Study of the dissolution of three synthetic minerals: zirconolite, Y-britholite and mono-silicate fluor-apatite; Etude de la solubilite de trois mineraux synthetiques: la zirconolite, la britholite-Y et la fluorapatite monosilicatee

Energy Technology Data Exchange (ETDEWEB)

Kamel, N.E.H.; Telmoune, S.A. [Centre de Recherche Nucleaire d' Alger, Div. des Techniques Nucleaires, Alger (Algeria); Ait-Amar, H. [Unitersite des Sciences et de la Technologie Houari Boumediene, Dept. de Genie des Procedes, Alger (Algeria)

2007-11-15

In this study, we were interested in the synthesis by natural sintering of three minerals analogue of natural rocks: zirconolite, Y-britholite and mono-silicated fluor-apatite. Cerium was used as an actinide surrogate. A simple physical characterization of the materials was made by X-ray diffraction and by measuring both densities and hardnesses. A static leaching test allowed determining the cerium immobilization capacity of the minerals. The most stable mineral was mono-silicated fluor-apatite, with a maximum amount of released cerium less than 2 %. For zirconolite and Y-britholite, this amount reached 15 and 18 % of the total cerium in the minerals, respectively. For the latter compounds, the cerium content in the materials was too weak, and the chosen synthesis method gave less satisfactory physicochemical mineral properties compared to those obtained for mono-silicated fluor-apatite. (authors)

Krypton irradiation damage in Nd-doped zirconolite and perovskite

International Nuclear Information System (INIS)

Davoisne, C.; Stennett, M.C.; Hyatt, N.C.; Peng, N.; Jeynes, C.; Lee, W.E.

2011-01-01

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 + at a dose of 5 x 10 15 ions cm -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.

Status of the synroc project

International Nuclear Information System (INIS)

Reeve, K.D.; Ramm, E.J.; Woolfrey, J.L.; Ryan, R.K.; Buykx, W.J.; Cassidy, D.J.; Webb, C.E.

1980-10-01

SYNROC-B has been proposed as a vehicle for the immobilisation of solidified radioactive waste. It consists of an assemblage of three synthetic mineral phases: perovskite, barium hollandite and zirconolite. Fabrication studies, leach testing and irradiation testing of SYNROC are reported

Zirconolite glass-ceramics for plutonium immobilization: The effects of processing redox conditions on charge compensation and durability

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yingjie, E-mail: yzx@ansto.gov.au; Gregg, Daniel J.; Kong, Linggen; Jovanovich, Miodrag; Triani, Gerry

2017-07-15

Zirconolite glass-ceramic samples doped with plutonium have been prepared via hot isostatic pressing. The effects of processing redox and plutonium loadings on plutonium valences, the presence of cation vacancies, zirconolite phase compositions, microstructures and durability have been investigated. Either tetravalent or trivalent plutonium ions may be incorporated on the Ca-site of CaZrTi{sub 2}O{sub 7} zirconolite with the Ca-site cation vacancies and the incorporation of Al{sup 3+} ions on the Ti-site for charge compensation. Plutonium and gadolinium (as a neutron absorber) are predominantly partitioned in zirconolite phases leading to the formation of chemically durable glass-ceramics suitable for the immobilization of impure plutonium wastes arising from the nuclear fuel cycle. - Highlights: •Plutonium validations of zirconolite glass-ceramics. •Effects of processing redox and plutonium loading. •Zirconolite phase compositions and plutonium valences. •Cation vacancies and chemical durability.

Solid-state reaction synthesis and aqueous durability of Ce-doped zirconolite-rich ceramics

Energy Technology Data Exchange (ETDEWEB)

Wen, Guanjun [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Zhang, Kuibao, E-mail: xiaobao320@163.com [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Yin, Dan [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); Zhang, Haibin, E-mail: hbzhang@imr.ac.cn [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

2015-11-15

In this study, Ce-doped zirconolite-rich ceramics were prepared by solid-state reaction process using cerium as the surrogate of tetravalence actinide nuclide. The occupancy of Ce in the waste forms was investigated. The aqueous durability of Ce-doped zirconolite-rich ceramic was examined as well. The results show that zirconolite and pseudobrookite coexisted after being sintered at 1200 °C for 6 h. Meanwhile, perovskite is inevitable generated during the process. CeO{sub 2} can be successfully incorporated into the lattice structure of the zirconolite-rich ceramics. The maximum containing capacity of CeO{sub 2} is up to 14.95 wt% or y = 0.4. The normalized elemental leaching rates of Ce and Ca are fairly constant in low values of 1.2 × 10{sup −6} and 2.3 × 10{sup −2} g m{sup −2} d{sup −1} after 28 days. The normalized leaching rate of Fe is also in a low value of 2.9 × 10{sup −4} g m{sup −2} d{sup −1} after 7 days. - Highlights: • Ce-doped zirconolite-rich ceramic was produced at 1200 °C. • Pseudobrookite-type Fe{sub 2}TiO{sub 5} was employed to incorporate Fe element. • Ce{sup 3+} and Ce{sup 4+} coexisted in the Ce-doped zirconolite-rich waste form after being sintered at 1200 °C for 6 h. • The leaching rate of Ca was relatively higher than that of borosilicate glasses.

Long-term behavior of glass-ceramic zirconolite

International Nuclear Information System (INIS)

Martin, Ch.

2003-01-01

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 2 O 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)

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)

Characterization of the microstructure of zirconolite-based glass-ceramics

International Nuclear Information System (INIS)

Loiseau, P.; Caurant, D.; Touet, I.; Destre, Y.; Fillet, C.

2000-01-01

December 1991 legislation in France has spurred research on enhanced separation and conditioning or transmutation of long-lived radionuclides from high level radioactive wastes (HLW). In this field, we have studied zirconolite-based glass-ceramics in which the crystalline phase (zirconolite: CaZrTi 2 O 7 ) aimed to preferentially incorporate minor actinides is embedded in a glassy calcium aluminosilicate matrix. At the laboratory scale, the crystallization of the parent glass is carried out thanks to a two-step thermal treatment: a nucleation stage followed by a growth stage. This paper presents the evolution of the crystallization, followed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), with the temperature of the crystal growth thermal treatment, in the range 950 deg. C - 1350 deg. C. (authors)

Neodymium partitioning in zirconolite-based glass-ceramics designed for minor actinides immobilization

International Nuclear Information System (INIS)

Loiseau, P.; Caurant, D.; Baffier, N.; Fillet, C.

2000-01-01

This study deals with glass-ceramic matrices designed for the conditioning of minor actinides, in which zirconolite crystals (CaZrTi 2 O 7 ) are homogeneously dispersed in a residual glassy matrix. Good immobilization performances require a high enrichment of actinides in the crystalline phase (double containment principle). Glass-ceramics are obtained by controlled devitrification of an aluminosilicate parent glass containing large amounts of TiO 2 and ZrO 2 . Neodymium was selected to simulate the trivalent minor actinides. Crystallization was performed at 1200 deg. C for various Nd 2 O 3 contents (0 - 10 wt. %). In all cases, zirconolite crystallization is obtained in the bulk of glass-ceramics. The evolution of Nd 3+ location between the crystals and the residual glass was followed by electron spin resonance and optical absorption. Both techniques demonstrate that neodymium is partly incorporated in zirconolite crystals. Moreover, total Nd 2 O 3 content in parent glass has a strong effect on Nd 3+ ions distribution. (authors)

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

Science.gov (United States)

Deschanels, X.; Seydoux-Guillaume, A. M.; Magnin, V.; Mesbah, A.; Tribet, M.; Moloney, M. P.; Serruys, Y.; Peuget, S.

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 238Pu, (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 × 1018 α g-1 (i.e. ∼1.3 × 1021 keV cm-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 238Pu doped samples was much smaller at ∼1%. Also, unlike the externally (Au) irradiated monazite these 238Pu doped samples remained crystalline up to 7.5 × 1018 α g-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 238Pu doped monazite samples indicates that alpha annealing took place within this material.

Preparation and leaching property of Nd-doped zirconolite-based glass-ceramic

International Nuclear Information System (INIS)

Wu Lang; Xu Dong; Teng Yuancheng; Li Yuxiang; Liu Zongqiang

2014-01-01

Nd-doped zirconolite-based glass-ceramics were prepared by melting-heat treatment technique. The effects of heat treatment processing on phase structure of the glass-ceramics were investigated. The leaching properties of the glass-ceramics were also evaluated by static leaching experiments (product consistency test, PCT). The results show that glass transformation temperature (T g ) and crystallization temperature of the glass-ceramics are about 580℃ and 740℃, respectively. CaTiO 3 phase forms easily when the glass-ceramics were prepared by two-step method, i.e. the glass was prepared first, and then it was heat-treated at the crystallization temperatures. 2M-zirconolite phase can be obtained by one-step method, i.e. the heat-treatment immediately followed by the melting process. In addition, the zirconolite crystals exhibit a dendritic shape. The normalized mass loss of B and Na in the glass-ceramics remains almost unchanged (about 1 mg/m 2 ) after 14 days, while the normalized mass loss of Nd reaches stable value (about 0.2 mg/m 2 ) after 28 days. The normalized mass loss of B, Na, and Nd in the glass-ceramics is an order of magnitude lower than that of borosilicate glasses, respectively. (authors)

Comparison of structure, morphology, and leach characteristics of multi-phase ceramics produced via melt processing and hot isostatic pressing

Science.gov (United States)

Dandeneau, Christopher S.; Hong, Tao; Brinkman, Kyle S.; Vance, Eric R.; Amoroso, Jake W.

2018-04-01

Melt processing of multi-phase ceramic waste forms offers potential advantages over traditional solid-state synthesis methods given both the prevalence of melters currently in use and the ability to reduce the possibility of airborne radionuclide contamination. In this work, multi-phase ceramics with a targeted hollandite composition of Ba1.0Cs0.3Cr1.0Al0.3Fe1.0Ti5.7O16 were fabricated by melt processing at 1675 °C and hot isostatic pressing (HIP) at 1250 and 1300 °C. X-ray diffraction analysis (XRD) confirmed hollandite as the major phase in all specimens. Zirconolite/pyrochlore peaks and weaker perovskite reflections were observed after melt processing, while HIP samples displayed prominent perovskite peaks and low-intensity zirconolite reflections. Melt processing produced specimens with large (>50 μm) well-defined hollandite grains, while HIP yielded samples with a more fine-grained morphology. Elemental analysis showed "islands" rich in Cs and Ti across the surface of the 1300 °C HIP sample, suggesting partial melting and partitioning of Cs into multiple phases. Photoemission data revealed multiple Cs 3d spin-orbit pairs for the HIP samples, with the lower binding energy doublets likely corresponding to Cs located in more leachable phases. Among all specimens examined, the melt-processed sample exhibited the lowest fractional release rates for Rb and Cs. However, the retention of Sr and Mo was greater in the HIP specimens.

SYNROC process. A geochemical approach to nuclear waste immobilization

Energy Technology Data Exchange (ETDEWEB)

Ringwood, A E; Kesson, S E; Ware, N G; Hibberson, W O; Major, A [Australian National Univ., Canberra. Research School of Earth Sciences

1979-08-01

The SYNROC process is proposed to immobilize high-level wastes as dilute solid solutions in the constituent minerals of a synthetic rock formed from a mixture of oxides. New modification of the SYNROC was developed. Experiments showed that the entire spectra of high-level waste elements can be incorporated in the crystal lattices of Ba-hollandite, perovskite and zirconolite. This titanate assemblage has been proved to be exceptionally resistant to hydrothermal leaching, and in this respect, amongst others, it is demonstrably superior to alternative ceramic waste forms and to borosilicate glasses. The relative stability of various waste forms was compared in hydrothermal leaching experiments using both pure water and 10 w/o NaCl solution. Borosilicate glasses were almost completely decomposed and disintegrated after only 24 hours at 350 deg C and 1000 bars, and the extensive loss of hazardous high-level waste elements occurred. The phase pollucite in ceramic waste forms began to decompose at 400 deg C. The hollandite-perovskite-zirconolite SYNROC assemblage was proved to be exceptionally resistant to leaching, surviving invariably the extreme conditions up to 900 deg C and 5000 bars. Geochemical studies of the naturally-occurring minerals containing radwaste elements are relevant to the problem of radiation damage to SYNROC phases. These imply that the 2-particle flux in SYNROC is unlikely to be enough to impair the ability to immobilize radwaste for the required period. The production of SYNROC is explained in detail. The SYNROC phases have the structures analogous to the natural minerals which have survived a variety of geological conditions for millions of years while retaining certain high-level waste elements in their crystal lattices.

