFQM para aplicarlos simultáneamente en la gestión de Tomando como base los 9 criterios del EFQM, se desarrolla un Mapa Estratégico del BSC, para que se alineen todas las perspectivas hacia el logro de los Objetivos Estratégicos de la Organización. El método integrado planteado se aplica en el caso de la Universidad Católica de Santa María (Arequipa- Perú, donde se analiza las ventajas que implicaría la implementación del mismo

  11. Study of the degradation of liquid-organic radioactive wastes by electrochemical methods; Estudio de la degradacion de desechos liquidos-organicos radiactivos mediante metodos electroquimicos

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez A, J. I.

    2015-07-01

    In this study degradation studies were performed on blank samples, in which two electrochemical cells with different electrodes were used, the first is constituted by mesh electrodes Ti/Ir-Ta/Ti and the second by rod electrodes Ti/Ddb, using as reference an electrolytic medium of scintillation liquid and scintillation liquid more water, applying different potentials ranging from 1 to 25 V. After obtaining the benchmarks, the treatment was applied to samples containing organic liquid radioactive waste, in this case a short half-life radioisotope as Sulfur-35, the degradation characterization of organic compounds was performed in infrared spectrometry. (Author)

  12. Optical coherence tomography signal analysis: LIDAR like equation and inverse methods; Analise de sinais de tomografia por coerencia optica: equacao LIDAR e metodos de inversao

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Marcello Magri

    2012-07-01

    Optical Coherence Tomography (OCT) is based on the media backscattering properties in order to obtain tomographic images. In a similar way, LIDAR (Light Detection and Range) technique uses these properties to determine atmospheric characteristics, specially the signal extinction coefficient. Exploring this similarity allowed the application of signal inversion methods to the OCT images, allowing to construct images based in the extinction coefficient, original result until now. The goal of this work was to study, propose, develop and implement algorithms based on OCT signal inversion methodologies with the aim of determine the extinction coefficient as a function of depth. Three inversion methods were used and implemented in LABView{sup R}: slope, boundary point and optical depth. Associated errors were studied and real samples (homogeneous and stratified) were used for two and three dimension analysis. The extinction coefficient images obtained from the optical depth method were capable to differentiate air from the sample. The images were studied applying PCA and cluster analysis that established the methodology strength in determining the sample's extinction coefficient value. Moreover, the optical depth methodology was applied to study the hypothesis that there is some correlation between signal extinction coefficient and the enamel teeth demineralization during a cariogenic process. By applying this methodology, it was possible to observe the variation of the extinction coefficient as depth function and its correlation with microhardness variation, showing that in deeper layers its values tends to a healthy tooth values, behaving as the same way that the microhardness. (author)

  13. Observability in electric power networks: identification critical measures methods; Observabilidade em redes de energia eletrica: metodos de identificacao de medidas criticas

    Energy Technology Data Exchange (ETDEWEB)

    London Junior, Joao Bosco Augusto

    1997-07-01

    One of the most important functions of the control and operation centers is to maintain service reliability in a electrical power system. In order to obtain a reliable operation of the power system, it is important to identify the critical measurements, and then to improve the measurement system using pseudo measurements. The goal of this work is to determine more efficient methods for critical measurement identification. A brief review of the some methods for observability analysis as well as two methodologies to identify critical measurements are presented. The first method has a combinatorial nature; the second one is supported by uni modular M matrix (incidence matrix of measurements for branches) and A matrix (incidence matrix of branch for nodes). The second method needs a combinatorial algorithm to be feasible, so that it becomes a slow method. Two new methods for critical measurements identification are presented in this work: the first one is based on the theory developed by Bretas (1996a), to analyse observability using graph paths; the second methods is supported y the Slutsker and Scudder (1987) theory, where identification is reached throughout the analysis of the jacobian matrix. (author)

  14. Calculation of Co2 emissions from the italian energy system; Calcolo delle emissioni di CO2 dal settore energetico italiano. 1990-2000. Metodo di riferimento IPCC

    Energy Technology Data Exchange (ETDEWEB)

    Contaldi, M. [Agenzia Nazionale per la Protezione dell' Ambiente, Rome (Italy); La Motta, S. [ENEA, Funzione Centrale Studi, Centro Ricerche Casaccia, Rome (Italy)

    2001-07-01

    The calculation of Co2 emissions from the Italian energy system is the object of this work. The inventory method used is the Reference Approach from the Intergovernmental Panel for Climate Change (IPCC, 1996 revised Guidelines for National Greenhouse Gas Inventories) and the energy consumption data are taken from the Italian Energy Balance edited by the Ministry of Industry. The years analysed are those from 1990 to 2000. [Italian] Lo scopo di questo lavoro e' quello di contabilizzare le emissioni di CO2 provenienti dal settore energetico per fonte di utilizzo dell'energia, a partire direttamente dal Bilancio Energetico Nazionale (Bilancio Energetico Nazionale, BEN, a cura del Ministero Industria, Commercio ed Artigianato) ed applicando all'Italia la metodologia di riferimento per il calcolo delle emissioni della CO2 elaborata dall'Intergovernmental Panel for Climate Change (IPCC, 1996 revised Guidelines for National Greenhouse Gas Inventories). Gli anni presi in considerazione in queto lavoro sono quelli dal 1990 al 2000.

  15. Safety assessment of nuclear medicine practice using the Risk Matrix Method; Evaluaciones de seguridad de la practica de medicina nuclear utilizando el metodo de Matrices de Riesgo

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Dumenigo; Cruz, Yoanis; Soler, Karen, E-mail: cruz@orasen.co.cu [Centro Nacional de Seguridad Nuclear (CNSN), La Habana (Cuba); Guerrero, Mayka, E-mail: mayka@infomed.sld.cu [Centro de investigaciones Medico Quirurgicas (CIMEQ), La Habana (Cuba)

    2013-10-01

    This paper presents the main results from the application of the methodology of Risk Matrices in a hypothetical service / department of the Nuclear medicine that realize metabolic radiotherapy treatment and diagnostic studies with {sup 131}I and {sup 99} m Tc and {sup 18}F. We could identify major equipment failures and human errors that could potentially lead to a accident in practice. For each analyzed initiating events evaluated the frequency of occurrence, identified key existing defenses to avoid the accident and assessed the potential consequences of an accident if this comes to fruition. With this methodology we could identify which accident sequences increased risk and to propose means to reduce the risk in such cases. As a result of this work was developed the 'RMA Nuclear Medicine' computer tools that will apply this methodology in nuclear medicine services that need to do similar risk assessments.

  16. Avaliação dos metodos de determinação e incidencia de aflatoxina M1, patulina e acido ciclopiazonico em alguns alimentos brasileiros

    OpenAIRE

    Celia Maria de Sylos

    1994-01-01

    Resumo: Avaliou-se os métodos analíticos e a incidência de aflatoxina, patulina e ácido ciclopiazônico em produtos alimentícios comercializados na cidade de Campinas. Varias tentativas foram realizadas para a escolha do solvente extratante e da melhor técnica para remover os interferentes das amostras de leite e derivados para determinação de aflatoxina M1. Na extração foram utilizados acetona, metanol e clorofórmio puros, misturados entre si ou com água. Precipitação com sais de metais pesad...

  17. Synthesis of lithium silicates by the modified method of combustion. XRD and IR; Sintesis de silicatos de litio por el metodo modificado de combustion. DRX e IR

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, D.; Bulbulian, S. [Instituto nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The combustion method is fixed in exothermic reactions for producing ceramic compounds. The precursor solutions are mixtures of metal nitrates and the fuels. This method was modified using non-oxidant compounds as lithium hydroxide and silicide acid and urea as fuel. The precursors were heated during 5 minutes at temperatures between 250 C and 550 C allowing so the mixture combustion. The obtained ceramics were characterized by X-ray diffraction and IR spectroscopy. The sample pollution with carbonates was evaluated and it was found that the presence of these diminish according as increase the calcination temperature. (Author)

  18. Radiographic evaluation of adenoidal size in children: methods of measurement and parameters of normality; Avaliacao radiografica da adenoide em criancas: metodos de mensuracao e parametros da normalidade

    Energy Technology Data Exchange (ETDEWEB)

    Araujo Neto, Severino Aires de [Centro de Assistencia Integral a Saude da Mulher (CAISM), Campinas, SP (Brazil)]. E-mail: severinoaires@hotmail.com; Queiroz, Suelio Marinho de [Tomovale, Sao Jose dos Campos, SP (Brazil); Baracat, Emilio Carlos Elias [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Pediatria; Pereira, Ines Minniti Rodrigues [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Radiologia

    2004-12-01

    Radiograph of the nasopharynx is still the most commonly used imaging method to investigate the adenoidal tissue. Due to the variety and complexity of proposed methods to measure the adenoid size, some radiologists prefer subjective evaluation, which can, however, be imprecise and inaccurate. We review and describe several methods to determine the adenoid size, taking into account the practicity, accuracy and precision with the aim of pointing out the best methods to be applied in daily routine practice. (author)

  19. APLICAÇÃO DO METODO DE ANÁLISE HIERARQUICA (MAH NA ANALISE E AVALIAÇÃO DE IMPACTOS AMBIENTAIS DOS SISTEMAS DE TRANSPORTES URBANOS

    Directory of Open Access Journals (Sweden)

    Dominique Mouette

    2010-04-01

    Full Text Available

    O estudo de impacto ambiental envolve uma grande quantidade de critérios e parâmetros, sendo necessário o trabalho conjunto de uma equipe multidisciplinar. A complexidade dos impactos decorrentes dos sistemas de transporte urbanos que possuem características e magnitudes muito diferentes, somada a não obrigatoriedade do estudo, fizeram com que poucos estudos fossem efetuados e tornou evidente a necessidade de metodologias de avaliação dos mesmos. Este estudo aborda a utilização do Método de Analise Hierárquica, um procedimento multicriterial na analise e avaliação dos impactos ambientais dos sistemas de transportes urbanos.

    ABSTRACT

    The study of environmental impacts involves a large amount of criteria and parameters being necessary to work with a multisciplinary team. The impacts due to urban transportation are very complex having different characteristics and magnitude, besides that, in Brazil, these studies are not obliged by law. These facts leads to few studies of the environmental impacts and evidences the necessity of developing methodologies which makes possible the impact's evaluation. This study refers to the utilization of the Analytical Hierarchy Process, a multicriteria procedure in the evaluation and analysis of environmental impacts in urban transportation.

  20. Magnetic resonance angiography: technical aspects of a noninvasive method for vascular study; Angiografia por ressonancia magnetica: aspectos tecnicos de um metodo de estudo vascular nao-invasivo

    Energy Technology Data Exchange (ETDEWEB)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Sergio de Araujo; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem]. E-mail: rogercal@uol.com.br; Soares, Adriano Fleury de Faria [Complexo Hospitalar Sao Luiz, Sao Paulo, SP (Brazil)

    2004-02-01

    Early magnetic resonance angiography techniques used flow-sensitive sequences to obtain contrast of the vascular structures. Three techniques are based on this approach: phase-contrast, time-of-flight and black blood techniques. However, these acquisition methods are time-consuming and more susceptible to movement artifacts, flow-related artifacts and signal loss due to stenotic lesions. They also present low sensitivity for slow flow detection. The use of paramagnetic contrast medium in magnetic resonance angiography studies provides a simple and quick way of obtaining vascular enhancement. Image contrast is based on vascular enhancement in opposition to background suppression. Important factors for the technical improvement of gadolinium-enhanced magnetic resonance angiography is a useful diagnostic tool for investigation of anatomical anomalies, stenotic and occlusive disease, and surgical complications, particularly in patients with organ transplants. Gadolinium-enhanced magnetic resonance angiography is a useful diagnostic tool for investigation of anatomical anomalies, stenotic and occlusive disease, and surgical complications, particularly in patients with organ transplants. Gadolinium-enhanced magnetic resonance angiography has the advantage of a noninvasive method since it does not require ionizing radiation or an iodine contrast medium and allows the evaluation of parenchymatous structures for additional diagnostic information. (author)

  1. Method for automatic re contouring straight adaptive radiotherapy for prostate cancer; Metodo para el recontorneo automatico del recto en radioterapia adaptativa en cancer de prostata

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Vila, B.; Garcia Vicente, F.; Aguilera, E. J.

    2011-07-01

    Outline of quickly and accurately the rectal wall is important in Image Guided Radiotherapy (IGRT in the acronym) as an organ of greatest influence in limiting the dose in the planning of radiation therapy in prostate cancer. Deformabies registration methods based on image intensity can not create a correct spatial transformation if there is no correspondence between the image and image planning session. The rectal content variation creates a non-correspondence in the image intensity becomes a major obstacle to the deformable registration based on image intensity.

  2. Analytical methods for 2,4-D (Dichlorophenoxyacetic acid) determination; Metodos analiticos para la determinacion del 2,4-D (Acido diclorofenoxiacetico)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez G, M.S.M

    1999-06-01

    The 2,4-D herbicide is one of the main pesticides for controlling the bad grass in crops such as the water undergrowth. In Mexico the allowed bound of this pesticide is 0.05 mg/l in water of 2,4-D so it is required to have methods trusts and exacts, which can used in order to detected low concentration of it. In this work we show some for the conventional techniques and for establishing the 2,4-D concentrations. The UV-Vis spectrometer and liquids chromatography due that they are the most common used nowadays. Beside, we introduce a now developed technique, which is based on the neutronic activation analysis. Though use of the UV-Vis spectrometer technique it was possible target the concentrations interval between 1 and 200 mg/l. In the liquids chromatography interval was between 0.1 and 0.9, and by the neutronic activation analysis the interval was between 0.01 and 200 mg/l. (Author)

  3. Utilizacion del metodo de hidrolisis de los amilostatolitos para el diagnostico de resistencia al calor, la sequia y la salinidad en el tomate

    Directory of Open Access Journals (Sweden)

    Jorge A. Sánchez

    2000-01-01

    Full Text Available Se propone 5 indices de calidad que penni- ten estimar certerarnentel nivel de calidad y po- tencial productivo de una plantaci6n forestal. £1 primer indice es el de calidad general y debe uti- lizarse preferiblemente en plantaciones no ralea- das. £ste indiceproducira valores de 1.0-4.0. Valo- res cercanos a 1 serlin de plantaciones de la mas al- ta calidad. £1 segundo es el de calidad de cosecha y se basa en la cantidad de individuos presentes por ha de calidad 1 y 2. Una plantaci6n con 400 indi- viduos de calidad 1 +2 seria excelente y con menos de 200 individuos seria de mala calidad. £1 tercero es el de calidad maxima, que busca reflejar en que proporci6n la plantaci6n se aproxima al maximo numero posible de individuos de calidad 1 y de 40 cm de dap que puede contener una plantaci6n fo- festal ala cosecha; es basado en N 1=250 Y genera harvalores porcentuales, donde una plantaci6n con >90% seria excelente y 1600 trozas/ha de calidad 1+2 son excelentes y aquellas <800 trozas son inaceptables. Por ultimo se incluye el indice de calidad de productividad, que permite valorar la calidad de una plantaci6n en

  4. "Mastery Learning" Como Metodo Psicoeducativo para Ninos con Problemas Especificos de Aprendizaje. ("Mastery Learning" as a Psychoeducational Method for Children with Specific Learning Problems.)

    Science.gov (United States)

    Coya, Liliam de Barbosa; Perez-Coffie, Jorge

    1982-01-01

    "Mastery Learning" was compared with the "conventional" method of teaching reading skills to Puerto Rican children with specific learning disabilities. The "Mastery Learning" group showed significant gains in the cognitive and affective domains. Results suggested Mastery Learning is a more effective method of teaching…

  5. External individual monitoring: experiments and simulations using Monte Carlo Method; Monitoracao individual externa: experimentos e simulacoes com o metodo de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Carla da Costa

    2005-07-01

    In this work, we have evaluated the possibility of applying the Monte Carlo simulation technique in photon dosimetry of external individual monitoring. The GEANT4 toolkit was employed to simulate experiments with radiation monitors containing TLD-100 and CaF{sub 2}:NaCl thermoluminescent detectors. As a first step, X ray spectra were generated impinging electrons on a tungsten target. Then, the produced photon beam was filtered in a beryllium window and additional filters to obtain the radiation with desired qualities. This procedure, used to simulate radiation fields produced by a X ray tube, was validated by comparing characteristics such as half value layer, which was also experimentally measured, mean photon energy and the spectral resolution of simulated spectra with that of reference spectra established by international standards. In the construction of thermoluminescent dosimeter, two approaches for improvements have. been introduced. The first one was the inclusion of 6% of air in the composition of the CaF{sub 2}:NaCl detector due to the difference between measured and calculated values of its density. Also, comparison between simulated and experimental results showed that the self-attenuation of emitted light in the readout process of the fluorite dosimeter must be taken into account. Then, in the second approach, the light attenuation coefficient of CaF{sub 2}:NaCl compound estimated by simulation to be 2,20(25) mm{sup -1} was introduced. Conversion coefficients C{sub p} from air kerma to personal dose equivalent were calculated using a slab water phantom with polymethyl-metacrilate (PMMA) walls, for reference narrow and wide X ray spectrum series [ISO 4037-1], and also for the wide spectra implanted and used in routine at Laboratorio de Dosimetria. Simulations of backscattered radiations by PMMA slab water phantom and slab phantom of ICRU tissue-equivalent material produced very similar results. Therefore, the PMMA slab water phantom that can be easily constructed with low price can be considered a convenient practical alternative to substitute the tissue-equivalent slab. Conversion coefficients from air kerma to personal dose equivalent obtained were compared with published data. lt was found that the quantity kerma in the medium commonly used for the evaluation of conversion coefficients at depths of the order or less than 0,07 mm does not provide good results for monoenergetic photon beams with energy between 200 to 1250 keV. In this range, it is necessary to consider the absorbed dose quantity. We conclude that the GEANT4 is a suitable toolkit not only to simulate thermoluminescent dosimeters and experimental procedures employed in the routine of a dosimetry laboratory, but also to shed light upon ali the experimental results obtained in external individual monitoring that are not always expected. (author)

  6. A digital method for period measurements in a nuclear reactor; Um metodo digital para medidas de periodo em um reator nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Mundim, Sergio Gorretta

    1971-02-15

    The present paper begins by giving a theoretical treatment for the nuclear reactor period. The conventional method of measuring the period is analysed and some previously developed digital methods are described. The paper criticises the latter, pointing out some deficiencies which the proposed process is able to eliminate. All errors connected with this process are also analysed. The paper presents suitable solutions to reduce them to a minimum. The total error is found to he less than the error presented by the other methods described. A digital period meter is designed with memory resources and an automatic scaler changer. Integrated circuits specifications are used in it. Real time experiments with nuclear reactors were made in order to check te validity of the method. The data acquired were applied to a simulated digital period meter implemented in a general purpose computer. The nuclear part of the work was developed at the 'Comissao Nacional de Energia Nuclear' and the simulation work was dane at the 'Departamento de Calculo Cientifico' of COPPE, which also advised the author in the completion of this thesis. (author)

  7. Vrednotenje ureditve notranjih kontrol z metodo COSO v trgovskem podjetju = Evaluation of Structures Regarding Internal Controls by Way of the COSO Method in a Trading Company

    Directory of Open Access Journals (Sweden)

    Karmen Markoja

    2009-12-01

    Full Text Available In carrying out internal audit, the selection of methodological tools forevaluation of internal control procedures, used to identify and evaluatekey places of exposure to risks in individual areas, is of partic ular importance. The approved coso method, taking into considerationthe wider meaning of control environment, has significantly contributedto integrated evaluation of internal control mechanisms in individualorganizations by defining the so-called soft controls. A possibleexample of internal audit implementation by using the coso methodon the example of a trading company is shown in the article. It introducesan example of how to apply the coso method in a given areaof internal audit, which can serve as a starting point for further auditprogramme development in accordance with the COSO method.

  8. A parametric study of VAPEX process as improved oil recovery method; Estudo parametrico do processo VAPEX como metodo de recuperaco avancada de oleo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.F.; Barillas, J.L.M.; Mata, W.; Dutra Junior, T.V. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    There is still a large amount of natural resources in heavy oil reservoirs which can be explored using new methods. The world estimate of resources as heavy oil and bitumen may be 6 trillion barrels of OOIP. However, this enormous amount of hydrocarbon resources which are in these reservoirs may be explored with new concepts. The VAPEX process is a promising recovery method since its invention in 1991 by Dr. Roger Butler. The process consists of two horizontal wells, parallel between themselves, producer and injector, where vaporized solvent is injected with the objective of reducing the oil or bitumen viscosity. The purpose of this study is to examine how some important operational parameters influence the VAPEX process, in the produced oil rates, the cumulative produced oil and the recovery factor. Parameters such as the spacing between wells, the injection pressure and the type of solvent are addressed in this study. The choice of solvent to be used was the factor that showed more influence in the process and this allowed a greater recovery factor. Another important parameter was the injection pressure. (author)

  9. Handling of the fruit of guava tree by ionizing gamma radiation method; Tratamento do fruto de goiabeira pelo metodo da radiacao ionizante gama

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Selma F.; Jesus, Edgar F. Oliveira de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear; Soares, Antonio G. [Empresa Brasileira de Pesquisa Agropecuaria, Rio de Janeiro, RJ (Brazil). Agroindustria de Alimentos

    2000-07-01

    Guavas 'in natura' were treated for the method of the ionizing radiation it loves and stored under refrigeration of 12 {+-} 1 deg C, for extension of the shelf life. They were appraised the following parameters: texture, {sup o}brix, vitamin C, sugars, appearance, flavor and aroma. The shelf life in the irradiated fruits had a increase meaning not affecting the quality of the same ones. (author)

  10. Lengua nacional: Fichas de trabajo 1. Metodo de lectura y escritura (National Language: Workbook 1. A Method of Reading and Writing).

    Science.gov (United States)

    Peniche Leger, Maria Elena, Ed.

    This consumable, graded workbook can be used for exercises, tests, and individualized learning. Each level contains 30 units divided into four groups of exercises: reading analysis, grammar, composition, and spelling. Ten general tests are also included. For the accompanying reader, see FL 004 047. (Author/SK)

  11. Uso de métodos anticoncepcionais entre adolescentes universitários El uso de metodos anticonceptivos en adolescentes universitarios Use of contraceptive methods among university adolescents

    Directory of Open Access Journals (Sweden)

    Aline Salheb Alves

    2008-04-01

    Full Text Available Objetivou-se identificar o uso de métodos anticoncepcionais entre adolescentes, ingressantes de uma universidade pública paulista e descrever o perfil desses universitários quanto a algumas características sócio-demográficas. Foi utilizado um questionário e a amostra foi composta por 295 adolescentes. Relataram ter iniciado atividade sexual 48,8%. A idade média para o início foi aos 17 anos, e a maioria relatou ter usado um método contraceptivo. O método mais utilizado foi o preservativo e este em combinação com a pílula, principalmente. Observou-se que os adolescentes buscam informações, seja através de profissionais da saúde, professores, ou através de livros, com destaque para a mídia. Conclui-se que os universitários iniciam atividade sexual mais tardiamente e buscam conhecimento sobre anticoncepção.El objetivo de este trabajo es identificar el uso de los métodos anticonceptivos entre adolescentes, alumnos de una universidad paulista, y describir su perfil basados en algunas características socio-demográficas. Se utilizó un cuestionario aplicado a 295 adolescentes. El 48,8% relataron haber iniciado actividad sexual. En media, la edad para el inicio son los 17 años y la mayoría afirma haber usado métodos anticonceptivos. El más utilizado fue, principalmente, el preservativo combinado con la píldora. Se observó que los adolescentes buscan información consultando a profesionales de la salud, profesores o a través de libros, y sobretodo por los medios de comunicación. Se concluye que los universitarios inician su actividad sexual más tarde y buscan conocimiento sobre métodos anticonceptivos.The objective of this study was to identify the use of contraceptive methods among teenagers at a public University in São Paulo, as well as to describe their profile concerning social and demographic characteristics. A questionnaire was used and the sample was composed by 295 teenagers. The initiation of sexual activity was reported by 48,8%. The mean age was seventeen and most of them reported that they used some type of contraceptive method. The method used with highest frequency was the preservative, and this in combination with the pill. It could be observed that teenagers seek information through health professionals, teachers or books, and mainly media. It was concluded that the students had sexual initiation late and seek information about contraception.

  12. Comparison between subjective and quantitative methods for assessing the resolution limit of radiographic systems; Comparacao entre metodos subjetivos e quantitativos na medida da resolucao limite de sistemas radiograficos

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Matheus; Oliveira, Marcela de; Miranda, Jose R.A. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Inst. de Biociencias de Botucatu; Pina, Diana R., E-mail: matheus@ibb.unesp.br [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicais e Diagnostico por Imagem

    2012-07-01

    The aim of this study was to compare two ways of measuring the resolution limit of radiographic systems, one subjective and one quantitative. To this end, nine images were acquired with different radiographic techniques using a pattern of bars and aluminum plates. With these images were acquired modulation transfer function (MTF) through the edge image obtained by the aluminum plate - the MTF 10% was measured on all images - and the variation of these points, which was faced with the evaluation obtained by the resolution limit of the standard bar. Although we have observed a greater variation between measurements obtained using the bar-pattern, the simplicity of this measuring technique favors the common use of the same. We concluded that, to optimize the quality control of radiographic equipment, it is suggested to measure the MTF at least in periods of time while the annual pattern of bars to be used in shorter time periods to measure changes in resolution of the system. (author)

  13. Determination of the fast neutrons spectra by the Elastic scattering method (n, p); Determinacion del espectro de neutrones rapidos por el metodo de la dispersion elastica (n, p)

    Energy Technology Data Exchange (ETDEWEB)

    Elizalde D, J

    1973-07-01

    This work consists in determining the fast neutron spectra emitted by a Pu-Be isotopic source. The implemented technique is based in the spectrometry (n, p). This consists in making to fall on a fast neutrons beams (polyenergetic) over a thin film of hydrogenated material, detecting the spectra of emitted protons at a fix angle. The polyethylene film and the used solid state detector are inside of a vacuum chamber. The detector is placed at 30 degree with respect to direction of the incident neutrons beam. The protons spectra is stored in a multichannel. the energy is obtained with the prior calibration of the system. The data processing involves the transformation of the protons spectra observed at the falling on neutrons spectra over the film. The energy of the neutrons is related with that of the protons, according to the collision kinematical equations. The cross section of elastic collision of the neutrons with the hydrogen atoms is obtained from literature. Applying these relations to the observed spectra it is obtained the falling on neutron spectra over the film. (Author)

  14. Analysis of medicinal plant extracts by neutron activation method; Analise de extratos de plantas medicinais pelo metodo de ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Vaz, Sandra Muntz

    1995-12-31

    This dissertation has presented the results from analysis of medicinal plant extracts using neutron activation method. Instrumental neutron activation analysis was applied to the determination of the elements Al, Br, Ca, Ce, Cl, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc and Zn in medicinal extracts obtained from Achyrolcline satureoides DC, Casearia sylvestris, Centella asiatica, Citrus aurantium L., Solano lycocarpum, Solidago microglossa, Stryphnondedron barbatiman and Zingiber officinale R. plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyl-dithiocarbamate solution. Precision and accuracy of the results have been evaluated by analysing reference materials. The therapeutic action of some elements found in plant extracts analyzed was briefly discussed 70 refs., 13 figs., 15 tabs

  15. METODOS MATEMATICOS DE OPTIMIZACION PARA ESTABLECER FASES ACTIVAS EN LA CATALISIS HETEROGENEA: CASO DE LOS SULFUROS DE METALES DE TRANSICION MASICOS

    Directory of Open Access Journals (Sweden)

    Iván Machín

    2015-01-01

    Full Text Available En este trabajo se propone un conjunto de procedimientos basados en métodos matemáticos de optim ización que permiten establecer fases activas óptimas de sulfuros que pueden generar mayores actividades a HDS. Se propone n en este trabajo una lista de las fases activas óptimas como una guía para ayudar a orientar el trabajo experimental en la búsqueda d e nuevos catalizadores que permitan optimizar el proceso de HDS . Los estudios realizados en este trabajo permiten establecer que los sistemas Co - S, Cr - S, Nb - S y Ni - S tienen la mayor posibilidad de mejorar la actividad a HDS.

  16. Effect tetrahydrofuran as solvent in the synthesis of mullite by the Pechini; Efeito do tetrahidrofurano como solvente na sintese de mulita pelo Metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Braga, A.N.S.; Santos, V.B. [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil); Simoes, V.N.; Neves, G.A.; Lira, H.L.; Menezes, R.R., E-mail: Aluskasimoes@homail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

    2016-07-01

    Mullite has been considered interesting in recent decades, due to its properties. The reaction mechanisms in the mullite formation may vary according to the precursor and the methods employed. In order to get mullite by a promising chemical synthesis and understudied in its production, this paper aims to synthesize mullite by Pechini method. We investigated the mullite crystallization kinetics from use of tetrahydrofuran as solvent. The samples were characterized by diffraction of X-ray (XRD), thermal analysis and scanning electron microscopy (SEM). The XRD results showed the formation of mullite, but together with the alpha alumina phase. Thermal analysis confirmed the disruption of the polymer chain prior to the formation of crystalline phases, with a total weight loss of 97%. The SEM showed a morphology consists of large aggregates, damaging the properties of refractory and performance of the material. (author)

  17. Synthesis of nanoparticles of barium strontium titanate using hydrothermal microwave method; Sintese de nanoparticulas de titanato de bario estroncio utilizando o metodo hidrotermal assistido por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.A.; Souza, A.E.; Teixeira, S.R. [Universidade Estadual Paulista (DFQB/FCT/UNESP), Presidente Prudente, SP (Brazil). Fac. de Ciencia e Tecnologia. Dept. de Fisica, Quimica e Biologia; Moreira, M.L.; Volanti, D.P. [Universidade Federal de Sao Carlos (LiEC/UFSCAR), SP (Brazil). Lab. Interdisciplinar de Eletroquimica e Ceramica; Longo, E. [Universidade Estadual Paulista (UNESP/LiEC), Araraquara, SP (Brazil). Lab. Interdisciplinar de Eletroquimica e Ceramica

    2009-07-01

    Nanoparticles of barium strontium titanate Ba{sub x}Sr{sub 1}-{sub x}TiO{sub 3} (BST) had been prepared, with x = 0.5, using the hydrothermal method attended by microwaves (HTMW). A solution was prepared using deionized water, barium chloride (BaCl{sub 2}.2H{sub 2}O), strontium chloride (SrCl{sub 2}.6H{sub 2}O), titanium (IV) isopropoxide (C{sub 12}H28O{sub 4}Ti) and potassium hydroxide (KOH). Afterward the solution was heated to 140 deg C in a microwave oven, at a heating rate of 140 deg C/min, and maintained at this temperature for 40 min, under a pressure of 3 to 4 bar. X-ray diffraction (DRX) and field emission scanning electron microscopy (FE-SEM) had been used in the particles characterization. DRX was used to identify the crystallized phases and the images taken from (FE-SEM) show that the material has a wide particle-size distribution with most of them between 10 and 30 nm. (author)

  18. Evaluation method of reference levels of radiation diagnostic in computerized tomography; Metodo de evaluacion de niveles de referencia de radiodiagnostico en tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Walter; Borges, Jose C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear; Mota, Helvecio C. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil). Dept. de Fisica Medica

    2000-07-01

    The computerized tomography (CT) is a complex technique, with many parameters to be selected and protocols of quality control not standardized, connected with high doses in the patients. In this work a simple methodology is developed, to evaluate levels of reference of diagnosis in computerized tomography using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Ministry of Health of Brazil. This methodology, can be used in the routine of inspection of evaluation of radiological safety in medical radiation diagnostics, executed by the Department of Medical Physics of the Institute of Radiation Protection and Dosimetry and by the sanitary authorities in Brazil. In order to evaluate this dosimeter magnitude the distribution of dose it was studied the dose distribution obtained trough a profile of dose measured in the axial axis of a simulator(phantom) of water with thermoluminescent dosimeters, TLD-100, for three techniques of examination by CT. The magnitude MSAD was evaluated by means of two different methods. In first, it was evaluated for an only cut, and in the second for multiple cuts. This last method presents/displays to be more practical and adapted to be applied in the routine of evaluation of reference levels, with TLDs.

  19. Dating of Chichen Itza ceramics by the method of thermoluminescence; Datacion de ceramica de Chichen Itza por el metodo de termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R.; Mendoza A, D.; Cuapio O, L.A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Ramirez L, A.; Schaaf, P. [Instituto de Geofisica-UNAM, 04510 Mexico D.F. (Mexico); Chung, H. [Dept. of Anthropology, Duksung University, Seoul (Korea, Republic of); FFL-UNAM, 04510 Mexico D.F. (Mexico)

    2005-07-01

    In this work we present some results about thermoluminescent dating of some archaeological ceramic samples belonging to Chichen Itza, Yucatan, Mexico: CH11, CH13, CH14 and CH15. The analysis was realized using the fine grained mode in a Daybreak model 1100 reader Tl System. The radioisotopes that contribute in the accumulate annual dose in ceramic samples ({sup 40} K, {sup 238} U, {sup 232} Th) were determined by means of techniques such as Energy Dispersive X-ray Spectroscopy (EDS) and Neutron Activation Analysis (NAA), while the artificial irradiation of samples was carried out with a {sup 90} Sr source beta radiation. The resulting mean CH11 ceramic sample was 934 {+-}45 years old, CH13 was 465 {+-} 26, CH14 was 888 {+-} 34 and CH15 was 867 {+-} 42. These results are in agreement with results obtained through other methods. (Author)

  20. Las historias de la narrativa hispanoamericana: Criterios, metodos y ausencias. (Histories of the Latin-American Narrative: Criteria, Methods, and Absences).

    Science.gov (United States)

    Zavalo, Lauro

    This paper explains that materials on the teaching of Latin-American literature are sparse, even though most researchers in the field will dedicate much of their time to teaching. The paper adds that, in scholarly journals, little attention is given to teaching literature, and the topic is also absent from most academic congresses. The paper then…

  1. A simple method for verifying brachytherapy dose calculation high rate; Un metodo simple para la verificacion del calculo de dosis en braquiterapia de alta tasa

    Energy Technology Data Exchange (ETDEWEB)

    Almansa Lopez, J.; Jover Perez, C. I.; Alaman Sanchez, C.; Osorio Ceballos, J. L.

