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Sample records for cinco casos tratados

  1. Phoenix : Complex Adaptive System of Systems (CASoS) engineering version 1.0.

    SciTech Connect

    Moore, Thomas W.; Quach, Tu-Thach; Detry, Richard Joseph; Conrad, Stephen Hamilton; Kelic, Andjelka; Starks, Shirley J.; Beyeler, Walter Eugene; Brodsky, Nancy S.; Verzi, Stephen J.; Brown, Theresa Jean; Glass, Robert John, Jr.; Sunderland, Daniel J.; Mitchell, Michael David; Ames, Arlo Leroy; Maffitt, S. Louise; Finley, Patrick D.; Russell, Eric Dean; Zagonel, Aldo A.; Reedy, Geoffrey E.; Mitchell, Roger A.; Corbet, Thomas Frank, Jr.; Linebarger, John Michael

    2011-08-01

    Complex Adaptive Systems of Systems, or CASoS, are vastly complex ecological, sociological, economic and/or technical systems which we must understand to design a secure future for the nation and the world. Perturbations/disruptions in CASoS have the potential for far-reaching effects due to pervasive interdependencies and attendant vulnerabilities to cascades in associated systems. Phoenix was initiated to address this high-impact problem space as engineers. Our overarching goals are maximizing security, maximizing health, and minimizing risk. We design interventions, or problem solutions, that influence CASoS to achieve specific aspirations. Through application to real-world problems, Phoenix is evolving the principles and discipline of CASoS Engineering while growing a community of practice and the CASoS engineers to populate it. Both grounded in reality and working to extend our understanding and control of that reality, Phoenix is at the same time a solution within a CASoS and a CASoS itself.

  2. Complex Adaptive Systems of Systems (CASoS) engineering and foundations for global design.

    SciTech Connect

    Brodsky, Nancy S.; Finley, Patrick D.; Beyeler, Walter Eugene; Brown, Theresa Jean; Linebarger, John Michael; Moore, Thomas W.; Glass, Robert John, Jr.; Maffitt, S. Louise; Mitchell, Michael David; Ames, Arlo Leroy

    2012-01-01

    Complex Adaptive Systems of Systems, or CASoS, are vastly complex ecological, sociological, economic and/or technical systems which must be recognized and reckoned with to design a secure future for the nation and the world. Design within CASoS requires the fostering of a new discipline, CASoS Engineering, and the building of capability to support it. Towards this primary objective, we created the Phoenix Pilot as a crucible from which systemization of the new discipline could emerge. Using a wide range of applications, Phoenix has begun building both theoretical foundations and capability for: the integration of Applications to continuously build common understanding and capability; a Framework for defining problems, designing and testing solutions, and actualizing these solutions within the CASoS of interest; and an engineering Environment required for 'the doing' of CASoS Engineering. In a secondary objective, we applied CASoS Engineering principles to begin to build a foundation for design in context of Global CASoS

  3. Complex Adaptive System of Systems (CASoS) Engineering Applications. Version 1.0.

    SciTech Connect

    Linebarger, John Michael; Maffitt, S. Louise; Glass, Robert John, Jr.; Beyeler, Walter Eugene; Brown, Theresa Jean; Ames, Arlo Leroy

    2011-10-01

    Complex Adaptive Systems of Systems, or CASoS, are vastly complex eco-socio-economic-technical systems which we must understand to design a secure future for the nation and the world. Perturbations/disruptions in CASoS have the potential for far-reaching effects due to highly-saturated interdependencies and allied vulnerabilities to cascades in associated systems. The Phoenix initiative approaches this high-impact problem space as engineers, devising interventions (problem solutions) that influence CASoS to achieve specific aspirations. CASoS embody the world's biggest problems and greatest opportunities: applications to real world problems are the driving force of our effort. We are developing engineering theory and practice together to create a discipline that is grounded in reality, extends our understanding of how CASoS behave, and allows us to better control those behaviors. Through application to real-world problems, Phoenix is evolving CASoS Engineering principles while growing a community of practice and the CASoS engineers to populate it.

  4. Complex Adaptive Systems of Systems (CASOS) engineering environment.

    SciTech Connect

    Detry, Richard Joseph; Linebarger, John Michael; Finley, Patrick D.; Maffitt, S. Louise; Glass, Robert John, Jr.; Beyeler, Walter Eugene; Ames, Arlo Leroy

    2012-02-01

    Complex Adaptive Systems of Systems, or CASoS, are vastly complex physical-socio-technical systems which we must understand to design a secure future for the nation. The Phoenix initiative implements CASoS Engineering principles combining the bottom up Complex Systems and Complex Adaptive Systems view with the top down Systems Engineering and System-of-Systems view. CASoS Engineering theory and practice must be conducted together to develop a discipline that is grounded in reality, extends our understanding of how CASoS behave and allows us to better control the outcomes. The pull of applications (real world problems) is critical to this effort, as is the articulation of a CASoS Engineering Framework that grounds an engineering approach in the theory of complex adaptive systems of systems. Successful application of the CASoS Engineering Framework requires modeling, simulation and analysis (MS and A) capabilities and the cultivation of a CASoS Engineering Community of Practice through knowledge sharing and facilitation. The CASoS Engineering Environment, itself a complex adaptive system of systems, constitutes the two platforms that provide these capabilities.

  5. Diet of fishes in Passa Cinco stream, Corumbataí River sub-basin, São Paulo state, Brazil.

    PubMed

    Rondineli, G; Gomiero, L M; Carmassi, A L; Braga, F M S

    2011-02-01

    The aim of this study was to describe and classify the food preference of fish species in Passa Cinco stream. The grade of feeding preference was applied to stomachs considered replete. This method consists of attributing values to food items found in certain species, according to the participation of each item in the analysed stomach. We analysed 576 full stomachs of 28 species. The autochthonous insects were the main constituents of the diets of these species, and the majority of ingested items classified as occasional. Allochthonous items such as plant debris, seeds and earthworms were associated with higher-order site. Of the total possible combination pairs of species, 29.4% showed high overlap, which occurred mainly within species that consumed aquatic insect larvae. However, those species showed significant differences in the exploitation of food resources. Omnivory was common, showing the plasticity of the required species that inhabit environments as found in streams. PMID:21437413

  6. Population biology of Trichomycterus sp. (Siluriformes, Trichomycteridae) in Passa Cinco stream, Corumbataí River sub-basin, São Paulo State, southeastern Brazil.

    PubMed

    Rondineli, G R; Carmassi, A L; Braga, F M S

    2009-08-01

    The aim of this work was to characterise the population of Trichomycterus sp. in Passa Cinco stream, regarding length structure, sex ratio, diet and reproductive aspects, in accordance with drought and rainy season periods and longitudinal gradient, as well as to analyse its corporal condition in a temporal dimension. Six samplings were accomplished with the use of electric fishing equipment in three different sites in Passa Cinco stream, contemplating sites of order two, three and four, during the months of May, July, September and November of 2005; and January and March of 2006. Three hundred and forty one individuals were captured, composed of 203 males, 99 females and 39 immatures. The smallest captured individual, an immature, presented 28 mm of standard length and the largest, a male, 85 mm. There was not significant variation in repletion degree and accumulated fat in the visceral cavity of the individuals analysed during the considered periods. Eleven different food items were found in the stomach contents. Considering the whole sampling period, immature Diptera was a preferential item and other items were found as occasionally ingested. Spearman and Friedman tests did not find significant differences in the diet of Trichomycterus sp. in the periods and sampling sites, respectively. The average of absolute fecundity was of 73 oocytes, and the parceled type of spawning was performed. Both males and females of Trichomycterus sp. presented significant differences in their corporal conditions in the considered periods, and in the rainy season, these fishes were in better condition. PMID:19802454

  7. On the luminescence properties of CaSO4:Ce.

    PubMed

    Lapraz, D; Prevost, H; Iacconi, P; Guigues, C; Benabdesselam, M; Briand, D

    2002-01-01

    The luminescent properties of cerium doped calcium sulphate are studied: fluorescence and excitation spectra, optical absorption and thermoluminescence (TSL). It is known that, in rare earth doped CaSO4, only cerium induces a strong 400 degrees C TSL peak. In CaSO4:0.2%Ce samples synthesised under oxidising conditions, the recovery step of Ce3+ fluorescence is correlated with the 400 degrees C TSL peak readout, as mentioned by Nair er al. Our results indicate that an oxidation of Ce3+ ion does occur under X-irradiation (Ce3+ --> Ce4+), followed by a complete return to the trivalent state after thermal annealing at about 500 degrees C; our results confirm the hypothesis of Nair et al that Ce3+ ions are oxidised by ionising irradiation. So, a pure redox reaction seems the most probable for the 400 degrees C TSL peak of CaSO4:Ce. Moreover, the use of the 400 degrees C TSL peak for high temperature dosimetry applications is discussed. PMID:12382899

  8. The binary system K2SO4CaSO4

    USGS Publications Warehouse

    Rowe, J.J.; Morey, G.W.; Hansen, I.D.

    1965-01-01

    The binary system K2SO4CaSO4 was studied by means of heating-cooling curves, differential thermal analysis, high-temperature quenching technique and by means of a heating stage mounted on an X-ray diffractometer. Compositions and quench products were identified optically and by X-ray. Limited solid solution of CaSO4 in K2SO4 was found. There is a eutectic at 875??C and 34 wt. per cent CaSO4. Calcium langbeinite melts incongruently at 1011??C. The melting-point of CaSO4 (1462??C) was determined by the quenching technique using sealed platinum tubes. The only intermediate crystalline phase found in the system is K2SO4??2CaSO4 (calcium langbeinite). ?? 1965.

  9. The ternary system K2SO4MgSO4CaSO4

    USGS Publications Warehouse

    Rowe, J.J.; Morey, G.W.; Silber, C.C.

    1967-01-01

    Melting and subsolidus relations in the system K2SO4MgSO4CaSO4 were studied using heating-cooling curves, differential thermal analysis, optics, X-ray diffraction at room and high temperatures and by quenching techniques. Previous investigators were unable to study the binary MgSO4CaSO4 system and the adjacent area in the ternary system because of the decomposition of MgSO4 and CaSO4 at high temperatures. This problem was partly overcome by a novel sealed-tube quenching method, by hydrothermal synthesis, and by long-time heating in the solidus. As a result of this study, we found: (1) a new compound, CaSO4??3MgSO4 (m.p. 1201??C) with a field extending into the ternary system; (2) a high temperature form of MgSO4 with a sluggishly reversible inversion. An X-ray diffraction pattern for this polymorphic form is given; (3) the inversion of ??-CaSO4 (anhydrite) to ??-CaSO4 at 1195??C, in agreement with grahmann; (1) (4) the melting point of MgSO4 is 1136??C and that of CaSO4 is 1462??C (using sealed tube methods to prevent decomposition of the sulphates); (5) calcium langbeinite (K2SO4??2CaSO4) is the only compound in the K2SO4CaSO4 binary system. This resolved discrepancies in the results of previous investigators; (6) a continuous solid solution series between congruently melting K2SOP4??2MgSO4 (langbeinite) and incongruently melting K2SO4??2CaSO4 (calcium langbeinite); (7) the liquidus in the ternary system consists of primary phase fields of K2SO4, MgSO4, CaSO4, langbeinite-calcium langbeinite solid solution, and CaSO4??3MgSO4. The CaSO4 field extends over a large portion of the system. Previously reported fields for the compounds (K2SO4??MgSO4??nCaSO4), K2SO4??3CaSO4 and K2SO4??CaSO4 were not found; (8) a minimum in the ternary system at: 740??C, 25% MgSO4, 6% CaSO4, 69% K2SO4; and ternary eutectics at 882??C, 49% MgSO4, 19% CaSO4, 32% K2SO4; and 880??, 67??5% MgSO4, 5% CaSO4, 27??5% K2SO4. ?? 1967.

  10. Atomistic modelling of the hydration of CaSO 4

    NASA Astrophysics Data System (ADS)

    Adam, Craig D.

    2003-08-01

    Atomistic modelling techniques, using empirical potentials, have been used to simulate a range of structures formed by the hydration of γ-CaSO 4 and described as CaSO 4· nH 2O (0< n<1). The hemihydrate phase ( n=0.5) is of commercial importance and has been subjected to much experimental study. These simulation studies demonstrate significant water-matrix interactions that influence the crystallography of the hydrated phase. The existence of two types of hydration site has been predicted, including one within the Ca 2+coordination sphere. Close correlation between water molecule bonding energy, Ca 2+-O w bond length and unit-cell volume have been established. This shows that as the number of water molecules within the unit cell increases, the bonding energy increases and the unit cell contracts. However around n=0.5, this process reaches a turning point with the incorporation of further waters resulting in reduced binding energy and an expanding unit cell.

  11. Estudios Sociales Para ninos de cinco anos.

    ERIC Educational Resources Information Center

    Van Camp, Sara S.

    1982-01-01

    Suggests that kindergarten teachers should once a week bring to class a news photograph which they can discuss with the children. Such an exercise can be used to create among the children a wider awareness of the world and to counter their tendency to focus exclusively on the self. (Author/RH)

  12. Thermoluminescent response of CaSO4:Dy+PTFE induced by X-ray beams.

    PubMed

    Hernández, L; Rivera, T; Jimenez, Y; Alvarez, R; Zeferino, J; Vázquez, A; Azorín, J

    2012-07-01

    The aim of the present work was to evaluate the feasibility of the utilization of CaSO4:Dy pellets for X-ray measurements in a general radiology department. Thermoluminescence (TL) response of CaSO4:Dy+PTFE was compared to the TL response of commercial LiF:Mg,Ti (TLD-100) samples. TL pellets were exposed to X-ray beam from X-ray machine CMR for clinical diagnosis purpose. The calibration curve of CaSO4:Dy+PTFE was obtained and it showed a linear response as a function of absorbed dose in air at the studied dose interval. Despite this fact, this material can be used for X-ray beams measurements if appropriate calibration procedures are performed. PMID:22182627

  13. Dosimetry of fast neutron beams using CaSO 4:Dy (TLD-900) pellets

    NASA Astrophysics Data System (ADS)

    Pradhan, A. S.; Rassow, J.; Meissner, P.

    1985-05-01

    This paper describes the use of commercially avialable CaSO 4:Dy (TLD-900) pellets for the measurement of absorbed doses of fast neutrons and gamma rays in mixed fields with one single detector. The gamma ray absorbed doses could be estimated by recording the thermoluminiscence (TL) induced during the neutron beam irradiations, whereas the fast neutron absorbed doses were measured by employing a post-irradiation TL accumulation due to activation of sulphur by the threshold nuclear reaction 32S(n, p) 32P in CaSO 4:Dy.

  14. An alternative method for immediate dose estimation using CaSO4:Dy based TLD badges

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Menon, S. N.; Dhabekar, Bhushan; Kadam, Sonal; Chougaonkar, M. P.; Babu, D. A. R.

    2014-11-01

    CaSO4:Dy based Thermoluminescence dosimeters (TLDs) are being used in country wide personnel monitoring program in India. The TL glow curve of CaSO4:Dy consists of a dosimetric peak at 220 °C and a low temperature peak at 120 °C which is unstable at room temperature. The TL integral counts in CaSO4:Dy reduces by 15% in seven days after irradiation due to the thermal fading of 120 °C TL peak. As the dosimetric procedure involves total integrated counts for dose conversion, the dosimeters are typically read about a week after receiving. However in the event of a suspected over exposure, where urgent processing is expected, this poses limitation. Post irradiation annealing treatment is used in such cases of immediate readout of cards. In this paper we report a new and easier to use technique based on optical bleaching for the urgent processing of TLD cards. Optical bleaching with green LED (∼555 nm photons) of 25,000 lux for one and half hour removes the low temperature TL peak without affecting the dosimetric peak. This method can be used for immediate dose estimation using CaSO4:Dy based TLD badges.

  15. IDENTIFICATION OF CASO4 FORMED BY REACTION OF CAO AND SO2

    EPA Science Inventory

    The article discusses the XRD-determination of the identity of CaSO4, formed by the reaction between CaO and S02, and the support of that determination by density measurements with helium pycnometry. The anhydrous CaS04 compound formed has an orthorhombic crystal structure and an...

  16. Modeling the thermoluminescent response of CaSO4:Dy by the MCNPX method.

    PubMed

    Furetta, C; Roman, J; Rivera, T; Azorín, J; Azorín, C G; Vega-Carrillo, H R

    2010-01-01

    This work describes an algorithm for absorbed dose evaluation in the region of X-ray diagnostic energy based on the response of CaSO(4):Dy thermoluminescence powder detectors. The absorbed dose was calculated using Monte Carlo simulation code (MCSC) and then compared to the experimental TLD results for X-rays effective energies (60)Co gamma radiation. In order to study the photon interaction in the matter, a cylindrical model of 1 cm(3) was used. The gamma radiation source was placed at 100 cm to the object; the source is considered as an isotropic source of (60)Co. The energy deposited into the cylindrical model was determined by the Monte Carlo N-particle (MCNPX) method. Measurements of the TL phosphors were obtained by irradiating the powder by gamma radiation. TL glow curve of CaSO(4):Dy after gamma irradiated at a 1 Gy of absorbed dose was then obtained. PMID:20079655

  17. Preparation and investigation of thermoluminescence properties of CaSO4:Tm,Cu.

    PubMed

    Kása, I; Chobola, R; Mell, P; Szakács, S; Kerekes, A

    2007-01-01

    A new sort of thermoluminescent phosphor has been developed with the purpose of enlarging the range of linear dose-response. The thermoluminescence properties of CaSO(4):Tm,Cu, prepared according to our method, were studied in the dose range of 0.5 Gy-125.0 kGy. The results of the present work show that the CaSO(4):Tm,Cu is an excellent new dosimetric material due to its relatively simple glow curve, as a consequence of its simple trap system. Several applications are possible in dosimetry due to its wide range of linearity (2 x 10(-6) to 2 x 10(3) Gy), from environmental and space dosimetry to accidental and high-dose irradiation, e.g. gamma irradiation facilities, electron accelerators, nuclear power plants, radiotherapy, medical physics, and so on. PMID:16905762

  18. CaSO4:DY,Mn: A new and highly sensitive thermoluminescence phosphor for versatile dosimetry

    NASA Astrophysics Data System (ADS)

    Bahl, Shaila; Lochab, S. P.; Kumar, Pratik

    2016-02-01

    With the advent of newer techniques for dose reduction coupled with the development of more sensitive detectors, the radiation doses in radiological medical investigation are decreasing. Nevertheless, keeping the tenet in mind that all radiation doses could entail risk, there is a need to develop more sensitive dosimeters capable of measuring low doses. This paper gives the account of the development of a new and sensitive phosphor CaSO4:Dy,Mn and its characterization. The standard production procedure based on the recrystallization method was used to prepare CaSO4:Dy,Mn. The Thermoluminescence (TL) studies were carried out by exposing it with gamma radiation (Cs-137) from 10 μGy to 100 Gy. The theoretical studies to determine the number of peaks and kinetic parameters related to the TL glow peaks in CaSO4:Dy,Mn was performed using the Computerized Glow Curve Deconvolution (CGCD) method. Experiments were performed to determine optimum concentration of the dopants Dysprosium (Dy) and Mangnese (Mn) in the host CaSO4 so that maximum sensitivity of the phosphor may be achieved. The optimum dopant concentration turned out to be 0.1 mol%. As there were two dopants Dy and Mn their relative ratio were varied in steps of 0.025 keeping the concentration of total dopant (Dy and Mn) 0.1 mol% always. The maximum TL intensity was seen in the CaSO4:Dy(0.025),Mn(0.075) combination. The TL sensitivity of this phosphor was found to be about 2 and 1.8 times higher than that of popular phosphor CaSO4:Dy and LiF:Mg,Cu,P (TLD-700H) respectively. This new phosphor CaSO4:Dy,Mn showed fading of 11% which is similar to that of the standard phosphor CaSO4:Dy. The paper concludes that the new, highly sensitive TL phosphor CaSO4:Dy,Mn has shown higher sensitivity and hence the potential to replace commonly used CaSO4:Dy.

  19. Evaluation of the dosimetric response for CaSO4:Dy at low temperature.

    PubMed

    Cruz-Zaragoza, E; Ramos-Bernal, S; Negrón-Mendoza, A; Azoŕin, J

    2002-01-01

    Homemade solid state CaSO4:Dy detectors were tested to evaluate their response to gamma radiation at liquid nitrogen temperature (77 K). The dosemeters were irradiated with doses between 12 and 1071 Gy. For this study these dosemeters were exposed to gamma rays with a dose rate of 1.19 Gy.min(-1). The analysis for these crystals was made by thermoluminiscence. The dose response at liquid nitrogen temperature was linear in the dose range studied and it is about 20% lower with respect to the response at room temperature. The response is reproducible with the same geometric set-up. PMID:12382918

  20. Thermoluminesence of gamma rays irradiated CaSO4 nanorods doped with different elements

    NASA Astrophysics Data System (ADS)

    Salah, Numan

    2015-01-01

    Nanorods of calcium sulfate (CaSO4) activated by Ag, Cu, Dy, Eu and Tb were synthesized by the co-precipitation technique. They were irradiated by γ-rays in a wide range of exposures and studied for their thermoluminesence (TL) properties. The as-synthesized samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL) emission spectra. SEM images show that the samples doped with rare earths elements (i.e. Dy, Eu and Tb) have thinner nanorods than the other samples, while XRD pattern shows a complete crystalline structures in a monoclinic phase. The TL glow curves of these samples show two components. The first one include low temperature glow peaks at around 125 °C, while the second component shows high temperature peaks in the range 230-270 °C. These glow peaks diver from sample to sample by their TL intensity. The TL results are promising, particularly that of Tb and Eu. Tb doped sample is found to be a highly TL sensitive with a prominent glow peak at around 270 °C, while Eu has created very active, high dense electron traps. The later shows quite linear response in the whole studied exposures i.e. 10 Gy-10 kGy. These results show that Eu or Tb doped CaSO4 nanorods might be proper candidates as dosimeters for high doses of ionizing radiations used in irradiation of foods and seeds.

  1. High-sensitive CaSO4:Dy thermoluminescent phosphor synthesis by co-precipitation technique.

    PubMed

    Lakshmanan, A R; Jose, M T; Annalakshmi, O

    2008-01-01

    This paper describes the successful development of the co-precipitation technique for the preparation of a high-sensitive dysprosium-doped calcium sulphate (CaSO(4):Dy) thermoluminescent dosimetry (TLD) phosphor with dosimetric glow peak at approximately 230 degrees C which is a desired development in the field of radiation protection dosimetry. The main advantages of this co-precipitation technique over the conventional recrystallisation technique of phosphor preparation are: (i) preparation time is very less; (ii) quantity of sulphuric acid evaporated is insignificant; (iii) higher TL sensitivity -20% more than the present material; (iv) better glow curve structure; (v) lesser glow peak shift and better linearity to gamma and (vi) uniform crystal morphology and lower grain size-all grains are mostly cuboidal in shape, quite uniform and small (average size about 25 microm), suitable for manufacturing teflon discs in as-prepared form. Optimum values of various parameters in the method of preparation for a batch of 20 g CaSO(4):Dy phosphors to obtain maximum TL sensitivity, with favourable glow curves are studied. PMID:18716066

  2. Complex terbium luminescence centers in spectral transformers based on CaSO4

    NASA Astrophysics Data System (ADS)

    Kudryavtseva, I.; Lushchik, A.; Lushchik, Ch.; Maaroos, A.; Nagirnyi, V.; Pazylbek, S.; Tussupbekova, A.; Vasil'chenko, E.

    2015-11-01

    The blue and green terbium luminescence excitation spectra (5-15 eV) at a temperature of 9 or 300 K have been measured for a set of CaSO4 : Tb3+ phosphors with calcium and terbium ions characterized by fundamental features, which were synthesized by the solid-state reaction method with variations in the composition of the raw material, the type of terbium compounds, and the concentration of introduced terbium. A comprehensive analysis of these data, emission spectra, and decay kinetics (with the rising stage) of the terbium luminescence has revealed that the main luminescence centers in an efficient phosphor with 4 at % Tb3+ each contain four closely spaced Tb3+ ions in calcium positions, as well as Na+ ions and hydrogen-containing radicals. In such complex luminescence centers, cooperative nonradiative resonant transitions in neighboring terbium ions leads to a nearly complete concentration of the terbium luminescence in the green spectral region (5 D 4 → 7 F J ). The quantum yield of the green luminescence in CaSO4 : Tb3+ (4 at %) exceeds unity, QY > 1, in the region of direct excitation of Tb3+ into the 5 d state (~5.9 eV) or excitation of oxyanions near the terbium ions (~8.1 eV).

  3. High energy electron beams characterization using CaSO4:Dy+PTFE phosphors for clinical therapy applications.

    PubMed

    Rivera, T; Espinoza, A; Von, S M; Alvarez, R; Jiménez, Y

    2012-07-01

    In the present work high energy electron beam dosimetry from linear accelerator (LINACs) for clinical applications using dysprosium doped calcium sulfate embedded in polytetrafluorethylene (CaSO4:Dy+PTFE) was studied. The irradiations were carried out using high electron beams (6 to 18 MeV) from a linear accelerator (LINAC) Varian, CLINAC 2300C/D, for clinical practice purpose. The electron irradiations were obtained using the water solid in order to guarantee electronic equilibrium conditions (EEC). Field shaping for electron beams was obtained with electron cones. Glow curve and other thermoluminescent characteristics of CaSO4:Dy+PTFE were conducted under high electrons beams irradiations. The TL response of the pellets showed an intensity peak centered at around 215 °C. TL response of CaSO4:Dy+PTFE as a function of high electron absorbed dose showed a linearity in a wide range. To obtain reproducibility characteristic, a set of pellets were exposed repeatedly for the same electron absorbed dose. The results obtained in this study can suggest the applicability of CaSO4:Dy+PTFE pellets for high electron beam dosimetry, provided fading is correctly accounted for. PMID:22182630

  4. Phase relation of CaSO4 at high pressure and temperature up to 90 GPa and 2300 K

    NASA Astrophysics Data System (ADS)

    Fujii, Taku; Ohfuji, Hiroaki; Inoue, Toru

    2016-05-01

    Calcium sulfate (CaSO4), one of the major sulfate minerals in the Earth's crust, is expected to play a major role in sulfur recycling into the deep mantle. Here, we investigated the crystal structure and phase relation of CaSO4 up to ~90 GPa and 2300 K through a series of high-pressure experiments combined with in situ X-ray diffraction. CaSO4 forms three thermodynamically stable polymorphs: anhydrite (stable below 3 GPa), monazite-type phase (stable between 3 and ~13 GPa) and barite-type phase (stable up to at least 93 GPa). Anhydrite to monazite-type phase transition is induced by pressure even at room temperature, while monazite- to barite-type transition requires heating at least to 1500 K at ~20 GPa. The barite-type phase cannot always be quenched from high temperature and is distorted to metastable AgMnO4-type structure or another modified barite structure depending on pressure. We obtained the pressure-volume data and density of anhydrite, monazite- and barite-type phases and found that their densities are lower than those calculated from the PREM model in the studied P-T conditions. This suggests that CaSO4 is gravitationally unstable in the mantle and fluid/melt phase into which sulfur dissolves and/or sulfate-sulfide speciation may play a major role in the sulfur recycling into the deep Earth.

  5. Thermoluminescent characteristics of LiF:Mg, Cu, P and CaSO4:Dy for low dose measurement.

    PubMed

    Del Sol Fernández, S; García-Salcedo, R; Mendoza, J Guzmán; Sánchez-Guzmán, D; Rodríguez, G Ramírez; Gaona, E; Montalvo, T Rivera

    2016-05-01

    Thermoluminescence (TL) characteristics for LiF:Mg, Cu, P, and CaSO4:Dy under the homogeneous field of X-ray beams of diagnostic irradiation and its verification using thermoluminescence dosimetry are presented. The irradiation were performed utilizing a conventional X-ray equipment installed at the Hospital Juárez Norte of México. Different thermoluminescence characteristics of two material were studied, such as batch homogeneity, glow curve, linearity, detection threshold, reproducibility, relative sensitivity and fading. Materials were calibrated in terms of absorbed dose to the standard calibration distance and they were positioned in a generic phantom. The dose analysis, verification and comparison with the measurements obtained by the TLD-100 were performed. Results indicate that the dosimetric peak appears at 202°C and 277.5°C for LiF:Mg, Cu, P and CaSO4:Dy, respectively. TL response as a function of X-ray dose showed a linearity behavior in the very low dose range for all materials. However, the TLD-100 is not accurate for measurements below 4mGy. CaSO4:Dy is 80% more sensitive than TLD-100 and it show the lowest detection threshold, whereas LiF:Mg, Cu, P is 60% more sensitive than TLD-100. All materials showed very good repeatability. Fading for a period of one month at room temperature showed low fading LiF:Mg, Cu, P, medium and high for TLD-100 and CaSO4:Dy. The results suggest that CaSO4:Dy and LiF:Mg, Cu, P are suitable for measurements at low doses used in radiodiagnostic. PMID:26922395

  6. Shock induced vaporization of anhydrite CaSO4 and calcite CaCO3

    NASA Astrophysics Data System (ADS)

    Gupta, Satish C.; Ahrens, Thomas J.; Yang, Wenbo

    2000-04-01

    Discovery of abundant anhydrite (CaSO4) and gypsum (CaSO4.2H2O) in the otherwise carbonate sediments comprising the upper portion of the rocks contained within the Chicxulub impact crater has prompted research on the shock-induced vaporization of these minerals. We use a vaporization criterion determined by shock-induced entropy. We reanalyze the shock wave experiments of Yang [1]. He shocked 30% porous anhydrite and 46% porous calcite. Post-shock adiabatic expansion of the sample across a 5 mm-thick gap and then impact upon an aluminum witness plate backed by LiF window that is monitored with a VISAR. Reanalysis uses Herrman's P-α model [2] for porous materials, and a realistic interpolation gas equation-of-state for vaporization products. Derived values of the entropies for incipient and complete vaporization for anhydrite are 1.65±0.12 and 3.17±0.12 kJ(kg.K)-1, and for calcite these are 0.99±0.11 and 1.93±0.11 kJ(kg.K)-1. Corresponding pressures for incipient and complete vaporization along the Hugoniot of non-porous anhydrite are 32.5±2.5 and 122±13 GPa and for non-porous calcite are 17.8±2.9 and 54.1±5.3 GPa, respectively. These pressures are a factor of 2-3 lower than reported earlier by Yang.

  7. Operational experience of electronic active personal dosemeter and comparison with CaSo4:Dy TL dosemeter in Indian PHWR.

    PubMed

    Singh, Vishwanath P; Managanvi, S S; Bihari, R R; Bhat, H R

    2013-01-01

    Direct reading dosemeter has been used for day-to-day radiation exposure control and management for last four decades in Indian nuclear power plants (NPPs). Recently new real time, alarm and pre-alarm on equivalent dose/dose rate, storage of dose/dose rate and maximum dose rate, user-friendly electronic active personal dosemeter (APD) has been implemented into practice for the first time at Kaiga Atomic Power Station-3&4,  of Indian NPPs. The dosemeter showed tolerance level (L) 0.1085±0.0450 compared with 0.1869±0.0729 (average±SD) for CaSO4:Dy, TL dosemeter, having narrow range trumpet curve, nil electromagnetic interference. Records of >29 000 for APD and TL dosemeter were analysed for comparasion of the measurement of the individual dose. APD followed general acceptance rule of ±25 % for dose >1 mSv. Monthly Station collective dose by TL dosemeters and APD for normal reactor operation as well as outage are found in good agreement. Operational experiences and statistical analysis support that an APD dosemeter is reasonably equivalent to CaSO4:Dy TL dosemeter. The accuracy, reproducibility and repeatability of the measurement of radiation for (137)Cs are comparable with CaSO4:Dy, TL dosemeter. Operational experience of APD during the normal operation as well as outage showed as one of the best ALARA tool for occupational dose monitoring, control, management and future outage planning. PMID:23528326

  8. Thermoluminescence (TL) properties and x-ray diffraction (XRD) analysis of high purity CaSO4:Dy TL material

    NASA Astrophysics Data System (ADS)

    Kamarudin, Nadira; Abdullah, Wan Saffiey Wan; Hamid, Muhammad Azmi Abdul; Dollah, Mohd Taufik

    2014-09-01

    This paper presents the characterization and TL properties of dysprosium (Dy) doped calcium sulfate (CaSO4) TL material produced by co-precipitation technique with 0.5mol% concentration of dopant. The morphology of the produced TL material was studied using scanning electron microscope (SEM) and the micrograph shows that rectangular parallelepiped shaped crystal with the average of 150 μm in length were produced. The crystallinity of the produced powder was studied using x-ray powder diffraction (XRD). The XRD spectra show that the TL material produced is high purity anhydrite CaSO4 with average crystallite size of 74 nm with orthorhombic crystal system. The TL behavior of produced CaSO4:Dy was studied using a TLD reader after exposure to gamma ray by Co60 source with the doses of 1,5 and 10 Gy. The glow curve shows linear response with glow peak around 230°C which is desired development in the field of radiation dosimetry.

  9. Nano-fibrin stabilized CaSO4 crystals incorporated injectable chitin composite hydrogel for enhanced angiogenesis & osteogenesis.

    PubMed

    Arun Kumar, R; Sivashanmugam, A; Deepthi, S; Bumgardner, Joel D; Nair, Shantikumar V; Jayakumar, R

    2016-04-20

    Calcium sulfate (CaSO4), an excellent biodegradable bone forming agent that is an ideal choice as additive in gels, however, its disadvantage being poor gel rheology and angiogenesis. Here, we have synthesized chitin-CaSO4-nano-fibrin based injectable gel system which shows improved rheology and angiogenic potential. Rheological studies showed that the composite gel was a shear thinning gel with elastic modulus of 15.4±0.275kPa; a 1.67 fold increase over chitin control. SEM and XRD analyses revealed the effect of nano-fibrin (nFibrin) in transforming CaSO4 crystal shape from needle to hexagonal. It also masked the retarding effect of CaSO4 towards in vitro early cell attachment and angiogenesis using rabbit adipose derived mesenchymal stem cells (rASCs) and HUVECs, respectively. rASCs osteogenesis was confirmed by spectrophotometric endpoint assay, which showed 6-fold early increase in alkaline phosphatase levels and immuno-cytochemistry analysis. These in vitro results highlight the potential of injectable chitin-CaSO4-nFibrin gel for osteo-regeneration via enhanced angiogenesis. PMID:26876838

  10. La implantacion del enfoque constructivista en el aula de ciencia: Estudio de caso multiple

    NASA Astrophysics Data System (ADS)

    Arroyo Betancourt, Luz I.