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)

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

International Nuclear Information System (INIS)

Lumpkin, G.R.; Begg, B.D.; Smith, K.L.

2000-01-01

Actinide-doping experiments using short-lived 238 Pu and 244 Cm have demonstrated that pyrochlore and zirconolite become fully amorphous at a dose of 0.2-0.5 x 10 16 α/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)

Reduction and structural modification of zirconolite on He{sup +} ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Gupta, Merry, E-mail: g41merry@gmail.com [Sant Longowal Institute of Engineering and Technology, Longowal, Sangrur, Punjab 148106 (India); Kulriya, P.K. [Inter-University Accelerator Centre, Aruna Asaf Ali Road, New Delhi 110067 (India); Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Shukla, Rishabh; Dhaka, R.S. [Novel Materials and Interface Physics Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Kumar, Raj [Inter-University Accelerator Centre, Aruna Asaf Ali Road, New Delhi 110067 (India); Ghumman, S.S. [Sant Longowal Institute of Engineering and Technology, Longowal, Sangrur, Punjab 148106 (India)

2016-07-15

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. CaZrTi{sub 2}O{sub 7} pellets prepared using solid state reaction techniques, were irradiated with 30 keV He{sup +} ions for the ion fluence varying from 1 × 10{sup 17} to 1 × 10{sup 21} ions/m{sup 2}. 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 × 10{sup 20} ions/m{sup 2}. These indicate a decrease in co-ordination number and the ionic character of M−O bond. Moreover, core level XPS signal was not detected for sample irradiated with ion fluence of 1 × 10{sup 21} ions/m{sup 2}, 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 × 10{sup 21} ion/m{sup 2}. 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

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

Raman scattering studies of mobile ions in superionic conductor hollandites

International Nuclear Information System (INIS)

Shibata, Y.; Suemoto, T.; Ishigame, M.

1986-01-01

The Raman spectra of the superionic conductors K/sub 1.6/Mg/sub 0.8/Ti/sub 7.2/O 16 , Cs/sub 1.2/Mg/sub 0.6/Ti/sub 7.4/O 16 , and (KTl)/sub 1.6/Mg/sub 0.8/Ti/sub 7.2/O 16 are measured in the frequency range from 5 to 1000 cm -1 . In the range from 100 to 1000 cm -1 Raman spectra hardly show alkali ion dependence. On the contrary, in the frequency range from 5 to 100 cm -1 , an additional Raman band is observed. This Raman band shows alkali ion dependence. By using the Frenkel-Kontorova model for the hollandite crystal with the given configuration of the mobile ions, it is found that the dependence of vibrational frequency of mobile ions with kinds of alkali ion is well explained and that the concept of 'super unit cell' that is introduced by Beyeler is very useful to explain the Raman bands which are observed below 100 cm -1 in hollandite crystals. (author)

Alkali-Resistant Mechanism of a Hollandite DeNOx Catalyst.

Science.gov (United States)

Hu, Pingping; Huang, Zhiwei; Gu, Xiao; Xu, Fei; Gao, Jiayi; Wang, Yue; Chen, Yaxin; Tang, Xingfu

2015-06-02

A thorough understanding of the deactivation mechanism by alkalis is of great importance for rationally designing improved alkali-resistant deNOx catalysts, but a traditional ion-exchange mechanism cannot often accurately describe the nature of the deactivation, thus hampering the development of superior catalysts. Here, we establish a new exchange-coordination mechanism on the basis of the exhaustive study on the strong alkali resistance of a hollandite manganese oxide (HMO) catalyst. A combination of isothermal adsorption measurements of ammonia with X-ray absorption near-edge structure spectra and X-ray photoelectron spectra reveals that alkali metal ions first react with protons from Brønsted acid sites of HMO via the ion exchange. Synchrotron X-ray diffraction patterns and extended X-ray absorption fine structure spectra coupled with theoretical calculations demonstrate that the exchanged alkali metal ions are subsequently stabilized at size-suitable cavities in the HMO pores via a coordination model with an energy savings. This exchange-coordination mechanism not only gives a wholly convincing explanation for the intrinsic nature of the deactivation of the reported catalysts by alkalis but also provides a strategy for rationally designing improved alkali-resistant deNOx catalysts in general.

Structure, properties, and disorder in the new distorted-Hollandite PbIr{sub 4}Se{sub 8}

Energy Technology Data Exchange (ETDEWEB)

Trump, Benjamin A., E-mail: btrump1@jhu.edu [Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218 (United States); Department of Physics and Astronomy, Institute for Quantum Matter, Johns Hopkins University, Baltimore, MD 21218 (United States); McQueen, Tyrel M., E-mail: mcqueen@jhu.edu [Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218 (United States); Department of Physics and Astronomy, Institute for Quantum Matter, Johns Hopkins University, Baltimore, MD 21218 (United States); Department of Material Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States)

2016-10-15

The synthesis and physical properties of the new distorted-Hollandite PbIr{sub 4}Se{sub 8} are reported. Powder X-ray diffraction and transmission electron microscopy show that the structure consists of edge- and corner-sharing IrSe{sub 6} octahedra, with one-dimensional channels occupied by Pb. The structure contains Se-Se anion-anion bonding, leading to an electron count of Pb{sup 2+}(Ir{sup 3+}){sub 4}(Se{sub 2}){sup 2-}(Se{sup 2−}){sub 6}, confirmed by bond-valence sums and diamagnetic behavior. Structural and heat capacity measurements demonstrate disorder on the Pb site, due to the combination of lone-pair effects and the large size of the one-dimensional channels. Comparisons are made to known Hollandite and pseudo-Hollandite structures, which demonstrates that the anion-anion bonding in PbIr{sub 4}Se{sub 8} distorts its structure, to accommodate the Ir{sup 3+} state. An electronic structure calculation indicates semiconductor character with a band gap of 0.76(11) eV.

Study of the effect of water radiolysis on zirconolite dissolution

International Nuclear Information System (INIS)

Tribet, M.

2007-09-01

Zirconolite is one of the matrices foreseen for the confinement of minor actinides in case of deep geological disposal. Indeed, zirconolite (general formula: CaZr x Ti 3-x O 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 0,8 Nd 0,2 ZrTi 1,8 Al 0,2 O 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 15 to 10 16 ions.cm -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 - . The sample dissolution has been monitored through the release of cations. The radiolytic production of H 2 O 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 surface state (crystalline or amorphous) and the experimental

Quantification of the Partitioning Ratio of Minor Actinide Surrogates between Zirconolite and Glass in Glass-Ceramic for Nuclear Waste Disposal.

Science.gov (United States)

Liao, Chang-Zhong; Liu, Chengshuai; Su, Minhua; Shih, Kaimin

2017-08-21

Zirconolite-based glass-ceramic is considered a promising wasteform for conditioning minor actinide-rich nuclear wastes. Recent studies on this wasteform have sought to enhance the partitioning ratio (PR) of minor actinides in zirconolite crystal. To optimize the PR in the SiO 2 -Al 2 O 3 -CaO-TiO 2 -ZrO 2 system, a novel conceptual approach, which can be derived from the chemical composition and quantity of zirconolite crystal in glass-ceramic, was introduced based on the results of Rietveld quantitative X-ray diffraction analysis and transmission electron microscopy energy dispersive X-ray spectroscopy. To verify this new conceptual approach, the influences of the crystallization temperature, the concentration of additives, and ionic radii on the PR of various surrogates (Ce, Nd, Gd, and Yb) in zirconolite were examined. The results reveal that the PR of Nd 3+ in zirconolite can be as high as 41%, but it decreases as the crystallization temperature increases. The quantities of all phases (including crystalline and amorphous) remained nearly constant when increasing the loading of Nd 2 O 3 in glass-ceramic products crystallized at 1050 °C for 2 h. Correspondingly, the PR of Nd 3+ decreases in a linear fashion with the loading contents of Nd 2 O 3 . The radius of ions also has a great influence on the PR, and an increase in the ionic radius leads to a decrease in the PR. This new approach will be an important tool to facilitate the exploration of a glass-ceramic matrix for the disposal of minor actinide-rich nuclear wastes.

Synthesis, characterization and structural refinement of polycrystalline uranium substituted zirconolite

International Nuclear Information System (INIS)

Shrivastava, O.P.; Narendra Kumar; Sharma, I.B.

2005-01-01

Ceramic precursors of Zirconolite (CaZrTi 2 O 7 ) family have a remarkable property of substitution Zr 4+ cationic sites. This makes them potential material for nuclear waste management in 'synroc' technology. In order to simulate the mechanism of partial substitution of zirconium by tetravalent actinides, a solid phase of composition CaZr 0.95 U 0.5 Ti 2 O 7 has been synthesized through ceramic route by taking calculated quantities of oxides of Ca, Ti and nitrates of uranium and zirconium respectively. Solid state synthesis has been carried out by repeated pelletizing and sintering the finely powdered oxide mixture in a muffle furnace at 1050 degC. The polycrystalline solid phase has been characterized by its typical powder diffraction pattern. Step analysis data has been used for ab initio calculation of structural parameters. The uranium substituted zirconolite crystallizes in monoclinic symmetry with space group C2/c (15). The following unit cell parameters have been calculated: a =12.4883(15), b =7.2448(5), c 11.3973(10) and β = 100.615(9)0. The structure was refined to satisfactory completion. The Rp and Rwp are found to be 7.48% and 9.74% respectively. (author)

pH dependence of the aqueous dissolution rates of perovskite and zirconolite at 90 C

International Nuclear Information System (INIS)

McGlinn, P.J.; Hart, K.P.; Loi, E.H.; Vance, E.R.

1995-01-01

Perovskite and zirconolite are two of the major phases of the Synroc titanate mineral assemblage. Their aqueous durability under a range of pH conditions at 90 C has been examined. Solution analysis, electron microscopy and X-ray diffraction have been used to investigate the dissolution behavior of these phases, and a perovskite phase doped with Nd, Sr and Al, using buffered solutions at pH levels of 2.1, 3.7, 6.1, 7.9 and 12.9. After 43 days of leaching, Ca and Ti extractions from perovskite and zirconolite show only a weak pH-dependence. SEM investigation of the samples leached at pH 2.1, 6.1 and 12.9 showed that a titanaceous surface layer formed on the perovskite specimens. XRD analysis of the perovskite samples showed that anatase formed on the leached surface at acidic and neutral pHs, but not under alkaline conditions, and that minor amounts of rutile also formed. In the leached perovskite specimens doped with Nd, Sr and Al, no rule was found by XRD and anatase was only detected in the sample leached at pH 2.1. There were no detectable changes in the leached zirconolite samples examined by SEM and XRD

Phase equilibria, leaching characteristics and ceramic processing of SYNROC D formulations for US defense wastes

International Nuclear Information System (INIS)

Newkirk, H.; Ryerson, F.; Coles, D.; Hoenig, C.; Rozsa, R.; Rossington, C.; Bazan, F.; Tewhey, J.

1980-01-01

The assemblage of coexisting phases in SYNROC D is perovskite, zirconolite, nepheline and spinel. Cesium from the supernate is to be immobilized in hollandite. In the current processing scheme, presynthesized granules of hollandite are added to calcined SYNROC D powders prior to hot procesing or sintering. The disposition of inert and radwaste components of Savannah River Plant (SRP) wastes in SYNROC D formulations has been determined by means of optical microscopy, XRD, XRF, SEM, STEM, electron microprobe analysis and autoradiography. A summary of results is presented. Leaching studies of SYNROC D have been done by means of static, high temperature experiments and continuous-flow experiments. The data reported are from high-temperature experiments (distilled water, powdered sample, 150 0 C, one day). The elements reported are the only ones observed in the leachate. Analysis was done by means of XRF. The flowsheet which depicts the current experimental methods that are being employed at LLNL to produce SYNROC D samples containing presynthesized Cs-bearing hollandite is presented. The starting material for SYNROC D (high Fe, high Al and composite compositions) is simulated sludge obtained in 55 gallon quantities from Southwestern Chemical Corporation. Hot pressing temperatures for SYNROC D are 1000 to 1150 0 C. Hot pressing temperatures for hollandite are 1200 to 1400 0 C

Corrosion of a Pu-doped zirconolite-rich ceramic

International Nuclear Information System (INIS)

Bakel, A.J.; Buck, E.C.; Wolf, S.F.; Chamberlain, D.B.; Bates, J.K.; Ebbinghaus, B.B.