    2013-07-01

    Variations in the time of treatment can cause adverse side effects in the patient or a failure of the effectiveness of the treatment. In addition RD 1566 / 1998 on quality criteria in radiotherapy establishes the need for a control monitor units or the treatment times in the schedules of teletherapy and brachytherapy. (Author)

  2. Maxillary sinusitis - a comparative study of different imaging diagnosis methods; Sinusopatias maxilares - um estudo comparativo de diferentes metodos de diagnostico por imagem

    Energy Technology Data Exchange (ETDEWEB)

    Hueb, Marcelo Miguel; Borges, Fabiano de Almeida; Pulcinelli, Emilte; Souza, Wandir Ferreira; Borges, Luiz Marcondes [Faculdade de Medicina do Triangulo Mineiro (FMTM), Uberaba, MG (Brazil)

    1999-12-01

    We conducted prospective study comparing different methods (plain X-rays, computed tomography and ultrasonography mode-A) for the initial diagnosis of maxillary sinusitis. Twenty patients (40 maxillary sinuses) with a clinical history suggestive of sinusitis included in this study. The results were classified as abnormal or normal, using computed tomography as gold standard. The sensitivity for ultrasonography and plain X-rays was 84.6% and 69.2%, respectively. The specificity of both methods was 92.6%. This study suggests that ultrasonography can be used as a good follow-up method for patients with maxillary. sinusitis. (author)

  3. Computer simulating for oil fields with artificial elevation method by electrical submersible pump; Simulacao computacional para pocos de petroleo com metodo de elevacao artificial por bombeio centrifugo submerso

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Evellyne da Silva; Maitelli, Andre Laurindo [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Costa, Rutacio de Oliveira [PETROBRAS S.A., Natal, RN (Brazil). Unidade de Negocio RN/CE; Barbosa, Tiago de Souza [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Engenharia de Computacao

    2008-07-01

    The architecture heterogeneities and petrophysical properties of carbonate reservoirs result from a combination of platform morphology, related depositional environments, relative sea level changes and diagenetic events. The reservoir layering built for static and dynamic modelling purposes should reflect the key heterogeneities (depositional or diagenetic) which govern the fluid flow patterns. The layering needs to be adapted to the goal of the modelling, ranging from full field computations of hydrocarbon volumes, to sector-based fine-scale simulations to test the recovery improvement. This paper illustrates various reservoir layering types, including schemes dominated by depositional architecture, and those more driven by the diagenetic overprint. The examples include carbonate platform reservoirs from different stratigraphic settings (Tertiary, Cretaceous, Jurassic and Permian) and different regions (Europe, Africa and Middle East areas). This review shows how significant stratigraphic surfaces (such as sequence boundaries or maximum flooding) with their associated facies shifts, can be often considered as key markers to constrain the reservoir layering. Conversely, how diagenesis (dolomitization and karst development), resulting in units with particular poroperm characteristics, may significantly overprint the primary reservoir architecture by generating flow units which cross-cut depositional sequences. To demonstrate how diagenetic processes can create reservoir bodies with geometries that cross-cut the depositional fabric, different types of dolomitization and karst development are illustrated. (author)

  4. Hybrid nodal methods in the solution of the diffusion equations in X Y geometry; Metodos nodales hibridos en la solucion de las ecuaciones de difusion en geometria XY

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, N. [CFE, Carretera Cardel-Nautla Km. 43.5, 91680 Veracruz (Mexico); Alonso V, G.; Valle G, E. del [IPN-ESFM, 07738 Mexico D.F. (Mexico)]. e-mail: nhmiranda@mexico.com

    2003-07-01

    In 1979, Hennart and collaborators applied several schemes of classic finite element in the numerical solution of the diffusion equations in X Y geometry and stationary state. Almost two decades then, in 1996, himself and other collaborators carried out a similar work but using nodal schemes type finite element. Continuing in this last direction, in this work a group it is described a set of several Hybrid Nodal schemes denominated (NH) as well as their application to solve the diffusion equations in multigroup in stationary state and X Y geometry. The term hybrid nodal it means that such schemes interpolate not only Legendre moments of face and of cell but also the values of the scalar flow of neutrons in the four corners of each cell or element of the spatial discretization of the domain of interest. All the schemes here considered are polynomials like they were it their predecessors. Particularly, its have developed and applied eight different hybrid nodal schemes that its are very nearby related with those developed by Hennart and collaborators in the past. It is treated of schemes in those that nevertheless that decreases the number of interpolation parameters it is conserved the accurate in relation to the bi-quadratic and bi-cubic schemes. Of these eight, three were described and applied in a previous work. It is the bi-lineal classic scheme as well as the hybrid nodal schemes, bi-quadratic and bi-cubic for that here only are described the other 5 hybrid nodal schemes although they are provided numerical results for several test problems with all them. (Author)

  5. Analysis of human enamel and dentine by neutron activation analysis; Analise de esmalte e dentina de humanos pelo metodo de ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Marco A.B. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica]. E-mail: vankfire@gmail.com; Adachi, Eduardo M.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2005-07-01

    Determination of trace elements in dental tissues has been of great interest to study the correlation between element composition and caries as well as food habits of individuals. In the present study dentine and enamel samples from healthy individuals were analysed by neutron activation analysis. The teeth were provided form dental clinics, and they were previously washed using purified water and acetone. Then they were dried at 40 deg C and ground in a agate mortar. The samples and element standards were irradiated with thermal neutrons at the IEA-R1 nuclear reactor. Long irradiations of 8 h under thermal neutron flux of 5x10{sup 12} n cm{sup -2} s{sup -1} were used for Ca, Na, Sr and Zn determinations. In short irradiations of 15 s and under neutron flux of 10{sup 12} n cm{sup -2} s{sup -1} the elements Mg, Mn, Na e Sr were determined. The induced gamma activities of the samples and standards were measured using a hyperpure Ge detector coupled to a gamma ray spectrometer. Elemental concentrations were calculated by comparative method. Results obtained showed that Ca, Mg and Na are present in both tissues at the level of percentages and the elements Mn, Sr and Zn at the {mu}g g{sup -1} levels. For quality control of the results the certified reference materials NIST 1400 Bone Ash and NIST 1486 Bone Meal were analysed. (author)

  6. Arboreal biomass estimation: a comparison between neural networks and statistical methods; Estimativa de biomassa arborea: uma comparacao entre metodos estatisticos e redes neurais

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Arthur C.; Barros, Paulo L.C.; Monteiro, Jose H.A.; Rocha, Brigida R.P. [Universidade Federal do Para (DEEC/UFPA), Belem, PA (Brazil). Dept. de Engenharia Eletrica e Computacao. Grupo de Pesquisa ENERBIO], e-mails: arthur@ufpa.br, jhumberto01@yahoo.com.br, brigida@ufpa.br, paulo.contente@ufra.edu.br

    2006-07-01

    The current methodologies for calculating the volume of biomass and the consequent potential energy widely used in forest inventories, based primarily in statistical methodology to obtain their results. However, more recent techniques, based on the ability of nonlinear mappings, offered by artificial neural networks, have been used successfully in several areas of technology, with superior performance. This work shows a comparison between the statistical model to estimate the volume of trees and a model based on neural networks, which can be used with advantage for this activity related with biomass energy planning.

  7. Hydrocarbons thermal maturation: Leopatin method applied to the Parana basin; Maturacao termica de hidrocarbonetos: aplicacao do metodo de Lopatin a Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Eston, Sergio Medici de; Jardim, Niza S.

    1986-12-31

    One of the requirements for the existent of economic deposits of hydrocarbons is that the organic matter has undergone adequate thermal maturation. Several techniques have been proposed in order to quantity the catagenetic state of kerogen, and the Lopatin-Waples methodology permits quantification at any past time and does not require laboratory tests on samples of the material. For this reason it is an useful techniques for predicting mature zones using as basic information the thermal and subsidence histories of each stratum. Lopatin`s technique was applied to the Parana basin, with McKenzie`s crustal stretching model fitted to the data of 18 wells, and the areas predicted as mature for oil and/or gas were in good agreement with the field results. The technique predicted oil phone areas at the east border of the basin for the Ponta Grossa and Irati formation, and also that most of the thermal maturation occurred after the basalt flows of the Cretaceous period. (author) 41 refs., 6 figs., 6 tabs.

  8. Aplicação de metodos quimiometricos de primeira e segunda ordem na determinação direta de farmacos por espectroscopia molecular

    OpenAIRE

    Marcelo Martins de Sena

    2004-01-01

    Resumo: o objetivo desta tese foi a aplicação conjunta de métodos quimiométricos de primeira e segunda ordens (PLS, PARAFAC e N-PLS) e técnicas de espectroscopia molecular (absorção no UV e espectrofluorimetria) na determinação direta de fármacos, contribuindo assim para a divulgação destas metodologias como alternativas viáveis às tradicionais determinações cromatográficas univariadas. Para isso, foram realizadas quatro aplicações originais. As três primeiras foram as determinações simultâne...

  9. Algoritimos geneticos para seleção de variaveis em metodos de calibração de segunda ordem

    OpenAIRE

    Renato Lajarim Carneiro

    2007-01-01

    Resumo: Esse trabalho teve por objetivo desenvolver um programa em MatLab baseado no Algoritmo Genético (GA) para aplicar e verificar as principais vantagens deste na seleção de variáveis para métodos de calibração de segunda ordem (BLLS-RBL, PARAFAC e N-PLS). Para esta finalidade foram utilizados três conjuntos de dados: 1. Determinação de pesticidas e um metabólito em vinho tinto por HPLC-DAD em três situações distintas. Nestas três situações foram observadas sobreposições dos interferentes...

  10. Determination of the most reactivity control rod by pseudo-harmonics perturbation method; Determinacao da barra de controle mais reativa usando o metodo de pseudo-harmonicos

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Fernando S.; Silva, Fernando C.; Martinez, Aquilino S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: ffreire@con.ufrj.br; fernando@con.ufrj.br; aquilino@.con.ufrj.br

    2005-07-01

    Frequently it is necessary to compute the change in core multiplication caused by a change in the core temperature or composition. Even when this perturbation is localized, such as a control rod inserted into the core, one does not have to repeat the original criticality calculation, but instead we can use the well-known pseudo-harmonics perturbation method to express the corresponding change in the multiplication factor in terms of the neutron flux expanded in the basis vectors characterizing the unperturbed core. Therefore we may compute the control rod worth to find the most reactivity control rod to calculate the fast shutdown margin. In this thesis we propose a simple and precise method to identify the most reactivity control rod. (author)

  11. Metodos de enseñanza-aprendizaje aplicables en magisterio en el marco del Espacio Europeo de Educación Superior

    OpenAIRE

    Carpio de los Pinos, Carmen

    2008-01-01

    Este trabajo propone una selección de técnicas metodológicas didácticas para grupos grandes de alumnos, como los existentes en Magisterio en la Universidad de Castilla-La Mancha. Se fundamentan sobre estudios empíricos en el ámbito universitario y teorías educativas y psicológicas. Se tiene en cuenta la carga de trabajo para el profesor y para el alumno, así como el tipo de evaluación de cada técnica, y se exponen actividades concretas para las diferentes metodologías. Se describen según un...

  12. Calibration methods of plane-parallel ionization chambers used in electron dosimetry; Metodos de calibracao de camaras de ionizacao de placas paralelas para dosimetria de feixes de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Bulla, Roseli Tadeu

    1999-07-01

    The use of linear accelerators in radiotherapy is of great importance in Medicine, and according to international recommendations the electron beam dosimetry has to be performed using plane-parallel ionization chambers, previously calibrated in standard gamma radiation fields at accredited laboratories. In this work, calibration methods of plane-parallel ionization chambers used in dosimetry procedures of high energy electron beams of clinical accelerators were presented, tested and intercompared. The experiments were carried out using gamma radiation beams of {sup 60} Co at the Calibration Laboratory of Clinical Dosemeters at IPEN and electron beams od 4 to 16 MeV at the Radiotherapy Department of Hospital Israelita Albert Einstein, Sao Paulo. A method was chosen to be established at IPEN. Proposals of the calibration procedure, calibration certificate and data sheets are presented. (author)

  13. Production of nano structured zinc oxide by the flame spray method; Obtencao de oxido de zinco nanoestruturado pelo metodo de aspersao de solucao em chama

    Energy Technology Data Exchange (ETDEWEB)

    Trommer, R.M.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (LACER/PPGEM/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Engenharia de Minas, Metalurgica e de Materiais. Lab. de Materiais Ceramicos

    2009-07-01

    Nanostructured zinc oxide has been widely employed in several applications, mainly as antibactericidal and absorber of ultraviolet radiation (UV). The preference for a nanostructured material is associated with the different properties presented by these entities when compared to the bulk material. Thus, this work employed the flame spray technique, an alternative method with an enormous potential in nanoparticles production, to obtain ZnO powders. Basically, a precursor solution is prepared, atomized and then sprayed in the flame, where it burns and leads to the formation of particles. X-ray diffraction analysis pointed the crystalline phase zincite. By scanning electronic microscopy, it was possible to observe irregular and aggregated particles in the powder. By transmission electronic microscopy, images of the nanometric ZnO particles were obtained, being later confirmed by the single line method. (author)

  14. Determination of the response time of pressure transducers using the direct method; Determinacao do tempo de resposta de transdutores de pressao utilizando o metodo de medida direta

    Energy Technology Data Exchange (ETDEWEB)

    Perillo, S.R.P.

    1994-12-31

    The available methods to determine the response time of nuclear safety related pressure transducers are discussed, with emphasis to the direct method. In order to perform the experiments, a Hydraulic Ramp Generator was built. The equipment produces ramp pressure transients simultaneously to a reference transducer and to the transducer under test. The time lag between the output of the two transducers, when they reach a predetermined setpoint, is measured as the time delay of the transducer under test. Some results using the direct method to determine the time delay of pressure transducers (1 E Class Conventional) are presented. (author). 18 refs, 35 figs, 12 tabs.

  15. Studies of trace element determinations in nails by neutron activation analysis method; Estudo de elementos traco em unhas pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Amilton Reinaldo; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-07-01

    The purpose of this work was to develop the neutron activation analysis for trace element determinations in nails in order to apply this method to the study of the cystic fibrosis disease. It was verified that the elements Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Se and Zn can be determined by using short and long irradiations with thermal neutron flux from 10{sup 11} to 10{sup 13} n.cm{sup -2}.{sup -1} at the IEA-R1 nuclear research reactor. The washing solutions of triton-X100, NH{sub 4} OH and acetone were tested in order to eliminate external contaminants from the nail samples. The nail analyses of the individual fingers from both of hands showed that the samples must be collected from all the fingers from both of hands to have a representative sample. The precision and the accuracy of the results were also examined by analyzing NIES 10C Rice Flour, IUPAC Bowen's Kale and NIST 1572 Citrus Leaves reference materials. (author)

  16. Application of geophysical methods to gold prospecting in Minas de Corrales, Uruguay; Aplicacao de metodos geofisicos a prospeccao de ouro. Teste nas minas de Corrales, Uruguai

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Antonio Flavio U. [Companhia de Pesquisas de Recursos Minerais (CPRM), Rio de Janeiro, RJ (Brazil); Dias, Rogerio Aguirre; Barcelos, Andre B.B. de [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil)

    1993-07-01

    Geophysical methods were tested in San Gregorio gold mine, Minas de Corrales, north region of Uruguay. The ores are mainly stockworks, sheeted veinlet zones, ore shoot and disseminated sulfides types, situated in a silicated and carbonated shear zone structure, over granitic mylonites, quartz diorites, quartz-feldspathic breccia, basic rocks and quartz veins. Magnetic and radiometric methods were applied . VLF and EM34-3 detected the high resistivity silicated and carbonated zone and IP detected a weak PFE anomaly associated with pyrite/gold zone. (author)

  17. Synthesis and characterization of NiO nanoparticles by Pechini method; Sintese e caracterizacao de nanoparticulas de NiO pelo metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, A.; Ribeiro, M.A.; Costa, A.C.F.M.; Gama, L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Bernardi, M.I.B. [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica

    2009-07-01

    In recent years, ultrafine magnetic particles of NiO have attracting the attention because of its unknown behavior, enormous scientific potential and technological application. Some of its more important properties are accented magnetic moments, double dynamic exchange, quantization of wave of spin and etc. In this context, this work has for objective to synthesize and to characterize nanoparticles of NiO for the Pechini method. The powder was analyzed by X-rays diffraction. The results of scanning electron microscopy, adsorption of nitrogen. The analysis of X-rays diffraction of the sample showed single-phase peaks of NiO, with crystallite size close to 38 nm. The surface area was 6.44 m{sup 2}/g. The image from scanning electron microscopy shows soft homogeneous agglomerates. The Pechini synthesis was efficient in the production of powders of NiO nano metrics and single-phase. (author)

  18. El uso del metodo MICMAC y MACTOR analisis prospectivo en un area operativa para la busqueda de la excelencia operativa a traves del Lean Manufacturing

    OpenAIRE

    Juan Baldemar Garza Villegas; Dante Vladimir Cortez Alejandro

    2011-01-01

    Presents the MICMAC and MACTOR prospective analysis study in an operational area which looks for world-class management with reference to the concepts of lean manufacturing. The results of a qualitative analysis and his conclusions are presented.

  19. Investigation of multi-phases dynamic systems by means of optical and electrochemical methods; Investigacion de sistemas dinamicos multifasicos mediante metodos opticos y electroquimicos

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento Martinez, Oscar

    2008-09-15

    During former investigations, the utilization of optical interferometric techniques was proposed to perform the monitoring of oxide layers growing or metallic degradation occurring in aluminum samples immersed in aqueous solutions, during initial stages of related oxidation processes without direct physical contact. Additionally a mathematical model was developed in order to obtain, from orthogonal displacements located in the metal surface during the anodic reaction, the metallic layer thickness loss or growth in the sample by interference fringes count. Here in this doctoral thesis, experimental and numerical results related to certain corrosion processes observed in different electrochemical systems using simultaneously Michelson interferometry optical monitoring and polarization curves electrochemical monitoring are presented. The qualitative and quantitative information resumed by important physical parameters related with the corrosion processes and their dynamics is analyzed, same as the alternated appearance and disappearance of interference patterns which optical visibility is lost and recovered as time goes by. On the other hand, a mathematical model for the optical-electrochemical system was developed in order to quantify metal loss or oxide layer growth in metallic samples, and also the reconstruction of conventional electrochemical dependences by using alternative experimental data obtained by interference maxima fringes counting. Lastly, and according to non-linear dynamical systems theoretical concepts, the non-linear parameters related to the existence of chaotic complex solutions are analyzed and discussed, based on experimental and numerical data obtained from the observation of corrosion processes of metals in aqueous solutions and hydrocarbons, during optical-electrochemical monitoring of our system. [Spanish] En un estudio previo, se propuso la utilizacion de tecnicas opticas interferometricas para monitorear el crecimiento de capas de oxidos o de la degradacion metalica en muestras de aluminio durante los estados iniciales de procesos de oxidacion en soluciones acuosas, sin medir contacto fisico alguno. Adicionalmente, se desarrollo un modelo matematico el cual permite, a partir de los desplazamientos ortogonales que ocurren en la superficie del metal durante la reaccion anodica, encontrar la perdida o crecimiento del espesor de la capa metalica de la muestra a partir del conteo de franjas de interferencia. En la presente tesis doctoral, se presentan resultados experimentales y numericos referentes a ciertos procesos de corrosion en diferentes sistemas electroquimicos utilizando simultaneamente el monitoreo optico mediante interferometria de Michelson y el monitoreo electroquimico mediante curvas de polarizacion. Se analiza la informacion tanto cualitativa como cuantitativa de importantes parametros fisicos relacionados con los procesos de corrosion y su dinamica, asi como la formacion de patrones de interferencia cuyo contraste optico se pierde con el paso de tiempo, para subitamente reaparecer y con ello nuevamente la aparicion del patron de interferencia inicial. Por otro lado, se desarrollo un modelo matematico a partir del sistema optico-electroquimico, el cual permite cuantificar mediante parametros opticos la perdida de material o crecimiento de oxido en metales, permitiendo reproducir las curvas electroquimicas mediante el conteo de maximos de interferencia. Finalmente, y de acuerdo a conceptos de la teoria de sistemas dinamicos no lineales, se analizan y discuten los parametros fisicos dinamicos no lineales relativos a la existencia de soluciones complejas de tipo caotico con base en los datos obtenidos de los procesos de corrosion en soluciones acuosas e hidrocarburos observados durante el monitoreo optico-electroquimico de nuestro sistema.

  20. Evaluation of occupational exposure in interventionist procedures using Monte Carlo Method; Avaliacao das exposicoes dos envolvidos em procedimentos intervencionistas usando metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, William S.; Neves, Lucio P.; Perini, Ana P.; Caldas, Linda V.E., E-mail: williathan@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Belinato, Walmir; Maia, Ana F. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Fisica

    2014-07-01

    This study presents a computational model of exposure for a patient, cardiologist and nurse in a typical scenario of cardiac interventional procedures. In this case a set of conversion coefficient (CC) for effective dose (E) in terms of kerma-area product (KAP) for all individuals involved using seven different energy spectra and eight beam projections. The CC was also calculated for the entrance skin dose (ESD) normalized to the PKA for the patient. All individuals were represented by anthropomorphic phantoms incorporated in a radiation transport code based on Monte Carlo simulation. (author)

  1. Statistical method for the control of the electric power service interruptions (second part); Metodo de control estadistico de las interrupciones del servicio electrico (2a. parte)

    Energy Technology Data Exchange (ETDEWEB)

    Issouribehere, Pedro E.; Barbero, Juan C. [Universidad Nacional de La Plata (UNLP), Buenos Aires (Argentina). Facultad de Ingenieria. Inst. de Investigaciones Tecnologicas para Redes y Equipos Electricos (IITREE-LAT)]. E-mail: iitree@.ing.unlp.edu.ar; Martinez, Jorge L.; Galinski, Alejandro [Ente Nacional Regulador de la Electricidad (ENRE), Buenos Aires (Argentina)

    2001-07-01

    This paper presents the register of interruptions in application points of the concession areas of three concessionaires. The reliability indexes are presented of the controlled sites: interruption ratio {lambda}, time of average reposition r and unavailability Q obtained with the field information recompiled during three years from June 2000. The paper also obtains by concessionaire, the ratios of brief interruptions occurrence which constitutes another indicator of the Electric Service Quality.

  2. Recovery of Americium-241 from lightning rod by the method of chemical treatment; Recuperacion del Americio-241 provenientes de los pararrayos por el metodo de tratamiento quimico

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, W.H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (GRRA/IPEN), Lima (Peru). Division de Gestion de Residuos Radiactivos

    2013-07-01

    About 95% of the lightning rods installed in the Peruvian territory have set in their structures, pose small amounts of radioactive sources such as Americium-241 ({sup 241}Am), fewer and Radium 226 ({sup 226}Ra) these are alpha emitters and have a half life of 432 years and 1600 years respectively. In this paper describes the recovery of radioactive sources of {sup 241}Am radioactive lightning rods using the conventional chemical treatment method using agents and acids to break down the slides. The {sup 241}Am recovered was as excitation source and alpha particle generator for analysing samples by X Ray Fluorescence, for fixing the stainless steel {sup 241}Am technique was used electrodeposition. (author)

  3. Volatilization mechanism of certain elements in a method of semiquantitative spectrographic analysis; Mecanismo de volatilizacion de ciertos elementos en un metodo de analisis espectrografico semicuantitativo

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.

    1972-07-01

    The efficiency of the compounds GeO{sub 2}, Li{sub 2}B{sub 4}O{sub 7}, Li{sub 2}CO{sub 3}, SiO{sub 2} and SrCO{sub 3} as spectrochemical buffers, in the development of a semiquantitative spectrographic method of analysis, that can be applied to the determination of 47 elements in different matrices, has been tested. It has been shown that trough the use of Li{sub 2}B{sub 4}O{sub 7} or Geo{sub 2} adequate accuracy is obtained, attaining with the latter the detection of much lower concentrations, specially for the elements Mo. Ti, V and W. In order to account for the different behaviour of these elements their volatilization mechanism has been studied. MoB{sub 2}, TiB{sub 2}, VB{sub 2}.{delta}WB and {epsilon}-WB were found, by x-ray diffraction analysis, to be reaction products in the case of mixtures with Li{sub 2}B{sub 4}O{sub 7}. (Author)

  4. Standardization of {sup 153}Sm using anti-coincidence method; Padronizacao do {sup 153}Sm pelo metodo de anti-coincidencia

    Energy Technology Data Exchange (ETDEWEB)

    Laranjeira, Adilson da Silva; Silva, Carlos J. da; Delgado, Jose Ubiratan; Cruz, Paulo A.L. da; Poledna, Roberto; Silva, Ronaldo L. da; Oliveira, Antonio E. de; Gomes, Regio S.; Veras, Eduardo V. de; Araujo, Miriam Taina Ferreira de, E-mail: adilson@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    {sup 153}Sm was standardized at the Brazilian National Laboratory of Metrology of Ionizing Radiation to provide traceability for measurements in nuclear medicine services and manufacturers of radiopharmaceuticals in Brazil. {sup 153}Sm decays by emission β-γ to {sup 153}Eu, the gamma rays of higher-intensity are 69.7 keV (4.7%) and 103.2 keV (29.2%). The standardization was made by anticoincidence and CIEMAT/NIST methods with uncertainties combined (0.4% and 0.3%) and (0.5% and 0.4%), respectively. The difference between the standardized activities was 0.15%. The uncertainties are consistent with other publications. (author)

  5. Methods for fitting of efficiency curves obtained by means of HPGe gamma rays spectrometers; Metodos de ajuste de curvas de eficiencia obtidas por meio de espectrometros de HPGe

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Vanderlei

    2002-07-01

    The present work describes a few methodologies developed for fitting efficiency curves obtained by means of a HPGe gamma-ray spectrometer. The interpolated values were determined by simple polynomial fitting and polynomial fitting between the ratio of experimental peak efficiency and total efficiency, calculated by Monte Carlo technique, as a function of gamma-ray energy. Moreover, non-linear fitting has been performed using a segmented polynomial function and applying the Gauss-Marquardt method. For the peak area obtainment different methodologies were developed in order to estimate the background area under the peak. This information was obtained by numerical integration or by using analytical functions associated to the background. One non-calibrated radioactive source has been included in the curve efficiency in order to provide additional calibration points. As a by-product, it was possible to determine the activity of this non-calibrated source. For all fittings developed in the present work the covariance matrix methodology was used, which is an essential procedure in order to give a complete description of the partial uncertainties involved. (author)

  6. Evaluation of the open vial method in the radon measurement; Evaluacion del metodo del vial abierto en la medicion de radon

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The open vial method is a simple technique, under-utilized but that take advantage of the great radon solubility in organic solvents, therefore applies in the measurement of the radon concentration exhaled in soil. The method consists on the exposition to the gas radon of an open vial with scintillating solution. An integral mathematical model for indoors that describes the emanation processes and gas radon exhalation was developed, as well as the radon dissolution in the scintillation liquid, besides obtaining the characteristic parameters of the experimental system proposed for the radon concentration calculation exhaled by soils. Two experimental arrangements were designed with exposition cameras of 12 and 6 L and quantity of different soil. The open vial was prepared with a mixture of 8 ml of deionized water and 12 ml of scintillation liquid OptiPhase Hi Safe 3 in polyethylene vials; the measurements of the dissolved radon were carried out in scintillation liquid equipment. As a result, on average 2.0% of the exhaled radon is dissolved in the open vial and the dissolved fraction is independent of the experimental arrangement. Also was observed that the exposition time does not affect the radon dissolution significantly, in correspondence with the reported in the literature. (Author)

  7. Coincidence in the dose estimation in a OEP by different methods; Coincidencia en la estimacion de dosis en un POE por diferentes metodos

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C.; Brena V, M. [ININ, Km. 36.5, Carretera Mexico-Toluca, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: cgc@nuclear.inin.mx

    2007-07-01

    The case of an apparent overexposure to radiation according to that indicated for the thermoluminescent dosemeter 81.59 mSv (TLD) of a occupationally exposed hard-working (POE), for that was practiced the study of biological dosimetry. The estimated dose was 0.12 Gy with which was proven the marked dose registration by the TLD dosemeter. It was concluded that both doses are the same ones. (Author)

  8. Synthesis of lithium silicates generators of tritium by a modified method of combustion; Sintesis de silicatos de litio generadores de tritio por un metodo modificado de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Cruz G, D

    2003-07-01

    The ceramics of lithium have been proposed as generating materials of tritium through the following reaction: {sup 6} Li + {sup 1} n {yields} {sup 4} He + {sup 3} H . In previous works carried out by Pfeiffer and collaborators, the lithium silicates generators of tritium were prepared using the following methods: reactions of solid state, precipitation and sol-gel synthesis. Although those methods have advantages, it is required of heating at high temperatures (900 C during four hours) to be able to obtain the crystalline compounds. Those products found in these works were diverse crystallization forms of the lithium silicates and of SiO{sub 2}, such as, Li{sub 2}SiO{sub 3}, Li{sub 2}Si{sub 2}0{sub 5}, Li{sub 4}SiO{sub 4}, and quartz (SiO{sub 2}). The combustion method uses exothermic reactions to take place ceramic compounds. The precursor solutions are mixtures of the nitrate of metal oxidizer and the fuels (urea, glycine, carbohydrazide). However the reported method in the literature, it is not useful to prepare lithium silicates, for what was modified using non oxidizers compounds. The lithium hydroxide (LiOH) and the silicic acid (H{sub 2}SiO{sub 3}) they were the compounds non oxidizers used, and the urea (CH{sub 4}N{sub 2}O) it was the one fuel. They were carried out two series of experiments; inside the series 1 of experiments are varied the molar ratio of lithium hydroxide and urea (LiOH : H{sub 2}SiO{sub 3} = 1, 2 and 3, LiOH : CH{sub 4}N{sub 2}O = 1, 2, 3, 4 and 5) and the prepared mixtures were taken to one muffle previously preheated to a temperature of 450 C during 5 minutes. In the series 2 of experiments was studied the effect of the temperature and of the washed with distilled water in the prepared samples with the following molar ratios: LiOH : H{sub 2}SiO{sub 3} : CH{sub 4}N{sub 2}O = 1:1:3, 2:1:3, 3:1:3 and 3:1:6, those which were heated to temperatures from 450 C up to 750 C and were washed. The obtained samples were characterized by X-ray diffraction (XRD), Infrared spectroscopy (I S), semiquantitative elemental analysis (EDS) and Thermal gravimetric analysis (TGA). It was found that the molar ratios more adequate of LiOH : H{sub 2}SiO{sub 3} : CH{sub 4}N{sub 2}O to produce Li{sub 2}SiO{sub 3} were: 3:1:3 and 3:1:6. The present carbonates in the powders prepared were eliminated in the second series by heating of the mixture to higher temperatures (650 C), or for washed of the same distilled water. The urea in excess produced coesite (SiO{sub 2}) as main product in the ceramics. Presently work was obtained, in accordance with the results, a sample of lithium silicate (Li{sub 2}SiO{sub 3}) not polluted with any type of compound that it contained coal. (Author)

  9. Simulation of the functioning of a gamma camera using Monte Carlo method; Simulacion del funcionamiento de una camara gamma mediante metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Oramas Polo, I.

    2014-07-01

    This paper presents the simulation of the gamma camera Park Isocam II by Monte Carlo code SIMIND. This simulation allows detailed assessment of the functioning of the gamma camera. The parameters evaluated by means of the simulation are: the intrinsic uniformity with different window amplitudes, the system uniformity, the extrinsic spatial resolution, the maximum rate of counts, the intrinsic sensitivity, the system sensitivity, the energy resolution and the pixel size. The results of the simulation are compared and evaluated against the specifications of the manufacturer of the gamma camera and taking into account the National Protocol for Quality Control of Nuclear Medicine Instruments of the Cuban Medical Equipment Control Center. The simulation reported here demonstrates the validity of the SIMIND Monte Carlo code to evaluate the performance of the gamma camera Park Isocam II and as result a computational model of the camera has been obtained. (Author)

  10. Estudio cuasi-experimental en la aplicación de metodos cooperativos para la enseñanza de la asignatura en filosofia

    Directory of Open Access Journals (Sweden)

    Carmen Teresa Medrano-Lindarte

    2010-01-01

    Full Text Available We did the investigation with 62 students (men and women, they study at Nuestra Señora de las Mercedes School in Sardinata, they are in 10th grade; 29 of these students are in 10 B grade and the other 33 are in 10A grade. By an experimental designed with an experimental group, a group of control and using some qualified post-test in both grades; we realized how important is learning a topic and improving the academic performance by using cooperative methods to teach this subject in Philosophy We measured the rank of getting the topic and improving the academic performance by applying some post-tests with 80% of reliability, we got this result by using the divided Halves method, we applied the Shapiro-Wilk test for samples fewer than 50% and we found Previous values of the normal assumptions, and the grades of these two groups show the same variance with a value of p=0.073 on the Levene test and it has a very important diference between the different grades of the two groups (p=0.000 prueba t.

  11. Evaluation of imaging methods in the diagnosis of urolithiasis: review of the literature; Avaliacao dos metodos de imagem no diagnostico da urolitiase: revisao da literatura

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Ricardo Miguel Costa de; Silva, Luciana Costa; Santos, Jovita Lane Soares; Tavares Junior, Wilson Campos [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Hospital das Clinicas. Servico de Radiologia e Diagnostico por Imagem]. E-mail: rmcfreitas@ig.com.br

    2004-08-01

    The aim of this study is to compare helical computed tomography with imaging studies currently used to evaluate patients with acute low back pain. In addition, we briefly review the pathophysiology of urolithiasis. The literature published in the last 30 years was reviewed, and the following methods were discussed: plain abdominal radiographs, intravenous pyelography, ultrasound of the urinary tract, and helical computed tomography. Helical computed tomography showed high sensitivity and specificity for detecting urolithiasis, virtually showing all stones, except in patients receiving indinavir. The accuracy of plain abdominal radiographs associated with ultrasound was similar to helical computed tomography, although the latter showed superiority as an isolated method. Data from literature suggest that whenever helical computed tomography is available, it is helpful in the evaluation of low back pain and also allows differential diagnosis between conditions that mimic the symptoms of urolithiasis.(author)

  12. Metodo y Proceso de la Investigacion Participativa en la Capacitacion Rural (The Method and Process of Participatory Research in Rural Leadership Training). Cuadernos del CREFAL 19.

    Science.gov (United States)

    de Schutter, Anton

    In participatory research, education and learner participation are directly connected. The document analyzes the role of a participatory research method in the basic education of rural adults. The different phases of the Participant Research method are presented, along with a profound analysis of both research and participation. The claim is that…

  13. Calibration and intercomparison methods of dose calibrators used in nuclear medicine facilities; Metodos de calibracao e de intercomparacao de calibradores de dose utilizados em servicos de medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Alessandro Martins da

    1999-07-01

    Dose calibrators are used in most of the nuclear medicine facilities to determine the amount of radioactivity administered to a patient in a particular investigation or therapeutic procedure. It is therefore of vital importance that the equipment used presents good performance and is regular;y calibrated at a authorized laboratory. This occurs of adequate quality assurance procedures are carried out. Such quality control tests should be performed daily, other biannually or yearly, testing, for example, its accuracy and precision, the reproducibility and response linearity. In this work a commercial dose calibrator was calibrated with solution of radionuclides used in nuclear medicine. Simple instrument tests, such as response linearity and the response variation of the source volume increase at a constant source activity concentration, were performed. This instrument can now be used as a working standard for calibration of other dose calibrators/ An intercomparison procedure was proposed as a method of quality control of dose calibrators used in nuclear medicine facilities. (author)

  14. Method of evaluation of diagnostics reference levels in computerized tomography; Metodo de avaliacao de niveis de referencia de radiodiagnostico em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Walter Flores

    1999-04-01

    Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

  15. Analytical performance of radiochemical method for americium determination in urine; Desempenho analitico do metodo radioquimico para determinacao de americio em urina

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Juliana Ferreira; Carneiro, Janete C.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: ju_barreto@terra.com.br

    2005-07-01

    This paper presents an analytical method developed and adapted for separation and analysis of Plutonium (Pu) isotopes and Americium (Am) in urine samples. The proposed method will attend the demand of internal exposure monitoring program for workers involved mainly with dismantling rods and radioactive smoke detectors. In this experimental procedure four steps are involved as preparation of samples, sequential radiochemical separation, preparation of the source for electroplating and quantification by alpha spectrometry. In the first stage of radiochemical separation, plutonium is conventionally isolated employing the anion exchange technique. Americium isolation is achieved sequentially by chromatographic extraction (Tru.spec column) from the load and rinse solutions coming from the anion exchange column. The {sup 243}Am tracer is added into the sample as chemical yield monitors and to correct the results improving the precision and accuracy. The mean recovery obtained is 60%, and the detection limit for 24h urine sample is 1.0 mBq L{sup -1} in accordance with the literature. Based in the preliminary results, the method is appropriate to be used in monitoring programme of workers with a potential risk of internal contamination. (author)

  16. Validation of analytical method to calculate the concentration of conjugated monoclonal antibody; Validacao de metodo analitico para calculo de concentracao de anticorpo monoclonal conjugado

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Lais F.; Massicano, Adriana V.F.; Oliveira, Ricardo S.; Araujo, Elaine B. de, E-mail: lais_alcarde@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of this study was to develop a quantitative analytical method using high performance liquid chromatography (HPLC) to determine the antibody concentration in conjunction with bifunctional chelator. Assays were performed using a high performance liquid chromatograph, and the following conditions were used: flow rate of 1 mL / min, 15 min run time, 0.2 M sodium phosphate buffer pH 7.0 as the mobile phase and column of molecular exclusion BioSep SEC S-3000 (300 x 7.8 mm, 5 μM - Phenomenex). The calibration curve was obtained with AcM diluted in 0.2 M sodium phosphate buffer pH 7.0 by serial dilution, yielding the concentrations: 400 μg/mL, 200 μg/mL, 100 μg/mL, 50 μg/mL, 25 μg/mL and 12.5 μg/mL. From the calibration curve calculated the equation of the line and with it the concentration of the immunoconjugate. To ensure the validity of the method accuracy and precision studies were conducted. The accuracy test consisted in the evaluation of 3 samples of known concentration, being this test performed with low concentrations (50 μg/mL), medium (100 μg/mL) and high (200 μg/mL). The precision test consisted of 3 consecutive measurements of one sample of known concentration, subject to the conditions set forth above for the other tests. The correlation coefficient of the standard curve was greater than 97%, the accuracy was satisfactory at low concentrations as well as accuracy. The method was validated by showing it for the accurate and precise determination of the concentration of the immunoconjugate. Furthermore, this assay was found to be extremely important, because using the correct mass of the protein, the radiochemical purity of the radioimmunoconjugate was above 95% in all studies.