    Esta investigacion estudia la implantacion del enfoque constructivista en tres aulas de ciencia del contexto puertorriqueno. Se auscultaron las practicas educativas que utilizan maestras consideradas constructivistas y la correspondencia de sus practicas educativas con los elementos esenciales de la didactica que proponen los teoricos de los planteamientos constructivistas. Se ausculto, ademas, a que vision del enfoque constructivista responden las expresiones de las maestras acerca de su practica educativa y como compara con su quehacer, a la luz de los elementos esenciales de las visiones constructivistas piagetiana, social y radical. Se utilizo el diseno de estudio descriptivo de caso multiple. El estudio se baso en entrevistas a profundidad, revision de documentos y observacion no participativa a la sala de clases. El contexto fueron tres escuelas publicas de la Region Educativa de San Juan, una elemental, una intermedia y una superior. Los resultados confirmaron que la transicion hacia el enfoque constructivista es un proceso que toma tiempo, dedicacion y la participacion en adiestramientos y readiestramientos acerca del nuevo enfoque. Las maestras coinciden en la mayoria de las practicas educativas que utilizan para implantar el enfoque constructivista de ensenanza y difieren en algunas debido, probablemente, a que han tenido que adaptarlas a los correspondientes niveles de ensenanza: elemental, intermedio y superior. Dos de las maestras planifican por conceptos generadores, mientras que una de ellas planifica siguiendo la guia que recibe del Departamento de Educacion. Difieren ademas, en el enfasis que confieren al inquirir cientifico. Con relacion a la correspondencia entre la vision manifestada por las maestras a la luz de las visiones piagetiana, social y radical, aparentemente, las preguntas del protocolo de entrevistas no lograron evocar la informacion con suficiente profundidad, por lo que la investigadora tuvo que inferir las visiones de las

  11. Energy response of CaSO4:Dy teflon TLD disk dosimeters to photons and electrons.

    PubMed

    Sharada, K S

    1983-01-01

    The photon energy response of CaSO4:Dy teflon disk dosimeters used widely in radiation dosimetry is computed using the energy absorption coefficient values for calcium, sulfur, oxygen, and carbon taken from J. H. Hubbell's tables. For fluorine, the energy absorption coefficients were obtained from the values given by F. H. Attix for CaF2 and Ca. The energy response of the radiation-monitoring disk for the range of 10 keV to 10 MeV, relative to air, is computed and plotted. The response is maximum between 20 and 30 keV and then gradually falls to a constant at 200 keV to 10 MeV. This computed response for different energies is compared with the experimental TL response of the dosimeter. The electron energy response of these TLD disks is computed using the stopping-power values for the different component elements. The electron stopping power for sulfur and calcium from 10 keV to 10 MeV is computed using the Bethe-Bloch formula. Those for oxygen and carbon are taken from the tables given by M. J. Berger and S. M. Seltzer. For fluorine, the values are computed from those for Li and LiF given in the same tables. This calculated response is compared with the experimental beta response of the TL dosimeter. PMID:6823508

  12. Raman spectra of the different phases in the CaSO4-H2O system.

    PubMed

    Prieto-Taboada, Nagore; Gómez-Laserna, Olivia; Martínez-Arkarazo, Irantzu; Olazabal, María Ángeles; Madariaga, Juan Manuel

    2014-10-21

    Although it is known that the CaSO4/H2O system is formed by at least five different phases, this fact is not correctly documented in Raman spectroscopy studies. The main problem detected in the literature was the incorrect definition of the anhydrite, which produced the assignation of different spectra for a single compound. In this sense, two different spectra were clearly identified from the bibliography, which showed different main Raman bands at 1017 or 1025 cm(-1), although anhydrite could be present even as three different polymorphous species with different structures. A better understanding of the whole system obtained from a review of the literature allowed new conclusions to be established. Thanks to that revision and the development of different thermodynamical experiments by Raman spectroscopy, the Raman spectra of each phase were successfully identified for the first time. In this way, the main Raman bands of gypsum, bassanite, anhydrite III, anhydrite II and anhydrite I were identified at 1008, 1015, 1025, 1017 and 1017 cm(-1), respectively. To conclude this work, the contradictions found in literature were critically summarized. PMID:25226433

  13. Effects of Partial Substitutions of NaCl with KCl, CaSO4 and MgSO4 on the Quality and Sensorial Properties of Pork Patties

    PubMed Central

    Chun, Ji-Yeon; Cho, Hyung-Yong; Min, Sang-Gi

    2014-01-01

    This study investigated the effects of NaCl replacers (KCl, CaSO4, and MgSO4) on the quality and sensorial properties of pork patty. In the characteristics of spray-dried salt particles, KCl showed the largest particle size with low viscosity in solution. Meanwhile CaSO4 treatment resulted in the smallest particle size and the highest viscosity (p<0.05). In comparison of the qualities of pork patties manufactured by varying level of Na replacers, MgSO4 treatment exhibited low cooking loss comparing to control (p<0.05). Textural properties of KCl and MgSO4 treatments showed similar pattern, i.e., low level of the replacers caused harder and less adhesive texture than those of control (p<0.05), whereas the hardness of these products was not different with control when the replacers were added more than 1.0%. The addition of CaSO4 also manifested harder and less adhesive than control (p<0.05), but the textural properties of CaSO4 treatment was not affected by level of Ca-salt. Eventually, sensorial properties indicated that KCl and CaSO4 influenced negative effects on pork patties. In contrast, MgSO4 showed better sensorial properties in juiciness intensity, tenderness intensity as well as overall acceptability than control, reflecting that MgSO4 was an effective Na-replacer in meat product formulation. PMID:26761288

  14. Hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) into gypsum (CaSO 4·2H 2O). The influence of the sodium poly(acrylate)/surface interaction and molecular weight

    NASA Astrophysics Data System (ADS)

    Boisvert, Jean-Philippe; Domenech, Marc; Foissy, Alain; Persello, Jacques; Mutin, Jean-Claude

    2000-12-01

    The retarding influence of sodium poly(acrylate) (PANa) on the hydration of calcium sulfate hemihydrate (CaSO 4· {1}/{2}H 2O) was investigated. This study reports the influence of sodium poly(acrylate) on hemihydrate dissolution, on homogenous and heterogeneous gypsum (CaSO 4·2H 2O) nucleation as well as on gypsum growth. It is shown that adsorption of PANa does not hinder the dissolution of hemihydrate in the present experimental conditions. The specific interaction of PANa with gypsum can explain the oriented growth of gypsum crystal. The gypsum growth is slowed down but cannot be blocked by the adsorption of PANa. On the other hand, PANa can block the heterogeneous and homogenous gypsum nucleation. As soon as a critical surface density of PANa onto the hemihydrate surface is reached, the heterogeneous gypsum nucleation is prevented and hemihydrate hydration is indefinitely blocked. The interaction between PANa and the hemihydrate surface is of prime importance to control hydration. Also, the influence of the molecular weight of PANa on homogenous nucleation has been investigated. The precipitation of calcium polyacrylate can explain the differences between the two molecular weights used (2100 and 20 000). This work leads to the conclusion that heterogeneous nucleation is the key process that controls hydration of a system in which hemihydrate dissolution, gypsum nucleation and growth are all occurring at the same time in a continuous manner.

  15. Impact-induced devolatilization of CaSO4 anhydrite and implications for K-T extinctions: Preliminary results

    NASA Technical Reports Server (NTRS)

    Tyburczy, James A.; Ahrens, Thomas J.

    1993-01-01

    The recent suggestions that the target area for the K-T bolide may have been a sulfate-rich evaporite and that the resulting sulfuric acid-rich aerosol was responsible for the subsequent cooling of the Earth and the resulting biological extinctions has prompted us to experimentally examine the impact-induced devolatization of the sulfate minerals anhydrite (CaSO4) and gypsum (CaSO4(2H2O)). Preliminary results for anhydrite are reported. Up to 42 GPa peak shock pressure, little or no devolatilization occurs, consistent with chemical thermodynamic calculations. Calculation of the influence of the partial pressure of the gas species on impact-induced devolatilization suggests that an even greater amount of sulfur than that proposed by Brett could have been released to the atmosphere by an impact into a sulfate-rich layer. Solid recovery, impact-induced devolatilization experiments were performed on the Caltech 20mm gun using vented, stainless steel sample assemblies.

  16. Soluble minerals in chemical evolution. I - Adsorption of 5-prime-AMP on CaSO4 - A model system

    NASA Technical Reports Server (NTRS)

    Orenberg, J. B.; Chan, S.; Calderon, J.; Lahav, N.

    1985-01-01

    The adsorption of 5-prime-AMP onto solid CaSO4-2H2O was studied in a saturated suspension as a function of pH and electrolyte concentration. The adsorption is pH-dependent and is directly correlated with the charge on the 5-prime-AMP molecule which is determined by the state of protonation of the N-1 nitrogen of the purine ring and the phosphate oxygens. It is proposed that the binding that occurs between the nucleotide and the salt is electrostatic in nature. The adsorption decreases with increasing ionic strength of the solution which means that in a fluctuating environment of wetting and drying cycles, a biomolecule similar to 5-prime-AMP could be expected to desorb during the drying phase. The results indicate that CaSO4-2H2O can serve as a concentrating surface for biomolecules. The significance of this is discussed with regard to the possible role of soluble minerals and their surfaces in a geochemical model consistent with the evolution of the earth and the origin of life.

  17. Pneumatocele selar a tensión: Reporte de un caso y revisión de la literatura

    PubMed Central

    Campero, Álvaro; Ajler, Pablo; Goldschmidt, Ezequiel; Bendersky, Damián; Campero, Abraham

    2012-01-01

    Introducción: El neumoencéfalo a tensión luego de la cirugía transesfenoidal es poco común. En la literatura existen pocos casos reportados en los cuales el aire se encuentra localizado exclusivamente en las regiones selar y supraselar, constituyendo un pneumatocele selar. En este artículo se describe un caso inusual de pneumatocele selar a tensión de presentación tardía. Descripción del caso: Una mujer de 57 años consultó por hemianopsia bitemporal. Previamente, ya se le había realizado una cirugía transnasal por un adenoma hipofisario y se le había colocado una derivación lumbo-peritoneal por la presencia de una fístula de líquido cefalorraquídeo. Además, se le había realizado una resección transcraneal de un componente intracavernoso del tumor y radiocirugía debido a la agresividad del mismo. Se llevó a cabo una resonancia magnética que demostró un pneumatocele selar y supraselar. Intervención: Se realizó un abordaje transciliar. La región selar estaba encapsulada por tejido cicatrizal debido a los procedimientos previos. Se abrió la cicatriz y el aire fue evacuado. Posteriormente, el piso selar fue cerrado con grasa y cola de fibrina. Despuós del procedimiento, su campo visual retornó a la normalidad. Un año después de su última cirugía, continua asintomática. Conclusión: El pneumatocele selar y supraselar a tensión es un hallazgo extremadamente raro luego de una cirugía transesfenoidal. Su manifestaciónw clínica sería la alteración visual debida a la compresión inferior de la vía óptica. El pneumatocele selar a tensión debe ser evacuado en un corto plazo. PMID:23596554

  18. An Investigation of the Adsorption Characteristics of 5'ATP and 5'AMP onto the Surface of Caso4 x 2H2O

    NASA Technical Reports Server (NTRS)

    Calderon, J.; Sweeney, M. A.

    1984-01-01

    A model has been proposed in which solid surfaces can act as a site for cataletic activity of condensation reactions for certain biomolecules. From this model, the adsorption characteristics of 5'ATP and 5'AMP onto the surface of CaSO4.2H2O was chosen for study. It has been proven that 5'ATP and 5'AMP do adsorb onto the surface of CaSO4. Studies were then made to determine the dependence of absorption versus time, concentration, ionic strength and pH. It was found that the adsorption of the nucleotides is highly pH dependent, primarily determined by the phosphate acid groups of the nucleic acid molecule. From this investigation, the data obtained is discussed in relation to the model for the prebiotic earth.

  19. Descompresión microvascular en espasmo hemifacial: Reporte de 13 casos y revisión de la literatura

    PubMed Central

    Campero, Alvaro; Herreros, Isabel Cuervo-Arango; Barrenechea, Ignacio; Andjel, Germán; Ajler, Pablo; Rhoton, Albert

    2016-01-01

    Objetivo: El propósito del presente trabajo es presentar los resultados de 13 pacientes con diagnóstico de espasmo hemifacial (EHF), en los cuales se realizó una descompresión microvascular (DMV). Material y Método: Desde Junio de 2005 a Mayo de 2014, 13 pacientes con diagnóstico de EHF fueron intervenidos quirúrgicamente, realizando una DMV. Se evaluó: edad, sexo, tiempo de evolución de la sintomatología, hallazgos intraoperatorios y resultados postoperatorios. Resultados: De los 13 pacientes intervenidos, 7 fueron mujeres y 6 varones. La media de edad fue de 53 años. El tiempo medio entre el inicio de la sintomatología y la intervención quirúrgica osciló entre 3 y 9 años. En todos los casos el EHF era típico, uno de ellos con neuralgia trigeminal concomitante, observándose en todos compresión neurovascular intraoperatoria. Por orden decreciente de frecuencia la causa de la compresión fue arteria cerebelosa anteroinferior, arteria cerebelosa posteroinferior, arteria dolicomega basilar y arteria dolicomega vertebral. El seguimiento postoperatorio fue en promedio de 24 meses. El 62% presentó desaparición postquirúrgica inmediata de la sintomatología preoperatoria, el 30% desaparición tras un período de 3 semanas a 2 meses (8% con mejoría parcial), y en el 8% no hubo mejoría. En cuanto a las complicaciones postoperatorias: 3 pacientes presentaron paresia facial II-III en la escala de House-Brackman (se recuperaron en un período de 6 meses), y 1 paciente presentó fístula de líquido cefalorraquídeo. Ninguno de los pacientes de la serie presentaron hipoacusia transitorio o permanente. Conclusión: La DMV como tratamiento del EHF es un procedimiento efectivo y seguro, que permite la resolución completa de la patología en la mayoría de los casos. PMID:27127708

  20. X- and gamma-ray response of the TLD badge based on CaSO4:Dy Teflon TLD discs.

    PubMed

    Vohra, K G; Pradhan, A S; Bhatt, R C

    1982-09-01

    A TLD badge based on CaSO4: Dy Teflon TLD discs has been designed for personnel monitoring of radiation workers encountering X-rays of effective energies above 20 keV. The badge had two Teflon TLD discs, one of which is used bare (without any filter) and other which is used with a metal filter. By taking into account the TL readout of both of these discs, the problems of photon energy dependence as well as directional dependence of the badge have been reduced to a minimum. The uncertainty due to photon energy dependence above 29 KeV (eff.) was found to be within a value of +/- 15% (at an angle of incidence of 45 degrees). The directional dependence of the badge is within +/- 30% in the energy range from 35 KeV to 1.25 MeV. The badge is designed so as to provide approximate information on the effective photon energy of the X-ray exposures. PMID:7174332

  1. Intensity variation study of the radiation field in a mammographic system using thermoluminescent dosimeters TLD-900 (CaSO4:Dy)

    NASA Astrophysics Data System (ADS)

    Corrêa, E. L.; Silva, J. O.; Vivolo, V.; Potiens, M. P. A.; Daros, K. A. C.; Medeiros, R. B.

    2014-02-01

    This study presents the results of the intensity variation of the radiation field in a mammographic system using the thermoluminescent dosimeter TLD-900 (CaSO4:Dy). These TLDs were calibrated and characterized in an industrial X-ray system used for instruments calibration, in the energy range used in mammography. They were distributed in a matrix of 19 lines and five columns, covering an area of 18 cm×8 cm in the center of the radiation field on the clinical equipment. The results showed a variation of the intensity probably explained by the non-uniformity of the field due to the heel effect.

  2. Magnetic removal of electron contamination for 60Co panoramic gamma ray exposure--Investigations with CaSO4:Dy and LiF based dosimeters.

    PubMed

    Kumar, Munish; Sahani, G; Chourasiya, G

    2010-06-01

    Electron contamination from a sealed (60)Co radiation source has been investigated comprehensively using a CaSO(4):Dy based TLD badge and LiF crystals. It has been found that due to electron contamination, the thermoluminescence (TL) detectors exhibit over response which can be corrected by applying a magnetic field. It has also been found that for a source-to-dosimeter distance of 50 cm, the ratio of the TL readouts of the third to first discs of the TLD badge reduces from approximately 1.5 to approximately 1.00 after applying a magnetic field. Hence detectors which are sensitive to electrons as well as photons, and are capable of distinguishing them, can lead to an erroneous measurement. This happens because the contribution due to electron contamination interferes with pure gamma calibration. The study is helpful in establishing accurate calibration and appropriate correction factors for personnel monitoring carried out using CaSO(4):Dy based TLD badge. PMID:20071190

  3. Dosimetric properties and stability of thermoluminescent foils made from LiF:Mg,Cu,P or CaSO4:Dy during long-term use

    NASA Astrophysics Data System (ADS)

    Kłosowski, M.; Liszka, M.; Kopeć, R.; Bilski, P.; Kędzierska, D.

    2014-11-01

    A few dosimetric systems based on thermoluminescence [TL] foils were developed in recent years (Nariyama et al. 2006, Radiat. Prot. Dosim. 120, 213-218; Olko et al. 2006 Radiat. Prot. Dosim. 118, 213-218) (Czopyk et al. 2008, Radiat. Meas., 43, 977-980; Kłosowski et al. 2010, Radiat. Meas., 45, 719-721; Kopeć et al. 2013, Radiat.Meas., 56, 380-383). Major application of these systems is mapping of 2D dose distribution for medical treatment plan verification, similarly to photochromic or radiochromic films. The advantage of TL foils compared to other films is their re-usability. In this work we present dosimetric properties as dose linearity and fadding of the foils made from LiF:Mg,Cu,P or CaSO4:Dy phosphors and high temperature polymers. Both types of the foils have good linearity in the range 1-20 Gy for LiF:Mg,Cu,P and 0.1-2 Gy for CaSO4:Dy. Their long term fading does not exceed 3.7% and 9% respectively. We additionally investigated effects of sensitivity loss and emission spectra for both types of the foils. One shortcoming of TL foils is that every heat process may have negative influence on their properties, causing changes of their sensitivity. Register signal of the foils after 15 readouts may be reduced by 16% of the initial. We consider that the main reason of these changes is oxidation of organic contamination on the surface and degradation of a polymer which is one of the components of the foils. Effect of sensitivity decreasing may be slowed down by proper use and cleaning detectors by solvent.

  4. An investigation of the adsorption characteristics of 5 prime ATP and 5 prime AMP onto the surface of CaSO sub 4 x 2H sub 2 O

    NASA Technical Reports Server (NTRS)

    Calderon, J.; Sweeney, M. A.

    1986-01-01

    A model has been proposed (Lahev and Chans, 1982) in which solid surfaces can act as a site for catalytic activity of condensation reactions for certain biomolecules. From this model, the adsorption characteristics of 5'ATP and 5'AMP onto the surface of CaSO4 2H2O was chosen for study. It has been proven that 5'ATP and 5'AMP do adsorb onto the surface of CaSO4. Studies were then made to determine the dependence of adsorption versus time, concentration, ionic strength and pH. It was found that the adsorption of the nucleotides is highly pH dependent, primarily determined by the phosphate acid groups of the nucleic acid molecule. From this investigation, the data obtained are discussed in relation to the model for the prebiotic earth.

  5. Five Stories Written in Spanish & English. Cinco Cuentos Escrito en Espanol y Ingles.

    ERIC Educational Resources Information Center

    Alvarez, Juan; Kwapil, Marie Jo

    This textbook is intended as supplementary material for children who need a K-4 interest-level and K-2 skill-level reader in either English or Spanish. The basic vocabulary is common to five of the seven most widely used basic English primers. A special feature of this reader is the introduction of new words in both languages. The color coding is…

  6. A resolution recognizing the historic significance of the Mexican holiday of Cinco de Mayo.

    THOMAS, 113th Congress

    Sen. Udall, Mark [D-CO

    2013-04-25

    04/25/2013 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S3060; text as passed Senate: CR S3048-3049) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  7. A resolution recognizing the historic significance of the Mexican holiday of Cinco de Mayo.

    THOMAS, 112th Congress

    Sen. Udall, Mark [D-CO

    2012-04-26

    04/26/2012 Referred to the Committee on the Judiciary. (text of measure as introduced: CR S2831) (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  8. A resolution recognizing the historical significance of the Mexican holiday of Cinco de Mayo.

    THOMAS, 112th Congress

    Sen. Menendez, Robert [D-NJ

    2011-05-05

    05/05/2011 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S2752-2753; text as passed Senate: CR S2753; text of measure as introduced: CR S2745) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  9. A resolution recognizing the historic significance of the Mexican holiday of Cinco de Mayo.

    THOMAS, 113th Congress

    Sen. Udall, Mark [D-CO

    2014-05-05

    05/05/2014 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S2676-2677; text as passed Senate: CR S2649-2650) (All Actions) Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

  10. An energy atlas of five Central American countries. Un atlas energetico de cinco paises Centroamericanos

    SciTech Connect

    Trocki, L.; Newman, C.K.; Gurule, F.; Aragon, P.C.; Peck, C.

    1988-08-01

    In a series of maps and figures, this atlas summarizes what is known about the energy resources and how these resources and oil imports supply the energy needs of five Central American countries: Guatemala, El Salvador, Honduras, Costa Rica, and Panama. The main exploited energy resources are firewood, hydroelectric energy, bagasse from sugar cane residues, and geothermal energy. Limited oil exploration in the region has uncovered modest oil resources only in Guatemala. Peat and small coal deposits are also known to exist but are not presently being exploited. After the description of energy resources, this atlas describes energy supply and demand patterns in each country. It concludes with a description of socioeconomic data that strongly affect energy demand. 4 refs.

  11. The Aztec, Frida Kahlo, and Cinco de Mayo: Mexico in Children's Literature

    ERIC Educational Resources Information Center

    Bauml, Michelle; Field, Sherry L.

    2012-01-01

    The authors provide an overview of children's books published in the United States during the last decade (2000-2010) that deal with Mexico and Mexican people. Suggested guidelines for selecting quality books and a list of award-winning titles are included as resources for teaching about Mexico. (Contains 2 tables and 4 figures.)

  12. Determination of self attenuation coefficient and relative TL efficiency of CaSO 4 :Dy, LiF:Mg,Cu,P and LiF:Mg,Ti TLDs - An alternate approach

    NASA Astrophysics Data System (ADS)

    Bakshi, A. K.; Chatterjee, S.; Palani Selvam, T.; Joshi, V. J.; Chougaonkar, M. P.

    2011-10-01

    Self attenuation of TL and relative TL efficiency of polytetra fluoro ethylene (PTFE) embedded CaSO 4:Dy disc, LiF:Mg,Ti (MTS) disc and LiF:Mg,Cu,P (MCP-N) chip were determined in the present study for photons of energy 10-34 keV. The relative TL efficiency was determined using an alternative approach in which ratio of experimental response and corrected theoretical response was used instead of measuring the absolute TL emission in photon counting mode. For CaSO 4:Dy disc, it was found that with increasing the proportion of CaSO 4:Dy phosphor in the disc, the light attenuation coefficient increases. The light attenuation coefficient of MTS disc and MCP-N chip was found to be 23.4 and 45.5 cm -1, respectively. The relative TL efficiency in the photon energy range of 10-34 keV for MTS discs and MCP-N chips, evaluated in the present study matches well with the reported values in the literature.

  13. Aspergilosis cervical con diseminación al sistema nervioso central. Presentación de un caso y revisión de bibliografía

    PubMed Central

    Vergara, Guillermo Enrique; Roura, Natalia; del Castillo, Marcelo; Mora, Andrea; Alcorta, Santiago Condomi; Mormandi, Rubén; Cervio, Andrés; Salvat, Jorge

    2015-01-01

    Introducción: la Aspergilosis Invasiva (AI) del Sistema Nervioso Central (SNC) es infrecuente y ocurre generalmente en pacientes inmunocomprometidos. Puede presentarse con cuadros de meningitis, aneurismas micóticos, infartos o abscesos. Es una infección con pronóstico reservado y puede afectar el SNC de forma primaria o secundaria a partir de un foco que se disemina por vía hematógena. Presentamos el caso de un paciente con AI con invasión primaria a nivel óseo y diseminación posterior al cerebro. Caso clínico: Paciente masculino de 25 años con diagnóstico de leucemia linfática aguda en tratamiento quimioterápico que presentó neumonitis por metotrexate por lo que inicia tratamiento con corticoides. Posteriormente agregó cervicalgia y con el diagnóstico de osteomielitis cervical se realiza punción bajo tomografía computada (TC) sin aislarse gérmenes. Se colocó Halo Vest e inició tratamiento antibiótico empírico. Posteriormente presentó afasia de expresión secundaria a lesión frontal izquierda. Se realizó evacuación de absceso cerebral aislando A. fumigatus. El tratamiento antibiótico específico posterior permitió una buena respuesta clínica y radiológica. Conclusión: La presencia de lesiones en el SNC de pacientes inmunocomprometidos debe incluir a las micosis como diagnóstico diferencial. La evacuación quirúrgica permite llegar rápidamente al diagnóstico mejorando la respuesta posterior al tratamiento antibiótico. Para evaluar la respuesta terapéutica y posibles recaídas se debe realizar un seguimiento periódico clínico radiológico. Palabras clave: Aspergilosis cerebral; Aspergilosis cervical; Aspergilosis invasiva; Voriconazol. PMID:26600985

  14. Gypsum (CaSO4·2H2O) Scaling on Polybenzimidazole and Cellulose Acetate Hollow Fiber Membranes under Forward Osmosis

    PubMed Central

    Chen, Si Cong; Su, Jincai; Fu, Feng-Jiang; Mi, Baoxia; Chung, Tai-Shung

    2013-01-01

    We have examined the gypsum (CaSO4·2H2O) scaling phenomena on membranes with different physicochemical properties in forward osmosis (FO) processes. Three hollow fiber membranes made of (1) cellulose acetate (CA), (2) polybenzimidazole (PBI)/polyethersulfone (PES) and (3) PBI-polyhedral oligomeric silsesquioxane (POSS)/polyacrylonitrile (PAN) were studied. For the first time in FO processes, we have found that surface ionic interactions dominate gypsum scaling on the membrane surface. A 70% flux reduction was observed on negatively charged CA and PBI membrane surfaces, due to strong attractive forces. The PBI membrane surface also showed a slightly positive charge at a low pH value of 3 and exhibited a 30% flux reduction. The atomic force microscopy (AFM) force measurements confirmed a strong repulsive force between gypsum and PBI at a pH value of 3. The newly developed PBI-POSS/PAN membrane had ridge morphology and a contact angle of 51.42° ± 14.85° after the addition of hydrophilic POSS nanoparticles and 3 min thermal treatment at 95 °C. Minimal scaling and an only 1.3% flux reduction were observed at a pH value of 3. Such a ridge structure may reduce scaling by not providing a locally flat surface to the crystallite at a pH value of 3; thus, gypsum would be easily washed away from the surface. PMID:24957062

  15. Shock induced reaction in Chicxulub target materials (CaSO4 and SiO2) and their relation to extinctions

    NASA Technical Reports Server (NTRS)

    Chen, Guangqing; Ahrens, Thomas J.

    1993-01-01

    The global platinum element rich layer, the presence of shocked quartz grains (in some cases with stishovite), and the observation of a tektite-rich layer, precisely at the K-T boundary, are the three major arguments for the extinction bolide impact hypothesis of Alvarez et al. Tektites (spherules) from Beloc in Haiti and Mimbral in Mexico received particular interest because of their geological proximity to the Chicxulub impact structure, which is a leading candidate for at least one of the K-T impact craters. Although in most localities the original glass has weathered to clay minerals, some shock-induced glass is found in outcrops and drill cores which is used for Ar-38/Ar-39 dating. The glassy tektites were found to be chemically similar and coeval at 65.0 Ma with Chicxulub melt rock. Two kinds of K-T spherules were discovered: (1) a silic black glass; and (2) a yellow glass, enriched in Ca, Mg, and S. The high sulfur content of the glass and the abundance of anhydrite (CaSO4) in the carbonate-evaporite sequence observed in Drill Holes Y-1 and Y-2 at Chicxulub prompted studies of calcium sulfate devolatization. Further discussion of our experiments is presented.

  16. Microwave-promoted pure host phase for red emission CaS:Eu2+ phosphor from single CaSO4 precursor and the photoluminescence property

    NASA Astrophysics Data System (ADS)

    Ma, Jian; Lu, Qi-Fei; Wang, Yan-Ze; Lu, Zhi-Juan; Sun, Liang; Dong, Xiao-Fei; Wang, Da-Jian

    2014-08-01

    We report a novel approach to obtaining a classical blue-green excitable CaS:Eu2+ phosphor with desired red emission by microwave (MW) firing procedure in the absence of adding elemental sulphur. The disturbing effect of MW electromagnetic field on decomposition of CaSO4 into CaS activated by europium is distinctly observed to give pure host phase without adding any elemental sulphur and carbon. The host phase evolution is observed to be highly dependent on the variation of applied MW power from X-ray diffraction (XRD) patterns and the corresponding photoluminescence (PL), and a maximum PL intensity at 1100 W of MW power is acquired for the obtained purer host phase. The non-thermal and non-equilibrium effects by MW are revealed to correlate with the interaction between polar structure of the host and applied electromagnetic field. The results demonstrate an optional procedure to prepare this red-emitting phosphor in an effective, environment-friendly and scalable approach for phosphor production in the application of bio-illumination for plant cultivation and artificial photosynthesis.

  17. Development of a technique for improving coefficient of variation of CaSO4:Dy teflon-based TLD personnel monitoring system in low-dose region.

    PubMed

    Pradhan, S M; Sneha, C; Sahai, M K; Chougaonkar, M P; Babu, D A R

    2015-12-01

    In view of the importance of zero-dose background (null signal) in influencing the coefficient of variation in low-dose region, a technique for the estimation of the same from composite (gross) signal is developed for CaSO4:Dy-based personnel monitoring system being used in India. The technique is based on simple analysis of glow curves (GCs) of unexposed and exposed dosemeters, evolution of trend/model for the zero-dose curves, generation of simulation protocol for individual zero-dose curves, establishment of characteristics of GCs of exposed dosemeters and finally preparation of an algorithm to segregate the components from composite signal. The technique offers the separation of real-time background and gives superior results over other method of approximation of the background. The results also prove efficiency of the empirical trending and simulation protocol of background GCs. The proposed technique can be implemented in routine monitoring without any extra man hours and reader time. PMID:25527179

  18. Descompresión microvascular en neuralgia del trigémino: Reporte de 36 casos y revisión de la literatura

    PubMed Central

    Campero, Alvaro; Ajler, Pablo; Campero, Abraham Agustín

    2014-01-01

    Objetivo: El propósito del presente trabajo es presentar los resultados de 36 pacientes con diagnóstico de neuralgia del trigémino (NT), en los cuales se realizó una descompresión microvascular (DMV). Material y Método: Desde junio de 2005 a mayo de 2012, 36 pacientes con diagnóstico de NT fueron operados por el primer autor (AC), realizando una DMV. Se evaluó: Edad, sexo, tiempo de sintomatología previo a la cirugía, hallazgos intraoperatorios (a través de los videos quirúrgicos), y resultados postoperatorios. Resultados: De los 36 pacientes operados, 25 fueron mujeres y 11 varones. El promedio de edad fue de 48 años. El seguimiento postoperatorio fue en promedio de 38 meses. De los 36 pacientes, 32 (88%) evolucionaron sin dolor hasta la fecha. De los 4 casos con recurrencia de dolor, en dos pacientes se observó como hallazgo intraoperatorio un conflicto venoso. Conclusión: La DMV como tratamiento de la NT es un procedimiento efectivo y seguro. El hallazgo intraoperatorio de una “compresión” venosa podría indicar una evolución postoperatoria desfavorable. PMID:25379343

  19. Variabilidade óptica de longo período e precessão de jato: o caso de BL Lacertae

    NASA Astrophysics Data System (ADS)

    Caproni, A.; Abraham, Z.

    2003-08-01

    Variabilidade é tipicamente uma característica de AGNs, sendo observada em toda a faixa eletromagnética. Em relação às escalas de tempo, variações desde horas até de algumas décadas foram encontradas por vários autores. Em alguns casos, análises temporais de curvas de luz mostram a existência de periodicidade nas variações observadas. Um exemplo de objeto que preenche as características mencionadas acima é BL Lacertae, o protótipo da classe BL Lac dos AGNs. Neste trabalho, nós interpretamos a variabilidade periódica de longo período detectada na curva de luz na banda B (~7,5 anos) como o resultado da periodicidade na amplificação da radiação oriunda do jato relativístico. Neste cenário, a amplificação periódica seria induzida pela precessão, que muda o ângulo entre o jato e a linha de visada. Com esta abordagem e vínculos adicionais fornecidos por observações em altas energias, nós podemos impor limites para os parâmetros do modelo de precessão, tais como o fator de Lorentz associado ao movimento global do jato, o ângulo de abertura do cone de precessão e o ângulo entre o eixo do cone e a linha de visada.

  20. Constraints on the distribution of CaSO4·nH2O phases on Mars and implications for their contribution to the hydrological cycle

    NASA Astrophysics Data System (ADS)

    Robertson, Kevin; Bish, David

    2013-03-01

    The stability of minerals in the CaSO4·nH2O system was investigated using a Bruker D8 X-ray powder diffractometer equipped with an environmental cell interfaced to a heating stage, low-temperature chiller, and relative humidity (RH) generator. This in situ analysis procedure allowed for precise monitoring of dehydration/hydration reactions over a range of PH2O values from 4 to 15,000 Pa. The formation of bassanite from gypsum was sluggish below 323 K and is unlikely to occur under current martian conditions over a diurnal/seasonal cycle from desiccation alone. Dehydration is possible on a localized scale in association with volcanic/impact events although temperatures of dehydration and rates of reaction depend on PH2O, particle size, sample thickness and heating rate. Analysis of anhydrite rehydration at 258 K suggests that if gypsum dehydration were to occur, bassanite would be observed on the martian surface under present low PH2O conditions. In addition, a stable bassanite phase could potentially cycle between n = 0.5 and n = 0.67 as a function of relative humidity (1-80%), resulting in a small flux of H2O between the atmosphere and the regolith over a diurnal cycle. Rehydration of bassanite to gypsum occurs only under conditions of 100%RH; therefore the presence of a bassanite phase on the surface of Mars can be used to help constrain paleoclimates. Low-temperature (258 K) XRD hydration experiments of bassanite resulted in the formation of gypsum in the presence of ice, suggesting that bassanite will not be present in association with H2O ice. This behavior could simulate a potential hydration mechanism on the martian surface at higher latitudes as well as at depth in association with subsurface ice at lower latitudes.

  1. Corrosion study on high power feeding of telecomunication copper cable in 5 wt.% CaSO4.2H2O solution

    NASA Astrophysics Data System (ADS)

    Shamsudin, Shaiful Rizam; Hashim, Nabihah; Ibrahim, Mohd Saiful Bahri; Rahman, Muhammad Sayuzi Abdul; Idrus, Muhammad Amin; Hassan, Mohd Rezadzudin; Abdullah, Wan Razli Wan

    2016-07-01

    The studies were carried out to find out the best powering scheme over the copper telephone line. It was expected that the application of the higher power feeding could increase the data transfer and capable of providing the customer's satisfaction. To realize the application of higher remote power feeding, the potential of corrosion problem on Cu cables was studied. The natural corrosion behaviour of copper cable in the 0.5% CaSO4.2H2O solution was studied in term of open circuit potential for 30 days. The corrosion behaviour of higher power feeding was studied by the immersion and the planned interval test to determine the corrosion rate as well as the effect of voltage magnitudes and the current scheme i.e. positive direct (DC+) and alternating current (AC) at about 0.40 ± 0.01 mA/ cm2 current density. In the immersion test, both DC+ and AC scheme showed the increasing of feeding voltage magnitude has increased the corrosion rate of Cu samples starting from 60 to 100 volts. It was then reduced at about 100 - 120 volts which may due to the passive and transpassive mechanism. The corrosion rate was slowly reduced further from 120 to 200 volts. Visually, the positively charged of Cu cable was seems susceptible to severe corrosion, while AC scheme exhibited a slight corrosion reaction on the surface. However, the planned interval test and XRD results showed the corrosion activity of the copper cable in the studied solution was a relatively slow process and considered not to be corroded as a partially protective scale of copper oxide formed on the surface.

  2. Arsenic speciation in synthetic gypsum (CaSO4·2H2O): A synchrotron XAS, single-crystal EPR, and pulsed ENDOR study

    NASA Astrophysics Data System (ADS)

    Lin, Jinru; Chen, Ning; Nilges, Mark J.; Pan, Yuanming

    2013-04-01

    Gypsum (CaSO4·2H2O) is a major by-product of mining and milling processes of borate, phosphate and uranium deposits worldwide and, therefore, potentially plays an important role in the stability and bioavailability of heavy metalloids, including As, in tailings and surrounding areas. Gypsum containing 1900 and 185 ppm As, synthesized with Na2HAsO4·7H2O and NaAsO2 in the starting materials, respectively, have been investigated by synchrotron X-ray absorption spectroscopy (XAS), single-crystal electron paramagnetic resonance spectroscopy (EPR), and pulsed electron nuclear double resonance spectroscopy (ENDOR). Quantitative analyses of As K edge XANES and EXAFS spectra show that arsenic occurs in both +3 and +5 oxidation states and the As3+/As5+ value varies from 0.35 to 0.79. Single-crystal EPR spectra of gamma-ray-irradiated gypsum reveal two types of arsenic-associated oxyradicals: [AsO3]2- and an [AsO2]2-. The [AsO3]2- center is characterized by principal 75As hyperfine coupling constants of A1 = 1952.0(2) MHz, A2 = 1492.6(2) MHz and A3 = 1488.7(2) MHz, with the unique A axis along the S-O1 bond direction, and contains complex 1H superhyperfine structures that have been determined by pulsed ENDOR. These results suggest that the [AsO3]2- center formed from electron trapping on the central As5+ ion of a substitutional (AsO4)3- group after removal of an O1 atom. The [AsO2]2- center is characterized by its unique A(75As) axis approximately perpendicular to the O1-S-O2 plane and the A2 axis along the S-O2 bond direction, consistent with electron trapping on the central As3+ ion of a substitutional (AsO3)3- group after removal of an O2 atom. These results confirm lattice-bound As5+ and As3+ in gypsum and point to potential application of this mineral for immobilization and removal of arsenic pollution.

