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Sample records for hollandite natural zirconolite

  1. Cesium incorporation in hollandite-rich multiphasic ceramic waste forms

    Science.gov (United States)

    Tumurugoti, P.; Clark, B. M.; Edwards, D. J.; Amoroso, Jake; Sundaram, S. K.

    2017-02-01

    Hollandite-rich multiphase waste form compositions processed by melt-solidification and spark plasma sintering (SPS) were characterized, compared, and validated for nuclear waste incorporation. Phase identification by x-ray diffraction (XRD) and electron back-scattered diffraction (EBSD) confirmed hollandite as the major phase present in these samples along with perovskite, pyrochlore and zirconolite. Distribution of selected elements observed by wavelength dispersive spectroscopy (WDS) maps indicated that Cs formed a secondary phase during SPS processing, which was considered undesirable. On the other hand, Cs partitioned into the hollandite phase in melt-processed samples. Further analysis of hollandite structure in melt-processed composition by selected area electron diffraction (SAED) revealed ordered arrangement of tunnel ions (Ba/Cs) and vacancies, suggesting efficient Cs incorporation into the lattice.

  2. Radiation damage of hollandite in multiphase ceramic waste forms

    Science.gov (United States)

    Clark, Braeden M.; Tumurgoti, Priyatham; Sundaram, S. K.; Amoroso, Jake W.; Marra, James C.; Shutthanandan, Vaithiyalingam; Tang, Ming

    2017-10-01

    Radiation damage was simulated in multiphase titanate-based ceramic waste forms using an ion accelerator to generate high energy alpha particles (He+) and an ion implanter to generate 7 MeV gold (Au3+) particles. X-ray diffraction and transmission electron microscopy were used to characterize the damaged surfaces and nearby regions. Simulated multiphase ceramic waste forms were prepared using two processing methods: spark plasma sintering and melt-processing. Both processing methods produced ceramics with similar phase assemblages consisting of hollandite-, zirconolite/pyrochlore-, and perovskite-type phases. The measured heavy ion (Au3+) penetration depth was less in spark plasma sintered samples than in melt-processed samples. Structural breakdown of the hollandite phase occurred under He+ irradiation indicated by the presence of x-ray diffraction peaks belonging to TiO2, BaTiO5, and other hollandite related phases (Ba2Ti9O20). The composition of the constituent hollandite phase affected the extent of damage induced by Au3+ ions.

  3. Naturally occurring crystalline phases: analogues for radioactive waste forms

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    Haaker, R.F.; Ewing, R.C.

    1981-01-01

    Naturally occurring mineral analogues to crystalline phases that are constituents of crystalline radioactive waste forms provide a basis for comparison by which the long-term stability of these phases may be estimated. The crystal structures and the crystal chemistry of the following natural analogues are presented: baddeleyite, hematite, nepheline; pollucite, scheelite;sodalite, spinel, apatite, monazite, uraninite, hollandite-priderite, perovskite, and zirconolite. For each phase in geochemistry, occurrence, alteration and radiation effects are described. A selected bibliography for each phase is included.

  4. Solid-state diffusion in amorphous zirconolite

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    Yang, C.; Dove, M. T.; Trachenko, K. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Zarkadoula, E. [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6138 (United States); Todorov, I. T. [STFC Daresbury Laboratory, Warrington WA4 1EP (United Kingdom); Geisler, T. [Steinmann-Institut für Geologie, Mineralogie und Paläontologie, University of Bonn, D-53115 Bonn (Germany); Brazhkin, V. V. [Institute for High Pressure Physics, RAS, 142190 Moscow (Russian Federation)

    2014-11-14

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  5. Stability region of K0.2Na0.8AlSi3O8 hollandite at 22 GPa and 2273 K

    Science.gov (United States)

    Zhou, Youmo; Irifune, Tetsuo; Ohfuji, Hiroaki; Shinmei, Toru; Du, Wei

    2017-01-01

    Lingunite (hollandite with Na contents of 80-85 mol%) discovered in the shock veins of strongly shocked meteorites is an important signature of shock metamorphism. To seek the stability region of lingunite, phase relations in the system KAlSi3O8-NaAlSi3O8 have been investigated by multi-anvil experiments at pressures of 20-23 GPa and temperatures of 1873 and 2273 K. Phase assemblages of hollandite + jadeite + stishovite, hollandite + calcium ferrite-type NaAlSiO4 + stishovite and hollandite single phase have been recovered, depending on the pressure-temperature conditions and the compositions of starting materials. Both pressure and temperature have large effects on the solubility of Na in hollandite, and hollandite with 79 mol% Na, similar to the natural lingunite in terms of Na content, has been firstly synthesized at 22 GPa and 2273 K. The stability region of K0.2Na0.8AlSi3O8 hollandite is comparable to the typical pressure-temperature conditions of the shock veins of strongly shocked meteorites (20-25 GPa and 2273-2500 K).

  6. Phase evolution in zirconolite glass-ceramic wasteforms

    Science.gov (United States)

    Maddrell, Ewan R.; Paterson, Hannah C.; May, Sarah E.; Burns, Kerry M.

    2017-09-01

    The evolution of crystalline phases in a model glass-ceramic wasteform system has been studied as a function of temperature and time. The work has shown that perovskite and sphene form as transient phases before final formation of zirconolite. The study also suggests some evidence for subtle structural transformations within the zirconolite phase.

  7. Trapping of He in intrinsic defects in zirconolite

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    Mulroue, Jack; Watkins, Matthew; Morris, Andrew J. [Department of Physics and Astronomy and The London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT (United Kingdom); Duffy, Dorothy M., E-mail: d.duffy@ucl.ac.uk [Department of Physics and Astronomy and The London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2013-06-15

    Zirconolite (CaZrTi{sub 2}O{sub 7}) is a proposed ceramic for the disposal of plutonium. Density functional theory with the dispersion correction (DFT-D3) has been used to study the behaviour of the He defect in zirconolite. The lowest energy He interstitial site is located in the 〈0 1 0〉 channels and found to have a migration barrier of 1.46 eV. There was a significant charge state dependence on the binding energies of a He atom to the vacancies, with the neutral 5-fold coordinated Ti having the strongest binding followed by the Ca vacancies. Multiple He interstitials were studied to examine if He bubbles were likely to form in bulk zirconolite. It was found that it was unfavourable for He to cluster at the concentrations studied.

  8. Leaching behavior of hollandite ceramics for cesium immobilization

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    Bart, F.; Rabiller, H.; Leturcq, G.; Rigaud, D

    2004-07-01

    Barium hollandite (BaAl{sub 2}Ti{sub 6}O{sub 16}) ceramics are suitable for cesium immobilization by virtue of their loading capacity and high chemical durability. A 5 wt% Cs{sub 2}O-doped Fe-substituted hollandite was synthesized at laboratory scale (100 g), using an alkoxide process. The resulting materials were dense single-phase pellets. Leaching experiments were carried out to assess the chemical durability of this specific hollandite. In pure water at 100 deg C, the measured rate was about 6 x 10{sup -4} g m{sup -2}d{sup -1}. Tests were also conducted under static conditions for 1 year at 90 deg C. Under saturation conditions the mean alteration rate measured between 7 and 30 days dropped to about 8 x 10{sup -5} g m{sup -2}d{sup -1}. The residual rate over longer durations was less than 10{sup -5} g m{sup -2}d{sup -1}. The chemical durability of iron hollandites, loaded with 5 wt% cesium oxide was comparable to that of Synroc hollandite. (authors)

  9. Krypton irradiation damage in Nd-doped zirconolite and perovskite

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    Davoisne, C. [Department of Materials, Imperial College London, London (United Kingdom); LRCS, CNRS-UMR 6007, Universite de Picardie Jules Verne, Amiens (France); Stennett, M.C.; Hyatt, N.C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sheffield (United Kingdom); Peng, N.; Jeynes, C. [Ion Beam Centre, University of Surrey, Guildford (United Kingdom); Lee, W.E., E-mail: w.e.lee@imperial.ac.uk [Department of Materials, Imperial College London, London (United Kingdom)

    2011-08-01

    Understanding the effect of radiation damage and noble gas accommodation in potential ceramic hosts for plutonium disposition is necessary to evaluate their long-term behaviour during geological disposal. Polycrystalline samples of Nd-doped zirconolite and Nd-doped perovskite were irradiated ex situ with 2 MeV Kr{sup +} at a dose of 5 x 10{sup 15} ions cm{sup -2} to simulate recoil of Pu nuclei during alpha decay. The feasibility of thin section preparation of both pristine and irradiated samples by Focused Ion Beam sectioning was demonstrated. After irradiation, the Nd-doped zirconolite revealed a well defined amorphous region separated from the pristine material by a thin (40-60 nm) damaged interface. The zirconolite lattice was lost in the damaged interface, but the fluorite sublattice was retained. The Nd-doped perovskite contained a defined irradiated layer composed of an amorphous region surrounded by damaged but still crystalline layers. The structural evolution of the damaged regions is consistent with a change from orthorhombic to cubic symmetry. In addition in Nd-doped perovskite, the amorphisation dose depended on crystallographic orientation and possibly sample configuration (thin section or bulk). Electron Energy Loss Spectroscopy revealed Ti remained in the 4+ oxidation state but there was a change in Ti coordination in both Nd-doped perovskite and Nd-doped zirconolite associated with the crystalline to amorphous transition.

  10. Krypton and helium irradiation damage in neodymium-zirconolite

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    Gilbert, M., E-mail: m.gilbert@imperial.ac.uk [Centre for Advanced Structural Ceramics, Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Davoisne, C. [Laboratoire de Reactivite et Chimie des Solides, CNRS-UMR 6007, Universite de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens (France); Stennett, M.; Hyatt, N. [Immobilisation Science Laboratory, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Peng, N.; Jeynes, C. [Surrey Ion Beam Centre, Nodus Laboratory, University of Surrey, Guildford, GU2 7XH Surrey (United Kingdom); Lee, W.E. [Centre for Advanced Structural Ceramics, Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

    2011-09-01

    A leading candidate for the immobilisation of actinides, zirconolite's suitability as a potential ceramic host for plutonium disposition, both in storage and geological disposal, has been the subject of much research. One key aim of this study is to understand the effects of radiation damage and noble gas accommodation within the zirconolite material. To this end, a series of ex situ irradiations have been performed on polycrystalline (Ca{sub 0.8}Nd{sub 0.2})Zr(Ti{sub 1.8}Al{sub 0.2})O{sub 7} zirconolite samples. Zirconolite samples, doped with Nd{sup 3+} (as a Pu surrogate) on the Ca-site and charge-balanced by substituting Al{sup 3+} onto the Ti-site, were irradiated with {sup 36}Kr{sup +} (2 MeV) ions at fluences of 1 x 10{sup 14} and 5 x 10{sup 15} cm{sup -2} and {sup 4}He{sup +} (200 keV) ions at fluences of 1 x 10{sup 14}, 5 x 10{sup 15} and 1 x 10{sup 17} cm{sup -2} to simulate the impact of alpha decay on the microstructure. Microstructural analysis revealed no damage present at the lower Kr{sup +} fluence, but that the higher {sup 36}Kr{sup +} fluence rendered the zirconolite completely amorphous. Similarly, evidence of helium accumulation was only seen at the highest {sup 4}He{sup +} fluence (1 x 10{sup 17} cm{sup -2}). Monte Carlo simulations using the TRIM code predict the highest concentration of helium accumulating at a depth of 720 nm, in good agreement with the experimental observations.

  11. Swelling induced by alpha decay in monazite and zirconolite ceramics: A XRD and TEM comparative study

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    Deschanels, X., E-mail: xavier.deschanels@cea.fr [ICSM, UMR 5257, BP 17171, F-30207 Bagnols-sur-Cèze (France); Seydoux-Guillaume, A.M., E-mail: anne-magali.seydoux@get.obs-mip.fr [GET, UMR 5563CNRS, UPS, IRD, OMP-14 Avenue Édouard Belin, F-31400 Toulouse (France); Magnin, V. [ISTerre, UMR 5275, BP53, F-38041 Grenoble (France); Mesbah, A. [ICSM, UMR 5257, BP 17171, F-30207 Bagnols-sur-Cèze (France); Tribet, M. [CEA/DTCD/LMPA Centre de Marcoule, BP 17171, F-30207 Bagnols-sur-Cèze (France); Moloney, M.P. [ICSM, UMR 5257, BP 17171, F-30207 Bagnols-sur-Cèze (France); Serruys, Y. [CEA, SRMP, DEN, Lab JANNUS, F-91191 Gif Sur Yvette (France); Peuget, S. [CEA/DTCD/LMPA Centre de Marcoule, BP 17171, F-30207 Bagnols-sur-Cèze (France)

    2014-05-01

    Zirconolite and monazite matrices are potential ceramics for the containment of actinides (Np, Cm, Am, Pu) which are produced over the reprocessing of spent nuclear fuel. Actinides decay mainly through the emission of alpha particles, which in turn causes most ceramics to undergo structural and textural changes (amorphization and/or swelling). In order to study the effects of alpha decays on the above mentioned ceramics two parallel approaches were set up. The first involved the use of an external irradiation source, Au, which allowed the deposited recoil energy to be simulated. The second was based on short-lived actinide doping with {sup 238}Pu, (i.e. an internal source), via the incorporation of plutonium oxide into both the monazite and zirconolite structures during synthesis. In both types of irradiation experiments, the zirconolite samples became amorphous at room temperature with damage close to 0.3 dpa; corresponding to a critical dose of 4 × 10{sup 18} α g{sup −1} (i.e. ∼1.3 × 10{sup 21} keV cm{sup −3}). Both zirconolite samples also showed the same degree of macroscopic swelling at saturation (∼6%), with ballistic processes being the predominant damaging effect. In the case of the monazite however, the macroscopic swelling and amorphization were dependent on the nature of the irradiation. Externally, (Au), irradiated samples became amorphous while also demonstrating a saturation swelling of up to 8%. In contrast to this, the swelling of the {sup 238}Pu doped samples was much smaller at ∼1%. Also, unlike the externally (Au) irradiated monazite these {sup 238}Pu doped samples remained crystalline up to 7.5 × 10{sup 18} α g{sup −1} (0.8 dpa). XRD, TEM and swelling measurements were used to fully characterize and interpret this behavior. The low swelling and the conservation of the crystalline state of {sup 238}Pu doped monazite samples indicates that alpha annealing took place within this material.

  12. Modulation mechanism and disorder structure in hollandite-type crystals

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    Wu Xiaojing; Fujiki, Yoshiki; Horiuchi, Shigeo (National Inst. for Research in Inorganic Materials, Ibaraki (Japan)); Ishigame, Mareo (Research Inst. for Scientific Measurements, Tohoku Univ., Sendai (Japan))

    1991-07-01

    The structural modulation in some hollandite-type crystals is explained by a vacancy-displacive modulation model. In this model the large cations located in the tetragonal channels along the c axis deviate from the average position to form a modulation wave. Three types of disorder in the initial phase of the modulation wave have been introduced to interpret apparently different diffraction patterns in hollandite-type crystals. A mathematical analysis as well as optical diffraction give results similar to those experimentally observed. High-resolution transmission electron microscope images have been observed to confirm the discussion further. (orig.).

  13. The synthesis and chemical durability of Nd-doped single-phase zirconolite solid solutions

    Science.gov (United States)

    Cai, Xin; Teng, Yuancheng; Wu, Lang; Zhang, Kuibao; Huang, Yi

    2016-10-01

    Nd-doped single-phase zirconolite solid solutions was synthesized by solid-state reaction and following two steps of acid treatment. The phase composition, microstructure, and chemical durability of the zirconolite solid solutions were investigated. About 15 at% Nd was successfully stabilized into the zirconolite. The element mapping images of Ca, Zr, Nd and Ti show that all the elements are almost distributed homogeneously in the zirconolite waste forms. Product Consistency Test (PCT) was conducted under different pH values (pH = 5, 7 and 9) to evaluate the chemical durability of the Nd-doped zirconolite waste forms. The normalized element release rate of Ca (LRCa) in pH = 5 medium is higher than that of pH = 7 and 9, while the LRNd value remains almost unchanged under different pH values. The LRNd value is as low as 10-5 g m-2 d-1 after 42 days.

  14. Pu-doped zirconolite for minor actinide containment

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    Deschanels, X.; Broudic, V.; Jegou, C.; Peuget, S.; Roudil, D.; Jorion, F.; Advocat, T

    2004-07-01

    Zirconolite is a potential matrix for the immobilization of the minor actinides stream produced by the reprocessing of the spent fuel. In order to check the incorporation of actinide into the structure, zirconolite ceramic pellets doped with 10 wt% in {sup 239}PuO{sub 2} were sintered. Characterization by SEM, XRD and XANES spectroscopy have been done on this material. The microstructural homogeneity of the pellets is good, and their relative density is higher than 90% of the theoretical density. XANES spectroscopy shows that Pu is at the oxidation state IV in this material. To investigate the effects of radiation damage on zirconolite structure, pellets doped with 10 wt% of {sup 238}PuO{sub 2} were fabricated. The {sup 238}Pu accelerates the radiation damage relative to the {sup 239}Pu because of its much higher specific activity (63.2 x 10{sup 10} Bq/g for {sup 238}Pu vs. 2.2 x 10{sup 9} Bq/g for {sup 238}Pu). Some pellets are storing at ambient, 250 deg. C and 500 deg C. Up 10{sup 19} {alpha}/cm{sup 3}, the macroscopic swelling of the samples stored at ambient is about 0.5% by 10{sup 18} {alpha}/cm{sup 3}, and the microscopic one near 0.35% by 10{sup 18} {alpha}/cm{sup 3}. Some microcracks are observed on these pellets. The samples started to become amorphous at 10{sup 19} {alpha}/cm{sup 3}. The swelling strongly decreases with the storage temperature of the samples. The leaching rate of {sup 239}Pu doped ceramics measured by Soxhlet tests at 100 deg. C in deionized water appears to be the same as inactive material. (authors)

  15. Reduction and structural modification of zirconolite on He+ ion irradiation

    Science.gov (United States)

    Gupta, Merry; Kulriya, P. K.; Shukla, Rishabh; Dhaka, R. S.; Kumar, Raj; Ghumman, S. S.

    2016-07-01

    The immobilization of minor actinides and alkaline-earth metal is a major concern in nuclear industry due to their long-term radioactive contribution to the high level waste (HLW). Materials having zirconolite, pyrochlore, and perovskite structure are promising candidates for immobilization of HLW. The zirconolite which exhibits high radiation stability and corrosion resistance behavior is investigated for its radiation stability against alpha particles in the present study. CaZrTi2O7 pellets prepared using solid state reaction techniques, were irradiated with 30 keV He+ ions for the ion fluence varying from 1 × 1017 to 1 × 1021 ions/m2. Scanning electron microscopy (SEM) images of the un-irradiated sample exhibited well separated grains with average size of about 6.8 μm. On the ion irradiation, value of the average grains size was about 7.1 μm, and change in the microstructure was insignificant. The X-ray photoelectron spectroscopy (XPS) studies showed a shift in the core level peak position (of Ca 2p, Ti 2p and Zr 3d) towards lower binding energy with respect to pristine sample as well as loss of oxygen was also observed for sample irradiated with the ion fluence of 1 × 1020 ions/m2. These indicate a decrease in co-ordination number and the ionic character of Msbnd O bond. Moreover, core level XPS signal was not detected for sample irradiated with ion fluence of 1 × 1021 ions/m2, suggesting surface damage of the sample at this ion fluence. However, X-ray diffraction (XRD) studies showed that zirconolite was not amorphized even on irradiation up to a fluence order of 1 × 1021 ion/m2. But, significant decrease in peak intensity due to creation of defects and a marginal positive peak shift due to tensile strain induced by irradiation, were observed. Thus, XRD along with XPS investigation suggests that reduction, decrease in co-ordination number, and increase in covalency are responsible for the radiation damage in zirconolite.

  16. Chemical durability of hollandite ceramic for conditioning cesium

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, Frederic [CEA Marcoule, DEN/DTCD/SECM/LCLT, F-30207 Bagnols-sur-Ceze (France)], E-mail: frederic.angeli@cea.fr; McGlinn, Peter [ANSTO, New Illawarra Road, Menai, PMB1, NSW 2234 (Australia); Frugier, Pierre [CEA Marcoule, DEN/DTCD/SECM/LCLT, F-30207 Bagnols-sur-Ceze (France)

    2008-10-15

    The aqueous corrosion behavior of Cs-doped hollandite ceramic (BaCs{sub 0.28}Fe{sub 0.82}Al{sub 1.46}Ti{sub 5.72}O{sub 16}) was studied using several different static experimental protocols, with leachants of varying pH, and at different surface area to volume ratios, for periods ranging from six months to three years. All leach tests were carried out at 90 deg. C. X-ray diffraction (XRD) and scanning electron microscopy (SEM), coupled with energy dispersive X-ray spectroscopy (EDS), were used to characterize the surfaces of the hollandite before and after leaching. The most pronounced elemental releases, and corresponding changes to surface composition and microstructure, was evident at low pH, in particular pH 1. Cs and Ba releases were highest at low pH, with surface alteration exhibited by the formation of secondary rutile (prevalent at pH 1) and Al- and Ba-depleted hollandite (prevalent at pH 2). After rapid initial Cs release, the alteration rate was extremely low over the pH range from 2 to 10, as well as in pure water experiments with a sample-surface-area-to-solution-volume ratio ranging from 0.1 cm{sup -1} to 1200 cm{sup -1}. The rates were about 10{sup -5} g m{sup -2} d{sup -1}, corresponding to alteration thicknesses of a few nanometers per year. Higher rates (5 x 10{sup -3} g m{sup -2} d{sup -1}) were observed only under very acidic conditions (pH 1). Congruency in Cs and Ba releases occurred only at pH 1, with incongruency between the two elements increasing with increasing pH. There were no apparent solubility constraints on Cs releases regardless of the SA/V ratio, whereas geochemical modeling suggested that Ba releases could have been affected by the formation of BaCO{sub 3}, particularly at high SA/V ratios. Extended leaching (with the leachant renewed once after 261 days of leaching) confirmed the high durability of hollandite with altered thicknesses of less than one nanometer per year over the last two years. Whilst Cs depletion of the

  17. Chemical durability of hollandite ceramic for conditioning cesium

    Science.gov (United States)

    Angeli, Frédéric; McGlinn, Peter; Frugier, Pierre

    2008-10-01

    The aqueous corrosion behavior of Cs-doped hollandite ceramic (BaCs 0.28Fe 0.82Al 1.46Ti 5.72O 16) was studied using several different static experimental protocols, with leachants of varying pH, and at different surface area to volume ratios, for periods ranging from six months to three years. All leach tests were carried out at 90 °C. X-ray diffraction (XRD) and scanning electron microscopy (SEM), coupled with energy dispersive X-ray spectroscopy (EDS), were used to characterize the surfaces of the hollandite before and after leaching. The most pronounced elemental releases, and corresponding changes to surface composition and microstructure, was evident at low pH, in particular pH 1. Cs and Ba releases were highest at low pH, with surface alteration exhibited by the formation of secondary rutile (prevalent at pH 1) and Al- and Ba-depleted hollandite (prevalent at pH 2). After rapid initial Cs release, the alteration rate was extremely low over the pH range from 2 to 10, as well as in pure water experiments with a sample-surface-area-to-solution-volume ratio ranging from 0.1 cm -1 to 1200 cm -1. The rates were about 10 -5 g m -2 d -1, corresponding to alteration thicknesses of a few nanometers per year. Higher rates (5 × 10 -3 g m -2 d -1) were observed only under very acidic conditions (pH 1). Congruency in Cs and Ba releases occurred only at pH 1, with incongruency between the two elements increasing with increasing pH. There were no apparent solubility constraints on Cs releases regardless of the SA/ V ratio, whereas geochemical modeling suggested that Ba releases could have been affected by the formation of BaCO 3, particularly at high SA/ V ratios. Extended leaching (with the leachant renewed once after 261 days of leaching) confirmed the high durability of hollandite with altered thicknesses of less than one nanometer per year over the last two years. Whilst Cs depletion of the hollandite surface was evidenced when leachates were replenished with the

  18. Excess Pu disposition in zirconolite-rich Synroc containing nepheline

    Energy Technology Data Exchange (ETDEWEB)

    Vance, E.R.; Hart, K.P.; Day, R.A.; Begg, B.D.; Angel, P.J.; Loi, E.; Weir, J. [ANSTO, Menai, New South Wales (Australia); Oversby, V.M. [Lawrence Livermore Nation Lab., CA (United States)

    1996-08-01

    A titanate Synroc ceramic for the immobilization of Pu-bearing waste was designed to consist of 70 wt% zirconolite (CaZrTi{sub 2}O{sub 7}) + 15 wt% nepheline (NaAlSiO{sub 4}) + 15 wt% rutile (TiO{sub 2}). It contained 10 wt% of Pu plus 6 wt% of Gd as a neutron poison. The material was made by the standard sol-gel route, using a mixture of alkoxides and nitrates, followed by stir-drying and calcination. It was fabricated by hot-pressing at 1,150--1,250 C/20 MPa for 2 hours in a collapsible metal bellows. Though zirconolite was the majority phase, {approximately} 20 wt% of perovskite also formed. Some of the Na, intended for nepheline, partitioned into the titanate phases. 84-day differential total leach rates of Pu were in the order of 10{sup {minus}5} g/m{sup 2}/d at 90 and 200 C. Companion ceramics using molar substitution of Ce for Pu confirmed the idea that Ce is a good simulant of Pu from a solid state chemical view, but that there are limitations in terms of leach rate parallels.

  19. Crystal Structures of Al-Nd Codoped Zirconolite Derived from Glass Matrix and Powder Sintering.

    Science.gov (United States)

    Liao, Chang-Zhong; Shih, Kaimin; Lee, William E

    2015-08-03

    Zirconolite is a candidate host for immobilizing long-lived radionuclides. Zirconolite-based glass-ceramics in the CaO-SiO2-Al2O3-TiO2-ZrO2-Nd2O3-Na2O matrix are a potential waste form for immobilizing actinide radionuclides and can offer double barriers to immobilize radioactive elements. However, the X-ray diffraction patterns of the zirconolite derived from the glass matrix (glass ceramic, GC) are significantly different from those prepared by powder sintering (PS). In this Article, the crystal structures of Al-Nd codoped zirconolite grown via the glass matrix route and the powder sintering route are investigated in detail. Two samples of Al-Nd codoped zirconolite were prepared: one was grown from a CaO-SiO2-Al2O3-TiO2-ZrO2-Nd2O3-Na2O glass matrix, and the other was prepared with a Ca0.75Nd0.25ZrTi1.75Al0.25O7 composition by powder sintering. The samples were then characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX), and selected area electron diffraction (SAED). The chemical composition of the 100-500 nm zirconolite crystals grown from a glass matrix was determined by TEM-EDX to be Ca0.83Nd0.25Zr0.85Ti1.95Al0.11O7. PXRD and SAED results showed that these two Al-Nd codoped zirconolite phases were crystallized in space group C12/c1. The HRTEM images and SAED results showed that there were heavy stacking faults in the zirconolite crystals grown from the glass matrix. In contrast, far fewer defects were found in the zirconolite crystals prepared by powder sintering. The split-atom model was adopted for the first time to construct the Al-Nd codoped zirconolite structure grown from glass during the Rietveld refinement. The isostructural method assisted by Rietveld refinement was used to resolve the Al-Nd codoped zirconolite structures prepared by different methods. The occupancies of the cation sites were identified, and the distribution behavior of Nd

  20. Radiation damage effects in pyrochlore and zirconolite ceramic matrices for the immobilization of actinide-rich wastes

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    Lumpkin, G.R.; Begg, B.D.; Smith, K.L. [Materials Div., Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia)

    2000-07-01

    Actinide-doping experiments using short-lived {sup 238}Pu and {sup 244}Cm have demonstrated that pyrochlore and zirconolite become fully amorphous at a dose of 0.2-0.5 x 10{sup 16} {alpha}/mg at ambient temperature and exhibit bulk swelling of 5-7%. Detailed studies of natural samples have included determination of the critical amorphization dose, long-term annealing rate, microstructural changes as a function of dose, and the thermal histories of the host rocks. Together, the laboratory based work and studies of natural samples indicate that the critical amorphization dose will increase by about a factor of 2-4 for samples stored at temperatures of 100-200 deg. C for up to 10 million years. These studies of alpha-decay damage have been complemented by heavy ion irradiation studies over the last ten years. Most of the irradiation work has concerned the critical amorphization dose as a function of temperature in thin films; however, some work has been carried out on bulk samples. The irradiation work indicates that most pyrochlore and zirconolite compositions will have similar critical amorphization doses at low temperatures (e.g., below 300-400 deg. C). Pyrochlore with Zr as the major B-site cation transform to a defect fluorite structure with increasing ion irradiation dose, but do not become amorphous. (authors)

  1. The mechanism of the hydrothermal alteration of cerium- and plutonium-doped zirconolite

    Science.gov (United States)

    Pöml, P.; Geisler, T.; Cobos-Sabaté, J.; Wiss, T.; Raison, P. E.; Schmid-Beurmann, P.; Deschanels, X.; Jégou, C.; Heimink, J.; Putnis, A.

    2011-03-01

    A comprehensive study on the aqueous stability of Ce- and Pu-doped zirconolite has been performed. Four series of hydrothermal experiments were carried out with Ce-doped zirconolite powders: (1) a solution series (1 M HCl, 2 M NaCl, 1 M NaOH, 1 M NH 3, pure H 2O), (2) a temperature series ( T = 100-300 °C), (3) a surface area-to-fluid volume ratio series, and (4) a series using different reactor materials (Teflon ©, Ni, and Ag). In addition, experiments on 238Pu- and 239Pu-doped zirconolite ceramics in a 1 M HCl solution have been performed. The 238Pu-doped zirconolite had already accumulated significant radiation damage and was X-ray amorphous, while the 239Pu-doped zirconolite was still well-crystalline. The results of the different experimental series can be summarized as follows: (1) After 14 days the degree of alteration is insignificant for all solutions other than 1 M HCl, which was therefore used for all other experimental series; (2) TiO 2 and m-ZrO 2 replaced the zirconolite grains to varying degrees in the 1 M HCl solution, i.e., zirconolite dissolution is incongruent; (3) the degree of alteration increases only slightly with increasing temperature; (4) the alteration rate is independent on the surface to volume ratio; (5) Ag dissolved from the silver reactors dramatically increases the reaction rate, while Ni from the Ni reactors reduces the solubility of Ti and Zr in the HCl solution, indicating that background electrolytes have a strong effect on the alteration rate. From the experiment with the Pu-doped samples at 200 °C in a 1 M HCl solution it was found that the amorphous 238Pu-doped zirconolite was altered to a significantly greater extent than the crystalline counterparts. The results suggest a coupled dissolution-reprecipitation mechanism, which is discussed in detail.

  2. NaAlSi3O8-hollandite and other high-pressure minerals in the shock melt veins of the Suizhou meteorite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Suizhou L6 chondrite contains a few very thin shock melt veins of 0.02-0.09 mm in width. In spite of small width of the veins, shock-induced high-pressure phases, such as coarse-grained NaAlSi3O8-hollandite, ringwoodite, majorite and fine-grained matrix majorite-pyropess have been discovered in these veins. NaAlSi3O8-hollandite, the high-pressure phase of plagioclase, in Suizhou shock veins occurs as a single phase mineral, no silicate glassy phase, such as albitic glass, was incorporated with it. The presence of above-mentioned high-pressure phases constrains the high pressure (up to 23-24 GPa) and high temperature (up to 1900-2000℃) regime in Suizhou shock veins, and indicates that the duration of high-pressure regime in the veins should be long enough (a few seconds) for phase transformation and crystallization of minerals under pressure. The discovery of the first natural single-phase crystalline NaAlSi3O8- hollan-dite in Suizhou meteorite is of important significance in un-derstanding the Earth's mantle geochemistry.

  3. Long-term behavior of glass-ceramic zirconolite; Etude du comportement a long terme des vitrocristallins a base de zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ch

    2003-07-01

    This work is a part of the investigation of new containment matrices considered for specific conditioning of radionuclides after separation. The aim was to demonstrate the long-term aqueous corrosion resistance of the glass-ceramic zirconolite considered for the conditioning of plutonium and the minor actinides. This material is composed of crystals of zirconolite (CaZrTi{sub 2}O{sub 7}) dispersed in a residual vitreous phase. It appears that glass-ceramic zirconolite presents a better kinetic behavior than the nuclear glass R 7T7. This is mainly due to a more important rate decrease that occurs more rapidly, that induces a quantity of glass altered at least 10 times as small as for R 7T7 glass. This high slowdown of the alteration rate is attributed to the formation of an alteration film that has been the subject of a specific study. We have demonstrated that the rate decrease was controlled as for the R7T7 glass by the amorphous phase of the alteration film forming a diffusion barrier for reactive species. It seems that the porosity is not the single parameter that explains the protective effect of the gel. The main differences compared with R7T7 glass are that silicon does not control the alteration of the material and that the gel is composed of two distinct phases. We have in particular identified a dense phase enriched in titanium and neodymium that probably influences deeply the kinetics. (author)

  4. Intergrowth Structure in U- and Hf-Bearing Pyrochlore and Zirconolite: TEM Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H; Wang, Y; Zhao, P; Bourcier, W L; Van Konynenburg, R; Shaw, H F

    2002-12-04

    Transmission electron microscopy results from a sintered ceramics with stoichiometry of Ca(U{sub 0.5}Ce{sub 0.25}Hf{sub 0.25})Ti{sub 2}O{sub 7} show the material contains both pyrochlore and zirconolite phases and structural intergrowth of zirconolite lamellae within pyrochlore. (001) plane of zirconolite is parallel to (111) plane of pyrochlore because of their structural similarities. The pyrochlore is relatively rich in U, Ce, and Ca with respect to the coexisting zirconolite. Average compositions for the coexisting pyrochlore and zirconolite produced by sintering at 1350 C are (Ca{sub 1.01}Ce{sub 0.13}{sup 3+}Ce{sub 0.19}{sup 4+}U{sub 0.52}Hf{sub 0.18})(Ti{sub 1.95}Hf{sub 0.05})O{sub 7} (with U/(U+Hf) (in the AB sites) = 0.74) and (Ca{sub 0.91}Ce{sub 0.09})(Ce{sub 0.08}{sup 3+}U{sub 0.26}Hf{sub 0.66}Ti{sub 0.01})Ti{sub 2.00}O{sub 7} (with U/(U+Hf) = 0.28) respectively. A single pyrochlore ((Ca,U,Hf){sub 2}Ti{sub 2}O{sub 7}) phase may be synthesized at 1350 C if the ratio of U/(U+Hf) is greater than 0.72, and a single zirconolite (Ca(Hf,U)Ti{sub 2}O{sub 7}) phase may be synthesized at 1350 C if the ratio of U/(U+Hf) is less than 0.28. An amorphous leached layer that is rich in Ti and Hf forms on the surface after the ceramics has been leached in pH 4 buffered solution. The thickness of the layer ranges from 5 nm to 15 nm. It is suggested that under these conditions, the leached layer functions as a protective layer, and reduces the leaching rate over time.

  5. Synthesis and structural and thermodynamical characterization of hollandite type material intended for the specific containment of cesium; Synthese et caracterisation de ceramiques de type hollandite destinees au conditionnement specifique du cecium

    Energy Technology Data Exchange (ETDEWEB)

    Leinekugel-Le-Cocq-Errien, A.Y

    2005-09-15

    This thesis deals with the characterization of the Ba{sub 1}Cs{sub 0.28}Fe{sub 0.82}Al{sub 1.46}Ti{sub 5.72}O{sub 16} hollandite envisaged for Cs containment. Techniques used are essentially classical powder XRD or synchrotron radiation at the absorption threshold of Ba and Cs, TEM and high-temperature calorimetry. Two syntheses have been studied: an alcoxide route and a dry route. After sintering, both routes lead to an incommensurate modulated tetragonal hollandite structure (space group: I4/m(00{gamma})00) with a modulation vector distribution. Before sintering, the material obtained by the alcoxide route is composed of three phases: a tetragonal hollandite like above, a monoclinic Ba-free hollandite and a weak-coherence-length phase containing only Ba. On contrary, the dry route already leads to the tetragonal hollandite at this step of the synthesis. High temperature oxide melt solution calorimetry was used to derive standard enthalpy of formation of hollandite to deduce its free enthalpy of formation. (author)

  6. First-principles prediction of fast migration channels of potassium ions in KAlSi3O8 hollandite: Implications for high conductivity anomalies in subduction zones

    Science.gov (United States)

    He, Yu; Sun, Yang; Lu, Xia; Gao, Jian; Li, Hong; Li, Heping

    2016-06-01

    Materials sharing the hollandite structure were widely reported as fast ionic conductors. However, the ionic conductivity of KAlSi3O8 hollandite (K-hollandite), which can be formed during the subduction process, has not been investigated so far. Here first-principles calculations are used to investigate the potassium ion (K+) transport properties in K-hollandite. The calculated K+ migration barrier energy is 0.44 eV at a pressure of 10 GPa, an energy quite small to block the K+ migration in K-hollandite channels. The calculated ionic conductivity of K-hollandite is highly anisotropic and depends on its concentration of K+ vacancies. About 6% K+ vacancies in K-hollandite can lead to a higher conductivity compared to the conductivity of hydrated wadsleyite and ringwoodite in the mantle. K+ vacancies being commonly found in many K-hollandite samples with maximum vacancies over 30%, the formation of K-hollandite during subduction of continental or alkali-rich oceanic crust can contribute to the high conductivity anomalies observed in subduction zones.

  7. Self-propagating synthesis of Nd2O3-incorporated zirconolite/Mo composites and their aqueous durability

    Science.gov (United States)

    Zhang, Kuibao; Yin, Dan; Peng, Le; Wu, Jingjun; Xue, Jiali

    2017-08-01

    In this study, zirconolite/Mo composites were rapidly synthesized by a self-propagation reaction that uses MoO3 as the oxidant accompanied with pressing. Zirconolite is one of the several materials that are being researched as host for lanthanides and actinides in nuclear waste. Nd was used in this study as a surrogate for actinides and was substituted into zirconolite at a stoichiometric ratio to charge balance the Ca and Zr sites (nominal formulation of Ca1-xZr1-xNd2xTi2O7). Perovskite, zirconia, and rutile were generated as the minor phases with the addition of Nd2O3. The XRD results demonstrated that the Nd2O3 loading is approximately 30 wt%. Nd was mainly incorporated into the lattice structure of zirconolite and perovskite. A 42-day leaching test of the Nd-bearing zirconolite/Mo composite showed that the computed normalized leaching rates for Ca and Nd at fairly low values of 9.02 × 10-2 and 2.10 × 10-4 g m-2 d-1, respectively.

  8. Effect of water radiolysis and complexing species on the leaching of zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Tribet, M. [Institut de Physique Nucleaire de Lyon (IPNL), Universite de Lyon, Universite Lyon1, CNRS/IN2P3, 4 Rue E. Fermi, 69622 Villeurbanne cedex (France); CEA/DEN/DTCD.SECM/LMPA, Marcoule, BP 17171, 30207 Bagnols sur Ceze cedex (France); Toulhoat, N. [CEA/DEN/Saclay, 91191 Gif sur Yvette cedex (France); Institut de Physique Nucleaire de Lyon (IPNL), Universite de Lyon, Universite Lyon1, CNRS/IN2P3, 4 Rue E. Fermi, 69622 Villeurbanne cedex (France); Moncoffre, N. [Institut de Physique Nucleaire de Lyon (IPNL), Universite de Lyon, Universite Lyon1, CNRS/IN2P3, 4 Rue E. Fermi, 69622 Villeurbanne cedex (France); Jegou, C.; Leturcq, G. [CEA/DEN/DTCD.SECM/LMPA, Marcoule, BP 17171, 30207 Bagnols sur Ceze cedex (France); Corbel, C. [CEA/DSM/DRECAM/LSI, Ecole Polytechnique, 91 128 Palaiseau (France); Toulhoat, P. [Universite de Lyon, Universite Lyon1, CNRS/ISA, UFR de Chimie Biochimie, 69622 Villeurbanne cedex (France); INERIS, Parc Technologique Alata, BP2 F-60550 Verneuil en Halatte (France)

    2008-07-01

    Zirconolite is one of the matrices considered for the confinement of minor actinides in case of deep geological disposal. Its chemical durability has been studied during dissolution under charged particle-induced water radiolysis (He{sup 2+} and proton external beams) to identify possible effects on dissolution rates and mechanisms. Two experimental geometries have been used to assess the influence of the solid irradiation on one hand and the total deposited energy into water on the other hand. These irradiations have been performed on polycrystalline zirconolite (Ca{sub 0.8}Nd{sub 0.2}ZrTi{sub 1.8}Al{sub 0.2}O{sub 7}) in pure water or in presence of complexing ions such as F{sup -}. The sample dissolution has been monitored through the release of cations. Under radiolysis, an increase in the Zr, Ti and Nd releases of one order of magnitude has been observed compared to results obtained without radiolysis. The presence of complexing species has induced an additional increase of two orders of magnitude in the Ti and Zr releases. (authors)

  9. Competing antiferromagnetic and spin-glass phases in a hollandite structure

    Science.gov (United States)

    Crespo, Y.; Andreanov, A.; Seriani, N.

    2013-07-01

    We introduce a simple lattice model with Ising spins as a zeroth-order approximation of the hollandite-type magnetic compounds. We argue that geometrical frustration of the lattice in combination with nearest-neighbor antiferromagnetic (AFM) interactions are responsible for the appearance of a spin-glass phase in presence of disorder. We investigate this system numerically using parallel tempering. The model reproduces magnetic transitions present in some oxides with hollandite structure and displays a rich phenomenology: in the absence of disorder we have identified five different ground states, depending on the relative strength and sign of the interactions: one ferromagnetically ordered, three antiferromagnetically ordered, and one disordered, macroscopically degenerate ground state. Remarkably, for the sets of AFM couplings having an AFM ground state in the clean system, there exists a critical value of the disorder above which the ground state becomes a spin glass while maintaining all the couplings antiferromagnetically. This model presents this kind of transition with nearest-neighbor frustrated AFM interactions. We argue that this model is useful for understanding the relation between AFM coupling, disorder, and appearance of spin-glass phases.

  10. Fabrication, characterization and radiation damage stability of hollandite based ceramics devoted to radioactive immobilisation; Synthese, caracterisation et etude du comportement sous irradiation electronique de matrices de type hollandite destinees au confinement du cesium radioactif

    Energy Technology Data Exchange (ETDEWEB)

    Aubin-Chevaldonnet, V. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DETCD/SCDV), Dept. d' Etudes du Traitement et du Conditionnement des Dechets, Service de Conditionnement des Dechets et Vitrification, 30 - Marcoule (France)

    2004-11-01

    Research on treating specifically the long-lived and high level nuclear wastes, notably cesium, is currently carried out in France. Cesium immobilization in host matrices of high chemical durability constitutes the favoured option. Hollandite matrix is a good candidate because of its high cesium incorporation ability and its excellent chemical stability. During this study, different compositions of hollandite ceramics Ba{sub x}Cs{sub y}C{sub z}Ti{sub 8-z}O{sub 16} (C = Al{sup 3+}, Cr{sup 3+}, Ga{sup 3+}, Fe{sup 3+}, Mg{sup 2+}, Sc{sup 3+}), synthesized by oxide route, were characterized in terms of structure, microstructure and physical and chemical properties. Iron ions seems to be the most suitable of the studied C cations to get high-performance hollandites. The stability of these ceramics under external electron irradiation, simulating the {beta} particles emitted by radioactive cesium, were also estimated, at the macroscopic and atomic scale. The point defects creation and their thermal stability were followed by electron paramagnetic resonance. (author)

  11. Structural characterization of hollandite-type material intended for the specific containment of cesium

    Energy Technology Data Exchange (ETDEWEB)

    Leinekugel-le-Cocq, A.Y.; Deniard, P.; Jobic, S.; Bart, F.; Evain, M.; Gautier, E

    2004-07-01

    Investigations on the Ba{sub 1}Cs{sub 0.28}Fe{sub 0.82}Al{sub 1.46}Ti{sub 5.72}O{sub 16} hollandite powdered compound, used as potential host for radioactive cesium waste, highlight an incommensurate modulated structure and the presence of an amorphous phase. On XRD pattern, this modulation leads to two wide peaks (2 {theta} =19.5 and 27 angle, {lambda} = 1.54059 A). The space group I4/m(0 0 {gamma}) 0 0 was determined thanks to the X-Ray of single crystal analysis on a simplified Ba{sub 1.16}Al{sub 2.32}Ti{sub 5.68}O{sub 16} material. The electron diffraction confirmed that this result could be transposed to our formulation Ba{sub 1}Cs{sub 0.28}Fe{sub 0.82}Al{sub 1.46}Ti{sub 5.72}O{sub 16}. This material exhibits a distribution of modulation vectors ranging from q = (0 0 0.30) to (0 0 0.48) explaining perfectly the two wide XRD peaks. In addition, an amorphous phase is observed and has been quantified (about 13%wt). (authors)

  12. The Active Sites of a Rod-Shaped Hollandite DeNOx Catalyst.

    Science.gov (United States)

    Hu, Pingping; Schuster, Manfred Erwin; Huang, Zhiwei; Xu, Fei; Jin, Shifeng; Chen, Yaxin; Hua, Weiming; Su, Dang Sheng; Tang, Xingfu

    2015-06-26

    The identification of catalytically active sites (CASs) in heterogeneous catalysis is of vital importance to design and develop improved catalysts, but remains a great challenge. The CASs have been identified in the low-temperature selective catalytic reduction of nitrogen oxides by ammonia (SCR) over a hollandite manganese oxide (HMO) catalyst with a rod-shaped morphology and one-dimensional tunnels. Electron microscopy and synchrotron X-ray diffraction determine the surface and crystal structures of the one-dimensional HMO rods closed by {100} side facets and {001} top facets. A combination of X-ray absorption spectra, molecular probes with potassium and nitric oxide, and catalytic tests reveals that the CASs are located on the {100} side facets of the HMO rods rather than on the top facets or in the tunnels, and hence semi-tunnel structural motifs on the {100} facets are evidenced to be the CASs of the SCR reaction. This work paves the way to further investigate the intrinsic mechanisms of SCR reactions.