  17. How to identify partial exposures to ionizing radiation? Proposal for a cytogenetic method; Como identificar exposicoes parciais as radiacoes ionizantes? Proposta de um metodo citogenetico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, T.S.; Silva, E.B.; Pinto, M.M.P.L.; Amaral, A., E-mail: thiagosalazar@hotmail.com [Universidade Federal de Pernambuco (LAMBDA/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Lab. de Modelagem e Biodosimetria Aplicada; Lloyd, David [Health Protection Agency, Oxford (United Kingdom). Radiation Protection Division

    2013-08-15

    In cases of radiological incidents or in occupational exposures to ionizing radiation, the majority of exposures are not related to the total body, but only partial. In this context, if the cytogenetic dosimetry is performed, there will be an underestimation of the absorbed dose due to the dilution of irradiated cells with non-irradiated cells. Considering the norms of NR 32 - Safety and Health in the Work of Health Service - which recommends cytogenetic dosimetry in the investigation of accidental exposures to ionizing radiations, it is necessary to develop of a tool to provide a better identification of partial exposures. With this aim, a partial body exposure was simulated by mixing, in vitro, 70% of blood irradiated with 4 Gy of X-rays with 30% of unirradiated blood from the same healthy donor. Aliquots of this mixture were cultured for 48 and 72 hours. Prolonging the time of cell culture from 48 to 72 hours produced no significant change in the yield of dicentrics. However, when only M1 (first division cells) were analyzed, the frequency of dicentrics per cell was increased. Prolonging the time of cell culture allowed cells in mitotic delay by irradiation to reach metaphase, and thus provides enough time for the damage to be visualized. The results of this research present the proposed method as an important tool in the investigation of exposed individuals, allowing associating the cytogenetic analysis with the real percentage of irradiated cells, contributing significantly for the decision making in terms of occupational health. (author)

  18. Some results about the dating of pre hispanic mexican ceramics by the thermoluminescence method; Algunos resultados sobre el fechamiento de ceramica prehispanica mexicana por el metodo de termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.; Mendoza A, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Ramirez L, A.; Schaaf, P. [Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    One of the most frequently recurring questions in Archaeometry concerns the age of the studied objects. The some first dating methods were based in historical narrations, style of buildings manufacture techniques. However, has been observed that as consequence the continuous irradiation from naturally occurring radioisotopes and from cosmic rays some materials, such as archaeological ceramic, accumulate certain quantity of energy. These types of material can, in principle, be dated through the analysis of these accumulate energy. In that case, ceramic dating can be realized by thermoluminescence (TL) dating. In this work, results obtained by our research group about TL dating of ceramic belonging to several archaeological zones like to Edzna (Campeche), Calixtlahuaca and Teotenango (Mexico State) and Hervideros (Durango) are presented. The analysis was realized using the fine grained mode in a Daybreak model 1100 reader TL system. The radioisotopes that contribute in the accumulate annual dose in ceramic samples ({sup 40} K, {sup 238} U, {sup 232} Th) were determined by means of techniques such as Energy Dispersive X-ray Spectroscopy (EDS) and Neutron Activation Analysis (AAN). Our results are agree with results obtained through other methods. (Author) 7 refs., 2 tabs., 5 figs.

  19. Cuantificacion de huevo en fideos secos según metodo electroforético (SDS PAGUE) Quantification of egg in dried noodles by electrophoretic methods (SDS PAGE)

    OpenAIRE

    LB López; K Cellerino; MJ Binaghi; MS Giacomino; ME Valencia

    2011-01-01

    La cuantificación de huevo en fideos secos elaborados con harina y agregado de huevo. Se analizaron 6 sistemas modelos (SM) de fideos que contenían 0,0; 1,0; 2,5; 4,0; 6,0 y 8,0% de huevo en polvo. Se extrajeron proteínas totales con un buffer que contiene dodecilsulfato de sodio (SDS) y 2-Mercaptoetanol y se realizó electroforesis en gel de poliacrilamida con SDS. Se establecieron las relaciones de las áreas de los picos de los densitogramas (de huevo y de trigo) que permiten una correcta cu...

  20. Synthesis and characterization photocatalyst of titanium oxide obtained by the Pechini; Sintese e caracterizacao fotocatalitica do oxido de titanio obtido pelo Metodo Pechini

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, P.C.; Costa, A.C.F.M.; Lira, H.L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia de Materiais; Sasaki, J.M. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Departamento de Fisica; Santos, S.K., E-mail: pollyanacae@yahoo.com.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Quimica

    2011-07-01

    The photocatalysis using TiO{sub 2} semiconductor has shown great efficiency in the treatment of toxic pollutants and non-biodegradable materials, commonly present in air and domestic and industrial effluents. Thus, the aim of this work is to study the evaluation of photocatalytic activity of TiO{sub 2} samples synthesized by the Pechini method at a ratio of citric acid / metal cation of 2:1 and 4:1. The synthesized samples were characterized by X-ray diffraction, quantification of phases using the Rietveld method of refinement of the structure and after analyzed in photocatalytic bench tests using methyl red dye. The results showed that in a 2:1 ratio, the sample resulted in the formation of 100% of anatase phase, while in the 4:1 ratio sample showed 73.51% of anatase phase and 10.5% of rutile phase. The 4:1 sample showed the best performance discoloring over 70% of the dye for a period close to 24h. (author)

  1. Determination of Sn in 99{sup m}Tc Radiopharmaceutical Kits by Polarographic Methods; Determinacion de Estano en Radiofarmacos de 99{sup m}Tc mediante Metodos Polarograficos

    Energy Technology Data Exchange (ETDEWEB)

    Castro, M.; Cruz, J.; Sanchez, M.

    2009-07-01

    Kits of 99{sup m}Tc radiopharmaceuticals are used in nuclear medicine for diagnosis of different diseases. Sn (II) is one of the essential components in their formulations, which is used for reduction 99{sup m}Tc-pertechnetate in cold kits for on-site preparation 99{sup m}Tc-pertechnetate radiopharmaceuticals. Usually, these cold kits contain different additives (complexing agents, antioxidants, buffers, etc.) and the amount of Sn (II) varies from kit to kit. The determination of Sn in these products is essential in assessing their quality. We report here the development of a new polarographic method for the determination of Sn (II) and total Sn in representative radiopharmaceuticals kits (for the content of Sn and chemical composition) produced at the Center of Isotopes of Cuba (CENTIS). These methods were validated by analysis of variance and recovery techniques. From the results of the validation, the characteristic functions of uncertainties and fits are considered for the established methods, which give the necessary evidences to demonstrate the usefulness of these methods according to the current trends in Analytical Chemistry. This work provides practical results of great importance for CENTIS. After the speciation of Sn in the MAG3 radiopharmaceuticals kit is inferred that the production process is affected by uncontrolled factors that influence in the product stability, which demonstrates the necessity for analytical tools for the characterization of products and processes. (Author) 57 refs.

  2. Method to determine the activity concentration and total activity of radioactive waste; Metodo para determinar la concentracion de actividad y actividad total de desechos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A

    2001-02-15

    A characteristic system of radioactive waste is described to determine the concentration of radionuclides activity and the total activity of bundles of radioactive waste. The system this integrated by three subsystems: - Elevator of drums. - Electromechanics. - Gamma spectroscopy. In the system it is analyzed waste of issuing gamma specifically, and this designed for materials of relative low density and it analyzes materials of cylindrical recipients.

  3. The comparison of two methods to obtain human oral keratinocytes in primary culture; Comparacao de dois metodos de obtencao celular para cultura primaria de queratinocitos bucais humanos

    Energy Technology Data Exchange (ETDEWEB)

    Klingbeil, Maria Fatima Guarizo

    2006-07-01

    The therapeutic procedures frequently used in oral treatments for the pathological diseases are surgical, resulting in failures of the mucosal continuity.The possibility to obtain transplantable oral epithelia from an in vitro cell culture opens new utilization perspectives not only to where it comes from, but also as a reconstructive material for other parts of the human body, such as: urethra, epithelia corneo-limbal, cornea, ocular surface. Many researchers still use controversial methods for obtaining cells. It was therefore evaluated and compared the efficiency in both methods: enzymatic and direct explant to obtain oral keratinocytes from human oral mucosa. Fragments of intra oral epithelial tissues from healthy human subjects, undergoing dental surgeries, were donated to the research project. The keratinocytes were cultivated over a feeder-layer from a previously irradiated 3T3 Swiss albino fibroblasts. In this study it was compared the time needed in the cell obtention, the best cell amount between both methods, the life-span, the cell capacity to form an in vitro epithelia and its morphologic structure. The results in the assessment of both methods have shown the possibility to obtain keratinocytes from a small oral fragment, but at the same time we may verify the advantages and peculiar restrictions for each one of both analyzed methods. (author)

  4. Solution for the nuclear reactor point-kinetics problem via decomposition method; Solucao via metodo da decomposicao do problema de cinetica puntual de um reator nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Rubem Mario Figueiro [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Faculdade de Engenharia. Dept. de Engenharia Quimica]. E-mail: rvargas@pucrs.br; Vilhena, Marco Tullio de [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Matematica]. E-mail: vilhena@mat.ufrgs.br; Cardona, Augusto Vieira [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Faculdade de Matematica]. E-mail: acardona@pucrs.br

    2005-07-01

    The decomposition method is a mathematical technique, usually, applied to solve nonlinear problems, but can be an effective procedure for analytical solution of linear problems presenting advantages when compared with others techniques. In this work, an analytical solution for the nuclear reactor point-kinetics equations is developed using the decomposition method. (author)

  5. Statistics of electron multiplication in a multiplier phototube; Iterative method; Estadistica de la multiplicacion de electrones en un fotomultiplicador: Metodos iterativos

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J. F.; Grau, A.

    1985-07-01

    In the present paper an iterative method is applied to study the variation of dynode response in the multiplier phototube. Three different situation are considered that correspond to the following ways of electronic incidence on the first dynode: incidence of exactly one electron, incidence of exactly r electrons and incidence of an average r electrons. The responses are given for a number of steps between 1 and 5, and for values of the multiplication factor of 2.1, 2.5, 3 and 5. We study also the variance, the skewness and the excess of jurtosis for different multiplication factors. (Author) 11 refs.

  6. Metodo y teoría en la evaluación de desayunos escolares Method and theory in school breakfast program evaluation

    Directory of Open Access Journals (Sweden)

    José Angel Vera Noriega

    2000-06-01

    Full Text Available Se llevó a cabo un estudio para evaluar el impacto de un programa de desayunos escolares en repertorios de discriminación, memoria y atención, comparando la zona urbana y rural. En la zona rural, fueron evaluados 300 niños elegidos al azar de los listados de preescolar que recibieron desayuno en los municipios en pobreza extrema y 150, que no lo recibieron. En la zona urbana, fueron evaluados 300 niños seleccionados aleatoriamente de los listados de las escuelas ubicadas en las colonias marginadas que recibieron desayuno y 150, que no recibieron desayuno. En una prueba sintética de atención y memoria, los resultados muestran que en la zona urbana no existen diferencias en las medidas atribuibles al programa de desayunos. En la zona rural, los niños mejoraron en sus ejecuciones y tiempos. Se encontraron algunas diferencias relacionadas con el impacto del desayuno sobre niños con diferente estado nutricional. Los niños rurales se beneficiaron más que los urbanos del programa.In order to compare and evaluate a school breakfast program impact and discrimination memory and attention repertories on urban and rural children. A study was done 300 rural children were randomly chosed to have breakfast and 150 didn´t have breakfast were evaluated and compared to 300 urban children who were randomly chose of extreme poverty marginal to have breakfast and 150 that didn´t have breakfast. A designed test to evaluate attention and memory shows that in urban children do not exist differences between measures of the behavior. Rural children improve their time and performance. It was found differences on breakfast impact based on nutrimental status. The rural children got more benefits than the urban children with the program.

  7. Analytical Comparison of Miniaturized Methods for Selected PAH Determination in Clean Waters; Comparacion Analitica de 4 Metodos Miniaturizados de Determinacion de PAHs mediante HPLC en Aguas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.; Fernandez, O.

    2012-04-11

    A study on the comparison and evaluation of 4 miniaturized extraction methods for the determination of selected PAHs in clear waters is presented. Four types of liquid-liquid extraction were used for chromatographic analysis by HPLC/ FD. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the scope of the methods developed at low and high levels of concentration. (Author) 13 refs.

  8. Covering localization, mapping and evaluation of ducts, using Pipeline Current Mapper Methods (PCM); Localizacao, mapeamento e avaliacao de revestimento de dutos, utilizando o metodo Pipeline Current Mapper (PCM)

    Energy Technology Data Exchange (ETDEWEB)

    Furquim, Antonio Jorge [ESTEIO Engenharia e Aerolevantamentos S.A., Curitiba, PR (Brazil)

    2005-07-01

    Esteio Engenharia e Aerolevantamentos S.A., together with the PETROBRAS - Petroleo Brasileiro S.A., comes accomplishing the Location, Geo positioning, Mapping and Inspection of the Coating in more than 5.000 km of pipes in several areas of the country. The works come being executed seeking the obtaining of the real position of Ducts (They-Built) and the conditions in that meets the coating of the same ones. The risings base on the method Pipeline Current Mapper (PCM), using the equipment of production of Radio detection to locate and to inspect the conditions of the coating. This work presents the results, analyses, precision, benefits and difficulties found during the execution of the surveying. (author)

  9. The Muhlbauer method for pipeline risk management in onshore environment; O metodo de Muhlbauer para gerenciamento de risco em linhas de dutos em ambiente 'onshore'

    Energy Technology Data Exchange (ETDEWEB)

    Schafer, Alexandro G.; Miguelis, Paula M.F. [UNIPAMPA, RS (Brazil)

    2008-07-01

    There are several methods for the risk assessment and risk management applied to pipelines, among them the Muhlbauer's Method. W. Kent Muhlbauer is an internationally recognized authority on pipeline risk management. He made a detailed identification about 300 distinct conditions that influence the risk assessment in pipelines and he proposed a score system that is known as method of Muhlbauer. The purpose of this model is to evaluate the public exposure to the risk and identify ways for management that risk in fact. The assessment is made by the attribution of quantitative values to the several items that influences in the pipeline risk. This paper approaches the Muhlbauer's basic model for risk assessment and management in pipelines. In the beginning, the basic model for risk assessment is presented, and methodology for pipelines in onshore environment is detailed. After, presents major items in risk assessment and this relative score. Finally, present the additional modules for Muhlbauer's method customizing. (author)

  10. Method for radon measurement in the subsoil in geothermal prospectus; Metodos de medicion de radon en el subsuelo en prospeccion geotermica

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar G, M

    1991-02-15

    The present formless describe the technique for radon measurement in the underground, being able to be used as an additional study in the geothermal prospecting. This methodology has been developed in the National Institute of Nuclear Research of Mexico using a film of cellulose nitrate to detect those emanated alpha particles, by the Rn (222). By means of the trace account in this films its settle down the present radon levels in the underground. The present method thinks about as an alternating one to overcome in it leaves the limitations found in the development of the methodology using a radon emanometer ETR-1, of the trade mark SCINTREX. The radon detected by plastics is also an integral method of measuring in a geothermal field that avoids the problems of variations of radon to pluvial precipitations and barometric variations. These variations affect the results strongly when it is used the punctual sampler as it is the ETR-1. (Author)

  11. Trace element determination study in human hair by neutron activation analysis; Estudo da determinacao de elementos traco em cabelos humanos pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Frazao, Selma Violato

    2008-07-01

    Human hair analysis studies have been subject of continuous interest due to the fact that they can be used as an important tool to evaluate trace element levels in the human body. These determinations have been carried out to use hair for environmental and occupational monitoring, to identify intoxication or poisoning by toxic metals, to assess nutritional status, to diagnose and to prevent diseases and in forensic sciences. Although hair analysis presents several advantages over other human tissue or fluid analyses, such as organ tissue, blood, urine and saliva, there are some controversies regarding the use of hair analysis data. These controversies arise from the fact that it is difficult to establish reliable reference values for trace elements in hair. The purpose of this study was to evaluate the factors that affect element concentrations in hair samples from a population considered healthy and residing in the Sao Paulo metropolitan area. The collected human head hair was cut in small pieces, washed, dried and analyzed by neutron activation analysis (NAA). Aliquots of hair samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor for 16 h under a thermal neutron flux of about 5x10{sup 12} n cm{sup -2} s{sup -1} for As, Br, Ca, Co, Cr, Cs, Cu, Fe, K, La, Na, Sb, Sc, Se and Zn determinations. The induced gamma activities of the standards and samples were measured using a gamma ray spectrometer coupled to an hiperpure Ge detector. For quality control of the results, IAEA- 85 Human Hair and INCT-TL-1 Tea Leaves certified reference materials (CRMs) were analyzed. Results obtained in these CRMs presented for most of elements, good agreement with the values of the certificates (relative errors less than 10%) and good precision (variation coefficients less than 13.6%). Results of replicate hair sample analysis showed good reproducibility indicating homogeneity of the prepared sample. Results obtained in the analyses of dyed and non-dyed hair showed that element adsorption or desorption occurs due to the dye. Analysis of hair samples collected from different regions of the head presented significant differences for the elements Fe, Sc, Se and Cr, indicating the importance of defining head regions for hair sample collection. Results of hair analysis from individuals residing in Sao Paulo metropolitan area showed individual differences for age, gender and natural hair color. Results obtained in this population also showed, that the mean element concentrations found are within the literature values. (author)

  12. Use of the event tree method for evaluate the safety of radioactive facilities; Utilizacion del metodo de arboles de eventos para evaluar la seguridad de instalaciones radiactivas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez S, A.; Cornejo D, N.; Callis F, E. [CPHR, Calle 20 No. 4113, e/41 y 47 Playa, CP 11300, La Habana (Cuba)]. e-mail: ale@cphr.edu.cu

    2006-07-01

    The work shows the validity of the use of Trees of Events like a quantitative method appropriate to carry out evaluations of radiological safety. Its were took like base the evaluations of safety of five Radiotherapy Departments, carried out in the mark of the process of authorization of these facilities. The risk values were obtained by means of the combination of the probabilities of occurrence of the events with its consequences. The use of the method allowed to suggest improvements to the existent safety systems, as well as to confirm that the current regulator requirements for this type of facilities to lead to practices with acceptable risk levels. (Author)

  13. Immunosensore amperometrico competitivo per la determinazione di p53 in urina: metodo di screening rapido e non invasivo per la diagnosi precoce del carcinoma della vescica

    OpenAIRE

    Bianchi, Maria Vittoria

    2017-01-01

    La proteina p53, è il soppressore tumorale più studiato e conosciuto ed è un fondamentale fattore trascrizionale, la cui azione viene modulata in risposta a diversi stimoli genetici e ambientali. Essa rappresenta un’importante difesa contro lo sviluppo del cancro e la sua progressione, agendo come un “guardiano del genoma”. Studi clinici hanno evidenziato che lo sviluppo del Carcinoma a cellule transizionali della vescica (BTCC) può determinare una significativa sovra espressione di p53 ne...

  14. Application of Monte Carlo method for dose calculation in thyroid follicle; Aplicacao de metodo Monte Carlo para calculos de dose em foliculos tiroideanos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Frank Sinatra Gomes da

    2008-02-15

    The Monte Carlo method is an important tool to simulate radioactive particles interaction with biologic medium. The principal advantage of the method when compared with deterministic methods is the ability to simulate a complex geometry. Several computational codes use the Monte Carlo method to simulate the particles transport and they have the capacity to simulate energy deposition in models of organs and/or tissues, as well models of cells of human body. Thus, the calculation of the absorbed dose to thyroid's follicles (compound of colloid and follicles' cells) have a fundamental importance to dosimetry, because these cells are radiosensitive due to ionizing radiation exposition, in particular, exposition due to radioisotopes of iodine, because a great amount of radioiodine may be released into the environment in case of a nuclear accidents. In this case, the goal of this work was use the code of particles transport MNCP4C to calculate absorbed doses in models of thyroid's follicles, for Auger electrons, internal conversion electrons and beta particles, by iodine-131 and short-lived iodines (131, 132, 133, 134 e 135), with diameters varying from 30 to 500 {mu}m. The results obtained from simulation with the MCNP4C code shown an average percentage of the 25% of total absorbed dose by colloid to iodine- 131 and 75% to short-lived iodine's. For follicular cells, this percentage was of 13% to iodine-131 and 87% to short-lived iodine's. The contributions from particles with low energies, like Auger and internal conversion electrons should not be neglected, to assessment the absorbed dose in cellular level. Agglomerative hierarchical clustering was used to compare doses obtained by codes MCNP4C, EPOTRAN, EGS4 and by deterministic methods. (author)

  15. Evaluation of the reconstruction method and effect of partial volume in brain scintiscanning; Avaliacao do metodo de reconstrucao e efeito do volume parcial em cintilografia cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Monica Araujo

    2016-10-01

    Alzheimer's disease is a neurodegenerative disorder, on which occurs a progressive and irreversible destruction of neurons. According to the World Health Organization (WHO) 35.6 million people are living with dementia, being recommended that governments prioritize early diagnosis techniques. Laboratory and psychological tests for cognitive assessment are conducted and further complemented by neurological imaging from nuclear medicine exams in order to establish an accurate diagnosis. The image quality evaluation and reconstruction process effects are important tools in clinical routine. In the present work, these quality parameters were studied, and the effects of partial volume (PVE) for lesions of different sizes and geometries that are attributed to the limited resolution of the equipment. In dementia diagnosis, this effect can be confused with intake losses due to cerebral cortex atrophy. The evaluation was conducted by two phantoms of different shapes as suggested by (a) American College of Radiology (ACR) and (b) National Electrical Manufacturers Association (NEMA) for Contrast, Contrast-to-Noise Ratio (CNR) and Recovery Coefficient (RC) calculation versus lesions shape and size. Technetium-99m radionuclide was used in a local brain scintigraphy protocol, for proportions lesion to background of 2:1, 4:1, 6:1, 8:1 and 10:1. Fourteen reconstruction methods were used for each concentration applying different filters and algorithms. Before the analysis of all image properties, the conclusion is that the predominant effect is the partial volume, leading to errors of measurement of more than 80%. Furthermore, it was demonstrate that the most effective method of reconstruction is FBP with Metz filter, providing better contrast and contrast to noise ratio results. In addition, this method shows the best Recovery Coefficients correction for each lesion. The ACR phantom showed the best results assigned to a more precise reconstruction of a cylinder, which does not occur with spherical lesions in the NEMA simulator. The obtained RC values can be applied to correct the lesions quantification for different sizes and intake relations, assisting medical staff in the quantification process and an accurate diagnosis. Each Nuclear Medicine Service should establish its own RC levels to improve quality of the service provided to the population. (author)

  16. Chemical analysis of cyanide in cyanidation process: review of methods; Analisis quimico de cianuro en el proceso de cianuracion: revision de los principales metodos

    Energy Technology Data Exchange (ETDEWEB)

    Nova-Alonso, F.; Elorza-Rodriguez, E.; Uribe-Salas, A.; Perez-Garibay, R.

    2007-07-01

    Cyanidation, the world wide method for precious metals recovery, the chemical analysis of cyanide, is a very important, but complex operation. Cyanide can be present forming different species, each of them with different stability, toxicity, analysis method and elimination technique. For cyanide analysis, there exists a wide selection of analytical methods but most of them present difficulties because of the interference of species present in the solution. This paper presents the different available methods for chemical analysis of cyanide: titration, specific electrode and distillation, giving special emphasis on the interferences problem, with the aim of helping in the interpretation of the results. (Author)

  17. Evaluation of visual impact of solar hermal systems on urban landscape; Metodo de evaluacion del impacto visual de las instalaciones de energia solar termica en el paisaje urbano

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, G.; Martinez, J.

    2004-07-01

    This article proposes a methodology and systematics for the valuation and evaluation of the visual impact produced by solar thermal systems on urban landscapes. On the one hand, from the characteristics of solar thermal systems capable of producing a visual impact and, on the second hand, from the analysis of the urban landscape (character and perception; classification in three subtypes), an interrelationship of the system and the urban landscape parameters is established by means of matrixes. The result shall be the visual impact of a solar thermal system on an urban landscape, which may range from a minimum (Nonexistent) to a maximum (Unacceptable), including other categories like Acceptable, Compatible, Compatible with Corrections, and Incompatible. (Author)

  18. Technique of reducing doses CR using non-linear diffusion method; Tecnica de reduccion de dosis en CR usando el metodo de Difusion no lineal

    Energy Technology Data Exchange (ETDEWEB)

    Vidal Gimeno, C.

    2012-07-01

    A technique to obtain good quality in the image, in order to show the viability of CR dose reduction is presented. especially in pediatric applications, while maintaining the integrity of the diagnosis.

  19. Implementation of the Bee Colony Optimization method for the design of fuel cells; Implementacion del metodo Bee Colony Optimization para el diseno de celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel E, J.; Ortiz S, J. J., E-mail: jaime.esquivel@fi.uaemex.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The present work shows the results obtained after applying the Bee Colony Optimization algorithm in the design of fuel cells for a BWR. The algorithm that is implemented, works following the behavior that have the bees when pollinating a flowers field. The bees carry out an exhaustive analysis in the cell, so they leave generating diverse configurations where different fuel bars are placed with different uranium enrichments to reach a value mean, with a specific number of gadolinium bars. The behavior of the generated cell is evaluated by means of the use of the commercial code CASMO-4, which shows the variables that allow fixing if the cell fulfills the requirements. Such variables are the local potential peak factor and the neutrons multiplication factor in an infinite medium. (Author)

  20. Determinação e padronização da vitamina E e seus isomeros : comparação entre o metodo de cromatografia liquida de alta eficiencia (CLAE) e o metodo espectrofotometrico por redução de ions cupricos

    OpenAIRE

    Andrea Scabora Boix Caro

    2002-01-01

    Resumo: A presente Tese visou estudar a determinação da vitamina E, estabelecendo uma comparação entre o método clássico modificado com um outro método de determinação, a cromatografia líquida de alta eficiência (CLAE).Para efeito de comparação foram utilizados cinco tipos de amostras diferentes: suplementos vitamínicos, óleos vegetais, DDOS, farinha de germe de trigo e fígados liofilizados de ratos. Os resultados encontrados nos métodos avaliados diferiram quanto ao tipo de isômero encontrad...

  1. Blind method of clustering for the evaluation of the dose received by personnel in two methods of administration of radiopharmaceuticals; Metodo ciego de clusterizacion para la evaluacion de la dosis recibida por el personal en dos metodos de administracion de radioformacos

    Energy Technology Data Exchange (ETDEWEB)

    VerdeVelasco, J. M.; Gonzalez Gonzalez, M.; Montes Fuentes, C.; Verde Velasco, J.; Gonzalez Blanco, F. J.; Ramos Pacho, J. A.

    2013-07-01

    The difficulty for the injection of drugs marked with radioactive isotopes while syringe is located within the lead protector does that in many cases staff do it chooses to use the syringe outside the lead protector, increasing therefore the dose of radiation received. In our service raises the possibility of using a different methodology, channeling a pathway through a catheter, which allows administer, in all cases, with the syringe within the lead guard. We will check if significant differences can be seen both in the dose absorbed by the staff as in the time it takes to perform the administration of the drug using the method proposed compared injection without guard. (Author)

  2. Deteccion de amastigotas en Leishmaniasis cutanea y mucocutanea por el metodo de inmunoperoxidasa, usando anticuerpo policlonal: sensibilidad y especificidad comparadas con metodos convencionales de diagnostico Detection of amastigotes in cuteneous and mucocutaneous leishmaniasis by the immunoperoxidase method, using polyclonal antibody sensibility and specifity compared with conventional diagnosis methods

    Directory of Open Access Journals (Sweden)

    Graciela Salinas

    1989-03-01

    Full Text Available Con el objeto de aumentar la sensibilidad del diagnóstico histopatológico de lesiones cutáneas y mucocutáneas causada por subespecies del complejo Leismania braziliensis y para lograr una mejor visualización de los parásitos en las lesiones, se evaluó el método de la inmunoperoxidas indirecta para localizar en forma rápida y específica los amastigotas en biopsia de tejido afectado. Los cortes de tejido se fijaron en formol y se incluyeron en parafina; después se evaluaron por inmunohistoquímica usando un antisuero policlonal producido en conejo, como reactivo primario, Se examinaron 265 biopsias de pacientes con lesiones sospechosas de leishmaniasis de la costa Pacífica y región suroriental colombiana. a 1983 (72.8% pacientes se les estableció el diagnóstico por métodos clínicos y/o poarasitológicos. Los resultados obtenidos por la inmunoperoxidasa en el grupo de pacientes a los cuales se les confirmó la leishmaniasis se compararn con la histopatología convencional, el examen directo de frotis y el aislamiento del parásito por cultivo del aspirado de la lesión. La localización inmunoenzimática de las amastigotas fue más efectivas (61.3% que la histopatología com hematoxilina y eosina (34.6%, y que el frotis (43,9%. En cambio, el cultivo de aspirado fue más sensible (89.8%. La eficiencia del método de inmunoperoxidasa fue mayor en las lesiones recientes (72.5% positivos en los casos con menos de tres meses de evolución que en las lesiones más antiguas (55.6, 37.5 y 21.1% para 3-5.9, 6-11 meses y mayores o iguales a 12 mese, respectivamente. La combinación de frotis e inmunoperoxidasa incrementó el porcentaje de caso diagnosticados a 72.0%, lo que indica la importancia de combinar métodos para obtener una mayor eficiencia de diagnóstico. La especificidad fue de 100% en controles sanos y 92.9% en pacientes con lesiones causadas por agentes etiológicos distintos a leishmania.The indirect immunoperoxidase method was evaluated in 265 biopsies with the purpose of increasing the sensitivity of the diagnostic histopathology of tegumentary lesions caused by subspecies of the Leishmania braziliensis complex. A diagnosis of leishmaniasis was established by parasitological methods (181 or clinical criteria (12 in 193 patients (72.8%. In the latter group of confirmed cases standard histochemstry and immunoperoxidase were compared with direct examination of tissue scraping and culture of lesion aspirates. The detection and localization of amastigotes was more efficient using the immunoperoxidase method (61.3% than conventional histopathology with hematoxilin and eosin (34.6% or direct examination of tissue scraping (43.9%. Howerver, culture of lesion aspirates was the most sensitive procedure (89.8%. The efficiency of the immunoperoxidase method was greater in recent lesions, being positive in 75% of cases with less than 3 months evolution, while 55.6%, 37.5% and 21.1% of cases with lesion evolution of 3-5.9, 6-11, and 12 months or greater, respectively, were positive. The combined use of the direct examination of lesion scraping and immunoperoxidase applied to histological sections of the biopsy from the lesion border allowed an etiologic diagnosis of 72% of confirmed cases. Cross-reactivity was observed with Paracoccidioides braziliensis but not with Mycobacterium leprae, Sporothrix schenckii, or Histoplasma capsulatum.

  3. Responsabilità giuridica e scienze sperimentali sul vivente

    Directory of Open Access Journals (Sweden)

    Patrick Nerhot

    2017-12-01

    Full Text Available SOMMARIO: 1. Il "vivente": inoperosità dei concetti della filosofia profana dei Lumi - 2. La ricerca-costruzione di una infinita-fine - 3. Le scienze "sperimentali" come la non distinzione tra "causa" e "effetto" - 4. La nuova questione di metodo posta al "vivente" - 5. La sfida di una etica come adeguazione tra etica e metodo.

  4. A spanish mineral of zirconium and hafnium. Separation of the two elements by liquid-liquid extraction, using tributyl phosphate as chelating agent; Beneficio de un mineral espanol de circonio-hafnio. Separacion de ambos elementos por extraccion liquido-liquido, empleando fosfato de tributilo como agente de quelacion

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Sanchez, F.; Cruz Castillo, F. de la; Fernandez Cellini, R.

    1962-07-01

    The zirconium and Hafnium oxides are obtained from a Spanish mineral of zircon with an average contest of 55% in ZrO{sub 2}-HfO{sub 2}. An alkaline fusion to open the mineral, followed by a purification by crystallization as (Zr O-Hf O)Cl{sub 2} H{sub 2}O or as (Zr-Hf) (SO{sub 4}){sub 2}. 4H{sub 2}O, is used. A discussion of the best experimental conditions for opening the mineral and of the purification method is made. (Author) 45 refs.

  5. Construction of the Tangent to a Cycloid Proposed by Wallis and Fermat

    Directory of Open Access Journals (Sweden)

    Loredana Biacino

    2017-02-01

    Full Text Available In this paper some methods used in the XVII century for the construction of the tangents to a cycloid in a point are exposed: the kinematical method employed by Roberval, the classical geometrical  method used by Wallis and the Fermat’s construction as a consequence of his tangents method. Le Costruzioni della Tangente alla Cicloide Proposte da Wallis e da Fermat In questo lavoro sono esposti vari metodi in uso nel ‘600 per la costruzione della tangente ad una cicloide in un suo punto: il metodo cinematico impiegato da Roberval, il metodo geometrico classico usato dal Wallis e la costruzione di Fermat come conseguenza del suo metodo delle tangenti. Parole Chiave: Cicloide, Tangente ad una curva, Metodo cinematico delle tangenti, Metodo delle tangenti di Fermat.

  6. Hydraulic Brake Fluid,

    Science.gov (United States)

    A hydraulic brake fluid consisting of diethylene glycol , monoethyl ether of diethylene glycol , and castor oil has been improved as described in the patent by adding the fluid tributyl ether of orthophosphoric acid.

  7. Formulation and Characterization of Biodegradable Medicated ...

    African Journals Online (AJOL)

    PEG)-600, tributyl citrate, PEG-200, PEG-300, PEG-400, PEG-4000, triethyl citrate and castor oil. The gum formulations were characterized for the following parameters: texture profile analysis (TPA), biodegradation, in vitro drug release using a ...

  8. Distribution coefficients of UO2(NO3)2 . 2TBP in supercritical fluid CO2 as determined by on-line time resolved laser induced fluorescence

    International Nuclear Information System (INIS)

    Addleman, R.S.; Wai, C.M.

    2001-01-01

    Time resolved laser induced fluorescence has been used for on-line analysis of uranium extraction from acidic solutions with tributyl phosphate modified supercritical carbo dioxide. The in-situ measurement allows direct characterization of the supercritical fluid extraction. The extractions were found to be first order with respect to uranium and the distribution coefficient was observed to increase with temperature and tributyl phosphate concentration. (orig.)

  9. Influence of nitric acid on the kinetic of complexation of uranyl nitrate extracted by TBP

    International Nuclear Information System (INIS)

    Pushlenkov, M.F.; Zimenkov, V.V.

    1982-02-01

    The effect of nitric acid on the solvatation rate of uranyl nitrate with tributyl phosphate is studied. In the process of mass transfer, it is shown that nitric acid enables the extraction of uranyl nitrate, therefore its concentration in the organic phase exceeds that in equilibrium solution. Subsequently uranyl nitrate ''displaces'' nitric acid. The presence of the acid in aqueous and organic phases affects in a complicated manner the rate of solvatation of uranyl nitrate with tributyl phosphate [fr

  10. Contents evaluation of some essential and toxic elements in children and elders diet by neutron activation analysis; Avaliacao do conteudo de alguns elementos essenciais e toxicos em dietas de criancas e idosos pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Maihara, Vera Akiko

    1996-12-31

    Essential and toxic elements in the 19 diet samples from pre-school children and 23 diet samples from elderly people, have been determined by neutron activation analysis. The diet samples were collected by duplicate portion method. A radiochemical separation procedure was developed and applied for determining Cd, Co, Cr, Fe, Mo, Sb, U, Th, W and Zn, based on retention of these elements in a Chelex-100 resin. In the case of As and Se, the procedure was based on retention in inorganic exchanger TDO (tin dioxide). The contents of proteins, lipids and carbohydrates were also analysed. The results have been presented and discussed 135 refs., 29 figs., 36 tabs.

  11. Method of conjugate gamma camera image to determine tumor uptake in other thyroid treatments with I-131; Metodo de la imagen conjugada en Gammacamara para determinar la captacion en resto tumoral tiroideo en tratamientos con I-131

    Energy Technology Data Exchange (ETDEWEB)

    Barquero, R.; Sainz, A.; Tortosa, R.; Mari, A.

    2011-07-01

    The efficacy of ablation of thyroid remnants with 1-131 in the treatment of CDT depends on the activity captured in these remains, the optimal method for quantifying this activity is based on the gamma camera imaging with in the course of treatment. However, due to saturation of the image with high activities and time-cost optimization of machine, not usually get those images, except in a post-treatment scan. In our service MN tracking each patient is between 6 and 9 after administration. A method of quantification of the activity captured in other thyroid screening using this image.