  3. Los Sentimientos, Luchas, y Esperanzas de Cinco Familias Mexicana: The Sentiments, Struggles, and Hopes of Five Mexican Families

    ERIC Educational Resources Information Center

    Dueñas, Gilbert

    2015-01-01

    Within the everyday space of their modest trailer homes, I observed compelling environments in the households of 5 Mexican families. In their homes, there existed "los padres con sus hijos" (parents with their children) who intuitively expressed "cariño," or love, for one another, conversed in multiple languages, practiced…

  4. Buen Comienzo, Buen Futuro: El Bebe de Cinco Meses (Healthy Start, Grow Smart: Your Five-Month Old).

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    Distributed by the U.S. Departments of Agriculture, Education, and Health and Human Services, this Spanish-language pamphlet provides parents with information and advice about their infants in the fifth month of life. Following a brief description of developmental characteristics at this age, the pamphlet offers information on topics including…

  5. Los Cinco Grandes across cultures and ethnic groups: multitrait multimethod analyses of the Big Five in Spanish and English.

    PubMed

    Benet-Martínez, V; John, O P

    1998-09-01

    Spanish-language measures of the Big Five personality dimensions are needed for research on Hispanic minority populations. Three studies were conducted to evaluate a Spanish version of the Big Five Inventory (BFI) (O. P. John et al., 1991) and explore the generalizability of the Big Five factor structure in Latin cultural groups. In Study 1, a cross-cultural design was used to compare the Spanish and English BFI in college students from Spain and the United States, to assess factor congruence across languages, and to test convergence with indigenous Spanish Big Five markers. In Study 2, a bilingual design was used to compare the Spanish and English BFI in a college-educated sample of bilingual Hispanics and to test convergent and discriminant validity across the two languages as well as with the NEO Five Factor Inventory in both English and Spanish. Study 3 replicated the BFI findings from Study 2 in a working-class Hispanic bilingual sample. Results show that (a) the Spanish BFI may serve as an efficient, reliable, and factorially valid measure of the Big Five for research on Spanish-speaking individuals and (b) there is little evidence for substantial cultural differences in personality structure at the broad level of abstraction represented by the Big Five dimensions. PMID:9781409

  6. El rol de Ia colaboracion y el Modelo de Aprendizaje Basado en Proyectos (ABPr) mediante el lente de la Teoria de Actividad (CHAT): un estudio de caso con estudiantes de 9no grado

    NASA Astrophysics Data System (ADS)

    Delgado, Isabel C.

    Los modelos de eensenanza y aprendizaje constructivistas conceptualizan el aprendizaje como un proceso activo. El modelo de Aprendizaje Basado en Proyectos (ABPr) se distingue por una serie de componentes, entre los cuales se destaca el aspecto colaborativo y cooperativo como un reto al momento de su implantacion. Son pocas las investigaciones que se concentran en este aspecto del modelo. En este estudio, se analizaron las diversas interacciones que surgen durante la implantacion de una unidad curricular sobre el tema de Geologia de Puerto Rico, la cual se diseno con el modelo ABPr cuyo enfoque es orientacion a proyectos. Particularmente, se examinaron las interacciones sociales que surgen entre los pares y entre pares y docente durante el proceso de planificacion y desarrollo de los productos finales, al igual que las interacciones entre los estudiantes y el material didactico en estas etapas del modelo. La investigacion es de tipo cualitativo e incorpora como diseno el estudio de caso. Las diversas interacciones constituyen la unidad de analisis. En el estudio participaron 19 estudiantes de 9no grado, a quienes se organizaron en 5 grupos colaborativos por temas de interes (Pangea, Placas tectonicas, Volcanes, Tsunamis y Terremotos). Las tecnicas que se utilizaron para recopilar los datos fueron: observaciones participativas, grupos focales y analisis de documentos (cuadernos reflexivos y respuestas de los estudiantes a la pregunta central del proyecto). Para el analisis de los datos se aplico la teoria de actividad (CHAT) que concentra la unidad de analisis en la actividad humana en un contexto particular. Los resultados del estudio senalan que las interacciones entre pares, entre pares y docente, asi como entre estudiantes y material didactico son fundamentales en el proceso de aprendizaje. Una mayor interaccion entre pares durante las etapas de planificar y desarrollar los productos finales de la unidad, promueve una mejor comprension de los conceptos de la

  7. A thermodynamic model for the prediction of phase equilibria and speciation in the H 2O-CO 2-NaCl-CaCO 3-CaSO 4 system from 0 to 250 °C, 1 to 1000 bar with NaCl concentrations up to halite saturation

    NASA Astrophysics Data System (ADS)

    Li, Jun; Duan, Zhenhao

    2011-08-01

    A thermodynamic model is developed for the calculation of both phase and speciation equilibrium in the H 2O-CO 2-NaCl-CaCO 3-CaSO 4 system from 0 to 250 °C, and from 1 to 1000 bar with NaCl concentrations up to the saturation of halite. The vapor-liquid-solid (calcite, gypsum, anhydrite and halite) equilibrium together with the chemical equilibrium of H+,Na+,Ca, CaHCO3+,Ca(OH)+,OH-,Cl-, HCO3-,HSO4-,SO42-, CO32-,CO,CaCO and CaSO 4(aq) in the aqueous liquid phase as a function of temperature, pressure and salt concentrations can be calculated with accuracy close to the experimental results. Based on this model validated from experimental data, it can be seen that temperature, pressure and salinity all have significant effects on pH, alkalinity and speciations of aqueous solutions and on the solubility of calcite, halite, anhydrite and gypsum. The solubility of anhydrite and gypsum will decrease as temperature increases (e.g. the solubility will decrease by 90% from 360 K to 460 K). The increase of pressure may increase the solubility of sulphate minerals (e.g. gypsum solubility increases by about 20-40% from vapor pressure to 600 bar). Addition of NaCl to the solution may increase mineral solubility up to about 3 molality of NaCl, adding more NaCl beyond that may slightly decrease its solubility. Dissolved CO 2 in solution may decrease the solubility of minerals. The influence of dissolved calcite on the solubility of gypsum and anhydrite can be ignored, but dissolved gypsum or anhydrite has a big influence on the calcite solubility. Online calculation is made available on www.geochem-model.org/model.

  8. S.Res.167 — 112th Congress (2011-2012) A resolution recognizing the historical significance of the Mexican holiday of Cinco de Mayo.

    THOMAS, 112th Congress

    Sen. Menendez, Robert [D-NJ

    2011-05-05

    05/05/2011 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S2752-2753; text as passed Senate: CR S2753; text of measure as introduced: CR S2745) (All Actions)

  9. S.Res.437 — 113th Congress (2013-2014) A resolution recognizing the historic significance of the Mexican holiday of Cinco de Mayo.

    THOMAS, 113th Congress

    Sen. Udall, Mark [D-CO

    2014-05-05

    05/05/2014 Submitted in the Senate, considered, and agreed to without amendment and with a preamble by Unanimous Consent. (consideration: CR S2676-2677; text as passed Senate: CR S2649-2650) (All Actions)

  10. La Educacion Especial para Ninos con Impedimentos Desde Recien Nacidos Hasta Cinco Anos de Edad = Special Education for Handicapped Children Birth to Five.

    ERIC Educational Resources Information Center

    New York State Education Dept. Albany. Office for the Education of Children with Handicapping Conditions.

    The manual, in Spanish, describes programs and resources available for preschool handicapped children and their families in conjunction with the New York State Education Department. Section 1 on assistance in securing services, reviews the service provided by Early Childhood Direction Centers, and outlines the role of local Committees on the…

  11. Yo Ciudadano: Un Curriculo de Experiencias para Educacion Civica. Nivel: Cinco (Citizen Me: An Experiential Curriculum for Citizenship Education. Level: Five).

    ERIC Educational Resources Information Center

    Gutierrez, Merri

    Integrating concepts of basic citizenship education with community involvement, this experiential curriculum provides a means for developing decision making and critical thinking skills within the existing fifth grade social studies curriculum. The 12 lessons, translated into Spanish, cover the following concepts: responsibility, rules and laws,…

  12. Sobre la naturaleza de cinco candidatos a cúmulos abiertos ubicados próximos a la dirección del centro galáctico

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Clariá, J. J.

    CCD BVI Johnson-Cousins observations obtained for 1759 stars in 4'×4' regions around the unstudied southern stellar aggregates Ruprecht 103, 124, 129, 146 and 166 are presented. The objects are described as open clusters in the catalogues of star clusters and associations of Alter et al. (1970) and LyngÅ (1987), as well as, in the ESO/Uppsala Survey of the ESO (B) Atlas (Lauberts 1982). Our analysis shows that none of these objects are genuine open clusters, except perhaps Ruprecht 166, since no clear main sequences (MSs) or other meaningful features can be seen in the extracted (V,B-V) and (V,V-I) colour-magnitude diagrams (CMDs). The star sequences seen in the distinct CMDs, specially for Ruprecht 124 and 129, are apparently formed by the superimposition of MS field stars affected by varying amounts of interstellar absorption and/or placed at different distances from the Sun. The CMDs of Ruprecht 166 present a pronounced variation in the luminosity function along the apparent MS, a fact from which we can infer the notion of these stars had a different origin. Star counts carried out within and outside the cluster candidate fields not only support the results that the objects do not present a significant number density contrast with respect to the Galactic disk, but also show that they do not appear to be candidate late stages of star cluster dynamical evolution. Several other stellar aggregates included in open cluster catalogues have previously been disproved as genuine physical systems (see, e.g., Carraro & Patat 1995, MNRAS, 276, 563; Carraro 2000, A&A, 357, 145; Piatti & Clariá 2001, A&A, 370, 931). Thus, the present work implies the potential likelihood of other wrongly classified open clusters.

  13. Encefalitis por anticuerpos contra el receptor de NMDA: experiencia con seis pacientes pediátricos. Potencial eficacia del metotrexato

    PubMed Central

    Bravo-Oro, Antonio; Abud-Mendoza, Carlos; Quezada-Corona, Arturo; Dalmau, Josep; Campos-Guevara, Verónica

    2016-01-01

    Introducción La encefalitis por anticuerpos contra el receptor de N-metil-D-aspartato (NMDA) es una entidad cada vez más diagnosticada en edad pediátrica. A diferencia de los adultos, en muchos casos no se asocia a tumores y las manifestaciones iniciales en niños más frecuentes son crisis convulsivas y trastornos del movimiento, mientras que en los adultos predominan las alteraciones psiquiátricas. Casos clínicos Presentamos seis casos pediátricos confirmados con anticuerpos contra la subunidad NR1 del receptor de NMDA en suero y líquido cefalorraquídeo. Cinco de los casos comenzaron con crisis convulsivas como manifestación clínica inicial antes de desarrollar el cuadro clásico de esta entidad. En todos los casos se utilizaron esteroides como primera línea de tratamiento, con los que sólo se observó control de las manifestaciones en uno, por lo que el resto de los pacientes requirió inmunomoduladores de segunda línea. Todos los pacientes recibieron metotrexato como tratamiento inmunomodulador para evitar recaídas y la evolución fue a la mejoría en todos ellos. Conclusiones En nuestra serie de pacientes con encefalitis por anticuerpos contra el receptor de NMDA, ninguno se asoció a tumores. Todos los casos recibieron metotrexato por lo menos durante un año, no observamos eventos adversos clínicos ni por laboratorio, ni hubo secuelas neurológicas ni recaídas durante el tratamiento. Aunque es una serie pequeña y es deseable incrementar el número y tiempo de evolución, consideramos el metotrexato una excelente alternativa como tratamiento inmunomodulador para esta patología. PMID:24150952

  14. PROCENTAJE DE PSILIDOS PORTADORES DE Canidatus Liberibacter asiaticus Y SU RELACION CON LA INCIDENCIA DE HLB EN CINCO HUERTAS COMERCIALES DE LIMON MEXICANO {Citrus aurantifolia (Christm) Swingle} EN EL ESTADO DE COLIMA MEXICO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian citrus psyllids (Diaphorina citri) were individually analyzed by qPCR to detect Candidatus Liberibacter asiaticus (CLas). The psyllids were collected in Mexican lime (Citrus aurantifolia) trees in five commercial orchards in Tecomán and Manzanillo, Colima with severe symptoms of classical mott...

  15. National Migrant Education Program: Early Childhood Development Skills--Birth Through 5 Years (Desarrollo de Destrezas en la Temprana Infancia--Desde el Nacimiento Hasta los Cinco Anos de Edad).

    ERIC Educational Resources Information Center

    1979

    Compiled to ensure cooperation between states and to provide continuity of reporting on developmental skills for the migrant child from birth through five years of age, this booklet lists the psychomotor, cognitive, and affective skills which are reported through the Migrant Student Record Transfer System (MSRTS). Published in both English and…

  16. Edades y metalicidades de cinco cúmulos estelares proyectados en dirección a la Nube Menor de Magallanes: implicaciones sobre los procesos de formación y evolución de estos sistemas

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Santos, J. F. C.; Clariá, J. J.; Bica, E.; Sarajedini, A.; Geisler, D.

    Washington photometry of the 5 star clusters Lindsay 32, Lindsay 38, Kron 28, Kron 44 and Lindsay 116 and their surrounding fields located towards the Small Magellanic Cloud (SMC) is presented for the first time. From the color-magnitude diagrams, cleaned from field stars contamination, the cluster and SMC field reddenings, ages and metallicities are determined. The ages - derived from the difference in the T1 magnitude betweem the giant clump and the Main Sequence turnoff point - vary between 2 and 6 Gyr, and the metallicities ([Fe/H]) between -1.65 and -1.10. Lindsay 116 is located closer to the Large Magellanic Cloud (LMC) than to the SMC and its fundamental parameters suggests a higher probability of belonging to the LMC. The results obtained in this work, combined with previous estimates of age and metallicity for other seven clusters, allow us to draw the following conclusions: (1) There does not exist an age-position relation in the SMC, but a age-metallicity one. (2) The chemical enrichment in the SMC has been very efficient during the last 5 Gyr. (3) The SMC clusters formation and evolution can be better represented by a bursting star formation process than by a continuum star formation mechanism.

  17. Comportamiento dinámico de asteroides en la resonancia 2:1

    NASA Astrophysics Data System (ADS)

    López García, F.; Brunini, A.

    El propósito de este trabajo es mostrar los resultados obtenidos del estudio del movimiento de asteroides cercanos a la conmensurabilidad 2:1 con el movimiento medio de Júpiter, analizando el comportamiento de órbitas de asteroides reales y ficticios. Se analizan los tiempos de Lyapunov obtenidos a partir de la integración de las ecuaciones del movimiento. Se han estudiado la órbitas utilizando el modelo de cinco cuerpos y se han considerado los casos planar y espacial. Las simulaciones numéricas se realizaron utilizando integradores simpléticos y el intervalo de tiempo de integración fue de T = 107 años.

  18. Materials Data on CaSO4 (SG:63) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. IDENTIFICATION OF CASO4 FORMED BY REACTION OF CAO AND SO2

    EPA Science Inventory

    The injection of calcium-based sorbents into coal-fired boilers for reaction with, and reduction in the levels of, sulfur dioxide (SO2) in the flue gas has undergone considerable research and development. Significant effort has also been made in developing models for the overall ...

  20. Etologia aplicada al manejo de especies amenazadas: el caso del turon de patas negras (Mustela nigripes)

    USGS Publications Warehouse

    Vargas, A.; Biggins, D.; Miller, B.

    1999-01-01

    de esta especie de un modo más eficaz y rentable. Black-footed ferrets are considered one of the world's most endangered mammals. The last wild population was discovered in 1981 in Meteetsee, Wyoming, and, in 1985 it collapsed due to an epizootic of canine distemper in combination with sylvatic plague. Prior to the extinction of the last remnant population, 18 wild black-footed ferrets were captured to initiate captive propagation efforts. Captive breeding has been successful and, during the last 11 years, more than 2600 black-footed ferrets have been born in captive breeding centers. Since 1991, approximately 870 ferrets have been reintroduced in 5 areas located within the ferret's original geographic distribution, including sites in Wyoming, Montana, South Dakota, and Arizona. Scientific research has been, and continues to be, a critical tool to direct recovery efforts. Studies in applied ethology conducted on captive and reintroduced ferret populations have demonstrated that a naturalistic captive environment, particularly during early developmental periods, enhances the expression of behaviors necessary for survival in nature. Ferrets raised in a naturalistic environment develop better predatory skills, are able to recognize prairie dog burrows as a home and shelter from predators, and are more physically fit. Results from these studies have been adapted into management strategies to help implement a more cost-effective road to black-footed ferret recovery.

  1. Acentos, Tildes, Casas, Cosas, Casos, Cosos? (Accents, Tildes, [Punctuation, and Spelling Accuracy]).

    ERIC Educational Resources Information Center

    Fabri Diaz, Victor

    1972-01-01

    Correct spelling, punctuation marks, and spelling accents must be taught in the beginning Spanish course. Accent marks make a difference in the interpretation of the written word. Rules govern the placing of exclamation and question marks and make up an integral part of written Spanish. Teachers have a duty and a responsibility to teach these…

  2. Materials Data on CaSO4 (SG:180) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  3. Very deep traps in Al 2O 3 and CaSO 4 : Dy

    NASA Astrophysics Data System (ADS)

    Portal, Guy; Lorrain, Serge; Valladas, Georges

    1980-09-01

    In dosimetry, empty traps were generally used at temperatures lower than 350°C. On account of the difficulties due to the black body emission, very few searchers have studied traps stimulated at higher temperatures [1,5]. The present work deals with the study of energetic levels stimulated at temperatures higher than 500°C. These levels have the advantage of being very stable even at conservation temperatures near 350°C.

  4. Heat capacities and entropies from 8 to 1000 K of langbeinite (K2Mg2(SO4)3), anhydrite (CaSO4) and of gypsum (CaSO4·2H2O)

    USGS Publications Warehouse

    Robie, Richard A.; Russell-Robinson, Susan; Hemingway, Bruce S.

    1989-01-01

    Although Bond (Bell Sys. Tech. J., 22 (1943) 145) reported that langbeinite was piezoelectric at room temperature, we found no evidence in our Cpo measurements for a Curie temperature above which langbeinite would no longer be piezoelectric.

  5. Síndrome de Poland. Presentacíon de un caso. [Poland's syndrome. A case report].

    PubMed

    Fernández González, A L; García Redondo, A; García Castro, A

    1990-01-01

    A case of Poland's syndrome in a 19-year-old male is briefly described. This syndrome is characterized by congenital absence of the pectoralis major and minor muscles as well as homolateral brachysyndactyly. The etiology is unknown. Surgical repair is aimed at constructing a functional hand. Chest deformities usually does not require surgery except in cases of lung herniation or breast hypoplasia. PMID:2096446

  6. POBREZA Y VULNERABILIDAD EN MÉXICO: EL CASO DE LOS JÓVENES QUE NO ESTUDIAN NI TRABAJAN*

    PubMed Central

    Aguila, Emma; Mejía, Nelly; Pérez, Francisco; Rivera, Alfonso; Ramírez, Edgar

    2015-01-01

    La situación de los jóvenes que no estudian ni trabajan (ninis) se ha vuelto evidente en los últimos años debido a los riesgos que enfrenta dicha población. Este artículo contribuye a la literatura al analizar las características económicas y laborales de los ninis, explora la situación laboral de sus parejas y provee proyecciones al año 2030. Asimismo, propone una clasificación de ninis para focalizar el diseño de políticas públicas, que identifica una tendencia a la baja de éstos debido a las mujeres que acceden al sistema educativo y al mercado laboral y que una mayor proporción de esta población estará compuesta por desempleados. PMID:25918452

  7. Medicinal ethnobotany in Huacareta (Chuquisaca, Bolivia)

    PubMed Central

    2012-01-01

    used as a base for subsequent work related to traditional medicine and its contribution to allopathic medicine in San Pablo de Huacareta. Resumen Introducción El objetivo del presente estudio fue documentar los tipos de enfermedades tratadas mediante el uso de plantas medicinales, sus aplicaciones principales y también tener un reporte de las enfermedades mayormente atendidas en el Hospital de San Pablo de Huacareta (Chuquisaca, Bolivia). Métodos Se realizaron encuestas semiestructuradas a 10 informantes locales anotando los usos atribuidos a sus plantas medicinales, se agruparon las plantas por categorías de enfermedades tratadas en la medicina tradicional. Se obtuvieron reportes de casos tratados en el Hospital de Huacareta para poder relacionar el tratamiento de enfermedades recurrentes en la zona entre la medicina tradicional y la medicina occidental. Resultados Se reportaron 91 especies nativas y exóticas, además de un espécimen indeterminado exótico que intervienen en un total de 258 aplicaciones medicinales, las cuales son empleadas en un total de 13 categorías de enfermedades. Los desórdenes gastrointestinales (55%) son mayormente tratados mediante plantas medicinales, seguidas de las afecciones al sistema esqueleto-muscular (25%) y enfermedades dermatológicas (24%). La información del Hospital indica que las enfermedades más frecuentes son Infecciones Respiratorias Agudas (47%) y Enfermedades Diarreicas Agudas (37%). Los remedios vegetales se emplean en forma de infusiones y cocciones principalmente. Se emplean mayormente plantas nativas, también se introdujo en la farmacopea médica el uso de plantas exóticas al lugar. Conclusiones El tratamiento de trastornos gastrointestinales constituye el objetivo primordial de la etnobotánica médica de los habitantes de Huacareta, las enfermedades del sistema respiratorio, son mayormente tratadas en el Hospital. Observando los datos del libro de consultas del Hospital, se puede inferir que los des

  8. Espectroscopia de candidatos a remanescentes de aglomerados abertos

    NASA Astrophysics Data System (ADS)

    Pavani, D. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2003-08-01

    A pesquisa sobre remanescentes de aglomerados abertos tem despertado grande interesse. Seguindo esta tendência encontramos estudos teóricos e observacionais. Os primeiros baseiam-se em simulações numéricas buscando determinar fração de binárias e distâncias galatocêntricas, tempo de vida e conteúdo estelar. Estes estão relacionados à função inicial de massa e densidade de estrelas, ou seja, se ricos ou pobremente povoados, compactos ou esparsos. No caso observacional procuram-se identificar os remanescentes considerando-se que trazem estas assinaturas de seus percursores. No presente estudo empregamos espectroscopia para analisar oito concentrações pobremente povoadas, previamente classificadas como aglomerados abertos, sendo sete compactas e uma esparsa. As observações foram obtidas através do telescópio de 2,15 m do CASLEO em San Juan, Argentina, em turnos entre 2001 e 2003. Utilizamos uma câmara CCD contendo um chip Tektronics de 1024X1024 pixeis aliado a um espectrógrafo REOSC. O domínio espectral vai de 3700 a 7000 Å. As reduções foram realizadas no Observatório Astronômico de Córdoba (Argentina) usando pacotes IRAF padrões. Determinamos idades, avermelhamentos e tipos espectrais através de comparações com biblioteca de estrelas e de aglomerados. Em alguns casos nossos espectros estavam dominados por estrelas individuais às quais determinamos seus tipos espectrais. Aos oito objetos adicionamos mais cinco da literatura recente analisados via espectro ou diagrama cor-magnitude. O histograma resultante contém idades típicas entre 0.5 e 3 Ganos. Considerando que predominantemente estes objetos encontram-se na vizinhança solar e, portanto, não cruzaram muitas vezes o plano Galático esperamos que a diferença no tempo necessário para dissolução destes prováveis remanescentes seja em função de diferentes massas iniciais.

  9. [In Process Citation].

    PubMed

    Calleja Fernández, Alicia; Vidal Casariego, Alfonso; Cano Rodríguez, Isidoro; Ballesteros Pomar, María D

    2016-01-01

    Introducción: la cuantificación y registro de la ingesta alimentaria del paciente hospitalizado es clave dentro del plan de cuidado nutricional. Objetivo: evaluar la validez de un cuestionario semicuantitativo de valoración del consumo comparado con una técnica de registro de alimentos por observación y pesada de los platos incluidos en la dieta hospitalaria. Métodos: estudio transversal realizado en condiciones de práctica clínica habitual. Las técnicas de valoración del consumo que se compararon fueron un registro por doble pesada y un cuestionario semicuantitativo por observación de la ingesta de cinco categorías (todo [> 80%], casi todo [80-60%], la mitad [60-40%], casi nada [40-20%] o nada [< 20%]), ambas realizadas por un dietista-nutricionista. La comparación entre ambas herramientas fue realizada con el índice kappa con ponderación cuadrática e intervalo de confianza del 95%. Resultados: fueron realizadas un total de 1.980 valoraciones. Se observó con el cuestionario semicuantitativo que en el 50% de los casos se ingirió todo, en el 19% casi todo, en el 13% la mitad, en el 9% menos de la mitad y en el 9% nada. La mediana de la ingesta por doble pesada de alimentos fue de 76,8 (RIC 45,8)%. Se observó que existió un acuerdo satisfactorio entre la técnica de doble pesada y la valoración visual del consumo con un valor κ = 0,907 (IC 95% 0,894-0,925). Conclusión: la escala visual empleada en este estudio permite cuantificar la ingesta real del paciente de forma precisa y adecuada por personal cualificado. PMID:27238794

  10. Tratamiento Quirúrgico de los Meningiomas del Foramen Óptico, Técnicay Resultados de una Serie de 18 Pacientes

    PubMed Central

    Goldschmidt, Ezequiel; Ajler, Pablo; Campero, Álvaro; Landriel, Federico; Sposito, Maximiliano; Carrizo, Antonio

    2014-01-01

    Introducción: los meningiomas del foramen óptico producen un rápido deterioro de la función visual aún cuando su tamaño es pequeño, por eso su diagnóstico y manejo difiere del resto de los meningiomas clinoideos. El propósito de este estudio es presentar la técnica y los resultados de nuestro manejo quirúrgico de meningiomas foraminales (MF). Pacientes y Métodos: se llevó a cabo una revisión de las historias clínicas de 47 pacientes con meningiomas primarios intraorbitarios. Se realizaron 52 cirugías en los pacientes con MF. Se empleó una craneotomía fronto-orbitaria, seguida de una descompresión extradural del canal óptico, resección del componente intraorbitario y exploración intradural del nervio óptico. Resultados: de los 12 pacientes con MF que presentaban la visión conservada, la agudeza visual fue preservada en 7 casos, mejoró en 2, y empeoró en 3. En 18 pacientes, el principal síntoma fue exoftalmos y en 35 pacientes ceguera unilateral. Ocurrieron 6 recurrencias, 2 a 10 años después de la resección quirúrgica. Cinco de ellos fueron reoperados. Se indicó radioterapia después de la recurrencia en 3 pacientes. Conclusión: el manejo de los MF continúa siendo controvertido y frecuentemente se propone un tratamiento conservador. Basados en nuestros hallazgos de frecuente extensión intracraneal, proponemos realizar una resección total o subtotal del tumor, preservando el nervio óptico en pacientes con visión prequirúrgica conservada. PMID:25165616

  11. Foraminotomia cervical posterior en el tratamiento de conflictos foraminales

    PubMed Central

    Campero, Álvaro; Barrera, Ramiro; Ajler, Pablo

    2012-01-01

    Introducción: La foraminomotima cervical posterior es un procedimiento utilizado para la descompresion radicular por via posterior y constituye una alternativa a la via clásica anterior. En este trabajo evaluamos nuestra serie de pacientes tratados por esta via. Método: Desde enero de 2008 a diciembre de 2011, 17 pacientes (18 foraminotomías) fueron operados por presentar cervicobraquialgia a causa de un conflicto foraminal, realizando un foraminotomía cervical posterior. Los pacientes fueron evaluados en el postoperatorio inmediato, al mes y a los 3 meses de la cirugía. Los parámetros para valorar los resultados fueron la Escala Análoga del Dolor (VAS), la Neck Disability Index y los criterios de Odom. Resultados: El dolor radicular por conflicto foraminal secundario a hernia de disco cervical fue el síntoma y la patología predominante. El nivel más afectado fue C5-C6. La resolución completa del dolor radicular se observó en casi todos los pacientes. La VAS preoperatoria en promedio fue de 8.8 (mínimo 8 – máximo 10), con una franca mejoría en todos los casos (0.4 en el último control). La media en la Neck Disability Index al inicio fue de 35.3 (mínimo 32 – máximo 45), con una evolución favorable en la evaluación final (0.6). Los Criterios de Odom para la evaluación de pacientes operados de columna cervical fueron satisfactorios con un promedio de 1.17. Se observaron complicaciones en 4 pacientes (23%), todas tuvieron una evolución favorable. No hubo infecciones, discitis ni empeoramiento de los síntomas preexistentes en ningún paciente. Conclusión: La foraminotomía cervical posterior es un procedimiento efectivo para el tratamiento del dolor radicular en los conflictos foraminales PMID:23596556

  12. [Radiological percutaneous gastrostomy (GRP), 17 años de experiencia, serie de casos del hospital Universitario Virgen del Rocío].

    PubMed

    Navarro Falcón, Magnolia Del Carmen; Parejo Campos, Juana; Pereira Cunill, José Luis; García Luna, Pedro Pablo

    2015-01-01

    When assessing a patient nutritional support the state of the gastrointestinal tract is the most important point to consider, whenever possible we should choose the enteral nutrition (EN) over parenteral nutrition (PN) and recognized by its various advantages. The percutaneous gastrostomy (GRP) were introduced in clinical practice as an alternative to surgical gastrostomy (GQ). The speed, simplicity, low cost, low morbidity and low mortality of these techniques has allowed its rapid development.The feeding tubes types used were the balloon-retained devices catheter, the pig tail and the ballon-retained with gastropexia (gastropexia). It is a retrospective study of all patients who were placed GPR in the Virgen del Rocío University Hospital, Sevilla, between September 1996 and September 2013, which aims to study is to describe the characteristics of patients and the complications presented for different types of enteral feeding tubes used. GPR 186 were performed in 176 patients (135 males (76.70%), with an average duration of 303.6 days, the most frequent diseases were cancers of the head and neck 49.46%. The types of feeding tubes used were pigtail 118 (63.44%), balloon-retained devices 22 (11.83%), and gastropexia 46 (24.73%). The most common early complications in the pigtail group were early purulent exudate and early bleeding (2.5 and 3.4% respectively), while in the balloon catheter group the initial output of the probe was most frequent early complication (13.7%), none of these complications were observed in the group of gastropexy. The most common late complication was obstruction probe. The GPR is a safe technique with lower mortality of 1%; Low frequently of early and late complications. A better understanding of this technique can reduce the frequency of complications. PMID:25561125

  13. Reforma Ortografica, Planejamento e Difusao Linguistica: O Caso da Lingua Portuguesa (Orthographic Reform, Planning, and Linguistic Diffusion: The Case of Portuguese).

    ERIC Educational Resources Information Center

    Schmitz, John Robert

    1998-01-01

    Suggests that the Luso-Brazilian Accord is a strategy to spread the Portuguese language in Africa, particularly in the former colonies of Angola, Mozambique, Guinea-Bissau, Cape Verde, and Sao Tome e Principe, and to construct and solidify a community of lusophone nations in geopolitical terms in world affairs. Language planning in these countries…

  14. Educacion Fundamental Integral #2: Teoria y Aplicacion en el Caso de ACPO. (Fundamental Integral Education #2: Theory and Application in the Case of ACPO.)

    ERIC Educational Resources Information Center

    Alarcon, Hernando Bernal

    Educacion Fundamental Integral (EFI) is an educational process which aims to help Colombia's rural population to improve their living conditions. EFI adapts to the concrete circumstances of the person in his own environment. Objectives of EFI are to make the rural people: responsible for the work necessary for their own development; work together;…

  15. Experiencias de Vida de la Mujer Adulta: Estudio de Caso de Lideres en Desarrollo del Programa de Administracion y Supervision Educativa

    ERIC Educational Resources Information Center

    Morales-Roman, Gildrette M.

    2012-01-01

    Since the twentieth century to present, the role of women in society has undergone fundamental changes. Women, today, has assumed many different task and new roles, becoming part of professional workforce and increasing level of education by aspiring a higher education gaining access to leadership positions. The purpose of this qualitative…

  16. Experiencias, Sentido y Significado de la Consejeria en Justicia Social a Nivel Universitario: Estudio de Caso Cualitativo Mediante Tres Narrativas De Consejeros Profesionales en Educacion Superior

    ERIC Educational Resources Information Center

    Santiago Tosado, Virginia

    2012-01-01

    The purpose of the study was to understand and profoundly describe the nature of social justice practice, as is comes up from the experience of three professional counselors whose working settings are the academic arena. Detailed descriptions are presented concerning the meanings and sense of counseling for social justice, as the interviews…

  17. La Observación Sistemática de Vecindarios: El caso de Chile y sus perspectivas para Trabajo Social

    PubMed Central

    Sanhueza, Guillermo E.; Delva, Jorge; Andrade, Fernando H.; Grogan-Kaylor, Andrew; Bares, Cristina; Castillo, Marcela

    2012-01-01

    El estudio acerca de las características de los vecindarios y sus efectos sobre las personas ha llegado a ser un área de creciente atención por parte de investigadores de diversas disciplinas en países desarrollados. Aunque actualmente existen diversas metodologías para estudiar efectos del vecindario, una de las más utilizadas es la Observación Sistemática de Vecindarios –Systematic Social Observation SSO, en inglés—porque permite recolectar información acerca de diversas características del entorno físico, social, ambiental y económico de los vecindarios donde se aplica. El objetivo de este artículo es (i) dar a conocer sumariamente algunas investigaciones influyentes sobre efectos del vecindario en Estados Unidos, ii) describir cómo se diseñó e implementó la Observación Sistemática de Vecindarios en la ciudad de Santiago de Chile, iii) señalar algunos facilitadores y obstaculizadores de la implementación del proyecto y, finalmente iv) enunciar posibles contribuciones y limitaciones que esta metodología ofrecería al trabajo social en Chile. PMID:24791060

  18. Catalysts for Change: Three Case Studies of Quality Education Worldwide = Catalizadores del Cambio: Tres Casos de Estudio sobre la Educacion de Calidad en el Mundo

    ERIC Educational Resources Information Center

    Puriefoy, Wendy D.