1997-01-01

As part of a large Pu disposition program, a zirconolite-rich titanate ceramic is being developed at Lawrence Livermore National Laboratory (LLNL) as a possible immobilization material. This same material is being tested at Argonne National Laboratory (ANL). The goal of this study is to describe the corrosion behavior of this ceramic, particularly the release of Pu and Gd, using results from several static corrosion tests (MCC-1, PCT-A, and PCT-B). The release of relatively large amounts of Al, Ba, and Ca in short-term tests (3 day MCC-1 and 7 day PCT-A) indicates that these elements are released from grain boundaries or from highly soluble phases. Results from long-term (28, 98, and 182 day) PCT-B show that the releases of Al, Ba, and Ca decrease with time, the releases of U and Zr increase with time, and that the releases of Cs, Gd, Mo, and Pu remain fairly constant. Formation of alteration phases may lead to the decrease of Ba and Ca in leachate solutions. Due to the heterogeneous nature of the material, the formation of alteration phases, and the inherently low solubility of several elements, no element(s) could be recommended as good markers for the overall corrosion of this ceramic. Data show that, due to the complex nature of this material, the release of each element should be considered separately

Heavy ion irradiations on synthetic hollandite-type materials: 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)

Tang, Ming, E-mail: mtang@lanl.gov [Materials Science & Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tumurugoti, Priyatham; Clark, Braeden; Sundaram, S.K. [Kazuo Inamori School of Engineering, The New York State College of Ceramics, Alfred University, Alfred, NY 14802 (United States); Amoroso, Jake; Marra, James [Materials Science & Technology Directorate, Savannah River National Laboratory, Aiken, SC 29808 (United States); Sun, Cheng [Materials Science & Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lu, Ping [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Wang, Yongqiang [Materials Science & Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Jiang, Ying-Bing [TEM Laboratory, University of New Mexico, Albuquerque, NM 87131 (United States)

2016-07-15

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 Ba{sub 1.0}Cs{sub 0.3}A{sub 2.3}Ti{sub 5.7}O{sub 16} (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 2.5×10{sup 14} Kr/cm{sup 2} and 5×10{sup 14} Kr/cm{sup 2}. The critical amorphization fluence of single phase hollandite compounds obtained by in situ 1 MeV Kr ion irradiation was around 3.25×10{sup 14} Kr/cm{sup 2}. The hollandite phase exhibited similar amorphization susceptibility under Kr ion irradiation when incorporated into a multiphase system. - Graphical abstract: 600 keV Kr irradiation-induced amorphization on single phase hollandites compounds occurred at a fluence between 2.5×10{sup 14} Kr/cm{sup 2} and 5×10{sup 14} Kr/cm{sup 2}. The hollandite phase exhibited similar amorphization susceptibility under Kr ion irradiation when incorporated into a multiphase system. This is also the first time that the critical amorphization fluence of single phase hollandite compounds were determined at a fluence of around 3.25×10{sup 14} Kr/cm{sup 2} by in situ 1 MeV Kr ion irradiation. Display Omitted.

Structure and chemical durability of barium borosilicate glass–ceramics containing zirconolite and titanite crystalline phases

International Nuclear Information System (INIS)

Li, Huidong; Wu, Lang; Xu, Dong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang

2015-01-01

In order to increase the solubility of actinides in the glass matrix, the effects of CaO, TiO 2 , and ZrSiO 4 addition (abbreviated as CTZ, in the mole ratio of 2:2:1) on crystalline phases, microstructure, and chemical durability of barium borosilicate glass–ceramics were investigated. The results show that the samples possess both zirconolite-2M and titanite phase when the CTZ content is greater than or equal to 45 wt.%. For the glass–ceramics with 45 wt.% CTZ (CTZ-45), only zirconolite-2M phase is observed after annealing at 680–740 °C for 2 h. The CTZ-45 possess zirconolite-2M and titanite phases after annealing at 700 °C first, and then annealing at 900–1050 °C for 2 h. Furthermore, the zirconolite-2M and titanite grains show a strip and brick shape, respectively. The CTZ-45 annealing at 950 °C shows the lower normalized leaching rates of B, Na and Nd when compared to that of CTZ-0 and CTZ-55. - Highlights: • CaO, TiO 2 , ZrSiO 4 (CTZ) as nucleating agents were added to barium borosilicate glass. • The samples with 45–55 wt% CTZ possess CaZrTi 2 O 7 -2M and CaTiSiO 5 crystalline phases. • CTZ-45 (45wt% CTZ) possesses only CaZrTi 2 O 7 -2M phase after annealing at 680–740 °C. • CTZ-45 possesses CaZrTi 2 O 7 -2M and CaTiSiO 5 phases after annealing at 900–1050 °C. • CTZ-45 annealing at 950 °C shows the lower leaching rates of B, Na and Nd than CTZ-0 and CTZ-55.

Hollandit a kryptomelan z Poniklé u Jilemnice, Česká republika

Czech Academy of Sciences Publication Activity Database

Jirásek, J.; Matýsek, D.; Vaculíková, Lenka; Sivek, M.

-, č. 23 (2015), s. 1-6 ISSN 1211-0329 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : hollandite supergroup * coronadite group * mineralogy * infrared spectroscopy * Poniklá Group Subject RIV: DB - Geology ; Mineralogy http://www.nm.cz/publikace/archiv.php?id=13

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

Self-propagating synthesis and aqueous durability of Nd-bearing zirconolite-rich composites using Ca(NO{sub 3}){sub 2} as the oxidant

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kuibao, E-mail: xiaobao320@163.com [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); National Defense Key Discipline Lab of Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010 (China); He, Shihong [State Nuclear Power Research Institute, Beijing 100029 (China); Yin, Dan; Peng, Le; Wu, Jingjun [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China)

2016-09-15

Synroc is recognized as the second-generation waste form for safety disposal of high-level radioactive waste (HLW). In this study, zirconolite-rich Synroc waste form was readily synthesized by self-propagating high-temperature plus quick pressing (SHS/QP) using Ca(NO{sub 3}){sub 2} as the oxidant and Ti as the reductant. As the surrogate of trivalent actinides, Nd{sub 2}O{sub 3} was introduced to equally substitute the Ca and Zr sites of zirconolite with nominal stoichiometry of Ca{sub 1−x}Zr{sub 1−x}Nd{sub 2x}Ti{sub 2}O{sub 7}. The results demonstrate that zirconolite, perovskite and pyrochlore (Ca{sub 2}Ti{sub 2}O{sub 6}) coexist as the ceramic components after SHS reaction. The introduction of Nd{sub 2}O{sub 3} promotes the formation of perovskite. Nd is mostly incorporated into the Ca sites of these phases. The normalized elemental leaching rates of Ca and Nd are fairly constant in low values of 1.80 × 10{sup −2} g m{sup −2} d{sup −1} and 6.12 × 10{sup −4} g m{sup −2} d{sup −1} after 42 days. - Highlights: • Zirconolite-rich composite was synthesized by SHS using Ca(NO{sub 3}){sub 2} as the oxidant. • Nd{sub 2}O{sub 3} was successfully immobilized into the crystal structure of this waste form. • Nd was mostly incorporated into the Ca sites of zirconolite, perovskite and pyrochlore. • The normalized leaching rates of Ca and Nd are in relatively low values.

An Electrochemical Sensor Based on Nanostructured Hollandite-type Manganese Oxide for Detection of Potassium Ions

Directory of Open Access Journals (Sweden)

Alex S. Lima

2009-08-01

Full Text Available The participation of cations in redox reactions of manganese oxides provides an opportunity for development of chemical sensors for non-electroactive ions. A sensor based on a nanostructured hollandite-type manganese oxide was investigated for voltammetric detection of potassium ions. The detection is based on the measurement of anodic current generated by oxidation of Mn(III to Mn(IV at the surface of the electrode and the subsequent extraction of the potassium ions into the hollandite structure. In this work, an amperometric procedure at an operating potential of 0.80 V (versus SCE is exploited for amperometric monitoring. The current signals are linearly proportional to potassium ion concentration in the range 4.97 × 10−5 to 9.05 × 10−4 mol L−1, with a correlation coefficient of 0.9997.

Fibers and cylinders of cryptomelane-hollandite in Permian bedded salt, Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Belkin, H.E.; Libelo, E.L.

1987-01-01

Fibers and thin-walled, hollow cylinders of cryptomelane-hollandite have been found in both the chevron and the clear salt from various drill cores in Permian bedded salt from the Palo Duro Basin, Texas. The authors have found fibers or cylinders from only the lower San Andres Formation units 4 and 5, the upper San Andres Formation, and the Salado-Transill salt. The fibers are inorganic, light to dark reddish brown, pleochroic, highly birefringent, filamentary single crystals, < 1 to ∼ 5 μm in diameter, with length-to-diameter ratios of at least 20:1. The fibers can be straight and/or curved, can bifurcate, can form loops, waves or spirals, and can be isolated or in parallel groups. Detailed petrographic analyses show no evidence for recrystallization or deformation of the enclosing salt after fiber formation. Although the authors observations do not provide a definitive explanation for fiber origin, they suggest that the fibers grew in situ by a solid-state diffusional process at low temperatures. The cylinders are pleochroic, highly birefringent, light to dark reddish brown, hollow, thin-walled, open-ended right cylinders, having a 1- to 2-μm wall thickness and variable lengths and diameters. There also appear to be single crystals of cryptomelane-hollandite, but these are found almost entirely in fluid inclusions in the chevron and clear salt. Their presence in the primary halite suggests that they were formed contemporaneously with the chevron structure and were accidentally trapped in the fluid inclusions. The observation of cylinders partially or completely enclosed by salt stratigraphically above large fluid inclusions suggests that natural downward fluid-inclusion migration has occurred, in response to the geothermal gradient

The CaO-TiO2-ZrO2 system at 1,200 degree C and the solubilities of Hf and Gd in zirconolite

International Nuclear Information System (INIS)

Swenson, D.; Nieh, T.G.; Fournelle, J.H.

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 2 -ZrO 2 system is an integral part of the Synroc formulation. Phase equilibria are established in the CaO-TiO 2 -ZrO 2 system at 1,200 C, using X-ray diffraction and electron probe microanalysis. The existence of two previously reported ternary phases, zirconolite (CaZrTi 2 O 7 ) and calzirtite (Ca 2 Zr 5 Ti 2 O 16 ), is confirmed. Each of these phases exhibits a significant range of homogeneity between TiO 2 and ZrO 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 2 O 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 0.88 Zr 0.88 Gd 9.24 Ti 2 O 7 is found to be essentially single phase zirconolite, in agreement with previous investigations at higher temperatures

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

Synthesis and characterisation of the hollandite solid solution Ba1.2-xCsxFe2.4-xTi5.6+xO16 for partitioning and conditioning of radiocaesium

Science.gov (United States)

Bailey, Daniel J.; Stennett, Martin C.; Mason, Amber R.; Hyatt, Neil C.

2018-05-01

The geological disposal of high level radioactive waste requires careful budgeting of the heat load produced by radiogenic decay. Removal of high-heat generating radionuclides, such as 137Cs, reduces the heat load in the repository allowing the remaining high level waste to be packed closer together therefore reducing demand for repository space and the cost of the disposal of the remaining wastes. Hollandites have been proposed as a possible host matrix for the long-term disposal of Cs separated from HLW raffinate. The incorporation of Cs into the hollandite phase is aided by substitution of cations on the B-site of the hollandite structure, including iron. A range of Cs containing iron hollandites were synthesised via an alkoxide-nitrate route and the structural environment of Fe in the resultant material characterised by Mössbauer and X-ray Absorption Near Edge Spectroscopy. The results of spectroscopic analysis found that Fe was present as octahedrally co-ordinated Fe (III) in all cases and acts as an effective charge compensator over a wide solid solution range.

(Alpha, gamma) irradiation effect on the alteration of high-level radioactive wastes matrices (UO2, hollandite, glass SON68)

International Nuclear Information System (INIS)

Suzuki, T.

