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Sample records for hastelloy n

  1. Corrosion characteristics of Hastelloy N alloy after He+ ion irradiation

    International Nuclear Information System (INIS)

    Lin Jianbo; Yu Xiaohan; Li Aiguo; He Shangming; Cao Xingzhong; Wang Baoyi; Li Zhuoxin

    2014-01-01

    With the goal of understanding the invalidation problem of irradiated Hastelloy N alloy under the condition of intense irradiation and severe corrosion, the corrosion behavior of the alloy after He + ion irradiation was investigated in molten fluoride salt at 700 °C for 500 h. The virgin samples were irradiated by 4.5 MeV He + ions at room temperature. First, the virgin and irradiated samples were studied using positron annihilation lifetime spectroscopy (PALS) to analyze the influence of irradiation dose on the vacancies. The PALS results showed that He + ion irradiation changed the size and concentration of the vacancies which seriously affected the corrosion resistance of the alloy. Second, the corroded samples were analyzed using synchrotron radiation micro-focused X-ray fluorescence, which indicated that the corrosion was mainly due to the dealloying of alloying element Cr in the matrix. Results from weight-loss measurement showed that the corrosion generally correlated with the irradiation dose of the alloy. (author)

  2. Status of tellurium--hastelloy N studies in molten fluoride salts

    International Nuclear Information System (INIS)

    Keiser, J.R.

    1977-10-01

    Tellurium, which is a fission product in nuclear reactor fuels, can embrittle the surface grain boundaries of nickel-base structural materials. This report summarizes results of an experimental investigation conducted to understand the mechanism and to develop a means of controlling this embrittlement in the alloy Hastelloy N. The addition of a chromium telluride to salt can be used to provide small partial pressures of tellurium simulating a reactor environment where tellurium appears as a fission product. The intergranular embrittlement produced in Hastelloy N when exposed to this chromium telluride-salt mixture can be reduced by adding niobium to the Hastelloy N or by controlling the oxidation potential of the salt in the reducing range

  3. Long-term corrosion behaviors of Hastelloy-N and Hastelloy-B3 in moisture-containing molten FLiNaK salt environments

    International Nuclear Information System (INIS)

    Ouyang, Fan-Yi; Chang, Chi-Hung; Kai, Ji-Jung

    2014-01-01

    Highlights: •Corrosion behaviors of Hastelloy-N and -B3 in molten FLiNaK salt at 700 °C. •The alleviated corrosion rate of alloys was observed after long-hour immersion. •Long-term corrosion rate was limited by diffusion from matrix to alloy surface. •Corrosion pattern transferred from intergranular corrosion into general corrosion. •Presence of minor H 2 O did not greatly influence the long-term corrosion behavior. -- Abstract: This study investigated long-term corrosion behaviors of Ni-based Hastelloy-N and Hastelloy-B3 under moisture-containing molten alkali fluoride salt (LiF–NaF–KF: 46.5–11.5–42%) environment at an ambient temperature of 700 °C. The Hastelloy-N and Hastelloy-B3 experienced similar weight losses for tested duration of 100–1000 h, which was caused by aggregate dissolution of Cr and Mo into FLiNaK salts. The corrosion rate of both alloys was high initially, but then reduced during the course of the test. The alleviated corrosion rate was due to the depletion of Cr and Mo near surface of the alloys and thus the long-term corrosion rate was controlled by diffusion of Cr and Mo outward to the alloy surface. The results of microstructural characterization revealed that the corrosion pattern for both alloys tended to be intergranular corrosion at early stage of corrosion test, and then transferred to general corrosion for longer immersion hours

  4. Composition of eta carbide in Hastelloy N after aging 10,000 hr at 8150C

    International Nuclear Information System (INIS)

    Leitnaker, J.M.; Potter, G.A.; Bradley, D.J.; Franklin, J.C.; Laing, W.R.

    1977-11-01

    The composition of the eta carbide in Hastelloy N containing 0.7 wt percent Si in the alloy approaches M 12 C, rather than M 6 C as indicated in the alloy literature. The silicon content of the eta phase in this case was about 25 at. percent, much higher than has been observed in less highly alloyed material. The data do not permit a definition of the limiting compositions of the phases

  5. ERDA, RBS, TEM and SEM characterization of microstructural evolution in helium-implanted Hastelloy N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jie [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China); Bao, Liangman [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Huang, Hefei, E-mail: huanghefei@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, Yan, E-mail: liyan@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Lei, Qiantao [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Deng, Qi [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Liu, Zhe; Yang, Guo [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China); Shi, Liqun [Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2017-05-15

    Hastelloy N alloy was implanted with 30 keV, 5 × 10{sup 16} ions/cm{sup 2} helium ions at room temperature, and subsequent annealed at 600 °C for 1 h and further annealed at 850 °C for 5 h in vacuum. Using elastic recoil detection analysis (ERDA) and transmission electron microscopy (TEM), the depth profiles of helium concentration and helium bubbles in helium-implanted Hastelloy N alloy were investigated, respectively. The diffusion of helium and molybdenum elements to surface occurred during the vacuum annealing at 850 °C (5 h). It was also observed that bubbles in molybdenum-enriched region were much larger in size than those in deeper region. In addition, it is worth noting that plenty of nano-holes can be observed on the surface of helium-implanted sample after high temperature annealing by scanning electron microscope (SEM). This observation provides the evidence for the occurrence of helium release, which can be also inferred from the results of ERDA and TEM analysis.

  6. Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, D.H.; Chen, H.C.; Lei, G.H.; Huang, H.F.; Zhang, W.; Wang, C.B. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Yan, L., E-mail: yanlong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Fu, D.J. [Key Laboratory of Artificial Micro-and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Tang, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2017-06-15

    The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness. - Highlights: •Irradiation Swelling: The irradiation induced volumetric swelling increases with ion dose. •Irradiation Hardening: The irradiation hardening initiates below 1 dpa, then saturates with higher ion dose (1–10 dpa). •Irradiation Mechanism: The irradiation phenomena are ascribed to the microstructural evolution of the irradiation defects.

  7. Electrochemical impedance spectrometry using 316L steel, hastelloy, maraging, Inconel 600, Elgiloy, carbon steel, TiN and NiCr. Simulation in tritiated water. 2 volumes

    International Nuclear Information System (INIS)

    Bellanger, G.

    1994-03-01

    Polarization and electrochemical impedance spectrometry curves are presented and discussed. These curves make it possible to ascertain the corrosion domains and to compare the slow and fast kinetics (voltammetry) of different stainless steel alloys. These corrosion kinetics, the actual or simulated tritiated water redox potentials, and the corrosion potentials provide a classification of the steels studied here: 316L, Hastelloy, Maraging, Inconel 600, Elgiloy, carbon steel and TiN and NiCr deposits. From the results it can be concluded that Hastelloy and Elgiloy have the best corrosion resistance. (author). 49 refs., 695 figs., tabs

  8. Electrochemical impedance spectrometry using 316L steel, hastelloy, maraging, Inconel 600, Elgiloy, carbon steel, TiN and NiCr. Simulation in tritiated water. 2 volumes; Spectrometrie d`impedance electrochimique sur acier 316L, hastelloy, maraging inconel 600, elgiloy, acier au carbone, TiN, NiCr. Simulations en eau tritiee. 2 volumes

    Energy Technology Data Exchange (ETDEWEB)

    Bellanger, G.

    1994-03-01

    Polarization and electrochemical impedance spectrometry curves are presented and discussed. These curves make it possible to ascertain the corrosion domains and to compare the slow and fast kinetics (voltammetry) of different stainless steel alloys. These corrosion kinetics, the actual or simulated tritiated water redox potentials, and the corrosion potentials provide a classification of the steels studied here: 316L, Hastelloy, Maraging, Inconel 600, Elgiloy, carbon steel and TiN and NiCr deposits. From the results it can be concluded that Hastelloy and Elgiloy have the best corrosion resistance. (author). 49 refs., 695 figs., tabs.

  9. Compatibility studies of type 316 stainless steel and Hastelloy N in KNO3--NaNO2--NaNO3

    International Nuclear Information System (INIS)

    Devan, J.H.; Keiser, J.R.

    1978-01-01

    The nitrate-based fused salt mixture KNO 3 --NaNO 2 --NaNO 3 (44--49--7 mol %) has been widely used as a heat transport fluid and for metallurgical heat-treating. We have measured the corrosion rate of this salt in the presence of a temperature gradient for an iron-base material, type 316 stainless steel, and a nickel-base material, Hastelloy N. Corrosion rates were measured with maximum loop temperatures of 431 and 504 0 C. Measured corrosion rates were in all cases less than 8 μm/year

  10. Relaxation characteristics of hastelloy X

    International Nuclear Information System (INIS)

    Suzuki, Kazuhiko

    1980-02-01

    Relaxation diagrams of Hastelloy X (relaxation curves, relaxation design diagrams, etc.) were generated from the creep constitutive equation of Hastelloy X, using inelastic stress analysis code TEPICC-J. These data are in good agreement with experimental relaxation data of ORNL-5479. Three typical inelastic stress analyses were performed for various relaxation behaviors of the high-temperature structures. An attempt was also made to predict these relaxation behaviors by the relaxation curves. (author)

  11. Influencia de los parámetros de soldeo fuerte en la microestructura y propiedades mecánicas de la unión de la aleación base níquel Hastelloy B2

    Directory of Open Access Journals (Sweden)

    Sotelo, José Carlos

    2014-09-01

    Full Text Available A study of the high vacuum brazing process of solid solution strengthened Hastelloy B2 nickel alloy has been done. A first stage of research has focused on the selection of the most appropriate brazing filler metal to the base material and vacuum furnace brazing process. The influence of welding parameters on joint microstructure constituents, relating the microstructure of the joint to its mechanical properties, has been evaluated. Two gaps of 50 and 200 micrometers, and two dwell times at brazing temperature of 10 and 90 minutes were studied. The braze joint mainly consists of the nickel rich matrix, nickel silicide and ternary compounds. Finally, the results of this study have shown the high bond strength for small gaps and increased dwell times of 90 minutes.Se realizó un estudio pormenorizado del proceso de soldeo fuerte en horno de alto vacío de la aleación base níquel Hastelloy B2 fortalecida por solución sólida. En una primera fase del trabajo se seleccionó el material de aporte acorde al material objeto de unión y a la fuente de calentamiento seleccionada. Posteriormente, se evaluó la influencia del gap (50 y 200 micrómetros y tiempo de permanencia a temperatura de soldeo (10 y 90 minutos sobre los microconstituyentes de la unión, relacionando la microestructura con las propiedades mecánicas de la junta. Los análisis metalográficos mostraron una unión constituida por una matriz rica en níquel, siliciuros de níquel y compuestos ternarios. Finalmente, los resultados de los ensayos mecánicos a esfuerzos cortantes mostraron una elevada resistencia para gaps de 50 micrómetros y tiempos de permanencia de 90 minutos.

  12. Design fatigue curve for Hastelloy-X

    International Nuclear Information System (INIS)

    Nishiguchi, Isoharu; Muto, Yasushi; Tsuji, Hirokazu

    1983-12-01

    In the design of components intended for elevated temperature service as the experimental Very High-Temperature gas-cooled Reactor (VHTR), it is essential to prevent fatigue failure and creep-fatigue failure. The evaluation method which uses design fatigue curves is adopted in the design rules. This report discussed several aspects of these design fatigue curves for Hastelloy-X (-XR) which is considered for use as a heat-resistant alloy in the VHTR. Examination of fatigue data gathered by a literature search including unpublished data showed that Brinkman's equation is suitable for the design curve of Hastelloy-X (-XR), where total strain range Δ epsilon sub(t) is used as independent variable and fatigue life Nsub(f) is transformed into log(log Nsub(f)). (author)

  13. Study on the creep constitutive equation of Hastelloy X, (1)

    International Nuclear Information System (INIS)

    Hada, Kazuhiko; Mutoh, Yasushi

    1983-01-01

    A creep constitutive equation of Hastelloy X was obtained from available experimental data. A sensitivity analysis of this creep constitutive equation was carried out. As the result, the following were revealed: (i) Variations in creep behavior with creep constitutive equation are not small. (ii) In a simpler stress change pattern, variations in creep behavior are similar to those in the corresponding fundamental creep characteristics (creep strain curve, stress relaxation curve, etc.). (iii) Cumulative creep damage estimated in accordance with ASME Boiler and Pressure Vessel Code Case N-47 from a stress history predicted by ''the standard creep constitutive equation'' which predicts the average behavior of creep strain curve data is not thought to be on the safe side on account of uncertainties in creep damage caused by variations in creep strain curve. (author)

  14. Hastelloy X fuel element creep relaxation and residual effects

    International Nuclear Information System (INIS)

    Castle, R.A.

    1971-01-01

    A worst case, seven element, asymmetric fuel, thermal environment was assumed and a creep relaxation analysis generated. The fuel element clad is .020 inch Hastelloy X. The contact load decreased from 11.6 pounds to 5.87 pounds in 100,000 hours. The residual stresses were then computed for various shutdown times. (U.S.)

  15. Creep properties of Hastelloy X in a carburizing helium environment

    International Nuclear Information System (INIS)

    Nakanishi, T.; Kawakami, H.

    1982-01-01

    In this work, we investigate the environmental effect on the creep behavior of Hastelloy X at 900 0 C in helium and air. Since helium coolant in HTGR is expected to be carburizing and very weakly oxidizing for most metals, testings were focused on the effect of carburizing and slight oxidation. Carburization decreases secondary creep strain rate and delays tertiary creep initiation. On the other hand, the crack growth rate on the specimen surface is enhanced due to very weak oxidation in helium, therefore the tertiary creep strain rate becomes larger than that in air. The rupture time of Hastelloy X was shorter in helium when compared with in air. Stress versus rupture time curves for both environments do not deviate with each other during up to 5000 hours test, and a ratio of rupture stress in helium to that in air was about 0.9

  16. Study on the creep constitutive equation of Hastelloy X, (1)

    International Nuclear Information System (INIS)

    Suzuki, Kazuhiko; Mutoh, Yasushi

    1983-01-01

    In order to carry out the structural design of high temperature pipings, intermediate heat exchangers and isolating valves for a multipurpose high temperature gas-cooled reactor, in which coolant temperature reaches 1000 deg C, the creep characteristics of Hastelloy X used as the heat resistant material must be clarified. In addition to usual creep rupture life and the time to reach a specified creep strain, the dependence of creep strain curves on time, temperature and stress must be determined and expressed with equations. Therefore, using the creep data of Hastelloy X given in the literatures, the creep constitutive equation was made. Since the creep strain curves under the same test condition were different according to heats, the sensitivity analysis of the creep constitutive equation was performed. The form of the creep constitutive equation was determined to be Garofalo type. The result of the sensitivity analysis is reported. (Kako, I.)

  17. High temperature strength of Hastelloy XR under biaxial stress states

    International Nuclear Information System (INIS)

    Muto, Yasushi; Hada, Kazuhiko; Koikegami, Hajime; Ohno, Nobutada.

    1991-01-01

    Biaxial(tension/torsion) creep and creep-fatigue tests were conducted on Hastelloy XR at 950degC in air. Hastelloy XR is a nickel base solution-annealed heat resistant alloy. Thin-walled tubular test specimens were employed. As results of the creep tests, the von Mises' flow rule was revealed to be applicable very well. Under the torsion load, sufficient growth of voids was necessary to initiate the fracture and this resulted in longer life time compared with that under the tension load. Only a few number of small voids could be observed and very long life times were attained under the compression load. The creep-fatigue tests revealed that superposition of constant torsion load on a cyclic axial load reduced the cycles to failure significantly and the amount of reduction was consistent with the prediction by the linear life fraction rule. (author)

  18. Cavitation erosion behavior of Hastelloy C-276 nickel-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhen [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Han, Jiesheng; Lu, Jinjun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Chen, Jianmin, E-mail: chenjm@lzb.ac.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2015-01-15

    Highlights: • Cavitation erosion behavior of Hastelloy C-276 was studied by ultrasonic apparatus. • The cavitation-induced precipitates formed in the eroded surface for Hastelloy C-276. • The selective cavitation erosion was found in Hastelloy C-276 alloy. - Abstract: The cavitation erosion behavior of Hastelloy C-276 alloy was investigated using an ultrasonic vibratory apparatus and compared with that of 316L stainless steel. The mean depth of erosion (MDE) and erosion rate (ER) curves vs. test time were attained for Hastelloy C-276 alloy. Morphology and microstructure evolution of the eroded surface were observed by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) and the predominant erosion mechanism was also discussed. The results show that the MDE is about 1/6 times lower than that of the stainless steel after 9 h of testing. The incubation period of Hastelloy C-276 alloy is about 3 times longer than that of 316L stainless steel. The cavitation-induced nanometer-scaled precipitates were found in the local zones of the eroded surface for Hastelloy C-276. The selective cavitation erosion was found in Hastelloy C-276 alloy. The formation of nanometer-scaled precipitates in the eroded surface may play a significant role in the cavitation erosion resistance of Hastelloy C-276.

  19. Cavitation erosion behavior of Hastelloy C-276 nickel-based alloy

    International Nuclear Information System (INIS)

    Li, Zhen; Han, Jiesheng; Lu, Jinjun; Chen, Jianmin

    2015-01-01

    Highlights: • Cavitation erosion behavior of Hastelloy C-276 was studied by ultrasonic apparatus. • The cavitation-induced precipitates formed in the eroded surface for Hastelloy C-276. • The selective cavitation erosion was found in Hastelloy C-276 alloy. - Abstract: The cavitation erosion behavior of Hastelloy C-276 alloy was investigated using an ultrasonic vibratory apparatus and compared with that of 316L stainless steel. The mean depth of erosion (MDE) and erosion rate (ER) curves vs. test time were attained for Hastelloy C-276 alloy. Morphology and microstructure evolution of the eroded surface were observed by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) and the predominant erosion mechanism was also discussed. The results show that the MDE is about 1/6 times lower than that of the stainless steel after 9 h of testing. The incubation period of Hastelloy C-276 alloy is about 3 times longer than that of 316L stainless steel. The cavitation-induced nanometer-scaled precipitates were found in the local zones of the eroded surface for Hastelloy C-276. The selective cavitation erosion was found in Hastelloy C-276 alloy. The formation of nanometer-scaled precipitates in the eroded surface may play a significant role in the cavitation erosion resistance of Hastelloy C-276

  20. Comparison of creep behavior under varying load/temperature conditions between Hastelloy XR alloys with different boron content levels

    International Nuclear Information System (INIS)

    Tsuji, Hirokazu; Nakajima, Hajime; Shindo, Masami; Tanabe, Tatsuhiko; Nakasone, Yuji.

    1996-01-01

    In the design of the high-temperature components, it is often required to predict the creep rupture life under the conditions in which the stress and/or temperature may vary by using the data obtained with the constant load and temperature creep rupture tests. Some conventional creep damage rules have been proposed to meet the above-mentioned requirement. Currently only limited data are available on the behavior of Hastelloy XR, which is a developed alloy as the structural material for high-temperature components of the High-Temperature Engineering Test Reactor (HTTR), under varying stress and/or temperature creep conditions. Hence a series of constant load and temperature creep rupture tests as well as varying load and temperature creep rupture tests was carried out on two kinds of Hastelloy XR alloys whose boron content levels are different, i.e., below 10 and 60 mass ppm. The life fraction rule completely fails in the prediction of the creep rupture life of Hastelloy XR with 60 mass ppm boron under varying load and temperature conditions though the rule shows good applicability for Hastelloy XR with below 10 mass ppm boron. The change of boron content level of the material during the tests is the most probable source of impairing the applicability of the life fraction rule to Hastelloy XR whose boron content level is 60 mass ppm. The modified life fraction rule has been proposed based on the dependence of the creep rupture strength on the boron content level of the alloy. The modified rule successfully predicts the creep rupture life under the two stage creep test conditions from 1000 to 900degC. The trend observed in the two stage creep tests from 900 to 1000degC can be qualitatively explained by the mechanism that the oxide film which is formed during the prior exposure to 900degC plays the role of the protective barrier against the boron dissipation into the environment. (J.P.N.)

  1. Application of Hastelloy X in gas-cooled reactor systems

    International Nuclear Information System (INIS)

    Brinkman, C.R.; Rittenhouse, P.L.; Corwin, W.R.; Strizak, J.P.; Lystrup, A.; DiStefano, J.R.

    1976-10-01

    Hastelloy X, an Ni--Cr--Fe--Mo alloy, may be an important structural alloy for components of gas-cooled reactor systems. Expected applications of this alloy in the High-Temperature Gas-Cooled Reactor (HTGR) are discussed, and the development of interim mechanical properties and supporting data are reported. Properties of concern include tensile, creep, creep-rupture, fatigue, creep-fatigue interaction, subcritical crack growth, thermal stability, and the influence of helium environments with controlled amounts of impurities on these properties. In order to develop these properties in helium environments that are expected to be prototypic of HTGR operating conditions, it was necessary to construct special environmental test systems. Details of construction and operating parameters are described. Interim results from tests designed to determine the above properties are presented. To date a fairly extensive amount of information has been generated on this material at Oak Ridge National Laboratory and elsewhere concerning behavior in air, which is reviewed. However, only limited data are available from tests conducted in helium. Comparisons of the fatigue and subcritical growth behavior in air between Hastelloy X and a number of other structural alloys are given

  2. Evaluation of creep and relaxation data for hastelloy alloy x sheet

    International Nuclear Information System (INIS)

    Booker, M.K.

    1979-02-01

    Hastelloy alloy X has been a successful high-temperature structural material for more than two decades. Recently, Hastelloy alloy X sheet has been selected as a prime structural material for the proposed Brayton Isotope Power System (BIPS). The material also sees extensive application in the High-Temperature Gas-Cooled Reactor (HTGR). Design of these systems requires a detailed consideration of the high-temperature creep properties of this material. Therefore, available creep, creep-rupture, and relaxation data for Hastelloy alloy X were collected and analyzed to yield mathematical representations of the behavior for design use

  3. Creep properties of 20% cold-worked Hastelloy XR

    International Nuclear Information System (INIS)

    Kurata, Y.

    1996-01-01

    The creep properties of Hastelloy XR, in solution-treated and in 20% cold-worked conditions, were studied at 800, 900 and 1000 C. At 800 C, the steady-state creep rate and rupture ductility decrease, while rupture life increases after cold work to 20%. Although the steady-state creep rate and ductility also decrease at 900 C, the beneficial effect on rupture life disappears. Cold work to 20% enhan ces creep resistance of this alloy at 800 and 900 C due to a high density of dislocations introduced by the cold work. Rupture life of the 20% cold-worked alloy becomes shorter and the steady-state creep rate larger at 1000 C during creep of the 20% cold-worked alloy. It is emphasized that these cold work effects should be taken into consideration in design and operation of high-temperature structural components of high-temperature gas-cooled reactors. (orig.)

  4. The corrosion behavior of molybdenum and Hastelloy B in sulfur and sodium polysulfides at 623 K

    International Nuclear Information System (INIS)

    Brown, A.P.

    1987-01-01

    An experimental study was completed to determine the corrosion behavior of molybdenum and Hastelloy B, a nickel-based alloy with high molybdenum content, in sulfur and sodium polysulfides (Na/sub 2/S/sub 3/,Na/sub 2/S/sub 4/, Na/sub 2/S/sub 5/) at 623 K. In sulfur, molybdenum corrodes very slowly, with a parabolic rate constant of 3.6 x 10/sup -9/ cm s/sup -1/2/. Hastelloy B shows no measurable corrosion after 100h of exposure to sulfur. The corrosion reaction of molybdenum in Na/sub 2/S/sub 3/ is characterized by the formation of a protective film that effectively eliminates further corrosion after the first 100h of exposure. Hastelloy B, however, corrodes rapidly in Na/sub 2/S/sub 3/, with corrosion rates approaching those of pure nickel under the same conditions. After the first 4h of exposure, the kinetics for the corrosion of Hastelloy B in Na/sub 2/S/sub 3/ follows a linear rate law. The scale morphology has multiple spalled layers of NiS/sub 2/, with some crystallites of NiS/sub 2/ appearing on the leading face of the scale and between the individual scale layers. This spalling causes smaller coupons of the Hastelloy B to corrode faster than larger coupons

  5. Creep properties of EB welded joint on Hastelloy X

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Susei, Shuzo; Shimizu, Shigeki; Satoh, Keisuke; Nagai, Hiroyoshi.

    1980-01-01

    In order to clarify the creep properties of EB welds on Hastelloy X which is one of the candidate alloys for components of VHTR, creep tests on EB weld metal and welded joint were carried out. The results were discussed in comparison with those of base metal and TIG welds. Further, EB welds were evaluated from the standpoint of high temperature structural design. The results obtained are summarized as follows. 1) Both creep rupture strengths of EB weld metal and EB welded joint are almost equal to that of base metal, but those of TIG welds are lower than base metal. As for the secondary creep rate, EB weld metal is higher and TIG weld metal is lower than base metal. As for the time to onset of tertiary creep, no remarkable difference among base metal, EB weld metal and TIG weld metal is observed. 2) In case of EB weld metal, although anisotropy is slightly observed, the ductility is same or more as compared with base metal. In case of TIG weld metal, on the contrary, anisotropy is not observed and the ductility is essentially low. 3) Such rupture morphology of EB weld metal as appears to have resulted from interconnection of voids which occurred at grain boundary is similar to base metal. In case of TIG weld metal, however, many cracks with sharp tips are observed at grain boundary, and the rupture appears to have occurred in brittle by propagation and connection of the cracks. 4) It can be said from the standpoint of high temperature structural design that EB welding is very suitable to welding for structure where creep effects are significant, because both of the creep ductility and the rupture strength are almost equal to those of base metal. (author)

  6. Applicability of creep damage rules to a nickel-base heat-resistant alloy Hastelloy XR

    International Nuclear Information System (INIS)

    Tsuji, Hirokazu; Nakajima, Najime; Tanabe, Tatsuhiko; Nakasone, Yuji

    1992-01-01

    A series of constant load and temperature creep rupture tests and varying load and/or temperature creep rupture tests was carried out on a nickel-base heat-resistant alloy Hastelloy XR, which was developed for applications in the High-Temperature Engineering Test Reactor, at temperatures ranging from 850 to 1000deg C in order to examine the applicability of the conventional creep damage rules, i.e., the life fraction, the strain fraction and their mixed rules. The life fraction rule showed the best applicability of these three criteria. The good applicability of the rule was considered to result from the fact that the creep strength of Hastelloy XR was not strongly affected by the change of the chemical composition and/or the microstructure during exposure to the high-temperature simulated HTGR helium environment. In conclusion the life fraction rule is applicable in engineering design of high-temperature components made of Hastelloy XR. (orig.)

  7. Creep properties of hastelloy x and their application to the structural design

    International Nuclear Information System (INIS)

    Kiyoshige, Masanori; Murase, Hirokazu; Fujioka, Junzo; Shimizu, Shigeki; Satoh, Keisuke.

    1978-01-01

    In the creep curve of Hastelloy X, it was difficult to divide it into the three stages of creep. However, these stages were made distinguishable by plotting the relationship between creep rates and time in double-logarithmic coordinates. All the creep data of Hastelloy X, except the isochronous stress-strain curves, required for determining the design stress intensities S sub(o) and S sub(t) were arranged through the Larson-Miller parameter. The isochronous stress-strain curves for a heat of Hastelloy X were derived from the constitutive equations obtained from short-term data. A fairly good agreement between the predicted data and the experimental data was obtained. (auth.)

  8. Influence of temperature, environment, and thermal aging on the continuous cycle fatigue behavior of Hastelloy X and Inconel 617

    International Nuclear Information System (INIS)

    Strizak, J.P.; Brinkman, C.R.; Booker, M.K.; Rittenhouse, P.L.

    1982-04-01

    Results are presented for strain-controlled fatigue and tensile tests for two nickel-base, solution-hardened reference structural alloys for use in several High-Temperature Gas-Cooled Reactor (HTGR) concepts. These alloys, Hastelloy X and Inconel 617, were tested from room temperature to 871 0 C in air and impure helium. Materials were tested in both the solution-annealed and the preaged conditios, in which aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are given between the strain-controlled fatigue lives of these and several other commonly used alloys, all tested at 538 0 C. An analysis is also presented of the continuous cycle fatigue data obtained from room temperature to 427 0 C for Hastelloy G, Hastelloy X, Hastelloy C-276, and Hastelloy C-4, an effort undertaken in support of ASME code development

  9. FINITE ELEMENT ANALYSIS OF HASTELLOY C-22HS IN END MILLING

    Directory of Open Access Journals (Sweden)

    K. Kadirgama

    2011-12-01

    Full Text Available This paper presents a finite element analysis of the stress distribution in the end milling operation of nickel-based superalloy HASTELLOY C-2000. Commercially available finite element software was used to develop the model and analyze the distribution of stress components in the machined surface of HASTELLOY C-22HS following end milling with coated carbide tools. The friction interaction along the tool-chip interface was modeled using the Coulomb friction law. It was found that the stress had lower values under the cut surface and that it increased gradually near the cutting edge.

  10. Effect of temperature upon the fatigue-crack propagation behavior of Hastelloy X-280

    International Nuclear Information System (INIS)

    James, L.A.

    1976-05-01

    The techniques of linear-elastic fracture mechanics were employed to characterize the effect of temperature upon the fatigue-crack propagation behavior of Hastelloy X-280 in an air environment. Also included in this study are survey tests to determine the effects of thermal aging and stress ratio upon crack growth behavior in this alloy

  11. Creep properties of Hastelloy X and their application to structural design

    International Nuclear Information System (INIS)

    Kiyoshige, Masanori; Murase, Koichi; Fujioka, Junzo; Shimizu, Shigeki; Satoh, Keisuke

    1977-01-01

    Creep and stress rupture tests on three heats of Hastelloy X differing in the manufacturing process were carried out at 800 0 C, 900 0 C and 1000 0 C. Interpretation of the observed creep properties was made, and a method for predicting necessary design data from the experimentally obtained results was discussed. The results are as follows. (1) It was difficult to separate the primary, secondary and tertiary creep stages in the creep curve of Hastelloy X of the present tests. However, those were made distinguishable by plotting the results in a double-logarithmic coordinates. From these creep rate curves, the primary and secondary creep rates and the times to the initiation of secondary and tertiary creeps were derived. (2) It is considered that the same stress and temperature dependences between the primary and secondary creep rates exist in the creep behaviour of Hastelloy X of the present tests. (3) All the creep data, except the isochronous stress-strain curve, required for the design such as stress vs. rupture time, stress vs. secondary creep rate and stress vs. time to initiation of tertiary creep could be arranged through the Larson-Miller parameter. On the other hand, the isochronous stress-strain curve was figured out by estimating creep curves. The constitutive equations of creep for a heat of Hastelloy X proposed in this paper and the isochronous stress-strain curves derived from these constitutive equations were consistent with the experimental data obtained for the corresponding material. (auth.)

  12. Oxidation in air of two refractory alloys (Nicral D and Hastelloy X) at 900 and 1100 deg. C

    International Nuclear Information System (INIS)

    Sannier, J.; Dominget, R.; Darras, R.

    1960-01-01

    The oxidation in air of two refractory alloys (Nicral D and Hastelloy X) has been studied at 900 and 1100 deg. C, by means of recording thermo-balances and microscopic cross section examination. At 900 deg. C, the surface oxidation rates of the two alloys are quite similar, but at 1100 deg. C the alloy Nicral D oxidizes faster than the alloy Hastelloy X. On the other hand, after heating at 1100 deg. C for 150 hours, Nicral D shows both intergranular oxidation and a small amount of internal oxidation, whereas Hastelloy X is especially subject to internal oxidation. In addition, two descaling methods were compared: an electrolytic method, in a sodium hydroxide-sodium carbonate bath, and a chemical method using a sodium nitrate-sodium peroxide bath; the latter appears suitable only for Hastelloy X. Reprint of a paper published in Journal of nuclear materials, 3, p. 213-225, 1959 [fr

  13. Microstructures, mechanical properties and corrosion resistance of Hastelloy C22 coating produced by laser cladding

    International Nuclear Information System (INIS)

    Wang, Qin-Ying; Zhang, Yang-Fei; Bai, Shu-Lin; Liu, Zong-De

    2013-01-01

    Highlights: ► Hastelloy C22 coatings were prepared by diode laser cladding technique. ► Higher laser speed resulted in smaller grain size. ► Size-effect played the key role in the hardness measurements by different ways. ► Coating with higher laser scanning speed displayed higher nano-scratch resistance. ► Small grain size was beneficial for improvement of coating corrosion resistance. -- Abstract: The Hastelloy C22 coatings H1 and H2 were prepared by laser cladding technique with laser scanning speeds of 6 and 12 mm/s, respectively. Their microstructures, mechanical properties and corrosion resistance were investigated. The microstructures and phase compositions were studied by metallurgical microscope, scanning electron microscope and X-ray diffraction analysis. The hardness and scratch resistance were measured by micro-hardness and nanoindentation tests. The polarization curves and electrochemical impedance spectroscopy were tested by electrochemical workstation. Planar, cellular and dendritic solidifications were observed in the coating cross-sections. The coatings metallurgically well-bonded with the substrate are mainly composed of primary phase γ-nickel with solution of Fe, W, Cr and grain boundary precipitate of Mo 6 Ni 6 C. The hardness and corrosion resistance of steel substrate are significantly improved by laser cladding Hastelloy C22 coating. Coating H2 shows higher micro-hardness than that of H1 by 34% and it also exhibits better corrosion resistance. The results indicate that the increase of laser scanning speed improves the microstuctures, mechanical properties and corrosion resistance of Hastelloy C22 coating

  14. Weldability and weld performance of a special grade Hastelloy-X modified for high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Shimizu, S.; Mutoh, Y.

    1984-01-01

    The characteristics of weld defects in the electron beam (EB) welding and the tungsten inert gas (TIG) arc welding for Hastelloy-XR, a modified version of Hastelloy-X, are clarified through the bead-on-plate test and the Trans-Varestraint test. Based on the results, weldabilities on EB and TIG weldings for Hastelloy-XR are discussed and found to be almost the same as Hastelloy-X. The creep rupture behaviors of the welded joints are evaluated by employing data on creep properties of the base and the weld metals. According to the evaluation, the creep rupture strength of the EB-welded joint may be superior to that of the TIG-welded joint. The corrosion test in helium containing certain impurities is conducted for the weld metals. There is no significant difference of such corrosion characteristics as weight gain, internal oxidation, depleted zone, and so on between the base and the weld metals. Those are superior to Hastelloy-X

  15. Corrosion tests of 316L and Hastelloy C-22 in simulated tank waste solutions

    International Nuclear Information System (INIS)

    Danielson, M.J.; Pitman, S.G.

    2000-01-01

    Both the 316L stainless steel and Hastelloy C-22 gave satisfactory corrosion performance in the simulated test environments. They were subjected to 100 day weight loss corrosion tests and electrochemical potentiodynamic evaluation. This activity supports confirmation of the design basis for the materials of construction of process vessels and equipment used to handle the feed to the LAW-melter evaporator. BNFL process and mechanical engineering will use the information derived from this task to select material of construction for process vessels and equipment

  16. Effect of grain size and cold working on high temperature strength of Hastelloy X

    International Nuclear Information System (INIS)

    Fujioka, J.; Murase, H.; Matsuda, S.

    1980-01-01

    Effect of grain size and cold working on creep, creep rupture, low cycle fatigue and tensile strengths of Hastelloy X were studied at temperatures ranging from 800 to 1000 0 C. In order to apply these data to design, the allowable design stresses were estimated by expanding the criteria of ASME Code Case 1592 to such a high temperature range. The allowable design stress increased, on the other hand, the low cycle fatigue life decreased with increasing grain size. Cold working up to a ratio of 5 per cent may not be a serious problem in design, because the allowable design stress and the fatigue life were little affected. The cause of these variations in strength was discussed by examining the initiation and growth of cracks, and the microstructures. (author)

  17. Creep curve formularization at 950degC for Hastelloy XR

    International Nuclear Information System (INIS)

    Kaji, Yoshiyuki; Muto, Yasushi

    1991-03-01

    Creep tests under constant stress were conducted on a nickel-base heat-resistant alloy, Hastelloy XR, in air at 950degC. Minimum creep strain rate, time to the onset of tertiary creep and time to rupture were obtained as a function of applied stress. Then, a creep constitutive equation was made based on the Garofalo formula for primary and secondary creep and based on the Kachanov-Rabotnov formula for tertiary creep, which could represent fairly well the experimental creep deformation curves under the constant stress conditions. The creep deformation under the constant load condition corresponding to the stress increment was analysed using the creep constitutive equation and strain hardening law. Then the calculated creep strain showed slightly higher value than the experimental creep strain, and the calculated life was shorter than the experimental one. (author)

  18. Metallurgical and environmental factors influencing creep behaviour of hastelloy-X

    International Nuclear Information System (INIS)

    Kiuchi, Kiyoshi; Kondo, Tatsuo

    1979-03-01

    Creep and rupture behaviours of Hastelloy-X and its modified version were examined with special reference to the effect of different test environments; i.e. air, high vacuum and the simulated HTR helium coolant. The respective environments showed different effects. The vacuum environment of about 10 -8 torr. gave best reproducible behaviour with essentially no surface-to-volume ratio effect. Such size effect was significant in the other two environments. The simulated HTR environment was characterized in its potentiality of both oxidizing selected alloy constituents and carburization. The observed behaviour was attributed to the depletion of strengthning solute elements caused by the surface reactions and the associated solid state reactions. (author)

  19. Creep curve modeling of hastelloy-X alloy by using the theta projection method

    International Nuclear Information System (INIS)

    Woo Gon, Kim; Woo-Seog, Ryu; Jong-Hwa, Chang; Song-Nan, Yin

    2007-01-01

    To model the creep curves of the Hastelloy-X alloy which is being considered as a candidate material for the VHTR (Very High Temperature gas-cooled Reactor) components, full creep curves were obtained by constant-load creep tests for different stress levels at 950 C degrees. Using the experimental creep data, the creep curves were modeled by applying the Theta projection method. A number of computing processes of a nonlinear least square fitting (NLSF) analysis was carried out to establish the suitably of the four Theta parameters. The results showed that the Θ 1 and Θ 2 parameters could not be optimized well with a large error during the fitting of the full creep curves. On the other hand, the Θ 3 and Θ 4 parameters were optimized well without an error. For this result, to find a suitable cutoff strain criterion, the NLSF analysis was performed with various cutoff strains for all the creep curves. An optimum cutoff strain range for defining the four Theta parameters accurately was found to be a 3% cutoff strain. At the 3% cutoff strain, the predicted curves coincided well with the experimental ones. The variation of the four Theta parameters as the function of a stress showed a good linearity, and the creep curves were modeled well for the low stress levels. Predicted minimum creep rate showed a good agreement with the experimental data. Also, for a design usage of the Hastelloy-X alloy, the plot of the log stress versus log the time to a 1% strain was predicted, and the creep rate curves with time and a cutoff strain at 950 C degrees were constructed numerically for a wide rang of stresses by using the Theta projection method. (authors)

  20. A possibility of enhancing Jc in MgB2 film grown on metallic hastelloy tape with the use of SiC buffer layer

    International Nuclear Information System (INIS)

    Putri, W. B. K.; Kang, B.; Ranot, M.; Lee, J. H.; Kang, W. N.

    2014-01-01

    We have grown MgB 2 on SiC buffer layer by using metallic Hastelloy tape as the substrate. Hastelloy tape was chosen for its potential practical applications, mainly in the power cable industry. SiC buffer layers were deposited on Hastelloy tapes at 400, 500, and 600 degrees C by using a pulsed laser deposition method, and then by using a hybrid physical-chemical vapor deposition technique, MgB 2 films were grown on the three different SiC buffer layers. An enhancement of critical current density values were noticed in the MgB 2 films on SiC/Hastelloy deposited at 500 and 600 degrees C. From the surface analysis, smaller and denser grains of MgB 2 tapes are likely to cause this enhancement. This result infers that the addition of SiC buffer layers may contribute to the improvement of superconducting properties of MgB 2 tapes.

  1. Etude expérimentale du soudage par laser YAG de l'alliage base nickel Hastelloy X Experimental study of YAG laser welding of nickel base alloy Hastelloy X

    Directory of Open Access Journals (Sweden)

    Graneix Jérémie

    2013-11-01

    Full Text Available Le procédé de soudage laser YAG est envisagé pour remplacer le procédé de soudage TIG manuel pour la réalisation de pièces de turboréacteur en alliage nickel-chrome-molybdène Hastelloy X. Cette étude expérimentale a permis de définir un domaine de soudabilité de cet alliage répondant aux critères spécifiques du secteur aéronautique. The YAG laser welding process is contemplated to replace the manual TIG welding process for the production of parts of turbojet in Hastelloy X. This experimental study has identified the field of weldability of this alloy to meet the specific requirements of the aerospace industry.

  2. Creep properties of base metal and welded joint of Hastelloy XR produced for High-Temperature Engineering Test Reactor in simulated primary coolant helium

    International Nuclear Information System (INIS)

    Kurata, Yuji; Tsuji, Hirokazu; Shindo, Masami; Suzuki, Tomio; Tanabe, Tatsuhiko; Mutoh, Isao; Hiraga, Kenjiro

    1999-01-01

    Creep tests of base metal, weld metal and welded joint of Hastelloy XR, which had the same chemical composition as Hastelloy XR produced for an intermediate heat exchanger of the High-Temperature Engineering Test Reactor, were conducted in simulated primary coolant helium. The weld metal and welded joint showed almost equal to or longer rupture time than the base metal of Hastelloy XR at 850 and 900degC, although they gave shorter rupture time at 950degC under low stress and at 1,000degC. The welded joint of Hastelloy XR ruptured at the base metal region at 850 and 900degC. On the other hand, it ruptured at the weld metal region at 950 and 1,000degC. The steady-state creep rate of weld metal of Hastelloy XR was lower than that of base metal at 850, 900 and 950degC. The creep rupture strengths of base metal, weld metal and welded joint of Hastelloy XR obtained in this study were confirmed to be much higher than the design allowable creep-rupture stress (S R ) of the Design Allowable Limits below 950degC. (author)

  3. The anti-corrosion behavior under multi-factor impingement of Hastelloy C22 coating prepared by multilayer laser cladding

    Science.gov (United States)

    Chen, Lin; Bai, Shu-Lin

    2018-04-01

    Hastelloy C22 coating was prepared on substrate of Q235 steel by high power multilayer laser cladding. The microstructure, hardness and anti-corrosion properties of coating were investigated. The corrosion tests in 3.5% NaCl solution were carried out with variation of impingement angle and velocity, and vibration frequency of sample. The microstructure of coating changes from equiaxed grain at the top surface to dendrites oriented at an angle of 60° to the substrate inside the coating. The corrosion rate of coating increases with the increase of impingement angle and velocity, and vibrant frequency of sample. Corrosion mechanisms relate to repassivation and depassivation of coating according to electrochemical measurements. Above results show that multilayer laser cladding can endow Hastelloy C22 coating with fine microstructures, high hardness and good anti-corrosion performances.

  4. Relationship between carburization and zero-applied-stress creep dilation in Alloy 800H and Hastelloy X

    International Nuclear Information System (INIS)

    Inouye, H.; Rittenhouse, P.L.

    1981-01-01

    Typical HTGR candidate alloys can carburize when exposed to simulated service environments. The carbon concentration gradients so formed give rise to internal stresses which could cause dilation. Studies performed with Hastelloy X and Alloy 800H showed that dilations of up to almost 1% can occur at 1000 0 C when carbon pickup is high. Dilation was normally observed only when the carbon increase was >1000 μg/cm 2 and ceased when diffusing carbon reached the center of the specimen. (Auth.)

  5. Weldability of the superalloys Haynes 188 and Hastelloy X by Nd:YAG

    Directory of Open Access Journals (Sweden)

    Graneix Jérémie

    2014-01-01

    Full Text Available The requirements for welded aircraft parts have become increasingly severe, especially in terms of the reproducibility of the geometry and metallurgical grade of the weld bead. Laser welding is a viable method of assembly to meet these new demands, because of automation, to replace the manual TIG welding process. The purpose of this study is to determine the weldability of Hastelloy X and Haynes 188 alloys by the butt welding process with a Nd:YAG laser. To identify the influential parameters of the welding process (laser power, feed rate, focal diameter and flow of gas while streamlining testing, an experimental design was established with the CORICO software using the graphic correlation method. The position of the focal point was fixed at 1/3 of the thickness of the sheet. The gas flow rate and the power of the beam have a major effect on the mechanical properties and geometry of the weld. The strength of the weld is comparable to that of the base metal. However, there is a significant decrease in the elongation at break of approximately 30%. The first observations of the cross section of the weld by scanning electron microscopy coupled with EBSD analysis show a molten zone presenting dendritic large grains compared to the equiaxed grains of the base metals without a heat affected zone.

  6. Laser texturing of Hastelloy C276 alloy surface for improved hydrophobicity and friction coefficient

    Science.gov (United States)

    Yilbas, B. S.; Ali, H.

    2016-03-01

    Laser treatment of Hastelloy C276 alloy is carried out under the high pressure nitrogen assisting gas environment. Morphological and metallurgical changes in the laser treated layer are examined using the analytical tools including, scanning electron and atomic force microscopes, X-ray diffraction, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. Microhardness is measured and the residual stress formed in the laser treated surface is determined from the X-ray data. The hydrophibicity of the laser treated surface is assessed using the sessile drop method. Friction coefficient of the laser treated layer is obtained incorporating the micro-tribometer. It is found that closely spaced laser canning tracks create a self-annealing effect in the laser treated layer and lowers the thermal stress levels through modifying the cooling rates at the surface. A dense structure, consisting of fine size grains, enhances the microhardness of the surface. The residual stress formed at the surface is compressive and it is in the order of -800 MPa. Laser treatment improves the surface hydrophobicity significantly because of the formation of surface texture composing of micro/nano-pillars.

  7. Temperature dependence of creep properties of cold-worked Hastelloy XR

    International Nuclear Information System (INIS)

    Kurata, Yuji; Nakajima, Hajime

    1995-01-01

    The creep properties of Hastelloy XR, in a solution treated, 10% or 20% cold-worked condition, were investigated at temperatures from 800 to 1,000degC for the duration of creep tests up to about 2,500 ks. At 800 and 850degC, the steady-state creep rate and rupture ductility decreased and the rupture life increased after cold work of 10% or 20%. Although the rupture life of the 10% cold-worked alloy was longer at 900degC than that of the solution treated one, the rupture lives of the 10% cold-worked and solution treated alloys were almost equal at 950degC, which is the highest helium temperature in an intermediate heat exchanger of the High Temperature Engineering Test Reactor (HTTR). The beneficial effect of 10% cold work on the rupture life and the steady-state creep rate disappeared at 1,000degC. The beneficial effect of 20% cold work disappeared at 950degC because significant dynamic recrystallization occurred during creep. While rupture ductility of this alloy decreased after cold work of 10% or 20%, it recovered to a considerable extend at 1,000degC. It is emphasized that these cold work effects should be taken into consideration in design, operation and residual life estimation of high temperature components of the HTTR. (author)

  8. Creep strength of hastelloy X TIG-welded cylinder under internal pressure at elevated temperature

    International Nuclear Information System (INIS)

    Udoguchi, Teruyoshi; Indo, Hirosato; Isomura, Kazuyuki; Kobatake, Kiyokazu; Nakanishi, Tsuneo.

    1981-01-01

    Creep tests on circumferentially TIG-welded Hastelloy x cylinders were carried out under internal pressure for the investigation of structural behavior of welded components in high temperature environment. The creep rupture strength of TIG-welded cylinders was much lower than that of non-welded cylinders, while such reduction was not found in uniaxial creep tests on TIG-welded bars. It was deduced that the reduction was due to the low ductility (ranging from 1 to 5%) of the weld metal to which enhanced creep was induced by the adjacent base metal whose creep strain rate was much higher than that of the weld metal. Therefore, uniaxial creep tests on bar specimens is not sufficient for proper assessment of the creep rupture strength of welded components. Both creep strain rate and creep ductility should be concerned for the assessment. Creep tests by using components such as cylinder under internal pressure are recommendable for the confirmation of creep strength of welded structures and components. (author)

  9. Effects of product form and boron addition on the creep damage in the modified Hastelloy X alloys in a simulated HTGR helium gas environment

    International Nuclear Information System (INIS)

    Nakasone, Yuji; Tanabe, Tatsuhiko; Tsuji, Hirokazu; Nakajima, Hajime.

    1992-01-01

    The present paper investigates early-stage-creep damage of Hastelloy XR and XR-II alloys, modified versions of Hastelloy X alloy, which have been developed in Japan as most promising candidate structural alloys for Japanese high-temperature gas-cooled reactors (HTGRs). Creep tests were made on Hastelloy XR forging, tube and XR-II tube at 1,123 to 1,273 K in a simulated HTGR helium gas environment. The tests were interrupted at different strain levels of up to 5 % in order to evaluate creep damage via intergranular voids. The void sizes along grain boundaries and the A-parameter, the ratio of the number of damaged grain boundaries, on which one or more voids are found, to that of the total grain boundaries observed are used in order to evaluate creep damage. Statistical analysis of the A-parameter as well as the void sizes reveals that the values of the parameter show wide variations and follow the Weibull distribution, reflecting spatial randomness of the voids. The void sizes along grain boundaries, on the other hand, follow the log-normal distribution. The maximum void size d max and the mean value of the A-parameter A m are calculated and plotted against interruption creep strain ε int . The resultant d max vs. ε int and A m vs. ε int diagrams show that Hastelloy XR forging had suffered more damage than Hastelloy XR tube; nevertheless, the forging has longer interruption life, or the time to reach a given interruption creep strain. The result indicates that grains may have been deformed more easily in Hastelloy XR in the form of tube than in the form of forging. The diagrams also imply that the addition of boron has suppressed the nucleation as well as the growth of voids and thus has brought about longer interruption life of Hastelloy XR-II. (author)

  10. Application of the Taguchi technique for the optimization of surface roughness and tool life during the milling of Hastelloy C22

    International Nuclear Information System (INIS)

    Kivak, Turgay; Mert, Senol

    2017-01-01

    In this study, the effects of machining parameters on surface roughness (Ra) and tool life (Tl) were investigated in the milling of Hastelloy C22 alloy with TiAlN-coated carbide inserts. A number of milling experiments were conducted using the L_2_7 (3"3) Taguchi orthogonal array on a CNC milling machine under different cutting conditions (dry, compressed air and wet). The cutting condition, cutting speed and feed rate were determined as the essential machining parameters. Analysis of variance (ANOVA) and signal-to-noise (S/N) ratio were employed to evaluate the effects of the machining parameters on Ra and Tl, and prediction models were created using quadratic regression analyses. The results revealed that the feed rate and cutting condition were the most influential factors on surface roughness and flank wear. The maximum tool life was achieved under wet cutting condition using a cutting speed of 30 x min"-"1 and a feed rate of 0.08 mm x rev"-"1, while the minimum surface roughness value was obtained under wet cutting condition using a cutting speed of 50 m x min"-"1 and the same feed rate. Using the optimum cutting parameters for Tl (30 m x min"-"1, 0.08 mm x rev"-"1), increases of 234 % and 67 % in tool life were observed under wet and compressed air cutting conditions, respectively, compared to the dry cutting condition.