    2007-01-01

    Public education is the cornerstone of democracy and is absolutely fundamental to a democratic, civil and prosperous society. Beyond the boundaries of the United States, other countries are working to provide quality education to their children through civil society institutions. In particular, there are three extraordinary organizations in Peru,…

  19. Protegiendo a su familia de los terremotos-Los siete pasos a la seguridad para prepararse en caso de un terremoto (en espa?ol y en ingles)

    USGS Publications Warehouse

    Desarrollado por American Red Cross, Asian Pacific Fund, California Earthquake Authority, Governor's Office of Emergency Services, New America Media, U.S. Department of Homeland Security Federal Emergency Management Agency, and U.S. Geological Survey

    2007-01-01

    Les escribimos esta carta para comunicarle un mensaje sumamente importante sobre las preparaciones de emergencia. Historicamente, hemos sufrido terremotos aqui en el Area de la Bahia de San Francisco que han causado graves privaciones para los residentes de la comunidad y da?os increibles a nuestras ciudades. Es probable que suframos un terremoto de gran magnitud en los proximos 30 a?os. Muchos de nosotros venimos de otros paises donde hemos pasado por terremotos y por eso creemos entenderlos. Sin embargo, la manera que nos preparamos para terremotos en nuestros paises de origen puede ser distinta a la que empleamos aca en los Estados Unidos. Muy pocas personas mueren a causa de los derrumbes de los edificios en el Area de la Bahia porque la mayoria de los edificios son construidos para resistir el sacudimiento de la tierra. Pero es muy probable que su familia no tenga atencion medica, alimentos o que esten separados del uno al otro por dias o semanas. Finalmente depende de usted mantener a su familia a salvo hasta que llegue asistencia, por eso les pedimos que nos unamos para aprender a cuidar a su familia antes, durante, y despues de un terremoto. El primer paso es leer este libro. Cada uno de su familia, ni?os y adultos, pueden aprender como prepararse para un terremoto. Haga participar e incluya sus ni?os; pueden ayudarle a prepararse. Aproveche las clases ofrecidas en su comunidad sobre las preparaciones de terremotos por la Cruz Roja Estadounidense (American Red Cross). Estos cursos de preparacion son gratis y disponibles en espa?ol para todos en la comunidad sin tomar en cuenta la historia de la familia, estado legal, genero o edad. Les recomendamos que tome ventaja de estas clases gratuitas. Para mas informacion consulte la ultima pagina de este libro. Recuerde que un terremoto puede ocurrir sin aviso y la unica manera de reducir el da?o de terremotos es estar preparados. !Preparese!

  20. The residual and direct effects of reduced-risk and conventional miticides on twospotted spider mites, Tetranychus urticae (Acari: Tetranychidae) and predatory mites (Acari: Phytoseiidae)

    SciTech Connect

    Liburd, O.E.; White, J.C.; Rhodes, E.M.; Browdy, A.A.

    2007-03-15

    Neoseiulus californicus McGregor y Phytoseilus persimilis Athias-Henriot (Acari: Phytoseiidae) causados por varios acaricidas convencionales y de riesgo-reducido fueron evaluados en fresas (Fragaria x ananassa Duchense). Los experimentos fueron realizados en laboratorio e invernadero. Los experimentos en el invernadero evaluaron tambien el efecto directo de los acaricidas en la 'arana roja'. La eficacia para controlar la 'arana roja' de los acaricidas convencionales y de riesgo-reducido fue evaluada en discos de las hojas y en plantas de fresa, y los efectos residuales de los acaricidas en los acaros predadores fueron evaluados en plantas completas. Para la 'arana roja' se evaluaron cinco tratamientos: el acaricida convencional fenbutatin-oxido (Vendex[reg]), 3 acaricidas de riesgo-reducido binfenazate (Acaramite 50WP[reg]), extracto de ajo activado (Repel[reg]), aceite de semillas de ajonjoli y ricino (Wipeout[reg]) y un control tratado con agua. Para los acaros predadores solamente los efectos de Acaramite[reg] y Vendex[reg] fueron evaluados. Acaramite[reg] fue el tratamiento mas efectivo para la 'arana roja' en el laboratorio y el invernadero. Vendex[reg] y Wipeout[reg] fueron tambien efectivos en el laboratorio, pero no causaron una reduccion significativa de 'aranas rojas' en el invernadero. Repel[reg] fue el tratamiento evaluado menos eficaz. Ni Acaramite[reg] ni Vendex[reg] redujeron significativamente las poblaciones de acaros predadores. Sin embargo, aparentemente hay mas acaros predadores en Vendex[reg] que en Acaramite[reg]. Tambien se encontraron significativamente mas acaros predadores en plantas inoculadas que en plantas no inoculadas. (author)

  1. Complicaciones orales de la quimioterapia y la radioterapia (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de las complicaciones orales, como la mucositis y la disfunción de la glándula salival, que se presentan en pacientes de cáncer tratados con quimioterapia y radioterapia dirigida a la cabeza y el cuello.

  2. Complicaciones orales de la quimioterapia y la radioterapia (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca de las complicaciones orales, como la mucositis y la disfunción de la glándula salival, que se presentan en pacientes de cáncer tratados con quimioterapia y radioterapia a la cabeza y el cuello.

  3. "Processing Instruction": un tipo di grammatica comunicativa per la classe di lingua straniera. Il caso del futuro italiano. (Processing Instruction: One Type of Communicative Grammar for the Foreign Language Classroom. The Case of the Italian Future Tense).

    ERIC Educational Resources Information Center

    Benati, Alessandro

    2000-01-01

    Examines the theoretical and practical rationale for processing instruction as a method of incorporating grammar instruction in a communicative foreign language approach. Presents results of a study on the role of processing instruction on the learning of the Italian future indicative tense by a group of English-speaking students. Results…

  4. On ambiente de binárias de pequena massa em formação: o caso do glóbulo cometário CG30 e IRAS08076-3556

    NASA Astrophysics Data System (ADS)

    Hickel, G. R.; Vilas-Boas, J. W. S.

    2003-08-01

    Neste trabalho, combinamos observações de polarização linear no óptico (banda R), dados no infravermelho distante (IRAS) e observações de transições moleculares em radiofreqüências (CO e espécies isotópicas, HCN e HCO+) para analisar o glóbulo cometário (GC) CG30 (na região da IRAS Vela Shell), que apresenta objetos Herbig-Haro e ejeções de matéria, além de uma fonte pontual IRAS em seu interior. Os objetivos deste estudo são: determinar a eficiência de formação estelar nos glóbulos cometários, através da relação entre a massa total do GC e da massa das estrelas em formação; determinar como o campo magnético influencia na formação de estrelas no interior destes objetos; e analisar as modificações que ejeções de matéria de estrelas em formação causam no gás e no campo magnético dos GCs. Combinando nossos dados com trabalhos já publicados, mostramos que CG30 tem uma eficiência de formação estelar em torno de 3%; que o campo magnético é importante na manutenção da estrutura global do GC e demonstra sinais de torção e compressão; e que a ejeção bipolar de matéria das estrelas do par formam uma ejeção quadripolar, a qual influencia na densidade e temperatura do gás e no grau de polarização dos grãos de poeira associados ao gás do GC.

  5. Algunos Criterios para Evaluar Programas de Educacion Superior a Nivel de Posgrado: El Caso Particular de la Administracion Publica (Some Criteria to Evaluate Higher Education Programs at the Graduate Level: The Special Case of Public Administration).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Intended as a contribution to a workshop discussion on program evaluation in higher education, the paper covers five major evaluation issues. First, it deals with evaluation concepts, explaining the purposes of evaluation; pertinent terms; and the sources of evaluation in public health procedures, the scientific method, the systems approach, and…

  6. Planificacion linguistica y constitucion de un bloque regional: El caso del Mercosur (Argentina, Brasil, Paraguay y Uraguay) y de Chile (Language Planning and the Constitution of a Regional Bloc: The Case of Mercosur (Argentina, Brazil, Paraguay, and Uruguay) and Chile.

    ERIC Educational Resources Information Center

    Chareille, Samantha

    2003-01-01

    The common market of the South is a new linguistic and cultural area. The resurgence of innermost identities within member states proves that Mercosur identity can neither be universal nor specific. The outcome of this quest for identity will depend on the ability to carefully handle an area of cultural diversity and a place of common allegiance…

  7. Research Culture in Higher Education: The Case of a Foreign Language Department in Mexico (Cultura de la investigación: el caso de un Departamento de Lenguas Extranjeras en México)

    ERIC Educational Resources Information Center

    Hernández Méndez, Edith; Reyes Cruz, María del Rosario

    2014-01-01

    In the case of Mexico, until recently, many universities focused mainly on teaching, but recent changes have led to new appointments in research, administration, and community service. There now seems to be, however, a view of the predominance of research in the academic environment. Therefore, the purpose of this paper was to examine and…

  8. In Situ Raman Spectroscopic Study of Gypsum (CaSO4·2H2O) and Epsomite (MgSO4·7H2O) Dehydration Utilizing an Ultrasonic Levitator.

    PubMed

    Brotton, Stephen J; Kaiser, Ralf I

    2013-02-21

    We present an original apparatus combining an acoustic levitator and a pressure-compatible process chamber. To characterize in situ the chemical and physical modifications of a levitated, single particle while heated to well-defined temperatures using a carbon dioxide laser, the chamber is interfaced to a Raman spectroscopic probe. As a proof-of-concept study, by gradually increasing the heating temperature, we observed the variations in the Raman spectra as 150 μg of crystals of gypsum and epsomite were dehydrated in anhydrous nitrogen gas. We display spectra showing the decreasing intensities of the ν1 symmetric and ν3 asymmetric stretching modes of water with time and the simultaneous shift of the ν1(SO4(2-)) symmetric stretch mode to higher wavenumbers. Our results demonstrate that the new apparatus is well suited to study the dehydration of levitated species such as minerals and offers potential advantages compared with previous experiments on bulk samples. PMID:26281883

  9. Hydrochemistry of waters from five cenotes and evaluation of their suitability for drinking-water supplies, northeastern Yucatan, Mexico

    NASA Astrophysics Data System (ADS)

    Alcocer, Javier; Lugo, Alfonso; Marín, Luis E.; Escobar, Elva

    recreativas, para determinar su potencial de uso como fuente de abastecimiento de agua potable. La mayor parte de los parámetros excedieron los criterios establecidos en la Norma Mexicana para Agua Potable (NMAP), sin embargo, como éstas no representan una riesgo para la salud, el agua de cuatro de los cinco cenotes puede ser emplada como fuente de abastecimiento de agua potable. Los contaminantes comúnes del agua subterránea de la península de Yucatán, coliformes fecales y nitratos, se encuentran en la mayoría de los casos por debajo de la NMAP (0-460 NMP/ 100ml y 0.31-1.18mg/l, respectivamente). A pesar de que estos cuatro cenotes cumplen con la NMAP, es necesario desarrollar una política de manejo adecuada del agua subterránea para evitar la contaminación de este recurso (fecal y por nitratos), así como la intrusión de agua salina.

  10. Focused Cardiac Ultrasound Using a Pocket-Size Device in the Emergency Room.

    PubMed

    Mancuso, Frederico José Neves; Siqueira, Vicente Nicoliello; Moisés, Valdir Ambrósio; Gois, Aécio Flavio Teixeira; Paola, Angelo Amato Vincenzo de; Carvalho, Antonio Carlos Camargo; Campos, Orlando

    2014-10-28

    direcionada como complemento diagnóstico ao exame físico em um serviço terciário de emergências clínicas. Métodos: Foram incluídos cem pacientes adultos sem doenças cardíacas ou pulmonares conhecidas que procuraram atendimento de urgência com queixas cardiológicas. Foram excluídos pacientes com alterações isquêmicas no eletrocardiograma ou febre. A ecocardiografia direcionada foi realizada logo após a avaliação inicial do paciente na sala de emergência, com aparelho ultraportátil GE Vscan, avaliando subjetivamente: dimensões das cavidades, função sistólica ventricular, fluxos intracardíacos pelo mapeamento de fluxo em cores, pericárdio e aorta. Resultados: A idade média dos pacientes foi 61 ± 17 anos. O quadro clínico inicial foi dor torácica (52 pacientes), dispneia (32 pacientes), arritmia/avaliação da função ventricular (dez pacientes), hipotensão/tontura (cinco pacientes) e edema periférico (um paciente). Em 28 pacientes a ecocardiografia direcionada confirmou a hipótese diagnóstica inicial: 19 pacientes com insuficiência cardíaca, cinco com síndrome coronariana aguda, dois com tromboembolismo pulmonar e dois com tamponamento cardíaco. Em 17 pacientes, a ecocardiografia direcionada alterou o diagnóstico, afastando a hipótese clínica inicial em dez casos com suspeita de insuficiência cardíaca, dois com suspeita de tromboembolismo pulmonar, dois com hipotensão a esclarecer, e em cada um dos três restantes com suspeitas de síndrome coronariana aguda, tamponamento cardíaco e dissecção de aorta. Conclusão: A ecocardiografia direcionada ultraportátil em serviço de emergências clínicas pode definir rapidamente o diagnóstico e, com isso, é possível iniciar mais precocemente o tratamento adequado. PMID:25352461

  11. Effect of sulfation on the surface activity of CaO for N2O decomposition

    NASA Astrophysics Data System (ADS)

    Wu, Lingnan; Hu, Xiaoying; Qin, Wu; Dong, Changqing; Yang, Yongping

    2015-12-01

    Limestone addition to circulating fluidized bed boilers for sulfur removal affects nitrous oxide (N2O) emission at the same time, but mechanism of how sulfation process influences the surface activity of CaO for N2O decomposition remains unclear. In this paper, we investigated the effect of sulfation on the surface properties and catalytic activity of CaO for N2O decomposition using density functional theory calculations. Sulfation of CaO (1 0 0) surface by the adsorption of a single gaseous SO2 or SO3 molecule forms stable local CaSO3 or CaSO4 on the CaO (1 0 0) surface with strong hybridization between the S atom of SOx and the surface O anion. The formed local CaSO3 increases the barrier energy of N2O decomposition from 0.989 eV (on the CaO (1 0 0) surface) to 1.340 eV, and further sulfation into local CaSO4 remarkably increases the barrier energy to 2.967 eV. Sulfation from CaSO3 into CaSO4 is therefore the crucial step for deactivating the surface activity for N2O decomposition. Completely sulfated CaSO4 (0 0 1) and (0 1 0) surfaces further validate the negligible catalytic ability of CaSO4 for N2O decomposition.

  12. An open, self-controlled study on the efficacy of topical indoxacarb for eliminating fleas and clinical signs of flea-allergy dermatitis in client-owned dogs in Queensland, Australia

    PubMed Central

    Fisara, Petr; Sargent, Roger M; Shipstone, Michael; von Berky, Andrew; von Berky, Janet

    2014-01-01

    oxadiacina. Animales 25 animales de propietarios particulares en Queensland, Australia, diagnosticados con FAD en base a los signos clínicos, y pruebas serológicas intradérmicas para el antígeno de las pulgas. Métodos se realizó un estudio abierto no controlado en el cual los perros fueron tratados con indoxacarb por vía tópica a intervalos de cuatro semanas, tres veces en el curso de 12 semanas. Resultados 24 perros completaron el estudio. La resolución completa de los signos clínicos de FAD fue observada en 21 casos (87,5%), con casi completa resolución o una marcada mejora en los restantes tres casos. El valor medio de evaluación clínica (índice de extensión y severidad de la dermatitis atópica canina-03) se redujo un 93,3% en la semana 12. Los valores medios de prurito evaluados por los propietarios se redujeron en un 88% en la semana 12 los recuentos medios de pulgas se redujeron un 98,7 y un 100% en las semanas 8 y 12, respectivamente. Conclusiones e importancia clínica el tratamiento tópico con indoxacarb aplicado cada cuatro semanas durante 12 semanas, sin tratamientos complementarios antipruriticos o terapia ectoparásiticida, alivian completamente la infestación por pulgas en todos los perros y los signos clínicos asociados con FAD en una alta proporción de esta población de perros en un ambiente con contacto con pulgas. Zusammenfassung Hintergrund Die Flohspeichelallergie des Hundes (FAD), bei der es sich um eine Hypersensibilitätsreaktion auf das Antigenmaterial im Speichel von saugenden Flöhen handelt, kommt weltweit vor und stellt einen häufigen Vorstellungsgrund in der Kleintierpraxis dar, obwohl weltweit wirksame systemische und topische Flohkontrollprodukte verfügbar sind. Hypothese/Ziele Eine Evaluierung der klinischen Antwort von Hunden mit FAD, die topisch mit Indoxacarb, einem neuen Oxadiazin Insektizid, behandelt worden waren. Tiere Fünfundzwanzig private Hunde in Queensland, Australien, die mit bereits existierender FAD

  13. Viva Mexico!

    ERIC Educational Resources Information Center

    Hale, Judy; Hawkes, Brent

    This curriculum presentation outlines how to celebrate five Mexican holidays in the classroom: Cinco de Mayo, Dia de los Muertos, Fiesta, Las Posados, and Three Kings Day. The goal is to help children learn through hands-on activities and real-life experiences. The format for each holiday celebration includes a brief history with ideas for…

  14. NCI adopta el sendero científico para lograr las metas de la Misión contra el Cáncer

    Cancer.gov

    El director interino del NCI, doctor Douglas Lowy, aceptó hoy las recomendaciones de un Panel Listón Azul para 10 planteamientos científicos que en cinco años lograrán un progreso contra el cáncer equivalente a una década de trabajo.

  15. NCI adopta el sendero científico para lograr las metas de la Misión Nacional contra el Cáncer

    Cancer.gov

    El director interino del NCI, doctor Douglas Lowy, aceptó hoy las recomendaciones de un Panel Listón Azul para 10 planteamientos científicos que en cinco años lograrán un progreso contra el cáncer equivalente a una década de trabajo.

  16. Influence of hydroxylation on fabrication of PVC/CaSO4 composite

    NASA Astrophysics Data System (ADS)

    Chen, H. Y.; Wang, J.; Ma, P. Y.; Liang, J.; Xiang, L.

    2015-12-01

    The influences of hydroxylation on grafting of aminopropyltrimethoxysilane ((CH3O)3sbnd Sisbnd CH2sbnd CH2sbnd CH2sbnd NH2, abbreviated as APS) and fabrication of CaSO4/PVC composite were investigated in this paper. The experimental results indicated that the pre-treatment of CaSO4 particles by NaOH promoted the formation of OH-, which enhanced the grafting of APS on CaSO4 surface and improved the interfacial adhesion between CaSO4 and PVC matrix. Compared with the use of CaSO4 with sole APS modification, the use of the CaSO4 with NaOH and APS modification led to the increase of the impact strength of the CaSO4/PVC composite from 36.5 kJ m-2 to 50.2 kJ m-2 and the flexural strength from 48.7 MPa to 62.1 MPa.

  17. The Understanding of Astronomy Concepts by Students from Basic Education of a Public School. (Spanish Title: El Entendimiento de Conceptos de Aastronmía Por Los Alumnos de Educación Básica en Una Escuela Pública.) O Entendimento de Conceitos de Astronomia Por Alunos da Educação Básica: O Caso de Uma Escola Pública Brasileira

    NASA Astrophysics Data System (ADS)

    Iria Machado, Daniel; dos Santos, Carlos

    2011-07-01

    We present the results obtained in a research on the comprehension of basic astronomical concepts, in which 561 students from fifth grade middle school to third grade high school of a public school of the city of Foz do Iguaçu (Brazil) took part. A test with 20 multiple-choice questions was applied to indentify the most common conceptions expressed by the students. This test was elaborated based on the literature about misconceptions and covered the following topics: the day-night cycle; the time zones; the seasons of the year; the phases of the Moon; the movement of the Moon; the apparent movement of the Sun in the celestial sphere; the eclipses; the dimensions and distances in the Universe; the brightness of the stars and its observation from Earth. Though a small progress was verified in the proportion of scientifically acceptable answers when comparing the eighth grade of middle school to the fifth, and the third grade of high school to the first, there was an overall predominance of alternative conceptions regarding most of the explored subjects, which persisted up to the last year of secondary school. The comparison to data found in this research made in other socio-cultural contexts revealed, in many aspects, similar notions and difficulties revealed by the students. Se presentan los resultados de una investigación sobre la comprensión de conceptos astronómicos básicos, en la cual participaron 561 estudiantes que cursaban entre el quinto grado de la enseñanza primaria y el tercer año de la enseñanza secundaria de una escuela pública de la ciudad de Foz do Iguaçu (Brasil). Se utilizó un test de 20 preguntas de opción múltiple para identificar las concepciones más comunes expresadas por los estudiantes. Este instrumento de recolección de datos se desarrolló en base a la literatura sobre las concepciones alternativas y trató los siguientes temas: el ciclo día-noche, los husos horarios, las estaciones del año, las fases de la Luna, el movimiento de la Luna, el movimiento aparente del Sol sobre la esfera celeste, los eclipses, las dimensiones y las distancias en el Universo, el brillo de las estrellas y su observación de la Tierra. Si bien ha habido un pequeño progreso en la proporción de respuestas aceptables científicamente cuando se cotejó el octavo grado de la enseñanza primaria con el quinto, y el último año de la enseñanza secundaria con el primero, se observó un predominio de las concepciones alternativas en relación a la mayoría de los temas explorados, que continuó hasta los últimos años de la educación básica. Una comparación con los datos encontrados en investigaciones realizadas en otros contextos socioculturales revelaron, en muchos aspectos, conceptos y dificultades similares expresadas por los estudiantes. Apresentam-se os resultados de uma investigação sobre a compreensão de conceitos astronômicos básicos, da qual participaram 561 estudantes da quinta série do Ensino Fundamental ao terceiro ano do Ensino Médio de uma escola pública da cidade de Foz do Iguaçu. Um teste com 20 questões de múltipla escolha foi aplicado para identificar as concepções mais comuns expressadas pelos alunos. Esse instrumento de coleta de dados foi elaborado com base na literatura sobre concepções alternativas e abordou os seguintes temas: o ciclo dia-noite; os fusos horários; as estações do ano; as fases da Lua; o movimento da Lua; o movimento aparente do Sol na esfera celeste; os eclipses; as dimensões e distâncias no Universo; o brilho das estrelas e sua observação da Terra. Embora se tenha verificado um pequeno progresso na proporção de respostas cientificamente aceitáveis ao se cotejar a oitava série do Ensino Fundamental com a quinta, e a terceira série do Ensino Médio com a primeira, houve o predomínio de concepções alternativas em relação à maior parte dos temas explorados, as quais persistiram até o último ano da Educação Básica. A comparação com dados encontrados em investigações realizadas em outros contextos socioculturais revelaram, em muitos aspectos, noções e dificuldades similares manifestadas pelos estudantes.

  18. EFL Teachers' Perceptions of Continuing Professional Development: A Case of Iranian High School Teachers (La percepción de docentes de inglés como lengua extranjera acerca del desarrollo profesional continuado: el caso de profesores iraníes de bachillerato)

    ERIC Educational Resources Information Center

    Alibakhshi, Goudarz; Dehvari, Najibeh

    2015-01-01

    English, particularly regarding a foreign language teachers' professional development, has been studied in depth. However, it is not known how Iranian English as a foreign language teachers perceive continuing professional development. This study explored the perceptions of Iranian English as a foreign language teachers of continuing professional…

  19. The Understanding of Astronomy Concepts by Students from Basic Education of a Public School. (Spanish Title: El Entendimiento de Conceptos de Aastronmía Por Los Alumnos de Educación Básica en Una Escuela Pública.) O Entendimento de Conceitos de Astronomia Por Alunos da Educação Básica: O Caso de Uma Escola Pública Brasileira

    NASA Astrophysics Data System (ADS)

    Iria Machado, Daniel; dos Santos, Carlos

    2011-07-01

    We present the results obtained in a research on the comprehension of basic astronomical concepts, in which 561 students from fifth grade middle school to third grade high school of a public school of the city of Foz do Iguaçu (Brazil) took part. A test with 20 multiple-choice questions was applied to indentify the most common conceptions expressed by the students. This test was elaborated based on the literature about misconceptions and covered the following topics: the day-night cycle; the time zones; the seasons of the year; the phases of the Moon; the movement of the Moon; the apparent movement of the Sun in the celestial sphere; the eclipses; the dimensions and distances in the Universe; the brightness of the stars and its observation from Earth. Though a small progress was verified in the proportion of scientifically acceptable answers when comparing the eighth grade of middle school to the fifth, and the third grade of high school to the first, there was an overall predominance of alternative conceptions regarding most of the explored subjects, which persisted up to the last year of secondary school. The comparison to data found in this research made in other socio-cultural contexts revealed, in many aspects, similar notions and difficulties revealed by the students. Se presentan los resultados de una investigación sobre la comprensión de conceptos astronómicos básicos, en la cual participaron 561 estudiantes que cursaban entre el quinto grado de la enseñanza primaria y el tercer año de la enseñanza secundaria de una escuela pública de la ciudad de Foz do Iguaçu (Brasil). Se utilizó un test de 20 preguntas de opción múltiple para identificar las concepciones más comunes expresadas por los estudiantes. Este instrumento de recolección de datos se desarrolló en base a la literatura sobre las concepciones alternativas y trató los siguientes temas: el ciclo día-noche, los husos horarios, las estaciones del año, las fases de la Luna, el movimiento de la Luna, el movimiento aparente del Sol sobre la esfera celeste, los eclipses, las dimensiones y las distancias en el Universo, el brillo de las estrellas y su observación de la Tierra. Si bien ha habido un pequeño progreso en la proporción de respuestas aceptables científicamente cuando se cotejó el octavo grado de la enseñanza primaria con el quinto, y el último año de la enseñanza secundaria con el primero, se observó un predominio de las concepciones alternativas en relación a la mayoría de los temas explorados, que continuó hasta los últimos años de la educación básica. Una comparación con los datos encontrados en investigaciones realizadas en otros contextos socioculturales revelaron, en muchos aspectos, conceptos y dificultades similares expresadas por los estudiantes. Apresentam-se os resultados de uma investigação sobre a compreensão de conceitos astronômicos básicos, da qual participaram 561 estudantes da quinta série do Ensino Fundamental ao terceiro ano do Ensino Médio de uma escola pública da cidade de Foz do Iguaçu. Um teste com 20 questões de múltipla escolha foi aplicado para identificar as concepções mais comuns expressadas pelos alunos. Esse instrumento de coleta de dados foi elaborado com base na literatura sobre concepções alternativas e abordou os seguintes temas: o ciclo dia-noite; os fusos horários; as estações do ano; as fases da Lua; o movimento da Lua; o movimento aparente do Sol na esfera celeste; os eclipses; as dimensões e distâncias no Universo; o brilho das estrelas e sua observação da Terra. Embora se tenha verificado um pequeno progresso na proporção de respostas cientificamente aceitáveis ao se cotejar a oitava série do Ensino Fundamental com a quinta, e a terceira série do Ensino Médio com a primeira, houve o predomínio de concepções alternativas em relação à maior parte dos temas explorados, as quais persistiram até o último ano da Educação Básica. A comparação com dados encontrados em investigações realizadas em outros contextos socioculturais revelaram, em m

  20. Global Professional Identity in Deterretorialized Spaces: A Case Study of a Critical Dialogue between Expert and Novice Nonnative English Speaker Teachers (Identidad profesional global en espacios desterritorializados: un estudio de caso de los diálogos críticos entre profesores de inglés no nativos)

    ERIC Educational Resources Information Center

    Guerrero Nieto, Carmen Helena; Meadows, Bryan

    2015-01-01

    This study analyzes the online, peer-peer dialogue between two groups of nonnative English-speaking teachers who are attending graduate programs in Colombia and the United States. Framed by the theoretical concepts of critical pedagogy and global professional identity, a qualitative analysis of the data shows that their expert vs. novice roles…

  1. Using Case Study Methodology to Approach the Views of Teachers of English on Classroom Disciplinary Strategies (Uso de la metodología de estudio de casos para aproximarse a las concepciones de profesores de inglés sobre las estrategias disciplinarias en el aula)

    ERIC Educational Resources Information Center

    Díaz Larenas, Claudio

    2012-01-01

    This qualitative study aims at identifying the disciplinary strategies claimed to be used by a group of five secondary classroom teachers of English in public or semi-public schools in Chile. To conduct this research, a semi-structured interview was applied to participants. The data were analyzed using the principles of semantic content analysis…

  2. Effects of Strategy Instruction in an EFL Reading Comprehension Course: A Case Study (Efectos de la instrucción de estrategias en un curso de comprensión de lectura en inglés como lengua extranjera: un estudio de caso)

    ERIC Educational Resources Information Center

    Lopera Medina, Sergio

    2012-01-01

    Strategy instruction is useful in teaching contexts. This paper examines the effects of strategy instruction in an EFL reading comprehension course carried out with 26 undergraduate students at a Colombian university. As a research method, a case study was implemented. There were three instruments with which to collect data: reading comprehension…

  3. Optimum position for wells producing at constant wellbore pressure

    SciTech Connect

    Camacho-Velazquez, R.; Rodriguez de la Garza, F.; Galindo-Nava, A.; Prats, M.

    1994-12-31

    This paper deals with the determination of the optimum position of several wells, producing at constant different wellbore pressures from a two-dimensional closed-boundary reservoirs, to maximize the cumulative production or the total flow rate. To achieve this objective they authors use an improved version of the analytical solution recently proposed by Rodriguez and Cinco-Ley and an optimization algorithm based on a quasi-Newton procedure with line search. At each iteration the algorithm approximates the negative of the objective function by a cuadratic relation derived from a Taylor series. The improvement of rodriguez and Cinco`s solution is attained in four ways. First, an approximation is obtained, which works better at earlier times (before the boundary dominated period starts) than the previous solution. Second, the infinite sums that are present in the solution are expressed in a condensed form, which is relevant for reducing the computer time when the optimization algorithm is used. Third, the solution is modified to take into account the possibility of having wells starting to produce at different times. This point allows them to deal with the problem of getting the optimum position for an infill drilling program. Last, the solution is extended to include the possibility of changing the value of wellbore pressure or being able to stimulate any of the wells at any time. When the wells are producing at different wellbore pressures it is found that the optimum position is a function of time, otherwise the optimum position is fixed.

  4. Sulfur Fertilization Changes the Community Structure of Rice Root-, and Soil- Associated Bacteria.

    PubMed

    Masuda, Sachiko; Bao, Zhihua; Okubo, Takashi; Sasaki, Kazuhiro; Ikeda, Seishi; Shinoda, Ryo; Anda, Mizue; Kondo, Ryuji; Mori, Yumi; Minamisawa, Kiwamu

    2016-03-26

    Under paddy field conditions, biological sulfur oxidation occurs in the oxidized surface soil layer and rhizosphere, in which oxygen leaks from the aerenchyma system of rice plants. In the present study, we examined community shifts in sulfur-oxidizing bacteria associated with the oxidized surface soil layer and rice roots under different sulfur fertilization conditions based on the 16S ribosomal RNA (rRNA) gene in order to explore the existence of oligotrophic sulfur-oxidizing bacteria in the paddy rice ecosystem. Rice plants were grown in pots with no fertilization (control) or CaCO3 or CaSO4 fertilization. A principal-coordinates analysis (PCoA) showed that CaSO4 fertilization markedly affected bacterial communities associated with rice roots and soil, whereas no significant differences were observed in plant growth among the fertilizer treatments examined. In rice roots, the relative abundance of Acidobacteria, Alphaproteobacteria, Gammaproteobacteria, and TM7 was significantly higher in CaSO4-fertilized pots than in control pots. Alphaproteobacteria, Bradyrhizobiaceae, and Methylocystaceae members were significantly more abundant in CaSO4-fertilized roots than in control roots. On the other hand, the abundance of Actinobacteria and Proteobacteria was lower in CaSO4-fertilized soil than in control soil. These results indicate that the bacteria associated with rice roots and soil responded to the sulfur amendment, suggesting that more diverse bacteria are involved in sulfur oxidation in the rice paddy ecosystem than previously considered. PMID:26947443

  5. Sulfur Fertilization Changes the Community Structure of Rice Root-, and Soil- Associated Bacteria

    PubMed Central

    Masuda, Sachiko; Bao, Zhihua; Okubo, Takashi; Sasaki, Kazuhiro; Ikeda, Seishi; Shinoda, Ryo; Anda, Mizue; Kondo, Ryuji; Mori, Yumi; Minamisawa, Kiwamu

    2016-01-01

    Under paddy field conditions, biological sulfur oxidation occurs in the oxidized surface soil layer and rhizosphere, in which oxygen leaks from the aerenchyma system of rice plants. In the present study, we examined community shifts in sulfur-oxidizing bacteria associated with the oxidized surface soil layer and rice roots under different sulfur fertilization conditions based on the 16S ribosomal RNA (rRNA) gene in order to explore the existence of oligotrophic sulfur-oxidizing bacteria in the paddy rice ecosystem. Rice plants were grown in pots with no fertilization (control) or CaCO3 or CaSO4 fertilization. A principal-coordinates analysis (PCoA) showed that CaSO4 fertilization markedly affected bacterial communities associated with rice roots and soil, whereas no significant differences were observed in plant growth among the fertilizer treatments examined. In rice roots, the relative abundance of Acidobacteria, Alphaproteobacteria, Gammaproteobacteria, and TM7 was significantly higher in CaSO4-fertilized pots than in control pots. Alphaproteobacteria, Bradyrhizobiaceae, and Methylocystaceae members were significantly more abundant in CaSO4-fertilized roots than in control roots. On the other hand, the abundance of Actinobacteria and Proteobacteria was lower in CaSO4-fertilized soil than in control soil. These results indicate that the bacteria associated with rice roots and soil responded to the sulfur amendment, suggesting that more diverse bacteria are involved in sulfur oxidation in the rice paddy ecosystem than previously considered. PMID:26947443

  6. [The role of additives in bio-mass coal briquette on sulfur retention enhancement].

    PubMed

    Lu, Yongqi; Xu, Kangfu; Ma, Yongliang; Wei, Tiejun; Hao, Jiming

    2002-01-30

    The research first conducted the sulfur-fixing experiment of bio-mass coal briquette in a tubular furnace. The impacts of three additives Al2O3, Fe2O3 and MnO2 on the sulfur retention by calcium-based sorbent in briquette were investigated, and only Al2O3 displayed the enhancement of sulfur retention. The TGA experiment was further carried out, and proved that the high-temperature decomposition of CaSO4 in the deoxidization atmosphere was effectively inhibited with the addition of Al2O3. The XPS and XRD analyses of briquette ash showed that due to the interaction among Al2O3, CaSO4 and CaO, the composite CaSO4.3CaO.3Al2O3 which has more thermal stability was formed. With its wrapping or binding onto the surface of CaSO4 crystal, the decomposition of CaSO4 was mitigated. PMID:11987400

  7. Dose-response and intrinsic efficiency of thermoluminescent dosimeters in a 15 MV clinical photon beam in a liquid water phantom.

    PubMed

    Bravim, A; Sakuraba, R K; Cruz, J C; Campos, L L

    2012-07-01

    This paper compares the performance of CaSO4:Dy and LiF dosimeters irradiated with a 15 MV photon beam of a clinical linear accelerator to 0.1-10 Gy in a liquid water. The dose-response curves are linear up to 5 Gy. The average TL sensitivity of CaSO4:Dy is 26 and 287 times higher than the sensitivities of LiF:Mg,Ti and microLiF:Mg,Ti, respectively. CaSO4:Dy has an intrinsic efficiency 71% and 94% higher than the intrinsic efficiencies of LiF:Mg,Ti and microLiF:Mg,Ti, respectively. PMID:22342311

  8. Measurement and evaluation of national family planning programs.

    PubMed

    Mauldin, W P

    1967-03-01

    RESUMEN: En los últimos quince años diez paises han inaugurado programas nacionales de planeamiento familiar: India, Pakistán, Corea del Sur, Taiwan, Turquía, Malasia, Ceilán, Túez, la República Arabe Unida, y Marruecos. Otros paises, incluyendo Tailandia, Hong Kong, Singapur, Kenya, Barbados, Trinidad y los Estados Unidos, apoyan y/o estimulan actividades de planeamiento familiar. En la mayor parte de los casos la razón fundamental del programa ha sido que si la tasa de crecimiento poblacional disminuyera, aumentaría la tasa de crecimiento económico.Las metas de largo alcance, expresadas típicamente en términos de reducir las tasa.de de natalidad o de crecimiento, tienen su ejemplo en el propósito de Pakistán de reducir su tasa de crecimiento a 26 para 1970; el de Corea de reducir su tasa de natalidad a 20 para 1971; y el de India de reducir su tasa de natalidad a 25 para 1973.Los objectivos intermedios, que cubren diversos aspectos del pro grama, incluyen metas específicas para un determinado mes a año, considerando personal, la adquisición de anticonceptivos, y el número de usarios por método. Las metas específicas anuales de aceptantes de dispositivos intrauterinos (IUD), para Taiwán, Corea, Túnez, Pakistán e India, son comunes, tanto por la naturaleza del artefacto, como por la facilidad de medición de los que continúan utilizándolos. El programa de evaluación en Taiwán, que trata de medir por diversos medios los efectos inmediatos, mediatos y de largo plazo del programa de planeamiento familiar sirve de modelo. El propósito de la evaiuación de un programa de planeamiento familiar es contribuir a la efectividad y eficiencia del programa, midiendo y analizando su progreso. Las áreas a medir pueden ser clasificadas como- (1) conocimiento acerca de; (2) actitudes hacia; (3) práctica de control de natalidad; y (4) nivel de fecundidad.Un buen sistema de evaluación debería incluir: A. Un buen conjunto de estadísticas de servicio

  9. Low energy/cost desalination: low dose and low mean ion resident time in concentrate stream of electro-dialysis reversal.