  12. Use of the 3DVH Software as a complementary method of IMRT pretreatment evaluation; Utilizacao do Software 3DVH como metodo complementar de avaliacao de pre-tratamento de IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Lyra, Jesse G.P.; Bruning, Fabio F.; Funchal, Melissa; Toledo, Hugo V.; Bornatto, Pricila; Fernandes, Tatiane C.O., E-mail: jesse_lyra@hotmail.com [Hospital Erasto Gaertner / Liga Paranaense de Combate ao Cancer (LPCC), Departamento de Radioterapia, Curitiba, PR (Brazil)

    2013-04-15

    The aim of this study is to compare the method of treatment planning evaluation for IMRT using the gamma index to the method of the 3DVH Software. The 3DVH Software was used with the MapCheck2 detector 2D array under a 6MV x-ray beam of linear accelerator equipped with 120 leafs MLC. Nine treatment plans of prostate patients chose randomly and fully anonimatize were performed in the Eclipse planning system, using the AAA calculation algorithm in IMRT sliding window technique. These plans were approved and treated according to the gamma analysis criteria of the institution. The comparisons were made in absolute dose and normalized at maximum dose for each field and then with the 3DVH Software the Dmax, Dmean, D15%, D25%, D35% and D50% parameters for the bladder and rectum, Dmean for the bulb, Dmax for the femur and D95% for the PTV were evaluated. In the planar analysis by field, the plans studied had a minimum of 97.5% approval. The PTV-related differences have relative variation from 1.3 to 2.2%, that is, greater coverage than expected for this structure. For the organs at risk, the relative differences observed were between -5.3 to 25.8%, which could result in a non-approved plan if these variations are close to the clinical tolerances of the OAR. The results show that even a plan compatible with greater than or equal to 95% of the points, the gamma analysis does not give enough information if this plan can or cannot be approved for treatment and that there is a need for more detailed verification of the plan which considers not only the planar evaluation, but also the evaluation of the DVH measured, and the 3DVH Software proved be adequate for this analysis. (author)

  13. Performance analysis of covered conductors and aerial bundled cables by the finite elements method; Analise de desempenho de cabos cobertos e pre-reunidos pelo metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joao Jose dos Santos

    1996-12-31

    The covered conductors and the aerial bundled cables (abc) for overhead distribution systems 15 kV systems, has been a good solution for the main brazilian electrical utilities when applied in areas with to limited space on poles and to satisfy the performance claimed in tree areas or narrow streets, focusing people safety and electrical service continuity. Otherwise, in this work it is presented that these cables show failures that can be related to the solid isolants used. It is showed the laboratory tests results to characterize its thermal and electric behaviour and an application of the Finite Element Method through the software Flux 2 d was done. The results obtained showed the requirements to be demanded through the specification and proposals elements to change the standard. (author) 57 refs., 20 figs., 73 tabs.

  14. Application of the Detrended Fluctuation Analysis method to the trajectory of the centre of pressure of the human body; Aplicacion del metodo Detrended Fluctuation Analysis a la trayectoria del centro de presion del cuerpo humano

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez, M. T.; Anguiano, M.; Arias de Saavedra, F.; Lallena, A. M.; Carpena, P.

    2009-07-01

    The Detrended Fluctuation Analysis is a signal analyzing method which permits to study the correlation properties of the signal analyzed. This algorithm admits different variants which can be used to eliminate trends of different order existing in the signal. In this work we show the results obtained when two of these different variants, the so-called DFA-1 and DFA-2, are applied to the time series of the position and velocity of the centre of pressure of the human body in static conditions. The results show that the correlation exponents {alpha} obtained for each of the four types of analysis performed, depend on the scale studied. For the scales corresponding to large time intervals (above 35 s) the {alpha} values found in the four analyses coincide. (Author) 24 refs.

  15. Practical methods for the functioning evaluation of the whole body counter system Accuscan II of the ININ; Metodos practicos para la evaluacion del comportamiento del sistema contador de cuerpo entero Accuscan II del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Alfaro L, M. M.; Ramirez J, F. J.; Mondragon C, L., E-mail: mercedes.alfaro@inin.gob.mx [ININ, Carretera Mexico-Touca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    The whole body counter system Accuscan II of the Instituto Nacional de Investigaciones Nucleares (ININ), was designed and built to quantify and to measure radionuclides fission product as well as gamma emitters, with a maximum sensibility of less than 10 n Ci for cobalt 60 at one time of counting of 5 minutes. The system has two detectors of Ge(Hp) with Beryllium window to a relative efficiency of 25% in a counting configuration of vertical scanning, this configuration gives a plane response of constant efficiency. In this work some practical methods developed in the Internal Dosimetry Laboratory to carry out the functioning evaluation of the whole body counter system Accuscan II of the ININ are described. With the obtained results of this evaluation we can decide fine adjustments will be necessary for the optimization of the equipment operation. The evaluation of this equipment was especially necessary, due to its 21 years-old antiquity and for the gradual changes that has in its functioning. The equipment is intrinsically a gamma spectrometry system and some described experiences could be applied too in other gamma spectrometry systems. (Author)

  16. Dynamical study of the Darrieus-type turbine runners by using finite element method; Estudo da dinamica de turbinas hidraulicas mare-motrizes do tipo Darrieus atraves do metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Sena, Manoel Jose dos Santos; Mesquita, Andre Luiz Amarante [Para Univ., Belem, PA (Brazil). Dept. de Engenharia Mecanica. Grupo de Turbomaquinas]. E-mail: gtdem@ufpa.br

    2000-07-01

    The purpose of this work is describe the implementation of a finite element model for dynamic response analysis of Darrieus-type turbine runners. A fluid-structure coupling is be used to put in evidence some aspects of the rotor-water interaction. The rotating system fixed to the rotor will be used when writing the equations governing the system. A procedure using the ANSYS Parametric Design Language is discussed and some results obtained for the free-free configuration are shown. (author)

  17. Uncertainty Evaluation and Influence of Gran Size to Determine PAHs in a Contaminated Soil; Influencia del Tamano de Particula de un Suelo Contaminado en las Incertidumbres Asociadas al Metodo de Determinacion de PAHs

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Escolano Segoviano, O.; Garcia Frutos, F. J.

    2007-07-20

    An evaluation of uncertainty associated to PAH determination in a contaminated soil is presented. The work was focused to measure the influence of grain size on concentration deviations and give a measure of result confidence of PAHs in the gasworks contaminated soil. This study was performed in the frame of the project 'Assessment of natural remediation technologies for PAHs in contaminated soils'(Spanish Plan Nacional I+D+i, CTM 2004-05832-CO2-01). This paper is presented as follows: A brief introduction which describes the main uncertainty contributions associated to chromatographic analysis. Afterwards, a statistic calculation was performed to measure each uncertainty component. Finally, a global uncertainty was calculated and the influence of grain size and distribution of compounds according to volatility was evaluated. (Author) 10 refs.

  18. A Simple Analytical Method Using HPLC with Fluorescence Detection to Determine Selected Polycyclic Aromatic Compounds in Filter Samples; Metodo Analitico Sencillo para la Determinacion de Compuestos Aromaticos Policiclicos en Muestras de Filtros mediante HPLC con Detector de Fluorescencia

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R. M.

    2014-06-01

    A study on the comparison and evaluation of a miniaturized extraction method for the determination of selected PACs in sample filters is presented. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the intermediate precision. (Author)

  19. The ion exchange and its connection the industry II.- Calculation methods for installations; El cambio de ion y su relacion con la industria II.- Metodos de calculo de instalaciones

    Energy Technology Data Exchange (ETDEWEB)

    Uriarte Hueda, A.; Lopez Perez, B.; Gutierrez Jodra, L.

    1960-07-01

    An exposure is made of calculation methods for ion exchange installations based on kinetic considerations and similarity with other unitary operations. Factors to be experimentally obtained as well as difficulties which may occur in its determination are also given. Calculation procedures most commonly used in industry are enclosed and explained with numerical resolution of a problem of water demineralization. (Author) 22 refs.

  20. Dancoff factors with partial neutrons absorption in cluster geometry by the direct method; Calculo dos fatores de Dancoff com absorcao parcial de neutrons em geometria cluster pelo metodo direto

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Leticia Jenisch

    2007-07-01

    Accurate analysis of resonance absorption in heterogeneous systems is essential in problems like criticality, breeding ratios and fuel depletion calculations. In compact arrays of fuel rods, resonance absorption is strongly affected by the Dancoff factor, defined in mis study as the probability that a neutron emitted from the surface of a fuel element, enters another fuel element without any collusion in the moderator or cladding. In fact, in the most practical cases of irregular cells, it is observed that inaccuracies in computing both Grey and Black Dancoff factors, i.e. for partially and perfectly absorbing fuel rods, can lead to considerable errors in the calculated values of such integral quantities. For this reason, much effort has been made in the past decades to further improve the models for calculating Dancoff factors, a task that has been accomplished in connection with the development of faster computers. In the WIMS code, Black Dancoff factors based on the above mentioned collusion probability definition are computed in cluster geometry, for each one of the symmetrically distinct fuel pin positions in the cell. Sets of equally-spaced parallel lines are drawn in subroutine PIJ, at a number of discrete equally-incremented azimuthal angles, covering the whole system and forming a mesh over which the in-plane integrations of the Bickley functions are carried out by simple trapezoidal rule, leading to the first-flight collusion matrices. Although fast, the method in PIJ is inefficient, since the constructed mesh does not depended on the system details, so that regions of small relative volumes are crossed out by relatively few lines, which affects the convergence of the calculated probabilities. A new routine (PIJM) was then created to incorporate a more efficient integration scheme considering each system region individually, minimizing convergence problems and reducing the number of neutron track lines required in the in-plane integrations for any given accuracy. In this routine, the radial integrations are performed by Gauss' formula whereas the angular ones are obtained by extended trapezoidal rule. In the present work, PIJM is extended to compute Grey Dancoff factors by the collision probability definition, in two-dimensional cylindrical cells in cluster geometry. The vi effectiveness of the method is accessed by comparing Grey Dancoff factors as calculated by PIJM, with those available in the literature by the Monte Carlo method, for the irregular geometries of the Canadian CANDU 37 assembly. Dancoff factors at five symmetrically distinct fuel pin positions are found in very good agreement with the literature results. (author)

  1. Windmills: selection method and results obtained by the Renewable Energy Center of UNESP - Guaratingueta Campus, Sao Paulo state, Brazil; Cata-vento: metodo de selecao e resultados obtidos pelo Centro de Energias Renovaveis da UNESP - Campus Guaratingueta

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Luis Fernando Silva; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis], e-mail: teofilo@feg.unesp.br, e-mail: lfernandosm@uol.com.br

    2004-07-01

    Windmills are always a good option to promote irrigate in areas with adequate potential wind. Its correct selection can guarantee the enough water supply with minimum cost. Since April 2004 the Renewable Energy Center of UNESP - Campus Guaratingueta' has tested a commercial windmill with 18 blades rotor and 3,4 diameter meters, that in a area with approximately 3 m/s average wind speed, has been obtained a average daily 1500 water liters. This volume is enough to supply a small country state, however, it could be get with a smaller capacity machine, if this worked properly. (author)

  2. Study of the navigation methods applicable to monitoring in sites with high level of radiation; Estudio de los metodos de navegacion aplicables al monitoreo en sitios con alto nivel de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Segovia de los Rios, J.A.; Rivero G, T. [ININ, Km. 36.5 Carretera Mexico-Toluca, 52045 Salazar, Estado de Mexico (Mexico)]. E-mail: asegovia@nuclear.inin.mx; Garduno G, M.; Zapata, R. [ITT, Av. Tecnologico s/n, Metepec, Estado de Mexico (Mexico)

    2004-07-01

    In places in which high radiation levels exist is desirable to have a system that allows the realization of mensurations without the necessity of the exhibition of human resources. It is in fact in these types of situations where a robot system, or automated, in a sense but wide, it is directly applicable. So that a monitoring system, based on a mobile robot, for example, be autonomous, it is necessary to develop and to implement functional and efficient sailing algorithms that allow its use with the minimum of human intervention. Several methods exist to achieve this objective, some of them already proven and others in roads of experimentation. The present work presents some in the sailing ways but used, and specifically, the one that intends for a system of detection of flights in a place with high temperatures and high radiation levels. (Author)

  3. Avaliação dos metodos de controle nas cooperativas de produtores rurais : das regiões do planalto médio, alto uruguai, missões e campos de cima da serra

    OpenAIRE

    Pedro Carlos Schenini

    1980-01-01

    O presente trabalho tem como propósito principal mostrar e analisar o uso da controladoria financeira em empresas cooperativas. A pesquisa foi realizada nas organizações que comercializam trigo e soja nas regiões do Planalto Médio, Alto Uruguai, Missões e Campos de Cima da Serra no Rio Grande do Sul. As empresas submetidas foram 68 filiadas ã Federação das Cooperativas de trigo e soja-FECOTRIGO, das quais selecionou-se uma amostra homogênea de 40 cooperativas para constituir o grupo experimen...

  4. Method for determining the wedge angle from the daily measurements made with the measurement enabled devices DC6; Metodo para la determinacion del angulo de cuna a partir de las medidas diarias realizadas con el dispositio de medida QC6

    Energy Technology Data Exchange (ETDEWEB)

    Marques Fraguela, E.; Suero Rodrigo, M. A.

    2011-07-01

    The aim of this paper is to present a method for determining the angle of the wedges virtual electron linear accelerator (ALE) Siemens Primus, from the daily measurements made with the measurement system PTW-QC6Plus and found to be sufficiently sensitive to determine variations of {+-} 1 of this parameter. In addition, we study the behavior statistically CUFLE angle over a year.

  5. Development of methods of labeling pentavalent DMSA with {sup 99m}Tc and {sup 188}Re; Desenvolvimento de metodos para marcacao de DMSA pentavalente com {sup 99m}Tc e {sup 188}Re

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, Tania de Paula, email: jtoniolo@ipen.br

    2009-07-01

    Technetium-99 m is the most useful radionuclide in diagnostic imaging procedures in Nuclear Medicine, more than 80 percent of radiopharmaceuticals are {sup 99m}Tc-labeled compounds. {sup 99m}Tc-DMSA(V) has been used for imaging of soft tissue, head and neck tumors. It shows a particularly high specificity for medullary thyroid carcinoma and bone metastases in a variety of cancers. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99m}Tc-DMSA(V), so this agent could be used for targeted radiotherapy of these tumors. The aim of this work is the development of methods of labeling DMSA(V) with {sup 99m}Tc and {sup 188}Re. {sup 99m}Tc-DMSA(V) can be prepared by two methods. One of them is the indirect one, through the use of a commercial kit of DMSA (III), by adjusting the pH from 2.5 to {approx} 8.5 with NaHCO{sub 3}. This method was evaluated and optimized presenting high labeling yields. The other method is the direct one, through the preparation of a lyophilised kit ready for labeling with {sup 99m}Tc, being the method of interest of this work, due to the easy of its clinical use. The most adequate formulation of the kit was: 1.71 mg of DMSA, 0.53 mg of SnCl{sub 2}.2H{sub 2}O and 0.83 mg of ascorbic acid (pH 9). Labeling yields higher than 95% were achieved labeling this kit with 1 to 2 m L of {sup 99m}Tc with activities up to 4736 MBq (128 mCi). The kit was stable up to 6 months and biodistribution studies confirmed the quality of the DMSA (V) labeled with {sup 99m}Tc using this kit. The reduction potential of Re is lower than the one for Tc, so the labeling conditions of {sup 188}Re-DMSA(V) are different from the ones used for {sup 99m}Tc- DMSA(V). {sup 188}Re-DMSA(V) is prepared in acid solution, that makes it possible to use the DMSA (III) commercial kit developed for labeling with {sup 99m}Tc, prepared in pH 2.5, for labeling with {sup 188}Re. Labeling yields higher than 95% were achieved with this methodology, with a rection time of 30 minutes at 100 deg C using no more than 1 m L of {sup 188}ReO{sub 4}{sup -}. Another method of preparing {sup 188}Re-DMSA(V) was also evaluated, using a liquid kit containing 2.5 mg of DMSA, 1.00 mg of SnCl{sub 2}.2H{sub 2}O and 30 mg of sodium oxalate at pH 5. This kit was labeled with 1 m L of {sup 188}ReO{sub 4}{sup -}, with 15 minutes of reaction at room temperature resulting in a labeling yield of about 91%. (author)

  6. Conjugate view gamma camera method for measuring activity in 131{sup I} treatments; Metodo de la imagen conjugada para la cuantificacion de la actividad en tratamientos de 131{sup I}

    Energy Technology Data Exchange (ETDEWEB)

    Barquero Sanz, R.; Placios, A. M.; Perez, D. M.; Tortosa Oliver, R.; Michel, R.

    2012-07-01

    A quantification method is developed to determine 131{sup I} activity and its associated uncertainty using regions of interest from gamma camera images. Inside a neck phantom, a known activity source is introduced to simulate thyroid remainders in thyroid differentiated cancer. The three parameters that define the accuracy of the method are: net count rates in ROI, the air calibration factor of the gamma camera and the attenuation correction factor. In order to obtain net count rates, four methods for background subtraction are tested. The best procedure to follow is based in two energy windows acquisitions, which gives an activity result of 47 {+-} 5 {mu}Ci Bq, in good agreement with the real activity value for the source, 46 {+-} 5 {mu}Ci. (Author) 12 refs.

  7. Analysis of uncertainties in a individualized method of estimation activity of {sup 1}31I for hyperthyroid patient; Analisis de incertidumbres en un metodo individualizado de estimacion de actividad de {sup 1}31I para el paciente hipertiroideo

    Energy Technology Data Exchange (ETDEWEB)

    Orellana Salas, A.; Melgar Perez, J.; Arrocha Acevedo, J. F.

    2013-07-01

    The determination of the activity to prescribe the hyperthyroid patients presented difficult consideration uncertainties. The uncertainties associated with the experimental design can exceed 20%, so it should be valued to customize activity therapy of {sup 1}31 I. (Author)

  8. Study radiolabeling of urea-based PSMA inhibitor with 68-Galliu: Comparative evaluation of automated and not automated methods; Estudo de radiomarcacao com Galio-68 do inibidor de PSMA baseado em ureia: avaliacao comparativa de metodo automatizado e nao automatizado

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Lais Fernanda

    2016-07-01

    The methods for clinical diagnosis of prostate cancer include rectal examination and the dosage of the prostatic specific antigen (PSA). However, the PSA level is elevated in about 20 to 30% of cases related to benign pathologies, resulting in false positives and leading patients to unnecessary biopsies. The prostate specific membrane antigen (PSMA), in contrast, is over expressed in prostate cancer and founded at low levels in healthy organs. As a result, it stimulated the development of small molecule inhibitors of PSMA, which carry imaging agents to the tumor and are not affected by their microvasculature. Recent studies suggest that the HBED-CC chelator intrinsically contributes to the binding of the PSMA inhibitor peptide based on urea (Glu-urea-Lys) to the pharmacophore group. This work describes the optimization of radiolabeling conditions of PSMA-HBED-CC with {sup 68}Ga, using automated system (synthesis module) and no automated method, seeking to establish an appropriate condition to prepare this new radiopharmaceutical, with emphasis on the labeling yield and radiochemical purity of the product. It also aimed to evaluate the stability of the radiolabeled peptide in transport conditions and study the biological distribution of the radiopharmaceutical in healthy mice. The study of radiolabeling parameters enabled to define a non-automated method which resulted in high radiochemical purity (> 95 %) without the need for purification of the labeled peptide. The automated method has been adapted, using a module of synthesis and software already available at IPEN, and also resulted in high synthetic yield (≥ 90%) specially when compared with those described in the literature, with the associated benefit of greater control of the production process in compliance with Good Manufacturing Practices. The study of radiolabeling parameters afforded the PSMA-HBED-CC-{sup 68}Ga with higher specific activity than observed in published clinical studies (≥ 140,0 GBq/μmol), with a sufficiently long stability, which will enable transport to clinics for use in diagnostic imaging. Biodistribution and pharmacokinetic profiles of the radiolabeled peptide were consistent with those founded in the literature. We concluded that PSMA-HBED-CC-{sup 68}Ga, important diagnostic tool for prostate cancer imaging with PET, can be produced by either automated or not automated method with high radiochemical purity, high synthetic yield and stability of the radiopharmaceutical. (author)

  9. Synthesis by the Pechini method and reaction combustion for the preparation of TiO{sub 2}: a comparative analysis; Sintese pelo metodo Pechini e reacao de combustao para preparacao de TiO{sub 2}: uma analise comparativa

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, E.P.; Ribeiro, P.C.; Freitas, N.L.; Lira, H.L.; Costa, A.C.F.M. da [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    The aim of this work is to prepare TiO{sub 2} powder by Pechini and combustion reaction methods. A comparative analysis between the structural and morphological results obtained by the two methods was investigated. The powders were characterized by X-ray diffractions (XRD), infrared analysis, nitrogen adsorption (BET) and particle size distribution. The results from XRD show that the powders prepared by Pechini method and by combustion reaction using aniline as fuel, present anatase as major phase and traces of rutile phase. The values of crystallite size and surface area from BET were: 30 e 44 nm; 6.2 e 4.4 m{sup 2}/g, for the powders prepared by Pechini and combustion reaction, respectively. The values of particle size were: 21.9 e 5.3 {mu}m, for the powders prepared by Pechini and combustion reaction, respectively. The Pechini method was more suitable to obtain powders with irregular agglomerates, in the block shape with particles bonded softly and small crystallite size. (author)

  10. Correlation between macro texture measures carried out by the volumetric method and by different laser texture meter; Correlacion de medidas de macrotextura tomadas con el metodo volumetrico y con diferentes texturometros lasar

    Energy Technology Data Exchange (ETDEWEB)

    Parra Ruiz, L.; Yanguas Gonzalez, S. J.

    2013-06-01

    The reference value for the measurement of surface macro texture in the Spanish Main Road Network is the MTD or Mean Texture Depth (PMT, Profundidad Media de Textura), obtained by means of the volumetric methods, in accordance with the standard UNE EN 13036-1:12010. The fact that it is a spot measurement that requires road closures makes it an expensive procedure as well as slow and dangerous. In addition to this, the test results are relatively sensitive to the operator, being the procedure not too suitable for systematic surveys. These are some of the reasons that have contributed to the development of texture meter laser devices that can be assembled on board of vehicles, circulating without interfering with the normal traffic flow and providing a parameter named the MPD (Mean Depth Profile). According to the standard UNE-EN ISO 13473-1:2006, it is possible to estimate the texture obtained by volumetric methods, with the parameter ETD (Estimated Texture Depth) through the equation: ETD=0,8 x MPD+0.2 In 2008 CEDEX conducted a study that correlated macro texture measures obtained by means of the volumetric method with such carried out by different laser texture meters. The equations yield a better relation between MPD and MTD were dependent on the measurement device used and were not linear equations type, as is it indicated in the standard, but exponential type equations. (Author) 6 refs.

  11. Optical and Scanning electron Microscopy as advanced analysis methods to determine the condition of synthetic geo membranes; Las microscopias optica de reflexion y electronica de barrido como metodos avanzados de analisis para conocer el estado de las geomembranes

    Energy Technology Data Exchange (ETDEWEB)

    Soriano Carrillo, J.; Blanco Fernandez, M.; Garcia Calleja, M. A.; Leiro Lopez, A.; Mateo Sanz, B.; Aguilar Gonzalez, E.; Rubin de Celix, M.

    2014-02-01

    Microscopic techniques have been widely used for years in the study of inorganic materials however their use in organic materials and specifically, in synthetic geo membranes, is very limited. In this study, this innovative technology has been used with the different geo synthetic polymeric barriers with which this research team is experienced: plasticized polyvinyl chloride, polyethylenes, rubbers such as ethenyltriphenyl-diene monomer terpolymer and butyl, polyolefins, ethylene-vinyl acetate copolymer, chlorosulfonated polyethylene and polypropylene. the influence of the extraction area and the time since their application is tested. (Author)

  12. PET/MRI: a novel hybrid imaging technique: major clinical indications and preliminary experience in Brazil; PET/RM: um novo metodo de imagem hibrida: principais indicacoes clinicas e experiencia preliminar no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Vitor, Taise; Martins, Karine Minaif; Ionescu, Tudor Mihai and others, E-mail: taisevitor@gmail.com [Hospital Israelita Albert Einstein, Sao Paulo, SP (Brazil)

    2017-04-01

    In recent years, medical imaging with hybrid techniques has widely accepted and employed in clinical routine. PET/MRI offers significant advantages, including excellent contrast and resolution and reduced ionizing radiation, as compared to well-established PET/ CT. Therefore, PET/MRI is a promising modality for oncologic imaging of some regions, such as brain, head and neck, liver and pelvis. This article set out to analyze clinical conditions that could benefit from PET/MRI imaging based on our caseload. The potential of PET/MRI to become the imaging modality of choice for assessment of neurologic and oncologic conditions associated with soft tissues is highlighted. Clinical aspects of PET/MRI and its application to clinical cases are illustrated with examples extracted from the authors' preliminary experience. (author)

  13. Dispersion of organoclays in polypropylene nanocomposites by ultrasound-assisted solution method; Estudo da dispersao de argilas organofilicas em nanocompositos de prolipropileno obtidos pelo metodo em solucao com auxilio de ultrassom

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, Eveline; Santos, Kelly Silva dos; Liberman, Susana Alcira; Mauler, Raquel Santos, E-mail: eve_bischoff@yahoo.com.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica

    2013-07-01

    Polypropylene nanocomposites PP/OMMT were prepared using two modified organic clays (C-15A and I-44P) and (PP-g-MA) as compatibilizer in the solution method using an ultrasound bath. The objective of this study was to understand the morphology of the nanocomposites and degree of clay dispersion in the polypropylene matrix, which are then correlated with the final properties. The morphology of nanocomposites was evaluated by X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The dynamic mechanical properties and thermal properties were measured by Dynamic Mechanical Analysis (DMA) and Differential Scanning Calorimetry (DSC). Statistical analyses of the transmission images were made in order to obtain the aspect ratio (length/thickness) of the clay particles. (author)

  14. Study of the precision and trueness of the Brazilian method for ethanol and gasoline determination; Estudo da precisao e exatidao do metodo brasileiro para determinacao de etanol e gasolina

    Energy Technology Data Exchange (ETDEWEB)

    Zucchini, Ricardo R.; Hinata, Patricia [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Gioseffi, Carla S.; Franco, Joao B.S. [Instituto Brasileiro de Petroleo, Gas e Biocombustiveis (IBP), Rio de Janeiro, RJ (Brazil); Nascimento, Cristina R.; Torres, Eduardo S. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The determination of repeatability and reproducibility standard deviations of an analytical method, s{sub r} and s{sub R}, obtained by Interlaboratory program, makes it possible to calculate many kinds of precision limits of the method, which are needed in every laboratory's routine result comparisons and also in between-laboratories comparisons. This paper presents the results of the first interlaboratory trial, accomplished in the Brazilian petroleum sector, performed to define the trueness and precision of the Brazilian standard method for the determination of fuel anhydrous ethylic alcohol content in gasoline, that was performed by 34 experienced laboratories. The r and R values were 0,7 and 2,3 and main factors that would improve and optimize the method are presented. (author)

  15. Optimization of the synthesis of a high specific activity 125{sup I}-labelled hapten for radioimmunoassays; Optimizacion de un metodo de preparacion de un radiohapteno-125''I para ria de alta actividad especifica

    Energy Technology Data Exchange (ETDEWEB)

    Suraez, C.; Paz, D.; Simon, M. A.; Romero del Hombrebueno, B.

    1994-07-01

    In this first report it is described the synthesis, separation and purification of the 2-radioiodinated histamine- I-labelled histamine by a mixed anhydride reaction. About 75% incorporation of I{sup -}125, from Na{sup 1}25I, was achieved with a molecular ratio of 1:1 mixed anhydride:histamine. The radiochemical purity of the conjugate by TLC was > 99% and its theoretical specific activity, 3850 {mu}Ci/{mu}g. Dissolved in ethanol and held at -20 degree centigree under darkness decomposition on storage didn't exceed 1% per month. (Author) 13 refs.

  16. RBI - Risk Based Inspection: new technologies and methods applied to inspections of FPSO (Floating Production, Storage and Offloading Vessel) hull; IBR - Inspecao Baseada em Risco: novas tecnologias e metodos aplicados as inspecoes de casco de FPSOs

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Bruno de; Figueiredo, Eduardo; Luiz, Marcio [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Meurer, Gustavo; Duarte, Romulo; Oliveira, Thais; Krzonkalla, Viviane [ABS Consulting, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    With the aging of the FPSO's, which are fundamental to the operation Offshore, better techniques and technologies must be applied to assess more accurately the actual efficiency and structural conditions of producing unit. With the emergence of new engineering techniques and equipment and methods of structural inspection, is now possible to use these new technologies to better manage risk and reliability of the structure of the FPSO, with that, the inspections and methods are more rational and efficient. The Risk-Based Inspection is the tool for monitoring operation of industrial plants with systemic use of technology in conjunction with risk analysis and reliability. His concept is applicable to various branches of industry. The companies began their implementation of oil by refineries. The group of ABS Consulting with PETROBRAS has been developing and implementing these new technologies in inspections of hulls of FPSO's. Applied successfully in the units of the Campos basin, these methods are used by the group of Risk-Based Inspection to improve the efficiency of all the steps involved with the structural integrity of the unit. (author)

  17. Method for evaluation of doses from ingestion of polonium, bismuth and lead as natural radioactive material(NORM); Metodo de evaluacion de dosis por ingestion de polonio, bismuto y plomo como materiales radiactivos naturales

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Vanessa; Puerta, Anselmo; Morales, Javier, E-mail: vpenam@ullal.edu.co, E-mail: japuerta@unal.edu.co, E-mail: jmorales@unal.cdu.co [Universidad Nacional de Colombia, Medellin (Colombia). Grupo de Fisica Radiologica

    2013-07-01

    In this work was carried out an evaluation of dose from ingestion of radioactive daughters of radon (lead, bismuth and polonium), taking into account ages from three months up to adult men, using the new model of the human alimentary tract HATM and methodology of calculating doses proposed by the ICRP publication 103, which allows the estimation of dose based on the concentration of the radionuclide present in the diet or in the water of consumption.

  18. An Evaluation of Uncertainty Associated to Analytical Measurements of Selected Polycyclic Aromatic Compounds in Ambient Air; Estudio sobre las Incertidumbres Asociadas al Metodo de Determinacion de PAC's Seleccionados en Muestras de Aire Ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Barrado, A. I.; Garcia, S.; Perez, R. M.

    2013-06-01

    This paper presents an evaluation of uncertainty associated to analytical measurement of eighteen polycyclic aromatic compounds (PACs) in ambient air by liquid chromatography with fluorescence detection (HPLC/FD). The study was focused on analyses of PM{sub 1}0, PM{sub 2}.5 and gas phase fractions. Main analytical uncertainty was estimated for eleven polycyclic aromatic hydrocarbons (PAHs), four nitro polycyclic aromatic hydrocarbons (nitro-PAHs) and two hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) based on the analytical determination, reference material analysis and extraction step. Main contributions reached 15-30% and came from extraction process of real ambient samples, being those for nitro- PAHs the highest (20-30%). Range and mean concentration of PAC mass concentrations measured in gas phase and PM{sub 1}0/PM{sub 2}.5 particle fractions during a full year are also presented. Concentrations of OH-PAHs were about 2-4 orders of magnitude lower than their parent PAHs and comparable to those sparsely reported in literature. (Author) 7 refs.

  19. Derivatizacijos metodo taikymas riebalų rūgščių sudėties nustatymui skirtingų rūšių augalų aliejuose

    OpenAIRE

    Genys, Arnoldas

    2017-01-01

    Master thesis of A. Genys/ scientific supervisor: prof. Ph.D. A. Jakštas; Lithuanian university of health sciences, Faculty of pharmacy, Department of analytical and toxicological chemistry. - Kaunas. Key words: saturated fatty acids, unsaturated fatty acids, gas chromatography, omega-3 unsaturated fatty acids, omega-6 unsaturated fatty acids, omega-9 unsaturated fatty acids, fatty acids, derivatization, oils. Aim: to identify the fatty acid composition in different kind of oils using...

  20. Preliminary results from the application of risk matrix method for safety assessment in industrial radiography; Resultados preliminares de la aplicacion del metodo de matrices de riesgo para evaluaciones de seguridad en radiografia industrial

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, A.; Cruz, D. [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan 779, Col. Narvarte, 03020 Ciudad de Mexico (Mexico); Truppa, W. [Autoridad Reguladora Nuclear, Buenos Aires (Argentina); Aravena, M. [Comision Chilena de Energia Nuclear, Santiago (Chile); Tamayo, B., E-mail: alopezg@cnsns.gob.mx [Consejo de Seguridad Nuclear, Madrid (Spain)

    2015-09-15

    Although the uses of ionizing radiation in industry are subject to procedures that provide a high level of safety, experience has shown that equipment failure, human errors, or the combination of both that can trigger accidental exposures may occur. Traditionally, the radiation safety checks whether these industrial practices (industrial radiography, industrial irradiators, among others) are sufficiently safe to prevent similar accidental exposures already occurred, so that becomes dependent on the published information and not always answers questions like: What other events can occur, or what other risks are present? Taking into account the results achieved by the Foro Iberoamericano de Organismos Reguladores Radiologicos y Nucleares, its leading position in the use of techniques of risk analysis in radioactive facilities and the need to develop a proactive approach to the prevention of accidents arising from the use of ionizing radiations in the industry, it intends to apply the risk analysis technique known as Risk Matrix to a hypothetical reference entity for the region in which industrial radiography is performed. In this paper the results of the first stage of this study are shown, that is the identification of initiating events (IE) and barriers that help mitigate the consequences of such IE, so that can appreciate the applicability of this method to industrial radiography services, to reduce the risk to acceptable levels. The fundamental advantage associated with the application of this methodology is that can be applied by the professionals working in the service and identifies specific weaknesses that from the point of view of safety there, so they can be prioritized resources depending on risk reduction. (Author)

  1. Voltage collapse - critical analysis of the attainment of collapse margin by successive power fluxes and parabolic approach; Colapso de tensao - analise critica do metodo de obtencao da margem de colapso por fluxos de potencia sucessivos e aproximacao parabolica

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Ramon Sade; Lima, Julio Cesar Marques de; Terra, Luiz Danilo Barbosa [Pontificia Univ. Catolica de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Engenharia Eletrica

    1997-12-01

    The present paper shows research results on Voltage Collapse when the Electrical Power System is submitted to several load variations. A study will be reported that validates a methodology of the determination of the Voltage Collapse Margin, in accordance with Ejebe (1996) and its applications in the contingency ranking using the Voltage Collapse as a Performance Index. The purpose is to obtain an accurate and fast method that perform security analysis in the operation system phase. The verifications will be developed using the IEEE 14 Bus System and, in sequence, checked to validated to any systems. The comparatives results of the method applications and approximations adopted will be assessed. Finally, the modifications that should be implemented in order to validate the method in the Electrical System Operation will be performed. (author) 7 refs., 5 figs.

  2. Visualisation of Proficiency Test Exercise by Means of Kiri Plots. Informatics Application; Metodo de Visualizacion de los Resultados de las Pruebas de Capacitacion por medio de la Grafica de Kiri. Aplicacion Informatica

    Energy Technology Data Exchange (ETDEWEB)

    Gasco, C.; Trinidad, J. A.

    2012-09-13

    This report describes the visualisation procedure of the proficiency tests by means of Kiri Plots, based on three tests: z-score, zeta-score and the relative uncertainty outlier. The results assessment of the intercomparison exercises and proficiency tests among Spanish environmental radioactivity laboratories and Spanish Nuclear Power Plants Laboratories is performed by Environmental Radioactivity and Radiological Surveillance Unit following the ISO-43 e ISO/ IUPAC standards and applying the z-score test. The application of new graphics methods and tests to a better evaluation of uncertainties reported by Labs is described in this paper. An informatics programme has been developed in Visual Basic for applications that allows the graphic representation of Tables and Figures automatically in an excel-sheet and later statistical simulations changing the ratios between the reference value uncertainties and the concentration activities values from the participants laboratories. (Author) 26 refs.

  3. Analytical Evaluation to Determine Selected PAHs by HPLC in a Type 2 Fuel; Evaluacion Analitica de 4 Metodos de Determinacion de PAHs medianteHPLC en un Fuel de Tipo II

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.; Sevillano Castano, M. L.; Escolano Segovia, O.; Garcia Frutos, F. J.