2007-06-01

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 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 2 colloids in aqueous carbonate media have enabled to distinguish between the oxidation of UO 2 matrix as initial and dissolution as subsequent step. The simultaneous presence of carbonate and H 2 O 2 (product resulting from water radiolysis) increased the dissolution rate of UO 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)

Sintering, microstructural and dilatometric studies of combustion synthesized Synroc phases

International Nuclear Information System (INIS)

Muthuraman, M.; Patil, K.C.; Senbagaraman, S.; Umarji, A.M.

1996-01-01

Sintering, microstructure, and linear thermal expansion properties of Synroc-B and constituent phases, viz. perovskite CaTiO 3 , zirconolite ZrTi 2 O 7 , hollandite (ideal formula BaAl2Ti 6 O 16 ) have been investigated. Synroc-B powder when pelletized and sintered at 1250 C for 2 h achieved >95% theoretical density. Sintered Synroc-B has a linear thermal expansion coefficient α of 8.72 x 10 -6 K -1 and Vicker's microhardness 9.88 GPa. The linear thermal expansion curves did not show any hysteresis indicating the absence of microcracking in the sintered bodies

Structural Defects of Silver Hollandite, Ag(x)Mn8O(y), Nanorods: Dramatic Impact on Electrochemistry.

Science.gov (United States)

Wu, Lijun; Xu, Feng; Zhu, Yimei; Brady, Alexander B; Huang, Jianping; Durham, Jessica L; Dooryhee, Eric; Marschilok, Amy C; Takeuchi, Esther S; Takeuchi, Kenneth J

2015-08-25

Hollandites (OMS-2) are an intriguing class of sorbents, catalysts, and energy storage materials with a tunnel structure permitting one-dimensional insertion and deinsertion of ions and small molecules along the c direction. A 7-fold increase in delivered capacity for Li/AgxMn8O16 electrochemical cells (160 versus 23 mAh/g) observed upon a seemingly small change in silver content (x ∼1.1 (L-Ag-OMS-2) and 1.6 (H-Ag-OMS-2)) led us to characterize the structure and defects of the silver hollandite material. Herein, Ag hollandite nanorods are studied through the combined use of local (atomic imaging, electron diffraction, electron energy-loss spectroscopy) and bulk (synchrotron based X-ray diffraction, thermogravimetric analysis) techniques. Selected area diffraction and high resolution transmission electron microscopy show a structure consistent with that refined by XRD; however, the Ag occupancy varies significantly even within neighboring channels. Both local and bulk measurements indicate a greater quantity of oxygen vacancies in L-Ag-OMS-2, resulting in lower average Mn valence relative to H-Ag-OMS-2. Electron energy loss spectroscopy shows a lower Mn oxidation state on the surface relative to the interior of the nanorods, where the average Mn valence is approximately Mn(3.7+) for H-Ag-OMS-2 and Mn(3.5+) for L-Ag-OMS-2 nanorods, respectively. The higher delivered capacity of L-Ag-OMS-2 may be related to more oxygen vacancies compared to H-Ag-OMS-2. Thus, the oxygen vacancies and MnO6 octahedra distortion are assumed to open the MnO6 octahedra walls, facilitating Li diffusion in the ab plane. These results indicate crystallite size and surface defects are significant factors affecting battery performance.

Crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics for immobilization of simulated sulfate bearing high-level liquid waste

Science.gov (United States)

Wu, Lang; Xiao, Jizong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang; Liao, Qilong

2018-01-01

The crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics with different content (0-30 wt %) of simulated sulfate bearing high-level liquid waste (HLLW) were evaluated. The sulfate phase segregation in vitrification process was also investigated. The results show that the glass-ceramics with 0-20 wt% of HLLW possess mainly zirconolite phase along with a small amount baddeleyite phase. The amount of perovskite crystals increases while the amount of zirconolite crystals decreases when the HLLW content increases from 20 to 30 wt%. For the samples with 20-30 wt% HLLW, yellow phase was observed during the vitrification process and it disappeared after melting at 1150 °C for 2 h. The viscosity of the sample with 16 wt% HLLW (HLLW-16) is about 27 dPa·s at 1150 °C. The addition of a certain amount (≤20 wt %) of HLLW has no significant change on the aqueous stability of glass-ceramic waste forms. After 28 days, the 90 °C PCT-type normalized leaching rates of Na, B, Si, and La of the sample HLLW-16 are 7.23 × 10-3, 1.57 × 10-3, 8.06 × 10-4, and 1.23 × 10-4 g·m-2·d-1, respectively.

(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)

Partitioning and Leaching Behavior of Actinides and Rare Earth Elements in a Zirconolite- Bearing Hydrothermal Vein System

International Nuclear Information System (INIS)

Payne, Timothy E.; Hart, Kaye P.; Lumpkin, Gregory R.; McGlinn, Peter J.; Giere, Reto

2007-01-01

Chemical extraction techniques and scanning electron microscopy were used to study the distribution and behavior of actinides and rare earth elements (REE) in hydrothermal veins at Adamello (Italy). The six samples discussed in this paper were from the phlogopite zone, which is one of the major vein zones. The samples were similar in their bulk chemical composition, mineralogy, and leaching behavior of major elements (determined by extraction with 9 M HCl). However, there were major differences in the extractability of REE and actinides. The most significant influence on the leaching characteristics appears to be the amounts of U, Th and REE incorporated in resistant host phases (zirconolite and titanite) rather than readily leached phases (such as apatite). Uranium and Th are very highly enriched in zirconolite grains. Actinides were more readily leached from samples with a higher content of U and Th, relative to the amount of zirconium. The results show that REE and actinides present in chemically resistant host minerals can be retained under aggressive leaching conditions. (authors)

Research On Stabilization Of Radioactive Waste By Method Of SYNROCK Ceramic

International Nuclear Information System (INIS)

Nguyen Hoang Lan; Nguyen Ba Tien; Vuong Huu Anh; Nguyen An Thai

2014-01-01

Separate phases from SYNROC polyphases ceramic were investigated to fabricate completely SYNROC and the distribution of stable isotopes (Sr) in SYNROC matrix was surveyed simultaneously with leaching test. The experimental conditions: 13.5 x 11mm pressed pellet SYNROC with pressure of 2.5 - 3 tons/cm 2 , sintering temperature t tk = 1250 o C, thermal lifting velocity v t = 20 o C/min with 2 hours prolongation in 1250 o C, Sr loading amount was 7% mole, the results showed that pellets contain 3 phases perovskite CaTiO 3 , zirconolite CaZrTi 2 O 7 , hollandite BaAl 2 Ti 6 O 16 with average density of 4.1 g/cm 3 , leaching rate R (g/m 2 .d) of 10 -6 , 10 -5 for Ti, Sr respectively. (author)

Reactive spark plasma synthesis of CaZrTi2O7 zirconolite ceramics for plutonium disposition

Science.gov (United States)

Sun, Shi-Kuan; Stennett, Martin C.; Corkhill, Claire L.; Hyatt, Neil C.

2018-03-01

Near single phase zirconolite ceramics, prototypically CaZrTi2O7, were fabricated by reactive spark plasma sintering (RSPS), from commercially available CaTiO3, ZrO2 and TiO2 reagents, after processing at 1200 °C for only 1 h. Ceramics were of theoretical density and formed with a controlled mean grain size of 1.9 ± 0.6 μm. The reducing conditions of RSPS afforded the presence of paramagnetic Ti3+, as demonstrated by EPR spectroscopy. Overall, this study demonstrates the potential for RSPS to be a disruptive technology for disposition of surplus separated plutonium stockpiles in ceramic wasteforms, given its inherent advantage of near net shape products and rapid throughput.

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.

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

Energy Technology Data Exchange (ETDEWEB)

Amoroso, Jake W., E-mail: jake.amoroso@srnl.doe.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Marra, James; Dandeneau, Christopher S. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Brinkman, Kyle; Xu, Yun [Clemson University, Clemson, SC 29634 (United States); Tang, Ming [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Maio, Vince [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Webb, Samuel M. [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94086 (United States); Chiu, Wilson K.S. [University of Connecticut, Storrs, Connecticut 06269-3139 (United States)

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.

Evaluation of the technical feasibility of new conditioning matrices for long-lived radionuclides

International Nuclear Information System (INIS)

Deschanels, X.

2004-01-01

Several matrices have been selected for the conditioning of long-lived radioactive wastes: a compound made of a iodo-apatite core coated with a densified matrice of vanadium-phosphorus-lead apatite for iodine; the hollandite ceramic for cesium; the britholite, zirconolite, thorium phosphate diphosphate, and the monazite-brabantite solid solution for minor actinides; and a Nb-based metal alloy and phosphate or titanate-type ceramics for technetium. This report presents the results of the researches carried out between 2002-2004 during the technical feasibility step. The main points described are: - the behaviour of matrices under irradiation. These studies were performed thanks to an approach combining the characterization of natural analogues, the doping of matrices with short-lived radionuclides and the use of external irradiations; - the behaviour of these matrices with respect to water alteration; - the sensibility of these structures with respect to the incorporation of chemical impurities; - a package-process approach including the optimization of the process and preliminary studies about the package concept retained. These studies show that important work remains to be done to develop conditioning matrices suitable for iodine and technetium, while for cesium and minor actinides, the first steps of the technical feasibility are made. However, it remains impossible today to determine the structure having the best global behaviour. (J.S.)

Solution chemistry techniques in SYNROC preparation

International Nuclear Information System (INIS)

Dosch, R.G.; Lynch, A.W.

1981-07-01

Investigations of titanate-based ceramic forms for radioactive waste immobilization are underway at Sandia National Laboratories (SNLA) and at Lawrence Livermore National Laboratory (LLNL). Although the waste forms differ as to overall product composition, the waste-containing phases in both ceramic products have similar crystalline structure types. These include metallic phases along with oxides with structure types of the mineral analogues perovskite, zirconolite, and hollandite. Significant differences also exist in the area of processing. More conventional ceramic processing methods are used at LLNL to produce SYNROC while solution chemistry techniques involving metal alkoxide chemistry and ion exchange have been developed at SNLA to prepare calcium titanate-based waste ceramics. The SNLA techniques were recently modified and applied to producing SYNROC (compositions C and D) as part of an interlaboratory information exchange between SNLA and LLNL. This report describes the methods used in preparing SYNROC including the solution interaction, and hot-pressing methods used to obtain fully dense SYNROC monoliths

Radiophase development in hot-pressed alkoxide-derived titanate ceramics for nuclear waste stabilization

International Nuclear Information System (INIS)

Dickson, F.J.; Mitamura, H.; White, T.J.

1989-01-01

This paper reports phase development as a function of hot-pressing temperature studied in alkoxide-derived titanate-based ceramics doped with a 10 wt% loading of a sodium-rich (NAR) and a sodium-poor (NAP) simulated high-level waste. Pyrochlore was found to be the most abundant phase in both calcine powders. A pseudobrookite phase existed metastably at hot-pressing temperatures between 890 degrees and 920 degrees C. After hot-pressing at 1100 degrees C, the final phase assemblage for the NAP material consisted of zirconolite, hollandite-type, perovskite, alloy, and reduced rutile (Magneli phases). In addition, NAR samples contained hibonite, freudenbergite, and loveringite. Phase development was driven to completion over a very narrow temperature range (≤50 degrees C), beginning at 870 degrees and 850 degrees C for NAP and NAR, respectively, although full densification was not achieved below 1100 degrees C. Both waste forms exhibited comparable microstructure and aqueous durability

Improving iron-enriched basalt with additions of ZrO2 and TiO2

International Nuclear Information System (INIS)

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 2 and TiO 2 to develop crystals of zirconolite upon cooling, in addition to the crystals that normally form in a cooling basalt. Zirconolite (CaZrTi 2 O 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 2 and TiO 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

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.