    PubMed

    Myint, M T; Ghassem, A; Nirmalakhandan, N

    2011-01-01

    Species, dose, and mean ion resident time (MIRT(c)) in the concentrate of electro-dialysis reversal (EDR) desalination are analysed. In the classical EDR, dimensions, flow, and velocity of dilute and concentrate are equal; Langelier saturation index (LSI) and CaSO4 saturation are used to control the scaling and fouling processes in concentrate, as such LSI < + 2.16 for preventing CaCO3 from fouling and CaSO4 saturation level < 200 for averting CaSO4 from precipitation. If LSI is more than allowable limit, acid is added in concentrate to keep CaCO3 continuously dissolving; if CaSO4 saturation level in concentrate is more than the allowable limit, sodium hexametaphosphate (SHMP) is added in concentrate to maintain CaSO4 dissolving. EDR, however, was successfully modernised to operate with the higher water recovery rate (R) without any anti-scalant and without acid; this new EDR operated with LSI at 2.29 and CaSO4 saturation level 358.9% at lower dose and lower MIRT(c). Dose and MIRT(c) are proposed to address the controlling process. Monographs for the acids and SHMP requirements, and for the desalting cost including desalting power, membrane surface area, and chemicals usage, are developed. By lowering R and polar reversal interval, EDR can be operated at MIRT(c) < 130 min; at MIRT(c0 < 130 min, desalting cost/ energy can be minimised by eliminating chemicals requirement. PMID:21902023

  10. TENDENCIA DE LA TUBERCULOSIS EN LA REGIÓN SANITARIA V DE LA PROVINCIA DE BUENOS AIRES, AÑOS 2000–2011

    PubMed Central

    CHIRICO, CRISTINA; SANJURJO, MYRIAM; IRIBARREN, SARAH; APPENDINO, ANDREA; ZERBINI, ELSA; ETCHEVARRIA, MIRTA

    2016-01-01

    El objetivo del presente trabajo fue analizar la situación epidemiológica de la tuberculosis (TB) en la Región Sanitaria V (RSV), provincia de Buenos Aires. El estudio de tendencia permitió conocer un valor promedio de las variaciones de la tasa de incidencia (TI), calculadas por regresión lineal simple y expresadas como variación anual promedio (VAP). Se analizaron el número de casos notificados y TI por 100 000 habitantes de todas las formas de TB, los casos de TB pulmonar (TBP) y TBP confirmados por bacteriología, total casos por grupos de edad: 0 – 14; 15 – 29 y mayores de 64 años, entre el 1° de enero de 2000 al 31 de diciembre de 2011. La declinación de la TI fue menor al 5% para todas las formas de TB e inferior en las TBP confirmadas bacteriológicamente. Los casos de TBP y TI más elevadas, se concentraron en el grupo de 15 a 29 años, con tendencia estable o ligeramente ascendente de la TI en la TBP bacilífera. El mismo comportamiento presentaron los casos de TBP infantil con confirmación bacteriológica. La mayor velocidad de descenso en la TI de la TBP se produjo en este grupo de edad, mientras que en mayores de 64 años, el descenso fue sostenido en el tiempo. La TB persiste como un riesgo de salud en la RSV, con casos en edades jóvenes, por lo que sigue siendo necesario fortalecer el control de la TB en esta región. PMID:26117604

  11. Planificación Neuroquirúrgica con Software Osirix

    PubMed Central

    Jaimovich, Sebastián Gastón; Guevara, Martin; Pampin, Sergio; Jaimovich, Roberto; Gardella, Javier Luis

    2014-01-01

    Introducción: La individualidad anatómica es clave para reducir el trauma quirúrgico y obtener un mejor resultado. Actualmente, el avance en las neuroimágenes ha permitido objetivar esa individualidad anatómica, permitiendo planificar la intervención quirúrgica. Con este objetivo, presentamos nuestra experiencia con el software Osirix. Descripción de la técnica: Se presentan 3 casos ejemplificadores de 40 realizados. Caso 1: Paciente con meningioma de la convexidad parasagital izquierda en área premotora; Caso 2: Paciente con macroadenoma hipofisario, operada previamente por vía transeptoesfenoidal en otra institución con una resección parcial; Caso 3: Paciente con lesiones en pedúnculo cerebeloso medio bilateral. Se realizó la planificación prequirúrgica con el software OsiriX, fusionando y reconstruyendo en 3D las imágenes de TC e IRM, para analizar relaciones anatómicas, medir distancias, coordenadas y trayectorias, entre otras funciones. Discusión: El software OsiriX de acceso libre y gratuito permite al cirujano, mediante la fusión y reconstrucción en 3D de imágenes, analizar la anatomía individual del paciente y planificar de forma rápida, simple, segura y económica cirugías de alta complejidad. En el Caso 1 se pudo analizar las relaciones del tumor con las estructuras adyacentes para minimizar el abordaje. En el Caso 2 permitió comprender la anatomía post-operatoria previa del paciente, para determinar la trayectoria del abordaje transnasal endoscópico y la necesidad de ampliar su exposición, logrando la resección tumoral completa. En el Caso 3 permitió obtener las coordenadas estereotáxicas y trayectoria de una lesión sin representación tomográfica. Conclusión: En casos de no contar con costosos sistemas de neuronavegación o estereotáxia el software OsiriX es una alternativa a la hora de planificar la cirugía, con el objetivo de disminuir el trauma y la morbilidad operatoria. PMID:25165617

  12. Identification of Calcium Sulphoaluminate Formation between Alunite and Limestone

    PubMed Central

    Kim, Hyung-Seok; Han, Gi-Chun; Ahn, Ji-Whan; Cho, Kye-Hong; Cho, Hee-Chan

    2009-01-01

    This study was carried out to identify the conditions of formation of calcium sulphoaluminate (3CaO·3Al2O3·CaSO4) by the sintering of a limestone (CaCO3) and alunite [K2SO4·Al2(SO4)3·4Al(OH)3] mixture with the following reagents: K2SO4, CaCO3, Al(OH)3, CaSO4·2H2O, and SiO2. When K2SO4, CaCO3, Al(OH)3, CaSO4·2H2O were mixed in molar ratios of 1:3:6:3 and sintered at 1,200∼1,300 °C, only 3CaO·3Al2O3·CaSO4 and calcium langbeinite (2CaSO4·K2SO4) were generated. With an amount of CaO that is less than the stoichiometric molar ratio, 3CaO·3Al2O3·CaSO4 was formed and anhydrite (CaSO4) did not react and remained behind. With the amount of CaSO4 that is less than the stoichiometric molar ratio, the amounts of 3CaO·3Al2O3·CaSO4 and 2CaSO4·K2SO4 decreased, and that of CaO·Al2O3 increased. In the K2SO4-CaO-Al2O3-CaSO4-SiO2 system, to stabilize the formation of 3CaO·3Al2O3·CaSO4, 2CaSO4·K2SO4, and β-2CaO·SiO2, the molar ratios of CaO: Al2O3: CaSO4 must be kept at 3:3:1 and that of CaO/SiO2, over 2.0; otherwise, the generated amount of 3CaO·3Al2O3·CaSO4 decreased and that of gehlenite (2CaO·Al2O3·SiO2) with no hydration increased quantitatively. Therefore, if all SO3(g) generated by the thermal decomposition of alunite reacts with CaCO3 (or CaO, the thermal decomposition product of limestone) to form CaSO4 in an alunite- limestone system, 1 mol of pure alunite reacts with 6 mol of limestone to form 1 mol of 3CaO·3Al2O3·CaSO4 and 1 mol of 2CaSO4·K2SO4. PMID:22346687

  13. The evolution of groundwater rights and groundwater management in New Mexico and the western United States

    NASA Astrophysics Data System (ADS)

    DuMars, Charles T.; Minier, Jeffrie D.

    coherente con las necesidades de bienestar social, pero protegidos por los principios de la ley de propiedad. Hasta el momento, cinco sistemas reguladores básicos han evolucionado en los Estados Unidos de América en relación a los derechos en las aguas subterráneas. Los problemas surgidos por las diferencias hidrológicas entre las aguas subterráneas conectadas a corrientes superficiales y las aguas subterráneas en acuíferos sobreexplotados han sido resueltos hasta cierto punto por un par de casos judiciales notables. La modelación numérica y otras metodologías técnicas han evolucionado también para evaluar aspectos científicos asociados a diversas circunstancias hidrológicas, pero no son inmunes a las críticas. El papel actual de los acuíferos está evolucionando hacia el de instalaciones de almacenamiento de agua reciclada y su utilización de esta forma puede expandirse incluso más en el futuro. Las implicaciones políticas de las decisiones relativas a la gestión conjunta de las aguas superficiales y subterráneas no pueden ser exageradas. Como este artículo demuestra, una administración proactiva de las extracciones futuras de aguas subterráneas con efectos en los ecosistemas superficiales es esencial para la capacidad final de planificar la explotación, gestión y utilización de los recursos hídricos de forma racional, coordinando las demandas presentes y futuras con la realidad de la escasez de suministro. Los ejemplos empleados en este artículo demuestran la necesidad de construir capacidad y no únicamente de desarrollar buenas técnicas de medida, o la de educar reguladores y jueces de talento que redacten buenas leyes, pero también de gestores profesionales y aplicados del agua que mantengan el proceso en un compromiso entre evitar la explotación ilimitada del recurso y ejercer un proteccionismo conservador que impida su uso para siempre.

  14. Lead isotope study of Zn-Pb ore deposits associated with the Basque-Cantabrian basin and Paleozoic basement, Northern Spain

    NASA Astrophysics Data System (ADS)

    Velasco, F.; Pesquera, A.; Herrero, J. M.

    1996-01-01

    A total of forty-three galena samples from syngenetic and epigenetic Pb-Zn mineralizations emplaced in the Lower Cretaceous Basque-Cantabrian basin and Paleozoic basement of the Cinco Villas massif in the western Pyrenees, have been analyzed for Pb-isotopic composition. Galena from sedex mineralizations hosted in Carboniferous clastic rocks in the Cinco Villas massif display an homogeneous lead isotopic signature (206Pb/2044Pb ≈ 18.43, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.69) suggesting a single lead reservoir. These values are slightly more radiogenic than lead from other European Hercynian deposits, possibly reflecting the influence of a more evolved upper crustal source. Underlying Paleozoic sediments are proposed as lead source for the Cinco Villas massif ores. Analyses from twenty-six galena samples from the four strata-bound ore districts hosted in Mesozoic rocks reveal the existence of two populations regarding their lead isotopic composition. Galena from the western Santander districts (e.g., Reocin) is characterized by more radiogenic isotope values (206Pb/204Pb ≈ 18.74, 207Pb/204Pb ≈ 15.67, 208Pb/ 204Pb ≈ 38.73) than those from the central and eastern districts (Troya-Legorreta, Central and Western Vizcaya, 206Pb/204Pb ≈ 18.59, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.73). In all districts, the most likely source for these mineralizations was the thick sequence of Lower Cretaceous clastic sediments. The existence of two separate lead isotopic populations could be the result of regional difference in the composition of the basement rocks and the clastic sediments derived of it or different evolution histories. In both sub-basins, isotopic ratios indicate an increase in crustal influence as the age of the ores decreases.

  15. Education Policy Analysis Archives, 2001: Numbers 23-45.

    ERIC Educational Resources Information Center

    Glass, Gene V., Ed.

    2001-01-01

    This document consists of articles 23-45 published in the electronic journal "Education Policy Analysis Archives" for the year 2001: (23) "La Participacion de las Minorias Nacionales dentro de Sistemas Educativas Pre-Modernos: El Caso de los Garifunas de Guatemala" (Carlos R. Ruano); (24) "'Alexander v. Sandoval': A Setback for Civil Rights"…

  16. Impact of FGD gypsum soil amendment applications on soil and environmental quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper will discuss the utilization of FGD gypsum in agriculture for improving soil quality and other environmental benefits. Gypsum (CaSO4 .2H2O) has been used as an agricultural soil amendment for over 250 years. It is a soluble source of calcium and sulfur- for crops and has been shown to i...

  17. 21 CFR 184.1230 - Calcium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium sulfate. 184.1230 Section 184.1230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1230 Calcium sulfate. (a) Calcium sulfate (CaSO4, CAS Reg. No. 7778-18-9...

  18. Slip casting and nitridation of silicon powder

    NASA Astrophysics Data System (ADS)

    Seiko, Y.

    1985-03-01

    Powdered Silicon was slip-cast with a CaSO4 x 0.5H2O mold and nitrided in a N atm. containing 0 or 5 vol. % H at 1000 to 1420 deg. To remove the castings, the modeling faces were coated successively with an aq. salt soap and powdered cellulose containing Na alginate, and thus prevented the sticking problem.

  19. Soluble calcium amendment: Co-Application with poultry litter to reduce P loss following surface application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper will discuss the utilization of gypsum (CaSO4 .2H2O) to reduce P losses from surface runoff when poultry litter is used as a fertilizer source in agriculture. Utilization of poultry litter as a fertilizer source is common in regions with intense poultry production. While poultry litter ha...

  20. Mineralization and Potential for Fossilization of an Extremotolerant Bacterium Isolated from a Past Mars Analog Environment

    NASA Astrophysics Data System (ADS)

    Gaboyer, F.; Bohmeier, M.; Foucher, F.; Le Milbeau, C.; Gautret, P.; Richard, A.; Sauldubois, A.; Guegan, R.; Westall, F.

    2016-05-01

    To better characterize the preservation of biomarkers during microbial fossilization, we mineralized a bacterial strain isolated from a cold-acidic-oligotrophic lake in SiO2 and CaSO4 and studied it using SEM, TEM, FT-IR, Raman, GC-MS or Rock-Eval.

  1. Estudio de NIH señala que la sigmoidoscopia reduce los índices de cáncer colorrectal

    Cancer.gov

    Estudio señala que la sigmoidoscopia flexible es efectiva para reducir los índices de casos nuevos y de muertes por cáncer colorrectal. Los investigadores encontraron que la mortalidad general por cáncer colorrectal se redujo 26% y que la incidencia se re

  2. Informe Anual a la Nación sobre el Estado del Cáncer, 1975 a 2012

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer, 1975 a 2012, es una actualización de los índices de casos nuevos, muertes y tendencias de los cánceres más comunes en los Estados Unidos.

  3. Sintering and sulfation of calcium silicate: Calcium aluminate

    SciTech Connect

    Borgwardt, R.H.; Rochelle, G.T.

    1990-01-01

    The effect of sintering on the reactivity of solids at high temperature was studied. The nature of the interaction was studied with calcium silicate-aluminate reacting with SO2 between 665 and 800 C. The kinetics of the sintering and sulfation processes were measured independently in terms of the common variables, temperature and specific surface area. Surface reduction parameters were evaluated by the German-Munir sinter model, modified to account for a strong catalytic effect of H2O vapor. Sulfation parameters were determined from a series of conversion vs. time measurements at various temperatures using calcined solids of known surface area. These show product layer diffusion through CaSO4 to be the probable controlling process above 670 C and diffusion through a mixture of CaSO3 and CaSO4 controlling below that temperature. Like sintering, sulfation was enhanced by the presence of H2O in the feed gas. With 7% H2O vapor, the enhancement factor for sulfation was 1.5 at 665 C and estimated to be 5.0 at higher temperatures where only CaSO4 is formed. A combined sinter/sulfation model, based on the parameters evaluated for the independent processes, is compared to sulfation rates measured for the uncalcined solid when sintering is occurring simultaneously.

  4. Application of gypsum to control P runoff from poultry litter fertilization of pasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper will discuss the utilization of gypsum (CaSO4 .2H2O) to reduce P losses from surface runoff when poultry litter is used as a fertilizer source in agriculture. Utilization of poultry litter as a fertilizer source is common in regions with intense poultry production. While poultry litter ...

  5. Flue gas desulfurization gypsum agricultural network alabama (cotton)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flue gas desulfurization gypsum (FGDG) is an excellent source of gypsum (CaSO4•2H2O) that can be beneficially used in agriculture. Research was conducted as part of the Flue Gas Desulfurization Gypsum Agricultural Network program sponsored by the Electric Power Research Institute in collaboration wi...

  6. Utilization of FGD gypsum in agriculture for environmental benefits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper will discuss the utilization of FGD gypsum in agriculture for environmental benefits. Gypsum (CaSO4 .2H2O) has been used as an agricultural soil amendment for over 250 years. It is a soluble source of calcium and sulfur for crops and has been shown to improve soil physical and chemical pr...

  7. SUMMARY REPORT: SULFUR OXIDES CONTROL TECHNOLOGY SERIES: FLUE GAS DESULFURIZATION - DUAL ALKALI PROCESS

    EPA Science Inventory

    Describes dual alkali (or double alkali) flue gas desulfurization (FGD) which is a throwaway process in which sulfur dioxide (SO2) is removed from the flue gas by a soluble sodium-based scrubbing liquor. he collected SO2 is precipitated as calcium sulfite (CaSO3), calcium sulfate...

  8. Calcium Sulfate in Atacama Desert Basalt: A Possible Analog for Bright Material in Adirondack Basalt, Gusev Crater

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    The Atacama Desert in northern Chile is one of the driest deserts on Earth (< 2mm/y). The hyper-arid conditions allow extraordinary accumulations of sulfates, chlorides, and nitrates in Atacama soils. Examining salt accumulations in the Atacama may assist understanding salt accumulations on Mars. Recent work examining sulfate soils on basalt parent material observed white material in the interior vesicles of surface basalt. This is strikingly similar to the bright-white material present in veins and vesicles of the Adirondack basalt rocks at Gusev Crater which are presumed to consist of S, Cl, and/or Br. The abundance of soil gypsum/anhydrite in the area of the Atacama basalt suggested that the white material consisted of calcium sulfate (Ca-SO4) which was later confirmed by SEM/EDS analysis. This work examines the Ca-SO4 of Atacama basalt in an effort to provide insight into the possible nature of the bright material in the Adirondack basalt of Gusev Crater. The objectives of this work are to (i) discuss variations in Ca-SO4 crystal morphology in the vesicles and (ii) examine the Ca-SO4 interaction(s) with the basalt interior.

  9. A proposed NRCS conservation practice standard: Amending soil properties with gypsiferous products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper will discuss the proposed new NRCS conservation practice standard regarding the use of gypsiferous products in agriculture. Gypsiferous products include gypsum (CaSO4 .2H2O), has been used as an agricultural soil amendment for over 250 years as a soluble source of calcium and sulfur for ...

  10. Sulphate Adsorption in Soils of North and Northeast Iran.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gypsum (CaSO4.2H2O) is used in agriculture both as a source of calcium (Ca) and sulphate (SO4) and as an amendment to improve soil structure. The effect of gypsum on the adsorption of SO4 in irrigated and nonirrigated soils was examined. Almost all of the indigenous sulphate (SO4) in a range of Gole...

  11. Slip casting and nitridation of silicon powder

    NASA Technical Reports Server (NTRS)

    Seiko, Y.

    1985-01-01

    Powdered Silicon was slip-cast with a CaSO4 x 0.5H2O mold and nitrided in a N atm. containing 0 or 5 vol. % H at 1000 to 1420 deg. To remove the castings, the modeling faces were coated successively with an aq. salt soap and powdered cellulose containing Na alginate, and thus prevented the sticking problem.

  12. Novel dry-desulfurization process using Ca(OH)2/fly ash sorbent in a circulating fluidized bed.

    PubMed

    Matsushima, Norihiko; Li, Yan; Nishioka, Masateru; Sadakata, Masayoshi; Qi, Haiying; Xu, Xuchang

    2004-12-15

    A dry-desulfurization process using Ca(OH)2/fly ash sorbent and a circulating fluidized bed (CFB) was developed. Its aim was to achieve high SO2 removal efficiency without humidification and production of CaSO4 as the main byproduct. The CaSO4 produced could be used to treat alkalized soil. An 83% SO2 removal rate was demonstrated, and a byproduct with a high CaSO4 content was produced through baghouse ash. These results indicated that this process could remove SO2 in flue gas with a high efficiency under dry conditions and simultaneously produce soil amendment. It was shown that NO and NO2 enhanced the SO2 removal rate markedly and that NO2 increased the amount of CaSO4 in the final product more than NO. These results confirmed that the significant effects of NO and NO2 on the SO2 removal rate were due to chain reactions that occurred under favorable conditions. The amount of baghouse ash produced increased as the reaction progressed, indicating that discharge of unreacted Ca(OH)2 from the reactor was suppressed. Hence, unreacted Ca(OH)2 had a long residence time in the CFB, resulting in a high SO2 removal rate. It was also found that 350 degrees C is the optimum reaction temperature for dry desulfurization in the range tested (320-380 degrees C). PMID:15669351

  13. The student health center as multicultural catalyst.

    PubMed

    Edwards, S

    1994-03-01

    Stanford's student health center participated with underrepresented students in observing Black Liberation Month; Bisexual, Gay, and Lesbian Awareness Days; and Cinco de Mayo, the commemoration of a Mexican Army defeat of the French in 1862. For minority students on a campus where a majority of the students and faculty are White, the health center's involvement in these events was viewed as an affirmation and acceptance of worth of these diverse student groups. The outreach effort exposed health center caregivers to the cultures of the three groups when staff members attended the special activities, interacted with the celebrants, and became more sensitized to their needs. PMID:8201136

  14. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    latossolo vermelho (solo novo: nunca foi usado para produção da batata semente): CaCO3 0.3-0.7%, humo 0.9-1.0%, pH (H2O) 5.3, pH (KCl) 4.5, AL- P2O5 3.2-3.5 mg kg-1, AL- K2O 180 mg kg-1, Mg (KCl) 70 mg kg-1, EDTA-Zn 0.5-0.8 mg kg-1, EDTA-Cu 0.5-0.6 mg kg-1 com abastecer fraco destes elementos, b., conteudos N, P2O5, K2O do esterco de curral (qualidade médio): N 1.8 g kg-1, P2O5 2.0 g kg-1, K2O 4.0 g kg-1, c., conteudos N, P2O5, K2O do palha de arroz queimado (palha de arroz foi queimado em um especial forno): N 0.8 g kg-1, P2O5 7.0 g kg-1, K2O 4.5 g kg-1. Nestas provas usarémos para controle a *mistura padrão. O este tratamento é a composição usual neste programa i.e.: 150 l de solo novo, 50 l de palha de arroz queimado, 50 l de esterco de curral, 350 gramas de cal e 300 gramas de adubo da fórmula 4N:14P:8K. Experimento 1. Efeito de diferentes misturas para produção da batata semente pré- básica em casa de vegetação O experimento foi instalado considerando-se sete misturas de substrato (latossolo vermelho novo, esterco de curral, palha de arroz queimado) em 3000 cm3 volume de capacidade de vasos preto com cinco repetições, no delineamento experimental de blocos ao acaso, na mésas experimentais em caso de vegetação. A cultivar foi a Achat, com plãntulas provenientes de cultura de tecidos. A data de plantio foi 18.04.1990. Plantarémos em cada vaso 3-3 "in vitro" plantulas com raiz embaixo de 4cm de superficie da mistura no vasos. Irrigarémos com 12 mm quantidade da augua 2 vezes por semana. Para produção aplicarémos sistema de proteção de plantas como usados no Brasíl. Ambiente foi controlado com ventilação automatizado. Temperatura médio foi 22 0C e humidade médio foi 68% durante de experimento. A data de colheta foi 04.07.1990. As pesagens foram feitos como peso fresco. Os resultados foram submetidos a analise de variáncia, ANOVA. As misturas do substrato utilizadas foram como a seguir no Tabela 1. Experimento 2. Efeito de adubo 4N:14P:8K

  15. [Not Available].

    PubMed

    Vales Montero, Marta; Chavarría Cano, Beatriz; Martínez Ginés, María Luisa; Díaz Otero, Fernando; Velázquez Pérez, José Miguel; Cuerda Compes, María Cristina; Bretón Lesmes, Irene

    2016-01-01

    La deficiencia de vitamina A es infrecuente en los países desarrollados. La cirugía bariátrica constituye un factor de riesgo de deficiencia de esta vitamina. Se han descrito varios casos en pacientes sometidos a técnicas con un importante componente malabsortivo, como la derivación biliopancreática. En este artículo se describe un caso de deficiencia clínica de vitamina A con manifestaciones oculares y cutáneas tras bypass gástrico y se revisan las publicaciones sobre este tema y las recomendaciones para la prevención de esta importante complicación. PMID:27571679

  16. Scale formation at various locations in a geothermal operation due to injection of imported waters

    SciTech Connect

    Vetter, O.J.; Kandarpa, V.

    1982-06-22

    The injection of waters that are not native to a geothermal formation generates various physical and chemical problems. The major chemical problem resulting from such injections is the formation of sulfate scales (particularly CaSO4, BaSO4 and SrSO4) at various locations starting from the injection well through the production well to the surface facilities of any geothermal operation. One of the ways to prevent this type of scale formation is by reducing the sulfate concentration of the injection waters. The effect of sulfate deionization on scale formation at various locations of the geothermal operations is studied. Some experimental results on the CaSO4 scale formation in porous media upon heating an injection water with and without addition of scale inhibitors are also given.

  17. Consideraciones acerca del método de los arcos de reducción de datos VLBI astrométricos

    NASA Astrophysics Data System (ADS)

    de Biasi, M. S.; Arias, E. F.

    Con el propósito de construir un marco de referencia cuasi-inercial, desarrollamos un sistema de coordenadas inercial introduciendo un nuevo observable: el arco entre un par de radiofuentes. Este método proveerá una mejor herramienta para el análisis y reducción de observaciones VLBI. También conducirá a una solución en donde se determinarán independientemente los parámetros astrométricos y geodésicos. En este trabajo analizamos el caso ideal de observaciones simultáneas de un par de radiofuentes y el caso más realista de observaciones cuasisimultáneas.

  18. A high sensitive phosphor for dosimetric applications

    NASA Astrophysics Data System (ADS)

    Kore, Bhushan P.; Dhoble, N. S.; Lochab, S. P.; Dhoble, S. J.

    2015-06-01

    In this study a novel TL phosphor CaMg3(SO4)4:Dy3+ was prepared by acid distillation method. The TL response of this phosphor towards γ-rays and carbon ion beam was tested. Good dosimetric glow curve was observed which is stable against both the type of radiations. The CaMg3(SO4)4:Dy3+ phosphor doped with 0.2 mol% of Dy3+, irradiated with γ-ray shows nearly equal sensitivity to that of commercially available CaSO4:Dy TLD phosphor whereas 3.5 times more sensitivity than CaSO4:Dy, when irradiated with carbon ion beam. The change in glow peak intensities and glow peak temperature with variation in irradiation species and energy of ion beam is discussed here. The effect of these on trapping parameters is also illustrated.

  19. The role and implications of bassanite as a stable precursor phase to gypsum precipitation.

    PubMed

    Van Driessche, A E S; Benning, L G; Rodriguez-Blanco, J D; Ossorio, M; Bots, P; García-Ruiz, J M

    2012-04-01

    Calcium sulfate minerals such as gypsum play important roles in natural and industrial processes, but their precipitation mechanisms remain largely unexplored. We used time-resolved sample quenching and high-resolution microscopy to demonstrate that gypsum forms via a three-stage process: (i) homogeneous precipitation of nanocrystalline hemihydrate bassanite below its predicted solubility, (ii) self-assembly of bassanite into elongated aggregates co-oriented along their c axis, and (iii) transformation into dihydrate gypsum. These findings indicate that a stable nanocrystalline precursor phase can form below its bulk solubility and that in the CaSO(4) system, the self-assembly of nanoparticles plays a crucial role. Understanding why bassanite forms prior to gypsum can lead to more efficient anti-scaling strategies for water desalination and may help to explain the persistence of CaSO(4) phases in regions of low water activity on Mars. PMID:22491851

  20. Estructura orbital en el Problema Restringido Rectilíneo Isósceles

    NASA Astrophysics Data System (ADS)

    Orellana, R. B.

    Para definir problemas en Mecánica Celeste se utilizan diferentes parámetros. El conocimiento de la dinámica del problema para valores particulares de estos parámetros nos permite entender el comportamiento en casos más generales. El Problema Restringido Rectilíneo Isósceles puede ser considerado como el caso límite del Problema de Sitnikov cuando la excentricidad tiende a uno o como el Problema Isósceles cuando la masa central tiende a cero. Se ha compactificado el espacio de fases y analizado la dinámica en el límite. Esto ha permitido separar el espacio de fases en diferentes regiones dependiendo de las clases de órbitas.

  1. A Complexity Science-Based Framework for Global Joint Operations Analysis to Support Force Projection: LDRD Final Report.

    SciTech Connect

    Lawton, Craig R.

    2015-01-01

    The military is undergoing a significant transformation as it modernizes for the information age and adapts to address an emerging asymmetric threat beyond traditional cold war era adversaries. Techniques such as traditional large-scale, joint services war gaming analysis are no longer adequate to support program evaluation activities and mission planning analysis at the enterprise level because the operating environment is evolving too quickly. New analytical capabilities are necessary to address modernization of the Department of Defense (DoD) enterprise. This presents significant opportunity to Sandia in supporting the nation at this transformational enterprise scale. Although Sandia has significant experience with engineering system of systems (SoS) and Complex Adaptive System of Systems (CASoS), significant fundamental research is required to develop modeling, simulation and analysis capabilities at the enterprise scale. This report documents an enterprise modeling framework which will enable senior level decision makers to better understand their enterprise and required future investments.

  2. Criptococosis cutánea primaria en paciente inmunocompetente.

    PubMed

    Osorio, Igor Vázquez; García-Rodiño, Sara; Rodríguez-Rodríguez, Marta; Labandeira, Javier; Suárez-Peñaranda, José Manuel; Sánchez-Aguilar, MDolores; Vázquez-Veiga, Hugo

    2016-01-01

    La criptococosis cutánea es una micosis propia de pacientes inmunodeprimidos, sobre todo aquellos con infección por el virusde la inmunodeficiencia humana (VIH). Sin embargo, existen casos infrecuentes de criptococosis cutánea en pacientes inmunocompetentes, que suelen simular otras dermatosis, lo que retrasa su diagnóstico y tratamiento. Presentamos el caso de un varón pluripatológico de 79 años, con úlceras dolorosas en dorso de mano derecha que no respondían a tratamientos tópicos. A través del estudio histopatológico y micológico se alcanzó el diagnóstico de criptococosis cutánea primaria, lográndose la remisión de las lesiones tras 6 meses de tratamiento con fluconazol. PMID:27617525

  3. The chemistry of Saudi Arabian sand - A deposition problem on helicopter turbine airfoils

    NASA Astrophysics Data System (ADS)

    Smialek, James L.; Archer, Frances A.; Garlick, Ralph G.

    Operations in the Persian Gulf have exposed military helicopter turbines to excessive amounts of ingested sand. Fine particles, less than 10 microns, are able to bypass the particle separators and enter the cooling and combustion systems. The initial sand chemistry varies by location, but is made up of a calcium aluminum silicate glass, SiO2 low quartz, (Ca,Mg)CO3 dolomite, CaCO3 calcite, and occasionally NaCl rocksalt. The sand reacts in the hot combustion gases and deposits onto the turbine vanes as CaSO4, glass, and various crystalline silicates. Deposits up to 5 mm thick have been collected. Although cooling hole plugging is a considerable problem, excessive corrosion is not commonly observed due to the high melting point of CaSO4.

  4. The Chemistry of Saudi Arabian Sand - A Deposition Problem on Helicopter Turbine Airfoils

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Archer, Frances A.; Garlick, Ralph G.

    1992-01-01

    Operations in the Persian Gulf have exposed military helicopter turbines to excessive amounts of ingested sand. Fine particles, less than 10 microns, are able to bypass the particle separators and enter the cooling and combustion systems. The initial sand chemistry varies by location, but is made up of a calcium aluminum silicate glass, SiO2 low quartz, (Ca,Mg)CO3 dolomite, CaCO3 calcite, and occasionally NaCl rocksalt. The sand reacts in the hot combustion gases and deposits onto the turbine vanes as CaSO4, glass, and various crystalline silicates. Deposits up to 5 mm thick have been collected. Although cooling hole plugging is a considerable problem, excessive corrosion is not commonly observed due to the high melting point of CaSO4.

  5. [In Process Citation].

    PubMed

    Gonçalves Schemitt, Elizângela; Raskopf Colares, Josieli; Minuzzo Hartmann, Renata; Morgan-Martins, María Isabel; Marroni, Cláudio Augusto; Tuñón, M Jesús; Possa Marroni, Norma

    2016-01-01

    Introducción: la insuficiencia hepática fulminante (IHF) es un síndrome clínico poco frecuente, que se caracteriza por una disfunción hepática severa y repentina. La tioacetamida (TAA) es una hepatotoxina cuya administración puede inducir necrosis centrolobulillar en las células hepáticas y aumentar la formación de especies reactivas de oxígeno y la peroxidación lipídica en ratas. La glutamina es un precursor para la síntesis de glutatión. Objetivo: el objetivo del estudio es evaluar los efectos antioxidantes de la glutamina en un modelo de rata de IHF inducida por TAA. Métodos: ratas macho Wistar se dividieron en cuatro grupos de acuerdo con el tratamiento y el tiempo de evaluación: control, glutamina (25 mg/kg), tioacetamida (400 mg/kg) y tioacetamida más glutamina. Los animales se evaluaron después de 24, 36 y 48 horas. Se recogieron muestras de sangre para el análisis de los niveles de aspartato aminotransferasa (AST), alanina aminotransferasa (ALT), fosfatasa alcalina (AP), bilirrubina total (TB) y creatinina (CRE), y muestras de hígado para evaluar la peroxidación lipídica, las sustancias reactivas al ácido tiobarbitúrico (TBARS), la actividad de las enzimas antioxidantes superóxido dismutasa (SOD), glutatión peroxidasa (GPx), catalasa (CAT) y glutatión S-transferasa (GST). Además se midieron mediante inmunohistoquímica el factor nuclear kappa N (NF-κB), el fator de necrosis tumoral (TNF-α) y la óxido nítrico sintasa inducible (iNOS). Resultados: la TAA causó alteraciones en los parámetros bioquímicos e histológicos, y el aumento de los marcadores del proceso inflamatorio. Los niveles de TBARS y la actividad de SOD y GST fueron significativamente inferiores en los grupos de glutamina en comparación con TAA. La actividad de CAT se incrementó en los animales tratados con glutamina en comparación con la TAA. La actividad GPx también fue menor a las 36 y 48 h en los animales tratados com glutamina. El daño tisular y

  6. Uma comparação entre técnicas de propagação de erros em astrofísica: Monte Carlo x Bootstrap

    NASA Astrophysics Data System (ADS)

    Waelkens, A. H.; Janot Pacheco, E.

    2003-08-01

    Recentemente Dhillon & Watson (2001) criticaram o procedimento de determinação de erros via simulações de Monte Carlo no caso do imageamento indireto de estrelas, por introduzir ruído nos dados e resultar em erros superestimados. Estes autores propuseram a utilização alternativa do método de Bootstrap como uma técnica superior para a estimativa de erros. Neste trabalho apresentamos os resultados de um estudo comparativo da performance das técnicas de simulação por Monte Carlo e por Bootstrap para a determinação de erros em duas situações de interesse: (i) ajuste de modelos a espectros observados e (ii) imageamento indireto de discos de acréscimo com técnicas de mapeamento por eclipse. No caso (i), os dados de entrada são espectros de emissão simples de hidrogênio aos quais é adicionado ruído gaussiano de amplitude selecionada. No caso (ii), são produzidas curvas de luz do eclipse de uma distribuição de brilho seguindo a lei TµR-3/4 para discos estacionários cuja taxa de acréscimo varia ao longo do eclipse segundo uma distribuição gaussiana de amplitude selecionada, simulando o ruído. A avaliação da performance é feita com o auxílio de um diagrama do erro relativo na grandeza ajustada, conforme obtido por cada método, versus o erro relativo (ruído/sinal) dos dados de entrada. O estudo mostra que as duas técnicas produzem resultados semelhantes nos dois casos, e que a suposta superioridade do método de Bootstrap não se confirma.