  11. Application of the Taguchi technique for the optimization of surface roughness and tool life during the milling of Hastelloy C22

    Energy Technology Data Exchange (ETDEWEB)

    Kivak, Turgay; Mert, Senol [Duezce Univ. (Turkey). Dept. of Manufacturing Engineering

    2017-02-01

    In this study, the effects of machining parameters on surface roughness (Ra) and tool life (Tl) were investigated in the milling of Hastelloy C22 alloy with TiAlN-coated carbide inserts. A number of milling experiments were conducted using the L{sub 27} (3{sup 3}) Taguchi orthogonal array on a CNC milling machine under different cutting conditions (dry, compressed air and wet). The cutting condition, cutting speed and feed rate were determined as the essential machining parameters. Analysis of variance (ANOVA) and signal-to-noise (S/N) ratio were employed to evaluate the effects of the machining parameters on Ra and Tl, and prediction models were created using quadratic regression analyses. The results revealed that the feed rate and cutting condition were the most influential factors on surface roughness and flank wear. The maximum tool life was achieved under wet cutting condition using a cutting speed of 30 x min{sup -1} and a feed rate of 0.08 mm x rev{sup -1}, while the minimum surface roughness value was obtained under wet cutting condition using a cutting speed of 50 m x min{sup -1} and the same feed rate. Using the optimum cutting parameters for Tl (30 m x min{sup -1}, 0.08 mm x rev{sup -1}), increases of 234 % and 67 % in tool life were observed under wet and compressed air cutting conditions, respectively, compared to the dry cutting condition.

  12. Compatibility of aluminide-coated Hastelloy x and Inconel 617 in a simulated gas-cooled reactor environment

    International Nuclear Information System (INIS)

    Chin, J.; Johnson, W.R.; Chen, K.

    1982-03-01

    Commercially prepared aluminide coatings on Hastelloy X and Inconel 617 substrates were exposed to controlled-impurity helium at 850 0 and 950 0 C for 3000 h. Optical and scanning electron (SEM) microscopy, electron microprobe profiles, and SEM X-ray mapping were used to evaluate and compare exposed and unexposed control samples. Four coatings were evaluated: aluminide, aluminide with platinum, aluminide with chromium, and aluminide with rhodium. With extended time at elevated temperature, nickel diffused into the aluminide coatings to form epsilon-phase (Ni 3 Al). This diffusion was the primary cause of porosity formation at the aluminide/alloy interface

  13. Creep-Rupture Properties and Corrosion Behaviour of 21/4 Cr-1 Mo Steel and Hastelloy X-Alloys in Simulated HTGR Environment

    DEFF Research Database (Denmark)

    Lystrup, Aage; Rittenhouse, P. L.; DiStefano, J. R.

    Hastelloy X and 2/sup 1///sub 4/ Cr-1 Mo steel are being considered as structural alloys for components of a High-Temperature Gas-Cooled Reactor (HTGR) system. Among other mechanical properties, the creep behavior of these materials in HTGR primary coolant helium must be established to form part...

  14. Collect Available Creep-Fatigue Data and Study Existing Creep-Fatigue Evaluation Procedures for Grade 91 and Hastelloy XR

    International Nuclear Information System (INIS)

    Asayama, Tai; Tachibana, Yukio

    2007-01-01

    This report describes the results of investigation on Task 5 of DOE/ASME Materials Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 5 is to collect available creep-fatigue data and study existing creep-fatigue evaluation procedures for Grade 91 steel and Hastelloy XR. Part I of this report is devoted to Grade 91 steel. Existing creep-fatigue data were collected (Appendix A) and analyzed from the viewpoints of establishing a creep-fatigue procedure for VHTR design. A fair amount of creep-fatigue data has been obtained and creep-fatigue phenomena have been clarified to develop design standards mainly for fast breeder reactors. Following this, existing creep-fatigue procedures were studied and it was clarified that the creep-fatigue evaluation procedure of the ASME-NH has a lot of conservatisms and they were analyzed in detail from the viewpoints of the evaluation of creep damage of material. Based on the above studies, suggestions to improve the ASME-NH procedure along with necessary research and development items were presented. Part II of this report is devoted to Hastelloy XR. Existing creep-fatigue data used for development of the high temperature structural design guideline for High Temperature Gas-cooled Reactor (HTGR) were collected. Creep-fatigue evaluation procedure in the design guideline and its application to design of the intermediate heat exchanger (IHX) for High Temperature Engineering Test Reactor (HTTR) was described. Finally, some necessary research and development items in relation to creep-fatigue evaluation for Gen IV and VHTR reactors were presented.

  15. Evaluation on materials performance of Hastelloy Alloy XR for HTTR uses-5 (Creep properties of base metal and weldment in air)

    International Nuclear Information System (INIS)

    Watanabe, Katsutoshi; Nakajima, Hajime; Koikegami, Hajime; Higuchi, Makoto; Nakanishi, Tsuneo; Saitoh, Teiichiro; Takatsu, Tamao.

    1994-01-01

    Creep properties of weldment made from Hastelloy Alloy XR base metals and filler metals for the High Temperature Engineering Test Reactor (HTTR) components were examined by means of creep and creep rupture tests at 900 and 950degC in air. The results obtained are as follows: creep rupture strength was nearly equal or higher than that of Hastelloy Alloy XR master curve and was much higher than design creep rupture strength [S R ]. Furthermore, creep rupture strength and ductility of the present filler metal was in the data band in comparison with those of the previous filler metals. It is concluded from these reasons that this filler metal has fully favorable properties for HTTR uses. (author)

  16. Response Surface Design Model to Predict Surface Roughness when Machining Hastelloy C-2000 using Uncoated Carbide Insert

    International Nuclear Information System (INIS)

    Razak, N H; Rahman, M M; Kadirgama, K

    2012-01-01

    This paper presents to develop of the response surface design model to predict the surface roughness for end-milling operation of Hastelloy C-2000 using uncoated carbide insert. Mathematical model is developed to study the effect of three input cutting parameters includes the feed rate, axial depth of cut and cutting speed. Design of experiments (DOE) was implemented with the aid of the statistical software package. Analysis of variance (ANOVA) has been performed to verify the fit and adequacy of the developed mathematical model. The result shows that the feed rate gave the more effect on the both prediction values of Ra compared to the cutting speed and axial depth of cut. SEM and EDX analyses were performed in different cutting conditions. It can be concluded that the feed rate and cutting force give the higher impact to influence the machining characteristics of surface roughness. Thus, the optimizing the cutting conditions are essential in order to improve the surface roughness in machining of Hastlelloy C-2000.

  17. Analyzing the effect of cutting parameters on surface roughness and tool wear when machining nickel based hastelloy - 276

    International Nuclear Information System (INIS)

    Khidhir, Basim A; Mohamed, Bashir

    2011-01-01

    Machining parameters has an important factor on tool wear and surface finish, for that the manufacturers need to obtain optimal operating parameters with a minimum set of experiments as well as minimizing the simulations in order to reduce machining set up costs. The cutting speed is one of the most important cutting parameter to evaluate, it clearly most influences on one hand, tool life, tool stability, and cutting process quality, and on the other hand controls production flow. Due to more demanding manufacturing systems, the requirements for reliable technological information have increased. For a reliable analysis in cutting, the cutting zone (tip insert-workpiece-chip system) as the mechanics of cutting in this area are very complicated, the chip is formed in the shear plane (entrance the shear zone) and is shape in the sliding plane. The temperature contributed in the primary shear, chamfer and sticking, sliding zones are expressed as a function of unknown shear angle on the rake face and temperature modified flow stress in each zone. The experiments were carried out on a CNC lathe and surface finish and tool tip wear are measured in process. Machining experiments are conducted. Reasonable agreement is observed under turning with high depth of cut. Results of this research help to guide the design of new cutting tool materials and the studies on evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy - 276 machining.

  18. Creep-rupture behavior of 2-1/4 Cr-1 Mo steel, Alloy 800H and Hastelloy Alloy X in a simulated HTGR helium environment

    International Nuclear Information System (INIS)

    Lai, G.Y.; Wolwowicz, R.J.

    1979-12-01

    Creep-rupture testing was conducted on 1 1/4 Cr-1 Mo steel, Alloy 800H and Hastelloy Alloy X in flowing helium containing nominal concentration of following gases: 1500 μatm H 2 , 450 μatm CO, 50 μatm CH 4 , 50 μatm H 2 O and 5 μatm CO 2 . This environment is believed to represent maximum permissible levels of impurities in the primary coolant for the steam-cycle system of a high-temperature gas-cooled reactor (HTGR) when it is operating continuously with a water and/or steam leak at technical specification limits. Two or three heats of material for each alloy were investigated. Tests were conducted at 482 0 C and 760 0 C (1200 0 F and 1400 0 F) for Alloy 800H, and at 760 0 C and 871 0 C (1400 0 F and 1600 0 F) for Hastelloy Alloy X for times up to 10,000 h. Selected tests were performed on same heat of material in both air and helium environments to make a direct comparison of creep-rupture behaviors between two environments. Metallurgical evaluation was performed on selected post test specimens with respect to gas-metal interactions which included oxidation, carburization and/or decarburization. Correlation between gaseous corrosion and creep-rupture behavior was attempted. Limited tests were also performed to investigate the specimen size effects on creep-rupture behavior in the helium environment

  19. Influence of the brazing parameters on microstructure and mechanical properties of brazed joints of Hastelloy B2 nickel base alloy; Influencia de los parametros de soldeo fuerte en la microestructura y propiedades mecanicas de la union de la aleacion base niquel Hastelloy B2

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo, J. C.; Gonzalez, M.; Porto, E.

    2014-07-01

    A study of the high vacuum brazing process of solid solution strengthened Hastelloy B2 nickel alloy has been done. A first stage of research has focused on the selection of the most appropriate brazing filler metal to the base material and vacuum furnace brazing process. The influence of welding parameters on joint microstructure constituents, relating the microstructure of the joint to its mechanical properties, has been evaluated. Two gaps of 50 and 200 micrometers, and two dwell times at brazing temperature of 10 and 90 minutes were studied. The braze joint mainly consists of the nickel rich matrix, nickel silicide and ternary compounds. Finally, the results of this study have shown the high bond strength for small gaps and increased dwell times of 90 minutes. (Author)

  20. One new route to optimize the oxidation resistance of TiC/hastelloy (Ni-based alloy) composites applied for intermediate temperature solid oxide fuel cell interconnect by increasing graphite particle size

    Science.gov (United States)

    Qi, Qian; Liu, Yan; Wang, Lujie; Zhang, Hui; Huang, Jian; Huang, Zhengren

    2017-09-01

    TiC/hastelloy composites with suitable thermal expansion and excellent electrical conductivity are promising candidates for IT-SOFC interconnect. In this paper, the TiC/hastelloy composites are fabricated by in-situ reactive infiltration, and the oxidation resistance of composites is optimized by increasing graphite particle size. Results show that the increase of graphite particles size from 1 μm to 40 μm reduces TiC particle size from 2.68 μm to 2.22 μm by affecting the formation process of TiC. Moreover, the decrease of TiC particles size accelerates the fast formation of dense and continuous TiO2/Cr2O3 oxide layer, which bring down the mass gain (800 °C/100 h) from 2.03 mg cm-2 to 1.18 mg cm-2. Meanwhile, the coefficient of thermal expansion decreases from 11.15 × 10-6 °C-1 to 10.80 × 10-6 °C-1, and electrical conductivity maintains about 5800 S cm-1 at 800 °C. Therefore, the decrease of graphite particle size is one simple and effective route to optimize the oxidation resistance of composites, and meantime keeps suitable thermal expansion and good electrical conductivity.

  1. Thermodynamic Assessment of Hot Corrosion Mechanisms of Superalloys Hastelloy N and Haynes 242 in Eutectic Mixture of Molten Salts KF and ZrF4

    Energy Technology Data Exchange (ETDEWEB)

    Michael V. Glazoff

    2012-02-01

    The KF - ZrF4 system was considered for the application as a heat exchange agent in molten salt nuclear reactors (MSRs) beginning with the work carried out at ORNL in early fifties. Based on a combination of excellent properties such as thermal conductivity, viscosity in the molten state, and other thermo-physical and rheological properties, it was selected as one of possible candidates for the nuclear reactor secondary heat exchanger loop.

  2. Material design data of 2.25Cr-1Mo steel and hastelloy-x for the experimental multi-purpose very-high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Kodaira, Tsuneo; Suzuki, Michiaki; Uga, Takeo

    1975-08-01

    The preliminary structural design guidelines for the experimental multi-purpose very-high temperature gas-cooled reactor have recently been prepared. The components of the primary system operating at temperatures of creep dominant range are grouped in those of pressure and temperature boundaries respectively. In the material selection, 2 1/4Cr-1Mo steel is chosen for the former and Hastelloy-X for the latter taking into account of material properties at operating temperature. Deriving from the literature in the field, material design data of the alloys are established in design forms such as Sy, So, Sm, St, 100% of minimum stress to rupture, design fatigue curves, isochronous stress-strain curves, creep-fatigue interaction damage factor and so on, which are defined in ASME Code Section III, Code Case 1592. (auth.)

  3. N

    KAUST Repository

    Babar, Vasudeo Pandurang; Sharma, Sitansh; Schwingenschlö gl, Udo

    2018-01-01

    Using density functional theory with van der Waals dispersion correction, the adsorption behavior of common gaseous pollutants (CO, NO, NO2, and NH3) on monolayer C3N is investigated. The adsorption sites and energies, binding distances, charge

  4. N

    KAUST Repository

    Babar, Vasudeo Pandurang

    2018-04-17

    Using density functional theory with van der Waals dispersion correction, the adsorption behavior of common gaseous pollutants (CO, NO, NO2, and NH3) on monolayer C3N is investigated. The adsorption sites and energies, binding distances, charge transfers, and electronic band structures are calculated to understand the influence of the adsorbed molecules on the transport properties of monolayer C3N. The current–voltage characteristics are calculated using the nonequilibrium Green\\'s function formalism. It turns out that all investigated molecules are physisorbed on monolayer C3N and that NO and NO2 gases can be sensed with high sensitivity. The recovery time of the sensor is found to be outstanding in the case of NO sensing (2.4 μs at room temperature) and competitive to other materials in the case of NO2 sensing.

  5. Corrosion of Inconel-625, Hastelloy-X280 and Incoloy-800 in 550 - 750°C superheated steam. Influence of alloy heat treatment, surface treatment, steam temperature and steam velocity. Part I: Results up to 6000 hours exposure time. RCN Report

    International Nuclear Information System (INIS)

    Tilborg, P.J. van; Linde, A. van der

    1969-10-01

    Sheet samples of Inconel-625, Hastelloy-X280 and Incoloy-800 were tested, in the solution annealed and in the solution annealed + 20% cold worked + 800°C tempered condition, in steam with a velocity of 5 m/sec. at 550, 650 and 750°C and in steam with a volocity of 15 and 85 m/sec. at 550°C. At 550°C and 750°C the samples were tested in the heat treated, annealed or tempered and the heat treated + electropolished condition. At 650°C moreover as heat treated + ground and pickled samples were tested. Post-corrosion sample investigations involved measurement of the adherent oxide thickness, the total amount of corroded metal, the metal loss to system, and the metallographic and microprobe investigation of the adherent oxide film and adjacent diffusion disturbed alloy layer. The results obtained up to 6000 hours exposure time showed that the surface treatment has a decisive influence on the corrosion behaviour of all three alloys tested. The differences in the corrosion data for the two heat treatment conditions are small. The influence of the steam velocity, as tested at 550°C, on the initial corrosion rate was surprisingly high, while the long-term linear corrosion rates are only slightly influenced by the gas velocity. In general the linear corrosion rates were low, 1-5 mg/dm 2 month, and not consistently affected by the test-temperature. The metal loss to system values were 2 <15 mg/dm 2 in the low velocity steam at all three test temperatures and <30 mg/dm 2 in the high velocity steam at 550°C. The metallographic and microprobe examinations revealed no remarkable results, as compared with the results of analogous tests reported in literature. (author)

  6. Minimização de defeitos em revestimentos de superligas de níquel depositada pelo processo TIG com alimentação de arame frio

    Directory of Open Access Journals (Sweden)

    Cleiton Carvalho Silva

    2014-12-01

    Full Text Available O objetivo do presente trabalho foi avaliar a influência dos parâmetros de soldagem na formação de defeitos na soldagem de revestimentos com ligas à base de níquel, e sua possível eliminação através do correto ajuste dos referidos parâmetros. Para tanto, foram depositados revestimentos com as ligas à base de Ni do tipo Inconel 625, Hastelloy C276 e Inconel 686, sobre um substrato de aço C-Mn, através do processo TIG com alimentação de arame frio. O planejamento dos experimentos foi realizado aplicando-se o método Taguchi. Os fatores de controle avaliados foram a Técnica da energia (TE, o nível de energia de soldagem (E, o tipo de liga (L, o gás de proteção (G e o tipo de tecimento (T. Outros parâmetros foram mantidos constantes, tendo sido investigados previamente. Os resultados mostraram que o tipo de tecimento em espiral, embora contribua significativamente para a redução da diluição, causa uma forte instabilidade ao processo, resultando na maioria dos casos em defeitos superficiais ou defeitos entre passes. A condição ótima para evitar a formação de defeitos entre passes identificada pelo método Taguchi foi constituída pelas seguintes combinação de fatores de controle 2-2-2-3-3, ou seja: TE-I; Emédia; Liga Hastelloy C276; Gás de proteção Ar+He; Tecimento Duplo-8. A condição ótima para a soldagem sem defeitos resulta em alto nível de diluição não sendo indicada para a soldagem de revestimentos resistentes à corrosão.

  7. Absorption of molten fluoride salts in glassy carbon, pyrographite and Hastelloy B

    Czech Academy of Sciences Publication Activity Database

    Vacík, Jiří; Naramoto, H.; Červená, Jarmila; Hnatowicz, Vladimír; Peka, I.; Fink, D.

    2001-01-01

    Roč. 289, č. 3 (2001), s. 308-314 ISSN 0022-3115 R&D Projects: GA ČR GA202/96/0077; GA ČR GV202/97/K038; GA AV ČR KSK1010104 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.366, year: 2001

  8. Fatigue performance of TBCs on Hastelloy X substrate during cyclic bending

    Czech Academy of Sciences Publication Activity Database

    Mušálek, Radek; Kovářík, O.; Tomek, L.; Medřický, Jan; Pala, Zdeněk; Haušild, P.; Čapek, J.; Kolařík, K.; Curry, N.; Bjorklund, S.

    2016-01-01

    Roč. 25, 1-2 (2016), s. 231-243 ISSN 1059-9630. [ITSC 2015: International Thermal Spray Conference and Exposition. Long Beach, California, 11.05.2015-14.05.2015] R&D Projects: GA ČR GB14-36566G Institutional support: RVO:61389021 Keywords : atmospheric plasma spray * failure mechanism * fatigue * HVAF * NiCoCrAlY * thermal barrier coatings * yttria-stabilized zirconia Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.488, year: 2016 http://link.springer.com/article/10.1007%2Fs11666-015-0321-4

  9. N,N,N-Tris(diphenylphosphorylmethylamine

    Directory of Open Access Journals (Sweden)

    Olaf Walter

    2017-10-01

    Full Text Available The structure of N,N,N-tris(diphenylphosphorylmethylamine, C39H36NO3P3, at 103 K has monoclinic (P21/c symmetry. Two molecules, each with pseudo-threefold rotation symmetry, crystallize in the asymmetric unit of the monoclinic unit cell. The compound acts as ligand for the stabilization of metal ions with flexible coordination enabling three- or fourfold coordination.

  10. N Veeraiah

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N Veeraiah. Articles written in Bulletin of Materials Science. Volume 23 Issue 4 August 2000 pp 285-293 Glasses. Dielectric properties of NaF–B2O3 glasses doped with certain transition metal ions · M Krishna Murthy K S N Murthy N Veeraiah · More Details Abstract Fulltext ...

  11. N Mukunda

    Indian Academy of Sciences (India)

    N Mukunda · More Details Fulltext PDF. Volume 13 Issue 5 May 2008 pp 403-404 Editorial. Statement on Plagiarism · S Mahadevan N Mukunda · More Details Fulltext PDF. Volume 13 Issue 9 September 2008 pp 843-865 General Article. Space and Time in Life and Science · Vasant Natarajan V Balakrishnan N Mukunda.

  12. Narrow n anti n resonances

    International Nuclear Information System (INIS)

    Bogdanova, L.N.; Dalkarov, O.D.; Kerbikov, B.O.; Shapiro, I.S.

    1975-01-01

    The present status of the problem of quasinuclear states in systems of nucleons and antinucleons is reviewed. The theoretical predictions are compared with experimental data on narrow meson resonances near N anti N threshold which appeared in 1971-74

  13. 1/N

    International Nuclear Information System (INIS)

    Coleman, S.

    1980-03-01

    There exist families of field theories with symmetry group SO(N) (or SU(N)) that become simpler as N becomes larger. More precisely, the solutions to these theories possess an expansion in powers of 1/N. This expansion is the subject of these lectures. The 1/N expansion can be used to analyze model field theories. The 1/N expansion is developed for phi 4 theory and applied to two two-dimensional models with similar combinatoric structures, the Gross-Neveu model and the CP/sup N-1/ model. These models display (in the leading 1/N approximation) such interesting phenomena as asymptotic freedom, dynamical symmetry breaking, dimensional transmutation, and non-perturbative confinement. It is possible that the 1/N expansion, with N the number of colors, might fruitfully be applied to quantum chromodynamics. Unfortunately, it is not possible to make a decisive test of the approximation, because no one knows how to compute even the first term in the expansion in closed form. However, it is possible to argue that this first term, whatever its detailed form, has many properties that are also shared by the real world, and which are otherwise underived from field theory. These include the saturation of scattering amplitudes by an infinite number of narrow resonances, the essential feature of dual-resonance models

  14. N Gopukumar

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N Gopukumar. Articles written in Resonance – Journal of Science Education. Volume 7 Issue 7 July 2002 pp 63-67 Feature Article. Nature Watch - Tent-making Bats · N Gopukumar J Balasingh · More Details Fulltext PDF ...

  15. N Nwathore

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N Nwathore. Articles written in Bulletin of Materials Science. Volume 34 Issue 1 February 2011 pp 129-132. Effect of temperature on polarization reversal of strontium-doped lead zirconate titanate (PSZT) ceramics · N Nwathore C M Lonkar D K Kharat · More Details Abstract ...

  16. N Rathnasree

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N Rathnasree. Articles written in Resonance – Journal of Science Education. Volume 9 Issue 3 March 2004 pp 65-75 Classroom. Preparing for the Transit of Venus · N Rathnasree Sanat Kumar · More Details Fulltext PDF. Volume 9 Issue 11 November 2004 pp ...

  17. n Sathyamurthy

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. N SATHYAMURTHY. Articles written in Journal of Chemical Sciences. Volume 128 Issue 10 October 2016 pp 1597-1606 Regular Article. The Effect of Hydration on the Cation-π Interaction Between Benzene and Various Cations · VIKASH DHINDHWAL N SATHYAMURTHY.

  18. N Jayaraman

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N Jayaraman. Articles written in Resonance – Journal of Science Education. Volume 22 Issue 9 September 2017 pp 835-845 General Article. 2016 Nobel Prize in Chemistry: Conferring Molecular Machines as Engines of Creativity · N Jayaraman · More Details ...

  19. N Kumar

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N Kumar. Articles written in Bulletin of Materials Science. Volume 29 Issue 4 August 2006 pp 379-384 Composites. Studies on conductivity and dielectric properties of polyaniline–zinc sulphide composites · H C Pant M K Patra S C Negi A Bhatia S R Vadera N Kumar.

  20. N Sankar

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N Sankar. Articles written in Bulletin of Materials Science. Volume 25 Issue 4 August 2002 pp 329-334 Semiconductors. On the symmetry of phosphorous doped ZnSe · N Sankar K Ramachandran · More Details Abstract Fulltext PDF. The site symmetry of P doped ZnSe is ...

  1. Preliminary lifetime predictions for 304 stainless steel as the LANL ABC blanket material

    International Nuclear Information System (INIS)

    Park, J.J.; Buksa, J.J.; Houts, M.G.; Arthur, E.D.

    1997-11-01

    The prediction of materials lifetime in the preconceptual Los Alamos National Laboratory (LANL) Accelerator-Based Conversion of Plutonium (ABC) is of utmost interest. Because Hastelloy N showed good corrosion resistance to the Oak Ridge National Laboratory Molten Salt Reactor Experiment fuel salt that is similar to the LANL ABC fuel salt, Hastelloy N was originally proposed for the LANL ABC blanket material. In this paper, the possibility of using 304 stainless steel as a replacement for the Hastelloy N is investigated in terms of corrosion issues and fluence-limit considerations. An attempt is made, based on the previous Fast Flux Test Facility design data, to predict the preliminary lifetime estimate of the 304 stainless steel used in the blanket region of the LANL ABC

  2. N Periasamy

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. N Periasamy. Articles written in Journal of Chemical Sciences. Volume 113 Issue 2 April 2001 pp 157-163 Physical and Theoretical. TRANES analysis of the fluorescence of nile red in organized molecular assemblies confirms emission from two species · A S R Koti N ...

  3. Compatibility studies of potential molten-salt breeder reactor materials in molten fluoride salts

    International Nuclear Information System (INIS)

    Keiser, J.R.

    1977-05-01

    The molten fluoride salt compatibility studies carried out during the period 1974--76 in support of the Molten-Salt Reactor Program are summarized. Thermal-convection and forced-circulation loops were used to measure the corrosion rate of selected alloys. Results confirmed the relationship of time, initial chromium concentration, and mass loss developed by previous workers. The corrosion rates of Hastelloy N and Hastelloy N modified by the addition of 1--3 wt percent Nb were well within the acceptable range for use in an MSBR. 13 figures, 3 tables

  4. N-Cyclohexyl-N-ethylbenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Islam Ullah Khan

    2009-11-01

    Full Text Available The title compound, C14H21NO2S, synthesized by N-methylation of cyclohexylamine sulfonamide with ethyl iodide is of interest as a precursor to biologically active sulfur-containing heterocyclic compounds. There are two independent molecules in the asymmetric unit. The dihedral angles between the mean planes of the phenyl ring and the cyclohexyl ring are 40.29 (11 and 37.91 (13° in the two molecules.

  5. One-pot Synthesis of Substituted Pyrroles with N,N,N',N'

    African Journals Online (AJOL)

    In this research, N,N,N'N'-tetrachlorobenzene-1,3-disulphonamide as novel catalytic reagent and N,N'-diiodo-N,N'-1,2-ethanediylbis(p-toluenesulphonamide) as new catalyst were used for the synthesis of N-substituted pyrroles in good to excellent yields under mild conditions. These reusable reagents were compared with ...

  6. N-barN interaction theoretical models

    International Nuclear Information System (INIS)

    Loiseau, B.

    1991-12-01

    In the framework of antinucleon-nucleon interaction theoretical models, our present understanding on the N-barN interaction is discussed, either from quark- or/and meson- and baryon-degrees of freedom, by considering the N-barN annihilation into mesons and the N-barN elastic and charge-exchange scattering. (author) 52 refs., 11 figs., 2 tabs

  7. Coulomb dissociation of N-20,N-21

    NARCIS (Netherlands)

    Roeder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos; Boretzky, Konstanze; Borge, Maria J. G.; Burgunder, G.; Caamano, Manuel; Caesar, Christoph; Casarejos, Enrique; Catford, Wilton; Cederkall, Joakim; Chakraborty, S.; Chartier, Marielle; Chulkov, Leonid; Cortina-Gil, Dolores; Crespo, Raquel; Pramanik, Ushasi Datta; Diaz-Fernandez, Paloma; Dillmann, Iris; Elekes, Zoltan; Enders, Joachim; Ershova, Olga; Estrade, A.; Farinon, F.; Fraile, Luis M.; Freer, Martin; Freudenberger, M.; Fynbo, Hans; Galaviz, Daniel; Geissel, Hans; Gernhaeuser, Roman; Goebel, Kathrin; Kalantar-Nayestanaki, Nasser; Najafi, Mohammad Ali; Rigollet, Catherine; Stoica, V.; Streicher, Branislav; Van de Walle, J.

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N-20,N-21 are reported. Relativistic N-20,N-21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a

  8. Presentación

    OpenAIRE

    Acevedo Tovar, Luz Marina

    2014-01-01

    El Instituto de Investigaciones Educativas presenta ante la comunidad universitaria y público en general un nuevo número de la Revista Investigación Educativa; el Tema Central del número 18 de nuestra Revista es: “La investigación educacional universitaria”, elegimos este tema porque creemos que no puede haber educación universitaria sin investigación y menos aún, formación universitaria de educadores sin investigación educativa y desde las páginas de este número de la Revista Investigación E...

  9. ERRADICACIÓN Y POSTERRADICACIÓN

    Directory of Open Access Journals (Sweden)

    Francisco Salmerón García

    2013-01-01

    Full Text Available La vacunación antipoliomielítica genera inmunidad de grupo (con vacunas atenuadas (VPO e inactivadas (VPI y ello permitirá la erradica- ción de la enfermedad. La VPO produce de 2-4 casos de poliomielitis por cohorte de un millón de niños y por ello los países que pueden hacer frente al coste de la VPI (unas 15 veces más cara la utilizan. En 1988 la Asamblea de la Organización Mundial de la Salud aprobó el objetivo de la erradicación como “la interrupción de la transmisión de poliovirus salvajes”. Si se conseguía su eliminación, el mantenimiento de la VPO produciría al año entre 250 y 500 casos de poliomielitis en el mundo. Desde 1999 era evidente que la erradicación requeriría la cesación de la vacunación con VPO. El 25 de enero del 2013 se aprobó el plan para la erradicación y la contención de todos los virus de la polio, salvajes o no, para que ningún niño sufra una poliomielitis paralítica. Los hitos más importantes incluyen, la no aparición de casos de polio saducción de al menos una dosis de VPI en todos los programas de vacunación y que se suspenda la vacunación con VPO tipo 2 al final del 2016 y que en 2019 se pueda cesar de utilizar la vacuna bivalente oral. Para todo ello será preciso un trabajo científico complejo y solidaridad financiera.

  10. [ital N][sub [ital p]N[ital n

    Energy Technology Data Exchange (ETDEWEB)

    Saha, M.; Sen, S. (Saha Institute of Nuclear Physics, Calcutta 700 064 (India))

    1993-02-01

    It is shown that the well known phenomenon of the saturation in the [ital B]([ital E]2;0[sub 1][sup +][r arrow]2[sub 1][sup +]), as well as the [ital E][sub 21][sup +] values near midshell in the even rare-earth and actinide nuclei, can be reproduced in the [ital N][sub [ital p]N[ital n

  11. Introducción

    DEFF Research Database (Denmark)

    Hansen, Hans Lauge

    2002-01-01

    Kritisk udgave, edición crítica, 27-generationen, generación del 27, digtning og maleri, poesía y pintura......Kritisk udgave, edición crítica, 27-generationen, generación del 27, digtning og maleri, poesía y pintura...

  12. LIE n-RACKS

    OpenAIRE

    Biyogmam, Guy Roger

    2011-01-01

    In this paper, we introduce the category of Lie $n$-racks and generalize several results known on racks. In particular, we show that the tangent space of a Lie $n$-Rack at the neutral element has a Leibniz $n$-algebra structure. We also define a cohomology theory of $n$-racks..

  13. Acción

    OpenAIRE

    Aranegui, Mónica; Cámara, Chari; Atrapados en el Acto, (Colectivo); Gagaliot, Azahara; García Vázquez, Alejandro; González Longino, Teresa; Osset, Blanca; Ríos, Alexander; Sáez de Asteasu, Estibalez; Sumatorio de vacíos, (Colectivo); Valls, Pierre; Ortega, Cristina; Bocanegra, Juan José; Sánchez, Ana Rosa; Cueto, Belén

    2012-01-01

    Coordinación, Belén Cueto y Nieves Correa. Acción es el compendio de tres actividades relacionadas con el arte de acción que se realizaron dentro del programa SIN CRÉDITOS del Vicedecanato de Extensión Universitaria en La Trasera de la Facultad de Bellas Artes durante 2012: Atrapados en el Acto propone un viaje teórico-práctico por la historia de la performance, seguido de un entramado de ejercicios que exploraban cuatro pilares del arte de acción: tiempo, espacio, cuerpo e interacción. Al...

  14. Instantons and Large N

    Science.gov (United States)

    Mariño, Marcos

    2015-09-01

    Preface; Part I. Instantons: 1. Instantons in quantum mechanics; 2. Unstable vacua in quantum field theory; 3. Large order behavior and Borel summability; 4. Non-perturbative aspects of Yang-Mills theories; 5. Instantons and fermions; Part II. Large N: 6. Sigma models at large N; 7. The 1=N expansion in QCD; 8. Matrix models and matrix quantum mechanics at large N; 9. Large N QCD in two dimensions; 10. Instantons at large N; Appendix A. Harmonic analysis on S3; Appendix B. Heat kernel and zeta functions; Appendix C. Effective action for large N sigma models; References; Author index; Subject index.

  15. Presentación

    Directory of Open Access Journals (Sweden)

    Lisandro José Alvarado Peña

    2014-01-01

    Full Text Available En América Latina y el Caribe, las redes académicas, juegan un papel importante en el fortalecimiento de la investigación, debido al compromiso que es-tas han venido asumiendo en la formulación, desarrollo y ejecución de proyectos de investigación, es decir, en primera instancia la organización del conocimiento,a través de centros e institutos de estudios e investigación, cuerpos académicos y/o grupos de investigación, como se les denomina dependiendo de algunos consejos nacionales de ciencia, tecnología e innovación y los sistemas de educación superior en la región, siendo estas investigaciones de carácter nacional e internacional.

  16. Presentación

    Directory of Open Access Journals (Sweden)

    Sandra Milena Restrepo Escobar

    2017-06-01

    Full Text Available La Fundación Universitaria Luis Amigó tiene el gusto de presentar el primer volumen de su revista Drugs and Addictive Behavior, que en consonancia con la misión institucional encaminada a la generación, conservación y divulgación del conocimiento científico, en procura de la formación de profesionales con conciencia crítica, aborda la temática de las adicciones desde su promoción, prevención y tratamiento, contribuyendo al desarrollo integral de la sociedad. Los artículos que en la revista se presentan son producción inédita de los autores y han sido sometidos a un proceso de selección y revisión por pares expertos en las diferentes áreas, que han consentido la publicación de los mismos. Para el volumen 1 número 1 se presentan siete artículos, cuatro productos de de investigación, dos revisiones teóricas y un artículo de reflexión.

  17. Evasión remisión de V. duración de la evasión.

    OpenAIRE

    2011-01-01

    [ES] Definición del término Evasión remisión de V. duración de la evasión. en el diccionario Dicter. [EN] Definition of the word Evasión remisión de V. duración de la evasión. in the dictionary Dicter.

  18. Current problems in (n,2n) reactions

    Energy Technology Data Exchange (ETDEWEB)

    Cindro, N; Frehaut, J

    1975-01-01

    Two kinds of problems related to (n,2n) reactions are briefly discussed. The first one is the understanding of the reaction mechanism. The nucleus evaporation formulas overestimate the experimental values of the cross sections. This difference can be accounted for either by reestimating the relative values of GAMMA sub(..gamma..) and GAMMA sub(n) or by adding nonequilibrium process contributions. The second problem is the Csikai-Petoe effect. A more extensive analysis of the data shows that they are not in agreement with its predictions.

  19. Current problems in (n,2n) reactions

    International Nuclear Information System (INIS)

    Cindro, N.; Frehaut, J.

    1975-01-01

    Two kinds of problems related to (n,2n) reactions are briefly discussed. The first one is the understanding of the reaction mechanism. The nucleus evaporation formulas overestimate the experimental values of the cross sections. This difference can be accounted for either by reestimating the relative values of GAMMA sub(γ) and GAMMA sub(n) or by adding nonequilibrium process contributions. The second problem is the Csikai-Petoe effect. A more extensive analysis of the data shows that they are not in agreement with its predictions [fr

  20. Introducción

    Directory of Open Access Journals (Sweden)

    ESTHER R. GREENGLASS

    2005-01-01

    Segundo, como el burnout se desarrolla en el tiempo, es necesario que se realicen más estudios longitudinales de burnout utilizando medidas de dos e incluso de tres tiempos. Tales diseños no sólo producirán información valiosa sobre los antecedentes del burnout, como se indicó anteriormente, sino que también permitirá la introducción y la evaluación de la intervención que puede utilizarse para reducir el burnout.

  1. IPv6:n tietoturvaominaisuudet

    OpenAIRE

    Sorsa, Kari

    2013-01-01

    Opinnäytetyön tavoitteena on esitellä IPv6-protokolla ja selvittää sen tärkeimmät tietoturvaominaisuudet ja -riskit. Työtä tullaan käyttämään teoreettisena apuna Turun Ammattikorkeakoulun Lemminkäisenkadun toimipisteen laboratorioverkon siirtämisessä IPv6:een. Opinnäytetyö on jaettu kolmeen osaan. Ensimmäisessä esitellään lyhyesti IPv6:n historia ja kehitysvaiheet sekä uuden protokollan ominaisuudet. Toinen osa koostuu ominaisuus- ja tietoturvavertailusta IPv4:n ja IPv6:n välillä, jo...

  2. Presentación

    Directory of Open Access Journals (Sweden)

    Gloria E Leal Leal

    2014-11-01

    Full Text Available En este nuevo fascículo de la revista del Departamento de Trabajo Social se publican quince artículos, productos de procesos de investigación, que analizan problemas sociales con relación a la exclusión social, la discriminación racial y sexual, el desplazamiento forzoso, la reconstrucción de la memoria, el fenómeno de la pobreza, la discapacidad, la problemática ambiental y la producción campesina; asuntos presentes tanto en el debate académico como en el de la sociedad en general.

  3. Dimethyl N-cyanodithioiminocarbonate

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2016-03-01

    Full Text Available The title compound, C4H6N2S2, crystallizes with four independent molecules in the asymmetric unit. Two of the molecules are disordered about a pseudo twofold rotation axis. The mean values of the C—N bonds are 1.143 (5 Å for C[triple-bond]N, 1.302 (5 Å for C=N and 1.341 (5 Å for the C—N single bond. In the crystal, molecules are linked via C—H...N hydrogen bonds, forming slabs parallel to the bc plane.

  4. Conformal potential in N dimensions (N>1)

    Energy Technology Data Exchange (ETDEWEB)

    Barucchi, G [Turin Univ. (Italy). Ist. di Fisica; Istituto di Fisica Matematica dell' Universita, Torino (Italy); Istituto Nazionale di Fisica Nucleare, Turin (Italy))

    1977-07-21

    The conformal invariant model of de Alfaro, Fubini and Furlan is studied in the case of potential V(Q) = g/2Q/sup 2/(Q/sup 2/ = ..sigma..sub(i=1)sup(N) Qsub(i)sup(2), N>1). By means of the invariance under projective transformations and the rotation symmetry of the system in configuration space, explicit solutions are obtained.

  5. 4-Bromo-N-(di-n-propylcarbamothioylbenzamide

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The synthesis of the title compound, C14H19BrN2OS, involves the reaction of 4-bromobenzoyl chloride with potassium thiocyanate in acetone followed by condensation of the resulting 4-bromobenzoyl isothiocyanate with di-n-propylamine. Typical thiourea carbonyl and thiocarbonyl double bonds, as well as shortened C—N bonds, are observed in the title compound. The short C—N bond lengths in the centre of the molecule reveal the effects of resonance in this part of the molecule. The asymmetric unit of the title compound contains two crystallographically independent molecules, A and B. There is very little difference between the bond lengths and angles of these molecules. In molecule B, one di-n-propyl group is twisted in a −antiperiplanar conformation with C—C—C—H = −179.1 (3° and the other adopts a −synclinal conformation with C—C—C—H = −56.7 (4°; in molecule A the two di-n-propyl groups are twisted in + and −antiperiplanar conformations, with C—C—C—H = −179.9 (3 and 178.2 (3°, respectively. In the crystal, the molecules are linked into dimeric pairs via pairs of N—H...S hydrogen bonds.

  6. PRESENTACIÓN

    OpenAIRE

    Acevedo Tovar, Luz Marina

    2014-01-01

    El Instituto de Investigaciones Educativas presenta ante la comunidad universitaria y público en general su Revista N.° 15. Como ya fuera anunciado, este número introduce modificaciones externas e internas en nuestra revista.

  7. Cross sections for the (n,p), (n,α) and (n,2n) threshold reactions

    International Nuclear Information System (INIS)

    Bychkov, V.M.; Manokhin, V.N.; Pashchenko, A.B.; Plyaskin, V.I.

    1980-07-01

    The (n,p), (n,α), (n,2n) threshold reactions are reviewed for nuclei with Z>=20 in the neutron energy range from the threshold up to 20MeV. The review consists of four parts. In the first part the theoretical methods of cross-section calculations and the empirical or semi-empirical systematics are considered. In the second, third and fourth parts the experimental data compilations on the (n,p), (n,α) and (n,2n) excitation functions are given. The recommended values of cross-sections at 14.5MeV neutron energy are given in tables. For some isotopes the recommended curves of excitation functions also are given in graphs. (author)

  8. Ruthenium (3) coordination compounds with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid

    International Nuclear Information System (INIS)

    Ezerskaya, N.A.; Buj Kuang Ki; Shubochkin, L.K.

    1987-01-01

    In the process of interaction of K 2 Ru(H 2 O)Cl 5 with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid (H 8 EDTP) Ru 3 mono-, bi- and trinuclear complexonates are synthesized. On the basis of IR and X-ray electron spectroscopy and potentiometry suppositions are made on the way of ligand (EDTP, Cl - , H 2 O) coordination. Ru 3 complexonates are characterized using spectrophotometry, polarography, conductometry. Thermal decomposition of the complexonates is studied

  9. Addition compounds between lanthanide trifluoromethane sulphonates and N,N,N',N' - tetrametilmalonamida (TMMA)

    International Nuclear Information System (INIS)

    Bellis, V.M. de.

    1984-01-01

    The preparation and characterization of the addiction compounds between lanthanide trifluoromethanesulphonates with the N,N,N',N' - tetramethylmodomamide (TMMA) are reported. The characterization of the compounds obtained by microanalytical procedures, infrared spectra, conductance measurements, X-ray powder patterns, absorption spectra of the praseodymium, neodymium, holmium and erbium and the emission spectra of the europium and the europium-doped lanthanum and lutetium adducts were made. (M.J.C.) [pt

  10. N,N'-Diethyl-N,N'-diphenylpyridine-2,6-dicarboxamide

    Czech Academy of Sciences Publication Activity Database

    Klepetářová, Blanka; Makrlík, E.; Babain, V.A.; Kašička, Václav

    2012-01-01

    Roč. 68, č. 4 (2012), o1099-o1100 ISSN 1600-5368 Grant - others:GA ČZU(CZ) 42900/1312/3114 Institutional research plan: CEZ:AV0Z40550506 Keywords : N,N'-Diethyl-N,N'-diphenylpyridine-2,6-dicarboxamide * crystal structure * amide nitrogen Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.347, year: 2011

  11. Impact of gate engineering in enhancement mode n++GaN/InAlN/AlN/GaN HEMTs

    Science.gov (United States)

    Adak, Sarosij; Swain, Sanjit Kumar; Rahaman, Hafizur; Sarkar, Chandan Kumar

    2016-12-01

    This paper illustrate the effect of gate material engineering on the performance of enhancement mode n++GaN/InAlN/AlN/GaN high electron mobility transistors (HEMTs). A comparative analysis of key device parameters is discussed for the Triple Material Gate (TMG), Dual Material Gate (DMG) and the Single Material Gate (SMG) structure HEMTs by considering the same device dimensions. The simulation results shows that an significant improvement is noticed in the key analysis parameters such as drain current (Id), transconductance (gm), cut off frequency (fT), RF current gain, maximum cut off frequency (fmax) and RF power gain of the gate material engineered devices with respect to SMG normally off n++GaN/InAlN/AlN/GaN HEMTs. This improvement is due to the existence of the perceivable step in the surface potential along the channel which successfully screens the drain potential variation in the source side of the channel for the gate engineering devices. The analysis suggested that the proposed TMG and DMG engineered structure enhancement mode n++GaN/InAlN/AlN/GaN HEMTs can be considered as a potential device for future high speed, microwave and digital application.

  12. D N GAME

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. D N GAME. Articles written in Bulletin of Materials Science. Volume 40 Issue 7 December 2017 pp 1441-1445. Microwave-assisted synthesis and photoluminescence properties of ZnS:Pb 2 + nanophosphor for solid-state lighting · D N GAME C B PALAN N B INGALE S K ...

  13. Buzón

    Directory of Open Access Journals (Sweden)

    Boletín Cultural y Bibliográfico Banco de la República

    1985-06-01

    Full Text Available Sección en donde se presentan los comentarios del público lector del Boletín Cultural y Bibliográfico, con respecto a los artículos, reseñas y contenido, en general, de ésta publicación.

  14. N K Man

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N K Man. Articles written in Bulletin of Materials Science. Volume 37 Issue 1 February 2014 pp 19-25. Influence of preparation conditions on superconducting properties of Bi-2223 thin films · N T Mua A Sundaresan N K Man D D Dung · More Details Abstract Fulltext PDF.

  15. N S Saxena

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N S Saxena. Articles written in Bulletin of Materials Science. Volume 23 Issue 5 October 2000 pp 369-375 Glasses. Differential scanning calorimetry studies of Se85Te15–Pb ( = 4, 6, 8 and 10) glasses · N B Maharajan N S Saxena Deepika Bhandari Mousa M Imran D D ...

  16. P N Shukla

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science. P N Shukla. Articles written in Journal of Earth System Science. Volume 110 Issue 2 June 2001 pp 103-110. High Iridium concentration of alkaline rocks of Deccan and implications to K/T boundary · P N Shukla N Bhandari Anirban Das A D Shukla J S Ray · More Details ...

  17. 15N-tomatine

    International Nuclear Information System (INIS)

    Elliger, C.A.

    1988-01-01

    A method for preparative isolation of 15 N-tomatine from foliage of tomato plants grown hydroponically with 15 N-containing nutrient salts is described. Extractive workup of plant material gave a crude product which was chromatographed on Sephadex LH-20 to yield pure tomatine. Assay of 15 N content by mass spectrometry showed that isotopic purity was ca. 95%. (author)

  18. n ammasai gounden

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. N AMMASAI GOUNDEN. Articles written in Sadhana. Volume 42 Issue 2 February 2017 pp 173-185. Wind-driven stand-alone DFIG with battery and pumped hydro storage system · K NAVIN SAM N KUMARESAN N AMMASAI GOUNDEN · More Details Abstract Fulltext PDF. A wind-driven doubly ...

  19. R N P Choudhary

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. R N P Choudhary. Articles written in Bulletin of Materials Science. Volume 23 Issue 4 August 2000 pp 239-241 Phase Transitions. Phase transitions in Na2TeO4 ceramics · N K Singh R N P Choudhary · More Details Abstract Fulltext PDF. Polycrystalline samples of NaTeO4 ...

  20. Ohmic contacts to n+-GaN capped AlGaN/AlN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Wang Liang; Mohammed, Fitih M.; Ofuonye, Benedict; Adesida, Ilesanmi

    2007-01-01

    Investigations of Ti/Al/Mo/Au Ohmic contact formation, premetallization plasma treatment effects, and interfacial reactions for n + -GaN capped AlGaN/AlN/GaN heterostructures are presented. Ti thickness played an important role in determining contact performance. Transmission electron microscopy studies confirmed that thick Ti layer was necessary to fully consume the GaN cap and the top of AlGaN to enable a higher tunneling current flow. A direct correlation of plasma treatment conditions with I-V linearity, current level, and contact performance was established. The plasma-affected region is believed to extend over 20 nm into the AlGaN and GaN

  1. Prefabricación

    Directory of Open Access Journals (Sweden)

    Eymar, J. M.

    1999-08-01

    Full Text Available Se han utilizado en la construcción del nuevo edificio del Instituto Técnico de la Construcción y del Cemento, algunos sistemas constructivos que han exigido la fabricación en taller de elementos tales como cercos de hormigón para ventanas, losas de forjado, gárgolas para desagües de cubierta, placas de cielorraso, conductos para aire acondicionado, etc, etc. En el presente artículo se exponen los tipos de estas piezas y el sistema adoptado para su fabricación y montaje.

  2. Conclusión

    OpenAIRE

    Blanquer, Jean-Michel; Fajardo Montaña, Dario

    2014-01-01

    Una descentralización efectiva debe conducir a un fortalecimiento real de las regiones y de los municipios, en términos económicos, políticos, culturales y sociales. Esto no puede lograrse solamente con acciones dirigidas a la dotación de servicios básicos. Es preciso incorporar otras áreas estratégicas de intervención del Estado, como son el acceso a los recursos productivos (tierras, crédito, tecnologías), condiciones de intercambio y la institucionalización y protección de la libre represe...

  3. Esterificación

    Directory of Open Access Journals (Sweden)

    Francisco J. Sánchez C.

    1996-01-01

    Full Text Available Los conceptos básicos en una reacción de esterificación ácido-alcohol, se plantean de una forma clara y concreta, incluyendo mecanismo de la reacción, efecto del alcohol y del ácido, tipos de catalizador, proporciones y forma de operación todo lo cual redunda en un buen diseño en un proceso de esterificación. Todos estos conceptos muy conocidos, son actualmente aplicados minuciosa y detalladamente en los procesos de esterificación, algunos de ellos en investigación y otros cubiertos por el velo de patentes recientes.

  4. Presentación

    Directory of Open Access Journals (Sweden)

    AIBR. Consejo de Redacción

    2009-05-01

    Full Text Available Al igual que en cualquier otra disciplina académica, el desarrollo de la comunicación científica en antropología social y cultural lleva experimentando desde los últimos cinco años un profundo proceso de transformación, en sus modelos y en sus criterios de calidad. La progresiva incorporación a la oferta editorial por parte de las revistas de acceso abierto, así como una creciente preocupación sobre los índices de impacto y la indexación de artículos, están conformando también este nuevo panorama en nuestra disciplina.

  5. On the effect of N-GaN/P-GaN/N-GaN/P-GaN/N-GaN built-in junctions in the n-GaN layer for InGaN/GaN light-emitting diodes.