  13. Paramagnetic defects induced by electron irradiation in barium hollandite ceramics for caesium storage.

    Science.gov (United States)

    Aubin-Chevaldonnet, V; Gourier, D; Caurant, D; Esnouf, S; Charpentier, T; Costantini, J M

    2006-04-26

    We have studied by electron paramagnetic resonance the mechanism of defect production by electron irradiation in barium hollandite, a material used for immobilization of radioactive caesium. The irradiation conditions were the closest possible to those occurring in Cs storage waste forms. Three paramagnetic defects were observed, independently of the irradiation conditions. A hole centre (H centre) is attributed to a superoxide ion O(2)(-) originating from hole trapping by interstitial oxygen produced by electron irradiation. An electron centre (E(1) centre) is attributed to a Ti(3+) ion adjacent to the resulting oxygen vacancy. Another electron centre (E(2) centre) is attributed to a Ti(3+) ion in a cation site adjacent to an extra Ba(2+) ion in a neighbouring tunnel, originating from barium displacement by elastic collisions. Comparison of the effects of external irradiations by electrons with the β-decay of Cs in storage waste forms is discussed. It is concluded that the latter would be dominated by E(1) and H centres rather than E(2) centres.

  14. Study of the effect of water radiolysis on zirconolite dissolution; Etude de l'effet de la radiolyse de l'eau sur la livixation de la zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Tribet, M

    2007-09-15

    Zirconolite is one of the matrices foreseen for the confinement of minor actinides in case of deep geological disposal. Indeed, zirconolite (general formula: CaZr{sub x}Ti{sub 3-x}O{sub 7} (0.8 {<=} x {<=} 1.37)) is able to incorporate rare earth elements and actinides by substitution in calcium and zirconium sites and, moreover, its chemical durability into water is well known. However, in case of deep geological disposal, after a long period, water can reach the confinement matrix and can be radiolysed at the moment of the radionuclide alpha decays. In this work we have thus studied the effects of water radiolysis induced by charged particles (alphas or protons) on the dissolution of a synthetic sintered zirconolite. The formula of this zirconolite is Ca{sub 0,8}Nd{sub 0,2}ZrTi{sub 1,8}Al{sub 0,2}O{sub 7} where Nd simulates the presence of trivalent and tetravalent actinides. We performed the irradiations with external ion beams in two distinct geometries where the fluences ranged from 10{sup 15} to 10{sup 16} ions.cm{sup -2}. In the first geometry the beam stops into water before the surface/water interface. In the second one the beam gets through the sample before stopping at the surface/water interface. The use of these different configurations allows to study the respective influence of parameters such as sample irradiation, Linear Energy Transfer at the surface/water interface or total deposited energy. The irradiations were performed on both crystalline and amorphous zirconolites in pure water or with complexing species such as F{sup -}. The sample dissolution has been monitored through the release of cations. The radiolytic production of H{sub 2}O{sub 2} has also been measured. Our results show that the water radiolysis has an effect on the preferential release of Zr, Ti and Nd: for these elements, releases are one or two order of magnitude higher than releases out of radiolysis. Such preferential releases occur whatever the temperature (20 or 50 C), the

  15. The CaO-TiO{sub 2}-ZrO{sub 2} system at 1200 C and the solubilities of Hf and Gd in zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, D.; Nieh, T.G. [Lawrence Livermore National Lab., CA (United States). Chemistry and Materials Science; Fournelle, J.H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Geology and Geophysics

    1996-08-01

    Phase equilibria are established in the CaO-TiO{sub 2}-ZrO{sub 2} system at 1,200 C, using X-ray diffraction and electron probe microanalysis. The existence of two previously reported ternary phases, zirconolite (CaZrTi{sub 2}O{sub 7}) and calzirtite (Ca{sub 2}Zr{sub 5}Ti{sub 2}O{sub 16}), is confirmed. Each of these phases exhibits a significant range of homogeneity between TiO{sub 2} and ZrO{sub 2} while maintaining a nearly constant concentration of CaO. The ternary solubilities of the constituent binary phases are found to be negligible, with the exceptions of the perovskites, which display mutual solubility of at least 22 mol.% and may in fact form a series of continuous solid solutions. The solubilities of Hf and Gd in zirconolite are also investigated. While Hf-bearing samples did not reach thermodynamic equilibrium under the experimental conditions employed, the existence of a Hf analog to zirconolite, CaHfTi{sub 2}O{sub 7}, is conclusively demonstrated. The phase is stable at the stoichiometric composition, and its lattice parameters are very close to those reported in the literature for stoichiometric zirconolite. A Gd-bearing sample of the composition Ca{sub 0.88}Zr{sub 0.88}Gd{sub 0.24}Ti{sub 2}O{sub 7} is found to be essentially single phase zirconolite, in agreement with previous investigations at higher temperatures.

  16. Characterization of Pu doped zirconolite by WDS-EPMA. Results of an interlaboratory round-robin test

    Energy Technology Data Exchange (ETDEWEB)

    Deschanels, X.; Roche, C.; Dugne, O. [CEA Marcoule BP 17171, FR-30207 Bagnols sur Ceze (France); Merlet, C. [Universite de Montpellier II, GM, CNRS, Pl. E. Bataillon. FR-34095 Montpellier Cedex 5 (France); Van Renterghem, W. [SCK CEN, Boeretang 200, B-2400 Mol (Belgium); Aufore, L.; Lamontagne, J. [CEA Cadarache, DEN/DEC, FR-13108 St-Paul-Lez-Durance (France); Restani, R. [Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland); Bremier, S. [EC, JRC, Institute for Transuranium Elements, P.O. Box 2340, DE-76125 Karlsruhe (Germany); Llovet, X. [SCT, Universitat de Barcelona. Lluis Sole i Sabarys, 1-3. ES-08028 Barcelona (Spain)

    2008-07-01

    Due to the capability of the technique to analyze quantitatively the elemental composition and its spatial distribution of samples at the micron scale, EPMA (electron probe microanalysis) is well suited for studies of physicochemical behaviour of the actinide elements and fission products in nuclear materials after irradiation. In the generation 4 (fuel, waste, etc..) context, the analytical tools must be optimized and adapted to the future nuclear materials such as carbide and nitride compounds taking into account the quantification of light elements, minor actinides or fission gas products. For that, some European partners have constituted an analytical network on EPMA for Actinide Materials. The paper describes the first results of the collaboration: a round robin on doped Pu Zirconolite and the interest and capability of virtual standard on Pu which is the first step towards standard-less methods in actinide materials. (authors)

  17. Heavy ion irradiations on synthetic hollandite-type materials: Ba1.0Cs0.3A2.3Ti5.7O16 (A=Cr, Fe, Al)

    Science.gov (United States)

    Tang, Ming; Tumurugoti, Priyatham; Clark, Braeden; Sundaram, S. K.; Amoroso, Jake; Marra, James; Sun, Cheng; Lu, Ping; Wang, Yongqiang; Jiang, Ying.-Bing.

    2016-07-01

    The hollandite supergroup of minerals has received considerable attention as a nuclear waste form for immobilization of Cs. The radiation stability of synthetic hollandite-type compounds described generally as Ba1.0Cs0.3A2.3Ti5.7O16 (A=Cr, Fe, Al) were evaluated by heavy ion (Kr) irradiations on polycrystalline single phase materials and multiphase materials incorporating the hollandite phases. Ion irradiation damage effects on these samples were examined using grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM). Single phase compounds possess tetragonal structure with space group I4/m. GIXRD and TEM observations revealed that 600 keV Kr irradiation-induced amorphization on single phase hollandites compounds occurred at a fluence between 2.5×1014 Kr/cm2 and 5×1014 Kr/cm2. The critical amorphization fluence of single phase hollandite compounds obtained by in situ 1 MeV Kr ion irradiation was around 3.25×1014 Kr/cm2. The hollandite phase exhibited similar amorphization susceptibility under Kr ion irradiation when incorporated into a multiphase system.

  18. Thermochemical investigations of zirconolite, pyrochlore and brannerite: Three materials relevant to issues of plutonium immobilization

    Science.gov (United States)

    Helean, Katheryn Bridget

    For the purpose of immobilizing plutonium, a crystalline ceramic waste form is being developed that can be described as a pseudo-quaternary system consisting of CaHfTi2O7- CaPuTi2O7- CaUTi2O7- GdTi2O7. High-temperature oxide melt solution calorimetry offers an effective methodology for the determination of enthalpies of formation of rare earth-bearing and other refractory oxides relevant to the proposed waste form. Calorimetric investigations of the waste form end-member phases (using Ce as a Pu analogue) plus brannerite, the major waste form impurity, were conducted using 3Na2O•4MoO3 solvent at 975 K. Standard enthalpies of formation, DeltaH°f (kJ/mol), were derived for three pyrochlore phases: Ca0.93Ce1.00Ti 2.035O7.00 (-3656.0 +/- 5.6), Ca1.46U 4+0.23U6+0.46Ti1.85O 7.00 (-3610.6 +/- 4.1) and Gd2Ti2O 7 (-3822.5 +/- 4.9). Enthalpies of formation with respect to an oxide phase assemblage, DeltaH°f-ox: CaO+MO2+2TiO2=CaMTi2O7 or Gd 2O3+2TiO2=Gd2Ti2O7 , and an oxide/perovskite phase assemblage, DeltaH° f-pv+ox: CaTiO3+MO2+TiO2=CaMTi 2O7, M = Ce, U were also calculated. DeltaH° f-ox (kJ/mol): Gd2Ti2O7 (-113.4 +/- 2.8); Ca1.46U4+0.23U 6+0.46Ti1.85O7.00 (-123.1 +/- 3.4); Ca0.93Ce1.00Ti2.035O7.00 (-54.1 +/- 5.2). DeltaH°f-pv+ox (kJ/mol): Ca1.46U4+0.23U6+ 0.46Ti1.85O7.00 (-5.1 +/- 4.0); Ca 0.93Ce1.00Ti2.035O7.00 (+21.0 +/- 5.5). A significant metastability field was defined with respect to an oxide/perovskite phase assemblage. DeltaH°f (kJ/mol) were derived for two zirconolite phases: CaZr1.03Ti1.97O7 (-3719.4 +/- 3.9) and CaHf1.02Ti1.98O 7 (-3720.5 +/- 3.9). DeltaH° f-ox (kJ/mol): CaZr1.03Ti1.97O7 (-89.6 +/- 2.8); CaHf1.02Ti1.98O7 (-74.8 +/- 3.1). CaZr1.03Ti1.97O7 was stable with respect to a perovskite plus oxides assemblage (DeltaH° f-pv+ox = -8.8 +/- 3.3 kJ/mol). CaHf1.02Ti 1.98O7 was marginally metastable in enthalpy (Delta H°f-pv+ox = +6.0 +/- 3.5 kJ/mol). DeltaH°f (kJ/mol) were derived for three brannerites: CeTi2O6 (-2948.8 +/- 4.3); U0.97Ti2.03O6

  19. Hollandite II phase in KAlSi 3O 8 as a potential host mineral of potassium in the Earth's lower mantle

    Science.gov (United States)

    Hirao, Naohisa; Ohtani, Eiji; Kondo, Tadashi; Sakai, Takeshi; Kikegawa, Takumi

    2008-01-01

    High-pressure and high-temperature experiments on the KAlSi 3O 8 composition were conducted in a laser-heated diamond-anvil cell at pressures up to 128 GPa, which correspond to the lowermost mantle conditions. In situ synchrotron X-ray diffraction measurements revealed that the hollandite II phase in KAlSi 3O 8 with a monoclinic symmetry of I2/ m was stable over the entire range of mantle conditions, and the tunnel structure formed by the double chains of edge-sharing (Si,Al)O 6 octahedra, which could accommodate a larger cation such as potassium, was sustained. The (Si,Al)O 6 octahedra in the KAlSi 3O 8 hollandite II phase showed a similar compression behavior to those in high-pressure silicate structures, such as rutile-type and perovskite-type phases, and were found to be less compressible than the KO 8 polyhedra. The KAlSi 3O 8 hollandite II phase is a potential host mineral for potassium under lower mantle conditions and, therefore, may have a significant influence on geochemistry if potassium feldspar KAlSi 3O 8 in the Earth's crust is transported into the Earth's mantle through subduction.

  20. Study of the irradiation effect on zirconolite and monazite-brabandite matrices: comparison of the damages induced by the auto irradiation and the external irradiation; Etude du comportement sous irradiation des matrices zirconolite et monazite-brabantite: comparaison des dommages induits par l auto irradiation et l irradiation externe

    Energy Technology Data Exchange (ETDEWEB)

    Picot, V. [CEA Centre de Marcoule BP17171 - 30207 Bagnols sur Ceze Cedex (France); Blondiaux, G. [CNRS/CERI, 3A rue de la Ferollerie 45071 Orleans Cedex 2 (France); Deschanels, X.; Peuget, S.; Fillet, C. [CEA/DEN Centre de Marcoule BP17171 - 30207 Bagnols sur Ceze Cedex (France); Glorieux, B. [CNRS/PROMES 7, rue du Four Solaire 66120 Font Romeu Odeillo (France); Loubet, J.L.; Pavan, S. [LTDS, UMR CNRS 5513, Ecole Centrale de Lyon 36 avenue Guy de Collongue 69134 Ecully Cedex (France); Henry, S. [CSNSM/IN2P3, Universite Paris-Sud 11, 91405 Orsay cedex (France)

    2006-07-01

    Two ceramics, the zirconolite matrix and the solid solution monazite-brabantite have been studied for the conditioning of minor actinides. Under the effects of irradiation damages due to {alpha} disintegrations, important changes of macroscopic and mechanical properties of matrices have been revealed. The doping of the matrices with short living actinides and the external irradiation of inactive materials by heavy and light ions are two techniques which have been used for simulating the effects of {alpha} disintegrations. The comparison of the obtained results on doped and ions implanted materials have allowed to dissociate the effects of the nuclear interactions (elastic collisions) of the electronic interactions (inelastic collisions) due to {alpha} disintegrations. The results have shown that the swelling and hardness variations of a zirconolite matrix doped with plutonium 238 are due to the nuclear interactions of the {alpha} disintegrations. (O.M.)

  1. (Alpha, gamma) irradiation effect on the alteration of high-level radioactive wastes matrices (UO{sub 2}, hollandite, glass SON68); Effet de l'irradiation (alpha, gamma) sur l'alteration des matrices de dechets nucleaires de hautes activites (UO{sub 2}, hollandite, verre SON68)

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, T

    2007-06-15

    The aim of this work is to determine the effect of irradiation on the alteration of high level nuclear waste forms matrices. The matrices investigated are UO{sub 2} to simulate the spent fuel, the hollandite for the specific conditioning of Cs, and the inactive glass SON68 representing the nuclear glass R7T7) The alpha irradiation experiments on UO{sub 2} colloids in aqueous carbonate media have enabled to distinguish between the oxidation of UO{sub 2} matrix as initial and dissolution as subsequent step. The simultaneous presence of carbonate and H{sub 2}O{sub 2} (product resulting from water radiolysis) increased the dissolution rate of UO{sub 2} to its maximum value governed by the oxidation rate. ii) The study of hollandite alteration under gamma irradiation confirmed the good retention capacity for Cs and Ba. Gamma irradiation had brought only a little influence on releasing of Cs and Ba in solution. Electronic irradiation had conducted to the amorphization of the hollandite only for a dose 1000 times higher than the auto-induced dose of Ba over millions of years. iii) The experiences of glass irradiation under alpha beam and of helium implantation in the glass SON68 were analyzed by positon annihilation spectroscopy. No effect has been observed on the solid surface for an irradiation dose equal to 1000 years of storage. (author)

  2. Report on the scientific feasibility of new matrices for the conditioning of long lived radionuclides; Rapport sur la faisabilite scientifique des matrices nouvelles de conditionnement des radionucleides a vie longue

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    New specific matrices for the conditioning of long lived radionuclides (I, Cs, Tc, minor actinides) have been developed. This report presents the conditions of their synthesis by sintering or melting and the quantifying of their crystallographic, physical and thermal properties. A 7% mass insertion of iodine can be reached with a phosphorus-vanadium-lead iodo-apatite. A 5% mass insertion of cesium is reached with the hollandite-type crystal structure (barium aluminate-titanate). An insertion level of at least 10% mass of rare earth oxides (simulating the presence of actinides) is reached for britholite, zirconolite, thorium phosphate, monazite, and zirconolite glass/ceramic materials. The chemical durability has been also determined. Enhanced aqueous corrosion resistance, 100 times better than for the glasses used today, are obtained for iodo-apatite (I), hollandite (Cs), britholite (actinides 3+/4+), thorium phosphate (actinides 4+) and monazite (3+/4+). The first elements of stability with respect to irradiation are reported for the minor actinide conditioning matrices. External post-irradiation examinations by heavy ion bombardment coupled to atomistic modeling have been performed. The characterization of self-irradiated natural analogues of britholite, zirconolite and monazite with more than 10{sup 20} {alpha}/g disintegrations confirms the very long time stability of these mineral structures (>10{sup 8} years). On the basis of the obtained results, it appears that the iodo-apatite, britholite, zirconolite, and thorium phosphate conditioning matrices have reached the stage of scientifical feasibility. The monazite matrice is on the way to reach the feasibility too. Other specific matrices for technetium (metal alloys) and cesium (hollandite) are also under development, but their long-term properties remain to be determined. (J.S.)

  3. The CaO-TiO{sub 2}-ZrO{sub 2} system at 1,200{degree}C and the solubilities of Hf and Gd in zirconolite

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, D.; Nieh, T.G. [Lawrence Livermore National Lab., CA (United States); Fournelle, J.H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Geology and Geophysics

    1995-12-01

    In recent years, significant technological advancements have been made in the Synroc scheme for the immobilization high-level nuclear waste. However, many basic scientific issues related to Synroc fabrication have yet to be addressed. The CaO-TiO{sub 2}-ZrO{sub 2} system is an integral part of the Synroc formulation. Phase equilibria are established in the CaO-TiO{sub 2}-ZrO{sub 2} system at 1,200 C, using X-ray diffraction and electron probe microanalysis. The existence of two previously reported ternary phases, zirconolite (CaZrTi{sub 2}O{sub 7}) and calzirtite (Ca{sub 2}Zr{sub 5}Ti{sub 2}O{sub 16}), is confirmed. Each of these phases exhibits a significant range of homogeneity between TiO{sub 2} and ZrO{sub 2} while maintaining a nearly constant concentration of CaO. The ternary solubilities of the constituent binary phases are found to be negligible, with the exceptions of the perovskites, which display mutual solubility of at least 22 mol.% and may in fact form a series of continuous solid solutions. The solubilities of Hf and Gd in zirconolite are also investigated. While Hf-bearing samples did not reach thermodynamic equilibrium under the experimental conditions employed, the existence of a Hf analog to zirconolite, CaHfTi{sub 2}O{sub 7}, is conclusively demonstrated. The phase is stable at the stoichiometric composition, and its lattice parameters are very close to those reported in the literature for stoichiometric zirconolite. A Gd-bearing sample of the composition Ca{sub 0.88}Zr{sub 0.88}Gd{sub 9.24}Ti{sub 2}O{sub 7} is found to be essentially single phase zirconolite, in agreement with previous investigations at higher temperatures.

  4. Crystallization behavior during melt-processing of ceramic waste forms

    Science.gov (United States)

    Tumurugoti, Priyatham; Sundaram, S. K.; Misture, Scott T.; Marra, James C.; Amoroso, Jake

    2016-05-01

    Multiphase ceramic waste forms based on natural mineral analogs are of great interest for their high chemical durability, radiation resistance, and thermodynamic stability. Melt-processed ceramic waste forms that leverage existing melter technologies will broaden the available disposal options for high-level nuclear waste. This work reports on the crystallization behavior in selected melt-processed ceramics for waste immobilization. The phase assemblage and evolution of hollandite, zirconolite, pyrochlore, and perovskite type structures during melt processing were studied using thermal analysis, x-ray diffraction, and electron microscopy. Samples prepared by melting followed by annealing and quenching were analyzed to determine and measure the progression of the phase assemblage. Samples were melted at 1500 °C and heat-treated at crystallization temperatures of 1285 °C and 1325 °C corresponding to exothermic events identified from differential scanning calorimetry measurements. Results indicate that the selected multiphase composition partially melts at 1500 °C with hollandite coexisting as crystalline phase. Perovskite and zirconolite phases crystallized from the residual melt at temperatures below 1350 °C. Depending on their respective thermal histories, different quenched samples were found to have different phase assemblages including phases such as perovskite, zirconolite and TiO2.

  5. Melt Processed Single Phase Hollandite Waste Forms For Nuclear Waste Immobilization: Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, Kyle [Savannah River National Laboratory, Aiken, SC 29808 (United States); Marra, James [Savannah River National Laboratory, Aiken, SC 29808 (United States); Amoroso, Jake [Savannah River National Laboratory, Aiken, SC 29808 (United States); Conradson, Steven D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tang, Ming [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-09-23

    Cs is one of the more problematic fission product radionuclides to immobilize due to its high volatility at elevated temperatures, ability to form water soluble compounds, and its mobility in many host materials. The hollandite structure is a promising crystalline host for Cs immobilization and has been traditionally fabricated by solid state sintering methods. This study presents the structure and performance of Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al hollandite fabricated by melt processing. Melt processing is considered advantageous given that melters are currently in use for High Level Waste (HLW) vitrification in several countries. This work details the impact of Cr additions that were demonstrated to i) promote the formation of a Cs containing hollandite phase and ii) maintain the stability of the hollandite phase in reducing conditions anticipated for multiphase waste form processing.

  6. The Crystal Structure and Chemistry of Pyrochlore-and Hollandite-Type Minerals and Their Application as Nuclear Waste-Forms%烧绿石及碱硬锰矿型矿物晶体化学及其核废料固化基材研究进展

    Institute of Scientific and Technical Information of China (English)

    李国武; 邢晓琳; 徐凯

    2016-01-01

    Pyrochlore- and hollandite-type minerals were extensively investigated as the nuclear waste-forms, showing the unique properties on thermal and chemical stabilities and irradiation resistance. In the past decade, our group methodically studied the crystal structure and chemistry of pyrochlore- and holladnite-type natural minerals and their synthesized compounds. According to X-ray diffraction analysis of fourteen synthesized rare-earth pyrochlore (Ree2B2O7, B=Ti, Zr), both Ree2Ti2O7 and Ree2Zr2O7 show obvious crystal structure variable. The study of hollandite crystal structure indicates that contents of cationA (A0-2B8O16,A=Na, K, Sr, Ba, etc.,B=Ti, Fe, Mn, Al, etc.) in the tunnel and parameters regarding anisotropy usually cause one-dimension incommensurate modulation structure along with c direction. This paper summarized our recent results on their structure and chemistry, and reviewed the research and development of their application in nuclear waste immobilization.%研究表明烧绿石和碱硬锰矿在固化核废料方面具有良好的性能。近年来我们对烧绿石型和碱硬锰矿型天然矿物以及系列人工合成矿物的晶体结构及晶体化学进行了系统详细的研究。通过人工合成14种镧系稀土的Ti和Zr的Ree2B2O7系列氧化物的X射线衍射实验,发现其Ti的Ree2Ti2O7系列氧化物和Zr的Ree2Zr2O7系列氧化物都出现了明显的晶变现象。晶体结构研究显示碱硬锰矿型结构矿物中 A 类阳离子在孔道中的含量变化及各向异性参数的变化导致了该型结构往往存在沿 c轴方向的一维非公度调制结构。同时对烧绿石和碱硬锰矿在固化核废料方面的研究现状及进展进行了综述。

  7. Magnetic and thermoelectric properties of the ternary pseudo-hollandite BaxCr5Se8 (0.5 solid solution.

    Science.gov (United States)

    Lefèvre, Robin; Berthebaud, David; Bux, Sabah; Hébert, Sylvie; Gascoin, Franck

    2016-07-26

    The structure of Ba0.5Cr5Se8 has been recently resolved, and its thermoelectric and magnetic properties have been studied. A ZT of 0.12 was found at around 800 K. Here, we report a study on the pseudo-hollandite BaxCr5Se8 solid-solution with 0.5 ≤ x ≤ 0.55 and its thermoelectric and magnetic properties. There is no significant impact either on the cell parameters depending on the cation content or on the magnetic properties. However, thermoelectric properties are radically changed depending on x content. While the low thermal conductivity, around 0.8 W m(-1) K(-1), remains similar for all samples, a respective increase and decrease of the resistivity and the Seebeck coefficient are observed with increasing Ba content. The maximum Seebeck coefficient is found with Ba0.5Cr5Se8 at around 635 K with 315 μV K(-1), and the Seebeck coefficient then decreases and is correlated with an activation of minority charge carriers confirmed by Hall measurements. A similar but steeper behavior is observed for the Ba0.55Cr5Se8 temperature dependence plot at around 573 K. Finally, the best thermoelectric performances are found using the lowest content of Ba, unlike when x tends to 0.55, ZT approaches a tenth of the initial best value. BaxCr5Se8 compounds are antiferromagnetic with TN = 58 K. A large peak in thermal conductivity is observed around the antiferromagnetic transition for all stoichiometry.

  8. Melt processed single phase hollandite waste forms for nuclear waste immobilization: Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, Jake; Marra, James [Savannah River National Laboratory, Aiken, SC 29808 (United States); Conradson, Steven D.; Tang, Ming [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Brinkman, Kyle, E-mail: kyle.brinkman@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States)

    2014-01-25

    Highlights: • This work shows Cr additions improve the performance of Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al hollandite • Fe–Hol sample exhibited the least Cs retention whereas the Cr–Hol exhibited the greatest Cs retention. • CAF–Hol and Fe–Hol samples exhibited secondary phases enriched in Cs. • X-ray absorption measurements confirmed the stability of Cr{sup +3} as compared to Fe{sup +3}. -- Abstract: Cs is one of the more problematic fission product radionuclides to immobilize due to its high volatility at elevated temperatures, ability to form water soluble compounds, and its mobility in many host materials. The hollandite structure is a promising crystalline host for Cs immobilization and has been traditionally fabricated by solid state sintering methods. This study presents the structure and performance of Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16}; A = Cr, Fe, Al hollandite fabricated by melt processing. Melt processing is considered advantageous given that melters are currently in use for High Level Waste (HLW) vitrification in several countries. This work details the impact of Cr additions that were demonstrated to (i) promote the formation of a Cs containing hollandite phase and (ii) maintain the stability of the hollandite phase in reducing conditions anticipated for multiphase waste form processing.

  9. Novel monoclinic zirconolite in Bi{sub 2}O{sub 3}–CuO–Ta{sub 2}O{sub 5} ternary system: Phase equilibria, structural and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Tan, K.B., E-mail: tankb@science.upm.my [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Chon, M.P. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Khaw, C.C. [Department of Mechanical and Material Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur (Malaysia); Zainal, Z.; Taufiq Yap, Y.H.; Tan, P.Y. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

    2014-04-01

    Highlights: • Novel BCT monoclinic zirconolite phase was prepared through solid state reaction. • Comprehensive study of reaction mechanism was performed by careful firing control. • Qualitative structural and phase analyses were conducted. • Electrical response in broad range of temperature and frequency was investigated. - Abstract: Synthesis of novel monoclinic zirconolite, Bi{sub 1.92}Cu{sub 0.08}(Cu{sub 0.3}Ta{sub 0.7}){sub 2}O{sub 7.06} (β-BCT) using solid state reaction had been finalised at the firing temperature of 900 °C over 24 h. The X–ray diffraction pattern of β-BCT was fully indexed on a monoclinic symmetry, space group, C2/c with lattice constants, a = 13.1052 (8), b = 7.6749 (5), c = 12.162 (6), α = γ = 90° and β = 101.32° (1), respectively. The reaction mechanism study indicated phase formation was greatly influenced by the reaction between intermediate bismuth tantalate binary phases and CuO at elevated temperatures. β-BCT was thermally stable up to a temperature of 900 °C and contained spherulite grains with sizes ranging from 1 to 14 μm. Electrical properties of this material were characterised over a broad temperature range covering temperatures from 10 K to 874 K. At the temperature of 304 K, two semicircles were discernible in complex Cole–Cole plot showing an insulating grain boundary with C{sub gb} = 6.63 × 10{sup −9} F cm{sup −1} and a bulk response capacitance, C{sub b} = 6.74 × 10{sup −12} F cm{sup −1}. The Power law frequency-dependent ac conductivity of β-BCT was apparent in three frequency regimes; a low–frequency plateau regime, a high-frequency plateau regime and a dispersive regime taking place in the temperature range of 220–576 K. The frequency-dependent ac conductivity of β-BCT with increasing temperature was attributed to the thermal activated electrical conduction mechanism within the structure.

  10. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  11. Zirconolite, zircon and monazite-(Ce) U-Th-Pb age constraints on the emplacement, deformation and alteration history of the Cummins Range Carbonatite Complex, Halls Creek Orogen, Kimberley region, Western Australia

    Science.gov (United States)

    Downes, Peter J.; Dunkley, Daniel J.; Fletcher, Ian R.; McNaughton, Neal J.; Rasmussen, Birger; Jaques, A. Lynton; Verrall, Michael; Sweetapple, Marcus T.

    2016-04-01

    In situ SHRIMP U-Pb dating of zirconolite in clinopyroxenite from the Cummins Range Carbonatite Complex, situated in the southern Halls Creek Orogen, Kimberley region, Western Australia, has provided a reliable 207Pb/206Pb age of emplacement of 1009 ± 16 Ma. Variably metamict and recrystallised zircons from co-magmatic carbonatites, including a megacryst ~1.5 cm long, gave a range of ages from ~1043-998 Ma, reflecting partial isotopic resetting during post-emplacement deformation and alteration. Monazite-(Ce) in a strongly foliated dolomite carbonatite produced U-Th-Pb dates ranging from ~900-590 Ma. Although the monazite-(Ce) data cannot give any definitive ages, they clearly reflect a long history of hydrothermal alteration/recrystallisation, over at least 300 million years. This is consistent with the apparent resetting of the Rb-Sr and K-Ar isotopic systems by a post-emplacement thermal event at ~900 Ma during the intracratonic Yampi Orogeny. The emplacement of the Cummins Range Carbonatite Complex probably resulted from the reactivation of a deep crustal structure within the Halls Creek Orogen during the amalgamation of Proterozoic Australia with Rodinia over the period ~1000-950 Ma. This may have allowed an alkaline carbonated silicate magma that was parental to the Cummins Range carbonatites, and generated by redox and/or decompression partial melting of the asthenospheric mantle, to ascend from the base of the continental lithosphere along the lithospheric discontinuity constituted by the southern edge of the Halls Creek Orogen. There is no evidence of a link between the emplacement of the Cummins Range Carbonatite Complex and mafic large igneous province magmatism indicative of mantle plume activity. Rather, patterns of Proterozoic alkaline magmatism in the Kimberley Craton may have been controlled by changing plate motions during the Nuna-Rodinia supercontinent cycles (~1200-800 Ma).

  12. DEVELOPMENT OF CRYSTALLINE CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.; Brinkman, K.

    2011-09-22

    The Savannah River National Laboratory (SRNL) is developing crystalline ceramic waste forms to incorporate CS/LN/TM high Mo waste streams consisting of perovskite, hollandite, pyrochlore, zirconolite, and powellite phase assemblages. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase crystalline ceramics. Fiscal Year 2011 (FY11) activities included (i) expanding the compositional range by varying waste loading and fabrication of compositions rich in TiO{sub 2}, (ii) exploring the processing parameters of ceramics produced by the melt and crystallize process, (iii) synthesis and characterization of select individual phases of powellite and hollandite that are the target hosts for radionuclides of Mo, Cs, and Rb, and (iv) evaluating the durability and radiation stability of single and multi-phase ceramic waste forms. Two fabrication methods, including melting and crystallizing, and pressing and sintering, were used with the intent of studying phase evolution under various sintering conditions. An analysis of the XRD and SEM/EDS results indicates that the targeted crystalline phases of the FY11 compositions consisting of pyrochlore, perovskite, hollandite, zirconolite, and powellite were formed by both press and sinter and melt and crystallize processing methods. An evaluation of crystalline phase formation versus melt processing conditions revealed that hollandite, perovskite, zirconolite, and residual TiO{sub 2} phases formed regardless of cooling rate, demonstrating the robust nature of this process for crystalline phase development. The multiphase ceramic composition CSLNTM-06 demonstrated good resistance to proton beam irradiation. Electron irradiation studies on the single phase CaMoO{sub 4} (a component of the multiphase waste form) suggested that this material exhibits stability to 1000 years at anticipated self-irradiation doses (2 x 10{sup 10}-2 x 10{sup 11} Gy), but that

  13. The durability of single, dual, and multiphase titanate ceramic waste forms for nuclear waste immobilization

    Science.gov (United States)

    Harkins, Devin J. H.

    A significant amount of the energy used in the United States comes from nuclear power, which produces a large amount of waste materials. Recycling nuclear waste is possible, but requires a way to permanently fix the unusable radionuclides remaining from the recycling process in a stable, leach resistant structure. Multiphase titanate ceramic waste forms are one promising option under consideration. However, there is insufficient work on the long term corrosion of the individual phases, as well as the multiphase systems of these ceramics. These multiphase titanate ceramic waste forms have three targeted phases: hollandite, pyrochlore, and zirconolite. Hollandite is a promising candidate for the incorporation of Cs, while pyrochlore is readily formed with lanthanides, such as Nd, the most prevalent lanthanide in the waste stream. The third targeted phase, zirconolite, is for the incorporation of zirconium and the actinides. This work looks into the formation of single phase systems of lanthanide titanates, formation of dual phase systems of Ga doped Ba hollandites and Nd titanate, durability of single phase hollandites and multiphase model systems using Vapor Hydration Testing (ASTM C 1663-09), dissolution of dual phase systems of Ga doped Ba hollandites and Nd titanate using Product Consistency Testing (ASTM C 1285-02), as well investigating how grain size affects amount of alterative phases formed using Vapor Hydration Testing. The dual phase systems of hollandites and Nd titanate show significant amounts of secondary phases forming, heavily influenced by the composition of hollandite used in the systems. The most significant phase present was BaNd2Ti5O14. This phase proves to be problematic due to the degradation to the hollandite structure. Using Vapor Hydration Testing to investigate single and multiphase systems presented many some possible alteration phases that could occur in the long term aging of these ceramics. Most notably, Cs rich phases were found in

  14. Comportamento térmico e evolução das fases de óxidos de Mn com estrutura hollandita da região Amazônica Thermal behavior and evolution of the Mn oxides phases with hollandite structure from Amazon region

    Directory of Open Access Journals (Sweden)

    B. A. M. Figueira

    2013-03-01

    Full Text Available Minerais de óxidos de Mn com estrutura em túnel, hollandita (Apuí, Amazonas, Brasil, zona em prospecção e criptomelana (Urucum, Mato Grosso do Sul, Brasil foram isolados e caracterizados quanto à composição química, mineralógica, estabilidade térmica e morfologia. As seguintes técnicas foram utilizadas para caracterização: microscopia eletrônica de varredura-EDS, análise térmica (TG-DTA e difração de raios X estático e com aquecimento contínuo entre 100-900 ºC. As seguintes fórmulas empíricas, calculadas com base em 16 átomos de oxigênios foram obtidas: (Ba0,18K0,12Ca0,02Pb0,040,76(Mn6,34Al0,61Si0,25Fe0,24Ti0,087,54O(160,4H2O para hollandita e (K0,9Na0,04Ca0,03Sr0,041,04(Mn7,38Fe0,28Al0,27Si0,088O16 para criptomelana. Mediante o uso de microscopia eletrônica de varredura foi possível diferenciar a morfologia da hollandita e da criptomelana. Os resultados de DRX e TG-DTA mostraram que os minerais apresentaram estabilidade térmica acima de 900 ºC.The tunnel-structure manganese oxide minerals, hollandite (Apuí, Amazonas state, Brazil, area in prospection and cryptomelane (Urucum, Mato do Sul Grosso state, Brazil were isolated and characterized chemical, mineralogical, thermal and morphologically. The following techniques were employed: scanning electron microscopy-EDS, thermal analysis (DTA-TG, X-ray diffraction with continuous-heating. The empirical formula, were calculated on the basis 16 oxygen gave as (Ba0.18K0.12Ca0.02Pb0.040.76(Mn6.34Al0.61Si0.25Fe0.24Ti0.087.54O(160.4H2O for hollandite and (K0.9Na0.04Ca0.03Sr0.041.04(Mn7.38Fe0.28Al0.27Si0.088O16 for cryptomelane. The SEM investigations allowed the differentiation of the morphologies for hollandite and cryptomelane. The minerals were thermally treated among 100-900 ºC and X-ray diffraction patterns in situ were collected. The analysis of X-ray diffractions experiments showed that a hollandite-crytomelane mineral has a thermal stability up to 900 ºC.

  15. Effect of natural zeolite on methane production for anaerobic digestion of ammonium rich organic sludge.

    Science.gov (United States)

    Tada, Chika; Yang, Yingnan; Hanaoka, Toshiaki; Sonoda, Akinari; Ooi, Kenta; Sawayama, Shigeki

    2005-03-01

    The effect of an inorganic additive on the methane production from NH(4+)-rich organic sludge during anaerobic digestion was investigated using different kinds of inorganic adsorbent zeolites (mordenite, clinoptilolite, zeolite 3A, zeolite 4A), clay mineral (vermiculite), and manganese oxides (hollandite, birnessite). The additions of inorganic materials resulted in significant NH4+ removals from the natural organic sludge ([NH4+]=1, 150 mg N/l), except for the H-type zeolite 3A and birnessite. However, an enhanced methane production was only achieved using natural mordenite. Natural mordenite also enhanced the methane production from the sludge with a markedly high NH4+ concentration (4500 mg N/l) during anaerobic digestion. Chemical analyses of the sludge after the digestion showed considerable increases in the Ca2+ and Mg2+ concentrations in the presence of natural mordenite, but not with synthetic zeolite 3A. The effect of Ca2+ or Mg2+ addition on the methane production was studied using Na(+)-exchanges mordenite and Ca2+ or Mg(2+)-enriched sludge. The simultaneous addition of Ca2+ ions and Na(+)-exchanged mordenite enhanced the methane production; the amount of produced methane was about three times greater than that using only the Na(+)-exchanged mordenite. In addition, comparing the methane production by the addition of natural mordenite or Ca2+ ions, the methane production with natural mordenite was about 1.7 times higher than that with only Ca2+ ions. The addition of 5% and 10% natural mordenite were suitable condition for obtaining a high methane production. These results indicated that the Ca2+ ions, which are released from natural mordenite by a Ca2+/NH4+ exchange, enhanced the methane production of the organic waste at a high NH4+ concentration. Natural mordenite has a synergistic effect on the Ca2+ supply as well on the NH4+ removal during anaerobic digestion, which is effective for the mitigation of NH4+ inhibition against methane production.

  16. Status of plutonium ceramic immobilization processes and immobilization forms

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.B.; Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (United States); Vance, E.R.; Jostsons, A. [Australian Nuclear Science and Technology Organization, Menai (Australia)] [and others

    1996-05-01

    Immobilization in a ceramic followed by permanent emplacement in a repository or borehole is one of the alternatives currently being considered by the Fissile Materials Disposition Program for the ultimate disposal of excess weapons-grade plutonium. To make Pu recovery more difficult, radioactive cesium may also be incorporated into the immobilization form. Valuable data are already available for ceramics form R&D efforts to immobilize high-level and mixed wastes. Ceramics have a high capacity for actinides, cesium, and some neutron absorbers. A unique characteristic of ceramics is the existence of mineral analogues found in nature that have demonstrated actinide immobilization over geologic time periods. The ceramic form currently being considered for plutonium disposition is a synthetic rock (SYNROC) material composed primarily of zirconolite (CaZrTi{sub 2}O{sub 7}), the desired actinide host phase, with lesser amounts of hollandite (BaAl{sub 2}Ti{sub 6}O{sub 16}) and rutile (TiO{sub 2}). Alternative actinide host phases are also being considered. These include pyrochlore (Gd{sub 2}Ti{sub 2}O{sub 7}), zircon (ZrSiO{sub 4}), and monazite (CePO{sub 4}), to name a few of the most promising. R&D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO{sub 2} powder, cold press and sinter fabrication methods, and immobilization form formulation issues.

  17. Natural gas; Gas Natural

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Carlos A.; Moraes, Claudia C.D. [Eletricidade de Sao Paulo S.A. (ELETROPAULO), Sao Paulo, SP (Brazil); Fonseca, Carlos H.F. [Centrais Eletricas de Santa Catarina S.A., Florianopolis, SC (Brazil); Silva, Clecio Fabricio da; Alves, Ricardo P. [Companhia Paranaense de Energia (COPEL), Curitiba, PR (Brazil); Sposito, Edivaldo Soares; Hulle, Lutero [Espirito Santo Centrais Eletricas S.A. (ESCELSA), Vitoria, ES (Brazil); S. Martins, Icaro da [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Belem, PA (Brazil); Vilhena, Joao Luiz S. de [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Fagundes, Zaluar Aquino [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    1996-12-31

    An increase in the consumption of natural gas in Brazil is an expected fact in what concerns energetic planning. This work presents the existing situation in what concerns natural gas utilization in the main world economies, as well as an analysis of the participation of this fuel among the energy final consumption per sources. The Brazilian consumption of natural gas is also analysed as well as the international agreement between Brazil and Bolivia for natural gas commercialization. Some legal, institutional and political aspects related to natural gas commercialization are also discussed. Finally, several benefits to be brought by the utilization of natural gas are presented 10 refs., 3 tabs.

  18. FY16 Annual Accomplishments - Waste Form Development and Performance: Evaluation Of Ceramic Waste Forms - Comparison Of Hot Isostatic Pressed And Melt Processed Fabrication Methods

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dandeneau, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-10-13

    FY16 efforts were focused on direct comparison of multi-phase ceramic waste forms produced via melt processing and HIP methods. Based on promising waste form compositions previously devised at SRNL, simulant material was prepared at SRNL and a portion was sent to the Australian Nuclear Science and Technology Organization (ANSTO) for HIP treatments, while the remainder of the material was melt processed at SRNL. The microstructure, phase formation, elemental speciation, and leach behavior, and radiation stability of the fabricated ceramics was performed. In addition, melt-processed ceramics designed with different fractions of hollandite, zirconolite, perovskite, and pyrochlore phases were investigated. for performance and properties.

  19. Improving iron-enriched basalt with additions of ZrO{sub 2} and TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, G.A.; Kong, P.C.