  7. Dosimetry for low temperature measurements using single and poly-crystals

    NASA Astrophysics Data System (ADS)

    Cruz-Zaragoza, E.; Ramos-Bernal, S.; Negrón-Mendoza, A.

    2001-06-01

    The aim of this work was to study the behavior of a single and poly crystalline homemade solid state dosimeters (a) LiF co-doped with Mg, Cu and P, and (b) CaSO 4 doped with Dy. We analyzed the response of these dosimeters using thermoluminiscence. The dose-response at liquid nitrogen temperature was followed to observe the nature of the response.

  8. Experimental study of the replacement of calcite by calcium sulphates

    NASA Astrophysics Data System (ADS)

    Ruiz-Agudo, E.; Putnis, C. V.; Hövelmann, J.; Álvarez-Lloret, P.; Ibáñez-Velasco, A.; Putnis, A.

    2015-05-01

    Among the most relevant mineral replacement reactions are those involving sulphates and carbonates, which have important geological and technological implications. Here it is shown experimentally that during the interaction of calcite (CaCO3) cleavage surfaces with sulphate-bearing acidic solutions, calcite is ultimately replaced by gypsum (CaSO4 2H2O) and anhydrite (CaSO4), depending on the reaction temperature. Observations suggest that this occurs most likely via an interface-coupled dissolution-precipitation reaction, in which the substrate is replaced pseudomorphically by the product. At 120 and 200 °C gypsum and/or bassanite (CaSO4·0.5H2O) form as precursor phases for the thermodynamically stable anhydrite. Salinity promotes the formation of less hydrated precursor phases during the replacement of calcite by anhydrite. The reaction stops before equilibrium with respect to calcite is reached and during the course of the reaction most of the bulk solutions are undersaturated with respect to the precipitating phase(s). A mechanism consisting of the dissolution of small amounts of solid in a thin layer of fluid at the mineral-fluid interface and the subsequent precipitation of the product phase from this layer is in agreement with these observations. PHREEQC simulations performed in the framework of this mechanism highlight the relevance of transport and surface reaction kinetics on the volume change associated with the CaCO3-CaSO4 replacement. Under our experimental conditions, this reaction occurs with a positive volume change, which ultimately results in passivation of the unreacted substrate before calcite attains equilibrium with respect to the bulk solution.

  9. Marine origin for Precambrian, carbonate-hosted magnesite?

    NASA Astrophysics Data System (ADS)

    Frank, Tracy D.; Fielding, Christopher R.

    2003-12-01

    Large-scale, carbonate-hosted magnesite (MgCO3) deposits, although rare, occur mainly in Precambrian strata. Although many occurrences have characteristics consistent with penecontemporaneous formation in an evaporative marine setting, the general absence of CaSO4 minerals has precluded the adoption of evaporative marine depositional models. In modern seawater, excess Ca2+ and Mg2+ relative to CO2-3 and HCO-3 as well as abundant SO2-4 require that, upon evaporation, MgCO3 precipitation is accompanied by substantial deposition of CaSO4 minerals. Here we use evidence from a Neoproterozoic magnesite deposit to suggest that differences in Precambrian seawater geochemistry enabled MgCO3 to form in isolation under evaporative conditions. During the Precambrian, precipitation of CaSO4 evaporites was hindered by (1) elevated dissolved inorganic carbon and enhanced precipitation of CaCO3, which limited the availability of Ca2+, and (2) a small marine sulfate reservoir. Because sulfate is an inhibitor to dolomitization, low sulfate concentrations increased the potential for penecontemporaneous dolomitization in marine settings. By utilizing Ca2+, dolomitization served to increase fluid Mg/Ca ratios. In this HCO-3-rich but SO2-4-poor system, dolomitization coupled with significant evaporative concentration resulted in magnesite formation without coprecipitation of CaSO4 minerals. Decreasing carbonate saturation, progressive oxygenation, and a concomitant increase in sulfate availability during the Proterozoic ultimately led to the development of the more familiar conditions of the Phanerozoic, in which dolomitization was restricted to environments where elevated Mg/Ca ratios could overcome the inhibitory effects of sulfate and significant magnesite deposition was restricted to sabkhas and alkaline lakes.

  10. Effects of pH and Salts on Physical and Mechanical Properties of Pea Starch Films.

    PubMed

    Choi, W S; Patel, D; Han, J H

    2016-07-01

    To identify the significant contribution of intermolecular hydrogen bonds of starch molecules to the film structure formation, pH of film-forming solutions was adjusted and also various salts (NaCl, CaCl2 , CaSO4 , and K2 SO4 ) were mixed into the glycerol-plasticized pea starch film. The film made from pH 7 possessed the highest tensile strength-at-break (2 times) and elastic modulus (4 to 15 times) and the lowest elongation-at-break compared with those of the films made from acid and alkali environments. The pH 7 film also has the highest film density and the lowest total soluble matter. At the level of 0.01 to 0.1 M of CaSO4 and 0.1 M of K2 SO4 in a kilogram of starch, the water solubility of the film increased, while chloride salts slightly lowered the solubility. NaCl and CaSO4 reduced water vapor permeability (WVP), while CaCl2 slightly increased WVP at 0.01 and 0.06 M concentrations, and K2 SO4 significantly increased WVP at 0.03 and 0.15 M. Presence of salts increased tensile strength (5 to 14 times than the control films) and elastic modulus (35 to 180 times) of starch film at 0.01 to 0.03 M of CaSO4 and K2 SO4 . Elongation-at-break increased significantly as salt concentration increases to an optimal level. However, when the concentration exceeded above the optimal level, the E of starch films decreased and showed no significant difference from the control film. Overall, the addition of salts modified physical and mechanical properties of pea starch films more than pH adjustment without any salt addition. PMID:27243801

  11. Calculating carbon mass balance from unsaturated soil columns treated with CaSO₄₋minerals: test of soil carbon sequestration.

    PubMed

    Han, Young-Soo; Tokunaga, Tetsu K

    2014-12-01

    Renewed interest in managing C balance in soils is motivated by increasing atmospheric concentrations of CO2 and consequent climate change. Here, experiments were conducted in soil columns to determine C mass balances with and without addition of CaSO4-minerals (anhydrite and gypsum), which were hypothesized to promote soil organic carbon (SOC) retention and soil inorganic carbon (SIC) precipitation as calcite under slightly alkaline conditions. Changes in C contents in three phases (gas, liquid and solid) were measured in unsaturated soil columns tested for one year and comprehensive C mass balances were determined. The tested soil columns had no C inputs, and only C utilization by microbial activity and C transformations were assumed in the C chemistry. The measurements showed that changes in C inventories occurred through two processes, SOC loss and SIC gain. However, the measured SOC losses in the treated columns were lower than their corresponding control columns, indicating that the amendments promoted SOC retention. The SOC losses resulted mostly from microbial respiration and loss of CO2 to the atmosphere rather than from chemical leaching. Microbial oxidation of SOC appears to have been suppressed by increased Ca(2+) and SO4(2)(-) from dissolution of CaSO4 minerals. For the conditions tested, SIC accumulation per m(2) soil area under CaSO4-treatment ranged from 130 to 260 g C m(-1) infiltrated water (20-120 g C m(-1) infiltrated water as net C benefit). These results demonstrate the potential for increasing C sequestration in slightly alkaline soils via CaSO4-treatment. PMID:24974014

  12. [In Process Citation].

    PubMed

    Santacruz-Cerdán, Elisa; Arcano, Karina; Arrieta Blanco, Francisco; Ortiz Flores, Andrés; Mateo Lobo, Raquel; Botella Carretero, José Ignacio; Vázquez Martínez, Clotilde; Zamarrón Cuesta, Isabel

    2016-01-01

    El uso de la nutrición parenteral domiciliaria (NPD) en pacientes que no pueden alcanzar sus requerimientos nutricionales por la vía enteral está aumentando en los últimos años, permitiendo la normalización del estilo de vida de los pacientes. Entre las patologías que más frecuentemente precisan de la NPD en España destacan la neoplasia y la isquemia mesentérica. Sin embargo, la NPD constituye uno de los pilares básicos del tratamiento de enfermedades mucho menos frecuentes como es el caso de la esclerosis peritoneal encapsulante. A continuación presentamos el caso de un paciente diagnosticado de esclerosis peritoneal encapsulante con soporte NPD de más de 7 años de NPD con un catéter central de inserción periférica (PICC) para la NPD sin complicaciones y pudiendo realizar su actividad laboral habitual. Dado lo excepcional del caso lo remitimos para su publicación. PMID:27019258

  13. Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis

    USGS Publications Warehouse

    Alexander Meshoulam; Ellis, Geoffrey S.; Ward Said Ahmad; Andrei Deev; Alex L. Sessions; Yongchun Tang; Jess Adkins; Liu Jinzhong; William P. Gilhooly III; Zeev Aizenshtat; Alon Amrani

    2016-01-01

    Experiments involving sparingly soluble CaSO4 show that during the second catalytic phase of TSR the rate of sulfate reduction exceeds that of sulfate dissolution. In this case, there is no apparent isotopic fractionation between source sulfate and generated H2S, as all of the available sulfate is effectively reduced at all reaction times. When CaSO4 is replaced with fully soluble Na2SO4, sulfate dissolution is no longer rate limiting and significant S-isotopic fractionation is observed. This supports the notion that CaSO4dissolution can lead to the apparent lack of fractionation between H2S and sulfate produced by TSR in nature. The S-isotopic composition of individual OSCs record information related to geochemical reactions that cannot be discerned from the δ34S values obtained from bulk phases such as H2S, oil, and sulfate minerals, and provide important mechanistic details about the overall TSR process.

  14. Chemical compositions of sulfate and chloride salts over the last termination reconstructed from the Dome Fuji ice core, inland Antarctica

    NASA Astrophysics Data System (ADS)

    Oyabu, Ikumi; Iizuka, Yoshinori; Uemura, Ryu; Miyake, Takayuki; Hirabayashi, Motohiro; Motoyama, Hideaki; Sakurai, Toshimitsu; Suzuki, Toshitaka; Hondoh, Takeo

    2014-12-01

    The flux and chemical composition of aerosols impact the climate. Antarctic ice cores preserve the record of past atmospheric aerosols, providing useful information about past atmospheric environments. However, few studies have directly measured the chemical composition of aerosol particles preserved in ice cores. Here we present the chemical compositions of sulfate and chloride salts from aerosol particles in the Dome Fuji ice core. The analysis method involves ice sublimation, and the period covers the last termination, 25.0-11.0 thousand years before present (kyr B.P.), with a 350 year resolution. The major components of the soluble particles are CaSO4, Na2SO4, and NaCl. The dominant sulfate salt changes at 16.8 kyr B.P. from CaSO4, a glacial type, to Na2SO4, an interglacial type. The sulfate salt flux (CaSO4 plus Na2SO4) inversely correlates with δ18O in Dome Fuji over millennial timescales. This correlation is consistent with the idea that sulfate salt aerosols contributed to the last deglacial warming of inland Antarctica by reducing the aerosol indirect effect. Between 16.3 and 11.0 kyr B.P., the presence of NaCl suggests that winter atmospheric aerosols are preserved. A high NaCl/Na2SO4 fraction between 12.3 and 11.0 kyr B.P. indicates that the contribution from the transport of winter atmospheric aerosols increased during this period.

  15. Thermoluminescent dosimeters for low dose X-ray measurements.

    PubMed

    Fernández, S Del Sol; García-Salcedo, R; Sánchez-Guzmán, D; Ramírez-Rodríguez, G; Gaona, E; de León-Alfaro, M A; Rivera-Montalvo, T

    2016-01-01

    The response of TLD-100, CaSO4:Dy and LiF:Mg,Cu,P for a range of X-ray low dose was measured. For calibration, the TLDs were arranged at the center of the X-ray field. The dose output of the X-ray machine was determined using an ACCU-Gold. All dosimeters were exposed at the available air kerma values of 14.69 mGy within a field 10×10 cm(2) at 80 cm of SSD. Results of LiF:Mg,Cu,P X-ray irradiated showed 4.8 times higher sensitivity than TLD-100. Meanwhile, TL response of CaSO4:Dy exposed at the same dose was 5.6 time higher than TLD-100. Experimental results show for low dose X-ray measurements a better linearity for LiF:Mg,Cu,P compared with that of TLD-100. CaSO4:Dy showed a linearity from 0.1 to 60 mGy. PMID:26609683

  16. [Not Available].

    PubMed

    Corella Aznar, Elena Guadalupe; Ayerza Casas, Ariadna; Samper Villagrasa, Pilar; Rodríguez Vigil, Carmen; Jiménez Montañés, Lorenzo; Calvo Escribano, Carlota; Labarta Aizpun, José Ignacio

    2016-01-01

    Introducción: los supervivientes de leucemia aguda (LA) infantil presentan un riesgo incrementado de alteraciones metabólicas y cardiovasculares que aumentan su morbimortalidad a largo plazo.Objetivo: estimar la prevalencia de obesidad, resistencia a la insulina, dislipemia e hipertensión arterial como factores de riesgo cardiometabólico (FRCM) en un grupo de supervivientes de LA infantil, y analizar las posibles causas asociadas a su desarrollo.Material y métodos: estudio observacional retrospectivo en 47 supervivientes de LA tratados en un periodo de 4 años, que recibieron seguimiento durante 10 años.Resultados: el 40% de los participantes presentaron al menos un FRCM durante el seguimiento, siendo la dislipemia (aumento LDL) el más frecuente (38,3%), seguido de obesidad/sobrepeso (31,9%) y HTA sistólica (23,4%). El sexo femenino se estableció como factor de riesgo parael desarrollo de todos ellos (RR 1,6; RR 3,16; RR 1,69; p < 0,05). Ningún superviviente desarrolló diabetes mellitus, pero sí resistencia a la insulina el 19,4%. Los pacientes con leucemias de peor pronóstico presentaron mayor riesgo de desarrollar obesidad, resistencia a la insulina y aumento de LDL (RR 3,56; RR 4,08; RR 2,53; p < 0,05). Los pacientes tratados con trasplante de progenitores hematopoyéticos presentaron mayor riesgo de obesidad, aumento de LDL e HTA sistólica (RR 2,86; RR 2,39; RR 3,12; p<0,05). La radioterapia se asoció de igual modo con un incremento de resistencia a la insulina e hipertensión arterial sistólica (RR 2,47; RR 2,53; p < 0,05).Conclusiones: existe un aumento en la prevalencia de obesidad/sobrepeso, dislipemia, resistencia a la insulina y alteración de la tensión arterial sistólica en supervivientes de leucemia aguda infantil a lo largo del tiempo, especialmente en aquellos con enfermedades y tratamientos más agresivos. PMID:27513487

  17. [In Process Citation].

    PubMed

    Álvarez-Altamirano, Karolina; Mendoza-Hernández, Alma Nubia; Carcoba-Tenorio, Carolina; García-García, José Antonio; Fuchs-Tarlovsky, Vanessa

    2016-01-01

    Introducción y objetivos: la terapia con antioxidantes durante la quimioterapia y radioterapia en pacientes con cáncer cervicouterino es controvertida. Mientras existe evidencia que sugiere que el uso de antioxidantes disminuye los efectos secundarios propios del tratamiento contra el cáncer, hay datos que sugieren que los antioxidantes incrementan el riesgo de recurrencia de cáncer por la afectación de la terapia de los tratamientos. Métodos: se dirigió un estudio clínico controlado en pacientes con cáncer cervicouterino que fueron suplementados con una mezcla de antioxidantes o placebo, con seguimiento por 4 años posteriores al término de su tratamiento antineoplásico para evaluar el efecto de los antioxidantes en la recurrencia. Tomamos datos de niveles de hemoglobina y albúmina. Se analizaron las diferencias entre grupos con la prueba de Chi-cuadrado, la sobrevida se calculó con un análisis multivariado por medio de regresión de COX. Resultados: se dio seguimiento a 103 pacientes con cáncer cervicouterino en etapa clínica IIB y IIIB de los cuales 48% fueron tratados con suplementación de antioxidantes y el 52% con placebo, originalmente y de estos se dio seguimiento a 88 pacientes durante 4 años. El 23,9% de los pacientes tratados presentaron recurrencia por cáncer mientras que el 76,1% no la presentó. El 21,6% de los pacientes presentaron metástasis, el 8% de los pacientes perteneció al grupo de antioxidantes y el 15,9% al grupo placebo (p > 0,05). Implicaciones para los pacientes supervivientes: la suplementación con antioxidantes aparentemente no interfiere con la recurrencia por cáncer, sin embargo no hay evidencia suficiente para probarlo. Posiblemente una dosis distinta sea la clave para un mejor efecto, pero serán necesarios futuros estudios que prueben efectos sobre otro tipo de dosis. Conclusiones: la suplementación con antioxidantes durante el tratamiento de pacientes con cáncer cervicouterino no tiene efectos en la

  18. Sulfurization of Fe-Ni-Cu-Co Alloy to Matte Phase by Carbothermic Reduction of Calcium Sulfate

    NASA Astrophysics Data System (ADS)

    Jeong, Eui Hyuk; Nam, Chul Woo; Park, Kyung Ho; Park, Joo Hyun

    2016-04-01

    Calcium sulfate (CaSO4) is proposed as an alternative sulfur source to convert the Fe-Ni-Cu-Co alloy to the matte phase. Solid carbon was used as a reducing agent and the influence of oxide fluxes on the sulfurization efficiency at 1673 K (1400 °C) in a CO-CO2-SO2-Ar atmosphere was investigated. When CaSO4 was equilibrated with the Fe-Ni-Cu-Co alloy without any reducing agent, it was reduced by Fe in the liquid alloy, resulting in the formation of FeS. The sulfurization efficiency was about 56 pct, even though an excess amount of CaSO4 (gypsum equivalent, G eq = 1.7) was added. Adding solid carbon as the reducing agent significantly shortened the equilibration time from 36 to 3.5 hours and increased the sulfurization efficiency from 56 to 91 pct, even though the amount of carbon was lower than the theoretical equivalent for carbothermic reduction of CaSO4, viz. C eq = 0.7. Although CaS (not FeS) was formed as a primary reaction product, it continuously reacted with CaSO4, forming CaO-rich slag. Neither the carbothermic reduction time nor the sulfurization efficiency were affected by the addition of Al2O3 (-SiO2) fluxes, but the equilibration time fell to 2.5 hours with the addition of Al2O3-Fe2O3 flux because the former systems produced primarily calcium silicate and calcium aluminate, which have relatively high melting points, whereas the latter system produced calcium ferrite, which has a lower melting point. Consequently, calcium sulfate (waste gypsum) can replace expensive pure sulfur as a raw material in the sulfurization of Fe-Ni-Cu-Co alloy with small amounts of iron oxide (Fe2O3) as a flux material. The present results can be used to improve the recovery of rare metals, such as Ni and Co, from deep sea manganese nodules.

  19. Tiempo para un cambio

    NASA Astrophysics Data System (ADS)

    Woltjer, L.

    1987-06-01

    En la reunion celebrada en diciembre dei ano pasado informe al Consejo de mi deseo de terminar mi contrato como Director General de la ESO una vez que fuera aprobado el proyecto dei VLT, que se espera sucedera hacia fines de este aAo. Cuando fue renovada mi designacion hace tres aAos, el Consejo conocia mi intencion de no completar los cinco aAos dei contrato debido a mi deseo de disponer de mas tiempo para otras actividades. Ahora, una vez terminada la fase preparatoria para el VLT, Y habiendose presentado el proyecto formalmente al Consejo el dia 31 de marzo, y esperando su muy probable aprobacion antes dei termino de este ano, me parece que el 10 de enero de 1988 presenta una excelente fecha para que se produzca un cambio en la administracion de la ESO.

  20. Volcanic history and 40Ar/39Ar and 14C geochronology of Terceira Island, Azores, Portugal

    USGS Publications Warehouse

    Calvert, A.T.; Moore, R.B.; McGeehin, J.P.; Rodrigues da Silva, A.M.

    2006-01-01

    Seven new 40Ar/39Ar and 23 new radiocarbon ages of eruptive units, in support of new geologic mapping, improve the known chronology of Middle to Late Pleistocene and Holocene volcanic activity on the island of Terceira, Azores and define an east-to-west progression in stratovolcano growth. The argon ages indicate that Cinco Picos Volcano, the oldest on Terceira, completed its main subaerial cone building activity by about 370-380??ka. Collapse of the upper part of the stratovolcanic edifice to form a 7 ?? 9??km caldera occurred some time after 370??ka. Postcaldera eruptions of basalt from cinder cones on and near the caldera floor and trachytic pyroclastic flow and pumice fall deposits from younger volcanoes west of Cinco Picos have refilled much of the caldera. The southern portion of Guilherme Moniz Volcano, in the central part of the island, began erupting prior to 270??ka and produced trachyte domes, flows, and minor pyroclastic deposits until at least 111??ka. The northern part of Guilherme Moniz Caldera is less well exposed than the southern part, but reflects a similar age range. The northwest portion of the caldera was formed sometime after 44??ka. Several well-studied ignimbrites that blanket much of the island likely erupted from Guilherme Moniz Volcano. The Pico Alto Volcanic Center, a tightly spaced cluster of trachyte domes and short flows, is a younger part of Guilherme Moniz Volcano. Stratigraphic studies and our new radiocarbon ages suggest that most of the Pico Alto eruptions occurred during the period from about 9000 to 1000??years BP. Santa Barbara Volcano is the youngest stratovolcano on Terceira, began erupting prior to 29??ka, and has been active historically. ?? 2006.

  1. Is Socioeconomic Status of the Rearing Environment Causally Related to Obesity in the Offspring?

    PubMed Central

    Fontaine, Kevin R.; Robertson, Henry T.; Holst, Claus; Desmond, Renee; Stunkard, Albert J.; Sørensen, Thorkild I. A.; Allison, David B.

    2011-01-01

    We attempt to elucidate whether there might be a causal connection between the socioeconomic status (SES) of the rearing environment and obesity in the offspring using data from two large-scale adoption studies: (1) The Copenhagen Adoption Study of Obesity (CASO), and (2) The Survey of Holt Adoptees and Their Families (HOLT). In CASO, the SES of both biological and adoptive parents was known, but all children were adopted. In HOLT, only the SES of the rearing parents was known, but the children could be either biological or adopted. After controlling for relevant covariates (e.g., adoptee age at measurement, adoptee age at transfer, adoptee sex) the raw (unstandardized) regression coefficients for adoptive and biological paternal SES on adoptee body mass index (BMI: kg/m2) in CASO were -.22 and -.23, respectively, both statistically significant (p = 0.01). Controlling for parental BMI (both adoptive and biological) reduced the coefficient for biological paternal SES by 44% (p = .034) and the coefficient for adoptive paternal SES by 1%. For HOLT, the regression coefficients for rearing parent SES were -.42 and -.25 for biological and adoptive children, respectively. Controlling for the average BMI of the rearing father and mother (i.e., mid-parental BMI) reduced the SES coefficient by 47% in their biological offspring (p≤.0001), and by 12% in their adoptive offspring (p = .09). Thus, despite the differing structures of the two adoption studies, both suggest that shared genetic diathesis and direct environmental transmission contribute about equally to the association between rearing SES and offspring BMI. PMID:22110724

  2. Programmed home visits by nursing professionals to older adults: prevention or treatment?1

    PubMed Central

    Dios-Guerra, Caridad; Carmona-Torres, Juan Manuel; Ruíz-Gándara, África; Muñoz-Alonso, Adoración; Rodríguez-Borrego, María-Aurora

    2015-01-01

    OBJETIVOS: conocer la repercusión de la visita domiciliaria de los profesionales en enfermería a personas de 65 años o más, pluripatológicas, en morbimortalidad. MÉTODO: estudio retrospectivo caso-control por auditoria de historias clínicas. Muestreo aleatorio. Variables principales morbilidad, mortalidad; descriptivas: visitas de la enfermera, filiación, datos clínicos y socio sanitarios. Análisis por medidas de tendencia central, dispersión, posición, tabulación, frecuencias relativas, absolutas; no paramétricas, contrastes χ2; Wilcoxon-Mann-Whitney. RESULTADOS: se estudiaron a 1743 pacientes, de ellos 199 recibieron visita domiciliaria; la edad media de quien recibe visita es de 81,99 años; estos presentan mayor número de patologías de media 3,76; habitan en domicilio particular, si bien en conjunto presentan más institucionalización que los controles; el 50% no tiene identificado el Cuidador Principal; es mayor el número de visitas de las enfermeras a los pacientes que viven en residencias (p < 0,001). El 50% de casos no tiene plan de cuidados, con relación significativa (p < 0,001). No existen diferencias significativas en tiempo de vida entre los casos y los controles. CONCLUSIÓN: la visita domiciliaria del profesional en enfermería no repercute en la morbimortalidad; visita a los pacientes cuando ya ha aparecido el problema de salud, no hay datos de prevención. PMID:26312638

  3. Effects of calcined aluminum salts on the advanced dewatering and solidification/stabilization of sewage sludge.

    PubMed

    Zhen, Guangyin; Yan, Xiaofei; Zhou, Haiyan; Chen, Hua; Zhao, Tiantao; Zhao, Youcai

    2011-01-01

    The high moisture content (80%) in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification (S/S) alternative for the sludge was developed, using calcined aluminum salts (AS) as solidifier, and CaCl2, Na2SO4 and CaSO4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS(0) obtained with 5% AS and 10% CaSO4 of AS by weight presented a moisture contents below 50%-60% and a compressive strength of (51.32 +/- 2.9) kPa after 5-7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry-differential scanning calorimetry investigations revealed that a large amount of hydrates (viz., gismondine and CaCO3) were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure (TCLP) and horizontal vibration (HJ 557-2009) leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill. PMID:22125919

  4. Construction of a composite thin-element TLD using an optical-heating method.

    PubMed

    Yamamoto, O; Yasuno, Y; Minamide, S; Hasegawa, S; Tsutsui, H; Takenaga, M; Yamashita, T

    1982-09-01

    A composite thermoluminescent dosimeter (TLD), composed of four, thin TL elements with a high-speed reader, has been developed by employing an optical-heating method. Each TL element, which is 15 mg/cm2 thick with a 3 mm dia., is prepared by applying Li2B4O7:Cu or CaSO4:Tm to a plastic substrate 14 mg/cm2 thick. Each element can be heated to 350 degree C within 0.8 sec. by IR radiation from a tungsten lamp. The characteristics of this TLD system include the following: (1) the detection limit of the Li2B4O7:Cu is 3 mR and the limit for CaSO4:Tm is 0.1 mR; (2) the energy-dependence curves are similar to the dose-equivalent curve, showing slight under-responses by 15% near 70 KeV for Li2B4O7:Cu and over-responses by 50% at high energies for CaSO4:Tm; (3) despite quick heating, the residual dose is as low as 0.1% of the last exposure signal; (4) responses are very stable for more than 1,000 cycles of repeated exposure readings; (5) no false signal could be detected, even in the cases of sweat or soil contamination; (6) the thin Li2B4O7;Cu element can be used for skin dose monitoring; and (7) the processing time of the automatic reader for the composite dosimeter is 3 hr/500 dosimeters. This TLD system can be applied to personnel dosimetry, gate monitoring and environmental monitoring. PMID:7174331

  5. Ependimoma myxopapilar sacro gigante con osteolisis

    PubMed Central

    Ajler, Pablo; Landriel, Federico; Goldschmidt, Ezequiel; Campero, Álvaro; Yampolsky, Claudio

    2014-01-01

    Objetivo: la presentación de un caso de una paciente con un ependimoma sacro con extensa infiltración y destrucción ósea local. Descripción del caso: una mujer de 53 años acudió a la consulta por dolor lumbosacro y alteraciones sensitivas perineales y esfinterianas. La imágenes por Resonancia Magnética (IRM) y la Tomografía Axial Computada (TAC) mostraron una lesión expansiva gigante a nivel S2-S4 con extensa osteólisis e invasión de tejidos adyacentes. Se realizó una exéresis tumoral completa con mejoría del estatus funcional. La anatomía patológica informó ependimoma mixopapilar. Discusión: la extensión de la resección quirúrgica es el mejor predictor de buen pronóstico. El tratamiento radiante se reserva como opción adyuvante para las resecciones incompletas y recidiva tumoral. La quimioterapia sólo debería utilizarse en casos en que la cirugía y la radioterapia estén contraindicadas. Conclusión: Los ependimomas mixopapilares sacros con destrucción ósea y presentación intra y extradural son muy infrecuentes y deben ser tenidos en cuenta entre los diagnósticos diferenciales preoperatorios. Su resección total, siempre que sea posible, es la mejor alternativa terapéutica. PMID:25165615

  6. Bloedite sedimentation in a seasonally dry saline lake (Salada Mediana, Spain)

    NASA Astrophysics Data System (ADS)

    Mees, Florias; Castañeda, Carmen; Herrero, Juan; Van Ranst, Eric

    2011-06-01

    Salt crusts covering the surface of the Salada Mediana, a seasonally dry saline lake in northern Spain, consist predominantly of bloedite (Na 2Mg(SO 4) 2.4H 2O). Microscopic features of the crust were investigated to understand processes of bloedite sedimentation. This study was combined with satellite and airborne observations, revealing asymmetrical concentric and parallel-linear patterns, related to wind action. Gypsum (CaSO 4.H 2O) and glauberite (Na 2Ca(SO 4) 2) in the calcareous sediments below the crust, and abundant eugsterite (Na 4Ca(SO 4) 3.2H 2O) along the base of the crust, largely formed at a different stage than bloedite. The main part of the crust consists predominantly of coarse-crystalline xenotopic-hypidiotopic bloedite, but fan-like aggregates with downward widening, radial aggregates, surface layers with vertically aligned elongated crystals, and partially epitaxial coatings occur as well. The upper part of the crust is marked by a bloedite-thenardite (Na 2SO 4) association, recording a change in brine composition that is not in agreement with results of modelling of local brine evolution. A thin fine-grained thenardite-dominated surface formed in part by subaqueous settling of crystals, but there are also indications for development by transformation of bloedite. Surface features include fan-like bloedite aggregates with upward widening, formed by bottom growth. Overall, the Salada Mediana crusts record a complex history of bloedite and thenardite precipitation by various processes.

  7. Influence of P ion on Sr2B5O9Cl:Eu for TL dosimetry

    NASA Astrophysics Data System (ADS)

    Oza, Abha H.; Dhoble, N. S.; Dhoble, S. J.

    2015-02-01

    This paper investigates luminescence properties of Sr2B5O9Cl:Eu phosphor prepared by modified solid state diffusion. The influence of Phosphorous ion as codopant is also explained in detail. The structural confirmation of the sample was done using the XRD technique. SEM revealed the microcrystalline nature of the prepared phosphor. The characteristic Eu2+ emission at 437 nm and 423 nm was observed for Sr2B5O9Cl:Eu and Sr2B5O9Cl:P,Eu, respectively under 338 nm excitation. Samples in powder form were irradiated with different doses under γ-ray irradiation with 60Co source and the TL glow curves for both Sr2B5O9Cl:Eu and Sr2B5O9Cl:P,Eu samples were studied. In case of Sr2B5O9Cl:Eu phosphor, single glow curve nature centered on 260 °C with a shoulder peak around 144 °C was observed. However; Sr2B5O9Cl:P,Eu have shown slight different and broad glow curve nature. The TL sensitivity in both the cases was compared with CaSO4:Dy phosphor. Sr2B5O9Cl:Eu sample have shown 1.17 times less sensitivity than CaSO4:Dy and for Sr2B5O9Cl:P,Eu it was found to be equal to CaSO4:Dy and Sr2B5O9Cl:P,Eu is 1.21 times more sensitive than Sr2B5O9Cl:Eu. Other TL properties like dose response, fading and reusability were studied for both the samples. The trapping parameters for both the samples were calculated using computerized glow curve deconvolution and reported in this paper.

  8. Raman imaging in geomicrobiology: endolithic phototrophic microorganisms in gypsum from the extreme sun irradiation area in the Atacama Desert.

    PubMed

    Vítek, Petr; Ascaso, Carmen; Artieda, Octavio; Wierzchos, Jacek

    2016-06-01

    The Raman imaging method was successfully applied for mapping the distribution of biomolecules (e.g., pigments) associated with cryptoendolithic and hypoendolithic microorganisms, as well as the inorganic host mineral matrix that forms the habitat for the biota. To the best of our knowledge, this is the first comprehensive study in the field of geomicrobiology based on this technique. The studied microbial ecosystem was located nearly 3000 m above sea level within the driest desert on Earth, the Atacama in Chile. Enhancement of carotenoid Raman signal intensity close to the surface was registered at different areas of endolithic colonization dominated by algae, with cyanobacteria present as well. This is interpreted as an adaptation mechanism to the excessive solar irradiation. On the other hand, cyanobacteria synthesize scytonemin as a passive UV-screening pigment (found at both the hypoendolithic and cryptoendolithic positions). The distribution of the scytonemin Raman signal was mapped simultaneously with the surrounding mineral matrix. Thus, mapping was done of the phototrophic microorganisms in their original microhabitat together with the host rock environment. Important information which was resolved from the Raman imaging dataset of the host rock is about the hydration state of Ca-sulfate, demonstrated on the presence of gypsum (CaSO4·2H2O) and the absence of both anhydrite (CaSO4) and bassanite (CaSO4·1/2H2O). Obtaining combined "in situ" simultaneous information from the geological matrix (inorganic) together with the microbial biomolecules (organic) is discussed and concluded as an important advantage of this technique. We discuss how selection of the laser wavelength (785 and 514.5-nm) influences the Raman imaging results. PMID:27055886

  9. Raman Spectroscopic Study Of The Dehydration Of Sulfates Using An Acoustic Levitator

    NASA Astrophysics Data System (ADS)

    Brotton, Stephen; Kaiser, R.

    2012-10-01

    The martian orbiters, landers, and rovers identified water-bearing sulfates on the martian surface. Furthermore, the Galileo mission suggests that hydrated salts such as magnesium sulfate are present on the surface of Europa and Ganymede. To understand the hydrologic history of Mars and some of Jupiter’s and Saturn’s moons, future missions need to identify in situ the hydration states of sulfates including magnesium sulfate (MgSO4 • nH2O n = 7, 6, . . ., 0), gypsum (CaSO4 • 2H2O), bassanite (CaSO4 • 0.5H2O) and anhydrite (CaSO4). Raman spectroscopy is ideally suited for this purpose, since the Raman spectrum for each different degree of hydration is unique. To obtain laboratory Raman spectra for comparison with the in situ measurements, we have developed a novel apparatus combining an acoustic levitator and a pressure-compatible process chamber. Particles with diameters between 10 µm and a few mm can be levitated at the pressure nodes of the ultrasonic standing wave. The chamber is interfaced to complimentary FTIR and Raman spectroscopic probes to characterize any chemical and physical modifications of the levitated particles. The particles can be heated to well-defined temperatures between 300 K and 1000 K using a carbon dioxide laser; the temperature of the particle will be probed via its black-body spectrum. The present apparatus enables (i) the production of high particle temperatures, (ii) precise measurement of the temperature, and (iii) accurate control of the environmental conditions (gas pressure and composition) within the chamber. Using this apparatus, we have studied the dehydration of sulfates including gypsum and epsomite (MgSO4 • 7H2O) in an anhydrous nitrogen atmosphere. We will present spectra showing the variation of the Raman spectra as gypsum, for example, is dehydrated to form anhydrite.