Thermal durability of modified Synroc material as reactor fuel matrix

International Nuclear Information System (INIS)

Kikuchi, Akira; Kanazawa, Hiroyuki; Togashi, Yoshihiro; Matumoto, Seiichiro; Nishino, Yasuharu; Ohwada, Isao; Nakata, Masahito; Amano, Hidetoshi; Mitamura, Hisayoshi

1994-08-01

A Synroc, a polyphase titanate ceramics composed of three mineral phases (perovskite, hollandite and zirconolite), has an excellent performance of immobilization of high level nuclear waste. A working group in the Department of Hot Laboratories paid special attention to this merit and started a development study on a LWR fuel named 'Waste Disposal Possible (WDP) Fuel', which has the two functions of a reactor fuel and a waste form. The present paper mainly describes thermal durability of a modified Synroc material, which is essentially important for applying the material to a fuel matrix. The two kinds of Synroc specimens, designated 'SM' as modified and 'SB' as a reference, were prepared by hot-pressing and annealed at 1200degC to 1500degC for 30 min in air. Unexpected and peculiar spherical voids were observed in the specimen SM at 1400degC and 1500degC, which caused the specimen swelling. The formation of the voids depends significantly on the existence of spherical precipitates seen in the as-fabricated specimen including latent micropores with high pressure. On the other hand, the heat treatment at 1500degC formed additional new phases, designated 'Phase A' for the specimen SB and 'Phase X' for SM. Phase A is a decomposition product of hollandite and Phase X a reaction product of Phase A and perovskite in the spherical voids. Furthermore, additional information and thermal properties examined are presented in Appendix 1 and Appendix 2, respectively. It was recognized that the modified Synroc specimen SM had excellent thermal properties. (author)

Status of plutonium ceramic immobilization processes and immobilization forms

International Nuclear Information System (INIS)

Ebbinghaus, B.B.; Van Konynenburg, R.A.; Vance, E.R.; Jostsons, A.

1996-01-01

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 ampersand 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 2 O 7 ), the desired actinide host phase, with lesser amounts of hollandite (BaAl 2 Ti 6 O 16 ) and rutile (TiO 2 ). Alternative actinide host phases are also being considered. These include pyrochlore (Gd 2 Ti 2 O 7 ), zircon (ZrSiO 4 ), and monazite (CePO 4 ), to name a few of the most promising. R ampersand D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO 2 powder, cold press and sinter fabrication methods, and immobilization form formulation issues

Use of linear free energy relationship to predict Gibbs free energies of formation of zirconolite phases (MZrTi2O7 and MHfTi2O7)

International Nuclear Information System (INIS)

Xu, H.

1999-01-01

In this letter, the Sverjensky-Molling equation derived from a linear free energy relationship is used to calculate the Gibbs free energies of formation of zirconolite crystalline phases (MZrTi 2 O 7 and MHfTi 2 O 7 ) from the known thermodynamic properties of the corresponding aqueous divalent cations (M 2+ ). Sverjensky-Molling equation is expressed as ΔG 0 f,M v X =a M v X ΔG 0 n,M 2+ +b M v X +β M v X r M 2+ , where the coefficients a M v X , b M v X , and β M v X characterize a particular structural family of M v X, r M 2+ is the ionic radius of M 2+ cation, ΔG f,M v X 0 is the standard Gibbs free energy of formation of M v X, and ΔG 0 n,M 2+ is the standard non-solvation energy of cation M 2+ . This relationship can be used to predict the Gibbs free energies of formation of various fictive phases (such as BaZrTi 2 O 7 , SrZrTi 2 O 7 , PbZrTi 2 O 7 , etc.) that may form solid solution with CaZrTi 2 O 7 in actual Synroc-based nuclear waste forms. Based on obtained linear free energy relationships, it is predicted that large cations (e.g., Ba and Ra) prefer to be in perovskite structure, and small cations (e.g., Ca, Zn, and Cd) prefer to be in zirconolite structure. (orig.)

Novel monoclinic zirconolite in Bi2O3–CuO–Ta2O5 ternary system: Phase equilibria, structural and electrical properties

International Nuclear Information System (INIS)

Tan, K.B.; Chon, M.P.; Khaw, C.C.; Zainal, Z.; Taufiq Yap, Y.H.; Tan, P.Y.

2014-01-01

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 1.92 Cu 0.08 (Cu 0.3 Ta 0.7 ) 2 O 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 gb = 6.63 × 10 −9 F cm −1 and a bulk response capacitance, C b = 6.74 × 10 −12 F cm −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

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.

Perovskite as a matrix for incorporation of long-lived radionuclides

International Nuclear Information System (INIS)

Chernyavskaya, N.E.; Ochkin, A.V.; Chizhevskaya, S.V.; Stefanovskij, S.V.

1998-01-01

SYNROC is titanate ceramics consisting mainly of zirconolite, perovskite, and hollandite, developed to immobilize high level waste. Perovskite is able to incorporate strontium, yttrium, and trivalent lanthanides and actinides. The main goal of the present work is leaching study of various radionuclides from perovskite. Samples of perovskite-rich ceramics were produced by cold pressing of oxide mixture followed by firing in resistive furnace at 1350 degC for 3 hours. For leaching tests, ceramic pellets were crushed and surface areas were measured using argon thermal desorption technique. Leach rate was measured by boiling in a Soxhlet apparatus for 5 hours. Leach rates in 0.1 M HNO 3 and NaCl solutions were measured by boiling with stirrer and reverse cooler. Leach rate was controlled with radioactive indicator technique. Density of the perovskite-rich ceramic samples prepared was about 75% of theoretical. From XRD examination, the target phase (perovskite) yield was found to be about 95 vol.%. Minor rutile (≤ 5 vol.%) was also present. Leach rate of 90 Sr from Sr-doped perovskites with specified composition Ca 1-x Sr x TiO 3 did not depend on x until certain x value. Leach rate of 90 Sr from control zirconolite sample was by one order of magnitude higher than from perovskite. Leach rates of 147 Pm, 238 Pu, and 241 Am from perovskite ceramics with nominal perovskite composition had the same order of magnitude (about 10 -4 g/(m 2 day)). Substitution of 5 at.% Ce for Ca and 5 at.% Al for Ti lowered leach rate of 238 Pu by a factor of 6. Leach rates of 90 Sr in 0.1 M HNO 3 and NaCl solutions were three and one orders of magnitude higher than in distilled water

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.

Application of SYNROC to high-level defense wastes

International Nuclear Information System (INIS)

Tewhey, J.D.; Hoenig, C.L.; Newkirk, H.W.; Rozsa, R.B.; Coles, D.G.; Ryerson, F.J.

1981-01-01

The SYNROC method for immobilization of high-level nuclear reactor wastes is currently being applied to US defense wastes in tank storage at Savannah River, South Carolina. The minerals zirconolite, perovskite, and hollandite are used in SYNROC D formulations to immobilize fission products and actinides that comprise up to 10% of defense waste sludges and coexisting solutions. Additional phase in SYNROC D are nepheline, the host phase for sodium; and spinel, the host for excess aluminum and iron. Up to 70 wt % of calcined sludge can be incorporated with 30 wt % of SYNROC additives to produce a waste form consisting of 10% nepheline, 30% spinel, and approximately 20% each of the radioactive waste-bearing phases. Urea coprecipitation and spray drying/calcining methods have been used in the laboratory to produce homogeneous, reactive ceramic powders. Hot pressing and sintering at temperatures from 1000 to 1100 0 C result in waste form products with greater than 97% of theoretical density. Hot isostatic pressing has recently been implemented as a processing alternative. Characterization of waste-form mineralogy has been done by means of XRD, SEM, and electron microprobe. Leaching of SYNROC D samples is currently being carried out. Assessment of radiation damage effects and physical properties of SYNROC D will commence in FY81

Synthesis of hollandite-type LixMnO2 by Li+ ion-exchange in molten salt and lithium insertion characteristics

International Nuclear Information System (INIS)

Kadoma, Yoshihiro; Oshitari, Satoru; Ui, Koichi; Kumagai, Naoaki

2007-01-01

The Li + ion-exchange reaction of K + -type α-K 0.14 MnO 1.93 .nH 2 O containing different amounts of water molecules (n = 0-0.15) with a large (2 x 2) tunnel structure has been investigated in a LiNO 3 -LiCl molten salt at 300 deg. C. The Li + ion-exchanged products were examined by chemical analysis, X-ray diffraction, and transmission electron microscopy measurements. The K + ions and the hydrogens of the water molecules in the (2 x 2) tunnels of α-MnO 2 were exchanged by Li + ions in the molten salt, resulting in the Li + -type α-MnO 2 containing different amounts of Li + ions and lithium oxide (Li 2 O) in the (2 x 2) tunnels with maintaining the original hollandite structure. The electrochemical properties and structural variation with initial discharge and charge-discharge cycling of the Li + ion-exchanged α-MnO 2 samples have been investigated as insertion compounds in the search for new cathode materials for rechargeable lithium batteries. The Li + ion-exchanged α-MnO 2 samples provided higher capacities and higher Li + ion diffusivity than the parent K + -type materials on initial discharge and charge-discharge cyclings, probably due to the structural stabilization with the existence of Li 2 O in the (2 x 2) tunnels

The influence of glass composition on crystalline phase stability in glass-ceramic wasteforms

International Nuclear Information System (INIS)

Maddrell, Ewan; Thornber, Stephanie; Hyatt, Neil C.

2015-01-01

Highlights: • Crystalline phase formation shown to depend on glass matrix composition. • Zirconolite forms as the sole crystalline phase only for most aluminous glasses. • Thermodynamics indicate that low silica activity glasses stabilise zirconolite. - Abstract: Zirconolite glass-ceramic wasteforms were prepared using a suite of Na 2 O–Al 2 O 3 –B 2 O 3 –SiO 2 glass matrices with variable Al:B ratios. Zirconolite was the dominant crystalline phase only for the most alumina rich glass compositions. As the Al:B ratio decreased zirconolite was replaced by sphene, zircon and rutile. Thermodynamic data were used to calculate a silica activity in the glass melt below which zirconolite is the favoured crystalline phase. The concept of the crystalline reference state of glass melts is then utilised to provide a physical basis for why silica activity varies with the Al:B ratio

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.

2017-09-01

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.

Study of the mixed ferrite Basub(x)Tisub(4-2x)Fesub(2x)Osub(8) (x=0.65) with hollandite structure by electrical, magnetic and Moessbauer effect measurements

International Nuclear Information System (INIS)

Abbas, Y.; Ahmed, M.A.

1982-01-01

Mixed ferrite Basub(x)Tisub(4-2x)Fesub(2x)Osub(8) with hollandite structure has been studies by electrical, magnetic and Moessbauer effect measurements. Electrical measurements show a semiconducting behaviour and a triclinic phase transition at about 455 K. Susceptibility data show that the compound is paramagnetic in the range 80-300 K and can be interpreted in terms of Curie-Weiss behaviour above about 200 K yielding the parameters usub(eff)5.95B.M. and Osub(p)-320 K. The susceptibility curve shows eveidence for an important ferromagnetic component due to the short range interactions preceeding the antiferromagnetic ordering and leads to the conclusion of the existance of spin canting magnetic ordering at Tsub(N)80 K. The values of the chemical shift 0.43mm/sec and quadrupole splitting 0.44mm/sec are typical of high spin Fesup(Fe 3+ ) in distorted octahedral coordination

Untitled

Indian Academy of Sciences (India)

derived zirconolite and sphene could be due to the large surface area and the fine particle nature of the combustion products. 4. Conclusion. The solution combustion process has been used successfully to prepare reactive oxide materials, which can be used for nuclear waste immobilization. The sintering of sphene and ...

A state-of-the-art report on the formulation and characterization of synroc

International Nuclear Information System (INIS)

Jung, C. H.; Park, J. Y.; Oh, S. J.; Kim, H. Y.; Kim, I. T.

1998-09-01

Synroc (Synthetic Rock), a titanate-based ceramic originally proposed by Prof. A. Ringwood (ANU) and designed for the immobilization of high level nuclear waste (HLW), consists of three principal phases such as hollandite, zirconolite and perovskite. Nearly all the fission products and actinides in HLW can be incorporated as solid-solution in at least one of these phase. The preferred form of Synroc can be obtained up to 20 % of high level waste calcine to form dilute solid solution. The constituent minerals, or close structural analogues, have survived in a wide range of geochemical environments for periods of 20-2000 Myr while immobilizing the same elements present in nuclear waste. A dense, compact, and mechanically strong form of Synroc can be formed by hot pressing reactive precursor powders at about 1200 dg C and 20 MPa. In this state-of-the-art report, formulation method and characterization of Syroc with respect to the crystal structure, the consisting substances, types, etc. were reviewed. Additionally, a new promising powder process, C ombustion Process , was proposed and the properties of the combustion-synthesized powder were described. An international cooperative program between JAERI and ANSTO, and US patents for early Synroc research in Australia were also introduced. From the literatures review, Synroc is expected to have advantages in using as an immobilizer of HLW. Therefore, a systematic research to develop the Synroc is needed. (author). 53 refs., 2 tabs., 16 figs

What fits best minor actinides as a die material?