    1993-06-01

    The iron-enriched basalt (IEB) waste form, developed at the Idaho National Engineering Laboratory a decade ago, was modified to IEB4 by adding sufficient ZrO{sub 2} and TiO{sub 2} to develop crystals of zirconolite upon cooling, in addition to the crystals that normally form in a cooling basalt. Zirconolite (CaZrTi{sub 2}O{sub 7}) is an extremely leach-resistant mineral with a strong affinity for actinides. Zirconolite crystals containing uranium and thorium have been found that have endured more than 2 billion years of natural processes. On this basis, zirconolite was considered to be an ideal host crystal for the actinides contained in transuranic (TRU)-contaminated wastes. Crystals of zirconolite were developed in laboratory melts of IEB4 that contained 5% each of ZrO{sub 2} and TiO{sub 2} and that were slow-cooled in the 1200--1000{degrees}C range. When actinide surrogates were added to IEB4, these oxides were incorporated into the crystals of zirconolite rather than precipitating in the residual glass phase. Zirconolite crystals developed in IEB4 should stabilize and immobilize the dilute TRUs in heterogeneous, buried low-level wastes as effectively as this same phase does in the various formulations of Synroc used for the more concentrated TRUs encountered in high-level wastes. Synroc requires hot-pressing equipment, while IEB4 precipitates zirconolite from a cooling basaltic melt.

  20. Synthesis of Nano-Polycrystalline Synroc-B Powders as a High Level Radioactive Wastes Ceramic Forms by a Solution Combustion Synthesis.

    Science.gov (United States)

    Han, Young-Min; Lee, Sang-Jin; Kim, Yeon-Ku; Jung, Choong-Hwan

    2016-02-01

    Synroc (Synthetic Rock) consists of four main titanate phases: peroveskite (CaTiO3), zirconolite (CaZrTi2O7), hollandite (BaAl2Ti6O16) and rutile (TiO2). Nano-polycrystalline synroc powders were made by a synthesis combustion process. The combustion process, an externally initiated reaction is self-sustained owing to the exothermic reaction. A significant volume of gas is evolved during the combustion reaction and leads to loosely agglomerated powders. This exothermic reaction provides necessary heat to further carry the reaction in forward direction to produce nanocrystalline powders as the final product. Glycine is used as a fuel, being oxidized by nitrate ions. It is inexpensive, has high energy efficiency, fast heating rates, short reaction times and high compositional homogeneity. In this study, combustion synthesis of nano-sized synroc-B powder is introduced. The fabrication of synroc-B powder result of observation XRD were prepared for polycrystalline (perovskite, zirconolite, hollandite, rutile) structures. The characterization of the synthesized powders is conducted by using XRD, SEM/EDS and TEM.

  1. Displaying Nature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Beijing Museum of Natural History is located in Chongwen District, close to the Temple of Heaven and Tianqiao Theater. It was founded in 1951 and formally named Beijing Museum of Natural History in 1962.

  2. PLURALIZING NATURE

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Denmark is widely recognised for its democratic approach to planning and the idea of planning for the common good. This interest in the common good and common values seems also to be reflected in the way which nature restoration is planned and managed – one common nature directed by the public...... authorities. But nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. However, evidence from Switzerland suggests that planning for the common good, in the case of nature restoration, does...

  3. Nature seconded

    OpenAIRE

    Gough, Tim

    2002-01-01

    Heidegger�s remark that the banks of the river (representing nature in its supposedly pure state) only become apparent because of the presence of the bridge (representing the artificial in its supposed opposition to that nature) will lead this presentation to a discussion of whether or not the idea of �nature� as prior to architecture remains unequivocally valid. If nature/the site - that which claims to come before the artificial/architecture - only appears as a result of the presence ...

  4. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  5. Natur formet

    DEFF Research Database (Denmark)

    Søberg, Martin

    2011-01-01

    Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011.......Anmeldelse af Malene Hauxner, "Fra naturlig natur til SUPERNATUR – Europæisk landskabsarkitektur 1967-2007 set fra Danmark", Risskov: Ikaros Press, 2011....

  6. Nature Detectives

    Science.gov (United States)

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  7. Matematica Natural.

    Science.gov (United States)

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  8. Nature Detectives

    Science.gov (United States)

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  9. Natural death.

    Science.gov (United States)

    Oehmichen, M; Meissner, C

    2000-01-01

    The increasing age of every human being is the beginning of the end of life, an obviously natural process, but any attempt to define the term 'natural death' soon encounters difficulties in defining what is meant by 'natural'. In the industrialized countries of the West, for example 'natural death' is thought of as the opposite of non-natural types of death such as accidental death, suicide, and homicide. The aim of our present survey is to discuss the meaning of the term 'natural death' under a clinical, a forensic and a scientific point of view with regard to recent developments especially in molecular biology. If there are 'external' physical influences, a medical-technical manipulation, a therapeutic or molecular biological intervention cannot be definitely ruled out as the cause of death, then use of the term 'natural death' in general is open to question. It will only remain meaningful if it can be applied with a specific meaning in definite practical situations. Current research and medical technology, however, do not allow use of the term 'natural death' in its conventional sense: it can thus be stricken from the medical vocabulary. Copyright 2000 S. Karger AG, Basel

  10. Dissonant Nature

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2013-01-01

    Nature restoration is far from being a neural undertaking. Just like any other type of heritage production it can be the source of dissonance – ‘our’ nature is not necessary ‘their’ nature. Often this dissonance is managed in ways, which are not particular sensitive to site......-specificity. As exemplified by the Skjern River Restoration Project (1999-2003), one interpretation of the landscape sometimes suppresses other valid interpretations neglecting its diverse history. Landscape architecture might, however, provide an alternative approach to nature restoration that is more site specific...... and allows for multiple interpretations to coexist. Evidence can be found in the Re-naturalization of River Aire (2002-2015), a restoration project, which reveals approaches that could be labelled landscape architecture specific....

  11. Natural Communities

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset shows the locations of known tracts of high quality natural communities in Kansas, generalized to the PLSS section. It is not a compehensive dataset of...

  12. Natural Propositions

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik

    Preface -- Introduction -- The generality of signs -- Dicisigns -- Some consequences of the dicisign doctrine -- Dicisigns and cognition -- Natural propositions--the evolution of semiotic self-control -- Dicisigns beyond language -- Operational and optimal iconicity in Peirce's diagrammatology...

  13. Writing Nature

    Directory of Open Access Journals (Sweden)

    Kristin Asdal

    2014-06-01

    Full Text Available This special issue of the Nordic Journal of Science and Technology Studies is interested in how nature, in different versions and forms, is invited into our studies, analyses, and stories. How is it that we “write nature”? How is it that we provide space for, and actually describe the actors, agents, or surroundings, in our stories and analyses? The articles in the issue each deal with different understandings of both the practices of writing and the introduction of various natures into these. In this introduction to the issue the editors engage with actor-network theory as a material semiotic resource for writing nature. We propose to foreground actor-network theory as a writing tool, at the expense of actor-network theory as a distinct vocabulary. In doing this and pointing out the semiotic origins to material-semiotics we also want to problematize a clear-cut material approach to writing nature.

  14. Natural Propositions

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik

    Preface -- Introduction -- The generality of signs -- Dicisigns -- Some consequences of the dicisign doctrine -- Dicisigns and cognition -- Natural propositions--the evolution of semiotic self-control -- Dicisigns beyond language -- Operational and optimal iconicity in Peirce's diagrammatology...

  15. Naturalness redux

    CERN Document Server

    Fabbrichesi, Marco

    2015-01-01

    The idea of naturalness, as originally conceived, refers only to the finite renormalization of the Higgs boson mass induced by the introduction of heavier states. In this respect, naturalness is still a powerful heuristic principle in model building beyond the standard model whenever new massive states are coupled to the Higgs field. The most compelling case is provided by the generation of neutrino masses. In this paper we confront this problem from a new perspective. The right-handed sector responsible for the seesaw mechanism---which introduces a large energy threshold above the electroweak scale---is made supersymmetric to comply with naturalness while the standard model is left unchanged and non-supersymmetric. Cancellations necessary to the naturalness requirement break down only at two loops, thus offering the possibility to increase the right-handed neutrino mass scale up to one order of magnitude above the usual values allowed by naturalness. If also the weak boson sector of the standard model is mad...

  16. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  17. Ley Natural

    OpenAIRE

    2010-01-01

    1. La expresión «ley natural» en la historia de las ideas. Uso ético y uso científico. 2. La cuestión de las leyes naturales en el ámbito de la naturaleza y en el ámbito de la conducta humana. 3. La ley natural como teoría moral se desarrolla en dos planos: a) plano práctico: el obrar humano responde a razones, depende de principios que constituyen una única ley; b) plano de fundamentación metafísica: la ley natural como participación de la ley eterna en la criatura racional. 4. La ley nat...

  18. Emancipating Nature

    DEFF Research Database (Denmark)

    Munk, Anders Kristian

    2012-01-01

    The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations of it – hydrodyn......The issue of riverine flooding in the UK is closely tied up with computer simulations. Arguably, these modelling practices are ripe with the anticipation of nature. They aspire to pre-empt it, hence expect it to be ‘out there’, and ultimately work through formalized distillations...... of it – hydrodynamic equations – which have their own anticipations and place their own demands on their modellers. Through the experience of a flood modelling apprenticeship I argue that the taking-place of such anticipations paradoxically relies on the birth of a hybrid, the model-modeller, and thus on a nature...

  19. Natural games

    CERN Document Server

    Anttila, Jani

    2011-01-01

    Behavior in the context of game theory is described as a natural process that follows the 2nd law of thermodynamics. The rate of entropy increase as the payoff function is derived from statistical physics of open systems. The thermodynamic formalism relates everything in terms of energy and describes various ways to consume free energy. This allows us to associate game theoretical models of behavior to physical reality. Ultimately behavior is viewed as a physical process where flows of energy naturally select ways to consume free energy as soon as possible. This natural process is, according to the profound thermodynamic principle, equivalent to entropy increase in the least time. However, the physical portrayal of behavior does not imply determinism. On the contrary, evolutionary equation for open systems reveals that when there are three or more degrees of freedom for behavior, the course of a game is inherently unpredictable in detail because each move affects motives of moves in the future. Eventually, wh...

  20. [Natural selection].

    Science.gov (United States)

    Mayr, E

    1985-05-01

    Much of the resistance against Darwin's theory of natural selection has been due to misunderstandings. It is shown that natural selection is not a tautology and that it is a two-step process. The first step, the production of variation, is under the control of chance; the second step, selection proper, is an anti-chance process, but subject to many constraints. The target of selection is the individual as a whole, and many neutral mutations can be retained as hitchhikers of successful genotypes. Sexual selection results from selection for pure reproductive success.

  1. Provincialising Nature

    DEFF Research Database (Denmark)

    Provincialising Nature: Multidisciplinary Approaches to the Politics of the Environment in Latin America offers a timely analysis of some of the crucial challenges, contradictions and promises within current environmental discourses and practices in the region. This book shows both challenging...... scenarios and original perspectives that have emerged in Latin America in relation to the globally urgent issues of climate change and the environmental crisis. Two interconnected analytical frameworks guide the discussions in the book: the relationship between nature, knowledge and identity and their role...

  2. Kritikkens natur

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Claus

    1999-01-01

    Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon.......Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon....

  3. Natural aerodynamics

    CERN Document Server

    Scorer, R S

    1958-01-01

    Natural Aerodynamics focuses on the mathematics of any problem in air motion.This book discusses the general form of the law of fluid motion, relationship between pressure and wind, production of vortex filaments, and conduction of vorticity by viscosity. The flow at moderate Reynolds numbers, turbulence in a stably stratified fluid, natural exploitation of atmospheric thermals, and plumes in turbulent crosswinds are also elaborated. This text likewise considers the waves produced by thermals, transformation of thin layer clouds, method of small perturbations, and dangers of extra-polation.Thi

  4. Nature Watch

    Science.gov (United States)

    Sterling, Donna R.

    2010-01-01

    Children are naturally curious about the world in which they live. To focus this sense of wonder, have your students investigate their local habitat as it changes over the year. This multiseason study will build connections and add relevance to the habitats that children learn about. This series of activities for grades 4-6 explores the changing…

  5. Nature's Palette

    Science.gov (United States)

    McBride, Brooke B.; Brewer, Carol A.

    2010-01-01

    Flower petals, acorn hats, exoskeletons of beetles, and lichens are just a few of the objects students may find in a surprising array of vivid colors. These tiny examples from nature's palette can be discovered in a school yard, a park, or even along the edges of a paved sidewalk...it simply takes careful observation! This article describes a…

  6. Kritikkens natur

    DEFF Research Database (Denmark)

    Schatz-Jakobsen, Claus

    1999-01-01

    Artiklen introducerer det nye forskningsfelt inden for samtænkning af litteratur, kultur og natur, den såkaldt økologiske kritik, og kaster et kritisk blik på  dens brug af romantisk litteratur som proto-økologisk kanon....

  7. Natural ecosystems

    Science.gov (United States)

    Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan

    2013-01-01

    Natural Ecosystems analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern ecosystems and their species, portraying ecosystem disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.

  8. Satellite (Natural)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  9. Natural Family Planning

    Science.gov (United States)

    ... Sex and Birth Control Birth Control Natural Family Planning Natural Family Planning Birth ControlPrevention and WellnessSex and Birth Control Share Natural Family Planning Natural Family PlanningWhat is natural family planning?Natural ...

  10. Natural relaxation

    Science.gov (United States)

    Marzola, Luca; Raidal, Martti

    2016-11-01

    Motivated by natural inflation, we propose a relaxation mechanism consistent with inflationary cosmology that explains the hierarchy between the electroweak scale and Planck scale. This scenario is based on a selection mechanism that identifies the low-scale dynamics as the one that is screened from UV physics. The scenario also predicts the near-criticality and metastability of the Standard Model (SM) vacuum state, explaining the Higgs boson mass observed at the Large Hadron Collider (LHC). Once Majorana right-handed neutrinos are introduced to provide a viable reheating channel, our framework yields a corresponding mass scale that allows for the seesaw mechanism as well as for standard thermal leptogenesis. We argue that considering singlet scalar dark matter extensions of the proposed scenario could solve the vacuum stability problem and discuss how the cosmological constant problem is possibly addressed.

  11. Alternative High-Performance Ceramic Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, S. K. [Alfred Univ., NY (United States)

    2017-02-01

    This final report (M5NU-12-NY-AU # 0202-0410) summarizes the results of the project titled “Alternative High-Performance Ceramic Waste Forms,” funded in FY12 by the Nuclear Energy University Program (NEUP Project # 12-3809) being led by Alfred University in collaboration with Savannah River National Laboratory (SRNL). The overall focus of the project is to advance fundamental understanding of crystalline ceramic waste forms and to demonstrate their viability as alternative waste forms to borosilicate glasses. We processed single- and multiphase hollandite waste forms based on simulated waste streams compositions provided by SRNL based on the advanced fuel cycle initiative (AFCI) aqueous separation process developed in the Fuel Cycle Research and Development (FCR&D). For multiphase simulated waste forms, oxide and carbonate precursors were mixed together via ball milling with deionized water using zirconia media in a polyethylene jar for 2 h. The slurry was dried overnight and then separated from the media. The blended powders were then subjected to melting or spark plasma sintering (SPS) processes. Microstructural evolution and phase assemblages of these samples were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion analysis of x-rays (EDAX), wavelength dispersive spectrometry (WDS), transmission electron spectroscopy (TEM), selective area x-ray diffraction (SAXD), and electron backscatter diffraction (EBSD). These results showed that the processing methods have significant effect on the microstructure and thus the performance of these waste forms. The Ce substitution into zirconolite and pyrochlore materials was investigated using a combination of experimental (in situ XRD and x-ray absorption near edge structure (XANES)) and modeling techniques to study these single phases independently. In zirconolite materials, a transition from the 2M to the 4M polymorph was observed with increasing Ce content. The resulting

  12. Cold crucible induction melter test for crystalline ceramic waste form fabrication: A feasibility assessment

    Science.gov (United States)

    Amoroso, Jake W.; Marra, James; Dandeneau, Christopher S.; Brinkman, Kyle; Xu, Yun; Tang, Ming; Maio, Vince; Webb, Samuel M.; Chiu, Wilson K. S.

    2017-04-01

    The first scaled proof-of-principle cold crucible induction melter (CCIM) test to process a multiphase ceramic waste form from a simulated combined (Cs/Sr, lanthanide and transition metal fission products) commercial used nuclear fuel waste stream was recently conducted in the United States. X-ray diffraction, 2-D X-ray absorption near edge structure (XANES), electron microscopy, inductively coupled plasma-atomic emission spectroscopy (and inductively coupled plasma-mass spectroscopy for Cs), and product consistency tests were used to characterize the fabricated CCIM material. Characterization analyses confirmed that a crystalline ceramic with a desirable phase assemblage was produced from a melt using a CCIM. Primary hollandite, pyrochlore/zirconolite, and perovskite phases were identified in addition to minor phases rich in Fe, Al, or Cs. The material produced in the CCIM was chemically homogeneous and displayed a uniform phase assemblage with acceptable aqueous chemical durability.

  13. FY16 Annual Accomplishments - Waste Form Development and Performance: Evaluation Of Ceramic Waste Forms - Comparison Of Hot Isostatic Pressed And Melt Processed Fabrication Methods

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dandeneau, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-10-13

    FY16 efforts were focused on direct comparison of multi-phase ceramic waste forms produced via melt processing and HIP methods. Based on promising waste form compositions previously devised at SRNL[13], simulant material was prepared at SRNL and a portion was sent to the Australian Nuclear Science and Technology Organization (ANSTO) for HIP treatments, while the remainder of the material was melt processed at SRNL. The microstructure, phase formation, elemental speciation, and leach behavior, and radiation stability of the fabricated ceramics was performed. In addition, melt-processed ceramics designed with different fractions of hollandite, zirconolite, perovskite, and pyrochlore phases were investigated. for performance and properties. Table 1 lists the samples studied.

  14. Nature and nature values in organic agriculture

    DEFF Research Database (Denmark)

    Hansen, Lene; Noe, Egon; Højring, Katrine

    2006-01-01

    The relationship between agriculture and nature is a centra issue in the current agricultural debate. Organic farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed...... to protecting natural qualities. However, the issue of nature, landscape, and land use is not straightforward. Nature is an ambiguous concept that involves multiple interests and actors reaching far beyond farmers. The Danish research project ......

  15. Terahertz Time-Domain Spectroscopy for In Situ Monitoring of Ceramic Nuclear Waste Forms

    Science.gov (United States)

    Clark, Braeden M.; Sundaram, S. K.

    2016-10-01

    The use of terahertz time-domain spectroscopy (THz-TDS) is presented as a non-contact method for in situ monitoring of ceramic waste forms. Single-phase materials of zirconolite (CaZrTi2O7), pyrochlore (Nd2Ti2O7), and hollandite (BaCs0.3Cr2.3Ti5.7O16 and BaCs0.3CrFeAl0.3Ti5.7O16) were characterized. The refractive index and dielectric properties in THz frequencies demonstrate the ability to distinguish between these materials. Differences in processing methods show distinct changes in both the THz-TDS spectra and optical and dielectric properties of these ceramic phases. The temperature dependence of the refractive index and relative permittivity of pyrochlore and zirconolite materials in the range of 25-200 °C is found to follow an exponential increasing trend. This can also be used to monitor the temperature of the ceramic waste forms on storage over extended geological time scales.

  16. Characterization of Ceramic Material Produced From a Cold Crucible Induction Melter Test

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Marra, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-04-30

    This report summarizes the results from characterization of samples from a melt processed surrogate ceramic waste form. Completed in October of 2014, the first scaled proof of principle cold crucible induction melter (CCIM) test was conducted to process a Fe-hollandite-rich titanate ceramic for treatment of high level nuclear waste. X-ray diffraction, electron microscopy, inductively coupled plasma-atomic emission spectroscopy (and inductively coupled plasma-mass spectroscopy for Cs), and product consistency tests were used to characterize the CCIM material produced. Core samples at various radial locations from the center of the CCIM were taken. These samples were also sectioned and analyzed vertically. Together, the various samples were intended to provide an indication of the homogeneity throughout the CCIM with respect to phase assemblage, chemical composition, and chemical durability. Characterization analyses confirmed that a crystalline ceramic with desirable phase assemblage was produced from a melt using a CCIM. Hollandite and zirconolite were identified in addition to possible highly-substituted pyrochlore and perovskite. Minor phases rich in Fe, Al, or Cs were also identified. Remarkably only minor differences were observed vertically or radially in the CCIM material with respect to chemical composition, phase assemblage, and durability. This recent CCIM test and the resulting characterization in conjunction with demonstrated compositional improvements support continuation of CCIM testing with an improved feed composition and improved melter system.

  17. Love thy nature

    National Research Council Canada - National Science Library

    Rokab, Sylvie; Souda, Elaine; Raven, Tamra; Roland, David Garfield; Chitraker, Rohan; Neeson, Liam; Rossi, Fernanda; Almeida, Eriberto

    2014-01-01

    Narrated by Liam Neeson, Love Thy Nature shows how deeply we've lost touch with nature, and takes viewers on a cinematic journey through the beauty and intimacy of our vital relationship with the natural world...

  18. Natural Language Processing.

    Science.gov (United States)

    Chowdhury, Gobinda G.

    2003-01-01

    Discusses issues related to natural language processing, including theoretical developments; natural language understanding; tools and techniques; natural language text processing systems; abstracting; information extraction; information retrieval; interfaces; software; Internet, Web, and digital library applications; machine translation for…

  19. Learning from nature: Nature-inspired algorithms

    DEFF Research Database (Denmark)

    Albeanu, Grigore; Madsen, Henrik; Popentiu-Vladicescu, Florin

    2016-01-01

    During last decade, the nature has inspired researchers to develop new algorithms. The largest collection of nature-inspired algorithms is biology-inspired: swarm intelligence (particle swarm optimization, ant colony optimization, cuckoo search, bees' algorithm, bat algorithm, firefly algorithm etc...... on collective social behaviour of organisms, researchers have developed optimization strategies taking into account not only the individuals, but also groups and environment. However, learning from nature, new classes of approaches can be identified, tested and compared against already available algorithms....... This work reviews the most effective nature-inspired algorithms and describes learning strategies based on nature oriented thinking. Examples and the benefits obtained from applying nature-inspired strategies in test generation, learners group optimization, and artificial immune systems for learning...

  20. Regularities, Natural Patterns and Laws of Nature

    Directory of Open Access Journals (Sweden)

    Stathis Psillos

    2014-02-01

    Full Text Available  The goal of this paper is to sketch an empiricist metaphysics of laws of nature. The key idea is that there are regularities without regularity-enforcers. Differently put, there are natural laws without law-makers of a distinct metaphysical kind. This sketch will rely on the concept of a natural pattern and more significantly on the existence of a network of natural patterns in nature. The relation between a regularity and a pattern will be analysed in terms of mereology.  Here is the road map. In section 2, I will briefly discuss the relation between empiricism and metaphysics, aiming to show that an empiricist metaphysics is possible. In section 3, I will offer arguments against stronger metaphysical views of laws. Then, in section 4 I will motivate nomic objectivism. In section 5, I will address the question ‘what is a regularity?’ and will develop a novel answer to it, based on the notion of a natural pattern. In section 6, I will raise the question: ‘what is a law of nature?’, the answer to which will be: a law of nature is a regularity that is characterised by the unity of a natural pattern.

  1. Natural Gas Transport

    OpenAIRE

    Tomás Correa; Nelson Osorio

    2009-01-01

    This paper reviews the present and future on natural gas transportation options, from oil and gas fields to markets, including liquefied natural gas, gas pipeline, compressed natural gas, natural gas hydrates, and gas to liquids and the perspectives of using them in Colombia, since this is the main fuel alternative to supply the world in at least the next 50 years.

  2. Natural Gas Transport

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2009-06-01

    Full Text Available This paper reviews the present and future on natural gas transportation options, from oil and gas fields to markets, including liquefied natural gas, gas pipeline, compressed natural gas, natural gas hydrates, and gas to liquids and the perspectives of using them in Colombia, since this is the main fuel alternative to supply the world in at least the next 50 years.

  3. The Nature of Natural Hazards Communication (Invited)

    Science.gov (United States)

    Kontar, Y. Y.

    2013-12-01

    Some of the many issues of interest to natural hazards professionals include the analysis of proactive approaches to the governance of risk from natural hazards and approaches to broaden the scope of public policies related to the management of risks from natural hazards, as well as including emergency and environmental management, community development and spatial planning related to natural hazards. During the talk we will present results of scientific review, analysis and synthesis, which emphasize same new trends in communication of the natural hazards theories and practices within an up-to-the-minute context of new environmental and climate change issues, new technologies, and a new focus on resiliency. The presentation is divided into five sections that focus on natural hazards communication in terms of education, risk management, public discourse, engaging the public, theoretical perspectives, and new media. It includes results of case studies and best practices. It delves into natural hazards communication theories, including diffusion, argumentation, and constructivism, to name a few. The presentation will provide information about: (1) A manual of natural hazards communication for scientists, policymakers, and media; (2) An up-to-the-minute context of environmental hazards, new technologies & political landscape; (3) A work by natural hazards scientists for geoscientists working with social scientists and communication principles; (4) A work underpinned by key natural hazards communication theories and interspersed with pragmatic solutions; (5) A work that crosses traditional natural hazards boundaries: international, interdisciplinary, theoretical/applied. We will further explore how spatial planning can contribute to risk governance by influencing the occupation of natural hazard-prone areas, and review the central role of emergency management in risk policy. The goal of this presentation is to contribute to the augmentation of the conceptual framework

  4. Nature's Nature: Ideas of Nature in Curricula for Environmental Education

    Science.gov (United States)

    St Maurice, Henry

    2006-01-01

    Two contrasting sets of ideas about nature in environmental education are described. An analytical framework is developed from inter-disciplinary histories of ideas and used in evaluating a specific curriculum. In conclusion, some general implications are suggested for curricula in environmental education. [This article was reprinted from…

  5. Naturally Colored Cotton

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Instead of using dye to color cotton, an Arizona cotton breeder is letting nature do the work. Through crossbreeding, Sally Fox of Natural Cotton Colours in Wickenberg is creating plants that yield fiber in an array

  6. Sunk Lake Natural Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Sunk Lake Natural Area Management Plan guides the long-range development of the Natural Area by identifying and integrating appropriate habitats, management...

  7. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  8. Vermont Natural Resources Atlas

    Data.gov (United States)

    Vermont Center for Geographic Information — The purpose of the Natural Resources Atlas is to provide geographic information about environmental features and sites that the Vermont Agency of Natural Resources...

  9. Natural gas annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    This document provides information on the supply and disposition of natural gas to a wide audience. The 1996 data are presented in a sequence that follows natural gas from it`s production to it`s end use.

  10. Natural Gas Basics

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-08

    Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide. Natural gas vehicles (NGVs) are a good choice for high-mileage fleets -- such as buses, taxis, and refuse vehicles -- that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. This brochure highlights the advantages of natural gas as an alternative fuel, including its domestic availability, established distribution network, relatively low cost, and emissions benefits.

  11. Natural Gas Basics

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-01

    Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide. Natural gas vehicles (NGVs) are a good choice for high-mileage fleets -- such as buses, taxis, and refuse vehicles -- that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. This brochure highlights the advantages of natural gas as an alternative fuel, including its domestic availability, established distribution network, relatively low cost, and emissions benefits.

  12. Natural Language Processing

    OpenAIRE

    Preeti; BrahmaleenKaurSidhu

    2013-01-01

    Natural language processing (NLP) work began more than sixty years ago; it is a field of computer science and linguistics devoted to creating computer systems that use human (natural) language. Natural Language Processing holds great promise for making computer interfaces that are easier to use for people, since people will be able to talk to the computer in their own language, rather than learn a specialized language of computer commands. Natural Language processing techniques can make possi...

  13. Natural gas annual 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-17

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1994 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1990 to 1994 for each Census Division and each State. Annual historical data are shown at the national level.

  14. Natural gas annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level.

  15. Passion, Rational, Nature

    Institute of Scientific and Technical Information of China (English)

    WU Ying

    2014-01-01

    Ralph Waldo Emerson and Henry David Thoreau, both being naturalists, emphasize a close relation between humans and nature. However, their views over the influences of nature towards human world are different in many aspects. Basing on a close discussion of“Nature”by Emerson and Walden by Thoreau, the paper would make a detailed comparison between the two naturalists’views over nature.

  16. Human nature and enhancement.

    Science.gov (United States)

    Buchanan, Allen

    2009-03-01

    Appeals to the idea of human nature are frequent in the voluminous literature on the ethics of enhancing human beings through biotechnology. Two chief concerns about the impact of enhancements on human nature have been voiced. The first is that enhancement may alter or destroy human nature. The second is that if enhancement alters or destroys human nature, this will undercut our ability to ascertain the good because, for us, the good is determined by our nature. The first concern assumes that altering or destroying human nature is in itself a bad thing. The second concern assumes that human nature provides a standard without which we cannot make coherent, defensible judgments about what is good. I will argue (1) that there is nothing wrong, per se, with altering or destroying human nature, because, on a plausible understanding of what human nature is, it contains bad as well as good characteristics and there is no reason to believe that eliminating some of the bad would so imperil the good as to make the elimination of the bad impermissible, and (2) that altering or destroying human nature need not result in the loss of our ability to make judgments about the good, because we possess a conception of the good by which we can and do evaluate human nature. I will argue that appeals to human nature tend to obscure rather than illuminate the debate over the ethics of enhancement and can be eliminated in favor of more cogent considerations.

  17. Nature in the City.

    Science.gov (United States)

    Ferbert, Mary Lou

    1981-01-01

    Describes a science program developed by the Cleveland Museum of Natural History, "Nature in the City," in which students and teachers learn together about the natural community surrounding their school. Includes program's rationale, list of "adventures," and methods. Discusses strategies of Sherlock Holmes'"adventure" focusing on animal tracks…

  18. Wordsworth and Nature

    Institute of Scientific and Technical Information of China (English)

    杨玉洁

    2013-01-01

    William Wordsworth was England’s Poet Laureate. He is the Romantic poet who is most often described as a“na⁃ture”write, and he is always sensitive to every subtle change in the world around him. In my opinion, his love for nature is boundless. To him, nature acts as a substitute for imaginative and intellectual engagement with the development of embodied hu⁃man beings in their diverse circumstances. It’s nature that gives him knowledge and strength. In this paper, I want to narrow Wordsworth’s conception of nature, and then we can find the harmony in the community of men and nature.

  19. Nature as Dissonant Heritage

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    concerns situations of mismatch between people and their heritage. The aim of the paper is to uncover the latent cultural dissonance in relation to nature restoration and to explain how landscape architecture could play an important role in the management of this dissonance. If one accepts that heritage...... of others, or in how landscapes sometimes are zones to accommodate different natures. In both cases the heritage production or nature restoration divides rather than unites. However, landscape architecture might provide an alternative approach to nature restoration that unites rather than divides......-evident. But who define and decide what kind of nature to restore? And is nature restoration not a contradiction in terms in our deeply cultivated landscapes? To examine these questions it makes sense to draw parallels between nature restoration and the concept of ‘dissonant heritage’ (Ashworth 2010), which...

  20. On nature and bioethics.

    Science.gov (United States)

    Peterson, Paul Silas

    2010-01-01

    The account of nature and humanity's relationship to nature are of central importance for bioethics. The Scientific Revolution was a critical development in the history of this question and many contemporary accounts of nature find their beginnings here. While the innovative approach to nature going out of the seventeenth century was reliant upon accounts of nature from the early modern period, the Middle Ages, late-antiquity and antiquity, it also parted ways with some of the understandings of nature from these epochs. Here I analyze this development and suggests that some of the insights from older understandings of nature may be helpful for bioethics today, even if there can be no simple return to them.

  1. Human Nature and the Nature of Science.

    Science.gov (United States)

    Stevens, Richard J.

    1988-01-01

    Examines the procedural and philosophical perspectives taken by science in examining human characteristics. Discusses the different levels of accuracy of various scientific fields. Encourages discussion of what biological and behavioral sciences can and cannot reveal about complex human nature. Considers some characteristics of quality science…

  2. Nature as Dissonant Heritage

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2014-01-01

    Many former sites of land reclamation, where rivers and wetlands have been cultivated for the purpose of modern agriculture, are now subject to projects of nature restoration. In this context nature is often referred to as ‘the nature’ or simply ‘nature’ as it was something objective and self......-evident. But who define and decide what kind of nature to restore? And is nature restoration not a contradiction in terms in our deeply cultivated landscapes? To examine these questions it makes sense to draw parallels between nature restoration and the concept of ‘dissonant heritage’ (Ashworth 2010), which...... concerns situations of mismatch between people and their heritage. The aim of the paper is to uncover the latent cultural dissonance in relation to nature restoration and to explain how landscape architecture could play an important role in the management of this dissonance. If one accepts that heritage...

  3. Engineered Natural Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — With its pressure vessels that simulate the pressures and temperatures found deep underground, NETL’s Engineered Natural Systems Laboratory in Pittsburgh, PA, gives...

  4. The City and Nature

    Directory of Open Access Journals (Sweden)

    Eduard Tovmasyan

    2016-09-01

    Full Text Available Animate “nature–1” around us is transforming into supported or non-supported by man “nature-2” within the framework of the urban development of town areas. Interaction of town and nature is a bilateral process. Experts underline 4 groups of town planning risks related to the interaction of town and nature: ecological, natural and biosphere, sanitary-epidemiologic risks as well as planning and management risks. The latter is often connected with protest population activities. The magazine is looking forward to readers comments.

  5. Natural gas annual 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

  6. A mathematical nature walk

    CERN Document Server

    Adam, John A

    2009-01-01

    How heavy is that cloud? Why can you see farther in rain than in fog? Why are the droplets on that spider web spaced apart so evenly? If you have ever asked questions like these while outdoors, and wondered how you might figure out the answers, this is a book for you. An entertaining and informative collection of fascinating puzzles from the natural world around us, A Mathematical Nature Walk will delight anyone who loves nature or math or both. John Adam presents ninety-six questions about many common natural phenomena--and a few uncommon ones--and then shows how to answer them using mostly b

  7. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  8. On Teaching Natural Law.

    Science.gov (United States)

    Forte, David F.

    1978-01-01

    A brief look at Columbia, Harvard, and Notre Dame law schools shows that the American tradition in teaching natural law has not been strong. The value of teaching natural law is discussed, a separate course or seminar is seen as the most effective option, and a selection of available sources for such a course is appended. (JMD)

  9. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  10. Nature as Measure

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    The potential for biomimicry lies far beyond the direct imitation of natural forms. Guest-editor Terri Peters describes how Janine Benyus, the biologist and innovation consultant, is using biomimicry to create performance metrics from natural technologies and processes for assessing aspects...

  11. Defects in Human Nature

    Institute of Scientific and Technical Information of China (English)

    黄靓

    2008-01-01

    By tracing the defects of society back to the defects of human nature, humanity's essence is proved to be inherent evil. Man's natural tendency to do evil remain harnessed through the controls and conventions imposed by civilization, however, when rules or civilization are weakened, man' s dark side is unleashed.

  12. Nature Foil Reliefs

    Science.gov (United States)

    Lane, Shaw J.

    2012-01-01

    Nature has always been a source of inspiration for artists across the centuries. Artists such as Leonardo da Vinci, Georgia O'Keeffe, Ansel Adams, and Andy Goldsworthy all drew inspiration for their work from nature. Seeds come from the dried pods, which when planted and cared for, bear fruit. In this article, the author describes how her…

  13. Nature Experience and Education

    Science.gov (United States)

    Rathunde, Kevin

    2013-01-01

    Kevin Rathunde turns his research lens to the task of finding out the relevance of the natural world, its impact on adolescent motivation, and its positive sustaining of concentration and focus. He cites "disembodiment and denaturing" as needing to be countered by contact with nature, leading to higher creativity, less drudgery, and more…

  14. Sig'natur 3

    DEFF Research Database (Denmark)

    Wadskjær, Lise Fabricius; Guldager, Ida; Jepsen, Peter;

    Sig´natur 3 arbejder med: - kortlære - sundhed - dyrs overlevelse - tid - elektricitet - Danmark og Norden - affald - Livet i en sø......Sig´natur 3 arbejder med: - kortlære - sundhed - dyrs overlevelse - tid - elektricitet - Danmark og Norden - affald - Livet i en sø...

  15. Agriculture: Natural Events and Disasters

    Science.gov (United States)

    Natural Events and DiasastersInformation on Natural Events and Disasters. Every year natural disasters, such as hurricanes, floods, fires, earthquakes, and tornadoes, challenge agricultural production.

  16. Closer to Nature?

    DEFF Research Database (Denmark)

    Borkfelt, Sune; Kondrup, Sara; Röcklinsberg, Helena

    2015-01-01

    discourses in order to sell one image of animal welfare in intensive animal production while the actual production at the same time presupposes a quite different paradigm of animal welfare. Specifically, product advertising utilizes representations tied to concepts of naturalness in depictions of both animal...... lives and product processes as “natural”. Product marketing suggests a coherence between nature, production process (farm, animal), and end product, thereby creating associations that the lives of production animals are lived in nature and that their products bring a wholesome and sustainable...... naturalness to the consumer—thus attempting to display a green, eco-, climate-, and animal friendly production. By analyzing a number of cases from the Scandinavian food market, this paper thus illustrates the tensions between paradigms of animal welfare and concepts of naturalness as these are used in animal...

  17. Closer to nature?

    DEFF Research Database (Denmark)

    Borkfelt, Sune; Kondrup, Sara Vincentzen; Röcklinsberg, Helena

    2015-01-01

    discourses in order to sell one image of animal welfare in intensive animal production while the actual production at the same time presupposes a quite different paradigm of animal welfare. Specifically, product advertising utilizes representations tied to concepts of naturalness in depictions of both animal...... lives and product processes as “natural”. Product marketing suggests a coherence between nature, production process (farm, animal), and end product, thereby creating associations that the lives of production animals are lived in nature and that their products bring a wholesome and sustainable...... naturalness to the consumer—thus attempting to display a green, eco-, climate-, and animal friendly production. By analyzing a number of cases from the Scandinavian food market, this paper thus illustrates the tensions between paradigms of animal welfare and concepts of naturalness as these are used in animal...

  18. Thermoacoustic natural gas liquefier

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.; Gardner, D.; Hayden, M.; Radebaugh, R. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Wollan, J. [Cryenco, Inc. (United States)

    1996-07-01

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to develop a natural-gas-powered natural-gas liquefier that has absolutely no moving parts and requires no electrical power. It should have high efficiency, remarkable reliability, and low cost. The thermoacoustic natural-gas liquefier (TANGL) is based on our recent invention of the first no-moving-parts cryogenic refrigerator. In short, our invention uses acoustic phenomena to produce refrigeration from heat, with no moving parts. The required apparatus comprises nothing more than heat exchangers and pipes, made of common materials, without exacting tolerances. Its initial experimental success in a small size lead us to propose a more ambitious application: large-energy liquefaction of natural gas, using combustion of natural gas as the energy source. TANGL was designed to be maintenance-free, inexpensive, portable, and environmentally benign.

  19. A natural monopoly in natural gas transmission

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, D.V.; Gunsch, K.; Pawluk, C.V. [Department of Economics, University of Calgary, 2500 University Dr. NW, Calgary, AB (Canada) T2N 1N4

    2003-09-01

    In this article, we test for subadditivity in the cost structure associated with transporting natural gas by Trans-Canada Pipelines Ltd. and measure for possible cost savings from increased competition that could be realized by removing the monopoly status granted by the National Energy Board. In measuring subadditivity, we apply both the Baumol et al. (Contestable Markets and the Theory of Industry Structure (1982)) and the Evans and Heckman (Am. Econ. Rev. 764 (1984) 613) procedures. Our results show evidence of subadditivity in the cost structure, and consequently, the possible benefits from increased competition resulting from splitting up the monopoly could be offset by the sacrifice of scale efficiencies.

  20. Almacenamiento de gas natural

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2008-12-01

    Full Text Available The largest reserves of natural gas worldwide are found in regions far of main cities, being necessary different alternatives to transport the fluid to the consumption cities, such as pipelines, CNG or ships, LNG, depending on distances between producing regions and demanding regions and the producing volumes. Consumption regions have three different markets to naturalgas; residential and commercial, industrial and power generation sector. The residential and commercial is highly seasonal and power generation sector is quite variable depending on increases of temperature during summer time. There are also external issuesthat affect the normal gas flow such as fails on the national system or unexpected interruptions on it, what imply that companies which distribute natural gas should design plans that allow supplying the requirements above mentioned. One plan is using underground natural gas storage with capacities and deliverability rates enough to supply demands. In Colombia there are no laws in this sense but it could be an exploration to discuss different ways to store gas either way as underground natural gas storage or above superficies. Existing basically three different types of underground natural gas storage; depleted reservoirs, salt caverns and aquifers. All ofthem are adequate according to geological characteristics and the needs of the distributors companies of natural gas. This paper is anexploration of technical and economical characteristics of different kind of storages used to store natural gas worldwide.

  1. Living in cities, naturally.

    Science.gov (United States)

    Hartig, Terry; Kahn, Peter H

    2016-05-20

    Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas.

  2. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2003-01-01

    It seemens that some very basic randomly produced geometric/topological patterns are commonly found in Nature and have often very distinctive structural qualities. In Nature we find the same pattern in all scales from the universe to molecules, from solar systems to packing of cells, from glaciers...... to sea shells, from river systems to trees etc. Sometimes this seeming archetypical morphology involve structrual action and sometimes not-but the fact that it often posses efficient structural action opens a tool for evaluation and analysis of structures in nature and at the same time might...

  3. Structural patterns in nature

    DEFF Research Database (Denmark)

    Wester, Ture

    2004-01-01

    It seems that some very basic randomly produced geometric/topological patterns are commonly found in Nature and have often very distinctive structural qualities. In nature we find the same pattern in all scales from the universe to molecules, from solar systems to packing of cells, from glaciers...... to sea shells, from river systems to trees etc. Sometimes this seeming archetypical morphology involve structural action and sometimes not - but the fact that it often posses efficient structural action opens a tool for evaluation and analyses of structures in nature and at the same time might...

  4. Natural Gas Market Hubs

    Data.gov (United States)

    Department of Homeland Security — A hub is a physical transfer point for natural gas where several pipelines are connected. A market center is a hub where the operator offers services that facilitate...

  5. Natural Hazards Image Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Photographs and other visual media provide valuable pre- and post-event data for natural hazards. Research, mitigation, and forecasting rely on visual data for...

  6. The "Natural Law Tradition."

    Science.gov (United States)

    Finnis, John

    1986-01-01

    A discussion of natural law outlines some of the theory and tradition surrounding it and examines its relationship to the social science and legal curriculum and to the teaching of jurisprudence. (MSE)

  7. Natural Gas Liquid Pipelines

    Data.gov (United States)

    Department of Homeland Security — Natural gas interstate and intrastate pipelines in the United States. Based on a variety of sources with varying scales and levels of accuracy and therefore accuracy...

  8. Nature in Hotel

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Marriott International and Conservation International recently partnered up to form Nobility of Nature, an ambitious program providing grants to sustainable conservation efforts for preserving fresh water sources in China. The first such initiative was to provide

  9. Natural Gas Acquisition Program

    Data.gov (United States)

    General Services Administration — The "NGAP" system is a web based application which serves NGAP GSA users for tracking information details for various natural gas supply chain elements like Agency,...

  10. Is image steganography natural?

    Science.gov (United States)

    Martín, Alvaro; Sapiro, Guillermo; Seroussi, Gadiel

    2005-12-01

    Steganography is the art of secret communication. Its purpose is to hide the presence of information, using, for example, images as covers. We experimentally investigate if stego-images, bearing a secret message, are statistically "natural." For this purpose, we use recent results on the statistics of natural images and investigate the effect of some popular steganography techniques. We found that these fundamental statistics of natural images are, in fact, generally altered by the hidden "nonnatural" information. Frequently, the change is consistently biased in a given direction. However, for the class of natural images considered, the change generally falls within the intrinsic variability of the statistics, and, thus, does not allow for reliable detection, unless knowledge of the data hiding process is taken into account. In the latter case, significant levels of detection are demonstrated.