  10. Nuclear microprobe analysis and source apportionment of individual atmospheric aerosol particles

    NASA Astrophysics Data System (ADS)

    Artaxo, Paulo; Rabello, Marta L. C.; Watt, Frank; Grime, Geoff; Swietlicki, Erik

    1993-04-01

    In atmospheric aerosol research, one key issue is to determine the sources of the airborne particles. Bulk PIXE analysis coupled with receptor modeling provides a useful, but limited view of the aerosol sources influencing one particular site or sample. The scanning nuclear microprobe (SNM) technique is a microanalytical technique that gives unique information on individual aerosol particles. In the SNM analyses a 1.0 μm size 2.4 MeV proton beam from the Oxford SNM was used. The trace elements with Z > 11 were measured by the particle induced X-ray emission (PIXE) method with detection limits in the 1-10 ppm range. Carbon, nitrogen and oxygen are measured simultaneously using Rutherford backscattering spectrometry (RBS). Atmospheric aerosol particles were collected at the Brazilian Antarctic Station and at biomass burning sites in the Amazon basin tropical rain forest in Brazil. In the Antarctic samples, the sea-salt aerosol particles were clearly predominating, with NaCl and CaSO 4 as major compounds with several trace elements as Al, Si, P, K, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb. Factor analysis of the elemental data showed the presence of four components: 1) soil dust particles; 2) NaCl particles; 3) CaSO 4 with Sr; and 4) Br and Mg. Strontium, observed at 20-100 ppm levels, was always present in the CaSO 4 particles. The hierarchical cluster procedure gave results similar to the ones obtained through factor analysis. For the tropical rain forest biomass burning aerosol emissions, biogenic particles with a high organic content dominate the particle population, while K, P, Ca, Mg, Zn, and Si are the dominant elements. Zinc at 10-200 ppm is present in biogenic particles rich in P and K. The quantitative aspects and excellent detection limits make SNM analysis of individual aerosol particles a very powerful analytical tool.

  11. Biospheric effects of a large extraterrestrial impact: Case study of the Cretaceous/Tertiary boundary crater

    NASA Technical Reports Server (NTRS)

    Pope, Kevin O.

    1994-01-01

    The Chicxulub Crater in Yucatan, Mexico, is the primary candidate for the impact that caused mass extinctions at the Cretaceous/Tertiary boundary. The target rocks at Chicxulub contain 750 to 1500 m of anhydrite (CaSO4), which was vaporized upon impact, creating a large sulfuric acid aerosol cloud. In this study we apply a hydrocode model of asteroid impact to calculate the amount of sulfuric acid produced. We then apply a radiative transfer model to determine the atmospheric effects. Results include 6 to 9 month period of darkness followed by 12 to 26 years of cooling.

  12. High-pressure and high-temperature study of the phase transition in anhydrite

    NASA Astrophysics Data System (ADS)

    Ma, Y. M.; Zhou, Q.; He, Z.; Li, F. F.; Yang, K. F.; Cui, Q. L.; Zou, G. T.

    2007-10-01

    The high-pressure and high-temperature behaviors of anhydrite (CaSO4) are studied up to 53.5 GPa and 1800 K using double-sided laser heating Raman spectroscopy and x-ray diffraction in diamond anvil cells. The evidence of phase transition from an anhydrite structure to the monazite type was observed at about 2 GPa under cold compression. Another phase transition and a change in color of the sample from transparent to black have been also observed at a pressure of 33.2 GPa after laser heating. The new phase after laser heating persists to 53.5 GPa and 1800 K.

  13. Molecular interactions of SO2 with carbonate minerals under co-sequestration conditions: a combined experimental and theoretical study

    SciTech Connect

    Glezakou, Vassiliki Alexandra; McGrail, B. Peter; Schaef, Herbert T.

    2012-09-01

    We present a combined experimental and theoretical study investigating the reactivity between selected and morphologically important surfaces of carbonate minerals with supercritical CO2 with co-existing H2O and SO2. Trace amounts of SO2 cause formation of CaSO3 in the form of hannebachite in the initial stages of SO2 adsorption and transformation. Atomistic simulations of these initial steps indicate a somewhat catalytic activity of water, which is enhanced by the presence of Magnesium atoms in the mineral surface. Under co-sequestration conditions, traces of water are not likely to cause carbonate dissolution, however the presence of SO2 greatly stabilizes the sulfite product.

  14. Irradiation dose determination below room temperature

    NASA Astrophysics Data System (ADS)

    Ramos-Bernal, S.; Cruz, E.; Negrón-Mendoza, A.; Bustos, E.

    2002-03-01

    The measurements presented were undertaken to provide quantitative information on the low temperature irradiation of thermoluminiscence phosphors. The crystals used were (a) LiF co-doped with Mg, Cu and P, and (b) CaSO 4 doped with Dy. The absorbed dose values in the interval studied showed a linear behavior at low doses and low temperature. The aim of this work is to test if these crystals can be used to measure the dose absorbed by solids at low temperature.

  15. Response of TL materials to diagnostic radiology X radiation beams.

    PubMed

    Maia, Ana F; Caldas, Linda V E

    2010-01-01

    The main objective of this study was to carry out a direct performance comparison among some known types of TLDs-three types of CaSO(4):Dy pellets, sintered Al(2)O(3) pellets, LiF:Mg,Ti (Harshaw TLD-100), CaF(2):Dy (Harshaw TLD-200) and CaF(2):Mn (Harshaw TLD-400)-in the energy and dose ranges of diagnostic radiology beams. Several dosimetric characteristics were evaluated, such as reproducibility, sensitivity, calibration curves, lower dose limits and energy dependence. PMID:20097569

  16. ?Cuales son las amenazas o peligros volcanicos?

    USGS Publications Warehouse

    Myers, Bobbie; Brantley, Steven R.; Stauffer, Peter; Hendley, James W., II

    2000-01-01

    Los volcanes son capaces de producir numerosos peligros geologicos e hidrologicos. Los cientificos del Servicio Geologico de los EE. UU. (USGS, por sus siglas en ingles) y de otras instituciones alrededor del mundo estan estudiando los peligros de muchos de los centenares de volcanes activos y potencialmente activos del mundo. Estos cientificos vigilan muy de cerca la actividad de algunos de los volcanes mas peligrosos, por lo que estan preparados para alertar a las autoridades y/o a la poblacion en caso de que aumente sustancialmente la probabilidad de que ocurra una erupcion u otro evento peligroso.

  17. [In Process Citation].

    PubMed

    Valdivielso Cortázar, E; Prieto Martínez, C; Fernández-Urién Sainz, I; Vila Costas, J J; Jiménez Pérez, F J; Guerra Lacunza, A

    2016-01-01

    La pancreatitis autoinmune (PAI) es una patología poco frecuente, aunque con una creciente incidencia en países orientales, si bien esto podría deberse a una mayor tasa de detección. Puede asociarse a otras patologías autoinmunes, y se ha descrito su asociación con la enfermedad sistémica por IgG4. La clínica es variada y el tratamiento habitualmente es médico, mediante corticoides.Se describe un caso clínico diagnosticado.Palabras clave. Pancreatitis autoinmune. IgG4. PMID:27125615

  18. Como Lo Hago Yo: Tratamiento Quirurgico Del Mielomeningocele

    PubMed Central

    Portillo, Santiago

    2014-01-01

    En Argentina hay plan de fortificación con ácido fólico. Diagnostico prenatal no siempre es correcto. Cierre según técnica. Cerramos músculo. No favorecemos corpectomía temprana en casos de cifosis. Suturamos la plaqueta. Cerramos el plano muscular. Hidrocefalia: Válvula de derivación, generalmente dentro de los dos primeros meses. Ventriculostomía no está indicada. Chiari II. Laminectomia cervical alta. Siringomielia: Derivación desde la cavidad al peritoneo. PMID:24791219

  19. Characterization of the electronic structure of crystalline compounds through their localized Wannier functions

    NASA Astrophysics Data System (ADS)

    Zicovich-Wilson, Claudio M.; Bert, Alberto; Roetti, Carla; Dovesi, Roberto; Saunders, Victor R.

    2002-01-01

    The crystalline orbitals of seven oxygen containing compounds with increasing degree of covalent character (MgO, MnO, ZnO, Al2O3, SiO2, AlPO4, and CaSO4) are localized according to a Wannier-Boys mixed scheme recently implemented. The resulting Wannier functions are analyzed in terms of various indices (centroids positions, second-order central moment tensor, its eigenvalues and principal axes, Mulliken population analysis, and atomic localization indices). Systematic trends are observed along the series.

  20. Eventos Planetarios Periodicos

    NASA Astrophysics Data System (ADS)

    Flores Gutierrez, J. D.

    1987-05-01

    El análisis de las coordenadas ecuatoriales para los planetas Mercurio, Venus, Marte, Júpiter, Saturno, en los instantes en que ocurren algunos eventos astronómicos, como conjunciones, oposiciones,etc., muestra un comportamiento periódico, característico a cada planeta. El caso de Venus es el mejor estudiado. El cálculo de las efemérides a lo largo de 1000 años , indica un período característico de aproximadamente 260 años. Resultados preliminares con otros planetas muestran períodos distintos.

  1. Calidad de Imagen del Telescopio UNAM212

    NASA Astrophysics Data System (ADS)

    Cobos, F. J.; Teiada de Vargas, C.

    1987-05-01

    El telescopio UNAM2l2, del Observatorio Astronómico Nacional, situado en la Sierra de San Pedro Mártir (Baja California, México), cumplira en un futuro muy cercano siete años de uso para fines de investigación astronómica. Aunque en este tiempo no se ha efectuado un estudio sistemático acerca de su comportamiento óptico y de los factores que influyen en la calidad de las imágenes, se han realizado pruebas diversas, estudios parciales y reuniones especificas, cuyos resultados no siempre se han difundido ampliamente y generalmente no se han presentado por escrito. Es por ello que hemos creido necesario intentar una recopilación de la información existente para poder con ella establecer un diagnóstjco que, aunque no sea definitivo, sirva de base para futuros trabajos tendientes a optimizar el comportamiento óptico del telescopio. Es evidente que un buen número de las conclusiones que se presentan son resultado del trabajo de muchas personas ó de esfuerzos colectivos. Asimismo, hemos tratado de localizar información bibliográfica que pueda ser de utilidad. Nuestro objetivo primordial ha consistido en centrarnos en la óptica del telescopio y su calidad, pero también se han considerado otros aspectos que puedan afectar las imágenes obtenidas tales como: celda del primario, `seeing' local y externo, flexiones posibles en la estructura mecánica del telescopio, etc.

  2. [IPS an ethical paradigm for biomedical research].

    PubMed

    Gámez Escalona, José Antonio

    2013-01-01

    One of the greatest advances in molecular and cell biology was the discovery of the Induced Pluripotent Stem cells (iPS) in mice, by Shinya Yamanka and his team in 2006. The possibility that these cells can be generated also in humans opens up unexpected ways of development for biomedicine. Its main contribution is the creation of a strong protocol that takes into account three major advances in biology such as; nuclear transfer techniques, the discovery of transcription factors associated with pluripotency and the isolation of mouse embryonic stem cells. A protocol that can be easily replicated in other laboratories to have the oportunity to design tests that allow modeling of many incurable diseases, drug testing for human cells or explore the possibilities of autologous transplants of tissues or organs. Yamanaka ethical motivation to find an alternative to embryonic stem cells (ES) and prevent the destruction of embryos produced by In Vitro Fertilization techniques (IVF), has proved to be a research model, in which the intuition of the ethical principles and its application in advanced biotechnology projects, has meant the opening of a whole new way of understanding the biology of embryonic development. It is clear that development, biologically understood (puede ser también ″treated″; tratado), is not a one-way street. The possibilities to deepen into the foundations of molecular biology and genetics, along with the expectations of its clinical applications have earned Yamanka the Nobel Prize in Medicine 2012, along with another great scholar Sir John Gurdon, discoverer of nuclear transfer techniques. PMID:24483317

  3. Bilayered construct for simultaneous regeneration of alveolar bone and periodontal ligament.

    PubMed

    Sundaram, M Nivedhitha; Sowmya, S; Deepthi, S; Bumgardener, Joel D; Jayakumar, R

    2016-05-01

    Periodontitis is an inflammatory disease that causes destruction of tooth-supporting tissues and if left untreated leads to tooth loss. Current treatments have shown limited potential for simultaneous regeneration of the tooth-supporting tissues. To recreate the complex architecture of the periodontium, we developed a bilayered construct consisting of poly(caprolactone) (PCL) multiscale electrospun membrane (to mimic and regenerate periodontal ligament, PDL) and a chitosan/2wt % CaSO4 scaffold (to mimic and regenerate alveolar bone). Scanning electron microscopy results showed the porous nature of the scaffold and formation of beadless electrospun multiscale fibers. The fiber diameter of microfiber and nanofibers was in the range of 10 ± 3 µm and 377 ± 3 nm, respectively. The bilayered construct showed better protein adsorption compared to the control. Osteoblastic differentiation of human dental follicle stem cells (hDFCs) on chitosan/2wt % CaSO4 scaffold showed maximum alkaline phosphatase at seventh day followed by a decline thereafter when compared to chitosan control scaffold. Fibroblastic differentiation of hDFCs was confirmed by the expression of PLAP-1 and COL-1 proteins which were more prominent on PCL multiscale membrane in comparison to control membranes. Overall these results show that the developed bilayered construct might serve as a good candidate for the simultaneous regeneration of the alveolar bone and PDL. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 761-770, 2016. PMID:26153674

  4. Uranyl (VI) and neptunyl (V) incorporation in carbonate and sulfate minerals: Insight from first-principles

    NASA Astrophysics Data System (ADS)

    Walker, Sarah M.; Becker, Udo

    2015-07-01

    The incorporation of radionuclides into low-temperature mineral hosts may strongly influence the concentration and migration of radioactive contaminants in the subsurface. One difficulty in evaluating the thermodynamics of incorporation is that experiments are often performed at high supersaturations and typically do not reach equilibrium. An alternative way to obtain the equilibrium thermodynamics is the quantum-mechanical analysis of the mineral host and the incorporated species before and after incorporation. In this contribution, density functional theory is used to calculate the energetics, resulting structures, and electronic configuration of uranyl (UO22+) and neptunyl (NpO2+) incorporation into sulfate and carbonate minerals. In each host mineral, gypsum (CaSO4·2H2O), anhydrite (CaSO4), anglesite (PbSO4), celestine (SrSO4), barite (BaSO4), calcite (CaCO3), aragonite (CaCO3), cerussite (PbCO3), strontianite (SrCO3), and witherite (BaCO3), a divalent cation is replaced with either UO22+ or NpO2+ (in the case of neptunyl, charge balance is maintained with an additional hydrogen ion). The source of the actinyl ion and the sink for the host cation are modeled as both solid and aqueous phases, the latter of which requires an expansion of previous descriptions of incorporation. By combining periodic and cluster computational methods, this newly-developed approach enables the quantum-mechanical simulation of reactions between charged, aqueous molecular species and solid mineral phases.

  5. Estudio de la envoltura fría en presencia de un campo magnético en estrellas tempranas

    NASA Astrophysics Data System (ADS)

    Montero, M. F.; Platzeck, A. M.

    En el estudio de la distribución espacial de la densidad en torno a estrellas tempranas, al menos en dos coordenadas, se consideran en general ``escenarios" cualitativos. Existen sólo dos modelos calculados a partir de la ecuación de conservación de momento: el de Poeckert y Marlborough (Astroph. Journal 220, 940, 1978) y el de Ringuelet e Iglesias (Astroph. Journal 369, 463, 1991). El primero es isotermo considerando campo gravitatorio y fuerza centrífuga. El segundo, resuelve un caso no isotermo en equilibrio hidrostático teniendo en cuenta los campos gravitatorios, de radiación y magnético. En esta comunicación presentamos el análisis, que se deriva de los resultados de Ringuelet e Iglesias para el caso hidrostático, de la estructura de líneas de campo magnético. A continuación estudiamos la forma en que se modifica la distribución espacial de la densidad en la envoltura fría, cuando se tiene en cuenta el movimiento del plasma.

  6. Mechanical properties and leaching modeling of activated incinerator bottom ash in Portland cement blends.

    PubMed

    Onori, Roberta; Polettini, Alessandra; Pomi, Raffaella

    2011-02-01

    In the present study the evolution of mechanical strength and the leaching behavior of major and trace elements from activated incinerator bottom ash/Portland cement mixtures were investigated. Chemical and mechanical activation were applied with the purpose of improving the reactivity of bottom ash in cement blends. Chemical activation made use of NaOH, KOH, CaCl(2) or CaSO(4), which were selected for the experimental campaign on the basis of the results from previous studies. The results indicated that CaCl(2) exhibited by far the best effects on the evolution of the hydration process in the mixtures; a positive effect on mechanical strength was also observed when CaSO(4) was used as the activator, while the gain in strength produced by KOH and NaOH was irrelevant. Geochemical modeling of the leaching solutions provided information on the mineral phases responsible for the release of major elements from the hardened materials and also indicated the important role played by surface sorption onto amorphous Fe and Al minerals in dictating the leaching of Pb. The leaching of the other trace metal cations investigated (Cu, Ni and Zn) could not be explained by any pure mineral included in the thermodynamic database used, suggesting they were present in the materials in the form of complex minerals or phase assemblages for which no consistent thermodynamic data are presently available in the literature. PMID:20646923

  7. RETOS EN LA INTERVENCIÓN CON ADOLESCENTES PUERTORRIQUEÑOS/AS QUE MANIFIESTAN COMPORTAMIENTO SUICIDA*

    PubMed Central

    Vélez, Yovanska Duarté; Dávila, Paloma Torres; Hernández, Samariz Laboy

    2015-01-01

    Presentamos un estudio de caso de una adolescente puertorriqueña con comportamiento suicida. Esta comenzó una Terapia Socio Cognitivo-Conductual para el Comportamiento Suicida (TSCC-CS) de tipo ambulatorio luego de una hospitalización por intento suicida. La TSCC-CS incorpora una perspectiva ecológica y de desarrollo a la terapia cognitivo-conductual. Inicialmente mostró baja autoestima y severos síntomas depresivos y de ansiedad. Al finalizar el tratamiento, manifestó un cambio significativo en su sintomatología clínica y evidenció una mejoría en sus destrezas de manejo. No presentó ideas suicidas durante meses previos, ni durante el seguimiento. El análisis de este caso permitió realizar cambios en el protocolo de tratamiento, particularmente en las sesiones de familia y de comunicación con el fin de aumentar la viabilidad del tratamiento. PMID:26702337

  8. Strengthening aerobic granule by salt precipitation.

    PubMed

    Chen, Yu-You; Pan, Xiangliang; Li, Jun; Lee, Duu-Jong

    2016-10-01

    Structural stability of aerobic granules is generally poor during long-term operation. This study precipitated seven salts inside aerobic granules using supersaturated solutions of (NH4)3PO4, CaCO3, CaSO4, MgCO3, Mg3(PO4)2, Ca3(PO4)2 or SiO2 to enhance their structural stability. All precipitated granules have higher interior strength at ultrasonic field and reveal minimal loss in organic matter degradation capability at 160-d sequential batch reactor tests. The strength enhancement followed: Mg3(PO4)2=CaSO4>SiO2>(NH4)3PO4>MgCO3>CaCO3=Ca3(PO4)2>original. Also, the intra-granular solution environment can be buffered by the precipitate MgCO3 to make the aerobic granules capable of degradation of organic matters at pH 3. Salt precipitation is confirmed a simple and cost-effective modification method to extend the applicability of aerobic granules for wastewater treatments. PMID:27377228

  9. Ultrasonication assisted and surfactant mediated synergistic approach for synthesis of calcium sulfate nano-dendrites.

    PubMed

    Bari, Sarang; Chatterjee, Aniruddha; Mishra, Satyendra

    2016-07-01

    Calcium sulfate (CaSO4) nano-dendrimers were fabricated successfully via ultrasonic irradiation method using calcium chloride [CaCl2] and ammonium per sulfate [(NH4)2SO4] as precursors in aqueous solution by using cetyl trimethyl ammonium bromide (CTAB) as chemical surfactants. Diffusion-induced branching growth mechanism (DIBGM), influenced with the action of head-group and hydrocarbon chain effect of cationic surfactants, was the backbone in the formation of CaSO4 nano-dendrites. Fourier Transform Infra-red Spectroscopy (FTIR), X-Ray powder Diffraction (XRD), Atomic Emission Spectroscopy (AES), Selected Area Electron Diffraction (SAED), Field-Emission Scanning Electron Microscopy (FE-SEM), Energy-Dispersive Spectroscopy (EDS), Dynamic Light Spectroscopy (DLS) and BET surface area analyzer were used to characterize the products. Results obtained were compared with conventional stirring method that proved the superiority of sonication method to obtain well-crystalline nanostructures. Also, surfactant concentration, sonication frequency and time were noticed as the critical factors to generate such absolute morphologies at nano-crystalline size. PMID:26964922

  10. El nuevo panorama de la Dinámica Galáctica

    NASA Astrophysics Data System (ADS)

    Pivovaroff, Michael James

    En general, la tendencia imperante en Dinámica Galáctica ha sido considerar que los movimientos estelares son básicamente regulares y que el caos no tiene mayor relevancia en los sistemas estelares. Sin embargo, en el último lustro se vienen acumulando pruebas de la importancia del movimiento caótico en ciertos sistemas estelares que existen en la naturaleza. Por una parte, sobre todo el grupo de David Merritt, lo ha mostrado en los casos de galaxias elípticas con concentraciones centrales de materia; por otra parte, en nuestro propio grupo, lo hemos mostrado para el caso de los satélites galácticos. Las consecuencias de estos hallazgos son tanto de tipo técnico, por la necesidad de construir modelos que contengan órbitas caóticas, como astrofísico, por los efectos del caos sobre la estacionariedad y evolución de los sistemas estelares en los que se presenta.

  11. Synthesis of Akaganeite in the Presence of Sulfate: Implications for Akaganeite Formation in Yellowknife Bay, Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Peretyazhko, T. S.; Fox, A.; Sutter, B.; Niles, P. B.; Adams, M.; Morris, R. V.; Ming, D. W.

    2016-01-01

    Akaganeite (beta-FeOOH) is an Fe(III) (hydr)oxide with a tunnel structure usually occupied by chloride. Akaganeite has been recently discovered in a mudstone on the surface of Mars by the Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM) instruments onboard the Mars Science Laboratory (MSL) Curiosity Rover in Gale crater [1, 2]. Akaganeite was detected together with sulfate minerals [anhydrite (CaSO4) and basanite (2CaSO4·2H2O)] in the drilled Cumberland and John Clein mudstone samples at Yellowknife Bay [2]. Discovery of akaganeite and sulfates in the same samples suggests that sulfate ions could be present in aqueous solution during akaganeite formation. However, mechanism and aqueous environmental conditions of akaganeite formation (e.g., pH and range of sulfate concentration) in Yellowknife Bay remain unknown. The objective of our work was to perform synthesis of akaganeite without or with sulfate addition at variable pHs in order to constrain formation conditions of akaganeite in Yellowknife Bay, Gale crater on Mars.

  12. [In Process Citation].

    PubMed

    Reyna, Nadia; Moreno-Rojas, Rafael; Mendoza, Laura; Parra, Karla; Linares, Sergia; Reyna, Eduardo; Cámara-Martos, Fernando

    2016-01-01

    Se estudió el consumo de tres tipos de suplementos, proteínas del lactosuero, caseínas y maltodextrinas (control) en la disminución de la ingesta energética y prolongación del efecto de saciedad de 60 mujeres obesas. Después de 10 semanas, la reducción del peso corporal, IMC, % de grasa corporal y circunferencia de la cintura fue significativamente mayor (p < 0,001) en el grupo que consumió las proteínas lactoséricas frente a los otros dos grupos (control y caseínas). También se observa un descenso en la ingesta energética de -383 kcal/día en las mujeres que consumieron las proteínas de lactosuero frente a un descenso de -144 kcal/día en el grupo de caseínas y de tan solo -70 kcal/día en el grupo control. Finalmente la regulación del efecto de saciedad mediante escala visual analógica fue también más efectiva en el caso de las proteínasséricas, que en el caso de las caseínas y maltodextrinas. PMID:27019242

  13. Extra dose due to extravehicular activity during the NASA4 mission measured by an on-board TLD system

    NASA Technical Reports Server (NTRS)

    Deme, S.; Apathy, I.; Hejja, I.; Lang, E.; Feher, I.

    1999-01-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO4:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly (SAA) three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO4:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 microGy h-1 at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET.

  14. Immobilizing Water into Crystal Lattice of Calcium Sulfate for its Separation from Water-in-Oil Emulsion.

    PubMed

    Jiang, Guangming; Li, Junxi; Nie, Yunliang; Zhang, Sen; Dong, Fan; Guan, Baohong; Lv, Xiaoshu

    2016-07-19

    This work report a facile approach to efficiently separate surfactant-stabilized water (droplet diameter of around 2.0 μm) from water-in-oil emulsion via converting liquid water into solid crystal water followed by removal with centrifugation. The liquid-solid conversion is achieved through the solid-to-solid phase transition of calcium sulfate hemihydrate (CaSO4. 0.5H2O, HH) to dihydrate (CaSO4·2H2O, DH), which could immobilize the water into crystal lattice of DH. For emulsion of 10 mg mL(-1) water, the immobilization-separation process using polycrystalline HH nanoellipsoids could remove 95.87 wt % water at room temperature. The separation efficiency can be further improved to 99.85 wt % by optimizing the HH dosage, temperature, HH size and crystalline structure. Property examination of the recycled oil confirms that our method has neglectable side-effect on oil quality. The byproduct DH was recycled to alpha-HH (a valuable cemetitious material widely used in construction and binding field), which minimizes the risk of secondary pollution and promotes the practicality of our method. With the high separation efficiency, the "green" feature and the recyclability of DH byproduct, the HH-based immobilization-separation approach is highly promising in purifying oil with undesired water contamination. PMID:27322639

  15. An optical method for evaluation of geometric fidelity for anatomically shaped tissue-engineered constructs.

    PubMed

    Ballyns, Jeffrey J; Cohen, Daniel L; Malone, Evan; Maher, Suzanne A; Potter, Hollis G; Wright, Timothy; Lipson, Hod; Bonassar, Lawrence J

    2010-08-01

    Quantification of shape fidelity of complex geometries for tissue-engineered constructs has not been thoroughly investigated. The objective of this study was to quantitatively describe geometric fidelities of various approaches to the fabrication of anatomically shaped meniscal constructs. Ovine menisci (n = 4) were imaged using magnetic resonance imaging (MRI) and microcomputed tomography (microCT). Acrylonitrile butadiene styrene plastic molds were designed from each imaging modality and three-dimensional printed on a Stratasys FDM 3000. Silastic impression molds were fabricated directly from ovine menisci. These molds were used to generate shaped constructs using 2% alginate with 2% CaSO(4). Solid freeform fabrication was conducted on a custom open-architecture three-dimensional printing platform. Printed samples were made using 2% alginate with 0.75% CaSO(4). Hydrogel constructs were scanned via laser triangulation distance sensor. The point cloud images were analyzed to acquire computational measurements for key points of interest (e.g., height, width, and volume). Silastic molds were within + or - 10% error with respect to the native tissue for seven key measurements, microCT molds for six of seven, microCT prints for four of seven, MRI molds for five of seven, and MRI prints for four of seven. This work shows the ability to generate and quantify anatomically shaped meniscal constructs of high geometric fidelity and lends insight into the relative geometric fidelities of several tissue engineering techniques. PMID:19788346

  16. Formation of calcium sulfate through the aggregation of sub-3 nanometre primary species.

    PubMed

    Stawski, Tomasz M; van Driessche, Alexander E S; Ossorio, Mercedes; Diego Rodriguez-Blanco, Juan; Besselink, Rogier; Benning, Liane G

    2016-01-01

    The formation pathways of gypsum remain uncertain. Here, using truly in situ and fast time-resolved small-angle X-ray scattering, we quantify the four-stage solution-based nucleation and growth of gypsum (CaSO4·2H2O), an important mineral phase on Earth and Mars. The reaction starts through the fast formation of well-defined, primary species of <3 nm in length (stage I), followed in stage II by their arrangement into domains. The variations in volume fractions and electron densities suggest that these fast forming primary species contain Ca-SO4-cores that self-assemble in stage III into large aggregates. Within the aggregates these well-defined primary species start to grow (stage IV), and fully crystalize into gypsum through a structural rearrangement. Our results allow for a quantitative understanding of how natural calcium sulfate deposits may form on Earth and how a terrestrially unstable phase-like bassanite can persist at low-water activities currently dominating the surface of Mars. PMID:27034256

  17. Formation of calcium sulfate through the aggregation of sub-3 nanometre primary species

    NASA Astrophysics Data System (ADS)

    Stawski, Tomasz M.; van Driessche, Alexander E. S.; Ossorio, Mercedes; Diego Rodriguez-Blanco, Juan; Besselink, Rogier; Benning, Liane G.

    2016-04-01

    The formation pathways of gypsum remain uncertain. Here, using truly in situ and fast time-resolved small-angle X-ray scattering, we quantify the four-stage solution-based nucleation and growth of gypsum (CaSO4.2H2O), an important mineral phase on Earth and Mars. The reaction starts through the fast formation of well-defined, primary species of <3 nm in length (stage I), followed in stage II by their arrangement into domains. The variations in volume fractions and electron densities suggest that these fast forming primary species contain Ca-SO4-cores that self-assemble in stage III into large aggregates. Within the aggregates these well-defined primary species start to grow (stage IV), and fully crystalize into gypsum through a structural rearrangement. Our results allow for a quantitative understanding of how natural calcium sulfate deposits may form on Earth and how a terrestrially unstable phase-like bassanite can persist at low-water activities currently dominating the surface of Mars.

  18. Shock-induced devolatization of calcium sulfate and implications for K-T extinctions

    NASA Technical Reports Server (NTRS)

    Chen, Guangqing; Tyburczy, James A.; Ahrens, Thomas J.

    1993-01-01

    Calcium sulfate devolatization during the impact at Chicxulub, Mexico and dispersal in the stratosphere of the resultant sulfuric acid aerosol have been suggested as a possible mechanism for the Cretaceous-Tertiary extinctions. In this paper, we investigated two shock-induced devolatization reactions of calcium sulfate up to 42 GPa in the laboratory: CaSO4 + SiO2 yields CaSiO3 + SO3(degassed) and CaSO4 yields CaO + SO2(degassed) + 1/2 O2(degassed). We found both to proceed to a much less extent than calculated by equilibrium thermodynamic calculations. Reaction products are found to be 10(exp -2) times those calculated for equilibrium. Consequently our estimate of the amount of sulfur oxides degassed into the atmosphere from shock devolatization of CaS04 in the Chicxulub lithographic section (6x10(exp 15)-2x10(exp 16)g in sulfur mass) is lower by a factor of 70 to 400 than previous estimates; the related environmental stress arising from the resultant global cooling of approximately 4 K and fallout of acid rain does not appear to suffice to explain the widespread K-T extinctions.

  19. Extra dose due to extravehicular activity during the NASA4 mission measured by an on-board TLD system.

    PubMed

    Deme, S; Apathy, I; Hejja, I; Lang, E; Feher, I

    1999-01-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO4:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly (SAA) three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO4:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 microGy h-1 at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET. PMID:11542227

  20. Assessment of geochemical evolution of groundwater in a mountainous area under agricultural land

    NASA Astrophysics Data System (ADS)

    Ledesma-Ruiz, Rogelio; Pasten-Zapata, Ernesto; Parra, Roberto; Harter, Thomas; Mahlknecht, Jürgen

    2014-05-01

    Zona Citricola is an important area to Mexico for its citriculture. Situated in a sub-humid to humid climate adjacent to Sierra Madre Occidental, this mountainouos valley hosts an aquifer system which represents sequences of shales, marls, conglomerates, and alluvial deposits. Groundwater flows from mountainous recharge areas to the basin-fill deposits and provides base flow to supply drinking water to an adjacent metropolitan area. The objective of this study was to characterize groundwater chemistry of this area and to assess the evolution. Correlation and principal component analysis were used to decipher various underlying natural and anthropogenic processes creating distinct water classes: (1) dissolution of evaporates, (2) surface organic waste or wastewater, and (3) silicate weathering and clay formation. Hierarchical cluster analysis was employed for partitioning the water samples into four hydrochemical groups: recharge waters (Ca-HCO3), transition zone waters (Ca-HCO3-SO4 to Ca-SO4-HCO3) and discharge waters (Ca-SO4). Inverse geochemical models of these groups were developed using PHREEQC to elucidate the chemical reactions controlling water chemistry between an initial (recharge) and final water. The main responsible reactions were: (1) dissolution of rock salts, (2) release of soil gas carbon dioxide, (3) dedolomitization,(4) albite weathering reactions with corresponding precipitation of silica and clay minerals, and (5) input from animal/human waste and manure, accompanied by denitrification processes. The hydrochemical groups could be related to lithological formations.

  1. Quality control of X-ray orthovoltage therapy units with a dual TL system.

    PubMed

    Zaránd, P; Polgár, I; Katona, E

    1989-01-01

    More than 40 orthovoltage X-ray therapy units are monitored by calibrated thermoluminescent dosimeters (TLD). Three pairs of LiF:Mg,Ti and CaSO4:Dy pellets are irradiated in air in a polypropane capsule. The range between 0.2 to 3.0 mm Cu the half-value layer (HVL) is determined from the CaSO4-LiF ratio. In this range, the response of the LiF dosimeters is corrected for energy dependence. We are using a fixed sensitivity for LiF in the MVL range of 2 mm Al to 0.2 mm Cu. In the first two years 173 monitorings were performed by using 485 badges. Usually not more then two different radiation qualities (in the HVL ranges 2 mm Al to 0.2 mm Cu and 0.9-2.5 mm Cu) or two beams used on a therapy unit are measured by using 2-3 badges per monitoring. In 134 cases (77.5%) the dose rates were within acceptable limits (+/- 10%). In 23 cases (13.3%) a failure of the X-ray unit was detected. We think that our system is simple enough and may be used for the dosimetric monitoring of orthovoltage X-ray therapy units. In some cases even the type of malfunction can be determined. PMID:2487013

  2. Calibration of TLD badges for photons of energy above 6 MeV and dosimetric intricacies in high energy gamma ray fields encountered in nuclear power plants.

    PubMed

    Pradhan, A S; Bakshi, A K

    2002-01-01

    CaSO4:Dy and LiF TLDs do not exhibit photon energy dependence beyond +/-55% for photons in the energy range from 1 MeV to about 7 MeV. However, when sandwiched between metal filters or used in TLD badge holders having metal filters, the response changes for irradiation from high energy photons as compared to that from 60Co gamma rays (generally used for reference calibrations). This effect is about the same for both the lower atomic number TLD (LiF) and higher atomic number TLD (CaSO4:Dy). For TLDs held on the surface of the phantom and irradiated in collimated photon beams, the response of TLDs without any filter or those under the open window of the TLD badge is considerably reduced due to insufficient build-up to high energy photons, whereas for uncollimated radiation fields from power reactors, an over-response is observed. It is observed that the use of inappropriate encapsulation of dosemeters would cause a significant error not only in the estimation of doses due to penetrating radiations but also in the estimation of beta doses in the mixed fields of beta radiation, high energy gamma rays and high energy electrons often encountered in the fields of pressurised heavy water reactors. PMID:12018745

  3. Suppression of chlorinated aromatics by nitrogen and sulphur inhibitors in iron ore sintering.

    PubMed

    Zhang, Yadi; Buekens, Alfons; Liu, Lina; Zhang, Yibo; Zeng, Xiaolan; Sun, Yifei

    2016-07-01

    Dioxins generated by iron and steel industry account for the majority of industrial dioxins emissions. This study compares the performance of different additives (including calcium sulphate dehydrate CaSO4·2H2O; calcium polysulphide CaSx; ammonium sulphate (NH4)2SO4; 4-methylthiosemicarbazide H3C-SC(NH)2NH2 and thiourea H2NCSNH2) as suppressant of chlorinated aromatics in iron ore sintering. The formation of chlorobenzenes (CBz) and polychlorinated biphenyls (PCBs), used as surrogates for dioxins, was suppressed significantly in the present of various inhibitors (1 wt%) except for CaSO4·2H2O. Moreover, a larger molar ratio of (S + N)/Cl leads to a higher suppression efficiency, so that the inhibition capacity of (NH4)2SO4 on both CBz and PCBs was weaker than H2NCSNH2. The generation of dioxin-like PCBs (Co- or dl-PCB) was also analysed. PMID:27131450

  4. Evolución de planetas gigantes y posibilidades de su detección directa

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Benvenuto, O. G.