    2009-05-21

    An evaluation of analytical parameters to determine selected PAHs in a fuel oil type II by HPLC coupled to fluorescence and diode detectors is presented. The study was focused on four conventional treatments of these kinds of oil samples and the main objective was giving a measure of confidence level of PAH results in the fuel oil. This study was performed in the frame of the project Assessment of natural attenuation of PAHs in agricultural soil contaminated with fuel from an accidental spill (Spanish National Plain I+D+I, CTM2007-64537). This paper is presented as follows: Analysis of reference material 1582 (NIST) by using the four kinds of sample treatments of interest. Application of variance analysis to compare results obtained from type II fuel by using each sample treatment and chromatographic detector. Finally, a statistic calculation was performed to measure uncertainty components in chromatographic analysis. (Author)

  4. Jaws calibration method to get a homogeneous distribution of dose in the junction of hemi fields; Metodo de calibracion de mandibulas para conseguir una distribucion homogenea de dosis en la zona de union de hemicampos

    Energy Technology Data Exchange (ETDEWEB)

    Cenizo de Castro, E.; Garcia Pareja, S.; Moreno Saiz, C.; Hernandez Rodriguez, R.; Bodineau Gil, C.; Martin-Viera Cueto, J. A.

    2011-07-01

    Hemi fields treatments are widely used in radiotherapy. Because the tolerance established for the positioning of each jaw is 1 mm, may be cases of overlap or separation of up to 2 mm. This implies heterogeneity of doses up to 40% in the joint area. This paper presents an accurate method of calibration of the jaws so as to obtain homogeneous dose distributions when using this type of treatment. (Author)

  5. Sistemas de control de malezas en maiz (Zea mays L.: efecto de metodos de control, densidad y distribucion del cultivo Weed control systems in corn: effects of control methods, density and plant distribution

    Directory of Open Access Journals (Sweden)

    G. Martinez

    1982-12-01

    Full Text Available Con el objetivo de integrar diferentes prácticas culturales en un sistema de control de malezas en maíz, se instaló un ensayo en el Campo Experimental de la Universidad Autónoma Chapingo (México (2250 msnm, precipitación media anual 550 mm, suelo franco, 1.7% M.O. bajo condiciones de secano, en donde se evaluaron dos densidades (44.400 y 66.600 pl/ha, dos distribuciones (normal y equidistante y siete métodos de control de malezas (cyanazine + alachlor (1,2 + 1,92 kg/ha, atrazine + alachlor (1,2 + 1,44 kg/ha, un escarda, dos escardas, testigo siempre desmalezado, testigo siempre desmalezado + dos escardas y testigo siempre enmalezado. Las principales malezas presentes fueron: quelite (Amaranthus sp., perlilla (Lopezia mexicana Jacq., rosilla chita (Galinsoga parviflora Cav., acahual (Encelia mexicana Mart., Sporobulus poiretti (Roem, et Sch. Hichc. y fresadilla (Digitaria sanguinalis (L. Scop.. El aumento de la densidad de siembra no se reflejó en el control de malezas, incidencia de enfermedades, crescimiento vegetativo y reproductivo del cultivo. La distribución equidistante aparejó un mejor control de malezas, en relación a la distribución normal, pero la incidencia de enfermedades fue mayor, lo que quizá pudo haber determinado la ausencia de diferencias en crecimiento vegetativo, un menor número de mazorcas/ha y consecuentemente la ausencia de respuesta en rendimiento de grano. De los tratamientos químicos, atrazine + alachlor tuvo un comportamiento superior a cyanazine + alachlor, en control de malezas, aunque sólo fue detectable estadisticamente en las evaluaciones. No hubo diferencia entre ambos en la incidencia de enfermedades, ni en su efecto sobre el cultivo. aunque el rendimiento de cyanazine + alachlor fue ligeramente inferior. Los métodos químicos fueron superiores a los mecánicos en control de malezas, pero no difirie -ron en la incidencia de enfermedades ni en los parámetros de desarrollo del cultivo. La realización de una escarda adicional no mejora significativamente el control de malezas, no afectando tampoco la incidencia de enfermedades, ni el desarrollo del cultivo, por lo cual resulta innecesaria. Las escardas tienen como principal efecto eliminar la interfe rencia presentada por las malezas y si éstas son eliminadas de otra manera, la realización de aquéllas no apareja beneficios significativos.An experiment was conducted at the Research Station of the University of Chapingo (Mexico (2250 m above sea level, average annual rainfall 550 mm( loamy soil, 1,7% O.M., where different cultural practices were combined in order to design a weed control system for corn. The work was done under rainfed conditions and the variables included were: two population densities (44.400 and 66.600 pl/ha, two plant distributions (normal and equidistant and seven weed control methods (cyanazine + alachlor (1,2 + 1,92 kg/ha, atrazine + alachlor (1,2 + 1,44 kg/ha, one cultivation, two cultivations, a weeded check, a weeded check + two cultivations and a weedy check. The main weed species were: pigweed (Amaranthus sp., Lopezia mexicana Jacq., hairy galinsoga (Galin-soga parviflora Cay., Encelia mexicana Mart., Sporobulus poiretti (Roem. et Sch. Hich., and large crabgrass (Digitaria sanguinalis (L. Scop.. The increase in plant population had no effect on the degree of weed control, incidence of diseases and crop growth. The equidistant distribution improved weed control over the normal one, but it also had a nigher incidence of diseases; this, is turn, may have caused the lack of differences in vegetative growth, a lower amount of cobs per ha and the lack of difference in grain yield between the two distributions. Atrazine + alachlor was better than cyanazine + alachlor in terms of weed control, although the difference was statistically observed only for the visual ratings. There were no differences between both chemical treatments in terms of incidence of diseases or their effect on crop growth, but grain yield for cyanazine + alachlor was slightly lower. The chemical methods were better than the mechanical ones regarding weed control, but no differences were detected in terms of in cidence of diseases or crop growth. One additional weeding does not improved weed control significantly, nor does it affect the incidence of diseases or crop growth, thus appearing to be unnecessary. The main effect of cultivations is weed control, and if this can be done in any other way, cultivating does not bring about additional benefits.

  6. Simulation of clinical X-ray tube using the Monte Carlo Method - PENELOPE code; Simulacao de um tubo de raios X clinico atraves do Metodo de Monte Carlo usando codigo PENELOPE

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, M.A.G.; David, M.G.; Almeida, C.E. de; Magalhaes, L.A.G., E-mail: malbuqueque@hotmail.com [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas; Bernal, M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Braz, D. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2015-07-01

    Breast cancer is the most common type of cancer among women. The main strategy to increase the long-term survival of patients with this disease is the early detection of the tumor, and mammography is the most appropriate method for this purpose. Despite the reduction of cancer deaths, there is a big concern about the damage caused by the ionizing radiation to the breast tissue. To evaluate these measures it was modeled a mammography equipment, and obtained the depth spectra using the Monte Carlo method - PENELOPE code. The average energies of the spectra in depth and the half value layer of the mammography output spectrum. (author)

  7. Reconstruction of X-rays spectra of clinical linear accelerators using the generalized simulated annealing method; Reconstrucao de espectros de raios-X de aceleradores lineares clinicos usando o metodo de recozimento simulado generalizado

    Energy Technology Data Exchange (ETDEWEB)

    Manrique, John Peter O.; Costa, Alessandro M., E-mail: johnp067@usp.br, E-mail: amcosta@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil)

    2016-07-01

    The spectral distribution of megavoltage X-rays used in radiotherapy departments is a fundamental quantity from which, in principle, all relevant information required for radiotherapy treatments can be determined. To calculate the dose delivered to the patient who make radiation therapy, are used treatment planning systems (TPS), which make use of convolution and superposition algorithms and which requires prior knowledge of the photon fluence spectrum to perform the calculation of three-dimensional doses and thus ensure better accuracy in the tumor control probabilities preserving the normal tissue complication probabilities low. In this work we have obtained the photon fluence spectrum of X-ray of the SIEMENS ONCOR linear accelerator of 6 MV, using an character-inverse method to the reconstruction of the spectra of photons from transmission curves measured for different thicknesses of aluminum; the method used for reconstruction of the spectra is a stochastic technique known as generalized simulated annealing (GSA), based on the work of quasi-equilibrium statistic of Tsallis. For the validation of the reconstructed spectra we calculated the curve of percentage depth dose (PDD) for energy of 6 MV, using Monte Carlo simulation with Penelope code, and from the PDD then calculate the beam quality index TPR{sub 20/10}. (author)

  8. Drawing up of a procedure for vanadium determination in mussels using the neutron activation analysis method; Estabelecimento de procedimento para determinacao de vanadio em mexilhoes pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele, E-mail: danyseo@uol.com.b [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias Biologicas e da Saude; Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vasconcellos, Marina B.A.; Saiki, Mitiko; Catharino, Marilia G.M.; Moreira, Edson G., E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b, E-mail: mgcatharino@uol.com.b, E-mail: emoreira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de; Pereira, Camilo D.S., E-mail: edvinett@usp.b, E-mail: camilo.pereira@usp.b [Universidade de Sao Paulo (IO/USP), SP (Brazil). Inst. Oceanografico. Lab. de Ecotoxicologia Marinha

    2009-07-01

    This work establishes an adequate procedure for obtaining reliable results for determination of vanadium in mussels, leg by leg by the neutron activation analysis (NAA), viewing the posterior application on the bio monitoring the coastal pollution, particularly near the petroleum terminals.For the evaluation of result quality concerning to the quality of those results, the work analysed the reference material certification NIST SRM 1566b Oyster Tissue. The precision of the results were also analysed using repetitions of mussel samples collected at the coastal of northern Sao Paulo state, Brazil. The NAA procedure consisted of 200 mg of sample and a synthetic standard of vanadium during a period of 8 s and under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} at the pneumatic station 4 of the IEA-R1 nuclear reactor of IPEN-CNEN/SP. After a 3 min decay, the measurements of the gamma activities of the sample and the standard were done using a Ge hyper pure semi-conductor detector, connected to gamma ray multichannel analyser. The vanadium were determined by the measurement of the gamma activity of the {sup 52}V through the 1434.08 keV peak, and half-life time of 3.75 min. The concentration of V were calculated by the comparative method. The obtained results indicated the viability of the NAA procedure established for the determination of vanadium in mussels

  9. H{sub 2} as source of renewable energy: production through catalytic methods by means of the reforming of methanol; H{sub 2} como fuente de energia renovable: produccion por metodos cataliticos mediante el reformado de metanol

    Energy Technology Data Exchange (ETDEWEB)

    Perez H, R.; Lopez, P.; Gutierrez M, A.; Gutierrez W, C.; Mondragon G, G.; Mendoza A, D. [ININ, Departamento de Tecnologia de Materiales, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Angeles Ch, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas Norte 152, Col. San Bartolo Atepehuacan, 07730 Mexico D. F. (Mexico); Arenas A, J., E-mail: raul.perez@inin.gob.m [UNAM, Instituto de Fisica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2010-07-01

    The fuel cells transform the chemical energy stored in the connection H-H of the H{sub 2} molecule in electric energy and water vapor when is combines with the oxygen. Even when the hydrogen has a high potential as energy source, its handling is difficult (storage and transport). This has motivated the search of hydrogen production methods in situ starting from liquid fuels like the methanol or ethanol through the reaction of reforming. The methanol is a fuel of easy availability for fuel cells with electronic applications and of transport. Although the methanol energy density is approximately half of the gasoline and diesel, it is more reagent and can be used directly in fuel cells or can also be reformed to low temperatures for the hydrogen obtaining to be used in fuel cells of proton exchange. In this article the results obtained of the systems, Cu-Ni/ZrO{sub 2} and Ag-Au(1-D)-CeO{sub 2} are presented and can be competitive to generate H{sub 2} and being used in the fuel cells to generate energy. (Author)

  10. Cost effective method for valuation of impacts caused by greenhouse gases emissions for oil and gas companies; Metodo de custo-efetividade para avaliacao de impactos causados pelas emissoes de gases de efeito estufa em empresas de oleo e gas

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Elisa Vieira [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Barros, Sergio Ricardo da Silveira [Universidade Federal Fluminense (LATEC/UFF), Niteroi, RJ (Brazil). Mestrado em Sistemas de Gestao

    2012-07-01

    The objective of this work is to apply the method of cost-effectiveness in economic evaluation of new investment projects, based on information about reducing greenhouse gases emissions. In the context of the commitment of companies with the Climate Change and Sustainability, this work is important and contributes to the oil and gas industry, because it integrates information on reducing emissions of greenhouse gases in negative Net Present Value (NPV) projects, helping the portfolio manager on decision making between alternative projects. In this article, examples are given of two investment projects, in which the cost effectiveness methodology is applied, considering the reduction of emission of greenhouse gases such as additional environmental benefit, or cost avoidance, in an adjusted model of the economic viability analysis of meritorious projects. (author)

  11. A combination between the differential and the perturbation theory methods for calculating sensitivity coefficients; Uma combinacao entre os metodos diferencial e da teoria de pertubacao para o calculo dos coeficientes de sensibilidade

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Antonio Andrade

    1998-07-01

    A new method for the calculation of sensitivity coefficients is developed. The new method is a combination of two methodologies used for calculating theses coefficients, which are the differential and the generalized perturbation theory methods. The method utilizes as integral parameter the average flux in an arbitrary region of the system. Thus, the sensitivity coefficient contains only the component corresponding to the neutron flux. To obtain the new sensitivity coefficient, the derivatives of the integral parameter, {phi}, with respect to {sigma} are calculated using the perturbation method and the functional derivatives of this generic integral parameter with respect to {sigma} and {phi} are calculated using the differential method. (author)

  12. Modelos de desarrollo de software de exportacion en el contexto de una region emergente: Caso area metropolitana de Monterrey, analisis de campo por el metodo de regresion lineal multiple.

    Directory of Open Access Journals (Sweden)

    Torres, F.

    2009-01-01

    Full Text Available The objective of this document is to give to know the advantages that the different successful development models have offered for companies development of export software, making a synthesis from the CMM, until arriving to the CMMI, without stopping to make a critical analysis on the two models that have identified the critical factors for the export of software of the called countries of "3I" that they have demonstrated its success in this segment like: the model of factors of success for the software export (Heeks and Nicholson, 2002 and the model Oval (Carmel, E., 2003b, giving the minimum recommendations to the Mexican companies, developments of software export, have the competitiveness required in the international environment. This work is the result of the bibliographical revision of the models of software development and it is part of the doctoral thesis, about a sample of 40 companies developments of software export and the critical factors: Standard technological, Capacity of technological innovation, Formation of human capital, financial Capital and Support in investigation and development, with the purpose of identifying the opportunity areas to improve their international competitiveness, besides the economic results that can be obtained. The present study is based on the application of the statistical technique of the model of multiple lineal regressions, giving the following values: R= 0.549, 2 R =0.302, 2 R Ajus = 0.275. The positioning of the companies Mexican developments of software export and, in the particular case in the Metropolitan Area of the City of Monterrey, in the world market of software and related services, it will depend: that the company has a model to develop software export; of the consolidation of managerial associations of TI for the development of the export software and of the development of managerial consortia of export software in the Metropolitan Area of the City of Monterrey that they come to consolidate this industry in the northeast of the country.

  13. Congenital anomalies of the inferior vena cava: importance of multiplanar imaging methods: an iconographic essay; Anomalias congenitas da veia cava inferior: valor dos metodos multiplanares em seu diagnostico - ensaio iconografico

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Sergio Lopes; Mendonca, Jose Luiz Furtado de; Freitas, Flavia Mendes Oliveira [Clinica Radiologica Vila Rica, Brasilia, DF (Brazil)] (and others). E-mail: radiolog@uol.com.br

    2006-10-15

    The inferior vena cava is the result of a complex embryologic process which takes place between 6 and 8 weeks of intra-uterine life. Several variations can occur during this process, and a defective embryogenesis of this vessel may lead to the development of anatomic variants. Although many of these variants are asymptomatic, the radiologist should be aware of them and of the potential medico-legal issues involved, especially in cases in which abdominal surgery or hemodynamic procedures are contemplated. In this paper, the major congenital anomalies involving the inferior vena cava are reviewed under the form of a pictorial essay, highlighting the role of the multiplanar imaging methods (volumetric computed tomography and magnetic resonance imaging) in their diagnosis. Keywords: Congenital variations; Inferior vena cava; Renal veins; Computed tomography; Magnetic resonance imaging. author)

  14. Uranium dioxide thermal characterization by the flash laser method from 23 Celsius to 175 Celsius; Caraterizacao termica de dioxido de uranio pelo metodo flash laser de 23 Celsius a 175 Celsius

    Energy Technology Data Exchange (ETDEWEB)

    Faeda, K.C.M.; Lameiras, F.S.; Carneiro, L.S.S.; Camarano, D.M.; Ferreira, R.A.N. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2010-07-01

    The Laser Flash Method has become one of the most common techniques for measuring thermal diffusivity and conductivity in solids and liquids. This method is recognized by INMETRO as standard to be used in Brazil for measuring thermophysical properties of materials, such as metals, carbon composites, ceramics, and also nuclear materials. This article describes the experimental bench of the LMPT-Laboratorio de Medicao de Propriedades Termofisicas de Combustiveis Nucleares e Materiais of the CDTN-Centro de Desenvolvimento da Tecnologia Nuclear, (LMPT), as well as the mathematical model developed based on this method. The obtained results for the thermal diffusivity and for the thermal conductivity of uranium dioxide (U0{sub 2}) pellets in the temperature range from 25 deg to 175 deg C, are discussed and compared with the literature data. The estimative of the input quantities uncertainty of the mathematical model was determined according to ISO - BIPM-Guide to the Expression of Uncertainty in Measurement and the Monte Carlo Method was used to estimate of the output quantities uncertainty (thermal diffusivity and thermal conductivity). Additionally the results of the x-rays of these pellets are presented. (author)

  15. Modification of the hydrotalcite with sodium stearate and its influence in the polyurethane nanocomposites obtained by the in situ polymerization; Nanocompositos de poliuretano/hidrotalcita via polimerizacao in situ: efeito da modificacao da argila e dos metodos dispersivos

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Danieli M. do, E-mail: danielimcarmo@hotmail.com [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil); Oliveira, Marcia G. de [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil); Soares, Bluma G. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas Profa. Eloisa Mano

    2015-07-01

    Nanocomposites of PU with synthetic hydrotalcite and organoclay were obtained by the in situ polymerization. The addition of clay in the reaction has occurred with and without dispersion previous, using equipment ultraturrax and ultrasound bath. The results of XRD and FTIR confirmed the clay organophilization process. The viscosity analysis of the dispersions showed increased nanocarga-monomer interaction with the time counter, especially for samples containing LDH-st. Such interactions with possibility reaction between the phases may have contributed to the unbalance of the stoichiometry required for polymerization, resulting in lower molecular weight polymer formed in situ. As a result there was minor degradation temperature values, modulus and viscosity for samples subjected to the methodologies TBT and T. However, these methods in conjunction with LDH-st were fundamentals to improving dispersion in the matrix, accord to visual analysis. (author)

  16. Probes for inspections of heat exchanges installed at nuclear power plants type PWR by eddy current method; Sondas para inspecao de trocadores de calor instalados em usinas nucleares tipo PWR pelo metodo de correntes parasitas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alonso F.O. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Enghenharia Mecanica]. E-mail: kauzz21@yahoo.com; Alencar, Donizete A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: daa@cdtn.br

    2007-07-01

    From all non destructive examination methods usable to perform integrity evaluation of critical equipment installed at nuclear power plants (NPP), eddy current test (ET) may be considered the most important one, when examining heat exchangers. For its application, special probes and reference calibration standards are employed. In pressurized water reactor (PWR) NPPs, a particularly critical equipment is the steam generator (SG), a huge heat exchanger that contains thousands of U-bend thin wall tubes. Due to its severe working conditions (pressure and temperature), that component is periodically examined by means of ET. In this paper a revision of the operating fundamentals of the main ET probes, used to perform SG inspections is presented. (author)

  17. No contaminant methods for the bio films formation control on metallic surfaces of industrial interest; Metodos no contaminantes para controlar la formacion de biopeliculas sobre superficies metalicas de interes industrial

    Energy Technology Data Exchange (ETDEWEB)

    Gomez de Saravia, S. G.; Guiamet, P. S.

    2003-07-01

    The aim of this paper was the control of aerobic and anaerobic bacterial biofilms formation on metal surfaces of industrial interest such as stainless steel and mild steel. A natural biocida obtained of an aqueous extract of seeds of black mustard (Brassica nigra) and mixtures of immunoglobulins IgA, IgG, and IgM were used. Microscopic techniques like scanning electron microscopy (SEM) and epifluorescens microscopy were used for observing bacterial adhesion of the metal surfaces. A marked inhibition of bacterial adherence was observed when an immunoglobulin film was formed on the metal surface. When the natural biocide was used, an important decrease in the number of microorganisms in the biofilms was observed. (Author) 8 refs.

  18. Sedimentation rates of Sao Paulo coast by carbonate calcium content: an alternative for radiometric methods; Levantamento das taxas de sedimentacao do litoral de Sao Paulo a partir do teor de carbonato de calcio: uma alternativa aos metodos radiometricos

    Energy Technology Data Exchange (ETDEWEB)

    Figueira, Rubens C.L. [Universidade Cruzeiro do Sul, Sao Paulo, SP (Brazil). Centro de Tecnologia e Ciencias Exatas]. E-mail: figueira@ipen.br; figueiraru@yahoo.com.br; Tessler, Moyses G.; Mahiques, Michel M. de; Fukumoto, Marina M.M. [Sao Paulo Univ., SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Geologica]. E-mail: mgtessle@usp.br; mahiques@usp.br; marina@io.usp.br

    2005-07-01

    In this work it is presented a methodology of sedimentation rate determination by carbonate calcium content. The technique developed is an alternative for radiometric methods where are used {sup 210}Pb{sub unsupported} and {sup 137}Cs radionuclides. This methodology consisted in a determination of chronologic event along sedimentary column. In this work two events were used: the tsunami in Sao Vicente city, in 1542, and the maximum of 1{sup 37}Cs radioactive fallout from nuclear atmospheric tests, in 1963-65. It was possible to calculate the accumulation rate of total sediments and precipitation rate of calcium carbonate, which values are necessary to determine the age of slice from sedimentary column and consequently the sedimentation rate. The results obtained for Sao Paulo Continental Shelf had a good agreement with radiometric methods, the values were: 0.32({+-}0.12) cm.y{sup -1}, 0.23({+-}0.08) cm.y{sup -1} and 0.25({+-}0.9) cm.y{sup -1} for carbonate method, {sup 210}Pb{sub unsupported} (CIC model) and {sup 137}Cs (radioactive fallout), respectively. The analytical procedure using carbonate calcium content showed to be fast, efficient and with low cost. However, it must be used carefully, because the results can be strongly influenced by environmental factors which could change the precipitation rate of calcium carbonate and it could cause errors on sedimentation rate values in a determined area (author)

  19. Structural analysis of a carbonated hydroxyapatite by the Rietveld method using different profile functions; Analise estrutural de uma hidroxiapatita carbonatada pelo metodo de Rietveld aplicando funcoes de perfil diferentes

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jorge C. de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Dept. de Matematica], e-mail: jcaraujo@iprj.uerj.br; Moreira, Elizabeth L.; Moraes, Valeria Conde Alves [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)], e-mail: beth@cbpf.br, e-mail: conde@cbpf.br; Moreira, Ana Paula D. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica], e-mail: duarteap@gmail.com

    2008-10-15

    The crystal structure of the synthetic hydroxyapatite with 12.8 ({+-} 0,64) wt. % CO{sub 3}{sup 2-} ion content was analyzed by X-ray diffraction using the Rietveld refinement method employing Pearson VII and pseudo-Voigt functions to fit the X-ray profile. The results obtained for unit cell parameters when compared to pattern hydroxyapatite showed a decrease in the a (=b) parameter and an increase in the c parameter without significant difference between the functions employed. The separation of the anisotropic broadening of reflections originated from unit cell strains indicated that this effect is dominant in reflection line broadening, principally to hkl plans with an interatomic distance lower than 2,24 angstrom. Modifications in the atomic coordinates of C atom were noted mainly in PO{sub 4}{sup 3-} (B site) and OH{sup -} (A site) sites. The average crystallite size in the crystallography axis directions (002 and 300) suggests equi axial morphology. The results obtained to CO{sub 3}{sup 2}- content were 11.72 ({+-} 0,64) wt. % to Pearson VII and 13.20 ({+-} 0,64) wt. % to pseudo-Voigt function. The refinement of the occupancy factors to C atoms in both sites PO{sub 4}{sup 3-}(B) and OH{sup -} (A) indicated higher insertion in phosphate site than hydroxide site. However, the relative occupancy of the C atom observed in the B site is lower than in the A site. (author)

  20. Physical-mechanical characterization of hydroxyapatite-titanium oxide composites made by the polymeric sponge method; Caracterizacao fisico-mecanica de compositos porosos de hidroxiapatita-titania confeccionados pelo metodo da esponja polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Galdino, A.G.S.; Zavaglia, C.A.C. [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil)

    2011-07-01

    Bioceramics have been used as bone reconstruction materials since last decades, where hydroxyapatite is one of the most used for this purpose. However, hydroxyapatite's mechanical strength is not so high when compared to other bioceramics. This work aimed on characterizing physically and mechanically composites of HA-TiO{sub 2}. Samples were made by the polymeric sponge method with 70% - 30% wt., 60% - 40% wt. and 50% - 50% wt. of HA - TiO{sub 2}, calcined at 550 deg C for sponge burning and sintered at 1250 deg C, 1300 deg C and 1350 deg C. Samples were submitted to mechanical essays of compression and Hardness Vickers and to physical essays of water absorption, apparent density, burning linear retraction and apparent density. Results showed relatively better than those of pure hydroxyapatite and they are in accordance with the literature. (author)

  1. Characterization of dental cement obtained from a glass prepared by the polymeric precursor method; Caracterizacao de cimento odontologico obtido a partir de um vidro preparado pelo metodo dos precursores polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Marcio Jose; Zaghete, Maria Aparecida; Gimenes, Rossano; Paiva-Santos, Carlos de Oliveira [UNESP, Araraquara, SP (Brazil). Inst. de Quimica]. E-mail: marciobert@yahoo.com.br; Palma-Dibb, Regina Guenka [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Odontologia

    2005-09-15

    Glass ionomer cements are glass and polymer composite materials. These materials currently find use in dentistry. The purpose of this work is to obtain glass powders based on the composition 4.5SiO{sub 2} - 3Al{sub 2}O{sub 3} - 2CaO to be used in dentistry. The powders were prepared by a chemical route at 700 deg C. The properties of glass ionomer cements obtained from powders prepared at 700 deg C were studied. Diametral tensile strength and microhardness were evaluated for the experimental glass ionomer cements and a commercial material. It was concluded that the properties of experimental cements were similar to those of the commercial ones. (author)

  2. National Nanotechnology Laboratory (LNNano) open facilities for scientific community: new methods for polymeric materials characterization; Instalacoes abertas a comunidade cientifica no Laboratorio Nacional de Nanotecnologia (LNNano): novos metodos de caracterizacao de materiais polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cristiane A.; Santos, Ramon H.Z. dos; Bernardes, Juliana S.; Gouveia, Rubia F., E-mail: rubia.gouveia@lnnano.cnpem.br [Centro Nacional de Pesquisa em Energia e Materiais (LNNano/CNPEM), Campinas, SP (Brazil). Laboratorio Nacional de Nanotecnologia

    2015-07-01

    National Nanotechnology Laboratory (LNNano) at the National Center for Energy and Materials (CNPEM) presents open facilities for scientific public in some areas. In this work will be discussed the facilities for mainly the polymeric community, as well as new methods for the characterization. Low density polyethylene (LDPE) surfaces were characterized by X-ray microtomography and X-ray photoelectron spectroscopy (XPS). The results obtained by microtomography have shown that these surfaces present different contrasts when compared with the bulk. These differences are correlated with the formation of an oxidized layer at the polymer surface, which consequently have a greater X-ray attenuation. This hypothesis is confirmed by XPS, which shows LDPE surface layers are richer in carbonyl, carboxyl and vinyl groups than the bulk. This work presents that microtomography can be used as a new method for detection and characterization of polymer surface oxidation. (author)

  3. Preparation and LSC Standardization of ''89Sr (DNP) Using the CIEMAT/NIST Method; Preparacion del ''89Sr(DNP) y calibracion por centelleo liquido, mediante el metodo CIEMAT/NIST

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Los Arcos Merino, J. M.; Grau Malonda, A.

    1994-07-01

    A procedure for preparation of liquid scintillation counting samples of the strontium DNP complex, labelled with ''89Sr, is described, the chemical quench, the counting stability and spectral evolution of this compound is studied in six scintillators, Toluene, Toluene-alcohol, Dioxane-naphthalene, HiSafe II, Ultima- Gold and Instagel. The liquid scintillation standardization of 89Sr-DNP by the CIEMAT/NIST method, using HiSafe II and Ultima-Gold scintillators, has been carried out. The discrepancies between experimental and computed efficiencies are lower than 0.38% and 0.48%, respectively. The solution has been standardized in terms of activity concentration to an overall uncertainty of 0,38%. (Author) 10 refs.

  4. Liquid Scintillation Counting Standardization of {sup 2}2NaCl by te CIEMAT/NIST method; Calibracion por Centelleo Liquido del ''22NaCl, mediante el metodo CIEMAT/NIST

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Grau Carles, A.; Grau Malonda, A.

    1995-07-01

    We describe a procedure for preparing a stable solution of ''22NaCl for liquid scintillation counting and its counting stability and spectral evolution in Insta-Gel''R is studied. The solution has been standardised in terms of activity concentration by the CIEMAT/NIST method with discrepancies between experimental and computed efficiencies lower than 0.4 % and an overall uncertainty of 0.35 %. (Author) 4 refs.

  5. Monte Carlo calculation of the total probability for gamma-Ray interaction in toluene; Aplicacion del metodo de Monte Carlo al calcu lo de la probabilidad de interaccion fotonica en tolueno

    Energy Technology Data Exchange (ETDEWEB)

    Grau Malonda, A.; Garcia-Torano, E.

    1983-07-01

    Interaction and absorption probabilities for gamma-rays with energies between 1 and 1000 KeV have been computed and tabulated. Toluene based scintillator solution has been assumed in the computation. Both, point sources and homogeneously dispersed radioactive material have been assumed. These tables may be applied to cylinders with radii between 1.25 cm and 0.25 cm and heights between 4.07 cm and 0.20 cm. (Author) 26 refs.

  6. Liquid scintillation counting standardization of 125I in organic and inorganic samples by the CIEMAT/NIST method; Calibracion por centelleo liquido del 125I en muestras inorganicas y organicas, mediante el metodo CIEMAT/NIST

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

    1994-07-01

    The liquid scintillation counting standardization of organic and inorganic samples of ''I25I by the CIEMAT/NIST method using five different scintillators is described. The discrepancies between experimental and computed efficiencies are lower than 1.4% and 1.7%, for inorganic and organic samples, respectively, in the interval 421-226 of quenching parameter. Both organic and inorganic solutions have been standardized in terms of activity concentration to an overall uncertainty of 0.76%. (Author) 14 refs.

  7. Application of the generator coordinates method to the intra-molecular proton tunneling in the malonaldehyde molecule; Aplicacao do metodo das coordenadas geradoras ao processo de tunelamento do proton intramolecular na molecula de malonaldeido

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Andre Campos Kersten

    1995-12-31

    The effects of different vibrational modes on the isomerization process of polyatomic molecules, or solvent`s effects on reaction rates are object of up-to-date interest. In general, such many body phenomena are, in principle, multidimensional, and they first require a reduction of relevant degrees of freedom. In order to investigated, some aspects of the intra-molecular proton tunneling on a malonaldehyde molecule, we use the Generator Coordinate Method. The model used to describe such a process is the so-called System-Bath model, where the system is the reaction coordinate and the bath are the intrinsic degrees of freedom (vibrational modes of the molecule), which are described by a harmonic oscillator set linearly coupled to the system. The reduction of the multidimensional problem to the effective unidimensional one is done using a energy related variational principle on the intrinsic degrees of freedom. we obtained analytically a effective Hamiltonian where the effects of the various degrees of freedom reveal themselves in the appearance of a effective mass and in changes of the shape of the potential barrier. The analyticity of the method was crucial on identifying clearly the roles played by the different physical parameters involved. (author) 17 refs., 29 figs.

  8. Different seeds to solve the equations of stochastic point kinetics using the Euler-Maruyama method; Diferentes semillas para solucionar las ecuaciones de la cinetica puntual estocastica empleando el metodo de Euler-Maruyama

    Energy Technology Data Exchange (ETDEWEB)

    Suescun D, D.; Oviedo T, M., E-mail: daniel.suescun@usco.edu.co [Universidad Surcolombiana, Av. Pastrana Borrero - Carrera 1, Neiva, Huila (Colombia)

    2017-09-15

    In this paper, a numerical study of stochastic differential equations that describe the kinetics in a nuclear reactor is presented. These equations, known as the stochastic equations of punctual kinetics they model temporal variations in neutron population density and concentrations of deferred neutron precursors. Because these equations are probabilistic in nature (since random oscillations in the neutrons and population of precursors were considered to be approximately normally distributed, and these equations also possess strong coupling and stiffness properties) the proposed method for the numerical simulations is the Euler-Maruyama scheme that provides very good approximations for calculating the neutron population and concentrations of deferred neutron precursors. The method proposed for this work was computationally tested for different seeds, initial conditions, experimental data and forms of reactivity for a group of precursors and then for six groups of deferred neutron precursors at each time step with 5000 Brownian movements per seed. In a paper reported in the literature, the Euler-Maruyama method was proposed, but there are many doubts about the reported values, in addition to not reporting the seed used, so in this work is expected to rectify the reported values. After taking the average of the different seeds used to generate the pseudo-random numbers the results provided by the Euler-Maruyama scheme will be compared in mean and standard deviation with other methods reported in the literature and results of the deterministic model of the equations of the punctual kinetics. This comparison confirms in particular that the Euler-Maruyama scheme is an efficient method to solve the equations of stochastic point kinetics but different from the values found and reported by another author. The Euler-Maruyama method is simple and easy to implement, provides acceptable results for neutron population density and concentration of deferred neutron precursors and is computationally efficient for obtaining solutions that minimize the problem of rigidity of the equations of the punctual stochastic kinetics at each step of time. (Author)

  9. Simplex network modeling for press-molded ceramic bodies incorporated with granite waste; Dosagem de massa ceramica para blocos prensados com adicao de residuo de granito atraves do metodo simplex

    Energy Technology Data Exchange (ETDEWEB)

    Pedroti, L.G.; Vieira, C.M.F.; Alexandre, J.; Monteiro, S.N.; Xavier, G.C., E-mail: lpedroti@gmail.com [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil)

    2012-07-01

    Extrusion of a clay body is the most commonly applied process in the ceramic industries for manufacturing structural block. Nowadays, the assembly of such blocks through a fitting system that facilitates the final mounting is gaining attention owing to the saving in material and reducing in the cost of the building construction. In this work, the ideal composition of clay bodies incorporated with granite powder waste was investigated for the production of press-molded ceramic blocks. An experimental design was applied to determine the optimum properties and microstructures involving not only the precursors compositions but also the press and temperature conditions. Press load from 15 ton and temperatures from 850 to 1050°C were considered. The results indicated that varying mechanical strength of 2 MPa to 20 MPa and varying water absorption of 19% to 30%. (author)

  10. Development of computational tools for automatic modeling and FE (Finite Element) analysis of corroded pipelines; Desenvolvimento de ferramentas computacionais para modelagem e analise automatica de defeitos de corrosao em dutos via MEF (Metodo de Elemento Finito)

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, Helder Lima Dias; Willmersdorf, Ramiro Brito; Lyra, Paulo Roberto Maciel [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia Mecanica], e-mail: hldcabral@yahoo.com.br, e-mail: ramiro@willmersdorf.net, e-mail: prmlyra@ufpe.br; Silva, Silvana Maria Bastos Afonso da [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia Civil], e-mail: smb@ufpe.br

    2008-06-15

    Corrosion is one of the most common causes of accidents involving oil and gas pipelines. The computational simulation through finite element method (FEM) is one of the most efficient tools to reliably quantify the remaining strength of corroded pipes. However, the modeling process demands intense manual engineering labor and it is also slow and extremely repetitive; therefore it is very prone to errors. The main purpose of this work is to present the PIPEFLAW program which has tools for generating automatically FE pipe models with corrosion defects, ready to be analyzed with commercial FEM programs. PIPEFLAW has computational tools based on MSC.Patran pre and post-processing program, and were written in PCL (patran command language). The program has a user friendly customized graphical interface, which allows the user to provide the main parameters of the pipe and defect (or a series of defects). The PIPEFLAW program allows the user to generate automatically FE pipe models with rectangular or elliptical shaped corrosion defects located on the internal or external pipe surface. Defects generated by the PIPEFLAW program can assume the configuration of an isolated defect (single defect) or multiple defects (aligned or located in an arbitrary position). These tools were validated by comparing the results of numerical simulations, made with the PIPEFLAW tools, with the numerical, experimental and semi-empiric results available in the literature. Results confirmed the robustness of PIPEFLAW tools which proved to be a rapid way of generating reliable FE models ready to be used on the structural evaluation of corroded pipelines. (author)

  11. Synthesis of the lithium metatitanate, Li{sub 2}TiO{sub 3}, by the modified combustion method; Sintesis del metatitanato de litio, Li{sub 2}TiO{sub 3}, por el metodo modificado de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, D.; Bulbulian, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Pfeiffer, H. [IIM-UNAM, A.P. 70-360, 04510 Mexico D.F. (Mexico)]. e-mail: sb@nuclear.inin.mx

    2005-07-01

    A modified combustion method to obtain Li{sub 2}TiO{sub 3} it was used, a compound to be used in fusion reactors like tritium generator material. To obtain Li{sub 2}TiO{sub 3} were proven different molar ratios of lithium hydroxide (LiOH), titanium oxide (TiO{sub 2}) and urea (CO(NH{sub 2}){sub 2}), as well as different heating temperatures (550, 650 and 750 C). The characterization of the products it was carried out using X-ray diffraction, Scanning electron microscopy and Thermal gravimetric analysis. The sample prepared with a molar ratio Li: Ti: urea = 2.75: 1: 3 was the one that presented as only product the Li{sub 2}TiO{sub 3}. The particle size and the morphology found in the Li{sub 2}TiO{sub 3}, showed similar particle size and morphology to the TiO{sub 2} used as precursor. (Author)

  12. CNOSSOS-EU: Development of a common environmental noise assessment method in the European Union; CNOSSOS-EU: desarrollo de un metodo comun de evaluacion del ruido ambiental en la Union Europea

    Energy Technology Data Exchange (ETDEWEB)

    Aspuru Soloaga, I.; Segues Echazarreta Segues, F.