    Science.gov (United States)

    Kyaw, Zabu; Zhang, Zi-Hui; Liu, Wei; Tan, Swee Tiam; Ju, Zhen Gang; Zhang, Xue Liang; Ji, Yun; Hasanov, Namig; Zhu, Binbin; Lu, Shunpeng; Zhang, Yiping; Sun, Xiao Wei; Demir, Hilmi Volkan

    2014-01-13

    N-GaN/P-GaN/N-GaN/P-GaN/N-GaN (NPNPN-GaN) junctions embedded between the n-GaN region and multiple quantum wells (MQWs) are systematically studied both experimentally and theoretically to increase the performance of InGaN/GaN light emitting diodes (LEDs) in this work. In the proposed architecture, each thin P-GaN layer sandwiched in the NPNPN-GaN structure is completely depleted due to the built-in electric field in the NPNPN-GaN junctions, and the ionized acceptors in these P-GaN layers serve as the energy barriers for electrons from the n-GaN region, resulting in a reduced electron over flow and enhanced the current spreading horizontally in the n- GaN region. These lead to increased optical output power and external quantum efficiency (EQE) from the proposed device.

  6. SIMULACIÓN Y EVALUACIÓN

    Directory of Open Access Journals (Sweden)

    Emilia Sande Lemos

    2005-12-01

    Full Text Available RESUMEN: Con este artículo se pretende realizar una revisión de la literatura sobre la evaluación de los impactos educativos de las simulaciones. Esta perspectiva de análisis de las simulaciones, ha retenido la atención de diversos investigadores, aunque sin conclusiones muy objetivas, siendo una de las principales la dificultad en crear instrumentos de evaluación para esta metodología de enseñanza y aprendizaje. PALABRAS CLAVE: Evaluación, simulaciones educativas, motivación, memoria a largo plazo.ABSTRACT: The subject of this paper is a bibliographic revue on the learning progress evaluation of simulation methods. At the end one can assume that is not easy to assert an accurate model to create tools to evaluate the different learning achievement obtained with simulations.KEY WORDS: Evaluation, educational simulations, motivation, long term retentationRÉSUMÉ: Dans cet article ont fait un  révision des études sur la évaluation des apprentissages éd~cationnelles dues a la application des simulations.Dans ces études on ne trouve pas des conclusions tres objectives, parce que ont a des dificultés dans la création des instruments pour les apprentissages dues A  les simulations.Avant de décnre ses études nous ferons une bref explication sur la définition de simulation et aussi sur les caractéristiques des simulation éducationnelles.MOTS CLÉ:Evaluation, simulations éducationnelles, motivation, mémorisation a long terme

  7. Presentación

    Directory of Open Access Journals (Sweden)

    AIBR. Consejo de Redacción

    2017-01-01

    Full Text Available Como si de un proceso evolutivo se tratase, el desarrollo y crecimiento de una revista científica también sigue una senda de cambios para adaptarse al entorno en el que vive. Por fortuna, en nuestro caso el entorno no es una naturaleza incierta ni hostil, sino un gran grupo social definido por los y las miles de lectores que desde hace ya catorce años nos siguen acogiendo y apoyando. Es por eso que el presente número de la revista, aunque algo más breve en contenidos que los números anteriores, emprende su marcha a través de uno de los retos «adaptativos» más ambiciosos llevados a cabo por una publicación periódica de antropología en acceso abierto. Este reto es la publicación de los textos íntegros de nuestros artículos en idioma inglés. En el momento de escribir estas líneas, un total de cuatro traductores, pertenecientes al Departamento de Lenguas Modernas en The State University of New York at Potsdam, están preparando la versión inglesa del número, que estará disponible dentro de los cinco próximos meses después de la aparición en su versión en castellano.

  8. Biogestión

    Directory of Open Access Journals (Sweden)

    Oscar Castellanos

    2001-12-01

    Full Text Available El presente artículo relaciona los conceptos de la gestión y de las ciencias de la vida, enlazándolos en el desarrollo tecnológico y empresarial. Inicialmente describe la evolución de la biotecnología, enfatizando que, aunque es un área estratégica en el país, la cantidad de grupos de investigación y empresas dedicadas a esta actividad es muy baja, además no se practica un manejo apropiado de su gestión. Igualmente se realiza una breve descripción histórica de las diferentes técnicas administrativas, desde el Taylorismo hasta la incidencia en las organizaciones de la cibernética y la complejidad. Mediante la metáfora biológica, se demuestra el impacto de los conceptos y sistemas biológicos en la evolución de la gestión. Los dos anteriores enfoques permiten plantear una opción metodológica para la interacción entre lo biológico y la gestión, denominada biogestión, compuesta de dos aspectos: el conceptual, que inserta en la gestión los modelos de la biología y áreas afines, y el instrumental, que desarrolla los elementos de la gestión, aplicados de forma integral en el paquete tecnológico de la biotecnología.

  9. "Zhizneopisanie" astronomia N. N. Pavlova, im samim napisannoe %t Astronomer N. N. Pavlov's autobiography

    Science.gov (United States)

    Zhukov, V. Yu.

    This document called by the author "the life story" is written for the human resources department. It is a document intended for the official departmental purposes. At the same time there is something facinating about this documentary testimony about the epoch and the man. This short autobiography describes the early years of the Pulkovo astronomer N. N. Pavlov that fell on hard times of the Civil War. In the years between the World War I and the World War II he was awarded Mendeleyev Prize. He defended his doctorate dissertation after the evacuation from Leningrad. He was one fo the first Pulkovo astronomers to return to Leningrad in order to start reconstruction of the observatory that had been completely ruined during the war. Astronomer N. N. Pavlov renewed the Time Service in the city. N. N. Pavlov was a successful scientist and an outstanding person, all his life was devoted to science.

  10. Presentación

    Directory of Open Access Journals (Sweden)

    David Esteban Zuluaga Mesa

    2016-06-01

    Full Text Available La tarea investigativa es ciertamente compleja. Exige apropiarse de un “objeto”, mirarlo desde diferentes ángulos, considerar todas sus dimensiones, hacerlo propio. Esto implica, sin embargo, no un acostumbramiento, sino la reinvención de lo que miramos, introducirse en cada uno de sus pliegues, curvaturas, entresijos y demás, para posibilitar el surgimiento natural de una motivación, de un “nuevo” problema de investigación.

  11. Nutrición /

    OpenAIRE

    España de Córdoba, Lucía

    2012-01-01

    Se profundiza en conocer todo lo relacionado con la nutrición, sus factores, su desarrollo y las enfermedades que se pueden llegar a dar por una mala alimentación, cómo llevar un estilo de vida saludable y se analizan además, algunos aspectos de la nutrición en el deporte y en la infancia

  12. Noncompact N=2 supergravity

    International Nuclear Information System (INIS)

    Wit, B. de; Lauwers, P.G.; Philippe, R.; Van Proeyen, A.

    1983-10-01

    A massive spin-1 multiplet with central charge is coupled to N=2 supergravity. Compared to conventional gauge fields the anomalous magnetic moment of the spin-1 particles is of opposite sign. The construction of this theory is based on an N=2 supersymmetric gauge theory associated with the noncompact group SO(2,1). As a byproduct we present a convenient expression for the N=2 Einstein-Yang-Mills lagrangian. (Auth.)

  13. 40 CFR 721.10056 - Benzenemethanaminium, N-(3-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenemethanaminium, N-(3-aminopropyl...-aminopropyl)-N,N-dimethyl-, N-soya acyl derivs., chlorides. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as benzenemethanaminium, N-(3-aminopropyl)-N,N...

  14. Ruthenium (3) coordination compounds with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Ezerskaya, N A; Ki, Buj Kuang; Shubochkin, L K

    1987-12-01

    In the process of interaction of K/sub 2/Ru(H/sub 2/O)Cl/sub 5/ with ethylenediamine-N,N,N',N'-tetramethylphosphonic acid (H/sub 8/EDTP) Ru/sup 3/ mono-, bi- and trinuclear complexonates are synthesized. On the basis of IR and X-ray electron spectroscopy and potentiometry suppositions are made on the way of ligand (EDTP, Cl/sup -/, H/sub 2/O) coordination. Ru/sup 3/ complexonates are characterized using spectrophotometry, polarography, conductometry. Thermal decomposition of the complexonates is studied.

  15. Presentación

    Directory of Open Access Journals (Sweden)

    Sandra Milena Restrepo Escobar

    2016-07-01

    Full Text Available En su labor de profundización en el tema de las adicciones, los artículos de este segundo número, del primer volumen, de la revista Drugs and Addictive Behavior, se refieren a las poblaciones vulnerables en diferentes contextos. Inicialmente, en el Editorial, la Doctora Xóchitl De San Jorge invita a reflexionar sobre el papel de las universidades ante el consumo de sustancias psicoactivas y el paso hacia las adicciones y la actuación de las Instituciones de Educación Superior frente a la responsabilidad de formar nuevos profesionales en el tema.

  16. Werksbetrokkenheid: 'n Empiriese ondersoek

    Directory of Open Access Journals (Sweden)

    A. S. Engelbrecht

    1982-11-01

    Aangesien daar 'n komplekse verwantskap tussen werksbetrokkenheid, werkstevredenheid en werksprestasie is en teenstrydige resultate hieroor bestaan, is daar 'n behoefte aan verdere navorsing ten einde hierdie verwantskappe op te klaar. Benewens hierdie verwantskappe is geslagsverskille en moontlike verskille tussen vol- en halfdag vroulike werknemers in werksbetrokkenheid ook ondersoek. Twee vraelyste en 'n grafiese beoordelingskaal is aan 'n monster bestaande uit 164 klerklike personeellede geadministreer. Beduidende positiewe korrelasies is tussen werksbetrokkenheid en werksprestasie en tussen werksbetrokkenheid en die verskillende dimensies van werkstevredenheid gevind. Geen beduidende verskil is tussen mans en vrouens asook tussen vol- en halfdag vroulike werknemers ten opsigte van werksbetrokkenheid verkry nie.

  17. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    Justus Fenner

    2009-12-01

    Full Text Available Como en los números anteriores, estaba previsto que el actual número ocho de nuestra revista Pueblos y Fronteras digital se constituyera a partir de una unidad temática, como un especial sobre una etnia poco estudiada: los garínagu o garífuna, nación caribeña producto del proceso de mestizaje entre esclavos africanos y población originaria, en el marco de un largo proceso de resistencia contra los colonizadores europeos. Hoy los aproximadamente trescientos mil garínagu habitan parte de la costa caribe de Belice, Guatemala, Honduras y Nicaragua....

  18. Neuroeducación

    OpenAIRE

    Herrero Martín, Sofía

    2017-01-01

    Actualmente, se están viviendo grandes cambios educativos, los tiempos han evolucionado y la enseñanza tradicional no tiene cabida en la escuela del siglo XXI. Debido a que vivimos en la cultura de la inmediatez, el profesorado debe buscar permanentemente la atención del alumnado y lograr su motivación se convierte cada vez más en una tarea compleja. El presente trabajo fin de grado tiene como finalidad analizar las ventajas e inconvenientes de la neuroeducación en el alumnado con y sin ne...

  19. Neuropharmacology of N,N-dimethyltryptamine.

    Science.gov (United States)

    Carbonaro, Theresa M; Gatch, Michael B

    2016-09-01

    N,N-dimethyltryptamine (DMT) is an indole alkaloid widely found in plants and animals. It is best known for producing brief and intense psychedelic effects when ingested. Increasing evidence suggests that endogenous DMT plays important roles for a number of processes in the periphery and central nervous system, and may act as a neurotransmitter. This paper reviews the current literature of both the recreational use of DMT and its potential roles as an endogenous neurotransmitter. Pharmacokinetics, mechanisms of action in the periphery and central nervous system, clinical uses and adverse effects are also reviewed. DMT appears to have limited neurotoxicity and other adverse effects except for intense cardiovascular effects when administered intravenously in large doses. Because of its role in nervous system signaling, DMT may be a useful experimental tool in exploring how the brain works, and may also be a useful clinical tool for treatment of anxiety and psychosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Presentación

    Directory of Open Access Journals (Sweden)

    AIBR. Consejo de Redacción

    2013-01-01

    Full Text Available Los últimos meses han traído algunas importantes novedades en nuestra revista. La primera de ellas fue el lanzamiento, a finales de 2012, de la primera convocatoria del Premio AIBR al Mejor Artículo de Antropología Iberoamericana. La respuesta por parte de público y autores fue contundente. En pocas semanas nuestra redacción duplicó la cantidad de manuscritos recibidos, una proporción que desde entonces ha seguido aumentando mes a mes. La segunda novedad destacada fue el lanzamiento de la nueva página web de AIBR, en la que nuestra Asociación lleva trabajando desde hace más de un año. La nueva página incorpora una profunda renovación en la clasificación de los contenidos que AIBR viene generando desde más de una década. Además, a partir de ahora todos los artículos publicados quedarán indexados en el repositorio digital DOI (Digital Object Identifier. La nueva web incorpora también un sistema de exportación de citas a programas habituales de uso académico, tales como Endnote, Procite, Reference Manager o Mendeley.

  1. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L

    2000-01-01

    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...

  2. N R Munirathnam

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N R Munirathnam. Articles written in Bulletin of Materials Science. Volume 25 Issue 2 April 2002 pp 79-83 Materials Synthesis. Preparation of high purity tellurium by zone refining · N R Munirathnam D S Prasad Ch Sudheer A J Singh T L Prakash · More Details Abstract Fulltext ...

  3. Presentación

    Directory of Open Access Journals (Sweden)

    AIBR. Consejo de Redacción

    2009-09-01

    Full Text Available El año 2009 ha traído cambios fundamentales en el funcionamiento de la revista AIBR, tales como la incorporación de la revista a los principales índices de impacto internacionales, el notable incremento de sus lectores y la triplicación de la cantidad de manuscritos recibidos para ser evaluados. Debido a estos y otros factores, algunos meses atrás nuestra revista llevó a cabo un proceso de ampliación de su consejo editorial y evaluador, cuyos nuevos miembros presentamos en esta edición. Se trata de especialistas procedentes de prestigiosas universidades, entidades y centros de investigación en diversos países de Iberoamérica y gracias a los cuales nuestra publicación está incrementando su alcance temático y geográfico. Las primeras palabras de este número, por lo tanto, son un mensaje de felicitación y agradecimiento para todas aquellas personas que se incorporan a nuestro consejo, y a quienes deseamos la mejor suerte en su labor editorial.

  4. Large N Scalars

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2016-01-01

    We construct effective Lagrangians, and corresponding counting schemes, valid to describe the dynamics of the lowest lying large N stable massive composite state emerging in strongly coupled theories. The large N counting rules can now be employed when computing quantum corrections via an effective...

  5. K N Ganeshaiah

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. K N Ganeshaiah. Articles written in Resonance – Journal of Science Education. Volume 3 Issue 1 January 1998 pp 36-46 General Article. Love Games that Insects Play - The Evolution of Sexual Behaviours in Insects · K N Ganeshaiah · More Details Fulltext PDF ...

  6. N R Krishnaswamy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N R Krishnaswamy. Articles written in Resonance – Journal of Science Education. Volume 1 Issue 1 January 1996 pp 56-62 Series Article. Learning Organic Chemistry Through Natural Products Natural Products - A Kaleidoscopic View · N R Krishnaswamy.

  7. R N Mandal

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. R N Mandal. Articles written in Resonance – Journal of Science Education. Volume 18 Issue 8 August 2013 pp 732-737 General Article. The Sacred Lotus - An Incredible Wealth of Wetlands · R N Mandal R Bar · More Details Fulltext PDF ...

  8. N L Khobragade

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. N L Khobragade. Articles written in Sadhana. Volume 30 Issue 4 August 2005 pp 555-563. Thermal deformation in a thin circular plate due to a partially distributed heat supply · N L Khobragade K C Deshmukh · More Details Abstract Fulltext PDF. In this paper, we develop an integral transform to ...

  9. M N Deshpande

    Indian Academy of Sciences (India)

    Articles written in Resonance – Journal of Science Education. Volume 7 Issue 7 July 2002 pp 89-91 Think It Over. A Problem in Number Theory · M N Deshpande · More Details Fulltext PDF. Volume 7 Issue 7 July 2002 pp 91-91 Think It Over. A Geometric Dissection Problem · M N Deshpande · More Details Fulltext PDF.

  10. S N Hasan

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. S N Hasan. Articles written in Resonance – Journal of Science Education. Volume 12 Issue 3 March 2007 pp 13-26 General Article. Interactions and Mergers of Galaxies · S M Alladin S N Hasan · More Details Fulltext PDF ...

  11. N S Vasanthi

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N S Vasanthi. Articles written in Resonance – Journal of Science Education. Volume 11 Issue 11 November 2006 pp 48-55 General Article. Cancer Vaccines: The New Fight Against Cancer · N S Vasanthi · More Details Fulltext PDF ...

  12. N Pon Saravanan

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N Pon Saravanan. Articles written in Resonance – Journal of Science Education. Volume 9 Issue 1 January 2004 pp 6-11 General Article. Indoor Air Pollution - Danger at Home · N Pon Saravanan · More Details Fulltext PDF ...

  13. n b shirsath

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N B SHIRSATH. Articles written in Bulletin of Materials Science. Volume 41 Issue 2 April 2018 pp 44. 3D Architectured polyazomethine gel synthesis: its self-assembled intercalating complexation with nitro aromatic acceptor · D S RAGHUVANSHI N B SHIRSATH P P ...

  14. M N Saha

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. M N Saha. Articles written in Resonance – Journal of Science Education. Volume 3 Issue 5 May 1998 pp 84-96 Classics. The Origin of Mass in Neutrons and Protons · M N Saha · More Details Fulltext PDF ...

  15. N D Pandey

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. N D Pandey. Articles written in Bulletin of Materials Science. Volume 29 Issue 3 June 2006 pp 233-238 Biomaterials. External stimuli response on a novel chitosan hydrogel crosslinked with formaldehyde · A Singh S S Narvi P K Dutta N D Pandey · More Details Abstract Fulltext ...

  16. C N Sundaresan

    Indian Academy of Sciences (India)

    Fascinating Organic Molecules from Nature - Colours in Flight - Pigments from Bird Feathers and Butterfly Wings · N R Krishnaswamy C N Sundaresan · More Details Fulltext PDF. Volume 18 Issue 3 March 2013 pp 218-225 Series Article. Fascinating Organic Molecules from Nature - Hunting with Poisoned Arrows: Story of ...

  17. Presentación

    OpenAIRE

    Instituto de Estudios Latinoamericanos, Temas de Nuestra América

    2016-01-01

    Este número de Temas de Nuestra América que reúne los materiales correspondientes a los números 31 y 32 se inicia con el artículo a titulado A mas de cien años de la muerte de José Martí, del historiador Juan Rafael Quesada Camacho.

  18. N B Vijayaprakash

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. N B Vijayaprakash. Articles written in Resonance – Journal of Science Education. Volume 18 Issue 8 August 2013 pp 748-755 General Article. Lipophorin Receptor: The Insect Lipoprotein Receptor · G Ravikumar N B Vijayaprakash · More Details Fulltext PDF ...

  19. N-Nitrosodiethanolamine Revisited

    DEFF Research Database (Denmark)

    Andersen, Jan Rud; Pedersen, Walther Batsberg; Carlsen, Lars

    1980-01-01

    N-nitrosodiethanolamine is believed to be a weakly carcinogenic chemical, and as it occurs widely--in consumer products for example--it may constitute a significant hazard to humans. However, the chemical evidence concerning the identity, purity and properties of N-nitrosodiethanolamine is incomp......N-nitrosodiethanolamine is believed to be a weakly carcinogenic chemical, and as it occurs widely--in consumer products for example--it may constitute a significant hazard to humans. However, the chemical evidence concerning the identity, purity and properties of N...... pressure column chromatography and distillation are shown to be inadequate. The purity and identity of purified N-nitrosodiethanolamine is established by means of electron impact and field ionization mass spectrometry, including metastable defocusing and collision induced decomposition techniques...

  20. Migración

    Directory of Open Access Journals (Sweden)

    Acreche, Noemí

    2007-01-01

    Full Text Available Se estudió la relación migración - deriva en tres poblaciones puneñas (Cobres, Santa Rosa de los Pastos Grandes y Tolar Grande. Se construyeron las correspondientes matrices de migración progenitor - descendiente. Se partió de las frecuencias alélicas en 8 loci de grupos sanguíneos eritrocitarios (L*M, L*S, Di*B, P1, C, D, E y k y se las proyectó 250 generaciones. Si bien las poblaciones estudiadas, desde el punto de vista de la demografía genética presentan coeficientes de aislamiento reproductivo que indican fuerte sujeción a la deriva (la migración efectiva no es suficiente para compensar los bajos efectivos poblacionales, con ayuda de este modelo se verifica que en muy pocas generaciones es factible llegar al equilibrio.

  1. Introducción

    OpenAIRE

    Galinier, Jacques

    2014-01-01

    En el capítulo precedente, la descripción de las estructuras del habitat permitió tener una idea de conjunto de la distribución de los grupos de unidades domésticas (pueblos, barrios y rancherías). A partir de ese bosquejo apareció el principio de clasificación jerárquica de los centros rituales otomíes, organizados dentro de un esquema dicotómico que opone religión católica y prácticas indígenas. Gracias al examen de esta compleja cuestión del dualismo territorial y cosmológico se revelaron ...

  2. Composite Cu/Fe/MgB{sub 2} superconducting wires and MgB{sub 2}/YSZ/Hastelloy coated conductors for ac and dc applications

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B A [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge (United Kingdom); Majoros, M [Interdisciplinary Research Centre in Superconductivity, University of Cambridge, Madingley Road, Cambridge (United Kingdom); Vickers, M [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge (United Kingdom); Eisterer, M [Atomic Institute of the Austrian Universities, A-1020 Vienna (Austria); Toenies, S [Atomic Institute of the Austrian Universities, A-1020 Vienna (Austria); Weber, H W [Atomic Institute of the Austrian Universities, A-1020 Vienna (Austria); Fukutomi, M [National Institute for Materials Science, Superconducting Materials Center, 1-2-1, Sengen, Ibaraki (Japan); Komori, K [National Institute for Materials Science, Superconducting Materials Center, 1-2-1, Sengen, Ibaraki (Japan); Togano, K [National Institute for Materials Science, Superconducting Materials Center, 1-2-1, Sengen, Ibaraki (Japan)

    2003-02-01

    We discuss the results of a study of MgB{sub 2} multifilamentary conductors and coated conductors from the point of view of their future dc and ac applications. The correlation between the slope of the irreversibility line induced by neutron irradiation defects and in situ structural imperfections and the critical temperature and critical current density is discussed with respect to the conductor performance and applicability. We debate the possible origin of the observed anomalous decrease of ac susceptibility at 50 K in copper clad in situ powder-in-tube MgB{sub 2} wires. Different conductor preparation methods and conductor architectures, and attainable critical current densities are presented. Some numerical results on critical currents, thermal stability and ac losses of future MgB{sub 2} multifilamentary and coated conductors with magnetic cladding of their filaments are also discussed.

  3. Étude du soudage LASER Yb : YAG homogène et hétérogène des superalliages Hastelloy X et Haynes 188

    OpenAIRE

    Graneix, Jérémie

    2015-01-01

    De nos jours, la complexité des pièces mécaniques est de plus en plus grande dans de nombreux secteurs industriels de pointes tels que l’aéronautique, l’aérospatiale ou bien encore le domaine médical. Pour répondre à ces nouvelles exigences, notamment en termes de géométrie, de nouvelles techniques de conception et de fabrication automatisées intègrant également une meilleure traçabilité des pièces, sont mises en place. Ce travail de thèse s’est inscrit dans un projet partenarial entre le Lab...

  4. Presentación

    Directory of Open Access Journals (Sweden)

    Leopoldo Múnera

    2015-07-01

    Full Text Available En el segundo semestre de 2012, las y los integrantes del Grupo de Investigación en Teoría Política Contemporánea (Teopoco iniciaron un proyecto colectivo sobre la autoidentificación y la relación con lo otro y lo diverso en el pensamiento político latinoamericano. De acuerdo con las propuestas presentadas y con las preferencias personales, escogimos doce autores y autoras para desarrollar la investigación nacidos en la subregión o cuyas experiencias vitales e intelectuales hubieran estado determinadas por ella. En el presente número de la revista Ciencia Política publicamos siete textos, alrededor de las obras de José Carlos Mariátegui, María Luisa Bemberg, Bolívar Echeverría, Aníbal Quijano, Flora Tristán, Fernando González Ochoa y Paulo Freire.

  5. Presentación

    Directory of Open Access Journals (Sweden)

    Wileidys Artigas

    2014-01-01

    Full Text Available El primero de ellos, referido al área educativa, de Ramon Acosta, Elizabeth Miquilena y Victor Riveros, titulado: LA INFRAESTRUCTURA DE LAS TECNOLOGÍAS DE LA INFORMACIÓN Y COMUNICACIÓN COMO MEDIADORAS Y EL APRENDIZAJE DE LA BIOLOGÍA; en el cual nos muestran cómo puede beneficiar el uso de la tecnología en el aprendizaje de esta área del conoci-miento. Seguido con el área gerencial, con el aporte de Alanis Ulasio y Mayela Yépez a través de PROCESOS DE LA GESTIÓN DE RIESGO TECNOLÓGICO EN CONSULTORES AMBIENTALES PRIVADOS en el cual se hace referencia a los riesgos tecnológicos de los cuales son objeto este tipo de empresas y la importancia de la gestión del riesgo como parte inherente de la gerencia. Continúa en la parte de gerencia,Alvaro Finali y Linda Chacín con BALANCED SCORECARD EN LAS EMPRESAS MIXTAS PETROLERAS DEL MUNICIPIO MARACAIBO DEL ESTADO ZULIA, en el cual se muestran los resultados de campo de la medición del uso e implementación de esta herramienta gerencial.

  6. Globalización e integración latinoamericana

    OpenAIRE

    Salgado Peñaherrera, Germánico

    1998-01-01

    SUMARIO: 1. Las características de la globalización: sus alcances. 2. La globalización económica. 2.1. Concepciones de la globalización. 2.2. Orígenes y elementos impulsores. 2.3. Manifestaciones de la globalización. 3. Los efectos de la globalización económica. 4. Globalización y regionalización. 5. ¿Qué clase de regionalización? 6. Conclusiones aplicables a nuestras políticas de integración. Instituto de Integración Latinoamericana

  7. CALIDAD, AUTOEVALUACIÓN Y ACREDITACIÓN UNIVERSITARIA

    OpenAIRE

    Maraví, Doris

    2014-01-01

    La Comisión Nacional de Rectores para la Acreditación Universitaria promueve la cultura de autoevaluación y la mejora continua de la institución, determina los lineamientos y estándares de autoevaluación con fines de acreditación, asesora y apoya a las universidades en sus procesos de autoevaluación, y promueve la capacitación de evaluadores La Comisión Nacional de Rectores para la Acreditación Universitaria inicia sus labores en abril de 2002, cumple las siguientes funciones: • Apoya a la Of...

  8. Presentación

    Directory of Open Access Journals (Sweden)

    Edgar Alberto Novoa Torres Departamento de Ciencia Política, Universidad Nacional de Colombia

    2014-07-01

    Full Text Available Los feminismos latinoamericanos expresan una gran diversidad teóri- co-analítica, nuevos caminos interpretativos, asi como variadas estrate- gias de organización y participación, en medio de una realidad comple- ja, difícil y diversa, en un panorama cargado de carencias y dificultades, así como de posibilidades agenciadas o potenciadas por las mismas mu- jeres. En medio de la profunda reestructuración económica neoliberal, los ajustes político-institucionales acompañados de la presencia de go- biernos alternativos y el auge de una diversidad de formas de organiza- ción y lucha (política, social, cultural, ambiental, propia de su misma realidad, se plantean escenarios en constante transformación y cambio, en donde las mujeres han jugado un papel muy importante. A pesar de los avances en algunos aspectos (reconocimiento de de- rechos, políticas sociales, aumento en la participación político-institu- cional, la exclusión en todas sus dimensiones, la manipulación y la vio- lencia en todas sus formas siguen asaltando los cuerpos de las mujeres. Sin embargo, hay tiempo para valorar el pasado y es posible encontrar en la actualidad destellos importantes de resistencias en medio de una cultura y política altamente machista y patriarcal, por la acción decidida de las mujeres en diversos espacios y a través de multiples estrategias, al interior de partidos y movimientos de todo tipo y, a través de sus pro- pias organizaciones. Esa diversidad compleja se expresa en los distintos textos que componen el presente numero de Ciencia Política, temas y problemas que dan cuenta de una materialidad que sigue teniendo una deuda no solamente acumulada, sino actual y definitivamente, a futuro con las mujeres.

  9. Presentación

    OpenAIRE

    Troncoso, Marino; Pontificia Universidad Javeriana

    2004-01-01

    El Departamento de Literatura de la Facultad de Ciencias Sociales y Educación de la Pontificia Universidad Javeriana es, ante todo, el espacio donde se desarrolla una conciencia de cultura. Por eso, las distintas seccio­nes que componen el número de Universitas Humanística quieren manifestar esa conciencia y proponerla al lector no como un hecho cumplido, sino como una tarea. Todos los días laboramos y pensamos nuestra cultura. Sin embargo, a partir de este número Universitas Humanística, ten...

  10. Presentación

    Directory of Open Access Journals (Sweden)

    Wileidys Artigas

    2016-01-01

    Full Text Available El primero de ellos titulado Innovación tecnológica. Caso: Centro de Audiovisuales de la Universidad de la Guajira colombiana, de Lilia Palacios Sprockely Gilberto Cotes Sprockel, el cual resalta la importancia de los centros en las Universidades y sus procesos internos; seguido del artículo de Arminda García, titulado Cultura de servicio en la optimización del servicio al cliente, en donde no podemos omitir la importancia de la orientación de la cultura del servicio hacia la mejora del resultado de cara a los clientes.

  11. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

  12. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

  13. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

  14. Introducción

    OpenAIRE

    Aguiar, Diego; Lugones, Manuel; Quiroga, Juan Martín; Aristimuño, Francisco

    2018-01-01

    Este libro tiene un doble significado. Por un lado, representa la culminación de un trabajo iniciado hace unos años por el Programa de Desarrollo, Política y Gestión de la Ciencia, la Tecnología y la Innovación en el Centro de Estudios en Ciencia, Tecnología, Cultura y Desarrollo (citecde) de la Universidad Nacional de Río Negro (unrn). En él, nos abocamos a estudiar los cambios en las políticas de ciencia, tecnología e innovación (cti) en la Argentina a partir del retorno a la democracia. Po...

  15. Presentación

    Directory of Open Access Journals (Sweden)

    El Editor

    2011-05-01

    Full Text Available Después de haber cumplido 75 años de vida, Letras renueva suvocación humanista y, a través de ella, la noble defensa de laimportancia de los estudios literarios, filosóficos, lingüísticos y sobrearte, en todos los niveles de la educación. En un mundo marcado afuego por la incomunicación y la ciega destrucción, ningún esfuerzoes suficiente para combatir los insustanciales y a la vez peligrososataques de aquellos que argumentan en contra de las humanidades yevalúan, injustamente, nuestro quehacer, llevados por un pragmatismodespojado de sensibilidad y solidaridad humanas.

  16. Presentación

    Directory of Open Access Journals (Sweden)

    Sandra Milena Restrepo Escobar

    2017-01-01

    Full Text Available Los cambios sociales que se han producido en las últimas décadas han generado grandes transformaciones en las dinámicas de la sociedad, lo que ha incluido nuevos consumos asociados a los procesos de globalización, que además amplían las posibilidades de ser adictos al plano comportamental, afectando así la vida de las personas en sus ámbitos individual, familiar y social. Este panorama hace que las posibilidades de estudios en el tema cada vez se diversifiquen más y abran alternativas a contenidos que en el pasado no se habían explorado. De esta forma, en el volumen 2, número 1, de la revista Drugs and Addictive Behavior se encontrarán textos variados sobre el consumo y las adicciones, además de los cuestionamientos por la prevención.

  17. Presentación

    Directory of Open Access Journals (Sweden)

    Sandra Milena Restrepo Escobar

    2017-07-01

    Full Text Available Investigar sobre consumo de sustancias psicoactivas o sobre adicciones comportamentales denota plantear múltiples perspectivas por la pluralidad de enfoques, aspectos a estudiar y variantes con la población, por solo mencionar estos factores; de ahí que cada número de la revista traiga siempre diversidad en los temas tratados que invitan, además, a cuestionarse por nuevos planteamientos problemáticos en las adicciones.

  18. Extracting properties of N,N,N'N'-tetraalkyl-2 alkyl propane -1,3 diamides

    International Nuclear Information System (INIS)

    Nigond, L.

    1992-01-01

    N,N,N',N'-tetraalkyl -2 alkyl propane -1,3 diamides (RR'NCO) 2 CHR'' are investigated in the aim to separate actinides from nuclear wastes. N,N'-dimethyl N,N'-dibutyl tetradecylmalonamide (DMDBTDMA) was selected. This molecule can extract trivalent actinides in aliphatic diluents. Americium extraction is faster than iron extraction, hydrolytic degradation and solubility in aqueous phase are satisfactory. In non acidic media, diamides form aggregates, the size of which is function of diluent and diamide concentration. Extraction equilibria of HNO 3 , UO 2 2+ , Pu 4+ , Am 3+ and Fe 3+ are investigated.Four complexes are formed with nitric acid: L 2 HNO 3 , LHNO 3 , L 2 (HNO 3 ) 2 and L(HNO 3 ) 3 with L=DMDBTDMA. UO 2 2+ and Pu 4+ extraction takes place via the formation of neutral complexes: LUO 2 (NO 3 ) 2 , LPu(NO 3 ) 4 and L 2 Pu(NO 3 ) 4 for any nitric acid concentration. Am 3+ extraction takes place via the formation of LAm(NO 3 ) 3 and L 2 Am(NO 3 ) 3 for low nitric acid concentration and L x H y Am(NO 3 ) 3+y at higher acidity. Fe 3+ extraction involves anionic complexes L x HFe(NO 3 ) 4 for any acid concentration. In the presence of metallic cations, two kinds of interactions are observed: in the inner sphere of the metal diamide-metal ion complexation and in the outer sphere diamide-metallic complex interaction. The malonamide DMDBTDMA can be used to separate (III), (IV) and (VI) actinides from radioactive wastes

  19. Presentación

    Directory of Open Access Journals (Sweden)

    AIBR. Consejo de Redacción

    2008-01-01

    Full Text Available Tenemos el gusto de lanzar primer número del año 2008 con un conjunto de colaboraciones procedentes de autores de diversas especialidades de la disciplina, a las que hemos querido recoger bajo el título genérico de “Humor, representación y tradición”. A pesar de su diversidad temática, estamos seguros de que algunos de los textos ofrecidos en esta edición podrán recibirse por nuestros lectores como bellas muestras de materias sobre las que la disciplina ha venido girando durante las últimas décadas. El espacio de ensayo corre en esta ocasión a cargo de José Antonio González Alcantud, que nos ofrece el relato etnohistórico de una de las tradiciones centenarias de la región española de Andalucía, como son las carocas y los pliegos de cordel. Durante el siglo XIX, estos elementos fueron uno de los más significativos vehículos satíricos en el debate político, religioso y social. González Alcantud nos describe su estudio documental y recorre los escenarios a lo largo de la Andalucía de dos siglos atrás.

  20. Presentación

    Directory of Open Access Journals (Sweden)

    Catalina Toro

    2016-01-01

    Full Text Available La ecología política es un campo teórico en construcción en el que se destacan los diversos aportes del pensamiento y movimiento ambientalista/ecologista latinoamericano, particularmente en la última década en la que el modelo de extracción de recursos ha colonizado espacios físicos, simbólicos, jurídicos y políticos claves en el desarrollo de las sociedades urbanas y rurales de la región. A partir de esa perspectiva, desde América Latina se construye una crítica al modelo de desarrollo capitalista colonial, depredador de la naturaleza, a la luz de los repertorios de acción social empleados en la región para la movilización social y de las condiciones institucionales para adecuarse a los cambios tanto climáticos como epistémicos.

  1. Electron states at electrolyte/n-GaN and electrolyte/n-InGaN interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rudinsky, M. E., E-mail: rudinskym@mail.ru; Gutkin, A. A.; Brunkov, P. N. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2012-06-15

    The differential capacitance and differential active conductance of rectifying contacts of n-GaN and n-In{sub x}Ga{sub 1-x}N (x Almost-Equal-To 0.15) with an electrolyte (0.2 M aqueous solutions of NaOH, NaCl, or HCl) have been studied. It was found that electron states with energies corresponding to the upper half of the energy gap of a semiconductor exist at the interface between these semiconductors and a NaOH solution. The density and characteristic recharging time of states noticeably contributing to the differential capacitance and differential active conductance at probe-voltage frequencies of 0.3-1 kHz grow with their binding energy and, for states lying at 0.15-0.3 eV below the conduction-band bottom of n-GaN, fall within the ranges 10{sup 12}-2 Multiplication-Sign 10{sup 13} cm{sup -2} eV{sup -1} and 10{sup -4}-10{sup -2} s, respectively. For contacts with NaCl and HCl solutions, there are no states of this kind. It is assumed that the observed states are related to the adsorption of hydroxyl groups.

  2. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    Ana Judith Paredes Chacín

    2008-05-01

    Full Text Available Aciertos de una política, lema con el cual se podría definir la iniciativa liderada por el Dr. Andrade, Editor de la Revista Científica Enl@ce, quien durante dos años consecutivos, 2007 y 2008,ha promovido que otros coordinen números especiales sobre temáticas de vanguardia adaptadas al perfil de la revista. En esta oportunidad me corresponde asumir la responsabilidad de la edición dedicada al Valor Jurídico de la Información Electrónica.Un tema, como es evidente, de gran trascendencia en el contexto de una sociedad regida por una altísima demanda de información, accesibilidad y usabilidad de documentos electrónicos;elementos todos que permiten fortalecer la socialización del conocimiento más allá de cualquier frontera. Cierto es, sin embargo, que estos avances, respaldados por las redes telecomunicacionales,aún requieren la promulgación de novedosas bases jurídicas y legales, a fin de impactar el quehacer y las formas de concebir los procesos en las organizaciones que administran la justicia, la ciencia, laeducación y la cultura.Y es esa necesidad la que promueve la reflexión de expertos nacionales y extranjeros acerca del alcance, impacto y beneficios del uso de firmas, documentos y pruebas electrónicas, así comoacerca de la posibilidad de acceder a servicios informativos en ambientes intra e internet, el Habeas Data y los lineamientos de la protección legal ante los posibles delitos informáticos. Procesos todos que constituyen recursos estratégicos a la hora de respaldar el proceso evolutivo de las tecnologías de información.Tales avances deben ser considerados para la permanente adecuación y definición de la jurisprudencia en el área, por lo cual se hace indispensable monitorear la operatividad y el accionar de éstas leyes o normativas para coadyuvar a la transformación de la cultura de los usuarios y las organizaciones, con miras a promover el uso eficiente de los recursos informativos y tecnológicos.En l

  3. SO(2N) and SU(N) gauge theories

    OpenAIRE

    Lau, Richard; Teper, Michael

    2013-01-01

    We present our preliminary results of SO(2N) gauge theories, approaching the large-N limit. SO(2N) theories may help us to understand QCD at finite chemical potential since there is an orbifold equivalence between SO(2N) and SU(N) gauge theories at large-N and SO(2N) theories do not have the sign problem present in QCD. We consider the string tensions, mass spectra, and deconfinement temperatures in the SO(2N) pure gauge theories in 2+1 dimensions, comparing them to their corresponding SU(N) ...

  4. Potentials in N=2 supergravity

    International Nuclear Information System (INIS)

    Zinov'ev, Yu.M.

    1985-01-01

    The potentials and Yukava interactions, that arise while introducing a gauge interaction of vector and scalar multiplets in N=2 supergravity are presented, in this the gauge group may be either compact or noncompact. The scalar multiplets geometry corresponds to nonlinear σ, models of the form Sp(2,2n)/Sp(2)xSp(2n), SU(2,n)/SU(2)SU(n)xU(1) and O(4,n)/O(4)xO(n)

  5. Grandes números primos

    OpenAIRE

    Bang, Thöger

    2012-01-01

    En las escuelas danesas la teoría de los números se ha ido restringiendo gradualmente hasta no incluir sino la demostración de la descomposición univoca de los números enteros en números primos y la demostración del teorema clásico de EUCLIDES sobre la existencia de un número primo arbitrariamente grande.

  6. African N Assessment

    Science.gov (United States)

    Bekunda, M.; Galford, G. L.; Hickman, J. E.; Palm, C.

    2011-12-01

    Africa's smallholder agricultural systems face unique challenges in planning for reducing poverty, concurrent with adaptation and mitigation to climate change. At continental level, policy seeks to promote a uniquely African Green Revolution to increase crop yields and food production, and improve local livelihoods. However, the consequences on the environment and climate are not clear; these pro-economic development measures should be linked to climate change adaptation and mitigation measures, and research is required to help achieve these policy proposals by identifying options, and testing impacts. In particular, increased nitrogen (N) inputs are essential for increasing food production in Africa, but are accompanied by inevitable increases in losses to the environment. These losses appear to be low at input levels promoted in agricultural development programs, while the increased N inputs both increase current food production and appear to reduce the vulnerability of food production to changes in climate. We present field and remote sensing evidence from Malawi that subsidizing improved seed and fertilizers increases resilience to drought without adding excess N to the environment. In Kenya, field research identified thresholds in N2O losses, where emissions are very low at fertilization rates of less than 200 kg ha-1. Village-scale models have identified potential inefficiencies in the food production process where the largest losses of reactive N occur, and which could be targeted to reduce the amount of N released to the environment. We further review some on-going research activities and progress in Africa that compare different methods of managing resources that target resilience in food production and adaptation to climate change, using nutrient N as an indicator, while evaluating the effects of these resource management practices on ecosystems and the environment.

  7. Presentación

    Directory of Open Access Journals (Sweden)

    Eutopía Revista de Desarrollo Económico

    2013-09-01

    Full Text Available EUTOPÍA es una revista nueva dentro de las ciencias sociales de la región y busca, tal como su nombre lo evoca, la reflexión sobre lo que sucede en nuestra sociedad tomando como eje de análisis el territorio. Eu- topia proviene del griego: eu, bueno y topos lugar, literalmente significaría buen lugar y es justo sobre lo que buscamos reflexionar tanto a nivel de Ecuador como de América Latina. No basta con la teoría de moda del “buen vivir”, si no se dispone de un “buen lugar” para implementar una nueva forma de hacer economía, de recrear las relaciones de reciprocidad, de hacer política participativa, en concreto de construir una sociedad más justa y solidaria. La construcción de un “buen lugar”, no como una Utopía sino como algo real y viable es un reto en el cual es necesaria la incorporación activa del pensamiento social de avanzada en la región.

  8. educación

    Directory of Open Access Journals (Sweden)

    MARIANO NARODOWSKI

    2013-01-01

    Full Text Available El artículo describe un escenario social a partir de los conceptos de monopolio estatal sobre la educación escolar en una sociedad democrática, escolaridad gratuita y obligatoria la mayor cantidad de tiempo posible; infancia como razón de Estado, alianza escuela familia con énfasis en lo escolar y ciencia como paradigma del conocimiento enseñable. Los elementos apuntan hacia políticas públicas para la educación fundamental que respetan el principio de igualdad en el marco del máximo derecho a la educación. Para que este escenario sea posible, se delimitarán algunas cuestiones: la potestad paterna sobre la infancia, un desarrollo urbano mercantilizado y el derecho absoluto a educar y a educarse según pautas culturales singulares. El artículo indaga sobre los motivos de estas limitaciones y sobre las posibilidades de la política pública de sostener el irrestricto respeto al principio de igualdad modificando algunos de los elementos del escenario social originariamente propuesto.

  9. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L

    2000-01-01

    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...... (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar...... to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since...

  10. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    René Salinas Meza

    2011-10-01

    Full Text Available En esta ocasión, las investigaciones están centradas en la reconstrucción de algunos hitos importantes del desarrollo de la izquierda política en Chile, de sus actores centrales y de sus propuestas ideológicas y programáticas. Al mismo tiempo, revelan interesantes aspectos acerca del impacto de la difusión de las ideas socialistas en nuestro país y de los efectos sobre una elite que no dejó de sentir temor frente al fantasma del comunismo, que parecía ser bastante más real en el último tercio del siglo XIX. Existe un cierto consenso que a partir de las primeras décadas del siglo XX el socialismo, en sus diversas expresiones, alcanzó la consistencia de alternativa política a través de la cual se podían hacer lecturas de la realidad y construir proyectos de transformación profunda.

  11. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    René Salinas Meza

    2011-10-01

    Full Text Available En esta ocasión, las investigaciones están centradas en la reconstrucción de algunos hitos importantes del desarrollo de la izquierda política en Chile, de sus actores centrales y de sus propuestas ideológicas y programáticas. Al mismo tiempo, revelan interesantes aspectos acerca del impacto de la difusión de las ideas socialistas en nuestro país y de los efectos sobre una élite que no dejó de sentir temor frente al fantasma del comunismo, que parecía ser bastante más real en el último tercio del siglo XIX. Existe un cierto consenso que a partir de las primeras décadas del siglo XX el socialismo, en sus diversas expresiones, alcanzó la consistencia de alternativa política a través de la cual se podían hacer lecturas de la realidad y construir proyectos de transformación profunda.

  12. Educación popular

    OpenAIRE

    Ortiz, Pedro P.

    2009-01-01

    Reflexiones sobre la relación entre la educación popular con el individuo, la sociedad, la moral, la religión, la industria y la riqueza pública - La educación i el individuo - La educación i la sociedad

  13. The structure of N = 2 supergravity in N = 1 superfields

    International Nuclear Information System (INIS)

    Awada, M.A.; Mokhtari, S.

    1985-01-01

    A formulation of N = 2 supergravity in N = 1 superspace is presented. The authors solve up to all orders the N = 2 supergravity constraints in terms of unconstrained N = 1 superfields. The structure of the N = 2 action in N = 1 superspace is examined. The proposed action coincides in the quadratic limit of the spin (3/2,1) matter fields with the action given by previous workers. (author)

  14. Structure of N = 2 supergravity in N = 1 superfields

    Energy Technology Data Exchange (ETDEWEB)

    Awada, M.A.; Mokhtari, S. (Imperial Coll. of Science and Technology, London (UK). Blackett Lab.)

    1985-01-01

    A formulation of N = 2 supergravity in N = 1 superspace is presented. The authors solve up to all orders the N = 2 supergravity constraints in terms of unconstrained N = 1 superfields. The structure of the N = 2 action in N = 1 superspace is examined. The proposed action coincides in the quadratic limit of the spin (3/2,1) matter fields with the action given by previous workers.

  15. Presentación

    Directory of Open Access Journals (Sweden)

    Fernando CARRIÓN MENA

    2009-01-01

    Full Text Available América Latina Hoy da cuenta de esta nueva mirada en torno a la seguridad ciudadana, que generalmente ha estado opacada por las visiones hegemónicas enunciadas. Para comprender lo que ocurre en la región se debe partir del econocimiento del carácter político-económico de la seguridad ciudadana, lo cual se evidencia en los análisis contenidos en la revista, bajo dos bloques: el primero, vinculado a los elementos económicos y de políticas públicas (con cuatro artículos y, el segundo, sobre los «neoenemigos» que requieren la represión y la visión comparada de las tasas de homicidios (dos artículos.

  16. Comunicación

    Directory of Open Access Journals (Sweden)

    Revista Chasqui

    2011-09-01

    Full Text Available La comunicación, refundada como teoría autónoma para el estudio de todas las formas de interacciones comunicativas, desde sus orígenes evolutivos hasta sus manifestaciones culturales. Se plantea la importancia teórica de Manuel Martín Serrano desde la segunda mitad de los años 70 hasta la presente, como su gran reto científico. El conjunto de esta parte de su obra, trasluce un trabajo sistemático, que abarca los diversos ámbitos comunicativos donde se requiere la creación de teoría en sucesivas etapas, comenzando por lo concreto y culminando en lo general.

  17. Investigación e investigación formativa

    OpenAIRE

    Carlos Augusto Hernández

    2003-01-01

    Este artículo hace una distinción entre investigación e investigación formativa. También señala los peligros de confundir estas dos formas de trabajo académico e insiste en la necesidad de desarrollarlas simultáneamente para enfrentar los nuevos retos de la educación superior. Igualmente habla de la importancia de intensificar los vínculos entre investigación y docencia y hace la diferencia entre investigación pedagógica e investigación formativa. Finalmente cuestiona la posibilidad de una fo...

  18. Gamnificación

    OpenAIRE

    Pérez Pérez, José Miguel

    2013-01-01

    Pretendemos exponer un incipiente método de marketing conocido como gamificación, el cual consiste fundamentalmente en aplicar juegos para alcanzar objetivos que no tienen nada que ver con el mismo, sino que se trata conseguir que algo rutinario y pesado se convierta en dinámico y entretenido. Para ello, inicialmente se da una visión genérica, posteriormente se contextualiza en el campo de la empresa, dando importancia a las redes sociales. Una vez visto teóricamente, para u...

  19. Gainers n' Drainers

    DEFF Research Database (Denmark)

    2007-01-01

    "Gainers n' Drainers" is a video game for cell phones. The game is a pervasive game and the object is to practise socialising skills. Some persons "drain" your energy, while you "gain" energy from others. With "Gainers n' Drainers" you have to get close to the gainers and avoid the drainers. People...... are shown on your screen as dots on a radar. One aspect of the game is that people don't known they are participating in your game. The game uses Bluetooth....

  20. Nonabelian N=2 superstrings

    International Nuclear Information System (INIS)

    Isaev, A.P.; Ivanov, E.A.

    1990-04-01

    The Green-Schwarz covariant N=2 superstring action can be consistently deduced as the action of the Wess-Zumino-Witten (WZW) sigma model defined on the direct product of two N=1, D=10 Poincare supertranslation groups. Generalizing this result, we construct new WZW sigma models on the supergroups with a nonabelian even part and interpret them as models of superstrings moving on the supergroup manifolds. We show that these models are completely integrable and in some special cases possess fermionic k-symmetry. (author). 20 refs

  1. N-Acryloyl glycinamide

    Directory of Open Access Journals (Sweden)

    Jan Seuring

    2011-08-01

    Full Text Available The molecule of the title compound [systematic name: N-(carbamoylmethylprop-2-enamide], C5H8N2O2, which can be radically polymerized to polymers with thermoresponsive behavior in aqueous solution, consists of linked essentially planar acrylamide and amide segments [maximum deviations = 0.054 (1 and 0.009 (1 Å] with an angle of 81.36 (7° between their mean planes. In the crystal, N—H...O hydrogen bonding leads to an infinite two-dimensional network along (100.

  2. Presentación

    Directory of Open Access Journals (Sweden)

    Carolina Jiménez

    2017-07-01

    Full Text Available Diversos debates se han tejido en Nuestra América sobre los impactos de la crisis capitalista del último tiempo y la necesidad imperativa de construir alternativas que permitan resolver los asuntos fundamentales que de ella se desprenden. Existe cierto consenso al interior del pensamiento crítico sobre el carácter multidimensional de la misma y, en consecuencia, el desafío creativo que representa su resolución para los pueblos de la región.