International Nuclear Information System (INIS)

Hinfray, J.

2003-01-01

Zirconolite might be the die material used to confine actinides definitively. Cea's teams have been investigating the ability of zirconolite to trap actinide atoms in its own crystal structure. These studies have been performed with 239 Pu that presents the same ability to set chemical links with the constituents of the die as 3 minor actinides do. Crystal materials like zirconolite are more sensitive to self irradiation than glass. The next step of the characterization of zirconolite is to evaluate its capacity to sustain self alpha irradiation. In order to do so, 238 Pu is used since its relatively short period (T = 87 years) allows an acceleration of the process : damages cumulated in the die material in 2 years will be equivalent to those produced by minor actinides for millions years. The results will be known in 2004. (A.C.)

Octahedral molecular sieve sorbents and catalysts

Science.gov (United States)

Li, Liyu [Richland, WA; King, David L [Richland, WA

2010-04-20

Octahedral molecular sieve sorbents and catalysts are disclosed, including silver hollandite and cryptomelane. These materials can be used, for example, to catalyze the oxidation of CO.sub.x (e.g., CO), NO.sub.x (e.g., NO), hydrocarbons (e.g., C.sub.3H.sub.6) and/or sulfur-containing compounds. The disclosed materials also may be used to catalyze other reactions, such as the reduction of NO.sub.2. In some cases, the disclosed materials are capable of sorbing certain products from the reactions they catalyze. Silver hollandite, in particular, can be used to remove a substantial portion of certain sulfur-containing compounds from a gas or liquid by catalysis and/or sorption. The gas or liquid can be, for example, natural gas or a liquid hydrocarbon.

Novel waste forms for HLW and ILW immobilisation

International Nuclear Information System (INIS)

Lee, William E.; Milestone, Neil B.; Ojovan, Michael I.; Hyatt, Neil C.; Stennett, Martin C.; Setiadi, Anthony; Zhou, Qizhi

2006-01-01

The complex nature and heterogeneity of legacy wastes means that a toolbox of different host systems must be developed in which to immobilize them. New zirconolite ceramic, glass composite materials and novel cement systems including calcium sulpho aluminate cements and alkali activated slags being examined in the Immobilisation Science Laboratory at the University of Sheffield are described. (authors)

Glass-ceramic nuclear waste forms obtained by crystallization of SiO 2-Al 2O 3-CaO-ZrO 2-TiO 2 glasses containing lanthanides (Ce, Nd, Eu, Gd, Yb) and actinides (Th): Study of the crystallization from the surface

Science.gov (United States)

Loiseau, P.; Caurant, D.

2010-07-01

Glass-ceramic materials containing zirconolite (nominally CaZrTi 2O 7) crystals in their bulk can be envisaged as potential waste forms for minor actinides (Np, Am, Cm) and Pu immobilization. In this study such matrices are synthesized by crystallization of SiO 2-Al 2O 3-CaO-ZrO 2-TiO 2 glasses containing lanthanides (Ce, Nd, Eu, Gd, Yb) and actinides (Th) as surrogates. A thin partially crystallized layer containing titanite and anorthite (nominally CaTiSiO 5 and CaAl 2Si 2O 8, respectively) growing from glass surface is also observed. The effect of the nature and concentration of surrogates on the structure, the microstructure and the composition of the crystals formed in the surface layer is presented in this paper. Titanite is the only crystalline phase able to significantly incorporate trivalent lanthanides whereas ThO 2 precipitates in the layer. The crystal growth thermal treatment duration (2-300 h) at high temperature (1050-1200 °C) is shown to strongly affect glass-ceramics microstructure. For the system studied in this paper, it appears that zirconolite is not thermodynamically stable in comparison with titanite growing form glass surface. Nevertheless, for kinetic reasons, such transformation (i.e. zirconolite disappearance to the benefit of titanite) is not expected to occur during interim storage and disposal of the glass-ceramic waste forms because their temperature will never exceed a few hundred degrees.

Formulation and synthesis by melting process of titanate enriched glass-ceramics and ceramics

International Nuclear Information System (INIS)

Advocat, T.; Fillet, C.; Lacombe, J.; Bonnetier, A.; McGlinn, P.

1999-01-01

The main objective of this work is to provide containment for the separated radionuclides in stable oxide phases with proven resistance to leaching and irradiation damage and in consequence to obtain a glass ceramic or a ceramic material using a vitrification process. Sphene glass ceramic, zirconolite glass ceramic and zirconolite enriched ceramic have been fabricated and characterized by XRD, SEM/EDX and DTA

Tunnel-Structured KxTiO2 Nanorods by in Situ Carbothermal Reduction as a Long Cycle and High Rate Anode for Sodium-Ion Batteries.

Science.gov (United States)

Zhang, Qing; Wei, Yaqing; Yang, Haotian; Su, Dong; Ma, Ying; Li, Huiqiao; Zhai, Tianyou

2017-03-01

The low electronic conductivity and the sluggish sodium-ion diffusion in the compact crystal structure of Ti-based anodes seriously restrict their development in sodium-ion batteries. In this study, a new hollandite K x TiO 2 with large (2 × 2) tunnels is synthesized by a facile carbothermal reduction method, and its sodium storage performance is investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses illustrate the formation mechanism of the hollandite K x TiO 2 upon the carbothermal reduction process. Compared to the traditional layered or small (1 × 1) tunnel-type Ti-based materials, the hollandite K x TiO 2 with large (2 × 2) tunnels may accommodate more sodium ions and facilitate the Na + diffusion in the structure; thus, it is expected to get a large capacity and realize high rate capability. The synthesized K x TiO 2 with large (2 × 2) tunnels shows a stable reversible capacity of 131 mAh g -1 (nearly 3 times of (1 × 1) tunnel-structured Na 2 Ti 6 O 13 ) and superior cycling stability with no obvious capacity decay even after 1000 cycles, which is significantly better than the traditional layered Na 2 Ti 3 O 7 (only 40% of capacity retention in 20 cycles). Moreover, the carbothermal process can naturally introduce oxygen vacancy and low-valent titanium as well as the surface carbon coating layer to the structure, which would greatly enhance the electronic conductivity of K x TiO 2 and thus endow this material high rate capability. With a good rate capability and long cyclability, this hollandite K x TiO 2 can serve as a new promising anode material for room-temperature long-life sodium-ion batteries for large-scale energy storage systems, and the carbothermal reduction method is believed to be an effective and facile way to develop novel Ti-based anodes with simultaneous carbon coating and Ti(III) self-doping.

Deep Recycling of Sedimentary Lithologies in Subduction Zones: Geochemical and Physical Constraints from Phase Equilibria and Synchrotron-Based Multi-Anvil Experiments at 15-25 GPa

Science.gov (United States)

Rapp, R. P.; Nishiyama, N.; Irifune, T.; Inoue, T.; Yamasaki, D.

2003-12-01

Ocean island basalts (OIBs) provide geochemical evidence for the presence of crustally-derived sedimentary material in the deep mantle plume source region for EM-type OIBs, and global seismic tomography provides us with dramatic images of subducted slabs, presumably carrying a sediment component, penetrating through the transition zone and into the lower mantle, in some cases to the core-mantle boundary. In an effort to better constrain the geochemical effects of deeply recycled sedimentary material in subduction zones, and their role in the petrogenesis of EM-type OIBs, we have undertaken a series of phase equlibria experiments in the multi-anvil apparatus at 10-25 GPa, using natural sediment lithologies as starting materials. The goal of these experiments is to identify the dominant phases in deeply subducted sediments, constrain their P-T stability limits, and to assess their role in crustal recycling and element redistribution in the deep mantle during subduction. The phase equilibria experiments were performed in a 2000-ton Kawai-type apparatus, using tungsten carbide cubes with 3 mm TEL and Cr-doped MgO and zirconia pressure media. A cylindrical lanthanum chromite heater was used, along with short (gold capsules to minimize thermal gradients and to retain the small amounts of water (< 1 wt%) present in the starting material, and long run-durations (12-48 hours) in order to facilitate future analyses of the dominant phases for key trace elements using the ion microprobe. Our preliminary results at 10-25 GPa indicate that K-hollandite (KalSi3O3) and stishovite are the primary high-pressure phases in the sediment composition, with subordinate garnet and an as-yet-unidentified (possibly hydrous) Al-silicate phase present as well. These results suggest that K-hollandite is the primary repository for incompatible elements (e.g., La, Ce, Sr, Ba, Rb, etc., and the heat-producing elements K, U and Th) in sedimentary material recycled into the deep mantle via

Ceramic Hosts for Fission Products Immobilization

Energy Technology Data Exchange (ETDEWEB)

Peter C Kong

2010-07-01

Natural spinel, perovskite and zirconolite rank among the most leach resistant of mineral forms. They also have a strong affinity for a large number of other elements and including actinides. Specimens of natural perovskite and zirconolite were radioisotope dated and found to have survived at least 2 billion years of natural process while still remain their loading of uranium and thorium . Developers of the Synroc waste form recognized and exploited the capability of these minerals to securely immobilize TRU elements in high-level waste . However, the Synroc process requires a relatively uniform input and hot pressing equipment to produce the waste form. It is desirable to develop alternative approaches to fabricate these durable waste forms to immobilize the radioactive elements. One approach is using a high temperature process to synthesize these mineral host phases to incorporate the fission products in their crystalline structures. These mineral assemblages with immobilized fission products are then isolated in a durable high temperature glass for periods measured on a geologic time scale. This is a long term research concept and will begin with the laboratory synthesis of the pure spinel (MgAl2O4), perovskite (CaTiO3) and zirconolite (CaZrTi2O7) from their constituent oxides. High temperature furnace and/or thermal plasma will be used for the synthesis of these ceramic host phases. Nonradioactive strontium oxide will be doped into these ceramic phases to investigate the development of substitutional phases such as Mg1-xSrxAl2O4, Ca1-xSrxTiO3 and Ca1-xSrxZrTi2O7. X-ray diffraction will be used to establish the crystalline structures of the pure ceramic hosts and the substitution phases. Scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX) will be performed for product morphology and fission product surrogates distribution in the crystalline hosts. The range of strontium doping is planned to reach the full substitution of the divalent

Synthesis of hollandite-type Li yMn 1- xCo xO 2 (x = 0-0.15) by Li + ion-exchange in molten salt and the electrochemical property for rechargeable lithium battery electrodes

Science.gov (United States)

Kumagai, Naoaki; Oshitari, Satoru; Komaba, Shinichi; Kadoma, Yoshihiro

The Li + ion-exchange reaction of K +-type α-K 0.14MnO 1.93·0.18H 2O and its Co-doped α-K 0.14(Mn 0.85Co 0.15)O 1.96·0.21H 2O with a large (2 × 2) tunnel structure has been investigated in a LiNO 3/LiCl molten salt at 300 °C. The Li + ion-exchanged products were examined by chemical analysis, X-ray diffraction, and scanning and transmission electron microscopic measurements. Almost all the K + ions and the hydrogens of water molecules in the (2 × 2) tunnel of α-MnO 2 and its Co-doped one were exchanged by Li + ions in the molten salt, resulting in Li +-type α-MnO 2 and its Co-doped one containing Li + ions as well as Li 2O (lithium oxide) in the (2 × 2) tunnel with maintaining the original hollandite structure. The electrochemical properties including charge-discharge cycling of the Li + ion-exchanged α-MnO 2 and its Co-doped samples have been investigated as insertion compounds in the search for new cathode materials for rechargeable lithium batteries. The Li + ion-exchanged α-MnO 2 and its Co-doped samples provided higher capacities than the K +-type parent materials on initial discharge and charge-discharge cyclings, probably due to the structural stabilization with the existence of Li 2O in the (2 × 2) tunnels.

EXAFS and XANES analysis of plutonium and cerium edges from titanate ceramics for fissile materials disposal

International Nuclear Information System (INIS)

Fortner, J. A.; Kropf, A. J.; Bakel, A. J.; Hash, M. C.; Aase, S. B.; Buck, E. C.; Chamerlain, D. B.