  11. Natural and political markets

    DEFF Research Database (Denmark)

    Tryggestad, Kjell

    2003-01-01

    as well as its master - the puretechnological relations. Neither the Natural market, nor Homo economicus can be brought intoexistence without pure technological relations. The existence of the latter is a necessary conditionfor the existence of the two former, as has already been recognized......technologies, natural markets and rational identities like homo economicus into existence, requirehuge investments, as do their maintenance. Technical knowledge turned out to be no exception. Asthe case suggests, technical knowledge was not just a given condition, but became a producedoutcome. Yet, the process...... the firms on both sides of the market, the government, the engineering-scientists,the economists, the union representatives and the machinists.It is argued that Natural markets is a special case of political markets in which technologies andhybrid entities and identities produce both the Natural market...

  12. Biomimetics: nature based innovation

    National Research Council Canada - National Science Library

    Bar-Cohen, Yoseph

    2012-01-01

    "Based on the concept that nature offers numerous sources of inspiration for inventions related to mechanisms, materials, processes, and algorithms, this book covers the topic of biomimetics and the inspired innovation...

  13. Art, Technology and Nature

    DEFF Research Database (Denmark)

    Since 1900, the connections between art and technology with nature have become increasingly inextricable. Through a selection of innovative readings by international scholars, this book presents the first investigation of the intersections between art, technology and nature in post-medieval times....... Transdisciplinary in approach, this volume’s 14 essays explore art, technology and nature’s shifting constellations that are discernible at the micro level and as part of a larger chronological pattern. Included are subjects ranging from Renaissance wooden dolls, science in the Italian art academies, and artisanal...... Camilla Skovbjerg Paldam and Jacob Wamberg trace the Kantian heritage of radically separating art and technology, and inserting both at a distance to nature, suggesting this was a transient chapter in history. Thus, they argue, the present renegotiation between art, technology and nature is reminiscent...

  14. The Nature of Grammar

    Institute of Scientific and Technical Information of China (English)

    王楠

    2012-01-01

    This paper describes the nature of grammar as "universalness". The universal grammar indicates that all the languages in the world have identical grammar. This is discussed from three aspects, which gives insight into grammar acquisition.

  15. Natural history of glaucoma

    National Research Council Canada - National Science Library

    Pan, Ying; Varma, Rohit

    2011-01-01

    .... This paper presents the natural history of open angle and angle closure glaucoma. We examine the glaucomatous progression in terms of changes in optic disk morphology and visual fields as well as the risk factors for progression...

  16. Managing soil natural capital

    DEFF Research Database (Denmark)

    Cong, Ronggang; Termansen, Mette; Brady, Mark

    2017-01-01

    Farmers are exposed to substantial weather and market related risks. Rational farmers seek to avoid large losses. Future climate change and energy price fluctuations therefore make adaptating to increased risks particularly important for them. Managing soil natural capital—the capacity of the soil...... to generate ecosystem services of benefit to farmers—has been proven to generate the double dividend: increasing farm profit and reducing associated risk. In this paper we explore whether managing soil natural capital has a third dividend: reducing the downside risk (increasing the positive skewness of profit......). This we refer to as the prudence effect which can be viewed as an adaptation strategy for dealing with future uncertainties through more prudent management of soil natural capital. We do this by developing a dynamic stochastic portfolio model to optimize the stock of soil natural capital—as indicated...

  17. Web life: Ask Nature

    Science.gov (United States)

    2012-11-01

    Ask Nature is a site devoted to biomimicry, an interdisciplinary field in which practitioners study how animals and plants solve problems, and then use those solutions to develop better human technologies.

  18. Natural Killer Cell Memory

    National Research Council Canada - National Science Library

    O'Sullivan, Timothy E; Sun, Joseph C; Lanier, Lewis L

    2015-01-01

    Natural killer (NK) cells have historically been considered short-lived cytolytic cells that can rapidly respond against pathogens and tumors in an antigen-independent manner and then undergo cell death...

  19. Vermont Designated Natural Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Under Natural Areas Law (10 Vermont Statutes Annotated, Chapter 83 § 2607) the FPR commissioner, with the approval of the governor, may designate and set aside areas...

  20. 5. Natural Family Planning

    African Journals Online (AJOL)

    Sitwala

    influencing utilization of Natural Family Planning .... Because of the potential benefits of FP, it is important to any community ... Data was collected over a period of 4 months after approval ..... The DHMT to educate parents on the importance of.

  1. Lesson "Balance in Nature

    Science.gov (United States)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  2. Natural polymers: an overview

    CSIR Research Space (South Africa)

    John, MJ

    2012-08-01

    Full Text Available bioplastics. There are two main types of natural polymers: those that come from living organisms (these include carbohydrates and proteins); and, those which need to be polymerized but come from renewable resources (lactic acid and triglycerides). Both... types are used in the production of bio-plastics. Among the different types of natural polymers, the best known resources capable of making biodegradable plastics are starch and cellulose. Cellulose is the most abundant carbohydrate in the world ? 40...

  3. Natural rubber: leather composites

    OpenAIRE

    K. Ravichandran; N. Natchimuthu

    2005-01-01

    Leather is a fibrous protein consisting of collagen in a three dimensionally crosslinked network. Chrome tanning of leather improves the appearance of leather but at the same time emits both solid and liquid chrome leather wastes. Scrap rubber recycling using untreated and neutralized leather fibrous particles in natural rubber has been studied. Vulcanization, mechanical, morphological and swelling properties of the natural rubber - scrap rubber composites containing neutralized leather have ...

  4. The system of nature

    CERN Document Server

    D'Holbac, Baron

    1999-01-01

    "The source of Man's unhappiness is his ignorance of Nature."D'Holbach believed that the misery he saw in mankind around him was caused by religion and its superstitious beliefs - that there was a God who controlled destiny and would reward or punish individuals. The System of Nature was written to replace these delusions with a schema of understanding based solely on the physical workings of nature. "Let Man study this nature, let him learn her laws, contemplate her energies." For d'Holbach the soul is only the physical body, understood from a certain point of view, which dies when the body dies. All the events and the nature of the world can be understood in terms of the motion and properties of matter; even the tiniest causes contribute to huge events - a simple change in the diet of an Emperor (or some other such insignificant cause), he suggests might have been capable of "saving kingdoms." For him, nature's laws are fixed and necessary, and if Man wants to find happiness it is best to accept this - if g...

  5. Natural Resource Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Green, T. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Schwager, K. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2016-10-01

    This comprehensive Natural Resource Management Plan (NRMP) for Brookhaven National Laboratory (BNL) was built on the successful foundation of the Wildlife Management Plan for BNL, which it replaces. This update to the 2003 plan continues to build on successes and efforts to better understand the ecosystems and natural resources found on the BNL site. The plan establishes the basis for managing the varied natural resources located on the 5,265-acre BNL site, setting goals and actions to achieve those goals. The planning of this document is based on the knowledge and expertise gained over the past 15 years by the Natural Resources management staff at BNL in concert with local natural resource agencies including the New York State Department of Environmental Conservation, Long Island Pine Barrens Joint Planning and Policy Commission, The Nature Conservancy, and others. The development of this plan works toward sound ecological management that not only benefits BNL’s ecosystems but also benefits the greater Pine Barrens habitats in which BNL is situated. This plan applies equally to the Upton Ecological and Research Reserve (Upton Reserve). Any difference in management between the larger BNL area and the Upton Reserve are noted in the text.

  6. Blackouts and natural risks

    Science.gov (United States)

    Danihelka, P.; Paldusová, E.; Dobeš, P.

    2009-04-01

    "Blackout" has become the common definition for the situation when electricity supply and demand are not balanced and security of supply fails. These failures have many impacts besides the lights going out, but this term is used commonly. Blackouts have drastic impacts for the society on whole and its citizens and some of them can influence big areas and last for long period, so the consequences are catastrophic. Even if at the European scale, the large extend blackouts are supposed to be exceptional, real frequency is relatively high, approximately once per two years. According to statistics, blackouts are often caused by natural causes, especially lightning. An example of lightning caused blackout is New York blackout 1977, leading to the stand-by of nuclear power plant Indian Point and with overall cost more than 300 mil. USD. There is a clear a distinction between those blackouts caused by nature and those that were caused by other faults. Usually, the nature-caused disturbances as Canada 1988, Sweden 2005 and France 1999, stay inside one country. However, their duration can extend to several weeks, and thus the costs of the interruptions and social impacts are high. Blackouts of only technologic and/or anthropogenic origin are frequently shorter, but may concern more end-users, when cascading from one country to another. Lightning is not the only natural event causing blackouts. Eighteen various case studies of blackout caused by natural events different then lightning were studied and following natural phenomenon found as a root causes: 1x forest fire, 1x snow calamity, 1x ice storm, 1x landslide, 1x high temperature, 1x geomagnetic storm, 2x earthquake, 2x inundation, 2x contact of line with trees, 6x storm (wind, hurricane…). We can conclude, that natural event are frequent cause of blackout of medium or large extend and this phenomena should be studied more in details. This contribution was supported by Ministry of Environment of the Czech Republic.

  7. Livelihoods and natural resources

    DEFF Research Database (Denmark)

    Cotta, Jamie Nicole

    This dissertation research contributes to the emerging body of knowledge on the economic contributions of natural resources to rural livelihoods, including their role in household shock coping, in the humid tropics. Data from one of the first comprehensive household income quantifications...... high degree of natural resource reliance compared to other forested regions (an average 42% of household income derived from forest and agroforestry products, plus 14% derived from fishing). Results from household shock coping surveys highlight the safety net functions of forest and fishery products......, particularly following a widespread flood, when crops and livestock are lost and mutual assistance is compromised. Furthermore, ethnicity, market distance, resource type/proximity, and household wealth, among other variables, are all significant determinants of natural resource harvest for household income...

  8. nature in the city

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2016-09-01

    The object of the issue is a wonderful museum on the Kulikovo Field designed by Sergey Gnedovsky. The unusual architecture of the new museum makes it akin to the earth’s tectonic fault caused by an intolerable tension in expectation of the battle (pp. 113-123. Oleg Yavein and Ilya Lezhava bring us back to the classic of the 20th century Mies van der Rohe and his unique dialogue with nature (pp. 162-175. Relationship between architecture and nature is a rich and limitless theme, like both of these substances. That is why the new Project Baikal issue contains, as usual, more questions than answers. Such is the nature of our journal.

  9. Antiplasmodial Natural Products

    Directory of Open Access Journals (Sweden)

    Cláudio R. Nogueira

    2011-03-01

    Full Text Available Malaria is a human infectious disease that is caused by four species of Plasmodium. It is responsible for more than 1 million deaths per year. Natural products contain a great variety of chemical structures and have been screened for antiplasmodial activity as potential sources of new antimalarial drugs. This review highlights studies on natural products with antimalarial and antiplasmodial activity reported in the literature from January 2009 to November 2010. A total of 360 antiplasmodial natural products comprised of terpenes, including iridoids, sesquiterpenes, diterpenes, terpenoid benzoquinones, steroids, quassinoids, limonoids, curcubitacins, and lanostanes; flavonoids; alkaloids; peptides; phenylalkanoids; xanthones; naphthopyrones; polyketides, including halenaquinones, peroxides, polyacetylenes, and resorcylic acids; depsidones; benzophenones; macrolides; and miscellaneous compounds, including halogenated compounds and chromenes are listed in this review.

  10. Natural photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  11. Nature/culture/seawater.

    Science.gov (United States)

    Helmreich, Stefan

    2011-01-01

    Seawater has occupied an ambiguous place in anthropological categories of "nature" and "culture." Seawater as nature appears as potentiality of form and uncontainable flux; it moves faster than culture - with culture frequently figured through land-based metaphors - even as culture seeks to channel water's (nature's) flow. Seawater as culture manifests as a medium of pleasure, sustenance, travel, disaster. I argue that, although seawater's qualities in early anthropology were portrayed impressionistically, today technical, scientific descriptions of water's form prevail. For example, processes of globalization - which may also be called "oceanization" - are often described as "currents," "flows," and "circulations." Examining sea-set ethnography, maritime anthropologies, and contemporary social theory, I propose that seawater has operated as a “theory machine” for generating insights about human cultural organization. I develop this argument with ethnography from the Sargasso Sea and in the Sea Islands. I conclude with a critique of appeals to water's form in social theory.

  12. Greenland and Natural Resources

    DEFF Research Database (Denmark)

    Lyck, Lise

    Greenland policy can delay and maybe change the future of the forecasted development of the use of natural resources. This book is relevant for anyone interested in Greenland in general and the development of Greenland both politically and economically and in relation natural resources.......The Greenland development is a story about: Having a hinterland position in relation to the global development. An indigenous people achieving more political influence. How conflicts and discussions on power and ownership of the subsurface resources between a state and an autonomy (Home Rule) can...

  13. Natural language modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, J.K. [Sandia National Labs., Albuquerque, NM (United States)

    1997-11-01

    This seminar describes a process and methodology that uses structured natural language to enable the construction of precise information requirements directly from users, experts, and managers. The main focus of this natural language approach is to create the precise information requirements and to do it in such a way that the business and technical experts are fully accountable for the results. These requirements can then be implemented using appropriate tools and technology. This requirement set is also a universal learning tool because it has all of the knowledge that is needed to understand a particular process (e.g., expense vouchers, project management, budget reviews, tax, laws, machine function).

  14. A Naturally Attractive Supermodel

    CERN Document Server

    Cohen, Timothy; Torroba, Gonzalo

    2012-01-01

    We propose an attractor mechanism which generates the "more minimal" supersymmetric standard model from a broad class of supersymmetry breaking boundary conditions. The hierarchies in the fermion masses and mixings are produced by the same dynamics and a natural weak scale results from gaugino mediation. These features arise from augmenting the standard model with a new SU(3) gauge group under which only the third generation quarks are charged. The theory flows to a strongly interacting fixed point which induces a negative anomalous dimension for the third generation quarks and a positive anomalous dimension for the Higgs. As a result, a split-family natural spectrum and the flavor hierarchies are dynamically generated.

  15. Natural Selection and Morality

    Directory of Open Access Journals (Sweden)

    Alejandro Rosas

    2006-12-01

    Full Text Available Resumen:En este ensayo abordo los intentos, relativamente recientes, de dar una explicación de la moralidad como adaptación por selección natural. Mi exposición tiene una introducción y cuatro partes: en la primera explico en qué consiste la paradoja del altruismo biológico. En la segunda expongo la solución que apela a la selección de grupos, recientemente resurgida; la solución que presuntamente aplicó Charles Darwin cuando formuló sus reflexiones biológicas sobre la moralidad humana. En la tercera expongo la solución sociobiológica, que opta por negar que la selección natural pueda explicar directamente la moralidad humana. La moralidad se presenta más bien como opuesta a la naturaleza diseñada por selección natural. En la cuarta parte desarrollo brevemente una explicación de la moralidad como adaptación que beneficia a los individuos. No opone la moralidad a la naturaleza, ni apela a la selección de grupos. Se sirve de un mecanismo de selección que opera a través de preferencias en la interacción social.Abstract:In this essay, I address recent attempts to account for morality as an adaptation due to natural selection. After a brief introduction, my exposition has four sections. I first explain the paradox of biological altruism. Second, I explain the solution to the paradox in terms of group selection. This solution was presumably applied by Darwin himself as he discussed human morality, and it has experienced a recent revival, though it remains suspicious to most biologists. In the third section I offer a socio-biological solution that opts for denying that morality can be explained by any form of natural selection. Morality is opposed to human nature as designed by natural selection. In the fourth, I argue for an explanation in terms of individual selection. It does not oppose morality to nature, and does not need the workings of group selection; rather, it operates through the agents’ psychological preferences

  16. Natures of Conduct

    DEFF Research Database (Denmark)

    Sielemann, Rasmus Basse

    Natures of Conduct explores the rationalities, practices and techniques of government processes in the Danish West Indies in the period between the late eighteenth century to the end of Danish colonial rule in 1917. In doing so, it engages Michel Foucault’s concepts of governmentality and the ‘di......Natures of Conduct explores the rationalities, practices and techniques of government processes in the Danish West Indies in the period between the late eighteenth century to the end of Danish colonial rule in 1917. In doing so, it engages Michel Foucault’s concepts of governmentality...

  17. Natural hazards in Australia

    DEFF Research Database (Denmark)

    Kiem, Anthony S.; Johnson, Fiona; Westra, Seth

    2016-01-01

    Droughts are a recurrent and natural part of the Australian hydroclimate, with evidence of drought dating back thousands of years. However, our ability to monitor, attribute, forecast and manage drought is exposed as insufficient whenever a drought occurs. This paper summarises what is known about...... characteristics with seasonal to multidecadal lead times and including more realistic modelling of the multiple factors that cause (or contribute to) drought so that the impacts of natural variability and anthropogenic climate change are accounted for and the reliability of long-term drought projections increases....

  18. MENOPAUSE AND NATURAL HEALING

    Directory of Open Access Journals (Sweden)

    Lucija Vrabič Dežman

    2008-12-01

    The studies could not decisively confirm the effectiveness of various phytoestrogens inamelioration of climacteric symptoms. Most studies have proven the effectiveness of thenatural medication made of Cimicifuga racemosa and its safe short-term use. Gynecologists should be familiar with the basics of phytotherapy and the results of clinical studiesin this field in order to confidently advise women to use the natural medications in caseswhere despite the climacteric symptoms they cannot or will not use HRT, consequentlygreatly reducing the quality of their lives. In cases where climacteric symptoms are mild tomoderate, some menopausal societies around the globe suggest trying natural medicationfirst, and only later implementing HRT

  19. Enhance Nature Exploration with Technology

    Science.gov (United States)

    Holloway, Patricia; Mahan, Carol

    2012-01-01

    Kids and nature seem like a natural combination, but what was natural a generation ago is different today. Children are spending less time outdoors but continue to need nature for their physical, emotional, and mental development. This fact has led author Richard Louv to suggest that today's children are suffering from "nature-deficit disorder"…

  20. Enhance Nature Exploration with Technology

    Science.gov (United States)

    Holloway, Patricia; Mahan, Carol

    2012-01-01

    Kids and nature seem like a natural combination, but what was natural a generation ago is different today. Children are spending less time outdoors but continue to need nature for their physical, emotional, and mental development. This fact has led author Richard Louv to suggest that today's children are suffering from "nature-deficit disorder"…

  1. Petrography and chemistry of tungsten-rich oxycalciobetafite in hydrothermal veins of the Adamello contact aureole, northern Italy

    Science.gov (United States)

    Lumpkin, Gregory R.; Gieré, Reto; Williams, C. Terry; McGlinn, Peter J.; Payne, Timothy E.

    2017-07-01

    Tungsten-rich oxycalciobetafite occurs in complex Ti-rich hydrothermal veins emplaced within dolomite marble in the contact aureole of the Adamello batholith, northern Italy, where it occurs as overgrowths on zirconolite. The betafite is weakly zoned and contains 29-34 wt% UO2. In terms of end-members, the betafite contains approximately 50 mol% CaUTi2O7 and is one of the closest known natural compositions to the pyrochlore phase proposed for use in titanate nuclear waste forms. Amorphization and volume expansion of the betafite caused cracks to form in the enclosing silicate mineral grains. Backscattered electron images reveal that betafite was subsequently altered along crystal rims, particularly near the cracks. Electron probe microanalyses reveal little difference in composition between altered and unaltered areas, except for lower totals, suggesting that alteration is primarily due to hydration. Zirconolite contains up to 18 wt% ThO2 and 24 wt% UO2, and exhibits strong compositional zoning, but no internal cracking due to differential (and anisotropic) volume expansion and no visible alteration. The available evidence demonstrates that both oxycalciobetafite and zirconolite retained actinides for approximately 40 million years after the final stage of vein formation. During this time, oxycalciobetafite and zirconolite accumulated a total alpha-decay dose of 3.0-3.6 × 1016 and 0.2-2.0 × 1016 α/mg, respectively.

  2. BEYOND NATURE AND CULTURE

    Directory of Open Access Journals (Sweden)

    Philippe Descola

    2015-06-01

    Full Text Available Tradução de Bruno Ribeiro. Original: DESCOLA, Philippe. ‘Beyond Nature and Culture’, Proceedings of the British Academy, volume 139, pp. 137-155. © British Academy 2006. Clique em PDF para acessar a tradução.

  3. Shooting mechanisms in nature

    NARCIS (Netherlands)

    Sakes, Aimée; Wiel, van der Marleen; Henselmans, Paul W.J.; Leeuwen, van Johan L.; Dodou, Dimitra; Breedveld, Paul

    2016-01-01

    Background In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these m

  4. Wasserpflanzen in der Natur

    DEFF Research Database (Denmark)

    Pedersen, Ole; Christensen, Claus

    2011-01-01

    Unsere Aquarienpflanzen kommen in der Natur vor oder sind Zuchtformen natürlicher Arten. Dennoch konnten erst sehr wenige Aquarianer diese Pflanzen in ihrer natürlichen Umgebung beobachten. Oft stellten sie fest, dass die Pflanzen meist ganz anders aussehen als im Aquarium. Neben einem ständigen ...

  5. Shooting mechanisms in nature

    NARCIS (Netherlands)

    Sakes, Aimée; Wiel, van der Marleen; Henselmans, Paul W.J.; Leeuwen, van Johan L.; Dodou, Dimitra; Breedveld, Paul

    2016-01-01

    Background In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

  6. Scenarios for nature development

    NARCIS (Netherlands)

    Harms, W.B.

    1995-01-01

    A procedure in backcasting scenarios is presented. Two case-studies differing in scale illustrate the differences in ecological contribution to plan design and to plan evaluation. Scenarios for nature development are presented for both case-studies, based on ecological objectives and spatial strateg

  7. Cultivating human nature

    NARCIS (Netherlands)

    Derksen, Maarten

    2007-01-01

    Evolutionary psychology claims to offer a unified perspective on human nature and culture, which can serve to further the integration of psychology and the social sciences. I describe four approaches to evolutionary psychology, and note increasing attention to the agency of the individual in constru

  8. Nature, Education and Things

    Science.gov (United States)

    Rømer, Thomas Aastrup

    2013-01-01

    In this essay it is argued that the educational philosophy of John Dewey gains in depth and importance by being related to his philosophy of nature, his metaphysics. The result is that any experiental process is situated inside an event, an existence, a thing, and I try to interpret this "thing" as schools or major cultural events such…

  9. Patagonia: nature and territories

    Directory of Open Access Journals (Sweden)

    Alejandro Fabián Schweitzer

    2014-12-01

    This paper analyzes the place occupied by Patagonia in today’s fin de siècle scenario of commodities, hegemony crisis and multi-polar world emergence concurring with the convergence of consumerist guidelines, all of which would apparently lead to an in-depth socio-ecological crisis as well as to an accelerated dispute over nature and territory sense.

  10. Natural Resources Management Program

    Science.gov (United States)

    1989-01-24

    Program, activity, or opportunity dependent on the natural environment. Examples are hunting, fishing, trapping, picnick- ing, birdwatching , off-road...fair market value. d. Planned forest products sales shall continue on land reported as excess until actual disposal or transfer occurs. When forested

  11. Hauntings of Human Nature

    DEFF Research Database (Denmark)

    Clasen, Mathias

    2017-01-01

    The central conflicts of Stephen King’s horror novel The Shining are rooted in human nature and reflect evolutionarily recurrent adaptive problems—the problem of balancing conflicting evolved motives, such as motives for selfish status striving versus motives for affiliative nurturing behavior...

  12. When Facing Natural Disasters

    Institute of Scientific and Technical Information of China (English)

    Liu Xinwen

    2008-01-01

    @@ China last experienced a strong earthquake in 1976 in Tang Shan, Hehei Province. At the beginning of this year, severe snow storms struck more than half of China. What impact have these natural disasters left on China, especially the latest earthquake in Sichuan? Let's do a comparison.

  13. Radioactivity: A Natural Phenomenon.

    Science.gov (United States)

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  14. Architecture and Nature

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Chinese-American architect Maya Lin has become renowned by people in China recently because of her latest work-"What is Missing?" The multi-site project aims to raise public awareness of the current crisis surrounding biodiversity and habitat loss. Lin recently talked about the project’s background and her understanding of the relation between architecture and nature with Beijing Review.

  15. The Nature of Atoms.

    Science.gov (United States)

    Holden, Alan

    This monograph was written for the purpose of presenting physics to college students who are not preparing for careers in physics. It deals with the nature of atoms, and treats the following topics: (1) the atomic hypothesis, (2) the chemical elements, (3) models of an atom, (4) a particle in a one-dimensional well, (5) a particle in a central…

  16. Nature as Inspiration

    Science.gov (United States)

    Tank, Kristina; Moore, Tamara; Strnat, Meg

    2015-01-01

    This article describes the final lesson within a seven-day STEM and literacy unit that is part of the Picture STEM curriculum (pictureSTEM. org) and uses engineering to integrate science and mathematics learning in a meaningful way (Tank and Moore 2013). For this engineering challenge, students used nature as a source of inspiration for designs to…

  17. Demystifying Nature of Science

    Science.gov (United States)

    Lederman, Judith; Bartels, Selina; Lederman, Norman; Gnanakkan, Dionysius

    2014-01-01

    With the emergence of the "Next Generation Science Standards" ("NGSS"; NGSS Lead States 2013), it is apparent that teaching and learning about nature of science (NOS) continues to be an important goal of science education for all K-12 students. With this emphasis on NOS, early childhood teachers are asking how to design…

  18. Livelihoods and natural resources

    DEFF Research Database (Denmark)

    Cotta, Jamie Nicole

    , particularly following a widespread flood, when crops and livestock are lost and mutual assistance is compromised. Furthermore, ethnicity, market distance, resource type/proximity, and household wealth, among other variables, are all significant determinants of natural resource harvest for household income...

  19. Bosbus; mobile nature reserve

    NARCIS (Netherlands)

    Matton, T.; Kuypers, V.H.M.; Timmermans, W.

    2004-01-01

    Nature has discovered the global village. Over the years, hundreds of exotic plants and animals have made their way into the Netherlands. They take advantage of the existing urban infrastructure to seek out suitable niches in the city. People rarely think of these urban ecosystems in terms of

  20. Natural Gas Price Rises

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ As was projected in the third-quarter monetary policy implementation report published by the People's Bank of China on November 15th, 2006, the residents' consumption price index in China would reach 1.5% in 2006. Prices of consumer commodities such as water, power and natural gas would rise and the pressure of inflation would persist in the future.

  1. Nature, Education and Things

    Science.gov (United States)

    Rømer, Thomas Aastrup

    2013-01-01

    In this essay it is argued that the educational philosophy of John Dewey gains in depth and importance by being related to his philosophy of nature, his metaphysics. The result is that any experiental process is situated inside an event, an existence, a thing, and I try to interpret this "thing" as schools or major cultural events such…

  2. Surfaces with Natural Ridges

    DEFF Research Database (Denmark)

    Brander, David; Markvorsen, Steen

    2015-01-01

    We discuss surfaces with singularities, both in mathematics and in the real world. For many types of mathematical surface, singularities are natural and can be regarded as part of the surface. The most emblematic example is that of surfaces of constant negative Gauss curvature, all of which...

  3. Picturing the Natural Environment

    Science.gov (United States)

    Johnson, Phyllis Scott

    2011-01-01

    Around Scout Island Education Center, a site used by schools in Fresno County to explore the area's natural environment, a total of 200 cylinder-shaped concrete stools display tiles representing small mammals, flying insects, birds, wildflowers, and more. Twenty sets have been created by elementary, middle, and high-school art students as part of…

  4. A new nature

    DEFF Research Database (Denmark)

    Abraham, Anders

    2009-01-01

    ”A New Nature - 9 ARCHITECTURAL CONDITIONS BETWEEN LIQUID AND SOLID” opbygger en tankegang om arkitektur som tilstande i modsætning til arkitektur som form og type.  Ved at se på verden som tilstande og organiseringer mellem ”flydende” og ”fast”, homogent og heterogent m.v., er det muligt...

  5. Nature Identical Prosody

    DEFF Research Database (Denmark)

    Juel Henrichsen, Peter

    2012-01-01

    ; such as low naturalness (DiSyn) and dependence on huge amounts of background data (UnitSyn). We present a hybrid model based on high-level speech data. As preliminary tests show, prosodic models combining DiSyn style at the phone level with UnitSyn style at the supra-segmental levels may approach Unit...

  6. Demystifying Nature of Science

    Science.gov (United States)

    Lederman, Judith; Bartels, Selina; Lederman, Norman; Gnanakkan, Dionysius

    2014-01-01

    With the emergence of the "Next Generation Science Standards" ("NGSS"; NGSS Lead States 2013), it is apparent that teaching and learning about nature of science (NOS) continues to be an important goal of science education for all K-12 students. With this emphasis on NOS, early childhood teachers are asking how to design…

  7. Nature as Inspiration

    Science.gov (United States)

    Tank, Kristina; Moore, Tamara; Strnat, Meg

    2015-01-01

    This article describes the final lesson within a seven-day STEM and literacy unit that is part of the Picture STEM curriculum (pictureSTEM. org) and uses engineering to integrate science and mathematics learning in a meaningful way (Tank and Moore 2013). For this engineering challenge, students used nature as a source of inspiration for designs to…

  8. Natural history of COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Lange, Peter

    2016-01-01

    The natural history of chronic obstructive pulmonary disease (COPD) is usually described with a focus on change in forced expiratory volume in 1 s (FEV1 ) over time as this allows for exploration of risk factors for an accelerated decline-and thus of developing COPD. From epidemiological studies we...

  9. Surfaces with Natural Ridges

    DEFF Research Database (Denmark)

    Brander, David; Markvorsen, Steen

    2015-01-01

    We discuss surfaces with singularities, both in mathematics and in the real world. For many types of mathematical surface, singularities are natural and can be regarded as part of the surface. The most emblematic example is that of surfaces of constant negative Gauss curvature, all of which...

  10. Natural generalized mirage mediation

    Science.gov (United States)

    Baer, Howard; Barger, Vernon; Serce, Hasan; Tata, Xerxes

    2016-12-01

    In the supersymmetric scenario known as mirage mediation (MM), the soft supersymmetry (SUSY) breaking terms receive comparable anomaly-mediation and moduli-mediation contributions leading to the phenomenon of mirage unification. The simplest MM SUSY breaking models which are consistent with the measured Higgs mass and sparticle mass constraints are strongly disfavored by fine-tuning considerations. However, while MM makes robust predictions for gaugino masses, the scalar sector is quite sensitive to specific mechanisms for moduli stabilization and potential uplifting. We suggest here a broader setup of generalized mirage mediation (GMM), where heretofore discrete parameters are allowed as continuous to better parametrize these other schemes. We find that natural SUSY spectra consistent with both the measured value of mh as well as LHC lower bounds on superpartner masses are then possible. We explicitly show that models generated from natural GMM may be beyond the reach of even high-luminosity LHC searches. In such a case, the proposed International Linear e+e- Collider will be required for natural SUSY discovery via higgsino pair production reactions. We also outline prospects for detection of higgsino-like WIMPs from natural GMM.

  11. Battles Fought in Nature

    DEFF Research Database (Denmark)

    Poulsen, Dorthe Varning; Stigsdottir, Ulrika S.

    2015-01-01

    the contradiction between the large number of programs using nature-based therapy to treat veterans with Post Traumatic Stress Disorder (PTSD) and the small amount of scientific studies in the field. In order to increase knowledge in this field, a project was initiated in Denmark. The overall aim of the project was...

  12. Natural hazards science strategy

    Science.gov (United States)

    Holmes, Jr., Robert R.; Jones, Lucile M.; Eidenshink, Jeffery C.; Godt, Jonathan W.; Kirby, Stephen H.; Love, Jeffrey J.; Neal, Christina A.; Plant, Nathaniel G.; Plunkett, Michael L.; Weaver, Craig S.; Wein, Anne; Perry, Suzanne C.

    2012-01-01

    The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research - founded on detailed observations and improved understanding of the responsible physical processes - can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events. To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science. In October 2010, the Natural Hazards Science Strategy Planning Team (H-SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory

  13. Natural hazards science strategy

    Science.gov (United States)

    Holmes, Jr., Robert R.; Jones, Lucile M.; Eidenshink, Jeffery C.; Godt, Jonathan W.; Kirby, Stephen H.; Love, Jeffrey J.; Neal, Christina A.; Plant, Nathaniel G.; Plunkett, Michael L.; Weaver, Craig S.; Wein, Anne; Perry, Suzanne C.

    2012-01-01

    The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research—founded on detailed observations and improved understanding of the responsible physical processes—can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events.To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science.In October 2010, the Natural Hazards Science Strategy Planning Team (H–SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory

  14. RTE and Significant Natural Communities

    Data.gov (United States)

    Vermont Center for Geographic Information — The Vermont Fish and Wildlife Department's Natural Heritage Inventory (NHI) maintains a database of rare, threatened and endangered species and natural (plant)...

  15. Natural light illumination system.

    Science.gov (United States)

    Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

    2010-12-10

    In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

  16. Design, science and naturalism

    Science.gov (United States)

    Deming, David

    2008-09-01

    The Design Argument is the proposition that the presence of order in the universe is evidence for the existence of God. The Argument dates at least to the presocratic Greek philosophers, and is largely based on analogical reasoning. Following the appearance of Aquinas' Summa Theologica in the 13th century, the Christian Church in Europe embraced a Natural Theology based on observation and reason that allowed it to dominate the entire world of knowledge. Science in turn advanced itself by demonstrating that it could be of service to theology, the recognized queen of the sciences. During the heyday of British Natural Theology in the 17th and 18th centuries, the watchmaker, shipbuilder, and architect analogies were invoked reflexively by philosophers, theologians, and scientists. The Design Argument was not systematically and analytically criticized until David Hume wrote Dialogues on Natural Religion in the 1750s. After Darwin published Origin of Species in 1859, Design withered on the vine. But in recent years, the Argument has been resurrected under the appellation "intelligent design," and been the subject of political and legal controversy in the United States. Design advocates have argued that intelligent design can be formulated as a scientific hypothesis, that new scientific discoveries validate a design inference, and that naturalism must be removed as a methodological requirement in science. If science is defined by a model of concentric epistemological zonation, design cannot be construed as a scientific hypothesis because it is inconsistent with the core aspects of scientific methodology: naturalism, uniformity, induction, and efficient causation. An analytical examination of claims by design advocates finds no evidence of any type to support either scientific or philosophical claims that design can be unambiguously inferred from nature. The apparent irreducible complexity of biological mechanisms may be explained by exaptation or scaffolding. The argument

  17. Why Is Nature Beneficial?: The Role of Connectedness to Nature

    Science.gov (United States)

    Mayer, F. Stephan; Frants, Cynthia McPherson; Bruehlman-Senecal, Emma; Dolliver, Kyffin

    2009-01-01

    Three studies examine the effects of exposure to nature on positive affect and ability to reflect on a life problem. Participants spent 15 min walking in a natural setting (Studies 1, 2, & 3), an urban setting (Study 1), or watching videos of natural and urban settings (Studies 2 & 3). In all three studies, exposure to nature increased…

  18. Biofouling: lessons from nature.

    Science.gov (United States)

    Bixler, Gregory D; Bhushan, Bharat

    2012-05-28

    Biofouling is generally undesirable for many applications. An overview of the medical, marine and industrial fields susceptible to fouling is presented. Two types of fouling include biofouling from organism colonization and inorganic fouling from non-living particles. Nature offers many solutions to control fouling through various physical and chemical control mechanisms. Examples include low drag, low adhesion, wettability (water repellency and attraction), microtexture, grooming, sloughing, various miscellaneous behaviours and chemical secretions. A survey of nature's flora and fauna was taken in order to discover new antifouling methods that could be mimicked for engineering applications. Antifouling methods currently employed, ranging from coatings to cleaning techniques, are described. New antifouling methods will presumably incorporate a combination of physical and chemical controls.

  19. Natural minimal dark matter

    CERN Document Server

    Fabbrichesi, Marco

    2015-01-01

    We show how the Higgs boson mass is protected from the potentially large corrections due to the introduction of minimal dark matter if the new physics sector is made supersymmetric. The fermionic dark matter candidate (a 5-plet of $SU(2)_L$) is accompanied by a scalar state. The weak gauge sector is made supersymmetric and the Higgs boson is embedded in a supersymmetric multiplet. The remaining standard model states are non-supersymmetric. Non vanishing corrections to the Higgs boson mass only appear at three-loop level and the model is natural for dark matter masses up to 15 TeV--a value larger than the one required by the cosmological relic density. The construction presented stands as an example of a general approach to naturalness that solves the little hierarchy problem which arises when new physics is added beyond the standard model at an energy scale around 10 TeV.

  20. Natural Evolution Strategies

    CERN Document Server

    Wierstra, Daan; Glasmachers, Tobias; Sun, Yi; Schmidhuber, Jürgen

    2011-01-01

    This paper presents Natural Evolution Strategies (NES), a recent family of algorithms that constitute a more principled approach to black-box optimization than established evolutionary algorithms. NES maintains a parameterized distribution on the set of solution candidates, and the natural gradient is used to update the distribution's parameters in the direction of higher expected fitness. We introduce a collection of techniques that address issues of convergence, robustness, sample complexity, computational complexity and sensitivity to hyperparameters. This paper explores a number of implementations of the NES family, ranging from general-purpose multi-variate normal distributions to heavy-tailed and separable distributions tailored towards global optimization and search in high dimensional spaces, respectively. Experimental results show best published performance on various standard benchmarks, as well as competitive performance on others.

  1. Hybrid Natural Inflation

    Science.gov (United States)

    Ross, Graham G.; Germán, Gabriel; Vázquez, J. Alberto

    2016-05-01

    We construct two simple effective field theory versions of Hybrid Natural Inflation (HNI) that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, V = Δ4(1 + acos( ϕ/f)), arises naturally, with the inflaton field a pseudo-Nambu-Goldstone boson. The end of inflation is triggered by a waterfall field and the conditions for this to happen are determined. Also of interest is the fact that the slow-roll parameter ɛ (and hence the tensor r) is a non-monotonic function of the field with a maximum where observables take universal values that determines the maximum possible tensor to scalar ratio r. In one of the models the inflationary scale can be as low as the electroweak scale. We explore in detail the associated HNI phenomenology, taking account of the constraints from Black Hole production, and perform a detailed fit to the Planck 2015 temperature and polarisation data.

  2. The natural holistic imperative.

    Science.gov (United States)

    Kermode, Stephen

    2002-10-01

    Biodiversity is nature's expression of the principle of holism. This 'natural holistic imperative' is manifested in all aspects of the environment. While environmental health originated through a concern for protecting humans from environmental risks, it is now concerned with protecting the environment from the activities of humans. In order to protect the health of humans, there is a need to be concerned with protection of the biosphere. Moreover, the environmental crisis is essentially a crisis in spirituality, and a spirituality that respects and nurtures the non-human parts of our universe as much as it does the human ones is likely to be the only means of securing the health and happiness of humanity.

  3. Natural Blue Food Colour

    DEFF Research Database (Denmark)

    Roda-Serrat, Maria Cinta

    In recent years, there has been a growing tendency to avoid the use of artificial colorants and additives in food products, especially after some studies linked their consumption with behavioural changes in children. However, the incorporation of colorants from natural origin remains a challenge...... for food technologists, as these are typically less vivid and less stable than their synthetic alternatives. Regarding blue colorants, phycocyanins from cyanobacteria are currently in the spotlight as promising new natural blue colorants. Phycocyanins are proteins which blue colour results from...... the presence of the chromophore phycocyanobilin (PCB), a covalently attached linear tetrapyrrole. The applications of phycocyanins as food colorants are however limited, as they show poor stability in certain conditions of pH, light and temperature. Cleavage of PCB from the protein followed by careful product...

  4. Natural history of glaucoma

    Directory of Open Access Journals (Sweden)

    Pan Ying

    2011-12-01

    Full Text Available Purpose: To present an overview of the recent observations and research that shed light on the understanding of open and closed angle glaucoma. Methods: Literature review. Results: Glaucoma is a major eye problem afflicting millions of people worldwide. As the population increases, the number of people with glaucoma also increases, with glaucoma becoming an increasing public health concern. This paper presents the natural history of open angle and angle closure glaucoma. We examine the glaucomatous progression in terms of changes in optic disk morphology and visual fi elds as well as the risk factors for progression. Conclusions: This present review highlights the magnitude of glaucoma globally and the need for a greater understanding of this disease and its natural progression.

  5. Natural generalized mirage mediation

    CERN Document Server

    Baer, Howard; Serce, Hasan; Tata, Xerxes

    2016-01-01

    In the supersymmetric scenario known as mirage mediation (MM), the soft SUSY breaking terms receive comparable anomaly-mediation and moduli-mediation contributions leading to the phenomenon of mirage unification. The simplest MM SUSY breaking models which are consistent with the measured Higgs mass and sparticle mass constraints are strongly disfavoured by fine-tuning considerations. However, while MM makes robust predictions for gaugino masses, the scalar sector is quite sensitive to specific mechanisms for moduli stabilization and potential uplifting. We suggest here a broader setup of generalized mirage mediation (GMM), where heretofore discrete parameters are allowed as continuous to better parametrize these other schemes. We find that natural SUSY spectra consistent with both the measured value of m(h). as well as LHC lower bounds on superpartner masses are then possible. We explicitly show that models generated from natural GMM may be beyond the reach of even high-luminosity LHC searches. In such a case...

  6. Closer to Nature

    DEFF Research Database (Denmark)

    Maier, Carmen Daniela

    2015-01-01

    naturalness to the consumer—thus attempting to display a green, eco-, climate-, and animal friendly production. By analyzing a number of cases from the Scandinavian food market, this paper thus illustrates the tensions between paradigms of animal welfare and concepts of naturalness as these are used in animal......As public awareness of environmental issues and animal welfare has risen, catering to public concerns and views on these issues has become a potentially profitable strategy for marketing a number of product types, of which animal products such as dairy and meat are obvious examples. Our analysis...... suggests that specific marketing instruments are used to sell animal products by blurring the difference between the paradigms of animal welfare used by producers, and the paradigms of animal welfare as perceived by the public. These instruments rely on ethical, political and sustainable consumption...

  7. Natural Products for Antithrombosis

    Directory of Open Access Journals (Sweden)

    Cen Chen

    2015-01-01

    Full Text Available Thrombosis is considered to be closely related to several diseases such as atherosclerosis, ischemic heart disease and stroke, as well as rheumatoid arthritis, hyperuricemia, and various inflammatory conditions. More and more studies have been focused on understanding the mechanism of molecular and cellular basis of thrombus formation as well as preventing thrombosis for the treatment of thrombotic diseases. In reality, there is considerable interest in the role of natural products and their bioactive components in the prevention and treatment of thrombosis related disorders. This paper briefly describes the mechanisms of thrombus formation on three aspects, including coagulation system, platelet activation, and aggregation, and change of blood flow conditions. Furthermore, the natural products for antithrombosis by anticoagulation, antiplatelet aggregation, and fibrinolysis were summarized, respectively.

  8. Natural Dark Energy

    CERN Document Server

    Scott, Douglas

    2007-01-01

    It is now well accepted that both Dark Matter and Dark Energy are required in any successful cosmological model. Although there is ample evidence that both Dark components are necessary, the conventional theories make no prediction for the contributions from each of them. Moreover, there is usually no intrinsic relationship between the two components, and no understanding of the nature of the mysteries of the Dark Sector. Here we suggest that if the Dark Side is so seductive then we should not be restricted to just 2 components. We further suggest that the most natural model has 5 distinct forms of Dark Energy in addition to the usual Dark Matter, each contributing precisely equally to the cosmic energy density budget.

  9. Natural toxicants in foods.

    Science.gov (United States)

    Coon, J M

    1975-09-01

    Food constitutes the most complex part of our chemical environment. Naturally occurring substances in food, such as goitrogens and estrogens, are toxicants. However, there is a difference of degree between toxicity and hazard, and the hazard to man in normal good health from naturally occurring toxicants in food is usually slight, because of (a) the small concentrations and (b) antagonistic interactions between toxicants which provide "safety in numbers." Hazard from foods may indeed exist under some circumstances, such as the presence of abnormal contaminants, ingestion of abnormal amounts, or abnormal susceptibility existing in some disease states. However, the major hazards of the dinner table can ordinarily be ascribed to careless food handling, unbalanced or fad diets, or overeating.

  10. Clathrate hydrates in nature.

    Science.gov (United States)

    Hester, Keith C; Brewer, Peter G

    2009-01-01

    Scientific knowledge of natural clathrate hydrates has grown enormously over the past decade, with spectacular new findings of large exposures of complex hydrates on the sea floor, the development of new tools for examining the solid phase in situ, significant progress in modeling natural hydrate systems, and the discovery of exotic hydrates associated with sea floor venting of liquid CO2. Major unresolved questions remain about the role of hydrates in response to climate change today, and correlations between the hydrate reservoir of Earth and the stable isotopic evidence of massive hydrate dissociation in the geologic past. The examination of hydrates as a possible energy resource is proceeding apace for the subpermafrost accumulations in the Arctic, but serious questions remain about the viability of marine hydrates as an economic resource. New and energetic explorations by nations such as India and China are quickly uncovering large hydrate findings on their continental shelves.