  3. Percepción

    OpenAIRE

    Sanfélix, Vicente

    1995-01-01

    En este trabajo se analiza la experiencia dentro de una instalación, donde se ponen en juego los sentidos de la persona y permite distintos tipos de estímulos que sobrepasan los meramente visuales, por esta razón se consideran experiencias inmersivas con el entorno. A su vez se busca encontrar como este espacio se puede modificar por medio de distintos tipos de estímulos, principalmente los auditivos, ya que nos permiten reconocer el objeto, desde donde se originan los sonidos, el lugar y la ...

  4. Introducción

    Directory of Open Access Journals (Sweden)

    Roberto Augusto Ferro

    2017-07-01

    Full Text Available Los tres ensayos críticos que componen este dossier tienen un punto de convergencia en torno del cual he pensado articularlos: son modalidades diversas del ensayo crítico literario expuestas como teorizaciones de la lectura. En la variación de sus modulaciones, los trabajos exhiben un conjunto de rasgos distintivos que se van insinuando en los estudios literarios latinoamericanos, al tiempo que despliegan una serie de conjeturas que anuncian un hacer crítico capaz de no olvidar o reprimir la resistencia que los textos literarios presentan a la lectura ni el residuo de indeterminación que toda ocurrencia de palabra siempre provoca. Ya a fines del siglo pasado, la preeminencia en el ámbito de los estudios literarios de los grandes modelos teóricos fue socavada por su transformación en principio de autoridad. Pero este colapso no hubiese sido posible sin la puesta en cuestión de la voluntad de verdad que esos modelos ejercían desde su posición hegemónica. Así, muchas de sus manifestaciones derivaron en jergas de estereotipos convirtiendo en novedad de circulación mediática lo que ya eran anacronismos académicos. En los aledaños del año 2000, el tipo de deterioro de la teoría causado por su cooptación como moneda devaluada parece haberse extendido como parte de cierto sentido común en la crítica latinoamericana; vinculada a la crisis que sacude las humanidades, una de sus consecuencias más perturbadoras ha sido el desvío de la crítica literaria hacia los estudios culturales, con el cuestionamiento de la especificidad tanto de los estudios literarios como de la entidad de los propios textos literarios. Los textos de este dossier se alejan y confrontan con esa perspectiva exhibiendo variados modos de interdependencia entre los discursos que configuran el campo de la crítica literaria con los que participan del campo de la teoría literaria. En “Héctor Libertella, de la narración al ensayo. Una poética de la ficción te

  5. Probabilistic n-normed spaces, D-n-compact sets and D-n-bounded sets

    International Nuclear Information System (INIS)

    Pourmoslemi, A.; Salimi, M.

    2009-01-01

    In this paper, first we define and study the probabilistic n-normed spaces and D-n-compactness, also we prove some theorems and inequalities. In the next section we define D-n-boundedness and prove some results in relation between D-n-compact and D-n-bounded sets in these spaces.

  6. Factorización algebraica

    OpenAIRE

    Torres, Johana Andrea; Mora, Lyda Constanza; Luque, Carlos Julio

    2003-01-01

    Se presenta la necesidad de la factorización de números y expresiones algebraicas haciendo un recorrido por la historia de las matemáticas, específicamente con la solución de ecuaciones polinómicas con coeficientes racionales. Finalmente se muestra cómo el problema de encontrar la solución de una ecuación algebraica lleva al estudio de dominios de factorización única.

  7. P N Kotru

    Indian Academy of Sciences (India)

    Volume 33 Issue 4 August 2010 pp 377-382 Electrical Properties. Dielectric and thermal studies on gel grown strontium tartrate pentahydrate crystals ... High resolution X-ray diffraction studies on unirradiated and irradiated strontium hexaferrite crystals · Balwinder Kaur Monita Bhat F Licci Ravi Kumar K K Bamzai P N Kotru.

  8. Presentación

    Directory of Open Access Journals (Sweden)

    HC Presentación

    2010-02-01

    Full Text Available Los volúmenes de Studia Histórica (Historia Contemporánea reciben al lector con un comentario del Consejo de Redacción sobre su contenido. Reiterarlo en este número sería tanto como «mirar hacia otro lado» cuando el Estado de Derecho está amenazado en el País Vasco. Lo ha dicho el rector de su Universidad y profesor de Historia Contemporánea, Manu Montero: «la barbarie, la coacción terrorista, las presiones fascistas están amenazando a la democracia en el País Vasco. La democracia, nuestra democracia, está en peligro, en grave peligro. Como sucediera en los períodos más negros de nuestra historia». Nuestra mirada hoy se dirige a vosotros, a los profesores de Historia Contemporánea que hacéis del cotidiano quehacer profesional en el País Vasco un ejercicio de libertad, que mantenéis en condiciones muy difíciles la dignidad intelectual, que nos estáis dando un ejemplo impagable: hacer historia de la mejor calidad —esta entrega de Studia Histórica (Historia Contemporánea lo acredita— sin ceder al oportunismo o al miedo. Con nuestra solidaridad, nuestro agradecimiento.

  9. Presentación

    Directory of Open Access Journals (Sweden)

    HC Presentación

    2010-02-01

    Full Text Available En 1898, la flota española es destrozada por la de los Estados Unidos de América del Norte y, poco después, el Tratado de París consagra la pérdida de los últimos restos del Imperio: Cuba, Puerto Rico y Filipinas. La imagen de España como gran potencia se rompe y sobre el país, despertado a la realidad, se extiende la sombra del fracaso histórico. Tal es la interpretación clásica, que acentúa, ante todo, la profunda depresión del espíritu público, manifestada, en términos de Altamira, "por una intensificación del pesimismo nacional. No se creía ya en España, y eran los mismos españoles los que no creían en ella". Había fracasado la nación, culminando de esta forma nuestra decadencia histórica.

  10. T N Avinash

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. T N Avinash. Articles written in Resonance – Journal of Science Education. Volume 7 Issue 2 February 2002 pp 33-45 General Article. Untangling the Mystery of Alzheimer's Disease - Understanding Molecular Mechanisms for Novel Therapeutic Approaches.

  11. N E Zavoiskaya

    Indian Academy of Sciences (India)

    Logo of the Indian Academy of Sciences. Indian Academy of Sciences. Home · About IASc ... Resonance – Journal of Science Education. N E Zavoiskaya. Articles written in Resonance – Journal of Science Education. Volume 20 Issue 11 November 2015 pp 963-968 General Article. Zavoisky and the Discovery of EPR.

  12. B N Panda

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. B N Panda. Articles written in Pramana – Journal of Physics. Volume 77 Issue 4 October 2011 pp 715-726 Research Articles. Effect of hybridization and dispersion of quasiparticles on the coexistent state of superconductivity and antiferromagnetism in Ni2B2C · B K Sahoo ...

  13. Comparison of electrical characteristic between AlN/GaN and AlGaN/GaN heterostructure Schottky diodes

    International Nuclear Information System (INIS)

    Lü Yuan-Jie; Feng Zhi-Hong; Gu Guo-Dong; Dun Shao-Bo; Yin Jia-Yun; Han Ting-Ting; Cai Shu-Jun; Lin Zhao-Jun

    2014-01-01

    Ni/Au Schottky contacts on AlN/GaN and AlGaN/GaN heterostructures are fabricated. Based on the measured current—voltage and capacitance—voltage curves, the electrical characteristics of AlN/GaN Schottky diode, such as Schottky barrier height, turn-on voltage, reverse breakdown voltage, ideal factor, and the current-transport mechanism, are analyzed and then compared with those of an AlGaN/GaN diode by self-consistently solving Schrödinger's and Poisson's equations. It is found that the dislocation-governed tunneling is dominant for both AlN/GaN and AlGaN/GaN Schottky diodes. However, more dislocation defects and a thinner barrier layer for AlN/GaN heterostructure results in a larger tunneling probability, and causes a larger leakage current and lower reverse breakdown voltage, even though the Schottky barrier height of AlN/GaN Schottky diode is calculated to be higher that of an AlGaN/GaN diode. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  14. Comunicación social

    OpenAIRE

    Aiger, Montserrat

    2014-01-01

    La presentación en power point de la comunicación social plantea los elementos básicos de la comunicación duracte la interacción social y la actividad grupal. Se plantea una visión de la comunicación desde las neurociencias sociales, la comunicación como eje vertebrador del grupo, y los elementos que constituyen el proceso comunicativo. El feedback y la ventana de Johari como técnicas para favorecer la comunicación en el grupo.

  15. Characterization of N-polar AlN in GaN/AlN/(Al,Ga)N heterostructures grown by metal-organic chemical vapor deposition

    Science.gov (United States)

    Li, Haoran; Mazumder, Baishakhi; Bonef, Bastien; Keller, Stacia; Wienecke, Steven; Speck, James S.; Denbaars, Steven P.; Mishra, Umesh K.

    2017-11-01

    In GaN/(Al,Ga)N high-electron-mobility transistors (HEMT), AlN interlayer between GaN channel and AlGaN barrier suppresses alloy scattering and significantly improves the electron mobility of the two-dimensional electron gas. While high concentrations of gallium were previously observed in Al-polar AlN interlayers grown by metal-organic chemical vapor deposition, the N-polar AlN (Al x Ga1-x N) films examined by atom probe tomography in this study exhibited aluminum compositions (x) equal to or higher than 95% over a wide range of growth conditions. The also investigated AlN interlayer in a N-polar GaN/AlN/AlGaN/ S.I. GaN HEMT structure possessed a similarly high x content.

  16. Lattice thermal expansions of NpN, PuN and AmN

    International Nuclear Information System (INIS)

    Takano, Masahide; Akabori, Mitsuo; Arai, Yasuo; Minato, Kazuo

    2008-01-01

    Lattice parameters of NpN, PuN and AmN were measured by a high temperature X-ray diffraction method from room temperature up to 1478 K. Linear thermal expansions of these TRU nitrides were determined as a function of temperature. The average coefficients of linear thermal expansion from 293 to 1273 K were 8.8, 11.1 and 11.2 x 10 -6 K -1 for NpN, PuN and AmN, respectively. The instantaneous coefficient of thermal expansion either at 293 or at 1273 K against the reciprocal decomposition temperature under 1 atm of nitrogen showed a linear relationship for TiN, ZrN, HfN, UN, NpN and PuN. Based on this relationship, the decomposition temperature of AmN was roughly predicted to be 2700 K

  17. kerkleierskap as bemiddeling van 'n onmoontlike werklikheid: 'n ...

    African Journals Online (AJOL)

    19 Mei 2010 ... Chaos is 'n kritieke deel van die proses waardeur organisasies voortdurend op hul eksterne omgewing inspeel. In 'n sekere sin vrees elke leier chaos, omdat chaos 'n verlies aan beheer veronderstel. (In die Newtoniaanse wêreld van orde en beheer, is beheer immers 'n noodsaaklike meganisme.) Flower ...

  18. Operación a corazón abierto

    OpenAIRE

    Camezzana, María Daniela

    2013-01-01

    Corazón de nuestro tango, el bandoneón es un instrumento en vías de extinción, de fabricación luthier. Sólo entre 1910 y 1933 entraron unos 60.000 bandoneones a la Argentina, pero conseguir uno hoy es tan complicado que ya hay cosecha en films y libros al respecto. En la Universidad Nacional de Lanús y a partir de la inquietud de su rectora, Ana Jaramillo, se desarrolló Pichuco, el primer bandoneón de fabricación seriada. Facultad de Periodismo y Comunicación Social

  19. Globalización y transmigración

    OpenAIRE

    Rodas Martínez, Hernán

    2001-01-01

    No cabe duda que el proceso de globalización ha transformado profundamente el carácter de la migración internacional. Las teorías clásicas de emigración, inmigración, remigración ya no explican los procesos que viven hoy millones de personas. Las nuevas trayectorias laborables, diversas residencias, secuencias y formas de movilización, identidades y redes que controlan, catalogan, expulsan o seleccionan la aceptación de los inmigrantes, ha puesto en crisis conceptos como comunidad de residen...

  20. Evaluación de la investigación

    OpenAIRE

    Tamayo y Tamayo, Mario

    2010-01-01

    La universidad ha desarrollado modelos en torno a la investigación evaluativa, pero es poco lo que ha realizado sobre la evaluación de la investigación, pues es bien diferente de la anterior, ya que la evaluación de la investigación está presente en todo proyecto, pues en último caso es ésta la que decidirá la realización o no del proyecto, mientras que algunos proyectos en diferentes áreas podrían presentarse como investigación evaluativa.

  1. Boletín Oficial núm. 53

    OpenAIRE

    Universidad Carlos III de Madrid

    2014-01-01

    Contiene: Modificación de la normativa sobre el nombramiento de profesores eméritos en la Universidad Carlos III de Madrid, aprobado por el Consejo de Gobierno en su sesión de 10 de julio de 2014. (p. 3) . -- Modificación de la normativa reguladora de los estudios con docencia en inglés y de matriculación y evaluación de los estudiantes en dichos estudios, aprobado por el Consejo de Gobierno en su sesión de 10 de julio de 2014. (pp. 3-4) . -- Reglamento del fondo de cooperación al desarrollo ...

  2. SIMULACIÓN DE MECANISMOS COMPLEJOS DE REACCIÓN.

    Directory of Open Access Journals (Sweden)

    Daniel A Barragán R.

    2010-10-01

    Full Text Available Se propone un método para la interpretación de mecanismos complejos de reacción, el cual es aplicado a la simulación del mecanismo de Gyórgyi-Field, (GF desarrollado para la reacción química oscilante de Belousov-Zhabotinsky (BZ. El método basado en la ley de acción de masas y en el principio de independencia y coexistencia de los pasos elementales, reproduce el comportamiento oscilatorio en la concentración de los intermediarios de reacción.

  3. Epitaxial NbN/AlN/NbN tunnel junctions on Si substrates with TiN buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Rui [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Makise, Kazumasa; Terai, Hirotaka [Advanced ICT Research Institute, National Institute of Information and Communications Technology (Japan); Zhang, Lu [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); Wang, Zhen, E-mail: zwang@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shanghai Tech University, Shanghai 201210 (China)

    2016-06-15

    We have developed epitaxial NbN/AlN/NbN tunnel junctions on Si (100) substrates with a TiN buffer layer. A 50-nm-thick (200)-oriented TiN thin film was introduced as the buffer layer for epitaxial growth of NbN/AlN/NbN trilayers on Si substrates. The fabricated NbN/AlN/NbN junctions demonstrated excellent tunneling properties with a high gap voltage of 5.5 mV, a large I{sub c}R{sub N} product of 3.8 mV, a sharp quasiparticle current rise with a ΔV{sub g} of 0.4 mV, and a small subgap leakage current. The junction quality factor R{sub sg}/R{sub N} was about 23 for the junction with a J{sub c} of 47 A/cm{sup 2} and was about 6 for the junction with a J{sub c} of 3.0 kA/cm{sup 2}. X-ray diffraction and transmission electron microscopy observations showed that the NbN/AlN/NbN trilayers were grown epitaxially on the (200)-orientated TiN buffer layer and had a highly crystalline structure with the (200) orientation.

  4. Noncompetitive inhibition of indolethylamine-N-methyltransferase by N,N-dimethyltryptamine and N,N-dimethylaminopropyltryptamine.

    Science.gov (United States)

    Chu, Uyen B; Vorperian, Sevahn K; Satyshur, Kenneth; Eickstaedt, Kelsey; Cozzi, Nicholas V; Mavlyutov, Timur; Hajipour, Abdol R; Ruoho, Arnold E

    2014-05-13

    Indolethylamine-N-methyltransferase (INMT) is a Class 1 transmethylation enzyme known for its production of N,N-dimethyltryptamine (DMT), a hallucinogen with affinity for various serotonergic, adrenergic, histaminergic, dopaminergic, and sigma-1 receptors. DMT is produced via the action of INMT on the endogenous substrates tryptamine and S-adenosyl-l-methionine (SAM). The biological, biochemical, and selective small molecule regulation of INMT enzyme activity remain largely unknown. Kinetic mechanisms for inhibition of rabbit lung INMT (rabINMT) by the product, DMT, and by a new novel tryptamine derivative were determined. After Michaelis-Menten and Lineweaver-Burk analyses had been applied to study inhibition, DMT was found to be a mixed competitive and noncompetitive inhibitor when measured against tryptamine. The novel tryptamine derivative, N-[2-(1H-indol-3-yl)ethyl]-N',N'-dimethylpropane-1,3-diamine (propyl dimethyl amino tryptamine or PDAT), was shown to inhibit rabINMT by a pure noncompetitive mechanism when measured against tryptamine with a Ki of 84 μM. No inhibition by PDAT was observed at 2 mM when it was tested against structurally similar Class 1 methyltransferases, such as human phenylethanolamine-N-methyltransferase (hPNMT) and human nicotinamide-N-methyltransferase (hNNMT), indicating selectivity for INMT. The demonstration of noncompetitive mechanisms for INMT inhibition implies the presence of an inhibitory allosteric site. In silico analyses using the computer modeling software Autodock and the rabINMT sequence threaded onto the human INMT (hINMT) structure (Protein Data Bank entry 2A14 ) identified an N-terminal helix-loop-helix non-active site binding region of the enzyme. The energies for binding of DMT and PDAT to this region of rabINMT, as determined by Autodock, were -6.34 and -7.58 kcal/mol, respectively. Assessment of the allosteric control of INMT may illuminate new biochemical pathway(s) underlying the biology of INMT.

  5. Novel quinazoline ring synthesis by cycloaddition of N-arylketenimines with N,N-disubstituted cyanamides.

    Science.gov (United States)

    Shimizu, Masao; Oishi, Akihiro; Taguchi, Yoichi; Gama, Yasuo; Shibuya, Isao

    2002-03-01

    The reaction of N-aryl-substituted ketenimines with N,N-disubstituted cyanamides or (MeS)2C=N-CN under high pressure afforded 4-(N,N-disubstituted amino) or 4-(MeS)2C=N-substituted quinazoline derivatives, respectively. These products were formed by [4+2] cycloaddition between the aza-diene moieties of the N-arylsubstituted ketenimines and cyano groups. A 4-(unsubstituted amino)quinazoline derivative was synthesized by hydrolysis of the latter product.

  6. Simulación, Optimización y Gestión

    OpenAIRE

    Momparler Pechuám, Juan

    2005-01-01

    En este trabajo divulgativo pretendemos mostrar como La Teoría de Colas, la Simulación de Eventos Discretos y la Optimización utilizadas conjuntamente, pueden ser una poderosa herramienta, de fácil aplicación, en la resolución de algunos problemas de gestión muy habituales en las empresas. Veremos sobre diferentes problemas de gestión como podemos utilizar para modelarlos las técnicas de Optimización y de Teoría de Colas. Para resolver los modelos planteados utilizaremos la programación...

  7. On Positive Solutions for the Rational Difference Equation Systems x n+1 = A/x n y n (2), and y n+1 = By n /x n-1 y n-1.

    Science.gov (United States)

    Ma, Hui-Li; Feng, Hui

    2014-01-01

    Our aim in this paper is to investigate the behavior of positive solutions for the following systems of rational difference equations: x n+1 = A/x n y n (2), and y n+1 = By n /x n-1 y n-1, n = 0,1,…, where x -1, x 0, y -1, and y 0 are positive real numbers and A and B are positive constants.

  8. Vapor Pressure of N,N’-Diisopropylcarbodiimide (DICDI)

    Science.gov (United States)

    2016-02-01

    11. Furumoto, S. The Synthesis of Carbodiimides from N,N-Disubstituted Thioureas and 2- Chloro-4,6-dimethylpyrimidine, 2,4-Dichloropyrimidine or...N-Phenylbenzimidoyl Chloride . Journal of Synthetic Organic Chemistry, Japan 1975, 33, 748–752. 12. Kagami, H.; Hanzawa, N.; Suzuki, N.; Yamaguchi...25. Brozena, A.; Buchanan, J.H.; Miles, R.W., Jr.; Williams, B.R.; Hulet, M.S. Vapor Pressure of Triethyl and Tri-n- Propyl Phosphates and Diethyl

  9. 40 CFR 180.1130 - N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false N-(n-octyl)-2-pyrrolidone and N-(n... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1130 N-(n-octyl)-2-pyrrolidone and N-(n-dodecyl)-2-pyrrolidone; exemptions from the requirement of a tolerance. N-(n-octyl)-2...

  10. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    René Salinas Meza

    2011-10-01

    Full Text Available El dossier central de este número de la Revista de Historia Social y de las Mentalidades se organiza en torno al tema de “Viñas, vino y sociedad en Chile Tradicional”. El cultivo de la vid aparece asociado muy tempranamente a las actividades agrícolas de Chile. Hasta el siglo XVIII, los viñedos locales satisfacían holgadamente el consumo doméstico, pero sin llegar a constituir una prometedora esperanza de desarrollo agrícola. El paso desde un cultivo arbustivo escasamente expansivo a una industria agraria moderna y consolidada se dio muy recientemente. De hecho, la presencia del vino chileno en los mercados internacionales, el auge de las exportaciones, el crecimiento de la superficie vitícola y la proliferación de empresas vinícolas solo se advierte en la segunda mitad del siglo XX.

  11. Compactación

    Directory of Open Access Journals (Sweden)

    López Saiz, José Manuel

    1968-12-01

    Full Text Available This article contains a number of practical data, whose purpose is to aid in the choice of the most suitable equipment and most paying methods of work for the various types of compaction jobs. In the present paper the strictly theoretical considerations have been omitted, in order to emphasize the experimental and practical aspects.Se presenta en este artículo una serie de datos prácticos, con objeto de ayudar a la elección de los equipos más adecuados y los sistemas de trabajo más rentables para los diferentes tipos de obra de compactación. Se han dejado a un lado las consideraciones puramente teóricas, con el fin de hacer hincapié en la experiencia y realizaciones prácticas.

  12. Presentación

    Directory of Open Access Journals (Sweden)

    Bernabéu Albert, Salvador

    2012-06-01

    Full Text Available Not available.

    Las crónicas de expediciones, los diarios de navegación e, incluso, la más estricta literatura de viajes constituyen, ante todo, formas de ver el mundo. Las narraciones de viajeros surgieron de la necesidad de difundir las memorias de sus periplos y, con ellas, recuperar las experiencias de encuentros con lo desconocido, con nuevos paisajes y nuevas costumbres, en una auténtica revelación del yo en el otro. Tras cinco años de peregrinar por el mundo, Giovanni Francesco Gemelli Carreri regresó a Nápoles a finales de 1698, portando en su equipaje los diarios y anotaciones que se convertirían en el basamento de su Giro del Mondo.

  13. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    Miguel Lisbona Guillén

    2006-12-01

    Full Text Available La práctica de actividades físico-deportivas ocupa, hoy en día, buena parte del tiempo de ocio de un alto porcentaje de la población en nuestras sociedades; y no sólo eso, sino que ha llegado a convertirse en un importante referente simbólico y cultural para determinados grupos sociales. Más evidente aún resulta la fuerza expansiva de sus universos simbólicos en la representación de espectáculos deportivos como el fútbol, convertido en un nuevo lenguaje universal, en la “nueva religión” de buena parte de las sociedades modernas. ...

  14. Phenyl N-(2-methylphenylcarbamate

    Directory of Open Access Journals (Sweden)

    Durre Shahwar

    2009-07-01

    Full Text Available In the title compound, C14H13NO2, the aromatic rings attached to the O and N atoms make dihedral angles of 62.65 (9 and 38.28 (11°, respectively, with the central carbamate group. The benzene rings are oriented at a dihedral angle of 39.22 (10°. In the crystal, a very weak C—H...π interaction occurs.

  15. Studies on the goitrogenic mechanism of action of N,N,N',N'-tetramethylthiourea

    International Nuclear Information System (INIS)

    Freyberger, Alexius; Ahr, Hans-Juergen

    2006-01-01

    N,N,N',N'-Tetramethylthiourea (TMTU) is a rat goitrogen inducing thyroid hyperplasia, hypertrophy, and tumor formation. Little is known about the exact underlying mechanism of action. As thyroid peroxidase (TPO) and type I iodothyronine deiodinase (ID-I) have been established as targets of goitrogenic thiourea derivatives, we investigated interactions of TMTU with target enzymes using a partially purified fraction from hog thyroids or solubilized hog thyroid microsomes and 10,000 g supernatant from rat liver homogenate, respectively, as enzyme sources. For comparison, comprehensively characterized goitrogenic thiourea derivatives were studied as well. In contrast to propylthiouracil (PTU), and like ethylenethiourea (ETU), TMTU only marginally affected TPO-catalyzed oxidation of guaiacol. TMTU, like ETU, concentration-dependently suppressed TPO-catalyzed iodine formation with concomitant oxidative metabolism. Suppression ceased upon consumption of thiourea derivatives, the rate of the reappearing iodine formation was similar to that of controls. TMTU, like ETU, also suppressed non-enzymatic and TPO-catalyzed monoiodination of L-tyrosine with a stoichiometry of 2:1, i.e., one molecule of thiourea derivative suppressed two times monoiodination. TMTU and ETU were unable to irreversibly inhibit TPO. In contrast to PTU, TMTU did not inhibit ID-I. These findings provide evidence that TMTU interferes with thyroid hormone synthesis at the level of iodination and demonstrate a metabolic route for the oxidative detoxification of TMTU in the thyroid suggesting that low-level or intermittent exposure to TMTU would have only minimal effects on thyroid hormone synthesis. Finally, it can be concluded that meaningful toxicological studies on TPO inhibition can be performed without a need for highly purified TPO

  16. S N Maitra

    Indian Academy of Sciences (India)

    Motion of a Tiny Tool Thrown by an Astronaut Inside a Spinning Space Vehicle in a State of Free Fall · S N Maitra · More Details Fulltext PDF. Volume 15 Issue 4 April 2010 pp 355-362 Classroom. Motion of a Tiny Tool Thrown by an Astronaut towards another Astronaut inside a Spinning Space Vehicle in a State of Free Fall ...

  17. Obregón

    Directory of Open Access Journals (Sweden)

    Juan Gustavo Cobo Borda

    1979-05-01

    Full Text Available Demasiado terco para percibir el paso del tiempo, Alejandro Obregón ha logrado que su furiosa vitalidad impregne todo cuanto toca. Así lo pienso, viéndolo en su casa de Cartagena, cerca de las flores que pintaba su abuelo, el que fue alcalde de Barcelona. España; el mismo que oía ópera, por teléfono, desde su lecho de enfermo.

  18. Presentación

    Directory of Open Access Journals (Sweden)

    Julio Cesar Calvo-Alvarado

    2014-12-01

    El Programa de Pasantías felicita a todos los pasantes y sus asesores por el éxito logrado. La Revista Tecnología en Marcha se siente complacida de apoyar estas dos ediciones dado que fomenta la excelencia académica del TEC fomentando así la vocación científica y el espíritu emprendedor de los estudiantes.

  19. Loopbaanbeplanningspraktyke binne 'n universiteitskonteks

    Directory of Open Access Journals (Sweden)

    G. A. Smith

    1990-06-01

    Opsomming Die uitdagings wat die nastrewing van hoer doelwitte aan die Universiteit stel, noodsaak die noukeurige beplanning en uitvoering van toepaslike mensekragontwikkelingsaksies. In hierdie artikel word die belangrikheid van hierdie aksies ter ondersteuning van gestelde strategiee in oenskou geneem. Huidige mensekragbeplanningspraktyke word aan die hand van 'n model geevalueer ten einde die waarde van die praktyke ter bereiking van die Universiteit se gestelde doelwitte en missie te bepaal.

  20. Introduction (Introducción

    Directory of Open Access Journals (Sweden)

    Giuliana Fazzion

    2015-06-01

    Full Text Available Abstract: Presentation of the monograph "Emancipation: Freeing the self in literature, arts, religion and sport".Resumen: Presentación del monográfico "Emancipación: La liberación del yo en la literatura, las artes, la religión y el deporte".

  1. Comunicación humana

    OpenAIRE

    Revista Chasqui

    2011-01-01

    La mirada del autor. Lo específicamente humano de la comunicación humana. Estraído de Manuel Martín Serrano, 2007, "Teoría de la comunicación. La comunicación la vida y la sociedad" p. 265. Madrid, McGraw-Hill / interamericana de España.

  2. Compounds of addition between yttrium and rare-earths (III) nitrates and the N,N,N'N'-tetramethyladipamide (TMAA)

    International Nuclear Information System (INIS)

    Lima, W.N. de.

    1974-01-01

    The synthesis of addition compounds between hydrated rare-earths and yttrium nitrates with the diamine N,N,N',N'-tetramethyladipamide (TMAA) in ethanol, is described. The compounds were characterized by elemental analisys, infrared, Raman, visible and near infrared spectra, molar conductance and molecular weight measurements, conductometric titrations and X-ray powder patterns. (Author) [pt

  3. La hipertensión

    OpenAIRE

    Sainz, Jesús

    2016-01-01

    La hipertensión, también conocida como presión arterial alta o hipertensión arterial, es una condición médica crónica en la que se eleva la presión sanguínea en las arterias. La presión arterial se expresa mediante dos mediciones, las presiones sistólica y diastólica, que son las presiones máximas y mínimas, respectivamente, en el sistema arterial.

  4. Estructuración de mantenimiento, gestión, administración y planeación

    OpenAIRE

    García Tamayo, Juan Luis

    2010-01-01

    Mediante esta propuesta de investigación se presenta un modelo para la estructuración del área de mantenimiento de Fábrica de Calcetines Crystal en cuanto a su gestión, administración y planeación. Adicionalmente, se incluye un esquema básico como iniciativa para una oficina o departamento de proyectos con un enfoque hacia dicha área. 58 p. Contenido parcial: ¿Qué es Mantenimiento? -- Mantenimiento basado en el tiempo -- Mantenimiento basado en la condición -- Estructuración de mantenim...

  5. PRESENTACIÓN

    Directory of Open Access Journals (Sweden)

    René Salinas Meza

    2011-10-01

    Full Text Available Normal 0 21 false false false ES-CL X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} EN ESTA OCASIÓN, LAS investigaciones están centradas en la reconstrucción de algunos hitos importantes del desarrollo de la izquierda política en Chile, de sus actores centrales y de sus propuestas ideológicas y programáticas. Al mismo tiempo, revelan interesantes aspectos acerca del impacto de la difusión de las ideas socialistas en nuestro país y de los efectos sobre una élite que no dejó de sentir temor frente al fantasma del comunismo, que parecía ser bastante más real en el último tercio del siglo XIX. Existe un cierto consenso que a partir de las primeras décadas del siglo XX el socialismo, en sus diversas expresiones, alcanzó la consistencia de alternativa política a través de la cual se podían hacer lecturas de la realidad y construir proyectos de transformación profunda. EN ESTA OCASIÓN, LAS investigaciones están centradas en la reconstrucciónde algunos hitos importantes del desarrollo de la izquierda política en Chile,de sus actores centrales y de sus propuestas ideológicas y programáticas. Almismo tiempo, revelan interesantes aspectos acerca del impacto de la difusiónde las ideas socialistas en

  6. Fermat'n pieni lause

    OpenAIRE

    Pitkänen, Heikki

    2009-01-01

    Tässä työssä tutkimme Fermat’n pientä lausetta, Eulerin funktiota ja yksiköiden ryhmää. Toteamme myös, että on olemassa lukuja, jotka toteuttavat Fermat’n lauseen kaavan olematta kuitenkaan alkulukuja. Todistamme lisäksi Fermat’n lausetta yleisemmän tuloksen. Lopuksi perehdymme hieman Eulerin ja Fermat’n lauseiden sovelluksiin salausmenetelmissä.

  7. Prevención del sarampión

    Directory of Open Access Journals (Sweden)

    Revista Biomédica

    1982-09-01

    Full Text Available Esta revisión de las recomendaciones del ACIP sobre la prevención del Sarampión hace continuidad con las anteriores [MMWE 1978; 27: 427 y 4351, para actualizar la información sobre la efectividad de la vacuna y los esfuerzos que se hacen para eliminar el Sarampión. No hay cambios básicos en los fundamentos trazados. Se incluyen nuevas discusiones respecto al síndrome de sarampión atípico y a la revacunación de los primovacunados con vacuna de virus muertos. Se revisan las recomendaciones para la vacunación de personas alérgicas. La confirmación serológica ha alcanzado mayor importancia ante el declinar de las tasas de incidencia. Se incluyen nuevas recomendaciones para los viajeros internacionales.

  8. Religión, educación y subjetividades

    Directory of Open Access Journals (Sweden)

    Juan Illicachi Guzñay

    2014-12-01

    Full Text Available El trabajo examina el papel de la religión en la educación y en la sociedad, y la relación entre religión, educación y la producción de subjetividades en los grupos subalternos, particularmente en los indígenas y la población estudiantil, pero antes justifica la vigencia del presente tema en el escenario geopolítico de Riobamba. Para abordar lo planteado, las preguntas que guían el desarrollo del presente artículo son: ¿cuál es el rol de la religión en la sociedad y, específicamente, en la educación? ¿Existen incidencias del “campo” religioso en el “campo” educativo? ¿Qué tipo de subjetividad construye tanto el campo educativo como el religioso?

  9. Investigación en Educación

    Directory of Open Access Journals (Sweden)

    Lígia Inés Moncada

    2006-10-01

    Full Text Available Se hace un análisis del proceso de investigación como estrategia didáctica y como método científico para la producción de conocimiento, a su vez como pilar para el desarrollo del profesor tanto en el ámbito de la disciplina o profesión como en su quehacer como educador. Se argumenta sobre la importancia de la formación docente y la renovación del modelo pedagógico tradicional. Se presentan diferentes estrategias de aprendizaje y enseñanza en la búsqueda de la creación de una cultura de investigación: ensayo-error, razonamiento lógico, repetición de conocimientos tradicionales, investigación, líneas o áreas de investigación, líneas de profundización, seminario investigativo. Finalmente, se describen las posibilidades de la investigación educativa con el enfoque cuantitativo y cualitativo, la investigación acción participativa, la etnografía y la fenomenología.

  10. Neutronics analysis for HYLIFE-II

    International Nuclear Information System (INIS)

    Tobin, M.T.

    1990-01-01

    A preliminary neutronics analysis of the HYLIFE-2 reactor concept gives a tritium breeding ratio of 1.17 and a system energy multiplication factor of 1.14. Modified SS-316 (in which Mn is substituted for Ni) is superior to Hastelloy X and Hastelloy N as a firstwall material considering He generation, dpa-limited lifetime, and shallow-burial index. Since Flibe is corrosive to Mn metals, however, a favorable first-wall material is yet to be decided on. Flibe impurities considered (e.g., inherent impurities and those arising from wall erosion or secondary-coolant leakage) do not increase the hazard to the public over that of pure Flibe. The main issues for HYLIFE-2 are the high shallow-burial index (106) and the requirement to contain some 99.7% of the 18 F inventory to prevent its release to the public 18 refs., 3 figs., 9 tabs

  11. Epitaxial NbN/AlN/NbN tunnel junctions on Si substrates with TiN buffer layers

    Directory of Open Access Journals (Sweden)

    Rui Sun

    2016-06-01

    Full Text Available We have developed epitaxial NbN/AlN/NbN tunnel junctions on Si (100 substrates with a TiN buffer layer. A 50-nm-thick (200-oriented TiN thin film was introduced as the buffer layer for epitaxial growth of NbN/AlN/NbN trilayers on Si substrates. The fabricated NbN/AlN/NbN junctions demonstrated excellent tunneling properties with a high gap voltage of 5.5 mV, a large IcRN product of 3.8 mV, a sharp quasiparticle current rise with a ΔVg of 0.4 mV, and a small subgap leakage current. The junction quality factor Rsg/RN was about 23 for the junction with a Jc of 47 A/cm2 and was about 6 for the junction with a Jc of 3.0 kA/cm2. X-ray diffraction and transmission electron microscopy observations showed that the NbN/AlN/NbN trilayers were grown epitaxially on the (200-orientated TiN buffer layer and had a highly crystalline structure with the (200 orientation.

  12. Equilibrium constant and nitrogen activity and the parameters of interaction eN(N), rN(N,Cr), rN(N,Mn) in high nitrogen steels of Fe-Cr-Mn-N type

    International Nuclear Information System (INIS)

    Svyazhin, A.G.; Siwka, J.; Rashev, T.

    1999-01-01

    In the paper a description of a thermodynamic of liquid solutions of Fe-Cr-Mn-N type with using a concept of parameters of an interaction has been presented. A temperature relationship of the equilibrium constant K N(Fe) and values of self interaction parameters e N (N) , r N (N,Cr) , r N (N,Mn) and t N (N,Cr,Cr) has been determined for mean values of temperatures of liquid metal equal 1990 K and 2090 K. By application of a theory of regular solutions those values were recalculated for a temperature 1873 K. (orig.)

  13. Gate length scaling effect on high-electron mobility transistors devices using AlGaN/GaN and AlInN/AlN/GaN heterostructures.

    Science.gov (United States)

    Liao, S Y; Lu, C C; Chang, T; Huang, C F; Cheng, C H; Chang, L B

    2014-08-01

    Compared to AlGaN/GaN HEMT with 0.15 μm T-gate length, the AlInN/AlN/GaN one exhibits much higher current density and transconductance of 1558 mA/mm at Vd = 2 V and 330 mS/mm, respectively. The high extrinsic ft and fmax of 82 GHz and 70 GHz are extracted from AlInN/AlN/GaN HEMT. Besides, we find that the transconductance roll-off is significant in AlGaN/GaN, but largely improved in AlInN/AlN/GaN HEMT, suggesting that the high carrier density and lattice-matched epitaxial heterostructure is important to reach both large RF output power and high operation frequency, especially for an aggressively gate length scaling.

  14. Notas sobre la investigación-intervención

    OpenAIRE

    Pacheco, Gerardo

    1990-01-01

    Como parte del compromiso del ITESO de profundizar en su labor de investigación científica, así como de diseñar estrategias que permitan un cambio social, se explora la propuesta teórica del enfoque investigación-intervención en las ciencias sociales que, desde el punto de vista metodológico, establece la relación permanente entre el conocimiento y la acción. El conocimiento y la acción son vistos como son dos aspectos inseparables de la actividad humana; se relacionan dialécticamente, se con...

  15. Revisión sedación paliativa

    OpenAIRE

    González Calabaza, Marta; González Arnáiz, Elena

    2016-01-01

    Los Cuidados Paliativos en su acepción moderna surgen en Reino Unido en 1967, pero las primeras publicaciones sobre sedación paliativa no aparecen hasta 1990. La sedación paliativa es la disminución intencional del nivel de conciencia del paciente por medio de fármacos, con el fin de aliviar el sufrimiento físico o psíquico refractario a otras medidas terapéuticas. La diferencia entre sedación paliativa y eutanasia es clara. Divergen en la intención, procedimiento y resultado. Es vital conoce...

  16. AlGaN/GaN double-channel HEMT

    International Nuclear Information System (INIS)

    Quan Si; Hao Yue; Ma Xiaohua; Zheng Pengtian; Xie Yuanbin

    2010-01-01

    The fabrication of AlGaN/GaN double-channel high electron mobility transistors on sapphire substrates is reported. Two carrier channels are formed in an AlGaN/GaN/AlGaN/GaN multilayer structure. The DC performance of the resulting double-channel HEMT shows a wider high transconductance region compared with single-channel HEMT. Simulations provide an explanation for the influence of the double-channel on the high transconductance region. The buffer trap is suggested to be related to the wide region of high transconductance. The RF characteristics are also studied. (semiconductor devices)

  17. Religión y Educación Pública

    OpenAIRE

    Palomino Lozano, Rafael

    2009-01-01

    Relación general sobre la presencia de la religión como materia docente en la educación reglada: actores implicados, derechos educativos, modelos educativos y enseñanza de la religión, modalidades de enseñanza de la religión como asignatura. Breve apunte sobre lo símbolos religiosos en la escuela. Versión parcial. Keynote speech. General account concerning the presence of religion in public education: social actors, educational rights, educational models, religion as a school subject. Bri...

  18. Introducción a Japón: historia

    OpenAIRE

    Pelegrín Solé, Ángeles

    2008-01-01

    Análisis del marco histórico de Japón, con una breve introducción sobre los orígenes del pueblo japonés y su cultura, la época aristocrática (Nara), la hegemonía samurai (Kamakura-Ashikaga), el periodo Tokugawa, y por último la apertura de Japón, la restauración Meiji y la aparición del Japón imperial.

  19. Producción cepalina sobre educación

    OpenAIRE

    Fernando Díaz Ortega

    2005-01-01

    El siguiente trabajo presenta una visión global del conjunto de la producción de la Comisión Económica para América Latina y el Caribe (CEPAL) sobre educación, mediante la clasificación y análisis de las publicaciones cepalinas relacionadas con el tema educativo desde 1949 hasta 2002. Para dar esa visión dividí los documentos bajo tres criterios temporales y bajo cuatro clasificaciones. Los criterios temporales fueron: anualmente, en dos periodos (1949-1976 y 1977-2002) y en seis etapas (1949...

  20. Photoluminescence and pressure effects in short period InN/nGaN superlattices

    DEFF Research Database (Denmark)

    Staszczak, G.; Gorczyca, I.; Suski, T.

    2013-01-01

    Measurements of photoluminescence and its dependence on hydrostatic pressure are performed on a set of InN/nGaN superlattices with one InN monolayer and with different numbers of GaN monolayers. The emission energies, EPL, measured at ambient pressure, are close to the value of the band gap, Eg......, in bulk GaN, in agreement with other experimental findings. The pressure dependence of the emission energies, dEPL/dp, however, resembles that of the InN energy gap. Further, the magnitudes of both EPL and dEPL/dp are significantly higher than those obtained from ab-initio calculations for 1In...

  1. Presentación

    Directory of Open Access Journals (Sweden)

    Hernane Borges de Barros Pereira

    2018-01-01

    Full Text Available Nossa pretensão é apresentar este número especial sobre teoria de redes, educação e difusão do conhecimento a partir de uma síntese dos artigos que o compõe. Considerando que o interesse da revista Obra digital consiste em pesquisas no âmbito da comunicação e áreas afins, nos indagamos: como preparar um número que esteja em conformidade com tais interesses? Nossa resposta foi a reunião de varios trabalhos. Os leitores deste número encontrarão modelos teóricos que, com base em simulações, auxiliam na explicação e predição de processos como a difusão de conhecimento em redes sociais, nas quais a colaboração e cooperação entre indivíduos tomam lugar; encontrarão também modelos de redes relacionados com o entendimento de discursos, sejam como ferramentas de apoio ou como método e técnica de análise. Há ainda um trabalho que versa sobre o mapeamento das redes de interação entre os diversos atores que compõem comunidades de prática. Finalmente, há um artigo que apresenta um protocolo padrão para a descrição de jogo digitais.

  2. Nonlocal N=1 supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Tetsuji [Research and Education Center for Natural Sciences, Keio University,Hiyoshi 4-1-1, Yokohama, Kanagawa 223-8521 (Japan); Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan); Mazumdar, Anupam [Consortium for Fundamental Physics, Physics Department, Lancaster University,Lancaster LA1 4YB (United Kingdom); Kapteyn Astronomical Institute, University of Groningen,9700 AV Groningen (Netherlands); Noumi, Toshifumi [Institute for Advanced Study, Hong Kong University of Science and Technology,Clear Water Bay (Hong Kong); Department of Physics, Kobe University,Kobe 657-8501 (Japan); Yamaguchi, Masahide [Department of Physics, Tokyo Institute of Technology,Tokyo 152-8551 (Japan)

    2016-10-05

    We construct N=1 supersymmetric nonlocal theories in four dimension. We discuss higher derivative extensions of chiral and vector superfields, and write down generic forms of Kähler potential and superpotential up to quadratic order. We derive the condition in which an auxiliary field remains non-dynamical, and the dynamical scalars and fermions are free from the ghost degrees of freedom. We also investigate the nonlocal effects on the supersymmetry breaking and find that supertrace (mass) formula is significantly modified even at the tree level.

  3. Introducción

    OpenAIRE

    Jorge Avendaño-Inestrillas

    2000-01-01

    Los tres ensayos críticos que componen este dossier tienen un punto de convergencia en torno del cual he pensado articularlos: son modalidades diversas del ensayo crítico literario expuestas como teorizaciones de la lectura. En la variación de sus modulaciones, los trabajos exhiben un conjunto de rasgos distintivos que se van insinuando en los estudios literarios latinoamericanos, al tiempo que despliegan una serie de conjeturas que anuncian un hacer crítico capaz de no olvidar o reprimir la ...

  4. Presentación

    OpenAIRE

    CABALLERO ACOSTA, JOSÉ HUMBERTO

    2010-01-01

    Infortunadamente hay que insistir en la dificultad que se presenta para mantener una revista con ésta temática en Colombia, cosa que parece bastante paradójica ya que de otro lado, el país experimenta un aumento generalizado y sostenido de la inversión en nuevos y grandes proyectos de minería e infraestructura, en los cuales se adelantan estudios e investigaciones geológicas, de mucho interés para la comunidad científica y que normalmente se quedan en los grandes e inaccesibles volúmenes que...

  5. Reaparición

    Directory of Open Access Journals (Sweden)

    Boletín Cultural y Bibliográfico Banco de la República

    1987-04-01

    Full Text Available Con un nuevo formato aparece la publicación universitaria y cultural más antigua de Colombia, la "Revista del Colegio Mayor de Nuestra Señora del Rosario". Con un blanco y negro muy bien usado en 200 páginas, la revista entrega al lector escolios inéditos de Nicolás Gómez Dávila, una cercamiento a la obra de César Vallejo, escrito por Fernando Charry Lara y un ensayo de Víctor Guedez, sobre los fundamentos de la crítica de arte.

  6. Enthalpies of solution of N,N,N',N'-tetramethylurea in amides, dimethylsulphoxide, and acetone at 298.15 K

    International Nuclear Information System (INIS)

    Ivanov, Evgeniy V.; Smirnov, Valeriy I.

    2008-01-01

    The enthalpies of solution Δ sol H m m were determined for N,N,N',N'-tetramethylurea in formamide, N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulphoxide, and acetone. Measurements were made at 298.15 K and molalities m = (0.004 to 0.031) mol . kg -1 with a precise isoperibol ampoule-type calorimeter. Standard enthalpies of solution Δ sol H m 0 and transfer Δ tr H m 0 from one solvent to another were computed. The enthalpies of solution of the solute in the hydrogen-non-bonding media were found to be endothermic and weak depending on the nature of methylation in a solvent molecule. It was concluded that the solvent proton-donor ability and existing steric hindrances for hydrogen bonding and other intermolecular interactions play the key role in solvation of tetramethylurea

  7. orientación sexual

    Directory of Open Access Journals (Sweden)

    Franklin Giovanni Soler

    2005-01-01

    Full Text Available La teoría evolutiva propuesta por Darwin sugiere el mecanismo de la selección natural para explicar la forma como las especies se adaptaron, sobrevivieron y evolucionaron, y el mecanismo de la selección sexual para explicar su reproducción. De esta manera, postula que los rasgos adaptativos son reproducidos más sucesivamente que los rasgos desadaptativos. De acuerdo con esto, la selección natural debería favorecer la heterosexualidad, pues ésta facilita la reproducción y la propagación de genes. Pero ¿qué sucede con la orientación sexual que no favorece la tesis darwiniana (por ejemplo, la homosexualidad y por qué se ha mantenido? La investigación en esta área se ha centrado en aspectos hormonales, de diferenciación cerebral y genéticos, arrojando resultados inconsistentes. Se parte de la tesis de que la orientación sexual humana, en particular la orientación homosexual, es tan compleja como para ser descrita y explicada tan solo por un modelo o una disciplina. Se hace una revisión de las diferentes áreas de investigación sobre orientación sexual y se sugiere la incapacidad de las teorías evolutivas para dar cuenta de ella.

  8. Editorial, n. 19, 2005

    Directory of Open Access Journals (Sweden)

    Editor Encontros Bibli

    2005-04-01

    Full Text Available http://dx.doi.org/10.5007/1518-2924.2005v10n19pi   FORMAÇÃO PROFISSIONAL E DESAFIOS ATUAIS NO CAMPO DA INFORMAÇÃO O título deste editorial aponta para mais que uma constatação; ele relembra a pluralidade com que está constituído o campo da informação de que tratam como campo profissional e de investigação bibliotecários, arquivistas e cientistas da informação. A atualidade decorre da circunstância de que há um sentimento em processo de generalização de que quase não há mais tempo para olhar o passado, senão como referência do que não pode mais servir como fonte de inspiração ou fonte de onde se poderá extrair idéias instrumentalmente aplicáveis ao mundo contemporâneo, especialmente de uma contemporaneidade que se mede em não mais que uma década. Desse modo, um artigo que examina a literatura sobre formação profissional, concentra a sua análise em textos que foram majoritariamente produzidos nos cinco anos recentes. Explica-se, sobretudo, pelo fato do enfoque estar dando relevância às tecnologias da informação e tecnologia, sabemos todos, não está sendo tomada nos dias atuais apenas como uma moeda que promove a competição entre países, através de suas elites dirigentes (políticas e econômicas e profissionais, mas, distorcidamente, está sendo levada à conta da razão da existência humana, sendo cada vez mais naturalizada. Por este motivo, um dos mais fortes desafios atuais no e ao campo da informação é incorporar em seu discurso e constante apreciação o trato ético da existência em sociedade e das relações que podem ser construídas nas interações entre homens e mulheres nesta contemporaneidade, sem perder de vista o futuro. Nesta edição, um artigo levanta parte das questões aí colocadas e, como trabalho intelectual, teve como base palestra realizada em 2004, por sua autora, em um Encontro dos Profissionais Bibliotecários do Estado de São Paulo, voltado para a discussão do tema

  9. Barrier height and interface effect of Pt-n-GaN and Pd-n-GaN Schottky diodes

    International Nuclear Information System (INIS)

    Khan, M.R.H.; Saha, S.L.; Sawaki, N.

    1999-01-01

    Schottky barriers on n-type GaN films by Pt and Pd are fabricated and characterized. A thin Pt or Pd layer is deposited on n-GaN layers to form Schottky contacts in a vacuum below 1x10/sup -6/ Torr. The area of all diodes is 3.46 x 10-4 cm/sup 2/. Several samples of Pt-n GaN and Pd-n GaN were studied. The ideality factor of Pt-n-GaN diode is 1.26 and of Pd-n-GaN is 1.17. The breakdown voltage of Pt-n-GaN and Pd-n-GaN diodes is 21 V and 26 V respectively. In both the cases the leakage current varies between 1x10-9 A and 5x 10-9 A. The Schottky barrier heights (phi/sub B/ ) of Pt-GaN diode is been determined to be 1.02 eV by current voltage (I-V) and 1.07 eV by capacitance (C-V) measurements Also, phi/sub B/ of Pd-GaN diode is determined to be 0.91 eV by I-V and 0.98 eV, by C-V measurements. The departure of the values of the ideality factor is considered to be due to spatial inhomogeneities at the meal semiconductor interface. The difference in the values of phi/sub B/ determined by I-V and C-V measurements is attributed to the deformation of the spatial barrier distribution. (author)

  10. n-Type Azaacenes Containing B←N Units.