    2011-07-01

    This article presents the main aspects of the work undertaken in the development of the common european method of environmental noise assessment CNOSSOS-EU. It summarizes the design, structure and content, and the methodological basis on which it is based. Taking into account the experience gained in the first round of strategic noise mapping, some conclusions are settled about its applications for the third round, and tits implications for the Spanish case. (Author) 9 refs.

  13. A study of the influence of the method of shaping ceramic materials prepared with waste as one of their properties; Estudio de la influencia del metodo de moldeo de materiales ceramicos elaborados a partir de residuos en sus propiedades

    Energy Technology Data Exchange (ETDEWEB)

    Cotes, M. T.; Martinez, C.; Iglesias, F. J.; Corpas, F. A.

    2013-09-01

    The properties of ceramic materials are intimately related to a variety of factors, among them shaping procedure and sintering time. These factors condition the microstructure and properties of the materials developed. Our study has formed materials from clays commonly used in the area of Bailen (Jaen) and sludge proceeding from the wastewater treatment plant. We shaped the materials through pressing and extrusion, the techniques most widely used in the ceramics industry in this region. Our goal is to determine which technique is the most appropriate by studying properties of interest, highlighting the thermal conductivity, such as compressive strength, water absorption, water suction, absolute and apparent density, among others. (Author)

  14. Comparison between different methods for inspection of wooden poles in service in electricity distribution networks; Comparacao entre diferentes metodos de inspecao de postes de madeira em servico em redes de distribuicao de energia

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, M.A.O.; Pires, M.; Dedavid, B.A.; Vidor, F.L.R.; Oliveira, W.S.; Abruzzi, R.C. [Pontificia Univ. Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia e Tecnologia de Materiais (PGETEMA)], Email: mpires@pucrs.br

    2010-07-01

    The pole is the main support structure of the electric network and should be inspected regularly to ensure system security. The aim of this study is to compare traditional and instrumental inspection methods of the wooden poles in service in AES Sul power distribution network (Montenegro, RS). The inspections were conducted in about 180 poles in two measurement campaigns (2001 and 2010). The procedure was based on the traditional inspection (visual inspection, percussion and effort lateral) and instrumental method based on Polux equipment that measures the penetration resistance and moisture content of wood. The results were compared in search of assertiveness of the methods used to subsidize the standardization of inspection procedures. (author)

  15. Contribution to the spectrographic determination of impurities in uranium by the carrier distillation method; Nuevas aportaciones a la determinacion espectrografica de impurezas en materiales de uranio por el metodo de distilacion fraccionada con portador

    Energy Technology Data Exchange (ETDEWEB)

    Capdevila, C.

    1967-07-01

    The carrier distillation method for the determination of impurities in uranium has been modified in order to get a greater sensitivity. Electrodes 9.5 mm. diam. with a crater 7 mm. diam. and 10 mm. deep have been used, being the weigh of charge 300 mg.. The elements considered were: Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Pb, Si, Sn, Ti and V, over the range 0.01 to 30 ppm. (Author) 13 refs.

  16. Development of and horizontal seams wining system by means of galleries and chambers; Demostracion de un Sistema de Explotacion de Capas Horizontales por el Metodo de Pilares y Galerias Trazadas Integramente con Maquinas de Ataque Puntual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The project Development of an horizontal seams wining system by means of galleries and chambers aimed on the solution of a mining problem kept unresolved during the last 35 years in Carrasconte mine, owned by the society Minero Siderurgica de Ponferrada, in the coal yield of Villablino, Leon, Spain. The problem was a horizontal seam, with a width from 2,5 to 3,5 m, with two specific characteristics; one, roof and floor extremely rigid, with a 30 m sandstone stratum by roof that practically could highly restrict the long wall face conventional system, and the other, an intercalation of shale with a width of 1,2 m and a hardness of near 400 kg/cm2 that required a suitable winning system. By means of investigation with galleries carried out by continuous miners the real width of shale intercalation was stated, an then suitable systems adopted as this width varied. So, short wall faces in areas with minimum shale were disposed, and in t areas with maximum shale width, two long wall faces each one in each different vein were designed. At the end, the borders of reserves were recovered by the conventional system of galleries and chambers. This development project has allowed to recover more than a million tons in three years by systems suitable to the different conditions of the seam. (Author)

  17. Analytical synthetic methods of solution of neutron transport equation with diffusion theory approaches energy multigroup; Metodos sinteticos analiticos de solucao da equacao de transporte de neutrons com aproximacoes da teoria da difusao multigrupo de energia

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Pedro Gabriel B.; Leite, Michel C.A.; Barros, Ricardo C., E-mail: pgbmoraes@gmail.com, E-mail: chell_leite@hotmail.com, E-mail: rcbarros@pq.cnpq.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico. Departamento de Modelagem Computacional

    2013-07-01

    In this work we developed a software to model and generate results in tables and graphs of one-dimensional neutron transport problems in multi-group formulation of energy. The numerical method we use to solve the problem of neutron diffusion is analytic, thus eliminating the truncation errors that appear in classical numerical methods, e.g., the method of finite differences. This numerical analytical method increases the computational efficiency, since they are not refined spatial discretization necessary because for any spatial discretization grids used, the numerical result generated for the same point of the domain remains unchanged unless the rounding errors of computational finite arithmetic. We chose to develop a computational application in MatLab platform for numerical computation and program interface is simple and easy with knobs. We consider important to model this neutron transport problem with a fixed source in the context of shielding calculations of radiation that protects the biosphere, and could be sensitive to ionizing radiation.

  18. Coupling between the differential and perturbation theory methods for calculating sensitivity coefficients in nuclear transmutation problems; Acoplamento entre os metodos diferencial e da teoria da perturbacao para o calculo dos coeficientes de sensibilidade em problemas de transmutacao nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Lubianka Ferrari Russo

    2014-07-01

    The main target of this study is to introduce a new method for calculating the coefficients of sensibility through the union of differential method and generalized perturbation theory, which are the two methods generally used in reactor physics to obtain such variables. These two methods, separated, have some issues turning the sensibility coefficients calculation slower or computationally exhaustive. However, putting them together, it is possible to repair these issues and build a new equation for the coefficient of sensibility. The method introduced in this study was applied in a PWR reactor, where it was performed the sensibility analysis for the production and {sup 239}Pu conversion rate during 120 days (1 cycle) of burnup. The computational code used for both burnup and sensibility analysis, the CINEW, was developed in this study and all the results were compared with codes widely used in reactor physics, such as CINDER and SERPENT. The new mathematical method for calculating the sensibility coefficients and the code CINEW provide good numerical agility and also good efficiency and security, once the new method, when compared with traditional ones, provide satisfactory results, even when the other methods use different mathematical approaches. The burnup analysis, performed using the code CINEW, was compared with the code CINDER, showing an acceptable variation, though CINDER presents some computational issues due to the period it was built. The originality of this study is the application of such method in problems involving temporal dependence and, not least, the elaboration of the first national code for burnup and sensitivity analysis. (author)

  19. Transmission of Helicobacter pylori via water for human consumption. Determination by means of the molecular method using PCR; Helicobacter pylori, su transmision a traves de las aguas para el consumo humano. Determinacion por metodo molecular con la PCR

    Energy Technology Data Exchange (ETDEWEB)

    Amo, A. J.; Moreno, C.; Apraiz, D.; Catalan, V. [LABAQUA. Alicante (Spain)

    1998-12-31

    Helicobacter pylori is the cause of chronic gastritis, duodenal ulcers and stomach cancer. Its natural reservoirs and transmission mechanisms are still little understood. The gastro-oral route-especially vomiting and regurgitation-is one transmission path, especially in young children and babies. It has been found in some patients saliva and dental plaque, which suggests a possible oral-oral contagion route. The discovery of H. Pylori human excrement points to a faecal-oral route as the main transmission pathway via water for human consumption. It is therefore important to develop detection methods such as isolation by culture and polymerase chain reaction (PCR) to effectively monitor this pathogen in human drinking water. (Author) 30 refs.

  20. Synthesis and characterization of Ni-CeO{sub 2} catalysts by the hydrothermal method; Sintesis y caracterizacion de catalizadores de Ni-CeO{sub 2} por el metodo hidrotermal

    Energy Technology Data Exchange (ETDEWEB)

    Lazcano O, I.

    2013-07-01

    At the present time the necessity exists to reduce the level of atmospheric pollutants, because these are the main originators of such problems as: the greenhouse effect, acid rain, global heating, among others and that are affecting the human being seriously. In this context, is necessary to look for new solutions that contribute to the improvement of the problems without appealing to limitations in the energy production, because this would imply a non only delay in the economic development, but also in the cultural, technological and of research in our country. An alternative for the energy solution is the use of renewable fuels, because they will decrease the production costs with the time, as well as to diminish the dependence of the fossil fuels, contributing this way to the improvement of the environment quality. The use of the hydrogen as an alternating fuel to the petroleum, is intends as energy solution. The objective of the present work is to develop Ni-CeO{sub 2} catalysts through the hydrothermal method for the hydrogen production starting from the partial oxidation reaction of methanol for the clean fuel generation that does not produce polluting emissions to the environment. As well as, to determine the importance of the metallic load in the catalytic activity for which catalysts to 1 and 2% in weight of Ni were prepared. To achieve these objective different techniques were used to characterize the prepared catalysts, as: Temperature Programmed Reduction to evidence the metal-support interaction, Scanning Electron Microscopy (Sem) to determine the morphology of the catalysts, Surface Area (Bet) with respect to the adsorption-desorption of N{sub 2} and X-Rays Diffraction (XRD) to know the crystalline structure of the catalysts. Also the catalytic properties (activity and selectivity) were studied under the reaction: CH{sub 3}OH + 1/2 O{sub 2} obtaining as products to the CO{sub 2} + 2H{sub 2}, with the help of the multi-tasks equipment Rig-100 that operated to temperatures among 200 at 450 C. In the results was observed that the Ni-CeO{sub 2} catalyst to 2% in nickel weight was more efficient in the interval of 275 to 400 C regarding the catalyst to 1% of Ni and the CeO{sub 2} matrix. (Author)

  1. Analysis of the thermoluminescent signal in the hydroxyapatite synthesized by the sol-gel method; Analisis de la senal termoluminiscente en la hidroxiapatita sintetizada por el metodo sol gel

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza A, D.; Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Lobato, M.; Rubio, E.; Rodriguez L, V. [Fac. de Ingenieria Quimica, BUAP, Av. San Claudio y 18 Sur, Col. San Manuel, 72570 Puebla (Mexico); Custodio, E. [Universidad Juarez Autonoma de Tabasco, DACB, Carr. Cunduacan-Jalpa Km. 1.5, 86680 Tabasco (Mexico)

    2004-07-01

    The physical properties of the ceramics are related with the chemical bonds and the crystalline structure, because the elements that constitute it can be united by ionic bonds or partially ionic giving a covalent character, this last causes that the outer layer is full of electrons. This property makes that the ceramic ones become interesting materials for thermoluminescent applications, as it demonstrates through the recent works presented on the hydroxyapatite that is a ceramic biomaterials that has shown an interesting thermoluminescent signal when being exposed to gamma radiation. In this sense, this work presents the thermoluminescent signal analysis induced by the UV and gamma radiation in a particular type of hydroxyapatite synthesized by sol gel method in which the temperature synthesis is varied. The final thermoluminescent sensitivity of materials is correlated with the crystalline degree, which is analysed through X-ray diffraction. (Author)

  2. Supersonic flow with shock waves. Monte-Carlo calculations for low density plasma. I; Flujo supersonico de un plasma con ondas de choque, un metodo de montecarlo para plasmas de baja densidad, I.

    Energy Technology Data Exchange (ETDEWEB)

    Almenara, E.; Hidalgo, M.; Saviron, J. M.

    1980-07-01

    This Report gives preliminary information about a Monte Carlo procedure to simulate supersonic flow past a body of a low density plasma in the transition regime. A computer program has been written for a UNIVAC 1108 machine to account for a plasma composed by neutral molecules and positive and negative ions. Different and rather general body geometries can be analyzed. Special attention is played to tho detached shock waves growth In front of the body. (Author) 30 refs.

  3. The two means method for the attenuation coefficient determination of archaeological ceramics from the North of Parana; Metodo dos dois meios para a determinacao do coeficiente de atenuacao de ceramicas arqueologicas do norte do Parana

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Richard Maximiliano Cunha e

    1997-12-31

    This work reports an alternative methodology for the linear attenuation coefficient determination ({mu} {rho}) of irregular form samples, in such a way that is not necessary to consider the sample thickness. With this methodology, indigenous archaeological ceramics fragments from the region of Londrina, north of Parana, were studied. These ceramics fragments belong to the Kaingaing and Tupiguarani traditions. The equation for the {mu} {rho} determination employing the two mean method was obtained and it was used for {mu} {rho} determination by the gamma ray beam attenuation if immersed ceramics, by turns, in two different means with known linear attenuation coefficient. By the other side, {mu} theoretical value was determined with the XCOM computer code. This code uses as input the ceramics chemistry composition and provides an energy versus mass attenuation coefficient table. In order to validate the two mean method validation, five ceramics samples of thickness 1.15 cm and 1.87 cm were prepared with homogeneous clay. Using these ceramics, {mu} {rho} was determined using the attenuation method, and the two mean method. The result obtained for {mu} {rho} and its respective deviation were compared for these samples, for the two methods. With the obtained results, it was concluded that the two means method is good for the linear attenuation coefficient determination of materials of irregular shape, what is suitable, specially, for archaeometric studies. (author) 25 refs., 29 figs., 28 tabs.

  4. Avaliação experimental dos metodos de prevenção de fissuras na interface alvenaria de vedação e pilar de concreto

    OpenAIRE

    Andre Penteado Tramontin

    2005-01-01

    Resumo: As fissuras na interface alvenaria-estrutura são comuns e pouco se conhece a respeito da sua ocorrência, embora sejam freqüentes, especialmente as que aparecem na ligação alvenaria-pilar de concreto. O objetivo deste trabalho foi estudar a melhor técnica de ancoragem entre alvenaria-estrutura, avaliando sua eficiência no combate a esse tipo de fissura. Foram utilizados para a elaboração dos ensaios, além dos materiais usados na alvenaria de vedação (bloco cerâmico, argamassa etc), dif...

  5. Uso integrado de metodos de simulação de eventos discretos e continuos na resolução de problems logisticos em parques de diversão

    OpenAIRE

    Sergio Adriano Loureiro

    2009-01-01

    Resumo: O objetivo deste estudo é desenvolver um modelo integrado de simulação de eventos discretos e contínuos que permita descrever e avaliar a dinâmica dos processos de gerenciamento de uma operação de serviços. O modelo foi desenvolvido especificamente no setor de entretenimento para um parque de diversões, sendo um instrumento de auxilio a análise de desempenho e desenvolvimento de políticas de operação. A importância do tema proposto esta na carência de pesquisas acadêmicas brasileiras ...

  6. Oral fox immunization against rabies in Italy: efficiency of the method and results / Esperienze italiane di immunizzazione orale delle volpi contro la rabbia: validità del metodo e risultati ottenuti

    Directory of Open Access Journals (Sweden)

    Angelo Civardi

    1991-07-01

    Full Text Available Abstract From 1984 to 1987 six campaigns of oral fox vaccination against Rabies by living modified antirabies vaccine (SAD-B 19 were carried out in the province of Brescia (Central Alps and in the provinces of Bolzano and Trento (Eastern Alps. The oral fox vaccination has been shown to be a rapid and safe method to estinguish enzootic foci of sylvatic Rabies. Laboratory tests have been performed in order to control the presence of tetracycline, the serum conversion and the presence of wild or attenutated viruses in the nervous tissue of foxes and other wild animals. Results confirm the effectiveness of the method. Riassunto Sono esposti i risultati degli esperimenti di immunizzazione orale della Volpe (Vulpes vulpes contro la rabbia silvestre in Italia, illustrando la preparazione e l'esecuzione dei piani di vaccinazione, il monitoraggio delle volpi ed i relativi controlli di laboratorio. Dal 1984 al 1987 sono state compiute 6 campagne vaccinali che hanno interessato le province di Brescia, Trento e Bolzano. I risultati ottenuti confermano la validità della vaccinazione orale della Volpe come strumento di lotta e di profilassi contro la rabbia silvestre.

  7. The influence of calcium magnesium, and sodium on the spectrographic analysis of natural waters; Estudio de la influencia del calcio, magnesio y sodio en un metodo de analisis espectrografico de aguas naturales

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Guerra, J. P.; Capdevilla, C.

    1969-07-01

    The influences of 1000 {mu}g/ml of calcium and sodium and 300 {mu}g/ml of magnesium, on the spectrographic determination of Al, Ba, Cr, Fe, Li , Mn, Ni, Pb, Sr and Ti, minor constituents in natural waters, have been studied, In order to eliminate them, the elements Ga, In, La, Ti and Zn, as well as a mixture containing 30 % Tl-70 % In, have been tested as spectrochemical buffers. (Author) 7 refs.

  8. Application of CalME incremental-recursive method to the evaluation of the structural condition as asphalt pavements; Aplicacion del metodo recursivo-incremental CalME a la evaluacion del estado estructural de los pavimentos bituminosas

    Energy Technology Data Exchange (ETDEWEB)

    Mateos Moreno, A.; Perez Ayuso, J.; Cadavid Jauregui, B.; Marron Fernandez, J. O.

    2011-07-01

    CalME procedure represents one of the most advanced tools for the design, of flexible pavements world-wide. It is an incremental-recursive method, which means that pavements service life must be divided into many time intervals where both structural integrity and environmental conditions can be regarded as constants. It also means that the damage calculated at the end of each interval must be considered as initial condition for the next one. The goal of this type of models is the prediction of the evolution of the different distress mechanisms. The advantages of incremental-recursive procedures versus classical analytical design are shown in this paper. Advantages are shown not only in terms of design, but also as a tool in order to support structural evaluation. In particular, the potential of asphalt fatigue model incorporated in CalME is presented. this model is initially calibrated in the laboratory, and it is then re-calibrated based on the actual performance observed from field deflection testing. The model provides a reliable prediction of the future evolution of the damage of the asphalt mixture. Fatigue model validation has been conducted based on the performance from several flexible sections evaluated in CEDEX full-scale pavements test track. (Author) 14 refs.

  9. Hydraulic conductivity obtained by instantaneous profile method using retention curve and neutron probes and Genuchten model; Condutividade hidraulica obtida pelo metodo do perfil instantaneo utilizando curva de retencao e sonda de neutrons e pelo modelo de Genuchten

    Energy Technology Data Exchange (ETDEWEB)

    Berretta, Ana Lucia Olmedo

    1999-07-01

    The hydraulic conductivity is one of the most important parameters to understand the movement of water in the unsaturated zone. Reliable estimations are difficult to obtain, once the hydraulic conductivity is highly variable. This study was carried out at 'Escola Superior de Agricultura Luiz de Queiroz', Universidade de Sao Paulo, in a Kandiudalfic Eutrudox soil. The hydraulic conductivity was determined by a direct and an indirect method. The instantaneous profile method was described and the hydraulic conductivity as a function of soil water content was determined by solving the Richards equation. Tensiometers were used to estimate the total soil water potential, and the neutron probe and the soil retention curve were used to estimate soil water content in the direct method. The neutron probe showed to be not adequately sensible to the changes of soil water content in this soil. Despite of the soil retention curve provides best correlation values to soil water content as a function of water redistribution time, the soil water content in this soil did not vary too much till the depth of 50 cm, reflecting the influence of the presence of a Bt horizon. The soil retention curve was well fitted by the van Genuchten model used as an indirect method. The values of the van Genuchten and the experimental relative hydraulic conductivity obtained by the instantaneous profile method provided a good correlation. However, the values estimated by the model were always lower than that ones obtained experimentally. (author)

  10. Boundary integral method application in the transportation modeling of radioactive tracers in porous ways; Aplicacao do metodo da integral de contorno na modelagem do transporte de tracadores radioativos em meios porosos

    Energy Technology Data Exchange (ETDEWEB)

    Ferroni, Jose Geraldo

    1996-03-01

    This work describes a method for estimating the effluent concentrations of radioactive tracers in production wells, considering well to well injection tests and piston-like displacements of fluids in the reservoir. The model for tracer transportation takes into account effects of convection and hydrodynamic dispersion. (author)

  11. Validation of quantitative {sup 1}H NMR method for the analysis of pharmaceutical formulations; Validacao de metodo quantitativo por RMN de {sup 1}H para analises de formulacoes farmaceuticas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maiara da S. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Quimica; Colnago, Luiz Alberto, E-mail: luiz.colnago@embrapa.br [Embrapa Instrumentacao, Sao Carlos, SP (Brazil)

    2013-09-01

    The need for effective and reliable quality control in products from pharmaceutical industries renders the analyses of their active ingredients and constituents of great importance. This study presents the theoretical basis of Superscript-One H NMR for quantitative analyses and an example of the method validation according to Resolution RE N. 899 by the Brazilian National Health Surveillance Agency (ANVISA), in which the compound paracetamol was the active ingredient. All evaluated parameters (selectivity, linearity, accuracy, repeatability and robustness) showed satisfactory results. It was concluded that a single NMR measurement provides structural and quantitative information of active components and excipients in the sample. (author)

  12. Quantification of the curvature of the spine by a method based on the projection harmful structured light; Cuantificacion de la curvatura de la columna vertebral mediante un metodo no lesivo basado en la proyeccion de luz estructurada

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de la O, F. J.; Cibrian, R.; Salvador, R.; Gonzalez-Pena, R.; Minguez, M. F.; Pino, L.; Jover, A.; Guillen, J.; Reinado, D.; Cortina, T.; Chinillach, N.; Dalmases, F.; Romero, M. C.; Martinez-Celerio, R.; Diez, R.; Rosello, J.

    2011-07-01

    This paper shows the application of a method for determining harmful surface topography based on structured light, to find back the topography of the variables that create a characteristic pattern and differentiating between different groups. Once the topography has calculated three angles along the backbone that characterize its curvature. This pattern has been determined for two study groups, one of athletes and other patients with scoliosis.

  13. Observability in electric power networks: a method of ways of factorization in state estimation with equality restrictions; Observabilidade em redes de energia: um metodo de caminhos de fatoracao em estimacao de estado com restricoes de igualdade

    Energy Technology Data Exchange (ETDEWEB)

    Vicentino, Flavio Antonio

    1997-07-01

    A theory of network observability that mixes graph concepts and factorization of the gain matrix G has been recently developed. It uses data already available in Power System Operating Centers. That theory is easy to understand and implement and does not require subroutines other than the ones used in static state estimation. However, this new theory has been implemented only for the case of state estimation in Normal Equation Formulation (N E). However, the N E Method presents some inherent numerical difficulties. Such numerical difficulties are usually related to the disparity in the measurements weights (high values for zero-injections measurements and low values for pseudo-measurements) and the presence of short lines in the network, as well. In order to solve such numerical difficulties, new methods have come up, such as: Normal Equation Method with Equality Constraints (N E/C), where Lagrange's Multiplier Method can be applied to minimize a function while satisfying a set of constraints; Hachtel's Method, which is formulated the same way as N E/C Method, although an equation of residual vector is introduced in solution process; Hybrid Method, which is a general formulation behaving as the N E/C Method at one extreme, and as Hachtel's Method at the other. Thus, the aim of this work is to treat the adaptation of the network observability Method by using path graphs, with the state estimation in the form of a minimization problem with equality constraints. As the Hybrid Method is a generalization form of the state estimator with constraints, this formulation is used to develop the proposed theory. Extreme case (as the pure Hachtel's Method) are also considered. (author)

  14. The radioactive equilibrium and determination methods for ratio e Ra/U; Desequilibrio Radiactivos-1. Metodo {sub {beta}}-{gamma}. Determinacion de la razon eRa/U. Valoracion del contenido en U{sub 3}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Mingarro, E.

    1966-07-01

    The main problems concerning the radioactive non-equilibrium on minerals and a simultaneous counting procedure for {beta}- and {gamma}- activities developed to solve those problems, are described. (Author)

  15. Evaluation of fracture toughness in dental ceramics using indentation and SEVNB (Single Edge V-Notched Beam)-method; Avaliacao da tenacidade a fratura de ceramicas dentarias atraves do metodo de entalhe - SEVNB (Single Edge V-Notched Beam)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, L.A.; Santos, C.; Souza, R.C.; Ribeiro, S. [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia de Lorena. Dept. de Engenharia de Materiais. Polo Urbo-Industrial; Strecker, K. [Universidade Federal de Sao Joao del-Rei (DME/UFSJ), MG (Brazil). Dept. de Materiais Eletricos; Oberacker, R. [Karlsruhe Univ. (Germany)

    2009-07-01

    In this work, the fracture toughness of different ceramics based on Al{sub 2}O{sub 3} and ZrO{sub 2} were evaluated using, comparatively two methods, Vickers indentation and SEVNB (Single Edge V-Notched Beam) method. Al{sub 2}O{sub 3}, ZrO{sub 2}(3%Y{sub 2}O{sub 3}) micro-particled and ZrO{sub 2}(3%Y{sub 2}O{sub 3}) nanometric, ZrO{sub 2}-Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}-ZrO{sub 2} composites were sintered at different temperatures. Samples were characterized by relative density, X-ray diffraction, SEM, and mechanical evaluation by hardness, bending strength and fracture toughness obtained by ickers indentation and SEVNB-method. The results were presented comparing the densification and microstructural results. Furthermore, the advantages and limitations of each method were discussed. (author)

  16. Implementation of the automated potentiometric titration method for total U at the CNEN Safeguard Laboratory, Brazil; Implementacao do metodo de titulacao potenciometrica automatizado para U total no Laboratorio de Salvaguardas da CNEN, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, Barbara F.G.; Delgado, Jose U.; Araujo, Radier M.S. de; Silva, Jose W.S. da; Barros, Pedro D. de, E-mail: barbara@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Brazilian nuclear facilities, in accordance with the regulation CNEN-NN-2.02, must have available measurement systems which allow to determine their nuclear material inventories. For the evaluation and the follow up the performance of the involved laboratories in those measurement systems, the accomplishment of interlaboratory comparison programmes becomes fundamental. Therefore, the implementation of the potentiometric titration viewing the characterization of uranium samples, represents an reference element for the Brazilian programs

  17. Estudio comparativo de los metodos analitico-sintetico y global en el aprendizaje de la lectura (Comparative Study of the Analytical-Synthetical (Phonics) and Global (Sight) Reading Methods).

    Science.gov (United States)

    Carbonell de Grompone, Maria A.; And Others

    An investigation into the phonics and sight methods of reading instruction being taught in Uruguay schools seeks valid predictions in support of each approach. The study, written in Spanish, examines the progressive reading habits and abilities of 12 first-grade classes. Teachers assigned to teach each method uniformly had equivalent training and…

  18. Fourier descriptors analysis of anisotropy and preferred Orientation in geological samples; Analisis de la anisotropia y la orientacion preferente en materiales geologicos mediante el Metodo de Descriptoes de Fourier

    Energy Technology Data Exchange (ETDEWEB)

    Santiago Buey, C. de

    2011-07-01

    This study focuses on the use of Fourier descriptors to evaluate and quantify two specific fabric characteristics of geological materials: anisotropy of particles or voids morphologies and particle orientation. To this end, a theoretical section of a rock was created, made of ellipses and rectangles of different axes ratios and different orientations. The Fourier descriptors method was applied to calculate the anisotropy and orientation of each particle and, finally, a rose diagram was constructed to represent the particles orientations distribution and to observe the presence or not of any preferred orientation. (Author) 15 refs.

  19. Characterization of gadolinia-doped ceria with manganese addition synthesized by the cation complexation technique; Caracterizacao de ceria-gadolinia e ceria-gadolinia-manganes sintetizados pelo metodo de complexacao de cations

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.D.; Muccillo, R.; Muccillo, E.N.S., E-mail: enavarro@usp.b [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais; Rocha, R.A. [Universidade Federal do ABC (CEMCSA/UFABC), Santo Andre, SP (Brazil). Centro de Engenharia, Modelagem e Ciencias Sociais Aplicadas

    2010-07-01

    Ceria-based compounds may be used for several technological applications like catalysts, grinding media and materials for electrolyte and electrodes in solid oxide fuel cells. For most of these applications fine powders are required. In this work, nanostructured ceria powders containing 20 mol % gadolinia with and without manganese addition were synthesized by the cation complexation technique. The prepared powders were calcined at 600 deg C for thermal decomposition of the metal citrate precursors. Results of X-ray diffraction, scanning electron microscopy and specific surface area evidenced the role of manganese on physical characteristics of the nanostructured materials. The cation complexation technique revealed to be a promising method for obtaining nanostructured powders with high yield and suitable physical properties for several technological applications. (author)

  20. Radiation field characterization of a BNCT research facility using Monte Carlo Method - Code MCNP-4B; Caracterizacao do campo de radiacao numa instalacao para pesquisa em BNCT o metodo de Monte Carlo Codigo - MCNP-4B

    Energy Technology Data Exchange (ETDEWEB)

    Hernandes, Antonio Carlos

    2002-07-01

    Boron Neutron Capture Therapy - BNCT- is a selective cancer treatment and arises as an alternative therapy to treat cancer when usual techniques - surgery, chemotherapy or radiotherapy - show no satisfactory results. The main proposal of this work is to project a facility to BNCT studies. This facility relies on the use of an AmBe neutron source and on a set of moderators, filters and shielding which will provide the best neutron/gamma beam characteristic for these BNCT studies, i.e., high intensity thermal and/or epithermal neutron fluxes and with the minimum feasible gamma rays and fast neutrons contaminants. A computational model of the experiment was used to obtain the radiation field in the sample irradiation position. The calculations have been performed with the MCNP 4B Monte Carlo Code and the results obtained can be regarded as satisfactory, i.e., a thermal neutron fluency {Nu}{sub {Tau}} = 1,35x10{sup 8} n/cm{sup 2}, a fast neutron dose of 5,86x{sup -1}0 Gy/{Nu}{sub {Tau}} and a gamma ray dose of 8,30x{sup -14} Gy/{Nu}{sub {Tau}}. (author)

  1. Radiation field characterization of a BNCT research facility using Monte Carlo method - code MCNP-4B; Caracterizacao do campo de radiacao numa instalacao para pesquisa em BNCT utilizando o metodo de Monte Carlo - codigo MCNP-4B

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Antonio Carlos

    2002-07-01

    Boron Neutron Capture Therapy - BNCT - is a selective cancer treatment and arises as an alternative therapy to treat cancer when usual techniques - surgery, chemotherapy or radiotherapy - show no satisfactory results. The main proposal of this work is to project a facility to BNCT studies. This facility relies on the use of an Am Be neutron source and on a set of moderators, filters and shielding which will provide the best neutron/gamma beam characteristic for these Becton studies, i.e., high intensity thermal and/or epithermal neutron fluxes and with the minimum feasible gamma rays and fast neutrons contaminants. A computational model of the experiment was used to obtain the radiation field in the sample irradiation position. The calculations have been performed with the MCNP 4B Monte Carlo Code and the results obtained can be regarded as satisfactory, i.e., a thermal neutron fluencyN{sub T} = 1,35x10{sup 8} n/cm , a fast neutron dose of 5,86x10{sup -10} Gy/N{sub T} and a gamma ray dose of 8,30x10{sup -14} Gy/N{sub T}. (author)

  2. Evaluation of the shield calculation adequacy of radiotherapy rooms through Monte Carlo Method and experimental measures; Avaliacao da adequacao do calculo de blindagens de salas de radioterapia atraves do metodo de Monte Carlos e medidas experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Meireles, Ramiro Conceicao

    2016-07-01

    The shielding calculation methodology for radiotherapy services adopted in Brazil and in several countries is that described in publication 151 of the National Council on Radiation Protection and Measurements (NCRP 151). This methodology however, markedly employs several approaches that can impact both in the construction cost and in the radiological safety of the facility. Although this methodology is currently well established by the high level of use, some parameters employed in the calculation methodology did not undergo to a detailed assessment to evaluate the impact of the various approaches considered. In this work the MCNP5 Monte Carlo code was used with the purpose of evaluating the above mentioned approaches. TVLs values were obtained for photons in conventional concrete (2.35g / cm{sup 3}), considering the energies of 6, 10 and 25 MeV, respectively, first considering an isotropic radiation source impinging perpendicular to the barriers, and subsequently a lead head shielding emitting a shaped beam, in the format of a pyramid trunk. Primary barriers safety margins, taking in account the head shielding emitting photon beam pyramid-shaped in the energies of 6, 10, 15 and 18 MeV were assessed. A study was conducted considering the attenuation provided by the patient's body in the energies of 6,10, 15 and 18 MeV, leading to new attenuation factors. Experimental measurements were performed in a real radiotherapy room, in order to map the leakage radiation emitted by the accelerator head shielding and the results obtained were employed in the Monte Carlo simulation, as well as to validate the entire study. The study results indicate that the TVLs values provided by (NCRP, 2005) show discrepancies in comparison with the values obtained by simulation and that there may be some barriers that are calculated with insufficient thickness. Furthermore, the simulation results show that the additional safety margins considered when calculating the width of the primary barrier of radiotherapy rooms are conservative. They also show that the attenuation provided by the patient's body decreases with increased energy, with the highest attenuation being 0.54, for the energy of 6 MeV. (author)

  3. Seeking tools for image fusion between computed tomography, structural and functional magnetic resonance methods for applications in neurosurgery; Ferramentas para fusao de imagens dos metodos de tomografia computadorizada, ressonancia magnetica e ressonancia magnetica funcional para aplicacao pre-neurocirurgica

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Liana Guerra Sanches da, E-mail: liana@einstein.br [Departamento de Diagnostico por Imagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo (SP) (Brazil); Amaro Junior, Edson [Faculdade de Medicina, Universidade de Sao Paulo - USP, Sao Paulo, SP (Brazil). Deptartamento de Diagnostico por Imagem; Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    To evaluate tools for the fusion of images generated by tomography and structural and functional magnetic resonance imaging. Methods: Magnetic resonance and functional magnetic resonance imaging were performed while a volunteer who had previously undergone cranial tomography performed motor and somatosensory tasks in a 3-Tesla scanner. Image data were analyzed with different programs, and the results were compared. Results: We constructed a flow chart of computational processes that allowed measurement of the spatial congruence between the methods. There was no single computational tool that contained the entire set of functions necessary to achieve the goal. Conclusion: The fusion of the images from the three methods proved to be feasible with the use of four free-access software programs (OsiriX, Register, MRIcro and FSL). Our results may serve as a basis for building software that will be useful as a virtual tool prior to neurosurgery. (author)

  4. Calibration method for a in vivo measurement system using mathematical simulation of the radiation source and the detector; Metodo de calibracao de um sistema de medida in vivo atraves da simulacao matematica da fonte de radiacao e do detector

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, John

    1998-12-31

    A Monte Carlo program which uses a voxel phantom has been developed to simulate in vivo measurement systems for calibration purposes. The calibration method presented here employs a mathematical phantom, produced in the form of volume elements (voxels), obtained through Magnetic Resonance Images of the human body. The calibration method uses the Monte Carlo technique to simulate the tissue contamination, the transport of the photons through the tissues and the detection of the radiation. The program simulates the transport and detection of photons between 0.035 and 2 MeV and uses, for the body representation, a voxel phantom with a format of 871 slices each of 277 x 148 picture elements. The Monte Carlo code was applied to the calibration of in vivo systems and to estimate differences in counting efficiencies between homogeneous and non-homogeneous radionuclide distributions in the lung. Calculations show a factor of 20 between deposition of {sup 241} Am at the back compared with the front of the lung. The program was also used to estimate the {sup 137} Cs body burden of an internally contaminated individual, counted with an 8 x 4 Nal (TI) detector and an {sup 241} Am body burden of an internally contaminated individual, who was counted using a planar germanium detector. (author) 24 refs., 38 figs., 23 tabs.