  11. Natural SUSY endures

    Energy Technology Data Exchange (ETDEWEB)

    Papucci, Michele; Ruderman, Joshua T. [Lawrence Berkeley National Laboratory, CA (United States). Theoretical Physics Group; California Univ., Berkeley, CA (United States). Dept. of Physics; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research, Geneva (Switzerland). Theoretical Physics Div.

    2011-10-31

    The first 1 fb{sup -1} of LHC searches have set impressive limits on new colored particles decaying to missing energy. We address the implication of these searches for naturalness in supersymmetry (SUSY). General bottom-up considerations of natural electroweak symmetry breaking show that higgsinos, stops, and the gluino should not be too far above the weak scale. The rest of the spectrum, including the squarks of the first two generations, can be heavier and beyond the current LHC reach. We have used collider simulations to determine the limits that all of the 1 fb{sup -1} searches pose on higgsinos, stops, and the gluino. We find that stops and the left-handed sbottom are starting to be constrained and must be heavier than about 200-300 GeV when decaying to higgsinos. The gluino must be heavier than about 600-800 GeV when it decays to stops and sbottoms. While these findings point toward scenarios with a lighter third generation split from the other squarks, we do find that moderately-tuned regions remain, where the gluino is just above 1 TeV and all the squarks are degenerate and light. Among all the searches, jets plus missing energy and same-sign dileptons often provide the most powerful probes of natural SUSY. Overall, our results indicate that natural SUSY has survived the first 1 fb{sup -1} of data. The LHC is now on the brink of exploring the most interesting region of SUSY parameter space. (orig.)

  12. Surprises with Nonrelativistic Naturalness

    CERN Document Server

    Horava, Petr

    2016-01-01

    We explore the landscape of technical naturalness for nonrelativistic systems, finding surprises which challenge and enrich our relativistic intuition already in the simplest case of a single scalar field. While the immediate applications are expected in condensed matter and perhaps in cosmology, the study is motivated by the leading puzzles of fundamental physics involving gravity: The cosmological constant problem and the Higgs mass hierarchy problem.

  13. Thermoacoustic natural gas liquefier

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.W. [Los Alamos National Lab., NM (United States). Condensed Matter and Thermal Physics Group

    1997-05-01

    Cryenco and Los Alamos are collaborating to develop a natural-gas-powered natural-gas liquefier that will have no moving parts and require no electrical power. It will have useful efficiency, remarkable reliability, and low cost. The liquefaction of natural gas, which occurs at only 115 Kelvin at atmospheric pressure, has previously required rather sophisticated refrigeration machinery. The 1990 invention of the thermoacoustically driven orifice pulse-tube refrigerator (TA-DOPTR) provides cryogenic refrigeration with no moving parts for the first time. In short, this invention uses acoustic phenomena to produce refrigeration from heat. The required apparatus consists of nothing more than helium-filled heat exchangers and pipes, made of common materials, without exacting tolerances. In the Cryenco-Los Alamos collaboration, the authors are developing a version of this invention suitable for use in the natural-gas industry. The project is known as acoustic liquefier for short. The present program plans call for a two-phase development. Phase 1, with capacity of 500 gallon per day (i.e., approximately 40,000 scfd, requiring a refrigeration power of about 7 kW), is large enough to illuminate all the issues of large-scale acoustic liquefaction without undue cost, and to demonstrate the liquefaction of 60--70% of input gas, while burning 30--40%. Phase 2 will target versions of approximately 10{sup 6} scfd = 10,000 gallon per day capacity. In parallel with both, they continue fundamental research on the technology, directed toward increased efficiency, to build scientific foundations and a patent portfolio for future acoustic liquefiers.

  14. Extremes in nature

    CERN Document Server

    Salvadori, Gianfausto; Kottegoda, Nathabandu T

    2007-01-01

    This book is about the theoretical and practical aspects of the statistics of Extreme Events in Nature. Most importantly, this is the first text in which Copulas are introduced and used in Geophysics. Several topics are fully original, and show how standard models and calculations can be improved by exploiting the opportunities offered by Copulas. In addition, new quantities useful for design and risk assessment are introduced.

  15. Nature, Nurture and Epigenetics

    OpenAIRE

    Crews, David; Gillette, Ross; Miller-Crews, Isaac; Gore, Andrea C.; Michael K Skinner

    2014-01-01

    Real life by definition combines heritability (e.g., the legacy of exposures) and experience (e.g. stress during sensitive or ‘critical’ periods), but how to study or even model this interaction has proven difficult. The hoary concept of evaluating traits according to nature vs. nurture continues to persist despite repeated demonstrations that it retards, rather than advances, our understanding of biological processes. Behavioral genetics has proven the obvious, that genes influences behavior...

  16. Chlorophylls - natural solar cells

    CERN Document Server

    Jantschi, Lorentz; Balan, Mugur C; Sestras, Radu E

    2011-01-01

    A molecular modeling study was conducted on a series of six natural occurring chlorophylls. Quantum chemistry calculated orbital energies were used to estimate frequency of transitions between occupied molecular orbital and unoccupied molecular orbital energy levels of chlorophyll molecules in vivo conditions in standard (ASTMG173) environmental conditions. Obtained results are in good agreement with energies necessary to fix the Magnesium atom by chlorophyll molecules and with occurrence of chlorophylls in living vegetal organisms.

  17. Natural gas outlook

    Energy Technology Data Exchange (ETDEWEB)

    Turner, R. [TransCanada Transmission, Calgary, AB (Canada)

    2004-07-01

    This presentation reviewed natural gas supply and demand issues facing Ontario and outlined TransCanada's role as a key player in Ontario's energy industry. TransCanada's gas transmission assets include 39,000 km of wholly owned pipelines from British Columbia to Atlantic Canada that carry 11 Bcf of gas per day. In addition, TransCanada operates 29 power generating plants, of which 6 are in Ontario. The company is also involved the proposed Mackenzie Valley and Alaska pipeline. A map illustrating Ontario and Quebec operations was included along with graphs depicting the 2004 base case for North American gas demand by region. Historical and forecasted gas demand by end use sector in Ontario and Quebec was also illustrated. A chart of North American gas supply indicates that new supply is needed to meet energy demands. Production forecasts for Western Canada for conventional and unconventional reserves indicates that by 2015, unconventional reserves such as coalbed methane (CBM) will make up a larger portion of the production mix. A map indicating existing and proposed import terminals along the Atlantic and Pacific coasts for liquefied natural gas (LNG) was included. The challenges facing the North American gas market include price volatility, the need to update energy policies, the need to improve regulatory efficiency, and aligning the interests of market participants. It was concluded that although natural gas from Western Canada will continue to be a stable supply source for many years, the natural gas market in North America is seeking new supply in frontier gas, LNG and CBM to meeting growing demand. 1 tab., 11 figs.

  18. Almacenamiento de gas natural

    OpenAIRE

    Tomás Correa; Elkin Castrillón

    2008-01-01

    The largest reserves of natural gas worldwide are found in regions far of main cities, being necessary different alternatives to transport the fluid to the consumption cities, such as pipelines, CNG or ships, LNG, depending on distances between producing regions and demanding regions and the producing volumes. Consumption regions have three different markets to naturalgas; residential and commercial, industrial and power generation sector. The residential and commercial is highly seasonal and...

  19. Nature's Book Keeping System

    CERN Document Server

    Hooft, Gerard t

    2016-01-01

    Establishing how one should describe and study natures fundamental degrees of freedom is a notoriously difficult problem. It is tempting to assume that the number of bits (or qubits) needed in a given Planckian 3-volume, or perhaps 2-volume, is a fixed finite number, but this ansatz does not make the problem much easier. We come not even close to solving this problem, but we propose various ingredients in phrasing the questions, possibilities and limitations that may serve as starting points.

  20. Nature Quality in Organic Farming

    DEFF Research Database (Denmark)

    Tybirk, Knud; Alrøe, Hugo; Frederiksen, Pia

    2004-01-01

    Nature quality in relation to farming is a complex field. It involves different traditions and interests, different views of what nature is, and different ways of valuing nature. Furthermore there is a general lack of empirical data on many aspects of nature quality in the farmed landscape....... In this paper we discuss nature quality from the perspective of organic farming, which has its own values and goals in relation to nature – the Ecologist View of Nature. This is in contrast to the Culturist View characteristic of much conventional agriculture and the Naturalist View characteristic...... of the traditional biological approach to nature quality. This threefold distinction forms a framework for exploration of nature quality criteria in the farmed landscape. The traditional work on nature quality has mainly focused on biological interests based on a Naturalist View of Nature. In this paper we...

  1. Natural language generation

    Science.gov (United States)

    Maybury, Mark T.

    The goal of natural language generation is to replicate human writers or speakers: to generate fluent, grammatical, and coherent text or speech. Produced language, using both explicit and implicit means, must clearly and effectively express some intended message. This demands the use of a lexicon and a grammar together with mechanisms which exploit semantic, discourse and pragmatic knowledge to constrain production. Furthermore, special processors may be required to guide focus, extract presuppositions, and maintain coherency. As with interpretation, generation may require knowledge of the world, including information about the discourse participants as well as knowledge of the specific domain of discourse. All of these processes and knowledge sources must cooperate to produce well-written, unambiguous language. Natural language generation has received less attention than language interpretation due to the nature of language: it is important to interpret all the ways of expressing a message but we need to generate only one. Furthermore, the generative task can often be accomplished by canned text (e.g., error messages or user instructions). The advent of more sophisticated computer systems, however, has intensified the need to express multisentential English.

  2. NATURAL RESOURCES ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    D.F. Fenster

    2000-12-11

    The purpose of this report is to summarize the scientific work that was performed to evaluate and assess the occurrence and economic potential of natural resources within the geologic setting of the Yucca Mountain area. The extent of the regional areas of investigation for each commodity differs and those areas are described in more detail in the major subsections of this report. Natural resource assessments have focused on an area defined as the ''conceptual controlled area'' because of the requirements contained in the U.S. Nuclear Regulatory Commission Regulation, 10 CFR Part 60, to define long-term boundaries for potential radionuclide releases. New requirements (proposed 10 CFR Part 63 [Dyer 1999]) have obviated the need for defining such an area. However, for the purposes of this report, the area being discussed, in most cases, is the previously defined ''conceptual controlled area'', now renamed the ''natural resources site study area'' for this report (shown on Figure 1). Resource potential can be difficult to assess because it is dependent upon many factors, including economics (demand, supply, cost), the potential discovery of new uses for resources, or the potential discovery of synthetics to replace natural resource use. The evaluations summarized are based on present-day use and economic potential of the resources. The objective of this report is to summarize the existing reports and information for the Yucca Mountain area on: (1) Metallic mineral and mined energy resources (such as gold, silver, etc., including uranium); (2) Industrial rocks and minerals (such as sand, gravel, building stone, etc.); (3) Hydrocarbons (including oil, natural gas, tar sands, oil shales, and coal); and (4) Geothermal resources. Groundwater is present at the Yucca Mountain site at depths ranging from 500 to 750 m (about 1,600 to 2,500 ft) below the ground surface. Groundwater resources are not discussed in this

  3. Synthesis and dielectric properties of MXTi7O16 (M = Ba and Sr;X = Mg and Zn) hollandite ceramics

    Indian Academy of Sciences (India)

    V M Manisha; K P Murali; S N Potty; V Priyadarsini; R Ratheesh

    2004-04-01

    MXTi7O16 (M = Ba and Sr; X = Mg and Zn) ceramics have been synthesized by the conventional solid state ceramic route. The dielectric properties such as dielectric constant (r), loss tangent (tan ) and temperature variation of dielectric constant ($\\tau_{\\varepsilon r}$) of the sintered ceramic compacts are studied using an impedance analyser up to 13 MHz region. The strontium compounds have relatively high dielectric constant and low loss tangent compared to the barium analogue. The phase purity of these materials has been examined using X-ray diffraction studies and microstructure using SEM method.

  4. Nature, Nurture and Epigenetics

    Science.gov (United States)

    Crews, David; Gillette, Ross; Miller-Crews, Isaac; Gore, Andrea C.; Skinner, Michael K.

    2015-01-01

    Real life by definition combines heritability (e.g., the legacy of exposures) and experience (e.g. stress during sensitive or ‘critical’ periods), but how to study or even model this interaction has proven difficult. The hoary concept of evaluating traits according to nature vs. nurture continues to persist despite repeated demonstrations that it retards, rather than advances, our understanding of biological processes. Behavioral genetics has proven the obvious, that genes influences behavior and, vice versa, that behavior influences genes. The concept of Genes X Environment (G X E) and its modern variants was viewed as an improvement on nature-nurture but has proven that, except in rare instances, it is not possible to fractionate phenotypes into these constituent elements. The entanglement inherent in terms such as nature-nurture or GXE is a Gordian knot that cannot be dissected or even split. Given that the world today is not what it was less than a century ago, yet the arbitrator (differential survival and reproduction) has stayed constant, de novo principles and practices are needed to better predict what the future holds. Put simply, the transformation that is now occurring within and between individuals as a product of global endocrine disruption is quite independent of what has been regarded as evolution by selection. This new perspective should focus on how epigenetic modifications might revise approaches to understand how the phenotype and, in particular its components, is shaped. In this review we summarize the literature in this developing area, focusing on our research on the fungicide vinclozolin. PMID:25102229

  5. Why Nature Chose Selenium.

    Science.gov (United States)

    Reich, Hans J; Hondal, Robert J

    2016-04-15

    The authors were asked by the Editors of ACS Chemical Biology to write an article titled "Why Nature Chose Selenium" for the occasion of the upcoming bicentennial of the discovery of selenium by the Swedish chemist Jöns Jacob Berzelius in 1817 and styled after the famous work of Frank Westheimer on the biological chemistry of phosphate [Westheimer, F. H. (1987) Why Nature Chose Phosphates, Science 235, 1173-1178]. This work gives a history of the important discoveries of the biological processes that selenium participates in, and a point-by-point comparison of the chemistry of selenium with the atom it replaces in biology, sulfur. This analysis shows that redox chemistry is the largest chemical difference between the two chalcogens. This difference is very large for both one-electron and two-electron redox reactions. Much of this difference is due to the inability of selenium to form π bonds of all types. The outer valence electrons of selenium are also more loosely held than those of sulfur. As a result, selenium is a better nucleophile and will react with reactive oxygen species faster than sulfur, but the resulting lack of π-bond character in the Se-O bond means that the Se-oxide can be much more readily reduced in comparison to S-oxides. The combination of these properties means that replacement of sulfur with selenium in nature results in a selenium-containing biomolecule that resists permanent oxidation. Multiple examples of this gain of function behavior from the literature are discussed.

  6. World Natural Gas Model

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    RAMSGAS, the Research and Development Analysis Modeling System World Natural Gas Model, was developed to support planning of unconventional gaseoues fuels research and development. The model is a scenario analysis tool that can simulate the penetration of unconventional gas into world markets for oil and gas. Given a set of parameter values, the model estimates the natural gas supply and demand for the world for the period from 1980 to 2030. RAMSGAS is based on a supply/demand framwork and also accounts for the non-renewable nature of gas resources. The model has three fundamental components: a demand module, a wellhead production cost module, and a supply/demand interface module. The demand for gas is a product of total demand for oil and gas in each of 9 demand regions and the gas share. Demand for oil and gas is forecast from the base year of 1980 through 2030 for each demand region, based on energy growth rates and price-induced conservation. For each of 11 conventional and 19 unconventional gas supply regions, wellhead production costs are calculated. To these are added transportation and distribution costs estimates associated with moving gas from the supply region to each of the demand regions and any economic rents. Based on a weighted average of these costs and the world price of oil, fuel shares for gas and oil are computed for each demand region. The gas demand is the gas fuel share multiplied by the total demand for oil plus gas. This demand is then met from the available supply regions in inverse proportion to the cost of gas from each region. The user has almost complete control over the cost estimates for each unconventional gas source in each year and thus can compare contributions from unconventional resources under different cost/price/demand scenarios.

  7. Pragmatic commitments to naturalized epistemology

    Institute of Scientific and Technical Information of China (English)

    Cong Hangqing; Cheng Xiaodong

    2006-01-01

    This essay explores numerous and complicated naturalized epistemology against the background of pragmatism.We distinguish three programmes of naturalized epistemology:strong,moderate,and weak.By considering commitments of pragmatism on which different programmes depend,we point out the close-knit relationship between pragmatism and naturalized epistemology.We also illustrate the essential origin of today's controversy over naturalized epistemology and predict the uptrend of naturalized epistemology.

  8. Naturalness as an educational value

    DEFF Research Database (Denmark)

    Frølund, Sune

    2016-01-01

    Existentialism and postmodernism have both abandoned the idea of a human nature. Also, the idea of naturalness as a value for education has been targeted as a blind for conservative ideology. There are, however, good reasons to re-establish a sound concept of human naturalness. First of all...... and culture. This paper presents two suggestions for a rehabilitation of the concept of naturalness: Gernot Böhme's phenomenology of body and nature, and Christoph Menke's ‘genealogical reflexion’....

  9. The nature of mathematics

    CERN Document Server

    Jourdain, Philip E B

    2007-01-01

    Anyone with an interest in mathematics will welcome the republication of this little volume by a remarkable mathematician who was also a logician, a philosopher, and an occasional writer of fiction and poetry. Originally published in 1913, and later included in the acclaimed anthology The World of Mathematics, Jourdain's survey shows how and why the methods of mathematics were developed, traces the development of mathematical science from the earliest to modern times, and chronicles the application of mathematics to natural science.Starting with the ancient Egyptians and Greeks, the author p

  10. Naturally Connecting the World

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ During China International Trade Fair for Home Textiles and Accessories held in Shanghai 2010(on Aug.25th the second day of the fair),Cotton Council International(CCI)hosted an exchange meeting targeted the COTTON USATM home textile licenses,taking"Naturally Connecting the World-Opportunities for Sourcing and Collaboration with Cotton-Made Home Textiles"as the theme of the meeting.CCI's representative institution in China invited the domestic famous home textile brands,enterprises and their customers to participate in the exchange which aims to introduce the current development trend of the global cotton textile industry through CCI,the powerful platform of communication.

  11. Modulated natural inflation

    Directory of Open Access Journals (Sweden)

    Rolf Kappl

    2016-02-01

    Full Text Available We discuss some model-independent implications of embedding (aligned axionic inflation in string theory. As a consequence of string theoretic duality symmetries the pure cosine potentials of natural inflation are replaced by modular functions. This leads to “wiggles” in the inflationary potential that modify the predictions with respect to CMB-observations. In particular, the scalar power spectrum deviates from the standard power law form. As a by-product one can show that trans-Planckian excursions of the aligned effective axion are compatible with the weak gravity conjecture.

  12. Knowledge and Natural Resources

    DEFF Research Database (Denmark)

    Bertelsen, Rasmus Gjedssø; Justinussen, Jens Christian Svabo

    2016-01-01

    Arctic economies are generally natural resource based economies, whether they are indigenous economies largely dependent on living on the land or industrialized economies depending on marine resources, mineral resources or fossil or renewable energy resources. However, the central role of knowledge...... on the Icelandic and Faroese experiences with marine resources and renewable energy resources in geothermal, hydro, tidal and wind power. Iceland and the Faroe Islands are selected because they are examples of very small Arctic societies, which particularly well illustrate how the combination of human capital...... and marine resources and renewable energy can contribute to socio-economic and political-constitutional development....

  13. Myxobacteria: natural pharmaceutical factories

    Science.gov (United States)

    2012-01-01

    Myxobacteria are amongst the top producers of natural products. The diversity and unique structural properties of their secondary metabolites is what make these social microbes highly attractive for drug discovery. Screening of products derived from these bacteria has revealed a puzzling amount of hits against infectious and non-infectious human diseases. Preying mainly on other bacteria and fungi, why would these ancient hunters manufacture compounds beneficial for us? The answer may be the targeting of shared processes and structural features conserved throughout evolution. PMID:22545867

  14. Spirit Coinciding with Nature

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    I have given a name to the studio where I make my soft sculptures: "Spirit Existing." It means that my life exists together with my spirit; that spirit is inseparable from body. I believe the original nature of life is the most beautiful thing in the world. On September 6th, 1997, I handed in my resignation to the tax bureau where I worked. Leaving my family and my son at home, I came to Beijing alone to create a new life for myself. As a woman making such a choice at the age of 35, I

  15. Natural Killer Cell Memory.

    Science.gov (United States)

    O'Sullivan, Timothy E; Sun, Joseph C; Lanier, Lewis L

    2015-10-20

    Natural killer (NK) cells have historically been considered short-lived cytolytic cells that can rapidly respond against pathogens and tumors in an antigen-independent manner and then undergo cell death. Recently, however, NK cells have been shown to possess traits of adaptive immunity and can acquire immunological memory in a manner similar to that of T and B cells. In this review, we discuss evidence of NK cell memory and the mechanisms involved in the generation and survival of these innate lymphocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Naturally in Love

    Institute of Scientific and Technical Information of China (English)

    Xue Peng

    2010-01-01

    @@ Beijing's warm summer air was filled with love on June 22,2010.Cotton Council International China held a fashion wedding party against the breathtaking backdrop of the Purple Jade Villas,for the winning couple of the COTTON USATM online video competition.Surrounded by beautiful swans,exotic peacocks and young deer fawns,people were deeply moved by the themes of love and nature this pure cotton wedding embodied,all presented by fashion icon and proud COTTON USATM ambassador Miss Xu Xiyuan(Da S).Approximately 136 media and 70 guests including representatives from China's cotton industry and Beijing's ATO attended this event.

  17. CERN in "Nature"

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    CERN is nestled within a verdant natural environment which, thanks to a conservation-oriented policy, is characterized by a remarkable biodiversity. The continued protection of that diversity calls for thoughtful, carefully planned measures.   CERN’s site is an extensive one: its 650 hectares include 210 hectares of buildings, roadways and parking lots, 100 hectares of fenced-off green area, and 340 hectares of non-fenced land, a patchwork of fields, woods and pasture. This land teems with a great variety of plants and animals, including some rare and unexpected species. In 2009 CERN received a certificate from the Swiss foundation Nature & économie for the Meyrin site, and the award was renewed in 2012 for three more years. “The green spaces inside the fenced area are tended by six ISS gardeners, whose duties also include keeping the sidewalks and footpaths clear of snow in winter. The Meyrin site also includes orchid sanctuaries, meadows and sheep pasture...

  18. Natural gas; Erdgas

    Energy Technology Data Exchange (ETDEWEB)

    Graf, Frank [DVGW-Forschungsstelle am KIT, Karlsruhe (Germany); Groeschl, Frank; Wetzel, Uwe [DVGW, Bonn (Germany); Heikrodt, Klaus [Hochschule Ostwestfalen-Lippe, Lemgo (Germany); Krause, Hartmut [DBI Gastechnologisches Institut, An-Institut der TU Bergakademie, Freiberg (Germany); Beestermoeller, Christina; Witschen, Bernhard [Team Consult G.P.E. GmbH, Berlin (Germany); Albus, Rolf; Burmeister, Frank [Gas- und Waerme-Institut Essen e.V., Essen (Germany)

    2015-07-01

    The reform of the EEG in Germany, a positive global development in natural gas, the decline in oil prices, questions about the security of supply in Europe, and not least the effect of the decision by E.on at the end of 2014 have moved the gas industry. Gas has the lowest CO{sub 2} emissions of fossil fuels. Flexibility, storability, useful for networks and the diversity in the application make it an ideal partner for renewable energy. However, these complementary properties are valued at wind and photovoltaics internationally and nationally different. The situation in the gas power plants remains tense. LNG - liquefied natural gas - is on the rise. [German] Die Reform des EEG in Deutschland, eine positive Entwicklung beim Gas weltweit, der Verfall der Oelpreises, Fragen zur Versorgungssicherheit in Europa und nicht zuletzt die Auswirkung der Entscheidung von E.on Ende 2014 haben die Gaswirtschaft bewegt. Gas weist die geringsten CO{sub 2}-Emissioen der fossilen Energietraeger auf. Flexibilitaet, Speicherbarkeit, Netzdienlichkeit sowie die Vielfalt in der Anwendung machen es zum idealen Partner der erneuerbaren Energien. Allerdings werden diese komplementaeren Eigenschaften zu Wind und Photovoltaik international und national unterschiedlich bewertet. Die Lage bei den Gaskraftwerken bleibt weiter angespannt. LNG - verfluessigtes Erdgas - ist auf dem Vormarsch.

  19. Gluino Meets Flavored Naturalness

    CERN Document Server

    Blanke, Monika; Galon, Iftah; Perez, Gilad

    2015-01-01

    We study constraints from LHC run I on squark and gluino masses in the presence of squark flavor violation. Inspired by the concept of `flavored naturalness', we focus on the impact of a non-zero stop-scharm mixing and mass splitting in the right-handed sector. To this end, we recast four searches of the ATLAS and CMS collaborations, dedicated either to third generation squarks, to gluino and squarks of the first two generations, or to charm-squarks. In the absence of extra structure, the mass of the gluino provides an additional source of fine tuning and is therefore important to consider within models of flavored naturalness that allow for relatively light squark states. When combining the searches, the resulting constraints in the plane of the lightest squark and gluino masses are rather stable with respect to the presence of flavor-violation, and do not allow for gluino masses of less than 1.2 TeV and squarks lighter than about 550 GeV. While these constraints are stringent, interesting models with sizabl...

  20. Thermoacoustic natural gas liquefier

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.W. [Los Alamos National Lab., NM (United States)

    1995-06-01

    In collaboration with Cryenco Inc. and NIST-Boulder, we intend to develop a natural gas-powered natural-gas liquefier which has absolutely no moving parts and requires no electrical power. It will have high efficiency, remarkable reliability, and low cost. Progress on the liquefier to be constructed at Cryenco continues satisfactorily. The thermoacoustic driver is still ahead of the pulse tube refrigerator, because of NIST`s schedule. We completed the thermoacoustics design in the fall of 1994, with Los Alamos providing physics input and checks of all aspects, and Cryenco providing engineering to ASME code, drafting, etc. Completion of this design represents a significant amount of work, especially in view of the many unexpected problems encountered. Meanwhile, Cryenco and NIST have almost completed the design of the pulse tube refrigerator. At Los Alamos, we have assembled a half-size scale model of the thermoacoustic portion of the 500 gal/day TANGL. This scale model will enable easy experimentation in harmonic suppression techniques, new stack geometries, new heat-exchanger geometries, resonator coiling, and other areas. As of March 1995, the scale model is complete and we are performing routine debugging tests and modifications.

  1. En-gauging naturalness

    Energy Technology Data Exchange (ETDEWEB)

    Bharucha, Aoife [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Technische Univ. Muenchen, Garching (Germany). Physik-Dept. T31; Goudelis, Andreas [Savoie Univ., CNRS, Annecy-le-Vieux (France). LAPTh; McGarrie, Moritz [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-10-15

    The discovery of a 125.5 GeV Higgs with standard model-like couplings and naturalness considerations motivate gauge extensions of the MSSM. We analyse two variants of such an extension and carry out a phenomenological study of regions of the parameter space statisfying current direct and indirect constraints, employing state-of-the-art two-loop RGE evolution and GMSB boundary conditions. We find that due to the appearance of non-decoupled D-terms it is possible to obtain a 125.5 GeV Higgs with stops below 2 TeV, while the uncolored sparticles could still lie within reach of the LHC. We compare the contributions of the stop sector and the non-decoupled D-terms to the Higgs mass, and study their effect on the Higgs couplings. We further investigate the nature of the next-to lightest supersymmetric particle, in light of the GMSB motivated searches currently being pursued by ATLAS and CMS.

  2. Nature's loss, Immunologists gain?

    Science.gov (United States)

    Aluvihare

    2000-01-01

    Nature Reviews Molecular Cell Biology Nature Publishing Group (2000). ISSN 1471-0072. Monthly First there was Annual Reviews, then came the monthly Elsevier Trends Journals, both of which try to identify hot topics in their chosen fields. The Current Opinion journals followed several years later, and Current Opinion in Cell Biology is presently one of the highest 'impact factor' review journals, with a distinguished board of editors and advisors and a systematic approach to regular coverage of the major fields of cell biology. Important topics are visited once a year, whether or not something specially exciting happened in the last 12 months. Add to this list Seminars in Cell and Developmental Biology, the FASEB journal and the countless minireviews in 'real' journals, and you begin to wonder how anyone finds any time for doing experiments, or indeed reading the primary literature. So, into this already crowded field arrive three important newcomers: Nature Reviews in Molecular Cell Biology, Genetics, and Neurosciences, of which the first two will probably interest readers of Journal of Cell Science the most. Backed by the name and money of Nature and edited by experienced Nature staff, it is hard to see how these publications can possibly do other than succeed with writers and readers alike. What's inside the first issue? The cover of Nature Reviews in Molecular Cell Biology presents a 3-colour montage of a blue cell nucleus surrounded by splotches of green GPI-anchored GFP overlaid by orange actin stress fibres that seem to come from somewhere else. This image trails a comprehensive review from Kai Simons and Derek Toomre about Lipid Rafts. There are another five major review articles: calcium puffs and sparks, rings around DNA, HIV inhibitors, kinesin and the circadian clock provide a rich and varied mix of topics from authors who know what they're talking about. Surrounding this core is an entertaining mixture of 'highlights' at the front: news and views about

  3. natural or artificial diets

    Directory of Open Access Journals (Sweden)

    A. O. Meyer-Willerer

    2005-01-01

    Full Text Available Se probaron alimentos artificiales y naturales con larva de camarón (Litopenaeus vannamei cultivados en diferentes recipientes. Estos fueron ocho frascos cónicos con 15L, ocho acuarios con 50L y como grupo control, seis tanques de fibra de vidrio con 1500L; todos con agua marina fresca y filtrada. La densidad inicial en todos los recipientes fue de 70 nauplios/L. Aquellos en frascos y acuarios recibieron ya sea dieta natural o artificial. El grupo control fue cultivado con dieta natural en los tanques grandes que utilizan los laboratorios para la producción masiva de postlarvas. El principal producto de excreción de larva de camarón es el ión amonio, que es tóxico cuando está presente en concentraciones elevadas. Se determinó diariamente con el método colorimétrico del indofenol. Los resultados muestran diferencias en la concentración del ión amonio y en la sobrevivencia de larvas entre las diferentes dietas y también entre los diferentes recipientes. En aquellos con volúmenes pequeños comparados con los grandes, se presentó mayor concentración de amonio (500 a 750µg/L, en aquellos con dietas naturales, debido a que este ión sirve de fertilizante a las algas adicionadas, necesitando efectuar recambios diarios de agua posteriores al noveno día de cultivo para mantener este ión a una concentración subletal. Se obtuvo una baja cosecha de postlarvas (menor a 15% con el alimento artificial larvario, debido a la presencia de protozoarios, alimentándose con el producto comercial precipitado en el fondo de los frascos o acuarios. Los acuarios con larvas alimentadas con dieta natural también mostraron concentraciones subletales de amonio al noveno día; sin embargo, la sobrevivencia fue cuatro veces mayor que con dietas artificiales. Los tanques control con dietas naturales presentaron tasas de sobrevivencia (70 ± 5% similares a la reportada por otros laboratorios.

  4. Natural gas : nirvana

    Energy Technology Data Exchange (ETDEWEB)

    Stonehouse, D.

    2001-04-01

    Despite completing 8,900 gas wells in year 2000, the deliverability of natural gas out of the Western Canadian Sedimentary Basin (WCSB) was stagnant which has left many analysts wondering whether the basin has reached its limit. It also leaves many wondering if gas producers will be able to meet the strong demand for natural gas in the future. Nearly all new electrical generation being built in the U.S. is gas-based due to strict new environmental standards limiting the growth in hydro and coal-powered generation. Any future coal plants will use gasification technology and combined cycle turbines. Combined cycle turbines developed by Boeing and Lockheed are more efficient than combustion turbines, making gas more competitive with fuel alternatives. The lack of growth in natural gas supply has left storage levels near record lows. Demand is expected to increase in 2001 by 3.2 per cent to 23 trillion cubic feet in the U.S. Longer term, major new reserves must be brought on stream to meet this demand. It was noted that the easy discoveries within the WCSB have been made. The new plays are smaller, more technically complex and expensive which suggests that more investment is needed in training geologists, geophysicists and petroleum engineers to find new reserves. The Canadian Energy Research Institute agrees that there is enough gas in Alberta and British Columbia to meet current demands but efforts must shift towards drilling in the foothills front and northwest regions of Alberta to increase deliverability. Brief notes on several gas finds by various oil and gas companies in the area were presented. The article also discussed the huge untapped potential of northern reserves. Analysts have noted 44 Tcf of proven reserve, with a potential of 165 Tcf. In addition, new pipelines from the Alaskan North Slope and the Mackenzie Delta could transport nearly 2 Tcf annually to market. Wells drilled by Chevron and Paramount at Fort Liard in 1999 initially flowed at rates up to

  5. Natural gas monthly, April 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-06

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. There are two feature articles in this issue: Natural gas 1998: Issues and trends, Executive summary; and Special report: Natural gas 1998: A preliminary summary. 6 figs., 28 tabs.

  6. Training and natural immunity

    DEFF Research Database (Denmark)

    Pedersen, Bente Klarlund; Helge, Jørn Wulff; Richter, Erik

    2000-01-01

    The purpose of the study was to investigate whether a carbohydrate-rich versus fat-rich diet influenced the effect of training on the immune system. Ten untrained young men ingested a carbohydrate-rich diet [65 energy percent (E%) carbohydrate] and ten subjects a fat-rich diet (62E% fat) while...... endurance training was performed 3-4 times a week for 7 weeks. Maximal oxygen uptake increased by 11% in both groups. Blood samples for immune monitoring were collected before and at the end of the study. Blood samples were also collected, in parallel, from 20 age-matched subjects, and data from...... these subjects were used to eliminate day-to-day variation in the immunological tests. Independently of diet, training increased the percentage of CD3-CD16+ CD56+ natural killer (NK) cells from [mean (SEM)] 14 (1) % to 20 (3) % (P = 0.05), whereas the NK-cell activity, either unstimulated or stimulated...

  7. Natural Bioenhancers: An overview

    Directory of Open Access Journals (Sweden)

    Deepthi V.Tatiraju

    2013-09-01

    Full Text Available Bioenhancers are chemical entities which promote and augment the bioavailability of the drugs which are mixed with them and do not exhibit synergistic effect with the drug. The need for bioenhancers arises due to drugs which are poorly available, administered for long periods, toxic and expensive. Bioenhancers can be classified based on their natural origin as well as based on the various mechanisms elicited by them when in combination with drugs to improve their bioavailability. The various bioenhancers available are piperine, garlic, Carum carvi, Cuminum cynimum, lysergol, naringin, quercetin, niaziridin, glycyrrhizin, stevia, cow urine distillate ginger. Out of these, Cuminum cynimum and niaziridin are the potential bioenhancers of future. Therefore, the need of the hour is to carry out extensive research on these bioenhancers so that they could be utilised in the drug formulations.

  8. Liquefied Natural Gas Transfer

    Science.gov (United States)

    1980-01-01

    Chicago Bridge & Iron Company's tanks and associated piping are parts of system for transferring liquefied natural gas from ship to shore and storing it. LNG is a "cryogenic" fluid meaning that it must be contained and transferred at very low temperatures, about 260 degrees below Fahrenheit. Before the LNG can be pumped from the ship to the storage tanks, the two foot diameter transfer pipes must be cooled in order to avoid difficulties associated with sharp differences of temperature between the supercold fluid and relatively warm pipes. Cooldown is accomplished by sending small steady flow of the cryogenic substance through the pipeline; the rate of flow must be precisely controlled or the transfer line will be subjected to undesirable thermal stress.

  9. Lorentz violation naturalness revisited

    CERN Document Server

    Belenchia, Alessio; Liberati, Stefano

    2016-01-01

    We revisit here the naturalness problem of Lorentz invariance violations on a simple toy model of a scalar field coupled to a fermion field via a Yukawa interaction. We first review some well-known results concerning the low-energy percolation of Lorentz violation from high energies, presenting some details of the analysis not explicitly discussed in the literature and discussing some previously unnoticed subtleties. We then show how a separation between the scale of validity of the effective field theory and that one of Lorentz invariance violations can hinder this low-energy percolation. While such protection mechanism was previously considered in the literature, we provide here a simple illustration of how it works and of its general features. Finally, we consider a case in which dissipation is present, showing that the dissipative behaviour does not percolate generically to lower mass dimension operators albeit dispersion does. Moreover, we show that a scale separation can protect from unsuppressed low-en...

  10. Natural radiative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.

    1979-01-01

    Natural radiative cooling at night was measured based on the surface-radiation spectrum after the heat balance of the surface exposed to the sun had been reradiated. A concept equivalent to the sky temperature and a concept useful for obtaining the net heat flux are discussed. The highest possible equilibrium temperature of the selective surface can be lowered; however, how to apply this practically is not yet known. A simple radiator, completely enclosed by a transparent screen, can produce a significant and inexpensive cooling effect. The results of experiments carried out in an area such as Padua, Italy, where the climate is not suitable for cooling purposes can still be predicted theoretically. The possibility of using the collector for heat collection during the day and as a radiator at night is indicated.

  11. Closer to Nature?

    DEFF Research Database (Denmark)

    Borkfelt, Sune; Kondrup, Sara; Röcklinsberg, Helena;

    2015-01-01

    As public awareness of environmental issues and animal welfare has risen, catering to public concerns and views on these issues has become a potentially profitable strategy for marketing a number of product types, of which animal products such as dairy and meat are obvious examples. Our analysis...... discourses in order to sell one image of animal welfare in intensive animal production while the actual production at the same time presupposes a quite different paradigm of animal welfare. Specifically, product advertising utilizes representations tied to concepts of naturalness in depictions of both animal...... product marketing, discusses the ethical implications of this type of marketing communication, and stresses the need for transparency in the area of animal welfare....

  12. Naturally light sterile neutrinos

    CERN Document Server

    Sarkar, U

    1999-01-01

    A simple model to accomodate light sterile neutrinos naturally with large mixing with the usual neutrinos has been proposed. The standard model gauge group is extended to include an $SU(2)_S$ gauge symmetry. Heavy triplet higgs scalars give small masses to the left-handed neutrinos, while a heavy doublet higgs scalar give mixing with the sterile neutrinos of the same order of magnitude. The neutrino mass matrix thus obtained can explain the solar neutrino deficit, the atmospheric neutrino deficit, the LSND data and hot dark matter. Lepton number is violated here through decays of the heavy triplet higgs, which generates the lepton asymmetry of the universe, which in turn generates a baryon asymmetry of the universe.

  13. Predicting natural catastrophes tsunamis

    CERN Document Server

    CERN. Geneva

    2005-01-01

    1. Tsunamis - Introduction - Definition of phenomenon - basic properties of the waves Propagation and dispersion Interaction with coasts - Geological and societal effects Origin of tsunamis - natural sources Scientific activities in connection with tsunamis. Ideas about simulations 2. Tsunami generation - The earthquake source - conventional theory The earthquake source - normal mode theory The landslide source Near-field observation - The Plafker index Far-field observation - Directivity 3. Tsunami warning - General ideas - History of efforts Mantle magnitudes and TREMOR algorithms The challenge of "tsunami earthquakes" Energy-moment ratios and slow earthquakes Implementation and the components of warning centers 4. Tsunami surveys - Principles and methodologies Fifteen years of field surveys and related milestones. Reconstructing historical tsunamis: eyewitnesses and geological evidence 5. Lessons from the 2004 Indonesian tsunami - Lessons in seismology Lessons in Geology The new technologies Lessons in civ...

  14. Natural dispersion revisited.

    Science.gov (United States)

    Johansen, Øistein; Reed, Mark; Bodsberg, Nils Rune

    2015-04-15

    This paper presents a new semi-empirical model for oil droplet size distributions generated by single breaking wave events. Empirical data was obtained from laboratory experiments with different crude oils at different stages of weathering. The paper starts with a review of the most commonly used model for natural dispersion, which is followed by a presentation of the laboratory study on oil droplet size distributions formed by breaking waves conducted by SINTEF on behalf of the NOAA/UNH Coastal Response Research Center. The next section presents the theoretical and empirical foundation for the new model. The model is based on dimensional analysis and contains two non-dimensional groups; the Weber and Reynolds number. The model was validated with data from a full scale experimental oil spill conducted in the Haltenbanken area offshore Norway in July 1982, as described in the last section of the paper.

  15. New probe of naturalness.

    Science.gov (United States)

    Craig, Nathaniel; Englert, Christoph; McCullough, Matthew

    2013-09-20

    Any new scalar fields that perturbatively solve the hierarchy problem by stabilizing the Higgs boson mass also generate new contributions to the Higgs boson field-strength renormalization, irrespective of their gauge representation. These new contributions are physical, and in explicit models their magnitude can be inferred from the requirement of quadratic divergence cancellation; hence, they are directly related to the resolution of the hierarchy problem. Upon canonically normalizing the Higgs field, these new contributions lead to modifications of Higgs couplings that are typically great enough that the hierarchy problem and the concept of electroweak naturalness can be probed thoroughly within a precision Higgs boson program. Specifically, at a lepton collider this can be achieved through precision measurements of the Higgs boson associated production cross section. This would lead to indirect constraints on perturbative solutions to the hierarchy problem in the broadest sense, even if the relevant new fields are gauge singlets.

  16. Natural Air Purifier

    Science.gov (United States)

    1993-01-01

    NASA environmental research has led to a plant-based air filtering system. Dr. B.C. Wolverton, a former NASA engineer who developed a biological filtering system for space life support, served as a consultant to Terra Firma Environmental. The company is marketing the BioFilter, a natural air purifier that combines activated carbon and other filter media with living plants and microorganisms. The filter material traps and holds indoor pollutants; plant roots and microorganisms then convert the pollutants into food for the plant. Most non-flowering house plants will work. After pollutants have been removed, the cleansed air is returned to the room through slits in the planter. Terra Firma is currently developing a filter that will also disinfect the air.

  17. Natural Radioactivity in Bananas

    Science.gov (United States)

    Zagatto, V. A. B.; Medina, N. H.; Okuno, E.; Umisedo, N. K.

    2008-08-01

    The content of 40K natural radionuclide in bananas (Musa sapientum) from the Vale do Ribeira region, São Paulo, Brazil, has been measured. We have collected several samples of bananas prata and nanica, its peels, leaves, and also different soils where the banana tree was planted, such as soil with a standard amount of fertilizer, the fertilizer itself and also soil without fertilizer for comparison. We have used the gamma-ray spectroscopy technique with a NaI(T1) crystal inside a 12 cm thick lead shield to detect the gamma-radiation. The results indicate that only part of the available potassium is absorbed by the plant, which is mainly concentrated in the banana peel.

  18. Natural gas shortage. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Boorstin, D.

    1975-11-07

    Curtailments of gas supplies in the winter of 1975-76 were estimated to be 2.9 trillion cubic feet or 15 percent of demand, which represented a 45 percent increase over curtailments in 1974-75. The scarcities are discussed under the following topics: probable dimensions of natural gas curtailment; effects of winter shortages, possibility of relief; debate over attempt to remove price ceilings; and charges of gas withholding and underreporting. The history of gas use and regulation is reviewed under the following: from unwanted oil by-product to useful fuel; development of regulation and extent of control; and policy change at the Federal Power Commission. The outlook for overcoming the shortage is discussed under the following: revised estimates of undiscovered resources; rival proposals to make Alaskan gas available; and continuing search for substitute energy sources. 37 references. (MCW)

  19. Art and human nature

    Directory of Open Access Journals (Sweden)

    Mirta Toledo

    2008-06-01

    Full Text Available This article presents a visual artist’s point of view about art. This view confronts the Eurocentric traditional cannon with some ignored, but valuable traditions, thus proposing a contra-canon. These ideas are examined on the light of a variety of sources, including prehistoric, pre-Columbian, and 20th century art expressions, in a variety of media, from sculpture to literature. Recent art expressions are characterized by their incorporation of minority values and perspectives that challenge “universal” views. Using samples of works from Latino and African American artists, the author shows that, even today, art is a means to know the world and its people, to exhibit personal life, to create personal symbolism, and to show one’s identity or the search for it. Like the human nature it represents, art has multiple faces.