    Science.gov (United States)

    Min, Yang; Dou, Chuandong; Tian, Hongkun; Geng, Yanhou; Liu, Jun; Wang, Lixiang

    2018-02-12

    We disclose a novel strategy to design n-type acenes through the introduction of boron-nitrogen coordination bonds (B←N). We synthesized two azaacenes composed of two B←N units and six/eight linearly annelated rings. The B←N unit significantly perturbed the electronic structures of the azaacenes: Unique LUMOs delocalized over the entire acene skeletons and decreased aromaticity of the B←N-adjacent rings. Most importantly, these B←N-containing azaacenes exhibited low-lying LUMO energy levels and high electron affinities, thus leading to n-type character. The solution-processed organic field-effect transistor based on one such azaacene exhibited unipolar n-type characteristics with an electron mobility of 0.21 cm 2  V -1  s -1 . © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. ADMINISTRACIÓN DE LA PRODUCCIÓN

    Directory of Open Access Journals (Sweden)

    Ana Urquiaga Rodríguez

    2004-11-01

    Full Text Available

    Este artículo presenta los resultados de una investigación descriptiva realizada durante el año 2003, al 57 % de las empresas de más de diez personas ocupadas en la agrupación 381 de la ciudad de Manizales. El objetivo de dicha investigación es establecer algunas de las principales características de la administración de la producción y los inventarios en estas empresas, siguiendo el enfoque jerárquico de la planificación, programación y control de la producción.

  12. La modernización del Japón

    Directory of Open Access Journals (Sweden)

    rikiwo Shikama

    1988-04-01

    Full Text Available RESUMEN El autor presenta de forma general una visión del proceso de modernización del Japón. El significado importante de la Revolución Meiji, haciendo alusión al contexto en el cual ésta se desarrolló. Hace un análisis comparativo de la China y Japón derivado de las tesis del doctor Reischaver, catedrático de la universidad de Harvard. Resalta la importancia que tuvo en el proceso de modernización las características específicas del régimen Feudad Japonés, y el alto nivel de alfabetización, que supuso una mayor capacidad  para absorber y asimilar la cultura occidental.

  13. Presentación

    Directory of Open Access Journals (Sweden)

    Bianchi, Susana

    2006-06-01

    Full Text Available Since the end of de latter military dictatorship in 1983, the history of the Catholicism in Argentina ceased to be a matter concerning only to the Catholic historians to enter in the academic ground. This situation permitted the development of new perspectives and renewal theoretical and methodological views. But, despite the advances realised, there are still many gaps, as happen in the case of the religious minorities. This dossier present some lines of research developed in the last years concerning to the history of the Catholicism.

    Desde fines la última dictadura militar, la historia del catolicismo dejó de ser una cuestión confesional para ingresar en el ámbito académico. Esto permitió el desarrollo de nuevas perspectivas y nuevos planteos teóricos y metodológicos. A pesar de los avances, aún quedan vacíos. Uno de ellos es el estudio de las minorías religiosas que integran el campo religioso argentino. Este dossier presenta algunas de las últimas líneas de investigación.

  14. Presentación

    Directory of Open Access Journals (Sweden)

    HC Presentación

    2010-02-01

    Full Text Available La Historiografía española conoce, desde los inicios de la transición democrática, un auténtico despliegue de la Historiografía regional y local, que se impone en los años noventa como ámbito preferente de investigación a la vez que crece su importancia en la enseñanza. Una Historiografía regional definida así, desde el 'deber ser', por J. A. Lacomba: «Sustentada en el firme desarrollo de las 'monografías locales', en lo posible programadas y coordinadas, será, en consecuencia, el análisis —del todo y áe\\ fondo— del grupo humano regional, a lo largo del tiempo, en el contexto del proceso más amplio de la historia nacional —^y de la historia general— en la que se halla inserto».

  15. Comunicación familiar

    OpenAIRE

    Antolínez Cáceres, Bertha Rebeca

    2010-01-01

    En el primer contacto la enfermera puede identificar algunos rasgos de la comunicación familiar, a medida que la intervención progresa podrá examinar y explorar sobre la comunicación familiar y orientar el manejo de conflictos. El análisis de la disfunción familiar inicia entonces por el análisis de la comunicación y dónde falla ésta: En el emisor, transmisor y sus causas. Luego viene la exploración del sistema familiar que aclara las reglas que mantienen y los procesos individuales que instr...

  16. Reanimación cardiopulmonar

    OpenAIRE

    Colina Torralva, Javier; Fabra, Montserrat; Force Sanmartín, Enriqueta

    1985-01-01

    Realizar con éxito una reanimación cardiopulmonar depende fundamentalmente de la rapidez y eficacia de nuestra actuación. Eficacia que, a su vez, vendrá condicionada por la aplicación correcta de las técnicas de reanimación que a continuación se describen, y que deben ir respondiendo a las necesidades prioritarias del paciente. Las medidas de reanimación pueden ser iniciadas en cualquier lugar por personas entrenadas, y sin necesidad de grandes medios o equipos.

  17. COMPORTAMIENTO DE CORROSIÓN-EROSIÓN EN RECUBRIMIENTOS DE TiN/ZrN DEPOSITADOS SOBRE ACERO AISI 4140

    OpenAIRE

    Aperador, Willian; Mejía, Aura S; Caicedo, Julio

    2014-01-01

    Se depositaron películas delgadas de nitruro de titanio/nitruro de zirconio sobre acero AISI 4140 mediante un sistema multi-blanco magnetrón pulverización (sputtering) con radiofrecuencia. El proceso se desarrolló bajo el sistema de rotación del sustrato que permitió situar el sustrato de frente a los blancos de titanio y zirconio, generando la super-red con periodos de 1, 50, 100 y 200 bicapas. Las multicapas fueron evaluadas frente a la sinergia corrosión-erosión en una solución compuesta p...

  18. Educación maternal

    OpenAIRE

    Carnicer Fuentes, Inmaculada Concepción

    2010-01-01

    Definir y/o describir los objetivos, metodología y contenidos de la educación maternal como componente del proceso asistencial integrado de atención al “Embarazo, Parto y Puerperio” de la Consejería de Salud de la Junta de Andalucía. Definir y/o describir los aspectos básicos del crecimiento y desarrollo ovular Definir y/o describir los aspectos básicos de la educación sanitaria durante el embarazo, incluyendo aspectos como nutrición, fármacos, vacunas, atención prenatal y prevención ...

  19. Introducción

    Directory of Open Access Journals (Sweden)

    Ana Beatriz Chiquito

    2014-11-01

    Full Text Available Resumen El libro Actitudes lingüísticas de los hispanohablantes hacia el idioma español y sus variantes es resultado del Proyecto LIAS (Linguistic Identity and Attitudes in Spanish-speaking Latin America. La investigación y el libro fueron financiados por El Consejo Noruego de Investigación (RCN y auspiciados por el Departamento de Lenguas Extranjeras (Institutt for framandspråk de la Universidad de Bergen, Noruega. En el libro se presentan los análisis de las entrevistas sobre actitudes cognitivas, afectivas y conductuales realizadas a 8000 personas procedentes de todas las capitales de Hispanoamérica y España. La investigación de campo se desarrolló entre 2009 y 2012, bajo un cuestionario común de entrevistas, de modo que diera pie a comparaciones entre los diversos países; el presente libro presenta los resultados más relevantes. Uno de ellos es haber constatado que, a pesar de las variaciones dialectales y sociolectales, los entrevistados sienten que hablan el mismo idioma -llámese español o castellano- lo cual habla en favor de una conciencia de unidad lingüística y cultural. Por otro lado, se demuestra la existencia de una creciente autoestima lingüística en la mayor parte de los países hispanohablantes, en los cuales se prefiere la propia variante nacional en los medios de comunicación del país y en la educación. Al mismo tiempo se expresa respeto por la existencia de otras variantes de la lengua española como símbolos de identidad nacional en sus respectivos países. Abstact This book, Actitudes lingüísticas de los hispanohablantes hacia el idioma español y sus variantes, is an outcome of the LIAS research project (Linguistic Identity and Attitudes in Spanish-speaking Latin America. The project and the book were funded by The Research Council of Norway (RCN and coordinated by researchers at the Department of Foreign Languages at the University of Bergen, Norway. The book presents the analyses of 8000

  20. 1/N expansion in SUSY CPsup(N-1) model

    International Nuclear Information System (INIS)

    Krivoshchekov, V.K.; Medvedev, P.B.

    1983-01-01

    The 1/N expansion for supersymmetric two-dimensional CPsup(N-1) model has been constructed in the superfield formalism. The subtraction procedure and the way to choose manifestly supersymmetric gauge is formulated to define UV and IR regular Green functions for any given order in 1/N

  1. DETECCIÓN DE RADIACIÓN NO IONIZANTE

    Directory of Open Access Journals (Sweden)

    GUSTAVO NAVAS

    2009-01-01

    Full Text Available Se diseñó y construyó una red de sensores para detección de radiación no ionizante en la banda comprendida entre 800MHz y 2.5GHz. El sistema se basa en el sensor que muestra a la salida una tensión DC proporcional a la potencia de la señal RF a su entrada, sin importar el tipo de modulación. Esta red comprende cuatro antenas banda ancha, cuatro tarjetas sensoras, una tarjeta central y un software de visualización de datos. El comportamiento del sistema se analizó con diferentes configuraciones y con múltiples fuentes de radiación. Igualmente, se muestran los resultados de la simulación de una antena espiral de Arquímedes utilizando CST STUDIOTM y los experimentos realizados para caracterizar la antena banda ancha HG2404CU. Los resultados mostraron un eficiente sistema de detección de radiación electromagnética en la banda estudiada. Una aplicación inmediata de este trabajo, para la cual se están haciendo pruebas de campo, es la detección de llamadas de celulares en lugares no permitidos como centros carcelarios, bancos, entre otros.

  2. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    International Nuclear Information System (INIS)

    Wang Yanping; Luo Yinhong; Wang Wei; Zhang Keying; Guo Hongxia; Guo Xiaoqiang; Wang Yuanming

    2013-01-01

    The testing techniques and experimental methods of the 60 Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained. (authors)

  3. Polarization-engineered GaN/InGaN/GaN tunnel diodes

    International Nuclear Information System (INIS)

    Krishnamoorthy, Sriram; Nath, Digbijoy N.; Akyol, Fatih; Park, Pil Sung; Esposto, Michele; Rajan, Siddharth

    2010-01-01

    We report on the design and demonstration of polarization-engineered GaN/InGaN/GaN tunnel junction diodes with high current density and low tunneling turn-on voltage. Wentzel-Kramers-Brillouin calculations were used to model and design tunnel junctions with narrow band gap InGaN-based barrier layers. N-polar p-GaN/In 0.33 Ga 0.67 N/n-GaN heterostructure tunnel diodes were grown using molecular beam epitaxy. Efficient interband tunneling was achieved close to zero bias with a high current density of 118 A/cm 2 at a reverse bias of 1 V, reaching a maximum current density up to 9.2 kA/cm 2 . These results represent the highest current density reported in III-nitride tunnel junctions and demonstrate the potential of III-nitride tunnel devices for a broad range of optoelectronic and electronic applications.

  4. Simulación, Optimización y Gestión

    Directory of Open Access Journals (Sweden)

    Momparler Pechuám, Juan

    2005-01-01

    Full Text Available En este trabajo divulgativo pretendemos mostrar como La Teoría de Colas, la Simulación de Eventos Discretos y la Optimización utilizadas conjuntamente, pueden ser una poderosa herramienta, de fácil aplicación, en la resolución de algunos problemas de gestión muy habituales en las empresas. Veremos sobre diferentes problemas de gestión como podemos utilizar para modelarlos las técnicas de Optimización y de Teoría de Colas. Para resolver los modelos planteados utilizaremos la programación en MATLAB y LINGO, Comentaremos también una bibliografía especializada sobre estos temas que sirva de referencia.

  5. Iniciación a número natural en Educación Infantil

    OpenAIRE

    Muñoz Millán, Vanesa

    2013-01-01

    En este Trabajo de Fin de Grado (TFG) hemos querido mostrar la evolución en la adquisición del número natural en el niño de Educación Infantil, haciendo una recopilación de modelos de aprendizaje para escoger cuál sería el más adecuado para trabajar en estas primeras edades. Posteriormente, ofrecemos una propuesta con ejemplos de actividades para trabajar la iniciación a los números naturales y algunas pinceladas sobre la iniciación a la posterior representación simbólica en niños de 3-4 años...

  6. Observations of HC3N, HC5N, and HC7N in molecular clouds

    International Nuclear Information System (INIS)

    Snell, R.L.; Schloerb, F.P.; Young, J.S.; Hjalmarson, A.; Friberg, P.

    1981-01-01

    We present observations of HC 3 N, HC 5 N, and HC 7 N in five molecular clouds. Statistical equilibrium calculations have been performed for HC 5 N and HC 7 N and compared with our data and data on other transitions of these molecules reported in the literature to derive the densities and the column densities of the cyanopolyynes in these clouds. We derive densities for TMC 1, TMC 2, and L1544 of between 1 and 4 x 10 4 cm -3 . We have found that the ratios of the cyanopolyynes in these three clouds are the following: HC 3 N/HC 5 Nroughly-equal1.4 and HC 5 N/HC 7 Nroughly-equal3. In L134 N and DR 21(OH) we have measured limits on the HC 5 N emission and find the HC 3 N/HC 5 N ratio to be substantially greater than in the three Taurus clouds. We have also compared the cyanopolyyne column densities with those of 13 CO and find that the abundance of HC 3 N in L134 N and DR 21(OH) is an order of magnitude smaller than that found in the Taurus clouds. The chemical differences between L134 N and the Taurus clouds are particularly interesting in view of their similar physical properties

  7. Walls of massive K\\"ahler sigma models on SO(2N)/U(N) and Sp(N)/U(N)

    OpenAIRE

    Arai, Masato; Shin, Sunyoung

    2011-01-01

    We study the Bogomol'nyi-Prasad-Sommerfield wall solutions in massive K\\"ahler nonlinear sigma models on SO(2N)/U(N) and Sp(N)/U(N) in three-dimensional spacetime. We show that SO(2N)/U(N) and Sp(N)/U(N) models have 2^{N-1} and 2^N discrete vacua, respectively. We explicitly construct the exact BPS multiwall solutions for N\\le 3.

  8. Integración curricular

    Directory of Open Access Journals (Sweden)

    Jesús F. Escanero Marcén

    Full Text Available Uno de los objetivos del Proceso de Bolonia de adaptación al Espacio Europeo de Educación Superior, es elaborar curricula basados en competencias. En este contexto, se plantea la conveniencia de adoptar modelos curriculares integrados. El artículo hace una revisión histórica de las experiencias de integración curricular llevadas a cabo a nivel internacional y español. En este último casose analizan dos documentos clave, la Declaración de Granada y el Libro Blanco de la Conferencia Nacional de Decanos de Medicina que abogan claramente por la integración curricular. Tras discutir las razones para la integración se describen las diferentes etapas a seguir en un proceso de integración de acuerdo con el modelo de Harden.

  9. Alfabetización Digital

    OpenAIRE

    Ramos, Martha; Rodrígez, Ana; Sánchez, Paz

    2011-01-01

    Inicio, POrtada, Introducción, Evaluación Diagnóstica y COntenido Tema 1¿Qué significala competencia de alfabetización digital en el uso de medios?, Tema 2 ¿Porque es relevante que adquiera la competencia de Alfabetización Digital en mi formación?, Tema 3 ¿Cómo aprender la competencia de Alfabetización Digital?, Tema 4 ¿Cóm aplico la competencia de Alfabetización Digital? Tema 5 ¿Cómo puede evaluar la competencia de alfabetización digital a través del empleo de un Wiki y blog educativos?...

  10. Happy birthday n_TOF!

    CERN Multimedia

    2010-01-01

    Picture CERN-GE-1011313_58 : From left to right: Enrique Gonzalez-Romero, Chairman of Collaboration Board, Enrico Chiaveri, Spokesperson of n_TOF Experiment, and Carlo Rubbia, the creator of the n_TOF experiment.

  11. Globalización

    Directory of Open Access Journals (Sweden)

    Dalia Solorio Zamora

    2013-04-01

    Full Text Available La globalización es uno de los fines que actualmente tiene el principal lugar e importancia en los campos de desarrollo de la economia mundial, e influencia en las sociedades culturales y politicas. Se analiza la transendedencia que a ido teniendo la globalizacion en los diferentes aspectos principales de la vida cotidiana del ser humano y su evolucion respecto a la problematica relativa a las ventajas y desventajas que ha causado la globalizacion en una serie de cambios e innovaciones en al menera de pensar hacer y organizar. La utora de esta investigacion propone que el resurgimiento en el desarrollo , y el proteccionismo en las políticas económicas de las naciones, a la vez que exigen restablecen a la sociedad en los valores y costumbres íntegros.

  12. Presentación

    Directory of Open Access Journals (Sweden)

    Claudio Hernández Burgos

    2015-06-01

    Full Text Available Presentación del Dossier "El franquismo local: el desarrollo de la dictadura en las provincias" Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

  13. COOPERACIÓN HUMANA Y SELECCIÓN DE GRUPO

    OpenAIRE

    Luis Alvaro Cadena Monroy

    2017-01-01

    Darwin pensaba que la cooperación entre los seres humanos podía ir en contra de su idea de selección natural. Para enfrentar este problema, introdujo la selección de grupos: se seleccionan grupos de seres humanos cooperadores por sobre los grupos de no cooperadores, No obstante, con el advenimiento del neodarwinismo, la selección de grupos cayó en el desprestigio. Poco a poco, y recientemente, fueron apareciendo varias propuestas para la selección de grupos. Aquí se miran algunas de estas pro...

  14. A Base Promoted Synthesis of N,N-dimethylformamidines

    International Nuclear Information System (INIS)

    Li, Bao Lin; Ding, Si Yi; Ren, Yu Fei; Wang, Liu Chang; Jia, Yu Cai; Zhang, Xi Quan; Gu, Hong Mei

    2013-01-01

    In conclusion, this report supplies a base promoted synthesis of N'-aryl-N,N-dimethylformamidines straight from arylamines bearing strong electron withdrawing group at o-position and imine complex from DMF and Me 2 SO 4 . The key advantage of the procedure is to avoid the preparation of N,N-dimethylformamide dimethyl acetal from DMF and Me 2 SO 4 . Using this method, some important intermediates shown as entry 1-4, 9-11 in Table 3 were efficiently prepared. With these intermediates in hand, various antitumor drugs containing quinazoline moiety such as gefitinib, erlotinib and lapatinib etc. can be synthesized conveniently

  15. REPRODUCCIÓN ASISTIDA Y FILIACIÓN. TRES CASOS

    OpenAIRE

    Julia Sandra Bernal Crespo

    2013-01-01

    Este artículo analiza uno de los principales problemas jurídicos que plantean las técnicas de reproducción asistida: determinar la filiación del nacido y la forma en que nuestros jueces de la República han resuelto este conflicto en los casos específicos de alquiler de vientre, inseminación asistida con donante, e inseminación post-mortem, teniendo en cuenta que, a diferencia de la filiación biológica, el consentimiento de los donantes de gametos y de los receptores es un elemento necesario p...

  16. Inmigración e incorporación laboral

    Directory of Open Access Journals (Sweden)

    Yolanda Herranz

    2016-10-01

    Full Text Available La perspectiva histórico-estructural neomarxista analiza los asentamientos inmigrantes en su variedad y en relación a coyunturas continuamente cambiantes en las sociedades receptores. La adaptación económica de los inmigrantes en la sociedad de acogida presenta una pluralidad de resultados que se muestran en formas de incorporación laboral diferenciadas. Desde esta perspectiva teórica se analizan las variables contextuales y relativas al propio grupo inmigrante que interactúan en la formación de tal diversidad en los modos de inserción laboral.

  17. N = 4 super KdV hierarchy in N = 4 and N = 2 superspaces

    International Nuclear Information System (INIS)

    Delduc, F.

    1995-10-01

    The results of further analysis of the integrability properties of the N = 4 supersymmetric KdV equation deduced earlier as a Hamiltonian flow on N 4 SU(2) superconformal algebra in the harmonic N = 4 superspace are presented. To make this equation and the relevant Hamiltonian structures more tractable, it is reformulated in the ordinary N = 4 and further in N = 2 superspaces. These results provide a strong evidence that the unique N = 4 SU(2) super KdV hierarchy exists. (author)

  18. Azobenzene Pd(II) complexes with N^N- and N^O-type ligands

    Science.gov (United States)

    Nikolaeva, M. V.; Puzyk, An. M.; Puzyk, M. V.

    2017-05-01

    Methods of synthesis of cyclometalated azobenzene palladium(II) complexes of [Pd(N^N)Azb]ClO4 and [Pd(N^O)Azb]ClO4 types (where Azb- is the deprotonated form of azobenzene; N^N is 2NH3, ethylenediamine, or 2,2'-bipyridine; and (N^O)- is the deprotonated form of amino acid (glycine, α-alanine, β-alanine, tyrosine, or tryptophan)) are developed. The electronic absorption and the electrochemical properties of these complexes are studied.

  19. Editorial, n. 16, 2003

    Directory of Open Access Journals (Sweden)

    Editor Encontros Bibli

    2003-01-01

    Full Text Available EDITORIAL Somos todos testemunhas das grandes mudanças que, nos últimos trinta anos, afetam a uma parcela muito ampla da vida no planeta. Grande parte dessas mudanças decorre de uma acentuada aventura tecnológica proporcionada pela incontrolável apropriação e inovação de conhecimentos. Saber que parte substancial disso resulta da pesquisa e que esta é um dos produtos do fazer acadêmico traz à tona a questão relativa aos públicos aos quais as pesquisas científicas respondem; seja pela atuação dos pesquisadores nas ciências definidas como duras ou naquelas afirmadas como humanas e sociais. Sem uma reflexão maior, quase com um simples olhar de senso comum, dá para perceber que embora os pesquisadores de um ou do outro ramo tenham, pelos seus ideais acadêmicos originais, a melhora da condição humana como fim de seus esforços, chegar a este alvo exige a transposição de caminhos sobre os quais percorrem com muito maior vigor os interesses econômicos e políticos dos grupos articuladores das forças de poder e de mando. Dentro deste espaço, claro está que não se coloca do lado dos produtores de ciência e tecnologia a capacidade de determinar onde aplicar o conhecimento, quanto aplicar na inovação, quanto extrair como lucro financeiro dos produtos a serem consumidos, para quem direcionar os produtos feitos, que benefícios efetivos serão alcançados pela humanidade, incluídos os próprios cientistas e tecnólogos, por exemplo. Como trabalhadores do saber ou da geração de máquinas, equipamentos e organizadores da informação e de seu fluxo, todos nós, pesquisadores e gestores de conhecimento, somos também parte do arcabouço científico e tecnológico da humanidade, seja como cérebros (a condição que nos percebemos seja como extensões das máquinas que processam e difundem o conhecimento básico ou aplicado (a condição com que os donos dos poderes nos vêem. Sobretudo na condição de cidadãos, sobretudo na

  20. Moderately inhibitory effects of N-dodecyloxymethylene-N-methylpiperidinium and N-dodecyloxymethylene-N-methylmorpholinium chlorides on seed germination

    Directory of Open Access Journals (Sweden)

    Stanisław J. Knypl

    2014-01-01

    Full Text Available N-Dodecyloxymethylene-N-methylpiperidinium chloride (DMMP and N-dodecyloxyme-thylene-N-methylmorpholinium chloride (DMMM retarded germination of seeds of 9 cultivated plant species when applied at a concentration of 10-3 M, and inhibited germination at a concentration of 10-2 M. The exceptions were represented by Lepidium sativum L. and Linum usitatissimum L. seeds which germinated well even in 10-2 M solutions of either DMMP or DMMM.

  1. Civilsamfundets ABC: N for Norm

    DEFF Research Database (Denmark)

    Lund, Anker Brink; Meyer, Gitte

    2016-01-01

    Bogstaveligt talt: Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til N for Norm.......Bogstaveligt talt: Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til N for Norm....

  2. Properties of Si{sub n}, Ge{sub n}, and Si{sub n}Ge{sub n} clusters

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yi; Rehman, Habib ur; Springborg, Michael [Physical and Theoretical Chemistry, University of Saarland, 66123 Saarbrücken (Germany)

    2015-01-22

    The structures of Si{sub n}, Ge{sub n}, and Si{sub n}Ge{sub n} clusters with up to 44 atoms have been determined theoretically using an unbiased structure-optimization method in combination with a parametrized, density-functional description of the total energy for a given structure. By analyzing the total energy in detail, particularly stable clusters are identified. Moreover, general trends in the structures are identified with the help of specifically constructed descriptors.

  3. Coordinación y acción colectiva

    Directory of Open Access Journals (Sweden)

    Miller Moya, Luis Miguel

    2007-04-01

    Full Text Available This paper highlights the importance of understanding coordination problems for the study of collective action. To this end, the paper consists of three parts. First, the main differences between cooperation and coordination problems are displayed. Second, the structure of a coordination problem is analysed, specially the relationship between coordination situations and the generation of common knowledge. Third, the most recurrent solutions to coordination problems are described, namely: agreements, salience and learning. After considering these solutions, the paper speculates about other possible ways of interpreting how people solve coordination problems.

    El presente trabajo destaca la importancia de comprender los problemas de coordinación para el estudio de la acción colectiva. Para ello, el artículo se compone de tres partes. En primer lugar, se presentan las principales diferencias entre problemas de cooperación y problemas de coordinación. En segundo lugar, se analiza la estructura de un problema de coordinación, con especial atención a la relación entre las situaciones de coordinación y la generación de conocimiento común. En tercer lugar, se describen las soluciones más recurrentes a los problemas de coordinación, a saber, acuerdos, prominencia y aprendizaje. Tras considerar este conjunto de soluciones, el artículo especula sobre otros modos de interpretar cómo se resuelven los problemas de coordinación.

  4. La reinvención de Medellín

    Directory of Open Access Journals (Sweden)

    Andres Sanchez Jabba

    2013-01-01

    Full Text Available Resumen: Con la adopción del modelo de industrialización por sustitución de importaciones, Medellín se convirtió en el centro industrial más importante de Colombia. Esto se debió al surgimiento de su aglomerado textil, el cual fue la fuente de crecimiento económico urbano durante gran parte del siglo XX. Sin embargo, el excesivo grado de especialización en la producción textil generó una profunda crisis industrial cuando inició el proceso de liberalización comercial en la década de 1990. Adicionalmente, el surgimiento del narcotráfico incrementó considerablemente los niveles de violencia. La combinación de estos dos factores dejó a la ciudad sumida en una profunda crisis urbana caracterizada por una gran inestabilidad institucional. Sin embargo, Medellín supo reinventarse: los niveles de violencia disminuyeron, los indicadores sociales y económicos mejoraron y la ciudad buscó el resurgimiento urbano orientando su economía hacia la generación de conocimiento apalancado en la innovación y el uso intensivo de la tecnología.

  5. La reinvención de Medellín

    Directory of Open Access Journals (Sweden)

    Andrés Sánchez Jabba

    2013-06-01

    Full Text Available Con la adopción del modelo de industrialización por sustitución de importaciones, Medellín se convirtió en el centro industrial más importante de Colombia. Esto se debió al surgimiento de su aglomerado textil, el cual fue la fuente de crecimiento económico urbano durante gran parte del siglo XX. Sin embargo, el excesivo grado de especialización en la producción textil generó una profunda crisis industrial cuando inició el proceso de liberalización comercial en la década de 1990. Adicionalmente, el surgimiento del narcotráfico incrementó considerablemente los niveles de violencia. La combinación de estos dos factores dejó a la ciudad sumida en una profunda crisis urbana caracterizada por una gran inestabilidad institucional. Sin embargo, Medellín supo reinventarse: los niveles de violencia disminuyeron, los indicadores sociales y económicos mejoraron y la ciudad buscó el resurgimiento urbano orientando su economía hacia la generación de conocimiento apalancado en la innovación y el uso intensivo de la tecnología.

  6. Structure of $^{22}$N and the N=14 subshell

    CERN Document Server

    Rodriguez-Tajes, C.; Alvarez-Pol, H.; Aumann, T.; Benjamim, E.; Benlliure, J.; Borge, M.J.G.; Caamano, M.; Casarejos, E.; Chatillon, A.; Chulkov, L.V.; Eppinger, K.; Faestermann, T.; Gascon, M.; Geissel, H.; Gernhauser, R.; Jonson, B.; Kanungo, R.; Krucken, R.; Kurtukian, T.; Larsson, K.; Maierbeck, P.; Nilsson, T.; Nociforo, C.; Parfenova, Yu.; Pascual-Izarra, C.; Perea, A.; Perez-Loureiro, D.; Prochazka, A.; Schwertel, S.; Simon, H.; Summerer, K.; Tengblad, O.; Weick, H.; Winkler, M.; Zhukov, M.V.

    2011-01-01

    One-neutron knockout data for (18-22)N are analyzed in the eikonal approximation of the Glauber model. The role of the s-d shell and the crossing of the N = 14 neutron subshell are discussed. Of particular interest is the nucleus (22)N, where the knockout data provide a sensitive experimental test for a possible halo structure of its ground state. The observation of a narrow momentum distribution of the (21)N fragments, together with an essential 1s(1/2) contribution needed to describe the observed longitudinal-momentum distribution, allow the firm conclusion that the ground state of (22)N is a well-developed nuclear halo. The results also show that the N = 14 subshell in (22)N is somewhat reduced as compared to that of (23)O.

  7. EN DIRECCIÓN A LA POSTCOMUNICACIÓN

    Directory of Open Access Journals (Sweden)

    Luis Rodolfo Rojas Vera

    1999-01-01

    Full Text Available El artículo desarrolla bajo el estilo de ensayo la idea de una teoría de la Postcomunicación. Centra la atención en los cambios acelerados del mundo comunicacional y los retos de entendimiento de la cultura postcomunicacional bajo los esquemas de los actuales modelos de comunicación. Señala que la sinergía de las comunicaciones será la clave que explicará el mundo postcomunicacional del Siglo XXI. Anuncia que la Postcomunicación cambiará las reglas de la Dirección y plantea la necesidad de enfoques transdisciplinarios para el estudio de la postcomunicación. Ofrece un conjunto de reflexiones que pueden ser útiles para los científicos de la Comunicación.

  8. La modernización del Japón

    OpenAIRE

    rikiwo Shikama

    1988-01-01

    RESUMEN El autor presenta de forma general una visión del proceso de modernización del Japón. El significado importante de la Revolución Meiji, haciendo alusión al contexto en el cual ésta se desarrolló. Hace un análisis comparativo de la China y Japón derivado de las tesis del doctor Reischaver, catedrático de la universidad de Harvard. Resalta la importancia que tuvo en el proceso de modernización las características específicas del régimen Feudad Japonés, y el alto nivel de alfabet...

  9. Oportuna compilación

    Directory of Open Access Journals (Sweden)

    Darío Fajardo Montaña

    1986-01-01

    Full Text Available El problema social agrario en Colombia. El pensamiento liberal en la solución del problema agrario. Hernán Toro Agudelo. Ediciones Tercer Mundo, Bogotá, 1984. 435 págs. Orión Agudelo Toro , compilador. Prólogo de Gerardo Molina.

  10. n vertaalwoordeboek vir professionele vertalers

    African Journals Online (AJOL)

    Die eerste. (die lemma big bang theory) is 'n leksikale item wat net een woordsoortelike funksie het en wat die gebruik van 'n leksikografiese etiket en die aanbied van ensiklopediese inligting toon. Die multileksikale leksikale item fast track het meer as een woordsoortelike funksie en toon die hantering van 'n wisselende ...

  11. Nutrición enteral

    OpenAIRE

    Barrachina Bellés, Lidón; García Hernández, Misericordia; Oto Cavero, Isabel

    1984-01-01

    Este trabajo nos introduce en la administración de la nutrición enteral, haciendo una revisión de los aspectos a tener en cuenta tanto en sus indicaciones, vias, tipos, métodos, cuidados y complicaciones más importantes.

  12. N-ov-emb-er

    Indian Academy of Sciences (India)

    " to. Andrew Z Fire - Stanford University School of Medicine Stanford, CA, USA. Craig C Mello - University of Massachusetts Medical School Worcester, MA, USA. -96----------------------------~~--------R-ES-O-N-A-N-C-E--1 -N-ov-e-m-b-er--2-oo-6.

  13. Comparison of trap characteristics between AlGaN/GaN and AlGaN/InGaN/GaN heterostructure by frequency dependent conductance measurement

    International Nuclear Information System (INIS)

    Chakraborty, Apurba; Biswas, Dhrubes

    2015-01-01

    Frequency dependent conductance measurement is carried out to observe the trapping effect in AlGaN/InGaN/GaN double heterostructure and compared that with conventional AlGaN/GaN single heterostructure. It is found that the AlGaN/InGaN/GaN diode structure does not show any trapping effect, whereas single heterostructure AlGaN/GaN diode suffers from two kinds of trap energy states in near depletion to higher negative voltage bias region. This conductance behaviour of AlGaN/InGaN/GaN heterostructure is owing to more Fermi energy level shift from trap energy states at AlGaN/InGaN junction compare to single AlGaN/GaN heterostructure and eliminates the trapping effects. Analysis yielded interface trap energy state in AlGaN/GaN is to be with time constant of (33.8–76.5) μs and trap density of (2.38–0.656) × 10 12  eV −1  cm −2 in −3.2 to −4.8 V bias region, whereas for AlGaN/InGaN/GaN structure no interface energy states are found and the extracted surface trap energy concentrations and time constants are (5.87–4.39) ×10 10  eV −1  cm −2 and (17.8–11.3) μs, respectively, in bias range of −0.8–0.0 V

  14. RELACIÓN DE LA INTENCIÓN E IDEACIÓN SUICIDA CON ALGUNAS VARIABLES

    Directory of Open Access Journals (Sweden)

    Paola Valderrama

    2006-06-01

    Full Text Available El objetivo de este estudio fue hallar la relación de la intención e ideación suicida con algunas variables sociodemográficas, las características de la enfermedad, el tratamiento antirretroviral y los aspectos piscoafectivos en personas con el VIH/SIDA que residen en Bogotá (Colombia y pertenecientes a una fundación. Para ello, se tomó una muestra de 75 pacientes con VIH positivo a quienes se evaluó a través de una entrevista semiestructurada y dos instrumentos: el inventario de depresión de Beck (IBD y la escala de Ideación Suicida (SSI. Los resultados mostraron que solo 29 personas tenían ideación suicida y 10 intención suicida: De los 10 solo 2 sujetos tenían intención después del diagnóstico. Se encontró una relación estadística significativa para ideación suicida e intención suicida con edad, estrato socioeconómico, estado civil, orientación sexual, las características de la enfermedad, el tratamiento antirretroviral y los aspectos piscoafectivos.

  15. 40 CFR 721.10193 - 1-Butanaminium, N-(3-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Butanaminium, N-(3-aminopropyl)-N...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. (a) Chemical substance and...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts (PMN P-06-263, Chemical B; CAS No...

  16. La noción patrón de reproducción del capital

    Directory of Open Access Journals (Sweden)

    Jaime Osorio

    2014-10-01

    Full Text Available El escrito se propone fundamentar teóricamente la noción patrón de reproducción del capital, tras asumir que cubre un espacio no desarrollado por la teoría marxista en el análisis de totalidades concretas. Tras establecer el tejido conceptual para estos objetivos, apoyado particularmente en la obra de Marx, y en la de Marini sobre las particularidades del capitalismo dependiente, el autor ofrece a su vez una propuesta para el análisis de los patrones de reproducción. De esta forma emerge una formulación que rompe con la dispersión y la fragmentación imperantes, justificadas por la especialización, y que permite retomar el sentido que asume la vida en común.

  17. Strain Balanced AlGaN/GaN/AlGaN nanomembrane HEMTs.

    Science.gov (United States)

    Chang, Tzu-Hsuan; Xiong, Kanglin; Park, Sung Hyun; Yuan, Ge; Ma, Zhenqiang; Han, Jung

    2017-07-25

    Single crystal semiconductor nanomembranes (NM) are important in various applications such as heterogeneous integration and flexible devices. This paper reports the fabrication of AlGaN/GaN NMs and NM high electron mobility transistors (HEMT). Electrochemical etching is used to slice off single-crystalline AlGaN/GaN layers while preserving their microstructural quality. A double heterostructure design with a symmetric strain profile is employed to ensure minimal residual strain in freestanding NMs after release. The mobility of the two-dimensional electron gas (2DEG), formed by the AlGaN/GaN heterostructure, is noticeably superior to previously reported values of many other NMs. AlGaN/GaN nanomembrane HEMTs are fabricated on SiO 2 and flexible polymeric substrates. Excellent electrical characteristics, including a high ON/OFF ratio and transconductance, suggest that III-Nitrides nanomembranes are capable of supporting high performance applications.

  18. Información incompleta y regulación: una introducción.

    Directory of Open Access Journals (Sweden)

    Carlos Pombo

    2010-05-01

    Full Text Available Este artículo describe el modelo de regulación de costos con información completa para monopolios naturales, y lo compara con modelo con modelos que presentan asimetrías e información incompleta como el modelo de regulación de monopolios naturales con selección adversa de Baron y Myerson y el modelo de gestión con riesgo moral De Laffont y Tirole. El enfoque básico sigue el marco de trabajo de principal agente para el caso de dos tipos, en el cual la distorsión causada por las rentas provenientes de la información se consideran más importantes debido al hecho de que el regulador no conoce el costo marginal de la firma por el esfuerzo efectivo de la firma en reducir los costos operativos.

  19. Advanced heat exchanger development for molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Sabharwall, Piyush, E-mail: Piyush.Sabharwall@inl.gov [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Clark, Denis; Glazoff, Michael [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark [University of Wisconsin, Madison (United States)

    2014-12-15

    Highlights: • Hastelloy N and 242, shows corrosion resistance to molten salt at nominal operating temperatures. • Both diffusion welds and sheet material in Hastelloy N were corrosion tested in at 650, 700, and 850 °C for 200, 500, and 1000 h. • Thermal gradients and galvanic couples in the molten salts enhance corrosion rates. • Corrosion rates found were typically <10 mils per year. - Abstract: This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non-nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, that show good corrosion resistance in molten salt at nominal operating temperatures up to 700 °C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in 58 mol% KF and 42 mol% ZrF{sub 4} at 650, 700, and 850 °C for 200, 500, and 1000 h. Corrosion rates were similar between welded and nonwelded materials, typically <100 μm per year after 1000 h of corrosion tests. No catastrophic corrosion was observed in the diffusion welded regions. For materials of construction, nickel-based alloys and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of the type of salt impurity and alloy composition, with respect to chromium and carbon, to better define the best conditions for corrosion resistance. Also presented is the division of the nuclear reactor and high-temperature components per American Society of Mechanical

  20. educación ambiental

    Directory of Open Access Journals (Sweden)

    Fernando Ojeda Barceló

    2008-01-01

    Full Text Available Las Tecnologías de la Información y Comunicación (TICs pueden constituir una herramienta de primer orden para la Educación Ambiental para la Sostenibilidad (EApS, pero todavía existe cierta reticencia por parte de educadores ambientales a hacer un uso de ellas de forma habitual. El objetivo fundamental de este trabajo es ofrecer una revisión del estado de la cuestión tanto a nivel nacional como internacional e intentar hacer una propuesta didáctica de trabajo colaborativo a través de Internet para estudiantes de secundaria.

  1. Degeneración Lattice

    OpenAIRE

    Rojas Bocanegra, Alberto

    2004-01-01

    Objetivo: Determinar la prevalencia de degeneración periférica de retina Lattice y su relación con estados refractivos y rupturas retinales. Metodología: Estudio de corte transversal con exploración de asociación, mediante análisis de casos y controles. Se examinaron 680 ojos en el Instituto de Investigaciones Optométricas e Instituto de Córnea. El estado refractivo se determinó mediante técnica estática y el estado retinal mediante oftalmoscopia indirecta con indentación escleral. Resultados...

  2. Relativistic scalar-vector models of the N-N and N-nuclear interactions

    International Nuclear Information System (INIS)

    Green, A.E.S.

    1985-01-01

    This paper for the Proceedings of Conference an Anti-Nucleon and Nucleon-Nucleus Interactions summarizes work by the principal investigator and his collaborators on the nucleon-nucleon (N-N) and nucleon-nuclear (N-eta) interactions. It draws heavily on a paper presented at the Many Body Conference in Rome in 1972 but also includes a brief review of our phenomenological N-eta interaction studies. We first summarize our 48-49 generalized scalar-vector meson field theory model of the N-N interactions. This is followed by a brief description of our phenomenological work in the 50's on the N-eta interaction sponsored by the Atomic Energy Commission (the present DOE). This work finally led to strong velocity dependent potentials with spin orbit and isospin terms for shell and optical model applications. This is followed by a section on the Emergence of One-Boson Exchange Models describing developments in the 60's of quantitative generalized one boson exchange potentials (GOBEP) including our purely relativistic N-N analyses. Then follows a section on the application of this meson field model to the N-eta interaction, in particular to spherical closed shell nuclei. This work was sponsored by AFOSR but funding was halted with the Mansfield amendment. We conclude with a discussion of subsequent collateral work by former colleagues and by others who have converged upon scalar-vector relativistic models of N-N, antiN-N, N-eta and antiN-eta interactions and some lessons learned from this extended endeavor. 61 refs

  3. N/sub p/.N/sub n/ systematics and their implications

    International Nuclear Information System (INIS)

    Casten, R.F.

    1985-01-01

    A substantial simplification of the systematics in nuclear phase transition regions is obtained if the data are plotted against the product, N/sub p/.N/sub n/, of the number of valence protons and neutrons instead of against N, Z, or A as is usually done. Such a scheme leads to a unified view of nuclear transition regions and to a simplified scheme for collective model calculations. 7 refs., 5 figs

  4. Reaction theories for N* excitations in πN and γN reactions

    International Nuclear Information System (INIS)

    Lee, T.S.H.

    1996-01-01

    The importance of developing reaction theories for investigating N* physics is illustrated in an analysis of pion photoproduction on the nucleon. It is shown that the γN ↔ Δ transition amplitudes predicted by the constituent quark model are in agreement with the values extracted from the γN → πN data only when the contributions from the reaction mechanisms calculated using a dynamical approach are taken into account in the analysis

  5. Editorial, n. 12, 2001

    Directory of Open Access Journals (Sweden)

    Editor Encontros Bibli

    2001-01-01

    Full Text Available EDITORIAL, n. 12, 2001 Este número da Encontros Bibli apresenta diferentes abordagens de questões relativas à sociedade do conhecimento. Esta sociedade vem acompanhada de uma evolução tecnológica que afeta, em diferentes graus, todos os países do mundo, produzindo impactos de natureza econômica, política, social e cultural. Tais impactos necessitam de parâmetros para sua análise e avaliação. A medição de bens intangíveis, neste caso, provenientes do uso das tecnologias da informação e da comunicação, é uma tarefa complexa. O artigo do professor Michel Menou, da City University, de Londres, apresenta uma metodologia original para análise desses indicadores na sociedade atual. O relato de pesquisa da professora Clarice Fortkamp Caldin, do Departamento de Ciência da Informação da UFSC, aborda o processo de leitura como função terapêutica. Este trabalho é baseado na sua dissertação de mestrado e representa um foco de abordagem pouco usual na Ciência da Informação. O professor Francisco das Chagas de Souza, também do Departamento de Ciência da Informação da UFSC, apresenta uma análise de sua experiência no ensino de fundamentos teóricos da Biblioteconomia. A estudante Maria Elizabeth Horn Pepulim, do Curso de Biblioteconomia da UFSC, reflete sobre o papel do bibliotecário na sociedade da informação, ressaltando os dilemas, atribuições e responsabilidades deste profissional no mundo globalizado. Esta edição divulga ainda uma pesquisa sobre bibliotecas públicas, sociedade da informação e tecnologia, que está sendo desenvolvida pelos colegas do Instituto de Investigaciones Bibliotecológicas da Universidad de Buenos Aires: Elsa Barber, Nicolás Tripaldi, Silvia Pisano, Valeria Werner, Sofia D´Alessandro, Sandra Romagnoli, Verónica Parsiale, Carolina Gregui e Gabriela De Pedro. Miriam Vieira da Cunha, editora Disponibilizado na WWW em 28/12/2001. Enc. Bibli: R. Eletr. Bibliotecon. Ci. Inf., ISSN 1518

  6. Comparative analysis of oxidative synthesis of N-alkyl, N,N-dialkyl and N-cykloalkyl-O-isobutyl thioncarbamate

    Directory of Open Access Journals (Sweden)

    Sovrlić Milica Ž.

    2011-01-01

    Full Text Available A optimized synthesis of N-alkyl, N,N-dialkyl- and N-cycloalkyl-O-isobutyl thioncarbamates by aminolysis of sodium isobutylxanthogenic acid (NaiBXAc and primary, secondary and cycloalkyl amines was developed at laboratory scale and applied at semi-industrial level. Studies on dependence of N-n-propyl-O-isopropylthiocarbamate yield and purity with respect to reaction parameters: reaction time and molar ratio of n-propylamine and NaiBXAc, were performed. In such way, optimal reaction conditions for synthesis of N-alkyl, N,N-dialkyl- and N-cycloalkyl-O-isobutyl thioncarbamates, by aminolysis of NaiBXAc, were established. Also, comparative results of thioncarbamates synthesis starting from potassium isobutyl xanthate (KiBX and corresponding amines in presence of different oxidants: hydrogen peroxide, sodium hypochlorite and new oxidative agent potassium peroxodisulfate were evaluated. Synthesized compounds have been fully characterized by FTIR, 1H and 13C NMR and MS data, elemental analysis and purity have been determined by gas chromatographic method (GC. According to our knowledge, ten synthesized thioncarbamates are for the first time characterized. Synthesized compounds could be used as selective reagents for flotation of copper and zinc ores. The presented methods offer several benefits, namely, high product yields and purity, simple operation, mild reaction conditions without use of hazardous organic solvents, while some of them could be implemented on industrial scale production.

  7. ADOLESCENCIA Y DEPRESIÓN

    Directory of Open Access Journals (Sweden)

    Diana Umbarila

    2004-06-01

    Full Text Available El presente artículo realiza una revisión sobre los principales factores de riesgo asociados al problema de la depresión en jóvenes. Se analizan los principales problemas conceptuales para definir con claridad el término depresión y se examinan las grandes interrelaciones existentes entre conceptos como estrés, ansiedad y depresión y sus implicaciones para el diagnóstico diferencial de la depresión en general y específicamente en jóvenes. En conclusión, este artículo sostiene que hay una dificultad teórica para establecer las relaciones que existen entre estrés, ansiedad y depresión.

  8. Presentación. Globalización e inmigración:los debates actuales.

    Directory of Open Access Journals (Sweden)

    Carlota Solé

    2006-01-01

    Full Text Available Este artículo sirve de presentación al monográfico de la Revista Española de Investigaciones Sociológicas sobre "Globalización e inmigración". Comienza poniendo de relieve algunos de los cambios que se están produciendo en los flujos migratorios (como su feminización y en las políticas de regulación de las migraciones (como las políticas europeas. A continuación apunta brevemente algunos de los debates teóricos y políticos actuales en torno a la inmigración en el marco de la globalización: transnacionalidad, ciudadanía e integración, identidad europea y multiculturalidad. La segunda parte del artículo presenta el desarrollo académico de las teorías de las migraciones a través de la comparación del contenido del Handbook of International Migration de 1999 y los artículos recogidos en el monográfico de la International Migration Review de 2004. Por último, sintetiza los artículos y notas de investigación de este monográfico de la Revista Española de Investigaciones Sociológicas, ubicándolos en esos desarrollos teóricos.

  9. Synthesis of multiple deuterated N-n-propyl-norapomorphine N-(d/sub 7/) and derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yigong; Trainor, T.M.; Vouros, Paul; Neumeyer, J.L.

    1988-03-01

    Novapomorphine has been labelled using n-propyl iodide through alkylation of norcodeine followed by a multistep route which also affords the related deuterated analogs N-n-propylnorapocodeine, the prodrug 10,11-methylenedioxy-NPA and 10,11-dimethoxy-NPA.

  10. Thermal stability of TaN Schottky contacts on n-GaN

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, J.R.; Kim, D-W.; Meidia, H.; Mahajan, S

    2003-02-07

    The thermal stability and electrical characteristics of tantalum-nitrogen alloy Schottky contacts on n-GaN were investigated. Non-stoichiometric {delta}-phase (40 atomic percent nitrogen) tantalum nitride contacts exhibited good electrical properties up to an annealing temperature of 600 deg. C. However, they degrade rapidly above this temperature due to outward diffusion of Ga and presumably nitrogen into the {delta}-phase tantalum nitride. It is surmised that excess Ta reacts with N at the GaN surface, freeing Ga which then diffuses into the TaN layer. Stoichiometric TaN Schottky contacts were stable at temperatures as high as 800 deg. C and had far superior electrical performance. This stems from the thermodynamic stability of the stoichiometric TaN/GaN interface. {delta}-phase TaN had I-V and C-V barrier heights of 0.55 eV and 0.8 eV respectively. On the other hand, TaN had an I-V barrier height near 0.7 eV and a C-V barrier height near 1.2 eV. The ideality factors for both {delta}-phase TaN and TaN were above 1.8 at all annealing temperatures, suggesting tunneling contributes significantly to current transport.

  11. Fitorremediación en la recuperación de suelos: una visión general

    OpenAIRE

    Andrea Angélica Bernal Figueroa

    2014-01-01

    En esta investigación se revisan aspectos fundamentales de la fitorremediación como técnica en la recuperación de suelos, la cual se emplea para eliminar o disminuir la contaminación o degradación de los mismos, por medio de la utilización de especies vegetales. Se encontró que técnicas tales como la fitoextracción, rizofiltración, fitoestabilización, fitodegradación, rizodegradación y fitovolatilización, están determinadas principalmente por el tipo de contaminante, diversidad microbiana y p...

  12. 40 CFR 721.10055 - 1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts.

    Science.gov (United States)

    2010-07-01

    ...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. 721.10055 Section 721.10055 Protection of...-amino-N-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts. (a) Chemical substance and...-(carboxymethyl)-N,N-dimethyl-, N-soya acyl derivs., inner salts (PMN P-03-46; CAS No. 136504-87-5) is subject to...

  13. N-(3-Nitrophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8N2O5, the molecule is slightly distorted from planarity. The molecular structure is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond (H...O distance = 1.57 Å within the maleamic acid unit and the second is a C—H...O hydrogen bond (H...O distance = 2.24 Å which connects the amide group with the benzene ring. The nitro group is twisted by 6.2 (2° out of the plane of the benzene ring. The crystal structure manifests a variety of hydrogen bonding. The packing is dominated by a strong intermolecular N—H...O interaction which links the molecules into chains running along the b axis. The chains within a plane are further assembled by three additional types of intermolecular C—H...O hydrogen bonds to form a sheet parallel to the (overline{1}01 plane.