  5. Organophosphorus pentavalent compounds: history, synthetic methods of preparation and application as insecticides and antitumor agents; Compostos organofosforados pentavalentes: historico, metodos sinteticos de preparacao e aplicacoes como inseticidas e agentes antitumorais

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Viviane Martins Rebello dos; Donnici, Claudio Luis [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Quimica; DaCosta, Joao Batista Neves; Caixeiro, Janaina Marques Rodrigues [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica]. E-mail: dacosta@ufrrj.br

    2007-01-15

    This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives. (author)

  6. Calculation method for electric power transmission towers isolation considering the risks-of-failure; Metodo de calculo de isolamento de torres de transmissao de energia eletrica face ao risco desejado para surto de manobra

    Energy Technology Data Exchange (ETDEWEB)

    Negrisoli, Manoel E.M.

    1989-12-31

    This work aims to present a method which permits an optimized design of the transmission towers insulating structures for a specified risk-of-failure, under different types of electrical stresses to which they might be submitted, considering statistical probabilities of unfavorable atmospheric conditions (pressure, temperature, humidity and wind speeds), amplitudes of voltage surges and its distribution along the line, as well as the number of parallel tower gaps and insulator swings. Convention design methods are used for a preliminary design based on all types of overvoltage stresses. The risk of failure is calculated considering the atmospheric conditions along the line route. Adjustments should be made until the design can be considered satisfactory and its risk-of-failure complies to the specified one. In order to complete the tower insulation coordination project, an evaluation of lightning impulse performance should be made. 24 refs., 41 figs., 6 tabs.

  7. Arsenic Mobility and Availability in Sediments by Application of BCR Sequential Extractions Method; Movilidad y Disponibilidad de Arsenico en Sedimentos Mediante la Aplicacion del Metodo de Extracciones Secuenciales BCR

    Energy Technology Data Exchange (ETDEWEB)

    Larios, R.; Fernandez, R.; Rucandio, M. I.

    2011-05-13

    Arsenic is a metalloid found in nature, both naturally and due to anthropogenic activities. Among them, mining works are an important source of arsenic release to the environment. Asturias is a region where important mercury mines were exploited, and in them arsenic occurs in para genesis with mercury minerals. The toxicity and mobility of this element depends on the chemical species it is found. Fractionation studies are required to analyze the mobility of this metalloid in soils and sediments. Among them, the proposed by the Bureau Community of Reference (BCR) is one of the most employed. This method attempts to divide up, by operationally defined stages, the amount of this element associated with carbonates (fraction 1), iron and manganese oxy hydroxides (fraction 2), organic matter and sulphides (fraction 3), and finally as the amount associated residual fraction to primary and secondary minerals, that is, from the most labile fractions to the most refractory ones. Fractionation of arsenic in sediments from two mines in Asturias were studied, La Soterrana and Los Rueldos. Sediments from La Soterrana showed high levels of arsenic in the non-residual phases, indicating that the majority of arsenic has an anthropogenic origin. By contrast, in sediments from Los Rueldos most of the arsenic is concentrated in the residual phase, indicating that this element remains bound to very refractory primary minerals, as is also demonstrated by the strong correlation of arsenic fractionation and the fractionation of elements present in refractory minerals, such as iron, aluminum and titanium. (Author) 51 refs.

  8. Analysis of a calculation method for the determination of the value of safety or control bars; Analisis de un metodo de calculo para la determinacion del valor de barras de seguridad o control

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F.; Torres A, C.; Filio L, C. [ININ, Gcia. de Reactores, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1982-09-15

    Due to the control or safety bars in a nuclear reactor are constituted by strongly absorbent materials, the Diffusion Theory like tool for the calculation of bar values is not directly applicable, should it use the Transport Theory. However the speed and economy of the Diffusion codes for the reactors calculation, those make attractiveness and by this reason its are used in the determination of characteristic parameters and even in the determination of bar values, not without before to make some theoretical developments that allow to make applicable this theory. The application of the Diffusion Theory in strongly absorbent media is based on the use of some effective cross sections distinct from the real ones obtained when imposing the reason that among the flow and it gradient in the external surface of such media (control element in general, bar type or flagstone) be similar to the one obtained using Transport Theory in all the control region (multiplicative and absorbent media) with those real cross sections. The effective cross sections were obtained of the Leopard-NUMICE cell code which has incorporate the respective calculation theory of effective cross sections. Later these constants its were used in the bidimensional diffusion code Exterminator-II, simulating in it, the distribution of safety or control bars. From the cell code its were also obtained the respective constants of the homogeneous fuel cell. The results as soon as those obtained bar values of the diffusion code, its were compared with some experimental results obtained in the R{phi} Swedish reactor of natural uranium and heavy water. In this work an analysis of the bar value of one of them, trying to determine the applicability of the method is made. (Author)

  9. Analisis comparativo de una metaheuristica en base a algoritmo genetico vs un metodo de ramificacion y corte para un caso de entrega y recolección con restricciones de ventana de horario

    Directory of Open Access Journals (Sweden)

    Lopez, F.

    2004-07-01

    Full Text Available En la solución de problemas combinatorios, es importante evaluar el costo-beneficio entre la obtención de soluciones de alta calidad en detrimento de los recursos computacionales requeridos. El problema planteado es para el ruteo de un vehículo con entrega y recolección de producto y con restricciones de ventana de horario. En la práctica, dicho problema requiere ser atendido con instancias de gran escala (nodos ≥100. Existe un fuerte porcentaje de ventanas de horario activas (≥90% y con factores de amplitud ≥75%. El problema es NP-hard y por tal motivo la aplicación de un método de solución exacta para resolverlo en la práctica, está limitado por el tiempo requerido para la actividad de ruteo. Se propone un algoritmo genético especializado, el cual ofrece soluciones de buena calidad (% de optimalidad aceptables y en tiempos de ejecución computacional que hacen útil su aplicación en la práctica de la logística. Para comprobar la eficacia de la propuesta algorítmica se desarrolla un diseño experimental el cual hará uso de las soluciones óptimas obtenidas mediante un algoritmo de ramificación y corte sin límite de tiempo. Los resultados son favorables.

  10. Development of a new technic for breast attenuation correction in myocardial perfusion scintigraphy using computational methods; Desenvolvimento de uma nova tecnica para correcao da atenuacao por tecidos moles em cintilografia de perfusao miocardica utilizando metodos computacionais

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Anderson de

    2015-07-01

    Introduction: One of the limitations of nuclear medicine studies are false-positive results that lead to unnecessary exams and procedures associated to morbidity and costs to the individual and society. One of the most frequent causes for reducing the specificity of myocardial perfusion imaging (MPI) is photon attenuation, especially by breast in women. Objective: To develop a new technique to compensate the photon attenuation by women breasts in myocardial perfusion imaging with {sup 99m}Tc-sestamibi, using computational methods. Materials and methods: A procedure was proposed which integrates Monte Carlo simulation, computational methods and experimental techniques. Initially, were obtained the chest attenuation correction percentages using a phantom Jaszczak and breast attenuation percentages by Monte Carlo simulation method, using the EGS4 program. The percentages of attenuation correction were linked to individual patients' characteristics by an artificial neural network and a multivariate analysis. A preliminary technical validation was done by comparing the results of the MPI and catheterism (CAT), before and after applying the technique to 4 patients. The t test for parametric data, Wilcoxon, Mann-Whitney and X{sup 2} for the others were used. Probability values less than 0.05 were considered statistically significant. Results: Each increment of 1 cm in the thickness of breast was associated to an average increment of 6% on photon attenuation, while the maximum increase related to breast composition was about 2%. The average chest attenuation percentage per unit was 2.9%. Both, the artificial neural network and linear regression, showed an error less than 3% as predictive models for percentage of female attenuation. The anatomical-functional correlation between MPI and CAT was maintained after the use of the technique. Conclusion: Results suggest that the proposed technique is promising and could be a possible alternative to other conventional methods employed today. (author)

  11. Hurdle technology to preserve the 'Golden' papaya post harvest quality;Metodos combinados para preservar a qualidade pos-colheita do mamao 'Golden' tipo exportacao

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, Andrea Cristina Fialho, E-mail: molinari_af@yahoo.co

    2007-07-01

    With the purpose of evaluating a combination of post harvest techniques on papaya Golden storage, the following treatments were investigated: carton boxes packaging (CP); CP + plastic bag of PEBD - low density polyethylene film, with 0.05mm of thickness (PE); CP + PEBD with 0.025mm of thickness impregnated with mineral ethylene scavenger (PEAbs); gamma-irradiation (0.4 kGy and 0.7 kGy); and refrigerated storage at 10 deg C e 90% of relative humidity for 2, 5, 10, 15, 20, 25, 30 and 35 days plus five days under environmental conditions to allow ripening and to simulate the product marketing. To evaluate the effects on fruit quality the following measurements were taken: - first experiment, disease incidence, skin color and loss of turgidity (as visual variables); skin and flesh color, weight loss, flesh firmness, total soluble solids, total titratable acidity, pH, lycopene and beta-carotene composition; - second experiment, sensorial analysis on samples submitted to the treatments with better results from the first experiment. Post harvest diseases were the main factor responsible for discarding fruits. Percentage of weight loss was higher on papayas stored without plastic packaging. Time affected the flesh firmness (F = 95%). However, there wasn't influence of the treatments on that parameter. A significant effect on skin color was observed with interaction between irradiation (0.4 and 0.7 kGy) and storage period. Once reached the edible stage, irradiated papayas presented more uniformity on skin color. For beta-carotene and Lycopene, the mean values were 1.27 to 1.79 and 19.16 to 23.90 mug/ml of flesh, respectively. But those substances weren't affected by the combined methods or the time. The same behavior were observed for total soluble solids, total titratable acidity and pH (mean values of 11.53 to 12.20 deg Brix, 0.117 to 0.136 g of citric acid/100g of flesh and 4.91 to 5.04, respectively). On sensory evaluation, the judges didn't get to detect significant differences among papayas submitted to different treatments. A synergism was verified on the techniques combination, with the best results obtained from the association of CP + PEabs + gamma-irradiation at 0.4 kGy, which reached a total storage period of 35 days. Thus, that is the post harvest hurdle technology recommend for exporting 'Golden' papayas to markets with quarantine restrictions to fruit-flies (author)

  12. Effect of synthesis method on the preparation of lanthanum chromite for using as ceramic pigment; Influencia do metodo de sintese na preparacao de cromita de lantanio para utilizacao como pigmento ceramico

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, G.C.B.; Ferreira, K.M.B.; Pimentel, P.M., E-mail: gerbeson_dantas@hotmail.com [Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro, RN (Brazil); Melo, D.M.A.; Gomes, D.K.S.; Costa, A.F. [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2016-07-01

    In this paper, LaCrO3 perovskites were synthesized by two synthesis methods, in order to compare these methods in function of microstructure and optical properties. The synthesis routes employed were a method that use gelatin as organic precursor and microwave assisted auto-combustion. The resulting powders were calcined at 800 ° C and 1000 ° C for obtaining the perovskite phase. Then, they were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM); UV-Visible spectroscopy and colorimetric analysis for color identification. No significant changes were observed in the powders synthesized by two routes. The oxides presented orthorhombic perovskite structure. The powders synthesized by the gelatin method were single phase. Chromite lanthanide presented grayish hue being darker in perovskites calcined at higher temperatures. (author)

  13. Influence of coprecipitation and mechanical mixture methods on the characteristics of nickel oxide-alumina composites; Influencia dos metodos de coprecipitacao e mistura mecanica nas caracteristicas de compositos oxido de niquel-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, G.L.; Yoshito, W.K.; Ussui, V.; Lima, N.B. de; Lazar, D.R.R., E-mail: gcordeiro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2014-07-01

    Alumina-supported nickel catalysts are currently used in the reforming process due to low cost and high activity for hydrogen production from alcohols. In this work, the effect of preparation methods on nickel oxide-alumina based materials has been investigated. Nickel content was fixed at 15 wt%. Ceramic powders were obtained by coprecipitation in ammonia medium and mechanical mixture. Coprecipitated materials were calcined in air at 750 deg C to obtain the corresponding oxides. Materials obtained by mechanical mixture were prepared by wet milling of nickel oxide and alumina powders, both synthesized by precipitation and calcination in air at 450 and 750 deg C, respectively. Powders were characterized by X-ray diffraction, nitrogen gas sorption by applying the BET method, laser diffraction, scanning electron microscopy, electrophoretic mobility measurements for zeta potential determination and infrared spectroscopy. The results showed that coprecipitation method allowed the production of mixed oxides with high surface area (232,7 ± 3,2 m{sup 2}.g{sup -1}) and normal granulometric distribution while mechanical mixture led to the formation of materials constituted by gamma alumina and nickel oxide phases, with low surface area (136,2 ± 0,5 m{sup 2}.g{sup -1}) and bimodal granulometric distribution. (author)

  14. Method for calibration of asymmetric jaws in hemi fields techniques and effects in clinical practice; Metodo para la calibracion de las mandibulas asimetricas en tecnicas de hemicampos y efectos en la practica clinica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Masgrau, V.; Sempau Roma, J.; Abella Cereigido, R.; Lopez Sanchez, M.; Perez Fernandez, M.; Gonzalez Leyba, M.; Artigues Pedrola, M.

    2013-07-01

    This paper presents a method improved very significantly the accuracy of calibration, providing a good homogeneity of the dose distribution in the area of union of fields. Also evaluates the effect that has this new calibration in clinical practice. (Author)

  15. Petroleum reservoir fault reactivation problem analysis through finite element viscodamage model; Analise de problema de reativacao de falha em reservatorio de petroleo por modelo de viscodano via metodo dos elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Julliana de P.V.; Guimaraes, Leonardo J. do N.; Gomes, Igor F.; Pontes Filho, Ivaldo Dario da S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2008-07-01

    Recently, many new constitutive models for geomechanical materials were developed taking into account its complex behavior. The continuum damage mechanics, formulated according to irreversible thermodynamics principles, can be used to model materials subjected to degradation of its mechanical properties. Reservoir depletion may result in compaction and subsidence that induces fault reactivation, among others consequences. The fault reactivation problem in petroleum reservoirs has been widely studied as its changes completely the flow regime in subsurface. Isotropic damage model can be used to model the fault reactivation process, where its hydro-mechanical properties (stiffness and permeability) are affected during the reservoir production. In this paper, a fault reactivation case in a synthetic reservoir is presented and a sensibility analysis is carried out to identify the main variables that influence this process. (author)

  16. Operational performance study of pipelines of liquid movement using data envelopment analyses method; Estudo de desempenho operacional de dutos de movimentacao de liquidos atraves do metodo analise envoltoria de dados

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcellos, Vinicius A. [Infotec Consultoria e Planejamento, Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This study implements a mathematical technique of Operational Research named Data Envelopment Analysis (DEA) to identify the operational best practices in a group of light petroleum products pipelines. DEA method evaluates efficiency of each unit (pipeline), based on a model compound 2 inputs (BHP potency and diameter) and 2 outputs (nominal flow, moved volume per km). Performance targets are established for units considered inefficient, according to reference information obtained from the system efficient units. (author)

  17. Microscopic model for the non-linear fluctuating hydrodynamic of {sup 4} He superfluid helium deduced by maximum entropy method; Modelo microscopico para la hidrodinamica fluctuante no lineal del {sup 4}He superfluido deducido mediante el metodo de maxima entropia

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T

    1998-10-01

    This thesis presents a microscopic model for the non-linear fluctuating hydrodynamic of superfluid helium ({sup 4} He), model developed by means of the Maximum Entropy Method (Maxent). In the chapter 1, it is demonstrated the necessity to developing a microscopic model for the fluctuating hydrodynamic of the superfluid helium, starting from to show a brief overview of the theories and experiments developed in order to explain the behavior of the superfluid helium. On the other hand, it is presented the Morozov heuristic method for the construction of the non-linear hydrodynamic fluctuating of simple fluid. Method that will be generalized for the construction of the non-linear fluctuating hydrodynamic of the superfluid helium. Besides, it is presented a brief summary of the content of the thesis. In the chapter 2, it is reproduced the construction of a Generalized Fokker-Planck equation, (GFP), for a distribution function associated with the coarse grained variables. Function defined with aid of a nonequilibrium statistical operator {rho}hut{sub FP} that is evaluated as Wigneris function through {rho}{sub CG} obtained by Maxent. Later this equation of GFP is reduced to a non-linear local FP equation from considering a slow and Markov process in the coarse grained variables. In this equation appears a matrix D{sub mn} defined with a nonequilibrium coarse grained statistical operator {rho}hut{sub CG}, matrix elements are used in the construction of the non-linear fluctuating hydrodynamics equations of the superfluid helium. In the chapter 3, the Lagrange multipliers are evaluated for to determine {rho}hut{sub CG} by means of the local equilibrium statistical operator {rho}hut{sub l}-tilde with the hypothesis that the system presents small fluctuations. Also are determined the currents associated with the coarse grained variables and furthermore are evaluated the matrix elements D{sub mn} but with aid of a quasi equilibrium statistical operator {rho}hut{sub qe} instead of the local equilibrium operator {rho}hut{sub l}-tilde. Matrix elements that lead to the local transport coefficients for the superfluid helium, by means of a generalization of the Green-Kubo fluctuation-dissipation relation, in analogy with the results present in the Appendix A, obtained with a local equilibrium statistical operator {rho}hut{sub l}-tilde. Specified the Lagrange multipliers, the currents and the local transport coefficients, a non-linear local FP equation is determined for the superfluid helium in the Fourier space. Starting with such FP equation their associated non-linear equations of the Langevin type are built, where the random forces that appear are of multiplicative type. Forces that are expressed as the product of Gaussian random variables and local variablesin such way that the variances of the random variables are independent of the local variables. Finally, applying the Fourier inverse transformed to the non-linear equations of the Langevin type in the space of Fourier, the equations of the non-linear fluctuating hydrodynamic are built for the superfluid helium in the configuration space. Lastly, in the chapter 4, it is presented a discussion of the results and the conclusions of this thesis. (Author)

  18. Recovery of the external anticorrosion protection systems of onshore pipelines - evaluation methods and practical results; Recuperacao de sistemas de protecao anticorrosiva externa de dutos terrestres - metodos de avaliacao e resultados praticos

    Energy Technology Data Exchange (ETDEWEB)

    Castinheiras, Wilson; Koebsch, Andre; Silva, Flavio A. da [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    The rehabilitation of an old pipeline means to increase its lifetime, making it safety to operate in the necessaries conditions to transport the product. The pipe steel wall evaluation, related to it thickness reduction, due to, basically, internal and external corrosion, is fundamental to guide its rehabilitation. The techniques used to this evaluation are 'pig' and specials field survey. These last surveys are realized over the soil surface (digs is not necessary to access the pipeline or the pipeline operation is not necessary to stop) and objective to verify the pipeline coating and Cathodic Protection System conditions. Due to the actual authors experience, this paper will only treat of the Rehabilitation of the External Anti corrosive Protection System (coating and cathodic protection) of onshore pipelines. This paper present the techniques current attenuation, ON-OFF pipe-to-soil potential close interval survey and DCVG and same practical results obtained with the application of these techniques on the Sergipe/Bahia gas pipeline. (author)

  19. Spectrometry and emission tomographic image reconstruction stimulated by neutrons via EM algorithm and Monte Carlo Method; Espectrometria e reconstrucao de imagens tomograficas de emissao estimulada por neutrons via algoritmo EM e metodo de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Rodrigo Sartorelo Salemi

    2014-07-01

    The NSECT (Neutron Stimulated Emission Computed Tomography) figures as a new spectrographic technique able to evaluate in vivo the concentration of elements using the inelastic scattering reaction (n,n'). Since its introduction, several improvements have been proposed with the aim of investigating applications for clinical diagnosis and reduction of absorbed dose associated with CT acquisition. In this context, two new diagnostic applications are presented using spectroscopic and tomographic approaches from NSECT. A new methodology has also been proposed to optimize the sinogram sampling that is directly related to the quality of the reconstruction by the irradiation protocol. The studies were developed based on simulations with MCNP5 code. Diagnosis of Renal Cell Carcinoma (RCC) and the detection of breast microcalcifications were evaluated in studies conducted using a human phantom. The obtained results demonstrate the ability of the NSECT technique to detect changes in the composition of the modeled tissues as a function of the development of evaluated pathologies. The proposed method for optimizing sinograms was able to analytically simulate the composition of the irradiated medium allowing the assessment of quality of reconstruction and effective dose in terms of the sampling rate. However, future research must be conducted to quantify the sensitivity of detection according to the selected elements. (author)

  20. Obtain ceramic porous alumina-zirconia by replica method calcium phosphate coated; Oobtencao de ceramicas porosas de alumina-zirconia pelo metodo da replica recobertas com fosfato de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.D.R.; Rigoli, W.R.; Osiro, Denise; Pallone, E.M.J.A., E-mail: adinizrs@yahoo.com.br [Universidade de Sao Paulo (FZEA/USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Lobo, A.O. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil)

    2016-07-01

    Biomaterials used in bone replacement, including porous bioceramics, are often used as support structure for bone formation and repair. The porous bioceramics are used because present features as biocompatibility, high porosity and pore morphology that confer adequate mechanical strength and induce bone growth. In this work were obtained porous specimens of alumina containing 5% by inclusion of volume of zirconia produced by the replica method. The porous specimens had its surface chemically treated with phosphoric acid and were coated with calcium phosphate. The coating was performed using the biomimetic method during 14 days and an initial pH of 6.1. The porous specimens were characterized using the follow techniques: porosity, axial compression tests, microtomography, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and pH measurements SBF solution. The results showed specimens with suitable pore morphology for application as biomaterial, and even a reduced time of incubation favored the calcium phosphate phases formation on the material surfaces. (author)

  1. Study of the calcination temperature in samples of calcium phosphate synthesized by the method of direct way; Estudo da temperatura de calcinacao em amostras de fosfatos de calcio sintetizadas pelo metodo de via direta

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M.G.; Santos, P.T.A.; Costa, A.C.F.M, E-mail: patyquimica@hotmail.com [Universidade Federal de Campina Grande (DEMA/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2012-07-01

    The use of phosphates in bioceramics have attracted the interest of many researchers, especially when it is in the Ca / P = 1.67, which allows the obtention of the hydroxyapatite. This work aims to investigate different calcination temperatures on the structural and morphological characteristics of samples of calcium phosphates synthesized by the method of direct way, aiming for hydroxyapatite as a major phase. For this purpose, we used the calcium hydroxide and phosphoric acid in the Ca / P = 1.67. The samples were calcined at temperatures of 600, 700, 800, 900, 1000, 1100, 1200 and 1350°C/2h, and characterized by XRD, FTIR and Size Distribution. The XRD showed that 600-800°C, the major phase is the tricalcium phosphate, 900-1100°C, there is a phase calcium pyrophosphate. And at 1200 and 1350 ° C, there is a phase monetite. The infrared spectrum showed the characteristic vibrations of calcium phosphates in all conditions studied. It was observed from the results of FTIR presence of bands of the P-OH group and HPO{sub 4}{sup 2-}, PO{sub 4}{sup 3}, for all temperatures studied. The highest average size of agglomerates of 108.05 mM was observed for the temperature of 1100 ° C. (author)

  2. Calibration of the identiFINDER detector for the iodine measurement in thyroid using the Monte Carlo method; Calibracion del detector identiFINDER para la medicion de yodo en tiroides utilizando el metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ramos M, D.; Yera S, Y.; Lopez B, G. M.; Acosta R, N.; Vergara G, A., E-mail: dayana@cphr.edu.cu [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/ 41 y 47, Playa, 10600 La Habana (Cuba)

    2014-08-15

    This work is based on the determination of the detection efficiency of {sup 125}I and {sup 131}I in thyroid of the identiFINDER detector using the Monte Carlo method. The suitability of the calibration method is analyzed, when comparing the results of the direct Monte Carlo method with the corrected, choosing the latter because the differences with the real efficiency stayed below 10%. To simulate the detector their geometric parameters were optimized using a tomographic study, what allowed the uncertainties minimization of the estimates. Finally were obtained the simulations of the detector geometry-point source to find the correction factors to 5 cm, 15 cm and 25 cm, and those corresponding to the detector-simulator arrangement for the method validation and final calculation of the efficiency, demonstrating that in the Monte Carlo method implementation if simulates at a greater distance than the used in the Laboratory measurements an efficiency overestimation can be obtained, while if simulates at a shorter distance this will be underestimated, so should be simulated at the same distance to which will be measured in the reality. Also, is achieved the obtaining of the efficiency curves and minimum detectable activity for the measurement of {sup 131}I and {sup 125}I. In general is achieved the implementation of the Monte Carlo methodology for the identiFINDER calibration with the purpose of estimating the measured activity of iodine in thyroid. This method represents an ideal way to replace the lack of patterns solutions and simulators assuring the capacities of the Internal Contamination Laboratory of the Centro de Proteccion e Higiene de las Radiaciones are always calibrated for the iodine measurement in thyroid. (author)

  3. Dating of the archaeological site 'El Tigre' by the thermoluminescent method; Fechamiento del sitio arqueologico 'El Tigre' por el metodo de termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Portilla, R. De la [ENAH, Periferico Sur y Zapote, 14030 Mexico D.F. (Mexico); Gonzalez, P.R.; Mendoza, D. [ININ, 52750 La Marquesa, Ocoyoacac, Estado de Mexico (Mexico); Vargas, E. [Instituto de Investigaciones Antropologicas, UNAM, 04510 Mexico D.F. (Mexico); Ramirez, A. [Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico)

    2007-07-01

    Full text: The dating of pre hispanic pottery, is supported by techniques such as stratigraphy, typology, in physical and chemical procedures, as the analysis of {sup 14}C and the thermoluminescence (TL). The last one permits us obtain absolute dating of archaeological pottery with an acceptable precision. In this work we apply the applied the thermoluminescent technique to verify the age of the Pre-Classic and Classic Terminal periods proposed for the archaeological site 'El Tigre', Campeche. The samples were obtained during a work period and the radiation of the ground of background (emitted by the ground), as well as the contribution of the cosmic radiation was measured with thermoluminescent dosemeters of LiF: Mg,Cu,P + PTFE, put in the sample zone. The preliminary results indicate that not all the analyzed samples can be dated. The viability of the dating of the samples is discussed based on the fact and function of the presence of certain crystalline phases such as calcite and quartz. The discussion is complemented emphsizing the importance of handling the conditions of handling of samples. (Author)

  4. Comparison between methods for fixing radioactive iodine in silver substrate for manufacturing brachytherapy sources; Comparacao entre metodos de fixacao do iodo radioativo em substrato de prata para confeccao de fontes utilizadas em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Carla Daruich

    2012-07-01

    Among the different ways to treat prostate cancer, brachytherapy with iodine- 125 seeds is an option that provides good results and fewer side effects. In the present study several deposition methods of radioactive iodine in a silver substrate were compared in order to choose the most suitable alternative for the routine production to be implemented at IPEN's laboratory. The methodology used was chosen based on the available infrastructure and experience of the researchers present. Therefore, the {sup 131}I was used for testing (same chemical behavior as {sup 131}I). Four methods were selected: Method 1 (test based on electrodeposition method developed by D.Kubiatowicz) presented 65.16% efficiency; Method 2 (chemical reaction based on the method developed by D. Kubiatowicz - HCl) with the result of 70.80% efficiency; method 3 (chemical reaction based on the method developed by Dr. Maria Elisa Rostelato) with 55.80% efficiency; Method 4 (IQ-IPEN) resulted in 99% efficiency. Since this method has more radioactive material fixation (which represents virtually the entire cost of the seed), the final price is the cheapest. This method is the suggested one to be implemented in the IPEN's laboratory for brachytherapy sources production. Besides, the method is the fasted one. (author)

  5. Refinement by Rietveld method of a rolled sheet Al-Mg-Si 6063 alloy with preferential orientation; Refinamento pelo metodo de Rietveld de uma chapa laminada com orientacao preferencial da liga Al-Mg-Si 6063

    Energy Technology Data Exchange (ETDEWEB)

    Carrio, J.A.G.; Hattori, C.S.; Miranda, L.F.; Domingues Junior, N.I. [Universidade Mackenzie, Sao Paulo, SP (Brazil); Lima, N.B.; Couto, A.A.; Aguiar, A.A., E-mail: acouto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    The Rietveld refinement of a sample with preferential orientation was accomplished using data of X ray diffraction of a rolled 6063 aluminum alloy. The refinement of the preferential orientation by spherical harmonic was accomplished using a symmetry of sample mmm (rolling) until the order of 8 and was compared with experimental pole figures. The four pole figures presented indicate a sharp texture of the planes (111), (200), (220) and (311). The calculated pole figures obtained from the refinement of the X ray diffraction spectrum can incur in mistakes of preferential orientation. This happens because the measure is restricted to the planes parallel to the surface without inference to the symmetry of the sample. (author)

  6. Determination of viscosity of fayalite slags for kv model and measurements by means of inclined plane; Estimacion de la viscosidad de escorias fayaliticas utilizando el modelo de calculo kv y el metodo experimental del plano inclinado

    Energy Technology Data Exchange (ETDEWEB)

    Bazan, V.; Goni, C.; Castella, L.; Brandaleze, E.; Verdeja, L. F.; Parra, R.

    2006-07-01

    The viscosity of the lands represents one of the most relevant variables of most of the processes metallurgical and kinetics of the refine operations, since it is one of the decisive factors of the efficiency in the reactions between metal and lag, as much as slag-refractory. In the last decades, the mathematical models of different metallurgical processes have established methods to predict viscosity of mixtures of oxides fused to high temperatures in function of the chemical composition. The model developed by Toguri, based on the data reported by Johasen and Winterhager et al has proposed the Kv model. The used index it is similar to the relationship used in the steel industry like the basicity index. It is presented in this work values determined of viscosity in experimental form by means of the technique of inclined plane. (Author)

  7. Steam and solvent injection as an advanced recovering method for heavy oil reservoirs; Injecao de vapor e solvente como um metodo de recuperacao avancada em reservatorios de oleo pesado

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Edney Rafael V.P.; Rodrigues, Marcos Allyson F.; Barbosa, Janaina Medeiros D.; Barillas, Jennys Lourdes M.; Dutra Junior, Tarcilio V.; Mata, Wilson da [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    Currently a resource more and more used by the petroleum industry to increase the efficiency of steam flood mechanism is the addition of solvents. The process can be understood as a combination of a thermal method (steam injection) with a miscible method (solvent injection), promoting, thus, the reduction of interfacial tensions and oil viscosity. The mobility of the displaced fluid is then improved, resulting in an increase of oil recovery. To better understand this improved oil recovery method, a numerical study of the process was driven contemplating the effects of some operational parameters (distance between wells, injection fluids rate, kind of solvent and injected solvent volume) on the accumulated production of oil and recovery factor. Semisynthetic models were used in this study but reservoir data can be extrapolated for practical applications situations on Potiguar Basin. Simulations were performed in STARS (CMG, 2007.11). It was found that injected solvent volumes increased oil recovery and oil rates. Further the majority of the injected solvent was produced and can be recycled. (author)

  8. Spectra and depth-dose deposition in a polymethylmethacrylate breast phantom obtained by experimental and Monte Carlo method; Espectros e deposicao de dose em profundidade em phantom de mama de polimetilmetacrilato: obtencao experimental e por metodo de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    David, Mariano G.; Pires, Evandro J.; Magalhaes, Luis A.; Almeida, Carlos E. de; Alves, Carlos F.E., E-mail: marianogd08@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Lab. Ciencias Radiologicas; Albuquerque, Marcos A. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Instituto Alberto Luiz Coimbra; Bernal, Mario A. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin; Peixoto, Jose G. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2012-08-15

    This paper focuses on the obtainment, using experimental and Monte Carlo-simulated (MMC) methods, of the photon spectra at various depths and depth-dose deposition curves for x-rays beams used in mammography, obtained on a polymethylmethacrylate (PMMA) breast phantom. Spectra were obtained for 28 and 30 kV quality-beams and the corresponding average energy values (Emed) were calculated. For the experimental acquisition was used a Si-PIN photodiode spectrometer and for the MMC simulations the PENELOPE code was employed. The simulated and the experimental spectra show a very good agreement, which was corroborated by the low differences found between the Emed values. An increase in the Emed values and a strong attenuation of the beam through the depth of the PMMA phantom was also observed. (author)

  9. Method of semi-automatic high precision potentiometric titration for characterization of uranium compounds; Metodo de titulacao potenciometrica de alta precisao semi-automatizado para a caracterizacao de compostos de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, Barbara Fernandes G.; Dias, Fabio C.; Barros, Pedro D. de; Araujo, Radier Mario S. de; Delgado, Jose Ubiratan; Silva, Jose Wanderley S. da, E-mail: barbara@ird.gov.b, E-mail: fabio@ird.gov.b, E-mail: pedrodio@ird.gov.b, E-mail: radier@ird.gov.b, E-mail: delgado@ird.gov.b, E-mail: wanderley@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Lopes, Ricardo T., E-mail: ricardo@lin.ufrj.b [Universidade Federal do Rio de Janeiro (LIN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Lab. de Instrumentacao Nuclear

    2011-10-26

    The method of high precision potentiometric titration is widely used in the certification and characterization of uranium compounds. In order to reduce the analysis and diminish the influence if the annalist, a semi-automatic version of the method was developed at the safeguards laboratory of the CNEN-RJ, Brazil. The method was applied with traceability guaranteed by use of primary standard of potassium dichromate. The standard uncertainty combined in the determination of concentration of total uranium was of the order of 0.01%, which is better related to traditionally methods used by the nuclear installations which is of the order of 0.1%

  10. TL dosimeters for gamma and thermal neutrons used at ENEA. Accuracy and calibration standards; Dosimetri a TL per neutroni termici e gamma impiegati in ENEA: metodo, calibrazione e qualificazione

    Energy Technology Data Exchange (ETDEWEB)

    Fantuzzi, E.; Gualdrini, G.F.; Monteventi, F.; Morelli, B.; Uleri, G. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1998-07-01

    This work summaries the experimental results achieved on the characterisation of dosimetric systems used at ENEA (National Agency for New Technology, Energy and the Environment) laboratory in Bologna (Italy) and describes the calibration method either for a two-element dosemeter Harshaw and for a two-element dosemeter assembled at ENEA with higher sensitivity LiF detectors. Both calculation algorithm and calibration procedure have been defined and analyzed in terms of the dosimetric reference quantities. In addition, parameters responsible and crucial for the dosimetric reference quantities. In addition, parameters responsible and crucial for the dosimetric results are pointed out. Finally, intercomparisons between experimental data and numerical data (Monte Carlo code) are shown. [Italian] Vengono esposti i metodi utilizzati per la calibrazione di un dosimetro Harshaw e di uno con maggiore sensibilita' prodotto dal centro ENEA di Bologna con LiF. Sono stati definiti sia l'algoritmo di calcolo sia la procedura di calibrazione ed analizzate le problematiche legate alle grandezze di riferimento. Sono state inoltre individuate le specifiche variabili che possono incidere sul dato dosimetrico ed infine esposti i risultati di interconfronti sperimentali e di calcolo con tecnica Monte Carlo.