1999-01-01

We report x-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) spectra from the plutonium L III edge and XANES from the cerium L II edge in prototype titanate ceramic hosts. The titanate ceramics studied are based upon the hafnium-pyrochlore and zirconolite mineral structures and will serve as an immobilization host for surplus fissile materials, containing as much as 10 weight % fissile plutonium and 20 weight % (natural or depleted) uranium. Three ceramic formulations were studied: one employed cerium as a ''surrogate'' element, replacing both plutonium and uranium in the ceramic matrix, another formulation contained plutonium in a ''baseline'' ceramic formulation, and a third contained plutonium in a formulation representing a high-impurity plutonium stream. The cerium XANES from the surrogate ceramic clearly indicates a mixed III-IV oxidation state for the cerium. In contrast, XANES analysis of the two plutonium-bearing ceramics shows that the plutonium is present almost entirely as Pu(IV) and occupies the calcium site in the zirconolite and pyrochlore phases. The plutonium EXAFS real-space structure shows a strong second-shell peak, clearly distinct from that of PuO 2 , with remarkably little difference in the plutonium crystal chemistry indicated between the baseline and high-impurity formulations

Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions

Energy Technology Data Exchange (ETDEWEB)

Vittorio, Luca; Drabarek, Elizabeth; Chronis, Harriet; Griffith, Christopher S

2004-07-01

It has previously been demonstrated that immobilization of Cs{sup +} and/or Sr{sup 2+} sorbed on hexagonal tungsten oxide bronze (HTB) adsorbent materials can be achieved by heating the materials in air at temperatures in the range 500 - 1300 deg C. Highly crystalline powdered HTB materials formed by heating at 800 deg C show leach characteristics comparable to Cs-containing hot-pressed hollandites in the pH range from 0 to 12. As a very harsh leaching test, and also to model in a basic manner, leaching in the presence of canister corrosion products in oxidising environments, leaching of the bronzoid phases has been undertaken in Fe(NO{sub 3}){sub 3} solutions of increasing concentration. This is done in comparison with Cs -hollandite materials in order to compare the leaching characteristics of these two materials under such conditions. Both the Cs-loaded bronze and hollandite materials leach severely in Fe(NO{sub 3}){sub 3} losing virtually all of the immobilized Cs in a period of four days at 150 deg C. Total release of Cs and conversion of hollandite to titanium and iron titanium oxides begins to be observed at relatively low concentrations and is virtually complete after four days reaction in 0.5 mol/L Fe(NO{sub 3}){sub 3}. In the case of the bronze, all of the Cs is also extracted but the HTB structure is preserved. The reaction presumably involves an ion-exchange mechanism and iron oxide with a spinel structure is also observed at high Fe concentrations. (authors)

Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions

International Nuclear Information System (INIS)

Vittorio, Luca; Drabarek, Elizabeth; Chronis, Harriet; Griffith, Christopher S.

2004-01-01

It has previously been demonstrated that immobilization of Cs + and/or Sr 2+ sorbed on hexagonal tungsten oxide bronze (HTB) adsorbent materials can be achieved by heating the materials in air at temperatures in the range 500 - 1300 deg C. Highly crystalline powdered HTB materials formed by heating at 800 deg C show leach characteristics comparable to Cs-containing hot-pressed hollandites in the pH range from 0 to 12. As a very harsh leaching test, and also to model in a basic manner, leaching in the presence of canister corrosion products in oxidising environments, leaching of the bronzoid phases has been undertaken in Fe(NO 3 ) 3 solutions of increasing concentration. This is done in comparison with Cs -hollandite materials in order to compare the leaching characteristics of these two materials under such conditions. Both the Cs-loaded bronze and hollandite materials leach severely in Fe(NO 3 ) 3 losing virtually all of the immobilized Cs in a period of four days at 150 deg C. Total release of Cs and conversion of hollandite to titanium and iron titanium oxides begins to be observed at relatively low concentrations and is virtually complete after four days reaction in 0.5 mol/L Fe(NO 3 ) 3 . In the case of the bronze, all of the Cs is also extracted but the HTB structure is preserved. The reaction presumably involves an ion-exchange mechanism and iron oxide with a spinel structure is also observed at high Fe concentrations. (authors)

Modeling of Materials for Energy Storage: A Challenge for Density Functional Theory

Science.gov (United States)

Kaltak, Merzuk; Fernandez-Serra, Marivi; Hybertsen, Mark S.

Hollandite α-MnO2 is a promising material for rechargeable batteries and is studied extensively in the community because of its interesting tunnel structure and the corresponding large capacity for lithium as well as sodium ions. However, the presence of partially reduced Mn ions due to doping with Ag or during lithiation makes hollandite a challenging system for density functional theory and the conventionally employed PBE+U method. A naive attempt to model the ternary system LixAgyMnO2 with density functionals, similar to those employed for the case y = 0 , fails and predicts a strong monoclinic distortion of the experimentally observed tetragonal unit cell for Ag2Mn8O16. Structure and binding energies are compared with experimental data and show the importance of van der Waals interactions as well as the necessity for an accurate description of the cooperative Jan-Teller effects for silver hollandite AgyMnO2. Based on these observations a ternary phase diagram is calculated allowing to predict the physical and chemical properties of LixAgyMnO2, such as stable stoichiometries, open circuit voltages, the formation of Ag metal and the structural change during lithiation. Department of Energy (DOE) under award #DE-SC0012673.

Subduction recycling of continental sediments and the origin of geochemically enriched reservoirs in the deep mantle

Energy Technology Data Exchange (ETDEWEB)

Rapp, R.P.; Irifune, T.; Shimizu, N.; Nishiyama, N.; Norman, M.D.; Inoue, T. (Ehime U); (WHOI); (UC); (ANU)

2008-10-08

the product of melting of deeply recycled (subducted) Archean-age metasediments in the mantle transition zone [Murphy, D.T., Collerson, K.D., Kamber, B.S., 2002. Lamproites from Gaussberg, Antartica: possible transition zone melts of Archaean subducted sediments. J. Petrol. 43, 981-1001]. Here we report the results of phase equilibria experiments on two different natural sedimentary compositions (a high-grade metapelite with < 1 wt.% H{sub 2}O, and a marine 'mud' with 8 wt.% H{sub O}) at 16-23 GPa. In both materials, the high-pressure mineral assemblages contain {approx} 15-30 wt.% K-hollandite (KAlSi{sub 3}O{sub 8}), in addition to stishovite, garnet, an Al-silicate phase (kyanite or phase egg), and a Fe-Ti spinel (corundum). Ion microprobe analyses of K-hollandite for a range of trace elements reveal that this phase controls a significant proportion of the whole-rock budget of incompatible, large-ion lithophile elements (LILEs, e.g., Rb, Ba, Sr, K, Pb, La, Ce and Th). Comparisons between the abundances and ratios of these elements in K-hollandite with those in EM-I type ocean-island basalts from Pitcairn Island and related seamounts, and with the Gaussberg lamproites, indicate the presence of deeply recycled, continent-derived sediments in these lavas sources. Our results suggest that the incompatible trace-element signature of EM-I OIB reservoirs in general and of the Gaussberg lamproites in particular can be attributed to recycling of K-hollandite-bearing continental sediments to transition zone depths.

Calculated Phase Relations in the System KFMASH Between 6 and 16 GPa

Science.gov (United States)

Massonne, H.; Brandelik, A.

2005-12-01

To better understand the modal compositions of deeply buried metagranitoids and metapelites, phase relations in the model system K2O-FeO-MgO-Al2O3-SiO2-H2O (KFMASH) with SiO2 in excess were calculated applying thermodynamic principles. We used the software package PTGIBBS, published data, and thermodynamic data (e.g. for phase egg (AlSiO3OH), K-hollandite (KAlSi3O8)) newly derived on the basis of former high-pressure (HP) experiments. Non-ideal mixing was considered for the solid solution series of garnet (components: pyrope, majorite, almandine) and potassic white mica (components: muscovite, MgAl-celadonite, FeAl-celadonite). For phases such as HP-clinoenstatite ((Mg,Fe)SiO3), Si-spinel ((Fe,Mg)2SiO4), and beta phase ((Mg,Fe)2SiO4) only binary solid solutions, assuming ideal mixing, were taken into account. On the basis of the above data, we constructed petrogenetic grids mainly for the P-T range 6 to 16 GPa and 600 to 1600 ° C. Typical features of these grids are, for instance, the disappearance of K-cymrite (KAlSi3O8 H2O) with rising pressure close to 10 GPa and the occurrence of phase egg above 12 GPa. In KMASH potassic white mica reacts with OH-topaz at about 11 GPa (1000-1200 ° C) to form pyrope + K-hollandite. The content of majorite component in pyrope is less than 1 mol% which is systematically so for all garnets coexisting with an Al-silicate at least up to 16 GPa. Potassic white mica, which is virtually pure MgAl-celadonite, finally breaks down at pressures close to 12 GPa. Decomposition assemblages are K-hollandite + HP-clinoenstatite + H2O (T free) garnet + Al-silicate. The latter phase is either OH-topaz (Al2SiO4(OH)2) or phase egg or kyanite also depending on the availability of H2O. Metagranitoids should be composed of shishovite + K-hollandite + majorite-bearing garnet + (enstatite-rich) clinopyroxene. Si-spinel is an important additional phase in this assemblage. This phase shows increasing amounts by approaching to 16 GPa.

Comparison of the properties of simulated synroc synthesized by sol-gel and a novel co - precipitation method

International Nuclear Information System (INIS)

Potdar, H.S.; Vijayanand, S.; Khaja Mohaideen, K.; Joy, P.A.; Raja Madhavan, R.; Kutty, K.V.G.; Ambashta, R.D.; Wattal, P.K.

2009-01-01

Synroc is a multiphase dense titanate based ceramic designed for the incorporation of high-level waste (HLW) from the reprocessing of spent nuclear fuel. Synroc or synthetic rock consists of four main titanate phases - zirconolite (CaZrTi 2 O 7 ), hollandite (BaAlO 2 Ti 6 O 16 ), perovskite (CaTiO 3 ) and rutile (TiO 2 ), with the matrix composition as shown in Table 1. It is known that these phases have the capacity to incorporate most of the elements into their crystal structures which are present in the HLW derived from the reprocessing of spent nuclear fuel from power reactors. Synroc is considered as the most effective and durable means of immobilising various forms of high-level radioactive wastes for disposal. Synroc is also considered as a low-risk, tailored waste form, offering higher waste loading and over all cost savings. Simulated synroc precursor powders are typically produced by advanced wet chemical methods such as alkoxide hydrolysis and sol-gel routes. These routes were developed to produce powders with well defined physical and chemical characteristics such as correct chemical composition, high degree of homogeneity, reactivity and readily densifiable material to 99% of theoretical density during hot isostatic pressing. However, the reported alkoxide hydrolysis and hydroxide routes suffer from several disadvantages such as use of large quantities of organic solvents and their disposal as effluent, difficulty in maintaining exact chemical composition, use of costly alkoxide precursors which are moisture sensitive and require critical processing conditions to control their rate of hydrolysis, etc. In the present work we report a comparative study the characteristics of synroc-C (14% waste loading) powders and sintered pellets synthesized by the known alkoxide hydrolysis method and a simple chemical co-precipitation route developed by us. The advantages of the co-precipitation route are its simplicity, ease of handling and utilization of cheaper raw

Laachite, (Ca,Mn){sub 2}Zr{sub 2}Nb{sub 2}TiFeO{sub 14}, a new zirconolite-related mineral from the Eifel volcanic region, Germany

Energy Technology Data Exchange (ETDEWEB)

Chukanov, Nikita V. [Institute of Problems of Chemical Physics, Chernogolovka (Russian Federation); Krivovichev, Sergey V.; Pakhomova, Anna S. [St. Petersburg State Univ. (Russian Federation). Faculty of Crystallography; Pekov, Igor V.; Vigasina, Marina F. [Moscow State Univ. (Russian Federation). Faculty of Geology; Schaefer, Christof [Suedwestdeutsche Salzwerke AG, Heilbronn (Germany); Van, Konstantin V. [Russian Academy of Sciences, Chernogolovka (Russian Federation). Inst. of Experimental Mineralogy