  14. Two different mechanisms of fatigue damage due to cyclic stress loading at 77 K for MOCVD-YBCO-coated conductors

    International Nuclear Information System (INIS)

    Sugano, M; Yoshida, Y; Hojo, M; Shikimachi, K; Hirano, N; Nagaya, S

    2008-01-01

    Tensile fatigue tests were carried out at 77 K for YBCO-coated conductors fabricated by metal-organic chemical vapor deposition (MOCVD). The S-N relationship, variation of critical current (I c ) during cyclic loading and microscopic fatigue damage were investigated. Fatigue strength at 10 6 cycles was evaluated to be σ max = 1300 MPa and 890 MPa under the stress ratios of 0.5 and 0.1. Two different mechanisms of fatigue damage, depending on the number of stress cycles to failure, were observed. In one of the fracture mechanisms, fatigue behavior is characterized by overall fracture which occurs at 10 4 -10 5 cycles. For these specimens, I c after unloading does not degrade before overall fracture. Although only shallow slip bands were found at the Ag surface, fatigue cracks were found on the Hastelloy C-276 surface of the fractured specimen. These results suggest that overall fracture due to cyclic stress was caused by fatigue of the Hastelloy substrate. In the other fracture mechanism, even though overall fracture did not occur at 10 6 cycles, a slight decrease of I c was detected after 10 5 cycles. No fatigue crack was found on the Hastelloy surface, while deep slip bands corresponding to the initial stage of fatigue crack were observed on the Ag surface. From these results, we concluded that I c degradation at a high cycle number is attributed to the fatigue of the Ag stabilizing layer

  15. Fabrication of TiN/AlN/TiN tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Takeru; Naruse, Masato; Myoren, Hiroaki; Taino, Tohru, E-mail: taino@mail.saitama-u.ac.jp

    2016-11-15

    Highlights: • We have fabricated TiN/AlN/TiN tunnel junctions with an epitaxial layer. • TiN and AlN films were deposited by dc and rf magnetron sputtering at ambient substrate temperatures. • The junctions have a V{sub g} = 1.1 mV, J{sub c} = 0.24 A/cm{sup 2}, R{sub sg}/R{sub n} of 7.2, and low subgap leakage current of 180 nA. - Abstract: We have fabricated TiN/AlN/TiN tunnel junctions with an epitaxial layer. The critical temperature of TiN can be changed in the range from 0.5 to 5.0 K. Therefore, it is easy to set 5.0 K as the target critical temperature. When a Superconducting Tunnel Junction (STJ) is operated as a photon detector, it is necessary to cool it to within 0.1 K of the critical temperature in consideration of the noise of the thermally stimulated currents. Because 0.3 K was desirable, as for the manufacture of general purpose photon detectors, the critical temperature 5.0 K. TiN and AlN films were deposited by dc and rf magnetron sputtering in a load-lock sputtering system at ambient substrate temperatures. The junctions have a gap voltage of V{sub g} = 1.1 mV, and critical current density of J{sub c} = 0.24 A/cm{sup 2}, and R{sub sg}/R{sub n} of 7.2, and low subgap leakage current (I{sub sub}@ 500 µV = 180 nA). We report our experiment system, the manufacture method and the junction properties in this paper.

  16. Administración del agua. - Introducción

    OpenAIRE

    Fernández Morales, Juan Carlos

    2008-01-01

    ÍNDICE Créditos Dedicatoria Agradecimiento Notas del autor Introducción Capítulo I: Marco jurídico conceptual de la gestión del agua. Capítulo II: Organización administrativa del agua. Capítulo III: Las confederaciones hidrográficas en la legislación española. Capítulo IV: Los usuarios y la gestión del agua. Capítulo V: Administración del agua y competencias sectoriales en las comunidades autonómas españolas. Capítulo VI: Abastecimien...

  17. Evaluation of Some (n,n'), (n,γ), (n,p), (n,2n) and (n,3n) Reaction Excitation Functions for Fission and Fusion Reactor Dosimetry Applications; Evaluation of the Excitation Functions for the 54Fe(n,p)54Mn, 58Ni(n,2n)57Ni, 67Zn(n,p)67Cu, 92Mo(n,p)92mNb, 93Nb(n,γ)94Nb, 113In(n,n')113mIn, 115In(n,γ) 116mIn, and 169Tm(n,3n)167Tm Reactions. Progress Report on Research Contract No 16242

    International Nuclear Information System (INIS)

    Zolotarev, K.I.; Zolotarev, P.K.

    2013-12-01

    Cross section data for the 54 Fe(n,p) 54 Mn, 58 Ni(n,2n) 57 Ni, 67 Zn(n,p) 67 Cu, 92 Mo(n,p) 92m Nb, 93 Nb(n,γ) 94 Nb, 113 In(n,n') 113m In, 115 In(n,γ) 116m In, 169 Tm(n,3n) 167 Tm reactions are needed to solve a wide spectrum of scientific and technical tasks. Activation detectors based on these reactions may be used in the field of reactor dosimetry. Furthermore, the 54 Fe(n,p) 54 Mn reaction is often used in experimental nuclear physics as a monitor reaction for measurements of unknown cross sections by means of the activation method over the neutron energy range from 5 to 15 MeV. The 93 Nb(n,γ) 94 Nb reaction is also very promising for using in retrospective neutron dosimetry for determination of total neutron fluence during a campaign of a reactor. In the existing version of the International Reactor Dosimetry File and the new extended version named as IRDFF data for excitation functions of 67 Zn(n,p) 67 Cu, 92 Mo(n,p) 92m Nb, 113 In(n,n') 113m In, and 169 Tm(n,3n) 167 Tm reactions are absent. Data for these reactions are also absent in the JENDL/D-99 dosimetry file. Excitation functions of 67 Zn(n,p) 67 Cu and 169 Tm(n,3n) 167 Tm are presented in the TENDL-2012, EAF-2010, JENDL-4.0, JEFF-3.1/A, MENDL-2 libraries. Cross section data for the 67 Zn(n,p) 67 Cu reaction up to 20 MeV are given also in the JENDL/HE-2007 library. Excitation functions of the 92 Mo(n,p) 92m Nb and 113 In(n,n') 113m In reactions are evaluated in the EAF-2010 and JEFF-3.1/A libraries. Cross section data for the 113 In(n,n') 113m In reaction are given also in the TENDL-2010 library. It is necessary to note that neutron data in the JEFF-3.1/A and JENDL-4.0 libraries were evaluated up to 20 MeV. Neutron data in the TENDL-2012, EAF-2010, MENDL-2 and TENDL-2010 libraries had been evaluated up to 30 MeV, 60 MeV, 100 MeV and 200 MeV, respectively. Neutron cross sections in the MENDL-2, TENDL-2010 and TENDL-2012 libraries had been obtained on the basis of pure theoretical model calculations

  18. La evaluación en educación

    Directory of Open Access Journals (Sweden)

    Alex Gutierrez Moreno

    2014-02-01

    Full Text Available La evaluación en educación es un problema edemas de complejo, bastante controvertido, en especial por las diferentes transformaciones sobrevenidas en las últimas décadas en las concepciones y prácticas educativas. En este artículo se propone una discusión sobre el sentido de evaluar contrastado con la cotidianidad de las instituciones educativas en donde se cambian sus propósitos fundamentales.

  19. Gestión en rehabilitación

    Directory of Open Access Journals (Sweden)

    Dr. L. Ricardo Eckardt

    2014-03-01

    Como un puente entre esos mundos diferentes, surgen médicos con formación en gestión. Entre ellos, la especialidad de fisiatría ocupa un lugar destacado debido a su perfil, el contexto epidemiológico actual y las competencias que lo hacen adecuado para asumir los roles con los que la actual gestión de las instituciones de salud se ven desafiadas.

  20. Effect of N incorporation on the characteristics of InSbN P–N diodes

    International Nuclear Information System (INIS)

    Lim, K.P.; Pham, H.T.; Yoon, S.F.; Tan, K.H.

    2012-01-01

    We report on the effect of N incorporation in the characteristics of the 2 μm thick InSbN photoabsorption layer of a p–n diode grown by molecular beam epitaxy using a radio-frequency plasma-assisted nitrogen source. As compared to N free InSb layer, the absorption wavelength extends to near 9 μm. On the other hand, high reverse dark current and series resistances are observed in the electrical characteristics of the InSbN diode which are contributed with the presence of planar growth defects. These results will be useful to those working on midinfrared photodetectors.

  1. Traducción comentada : transcripción y traducción forenses

    OpenAIRE

    Benito Vega, Mª del Pilar

    2016-01-01

    El documento objeto de esta investigación y traducción es un texto sobre la transcripción y traducción forenses. En él se abordan los problemas más habituales a los que se tienen que enfrentar los profesionales de este campo, tales como: 1. falta de concienciación social y del sistema jurídico estadounidense sobre la importancia de tener transcriptores y traductores forenses cualificados, 2. los problemas judiciales que una persona con bajo nivel de inglés padece como consecuencia...

  2. Gestión de residuos de construcción y demolición

    OpenAIRE

    Matallana Matallana, Carlos

    2010-01-01

    La concienciación social de la necesidad de llevar a cabo un Desarrollo Sostenible obliga en el campo de la construcción a potenciar el reciclaje de los materiales que han cumplido ya su vida útil, procedentes de las propias actividades constructivas así como de diversos procesos industriales. La ventaja más destacada de este reciclaje es la solución, a un mismo tiempo, de la problemática originada por la eliminación de unos subproductos de desecho así como la obtención de una nueva materia p...

  3. Natural 15N abundance of soil N pools and N2O reflect the nitrogen dynamics of forest soils

    DEFF Research Database (Denmark)

    Pörtl, K.; Zechmeister-Boltenstern, S.; Wanek, W.

    2007-01-01

    Natural N-15 abundance measurements of ecosystem nitrogen (N) pools and N-15 pool dilution assays of gross N transformation rates were applied to investigate the potential of delta N-15 signatures of soil N pools to reflect the dynamics in the forest soil N cycle. Intact soil cores were collected...

  4. Edición fundacional

    Directory of Open Access Journals (Sweden)

    Renzo Ramírez Bacca

    2009-01-01

    Full Text Available HiSTOReLo nace con la presente edición electrónica y como proyecto editorial de la Asociación Colombiana de Historia Regional y Local, órgano integrado por investigadores, historiadores y estudiantes de historia de distintas universidades públicas y privadas del país. HiSTOReLo es una publicación sometida a revisión anónima de pares académicos.  Promueve el debate teórico, historiográfico y metodológico en los estudios de historia local y regional.  Es también un espacio de socialización de resultados de investigación  elaborados por personas interesadas en la creación de conocimiento histórico. La revista acepta propuestas que propendan por la relación de la disciplina con otras ciencias, con miras potenciar el dialogo interdisciplinario. HiSTOReLo nace para editarse públicamente cada seis meses en Internet y proporcionar acceso libre e inmediato a cada edición electrónica.

  5. DE ACUMULACIÓN POR DESPOSESIÓN

    Directory of Open Access Journals (Sweden)

    Sebastián Gómez Lende

    2015-01-01

    Full Text Available Omnipresente, la acumulación por desposesión es uno de los elementos centrales del orden global contemporáneo. Observados desde una perspectiva crítica, los usos extractivos del territorio constituyen una de las principales expresiones de ese proceso. A la luz de ese sistema de ideas, este artículo procura demostrar que el modelo sojero actualmente vigente en la Argentina es una de las formas más completas, exhaustivas, actuales y sofisticadas, de acumulación por desposesión en el país. En ese sentido, el artículo analiza el boom de la soja transgénica y sus vínculos con las formas tanto seculares (endeudamiento financiero, concentración de la propiedad rural, usurpación de la tierra y actuales de desposesión (degradación de la naturaleza, despojo del derecho a la salud, pillaje de recursos genéticos efectuadas por los grandes agricultores, el capital financiero, las agroindustrias y las corporaciones biotecnológicas, en detrimento de los pequeños productores, los campesinos, los pueblos aborígenes y la población en general.

  6. La traducción del latín

    OpenAIRE

    Valcárcel Martínez, Vitalino

    1995-01-01

    Editor de la obra colectiva: Vitalino Valcárcel [ES] la filología latina tiene por objeto el estudio, el conocimiento y el entendimiento cabal de los textos latinos para mediante ello llegar a la cultura que representan. Pues bien, la traducción constituye tanto el método más habitual de acercamiento a esos fines (traducción pedagógica) como uno de los momentos cumbre de todo ese proceso (traducción destinada a la publicación). Por ello tiene su importancia que los filólogos latinos ...

  7. N,N′-Bis(4-bromophenyl-N,N′-dimethylurea

    Directory of Open Access Journals (Sweden)

    Alexandre Pocinho

    2018-02-01

    Full Text Available The structure of the title compound, C15H14Br2N2O, at 180 K has monoclinic (P21/n symmetry. It was obtained unexpectedly from the decomposition of the parent 4-bromo-N-tert-butoxycarbonyl-N-methyl-aniline. It exhibits an `endo' conformation with angles between the two aromatic rings slightly lower than the average values found for similar compounds on the Cambridge Structural Database. In the crystal, C—H...O hydrogen bonds and short Br...Br halogen bonds [3.444 (1 Å] are observed.

  8. EVALUACIÓN DE UN CARBÓN SULFONADO COMO CATALIZADOR EN DESTILACIÓN REACTIVA

    Directory of Open Access Journals (Sweden)

    Álvaro Orjuela

    2008-03-01

    Full Text Available A partir de la sulfonación de un carbón antracítico de origen colombiano, se prepararon pastillas catalíticas con las cuales se empacó una columna de destilación semi-continua,  a la cual se alimentaron ácido acético y etanol, con el fin de evaluar experimentalmente la factibilidad de la destilación reactiva para la producción de acetato de etilo. El empaque-catalizador  se caracterizó mediante la determinación de la capacidad total de intercambio, titulación potenciométrica, área BET. Se realizaron ensayos con tres relaciones ácido/etanol para obtener los valores de conversión, concentración de destilado y fondos. El empaque de carbón sulfonado demostró capacidad tanto catalítica, con conversiones entre 29 y 45%, como de separación.

  9. Transición de la ruralidad: resignificación y refuncionalización.

    Directory of Open Access Journals (Sweden)

    Zuluaga Sánchez Gloria Patricia

    1999-12-01

    Full Text Available Este artículo es una continuación de la tesis de maestría en Paisaje, Territorio y Medio ambiente y busca reflexionar sobre la nueva ruralidad colombiana, su resignificación y refuncionalización. La pregunta central del presente trabajo es: ¿La creciente consciencia ciudadana sobre el medio ambiente podrá generar una neorruralízación o llevará sólo a una diversificación de las actividades y funcionales de lo rural? Debemos recordar que estamos frente a un cambio fundamental de visión en la ciencia y la sociedad; un cambio de paradigma del modelo de desarrollo industrial hacia el denominado paradigma ambiental. Esta nueva visión ha empezado a transformar la percepción y la manera como pensamos el mundo y actuamos sobre él. No estamos pues, presenciando una simple propuesta de reformulación de nuestra gestión, que llama al cuidado de los bosques, estamos frente a un nuevo contrato social que determinará la concepción futura de la humanidad.

  10. Growth of high quality GaN epilayer on AlInN/GaN/AlInN/GaN multilayer buffer and its device characteristics

    International Nuclear Information System (INIS)

    Lee, Suk-Hun; Lee, Hyun-Hwi; Jung, Jong-Jae; Moon, Young-Bu; Kim, Tae Hoon; Baek, Jong Hyeob; Yu, Young Moon

    2004-01-01

    The role of AlInN 1st /GaN/AlInN 2nd /GaN multi-layer buffer (MLB) on the growth of the high quality GaN epilayers was demonstrated by atomic force microscope (AFM), X-ray diffraction (XRD), photoluminescence, and Hall measurement. The surface morphology and crystalline quality of GaN epilayers were considerably dependent on AlInN layers thicknesses rather than those of GaN inter layers. With optimal thickness of 2 nd AlInN layer, the pit density of GaN epilayers was substantially reduced. Also, the RMS roughness of the well ordered terraces generated on the GaN surface was 1.8 A at 5 x 5 μm 2 . The omega-rocking width of GaN(0002) Bragg peak and Hall mobility of GaN epilayers grown on AlInN 1st /GaN/AlInN 2nd /GaN MLB were 190 arcsec and 500 cm 2 /Vs, while those values of GaN epilayers on single GaN buffer layer were 250 arcsec and 250 cm 2 /Vs, respectively. Especially, the light output power and operating voltage of the fabricated light emitting diodes with this new buffer layer was about 5 mW and 3.1 V (dominant luminous wavelength ∝460 nm) at 20 mA, respectively. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Growth and properties of InN, InGaN, and InN/InGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Naoi, H.; Na, H. [Center for Promotion of the COE Program, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577 (Japan); Kurouchi, M.; Muto, D.; Takado, S.; Araki, T.; Nanishi, Y. [Dept. of Photonics, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577 (Japan); Miyajima, T. [Optoelectronics Laboratory, Materials Laboratories, Sony Corporation, 4-14-1 Asahi, Atsugi, Kanagawa 243-0014 (Japan)

    2006-01-01

    This paper describes our recent progress on InN, In-rich In{sub x}Ga{sub 1-x}N, and InN/In{sub x}Ga{sub 1-x}N quantum wells (QWs) grown by radio-frequency plasma-assisted molecular-beam epitaxy. Among the essential growth sequences to obtain high-quality InN, the nitridation process of (0001) sapphire substrates was reexamined. It was found that the lower-temperature and longer-period nitridation-process was very effective in improving crystalline quality of InN films. We succeeded in dramatically improving c -axis orientation of InN films without deteriorating their a -axis orientation by nitridating the substrates at a relatively low-temperature of 300 C for a relatively long period of 2 h. The full widths at half maximum (FWHMs) of (0002) X-ray rocking curves as narrow as 1 arcmin were obtained from only 400 nm thick InN films. These FWHMs are the narrowest value ever reported for InN and moreover approximately a twentieth part of the values obtained from our conventional InN films with a similar thickness, which were grown via the conventional nitridation process carried out at 550 C for 1 h. Furthermore interference fringes in X-ray diffraction ({omega}-2{theta} scan) were observed from these improved InN films. These high crystalline quality InN layers have been employed as a template for the growth of In-rich In{sub x}Ga{sub 1-x}N layers (0.70{<=}x{<=}0.94). The resultant In{sub x}Ga{sub 1-x}N layers have shown dramatic improvements in not only the surface morphology but also both the a- and c-axis orientations. By employing In{sub 0.8}Ga{sub 0.2}N layers of improved quality as the bottom barrier layer, InN/In{sub 0.8}Ga{sub 0.2}N multiple quantum well (MQW) and single quantum well (SQW) structures with different well widths were fabricated. Clear satellite peaks of X-ray diffraction were observed from these MQW structures. Both of these SQW and MQW structures have exhibited a blue shift of the photoluminescence peak energy with decreasing well width

  12. Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

    International Nuclear Information System (INIS)

    Peng, Enchao; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan; Hou, Xun; Wang, Zhanguo

    2013-01-01

    Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

  13. N-linked (N-) glycoproteomics of urinary exosomes. [Corrected].

    Science.gov (United States)

    Saraswat, Mayank; Joenväära, Sakari; Musante, Luca; Peltoniemi, Hannu; Holthofer, Harry; Renkonen, Risto

    2015-02-01

    Epithelial cells lining the urinary tract secrete urinary exosomes (40-100 nm) that can be targeted to specific cells modulating their functionality. One potential targeting mechanism is adhesion between vesicle surface glycoproteins and target cells. This makes the glycopeptide analysis of exosomes important. Exosomes reflect the physiological state of the parent cells; therefore, they are a good source of biomarkers for urological and other diseases. Moreover, the urine collection is easy and noninvasive and urinary exosomes give information about renal and systemic organ systems. Accordingly, multiple studies on proteomic characterization of urinary exosomes in health and disease have been published. However, no systematic analysis of their glycoproteomic profile has been carried out to date, whereas a conserved glycan signature has been found for exosomes from urine and other sources including T cell lines and human milk. Here, we have enriched and identified the N-glycopeptides from these vesicles. These enriched N-glycopeptides were solved for their peptide sequence, glycan composition, structure, and glycosylation site using collision-induced dissociation MS/MS (CID-tandem MS) data interpreted by a publicly available software GlycopeptideId. Released glycans from the same sample was also analyzed with MALDI-MS. We have identified the N-glycoproteome of urinary exosomes. In total 126 N-glycopeptides from 51 N-glycosylation sites belonging to 37 glycoproteins were found in our results. The peptide sequences of these N-glycopeptides were identified unambiguously and their glycan composition (for 125 N-glycopeptides) and structures (for 87 N-glycopeptides) were proposed. A corresponding glycomic analysis with released N-glycans was also performed. We identified 66 unique nonmodified N-glycan compositions and in addition 13 sulfated/phosphorylated glycans were also found. This is the first systematic analysis of N-glycoproteome of urinary exosomes. © 2015 by The

  14. Metal chelates of phosphonate-containing ligands-III Analytical applications of N,N,N',N'-ethylenediaminetetra(methylenephosphonic) acid.

    Science.gov (United States)

    Zaki, M T; Rizkalla, E N

    1980-05-01

    N,N*,N',N'-Ethylenediaminetetra(methylenephosphonic) acid is used as a titrant for the direct determination of Cu, Co and Ni, with murexide as indicator. Indirect titrimetric procedures are suggested for the determination of silver, mercury, zinc and cyanide and both direct and indirect methods are applied for the analysis of binary mixtures of silver (or mercury) and copper (cobalt or nickel). The stoichiometry of the reaction, interferences of some metal ions and the pH effects on the complexation reactions are discussed. The values of the equilibrium constants of the protonated CuH(n)L (n = 1, 2, 3 and 4) as well as the unprotonated CuL chelates have been measured.

  15. Programación Java

    OpenAIRE

    Martínez de Morentin Iribarren, Xabier

    2014-01-01

    Este proyecto trata de informar y dar una base sobre Java, así como los programas a los cuales se les da uso, para facilitar la programación en el mundo laboral, ya sean programas de gestión de datos como Assembla y Tortoise o de desarrollo de aplicaciones, como Eclipse o NetBeans. Trata de llevar al ámbito más profesional, la realización de una aplicación Java. Para ello se respetarán los convenios a la hora de denominaciones de clases, así como los métodos, etc., y la realización d...

  16. Guión Documental

    OpenAIRE

    Pancorbo, Juan Manuel

    2015-01-01

    La industria audiovisual en Andalucía muestra un vigor alto a pesar de la crisis económica y de la reducción de la financiación pública para los productos cinematográficos. Sin embargo, sí que existe un campo del sector audiovisual que ha tenido un incremento significativo, como es el caso de los documentales. El proceso de creación, gestión y elaboración de un guión documental tiene unos pasos específicos que lo hacen singular y que exige la necesidad de que los participantes sigan una serie...

  17. Proyección Memoria

    OpenAIRE

    Heilbron Jácome, Ana María; Hernández Delatorre, Juliana; Herrera Dimaté, Daniela

    2015-01-01

    El proyecto consiste en realizar una proyección de videomapping acompañada por una agenda cultural que busca promover a través del video y la tecnología la construcción colectiva de memoria histórica compartida y con perspectiva de futuro, inicialmente a una población que no ha tenido contacto directo con la guerra (población de Bogotá de alto poder adquisitivo). Se analiza el arte como factor generador de empatía entre ciudadanos.

  18. New nilpotent N =2 superfields

    Science.gov (United States)

    Kuzenko, Sergei M.; Tartaglino-Mazzucchelli, Gabriele

    2018-01-01

    We propose new off-shell models for spontaneously broken local N =2 supersymmetry, in which the supergravity multiplet couples to nilpotent Goldstino superfields that contain either a gauge one-form or a gauge two-form in addition to spin-1 /2 Goldstone fermions and auxiliary fields. In the case of N =2 Poincaré supersymmetry, we elaborate on the concept of twisted chiral superfields and present a nilpotent N =2 superfield that underlies the cubic nilpotency conditions given in J. High Energy Phys. 08 (2017) 109., 10.1007/JHEP08(2017)109 in terms of constrained N =1 superfields.

  19. Reanimación Cardiopulmonar

    OpenAIRE

    Pastor Durán, Xavier; Palomeque,A.

    1989-01-01

    Características de la Reanimación Cardiopulmonar en Pediatría La Reanimación Cardiopulmonar (RCP) es un tema que clásicamente se había reservado a la formación del pediatra durante los años de su residencia. Salvo contadas ocasiones, la educación en dicho sentido formaba parte de la docéncia práctica del residente durante su paso por las Unidades de Cuidados Intensivos Neonatales o Pediátricas....

  20. Radiación ultravioleta

    OpenAIRE

    Bohórquez-Ballén, Jaime; Pérez Mogollón, José Fernando

    2007-01-01

    La energía proveniente del sol que incide sobre la superficie de la tierra consta principalmente de radiación infrarroja, visible y ultravioleta (UV). La porción del espectro solar correspondiente al UV (cerca del 7%) afecta en gran manera la vida sobre la tierra. Pequeñas cantidades de UV son necesarias en los seres humanos para asimilar la vitamina D; en las plantas bajo condiciones normales ayudas en el proceso de foto-síntesis pero cuando la exposición a este tipo de radiación es exagerad...

  1. Educación inclusiva

    Directory of Open Access Journals (Sweden)

    Heylen Cordero-Aguilar

    2004-09-01

    Full Text Available La pobreza en América Latina es una realidad que la caracteriza. Asociada la pobreza, la exclusión social, ciudadana, económica, cultural y ética está presente en las sociedades latinas. Frente a la exclusión, la educación cumple una función esperanzadora como un medio para lograr superar las dificultades que impiden el desarrollo humano de las personas. Costa Rica es parte de esta realidad. La multiculturalidad provocada por la migración de extranjeros y las diferencias sociales y culturales de los mismos costarricenses, generan exclusión. La educación inclusiva se propone como un medio para integrar a todos, es una forma de asegurar a ricos y pobres el acceso a la promoción humana. Incluir implica una visión totalizadora y reflexiva del currículo, pensado dentro de un contexto social.

  2. Superspaces for N=3 supersymmetry

    International Nuclear Information System (INIS)

    Gal'perin, A.S.; Ivanov, E.A.; Ogievetskij, V.I.

    1986-01-01

    N=3 superconformal group (SU(2,2/3) is realized in the real analytic subspace of harmonic N=3 superspace. Bererzinian of its transformations is shown to be unity. Conformal invariance of the N=3 Yang-Mills superfield action becomes evident within such a framework. Obtained results are preliminary stage in construction of N=3 supergravity. A complex analytic superspaces are also indicated, having a smaller number of spinor coordinates. A realization of SU(2,2/3) in this superspaces is found

  3. Anticoncepción hormonal

    Directory of Open Access Journals (Sweden)

    Miguel Lugones Botell

    1997-02-01

    Full Text Available Se realizó una revisión de los anticonceptivos hormonales con énfasis en aspectos que van desde su descubrimiento, el mecanismo de acción, los diferentes tipos y formas de utilización, así como el esquema de administración terapéutica en algunas entidades, sus indicaciones, ventajas y contraindicaciones: A review of the hormonal contraceptives was carried out, emphasizing on features from their discovery, trigger mechanism, different kinds, and ways to use them, as well as the scheme of the therapeutical administration in some entities, its indications, advantages, and contraindications.

  4. Declinación forestal

    Directory of Open Access Journals (Sweden)

    D. Granados Sánchez

    2001-01-01

    Full Text Available Se analizan las causas de la declinación forestal como son los factores climáticos, la lluvia y niebla ácida, el exceso y deficiencia de nutrimentos, plagas y enfermedades, los contaminantes gaseosos y otros factores; abordándose a la vez, varias hipótesis en la relación causa-efecto. Además, se enfatizan síntomas y daños en el crecimiento de los árboles, métodos de evaluación y clasificación de los árboles de acuerdo a su salud, así como el impacto de la declinación en aspectos adaptativos de sensibilidad, tolerancia y evolución de las especies arbóreas. También, se propone la consideración del ciclo del bosque en la dinámica de la declinación forestal.

  5. Computación cognitiva

    OpenAIRE

    Chavarría Sánchez, Luis Javier

    2017-01-01

    La ciencia de la computación arrancó con la era de las máquinas tabulables para después pasar a las programables. Sin embargo el mundo actual vive una transformación radical de la información. Por un lado la avalancha masiva de datos, el llamado Big Data hace que los sistemas requieran de una inteligencia adicional para extraer conocimiento válido de los datos. Por otro lado demandamos cada día más ordenadores que nos entiendan y se comuniquen mejor con nosotros. La computación cognitiva, ...

  6. Unión Europea

    Directory of Open Access Journals (Sweden)

    Klaus Jörg Ruhl

    2007-01-01

    Full Text Available El impulso y la protección de los derechos humanos se ha convertido en un objetivo prominente en las políticas de la Unión Europea (ue. La integración de la Carta de Derechos Fundamentales en la Constitución Europea así como la creación de una gran cantidad de instituciones, oficinas y agencias son muestra de ello. Entre ellas destacan el Defensor del Pueblo Europeo, el Observatorio Europeo de los Fenómenos de Discriminación y Xenofobia y las divisiones o grupos de trabajo de la Comisión, el Parlamento y el Consejo Europeos. En la política exterior de la ue, la cooperación para el desarrollo cada vez está más ligada al respeto de los derechos humanos en terceros países. Además, la Unión Europea contribuye al financiamiento de una gran cantidad de proyectos que pretenden fortalecer el respeto a los derechos humanos, impulsar la democracia y el Estado de derecho en muchas y distintas regiones geográficas. Este artículo pretende ofrecer un panorama general de estas políticas y un breve análisis de su efectividad.

  7. Low temperature properties of spin filter NbN/GdN/NbN Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Massarotti, D., E-mail: dmassarotti@na.infn.it [Dipartimento di Ingegneria Industriale e dell’Informazione, Seconda Università di Napoli, via Roma 29, 81031 Aversa (CE) (Italy); CNR-SPIN UOS Napoli, Complesso Universitario di Monte Sant’Angelo, via Cinthia, 80126 Napoli (Italy); Caruso, R. [Dipartimento di Fisica, Università degli Studi di Napoli Federico II, Via Cinthia, 80126 Napoli (Italy); CNR-SPIN UOS Napoli, Complesso Universitario di Monte Sant’Angelo, via Cinthia, 80126 Napoli (Italy); Pal, A. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS (United Kingdom); Rotoli, G. [Dipartimento di Ingegneria Industriale e dell’Informazione, Seconda Università di Napoli, via Roma 29, 81031 Aversa (CE) (Italy); Longobardi, L. [Dipartimento di Ingegneria Industriale e dell’Informazione, Seconda Università di Napoli, via Roma 29, 81031 Aversa (CE) (Italy); American Physical Society, 1 Research Road, Ridge, New York 11961 (United States); Pepe, G.P. [Dipartimento di Fisica, Università degli Studi di Napoli Federico II, Via Cinthia, 80126 Napoli (Italy); CNR-SPIN UOS Napoli, Complesso Universitario di Monte Sant’Angelo, via Cinthia, 80126 Napoli (Italy); Blamire, M.G. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS (United Kingdom); Tafuri, F. [Dipartimento di Ingegneria Industriale e dell’Informazione, Seconda Università di Napoli, via Roma 29, 81031 Aversa (CE) (Italy); CNR-SPIN UOS Napoli, Complesso Universitario di Monte Sant’Angelo, via Cinthia, 80126 Napoli (Italy)

    2017-02-15

    Highlights: • We study the phase dynamics of ferromagnetic NbN/GdN/NbN Josephson junctions. • The ferromagnetic insulator GdN barrier generates spin-filtering properties. • Spin filter junctions fall in the underdamped regime. • MQT occurs with the same phenomenology as in conventional Josephson junctions. • Dissipation is studied in a wide range of critical current density values. - Abstract: A ferromagnetic Josephson junction (JJ) represents a special class of hybrid system where different ordered phases meet and generate novel physics. In this work we report on the transport measurements of underdamped ferromagnetic NbN/GdN/NbN JJs at low temperatures. In these junctions the ferromagnetic insulator gadolinium nitride barrier generates spin-filtering properties and a dominant second harmonic component in the current-phase relation. These features make spin filter junctions quite interesting also in terms of fundamental studies on phase dynamics and dissipation. We discuss the fingerprints of spin filter JJs, through complementary transport measurements, and their implications on the phase dynamics, through standard measurements of switching current distributions. NbN/GdN/NbN JJs, where spin filter properties can be controllably tuned along with the critical current density (J{sub c}), turn to be a very relevant term of reference to understand phase dynamics and dissipation in an enlarged class of JJs, not necessarily falling in the standard tunnel limit characterized by low J{sub c} values.

  8. LA FORMACIÓN INTEGRAL: UNA APROXIMACIÓN DESDE LA INVESTIGACIÓN

    Directory of Open Access Journals (Sweden)

    Ana Elsy Díaz Monsalve

    2013-12-01

    Full Text Available En este artículo se exponen los resultados de la investigación en la que se indagó acerca de las representaciones que tienen los docentes de inglés de educación básica primaria, en algunas instituciones públicas de Medellín, Colombia, acerca del ideal de formación integral. A partir de un enfoque de investigación cualitativa, se implementó una encuesta con preguntas abiertas aplicadas a diecinueve docentes y, posteriormente, se realizó una entrevista a profundidad a cinco de los encuestados. La información recogida fue sometida a la técnica del análisis crítico del discurso propuesta por Teun Van Dijk (2003. Los principales hallazgos permiten reconocer que dichas representaciones reflejan cinco líneas temáticas principales: (1 Formación integral de un ser humano multidimensional; (2 Formación de un ser humano valioso; (3 Formación integral, aprendizaje de una lengua extranjera y acercamiento a diferentes culturas; (4 Formación integral, enseñanza de las lenguas extranjeras y personas autónomas; (5 Formación integral y competencia comunicativa en lengua extranjera. Se encontró que las representaciones de los docentes, sobre la formación integral, poseen un marcado énfasis ético -moral, valores y normas- y que esta, analizada desde la enseñanza de la lengua extranjera, no debe reducirse al uso de estructuras lingüísticas básicas, en contextos de comunicación inmediatos y cotidianos.

  9. Evaluation of intramolecular charge transfer state of 4-N, N ...

    Indian Academy of Sciences (India)

    Abstract. Intramolecular charge transfer of 4-N,N-dimethylamino cinnamaldehyde (DMACA) in vacuum and in five different aprotic solvents has been studied by using time-dependent density functional theory. (TDDFT). Polarizable continuum model (PCM) was employed to consider solvent–solute interactions. The potential ...

  10. Stress Assignment in N+N Combinations in Arabic

    Directory of Open Access Journals (Sweden)

    Abdel Rahman Mitib Altakhaineh

    2017-09-01

    Full Text Available The validity of stress as a criterion to distinguish between compounds and phrases has been investigated in many languages, including English (see e.g. Lieber 2005: 376; Booij 2012: 84. However, the possibility of using stress as a criterion in this way has not been investigated for Arabic. Siloni (1997: 21 claims that in N+N combinations in Semitic languages, stress always falls on the second element. However, the results of a study using PRAAT reveal that, in Modern Standard Arabic (MSA and Jordanian Arabic (JA, stress plays no role in distinguishing between various N+N combinations, i.e. compounds and phrases, e.g.ˈmuʕallim lfiizyaaʔ ‘the physics teacher’ vs.ˈbayt lwalad ‘the boy’s house’, respectively. Analysis shows that the default position of stress in N+N combinations in MSA and JA is on the first element. There is only one systematic exception, which is phonetically conditioned: in N+N combinations with assimilated geminates on the word boundary, a secondary stress or perhaps double stress is assigned.

  11. InGaN/GaN Nanowire LEDs and Lasers

    KAUST Repository

    Zhao, Chao; Ng, Tien Khee; Jahangir, Shafat; Frost, Thomas; Bhattacharya, Pallab; Ooi, Boon S.

    2016-01-01

    -droop issues. The phonon and carrier confinement in nanowires also led to junction heating, and reduced heat dissipation. In this paper, we will present our studies on effective surface states passivation in InGaN/GaN quantum-disks (Qdisks)-in-nanowire light

  12. Cerebro, números y educación

    Directory of Open Access Journals (Sweden)

    Diego ALONSO CÁNOVAS

    2013-06-01

    Full Text Available En este artículo se aborda el tema de las posibles contribuciones que la Neurociencia Cognitiva puede realizar a la Educación Matemática. En particular, se analizan las bases cerebrales del llamado sentido numérico, y la diferencia entre el cálculo rutinario y el que requiere la comprensión de los números como magnitud. El estudio del cerebro también aporta explicaciones plausibles a algunas de las dificultades en el aprendizaje de las matemáticas que aparecen en nuestras aulas. Se expone, de forma breve, una posible relación entre la inmadurez del lóbulo frontal en el proceso de desarrollo y algunos errores debidos a respuestas impulsivas. Aunque algunas hipótesis son muy especulativas, hacemos referencia a la posible relación entre el talento para las matemáticas y la biología. Finalmente citamos algunos resultados provenientes desde la Psicología Cognitiva sobre la importancia del desarrollo de la intuición matemática en la Educación Primaria y Secundaria.

  13. N 2 O Emissions and Inorganic N Release Following Incorporation ...

    African Journals Online (AJOL)

    West African Journal of Applied Ecology ... The results from the study demonstrated that whilst there is the potential for N2O emission to be controlled through varying ratios of residue:fertiliser input, the magnitude and direction of interactions between these N sources vary between different species as a result of their ...

  14. Addition compounds between trifluoromethanessulfonates and N,N-Dimethylacetamide (DMA)

    International Nuclear Information System (INIS)

    1984-01-01

    Rare-earth complex ions were prepared using dissolution of hydrated lanthnide compounds in the species used as ligand, N,N-dimethylacetamide (DMA) followed by evaporation of the ligand excess, and by crystallization of the dissolved complexes in DMA medium using chloroform as precipitating agent. (M.J.C.) [pt

  15. Robust AlGaN/GaN MMIC Receiver Components

    NARCIS (Netherlands)

    Heijningen, M. van; Janssen, J.P.B.; Vliet, F.E. van

    2009-01-01

    Apart from delivering very high output powers, GaN can also be used to realize robust receiver components, such as Low Noise Amplifiersand Switches. This paper presents the designand measurement results of two GaN X-band switch and LNA MMICs, designed for integration in a radar front end. The switch

  16. Educación, cerebro y emoción

    Directory of Open Access Journals (Sweden)

    Joaquín GARCÍA CARRASCO

    2013-06-01

    Full Text Available El artículo resalta la importancia de la aproximación a la neurología para completar el marco desde el que construir una teoría de la educación. El planteamiento se considera especialmente importante si se atiende a que esa teoría debe ser inclusiva respecto a todas las formas de diferencia, respecto a todas las acciones educativas que tienen como marco el cuerpo y respecto a la importancia de fundamentar de una educación ambiental. Frente a una perspectiva fuertemente cognitivista de los procesos formativos, muestra el papel del sistema emocional en la estructura global de la mente, el de la emoción en los procesos de las operaciones mentales superiores. El estudio se propone desde una perspectiva sistémica, con diferentes niveles de organización y cómo dentro de todos esos niveles juegan un papel importante las emociones. Va dejando clara la medida en que los tres conceptos de educación, cerebro y emoción son conceptos mutuamente imbricados, ninguno puede ser soslayado si se busca la comprensión plena de los procesos educativos.

  17. Prospects for N-N* Transitions from Lattice QCD

    International Nuclear Information System (INIS)

    Richards, David

    2008-01-01

    I describe the status of calculations of N-N* transition form factors in lattice QCD, and the prospects for future calculations. I emphasise the need to reliably delineate the states in the spectrum, and the progress that has been made by the Hadron Spectrum Collaboration in so doing.

  18. Spinal N13 versus cortical N20 and dermatomal somatosensory ...

    African Journals Online (AJOL)

    Mohamed Imam

    2013-04-06

    Apr 6, 2013 ... Spinal N13 versus cortical N20 and dermatomal somatosensory .... recording point for the right upper limb stimulation and the. C40 for the left upper limb stimulation. The reference ..... Brain 1992;115:1209–34. 298. M. Imam ...

  19. 40 CFR 721.10175 - 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18 and C18-unsatd...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Propanaminium, N-(3-aminopropyl)-2... 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12-18 and C18-unsatd. acyl... chemical substance identified as 1-Propanaminium, N-(3-aminopropyl)-2-hydroxy-N,N-dimethyl-3-sulfo-, N-(C12...

  20. Preliminary hazard classification for buildings 1310-N and 1314-N

    International Nuclear Information System (INIS)

    Kloster, G.L.; Smith, R.I.

    1997-01-01

    This document establishes the preliminary hazard classification (PHC) for the 100-N Area facility segment comprised of the 1310-N ''silo'' building and the 1314-N Liquid Waste Disposal Building. To establish the PHC, the inventories of radioactive and nonradioactive hazardous materials present within the segment are identified and then compared to the corresponding threshold quantity values in DOE-STD-1027-92 and reportable quantity values in 40 CFR 302.4. In this evaluation, no credit is taken for the form, location, and dispersibility of the materials; for their interaction with available energy sources; or for safety features that could prevent or mitigate a radiological release. The result of the PHC determined that the 1310-N and 1314-N building segments are classified as radiological

  1. Gestión de nóminas

    OpenAIRE

    Sánchez González, Cristina

    2015-01-01

    El objetivo de este trabajo es el de realizar una aplicación EXCEL con su respectivo manual para la gestión de nóminas en una pequeña o mediana empresa (PYME). Desde el ámbito global de la política salarial en el que se desarrolla cada parte, se va acotando cada nivel hasta el tema principal del trabajo que es la nómina. Una vez descrito el concepto de nómina, se explica, junto con sus características, los tipos y partes, así como los cálculos a realizar a la hora de determinar las cantidades...

  2. REPRODUCCIÓN ASISTIDA Y FILIACIÓN. TRES CASOS

    Directory of Open Access Journals (Sweden)

    Julia Sandra Bernal Crespo

    2013-11-01

    Full Text Available Este artículo analiza uno de los principales problemas jurídicos que plantean las técnicas de reproducción asistida: determinar la filiación del nacido y la forma en que nuestros jueces de la República han resuelto este conflicto en los casos específicos de alquiler de vientre, inseminación asistida con donante, e inseminación post-mortem, teniendo en cuenta que, a diferencia de la filiación biológica, el consentimiento de los donantes de gametos y de los receptores es un elemento necesario para determinar la paternidad.

  3. Actualización en reconstrucción mamaria

    Directory of Open Access Journals (Sweden)

    Dr. U. Bruno Dagnino

    2010-01-01

    Full Text Available La Reconstrucción Mamaria es un amplio y demandante campo de la Cirugía Plástica que exige manejo en el ámbito estético y reparador. Existen numerosas técnicas que permiten ofrecer la mejor indicación a cada paciente, tales como uso de implantes, colgajos pediculados y libres, y reducción y pexia mamaria. El objetivo de este artículo es dar a conocer el estado actual de la cirugía de Reconstrucción Mamaria. Además se presenta una sugerencia de reconstrucción para cada una de las situaciones clínicas más frecuentes.

  4. N-particle nonclassicality without N-particle correlations

    Science.gov (United States)

    Wieśniak, Marcin; Nawareg, Mohamed; Żukowski, Marek

    2012-10-01

    Most of known multipartite Bell inequalities involve correlation functions for all subsystems. They are useless for entangled states without such correlations. We give a method of derivation of families of Bell inequalities for N parties, which involve, e.g., only (N-1)-partite correlations, but still are able to detect proper N-partite entanglement. We present an inequality which reveals five-partite entanglement despite using only four-partite correlations. Classes of inequalities introduced here can be put into a handy form of a single nonlinear inequality. An example is given of an N-qubit state, which strongly violates such an inequality, despite having no N-qubit correlations. This surprising property might be of potential value for quantum information tasks.

  5. INTEGRACIÓN Y COLABORACIÓN EN EL CIBERESPACIO

    Directory of Open Access Journals (Sweden)

    Wander M. Paes

    2011-08-01

    Full Text Available El concepto de compartir recursos computacionales entre participantes WEB, ha sidogradualmente extendido para apoyar escenarios en el mundo  wireless que introduce unavariedad posible de integración y colaboración. El concepto de “servicios” deviene en unaclave del compartir información dentro del mundo de la tecnología de información. En estepunto de vista se presenta la relación entre los movimientos dentro del entorno de informacióndigital enfocado en conceptos socio-tecnológico: tecnología persuasiva/ubicua, Arquitecturade Servicios/Sistema, Colaboración e Integración en aplicaciones WEB como un recurso delsistema e interoperabilidad de la información. La idea acerca del punto de vistainterdisciplinario, como un instrumento de sabiduría, producción de conocimiento, ycolaboración de información esparcida dentro del entorno digital, es un factor que se adapta alcontexto contemporáneo, alcanzando a los dispositivos móviles usando los serviciosdistribuidos en Internet. Este aproximamiento queda en la necesidad de un estudio relacionadoa la interoperabilidad que refiere a la comunicación y al intercambio de información entre lagente. Este fenómeno muestra una tendencia de las soluciones de sistemas en entornoswireless   y tecnología de Internet debido a una variedad de protocolos y a la popularidad de losdispositivos móviles (celular, PDAs, Smartphone, Tablets y Pocket PC. La consolidación deInternet como un entorno de colaboración así como también la aparición de las aplicacionsmóviles habiendo influenciado directamente en las solucions comerciales y en la arquitecturade sistemas en la sociedad contemporánea. Este renueva el mapa digital cartográfico de losservicios decentralizados en el ciberespacio. Deviene en un fértil entorno para el estudio de lasaplicaciones móviles, los componentes computacionales (como un servicio y su usabilidadentre accionistas en el ciberespacio. Una escena que representa el

  6. La investigación-acción en la formación del profesorado

    Directory of Open Access Journals (Sweden)

    Romera-Iruela, María Jesús

    2011-12-01

    Full Text Available Action research by teachers allows for continuous improvement in education and the bridging of theory and practice. This research, while traditionally used in teacher education, is currently becoming enormously important since it should be carried out both before and after educational reforms. The purpose of this study is to map the development of action research in teacher education through articles published in Spanish education journals. The research uses a survey approach and applies a documentary methodology. The results show how productive this line of research has been throughout its evolution, provide a database of all the articles, and offer a view of the personal, social and cognitive dimensions of this line of research: collaboration in publications, the most productive authors, research teams, main institutions performing the studies, specific journals dedicated to this line of research, main topics studied, and epistemological approaches, among others.

    La investigación en la acción del profesor posibilita la mejora continua de la educación y la vinculación entre la teoría y la práctica. Esta investigación, si bien tiene tradición en la formación del profesorado, adquiere, en estos momentos, una gran relevancia, puesto que ha de preceder y seguir a las reformas educativas. El objetivo de esta investigación es identificar la trayectoria de la investigación-acción en la formación del profesorado, a través de los artículos publicados en las revistas españolas de educación. El diseño de la misma es de examen y utiliza la metodología documental. Los resultados dan a conocer la productividad de esta línea de investigación duran te todo su desarrollo, aportando una base de datos con todos los artículos, y muestran sus dimensiones personales, sociales y cognitivas: grado de colaboración en las publicaciones, autores más productivos, grupos de investigación, principales instituciones en la realización de

  7. PRESENTACIÓN: EL SANGRADO CORAZÓN

    Directory of Open Access Journals (Sweden)

    Marco Julián Martínez y Carlos José Suárez

    2008-07-01

    Full Text Available La actual sociedad colombiana es descrita como una donde el uso de la violencia en la transformación de los conflictos es recurrente y privilegiada. Ello ocurre tanto en el plano estatal como en la intimidad familiar, incluyendo variadas relaciones personales y del día a día. Lo anterior constituye un objeto de preocupación pública y académica, que comúnmente equipara la violencia con la maldad. Algunos estudios asumen la violencia como corruptora del orden social, señalando el deber de algunas agencias por controlar aquel flagelo. Los agentes estatales buscan domesticar al perpetrador a través de intervenciones racionales, que suponen utopías justificadas en nombre del derecho, la ciencia y la religión. Otros estudios abordan la violencia como una expresión indeseada de los conflictos, que contribuye a la ruptura del paradigma social de la convivencia, que debe ser restablecido mediante acciones no-violentas. Hay acercamientos que resaltan las emociones y sensaciones que envuelven la teatralidad del momento disruptivo y sus huellas en la memoria, resaltando el drama humano y los testimonios. Por último, existen interpretaciones centradas en la relación víctima-victimario, reduciendo problemáticas sociales a responsabilidades individuales enmarcadas en la resiliencia y la reparación. Estas posturas han tenido incidencia en los discursos sociales y políticos sobre la opresión, la vulneración y la desigualdad, así como en la construcción y aplicación de políticas públicas para la paz y la seguridad.

  8. ATLAS irradiation studies of n-in-n and p-in-n silicon microstrip detectors

    CERN Document Server

    Allport, P P; Buttar, C M; Carter, J; Drage, L M; Ferrère, D; Morgan, D; Riedler, P; Robinson, D

    1999-01-01

    Prior to the module production of the ATLAS silicon microstrip tracker for the barrel and the forward wheels, the characterisation of full-size prototype silicon detectors after radiation to fluences corresponding to 10 years of ATLAS operation is required. The behaviour of p-in-n and n-in-n detectors produced by several manufacturers before and after irradiation to a fluence of 3*10/sup 14/ protons/cm/sup 2/ at the CERN PS facility is discussed. This article summarises some recent results from the ATLAS SCT collaboration. The measurements of leakage current, full depletion voltage, signal-to-noise ratio and charge collection efficiency are presented. Despite the better efficiency performance of n-in-n detectors below depletion, the collaboration chose the p-in-n technology due to its simpler and less costly production since good charge collection efficiencies were achieved at the desired maximum bias voltage. (14 refs).

  9. AlGaN/GaN HEMT structures on ammono bulk GaN substrate

    International Nuclear Information System (INIS)

    Kruszewski, P; Prystawko, P; Krysko, M; Smalc-Koziorowska, J; Leszczynski, M; Kasalynas, I; Nowakowska-Siwinska, A; Plesiewicz, J; Dwilinski, R; Zajac, M; Kucharski, R

    2014-01-01

    The work shows a successful fabrication of AlGaN/GaN high electron mobility transistor (HEMT) structures on the bulk GaN substrate grown by ammonothermal method providing an ultralow dislocation density of 10 4  cm −2  and wafers of size up to 2 inches in diameter. The AlGaN layers grown by metalorganic chemical vapor phase epitaxy method demonstrate atomically smooth surface, flat interfaces with reproduced low dislocation density as in the substrate. The test electronic devices—Schottky diodes and transistors—were designed without surface passivation and were successfully fabricated using mask-less laser-based photolithography procedures. The Schottky barrier devices demonstrate exceptionally low reverse currents smaller by a few orders of magnitude in comparison to the Schottky diodes made of AlGaN/GaN HEMT on sapphire substrate. (paper)

  10. EVOLUCIÓN O CREACIÓN, GENOMAS Y CLONACIÓN

    Directory of Open Access Journals (Sweden)

    Emilio Yunis

    2001-01-01

    Full Text Available El texto -siguiendo el proceso histórico-científico-, muestra la importancia de los estudios referidos a la creación y evolución, tanto del genoma humano como de la clonación, los temores que se generaron alrededor de los avances propuestos por la Ingeniería genética y sus implicaciones políticoéticas.