  11. A comparative analysis of the EEDF obtained by Regularization and by Least square fit methods; Un analisis comparativo de la EEDF obtenido por metodos de regularizacion y por un ajuste de minimos cuadrados

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Flores Ll, H. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    The second derived of the characteristic curve current-voltage (I - V) of a Langmuir probe (I - V) is numerically calculated using the Tikhonov method for to determine the distribution function of the electrons energy (EEDF). One comparison of the obtained EEDF and a fit by least square are discussed (LS). The I - V experimental curve is obtained in a plasma source in the electron cyclotron resonance (ECR) using a cylindrical probe. The parameters of plasma are determined of the EEDF by means of the Laframboise theory. For the case of the LS fit, the obtained results are similar to those obtained by the Tikhonov method, but in the first case the procedure is slow to achieve the best fit. (Author)

  12. Seed prepare for oil content determination by NMR method in six cotton varieties; Preparo de sementes para determinacao do teor de oleo pelo metodo de RMN em seis variedades de algodoeiro

    Energy Technology Data Exchange (ETDEWEB)

    Gondim-Tomaz, Rose Marry Araujo; Erismann, Norma de Magalhaes; Sabino, Nelson Paulieri; Kondo, Julio Isao; Cia, Edivaldo; Azzini, Anisio [Instituto Agronomico de Campinas, SP (Brazil). Centro de Algodao e Fibrosas Diversas]. E-mail: gondim@cec.iac.br; Soave, Daise [Instituto Agronomico de Campinas, SP (Brazil). Centro de Genetica, Biologia Molecular e Fitoquimica

    1998-07-01

    Three comparative methods (chemical seed-delinting with sulphuric acid solution, flaming and seed with linter) to prepare cotton seeds for oil determination by the Nuclear Magnetic Resonance (NMR) technique were considered. The chemical treatment with sulphuric acid was the best as long the linter interference was eliminated. The seed oil contents were determined by the NMR method in six cotton varieties from the national variety test. The IAPAR (Instituto Agronomico do Parana) 71 PR3 and IAC (Instituto Agronomico de Campinas) 20 varieties presented the highest oil content followed by the CNPA 7H, CS 50, IAC 22 and CNPA Precoce 2. (author)

  13. Durand, Guadet e Wagner. L'evoluzione del metodo compositivo tra XIX e XX secolo / Durand, Guadet and Wagner. The evolution of the compositive method between 19th and 20th Century

    Directory of Open Access Journals (Sweden)

    Andrés Caballero Lobera

    2017-01-01

    Full Text Available Il XIX secolo fu un’epoca convulsa per quanto riguarda l’evoluzione del pensiero architettonico. In quanto apice del pensiero illuminista del secolo precedente, tale epoca si manifestò nelle forme dell’architettura storica e allo stesso tempo divenne l’immagine della modernità, stabilendo le basi di quel razionalismo, che avrebbe costruito, ai margini della storia, la sua idea di forma. Tre dei maggiori protagonisti di questo sviluppo, sia per quanto riguarda il loro lavoro di architetti, che come insegnanti, furono Jean-Nicolas-Louis Durand, Julien Guadet e Otto Wagner / The 19th century was a time of upheaval in the development of architectonic thinking. As culmination of the enlightened thinking of the previous century it expressed itself through historical form, and as a reflection of modernity, it established the bases for a rationalist-based architecture that would construct its wish for form outside the margins of history. We highlight the teaching work of three professors and architects in the construction of that thinking: Durand, Guadet and Wagner.

  14. Structural and morphological characterization of TiO{sub 2} powders prepared using Pechini and combustion reaction; Caracterizacao estrutural e morfologica de nanopos de TiO{sub 2} preparados pelo metodo Pechini e por reacao de combustao

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, P.C.; Almeida, E.P.; Costa, A.C.F.M. da; Lira, H.L., E-mail: pollyanacae@yahoo.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    TiO{sub 2} is a semiconductor oxide and polymorphic and can exist in three crystallographic forms: anatase, rutile and broquita, and forms anatase and rutile are the major interests in scientific research. Thus, this study aims to synthesize TiO{sub 2} by Pechini methods and combustion reaction and to evaluate the influence of synthesis methods in structural and morphological characteristics of the samples. The nanopowders were characterized by X-ray diffraction, nitrogen adsorption, and particle size distribution and scanning electron microscopy. The results of X-ray diffraction showed that the samples obtained by the Pechini method showed the single phase anatase with crystallite size of 20 nm and surface area of 49.44 m{sup 2}/g, whereas the samples synthesized by combustion reaction using glycine as fuel showed the rutile phase as major phase and traces of anatase phase, with crystallite size of 65 nm and surface area 4.34 m{sup 2}/g. (author)

  15. Determination of silicon and chromium content in gray cast iron by the Van der Pauw method; Determinacion del contenido de silicio y cromo en fundiciones grises mediante el metodo de Van der Pauw

    Energy Technology Data Exchange (ETDEWEB)

    Tremps, E.; Enrique, J. L.; Moron, C.; Garcia, A.; Gomez, A.

    2013-07-01

    In this paper we show a system based on the resistivity measurement of samples of gray cast iron by the Van der Pauw method to calculate the silicon content in the samples. Twenty five trials have been carried out, studying resistive and metallographic characteristics of the samples. This has demonstrated that it is possible to obtain, by this method, the silicon content in molten flat with low content of alloying elements, also the content of chromium in series smelters where the rate of silicon remains constant. (Author)

  16. SÍNTESIS DE ÓXIDOS DE SILICIO DE ALTAS ÁREA SUPERFICIAL Y POROSIDAD EMPLEANDO EL METODO SOL-GEL EN PRESENCIA DE GLICEROL Y MONOESTEARATO DE GLICERILO COMO ESTRUCTURANTES

    Directory of Open Access Journals (Sweden)

    JUAN PEÑA

    2008-01-01

    Full Text Available Este trabajo reporta una forma novedosa para la producción de óxidos de silicio (sílice porosos mediante la técnica sol-gel usando tetraetilortosilicato (TEOS como precursor de silicio y como orientadores de la estructura porosa glicerol (Gly y monoestearato de glicerilo (ME, los cuales son de bajo costo y de alta disponibilidad comercial. Las sílices obtenidas presentan características porosas interesantes para una potencial aplicación en catálisis heterogénea, como por ejemplo áreas superficiales (método BET de alrededor de 736.3 m2/g, volumen total de poros de 0.41 cm3/g y estrecha distribución de tamaños de poro (método BJH de aproximadamente 36 Å.

  17. Comparative analysis between P1 and B1 equations for neutron moderation; Analise comparativa entre os metodos de obtencao e das solucoes das equacoes P1 e B1 para moderacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    In order to calculate the neutron flux in nuclear reactors, B1 or P1 equations are solved by numerical methods for several groups of energy. The neutron fluxes obtained from the solutions of the B1 and P1 equations are similar when they are applied to large nuclear power reactors. However, an important difference between the two fluxes is that the system of P1 equations uses one more approximation than the B1 system and then, its flux is less precise. The present work shows the relations between both equations and analyzes for what conditions the two equations systems are equivalent. Furthermore, this equations are numerically solved in 54 groups of energy for a quadrangular arrange. (author)

  18. Comparative study of patient doses calculated with two methods for breast digital tomosynthesis; Estudio de los valores de dosis a pacientes en examenes de tomosintesis de mama estimados con dos metodos distintos

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, M.; Chevalier, M.; Calzado, A.; Garayo, J.; Valverde, J.

    2015-07-01

    In this study, the average glandular doses (DG) delivered in breast tomosynthesis examinations were estimated over a sample of 150 patients using two different methods. In method 1, the conversion factors air-kerma to DG used were those tabulated by Dance et al. and in method 2 were the ones from Feng et al. The protocol for the examination followed in the unit of this study consists in two views per breast, each view composed by a 2D acquisition and a tomosynthesis scan (3D). The resulting DG values from both methods present statistically significant differences (p=0.02) for the 2D modality and were similar for the 3D scan (p=0.22). The estimated median value of DG for the most frequent breasts (thicknesses between 50 and 60 mm) delivered in a single 3D acquisition is 1.7 mGy (36% and 17% higher than the value for the 2D mode estimated with each method) which lies far below the tolerances established by the Spanish Protocol Quality Control in Radiodiagnostic (2011). The total DG for a tomosynthesis examination (6.0 mGy) is a factor 2.4 higher than the dose delivered in a 2D examination with two views (method 1). (Author)

  19. Estudos com carotenoides de leveduras do genero Rhodotorula : desenvolvimento de metodo analitico, influencia de inibidores e cultivo em meio alternativo a base de caldo de cana-de-açucar

    OpenAIRE

    Fabio Marcio Squina

    2001-01-01

    Resumo: Os carotenóides compõem um grupo de pigmentos naturais amplamente distribuídos na natureza com grande diversidade de estruturas e funções. O interesse pelos carotenóides tem aumentado onsideravelmente nos últimos anos, havendo uma potencial demanda por fontes naturais destes compostos nas indústrias de alimentos, farmacêutica e cosmética. As principais fontes industriais de carotenóides são a síntese química e a extração a partir de plantas, porém são poucos os carotenóides que possue...

  20. Radioimmunoassay method for measurement of plasma androstenedione. Its validation in ovulatory women and in patients with polycystic ovarian syndrome; Metodo de radioimunoensaio para medida da androstenediona plasmatica. Validacao em mulheres ovulatorias e com sindrome dos ovarios policisticos

    Energy Technology Data Exchange (ETDEWEB)

    Vilanova Socorro Veras, Maria do; Silva e Rosa, Alzira Amelia; Moura, Marcos Dias de; Ferriano, Rui Alberto; Sa, Marcos Felipe Silva de [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    1995-01-01

    The present paper has as objective the standardization of a radioimmunoassay method for measurement of androstenedione. Ethyl ether was used for plasma extraction. The sensitivity of the method was 6,8 pg/tube; the reproducibility (inter assay error) was 15,6%; the precision (intrassay error) was 5,2%. As biological control, 20 ovulatory women showed median plasma values of 1250 pg/ml and 24 women with polycystic ovary syndrome presented median plasma values of 2.037 pg/ml. (author). 6 refs., 2 figs., 1 tab.

  1. A study on chemical element determinations in human nails by neutron activation analysis; Estudo sobre determinacao de elementos quimicos em unhas humanas pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, Thalita Pinheiro

    2012-07-01

    Nail analyses have been the object of study in order to assess the levels of elements accumulated in the human organism and to use this tissue to monitor environmental and occupational exposure, to evaluate the nutritional status, to verify intoxication by toxic metals and to diagnose or to prevent diseases. Nail analyses present advantages due to easy sample collection, storage, transportation and this tissue provides element level accumulation over time. However, there is controversy regarding the application of nail analysis data due to difficulties to establish reliable reference values or element concentration ranges as control values. The objective of this study was to evaluate the factors that can affect nail element concentrations for further sample analyses of a group of individuals by applying neutron activation analysis (NAA). Fingernails and toenails collected from adult individuals of both genders, aged 18 to 71 years, living in the Sao Paulo Metropolitan Region were cut in small fragments, cleaned and dried for analyses. Samples and element standards were irradiated for 16 h under a thermal neutron flux of about 4.5 x 10{sup 12} n cm{sup -2} s{sup -1} at the IEA-R1 nuclear research reactor followed by gamma ray spectrometry. Element concentrations for As, Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se and Zn were determined. For quality control of the analytical results, certified reference materials were analysed and the results showed good accuracy and precision with relative errors and relative standard deviations lower than 5.1 % and 11.6 %, respectively. Preliminary assays indicated that the contribution due to impurities from plastic involucres used in the irradiation as well as those from nail polishes is very low and could be considered negligible. Results from the nail sample cleaning process using distinct procedures indicated that HNO{sub 3} solution may cause sample dissolution. Sample homogeneity was verified by analysis of a sample in replicate. A comparison of finger and toenail results indicated significant differences (p= 0.05) for the elements Br, Co and Zn. Element concentration comparisons were also made with gender, age and body mass index (BMI) parameters and for the most part showed no significant differences. The differences were found for Zn concentrations when compared between genders in fingernail, for Cs when compared between ages in fingernail. Elements concentrations obtained for both finger and toenail samples presented wide variability and they were of the same order of magnitude or within ranges as those reported in published literature. (author)

  2. Dating by fission track method: study of neutron dosimetry with natural uranium thin films; Datacao com o metodo dos tracos de fissao: estudo da dosimetria de neutrons com filmes finos de uranio natural

    Energy Technology Data Exchange (ETDEWEB)

    Iunes, P.J.

    1990-06-01

    Fission track dating is described, focalizing the problem of the decay constant for spontaneous fission of {sup 238} U and the use of neutron dosimetry in fission track analysis. Experimental procedures using thin films of natural uranium as neutron dosimeters and its results are presented. The author shows a intercomparison between different thin films and between the dosimetry with thin film and other dosimetries. (M.V.M.). 52 refs, 12 figs, 9 tabs.

  3. Use of activation analysis method for determining trace elements in human nail clippings; Aplicacao do metodo de analise por ativacao a determinacao de elementos tracos em aparas de unhas humanas

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Amilton Reinaldo; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1999-11-01

    This work presents results obtained in nail clipping samples analyses. These nail samples were collected from healthy group of individuals and from patients with cystic fibrosis disease. Irradiation of nail clippings was carried out with a thermal neutron flux from 10{sup 11} to 10{sup 13} n.cm{sup -2}.s{sup -1} at the IEA-R1m nuclear research reactor and the elements Al, As, Br, Ca, cd, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Se and Zn were determined. The results obtained for healthy group were within the range of concentrations published, for normal population. However for several elements, the group of patients presented higher concentrations than those presented for healthy individuals. The precision and the accuracy of the results were evaluated by analyzing reference materials NIST 1577b Bovine Liver and 1566a Oyster Tissue. (author) 6 refs., 4 tabs.

  4. Neutron activation analysis applied to the determination of trace elements in human nails; Aplicacao do metodo de analise por ativacao com neutrons a determinacao de elementos traco em unhas humanas

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Amilton Reinaldo

    2001-07-01

    There is a considerable interest in the determination of trace elements in human nails in order to use this tissue as a monitor of nutritional and healthy status of individuals, of occupational exposure diseases and of the environmental contamination. In this work, instrumental neutron activation analysis was applied to determine trace elements in finger nail clippings to make comparisons between the elemental concentrations obtained in nails from healthy individuals of a control group and those from cystic fibrosis (CF) patients. Firstly, a protocol for sample collection and preparation for analysis was established. Finger and toe nail samples from CF patients were collected at the Instituto da Crianca of Medicine School, University of Sao Paulo, SP. The nail samples from control group were collected from healthy adults and from children living in Sao Paulo city, SP. These samples were cleaned by stirring them witha a diluted Triton X100 solution and then by washing with distilled water and acetone. The analytical procedure consisted of irradiation nail samples and elemental standards in the IEA-R1m nuclear reactor under thermal neutro flux of about 10{sup 12} n cm{sup -2} s{sup -1}, for short and long period irradiations. The activities of the radionuclides were measured using a gamma-ray spectrometer comprising an hyperpure Ge detector and associated electronic system. The biological reference materials Bovine Liver 1577b and Oyster Tissue 1566a, both from National Institute of Standards and Technology, USA were analysed in order to evaluate the accuracy and precision of the results. The analysis of variance (ANOVA) and F-test at the significance level of 5% were used to make a comparison between the sets of results obtained in this work. In the comparison of the results obtained for finger and toe nails from CF patients, the Br concentrations were higher in finger nails that those obtained for toe nails. For the control group of children, the finger nails presented different levels of Br, Cl, Cr, Cu and Fe from those obtained for the toe nails and in the case of control group of adults, significant differences were obtained for Cr, Cl, Cu, K, Mg and Se. Concentrations of elements found in nails from control group of children were significantly different from those obtained for CF group for some elements. These two groups of individuals presented different concentrations of Br and Cr for toe nails and of Cl, Cr, K and Na for finger nails. The highest levels obtained for Cl and Na in nails from CF patients indicate the viability of using these analysis in the diagnosis of this disease. Comparisons between the results of nail samples from control group of children with those obtained for adults also indicated significant differences. Besides, the levels of the elements obtained in this work for nail samples from CF and control groups are within the range values presented in the literature. The elemental concentrations obtained in the analysis of hair samples indicated a good correlation with those obtained for nail samples. (author)

  5. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method; Preparacion de mezclas patrones de hidrocarburos gaseosos en aire por el metodo de dilucion por difusion

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Perez, M. M.

    1979-07-01

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs.

  6. Origin identification for Cantona, Puebla, obsidians by the analysis method of neutron activation (NAA); Identificacion de procedencia para obsidianas de Cantona, Puebla, por el metodo de analisis por activacion neutronica (AAN)

    Energy Technology Data Exchange (ETDEWEB)

    Tellez N, A. L.

    2013-07-01

    There are tests that most of the obsidian worked in the workshops of Cantona, Puebla, is coming from the mineral deposits of Oyameles-Zaragoza, but also has been detected obsidian that macroscopically belongs to other mineral deposits. The present work has as purpose to determine the provenance of an obsidian sample obtained in the Cantona Site to know if there was the presence of obsidian of other mineral deposits. For the study the neutron activation analysis was used to identify the presence of other deposits. An explanation on the treatment to the selected pieces is included, the preparation of the same ones for its irradiation in the nuclear reactor, the counting and statistical study of the results. Finally the results of the selected samples are presented, indicating their origin places, that time comes and the interpretation of the results is given. (Author)

  7. Standardization of a method to calculate absolute renal uptake of {sup 99m} Tc-DMSA in children; Padronizacao do metodo para calculo da captacao renal absoluta do {sup 99m}Tc-DMSA em criancas

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Carla Rachel; Sapienza, Marcelo Tatit; Watanabe, Tomoco; Costa, Paulo Luiz Aguirre; Okamoto, Miriam Roseli Yoshie; Garcez, Alexandre Teles; Buchpiguel, Carlos Alberto [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Servico de Medicina Nuclear]. E-mail: crachelo@usp.br; Machado, Beatriz Marcondes; Machado, Marcia Melo Campos [Paulo Univ., SP (Brazil). Faculdade de Medicina. Hospital Universitario; Liberato Junior, Waldyr de Paula

    2006-01-15

    Objective:To standardize a method and determine normal values for absolute renal uptake of 99m Tc-DMSA in children with normal creatinine clearance. Materials and methods: Twenty-two children (between 7 months and 10 years of age; mean 4.5 years) without clinical evidence of renal disease were studied using 99m Tc-DMSA scintigraphy. Eighteen had normal renal ultrasonography, micturating urethrocystography, creatinine clearance and visual interpretation of the scintigraphy with 99m Tc-DMSA. Four children were excluded, one with incomplete creatinine clearance and three due to reduction in the creatinine clearance. Absolute renal uptake of 99m Tc-DMSA (DMSA-Abs) was expressed as the fraction of the administered dose retained by each kidney six hours after administration of the radiopharmaceutical. Results: DMSA-Abs was 21.8 +- 3.2% for the right kidney and 23.1 +-3.3% for the left kidney. There was no correlation between renal uptake and the age groups studied, although there was a tendency to an increase in the creatinine clearance with age. Conclusion: Normal values of DMSA-Abs can be used as an additional parameter for the initial diagnostic evaluation and during follow-up of renal diseases, mainly when bilateral impairment of renal function is suspected or in a patient with a single functioning kidney (in which renal differential function is of limited value). (author)

  8. Valor de los metodos directos e indirectos de diagnóstico en las micosis sitémicas asociadas al SIDA Efficacy of different diagnosis methods in systemic mycoses associated with AIDS

    Directory of Open Access Journals (Sweden)

    A.I. Arechavala

    1993-04-01

    Full Text Available Durante 5 años se estudiaron 117 pacientes con micosis sistémicas asociadas al SIDA: 74 criptococosis, 39 histoplasmosis y 4 con ambas enfermedades. Para el diagnóstico analizamos los siguientes materiales: escarificaciones de lesiones cutáneas o mucosas, aspirados de médula ósea, secreciones bronquiales, biopsias de diversos órganos, líquido cefalorraquídeo, hemocultivos y sueros para determinaciones serológicas. Fueron estudiadas en total 203 muestras de pacientes con histoplasmosis, el 46.3% de las mismas acusó la presencia de H. capsulatum. Las escarificaciones cutáneas exhibieron la mayor sensibilidad (94.7%, seguidas por las biopsias (80% y los mielocultivos (42.1%. La demostración de anticuerpos circulantes por medio de 3 pruebas serológicas y con de 2 antígenos específicos dio resultados positivos en el 45.4% de los pacientes. Se estudiaron en total 413 especímenes de pacientes con criptococosis, la confirmación diagnóstica fue posible en el 69% de las muestras. El mayor rendimiento se obtuvo con el LCR (89.5%, le seguieron en sensibilidad los hemocultivos (61.2%, las escarificaciones cutáneas (42.9% y los urocultivos (41.7%. La búsqueda de antígeno en los fluidos orgánicos fue positiva en casi todos los casos. La revisión que presentamos permitirá una búsqueda más racional y rápida de los métodos de diagnóstico en las micosis asociadas al SIDA.One hundred and seventeen patients suffering systemic mycosis and AIDS were studied during 5 years in the Muñiz Hospital of Buenos Aires City. Seventy four of them presented cryptococcosis, 39 histoplasmosis and 4 both mycoses. The following specimens were studied for the diagnosis: skin and mucous membrane scrapings, bone marrow aspirations, bronchial secretions, biopsies of different organs, cerebral spinal fluid and blood cultures. Sera were also collected for serologic tests. A total of 203 samples from patients with histoplasmosis were studied, 46.3% of them showed H. capsulatum in microscopic examinations or in cultures, skin scraping was the most sensitive diagnostic method (94.7% of positive results, followed by biopsies (80% and bone marrow cultures (42.1%. Specific antibodies were detected in 45.4% of the patients with histoplasmosis, using 2 different antigens and 3 types of serologic reactions (complement fixation test, immunodiffusion and counterimmunoelectrophoresis. A total of 413 samples from patients with cryptococcosis were examined, 69% of them confirmed the diagnosis. The mycologic study of CSF was the most sensitive method of study, since it registered positive results in 89.5%, followed by blood cultures (61.2%, skin scrapings (42.9%, and urine cultures (41.7%. Polisaccharyde antigens from C. neoformans in organic fluids were detected in almost all the cases. The aim of this study is to compare all the suitable diagnostic methods which can be used in systemic mycosis associated with AIDS in order to find the most rapid way of diagnosis.

  9. Solvent-extraction methods applied to the chemical analysis of uranium. III. Study of the extraction with inert solvents; Metodos de extraccion con disolventes aplicados al analisis quimico del uranio. III. Estudio de la extraccion con disolvente inertes

    Energy Technology Data Exchange (ETDEWEB)

    Vera Palomino, J.; Palomares Delgado, F.; Petrement Eguiluz, J. C.

    1964-07-01

    The extraction of uranium on the trace level is studied by using tributylphosphate as active agent under conditions aiming the attainment of quantitative extraction by means of a single step process using a number of salting-out agents and keeping inside the general lines as reported in two precedent papers. Two inert solvents were investigated, benzene and cyclohexane, which allowed to derive the corresponding empirical equations describing the extraction process and the results obtained were compared with those previously reported for solvents which, like ethyl acetate and methylisobuthylketone, favour to a more or less extend the extraction of uranium. (Author) 4 refs.

  10. Solution of the transport equation in stationary state, in one and two dimensions, for BWR assemblies using nodal methods; Solucion de la ecuacion de transporte en estado estacionario, en 1 y 2 dimensiones, para ensambles tipo BWR usando metodos nodales

    Energy Technology Data Exchange (ETDEWEB)

    Xolocostli M, J.V

    2002-07-01

    The main objective of this work is to solve the neutron transport equation in one and two dimensions (slab geometry and X Y geometry, respectively), with no time dependence, for BWR assemblies using nodal methods. In slab geometry, the nodal methods here used are the polynomial continuous (CMPk) and discontinuous (DMPk) families but only the Linear Continuous (also known as Diamond Difference), the Quadratic Continuous (QC), the Cubic Continuous (CC), the Step Discontinuous (also known as Backward Euler), the Linear Discontinuous (LD) and the Quadratic Discontinuous (QD) were considered. In all these schemes the unknown function, the angular neutron flux, is approximated as a sum of basis functions in terms of Legendre polynomials, associated to the values of the neutron flux in the edges (left, right, or both) and the Legendre moments in the cell, depending on the nodal scheme used. All these schemes were implemented in a computer program developed in previous thesis works and known with the name TNX. This program was modified for the purposes of this work. The program discreetizes the domain of concern in one dimension and determines numerically the angular neutron flux for each point of the discretization when the number of energy groups and regions are known starting from an initial approximation for the angular neutron flux being consistent with the boundary condition imposed for a given problem. Although only problems with two-energy groups were studied the computer program does not have limitations regarding the number of energy groups and the number of regions. The two problems analyzed with the program TNX have practically the same characteristics (fuel and water), with the difference that one of them has a control rod. In the part corresponding to two-dimensional problems, the implemented nodal methods were those designated as hybrids that consider not only the edge and cell Legendre moments, but also the values of the neutron flux in the corner points. In this geometry nodal, continuous and discontinuous schemes were used. For the continuos schemes, only the Bi Quadratic (BiQ) and the Bi Cubic (BiC) were considered. In the case of the discontinuous ones two nodal schemes were considered, namely the Discontinuous Bi Linear (DBiL) and Discontinuous Bi Quadratic (DBiQ). The nodal schemes applied use from 4 up to 16 interpolation parameters per cell. These schemes are-defined for a set D{sub c} of interpolation parameters and a polynomial space S{sub h} corresponding to each one of the nodal schemes considered. All these four nodal hybrid schemes were implemented in a computer program called TNHXY starting from the computer program TNXY developed in previous thesis works. Several subroutines wae added to calculate the average neutron flux for each cell and for each energy group, generating two versions, one for the continuous schemes and one for the discontinuous schemes. For this geometry, two benchmark problems of the ANL-7416 document were analyzed. They are 7x7 BWR fuel assemblies, one without control rod and the other one with control rod. The computer program was also applied to a MOX assembly proposed by the Nuclear Energy Agency and it is considered as a reference problem. The results obtained for the one-dimensional problems using TNX for the effective multiplication factor were compared with the ones obtained with the code ANISN/PC. TNX code shows a faster convergence within four significant figures for the case with no control rod and three significant figures for the case with control rod (using double precision). These results suggest TNX is a very useful tool for this kind of calculations. For X Y geometry, the results obtained with TNHXY were compared with those calculated with the code TWOTRAN. To get these results, several spatial (1x1, 2x2, 4x4 per cell) and angular meshes (S{sub 2}, S{sub 4}, S{sub 6}, and S{sub 8}) were used. The results for the problem with no control rod were practically the same as those obtained with TWOTRAN using the scheme DBiL that is the simplest one. The results for the other three schemes are practically the same, except for differences in the fourth or fifth significant figure. For the MOX assembly, the results obtained for k{sub eff} with TNHXY were compared with the values obtained with the codes HELIOS, MCNP4B/ENDF-VI and CPM-3. The results obtained with TNHXY are comparable with those reported with the other codes. Particularly, when k{sub eff} values obtained with TNHXY are compared with those obtained with MCNP-4B/ENDF-VI the error was less than 0.5%. Finally, the cross sections used in TNHXY were obtained with the code HELIOS. (Author)

  11. Comparison in the determination of absorbed dose by biological and physical methods to patients in treatment of cardiac intervention; Comparacion en la determinacion de dosis absorbida por metodos biologicos y fisicos a pacientes en tratamiento de intervencionismo cardiaco

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C., E-mail: citlali.guerrero@inin.gob.mx [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    The use of less invasive procedures, lower risk and quick recovery as cardiac intervention have proven to be an efficient alternative to reestablish the correct bloodstream of the patient. In this case the patient is subjected to values of absorbed dose above to which is subjected in a study with X-rays for medical diagnosis, and this can cause radiation injuries to the skin. The target organ, in this case can be exposed to doses of 2 Gy above. Different methods to estimate the dose were use, physical by Radiochromic film, as biological by dicentric analysis. Both methods provided additional information demonstrating thus the risk in the target organ and the patient. The most reliable biological indicator of exposure to ionizing radiation is the study of chromosomal aberrations, specifically dicentric in human lymphocytes. This test allowed establishing the exposure dose depending of the damage. (Author)

  12. Optimizing the mercury mass measurement in industrial electrolytic cells by the radio-tracer method at ININ; Optimizacion de la medicion de masa de mercurio en celdas electroliticas industriales por el metodo de radiotrazado en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Valle R, J.; Angeles C, A., E-mail: Ing.valle.r@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    One method used in the production of chlorine and sodium is the use of electrolytic cells for the separation of chlorine and sodium from the brine; the industries apply very intense electromagnetic fields in this process. The electrolytic cells use mercury as electrode. In a chlorine production plant inventories are determined by total amount of mercury in the plant annually, since mercury losses are large and a very important parameter is to control the mass of mercury for it is necessary to measure with great precision the losses made. There are several methods to determine the mass of mercury ranging from take samples and weigh, but this involves continuous interruption of the process creating downtimes which in turn represent economic losses giving a result delimiting productivity for the industrial sector. An alternative and attractive method is to use a radioactive tracer whose principle has a similar behavior to study objective. The inert mercury has to be neutron activated in a nuclear reactor to having the characteristics of a tracer; the result makes one of the isotopes of mercury. The tracer is transported taking into account the recommendations of the Comision Nacional de Seguridad Nuclear y Salvaguardias (Mexico), then it is injected into the electrolytic cells mixing with the mercury in the system. By a relative radioactivity measurement and one sample by gamma spectrometry per interest cell, the mass of mercury without stopping the process is obtained. For optimal use of radio-tracer method must be taken into account as important features: irradiation time of mercury, counting conditions, vial geometry, sample volume, sample cells, mixing time and half-life of the tracer. (Author)

  13. Application of the Bow Tie method for evaluation of safety in the procedure of logging wells; Aplicacion del metodo de Bow Tie para la evaluacion de seguridad en la practica de perfilaje de pozos

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso Pallares, C; Perez Reyes, Y.; Sarabia Molina, I.I. [Centro Nacional de Seguridad Nuclear (CNSN), La Habana (Cuba)

    2013-07-01

    This work consists of an assessment of security in the practice of logging of oil wells, using the method of Bow Tie for being a simple method of evaluation of the risk, which makes it possible in a structured way to set priorities to manage risk.

  14. Simulation Monte Carlo as a method of verification of the characterization of fountains in ophthalmic brachytherapy; Simulacion Monte Carlo como metodo de verificacion de la caracterizacion de fuentes en braquiterapia oftalmica

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Lora, A.; Miras del Rio, H.; Terron Leon, J. A.

    2013-07-01

    Following the recommendations of the IAEA, and as a further check, they have been Monte Carlo simulation of each one of the plates that are arranged at the Hospital. The objective of the work is the verification of the certificates of calibration and intends to establish criteria of action for its acceptance. (Author)

  15. Numerical simulation methods applied to injection and storage of CO{sub 2} in saline aquifers; Metodos de simulacion numerica aplicados a la inyeccion y almacenamiento de CO{sub 2} en formaciones salinas

    Energy Technology Data Exchange (ETDEWEB)

    Arjona Garcia-Borreguero, J.; Rodriguez Pons-Esparver, R.; Iglesias Lopez, A.

    2015-07-01

    One of the Climate Change mitigation proposals suggested by the IPCC (Intergovernmental Panel on Climate Change) in its Synthesis Report 2007 involves the launch of applications for capturing and storing carbon dioxide, existing three different geological structures suitable for gas storage: oil and gas depleted reservoirs, useless coal layers and deep saline structures. In case of deep saline structures, the main problem to prepare a study of CO{sub 2} storage is the difficulty of obtaining geological data for some selected structure with characteristics that could be suitable for injection and gas storage. According to this situation, the solution to analyze the feasibility of a storage project in a geological structure will need numerical simulation from a 3D terrain model. Numerical methods allow the simulation of the carbon dioxide filling in saline structures from a well, used to inject gas with a particular flow. This paper presents a methodology to address the modeling and simulation process of CO{sub 2} injection into deep saline aquifers. (Author)

  16. Maps of sharpness: a methodology to present results of quality control for mammographic system; Mapas de nitidez: um metodo para apresentacao dos resultados do controle de qualidade dos sistemas mamograficos em funcao da nitidez das imagens

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Henrique Jesus Quintino de; Marques, Marcio Alexandre [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica. Dept. de Fisica e Informatica; Frere, Annie France; Schiable, Homero; Marques, Paulo M. Azevedo; Irita, Ricardo Toshiyuki [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Engenharia Eletrica

    1996-12-31

    A new method for evaluating radiologic imaging systems quality is presented. This method intends to relate the numeric results from quality control procedures to the magnitude of shadow and penumbra in the image from given objects. This evaluation is based on a computer simulation and it can be performed for any system and any object placed in any location of the radiation field 3 refs., 2 figs.

  17. A study of digital hardware architectures for nuclear reactors protection systems applications - reliability and safety analysis methods; Um estudo de arquiteturas de hardware para aplicacao em sistemas digitais de protecao de reatores nucleares - metodos de analise de confiabilidade e seguranca

    Energy Technology Data Exchange (ETDEWEB)

    Benko, Pedro Luiz

    1997-07-01

    A study of digital hardware architectures, including experience in many countries, topologies and solutions to interface circuits for protection systems of nuclear reactors is presented. Methods for developing digital systems architectures based on fault tolerant and safety requirements is proposed. Directives for assessing such conditions are suggested. Techniques and the most common tools employed in reliability, safety evaluation and modeling of hardware architectures is also presented. Markov chain modeling is used to evaluate the reliability of redundant architectures. In order to estimate software quality, several mechanisms to be used in design, specification, and validation and verification (V and V) procedures are suggested. A digital protection system architecture has been analyzed as a case study. (author)

  18. Characterization of AISI 444 stainless steel corrosion products by neutron activation analysis; Caracterizacao de produtos de corrosao do aco inoxidavel AISI 444 pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Rogero, Sizue Ota; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: sorogero@ipen

    2005-07-01

    Stainless steels present distinct mechanical properties and resistance to corrosion depending on the composition of their alloys. Consequently the characterization of the chemical composition of stainless steel becomes of great interest, due to the narrow relation between the element contents and its mechanical properties. The element determination in corrosion product solutions is also of great interest as an investigation method of the corrosive process, allowing evaluating if selective dissolution of the material occurred. The objective of this study was to apply the method of neutron activation analysis (NAA) to identify the products of corrosion of AISI 444 steels which are ferritic ones used in of exhaustion systems and catalytic converters. The corrosion products in the extracts (cell culture medium where the steel samples were immersed during 10 days at 37 deg C) were analyzed. The same extracts were used in the assay of cytotoxicity by the neutral red uptake method. The obtained results indicated the release of the elements Co, Fe, Mo and Zn in concentrations that presented no toxicity. Despite the AISI 444 steel showed no cytotoxicity, this metal cannot be used as biomaterial since it is ferromagnetic and presents susceptibility to the localized corrosion. The results indicated the viability of using NAA technique in studies of corrosion of AISI 444 stainless steel due to its high sensitivity and the possibility of a multielemental analysis. (author)

  19. Annihilation probability density and other applications of the Schwinger multichannel method to the positron and electron scattering; Densidade de probabilidade de aniquilacao e outras aplicacoes do metodo multicanal de Schwinger ao espalhamento de positrons e eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Varella, Marcio Teixeira do Nascimento

    2001-12-15

    We have calculated annihilation probability densities (APD) for positron collisions against He atom and H{sub 2} molecule. It was found that direct annihilation prevails at low energies, while annihilation following virtual positronium (Ps) formation is the dominant mechanism at higher energies. In room-temperature collisions (10{sup -2} eV) the APD spread over a considerable extension, being quite similar to the electronic densities of the targets. The capture of the positron in an electronic Feshbach resonance strongly enhanced the annihilation rate in e{sup +}-H{sub 2} collisions. We also discuss strategies to improve the calculation of the annihilation parameter (Z{sub eff} ), after debugging the computational codes of the Schwinger Multichannel Method (SMC). Finally, we consider the inclusion of the Ps formation channel in the SMC and show that effective configurations (pseudo eigenstates of the Hamiltonian of the collision ) are able to significantly reduce the computational effort in positron scattering calculations. Cross sections for electron scattering by polyatomic molecules were obtained in three different approximations: static-exchange (SE); tatic-exchange-plus-polarization (SEP); and multichannel coupling. The calculations for polar targets were improved through the rotational resolution of scattering amplitudes in which the SMC was combined with the first Born approximation (FBA). In general, elastic cross sections (SE and SEP approximations) showed good agreement with available experimental data for several targets. Multichannel calculations for e{sup -} -H{sub 2}O scattering, on the other hand, presented spurious structures at the electronic excitation thresholds (author)

  20. Continuous and discreet methods in the aggregation and des fuzzy stages of a diffuse controller of neutron power; Metodos continuo y discreto en las etapas de agregacion y desdifusificacion de un controlador disfuso de potencia neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Najera H, M.C.; Benitez R, J.S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    The results of a comparative study are presented of: to) A denominated diffuse controller 'exact', designed by means of an innovative method that determines analytically so much the group of exit resultant in the aggregation stage like the de fuzzy process, and b) a diffuse controller denominated 'discreet' based on the discretization of the variable of having left as much for the aggregation as for the de fuzzy. These stages incorporated to the control algorithms whose objective is the ascent and regulation of the neutron power, carrying out an analysis of its performance. (Author)