  20. Which naturalism for bioethics? A defense of moderate (pragmatic) naturalism.

    Science.gov (United States)

    Racine, Eric

    2008-02-01

    There is a growing interest in various forms of naturalism in bioethics, but there is a clear need for further clarification. In an effort to address this situation, I present three epistemological stances: anti-naturalism, strong naturalism, and moderate pragmatic naturalism. I argue that the dominant paradigm within philosophical ethics has been a form of anti-naturalism mainly supported by a strong 'is' and 'ought' distinction. This fundamental epistemological commitment has contributed to the estrangement of academic philosophical ethics from major social problems and explains partially why, in the early 1980s, 'medicine saved the life of ethics'. Rejection of anti-naturalism, however, is often associated with strong forms of naturalism that commit the naturalistic fallacy and threaten to reduce the normative dimensions of ethics to biological imperatives. This move is rightly dismissed as a pitfall since ethics is, in part, a struggle against the course of nature. Rejection of naturalism has drawbacks, however, such as deterring bioethicists from acknowledging the implicit naturalistic epistemological commitments of bioethics. I argue that a moderate pragmatic form of naturalism represents an epistemological position that best embraces the tension of anti-naturalism and strong naturalism: bioethics is neither disconnected from empirical knowledge nor subjugated to it. The discussion is based upon historical writings in philosophy and bioethics.

  1. Natural gas monthly, July 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 25 tabs.

  2. Natural gas monthly, June 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 25 tabs.

  3. Natural gas monthly, August 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-24

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  4. Natural gas monthly, June 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  5. Natural gas monthly, June 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 24 tabs.

  6. Natural gas monthly, October 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  7. Natural gas monthly, May 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  8. Natural gas monthly: December 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. Articles are included which are designed to assist readers in using and interpreting natural gas information.

  9. Natural gas monthly, July 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 25 tabs.

  10. Natural Gas Monthly, March 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-25

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  11. Natural gas monthly, July 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-20

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  12. Natural gas monthly, November 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-29

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground state data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  13. A Natural Logic for Natural-language Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker

    2017-01-01

    We describe a natural logic for computational reasoning with a regimented fragment of natural language. The natural logic comes with intuitive inference rules enabling deductions and with an internal graph representation facilitating conceptual path finding between pairs of terms as an approach......-conservative constructs in order to approach scientific use of natural language. Finally, we outline a prototype system addressing life science for the natural logic knowledge base setup being under continuous development....... to semantic querying. Our core natural logic proposal covers formal ontologies and generative extensions thereof. It further provides means of expressing general relationships between classes in an application. We discuss extensions of the core natural logic with various conservative as well as non...

  14. A Natural Logic for Natural-Language Knowledge Bases

    DEFF Research Database (Denmark)

    Andreasen, Troels; Styltsvig, Henrik Bulskov; Jensen, Per Anker

    2017-01-01

    We describe a natural logic for computational reasoning with a regimented fragment of natural language. The natural logic comes with intuitive inference rules enabling deductions and with an internal graph representation facilitating conceptual path finding between pairs of terms as an approach......-conservative constructs in order to approach scientific use of natural language. Finally, we outline a prototype system addressing life science for the natural logic knowledge base setup being under continuous development....... to semantic querying. Our core natural logic proposal covers formal ontologies and generative extensions thereof. It further provides means of expressing general relationships between classes in an application. We discuss extensions of the core natural logic with various conservative as well as non...

  15. US crude oil, natural gas, and natural gas liquids reserves

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-05

    This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1989, and production volumes for the year 1989 for the total United States and for selected states and state sub-divisions. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), its two major components (nonassociated and associated-dissolved gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, two components of natural gas liquids, lease condensate and natural gas plant liquids, have their reserves and production reported separately. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. 28 refs., 9 figs., 15 tabs.

  16. Nature and Nationhood: Danish Perspectives

    Science.gov (United States)

    Schnack, Karsten

    2009-01-01

    In this paper, I shall discuss Danish perspectives on nature, showing the interdependence of conceptions of "nature" and "nationhood" in the formations of a particular cultural community. Nature, thus construed, is never innocent of culture and cannot therefore simply be "restored" to some pristine, pre-lapsarian state. On the other hand,…

  17. Natural gas monthly, February 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 28 tabs.

  18. Percents Are Not Natural Numbers

    Science.gov (United States)

    Jacobs, Jennifer A.

    2013-01-01

    Adults are prone to treating percents, one representational format of rational numbers, as novel cases of natural number. This suggests that percent values are not differentiated from natural numbers; a conceptual shift from the natural numbers to the rational numbers has not yet occurred. This is most surprising, considering people are inundated…

  19. Natural gas monthly, November 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 27 tabs.

  20. Natural gas monthly, January 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 28 tabs.

  1. Natural gas monthly, December 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 6 figs., 28 tabs.

  2. Using metaphors in restoring nature

    NARCIS (Netherlands)

    Keulartz, F.W.J.

    2007-01-01

    There has recently been growing interest in the role of metaphors in environmentalism and nature conservation. Metaphors not only structure how we perceive and think but also how we should act. The metaphor of nature as a book provokes a different attitude and kind of nature management than the meta

  3. Nature and Nationhood: Danish Perspectives

    Science.gov (United States)

    Schnack, Karsten

    2009-01-01

    In this paper, I shall discuss Danish perspectives on nature, showing the interdependence of conceptions of "nature" and "nationhood" in the formations of a particular cultural community. Nature, thus construed, is never innocent of culture and cannot therefore simply be "restored" to some pristine, pre-lapsarian…

  4. Marine Natural Products Against Tuberculosis

    Directory of Open Access Journals (Sweden)

    Marcus Vinícius Nora De Souza

    2006-01-01

    Full Text Available Natural products represent an outstanding source of compounds that play an important role in the treatment of human diseases. Due to the importance of nature as a source of new drug candidates, the aim of this review is to highlight the marine natural products, which exhibit antituberculosis activity, discovered between 2000 and 2005.

  5. A natural contraceptive.

    Science.gov (United States)

    Shirkie, R

    1982-07-01

    Breastfeeding is a natural contraceptive against another pregnancy. The longer the mother nurses, the longer she delays the return of fertility. A natural mechanism triggered by breastfeeding interrupted Ms. El-Hady's monthly cycle of ovulation and menstruation. Depending on how long and how often she suckles her child, this infertility, termed lactational amenorrhea, could last as long as 2 years. This traditional method of spacing births offers protection against pregnancy to more women than all other methods of contraception combined, according to family planning researchers. With growing trends away from breastfeeding, the traditional practice is losing its impact on fertility. Not many women in Egypt use modern contraceptives. There is little understanding of lactational amenorrhea, but researchers are giving it more attention as they continue to search for effective family planning methods appropriate to the needs and circumstances of the rural population. They know that the effect is only temporary and varies from woman to woman. Ms. El-Hady has been amenorrheic for 15 months, but other women experience much shorter periods of amenorrhea, and some none at all. The secretion of milk is promoted by a hormone called prolactin that the anterior pituitary gland produces in large quantities during pregnancy. The frequency and duration of breastfeeding appear to determine the length of amenorrhea, although the mother's nutrition and any other type of contraceptive used may also play a role. Each month for 2 years, Dr. Olfat Darwish, professor of nutrition at the University of Alexandria's High Institute of Public Health, has visited 260 rural mothers and 290 urban mothers to gather data on diet, breastfeeding practices, state of amenorrhea, and use of contraception. The length of the breastfeeding period was found to affect the duration of amenorrhea. Early weaning brought an earlier return of ovulation and menstruation, and thus of fertility. The nutritional

  6. Natural resolution of inflammation.

    Science.gov (United States)

    Freire, Marcelo O; Van Dyke, Thomas E

    2013-10-01

    Inflammation is a protective response essential for maintaining human health and for fighting disease. As an active innate immune reaction to challenge, inflammation gives rise to clinical cardinal signs: rubor, calor, dolor, tumor and functio laesa. Termination of acute inflammation was previously recognized as a passive process; a natural decay of pro-inflammatory signals. We now understand that the natural resolution of inflammation involves well-integrated, active, biochemical programs that return tissues to homeostasis. This review focuses on recent advances in the understanding of the role of endogenous lipid mediators that modulate cellular fate and inflammation. Biosynthesis of eicosanoids and other lipids in exudates coincides with changes in the types of inflammatory cells. Resolution of inflammation is initiated by an active class switch in lipid mediators, such as classic prostaglandins and leukotrienes, to the production of proresolution mediators. Endogenous pro-resolving lipid mediators, including arachidonic acid-derived lipoxins, aspirin-triggered lipoxins, ω3-eicosapentaenoic acid-derived resolvins of the E-series, docosahexaenoic acid-derived resolvins of the D-series, protectins and maresins, are biosynthesized during the resolution phase of acute inflammation. Depending on the type of injury and the type of tissue, the initial cells that respond are polymorphonuclear leukocytes, monocytes/macrophages, epithelial cells or endothelial cells. The selective interaction of specific lipid mediators with G protein-coupled receptors expressed on innate immune cells (e.g. G protein-coupled receptor 32, lipoxin A4 receptor/formyl peptide receptor2, chemokine-like receptor 1, leukotriene B4 receptor type 1 and cabannoid receptor 2) induces cessation of leukocyte infiltration; vascular permeability/edema returns to normal with polymorphonuclear neutrophil death (mostly via apoptosis), the nonphlogistic infiltration of monocyte/macrophages and the removal

  7. Nature of eclipsing pulsars

    CERN Document Server

    Khechinashvili, D; Gil, J; Khechinashvili, David; Melikidze, George; Gil, Janusz

    2000-01-01

    We present a model for pulsar radio eclipses in some binary systems, and test this model for PSRs B1957+20 and J2051-0827. We suggest that in these binaries the companion stars are degenerate dwarfs with strong surface magnetic fields. The magnetospheres of these stars are permanently infused by the relativistic particles of the pulsar wind. We argue that the radio waves emitted by the pulsar split into the eigenmodes of the electron-positron plasma as they enter the companion's magnetosphere and are then strongly damped due to cyclotron resonance with the ambient plasma particles. Our model explains in a natural way the anomalous duration and behavior of radio eclipses observed in such systems. In particular, it provides stable, continuous, and frequency-dependent eclipses, in agreement with the observations. We predict a significant variation of linear polarization both at eclipse ingress and egress. In this paper we also suggest several possible mechanisms of generation of the optical and $X$-ray emission ...

  8. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    D. A. Konovalov

    2014-01-01

    Full Text Available Polyacetylenes (polyynes are compounds which contain two or more triple bonds in its structure. About 2 000 different polyacetylenes and biogenetically related substances were identified in 24 families of higher plants. However, most of these compounds were found in seven families of flowering plants: Apiaceae (Umbelliferae, Araliaceae, Asteraceae (Compositae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae. Polyacetylenes are relatively unstable, chemically and biologically active compounds, and present in fungi, microorganisms, marine invertebrates and other organisms except for plants. Acetylenes form distinct specialized group of chemically active natural compounds, which are biosynthesized in plants of unsaturated fatty acids. In addition to widespread aliphatic polyacetylenes thiophenes dithiacyclohexadienes (thiarubrines, thioethers, sulphoxides, sulphones, alkamides, chlorohydrins, lactones, spiroacetal enol ethers, furans, pyrans, tetrahydropyrans, isocoumarins, aromatic acetylenes were also found in plant species. Polyacetylenes are localized in different plant organs, and can be found both individually and as a compound with carbohydrates, terpene, phenolic and other compounds. Many polyacetylenes are found in the composition of the essential oils of plants and it confirms their strongly marked ecological functions. From biological point of view these compounds are often synthesized by plants as toxic or bitter antifeedants, allelopathic compounds, phytoalexins or broadly antibiotic components. Polyynes are strong photosensitizers. They exhibit anti-inflammatory, anti-coagulant, anti-bacterial, antituberculosis, anti-fungal, anti-viral, neuroprotective and neurotoxic activity. Immunostimulatory influence associated with certain allergenicity of some of these substances was established. Therefore, without a doubt polyacetylenes are of interest for the modern pharmacy and medicine.

  9. Lorentz violation naturalness revisited

    Energy Technology Data Exchange (ETDEWEB)

    Belenchia, Alessio; Gambassi, Andrea; Liberati, Stefano [SISSA - International School for Advanced Studies, via Bonomea 265, 34136 Trieste (Italy); INFN, Sezione di Trieste, via Valerio 2, 34127 Trieste (Italy)

    2016-06-08

    We revisit here the naturalness problem of Lorentz invariance violations on a simple toy model of a scalar field coupled to a fermion field via a Yukawa interaction. We first review some well-known results concerning the low-energy percolation of Lorentz violation from high energies, presenting some details of the analysis not explicitly discussed in the literature and discussing some previously unnoticed subtleties. We then show how a separation between the scale of validity of the effective field theory and that one of Lorentz invariance violations can hinder this low-energy percolation. While such protection mechanism was previously considered in the literature, we provide here a simple illustration of how it works and of its general features. Finally, we consider a case in which dissipation is present, showing that the dissipative behaviour does not percolate generically to lower mass dimension operators albeit dispersion does. Moreover, we show that a scale separation can protect from unsuppressed low-energy percolation also in this case.

  10. Nature of Upsilon Sagittarii

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberner, D.; Drilling, J.S.

    1983-05-01

    We present a new explanation for the nature and evolution of the extremely hydrogen-deficient binary upsilon Sgr which is consistent with all observational and theoretical facts. First, the system goes through a case B mass exchange in which most of the hydrogen-rich envelope of a massive primary (5--14 M/sub sun/) is lost. The remaining envelope still contains approx.50% hydrogen (by number), but is now of negligible mass, so that the star will evolve like a pure helium star. If its mass is between 1 and 2 M/sub sun/, the star will reach low surface temperatures and become a supergiant before the onset of carbon burning. This star (the original primary) will then fill its Roche lobe a second time, spilling its now helium-rich envelope over onto the secondary (case BB mass exchange). We argue that upsilon Sgr is in this state at the present time, and that the visible star is an evolved helium star of approx.1 M/sub sun/ with a degenerate carbon-oxygen core and a helium-burning shell which provides the high luminosity.

  11. SUSY naturalness without prejudice

    Science.gov (United States)

    Ghilencea, D. M.

    2014-05-01

    Unlike the Standard Model (SM), supersymmetric models stabilize the electroweak (EW) scale v at the quantum level and predict that v is a function of the TeV-valued SUSY parameters (γα) of the UV Lagrangian. We show that the (inverse of the) covariance matrix of the model in the basis of these parameters and the usual deviation δχ2 (from χmin2 of a model) automatically encode information about the "traditional" EW fine-tuning measuring this stability, provided that the EW scale v ˜mZ is indeed regarded as a function v =v(γ). It is known that large EW fine-tuning may signal an incomplete theory of soft terms and can be reduced when relations among γα exist (due to GUT symmetries, etc.). The global correlation coefficient of this matrix can help one investigate if such relations are present. An upper bound on the usual EW fine-tuning measure ("in quadrature") emerges from the analysis of the δχ2 and the s-standard deviation confidence interval by using v =v(γ) and the theoretical approximation (loop order) considered for the calculation of the observables. This upper bound avoids subjective criteria for the "acceptable" level of EW fine-tuning for which the model is still "natural."

  12. NATURAL POLYACETYLENE COMPOUNDS

    Directory of Open Access Journals (Sweden)

    A. M. Nasukhova

    2014-01-01

    Full Text Available In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

  13. Unified Maximally Natural Supersymmetry

    CERN Document Server

    Huang, Junwu

    2016-01-01

    Maximally Natural Supersymmetry, an unusual weak-scale supersymmetric extension of the Standard Model based upon the inherently higher-dimensional mechanism of Scherk-Schwarz supersymmetry breaking (SSSB), possesses remarkably good fine tuning given present LHC limits. Here we construct a version with precision $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ unification: $\\sin^2 \\theta_W(M_Z) \\simeq 0.231$ is predicted to $\\pm 2\\%$ by unifying $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ into a 5D $SU(3)_{\\rm EW}$ theory at a Kaluza-Klein scale of $1/R_5 \\sim 4.4\\,{\\rm TeV}$, where SSSB is simultaneously realised. Full unification with $SU(3)_{\\rm C}$ is accommodated by extending the 5D theory to a $N=4$ supersymmetric $SU(6)$ gauge theory on a 6D rectangular orbifold at $1/R_6 \\sim 40 \\,{\\rm TeV}$. TeV-scale states beyond the SM include exotic charged fermions implied by $SU(3)_{\\rm EW}$ with masses lighter than $\\sim 1.2\\,{\\rm TeV}$, and squarks in the mass range $1.4\\,{\\rm TeV} - 2.3\\,{\\rm TeV}$, providing distinct signature...

  14. Forces of nature

    CERN Document Server

    AUTHOR|(CDS)2072602

    2016-01-01

    A breathtaking and beautiful exploration of our planet. This groundbreaking book, which accompanies the new BBC1 TV series, provides the deepest answers to the simplest questions. 'Why is the sky blue?' 'Why is the Earth round?' 'Why is every snowflake unique?' To answer these and many other questions, Professor Brian Cox will reveal some of the most extraordinary phenomena and events on Earth and in the Universe and beyond. From the immensity of Earth's globe to all the world's myriad snowflakes, the forces of nature shape everything we see. Pushed to extremes, the results are astonishing. From the realm of auroras to the heart of our planet, the ingredients that make everything on Earth connect each one of us in an eternal cycle of life. Brian will reveal why Earth is the most colourful world we know, exploring the white light of the sun as it travels through the darkness of space until it hits Earth's atmosphere where it begins a new journey, splitting into a rainbow of colours. From the great plains of th...

  15. Natural rubber latex allergy

    Directory of Open Access Journals (Sweden)

    Deval Ravi

    2008-01-01

    Full Text Available Natural rubber latex (NRL is a ubiquitous allergen as it is a component of > 40,000 products in everyday life. Latex allergy might be attributed to skin contact or inhalation of latex particles. Latex allergy is an IgE-mediated hypersensitivity to NRL, presenting a wide range of clinical symptoms such as angioedema, swelling, cough, asthma, and anaphylactic reactions. Until 1979, latex allergy appeared only as type IV delayed hypersensitivity; subsequently, the proportion of different allergy types drifted towards type IV contact allergy reactions. Several risk factors for sensitization to NRL are already known and well documented. Some authors have established a positive correlation between a history of multiple surgical interventions, atopy, spina bifida malformation, and latex allergy incidence. We suspect an increase in latex allergy incidence in association with increased atopy and sensitivity to environmental allergens in the industrial population. It is often postulated in literature that the groups of workers at risk for this allergy are essentially workers in the latex industry and healthcare professionals. In this population, direct internal and mucosal contact with NRL medical devices may be the route of sensitization as factors such as the number of procedures and use of NRL materials (catheters and tubes were associated with increased risk of latex sensitization and allergy.

  16. A natural topological insulator.

    Science.gov (United States)

    Gehring, P; Benia, H M; Weng, Y; Dinnebier, R; Ast, C R; Burghard, M; Kern, K

    2013-03-13

    The earth's crust and outer space are rich sources of technologically relevant materials which have found application in a wide range of fields. Well-established examples are diamond, one of the hardest known materials, or graphite as a suitable precursor of graphene. The ongoing drive to discover novel materials useful for (opto)electronic applications has recently drawn strong attention to topological insulators. Here, we report that Kawazulite, a mineral with the approximate composition Bi2(Te,Se)2(Se,S), represents a naturally occurring topological insulator whose electronic properties compete well with those of its synthetic counterparts. Kawazulite flakes with a thickness of a few tens of nanometers were prepared by mechanical exfoliation. They exhibit a low intrinsic bulk doping level and correspondingly a sizable mobility of surface state carriers of more than 1000 cm(2)/(V s) at low temperature. Based on these findings, further minerals which due to their minimized defect densities display even better electronic characteristics may be identified in the future.

  17. Optically switchable natural silk

    Energy Technology Data Exchange (ETDEWEB)

    Krasnov, Igor, E-mail: Igor.Krasnov@hzg.de; Müller, Martin, E-mail: Martin.Mueller@hzg.de [Institut für Experimentelle und Angewandte Physik, Universität Kiel, D-24098 Kiel (Germany); Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), D-21502 Geesthacht (Germany); Krekiehn, Nicolai R.; Jung, Ulrich; Magnussen, Olaf M. [Institut für Experimentelle und Angewandte Physik, Universität Kiel, D-24098 Kiel (Germany); Krywka, Christina [Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), D-21502 Geesthacht (Germany); Zillohu, Ahnaf U.; Strunskus, Thomas [Institut für Materialwissenschaft, Universität Kiel, D-24098 Kiel (Germany); Elbahri, Mady [Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), D-21502 Geesthacht (Germany); Institut für Materialwissenschaft, Universität Kiel, D-24098 Kiel (Germany)

    2015-03-02

    An optically active bio-material is created by blending natural silk fibers with photoisomerizable chromophore molecules—azobenzenebromide (AzBr). The material converts the energy of unpolarized light directly into mechanical work with a well-defined direction of action. The feasibility of the idea to produce optically driven microsized actuators on the basis of bio-material (silk) is proven. The switching behavior of the embedded AzBr molecules was studied in terms of UV/Vis spectroscopy. To test the opto-mechanical properties of the modified fibers and the structural changes they undergo upon optically induced switching, single fiber X-ray diffraction with a micron-sized synchrotron radiation beam was combined in situ with optical switching as well as with mechanical testing and monitoring. The crystalline regions of silk are not modified by the presence of the guest molecules, hence occupy only the amorphous part of the fibers. It is shown that chromophore molecules embedded into fibers can be reversibly switched between the trans and cis conformation by illumination with light of defined wavelengths. The host fibers respond to this switching with a variation of the internal stress. The amplitude of the mechanical response is independent of the applied external stress and its characteristic time is shorter than the relaxation time of the usual mechanical response of silk.

  18. Periurbanisation and natural hazards

    Directory of Open Access Journals (Sweden)

    Delphine Loison

    2009-03-01

    Full Text Available In mountainous areas in recent decades urbanisation has expanded to areas where low ground adjoins mountainsides that are unstable in a number of respects. Periurbanisation in mountain basins with unstable sides poses specific problems that local players have to address. The Lavanchon basin (southeast of Grenoble, which is subject to very rapid urban growth combined with particularly dynamic mountainsides, is representative of the way activity is being brought into closer contact with potential hazards. A diachronic study of changes in land use between 1956 and 2001 shows how valley infrastructures at the bottom of mountainsides have become increasingly dense. In this context, a survey was carried out among a number of residents in the Lavanchon basin in an attempt to evaluate the degree of awareness that the population has of the natural hazards to which it is exposed. The results show that slightly more than half of the population surveyed was aware of the problem of natural hazards being present in the area, with most inhabitants being more concerned about industrial and pollution hazards. New residents were unaware of or were unwilling to accept the reality of hazards. The low incidence of significant natural events, the effectiveness of the protective structures built, the absence of information provided by the public authorities and the division of the basin between several management bodies appear to have engendered a feeling of safety from natural phenomena. The geographical distribution of appreciation of the hazard clearly shows a distinction between those inhabitants living on the low ground and those at the bottom of the mountainsides, and this corresponds fairly closely with the historical and current location of the main potentially hazardous events that have occurred.Dans les territoires de montagne, les dernières décennies ont vu l’expansion de l’urbanisation vers les zones de contact entre la plaine et les versants, lieux

  19. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  20. Natural gas conversion process

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The experimental apparatus was dismantled and transferred to a laboratory space provided by Lawrence Berkeley Laboratory (LBL) which is already equipped with a high-ventilation fume hood. This will enable us to make tests at higher gas flow rates in a safe environment. Three papers presented at the ACS meeting in San Francisco (Symposium on Natural Gas Upgrading II) April 5--10, 1992 show that the goal of direct catalytic conversion of Methane into heavier Hydrocarbons in a reducing atmosphere is actively pursued in three other different laboratories. There are similarities in their general concept with our own approach, but the temperature range of the experiments reported in these recent papers is much lower and this leads to uneconomic conversion rates. This illustrates the advantages of Methane activation by a Hydrogen plasma to reach commercial conversion rates. A preliminary process flow diagram was established for the Integrated Process, which was outlined in the previous Quarterly Report. The flow diagram also includes all the required auxiliary facilities for product separation and recycle of the unconverted feed as well as for the preparation and compression of the Syngas by-product.

  1. Prospects for natural SUSY

    Science.gov (United States)

    Kim, J. S.; Rolbiecki, K.; Ruiz, R.; Tattersall, J.; Weber, T.

    2016-11-01

    As we anticipate the first results of the 2016 run, we assess the discovery potential of the LHC to "natural supersymmetry." To begin with, we explore the region of the model parameter space that can be excluded with various center-of-mass energies (13 TeV and 14 TeV) and different luminosities (20 fb-1 , 100 fb-1 , 300 fb-1 and 3000 fb-1 ). We find that the bounds at 95% C.L. on stops vary from mt˜1≳800 GeV expected this summer to mt˜1≳1500 GeV at the end of the high luminosity run, while gluino bounds are expected to range from mg ˜≳1700 GeV to mg ˜≳2500 GeV over the same time period. However, more pessimistically, we find that if no signal begins to appear this summer, only a very small region of parameter space can be discovered with 5 σ significance. For this conclusion to change, we find that both theoretical and systematic uncertainties will need to be significantly reduced.

  2. Naturalness and supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Agashe, Kaustubh [Univ. of California, Berkeley, CA (United States)

    1998-05-01

    In this thesis, the author argues that the supersymmetric Standard Model, while avoiding the fine tuning in electroweak symmetry breaking, requires unnaturalness/fine tuning in some (other) sector of the theory. For example, Baryon and Lepton number violating operators are allowed which lead to proton decay and flavor changing neutral currents. He studies some of the constraints from the latter in this thesis. He has to impose an R-parity for the theory to be both natural and viable. In the absence of flavor symmetries, the supersymmetry breaking masses for the squarks and sleptons lead to too large flavor changing neutral currents. He shows that two of the solutions to this problem, gauge mediation of supersymmetry breaking and making the scalars of the first two generations heavier than a few TeV, reintroduce fine tuning in electroweak symmetry breaking. He also constructs a model of low energy gauge mediation with a non-minimal messenger sector which improves the fine tuning and also generates required Higgs mass terms. He shows that this model can be derived from a Grand Unified Theory despite the non-minimal spectrum.

  3. Natural Gas Monthly, October 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-10

    The (NGM) Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. This month`s feature articles are: US Production of Natural Gas from Tight Reservoirs: and Expanding Rule of Underground Storage.

  4. Natural gas monthly, August 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-25

    The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), US Department of Energy (DOE). The NGM highhghts activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  5. Natural gas monthly, May 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-25

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The featured articles for this month are: Opportunities with fuel cells, and revisions to monthly natural gas data.

  6. Natural gas monthly, March 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article is entitled ``Natural gas analysis and geographic information systems.`` 6 figs., 27 tabs.

  7. Natural gas monthly, October 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), U.S. Department of Energy (DOE). The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  8. Natural gas monthly, May 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is ``Restructuring energy industries: Lessons from natural gas.`` 6 figs., 26 tabs.

  9. Natural gas monthly, June 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is the executive summary from Natural Gas 1994: Issues and Trends. 6 figs., 31 tabs.

  10. Natural gas monthly, April 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are present3ed each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article is entitled ``Natural gas pipeline and system expansions.`` 6 figs., 27 tabs.

  11. Natural gas monthly, December 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The article this month is entitled ``Recent Trends in Natural Gas Spot Prices.`` 6 figs., 27 tabs.

  12. Natural gas monthly, July 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The feature article this month is entitled ``Intricate puzzle of oil and gas reserves growth.`` A special report is included on revisions to monthly natural gas data. 6 figs., 24 tabs.

  13. The Case for Natural History

    Science.gov (United States)

    King, Heather; Achiam, Marianne

    2017-03-01

    Fundamental knowledge of natural history is lacking in many western societies, as demonstrated by its absence in school science curricula. And yet, to meet local and global challenges such as environmental degradation, biodiversity loss and climate change, we need to better understand the living and non-living parts of the natural world. Many have argued passionately for an increased understanding of natural history; others have developed successful pedagogical programmes for applying knowledge of natural history in environmental initiatives. In joining wider calls, we choose here to focus on the educational value afforded by understanding the epistemological bases of natural history and its particular forms of reasoning. We also briefly discuss the ways in which an education in natural history provides the foundation for environmental and social justice efforts that directly affect the lives of young people and their communities. We end by highlighting the ease by which natural history may be incorporated in learning opportunities both in and outside of the classroom.

  14. Natural gas monthly, April 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This issue of the Natural Gas Monthly presents the most recent estimates of natural gas data from the Energy Information Administration (EIA). Estimates extend through April 1998 for many data series. The report highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, feature articles are presented designed to assist readers in using and interpreting natural gas information. This issue contains the special report, ``Natural Gas 1997: A Preliminary Summary.`` This report provides information on natural gas supply and disposition for the year 1997, based on monthly data through December from EIA surveys. 6 figs., 28 tabs.

  15. Crystalline Ceramic Waste Forms: Comparison Of Reference Process For Ceramic Waste Form Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, K. S. [Savannah River National Laboratory; Marra, J. C. [Savannah River National Laboratory; Amoroso, J. [Savannah River National Laboratory; Tang, M. [Los Alamos National Laboratory

    2013-08-22

    The research conducted in this work package is aimed at taking advantage of the long term thermodynamic stability of crystalline ceramics to create more durable waste forms (as compared to high level waste glass) in order to reduce the reliance on engineered and natural barrier systems. Durable ceramic waste forms that incorporate a wide range of radionuclides have the potential to broaden the available disposal options and to lower the storage and disposal costs associated with advanced fuel cycles. Assemblages of several titanate phases have been successfully demonstrated to incorporate radioactive waste elements, and the multiphase nature of these materials allows them to accommodate variation in the waste composition. Recent work has shown that they can be produced from a melting and crystallization process. The objective of this report is to explore the phase formation and microstructural differences between lab scale melt processing in varying gas environments with alternative densification processes such as Hot Pressing (HP) and Spark Plasma Sintering (SPS). The waste stream used as the basis for the development and testing is a simulant derived from a combination of the projected Cs/Sr separated stream, the Trivalent Actinide - Lanthanide Separation by Phosphorous reagent Extraction from Aqueous Komplexes (TALSPEAK) waste stream consisting of lanthanide fission products, the transition metal fission product waste stream resulting from the transuranic extraction (TRUEX) process, and a high molybdenum concentration with relatively low noble metal concentrations. Melt processing as well as solid state sintering routes SPS and HP demonstrated the formation of the targeted phases; however differences in microstructure and elemental partitioning were observed. In SPS and HP samples, hollandite, pervoskite/pyrochlore, zirconolite, metallic alloy and TiO{sub 2} and Al{sub 2}O{sub 3} were observed distributed in a network of fine grains with small residual pores

  16. Diffusion in natural ilmenite

    Science.gov (United States)

    Stenhouse, Iona; O'Neill, Hugh; Lister, Gordon

    2010-05-01

    Diffusion rates in natural ilmenite of composition Fe0.842+ Fe0.163+Mn0.07Mg0.01Ti 0.92O3 from the Vishnevye Mountains (Urals, Russia) have been measured at 1000° C. Experiments were carried out in a one atmosphere furnace with oxygen fugacity controlled by flow of a CO-CO2 gas mixture, over a period of four hours. The diffusant source was a synthetic ilmenite (FeTiO3) powder doped with trace amounts of Mg, Co, Ni, Zr, Hf, V, Nb, Ta, Al, Cr, Ga and Y. Since, the natural ilmenite crystal contained Mn it was also possible to study diffusion of Mn from the ilmenite crystal. The experiments were analysed using the electron microprobe and scanning laser ablation ICP-MS. Diffusion profiles were measured for Al, Mg, Mn, Co, Ni, Ga, and Y. Diffusion of Cr, Hf, Zr, V, Nb and Ta was too slow to allow diffusion profiles to be accurately measured for the times and temperatures studied so far. The preliminary results show that diffusion in ilmenite is fast, with the diffusivity determined in this study on the order of 10-13 to 10-16 m2s-1. For comparison, Chakraborty (1997) found interdiffusion of Fe and Mg in olivine at 1000° C on the order of 10-17 to 10-18m2s-1 and Dieckmann (1998) found diffusivity of Fe, Mg, Co in magnetite at 1200° C to be on the order of 10-13 to 10-14 m2s-1. The order in which the diffusivity of the elements decreases is Mn > Co > Mg ≥ Ni > Al ≥ Y ≥ Ga, that is to say that Mn diffuses the fastest and Ga the slowest. Overall, this study intends to determine diffusion parameters such as frequency factor, activation energy and activation volume as a function of temperature and oxygen fugacity. This research is taking place in the context of a larger study focusing on the use of the garnet-ilmenite system as a geospeedometer. Examination of the consequences of simultaneous diffusion of multiple elements is a necessity if we are to develop an understanding of the crystal-chemical controls on diffusion (cf Spandler & O'Neill, in press). Chakraborty

  17. Nonconventional natural gas resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-03-01

    It is concluded that it is impossible at this time to forecast the volume of natural gas dissolved in water that can be economically recovered. The investigation to southern Louisiana, both onshore and offshore was confined. Estimates of the dissolved methane content are based upon information on temperatures, pressures, sandstone thicknesses, sandstone porosities, salinity, and the solubility of methane. The salinity of waters encountered in wells was estimated from wireline logs, and in turn used to reduce the estimated content of dissolved gas. The reductions range from 51 to 61 percent of the solubility of methane in fresh water. The assessment does not include gas dissolved in water contained in shale beds. A series of maps display the information used in the computation. Methane solubility values were multiplied by porosity--feet values for each 1000-foot interval. The total dissolved methane in the resource base is estimated to be 6,143 trillion cubic feet (Tcf); assumptions on the effect of salinity reduce this to 3,264 Tcf. This figure does not include methane beneath the Texas coast. Very preliminary estimates of the recoverable proportion of dissolved gas in the highly ''geopressured'' zones range from 1 to over 20 percent. Not all of the resource base estimates of 3,264 Tcf occurs in the highly geopressured zone, and the proportions individually allocatable within the resource base to the highly ''geopressured'' zone, to the intermediate-pressure zone, and to the normal or ''hydropressure'' zone cannotbe estimated readily. The environmental aspects of recovery of dissolved gas are also presented. The review is necessarily generalized, since it could not be based on actual experience. The problems include subsidence of land surface and possibly increased seismic activity. Fluid withdrawal might result in subsidence of the land surface, as well as activation of growth faults, with adjustments

  18. Can Realism Be Naturalized?

    Directory of Open Access Journals (Sweden)

    Christopher Norris

    2000-06-01

    Full Text Available Hilary Putnam has famously undergone some radical changes of mind with regard to the issue of scientific realism and its wider epistemological bearings. In this paper I defend the arguments put forward by early Putnam in his essays on the causal theory of reference as applied to natural-kind terms, despite his own later view that those arguments amounted to a form of 'metaphysical' realism which could not be sustained against various lines of sceptical attack. I discuss some of the reasons for Putnam's retreat, first to the theory of 'internal (or framework-relative realism proposed in his middle-period writings, and then to a commonsense pragmatist stance which claims to resituate this whole discussion on ground that has not been trodden into ruts by the contending philosophical schools. In particular I examine his protracted engagement with various forms of anti-realist doctrine (Michael Dummet’s most prominent among them, with Wittgenstein's thinking about language-games or meaning-as-use, and with a range of skeptical - relativist positions adopted in the wake of Quine’s influential attack on the two last 'dogmas' of logical empiricism. My paper seeks to show that Putnam has been over-impressed by some of the arguments — from these and other sources — which he takes to constitute a knock-down case against the kind of externalist and causal-realist approach developed in his early essays. It concludes by re-stating that position in summary form and relating it to other, more recent defences of causal realism in epistemology and philosophy of science.

  19. Natural and engineered biosynthesis of fluorinated natural products.

    Science.gov (United States)

    Walker, Mark C; Chang, Michelle C Y

    2014-09-21

    Both natural products and synthetic organofluorines play important roles in the discovery and design of pharmaceuticals. The combination of these two classes of molecules has the potential to be useful in the ongoing search for new bioactive compounds but our ability to produce site-selectively fluorinated natural products remains limited by challenges in compatibility between their high structural complexity and current methods for fluorination. Living systems provide an alternative route to chemical fluorination and could enable the production of organofluorine natural products through synthetic biology approaches. While the identification of biogenic organofluorines has been limited, the study of the native organisms and enzymes that utilize these compounds can help to guide efforts to engineer the incorporation of this unusual element into complex pharmacologically active natural products. This review covers recent advances in understanding both natural and engineered production of organofluorine natural products.

  20. Tc immobilization by using perovskite-rich and rutile-rich synroc

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chuan-Zhi; LI Bao-Jun; LUO Shang-Geng

    2005-01-01

    The simulating technetium (Tc) separated from HLW was immobilized in perovskite-rich and rutile-rich synroc which contained 85wt% of perovskite or rutile, and 20, 25, 30 or 35wt% waste loading, respectively. The synroc was prepared by hot pressing under reducing condition. The fabricated samples have good physical properties (density and open porosity). The XRD analyses show that the major phase is perovskite or rutile and the minor phases are zirconolite, hollandite and metal alloy. At higher waste loading the metal alloy phase appeared, particularly in the rutile-rich synroc. The scanning electron microscopy (SEM) and backscattered electron images (BEI) show the samples to be homogeneous and densified. The MCC-1 leaching tests (90℃, 28 d) results show that: mass losses are at the level of 10-3 G·m-2·d-1,and the nominal element leaching rates are 10-5-10-3 G·m-2·d-1.It indicates that the fabricated samples have good leach resistance. According to their physical properties and leach resistance, the perovskite-rich and rutile-rich synroc can immobilize Tc up to 35 wt%. In comparison, Tc immobilization by using perovskite-rich synroc is more favorable.

  1. Nature's palette: the search for natural blue colorants.

    Science.gov (United States)

    Newsome, Andrew G; Culver, Catherine A; van Breemen, Richard B

    2014-07-16

    The food and beverage industry is seeking to broaden the palette of naturally derived colorants. Although considerable effort has been devoted to the search for new blue colorants in fruits and vegetables, less attention has been directed toward blue compounds from other sources such as bacteria and fungi. The current work reviews known organic blue compounds from natural plant, animal, fungal, and microbial sources. The scarcity of blue-colored metabolites in the natural world relative to metabolites of other colors is discussed, and structural trends common among natural blue compounds are identified. These compounds are grouped into seven structural classes and evaluated for their potential as new color additives.

  2. Natural gas and Brazilian energetic matrix; Gas natural no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Ricardo Luchese de [White Martins S.A., Rio de Janeiro, RJ (Brazil)

    1997-07-01

    Recent projection of the market in global scale shows a tendency in natural gas using replacing mostly the fuel oil. Its market share well increase from 21.1% in 1994 to 24.0% in 2010. The annual energetic use will reach 29.23 x 10{sup 9} Gcal in 2010 (8990 million Nm{sup 3} natural gas/day) versus 18.90 x 10{sup 9} Gcal in 1994 (5810 million Nm{sup 3} natural gas/day). For Brazil, its consumption will increase from 8.7 million Nm{sup 3} natural gas/day in 1994 to 35.9 million Nm{sup 3} natural gas/day in 2010. Projects like Brazil-Bolivia natural gas pipeline, will supply 18 million Nm{sup 3} natural gas/day, which expected to start-up before the year 2000. This projects will supply the Brazilian southern regions, that do not consume natural gas at the current moment. Although there are many different kind of natural gas consumption in the industry this paper presents the technical and economical estimate of the injection in the blast furnace operating with coke or charcoal. The process simulation is done assisted by math modeling developed by White Martins/Praxair Inc. (author)

  3. Naturalness judgments by lay Americans

    Directory of Open Access Journals (Sweden)

    Paul Rozin

    2006-11-01

    Full Text Available This study directly tests the hypothesis that, at least within the domains of food and drink for Americans, the judgment of naturalness has more to do with the history of an object, that is the processes that it has undergone, as opposed to its material content. Individuals rate the naturalness and acceptability of a natural entity (water or tomato paste, that same entity with a first transformation in which a natural substance is added (or some part removed, and then a second transformation in which the natural additive is removed (or the removed part is replaced. The twice transformed entity is stipulated to be identical to the original natural entity, yet it is rated much less natural and less acceptable. It differs from the original entity only in its history (the reversed processes it has experienced. The twice transformed entity is also rated as less natural than the once-transformed entity, even though the former is identical to the original natural entity, and the latter is not. Therefore, naturalness depends heavily on the process-history of an entity.

  4. Immigration, social cohesion, and naturalization

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2010-01-01

    social trust do not connect with issues of naturalization at all. Other conceptions of social cohesion are either politically controversial, problematic as part of the justification of stricter naturalization requirements, or in fact justify less demanding naturalization requirements.......The standard appeal to social cohesion in relation to immigration concerns admittance and residence. But social cohesion is sometimes also invoked as a relevant concern in relation to the attainment of citizenship in the state through naturalization. Many western states have recently tightened...... conditions for naturalization and introduced tougher language requirements and knowledge of society tests. The article discusses how concerns for social cohesion might function as a part of justifications of such restrictive naturalization requirements. It argues that standard concerns with generalized...

  5. The Case for Natural History

    DEFF Research Database (Denmark)

    King, Heather; Achiam, Marianne

    2017-01-01

    Fundamental knowledge of natural history is lacking in many western societies, as demonstrated by its absence in school science curricula. And yet to meet local and global challenges such as environmental degradation, biodiversity loss and climate change, we need to better understand the living...... and non-living parts of the natural world. Many have argued passionately for an increased understanding of natural history; others have developed successful pedagogical programmes for applying a knowledge of natural history in environmental initiatives. In joining wider calls, we choose here to focus...... on the educational value afforded by understanding the epistemological bases of natural history and its particular forms of reasoning. We also briefly discuss the ways in which an education in natural history provides the foundation for environmental and social justice efforts that directly affect the lives of young...

  6. Electrical Properties of Natural Pyroxenite

    Institute of Scientific and Technical Information of China (English)

    YI Li; WANG Duo-Jun; LI He-Ping

    2005-01-01

    @@ The complex electrical properties of natural pyroxenite were measured over a frequency range from 0.01 to 106 Hz, at 3.0GPa and 1266-1504K, using the solid buffers (Mo-MoO2) to control the oxygen fugacity. Thefrequency dependence of electrical properties for the natural pyroxenite is investigated. Two distinct conduction mechanisms of the natural pyroxenite are observed: grain interior and grain boundary conduction. Grain interior transport controls the response above 100 Hz, whereas grain boundary transport dominates between ~ 100 and 0.01 Hz. Electrical response of natural pyroxenite is modelled with an equivalent circuit in which parallel RC circuit elements representing grain interior and grain boundary responses act in series. The grain boundaries do not enhance the total conductivity of natural pryoxenite. The total electrical conductivity of natural pyroxenite is lower than either grain interior or grain boundary conductivity alone.

  7. Natural gas monthly, February 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-25

    The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. The NGM also features articles designed to assist readers in using and interpreting natural gas information.

  8. The nature of sports marketing

    OpenAIRE

    Bühler, André; Nufer, Gerd; Rennhak, Carsten

    2006-01-01

    Sports marketing has established itself over the last three decades not only as a very special form of marketing but also as an own subject of research. However, it is quite surprising that the nature of sports marketing is relatively unknown as different definitions of sports market-ing indicate. Indeed, a generally accepted definition does not exist to date and opinions about the nature of sports marketing differ widely. This paper examines the nature of sports market-ing and therefore seek...

  9. Natural gas monthly, April 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-26

    The National Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.

  10. Natural gas monthly, September 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The National Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. 6 figs., 27 tabs.