  11. Resonance particle production in inelastic N-N and π-N interactions

    International Nuclear Information System (INIS)

    Amelin, N.S.; Barashenkov, V.S.; Slavin, N.V.

    1984-01-01

    Using the considerations connected with the scaling hypothesis and the Regge pole model the phenomenological expressions are obtained for differential single-particle inclusive production cross sections (Δ + , Δ 0 , Δ ++ ) and (p +- , p 0 , ω) resonances in inelastic π-N and N-N collisions at high energies. These expressions describe the known experimental data in a wide region of kinematic variables from 10 to several thousand GeV

  12. educación intercultural

    Directory of Open Access Journals (Sweden)

    Mario Segura Castillo

    2005-01-01

    Full Text Available Con la creciente inmigración en nuestro país, se debe pensar en el desarrollo de políticas estratégicas de educación intercultural para atender los inmigrantes con justicia y dar mejores condiciones de vida a personas que dejan otras regiones del mundo en busca de mejores oportunidades, aparte de fortalecer los derechos humanos desde su base, es decir, desde el sistema educativo. El PEC es un “instrumento que recoge y comunica la propuesta integral para dirigir y orientar coherentemente los procesos de intervención educativa que se desarrollan en una intervención escolar” (Antúnez, S. 1992, p. 47. Se presenta a continuación un estudio de las condiciones que presenta un centro educativo de I y II ciclos de la Educación General Básica con base en un diagnóstico institucional que se realizó para determinar cuáles condiciones de dicho centro educativo favorecen y desfavorecen la puesta en práctica del PEC, centrado en la educación intercultural y en la transversalidad, de acuerdo con la opinión de los docentes y los estudiantes de dicho centro educativo

  13. Unikaalne näitus

    Index Scriptorium Estoniae

    2001-01-01

    25. veebruarini on Ermitaazhis näitus "Jeesuslaps Lääne-Euroopa XV-XVIII sajandi graafikas", näha saab Rembrandti, Albrecht Düreri, Albrecht Altdorferi, Henrik Goltsiuse, Pietro del Po, Giovanni Battista Tiepolo, Giovanni Domenico Tiepolo jt. töid

  14. Presentación (Introduction

    Directory of Open Access Journals (Sweden)

    Margarita Gómez Gómez

    2015-03-01

    Full Text Available Resumen: Presentación del monográfico "Rey, sello y representación: el poder de la escritura y el documento en el gobierno de las Indias".Abstaract: Introduction of the monograph "King, seal and representation: the power of writing and document in the government of the Spanish Indies."

  15. formación universitaria

    Directory of Open Access Journals (Sweden)

    Mª Elena García Puig

    2014-01-01

    Full Text Available Se ha detectado la necesidad de implementar el e-learning en la formación universitaria de enfermería. Para ello, esta investigación aplica el diseño instruccional al proceso de aprendizaje de un modelo profesional del cuidado, cuyo centro son las competencias a desarrollar por el estudiante. A partir de éstas se ha secuenciado el conocimiento a través de la Teoría de la Elaboración y la Técnica de Análisis de los Contenidos. Así mismo, en base a estos elementos se ha diseñado una serie de tareas teniendo en consideración la Técnica de Análisis de las Tareas y el Método de Simplificación de las Condiciones (SCM. Por otro lado, se ha diseñado y creado un objeto de aprendizaje a través del patrón EASA del software GLO Maker. Además en el planteamiento y diseño de la instrucción se ha tenido en consideración los cinco principios de David Merril. Todo ello orientado a un aprendizaje constructivista y una modalidad de enseñanza instruccional virtual.

  16. N-(Thiazol-2-ylacetamide

    Directory of Open Access Journals (Sweden)

    Uzma Yunus

    2008-08-01

    Full Text Available The title compound, C5H6N2OS, was synthesized from acetyl chloride and 2-aminothiazole in dry acetone. The asymmetric unit contains two molecules. The crystal structure is stabilized by N—H...N and C—H...O hydrogen bonds.

  17. Potabilización 76

    Directory of Open Access Journals (Sweden)

    Tobío, J. M.

    1976-06-01

    Full Text Available In this paper, that is a continuation of a previously published one, are listed the most interesting particulars in the field of water purification, with a short bibliography which ends in the beginning of 1976. The paper comments Decree 926/1973 which in our country regulates the financing of the purification plants and mentions the most outstanding characteristics of the dual purpose plants (water and energy, inverse osmosis, and freezing. Finally, the paper contains an appendix dedicated to elementary calculation of this type of installations, both with regard to the expenses of the installation as well as operation and maintenance costs.En este trabajo, que es continuación de otro publicado por el autor, se enumeran las particularidades más interesantes en el campo de la potabilización, con una breve aportación bibliográfica cerrada a comienzos de 1976. Se comenta el Decreto 926/1973, que regula en nuestro país la financiación de las plantas potabilizadoras, y se citan las características más salientes de las plantas duales (agua y energía, osmosis inversa, y congelación, para terminar con un apéndice dedicado al cálculo elemental de este tipo de instalaciones tanto en lo que se refiere a costes de primera instalación como a gastos de explotación y conservación.

  18. Confinement at large-N

    International Nuclear Information System (INIS)

    Klinkhamer, F.R.

    1985-06-01

    Recent numerical results indicate that QCD in the limit of an infinite number (N) of colors also has confinement and moreover that it looks rather similar to normal QCD with N = 3 colors. This imposes severe restrictions on what the mechanism of confinement can be

  19. Impermeabilización del hormigón

    Directory of Open Access Journals (Sweden)

    Gete-Alonso de Ylera, Antonio

    1977-03-01

    Full Text Available This article refers to concrete water-proofing, and the different sealing systems used. After a brief study of the different types of pores and air and water capillaries, the various kinds of water penetration —penetrability and hygroscopicity— are analyzed. The origin of the water is studied: natural moisture, construction humidity, moisture coming from absorption and condensation, rain, accumulated water pressure and miscellaneous moisture and the damaging effects they have on permeability and on hygroscopicity; losses in reservoirs, sub-pressure, Chemical reactions and oxidation. The different forms of measuring permeability are also studied: DIN Standard, by means of test tubes in the form of plates; ASTM Standard, by freezing and permeability tests, by means of a permeability meter, etc. After analyzing the basic conditions for decreasing water penetration in the concrete the following is considered. a Means of additives or treatments which improve the quality of same in order to obtain optimum conditions for waterproofing; b using products which avoid water penetration inside the concrete mass, without altering its basic properti.es. These two forms refer to different waterproofing systems: mass, hydrofugous, joints, sheets and continuous lining. These systems are studied in detail as far as their effects, characteristics and applications are concerned.Se trata en este artículo la impermeabilidad del hormigón y los diferentes sistemas de impermeabilización. Después de un breve estudio de las diversas clases de poros: capilares, de aire y de agua, se analizan los diversos modos de penetración del agua —penetrabilidad e higroscopicidad—, resaltando la mayor importancia de la permeabilidad, y su aumento en función del diámetro de los poros capilares mientras la higroscopicidad disminuye al aumentar el diámetro de aquéllos. Se estudia la procedencia del agua: humedad natural, humedad de construcción, humedad

  20. COOPERACIÓN HUMANA Y SELECCIÓN DE GRUPO

    Directory of Open Access Journals (Sweden)

    Luis Alvaro Cadena Monroy

    2017-12-01

    Full Text Available Darwin pensaba que la cooperación entre los seres humanos podía ir en contra de su idea de selección natural. Para enfrentar este problema, introdujo la selección de grupos: se seleccionan grupos de seres humanos cooperadores por sobre los grupos de no cooperadores, No obstante, con el advenimiento del neodarwinismo, la selección de grupos cayó en el desprestigio. Poco a poco, y recientemente, fueron apareciendo varias propuestas para la selección de grupos. Aquí se miran algunas de estas propuestas y se las critica. El autor se inclina por una propuesta de L. A. Cadena para la selección de grupos, y la aplica al caso del crecimiento poblacional inusual y al patrullaje de los chimpancés de Ngogo, a los cazadores y recolectores y a la extinción de los neandertales por manos del Homo sapiens.

  1. N=2 vacua in electrically gauged N=4 supergravities

    Energy Technology Data Exchange (ETDEWEB)

    Horst, Christoph

    2013-06-15

    In this thesis we study N= 2 vacua in gauged N=4 supergravity theories in fourdimensional spacetime. Using the embedding tensor formalism that describes general consistent magnetic gaugings of an ungauged N=4 matter-coupled supergravity theory in a symplectic frame with SO(1,1) x SO(6,n) off-shell symmetry we formulate necessary conditions for partial supersymmetry breaking and find that the Killing spinor equations can be solved for the embedding tensor components. Subsequently, we show that the classification of theories that allow for vacua with partial supersymmetry amounts to solving a system of purely algebraic quadratic equations. Then, we restrict ourselves to the class of purely electric gaugings and explicitly construct a class of consistent super-Higgs mechanisms and study its properties. In particular, we find that the spectrum fills complete N=2 supermultiplets that are either massless or BPS. Furthermore, we demonstrate that (modulo an abelian Lie algebra) arbitrary unbroken gauge Lie algebras can be realized provided that the number of N=4 vector multiplets is sufficiently large. Finally, we compute the relevant terms of the effective action below the scale of partial supersymmetry breaking and argue that the special Kaehler manifold for the scalars of the N=2 vector multiplets has to be in the unique series of special Kaehler product manifolds.

  2. 4-Bromo-N-(di-n-propyl-carbamothioyl)-benzamide.

    Science.gov (United States)

    Binzet, Gün; Flörke, Ulrich; Külcü, Nevzat; Arslan, Hakan

    2009-02-04

    The synthesis of the title compound, C(14)H(19)BrN(2)OS, involves the reaction of 4-bromo-benzoyl chloride with potassium thio-cyanate in acetone followed by condensation of the resulting 4-bromo-benzoyl isothio-cyanate with di-n-propyl-amine. Typical thio-urea carbonyl and thio-carbonyl double bonds, as well as shortened C-N bonds, are observed in the title compound. The short C-N bond lengths in the centre of the mol-ecule reveal the effects of resonance in this part of the mol-ecule. The asymmetric unit of the title compound contains two crystallographically independent mol-ecules, A and B. There is very little difference between the bond lengths and angles of these mol-ecules. In mol-ecule B, one di-n-propyl group is twisted in a -anti-periplanar conformation with C-C-C-H = -179.1 (3)° and the other adopts a -synclinal conformation with C-C-C-H = -56.7 (4)°; in mol-ecule A the two di-n-propyl groups are twisted in + and -anti-periplanar conformations, with C-C-C-H = -179.9 (3) and 178.2 (3)°, respectively. In the crystal, the mol-ecules are linked into dimeric pairs via pairs of N-H⋯S hydrogen bonds.

  3. DISFUNCIÓN TIROIDEA Y CORAZÓN

    Directory of Open Access Journals (Sweden)

    Dr. Juan Ramón Soto S.

    2015-03-01

    Full Text Available Los trastornos de la función tiroidea afectan profundamente al sistema cardiovascular. En esta revisión se presentan algunos aspectos fisiológicos de la interrelación entre tiroides y corazón, como tambiècn las consecuencias de la tirotoxicosis e hipotiroidismo sobre el aparato cardiovascular. Se analiza la influencia del hipertiroidismo en la gècnesis de la fibrilación auricular y del hipotiroidismo en el metabolismo de las lipoproteínas. Adicionalmente, el artículo se referirá a los potenciales efectos adversos del antiarrítmico amiodarona sobre la función tiroidea y cómo se investigan y tratan. Finalmente, se expone un caso clínico real para ilustrar con mayor claridad la enorme importancia que pueden alcanzar las relaciones fisiopatológicas entre el corazón y las afecciones de esta glándula endocrina.

  4. ALFABETIZACIÓN VIRTUAL Y GESTIÓN DEL CONOCIMIENTO

    Directory of Open Access Journals (Sweden)

    Emilio López-Barajas Zayas

    2010-12-01

    Full Text Available La alfabetización digital se hace necesaria especialmente en las llamadas sociedades avanzadas. Hace referencia al grado de competencia de los ciudadanos frente a un objetivo concreto que es la capacidad para utilizar las herramientas digitales básicas. La habilidad es entendida como una cierta aptitud permanente que se consigue mediante la práctica en estas nuevas formas de tecnología. La Sociedad del Conocimiento y la información se caracterizan por el uso generalizado de estas nuevas tecnologías de la información y la comunicación (TIC en cualquier entorno o actividad humanos que facilita la optimización de los recursos disponibles, ya sea a los individuos o a las organizaciones. La alfabetización digital se considera un proceso de aprendizaje significativo a través del cual se alcanzan los conocimientos tecnológicos necesarios para la utilización de lo que propiamente se podría denominar infotecnologías, con objeto de mejorar la calidad de los procesos y resultados en cualquier servicio o producto.

  5. Sección oficial

    Directory of Open Access Journals (Sweden)

    Facultad de Medicina Revista

    1936-01-01

    Full Text Available C. Torres Umaña. / ACUERDO NÚMERO 18 DE 1935 (Septiembre 20 (Por el cual se hacen algunas modificaciones al Presupuesto interno de la Escuela de Farmacia / ACUERDO NÚMERO 19 DE 1935 (Octubre 4 (Por el cual se crea en la Facultad el cargo de "Oficial Mayor" de la Secretaría / ACUERDO NÚMERO 20 DE 1935 (Octubre 4 (Por el cual se determinan las funciones del Contador de la Facultad /  RESOLUCIÓN NÚMERO 136 de 1935 (Julio 10 (Por la cual se concede un auxilio para una excursión de los alumnos de Clínica Dermatológica / RESOLUCIÓN NÚMERO 137 DE 1935 (Julio 1 (Por la cual se niega una solicitud de aplazamiento del pago de la matrícula, que elevan algunos estudiantes de la Escuela de Farmacia / RESOLUCIÓN NÚMERO 138 DE 1935 (Julio 3 (Por la cual se nombra mecanógrafa de la Biblioteca / RESOLUCIÓN NÚMERO 139 DE 1935 (Julio 3 (Por la cual se nombra un Interno Interino RESOLUCIÓN NÚMERO 140 DE 1935 (Julio 5 (Por la cual se amplía el plazo para pagar el segundo contado de la matrícula / RESOLUCIÓN NÚMERO 141 DE 1935 (Julio 5 (Por la cual se modifica en parte la Resolución número 136 del 1°  de julio de este año / RESOLUCIÓN NÚMERO 142 DE 1935 (Julio 15 (Por la cual se autoriza al Rector para que pueda efectuar un gasto / RESOLUCIÓN NÚMERO 143 DE 1935 (Julio 15 (Por la cual se accede a una solicitud de varios alumnos, en relación con las Clínicas Accesorias / RESOLUCIÓN NÚMERO 144 DE 1935 (Julio 15 Por la cual se aplaza definitivamente la fecha en que deben los alumnos cubrir el 2°  contado de la matrícula / RESOLUCIÓN NÚMERO 145 DE 1935 (Por la cual se nombra un sirviente en la Facultad.

  6. N Reactor Deactivation Program Plan

    International Nuclear Information System (INIS)

    Walsh, J.L.

    1993-12-01

    This N Reactor Deactivation Program Plan is structured to provide the basic methodology required to place N Reactor and supporting facilities · in a radiologically and environmentally safe condition such that they can be decommissioned at a later date. Deactivation will be in accordance with facility transfer criteria specified in Department of Energy (DOE) and Westinghouse Hanford Company (WHC) guidance. Transition activities primarily involve shutdown and isolation of operational systems and buildings, radiological/hazardous waste cleanup, N Fuel Basin stabilization and environmental stabilization of the facilities. The N Reactor Deactivation Program covers the period FY 1992 through FY 1997. The directive to cease N Reactor preservation and prepare for decommissioning was issued by DOE to WHC on September 20, 1991. The work year and budget data supporting the Work Breakdown Structure in this document are found in the Activity Data Sheets (ADS) and the Environmental Restoration Program Baseline, that are prepared annually

  7. Bootstrapping N=3 superconformal theories

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Madalena; Liendo, Pedro [DESY Hamburg, Theory Group,Notkestrasse 85, D-22607 Hamburg (Germany); Meneghelli, Carlo [Simons Center for Geometry and Physics,Stony Brook University, Stony Brook, NY 11794-3636 (United States); Mitev, Vladimir [PRISMA Cluster of Excellence, Institut für Physik,JGU Mainz, Staudingerweg 7, 55128 Mainz (Germany)

    2017-04-06

    We initiate the bootstrap program for N=3 superconformal field theories (SCFTs) in four dimensions. The problem is considered from two fronts: the protected subsector described by a 2d chiral algebra, and crossing symmetry for half-BPS operators whose superconformal primaries parametrize the Coulomb branch of N=3 theories. With the goal of describing a protected subsector of a family of N=3 SCFTs, we propose a new 2d chiral algebra with super Virasoro symmetry that depends on an arbitrary parameter, identified with the central charge of the theory. Turning to the crossing equations, we work out the superconformal block expansion and apply standard numerical bootstrap techniques in order to constrain the CFT data. We obtain bounds valid for any theory but also, thanks to input from the chiral algebra results, we are able to exclude solutions with N=4 supersymmetry, allowing us to zoom in on a specific N=3 SCFT.

  8. Molecular and component volumes of N,N-dimethyl-N-alkylamine N-oxides in DOPC bilayers

    DEFF Research Database (Denmark)

    Belicka, Michal; Klacsova, Maria; Karlovska, Janka

    2014-01-01

    The volumetric properties of fluid bilayers formed of dioleoylphosphatidylcholine (DOPC) with incorporated N ,N -dimethyl-N -alkylamine N -oxides (Cn NO, n = 6, 10–18 is the even number of carbons in alkyl chain) were studied by vibrating tube densitometry in the temperature interval from 20 °C...... to 50 °C. It was found that the DOPC and Cn NO mixed ideally in the investigated composition range and hence the molecular volumes of DOPC (V DOPC) and incorporated Cn NO (V CnNO) were constant and additive within error limits. From the temperature dependencies of the molecular volumes of DOPC and Cn...... NO their coefficients of isobaric thermal expansivities in the investigated temperature interval were obtained. The V CnNO volumes of Cn NO incorporated into DOPC bilayers showed linear dependencies on the Cn NO alkyl chain length at all measured temperatures. This allowed to calculate the component volume of the Cn...

  9. Edificación industrial

    Directory of Open Access Journals (Sweden)

    Hidalgo Fernández-Cano, Amalio

    1960-01-01

    Full Text Available La composición arquitectónica de esta importante rama de la edificación ha alcanzado en estos últimos años gran importancia, tras haber constituido una de las principales causas del nacimiento de la nueva arquitectura. La esclavitud que impone un proceso de fabricación al proyectista del edificio es tal, que no hay modo de salvar las imposiciones funcionales. Y ese funcionalismo a ultranza, junto a la ausencia de falsos elementos decorativos superfinos, han dado por resultado la realización de una serie de ejemplos de edificación industrial de indudable valor arquitectónico.

  10. Evaluación preoperatoria

    Directory of Open Access Journals (Sweden)

    Dr. C. Víctor Troncoso

    2011-05-01

    Full Text Available El texto que sigue muestra el enfrentamiento que tradicionalmente un anestesiólogo hace durante la evaluación preoperatoria de un paciente sea éste de urgencia o electivo. Esto consiste en interiorizarse de la historia, obteniendo la mayor cantidad de información de la condición médica actual y pasada del paciente, un examen físico dirigido, efectuar un análisis sistémico del paciente, solicitar y leer los exámenes pertinentes y dejar las indicaciones apropiadas. Toda la información anterior permitirá clasificar al enfermo de acuerdo a su condición física, evaluar su riesgo y planificar la conducta periopertoria.

  11. trans-Bis(N,N-diethylethylenediaminenickel(II dibromide

    Directory of Open Access Journals (Sweden)

    James P. Donahue

    2011-01-01

    Full Text Available The structure of the title compound, [Ni(C6H16N22]Br2 or [Ni(Et2en2]Br2 (Et2en is asymmetric N,N-diethylethylenediamine, containing an NiII atom (site symmetry overline{1} in square-planar NiN4 coordination, is described and contrasted with related structures containing NiII in octahedral coordination with axial X− ligands (X− = variable anions. The dialkylated N atom has an appreciably longer bond length to the NiII atom [1.9666 (13 Å] than does the unsubstituted N atom [1.9202 (14 Å]. The Ni—N bond lengths in [Ni(Et2en2]Br2 are significantly shorter than corresponding values in tetragonally distorted [Ni(Et2en2X2] compounds (X = −O2CCF3, OH2, or −NCS, which have a triplet ground state. The electronic configuration in these axially ligated [Ni(Et2en2X2] compounds populates the metal-based dx2-y2 orbital, which is Ni—N antibonding in character. Each Et2en ligand in each [Ni(Et2en2]2+ cation forms a pair of N—H...Br hydrogen bonds to the Br− anions, one above and below the NiN4 square plane. Thus, a ribbon of alternating Br− pairs and [Ni(Et2en2]2+ cations that are canted at 65° relative to one another is formed by hydrogen bonds.

  12. Stress analysis and microstructure of PVD monolayer TiN and multilayer TiN/(Ti,Al)N coatings

    NARCIS (Netherlands)

    Carvalho, NJM; Zoestbergen, E; Kooi, BJ; De Hosson, JTM

    2003-01-01

    Two PVD titanium nitride based coatings; monolayer TiN and multilayer resulting from the stacking of TiN and (Ti,Al)N layers were evaluated with respect to their stress state and microstructure. The TiN was deposited by triode evaporation ion plating, whereas the TiN/(Ti,AI)N was deposited using a

  13. Editorial, n. 15, 2003

    Directory of Open Access Journals (Sweden)

    Editor Encontros Bibli

    2003-01-01

    Informação da UFSC, que já está em seu oitavo ano, por sua Comissão Editorial, compartilhada com a presença de colegas do Brasil e exterior, manifesta sua alegria por esta conquista e exulta pela coincidência neste ano das Comemorações dos trinta anos do Curso de Biblioteconomia da UFSC e o início do Mestrado em Ciência da Informação desta instituição. Nesta edição do primeiro semestre do ano de 2003, Encontros Bibli tem a satisfação de trazer quatro artigos, dois oriundos da produção de pesquisadores da Escola de Ciência da Informação da Universidade Federal de Minas Gerais e dois oriundos da produção de pesquisa realizada por pesquisadores do Departamento de Ciência da Informação da UFSC. Aos leitores desejamos que estas contribuições ensejem questões que contribuam com a produção de reflexões e interrogações geradoras de novas investigações as quais naturalmente virão a contribuir para o progresso do conhecimento nacional em Ciência da Informação. Um grande abraço a todos e a todas! Prof. Francisco das Chagas de Souza Editor Departamento de Ciência da Informação Universidade Federal de Santa Catarina Brasil Disponibilizado na WWW em 20/05/2003. Enc. Bibli: R. Eletr. Bibliotecon. Ci. Inf., Florianópolis, n.15, 1º sem. 2003. 1

  14. Inflación y tributación

    OpenAIRE

    Martínez Gómez, Carlos Freddy

    1999-01-01

    En el contexto colombiano y en materia tributaria se ha considerado que 2Toda acumulación real que aumente la capacidad contributiva debe gravarse, sin embargo el proceso inflacionario introduce la desviación a la base que expresa el enriquecimiento de la unidad contributiva, desvirtuando el concepto de ingreso y conduciendo en consecuencia a una inequitativa distribución de los gravámenes fiscales", Siguiendo con los "Lineamientos" que la anterior cita plantea se expidieron a lo largo de los...

  15. Revolución y secularización

    Directory of Open Access Journals (Sweden)

    Sauquillo, Julián

    2008-12-01

    Full Text Available During the 19th century and the beginning of 20th, some classical authors of contemporary political theory wondered if the modern world was going to be exempt from magic and religious ways such the bourgeois revolutions were supposed to get. This paper about «Revolution and Secularization» deals with that kind of perplexity and assumes the plurisecular survival of these irrational aspects beyond every scientific revolution and materialist products of Enlightenment. Neither specialized nor mechanized world implied the extinction of mystery or magical and inexplicable phenomena, as Max Weber, Theodor Adorno and Max Horkheimer had suggested. In recent years, another review of modern assumptions was carried out by some classic authors who rethought the modern revolution. Not only the conservative work of Carl Schmitt, or reactionary thinking of Joseph de Maistre and Louis-Ambroise de Bonald, but also those authors which support Modernity, as Hans Blumenberg or Jacob Taubes, have raised the continuity or break of Modernity from Old Regime.

    Esta sección monográfica de Isegoria sobre «Revolución y secularización» surge de la perplejidad que, durante el siglo XIX y el inicio del siglo XX, algunos clásicos de la teoría política contemporánea mostraron ante las revoluciones burguesas y la supuesta consecución del mundo moderno exento de elementos mágicos y religiosos. El tema de reflexión se propone bajo la suposición de la pervivencia plurisecular de estos elementos irracionales más allá de todas las revoluciones científicas y materializaciones ilustradas. Cabe que la especialización y mecanización del mundo moderno no hayan supuesto, como en un principio temieron de MaxWeber a Theodor Adorno y Max Horkheimer, la desaparición de todos los elementos arcanos, mágicos e inexplicables. En los últimos años, se produjo otra revisión de los presupuestos modernos de las dos grandes revoluciones a

  16. Alimentación y nutrición /

    OpenAIRE

    Ramajo Aguilar, María Ángeles

    2013-01-01

    Se trata de analizar algunos de los conceptos a partir de sus características generales y esenciales para establecer los límites entre la alimentación y la nutrición y sus interconexiones y aspectos que les influyen, definir conceptos asociados como las clases de nutrientes que el cuerpo necesita, grupos de alimentos que deben estar presentes en toda dieta y sus proporciones o recomendaciones, tipos de dieta, la evolución de todo ello a lo largo de la historia de la humanidad y la importancia...

  17. Comunicación y movilización social

    Directory of Open Access Journals (Sweden)

    Gloria Dávila de Vela

    2015-01-01

    Full Text Available Hasta hace pocos años, la salud pública era concebida como responsabilidad exclusiva del Estado y como problema a ser resuelto por médicos y salubristas en los hospitales, centros o puestos de salud. Este concepto ha ido modificándose paralelamente al desarrollo de nuevas escuelas de pensamiento que han desplazado el eje de atención de la medicina curativa a la medicina preventiva. La comunicación deberá constituirse en un eje transversal que articule las distintas acciones de movilización social.

  18. Manipulaci?n manual de cargas. Ecuaci?n NIOSH

    OpenAIRE

    Ruiz Ruiz, Laura

    2016-01-01

    Se hace una breve introducci?n sobre los or?genes del m?todo, sus principales limitaciones y se describe el procedimiento para su aplicaci?n al an?lisis de tareas que involucran levantamiento de pesos. Se explica la ecuaci?n con todas sus variables, la forma de medirlas y se dan algunas recomendaciones de mejora de acuerdo a los resultados de los par?metros evaluados. Por ?ltimo se calcula el ?ndice de levantamiento para valorar el riesgo de una actividad de levantamiento determinada.

  19. Band offsets of non-polar A-plane GaN/AlN and AlN/GaN heterostructures measured by X-ray photoemission spectroscopy.

    Science.gov (United States)

    Sang, Ling; Zhu, Qin Sheng; Yang, Shao Yan; Liu, Gui Peng; Li, Hui Jie; Wei, Hong Yuan; Jiao, Chun Mei; Liu, Shu Man; Wang, Zhan Guo; Zhou, Xiao Wei; Mao, Wei; Hao, Yue; Shen, Bo

    2014-01-01

    The band offsets of non-polar A-plane GaN/AlN and AlN/GaN heterojunctions are measured by X-ray photoemission spectroscopy. A large forward-backward asymmetry is observed in the non-polar GaN/AlN and AlN/GaN heterojunctions. The valence-band offsets in the non-polar A-plane GaN/AlN and AlN/GaN heterojunctions are determined to be 1.33 ± 0.16 and 0.73 ± 0.16 eV, respectively. The large valence-band offset difference of 0.6 eV between the non-polar GaN/AlN and AlN/GaN heterojunctions is considered to be due to piezoelectric strain effect in the non-polar heterojunction overlayers.

  20. Improved InGaN/GaN quantum wells on treated GaN template with a Ga-rich GaN interlayer

    International Nuclear Information System (INIS)

    Fang, Zhilai; Shen, Xiyang; Wu, Zhengyuan; Zhang, Tong-Yi

    2015-01-01

    Treated GaN template was achieved by in situ droplet epitaxy of a Ga-rich GaN interlayer on the conventional GaN template. InGaN/GaN quantum wells (QWs) were grown on the conventional and treated GaN templates under the same growth conditions and then comprehensively characterized. The indium homogeneity in the InGaN layers and the interface sharpness between InGaN and GaN layers of the InGaN/GaN QWs on the treated GaN template were significantly improved. The emission intensity from the InGaN/GaN QWs on the treated GaN template was enhanced by 20% than that on the conventional GaN template, which was attributed to the strain reduction and the improvement in crystalline quality. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Coulomb dissociation of N 20,21

    OpenAIRE

    Röder, Marko; Adachi, Tatsuya; Aksyutina, Yulia; Alcantara, Juan; Altstadt, Sebastian; Alvarez-Pol, Hector; Ashwood, Nicholas; Atar, Leyla; Aumann, Thomas; Avdeichikov, Vladimir; Barr, M.; Beceiro, Saul; Bemmerer, Daniel; Benlliure, Jose; Bertulani, Carlos

    2016-01-01

    Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N20,21 are reported. Relativistic N20,21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the N19(n,γ)N20 and N20(n,γ)N21 excitation functions and thermonuclear reaction rates have been determined. The N19(n,γ)N20 rate is...

  2. Gestión del talento humano, satisfacción laboral y calidad de gestión en la Institución Educativa 20189

    OpenAIRE

    Castillo Calvo, Fedra Marisol

    2016-01-01

    El presente estudio titulado “Gestión del talento humano, satisfacción laboral y calidad de gestión en la Institución Educativa 20189”, tiene como objetivo “Determinar la relación entre la gestión del talento humano, satisfacción laboral y calidad de gestión en la Institución Educativa 20189”, el objetivo del estudio fue conocer los factores que determinan la satisfacción laboral asociado a la gestión de calidad y del talento humano para contribuir con la escuela. El enfoque...

  3. High breakdown voltage in AlGaN/GaN HEMTs using AlGaN/GaN/AlGaN quantum-well electron-blocking layers.

    Science.gov (United States)

    Lee, Ya-Ju; Yao, Yung-Chi; Huang, Chun-Ying; Lin, Tai-Yuan; Cheng, Li-Lien; Liu, Ching-Yun; Wang, Mei-Tan; Hwang, Jung-Min

    2014-01-01

    In this paper, we numerically study an enhancement of breakdown voltage in AlGaN/GaN high-electron-mobility transistors (HEMTs) by using the AlGaN/GaN/AlGaN quantum-well (QW) electron-blocking layer (EBL) structure. This concept is based on the superior confinement of two-dimensional electron gases (2-DEGs) provided by the QW EBL, resulting in a significant improvement of breakdown voltage and a remarkable suppression of spilling electrons. The electron mobility of 2-DEG is hence enhanced as well. The dependence of thickness and composition of QW EBL on the device breakdown is also evaluated and discussed.

  4. Evaluation of cross sections for 197Au(n,3n) and 197Au(n,4n) reactions from threshold to 50 MeV

    International Nuclear Information System (INIS)

    Yu Baosheng; Shen Qingbiao; Cai Dunjiu

    1994-01-01

    The measured data of cross sections for 197 Au(n,3n) and 197 Au(n,4n) reactions were collected and analysed. The theoretical calculations of above mentioned reactions were carried out to predict the data in higher energy region. The sets of cross sections for 197 Au(n,3n) and 197 Au(n,4n) reactions from threshold to 50 MeV were recommended on the basis of the experimental and calculated data. (2 figs)

  5. N,N'-diamidoketenimines via coupling of isocyanides to an N-heterocyclic carbene.

    Science.gov (United States)

    Hudnall, Todd W; Moorhead, Eric J; Gusev, Dmitry G; Bielawski, Christopher W

    2010-04-16

    Treatment of an N-heterocyclic carbene that features two amide groups N-bound to the carbene nucleus with various organic isocyanides afforded a new class of ketenimines in yields of up to 96% (isolated). DFT analyses revealed that the carbene exhibits a unique, low-lying LUMO, which may explain the atypical reactivity observed.

  6. Sustainable development in an N-rich/n-poor world.

    Science.gov (United States)

    Perrings, Charles; Kinzig, Ann; Halkos, George

    2014-11-01

    Sustainable development requires that per capita inclusive wealth-produced, human, and natural capital-does not decline over time. We investigate the impact of changes in nitrogen on inclusive wealth. There are two sides to the nitrogen problem. Excess use of nitrogen in some places gives rise to N-pollution, which can cause environmental damage. Insufficient replacement of nitrogen in other places gives rise to N-depletion, or loss of nutrient stocks. Neither is explicitly accounted for in current wealth measures, but both affect wealth. We calculate an index of net N-replacement, and investigate its relationship to wealth. In countries with low levels of relative N-loss, we find that the uncompensated loss of soil nitrogen in poorer countries is associated with declining rates of growth of inclusive per capita wealth. What is less intuitive is that increasing fertilizer application in both rich and poor countries can increase per capita inclusive wealth.

  7. Evolución, cerebro y cognición

    Directory of Open Access Journals (Sweden)

    Luis Felipe Zapata

    2009-01-01

    Full Text Available En esta revisión se presenta un recorrido sobre el proceso de la evolución cerebral en los últimos 4 millones de años; en la segunda parte, se enfatiza en el concepto de modularidad de la mente, y el papel del lenguaje y de la fluidez cognitiva en el paso de la mente primitiva a la mente moderna. Se hace referencia a las funciones ejecutivas, la memoria de trabajo y la teoría de la mente. El enfoque es el de la teoría de la complejidad, la cual concibe la mente como una emergencia, es decir, como una propiedad de la interacción, en este caso, de la interacción neural presente en el cerebro.

  8. Multiple blocking sets in PG(n,q), n>=3

    DEFF Research Database (Denmark)

    Barat, Janos

    2004-01-01

    This article discusses minimal s-fold blocking sets B in PG (n, q), q = ph, p prime, q > 661, n > 3, of size |B| > sq + cp q2/3 - (s - 1) (s - 2)/2 (s > min (cp q1/6, q1/4/2)). It is shown that these s-fold blocking sets contain the disjoint union of a collection of s lines and/or Baer subplanes....... To obtain these results, we extend results of Blokhuis–Storme–Szönyi on s-fold blocking sets in PG(2, q) to s-fold blocking sets having points to which a multiplicity is given. Then the results in PG(n, q), n ≥ 3, are obtained using projection arguments. The results of this article also improve results...

  9. Ageing behaviour of [(n-1)/n] active redundancy systems

    International Nuclear Information System (INIS)

    Eid, M.Y.

    1995-01-01

    Ageing of systems becomes a real concern if intelligent maintenance is required. Determining the ageing behaviour of a system necessitate having a powerful calculating tool and knowing the ageing behaviour of the basic components of the systems. Consequently, time dependent failure rates are required for basic components and need to be determined for systems. As, this is the general problem in reliability analysis, only (n-1)/n active redundancy system will be examined in the paper. Systems with (n-1)/n active redundancy are commonly used in a wide range of engineering fields. This should permit a priori improving the system reliability. Still, a deeper analysis of the ageing behaviour of such systems may reveal some particular aspects. (authors). 2 refs., 5 figs

  10. Investigación + publicación: mejoramos todos

    Directory of Open Access Journals (Sweden)

    Andrés Rodríguez NF.

    2009-01-01

    Full Text Available La sociedad demanda de la farmacia y del farmacéutico como profesional sanitario responsable de la provisión de los tratamientos farmacoterapéuticos que se comprometa en la consecución de sus objetivos, en la efectividad de los tratamientos, en su seguridad y, como consecuencia, en su uso eficiente. Para dar respuesta a esta demanda, la farmacia comunitaria ha incorporado a su cartera de servicios una serie de procedimientos o actividades asistenciales, que se engloban dentro del concepto de atención farmacéutica (AF y cuyos objetivos son la adecuada provisión, seguimiento y control de la farmacoterapia del paciente.

  11. y precisión

    Directory of Open Access Journals (Sweden)

    Jorge Luis Herrera-Fuentes

    2005-01-01

    Full Text Available El proceso docente - educativo dirigido a la formación de ingenieros no siempre responde a la necesidad de hacerlos competentes para medir magnitudes físicas propias del desempeño profesional, debido a lo cual no queda preparado para cumplir algunas de las funciones propias del egresado de estas carreras. La formación de esta capacidad depende de la sistematización de un conjunto de habilidades asociadas al proceso de medición, que circula entre varias disciplinas o queda en el marco estrecho de una de ellas, lo que conlleva a una pérdida en los niveles de asimilación y profundidad de los contenidos, y al final resulta que el ingeniero no está capacitado para medir con la exactitud y precisión requerida. El trabajo pretende presentar este problema, argumentarlo y hacer una propuesta para su solución, basada en un enfoque transdisciplinar

  12. de poltrusión

    Directory of Open Access Journals (Sweden)

    Francisco González

    2006-01-01

    Full Text Available El poliuretano es un compuesto que se forma por la reacción de un diisocianato y un polialcohol. Aprovechando la alta reactividad del prepolímero de difenilmetano- diisocianato (MDI se forman grupos uretánicos con el ácido ricinoleico proporcionado por el aceite de higuerilla, obteniéndose un poliuretano con una dureza shore D 45. Este polímero junto con la fibra de vidrio tipo E forman el compuesto reforzado, utilizando el mecanismo de manufactura denominado poltrusión. El proceso de poltrusión es un proceso de producción en serie y se realiza de manera industrial con resinas de poliéster con altas emisiones de compuestos orgánicos volátiles (VOC. En este trabajo se expone una alternativa de producción más eficiente y con materia prima renovable como lo es el aceite de higuerilla, eliminando las emisiones de VOC al ambiente; además, se analiza la interacción del poliuretano con fibra de vidrio en la obtención de un material compuesto (composito con alta resistencia química y excelentes propiedades mecánicas, asociadas a la sinergia entre la fibra de vidrio y el poliuretano.

  13. Diiodidobis(N,N,N′,N′-tetramethylthiourea-κScadmium(II

    Directory of Open Access Journals (Sweden)

    Sidra Nawaz

    2010-08-01

    Full Text Available In the title compound, [CdI2(C5H12N2S2], the CdII ion is located on a twofold rotation axis and is coordinated in a distorted tetrahedral mode by two iodide ions and by two tetramethylthiourea (tmtu ligands through their S atoms. The crystal structure is stabilized by C—H...N and C—H...S hydrogen bonds.

  14. Dichloridobis(N,N,N′,N′-tetramethylthiourea-κSmercury(II

    Directory of Open Access Journals (Sweden)

    Sidra Nawaz

    2010-08-01

    Full Text Available In the title compound, [HgCl2(C5H12N2S2], the HgII atom is located on a twofold rotation axis and is bonded in a distorted tetrahedral coordination mode to two chloride ions and to two tetramethylthiourea (tmtu molecules through their S atoms. The crystal structure is stabilized by C—H...N and C—H...S hydrogen bonds.

  15. Synthesis and conformational features of sym N,N′,N ...

    Indian Academy of Sciences (India)

    Administrator

    KOH in nitrobenzene at ≥105°C afforded sym N,N′,N″-triarylguanidine in fair to good yield and the ... acetonitrile and the pKa value of 5 is ca 4 units higher than ..... Found C, 69⋅60; H, 6⋅06; N, 10⋅75. The value of δC. 55⋅5 ppm for OCH3 was independently confirmed with the aid of two-dimensional HMQC NMR data.

  16. On the Dirac groups of rank n

    International Nuclear Information System (INIS)

    Ferreira, P.L.; Alcaras, J.A.C.

    1980-01-01

    The group theoretical properties of the Dirac groups of rank n are discussed together with the properties and construction of their IR's. The cases n even and n odd show distinct features. Furthermore, for n odd, the cases n=4K+1 and n=4K+3 exhibit some different properties too. (Author) [pt

  17. Groundwater Monitoring Plan for the 1301-N, 1324-N/NA, and 1325-N RCRA Facilities

    International Nuclear Information System (INIS)

    Hartman, Mary J.

    2001-01-01

    The 1301-N and 1325-N Liquid Waste Disposal Facilities, the 1324-N Surface Impoundment, and the 1324-NA Percolation Pond, located in the 100 N Area of the Hanford Site, are regulated under the Resource Conservation and Recovery Act of 1976 (RCRA). The closure plans for these facilities stipulate that groundwater is monitored according to the 100-N Pilot Project: Proposed Consolidated Groundwater Monitoring Program (BHI-00725). This document supplements the consolidated plan by providing information on sampling and analysis protocols, quality assurance, data management, and a conceptual model for the RCRA sites. Monitoring well networks, constituents, and sampling frequency remain the same as in the consolidated plan or the previous groundwater monitoring plan (Hartman 1996)

  18. Graphene in ohmic contact for both n-GaN and p-GaN

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Haijian; Liu, Zhenghui; Shi, Lin; Xu, Gengzhao; Fan, Yingmin; Huang, Zengli [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Wang, Jianfeng; Ren, Guoqiang; Xu, Ke, E-mail: kxu2006@sinano.ac.cn [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Suzhou Nanowin Science and Technology Co., Ltd., Suzhou 215123 (China)

    2014-05-26

    The wrinkles of single layer graphene contacted with either n-GaN or p-GaN were found both forming ohmic contacts investigated by conductive atomic force microscopy. The local I–V results show that some of the graphene wrinkles act as high-conductive channels and exhibiting ohmic behaviors compared with the flat regions with Schottky characteristics. We have studied the effects of the graphene wrinkles using density-functional-theory calculations. It is found that the standing and folded wrinkles with zigzag or armchair directions have a tendency to decrease or increase the local work function, respectively, pushing the local Fermi level towards n- or p-type GaN and thus improving the transport properties. These results can benefit recent topical researches and applications for graphene as electrode material integrated in various semiconductor devices.

  19. Definición, etiopatogenia, clasificación y formas de presentación

    Directory of Open Access Journals (Sweden)

    Xavier Mas Garriga

    2014-01-01

    La artrosis de rodilla tiene una prevalencia del 10,2% en España y muestra una importante disociación clinicorradiológica. La artrosis de manos, con una prevalencia de afectación sintomática de alrededor del 6,2% puede adoptar diferentes formas de presentación (artrosis nodal, artrosis generalizada, rizartrosis y artrosis erosiva. La artrosis sintomática de cadera afecta entre el 3,5 y 5,6% de los mayores de 50 años y tiene diferentes patrones radiológicos en función de la migración de la cabeza femoral.

  20. Hybrid mesons (Q anti Qg) in N anti N annihilation

    International Nuclear Information System (INIS)

    Dover, C.B.; Gutsche, T.; Faessler, A.

    1993-09-01

    N anti N annihilation reactions provide exciting possibilities to study mesonic resonances beyond the usual Q anti Q spectrum. Particularly the search for Q anti Qg mesons containing an explicit dynamical excitation of the gluon field is not promising, since hybrids are predicted to display unique features: exotic quantum numbers (J πC ) and dynamical selection rules for their decay modes. The authors have investigated the possibility of producing hybrids from p anti p atomic states in reactions of the type N anti N(L= 0,1) → π + Q anti Qg. Production rates for hybrid mesons are found to display a strong dependence on the quantum numbers and kinematical factors associated with the transition. The dependence on the orbital angular momentum L of the p anti p atomic state, accessible in p anti p annihilation at rest, would provide a striking signature for the production of hybrids. In estimating branching ratios for the formation of Q anti Qg hybrid mesons in N anti N annihilation reactions at rest, the authors have employed a microscopic model with constituent quarks and gluons in analogy to the annihilation model for the production of Q anti Q mesons

  1. Probings through proton decay and n-n-bar oscillations

    International Nuclear Information System (INIS)

    Pati, J.C.; Strathdee, J.

    1980-11-01

    Violation of baryon, lepton and in general fermion number is central to the hypothesis of quark lepton unification in a gauge context. Three of its characteristic signatures are proton decay, n-n-bar oscillation and neutrinoless double β decay. In 1974 and 1975 it was shown that within maximal gauging the proton may decay via four alternative modes (i.e. proton → one or three leptons or anti-leptons) satisfying ΔF = -2, 0, -4 and -6, some of which may coexist; the deuteron may decay into pions and neutrinoless double β decay occur in the context of spontaneous gauge symmetry breaking. It is now observed that n-n-bar oscillations (which are related to deuteron decays into protons) can coexist with proton decay especially of ΔF = -4 variety (p → e + π 0 ) and both these processes may possess measurable strength so as to be amenable to forthcoming searches. We exhibit alternative routes for spontaneous breakdown of the maximal one-family symmetry SU(16) and show that the coexistence of alternative proton decay modes (even with n-n-bar oscillations) does not pose any conflict with cosmological generation of baryon excess. Spontaneous rather than explicit violation of B, L and F plays an essential role in the realization of these features. (author)

  2. CUBA: TRANSICIÓN, SUCESIÓN, ESTABILIDAD, SEGURIDAD

    Directory of Open Access Journals (Sweden)

    Joaquín ROY

    2009-01-01

    Full Text Available Este análisis trata de la relación entre la estabilidad del presente gobierno cubano y la necesidad de seguridad en su territorio y en la zona circundante. Este vínculo se produce en un momento político de Cuba, entre un primer paso de la sucesión de Fidel Castro a Raúl, sin que se den señales claras de una transición hacia otro tipo de sistema político. Mientras tanto, el gobierno de Estados Unidos ha declarado que su prioridad estriba en el reestablecimiento de la democracia en Cuba, tanto durante el último periodo de la administración de George W. Bush como con Barack Obama ya asentado en la Casa Blanca. Sin embargo, las delicadas circunstancias de Cuba (precariedad económica, desastres naturales, dependencia alimentaria y energética, etc. señalan que la prioridad de los intereses nacionales de Estados Unidos se centran primero en la estabilidad del escenario. Incluso al precio del retraso de la evolución del régimen, un cierto grado de seguridad es necesario para enfrentarse a los riesgos de una emigración incontrolada y las hipotéticas tensiones internas que provoquen confrontaciones.

  3. GaN/NbN epitaxial semiconductor/superconductor heterostructures

    Science.gov (United States)

    Yan, Rusen; Khalsa, Guru; Vishwanath, Suresh; Han, Yimo; Wright, John; Rouvimov, Sergei; Katzer, D. Scott; Nepal, Neeraj; Downey, Brian P.; Muller, David A.; Xing, Huili G.; Meyer, David J.; Jena, Debdeep

    2018-03-01

    Epitaxy is a process by which a thin layer of one crystal is deposited in an ordered fashion onto a substrate crystal. The direct epitaxial growth of semiconductor heterostructures on top of crystalline superconductors has proved challenging. Here, however, we report the successful use of molecular beam epitaxy to grow and integrate niobium nitride (NbN)-based superconductors with the wide-bandgap family of semiconductors—silicon carbide, gallium nitride (GaN) and aluminium gallium nitride (AlGaN). We apply molecular beam epitaxy to grow an AlGaN/GaN quantum-well heterostructure directly on top of an ultrathin crystalline NbN superconductor. The resulting high-mobility, two-dimensional electron gas in the semiconductor exhibits quantum oscillations, and thus enables a semiconductor transistor—an electronic gain element—to be grown and fabricated directly on a crystalline superconductor. Using the epitaxial superconductor as the source load of the transistor, we observe in the transistor output characteristics a negative differential resistance—a feature often used in amplifiers and oscillators. Our demonstration of the direct epitaxial growth of high-quality semiconductor heterostructures and devices on crystalline nitride superconductors opens up the possibility of combining the macroscopic quantum effects of superconductors with the electronic, photonic and piezoelectric properties of the group III/nitride semiconductor family.

  4. Probings through proton decay and n-anti n oscillations

    International Nuclear Information System (INIS)

    Pati, J.C.; Strathdee, J.

    1981-01-01

    Violation of baryon, lepton and in general fermion number is central to the hypothesis of quark-lepton unification in a gauge context. Three of its characteristic signatures are proton decay, n-anti n oscillation and neutrinoless double β decay. In 1974 and 1975 it was shown that within maximal gauging the proton may decay via four alternative modes (i.e. proton → one or three leptons or antileptons) satisfying ΔF = -2, 0, -4 and -6, some of which may coexist; the deuteron may decay into pions and neutrinoless double β decay occur in the context of spontaneous gauge symmetry breaking. It is now observed that n-anti n oscillations (which are related to deuteron decays into pions) can coexist with proton decay especially of ΔF= -4 variety (p → e + π 0 ) and both these processes may possess measurable strength so as to be amenable to forthcoming searches. We exhibit alternative routes for spontaneous breakdown of the maximal one-family symmetry SU(16) and show that the coexistence of alternative proton decay modes (even with n-anti n oscillations) does not pose any conflict with cosmological generation of baryon excess. Spontaneous rather than explicit violation of B, L and F plays an essential role in the realization of these features. (orig.)

  5. Foreward | Presentación

    Directory of Open Access Journals (Sweden)

    Rubén Domínguez Méndez

    2012-12-01

    Full Text Available La parafernalia de la propaganda fascista del ventennio estuvo impregnada, en cuanto al modo de formular los mensajes políticos, por las continuas alusiones históricas. La habilidad para enlazar con el pasado del Imperio Romano llevó a la construcción de arquetipos como el de la hermandad latina. Sabido es que el fascismo proponía una redención espiritual de Italia a través de la recuperación de los valores de la civilización romana que debía plasmarse, en términos de política exterior, en una progresiva recuperación de los antiguos límites alcanzados. Por ese motivo, las jerarquías fascistas acentuaron la necesidad de ejercer una política similar a la desarrollada por las grandes potencias, pese a las evidentes deficiencias que presentaba el país para desplegarla. El presente dossier analiza el interés del fascismo por ejecutar esa política en un área vital para la retórica fascista; aquella que afectó a las naciones latinas, fueran éstas del continente europeo o americano. Las relaciones entre esta política exterior y la colectividad emigrada en el extranjero configuran un tema de gran relevancia en el análisis del fascismo porque su estudio nos lleva a adentrarnos en los complejos vínculos creados entre la nación, los emigrantes y su utilización al servicio del Estado. Partiendo de esas ideas, los trabajos presentados en este número de Pasado y Memoria suponen una aportación historiográfica que avanza en el conocimiento de la estructura diseñada por el fascismo entre sus emigrantes, especialmente mediante la creación de grupos del partido fascista en el extranjero, los Fasci all’Estero, la articulación del mensaje de propaganda política del régimen en éstos países y la búsqueda de simpatizantes afines a su causa entre la opinión pública internacional.