    Desde la reciente detección de planetas gigantes orbitando estrellas cercanas de tipo solar por medio de efecto Doppler, uno de los principales problemas, en cuanto al estudio de los sistemas planetarios extrasolares, se refiere a la posibilidad de obtener evidencia directa de su existencia. Esto parece ser factible gracias a que en un futuro cercano entrarán en operación algunos telescopios especialmente adecuados a estos propósitos. Por tal motivo, hemos comenzado desde hace un tiempo un esfuerzo en cuanto al estudio de la evolución planetaria. A tales efectos hemos adaptado el código de evolución estelar de nuestro Observatorio al caso planetario. Las principales diferencias entre el caso estelar y el planetario se encuentran en la ecuación de estado. A tales fines hemos incluído la reciente ecuación de estado de Saumon, Chabrier y Van Horn, las opacidades radiativas de Guillot et al., procesos de quema de Deuterio, etc. También se ha considerado la posible existencia de fases de hielo y roca en el interior planetario. Por el momento hemos despreciado los efectos de la rotación planetaria. Con este código hemos computado la evolución de planetas con masas desde 10 hasta 0.3 masas de Júpiter. Utilizando nuestros resultados numéricos discutimos la detectabilidad de estos objetos en condiciones realistas.

  5. An evaluation of carrier agents for desferoxamine, an up-regulator of vascular endothelial growth factor.

    PubMed

    Hertzberg, Brian P; Holt, Joshua B; Graff, Ronald D; Gilbert, Shawn R; Dahners, Laurence E

    2013-05-01

    Avascularity and hypoxia result in avascular necrosis and play a negative role in fracture healing. The FDA-approved iron chelating agent, desferoxamine (DFO) in a liquid form, has been shown to induce angiogenesis and improve fracture healing through upregulation of the vascular endothelial growth factor. We were concerned that local injection of DFO would either fail to adequately deliver sufficient drug to the desired site or lead to undesired delivery to adjacent sites. Therefore, a sustained release delivery system was desirable to direct DFO to the intended site. Calcium sulfate pellets, collagen sponges, and demineralized cortical bone matrix were all evaluated as potentially controlled release systems for DFO using a fetal mouse metatarsal angiogenesis assay. Angiogenesis was analyzed using a vascularity grading scale, by measuring the mean vessel length of the 5 longest vessels, and by counting the mean number of vessels per metatarsal. Although there was some evidence of angiogenesis with all three carriers, DFO loaded CaSO4 pellets increased vascularity grading, the mean length of the five longest vessels, and the mean number of vessels, all by statistically significant margins versus the control. These results suggest that CaSO4 pellets could be used as a viable, nontoxic, controlled release system for DFO in clinical situations where increased angiogenesis and bone growth are desirable. PMID:22262572

  6. Gypsum under pressure: A first-principles study

    NASA Astrophysics Data System (ADS)

    Giacomazzi, Luigi; Scandolo, Sandro

    2010-02-01

    We investigate by means of first-principles methods the structural response of gypsum (CaSO4ṡ2H2O) to pressures within and above the stability range of gypsum-I (P≤4GPa) . Structural and vibrational properties calculated for gypsum-I are in excellent agreement with experimental data. Compression within gypsum-I takes place predominantly through a reduction in the volume of the CaO8 polyhedra and through a distortion of the hydrogen bonds. The distance between CaSO4 layers becomes increasingly incompressible, indicating a mechanical limit to the packing of water molecules between the layers. We find that a structure with collapsed interlayer distances becomes more stable than gypsum-I above about 5 GPa. The collapse is concomitant with a rearrangement of the hydrogen-bond network of the water molecules. Comparison of the vibrational spectra calculated for this structure with experimental data taken above 5 GPa supports the validity of our model for the high-pressure phase of gypsum.

  7. First karyotype description of Hypostomus iheringii (Regan, 1908): a case of heterochromatic polymorphism

    PubMed Central

    Traldi, Josiane Baccarin; Vicari, Marcelo Ricardo; Blanco, Daniel Rodrigues; Martinez, Juliana de Fátima; Artoni, Roberto Ferreira; Moreira-Filho, Orlando

    2012-01-01

    Abstract In this study, which is the first karyotype analysis of Hypostomus iheringii, nine specimens collected in Córrego da Lapa (tributary of the Passa-Cinco River) showed a diploid number of 80 chromosomes. Silver nitrate staining and fluorescence in situ hybridization (FISH) with an 18S rDNA probe revealed the presence of multiple nucleolus organizer regions (NORs) (chromosome pairs 13, 20, and 34). FISH with a 5S rDNA probe showed that this cistron was only present in chromosome pair 2. When the karyotypes of individual animals were compared, unique heterochromatic polymorphisms were detected on chromosome pairs 1 and 5. Specifically, specimens had heterochromatic blocks (h+h+) on both chromosomes, one chromosome with heterochromatic blocks (h+h-) or chromosomes that lacked heterochromatic blocks (h-h-). Considering that heteromorphic pattern is not correlated with variation in size, the process of heterochromatinization might act on the long arms of these chromosomes. In summary, all chromosomal markers indicate that the karyotype of Hypostomus iheringii is highly differentiated and that the heterochromatinization of chromosomal segments may have contributed to its karyotypic differentiation. PMID:24260656

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

    USGS Publications Warehouse

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.

    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

  9. Chemistry, mineralogy and origin of the clay-hill nitrate deposits, Amargosa River valley, Death Valley region, California, U.S.A.

    USGS Publications Warehouse

    Ericksen, G.E.; Hosterman, J.W.; St., Amand, P.

    1988-01-01

    The clay-hill nitrate deposits of the Amargosa River valley, California, are caliche-type accumulations of water-soluble saline minerals in clay-rich soils on saline lake beds of Miocene, Pliocene(?) and Pleistocene age. The soils have a maximum thickness of ??? 50 cm, and commonly consist of three layers: (1) an upper 5-10 cm of saline-free soil; (2) an underlying 15-20 cm of rubbly saline soil; and (3) a hard nitrate-rich caliche, 10-20 cm thick, at the bottom of the soil profile. The saline constituents, which make up as much as 50% of the caliche, are chiefly Cl-, NO-3, SO2-4 and Na+. In addition are minor amounts of K+, Mg2+ and Ca2+, varying, though generally minor, amounts of B2O3 and CO2-3, and trace amounts of I (probably as IO-3), NO-2, CrO2-4 and Mo (probably as MoO2-4). The water-soluble saline materials have an I/Br ratio of ??? 1, which is much higher than nearly all other saline depostis. The principal saline minerals of the caliche are halite (NaCl), nitratite (NaNO3), darapskite (Na3(SO4)(NO3)??H2O), glauberite (Na2Ca(SO4)2), gypsum (CaSO4??2H2O) and anhydrite (CaSO4). Borax (Na2B4O5(OH)4??8H2O), tincalconite (Na2B4O5(OH)4??3H2O) and trona (Na3(CO3)(HCO3)??2H2O) are abundant locally. The clay-hill nitrate deposits are analogous to the well-known Chilean nitrate deposits, and probably are of similar origin. Whereas the Chilean deposits are in permeable soils of the nearly rainless Atacama Desert, the clay-hill deposits are in relatively impervious clay-rich soils that inhibited leaching by rain water. The annual rainfall in the Death Valley region of ??? 5 cm is sufficient to leach water-soluble minerals from the more permeable soils. The clay-hill deposits contain saline materials from the lake beds beneath the nitrate deposits are well as wind-transported materials from nearby clay-hill soils, playas and salt marshes. The nitrate is probably of organic origin, consisting of atmospheric nitrogen fixed as protein by photoautotrophic blue-green algae

  10. Simulação de ejeções de massa coronal

    NASA Astrophysics Data System (ADS)

    Corsini, M. A.; Silva, A. V. R.

    2003-08-01

    Ejeções de massa coronal (EMC) são bolhas gigantes de gás permeadas por campos magnéticos que são ejetadas do Sol durante um período de várias horas. Caso estas ejeções atinjam a Terra, geralmente, causam uma série de distúrbios às comunicações de longa distância e navegação, além de danos a satélites e transformadores. Portanto, é desejável que sejamos capazes de prever quando estas ejeções atingirão a Terra. Para tanto, é necessário um bom entendimento dos mecanismos causadores das ejeções e, principalmente, de como se dá a propagação das EMC e sua interação com o vento solar que permeia o meio interplanetário. Nesse sentido foi desenvolvido um programa computacional para resolver as equações MHD (Magneto-Hidro-Dinâmica) que regem a evolução das EMC. Primeiramente foram estabelecidas as condições necessárias para descrever o vento solar, no estado estacionário, que permeia todo o meio interplanetário. Num primeiro momento, resolveu-se o sistema de equações para o caso do vento isotérmico, conhecida como a solução de Parker, a fim de testarmos o modelo. Então, foi considerado o caso do vento solar com temperatura variável no meio interplanetário. Este resultado foi utilizado como a base de nosso sistema em seu instante inicial. Posteriormente foram feitas as considerações necessárias para descrever a propagação da Ejeção de Massa Coronal. As EMC foram simuladas como um aumento de densidade e temperatura local na coroa solar. A órbita e a posição da Terra foram incluídas no sistema. Os dados gerados possibilitaram uma análise da evolução da EMC pelo meio interplanetário até encontrar-se com a Terra. Os perfis de densidade e temperatura a 1 Unidade Astronômica são comparados com os dados de satélites reportados na literatura.

  11. Differences in crystal habitus of natural and synthetic colloids

    NASA Astrophysics Data System (ADS)

    Wieczorek, Arkadiusz K.; Händel, Matthias; Totsche, Kai Uwe

    2014-05-01

    The formation of colloids from natural aqueous solutions is influenced by a multitude of biogeochemical and physicochemical processes and the presence of a large diversity of geogen and biogen, inorganic and organic solution phase components. A thereby frequently neglected class of components is the dissolved and colloidal phase organic matter (DOM). As DOM will interact with other solution phase components, we hypothesize that nanosized and colloidal particles formed in DOM bearing solutions may differ from synthetic precipitates either by size, shape, crystal habitus, crystallinity, composition or combinations of that. To investigate this, we analyzed natural colloidal particles collected from a limestone aquifer of the Upper Muschelkalk formation at Hainich National Park, Thuringia, Germany. Major groundwater components are Ca2+, Mg2+, Na+, SO42-, Cl-, HCO3- , and about 1 ppm of total organic carbon (TOC) in dissolved and colloidal form. Synthetic nanoparticles were precipitated from a series of oversaturated solutions containing single or mixtures of the following salts CaSO4, MgSO4, Ca(HCO3)2 NaCl typical for limestone environments. The solutions were produced with both natural groundwater and pure water (milli-Q). Droplets of such produced colloidal suspension were pipetted on silicon wafers and subject to air drying. The wafers were then analyzed by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM). We found that particles from oversaturated CaSO4 solution in pure water precipitate as large needle shaped crystals, whereas precipitates from CaSO4 solution in natural water were much smaller and showed a rosette like shape - similar in size and shape to gypsum crystals collected from the limestone formation water. Similar differences we found for other aqueous solution compositions. From this pilot study we presume that even minute amounts of dissolved and colloidal phase organic matter in

  12. Astronomia cultural e meio ambiente segundo uma abordagem holística

    NASA Astrophysics Data System (ADS)

    Jafelice, L. C.

    2003-08-01

    Neste trabalho ampliamos a discussão da abordagem holística para o ensino de astronomia que temos desenvolvido nos últimos anos, analisamos novos resultados e apresentamos exemplos práticos para interessados em experimentá-la. A constatação básica a orientar este enfoque é que cursos introdutórios em astronomia costumam ser excessiva e prematuramente técnicos, além de assumirem uma visão tradicional, muito estreita, do que seja educação científica, herdada da era cartesiana e positivista da ciência. Fundamentamos porque é importante que elementos de astronomia cultural ofereçam o mote e constituam o eixo norteador daqueles cursos e porque é urgente revermos a visão que temos da relação entre astronomia e meio ambiente. Um ponto central nesta abordagem é explorar formas de reativar e atualizar uma relação orgânica com o meio e excitar a consciência de nossa inevitável e profunda interdependência com ele em nível cósmico. Neste trabalho exemplificamos a possibilidade de concretização desta proposta em três diferentes situações: disciplinas de cursos de licenciatura em geografia e em física; escolas de nível fundamental; e, neste caso ainda a ser implementada, comunidades carentes. Estes casos envolvem públicos e espaços diferenciados para educação formal e não-formal. Dos casos já implementados, destacamos os resultados alcançados pelos alunos: enriquecimento cultural, aprendizagem significativa de conteúdos astronômicos tradicionais; mudanças de comportamento, incorporando contato diário com o céu; e freqüentes vivências de sentimentos empáticos que redirecionam a relação com a natureza e a consciência ecológica global. Além disto, para interessados em aplicar esta proposta, também socializamos procedimentos e cuidados para a implementação de ações alternativas consonantes com a mesma. (PPGECNM/UFRN; PRONEX/FINEP; NUPA/USP; Temáticos/FAPESP)

  13. Heterogeneous reactions of NO2 with CaCO3-(NH4)2SO4 mixtures at different relative humidities

    NASA Astrophysics Data System (ADS)

    Tan, Fang; Tong, Shengrui; Jing, Bo; Hou, Siqi; Liu, Qifan; Li, Kun; Zhang, Ying; Ge, Maofa

    2016-07-01

    In this work, the heterogeneous reactions of NO2 with CaCO3-(NH4)2SO4 mixtures with a series of weight percentage (wt %) of (NH4)2SO4 were investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) at different relative humidity (RH) values. For comparison, the heterogeneous reactions of NO2 with pure CaCO3 particles and pure (NH4)2SO4 particles, as well as the reaction of CaCO3 with (NH4)2SO4 particles, were also studied. The results indicated that NO2 did not show any significant uptake on (NH4)2SO4 particles, and it reacted with CaCO3 particles to form calcium nitrate under both dry and wet conditions. The heterogeneous reactions of NO2 with CaCO3-(NH4)2SO4 mixtures were markedly dependent on RH. Calcium nitrate was formed from the heterogeneous reactions at all the RHs investigated, whereas CaSO4 ṡ 0.5H2O (bassanite), CaSO4 ṡ 2H2O (gypsum), and (NH4)2Ca(SO4)2 ṡ H2O (koktaite) were produced depending on RH. Under the dry condition, the heterogeneous uptake of NO2 on the mixtures was similar to that on CaCO3 particles with neglectable effects from (NH4)2SO4; the duration of initial stages and the NO3- mass concentrations had a negative linear relation with the mass fraction of (NH4)2SO4 in the mixtures. Under wet conditions, the chemical interaction of (NH4)2SO4 with Ca(NO3)2 enhances the nitrate formation, especially at medium RHs, while the coagulation of (NH4)2SO4 with CaCO3 exhibits an increasing inhibiting effects with increasing RH at the same time. In addition, the heterogeneous uptake of NO2 on the mixtures of CaCO3 and (NH4)2SO4 was found to favor the formation of bassanite and gypsum due to the decomposition of CaCO3 and the coagulation of Ca2+ and SO42-. A possible reaction mechanism was proposed and the atmospheric implications were discussed.

  14. Kinetics of gypsum crystal growth from high ionic strength solutions: A case study of Dead Sea - seawater mixtures

    NASA Astrophysics Data System (ADS)

    Reznik, Itay J.; Gavrieli, Ittai; Antler, Gilad; Ganor, Jiwchar

    2011-04-01

    Gypsum precipitation kinetics were examined from a wide range of chemical compositions (11<Ca/SO42-<115), ionic strengths (4.75-10 m) and saturation state with respect to gypsum (1.16-1.74) in seeded batch experiments of mixtures of Ca 2+-rich Dead Sea brine and SO42--rich seawater. Despite the variability in the experimental solutions, a single general rate law was formulated to describe the heterogeneous precipitation rate of gypsum from these mixtures: Ratehet=k1·(Ω0.5-1)10+k2·(Ω0.5-1)2mol ms, where k1 and k2 are heterogeneous rate coefficients (mol s -1 m -2) that vary as a function of the solution compositions, and is the saturation state with respect to gypsum. It is suggested that two parallel mechanisms control the heterogeneous precipitation rate. Under closer-to-equilibrium conditions, the reaction is dominated by a mechanism best described as a 2nd order reaction with respect to Ω0.5 - 1, which fits to the predictions of both the Burton Cabrera and Frank (BCF) crystal growth theory ( Burton et al., 1951) and other layer-by-layer growth mechanisms ( Goto and Ridge, 1967; Van Rosmalen et al., 1981; Bosbach and Rammensee, 1994). Under further-away-from-equilibrium conditions, the reaction is dominated by an apparent 10th order reaction. A conceptual model for gypsum growth kinetics is presented. The model is based on the 2nd order kinetic coefficients determined in the present study and data from the literature and is valid under a wide range of ionic strengths and Ca/SO42- ratios. According to this model, the integration of SO42- to kinks on the surface of the growing crystals is the rate-limiting step in the precipitation reaction. At ionic strengths above 8.5 m the precipitation rate of gypsum is enhanced, possibly due to the formation of CaSO4° ion pairs and/or a decrease in hydration frequencies.

  15. Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis

    NASA Astrophysics Data System (ADS)

    Meshoulam, Alexander; Ellis, Geoffrey S.; Said Ahmad, Ward; Deev, Andrei; Sessions, Alex L.; Tang, Yongchun; Adkins, Jess F.; Liu, Jinzhong; Gilhooly, William P.; Aizenshtat, Zeev; Amrani, Alon

    2016-09-01

    The sulfur isotopic fractionation associated with the formation of organic sulfur compounds (OSCs) during thermochemical sulfate reduction (TSR) was studied using gold-tube pyrolysis experiments to simulate TSR. The reactants used included n-hexadecane (n-C16) as a model organic compound with sulfate, sulfite, or elemental sulfur as the sulfur source. At the end of each experiment, the S-isotopic composition and concentration of remaining sulfate, H2S, benzothiophene, dibenzothiophene, and 2-phenylthiophene (PT) were measured. The observed S-isotopic fractionations between sulfate and BT, DBT, and H2S in experimental simulations of TSR correlate well with a multi-stage model of the overall TSR process. Large kinetic isotope fractionations occur during the first, uncatalyzed stage of TSR, 12.4‰ for H2S and as much as 22.2‰ for BT. The fractionations decrease as the H2S concentration increases and the reaction enters the second, catalyzed stage. Once all of the oxidizable hydrocarbons have been consumed, sulfate reduction ceases and equilibrium partitioning then dictates the fractionation between H2S and sulfate (∼17‰). Experiments involving sparingly soluble CaSO4 show that during the second catalytic phase of TSR the rate of sulfate reduction exceeds that of sulfate dissolution. In this case, there is no apparent isotopic fractionation between source sulfate and generated H2S, as all of the available sulfate is effectively reduced at all reaction times. When CaSO4 is replaced with fully soluble Na2SO4, sulfate dissolution is no longer rate limiting and significant S-isotopic fractionation is observed. This supports the notion that CaSO4 dissolution can lead to the apparent lack of fractionation between H2S and sulfate produced by TSR in nature. The S-isotopic composition of individual OSCs record information related to geochemical reactions that cannot be discerned from the δ34S values obtained from bulk phases such as H2S, oil, and sulfate minerals, and

  16. Drinkable rocks: plants can use crystallization water from gypsum

    NASA Astrophysics Data System (ADS)

    Palacio, Sara; Azorín, José; Montserrat-Martí, Gabriel; Ferrio, Juan Pedro

    2015-04-01

    Some minerals hold water in their crystalline structure. Such is the case of gypsum (CaSO4•2H2O), a rock forming mineral present in the arid and semi-arid regions of the five continents, including the dry most areas of the planet. Gypsum is also extensively found on Mars, where it constitutes a targeted substrate for the search of life. Under natural conditions and depending on the temperature, pressure, and dissolved electrolytes or organics, gypsum may lose crystallization water molecules, becoming bassanite (i.e. hemihydrate: CaSO4•½H2O) or anhydrite (CaSO4). As crystallization water can account for up to 20.8% of gypsum weight, it has been suggested that it could constitute a relevant source of water for organisms, particularly during summer. This suggestion is consistent with the phenology observed in some shallow-rooted plants growing on gypsum, which remain active when drought is intense, and with the increased soil moisture of gypsum soils during summer as compared to surrounding non-gypsum soils. Here we use the fact that the isotopic composition of free water differs from gypsum crystallization water to show that plants can use crystallization water from the gypsum structure. The composition of the xylem sap of gypsum plants during summer shows closer values to gypsum crystallization water than to free soil water. Crystallization water represents a significant water source for organisms growing on gypsum, especially during summer, when it accounts for 70-90% of the water used by shallow-rooted plants. These results significantly modify the current paradigm on water use by plants, where water held in the crystalline structure of mineral rocks is not regarded as a potential source. Given the existence of gypsum on the surface of Mars and its widespread occurrence on arid and semi-arid regions worldwide, our results have important implications for exobiology, the study of life under extreme conditions and arid land reclamation.

  17. Síndrome del Outlet Torácico: ¿Una Patología Siempre Quirúrgica? Análisis de una Serie de 31 Cirugías Realizadas por Vía Supraclavicular Serie clínica

    PubMed Central

    Socolovsky, Mariano; Di Masi, Gilda; Binaghi, Daniela; Campero, Álvaro; Páez, Miguel Domínguez; Dubrovsky, Alberto

    2014-01-01

    Introducción: El síndrome de outlet torácico es una compresión del plexo braquial que suscita polémica. Se clasifica en Outlet Torácico Verdadero o neurogénico (OTV) y Outlet Torácico Disputado o no neurogénico (OTD). El primero presenta síntomas motores en la mano, mientras que el segundo sólo síntomas sensitivos en el miembro superior. El objetivo de este trabajo es analizar los resultados obtenidos en una serie de 31 cirugías. Métodos: Se analizaron las cirugías de nervios efectuadas entre 2003-2012, tomando los diagnósticos de outlet torácico cuyo período de seguimiento post-operatorio mínimo fuera de 6 meses. Se buscaron los siguientes datos: edad, sexo, presencia de síntomas sensitivos y/o motores, clasificación, resultado de los estudios neurofisiológicos y de imágenes, resultado de la cirugía, complicaciones post-operatorias y recidivas. Resultados: Se incluyeron 31 cirugías realizadas en 30 pacientes, 9 OTV (8 mujeres) de 24.3 años, y 21 con OTD (18 mujeres) de 37.4 años de edad en promedio. Un 90% presentaron alteraciones neurofisiológicas preoperatorias, y 66,6% imagenológicas. En el intraoperatorio, el 100% de los OTV presentó una alteración anatómica relacionada con la sintomatología, hecho observado sólo en el 36.7% de los OTD operados. El 87,5% de los OTV mejoraron sensitivamente, mientras que 77,7% mejoraron la atrofia. Por el contrario, 45.4% de los OTD mejoraron permanentemente, 36.3% no tuvieron cambios, 13.6% mejoraron transitoriamente y 4.5% (un caso) empeoró. Las complicaciones post-operatorias fueron más frecuentes aunque transitorias en el grupo de OTV (3 casos sobre 9 operados, 33.3%) que en los OTD (3 casos sobre 22, un 13.6%). Conclusión: El OTV suele mayormente mejorar luego de la cirugía, igual que el OTD aunque en una proporción mucho menor. Estos hallazgos coinciden con otros reportes recientes de esta patología. PMID:25165614

  18. Anhydrite Solubility and Ca Isotope Fractionation in the Vapor-Liquid Field of the NaCl-H2O System: Implications for Hydrothermal Vent Fluids at Mid-ocean Ridges

    NASA Astrophysics Data System (ADS)

    Scheuermann, P.; Syverson, D. D.; Higgins, J. A.; Seyfried, W. E., Jr.

    2015-12-01

    Hydrothermal experiments were performed at 410, 420 and 450°C between 180-450 bar to investigate anhydrite (CaSO4) solubility and Ca isotope fractionation in the liquid-vapor stability field of the NaCl-H2O system. Experiments were conducted in flexible gold reaction cells and a fixed volume Ti reactor to reach all pressures between the critical curve and three-phase boundary. During isothermal decompression at 410°C, anhydrite solubility in the liquid phase increases (1 to 9 mmol/kg Ca), whereas the solubility decreases in the vapor phase (130 to < 10 umol/kg Ca). At 410°C and 290-270 bar, the partition coefficient, log Km = log (mv / ml), for Ca decreases from -1.35 to -2.46, and that of SO4 decreases from -1.76 to -2.82. At 420°C the Ca:SO4 ratio of the starting solution was 2:1, and the pH25°C decreases in the liquid and increases in the vapor upon decompression. Ca hydrolysis in the liquid and complex interactions between undetermined aqueous species in the vapor could explain this pattern. At 410 and 450°C, the experiments started with a Ca:SO4 ratio of 1:1. Along the 410°C isotherm, pH25°C initially increases in both the liquid and vapor, potentially caused by precipitation of an H+ bearing salt, such as NaHSO4. 30-40 bar below the critical curve there is a sudden decrease in pH25°C as the putative salt phase may become unstable and dissolve. At 450°C, pH25°C decreases in the vapor and increases in the liquid, as HCl and H2SO4 partition into the vapor. Ca isotope data at 420°C between 375-300 bar indicate that the vapor is isotopically light relative to the liquid. At lower pressures both phases approach the isotopic composition of the coexisting anhydrite, suggesting that dissolved Ca speciation becomes more structurally similar to anhydrite. This study furthers our understanding of elemental partitioning and isotopic fractionation in mineral-fluid systems with implications for mass transfer reactions at/near the magma-hydrothermal boundary at

  19. Characterization of several plasters and one retarder for repository sealing mixtures. Final report

    SciTech Connect

    Buck, A.D.; Burkes, J.P.; Reinhold, R.E.

    1985-09-01

    Samples of plasters (i.e., calcium sulfate hemihydrate, CaSO4.1/2H/sup 2/0) from six sources and one plaster retarder from a different source were obtained and characterized by a combination of chemical and physical testing and by petrographic examination. The petrographic examination included x-ray diffraction, optical microscopy, differential thermal analysis, and scanning electron microscopy procedures. The intent of this work was twofold. One purpose was to determine if plaster per se could be used as an ingredient for cementitious mixtures intended for repository sealing applications, Previous experience had been with use of a proprietary admixture that contained plaster. The second purpose was to determine one or more methods of distinguishing between the alpha and beta forms of calcium sulfate hemihydrate. Keywords: nuclear wastes; plaster of paris; tables(data).

  20. Estudio dinámico de un potencial perturbador dependiente de dos parámetros

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Brunini, A.

    El objeto del presente trabajo consiste en el estudio dinámico de un sistema dinámico caracterizado por la función hamiltoniana correspondiente a un satélite planetario perturbado por la acción del Sol y del achatamiento del planeta madre. Cuando dicha Hamiltoniana se promedia respecto de los términos de corto período, esta queda con dos grados de libertad, y su estudio puede ser realizado con las herramientas clásicas de la dinámica no-lineal. Se tratará de determinar regiones regulares y caóticas de movimiento. En el caso de estas últimas, es de particular interés la determinación de su orígen.

  1. Note: On the generation of sub-300 keV flash-X-rays using rod-pinch diode: an experimental investigation.

    PubMed

    Satyanarayana, N; Rajawat, R K; Basu, Shibaji; Rao, A Durga Prasad; Mittal, K C

    2014-09-01

    Generation of flash X-rays (FXRs) at less than 500 keV is described with emphasis on experimental investigation. The pulser is a Tesla transformer-Water transmission line based pulsed power generator operating in double resonance mode to power a rod-pinch diode. The configuration of aspect ratio reported here falls much below the normally reported ratios for the rod-pinch diode operation. Experimental investigation at such low pulsed voltage has revealed "flowering" of the anode tip and "pitting" of the perspex window. A possible explanation in terms of Lorentz body force is discussed rather than the pinch mechanism generally suggested in literature. The experimental investigation for the FXR generation is corroborated by measuring the radiation dose using CaSO4 (Dy) thermo luminescent dosimeters. PMID:25273793

  2. Spanish Summary (Nuevos meteoritos encountrados en lmilac)

    NASA Astrophysics Data System (ADS)

    1987-03-01

    Desde tiempos prehistoricos han sido coleccionadas piedras que caen dei cielo. Hasta hace poco eran la unica fuente para hacer estudios de laboratorio de la materia extragal, ktica, e incluso en nuestra era espacial, siguen siendo una valiosa fuente de investigacion de la temprana historia dei sistema solar. Se estima que como termine medio cada kilometro cuadrado de la superficie terrestre es golpeada cada millon de aiios por un meteorito con un pese superior a 500 gramos. La mayoria se pierden en los oceanos 0 caen en regiones con escasa poblacion. Como resultado, los museos en el munda reciben anualmente tan solo alrededor de 6 meteoritos cuya caida fuera atestiguada. Otros llegan por hallazgos casuales que en la mayoria de los casos son meteoritos que han cardo en tiempos prehistoricos.

  3. The Cretaceous-Tertiary extinction: A lethal mechanism involving anhydrite target rocks

    USGS Publications Warehouse

    Brett, R.

    1992-01-01

    The Chicxulub Crater, Yucatan, Mexico, is a leading contender as the site for the impact event that caused the Cretaceous-Tertiary (K-T) extinctions. A considerable thickness of anhydrite (CaSO4) forms part of the target rock. High temperatures resulting from impact would drive SO2 off from the anhydrite. Hundreds of billions of tonnes of sulfuric acid aerosol would thus enter the stratosphere and cause considerable cooling of the Earth's surface, decrease photosynthesis by orders of magnitude, deplete the ozone layer, and permit increased UV radiation to reach the Earth's surface. Finally, the aerosol would fall back to Earth as acid rain and devastate land and some lacustrine biota and near-surface marine creatures. The presence of anhydrite in the Chicxulub target rock may thus help explain the many extinctions observed at the K-T boundary. ?? 1992.

  4. Como Lo Hago Yo: Myelomeningocele

    PubMed Central

    Lazareff, Jorge

    2014-01-01

    Fortificación con ádico fólico es efectiva, pero aún falta conciencia en los jóvenes. La legalidad del aborto aumenta la importancia de la consulta prenatal. Realizo la cirugía bajo microcoscopio por razones didácticas. Irrigación continua para reducir la temperatura del tejido. Trato a la plaqueta como tejido viable. No suturo la plaqueta. No cierro músculo. ATB por una semana después de cirugía. Hidrocefalia: Válvula en todos los casos de ventriculomegalia. Médula anclada: Desanclar una sola vez. Chiari II: Revisar la válvula. Incluir en el seguimiento rendimiento escolar, puede indicar obstrucción de la válvula o médula anclada. PMID:24791217

  5. Effects of endogenous small molecular compounds on the rheological properties, texture and microstructure of soymilk coagulum: Removal of phytate using ultrafiltration.

    PubMed

    Wang, Ruican; Guo, Shuntang

    2016-11-15

    This study aims to clarify the roles played by endogenous small molecular components in soymilk coagulation process and the properties of gels. Soymilk samples with decreasing levels of small molecules were prepared by ultrafiltration, to reduce the amount of phytate and salts. CaSO4-induced coagulation process was analyzed using rheological methods. Results showed that removal of free small molecules decreased the activation energy of protein coagulation, resulting in accelerated reaction and increased gel strength. However, too fast a reaction led to the drop in storage modulus (G'). Microscopic observation suggested that accelerated coagulation generated a coarse and non-uniform gel network with large pores. This network could not hold much water, leading to serious syneresis. Endogenous small molecules in soymilk were vital in the fine gel structure. Coagulation rate could be controlled by adjusting the amount of small molecules to obtain tofu products with the optimal texture. PMID:27283662

  6. Adsorption of anionic and cationic polymers on porous and non-porous calcium carbonate surfaces

    NASA Astrophysics Data System (ADS)

    Bjorklund, Robert B.; Arwin, Hans; Järnström, Lars

    1994-01-01

    The adsorption of anionic and cationic polymers onto calcium carbonate surfaces was studied by ellipsometry. Sodium polyacrylate was observed to both adsorb on and promote dissolution of polished limestone surfaces in 5 mM CaSO 4 solution at pH 10.3. It was not possible to differentiate between the two processes when they occurred simultaneously. Cationic starch adsorbed on the limestone surfaces at low concentrations and caused mineral dissolution at higher concentrations. The adsorbed amount of starch was higher on surfaces which were first made porous by partial dissolution than on freshly polished surfaces. Surfaces created by cleavage of Iceland spar calcite were quite stable against dissolution and the amount of starch adsorbed determined by ellipsometry agreed well with the adsorbed mass determined from batch adsorption experiments on ground calcite.

  7. New sintered thermoluminescent dosimeters for personnel and environmental dosimetry.

    PubMed

    Prokic, M S

    1982-06-01

    We discuss the development of an original method preparing thermoluminescent dosimeters using magnesium borate and calcium sulfate materials activated with rare earths. This method is based upon the effect of sensitized thermoluminescent emission of basic TLD phosphors as well as on the method for producing these in solid form. Our technique resulted in unique TLD's in the form of sintered thermoluminescent dosimeters. For one of these, MgB4O7:RE+, the thermoluminescent response is up to five times more sensitive than non-sensitized magnesium borate thermoluminescent material. The other TLD, CaSO4:RE+, has dosimetric characteristics which stay unchanged and are equivalent with characteristics of the well-known calcium sulfate TLD phosphors. These new types of sintered TLD's are highly promising for personnel and environmental dosimetry. PMID:7107292

  8. Study of minimum detection limit of TLD personnel monitoring system in India.

    PubMed

    Sneha, C; Pradhan, S M; Adtani, M M

    2010-09-01

    Personnel monitoring of radiation workers in India is carried out using a thermoluminescence dosemeter (TLD) system based on CaSO(4):Dy Teflon TLD disc. The dose due to occupational exposure for a majority of radiation workers is very small and hence is reported as zero. In view of this the detection of low levels of occupational dose over and above a variable background assumes great importance. The present values of reporting levels are based on the standard deviations of annealed dosemeters and therefore are fixed irrespective of period of use and background radiation levels. The validity of these levels is investigated under laboratory conditions. The laboratory values of standard deviations cannot be used as an indication of the imprecision that occurs during service. Therefore, the validity of the reporting levels is also investigated for control dosemeters used in routine service. PMID:20511403

  9. Evaluation of two thermoluminescent detection systems for medical imaging environments.

    PubMed

    Kearfott, K J; Nabelssi, B K; Rucker, R H; Klingler, G W

    1990-12-01

    Thermoluminescent detectors (TLDs) can provide accurate and precise measurements for both patient and personnel dosimetry in the medical imaging environment. They have the advantages of tissue equivalency, an excellent dynamic range, and dose rate independence. In the work reported here, experiments with planar x-ray, fluoroscopy, and a 57Co source were conducted to test the repeatability and energy dependence of an LiF TL ribbon/automatic reader system and a four-element CaSO2 and Li2B4O7 badge/automatic reader system for diagnostic radiology and nuclear medicine dosimetry. The results indicate the usefulness and appropriateness of the TLD systems tested for both personnel and patient dosimetry in the medical diagnostic environment. PMID:2228610

  10. Development of an algorithm for evaluating personal doses due to photon fields in terms of operational quantities for TLD badge system in India.

    PubMed

    Pradhan, S M; Sneha, C; Chourasiya, G; Adtani, M M; Tripathi, S M; Singh, S K

    2009-09-01

    In order to evaluate and report the personal doses in terms of personal dose equivalent, the performance of the CaSO(4):Dy based thermoluminescence dosemeter (TLD) badge used for countrywide personnel monitoring in India is investigated using monoenergetic and narrow spectrum radiation qualities equivalent to those given in ISO standards. Algorithms suitable for evaluating H(p)(10) and H(p)(0.07) within +/- 30 % are developed from the responses of dosemeter elements/discs under different filters for normal as well as angular irradiation conditions using these beams. The algorithm is tested for TLD badges irradiated to mixtures of low- and high-energy ((137)Cs) beams in various proportions. The paper concludes with the results of test of algorithm by evaluation of badges used in the IAEA/RCA intercomparison studies and discussion on inherent limitations. PMID:19755432