  11. Essentials of natural gas microturbines

    CERN Document Server

    Boicea, Valentin A

    2013-01-01

    Addressing a field which, until now, has not been sufficiently investigated, Essentials of Natural Gas Microturbines thoroughly examines several natural gas microturbine technologies suitable not only for distributed generation but also for the automotive industry. An invaluable resource for power systems, electrical, and computer science engineers as well as operations researchers, microturbine operators, policy makers, and other industry professionals, the book: Explains the importance of natural gas microturbines and their use in distributed energy resource (DER) systemsDiscusses the histor

  12. Contaminant Removal From Natural Resources

    Science.gov (United States)

    Clausen, Christian A. (Inventor); Quinn, Jacqueline W. (Inventor); Geiger, Cheri L. (Inventor); Reinhart, Debra (Inventor); Fillpek, Laura B. (Inventor); Coon, Christina (Inventor); Devor, Robert (Inventor)

    2006-01-01

    A zero-valent metal emulsion containing zero-valent metal particles is used to remediate contaminated natural resources, such as groundwater and soil. In a preferred embodiment, the zero-valent metal emulsion removes heavy metals, such as lead (pb), from contaminated natural resources. In another preferred embodiment, the zero-valent metal emulsion is a bimetallic emulsion containing zero-valent metal particles doped with a catalytic metal to remediate halogenated aromatic compounds, such as polychlorinated biphenyls (PCBs), from natural resources.

  13. Natural gas monthly, October 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-23

    The Natural Gas Monthly highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. A glossary of the terms used in this report is provided to assist readers in understanding the data presented in this publication. 6 figs., 30 tabs.

  14. The 'Nature' of International Relations

    DEFF Research Database (Denmark)

    Corry, Olaf

    2017-01-01

    The discipline of IR is beginning to grapple with how nature is a condition for, and increasingly and object of, international politics. This chapter narrates how IR actually began with features of the natural world at its heart, narrowed this down to human nature, before then losing sight......, but then to think in dialectical terms about their mutual relations and transformations. Neither strategy is without pitfalls, but I suggest that the latter deserves more attention....

  15. Natural gas monthly, March 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The March 1998 edition of the Natural Gas Monthly highlights activities, events, and analyses associated with the natural gas industry. Volume and price data are presented for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. This report also features an article on the correction of errors in the drilling activity estimates series, and in-depth drilling activity data. 6 figs., 28 tabs.

  16. Natural gas monthly, March 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The March 1998 edition of the Natural Gas Monthly highlights activities, events, and analyses associated with the natural gas industry. Volume and price data are presented for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. This report also features an article on the correction of errors in the drilling activity estimates series, and in-depth drilling activity data. 6 figs., 28 tabs.

  17. Turbulence in Natural Environments

    Science.gov (United States)

    Banerjee, Tirtha

    Problems in the area of land/biosphere-atmosphere interaction, hydrology, climate modeling etc. can be systematically organized as a study of turbulent flow in presence of boundary conditions in an increasing order of complexity. The present work is an attempt to study a few subsets of this general problem of turbulence in natural environments- in the context of neutral and thermally stratified atmospheric surface layer, the presence of a heterogeneous vegetation canopy and the interaction between air flow and a static water body in presence of flexible protruding vegetation. The main issue addressed in the context of turbulence in the atmospheric surface layer is whether it is possible to describe the macro-states of turbulence such as mean velocity and turbulent velocity variance in terms of the micro-states of the turbulent flow, i.e., a distribution of turbulent kinetic energy across a multitude of scales. This has been achieved by a `spectral budget approach' which is extended for thermal stratification scenarios as well, in the process unifying the seemingly different and unrelated theories of turbulence such as Kolmogorov's hypothesis, Heisenberg's eddy viscosity, Monin Obukhov Similarity Theory (MOST) etc. under a common framework. In the case of a more complex scenario such as presence of a vegetation canopy with edges and gaps, the question that is addressed is in what detail the turbulence is needed to be resolved in order to capture the bulk flow features such as recirculation patterns. This issue is addressed by a simple numerical framework and it has been found out that an explicit prescription of turbulence is not necessary in presence of heterogeneities such as edges and gaps where the interplay between advection, pressure gradients and drag forces are sufficient to capture the first order dynamics. This result can be very important for eddy-covariance flux calibration strategies in non-ideal environments and the developed numerical model can be

  18. Mechanochemical modification of natural rubber

    Science.gov (United States)

    Mikhaylov, I. A.; Sukhareva, K. V.; Andriasyan, Yu. O.; Popov, A. A.; Vorontsov, N. V.

    2016-11-01

    Thermomechanochemical changes of SVR 3L natural rubber after the treatment in the internal rubber mixer in the self-heating mode were studied. The effect of the molecular mass and content of the gel fraction of natural rubber is shown. Properties of rubber compounds and vulcanized rubber are presented. Taking into account modern requirements, a new alternative technology of obtaining halogenated elastomers based on the solid-phase (mechanochemical) halide modification is created. New halogen-containing natural rubber produced by this technology proves themselves in the conditions of rubber production. New fluorinated natural rubber produced by this technology proves themselves in the conditions of rubber production.

  19. Natural gas monthly, January 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The featured article for this month is on US coalbed methane production.

  20. Extreme Weather and Natural Disasters

    CERN Document Server

    Healey, Justin

    2012-01-01

    Australia is a vast land in which weather varies significantly in different parts of the continent. Recent extreme weather events in Australia, such as the Queensland floods and Victorian bushfires, are brutal reminders of nature's devastating power. Is global warming increasing the rate of natural disasters? What part do La Niña and El Niño play in the extreme weather cycle? Cyclones, floods, severe storms, bushfires, landslides, earthquakes, tsunamis - what are the natural and man-made causes of these phenomena, how predictable are they, and how prepared are we for the impacts of natural dis

  1. Connection to Nature: Children's Affective Attitude toward Nature

    Science.gov (United States)

    Cheng, Judith Chen-Hsuan; Monroe, Martha C.

    2012-01-01

    A connection to nature index was developed and tested to measure children's affective attitude toward the natural environment. The index was employed through a survey that investigates students' attitude toward Lagoon Quest, a mandatory environmental education program for all fourth-grade, public school students in Brevard County, Florida. Factor…

  2. Super Natural II--a database of natural products.

    Science.gov (United States)

    Banerjee, Priyanka; Erehman, Jevgeni; Gohlke, Björn-Oliver; Wilhelm, Thomas; Preissner, Robert; Dunkel, Mathias

    2015-01-01

    Natural products play a significant role in drug discovery and development. Many topological pharmacophore patterns are common between natural products and commercial drugs. A better understanding of the specific physicochemical and structural features of natural products is important for corresponding drug development. Several encyclopedias of natural compounds have been composed, but the information remains scattered or not freely available. The first version of the Supernatural database containing ∼ 50,000 compounds was published in 2006 to face these challenges. Here we present a new, updated and expanded version of natural product database, Super Natural II (http://bioinformatics.charite.de/supernatural), comprising ∼ 326,000 molecules. It provides all corresponding 2D structures, the most important structural and physicochemical properties, the predicted toxicity class for ∼ 170,000 compounds and the vendor information for the vast majority of compounds. The new version allows a template-based search for similar compounds as well as a search for compound names, vendors, specific physical properties or any substructures. Super Natural II also provides information about the pathways associated with synthesis and degradation of the natural products, as well as their mechanism of action with respect to structurally similar drugs and their target proteins.

  3. Connection to Nature: Children's Affective Attitude toward Nature

    Science.gov (United States)

    Cheng, Judith Chen-Hsuan; Monroe, Martha C.

    2012-01-01

    A connection to nature index was developed and tested to measure children's affective attitude toward the natural environment. The index was employed through a survey that investigates students' attitude toward Lagoon Quest, a mandatory environmental education program for all fourth-grade, public school students in Brevard County, Florida. Factor…

  4. Major Nature Reserves in China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    At the end of 2010,China had 2,588 nature reserves,covering 14.9 percent of its land area.These nature reserves have effectively protected more than 90 percent of land ecosystems,85 percent of wild animals and 65 percent of higher plant species

  5. Natural gas monthly, August 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-05

    This report highlights activities, events, and analyses of interest to public and private sector oganizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. 33 tabs.

  6. Natural analog studies: Licensing perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, J.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This report describes the licensing perspective of the term {open_quotes}natural analog studies{close_quotes} as used in CFR Part 60. It describes the misunderstandings related to its definition which has become evident during discussions at the U.S Nuclear Regulatory Commission meetings and tries to clarify the appropriate applications of natural analog studies to aspects of repository site characterization.

  7. Natural Learning Case Study Archives

    Science.gov (United States)

    Lawler, Robert W.

    2015-01-01

    Natural Learning Case Study Archives (NLCSA) is a research facility for those interested in using case study analysis to deepen their understanding of common sense knowledge and natural learning (how the mind interacts with everyday experiences to develop common sense knowledge). The database comprises three case study corpora based on experiences…

  8. NATURE-RURAL SETTLEMENT INTERACTIONS

    Directory of Open Access Journals (Sweden)

    Zehra Eminağaoğlu

    2006-04-01

    Full Text Available Conservation and management of natural environments are generally brought up upon adverse developments against nature in the humannature interactions. Although individual actions are often considered to be more immediate innatıre-related issuesi ecologic problems tend to spread in time and lead to reginol or even global problems. For this reason, it stands imperative that economic, ecologic and aesthetic values of the environment we live in be protected and used sustainably. Being the scene of nature and the environment landscape signifies the whole with living and nonliving entities where we live in. Dameged and destroyed landscape scenes particularly in urban areas necessitaites the reconsideration of human-nature relations and nature-frendly life style. This study investigates the rural settlements that show harmony with nature and reflects qualities of natural environments on the dwellings. Particularly, with the examples of drawing and pictures it examines the associatiation of rural settlements with nature as well as the use of the green as an occasional or spacial element.

  9. Alternative sources of natural rubber

    NARCIS (Netherlands)

    Mooibroek, H.; Cornish, K.

    2000-01-01

    Rubber (cis-1,4-polyisoprene) is one of the most important polymers naturally produced by plants because it is a strategic raw material used in more than 40,000 products, including more than 400 medical devices. The sole commercial source, at present, is natural rubber harvested from the Brazilian r

  10. A natural human hand model

    NARCIS (Netherlands)

    Van Nierop, O.A.; Van der Helm, A.; Overbeeke, K.J.; Djajadiningrat, T.J.P.

    2007-01-01

    We present a skeletal linked model of the human hand that has natural motion. We show how this can be achieved by introducing a new biology-based joint axis that simulates natural joint motion and a set of constraints that reduce an estimated 150 possible motions to twelve. The model is based on obs

  11. Natural Learning Case Study Archives

    Science.gov (United States)

    Lawler, Robert W.

    2015-01-01

    Natural Learning Case Study Archives (NLCSA) is a research facility for those interested in using case study analysis to deepen their understanding of common sense knowledge and natural learning (how the mind interacts with everyday experiences to develop common sense knowledge). The database comprises three case study corpora based on experiences…

  12. The Problem of Naturalizing Semantics.

    Science.gov (United States)

    Sullivan, Arthur

    2000-01-01

    Investigates conceptual barriers prevalent in the works of both proponents and opponents of semantic naturalism. Searches for a tenable definition of naturalism according to which one can be a realist, a non-reductionist, and a naturalist about semantic content. (Author/VWL)

  13. Anania Shirakatsi's Natural Philosophical Views

    Science.gov (United States)

    Arevshatyan, Sen

    2014-10-01

    A review on Anania Shirakatsi's natural philosophical views is given. He was the first to distinguish natural sciences from philosophy, establishing the basis for such sciences as mathematics, cosmography, astronomy, meteorology, chronology, and metrology. Shirakatsi's works are discussed related to these sciences.

  14. Czech Children's Drawing of Nature

    Science.gov (United States)

    Yilmaz, Zuhal; Kubiatko, Milan; Topal, Hatice

    2012-01-01

    Do world children draw nature pictures in a certain way? Range of mountains in the background, a sun, couple clouds, a river rising from mountains. Is this type of drawing universal in the way these nature items are organized on a drawing paper? The sample size from Czech Republic included 33 participants from two kindergartens. They were 5 and 6…

  15. Evaluation of Natural Resource Interventions

    Science.gov (United States)

    Rowe, Andy

    2012-01-01

    This article provides a frame for evaluation of natural resource interventions, which necessarily involves both human and natural systems. Two-system evaluands require us to adapt evaluation methods for comparison and attribution and to address differences in time and space occurring across the systems as well as potentially very different values…

  16. Imagining Nature during Music Listening

    DEFF Research Database (Denmark)

    Bonde, Lars Ole; Beck, Bolette Daniels

    2017-01-01

    and traditional cultures worship nature as a place of holiness and wholeness. In GIM, a client or a group listens to music in a relaxed state and multi-modal imagery is evoked and supported by the music. The imagery is shared with the guide/therapist. This chapter will focus on ‘nature imagery’ in GIM through...

  17. Commentary: Biochemistry Re-Natured

    Science.gov (United States)

    White, Harold B.

    2010-01-01

    In his last commentary on "Biochemistry Denatured," this author dealt with his perception that college students today have spent too little of their childhood years playing outside in nature and as a consequence have not learned basic things about the world from personal experience. This "nature-deficit disorder" removes many opportunities for…

  18. The Case for Natural History

    Science.gov (United States)

    King, Heather; Achiam, Marianne

    2017-01-01

    Fundamental knowledge of natural history is lacking in many western societies, as demonstrated by its absence in school science curricula. And yet, to meet local and global challenges such as environmental degradation, biodiversity loss and climate change, we need to better understand the living and non-living parts of the natural world. Many have…

  19. Natural Gas Energy Educational Kit.

    Science.gov (United States)

    American Gas Association, Arlington, VA. Educational Services.

    Prepared by energy experts and educators to introduce middle school and high school students to natural gas and its role in our society, this kit is designed to be incorporated into existing science and social studies curricula. The materials and activities focus on the origin, discovery, production, delivery, and use of natural gas. The role of…

  20. Beholding Nature: Contemplation and Connectedness

    Science.gov (United States)

    Chambliss, Kathleen Mary

    2013-01-01

    Two related exploratory studies, one with families, and a second one with adult and child members of an independent school community, suggest that our connections with the rhythms, processes, species, and cycles of nature, our "love" and feelings of affinity for nature, can be strengthened by practicing contemplation outdoors. In The…

  1. Natural disasters and human mobility

    NARCIS (Netherlands)

    Mbaye, L.; Zimmermann, K.

    2016-01-01

    This paper reviews the effect of natural disasters on human mobility or migration. Although there is an increase of natural disasters and migration recently and more patterns to observe, the relationship remains complex. While some authors find that disasters increase migration, others show that

  2. Exploiting Natural Variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana . This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  3. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    J.A. Molenaar; J.J.B. Keurentjes

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of g

  4. Teaching about Natural Background Radiation

    Science.gov (United States)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  5. Measurement of natural background neutron

    CERN Document Server

    Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

    1982-01-01

    A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

  6. Making Artificial Seawater More Natural

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Marine fish will die if placed in fresh water and they cannot live in simple salt water. Instead, they need water that contains a mixture of different ingredients, as found in natural seawater. Conventional methods of making artificial seawater have shortcomings, because the water so achieved is only composed of mineral elements and lacks organic components similar to those in natural seawater.

  7. Reconceptualizing the "Nature" of Childhood

    Science.gov (United States)

    Taylor, Affrica

    2011-01-01

    This interdisciplinary article draws upon human geography to bring fresh new perspectives to the relationship between two commonly conflated concepts: "childhood" and "nature". Childhood studies scholars have gone a long way towards retheorizing childhood beyond the "natural" and the "universal" by pointing to its historical and cultural…

  8. [Are Mental Disorders Natural Kinds?].

    Science.gov (United States)

    Flórez Quintero, Daian Tatiana

    2015-01-01

    A problem for both philosophers of Psychiatry and Psychiatrists within the domain of nosology is to determine which could be the more appropriate model to classify mental illnesses. Such an endeavor also requires questioning the very nature of mental illness. While trying to cope with the philosophical challenges of such a task, Peter Zachar purports to show that the nosological work in Psychiatry should not adhere to the model of natural kinds. He even considers that it is mistaken to treat mental disorders as natural kinds. Nonetheless, Zachar's view on the existence of natural kinds-even in domains where there is little room for doubting about their existence, like Chemistry-is very unstable. In 2001 he holds that there are no natural kinds, but in 2008 he argues that his objections to the model of natural kinds are more the manifestation of his skepticism against a tradition. Although the problem of the existence of natural kinds shall not be dealt with in this article, a brief description on how deflated is Zachar's view on this matter in 2008 is presented, with the central part of the article devoted to reconstruct and examine his rationale for the thesis that mental disorders are not natural kinds. In the critical section of this paper, it is suggested that, although Zachar's thesis may be right, the arguments he gives to support it are quite flawed. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  9. Natural gas monthly, July 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-03

    This report highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. A glossary is included. 7 figs., 33 tabs.

  10. Mind in Nature, Nature in Mind: A Reply to Ule

    Directory of Open Access Journals (Sweden)

    Sebastjan Vörös

    2015-10-01

    Full Text Available This article is a response to Ule’s ideas on the (impossibility of naturalizing the mind. After providing a brief overview of some of the main inconsistencies in Ule’s account, I argue that a naturalistic explanation of the key feature of the mind as construed by Ule (“experiential perspectivity” is, in fact, feasible, but only if it is complemented by an equally important shift in our conception of nature. The central part of the article consists of two steps. First, following the line of thought developed (predominantly by Jonas and Varela, the article attempts to outline a route to the naturalization of “perspectivity” along the lines of the so-called autopoietic theory and the corresponding double dialectic of identity and sense making. Secondly, I emphasize that this is merely the first half of the story, and that the second element in Ule’s construal of the mind, “experientiality”, cannot be explained within the metaphysical framework of modern naturalism, but calls for a radical restructuring of our field of inquiry in terms of the fundamental circularity between lived experience and scientific endeavour. Thus, the process of the naturalization of life and mind needs to be reciprocated by the process of the phenomenologization of nature and reconceptualization of naturalism.

  11. Perspectives for Globalized Natural Medicines

    Institute of Scientific and Technical Information of China (English)

    Thomas EFFERTH

    2011-01-01

    Natural medicines provide valuable resources to meet the requirements for global health care at affordable prices.Therefore, safety and efficacy need to be proven in a comparable manner to conventional drugs. Evidence-based natural and western medicine may merge to a "one-world medicine" for the sake of all patients in industrialized and developing countries. In the present review, we discuss strategies for(1)preservation of traditional knowledge on natural medicines,(2)sustainability of medicinal herbs and natural products, and(3)standardization and quality control. Novel technologies will impact research on natural medicines in the years to come, e.g. remote sensing to map medicinal plant locations, DNA barcoding for plant authentication, hollow fiber extraction,high-end techniques for chemo-profiling of plant constituents in medicinal products and blood serum of patients as well as systems biological approaches.

  12. Natural products for plant protection

    Directory of Open Access Journals (Sweden)

    Čeković Živorad

    2006-01-01

    Full Text Available The advantage applying natural products, such as a secondary metabolites, in plant protection is shortly presented. Acceptable solutions for the enhanced ecological criteria, which are requested by the users of pesticides and consumers of agricultural goods, could be the replacement of classical pesticides by natural products in plant protection. Some natural products are already in use as insecticides, herbicides and fungicides because new biotechnological processes, fermentation and biotransformations provide procedures for their industrial production. In addition to biotechnical processes natural compounds possessing pesticide activities are also prepared by chemical synthesis. An active secondary metabolite must first be isolated from natural sauces and then, based on biological toxicological and ecological studies, acceptable compounds are selected for laboratory and industrial chemical synthesis. Several compounds possessing insecticidal, herbicidal and fungicidal activities, which have been successfully applied for plan protection are presented.

  13. Natural colorants from filamentous fungi.

    Science.gov (United States)

    Torres, Fábio Aurélio Esteves; Zaccarim, Bruna Regina; de Lencastre Novaes, Letícia Celia; Jozala, Angela Faustino; Dos Santos, Carolina Alves; Teixeira, Maria Francisca Simas; Santos-Ebinuma, Valéria Carvalho

    2016-03-01

    In the last years, there is a trend towards the replacement of synthetic colorants by natural ones, mainly due to the increase of consumer demand for natural products. The natural colorants are used to enhance the appearance of pharmaceutical products, food, and different materials, making them preferable or attractive. This review intends to provide and describe a comprehensive overview of the history of colorants, from prehistory to modern time, of their market and their applications, as well as of the most important aspects of the fermentation process to obtain natural colorants. Focus is given to colorants produced by filamentous fungal species, aiming to demonstrate the importance of these microorganisms and biocompounds, highlighting the production performance to get high yields and the aspects of conclusion that should be taken into consideration in future studies about natural colorants.

  14. Wordsworth and His Nature Poems

    Institute of Scientific and Technical Information of China (English)

    Gong Liyan

    2001-01-01

    Wordsworth is a famous British Romantic poet who belongs to the Lake School of the Romanticists, and one of the forerunners of 19th century English Romanticism. He is not only one of the greatest theoreticians in poetry, but also a great practitioner of his own theory. In early childhood, he lived in the beautiful Lake District in Northwest England, and that made him love deeply nature and the nearest beings to nature.He is a nature poet, and is especially at his best in descriptions of mountains and rivers, flowers and birds, children and peasants, and reminiscences of his own childhood and youth. With simple yet fresh words and strong emotion, he sings highly of the comfort and inspiration nature gives him, and shows his true love to the nearest beings to nature.

  15. Unnatural monopoly: natural gas industry

    Energy Technology Data Exchange (ETDEWEB)

    Copulos, M.

    1984-07-01

    There appears to be no change in position despite the annual congressional debate over natural gas issues. A fresh look is needed, particularly at the idea that interstate gas pipelines are a natural monopoly that require a government franchise. The Natural Gas Act of 1938 giving the Federal Power Commission jurisdiction over gas pipelines was intended to correct abuses, but resulted in encouraging the pipelines to assume a monopolistic behavior. This was not a serous problem until natural gas prices began rising and shortages appeared due to uneven distribution. The Natural Gas Policy Act reinforced the monopolistic behavior by extending federal controls to the intrastate market. Contract carriage is a remedy that would allow firms and utilities to contract for gas on their own. They would pay pipelines for transport costs only. Competition would increase because there would be new buyers and sellers, and pipelines would have an incentive to seek lower wellhead prices for their contract gas.

  16. The 'Nature' of International Relations

    DEFF Research Database (Denmark)

    Corry, Olaf

    2017-01-01

    The discipline of IR is beginning to grapple with how nature is a condition for, and increasingly and object of, international politics. This chapter narrates how IR actually began with features of the natural world at its heart, then narrowed this down to human nature, before losing sight...... of it almost entirely – only to rediscover it years later as ‘the environment’. A recent revival of realist geopolitics brings geography back in, but misses the environmental angle as well as the Anthropocene idea that due to human influence nature is now more dynamic, more prone to harm and in some ways more...... threatening than before. To theorise a non-anthropocentric IR, one way forward is to develop concepts that integrate the human with the non-human, as some post-human and ‘new materialist’ approaches do. Another strategy is to maintain an analytical distinction between the social and the natural...

  17. Natural Hazards - A National Threat

    Science.gov (United States)

    Geological Survey, U.S.

    2007-01-01

    The USGS Role in Reducing Disaster Losses -- In the United States each year, natural hazards cause hundreds of deaths and cost billions of dollars in disaster aid, disruption of commerce, and destruction of homes and critical infrastructure. Although the number of lives lost to natural hazards each year generally has declined, the economic cost of major disaster response and recovery continues to rise. Each decade, property damage from natural hazards events doubles or triples. The United States is second only to Japan in economic damages resulting from natural disasters. A major goal of the U.S. Geological Survey (USGS) is to reduce the vulnerability of the people and areas most at risk from natural hazards. Working with partners throughout all sectors of society, the USGS provides information, products, and knowledge to help build more resilient communities.

  18. Natural gas monthly, October 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-05

    The Natural Gas Monthly (NGM) is prepared in the Data Operations Branch of the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA), US Department of Energy (DOE). The NGM highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. The data in this publication are collected on surveys conducted by the EIA to fulfill its responsibilities for gathering and reporting energy data. Some of the data are collected under the authority of the Federal Energy Regulatory Commission (FERC), an independent commission within the DOE, which has jurisdiction primarily in the regulation of electric utilities and the interstate natural gas industry. Geographic coverage is the 50 States and the District of Columbia. 16 figs., 33 tabs.

  19. Mathematics in Nature Modeling Patterns in the Natural World

    CERN Document Server

    Adam, John A

    2011-01-01

    From rainbows, river meanders, and shadows to spider webs, honeycombs, and the markings on animal coats, the visible world is full of patterns that can be described mathematically. Examining such readily observable phenomena, this book introduces readers to the beauty of nature as revealed by mathematics and the beauty of mathematics as revealed in nature.Generously illustrated, written in an informal style, and replete with examples from everyday life, Mathematics in Nature is an excellent and undaunting introduction to the ideas and methods of mathematical modeling. It illustrates how mathem

  20. Natural gas pipeline technology overview.

    Energy Technology Data Exchange (ETDEWEB)

    Folga, S. M.; Decision and Information Sciences

    2007-11-01

    The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by

  1. Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes

    NARCIS (Netherlands)

    Knaus, T.; Paul, C.E.; Levy, C.W.; de Vries, S.; Mutti, F.G.; Hollmann, F.; Scrutton, N.S.

    2016-01-01

    The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenz

  2. Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes

    NARCIS (Netherlands)

    Knaus, T.; Paul, C.E.; Levy, C.W.; de Vries, S.; Mutti, F.G.; Hollmann, F.; Scrutton, N.S.

    2016-01-01

    The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural

  3. Nature's Trust: A Paradigm for Natural Resources Stewardship

    Science.gov (United States)

    Wood, M. C.; Whitelaw, E.; Doppelt, B.; Burchell, A.

    2007-12-01

    Climate change uncertainty puts a premium on all remaining natural resources. Farmland, air, water, wetlands, wildlife, soils, mineral resources and forests must be protected to ensure that Americans - present citizens and future generations - have the fundamental survival resources they need in a future that holds many unknowns. Moreover, in light of the need to manage resources given climate and particle forcing, government must mitigate dangerous carbon loading of the atmosphere. Confronting climate change and protecting natural resources requires a clear sense of government obligation that is inherent to sovereignty, not a matter of political choice. Our government representatives can and must reframe government's discretion into a trustee obligation to protect Nature and ensure natural resource stewardship. Drawing upon enduring legal principles and court decisions, government can be characterized as a trustee of the natural resources essential to human survival. A trust is a fundamental type of ownership whereby one manages property for the benefit of another. Viewed as a trust, the environment consists of a portfolio of quantified natural assets that government manages. As beneficiaries, citizens hold a common property interest in defined, bounded assets that make up Nature's Trust. Such trust principles form the bedrock of statutory law. Trustees have a fiduciary obligation to protect trust assets and may not allow destruction of property they manage. This session will provide a policy frame for current scientific efforts to address climate change and natural resources loss. Under the Nature's Trust frame, U.S. government leaders and agencies at every level inherit a strict fiduciary obligation to protect our collective natural resources, including our water and the atmosphere, as assets in the trust. Their fiduciary standard of care consists of a proportionate responsibility, which ties directly to "Nature's Mandate" as defined by current climate

  4. Natural gas monthly, February 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This issue of the Natural Gas Monthly (NGM) presents the most recent estimates of natural gas data from the Energy Information Administration. Estimates extend through February 1998 for many data series, and through November 1997 for most natural gas prices. Highlights of the natural gas data contained in this issue are: Preliminary estimates for January and February 1998 show that dry natural gas production, net imports, and consumption are all within 1 percent of their levels in 1997. Warmer-than-normal weather in recent months has resulted in lower consumption of natural gas by the residential sector and lower net withdrawals of gas from under round storage facilities compared with a year ago. This has resulted in an estimate of the amount of working gas in storage at the end of February 1998 that is 18 percent higher than in February 1997. The national average natural gas wellhead price is estimated to be $3.05 per thousand cubic feet in November 1997, 7 percent higher than in October. The cumulative average wellhead price for January through November 1997 is estimated to be $2.42 per thousand cubic feet, 17 percent above that of the same period in 1996. This price increase is far less than 36-percent rise that occurred between 1995 and 1996. 6 figs., 26 tabs.

  5. New methods for assessing the fascinating nature of nature experiences.

    Directory of Open Access Journals (Sweden)

    Yannick Joye

    Full Text Available In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an "attentional", an "affective" and an "effort" dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional depletion has taken place. The instruments that were used were: (a the affect misattribution procedure (Study 1, (b the dot probe paradigm (Study 2 and (c a cognitively effortful task (Study 3. These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension and that people have an attentional bias to natural (rather than urban environments (cfr., attentional dimension. The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

  6. New methods for assessing the fascinating nature of nature experiences.

    Science.gov (United States)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an "attentional", an "affective" and an "effort" dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

  7. New Methods for Assessing the Fascinating Nature of Nature Experiences

    Science.gov (United States)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual’s mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an “attentional”, an “affective” and an “effort” dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks. PMID:23922645

  8. Darwin's explanation of design: from natural theology to natural selection.

    Science.gov (United States)

    Ayala, Francisco J

    2010-08-01

    Copernicus, Galileo, Newton and other physical scientists ushered in a conception of the universe as matter in motion governed by natural laws. Their discoveries brought about a fundamental revolution, namely a commitment to the postulate that the universe obeys immanent laws that can account for natural phenomena. The workings of the universe were brought into the realm of science: explanation through natural laws. Darwin completed the Copernican revolution by extending it to the living world. Darwin demonstrated the evolution of organisms. More important yet is that he discovered natural selection, the process that explains the "design" of organisms. The adaptations and diversity of organisms, the origin of novel and complex species, even the origin of mankind, could now be explained by an orderly process of change governed by natural laws. The origin of species and the exquisite features of organisms had previously been explained as special creations of an Omniscient God. Darwin brought them into the domain of science. Evolution is a creative process that produces genuine novelty. The creative power of evolution arises from a distinctive interaction between chance and necessity, between random mutation and natural selection.

  9. The Nature of US Natural Hazards Research, 1988-2008

    Science.gov (United States)

    Hagelman, R., III

    2009-04-01

    Numerous academic disciplines have contributed to the body of published research on natural hazards and disasters. Geologists, engineers, geographers, and sociologists have participated since the topic first emerged as a formal research agenda in the early 1950s. In more recent decades, psychologists, political scientists, economists, historians, archeologists, anthropologists, architects, computer scientists, and artists have added to our understanding of environmental risk, hazard, and disaster. When examined in-print, what are the discipline-demographics of natural hazards? Who contributes and who tends to have the greater influence on scholarly discourse related to the topic? Are there clear trends in methods, techniques, or paradigmatic approaches? To what degree does this inherently interdisciplinary topic render interdisciplinary research? This paper will present initial findings from a larger data set on natural hazards and social science research. We will describe the discipline-demographics of natural hazards scholarship by examining college-level texts, peer-reviewed journal publications, federally-funded reports, and federally-funded research grants relating to natural hazards or disasters from 1988 to 2008. The citation frequency of sampled references will also be examined as a surrogate for influence on the scholarly discourse of natural hazards. In this paper, we will focus attention on the contributions of social scientists during this period, including an assessment of temporal trends relative to specific disaster events.

  10. Natural Alkali Shifts to the Methanol Business

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Inner Mongolia Yuanxing Natural Alkali Co., Ltd. (Natural Alkali SZ: 000683) established in 1997 is a large chemical enterprise with new energy as its leading business and natural gas chemicals and natural alkali chemicals as the supplement business.

  11. Combinatorial synthesis of natural products

    DEFF Research Database (Denmark)

    Nielsen, John

    2002-01-01

    for preparation of combinatorial libraries. In other examples, natural products or intermediates have served as building blocks or scaffolds in the synthesis of complex natural products, bioactive analogues or designed hybrid molecules. Finally, structural motifs from the biologically active parent molecule have......Combinatorial syntheses allow production of compound libraries in an expeditious and organized manner immediately applicable for high-throughput screening. Natural products possess a pedigree to justify quality and appreciation in drug discovery and development. Currently, we are seeing a rapid...

  12. Nature Conservation Policies and Strategies

    Directory of Open Access Journals (Sweden)

    Ildiko IOAN

    2011-08-01

    Full Text Available Humans dependence on nature is beyond doubt one of the most powerfulevidence that supports the thesis of environmental protection. This relation is manifold and it was approached in various frameworks. The paper focuses on the conservation of nature in its narrow sense, meaning natural ecosystems and biodiversity. Although this topic is among the top priorities in environmental policymaking, the progresses recorded to date are not reflecting this position. The analysis aims to highlight the main policies and strategies and the developments for new actions targeting improved effectiveness.

  13. Natural Law and Mechanical Engineering

    Directory of Open Access Journals (Sweden)

    P. C. Haarhoff

    1984-03-01

    Full Text Available The first technological revolution, in the fourth millennium BC, was followed by immense social progress. The second revolution, which is now taking place, could lead to an even greater development in the human sciences, by setting men free from their daily struggle for existence while simultaneously exacting high social standards. Natural law - the “marriage between the ways of heaven and the ways of earth” of the Chinese - represents a route to such progress. In natural science and technology, natural law demands that conclusions be based on observation rather than speculation. The social sciences would do well to follow this example.

  14. Natural killer cells in psoriasis.

    LENUS (Irish Health Repository)

    Tobin, A M

    2012-02-01

    Psoriasis is one of the most common immune-mediated disorders. There is evidence that it is mediated by Th1 and, more recently, Th17 cells. The cytokine pattern, particularly the dominance of TNF-alpha, implicates the innate immune system in psoriasis pathogenesis. Of the many components of the innate immune system known to be involved in psoriatic lesions, natural killer and natural killer T cells appear to have a unique role. We review the evidence supporting a role for natural killer cells in psoriasis.

  15. Natural hazard and disaster tourism

    Directory of Open Access Journals (Sweden)

    Rucińska Dorota

    2014-03-01

    Full Text Available An observed trend, which can be defined as tourist interest in natural hazards and disasters, has persuaded the authors to attempt to research several issues, including tourist motivations and specific tourism properties and functions of this form of activity. The objective also covered the allocation of this social and natural process in the general structure of tourism. This interest has a long history, and a new stage is currently forming, which partly results from factors affecting society, such as information and education, which provoke antagonistic reactions. Extreme natural phenomena entail a common reduction of tourist interest in the destination which hosted the event; however, it never drops to zero. Differences are visible depending on the type of phenomenon. On the other hand, natural hazards and disasters are considered to hold a specific tourism value. This article discusses the allocation of this human activity in the tourism forms known to scientists, accounting for its diversity and relating to ethics.

  16. Organic chemistry: Natural polarity inverted

    Science.gov (United States)

    Romanov-Michailidis, Fedor; Rovis, Tomislav

    2015-07-01

    The concept of umpolung describes the reversal of the naturally occurring electrostatic polarization of chemical groups. It has now been used to make single mirror-image isomers of nitrogen-containing molecules. See Letter p.445

  17. Natural Gas Monthly August 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. Explanatory notes supplement the information found in tables of the report. A description of the data collection surveys that support the NGM is provided. A glossary of the terms used in this report is also provided to assist readers in understanding the data presented in this publication.

  18. Thermal loading of natural streams

    Science.gov (United States)

    Jackman, Alan P.; Yotsukura, Nobuhiro

    1977-01-01

    The impact of thermal loading on the temperature regime of natural streams is investigated by mathematical models, which describe both transport (convection-diffusion) and decay (surface dissipation) of waste heat over 1-hour or shorter time intervals. The models are derived from the principle of conservation of thermal energy for application to one- and two-dimensional spaces. The basic concept in these models is to separate water temperature into two parts, (1) excess temperature due to thermal loading and (2) natural (ambient) temperature. This separation allows excess temperature to be calculated from the models without incoming radiation data. Natural temperature may either be measured in prototypes or calculated from the model. If use is made of the model, however, incoming radiation is required as input data. Comparison of observed and calculated temperatures in seven natural streams shows that the models are capable of predicting transient temperature regimes satisfactorily in most cases. (Woodard-USGS)

  19. Natural resources and control processes

    CERN Document Server

    Wang, Mu-Hao; Hung, Yung-Tse; Shammas, Nazih

    2016-01-01

    This edited book has been designed to serve as a natural resources engineering reference book as well as a supplemental textbook. This volume is part of the Handbook of Environmental Engineering series, an incredible collection of methodologies that study the effects of pollution and waste in their three basic forms: gas, solid, and liquid. It complements two other books in the series including Environmental and Natural Resources Engineering and Integrated Natural Resources Management that serve as a basis for advanced study or specialized investigation of the theory and analysis of various natural resources systems. This book covers the management of many waste sources including those from agricultural livestock, deep-wells, industries manufacturing dyes, and municipal solid waste incinerators. The purpose of this book is to thoroughly prepare the reader for understanding the sources, treatment and control methods of toxic wastes shown to have harmful effects on the environment. Chapters provide information ...

  20. Computing nature turing centenary perspective

    CERN Document Server

    Giovagnoli, Raffaela

    2013-01-01

    This book is about nature considered as the totality of physical existence, the universe, and our present day attempts to understand it. If we see the universe as a network of networks of computational processes at many different levels of organization, what can we learn about physics, biology, cognition, social systems, and ecology expressed through interacting networks of elementary particles, atoms, molecules, cells, (and especially neurons when it comes to understanding of cognition and intelligence), organs, organisms and their ecologies? Regarding our computational models of natural phenomena Feynman famously wondered: “Why should it take an infinite amount of logic to figure out what one tiny piece of space/time is going to do?” Phenomena themselves occur so quickly and automatically in nature. Can we learn how to harness nature’s computational power as we harness its energy and materials? This volume includes a selection of contributions from the Symposium on Natural Computing/Unconventional Com...

  1. Human economy and natural economy

    Directory of Open Access Journals (Sweden)

    Masullo Andrea

    2014-03-01

    Full Text Available The decline of economy is due to its dependency from a virtual value, the currency, the coin, that in the recent phase of consumerism is so far from real value: human capital and natural capital. If human economy wants to continue to produce wellbeing, it must accept to be a subset of natural economy, intercept flux of matter produced by its circular mechanisms, put constraints in it, i.e. machines and structures, to direct it temporarily for our advantage, and finally release it to the same original flux, in an still usable state. In this way it will assume a function no more parasitic but symbiotic. It will be connected to natural cycles without destroying it, recovering the co-evolutionary link between nature and culture, building an economic web suited to the ecological web; thus we will have a mosaic characterised by biodiversity, technological diversity, and cultural diversity, able to produce a durable prosperity.

  2. Naturally Time Dependent Cosmological Constant

    CERN Document Server

    Gregori, A

    2004-01-01

    In the light of the proposal of hep-th/0207195, we discuss in detail the issue of the cosmological constant, explaining how can string theory naturally predict the value which is experimentally observed, without low-energy supersymmetry.

  3. Natural products in chemical biology

    National Research Council Canada - National Science Library

    Civjan, Natanya

    2012-01-01

    "Based on the award winning Wiley Encyclopedia of Chemical Biology, this book provides a general overview of the unique features of the small molecules referred to as "natural products", explores how...

  4. Natural Heritage Inventory Element Occurrence

    Data.gov (United States)

    Kansas Data Access and Support Center — The database consists of three state-wide coverages representing location records for plant and animal species and natural community types contained in the Kansas...

  5. Current status of natural fibres

    CSIR Research Space (South Africa)

    Anandjiwala, RD

    2006-12-01

    Full Text Available , automotive, aerospace, marine, electronic, leisure and household uses. This paper will provide an overview of the current status of research and development. It will also deal with future drivers for the growth and competitiveness of natural fibres...

  6. The NCL natural constraint language

    CERN Document Server

    Zhou, Jianyang

    2012-01-01

    This book presents the Natural Constraint Language (NCL) language, a description language in conventional mathematical logic for modeling and solving constraint satisfaction problems. It uses illustrations and tutorials to detail NCL and its applications.

  7. Nature-inspired optimization algorithms

    CERN Document Server

    Yang, Xin-She

    2014-01-01

    Nature-Inspired Optimization Algorithms provides a systematic introduction to all major nature-inspired algorithms for optimization. The book's unified approach, balancing algorithm introduction, theoretical background and practical implementation, complements extensive literature with well-chosen case studies to illustrate how these algorithms work. Topics include particle swarm optimization, ant and bee algorithms, simulated annealing, cuckoo search, firefly algorithm, bat algorithm, flower algorithm, harmony search, algorithm analysis, constraint handling, hybrid methods, parameter tuning

  8. Natural horsemanship: a balanced view

    OpenAIRE

    Goodwin, Deborah

    2008-01-01

    The recent popularity of Natural Horsemanship has created something often difficult to achieve in the equestrian industry - change! Natural Horsemanship trainers have produced a cultural change in thinking and approach to horse:human interactions. These changes extend from individual horse owners through to conventional training organizations, including the BHS, who dubbed 2007 “The Year of Equine Ethology”. Academic equine ethologists were very interested in these developments, but became co...

  9. Lexpresso: a Controlled Natural Language

    OpenAIRE

    Saulwick, Adam

    2014-01-01

    This paper presents an overview of `Lexpresso', a Controlled Natural Language developed at the Defence Science & Technology Organisation as a bidirectional natural language interface to a high-level information fusion system. The paper describes Lexpresso's main features including lexical coverage, expressiveness and range of linguistic syntactic and semantic structures. It also touches on its tight integration with a formal semantic formalism and tentatively classifies it against the PENS sy...

  10. Natural Law and Mechanical Engineering

    OpenAIRE

    P. C. Haarhoff

    1984-01-01

    The first technological revolution, in the fourth millennium BC, was followed by immense social progress. The second revolution, which is now taking place, could lead to an even greater development in the human sciences, by setting men free from their daily struggle for existence while simultaneously exacting high social standards. Natural law - the “marriage between the ways of heaven and the ways of earth” of the Chinese - represents a route to such progress. In natural science and technolo...

  11. Natural gas monthly, November 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    This issue of the Natural Gas Monthly presents the most recent estimates of natural gas data from the Energy Information Administration. Estimates extend through November for many data series, and through August for most natural gas prices. Highlights of the most recent data estimates are: (1) Preliminary estimates of dry natural gas production and total consumption available through November 1997 indicate that both series are on track to end the year at levels close to those of 1996. Cumulative dry production is one-half percent higher than in 1996 and consumption is one-half percent lower. (2) Natural gas production is estimated to be 52.6 billion cubic feet per day in November 1997, the highest rate since March 1997. (3) After falling 8 percent in July 1997, the national average wellhead price rose 10 percent in August 1997, reaching an estimated $2.21 per thousand cubic feet. (4) Milder weather in November 1997 compared to November 1996 has resulted in significantly lower levels of residential consumption of natural gas and net storage withdrawls than a year ago. The November 1997 estimates of residential consumption and net withdrawls are 9 and 20 percent lower, respectively, than in November 1996.

  12. SuperNatural: a searchable database of available natural compounds.

    Science.gov (United States)

    Dunkel, Mathias; Fullbeck, Melanie; Neumann, Stefanie; Preissner, Robert

    2006-01-01

    Although tremendous effort has been put into synthetic libraries, most drugs on the market are still natural compounds or derivatives thereof. There are encyclopaedias of natural compounds, but the availability of these compounds is often unclear and catalogues from numerous suppliers have to be checked. To overcome these problems we have compiled a database of approximately 50,000 natural compounds from different suppliers. To enable efficient identification of the desired compounds, we have implemented substructure searches with typical templates. Starting points for in silico screenings are about 2500 well-known and classified natural compounds from a compendium that we have added. Possible medical applications can be ascertained via automatic searches for similar drugs in a free conformational drug database containing WHO indications. Furthermore, we have computed about three million conformers, which are deployed to account for the flexibilities of the compounds when the 3D superposition algorithm that we have developed is used. The SuperNatural Database is publicly available at http://bioinformatics.charite.de/supernatural. Viewing requires the free Chime-plugin from MDL (Chime) or Java2 Runtime Environment (MView), which is also necessary for using Marvin application for chemical drawing.

  13. Natural gas market under the Natural Gas Policy Act

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, M.; Ody, N.; O' Neill, R.; Rodekohr, M.; Shambaugh, P.; Thrasher, R.; Trapmann, W.

    1981-06-01

    This first of a series of analyses presents data on the exploration, development, production, and pricing of US natural gas since the passage of the Natural Gas Policy Act in 1978. Designed to give pricing incentives for new-well activity, the NGPA has apparently eliminated many of the pricing differences that existed between interstate and intrastate markets. Estimates of the annual production volumes in trillion CF/yr of gas for the categories defined by the NGPA include new gas 4.5, new onshore wells 4.1, high-cost unconventional gas 0.7, and stripper wells 0.4. Preliminary statistics on the end-use pricing of natural gas suggest that significant changes in the average wellhead prices have not caused correspondingly large increases in the price of delivered gas.