  6. Prevención primaria

    OpenAIRE

    Henao Gaviria, Luis Fernando

    1989-01-01

    Pretende este trabajo sobre "Prevención primaria" brindar en forma general una seria de conceptos sobre la salud y la enfermedad, las diferentes barreras que se pueden interponer para que esta no se presente o si se presenta sea lo menos virulenta posible, si deja secuelas buscar que el paciente las trate de superar y evitar la muerte, se logra lo anterior aplicando los niveles de prevención de Leavell y Clark, se hará enfasis en el 1° y 2° nivel que corresponden al fomento o promoción de la ...

  7. Operación fortuna

    OpenAIRE

    Bermúdez Sánchez, Laura Marcela

    2014-01-01

    Operación Fortuna es un guion que se desarrolla en la actualidad, trata sobre los defectos humanos tales como la ambición, avaricia y envidia, es la historia de cómo los diferentes personajes deben sobreponerse a sus defectos para lograr sus objetivos tales como el amor, dinero, estatus, etc. Ellos harán hasta lo impensable por obtener la herencia. A pesar de lo mucho que les cuesta cambiar su forma de ser, descubren que la familia es importante para conseguir las metas que se ...

  8. N-[3-(Benzenesulfonamidopropyl]benzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Tahir Ali Sheikh

    2011-07-01

    Full Text Available In the title compound, C15H18N2O4S2, the dihedral angle between the aromatic rings is 71.8 (2°. The conformation of the central N—C—C—C—N fragment is gauche–gauche [torsion angles = 72.5 (5 and 65.7 (5°]. Both N atoms adopt pyramidal geometries. In the crystal, molecules are linked by N—H...O hydrogen bonds, generating (001 sheets, and weak C—H...O interactions consolidate the packing.

  9. Educación Alimentaria

    OpenAIRE

    Micó, Lydia; Bretó, Patricia; Soriano, José Miguel

    2012-01-01

    Uso del video educativo y el podcasting como fortalecimiento en el aprendizaje de la Dietoterapia. El éxito del tratamiento dietoterapéutico requiere de una intervención a largo plazo, con el objetivo de poder cambiar hábitos alimentarios y desarrollar una nutrición adecuada y saludable en el futuro. En este video se enseñan diferentes tipos de herramientas aplicadas de educación alimentaria en el gabinete dietoterapéutico.

  10. N-flation in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Das, Kumar, E-mail: kumar.das@saha.ac.in; Dutta, Koushik, E-mail: koushik.dutta@saha.ac.in

    2014-11-10

    We have constructed a large field N-flation model in the supergravity framework. In this simple set-up, N fields collectively drive inflation where each field traverses sub-Planckian field values. This has been realised with a generalisation of the single-field chaotic inflation in supergravity. Interestingly, despite the presence of the field interactions, the dynamics can be described in terms of an effective single field. The observable predictions of our model, i.e., tensor-to-scalar ratio r and scalar spectral index n{sub s}, are akin to the chaotic inflation.

  11. N-(4-Chlorophenyl-2-(hydroxyiminoacetamide

    Directory of Open Access Journals (Sweden)

    Jie Sun

    2009-09-01

    Full Text Available The title compound, C8H7ClN2O2, is an intermediate in the synthesis of 5-chloroisatin, which can be further transformed to 5-chloro-2-indolinone via a Wolff–Kishne reduction. The C2N acetamide plane forms a dihedral angle of 6.3 (3° with the benzene ring. An intramolecular C—H...O interaction results in the formation of a six-membered ring. In the crystal, intermolecular N—H...O, N—H...N and O—H...O hydrogen bonds link the molecules into multimers, forming sheets.

  12. La educaci??n emocional

    OpenAIRE

    Garc??a Banderas, Mar??a Isabel

    2015-01-01

    Las investigaciones cient??ficas dan algunas respuestas a las preguntas planteadas y definen el concepto desde el an??lisis de su representaci??n tanto en la mente como en el cuerpo. Hay autores que las mencionan como un ??fen??meno emergente??, en lugar de una entidad absoluta, que surge de la interacci??n entre el contexto y nuestra percepci??n, en la que influye, entre otras cosas, nuestro estado afectivo principal (Barrett y Russell,2015). Entre estos estados afectivos, m??s durader...

  13. Pabellón Schindler

    Directory of Open Access Journals (Sweden)

    Boyer, A.

    1958-04-01

    Full Text Available Las ventajas que las estructuras metálicas ofrecen, son de todos conocidas: relación peso-resistencia reducida; facilidad de empalmes, uniones y corte de piezas; rapidez de montaje, etc., etc. Pero hasta hace pocos años las estructuras formadas por barras rectas, en retícula espacial de vigas y soportes de alma llena, era casi la única empleada en la construcción, prestando a sus edificaciones un aspecto característico de rígida y uniforme modulación.

  14. Preparation, composition, and solid state investigations of TiN, ZrN, NbN, and compounds from the pseudobinary systems NbN-NbC, NbN-TiC, and NbN-TiN

    International Nuclear Information System (INIS)

    Christensen, A.N.; Fregerslev, S.

    1977-01-01

    Single crystals of the cubic phases TiN, ZrN, delta-NbN and of compounds from the pseudobinary systems NbN-NbC, NbN-TiC, and NbN-TiN were obtained by zone melting, zone annealing and annealing of the metal carbides in nitrogen gas of 2 MPa. Single crystals of the tetragonal phase gamma-NbN were obtained in a similar way by annealing of niobium. The nitrides are non-stochiometric. TiN was obtained in the composition range TiNsub(0.99) to TiNsub(0.50), ZrN in the range ZrNsub(1.00) to ZrNsub(0.63), and in niobium nitrides were obtained in the composition range NbNsub(0.90) to NbNsub(0.69). The compounds from the pseudobinary systems have up to 35% vacant sites in the nitrogen-carbon sublattice. TiN and ZrN have only vacant sites in the nitrogen sublattice. A correlation is found between the unit cell parameters for titanium nitride and zirconium nitride and the nitrogen-metal ratios. (orig.) [de

  15. Thermal stability study of Cr/Au contact formed on n-type Ga-polar GaN, N-polar GaN, and wet-etched N-polar GaN surfaces

    International Nuclear Information System (INIS)

    Choi, Yunju; Kim, Yangsoo; Ahn, Kwang-Soon; Kim, Hyunsoo

    2014-01-01

    Highlights: • The Cr/Au contact on n-type Ga-polar (0 0 0 1) GaN, N-polar (0 0 0 −1) GaN, and wet-etched N-polar GaN were investigated. • Thermal annealing led to a significant degradation of contact formed on N-polar n-GaN samples. • Contact degradation was shown to be closely related to the increase in the electrical resistivity of n-GaN. • Out-diffusion of Ga and N atoms was clearly observed in N-polar samples. - Abstract: The electrical characteristics and thermal stability of a Cr/Au contact formed on n-type Ga-polar (0 0 0 1) GaN, N-polar GaN, and wet-etched N-polar GaN were investigated. As-deposited Cr/Au showed a nearly ohmic contact behavior for all samples, i.e., the specific contact resistance was 3.2 × 10 −3 , 4.3 × 10 −4 , and 1.1 × 10 −3 Ω cm 2 for the Ga-polar, flat N-polar, and roughened N-polar samples, respectively. However, thermal annealing performed at 250 °C for 1 min in a N 2 ambient led to a significant degradation of contact, i.e., the contact resistance increased by 186, 3260, and 2030% after annealing for Ga-polar, flat N-polar, and roughened N-polar samples, respectively. This could be due to the different disruption degree of Cr/Au and GaN interface after annealing, i.e., the insignificant interfacial reaction occurred in the Ga-polar sample, while out-diffusion of Ga and N atoms was clearly observed in N-polar samples

  16. Thermal stability study of Cr/Au contact formed on n-type Ga-polar GaN, N-polar GaN, and wet-etched N-polar GaN surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yunju [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Kim, Yangsoo [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Ahn, Kwang-Soon, E-mail: kstheory@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of); Kim, Hyunsoo, E-mail: hskim7@jbnu.ac.kr [School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2014-10-30

    Highlights: • The Cr/Au contact on n-type Ga-polar (0 0 0 1) GaN, N-polar (0 0 0 −1) GaN, and wet-etched N-polar GaN were investigated. • Thermal annealing led to a significant degradation of contact formed on N-polar n-GaN samples. • Contact degradation was shown to be closely related to the increase in the electrical resistivity of n-GaN. • Out-diffusion of Ga and N atoms was clearly observed in N-polar samples. - Abstract: The electrical characteristics and thermal stability of a Cr/Au contact formed on n-type Ga-polar (0 0 0 1) GaN, N-polar GaN, and wet-etched N-polar GaN were investigated. As-deposited Cr/Au showed a nearly ohmic contact behavior for all samples, i.e., the specific contact resistance was 3.2 × 10{sup −3}, 4.3 × 10{sup −4}, and 1.1 × 10{sup −3} Ω cm{sup 2} for the Ga-polar, flat N-polar, and roughened N-polar samples, respectively. However, thermal annealing performed at 250 °C for 1 min in a N{sub 2} ambient led to a significant degradation of contact, i.e., the contact resistance increased by 186, 3260, and 2030% after annealing for Ga-polar, flat N-polar, and roughened N-polar samples, respectively. This could be due to the different disruption degree of Cr/Au and GaN interface after annealing, i.e., the insignificant interfacial reaction occurred in the Ga-polar sample, while out-diffusion of Ga and N atoms was clearly observed in N-polar samples.

  17. Región Occidental

    OpenAIRE

    2014-01-01

    Acosta Hoyos, Luis Eduardo, Bibliografía anotada del departamento de Nariño, Pasto, Imprenta Departamental, 1966. Álvarez Lleras, Jorge, El Chocó. Apuntamientos de viajes referentes a esta interesante región del país, Bogotá, Minerva, 1923. Ariza, Andrés de, “Comentos de la rica y fertilísima provincia del Darién, año 1744”, en Anales de instrucción pública Estados Unidos de Colombia, Vol. 5, No. 29, Bogotá, mayo de 1883. Beltrán de Caycedo, M., Informe sobre las provincias del Chocó, s. p. i...

  18. Bootstrapping N=3 superconformal theories

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Madalena; Liendo, Pedro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Meneghelli, Carlo [Stony Brook Univ., Stony Brook, NY (United States). Simons Center for Geometry and Physics; Mitev, Vladimir [Mainz Univ. (Germany). PRISMA Cluster of Excellence

    2016-12-15

    We initiate the bootstrap program for N=3 superconformal field theories (SCFTs) in four dimensions. The problem is considered from two fronts: the protected subsector described by a 2d chiral algebra, and crossing symmetry for half-BPS operators whose superconformal primaries parametrize the Coulomb branch of N=3 theories. With the goal of describing a protected subsector of a family of =3 SCFTs, we propose a new 2d chiral algebra with super Virasoro symmetry that depends on an arbitrary parameter, identified with the central charge of the theory. Turning to the crossing equations, we work out the superconformal block expansion and apply standard numerical bootstrap techniques in order to constrain the CFT data. We obtain bounds valid for any theory but also, thanks to input from the chiral algebra results, we are able to exclude solutions with N=4 supersymmetry, allowing us to zoom in on a specific N=3 SCFT.

  19. EJST V9N2

    African Journals Online (AJOL)

    were assigned as main plots and management practices (fungicide and .... Data Collection and Analysis ... n = individual numerical ratings; a = total number ... who found an increment of air temperature up to ..... Centre, New Delhi, India. 995.

  20. La depresión

    OpenAIRE

    Rivas Nieto, Juan Carlos; Fundación Valle de Lili; Vidal Roa, Francisco

    1997-01-01

    Descripción clínica/Causas/Riesgos de la depresión/Manejo/ ¿Existe la posibilidad de recaer en una depresión, aún después de haber hecho un tratamiento completo; y de ser así, qué puedo hacer para prevenirla?/ ¿Si yo tengo la enfermedad, hay riesgos para mis hijos?/ ¿Puedo tomar la medicina indicada sólo cuando me sienta triste o debo tomarla todos los días?/ ¿Por canto tiempo debo tomar la medicina? ¿Puedo tomar bebidas alcohólicas si estoy recibiendo medicación antidepresiva?/ ¿Como familia...

  1. Graphite surveillance in N Reactor

    International Nuclear Information System (INIS)

    Woodruff, E.M.

    1991-09-01

    Graphite dimensional changes in N Reactor during its 24 yr operating history are reviewed. Test irradiation results, block measurements, stack profiles, top of reflector motion monitors, and visual observations of distortion are described. 18 refs., 14 figs., 1 tab

  2. N-substituted iminodiacetic acids

    International Nuclear Information System (INIS)

    Nunn, A.; Loberg, M.

    1982-01-01

    The chemical preparation of several new N-substituted iminodiacetic acid derivatives are described. These compounds when complexed with sup(99m)Tc provide useful radiopharmaceuticals for the external imaging of the hepatobiliary system. (U.K.)

  3. N-(2-Chlorophenyl-2-methylbenzamide

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2008-08-01

    Full Text Available In the structure of the title compound (N2CP2MBA, C14H12ClNO, the conformations of the N—H and C=O bonds are trans to each other. Furthermore, the conformation of the N—H bond is syn to the ortho-chloro group in the aniline ring and the C=O bond is syn to the ortho-methyl substituent in the benzoyl ring, similar to what is observed in 2-chloro-N-(2-chlorophenylbenzamide and 2-methyl-N-phenylbenzamide. The amide group makes almost the same dihedral angles of 41.2 (14 and 42.2 (13° with the aniline and benzoyl rings, respectively, while the dihedral angle between the benzoyl and aniline rings is only 7.4 (3°. The molecules in N2CP2MBA are packed into chains through N—H...O hydrogen bonds.

  4. formación universitaria

    Directory of Open Access Journals (Sweden)

    Viviana Fernández Marcial

    2008-01-01

    Full Text Available Las habilidades informacionales son clave para incrementar la eficacia del proceso de enseñanza-aprendizaje. Esto que es aplicable a todos los niveles de enseñanza es aún más importante para el caso de la educación superior. En su mayoría son los graduados universitarios, quienes tienen el futuro socioeconómico, cultural y político en sus manos. En el marco de la sociedad de la información, el conocimiento de los procesos asociados a la búsqueda, evaluación y uso se erige como la nueva forma de alfabetización sobre la cual descansan los pilares de la sociedad actual y del futuro.

  5. Fecundación Artificial

    Directory of Open Access Journals (Sweden)

    Ochoa. Fidel

    1939-10-01

    Full Text Available Por Fecundación artificial se entiende, la fecundación de una hembra sin el servicio directo del macho, es decir la introducción al aparato genital femenino, del esperma que se ha recogido por medios artificiales. Esta fecundación, practicada en debidas condiciones, tiene el mismo efecto de la fecundación natural, con las ventajas que veremos más adelante. La fecundación artificial permite explotar un reproductor a su máximum de capacidad, ya que se considera, para no hacer cálculos alegres, que un servicio de un caballo puede servir, diluido, por lo menos para cuatro yeguas, según los autores americanos, y para 10 a 15, según otros autores. El toro y el carnero pueden dar esperma suficiente en un servicio para fecundar de 10 a 12 hembras, según,los americanos, y según otros autores, hasta para 40. Los investigadores rusos han podido fecundar hasta 60 vacas con un solo servicio y han logrado con reproductores valiosos, fecundar 10.263 vacas por toro, a pesar de que éstos sólo han servido, durante un periodo de monta de sólo dos meses. Estos mismos han logrado fecundar artificialmente 2.733 ovejas con un solo carnero, y 1.403 con otro Los investigadores americanos han contado 22 servicios a un carnero vigoroso en un periodo de ocho horas, y durante este tiempo produjo esperma suficiente para haber fecundado 200 ovejas artificialmente. La fecundación artificial sirve para evitar la trasmisión de enfermedades que se contagian por el coito, tales como la durina, enfermedad ésta producida por un tripanosoma que por fortuna no existe entre nosotros. A las estaciones de monta llevan con frecuencia hembras afectadas de enfermedades como la vaginitis granulosa de la vaca, que se contagia al toro y de éste a otras hembras. Como el control sanitario de toda hembra llevada al servicio de un reproductor de estas estaciones de monta no siempre puede efectuarse por dificultades de distinta índole, mediante la fecundación artificial

  6. Aristoteles Ve İbn Sînâ’nın Reenkarnasyonu Reddi

    Directory of Open Access Journals (Sweden)

    Hasan Özalp

    2013-06-01

    Full Text Available Bu makalede düşünce tarihinin iki önemli düşünürü Aristoteles ve İbn Sînâ’nın reenkarnasyon/tenasüh hakkındaki görüşlerini inceledik. Her iki düşünürde reenkar-nasyonu reddetmektedir. Konuyu ele almadan önce kaynak olmaları bakımından Aristoteles ve İbn Sînâ’dan önceki bazı filozofların ruh ve reenkarnasyon hakkındaki görüşlerini araştırdık. Daha sonra da her iki filozofun ruh tanımlarım belirledikten sonra reenkarnasyone niçin reddettiklerini ortaya koymaya çalıştık. Nihayetinde görüşlerinde ki benzer ve farklı noktaları tespit için bir karşılaştırma yaptık

  7. 4-Bromo-N-phenylbenzamidoxime

    Directory of Open Access Journals (Sweden)

    Mihaela Cibian

    2009-11-01

    Full Text Available The title compound, C13H11BrN2O, a hydroxyamidine derivative (an amidoxime, was obtained by addition of the corresponding imidoyl chloride to hydroxylamine. The benzene and phenyl rings are twisted from the mean plane of the hydroxyamidine group by 34.4 (1 and 59.2 (1°, respectively. In the crystal structure, intermolecular O—H...N hydrogen bonds link pairs of molecules, forming centrosymmetric dimers.

  8. comunicación humana

    Directory of Open Access Journals (Sweden)

    Constanza Moya Pardo

    2006-01-01

    Full Text Available Este artículo pretende mostrar los planteamientos cognitivos más representativos de la Teoría de la Relevancia propuesta por Spelber & Wilson con respecto al modelo ostensivoinferencial. Este modelo plantea un mecanismo deductivo explícito que da cuenta de los procesos y estrategias que permiten el paso del significado literal a la interpretación pragmática de los mensajes en el proceso de comunicación humana.

  9. N-(4-Chloro-2-nitrophenylmethanesulfonamide

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem Arshad

    2008-10-01

    Full Text Available The title compound, C7H7ClN2O4S, is of interest as a precursor to biologically active substituted quinolines. Its structure resembles those of the previously reported N-phenylmethane sulfonamide and its 4-nitro, 4-fluoro and 4-bromo derivatives, with slightly different geometric parameters. An intramolecular N—H...O hydrogen bond gives rise to a six-membered ring. Intermolecular C—H...O contacts stabilize the crystal packing.

  10. Hidden supersymmetry and large N

    International Nuclear Information System (INIS)

    Alfaro, J.

    1988-01-01

    In this paper we present a new method to deal with the leading order in the large-N expansion of a quantum field theory. The method uses explicitly the hidden supersymmetry that is present in the path-integral formulation of a stochastic process. In addition to this we derive a new relation that is valid in the leading order of the large-N expansion of the hermitian-matrix model for any spacetime dimension. (orig.)

  11. SYNTHESIS AND STRUCTURAL FEATURES OF NOVEL VANADIUM(II) AMIDES - X-RAY STRUCTURES OF OCTAHEDRAL [(2-C5H4N)(CH3)N]2V(TMEDA) (TMEDA=N,N,N',N'-TETRAMETHYLETHYLENEDIAMINE) AND SQUARE-PYRAMIDAL [2,5-(CH3)2C4H2N]2V(PY)3 (PY=PYRIDINE)

    NARCIS (Netherlands)

    EDEMA, JJH; GAMBAROTTA, S; MEETSMA, A; SPEK, AL; VELDMAN, N

    1991-01-01

    The reaction of trans-(TMEDA)2VCl2 (TMEDA = N,N,N',N'-tetramethylethylenediamine) with both mono- and bidentate alkali-metal amides has been investigated. Utilization of 2 equiv of bidentate amide (N segment N)-M [M = Li, Na; N segment N = 2-?? (MeN)C5H4N (1), PhNNNPh (2), 7-azaindolyl (3),

  12. ENFERMEDAD CELIACA: REVISIÓN

    Directory of Open Access Journals (Sweden)

    FELIPE MOSCOSO J., DR.

    2015-09-01

    Full Text Available La Enfermedad Celiaca (EC tiene una prevalencia cercana al 1% de la población general y se considera que hay un número importante de pacientes asintomáticos no diagnosticados. Su presentación clínica es variable comprendiendo el clásico síndrome de malabsorción, formas menores y la EC silente. El diagnóstico serológico tiene una elevada sensibilidad y especificidad y siempre debe confirmarse con biopsia. El diagnóstico en pacientes en dieta libre de gluten incluye test de tipificación de HLA y prueba de dieta con gluten con estudio serológico e histológico posterior. El pilar del tratamiento es la dieta libre de gluten, que debe ser supervisada por un nutriólogo con experiencia. La monitorización de la terapia debe realizarse con serología. La EC mal controlada puede determinar complicaciones como linfoma y adenocarcinoma de intestino delgado. En el futuro es probable que nuevas terapias farmacológicas sean de utilidad en el manejo de la EC.

  13. DEPRESIÓN EN ANCIANOS

    Directory of Open Access Journals (Sweden)

    Diana Marcela Peña Solano

    2009-10-01

    Full Text Available La depresión en personas mayores de 65 años tiene una alta prevalencia y produce un impacto negativo en la calidad de vida. Dentro de los factores de riesgo se destacan: duelo, trastornos del sueño, discapacidad, episodio depresivo previo, género femenino, demencia y condiciones médicas crónicas. Los ancianos deprimidos muestran menos ánimo triste, más ansiedad y más quejas somáticas que los jóvenes con la misma patología. El pronóstico es en general pobre, pues este trastorno en los ancianos presenta mayor tasa de recaídas y mayor mortalidad general que en las personas de otras edades. La selección del tratamiento farmacológico requiere la individualización del paciente, la consideración de sus condiciones médicas asociadas y una cuidadosa evaluación del perfil de efectos adversos e interacciones medicamentosas. En este artículo se hace una revisión de la literatura, centrada en los aspectos clínicos concernientes a la epidemiología, diagnóstico, pronóstico y tratamiento de este trastorno, apoyada en las bases de datos electrónicas Medline y Lilacs.

  14. Nuevo León

    Directory of Open Access Journals (Sweden)

    Laura Nelly Medellín Mendoza

    2006-01-01

    Full Text Available El ensayo analiza la transición política nuevoleonesa a partir de un contexto de liberalización política. En Nuevo León el régimen político autoritario fue cediendo en el plano electoral, dada la presión que conjuntamente la sociedad política y la sociedad civil ejercieron por lograr reglas democráticas. Este avance gradual permitió garantizar un organismo electoral confiable y que determinó en buena medida la garantía de la alternancia en 1997. El pan fue el partido que capitalizó el bono democrático, pero una vez en la responsabilidad de gobierno, no pudo ampliar el proceso de liberalización política al mediatizar las reformas electorales y no comprometerse para sacar del atolladero legislativo las iniciativas que garantizaban mecanismos de participación ciudadana: referéndum y plebiscito.

  15. FORMACIÓN DEL EZLN

    Directory of Open Access Journals (Sweden)

    Sigfrido Miralles

    2012-04-01

    Full Text Available Se trataba de una organización marxistaleninistade origen urbano y universitario, conun corte militar (no político muy cercano al delas organizaciones guerrilleras de Centro ySudamérica, que se planteaba una guerrilla entérminos muy cercanos al foco guerrillero. Erauna organización compuesta por gente en su mayoría de clase media: profesionales, médicos,profesores universitarios. Se trataba de ungrupo muy pequeño, de una decena, tal vez dosdecenas de personas. Por la peculiaridad delEstado mexicano, solidario con losmovimientos revolucionarios del mundo y porsus relaciones con el campo socialista, estegrupo nunca tuvo apoyos exteriores, nitampoco de los grupos guerrilleros de Centro ySudamérica, ni en cuanto al armamento, ni alentrenamiento, ni al financiamiento. Por esarazón, y por la formación cultural de susmilitantes, ese grupo construyó su teoríapolítica más apegada a la situación de Méxicoque a la doctrina del comunismo internacional.Recurrió a los nombres de la historia deMéxico, de las luchas por la Independencia y dela Revolución de 1910: Hidalgo, Morelos,Guerrero, Zapata.

  16. Local lattice environment of indium in GaN, AlN, and InN

    International Nuclear Information System (INIS)

    Penner, J.

    2007-01-01

    After an introduction to the physical properties of the nitrides, their preparation, and the state of studies on the implantation in the nitrides the experimental method (PAC) applied in this thesis and the data analysis are presented. The next chapter describes then the applied materials and the sample preparation. The following chapters contain the PAC measurements on the annealing behaviout of GaN, AlN, and InN after the implantation as well as dose- and temperature dependent PAC studies. Finally the most important results are summarized

  17. Theoretical and Experimental Studies of N,N-Dimethyl-N'-Picryl-4,4'-Stilbenediamine.

    Science.gov (United States)

    Papper, Vladislav; Wu, Yuanyuan; Kharlanov, Vladimir; Sukharaharja, Ayrine; Steele, Terry W J; Marks, Robert S

    2018-01-01

    N,N-dimethyl-N'-picryl-4,4'-stilbenediamine (DMPSDA) was prepared, purified and crystallised in a form of black lustrous crystals, and its absorption and fluorescence spectra were recorded in cyclohexane, acetonitrile and dimethyl sulfoxide. Non-emissive intramolecular charge transfer state (ICT) was clearly observed in this molecule in all three solvents. Theoretical calculations demonstrating a betaine electronic structure of the trinitrophenyl group in the ground state of the molecule and a charge transfer nature of the long wavelength transition S 0  → S 1 supported the experimental observations of the ICT formation in the molecule.

  18. Interaction between N-methyl-N'-nitro-N-nitrosoguanidine and ultraviolet irradiation on Bacillus subtilis

    International Nuclear Information System (INIS)

    Lotareva, O.V.

    1990-01-01

    The mutagenic interaction between ultraviolet-irradiation and the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine was studied in a repaid-competent and excision-deficient strains of Bacillus subtilis. Pre-exposure to low doses of MNNG with following treatment by low and intermediate doses of UV-light increase the resistance of Bac. subtilis to UV-radiation (antagonistic effect). Probably pre-exposition with MNNG leads to induction of enzymes reparation, UV-damages being controlled with adaptive respons genes

  19. Understanding N timing in corn yield and fertilizer N recovery: An insight from an isotopic labeled-N determination

    Science.gov (United States)

    de Almeida, Rodrigo Estevam Munhoz; Pierozan Junior, Clovis; Lago, Bruno Cocco; Trivelin, Paulo Cesar Ocheuze

    2018-01-01

    Early fertilizer nitrogen (N) application on cover crops or their residues during the off-season is a practice adopted in Brazil subtropical conditions under no-tillage corn (Zea mays L.) systems. However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15N isotope. The N fertilization timings were: (i) oat tillering, (ii) 15 days before corn planting time, over the oat residues, (iii) at corn planting time, (iv) in-season at the three-leaf growth stage (V3), and (v) in-season split application at V3 and six-leaf (V6) growth stages. Based on the statistical analysis, the N fertilization timings were separated into three groups: 1) N-OATS, designated to N applied at oat; 2) N-PLANT, referred to pre-plant and planting N applications; and 3) N-CORN, designated to in-season corn N applications. Corn yield was not affected by the N fertilization timing. However, the N-CORN N fertilization timings enhanced NRE by 17% and 35% and final N recovery system (plant plus soil) by 16% and 24% all relative to N-OATS and N-PLANT groups, respectively. Overall, N-OATS resulted in the largest N derived from fertilizer (NDFF) amount in the deeper soil layer, in overall a delta of 10 kg N ha-1 relative to the rest of the groups. Notwithstanding corn yield was not affected, early N fertilization under subtropical conditions is not a viable option since NRE was diminished and the non-recovery N increased relative to the in-season N applications. PMID:29462178

  20. Understanding N timing in corn yield and fertilizer N recovery: An insight from an isotopic labeled-N determination.

    Science.gov (United States)

    Maciel de Oliveira, Silas; Almeida, Rodrigo Estevam Munhoz de; Ciampitti, Ignacio A; Pierozan Junior, Clovis; Lago, Bruno Cocco; Trivelin, Paulo Cesar Ocheuze; Favarin, José Laércio

    2018-01-01

    Early fertilizer nitrogen (N) application on cover crops or their residues during the off-season is a practice adopted in Brazil subtropical conditions under no-tillage corn (Zea mays L.) systems. However, the effect of early N application on yield, plant N content, and N recovery efficiency (NRE) for corn is not yet well documented. Five fertilizer N timings in an oat-corn system were evaluated in two studies utilizing an isotopic-labeled N determination, 15N isotope. The N fertilization timings were: (i) oat tillering, (ii) 15 days before corn planting time, over the oat residues, (iii) at corn planting time, (iv) in-season at the three-leaf growth stage (V3), and (v) in-season split application at V3 and six-leaf (V6) growth stages. Based on the statistical analysis, the N fertilization timings were separated into three groups: 1) N-OATS, designated to N applied at oat; 2) N-PLANT, referred to pre-plant and planting N applications; and 3) N-CORN, designated to in-season corn N applications. Corn yield was not affected by the N fertilization timing. However, the N-CORN N fertilization timings enhanced NRE by 17% and 35% and final N recovery system (plant plus soil) by 16% and 24% all relative to N-OATS and N-PLANT groups, respectively. Overall, N-OATS resulted in the largest N derived from fertilizer (NDFF) amount in the deeper soil layer, in overall a delta of 10 kg N ha-1 relative to the rest of the groups. Notwithstanding corn yield was not affected, early N fertilization under subtropical conditions is not a viable option since NRE was diminished and the non-recovery N increased relative to the in-season N applications.

  1. CONFECCIONES: MODELACIÓN Y SIMULACIÓN

    Directory of Open Access Journals (Sweden)

    Paola A. Sánchez

    2015-01-01

    Full Text Available Multiple rainfall-landslides relationships have been proposed for early warning systems in the world. This work presents a data base that synthesizes the state of the art of rainfall thresholds that generates mass movements in the entire world. The more common rainfall-landslides relationships are processed in order to analyze data in function of the Köppen climatic classification and the area for which it was proposed. The results show a wide range of parameters derived from rainfall that triggers landslides together with considerable differences between threshold values. Data analysis shows the necessity to obtain parameters and thresholds derived from the rainfall that generate landslides for each specific geographical and climatic zone. For that reason, it is possible to generate a rational background that allows us to establish early warning systems of landslides caused by rainfall with low variability. This work provides insights into the catalog of possible parameters derived from rainfall records that allow us to generate thresholds to predict the landslides occurrence. Researchers will have the possibility to search for rainfall-landslide relationships based on statistical analysis, with a wide spectrum of parameters, beyond the traditional variables of antecedent rainfall and the intensity occurred the day El modelado y simulación de pequeños sistemas industriales ha adquirido gran importancia en los procesos de toma de decisiones, toda vez que les permite a microempresas fundamentar sus decisiones de producción. Este artículo hace un análisis de una empresa dedicada a la confección de ropa exterior masculina con una producción semanal promedio de 490 prendas. La motivación del estudio radica en el interés de incrementar su productividad; por esto, se desarrolló un modelo del sistema real con la herramienta Arena®, logrando identificar las partes de los procesos responsables de atrasos y “cuellos de botella” que

  2. Polarization-enhanced InGaN/GaN-based hybrid tunnel junction contacts to GaN p-n diodes and InGaN LEDs

    Science.gov (United States)

    Mughal, Asad J.; Young, Erin C.; Alhassan, Abdullah I.; Back, Joonho; Nakamura, Shuji; Speck, James S.; DenBaars, Steven P.

    2017-12-01

    Improved turn-on voltages and reduced series resistances were realized by depositing highly Si-doped n-type GaN using molecular beam epitaxy on polarization-enhanced p-type InGaN contact layers grown using metal-organic chemical vapor deposition. We compared the effects of different Si doping concentrations and the addition of p-type InGaN on the forward voltages of p-n diodes and light-emitting diodes, and found that increasing the Si concentrations from 1.9 × 1020 to 4.6 × 1020 cm-3 and including a highly doped p-type InGaN at the junction both contributed to reductions in the depletion width, the series resistance of 4.2 × 10-3-3.4 × 10-3 Ω·cm2, and the turn-on voltages of the diodes.

  3. Polarization-enhanced InGaN/GaN-based hybrid tunnel junction contacts to GaN p–n diodes and InGaN LEDs

    KAUST Repository

    Mughal, Asad J.

    2017-11-27

    Improved turn-on voltages and reduced series resistances were realized by depositing highly Si-doped n-type GaN using molecular beam epitaxy on polarization-enhanced p-type InGaN contact layers grown using metal–organic chemical vapor deposition. We compared the effects of different Si doping concentrations and the addition of p-type InGaN on the forward voltages of p–n diodes and light-emitting diodes, and found that increasing the Si concentrations from 1.9 × 1020 to 4.6 × 1020 cm−3 and including a highly doped p-type InGaN at the junction both contributed to reductions in the depletion width, the series resistance of 4.2 × 10−3–3.4 × 10−3 Ωcenterdotcm2, and the turn-on voltages of the diodes.

  4. Polarization-enhanced InGaN/GaN-based hybrid tunnel junction contacts to GaN p–n diodes and InGaN LEDs

    KAUST Repository

    Mughal, Asad J.; Young, Erin C.; Alhassan, Abdullah I.; Back, Joonho; Nakamura, Shuji; Speck, James S.; DenBaars, Steven P.

    2017-01-01

    Improved turn-on voltages and reduced series resistances were realized by depositing highly Si-doped n-type GaN using molecular beam epitaxy on polarization-enhanced p-type InGaN contact layers grown using metal–organic chemical vapor deposition. We compared the effects of different Si doping concentrations and the addition of p-type InGaN on the forward voltages of p–n diodes and light-emitting diodes, and found that increasing the Si concentrations from 1.9 × 1020 to 4.6 × 1020 cm−3 and including a highly doped p-type InGaN at the junction both contributed to reductions in the depletion width, the series resistance of 4.2 × 10−3–3.4 × 10−3 Ωcenterdotcm2, and the turn-on voltages of the diodes.

  5. Synthesis and tribological properties of antimony N, N-diethanoldithiocarbamate

    Institute of Scientific and Technical Information of China (English)

    李丽; 黄可龙; 瞿龙; 舒万艮

    2001-01-01

    Antimony N, N-diethanoldithiocarbamate was synthesized with diethanolamine, antimony trioxide and carbon disulfide. The influences of temperature, reaction time, solvents and their dosages were investigated, and the optimum synthesis conditions were: reaction temperature 15~20 ℃, reaction time 2.5 h, 250 mL CH3OH as solvent and the hot CH3OH as recrystallization solvent. Element analysis, IR, 1HNMR and 13CNMR spectra were used to study its chemical composition and molecular structure. Antimony N, N-diethanol-dithiocarbamate was added in the base oil, and its properties of wear resistance and extreme pressure were studied by FB, FD and WSD. The synthesis product behaves per fectly as wear resistance and extreme pressure additive and its extreme pressure property is superior to its wear resistance property. The mechanism of tribological action was discussed by using XPS and AES spectra, and the reason of good wear resistance and extreme pressure properties is that the synthesis product decompose element C, S and N.

  6. Unified model studies of N = 84 and N = 80 nuclei

    International Nuclear Information System (INIS)

    Corrigan, T.M.

    1977-12-01

    The unified model which couples two valence nucleons to collective quadrupole surface vibrations is applied to the N = 84 and N = 80 nuclei which have respectively two neutrons and two neutron holes outside the closed N = 82 core. Two different interactions between these valence nucleons are considered. The first is a simple pairing interaction, and the second used matrix elements determined in a bare G matrix calculation. The simple pairing force gives much better results. A two step diagonalization is employed to treat the core and valence nucleons consistently. Up to four phonons are retained in the collective basis and the diagonalized (coupled) valence nucleon space is truncated at approximately the same energy. The experimental spectra and electromagnetic properties are well reproduced for both types of nuclei, and in the N = 84 nuclei the four phonon contribution was found to be nonnegligible. In addition, a closed form, multiplicity resolved expression for matrix elements of α (the collective surface coordinate) is presented, and a table of these values for N less than or equal to 6 is given

  7. LA OBSERVACIÓN E INTERPRETACIÓN DEL PAISAJE

    Directory of Open Access Journals (Sweden)

    Antonio Sanchez ogallar

    1997-12-01

    Full Text Available La contribución de la Didáctica de laGeografía a la enseñanza-aprendizaje de losnuevos contenidos relativos al paisaje en laEducación Obligatoria debe partir de una profundareflexión sobre los dos grandes pilaresen los que se asienta la reforma establecida porla LOGSE: las fuentes del currículo y los elementosdel mismo.La fuente sociocultural, que nos sitúa en lasactuales coordenadas espacio-temporales, nosinvita al análisis de la organización social, losvalores imperantes y la concienciación sobreel desarrollo tecnológico a la búsqueda de undiagnostico sobre los problemas ambientalesque justifica la necesidad de un desarrollo sostenibley a considerar el proceso educativocomo pieza clave para preservar y mejorar loque Ritter llamó "el cuerpo de la Humanidad",refiriéndose a la Tierra, de la que los hombresserían "el alma"(ESTÉBANEZ 1982

  8. INTERPRETACIÓN E INTEGRACIÓN NORMATIVA

    Directory of Open Access Journals (Sweden)

    Eleonora del Pilar Salazar Londoño

    2012-01-01

    Full Text Available El objetivo del presente artículo es reflexionar sobre el fenómeno de la interpretación en la norma jurídica. Por esta razón, se construye un diálogo con diversos horizontes teóricos que se sitúan entre los teóricos del derecho de un pensamiento iuspositivista e iusnaturalista, dentro de teorías constructivistas, como Dworkin y Hart, teoría argumentativa como Alexy y Habermas, positivistas puros como Kelsen, entre otros. Todos alimentan el discurso hermenéutico con nuevos conceptos de interpretación, como nuevas tendencias de interpretaciones jurídicas. El diálogo entre los teóricos se direcciona a través de preguntas para resolver el problema de la interpretación en el tema de los principios y la integración normativa.

  9. SU(N) Irreducible Schwinger Bosons

    OpenAIRE

    Mathur, Manu; Raychowdhury, Indrakshi; Anishetty, Ramesh

    2010-01-01

    We construct SU(N) irreducible Schwinger bosons satisfying certain U(N-1) constraints which implement the symmetries of SU(N) Young tableaues. As a result all SU(N) irreducible representations are simple monomials of $(N-1)$ types of SU(N) irreducible Schwinger bosons. Further, we show that these representations are free of multiplicity problems. Thus all SU(N) representations are made as simple as SU(2).

  10. Protección contra la contaminación acústica de Aragón.

    OpenAIRE

    Aragón.

    2011-01-01

    Contiene: la Ley 7/2010 de 18 de noviembre de Protección Contra la Contaminación Acústica de Aragón. Incluye (p. [111]-152): Ordenanza municipal tipo de Aragón en materia de contaminación acústica.

  11. Some topics concerning N--N and N--D experiments at medium energy

    International Nuclear Information System (INIS)

    Simmons, J.E.

    1975-01-01

    The status of recent proton-proton phase shift analyses is reviewed at medium energy with mention of the state of the n-p I = 0 analyses. Some conclusions are reached, including a recommendation for renewed theoretical effort to calculate absorption parameters for N--N scattering above 300 MeV in higher partial waves (l greater than or equal to 3). Recent experimental data are examined for p-p small angle scattering at 630 MeV and also near 500 MeV. Further small angle experiments on p-p and p-d scattering are deemed desirable. A brief discussion of recent n-p charge exchange experiments is given. Finally, the status of medium to high energy (100 to 2000 MeV) p-d elastic scattering is reviewed with emphasis on back angle scattering and the usefulness of p-d polarization measurements. (1 table, 12 figures, 94 references) (U.S.)

  12. Studies on the obtention and characterization of N,N,N-trimethyl chitosan (TMC)

    International Nuclear Information System (INIS)

    Curti, Elisabete; Campana Filho, Sergio P.

    2001-01-01

    In this work, a study was developed on the obtention of N,N,N-trimethyl chitosan (TMC) aiming the preparation of samples with different average degrees of quaternization under controlled experimental conditions. The effects of previous treatments of chitosan on the reactivity toward its N-alkylation were evaluated and it was concluded that the purification method previously applied to chitosan strongly influenced the reaction yield. The average degrees of quaternization of the TMC samples were determined by nuclear magnetic resonance spectroscopy and they ranged from 4,0% to 22%, depending on the previous treatment to which the chitosan was submitted and on the reaction conditions. It was also concluded that an average degree of quaternization close to 4,0% is already high enough to impart water solubility to this chitosan derivative. (author)

  13. Thermophysical properties of N, N-dimethylacetamide mixtures with n-butanol

    Science.gov (United States)

    Maharolkar, Aruna P.; Murugkar, A. G.; Khirade, P. W.; Mehrotra, S. C.

    2017-09-01

    The refraction, dielectric, viscosity, density, data of the binary mixtures of N, N-dimethylacetamide (DMA) with n-butanol at 308.15 and 313.15 K. The measured parameters used to obtain derived properties like Bruggeman factor, molar refraction and excess static dielectric constant, excess inverse relaxation time, excess molar volume and excess viscosity, excess molar refraction. The variation in magnitude with composition and temperature of these quantities has been used to discuss the type, strength and nature of binary interactions. Results confirm that there are strong hydrogen-bond interactions between unlike molecules of DMA+ n-butanol mixtures and that 1: 1 complexes are formed and strength of intermolecular interaction increases with temperature.

  14. Polarization-induced Zener tunnel diodes in GaN/InGaN/GaN heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xiaodong; Li, Wenjun; Islam, S. M.; Pourang, Kasra; Fay, Patrick [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Xing, Huili; Jena, Debdeep, E-mail: djena@cornell.edu [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Departments of ECE and MSE, Cornell University, Ithaca, New York 14853 (United States)

    2015-10-19

    By the insertion of thin In{sub x}Ga{sub 1−x}N layers into Nitrogen-polar GaN p-n junctions, polarization-induced Zener tunnel junctions are studied. The reverse-bias interband Zener tunneling current is found to be weakly temperature dependent, as opposed to the strongly temperature-dependent forward bias current. This indicates tunneling as the primary reverse-bias current transport mechanism. The Indium composition in the InGaN layer is systematically varied to demonstrate the increase in the interband tunneling current. Comparing the experimentally measured tunneling currents to a model helps identify the specific challenges in potentially taking such junctions towards nitride-based polarization-induced tunneling field-effect transistors.

  15. Detection of N-acetylglycine, N-acetylglycylglycine, and N-acetylglycylglycylglycine by paper chromatography

    International Nuclear Information System (INIS)

    Sokol, H.A.

    1978-06-01

    This paper reports that the developing solvent of Kirchenmayer and Kuffner, n-butanol-acetic acid-water (8:1:10, v/v) can be used to separate and detect N-acetylglycine, N-acetylglycylglycine, and N-acetylglycylglycylglycine. The chromatographic procedure is described. After heating at 100 0 C, the spots could be seen under uv light; acetone-bromocresol green-morpholine can also be used to make the spots show up. The R/sub f/ values are 0.59, 0.43, and 0.33, respectively. This procedure was used to detect these compounds in aqueous solutions of diglycine, triglycine, and tetraglycine, which were used as gamma-radiolysis targets

  16. Polarization-induced Zener tunnel diodes in GaN/InGaN/GaN heterojunctions

    International Nuclear Information System (INIS)

    Yan, Xiaodong; Li, Wenjun; Islam, S. M.; Pourang, Kasra; Fay, Patrick; Xing, Huili; Jena, Debdeep

    2015-01-01

    By the insertion of thin In x Ga 1−x N layers into Nitrogen-polar GaN p-n junctions, polarization-induced Zener tunnel junctions are studied. The reverse-bias interband Zener tunneling current is found to be weakly temperature dependent, as opposed to the strongly temperature-dependent forward bias current. This indicates tunneling as the primary reverse-bias current transport mechanism. The Indium composition in the InGaN layer is systematically varied to demonstrate the increase in the interband tunneling current. Comparing the experimentally measured tunneling currents to a model helps identify the specific challenges in potentially taking such junctions towards nitride-based polarization-induced tunneling field-effect transistors

  17. Enhanced sheet carrier densities in polarization controlled AlInN/AlN/GaN/InGaN field-effect transistor on Si (111

    Directory of Open Access Journals (Sweden)

    J. Hennig

    2015-07-01

    Full Text Available We report on GaN based field-effect transistor (FET structures exhibiting sheet carrier densities of n = 2.9 1013 cm−2 for high-power transistor applications. By grading the indium-content of InGaN layers grown prior to a conventional GaN/AlN/AlInN FET structure control of the channel width at the GaN/AlN interface is obtained. The composition of the InGaN layer was graded from nominally xIn = 30 % to pure GaN just below the AlN/AlInN interface. Simulations reveal the impact of the additional InGaN layer on the potential well width which controls the sheet carrier density within the channel region of the devices. Benchmarking the InxGa1−xN/GaN/AlN/Al0.87In0.13N based FETs against GaN/AlN/AlInN FET reference structures we found increased maximum current densities of ISD = 1300 mA/mm (560 mA/mm. In addition, the InGaN layer helps to achieve broader transconductance profiles as well as reduced leakage currents.

  18. Educación Primaria

    Directory of Open Access Journals (Sweden)

    Maite Serna

    2017-01-01

    Full Text Available Este trabajo surge del interés de evaluar la biblioteca escolar como medio lector, como generadora y aleccionadora de hábitos lectores. Pretende responder a la cuestión de si las directrices que rigen las actuaciones en torno a la lectura de las bibliotecas escolares de Bizkaia, en el País Vasco, son convenientes y fructíferas. Con este objetivo, primero se ha realizado un análisis detallado de los hábitos lectores y las percepciones sobre la importancia de la lectura que tienen los escolares y sobre quién los induce. Posteriormente hemos elaborado un estudio diagnóstico de las bibliotecas de centros de Educación Primaria, analizando su trabajo como agente lector y su integración e implicación con la comunidad educativa. Y finalmente se ha establecido la relación de los dos análisis anteriores para ver hasta qué punto la existencia de una biblioteca escolar favorece o no los hábitos lectores, concluyendo, por una parte, que la actitud y el estímulo familiar son elementos básicos para favorecer los hábitos lectores y, por otra, que la mera presencia de una biblioteca escolar en el centro no es suficiente para mejorar hábitos o valoración de la lectura, sino que la clave está en el tipo de biblioteca que trabaja con los escolares.

  19. GaN-based ultraviolet light-emitting diodes with AlN/GaN/InGaN multiple quantum wells.

    Science.gov (United States)

    Chang, Hung-Ming; Lai, Wei-Chih; Chen, Wei-Shou; Chang, Shoou-Jinn

    2015-04-06

    We demonstrate indium gallium nitride/gallium nitride/aluminum nitride (AlN/GaN/InGaN) multi-quantum-well (MQW) ultraviolet (UV) light-emitting diodes (LEDs) to improve light output power. Similar to conventional UV LEDs with AlGaN/InGaN MQWs, UV LEDs with AlN/GaN/InGaN MQWs have forward voltages (V(f)'s) ranging from 3.21 V to 3.29 V at 350 mA. Each emission peak wavelength of AlN/GaN/InGaN MQW UV LEDs presents 350 mA output power greater than that of the corresponding emission peak wavelength of AlGaN/InGaN MQW UV LEDs. The light output power at 350mA of AlN/GaN/InGaN MQWs UV LEDs with 375 nm emission wavelength can reach around 26.7% light output power enhancement in magnitude compared to the AlGaN/InGaN MQWs UV LEDs with same emission wavelength. But 350mA light output power of AlN/GaN/InGaN MQWs UV LEDs with emission wavelength of 395nm could only have light output power enhancement of 2.43% in magnitude compared with the same emission wavelength AlGaN/InGaN MQWs UV LEDs. Moreover, AlN/GaN/InGaN MQWs present better InGaN thickness uniformity, well/barrier interface quality and less large size pits than AlGaN/InGaN MQWs, causing AlN/GaN/InGaN MQW UV LEDs to have less reverse leakage currents at -20 V. Furthermore, AlN/GaN/InGaN MQW UV LEDs have the 2-kV human body mode (HBM) electrostatic discharge (ESD) pass yield of 85%, which is 15% more than the 2-kV HBM ESD pass yield of AlGaN/InGaN MQW UV LEDs of 70%.

  20. Study on (n,2n) and (n,p) reactions of strontium nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Yiğit, Mustafa, E-mail: mustafayigit@aksaray.edu.tr [Aksaray University, Department of Physics, Faculty of Arts and Science, Aksaray (Turkey); Tel, Eyyup [Osmaniye Korkut Ata University, Department of Physics, Faculty of Arts and Science, Osmaniye (Turkey)

    2015-11-15

    Highlights: • The cross sections for (n,2n) and (n,p) nuclear reactions on {sup 84,86,88,90}Sr target nuclei have been investigated. • The codes ALICE/ASH, PCROSS, CEM03.01, and cross section systematics are carried out in the calculations. • Cross section calculations are given at projectile energy range from the threshold up to 30 MeV. • Obtained results are compared with each other, experimental data, and ENDF/B-VII.1 and TENDL-2014 libraries. - Abstract: The cross sections for (n,2n) and (n,p) nuclear reactions on {sup 84,86,88,90}Sr target nuclei up to 30 MeV from threshold have been investigated. The determination of the cross sections has been done employing the codes ALICE/ASH, PCROSS, CEM03.01 which taking into consideration compound and precompound emissions. Calculations have been performed by using the Weisskopf Ewing model (WEM) of compound reaction mechanism, and the Hybrid model (HM), Geometry Dependent Hybrid model (GDHM) and Full Exciton model (FEM) of precompound reaction mechanism, and Cascade Exciton model (CEM) including Cascade interactions, and the empirical and semi-emipirical systematics. In order to test the theoretical nuclear models, the data obtained from the excitation function calculations are discussed and compared with available experimental values, ENDF/B-VII.1 and TENDL-2014 libraries. Finally the new cross section results calculated in the present paper may be useful for nuclear energy applications.