  14. Natural pigments and sacred art

    Science.gov (United States)

    Kelekian, Lena, ,, Lady

    2010-05-01

    Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

  15. What is Imbalance of Nature?

    Science.gov (United States)

    Kontar, V. A.

    2012-12-01

    The Mother Nature is imbalanced at all. The Mother Nature is every moment new, never returns to previous condition. The gravity and magnetosphere are changeable and imbalanced. The Sun is changeable and imbalanced. The climate is changeable and imbalanced. The atmosphere is changeable and imbalanced. The ocean is changeable and imbalanced. The crust and deep interior are changeable and imbalanced. The cryosphere is changeable and imbalanced. The life is simultaneously as the creator and the result of the imbalance of Nature. The people society is changeable and imbalanced. All chemical, physical, social, and other phenomenons are changeable and imbalanced. It's just that each phenomenon of the Mother Nature has some personal time-scale: one change in a nanosecond, and looks like for us as instable, i.e. imbalanced; while others change over millions years and, therefore, to us looks like not changeable, i.e. balanced. The scientists who are studying the Nature have convinced that the real balance never exist in Nature. Sometimes we can see something that is stable, i.e. balanced. But on closer study it appears that we are witnessing is not eternal rest and balance, it is not eternal STOP, but it is the perpetual motion, changing, there are a lot of imbalances. The balance it can be some result of the temporary mutual compensation the imbalanced processes in opposite directions. The balance it can be also some result of the inaccurate measurement, misunderstanding of conception or even request from bosses. But if we start use more accurate measurements, improve the models and not fear the bosses, than usually we got some new details. These new details show thet under the balanced visibility in really is hiding the interaction of many imbalanced processes of different directions. The balanced logic usually answers to question: What is it? The balanced answers are approximate and it will be updated many times during the development of science and practice. The

  16. Environmentalism and natural aggregate mining

    Science.gov (United States)

    Drew, L.J.; Langer, W.H.; Sachs, J.S.

    2002-01-01

    Sustaining a developed economy and expanding a developing one require the use of large volumes of natural aggregate. Almost all human activity (commercial, recreational, or leisure) is transacted in or on facilities constructed from natural aggregate. In our urban and suburban worlds, we are almost totally dependent on supplies of water collected behind dams and transported through aqueducts made from concrete. Natural aggregate is essential to the facilities that produce energy-hydroelectric dams and coal-fired powerplants. Ironically, the utility created for mankind by the use of natural aggregate is rarely compared favorably with the environmental impacts of mining it. Instead, the empty quarries and pits are seen as large negative environmental consequences. At the root of this disassociation is the philosophy of environmentalism, which flavors our perceptions of the excavation, processing, and distribution of natural aggregate. The two end-member ideas in this philosophy are ecocentrism and anthropocentrism. Ecocentrism takes the position that the natural world is a organism whose arteries are the rivers-their flow must not be altered. The soil is another vital organ and must not be covered with concrete and asphalt. The motto of the ecocentrist is "man must live more lightly on the land." The anthropocentrist wants clean water and air and an uncluttered landscape for human use. Mining is allowed and even encouraged, but dust and noise from quarry and pit operations must be minimized. The large volume of truck traffic is viewed as a real menace to human life and should be regulated and isolated. The environmental problems that the producers of natural aggregate (crushed stone and sand and gravel) face today are mostly difficult social and political concerns associated with the large holes dug in the ground and the large volume of heavy truck traffic associated with quarry and pit operations. These concerns have increased in recent years as society's demand for

  17. Statistics of natural binaural sounds.

    Directory of Open Access Journals (Sweden)

    Wiktor Młynarski

    Full Text Available Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD and level (ILD disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA. Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

  18. Toward a New Natural Medicine

    Science.gov (United States)

    Buckel, Peter

    Treatments summarized under the term "natural medicine," i.e., those offered as an alternative or in addition to conventional medicine, have enjoyed a surge in popularity in recent years. The "natural" descriptor employed in connection with these healing methods is frequently misunderstood, leading to underestimation of the risks arising from incorrect use. However, the essential principle underlying traditional natural medicine, mobilization of the body's own forces against disease, is increasingly being employed in a new, rational form of medicine: molecular medicine. A range of natural endogenous substances for medical use are already available. Human proteins such as erythropoietin can now be produced as medicines in highly pure form with the aid of genetic engineering techniques. Our increasing understanding of the function of our genes and the resulting descriptions of molecular mechanisms underlying disease are also helping us to utilize the body's own construction set. New techniques such as gene therapy will in future enable us to reproduce the natural conditions in the healthy body with increasing specificity in our attempts to cure illnesses. One such application will be the activation of the immune system to combat cancer. The complete decoding of the human genome will not only allow illnesses to be described, and possibly prevented, at an earlier stage. Illnesses will also be able to described more precisely and individually at the molecular level, opening up the possibility of targeted, patient-specific cures.

  19. Wittgenstein on language and nature

    Directory of Open Access Journals (Sweden)

    Sladeček Michal

    2012-01-01

    Full Text Available The text begins with the analysis of two terms regarding life crucial to both Wittgenstein's early and late philosophy. These are life form and nature, specifically, human nature. Wittgenstein treats both concepts in a very specific manner, different from the traditional approach of philosophy. He also criticized philosophical attempts to attribute special characteristics to human intellectual abilities which would separate them from natural processes. A particular 'spiritual' status of epistemic and other rational powers disappears when there is an insight into their dependence on discursive practices and specific forms of life on which these powers are based. Concepts such as certainty, knowledge, or explanations do not rest on a rational foundation, that is, they do not refer to processes with particular un-natural properties. Nor can they be reduced to neuro-physiological processes, either. Instead, it is a specific grammar of their usage that makes them different from other concepts describing physical or biological processes. In that sense, Wittgenstein develops a non-reductionist version of naturalism which preserves the diversity of human relations in the world. [Projekat Ministarstva nauke Republike Srbije, br. 43007

  20. Statistics of natural binaural sounds.

    Science.gov (United States)

    Młynarski, Wiktor; Jost, Jürgen

    2014-01-01

    Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

  1. Natural pedagogy as evolutionary adaptation.

    Science.gov (United States)

    Csibra, Gergely; Gergely, György

    2011-04-12

    We propose that the cognitive mechanisms that enable the transmission of cultural knowledge by communication between individuals constitute a system of 'natural pedagogy' in humans, and represent an evolutionary adaptation along the hominin lineage. We discuss three kinds of arguments that support this hypothesis. First, natural pedagogy is likely to be human-specific: while social learning and communication are both widespread in non-human animals, we know of no example of social learning by communication in any other species apart from humans. Second, natural pedagogy is universal: despite the huge variability in child-rearing practices, all human cultures rely on communication to transmit to novices a variety of different types of cultural knowledge, including information about artefact kinds, conventional behaviours, arbitrary referential symbols, cognitively opaque skills and know-how embedded in means-end actions. Third, the data available on early hominin technological culture are more compatible with the assumption that natural pedagogy was an independently selected adaptive cognitive system than considering it as a by-product of some other human-specific adaptation, such as language. By providing a qualitatively new type of social learning mechanism, natural pedagogy is not only the product but also one of the sources of the rich cultural heritage of our species.

  2. Dutch Natural History Museums in the service of nature preservation

    NARCIS (Netherlands)

    Engel, H.

    1961-01-01

    Since the time of the great geographical discoveries, since Henry the Navigator of Portugal and Christopher Columbus started to open up the whole world to the curiosity of naturalists, the Dutch and the English have played an important role in the explorations of the riches of God’s Nature. The

  3. Nature of Science Contextualized: Studying Nature of Science with Scientists

    Science.gov (United States)

    Tala, Suvi; Vesterinen, Veli-Matti

    2015-01-01

    Understanding nature of science (NOS) is widely considered an important educational objective and views of NOS are closely linked to science teaching and learning. Thus there is a lively discussion about what understanding NOS means and how it is reached. As a result of analyses in educational, philosophical, sociological and historical research,…

  4. New Methods for Assessing the Fascinating Nature of Nature Experiences

    NARCIS (Netherlands)

    Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

    2013-01-01

    In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theor

  5. On Adventure Therapy and the Natural Worlds: Respecting Nature's Healing.

    Science.gov (United States)

    Beringer, Almut; Martin, Peter

    2003-01-01

    The anthropomorphic paradigm in psychology and psychotherapy has prevented nature from being considered a factor in the curative relationship in adventure therapy. The effectiveness of therapeutic interventions are credited instead to human factors such as program design and facilitation. A paradigm shift is needed in adventure therapy to accept…

  6. On Adventure Therapy and the Natural Worlds: Respecting Nature's Healing.

    Science.gov (United States)

    Beringer, Almut; Martin, Peter

    2003-01-01

    The anthropomorphic paradigm in psychology and psychotherapy has prevented nature from being considered a factor in the curative relationship in adventure therapy. The effectiveness of therapeutic interventions are credited instead to human factors such as program design and facilitation. A paradigm shift is needed in adventure therapy to accept…

  7. Exploring Natural and Social Scientists' Views of Nature of Science

    Science.gov (United States)

    Bayir, Eylem; Cakici, Yilmaz; Ertas, Ozge

    2014-01-01

    Science education researchers recently turned their attention to exploring views about nature of science (NOS). A large body of research indicates that both students and teachers have many naïve views about the NOS. Unfortunately, less attention has been directed at the issue of exploring the views of the scientists. Also, the little research in…

  8. Dutch Natural History Museums in the service of nature preservation

    NARCIS (Netherlands)

    Engel, H.

    1961-01-01

    Since the time of the great geographical discoveries, since Henry the Navigator of Portugal and Christopher Columbus started to open up the whole world to the curiosity of naturalists, the Dutch and the English have played an important role in the explorations of the riches of God’s Nature. The Mona

  9. Nature of Science Contextualized: Studying Nature of Science with Scientists

    Science.gov (United States)

    Tala, Suvi; Vesterinen, Veli-Matti

    2015-01-01

    Understanding nature of science (NOS) is widely considered an important educational objective and views of NOS are closely linked to science teaching and learning. Thus there is a lively discussion about what understanding NOS means and how it is reached. As a result of analyses in educational, philosophical, sociological and historical research,…

  10. Nature of Science or Nature of the Sciences?

    Science.gov (United States)

    Schizas, Dimitrios; Psillos, Dimitris; Stamou, George

    2016-01-01

    The present essay examines the emerging issue of domain-general versus domain-specific nature of science (NOS) understandings from a perspective that illuminates the value of domain-specific philosophies of science for the growth and development of the NOS educational field. Under the assumption that individual sciences do have their own…

  11. Exploring Natural and Social Scientists' Views of Nature of Science

    Science.gov (United States)

    Bayir, Eylem; Cakici, Yilmaz; Ertas, Ozge

    2014-01-01

    Science education researchers recently turned their attention to exploring views about nature of science (NOS). A large body of research indicates that both students and teachers have many naïve views about the NOS. Unfortunately, less attention has been directed at the issue of exploring the views of the scientists. Also, the little research in…

  12. Natural selection: Finding specimens in a natural history collection

    NARCIS (Netherlands)

    Erp, M. van; Bosch, A.P.J. van den; Hunt, S.; Meij, M. van der; Dekker, R.; Lendvai, P.

    2011-01-01

    The natural history domain is rich in information. For hundreds of years, biodiversity researchers have collected specimens and samples, and meticulously recorded the how, what, and where of these objects of research. To retrace this information, however, deep knowledge of the collection and

  13. Playing with Nature: Supporting Preschoolers' Creativity in Natural Outdoor Classrooms

    Science.gov (United States)

    Kiewra, Christine; Veselack, Ellen

    2016-01-01

    Conducted at two separate natural outdoor classrooms with preschool-aged children from three to five years old, this qualitative research study investigated how outdoor environments supported children's creativity and imagination. Although many studies have explored the development of creative arts in the young children, few have focused on…

  14. Nature of Science or Nature of the Sciences?

    Science.gov (United States)

    Schizas, Dimitrios; Psillos, Dimitris; Stamou, George

    2016-01-01

    The present essay examines the emerging issue of domain-general versus domain-specific nature of science (NOS) understandings from a perspective that illuminates the value of domain-specific philosophies of science for the growth and development of the NOS educational field. Under the assumption that individual sciences do have their own…

  15. ETIKA NATURAL TAOISME DAN IMPLEMENTASINYA

    Directory of Open Access Journals (Sweden)

    Iriyanto Widisuseno

    2016-12-01

    Full Text Available Ethical life according to Taoism means a way of life back to nature. Man must be able to interpret the laws of nature in an ethical perspective, and practice in the life of others. Taoism teaches life ethics need to be equipped virtue, which has a purity of heart that is sacred, or the sincerity and willingness to live for others. Taoist virtues law contains universal values, relevant for the people of Indonesia who are experiencing erosion and weakening of the appreciation of moral values. In addition, the transition period of political culture, especially from the time period of bureaucratic power to a democratic system of popular sovereignty towards civil society. Universal values of natural ethics Taoism in line with the ethical teachings of Pancasila.

  16. Hegel's notion of natural purpose.

    Science.gov (United States)

    Michelini, Francesca

    2012-03-01

    This paper argues that the notion of natural purpose developed by Hegel can only be thoroughly grasped by considering its intimate connection with the idea of contradiction and, particularly, with what Hegel in his philosophy of nature called the 'activity of deficiency'. This expression is used by Hegel to denote the ontological situation of every living being, which is embodied most authentically in the concepts of need and drive. For Hegel, life itself is imbued with contradiction because it is inextricably bound up with what it lacks: its identity is at one with its negation. This paper defends the thesis that Hegel's philosophy-and not just his philosophy of nature-can be characterized as an 'ontology of life' (to use the same expression that Martin Heidegger applied to Aristotle's De Anima), or more precisely, as an ontology of living individuality.

  17. Natural gas monthly, August 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    This analysis presents the most recent data on natural gas prices, supply, and consumption from the Energy Information Administration (EIA). The presentation of the latest monthly data is followed by an update on natural gas markets. The markets section examines the behavior of daily spot and futures prices based on information from trade press, as well as regional, weekly data on natural gas storage from the American Gas Association (AGA). This {open_quotes}Highlights{close_quotes} closes with a special section comparing and contrasting EIA and AGA storage data on a monthly and regional basis. The regions used are those defined by the AGA for their weekly data collection effort: the Producing Region, the Consuming Region East, and the Consuming Region West. While data on working gas levels have tracked fairly closely between the two data sources, differences have developed recently. The largest difference is in estimates of working gas levels in the East consuming region during the heating season.

  18. Natural GUT and the cosmology

    Science.gov (United States)

    Maekawa, Nobuhiro

    2012-07-01

    In the natural GUT, not only realistic quark and lepton mass matrices can be obtained but also the most serious problem in the SUSY GUT, which is called the doublet-triplet splitting problem, can be solved under the natural assumption that all the interactions which are allowed by the symmetry are introduced with O(1) coefficients (including the higher dimensional operators). In this manuscript, we examine several cosmological aspects which are related with the natural GUT, B - L-genesis, non-thermal production of dark matter (DM), vacuum selection by particle production, and the inflation after the trapping. These works are based on several papers[1, 2, 3] collaborated with S. Enomoto, S. Iida, Y. Kurata, and T. Matsuda.

  19. Naturalizing phenomenology - A philosophical imperative.

    Science.gov (United States)

    Harney, Maurita

    2015-12-01

    Phenomenology since Husserl has always had a problematic relationship with empirical science. In its early articulations, there was Husserl's rejection of 'the scientific attitude', Merleau-Ponty's distancing of the scientifically-objectified self, and Heidegger's critique of modern science. These suggest an antipathy to science and to its methods of explaining the natural world. Recent developments in neuroscience have opened new opportunities for an engagement between phenomenology and cognitive science and through this, a re-thinking of science and its hidden assumptions more generally. This is so partly because of the shortcomings of conventional mechanistically-conceived science in dealing with complex and dynamic phenomena such as climate change, brain plasticity, the behaviour of collectives, the dynamics of various microbiological processes, etc. But it is also due to recent phenomenological scholarship focussed on the 'embodied' phenomenology of Husserl's Ideen II and Merleau Ponty's later ontology of nature which have helped to extend the insights of phenomenology beyond the narrowly 'human' to an understanding of nature (which includes the human) more generally. Thus re-contextualised, phenomenology is well placed to examine some of the assumptions that give rise to the reductionism and associated scientism which has characterised conventional science in its approach to the study of natural processes. In light of this, it might be suggested that the 'anti-science' of early articulations of phenomenology is more a hostility to the underlying assumptions of science as conventionally understood than to science itself - that it is scientism rather than science that is targeted. In this paper, I aim to show how a phenomenological naturalism might be seen as a necessary step towards the development of a non-reductionist and non-scientistic approach to scientific inquiry. A key to this is a reconceptualization of nature as inclusive of meanings and of mind. It

  20. Synthesis of Polycyclic Natural Products

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tuan Hoang [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    With the continuous advancements in molecular biology and modern medicine, organic synthesis has become vital to the support and extension of those discoveries. The isolations of new natural products allow for the understanding of their biological activities and therapeutic value. Organic synthesis is employed to aid in the determination of the relationship between structure and function of these natural products. The development of synthetic methodologies in the course of total syntheses is imperative for the expansion of this highly interdisciplinary field of science. In addition to the practical applications of total syntheses, the structural complexity of natural products represents a worthwhile challenge in itself. The pursuit of concise and efficient syntheses of complex molecules is both gratifying and enjoyable.

  1. New medicines from nature's armamentarium.

    Science.gov (United States)

    Crump, Andy

    2006-02-01

    Nature frequently unleashes a barrage of new and frightening diseases against humans--such as HIV, severe acquired respiratory syndrome, Ebola virus and avian flu recently--in addition to the seemingly ever-present scourges such as malaria and tuberculosis. Fortunately, nature also provides the wherewithal to help conquer the diseases that it sets loose. All that is needed is the human ingenuity to discover, develop and apply the solutions in an optimal fashion. Participants at the 9th Max Tishler Memorial Symposium (Tokyo, July 2005) were told about several new advances in the search for new anti-infective drugs derived from natural sources and were able to learn how one of the most effective drugs ever, ivermectin, made its way through what was, at the time, uncharted territory and how precedents were set at nearly every stage to form a model for all subsequent public-private partnerships.

  2. Natural Dynamics for Combinatorial Optimization

    CERN Document Server

    Ovchinnikov, Igor V

    2015-01-01

    Stochastic and or natural dynamical systems (DSs) are dominated by sudden nonlinear processes such as neuroavalanches, gamma-ray bursts, solar flares, earthquakes etc. that exhibit scale-free statistics. These behaviors also occur in many nanosystems. On phase diagrams, these DSs belong to a finite-width phase that separates the phases of thermodynamic equilibrium and ordinary chaotic dynamics, and that is known under such names as intermittency, noise-induced chaos, and self-organized criticality. Within the recently formulated approximation-free cohomological theory of stochastic differential equations, the noise-induced chaos can be roughly interpreted as a noise-induced overlap between regular (integrable) and chaotic (non-integrable) deterministic dynamics so that DSs in this phase inherit the properties of the both. Here, we analyze this unique set of properties and conclude that such DSs must be the most efficient natural optimizers. Based on this understanding, we propose the method of the natural dyn...

  3. Second nature: on Gramsci's anthropology.

    Science.gov (United States)

    Pizza, Giovanni

    2012-04-01

    The aim of this paper is to convey the relevance of a Gramscian perspective in medical anthropology, stressing his anti-essentialist way of reasoning about 'nature'. The author claims that Gramsci's understandings of the bodily life of the state can deconstruct naturalized realities in ways that are helpful for the ethnographer engaged in the political anthropology of embodiment and the management of health, persons, and life itself. The paper is presented in three parts. An attempt is made, first, to frame the relevance of Gramsci for Italian medical anthropology and second, to explore the components of the Gramscian concept of 'second nature' within the perspective that he himself calls 'an anthropology'. Third, an example is given of how the proposed Gramscian insights could inform an ethnography on the biopolitical aspects for the early detection of Alzheimer's disease, which is currently being carried out in Perugia.

  4. Human Response to Natural Disasters

    Directory of Open Access Journals (Sweden)

    Dara Nix-Stevenson

    2013-07-01

    Full Text Available This study elaborates on the connection between socioeconomic status, education, and the ability to respond to natural disasters. Using the aftermath of Hurricane Katrina and other natural disasters as teachable moments, I foreground how uneven access to resources and capital leave some people more vulnerable than others to natural disasters and how marginal communities inevitably bear the accompanying repercussions of who gets what, when, and how much in the postdisaster emergency relief and reconstruction phase. This occurs not necessarily and merely through a “natural” disaster, as the Boxer Day Tsunami or Hurricane Katrina, but through processes of social, political, and economic disempowerment associated with prior racialized histories and inequitable access to cultural capital.

  5. Naturally Occurring Radioactive Materials (NORM)

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [ed.

    1997-02-01

    This paper discusses the broad problems presented by Naturally Occuring Radioactive Materials (NORM). Technologically Enhanced naturally occuring radioactive material includes any radionuclides whose physical, chemical, radiological properties or radionuclide concentration have been altered from their natural state. With regard to NORM in particular, radioactive contamination is radioactive material in an undesired location. This is a concern in a range of industries: petroleum; uranium mining; phosphorus and phosphates; fertilizers; fossil fuels; forestry products; water treatment; metal mining and processing; geothermal energy. The author discusses in more detail the problem in the petroleum industry, including the isotopes of concern, the hazards they present, the contamination which they cause, ways to dispose of contaminated materials, and regulatory issues. He points out there are three key programs to reduce legal exposure and problems due to these contaminants: waste minimization; NORM assesment (surveys); NORM compliance (training).

  6. Natural anti-obesity agents

    Directory of Open Access Journals (Sweden)

    Gamal A. Mohamed

    2014-12-01

    Full Text Available Obesity is a complex disease caused by the interaction of a myriad of genetic, dietary, lifestyle, and environmental factors, which favors a chronic positive energy balance, and leads to increased body fat mass. The incidence of obesity is rising at an alarming rate and is becoming a major public health concern with incalculable social costs. Indeed, obesity facilitates the development of metabolic disorders such as diabetes, hypertension, and cardiovascular diseases in addition to chronic diseases such as stroke, osteoarthritis, sleep apnea, some cancers, and inflammation-based pathologies. Recent researches demonstrated the potential of natural products to counteract obesity. Multiple-natural product combinations may result in a synergistic activity that increases their bioavailability and action on multiple molecular targets, offering advantages over chemical treatments. In this review, we discuss the anti-obesity potential of natural products and analyze their mechanisms.

  7. Natural resources, innovation and development

    DEFF Research Database (Denmark)

    Andersen, Allan Dahl; Johnson, Bjørn Harold; Marín, Anabel

    In this Globelics Thematic Review, the author team presents and discusses recent research on the relationships between natural resources, innovation and development, and suggests some implications of this body of knowledge for policy makers. The Review sets out to explore three interlinked...... questions with a particular focus on innovation and industry dynamics. First, to what extent is it currently possible for a country to develop on the basis of natural resources? Second, what are the main underlying mechanisms of resource intensive development paths? Third, how can such mechanisms...... succeeded in transforming their natural resource wealth into long-term development and from recent obstacles to resource intensive development encountered by some developing economies. The review furthermore considers whether a resource intensive development path is more or less environmentally sustainable...

  8. A cosmopolitan return to nature

    DEFF Research Database (Denmark)

    Emontspool, Julie; Georgi, Carina

    2017-01-01

    This paper investigates how foodies’ adoption of New Nordic Food enables them to combine aesthetic and moral cosmopolitanism ideals. It demonstrates that consumers integrate aesthetic and moral cosmopolitan discourses through two complementary processes: the re-aesthetization of nature and the re......-moralization of the exotic. These processes combine in a cosmopolitan interest for one of the last unexplored foreign contexts: nature. The findings of this paper contribute to existing research by showing that moral cosmopolitanism reflects a more individualized and less engaged form of consumption than ethical consumption....... They illustrate how urban consumers perform distinction in contexts where nature is the most exotic unexplored context, highlighting further the reterritorialization of global cosmopolitan consumption, where food trends can only be consumed authentically in their context of origin. Finally, this paper shows how...

  9. Synthesis of Polycyclic Natural Products

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Hoang Nguyen

    2003-05-31

    With the continuous advancements in molecular biology and modern medicine, organic synthesis has become vital to the support and extension of those discoveries. The isolations of new natural products allow for the understanding of their biological activities and therapeutic value. Organic synthesis is employed to aid in the determination of the relationship between structure and function of these natural products. The development of synthetic methodologies in the course of total syntheses is imperative for the expansion of this highly interdisciplinary field of science. In addition to the practical applications of total syntheses, the structural complexity of natural products represents a worthwhile challenge in itself. The pursuit of concise and efficient syntheses of complex molecules is both gratifying and enjoyable.

  10. The Anthropocene, Ethics, and the Nature of Nature

    Science.gov (United States)

    Trachtenberg, Z.

    2012-12-01

    For Earth scientists the Anthropocene has a strict meaning, tied to evidence that human activities have produced pervasive impacts on the Earth. But it is also significant for scholars outside the Earth sciences. Social scientists study the ways human societies transform the landscape to make it more suited to human habitation; the Anthropocene idea has already served to reveal conceptual linkages among physical and social science research programs. And the Anthropocene has important implications for normative theorists who enquire into the basis of ethical standards that, ideally, guide human activities within the environment. An influential view has held the condition of the Earth's systems in the absence of human interference as such a standard. This view emphasizes the preservation of environmental systems in (or restoration to) their "natural" condition—either because that condition is the most advantageous for human beings, or because those systems have an intrinsic moral value human beings ought to respect. However, Anthropocene research destabilizes the concept of nature. For the "natural" is typically opposed to the artificial, i.e. to the results of human action, and although nature obviously provides the context for human activity, that context is taken to be exogenously given. For virtually all of Earth's history, its systems were "natural" in this sense. However, since the appearance of life on Earth, organisms engaging in what is called niche construction have fundamentally transformed those systems up to the planetary scale. There is no reason to regard human niche construction (e.g. agriculture) as different in kind—though of course anthropogenic impacts are greater than the impacts of other species. It follows that the Anthropocene demands that we move away from an outlook based on a strict opposition between a "natural" condition and the human activities which change it, towards one that conceives of the natural not as a condition, but as a

  11. Wettability of natural superhydrophobic surfaces.

    Science.gov (United States)

    Webb, Hayden K; Crawford, Russell J; Ivanova, Elena P

    2014-08-01

    Since the description of the 'Lotus Effect' by Barthlott and Neinhuis in 1997, the existence of superhydrophobic surfaces in the natural world has become common knowledge. Superhydrophobicity is associated with a number of possible evolutionary benefits that may be bestowed upon an organism, ranging from the ease of dewetting of their surfaces and therefore prevention of encumbrance by water droplets, self-cleaning and removal of particulates and potential pathogens, and even to antimicrobial activity. The superhydrophobic properties of natural surfaces have been attributed to the presence of hierarchical microscale (>1 μm) and nanoscale (typically below 200 nm) structures on the surface, and as a result, the generation of topographical hierarchy is usually considered of high importance in the fabrication of synthetic superhydrophobic surfaces. When one surveys the breadth of data available on naturally existing superhydrophobic surfaces, however, it can be observed that topographical hierarchy is not present on all naturally superhydrophobic surfaces; in fact, the only universal feature of these surfaces is the presence of a sophisticated nanoscale structure. Additionally, several natural surfaces, e.g. those present on rose petals and gecko feet, display high water contact angles and high adhesion of droplets, due to the pinning effect. These surfaces are not truly superhydrophobic, and lack significant degrees of nanoscale roughness. Here, we discuss the phenomena of superhydrophobicity and pseudo-superhydrophobicity in nature, and present an argument that while hierarchical surface roughness may aid in the stability of the superhydrophobic effect, it is nanoscale surface architecture alone that is the true determinant of superhydrophobicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. LIQUIFIED NATURAL GAS (LNG CARRIERS

    Directory of Open Access Journals (Sweden)

    Daniel Posavec

    2010-12-01

    Full Text Available Modern liquefied natural gas carriers are double-bottom ships classified according to the type of LNG tank. The tanks are specially designed to store natural gas cooled to -161°C, the boiling point of methane. Since LNG is highly flammable, special care must be taken when designing and operating the ship. The development of LNG carriers has begun in the middle of the twentieth century. LNG carrier storage space has gradually grown to the current maximum of 260000 m3. There are more than 300 LNG carriers currently in operation (the paper is published in Croatian.

  13. Mathematical aspects of natural dynamos

    CERN Document Server

    Dormy, Emmanuel

    2007-01-01

    Although the origin of Earth's and other celestial bodies' magnetic fields remains unknown, we do know that the motion of electrically conducting fluids generates and maintains these fields, forming the basis of magnetohydrodynamics (MHD) and, to a larger extent, dynamo theory. Answering the need for a comprehensive, interdisciplinary introduction to this area, ""Mathematical Aspects of Natural Dynamos"" provides a foundation in dynamo theory before moving on to modeling aspects of natural dynamos.Bringing together eminent international contributors, the book first introduces governing equatio

  14. An attractor for natural supersymmetry

    Science.gov (United States)

    Cohen, Timothy; Hook, Anson; Torroba, Gonzalo

    2012-12-01

    We propose an attractor mechanism which generates the more minimal supersymmetric standard model from a broad class of supersymmetry breaking boundary conditions. The hierarchies in the fermion masses and mixings are produced by the same dynamics and a natural weak scale results from gaugino mediation. These features arise from augmenting the standard model with a new SU(3) gauge group under which only the third generation quarks are charged. The theory flows to a strongly interacting fixed point which induces a negative anomalous dimension for the third generation quarks and a positive anomalous dimension for the Higgs. As a result, a split-family natural spectrum and the flavor hierarchies are dynamically generated.

  15. North American Natural Gas Markets

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-01

    This report summarizes die research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group's findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  16. Flow of wet natural pozzolana

    Energy Technology Data Exchange (ETDEWEB)

    Medici, M E; Benegas, O A; Aguirre, F; Baudino, M R [Departamento de Mineria, Universidad Nacional de San Luis, 5700 San Luis (Argentina); Unac, R O; Vidales, A M [INFAP-CONICET, Departamento de Fisica, Universidad Nacional de San Luis, 5700 San Luis (Argentina); Ippolito, I, E-mail: avidales@unsl.edu.a [GMP, CONICET y Facultad de Ingenieria, Universidad de Buenos Aires, 1063 Buenos Aires (Argentina)

    2009-05-01

    We present experimental results on the flow and stability conditions for natural pozzolana, a natural volcanic sand widely used in concrete production. We measured different angles involved in equilibrium conditions for sand piles and relate them to the flux parameters necessary to produce a silo evacuation. We vary some of the geometrical parameters in the silo to inspect the different flux responses of the system. Results are showed as a function of humidity present in the system. In this way, we related critical angles with flux conditions through a silo under different geometric setups and different humidity degrees, thus setting up a basic phase diagram for flux.

  17. Stratification in Natural Water Bodies

    DEFF Research Database (Denmark)

    Møller, Jacob Steen

    2004-01-01

    Density stratification of natural water bodies plays an important role for a number of civil engineering problems. The origin of stratification in natural water is discussed and the Black Sea, the Gulf of Katchch, and Maarmorilik Fiord in Greenland are described and used as examples. Stratification...... has a number of civil engineering implications. The lock exchange problem is used as a canonical example, and implications for water exchange and sedimentation is discussed by means of examples: Sedimentation in locks and estuaries, salt transport into fresh water reservoirs, water exchange...

  18. Natural Resources and Human Impact

    Science.gov (United States)

    Starkel, Leszek

    2016-01-01

    It is rotational movement of the Earth that decides on the climatic zonation of natural resources, as modified by the positions of the continents and oceans and the irregular spread of fossil fuels. Intensive human activity poses threats to the development of natural geoecosystems. The last century also brought growing civilizational threats to the environment on the global, regional and local scales. The author characterise the prospects in regard to global changes, and discuss the solutions needing to be pursued if human geoecosystems are to be protected (through management and education).

  19. Natural fertility in the Philippines.

    Science.gov (United States)

    Aquino, E G

    1982-01-01

    The hypothesis that modernization trends in the Philippines led to an increase in fecundity and natural fertility between 1953-1972 was tested, using data from the 1973 National Demographic Survey. More specifically, it was hypothesized that increases in education, income levels, urbanization, female labor force participation, and other factors exerted a positive influence on the population's health and nutritional status and increased the risk of pregnancy by diminishing the strength of sexual taboos and by decreasing the incidence of breastfeeding. These changes, in turn, had a positive impact on natural fertility. Natural fertility was defined as marital fertility in the absence of specific efforts to control fertility. The use of natural fertility instead of fecundity allowed for the influence of behavioral patterns, such as breastfeeding and sexual taboos, on fertility. Period analysis of age specific marital fertility rates for each 5 year period between 1953-72 and cohort analysis of age specific marital fertility rates for the birth cohorts, aged 55-59, 50-54, 45-49, 40-44, and 35-39 in 1973 were undertaken. The effect of fertility control was determined by using an index derived from an equation provided by Coale and Trussell. Findings of both the period and cohort analysis supported the hypothesis. Period analysis revealed that natural fertility increased between 1953-57 and 1969-72 by 10% and that the greatest increase occurred during the 1950s when Philippine society experienced major modernization changes. The increases in natural fertility were accompanied by corresponding increases in fertility regulation in each time period. These trends tended to cancel each other out and resulted in a relatively stable total marital fertility rate throughout the time period. Cohort analysis revealed that only the total marital fertility rate of the youngest cohort was influenced by fertility regulation. The level of natural fertility for all cohorts as a group

  20. Swift, Gulliver, and Human Nature

    OpenAIRE

    Carey, Daniel

    2012-01-01

    I have some Time since, with a World of Pains and Art, dissected the Carcass of Human Nature, and read many useful Lectures upon the several Parts … till at last it smelt so strong, I could preserve it no longer. The objects of Swift’s satire in Gulliver’s Travels are numerous and disparate, ranging from the follies of natural philosophers to the varieties of human pride, English politics under Queen Anne and King George, Walpole and ministerial government, and of course the genre of travel w...

  1. Platonism, Naturalism, and Mathematical Knowledge

    CERN Document Server

    Brown, James Robert

    2011-01-01

    This study addresses a central theme in current philosophy: Platonism vs Naturalism and provides accounts of both approaches to mathematics, crucially discussing Quine, Maddy, Kitcher, Lakoff, Colyvan, and many others. Beginning with accounts of both approaches, Brown defends Platonism by arguing that only a Platonistic approach can account for concept acquisition in a number of special cases in the sciences. He also argues for a particular view of applied mathematics, a view that supports Platonism against Naturalist alternatives. Not only does this engaging book present the Platonist-Natural

  2. Kelsen on Natural Law Theory

    OpenAIRE

    Chiassoni, Pierluigi

    2014-01-01

    In a series of essays published from the late 1920s up to the mid-1960s, Hans Kelsen carried out a radical critique of natural law theory. The present paper purports to provide an analytical reconstruction and critical assessment of such a critique. It contains two parts. Part one surveys the fundamentals of Kelsen’s argumentative strategy against natural law and its theorists. Part two considers, in turn, two critical reactions to Kelsen’s criticisms: by Edgar Bodenheimer, on behalf of tradi...

  3. Natural photonics for industrial inspiration.

    Science.gov (United States)

    Parker, Andrew R

    2009-05-13

    There are two considerations for optical biomimetics: the diversity of submicrometre architectures found in the natural world, and the industrial manufacture of these. A review exists on the latter subject, where current engineering methods are considered along with those of the natural cells. Here, on the other hand, I will provide a modern review of the different categories of reflectors and antireflectors found in animals, including their optical characterization. The purpose of this is to inspire designers within the $2 billion annual optics industry.

  4. 7 CFR 650.23 - Natural areas.

    Science.gov (United States)

    2010-01-01

    ... as a natural area and manage it accordingly. Several professional societies concerned with renewable natural resources encourage establishment of natural areas withdrawn from economic uses and recognition of natural areas maintained and managed in economic enterprises. (3) Natural areas are established and...

  5. The Curse of Natural Resources

    NARCIS (Netherlands)

    Wick, A.K.; Bulte, E.H.

    2009-01-01

    A large literature has developed that documents a negative association between the presence of natural resources and economic development. In this paper we explore the empirics and theories of the so-called resource curse and try to assess its robustness. We conclude that there are many open questio

  6. Aligned natural inflation with modulations

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kiwoon, E-mail: kchoi@ibs.re.kr [Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS), Daejeon, 34051 (Korea, Republic of); Kim, Hyungjin, E-mail: hjkim06@kaist.ac.kr [Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS), Daejeon, 34051 (Korea, Republic of); Department of Physics, KAIST, Daejeon, 305-701 (Korea, Republic of)

    2016-08-10

    The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the primordial power spectrum induced by such modulation, and discuss the resulting observational constraints on the model.

  7. Integrating the Nature of Science

    Science.gov (United States)

    Weiland, Ingrid; Blieden, Katherine; Akerson, Valarie

    2014-01-01

    The nature of science (NOS) describes what science is and how knowledge in science is developed (NSTA 2013). To develop elementary students' understandings of how scientists explore the world, the authors--an education professor and a third-grade teacher--endeavored to integrate NOS into a third-grade life science unit. Throughout the lesson,…

  8. Natural gas monthly, January 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    This publication, the Natural Gas Monthly, presents the most recent data on natural gas supply, consumption, and prices from the Energy Information Administration (EIA). Of special interest in this issue are two articles summarizing reports recently published by EIA. The articles are {open_quotes}Natural Gas Productive Capacity{close_quotes} and {open_quotes}Outlook for Natural Gas Through 2015,{close_quotes} both of which precede the {open_quotes}Highlights{close_quotes} section. With this issue, January 1997, changes have been made to the format of the Highlights section and to several of the tabular and graphical presentations throughout the publication. The changes to the Highlights affect the discussion of developments in the industry and the presentation of weekly storage data. An overview of the developments in the industry is now presented in a brief summary followed by specific discussions of supply, end-use consumption, and prices. Spot and futures prices are discussed as appropriate in the Price section, together with wellhead and consumer prices.

  9. The last vestiges of naturalness

    Science.gov (United States)

    Arvanitaki, Asimina; Baryakhtar, Masha; Huang, Xinlu; Van Tilburg, Ken; Villadoro, Giovanni

    2014-03-01

    Direct LHC bounds on colored SUSY particles now corner naturalness more than the measured value of the Higgs mass does. Bounds on the gluino are of particular importance, since it radiatively "sucks" up the stop and Higgs-up soft masses. As a result, even models that easily accommodate a 125 GeV Higgs are almost as tuned as the simplest version of SUSY, the MSSM: at best at the percent level. In this paper, we further examine how current LHC results constrain naturalness in three classes of models that may relax LHC bounds on sparticles: split families, baryonic RPV, and Dirac gauginos. In models of split families and bRPV, the bounds on the gluino are only slightly reduced, resulting in a few percent tuning. In particular, having a natural spectrum in bRPV models typically implies that tops, W s, and Zs are easily produced in the cascade decays of squarks and gluinos. The resulting leptons and missing energy push the gluino mass limit above 1 TeV. Even when the gluino has a Dirac mass and does not contribute to the stop mass at one loop, tuning reappears in calculable models because there is no symmetry imposing the supersoft limit. We conclude that, even if sparticles are found at LHC-14, naturalness will not emerge triumphant.

  10. Natural deduction : sharing by presentation

    NARCIS (Netherlands)

    Loeb, Iris

    2007-01-01

    Part I of this thesis studies a fragment of natural deduction to which we have added the notion of sharing of subresults. This formalism is called 'deduction graphs'. We show some properties of cut-elimination on deduction graphs, like strong normalisation and confluence. We discuss connections with

  11. Natural gas news; Gaz actualites

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-12-01

    This brochure is a compilation of practical information concerning the Gaz de France group: organization chart, daughter companies, services, economical activity, natural gas market, trade, regulations etc. A list of partners, directions, centres, groups, associations and other various organisms in relation with Gaz de France company is given. (J.S.)

  12. Economic development and natural disasters

    NARCIS (Netherlands)

    Klomp, Jeroen

    2016-01-01

    In this study we examine the impact of large-scale natural disasters on economic development. A major obstacle in exploring this relationship is the poor data quality on GDP per capita in low-income countries, while at the same time more than 90% of all disasters that happen worldwide occur in th

  13. Financial Protection Against Natural Disasters

    OpenAIRE

    World Bank Group

    2014-01-01

    The primary objective of this report is to take stock of the global progress on financial protection against natural disasters over the last decade and bring together the latest thinking on disaster risk financing and insurance. Disaster risk financing and insurance helps minimize the cost and optimize the timing of meeting post-disaster funding needs without compromising development goals...

  14. Aligned natural inflation with modulations

    Directory of Open Access Journals (Sweden)

    Kiwoon Choi

    2016-08-01

    Full Text Available The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the primordial power spectrum induced by such modulation, and discuss the resulting observational constraints on the model.

  15. Charming worms: crawling between natures

    NARCIS (Netherlands)

    Bertoni, F.

    2012-01-01

    Some anthropologists have argued that Euro-American culture is naturalist, anchored to the belief in a coherent, unitary universe in which natural laws operate. From a close ethnographic inspection, however, the allegedly naturalist sciences emerge as heterogeneous practices, engaging with complex a

  16. Natural gas monthly, March 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This issue of the Natural Gas Monthly contains estimates for March 1999 for many natural gas data series at the national level. Estimates of national natural gas prices are available through December 1998 for most series. Highlights of the data contained in this issue are listed below. Preliminary data indicate that the national average wellhead price for 1998 declined to 16% from the previous year ($1.96 compared to $2.32 per thousand cubic feet). At the end of March, the end of the 1998--1999 heating season, the level of working gas in underground natural gas storage facilities is estimated to be 1,354 billion cubic feet, 169 billion cubic feet higher than at the end of March 1998. Gas consumption during the first 3 months of 1999 is estimated to have been 179 billion cubic feet higher than in the same period in 1998. Most of this increase (133 billion cubic feet) occurred in the residential sector due to the cooler temperatures in January and February compared to the same months last year. According to the National Weather Service, heating degree days in January 1999 were 15% greater than the previous year while February recorded a 5% increase.

  17. Nature of Writing in ELT

    Institute of Scientific and Technical Information of China (English)

    梁玉朋

    2012-01-01

    In recent years, the analysis of writing has been emphasized more and more in the field of English Language Teaching(EFL). Before we start writing in English, it is of great significance to know about the nature of writing in learning and teaching of English.

  18. Using Natural Approach Teaching Techniques.

    Science.gov (United States)

    Whitman, Charles

    1986-01-01

    Describes a beginning foreign language class applying the principles of Stephen Krashen's "Natural Approach" and James Asher's "Total Physical Response" method. Initially students carry out the instructor's commands in the form of actions rather than being required to speak. In later stages role play and simple discussions are…

  19. Natural products as antimitotic agents.

    Science.gov (United States)

    Dall'Acqua, Stefano

    2014-01-01

    Natural products still play an important role in the medicinal chemistry, especially in some therapeutic areas. As example more than 60% of currently-used anticancer agents are derives from natural sources including plants, marine organisms or micro-organism. Thus natural products (NP) are an high-impact source of new "lead compounds" or new potential therapeutic agents despite the large development of biotechnology and combinatorial chemistry in the drug discovery and development. Many examples of anticancer drugs as paclitaxel, combretastatin, bryostatin and discodermolide have shown the importance of NP in the anticancer chemotherapy through many years. Many organisms have been studied as sources of drugs namely plants, micro-organisms and marine organisms and the obtained NP can be considered a group of "privileged chemical structures" evolved in nature to interact with other organisms. For this reason NP are a good starting points for pharmaceutical research and also for library design. Tubulin and microtubules are one of the most studied targets for the search of anticancer compounds. Microtubule targeting agents (MTA) also named antimitotic agents are compounds that are able to perturb mitosis but are also able to arrest cell growing during interphase. The anticancer drugs, taxanes and vinca alkaloids have established tubulin as important target in cancer therapy. More recently the vascular disrupting agents (VDA) combretastatin analogues were studied for their antimitotics properties. This review will consider the anti mitotic NP and their potential impact in the development of new therapeutic agents.

  20. Handbook of Natural Language Processing

    CERN Document Server

    Indurkhya, Nitin

    2010-01-01

    Provides a comprehensive, modern reference of practical tools and techniques for implementing natural language processing in computer systems. This title covers classical methods, empirical and statistical techniques, and various applications. It describes how the techniques can be applied to European and Asian languages as well as English