2014-02-15

The new mineral laachite was discovered in a sanidinite specimen from the Laach Lake (Laacher See) volcano, Eifel region, Rheinland-Pfalz, Germany. Associated minerals are sanidine, allanite-(Ce), baddeleyite, hau¨yne, hedenbergite, intermediate members of the jacobsite-magnetite series, phlogopite, rhodonite, spessartine, tephroite, thorite, zircon, and a pyrochlore-group mineral. Laachite is deep brownish-red, has an adamantine lustre, and is translucent; the streak is brownish red. It forms longprismatic crystals up to 0.02 x 0.04 x 0.5 mm, which are present as random intergrowths and twins in cavities within sanidinite. The density calculated from the empirical formula is 5.417 g/cm{sup 3}. The mean refractive index calculated from the Gladstone-Dale relationship is 2.26. The Raman spectrum shows the absence of hydrogen-bearing groups. The chemical composition is (electron microprobe, mean of 5 analyses, wt. %): CaO 4.29, MnO 9.42, FeO 5.73, Y{sub 2}O{sub 3} 2.56, La{sub 2}O{sub 3} 2.00, Ce{sub 2}O{sub 3} 6.37, Nd{sub 2}O{sub 3} 2.22, Al{sub 2}O{sub 3} 0.99, ThO{sub 2} 7.75, TiO{sub 2} 10.98, ZrO{sub 2} 19.39, Nb{sub 2}O{sub 5} 27.82, total 99.52. The empirical formula based on 14 O atoms is: (Ca{sub 0.66}Mn{sub 0.37}Th{sub 0.25}Y{sub 0.20}La{sub 0.11}Ce{sub 0.34}Nd{sub 0.11})(Zr{sub 1.3} {sub 6}Mn{sub 0.64})(Nb{sub 1.81}Ti{sub 1.19})(Fe{sub 0.69}Al{sub 0.17}Mn{sub 0.14})O{sub 14.00}. The simplified formula, taking into account the structural data, is: (Ca,Mn){sub 2}(Zr,Mn){sub 2}Nb{sub 2}TiFeO{sub 14}. Laachite is monoclinic, space group C2/c, a = 7.3119(5), b = 14.1790(10), c = 10.1700(7)Aa, β = 90.072(2), V = 1054.38(1) Aa{sup 3}, Z = 4. The crystal structure was solved using single-crystal X-ray diffraction data. Laachite is a monoclinic analogue of zirconolite-3O, CaZrTi{sub 2}O{sub 7}, with Nb dominant over Ti in the octahedral sites Nb1 and Nb2 and Fe dominant in a site with four-fold coordination. The strongest lines of the powder X-ray diffraction

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

Driving Curie temperature towards room temperature in the half-metallic ferromagnet K2Cr8O16 by soft redox chemistry.

Science.gov (United States)

Pirrotta, I; Fernández-Sanjulián, J; Moran, E; Alario-Franco, M A; Gonzalo, E; Kuhn, A; García-Alvarado, F

2012-02-14

The half-metallic ferromagnet K(2)Cr(8)O(16) with the hollandite structure has been chemically modified using soft chemistry methods to increase the average oxidation state of chromium. The synthesis of the parent material has been performed under high pressure/high temperature conditions. Following this, different redox reactions have been carried out on K(2)Cr(8)O(16). Oxidation to obtain potassium-de-inserted derivatives, K(2-x)Cr(8)O(16) (0 ≤x≤ 1), has been investigated with electrochemical methods, while the synthesis of sizeable amounts was achieved chemically by using nitrosonium tetrafluoroborate as a highly oxidizing agent. The maximum amount of extracted K ions corresponds to x = 0.8. Upon oxidation the hollandite structure is maintained and the products keep high crystallinity. The de-insertion of potassium changes the Cr(3+)/Cr(4+) ratio, and therefore the magnetic properties. Interestingly, the Curie temperature increases from ca. 175 K to 250 K, getting therefore closer to room temperature.

Use of linear free energy relationship to predict Gibbs free energies of formation of pyrochlore phases (CaMTi2O7)

International Nuclear Information System (INIS)

Xu, H.; Wang, Y.

1999-01-01

In this letter, a linear free energy relationship is used to predict the Gibbs free energies of formation of crystalline phases of pyrochlore and zirconolite families with stoichiometry of MCaTi 2 O 7 (or, CaMTi 2 O 7 ,) from the known thermodynamic properties of aqueous tetravalent cations (M 4+ ). The linear free energy relationship for tetravalent cations is expressed as ΔG f,M v X 0 =a M v X ΔG n,M 4+ 0 +b M v X +β M v X r M 4+ , where the coefficients a M v X , b M v X , and β M v X characterize a particular structural family of M v X, r M 4+ is the ionic radius of M 4+ cation, ΔG f,M v X 0 is the standard Gibbs free energy of formation of M v X, and ΔG n,M 4+ 0 is the standard non-solvation energy of cation M 4+ . The coefficients for the structural family of zirconolite with the stoichiometry of M 4+ CaTi 2 O 7 are estimated to be: a M v X =0.5717, b M v X =-4284.67 (kJ/mol), and β M v X =27.2 (kJ/mol nm). The coefficients for the structural family of pyrochlore with the stoichiometry of M 4+ CaTi 2 O 7 are estimated to be: a M v X =0.5717, b M v X =-4174.25 (kJ/mol), and β M v X =13.4 (kJ/mol nm). Using the linear free energy relationship, the Gibbs free energies of formation of various zirconolite and pyrochlore phases are calculated. (orig.)

Alteration and long-term behaviour of different types of innovative materials for long-lived radionuclides confinement

International Nuclear Information System (INIS)

Leturcq, G.

1998-01-01

The present work is an experimental study on alteration mechanisms of synthetic and natural materials: aluminosilicate glasses, glass ceramics and Ti, Zr or P based ceramics. It is a part of CEA's study program on the immobilization of long- lived radionuclides and deals with chemical processes which control dissolution of amorphous and crystallized solids. The different aluminosilicate glasses studied are altered according to a process of hydrolysis of the bonds between the glass network formers; the activation energy of this reaction is about 60 kJ/mol. Alteration rates of all the glasses decrease by four orders of magnitude when the reaction progress increases. Kinetic laws based on the deviation from the thermodynamic equilibrium between leachate and the fresh solid cannot explain these great decreases. Alteration layers in the reactional interface seem to control the alteration kinetics by providing a passivation process. The chemical durability of the glass ceramics (zirconolite and titanite) improves by a factor of ten in regard to the primary glasses which were obtained by thermal treatment. Zirconium-titanate ceramics are altered only slightly by water. The altered mass corresponds to a few atomic layers only. Steady stases are quickly observed. On the basis of thermodynamic calculations, they are not correlated with saturation between the leachate and primary zirconium-titanate phases. Alteration here also ceases due to the development of a passivating layer. Models aiming at studying the chemical durability of zirconium-titanate ceramics under conditions more representative of a clayey site of geological storage were carried out. The results of the interactions of these ceramics with clays, at 708 deg.C, show clearly that there is no modification of the process of alteration, compared to the simpler pure water systems. Thus, perovskite and zirconolite do not deteriorate under these conditions. (author)

Alteration and long-term behaviour of different types of innovative materials for long-lived radionuclides confinement; Alteration et comportement a long terme de differentes classes de materiaux innovants pour le confinement des radionucleides a vie longue

Energy Technology Data Exchange (ETDEWEB)

Leturcq, G

1998-09-29

The present work is an experimental study on alteration mechanisms of synthetic and natural materials: aluminosilicate glasses, glass ceramics and Ti, Zr or P based ceramics. It is a part of CEA's study program on the immobilization of long- lived radionuclides and deals with chemical processes which control dissolution of amorphous and crystallized solids. The different aluminosilicate glasses studied are altered according to a process of hydrolysis of the bonds between the glass network formers; the activation energy of this reaction is about 60 kJ/mol. Alteration rates of all the glasses decrease by four orders of magnitude when the reaction progress increases. Kinetic laws based on the deviation from the thermodynamic equilibrium between leachate and the fresh solid cannot explain these great decreases. Alteration layers in the reactional interface seem to control the alteration kinetics by providing a passivation process. The chemical durability of the glass ceramics (zirconolite and titanite) improves by a factor of ten in regard to the primary glasses which were obtained by thermal treatment. Zirconium-titanate ceramics are altered only slightly by water. The altered mass corresponds to a few atomic layers only. Steady stases are quickly observed. On the basis of thermodynamic calculations, they are not correlated with saturation between the leachate and primary zirconium-titanate phases. Alteration here also ceases due to the development of a passivating layer. Models aiming at studying the chemical durability of zirconium-titanate ceramics under conditions more representative of a clayey site of geological storage were carried out. The results of the interactions of these ceramics with clays, at 708 deg.C, show clearly that there is no modification of the process of alteration, compared to the simpler pure water systems. Thus, perovskite and zirconolite do not deteriorate under these conditions. (author)

PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES

Energy Technology Data Exchange (ETDEWEB)

Fox, K.; Billings, A.; Brinkman, K.; Marra, J.

2010-09-22

The Savannah River National Laboratory (SRNL) developed a series of ceramic waste forms for the immobilization of Cesium/Lanthanide (CS/LN) and Cesium/Lanthanide/Transition Metal (CS/LN/TM) waste streams anticipated to result from nuclear fuel reprocessing. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase ceramics containing hollandite-type phases, perovskites (particularly BaTiO{sub 3}), pyrochlores, zirconolite, and other minor metal titanate phases. Identification of excess Al{sub 2}O{sub 3} via X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) in the first series of compositions led to a Phase II study, with significantly reduced Al{sub 2}O{sub 3} concentrations and increased waste loadings. Three fabrication methodologies were used, including melting and crystallizing, pressing and sintering, and Spark Plasma Sintering (SPS), with the intent of studying phase evolution under various sintering conditions. XRD and SEM/EDS results showed that the partitioning of the waste elements in the sintered materials was very similar, despite varying stoichiometry of the phases formed. The Phase II compositions generally contained a reduced amount of unreacted Al{sub 2}O{sub 3} as identified by XRD, and had phase assemblages that were closer to the initial targets. Chemical composition measurements showed no significant issues with meeting the target compositions. However, volatilization of Cs and Mo was identified, particularly during melting, since sintering of the pressed pellets and SPS were performed at lower temperatures. Partitioning of some of the waste components was difficult to determine via XRD. SEM/EDS mapping showed that those elements, which were generally present in small concentrations, were well distributed throughout the waste forms. Initial studies of radiation damage tolerance using ion beam irradiation at Los

Fundamental Thermodynamics of Actinide-Bearing Mineral Waste Forms - Final Report

Energy Technology Data Exchange (ETDEWEB)

Williamson, Mark A.; Ebbinghaus, Bartley B.; Navrotsky, Alexandra

2001-03-01

The end of the Cold War raised the need for the technical community to be concerned with the disposition of excess nuclear weapon material. The plutonium will either be converted into mixed-oxide fuel for use in nuclear reactors or immobilized in glass or ceramic waste forms and placed in a repository. The stability and behavior of plutonium in the ceramic materials as well as the phase behavior and stability of the ceramic material in the environment is not well established. In order to provide technically sound solutions to these issues, thermodynamic data are essential in developing an understanding of the chemistry and phase equilibria of the actinide-bearing mineral waste form materials proposed as immobilization matrices. Mineral materials of interest include zircon, zirconolite, and pyrochlore. High temperature solution calorimetry is one of the most powerful techniques, sometimes the only technique, for providing the fundamental thermodynamic data needed to establish optimum material fabrication parameters, and more importantly understand and predict the behavior of the mineral materials in the environment. The purpose of this project is to experimentally determine the enthalpy of formation of actinide orthosilicates, the enthalpies of formation of actinide substituted zirconolite and pyrochlore, and develop an understanding of the bonding characteristics and stabilities of these materials.

Fundamental Thermodynamics of Actinide-Bearing Mineral Waste Forms - Final Report

International Nuclear Information System (INIS)

Williamson, Mark A.; Ebbinghaus, Bartley B.; Navrotsky, Alexandra

2001-01-01

The end of the Cold War raised the need for the technical community to be concerned with the disposition of excess nuclear weapon material. The plutonium will either be converted into mixed-oxide fuel for use in nuclear reactors or immobilized in glass or ceramic waste forms and placed in a repository. The stability and behavior of plutonium in the ceramic materials as well as the phase behavior and stability of the ceramic material in the environment is not well established. In order to provide technically sound solutions to these issues, thermodynamic data are essential in developing an understanding of the chemistry and phase equilibria of the actinide-bearing mineral waste form materials proposed as immobilization matrices. Mineral materials of interest include zircon, zirconolite, and pyrochlore. High temperature solution calorimetry is one of the most powerful techniques, sometimes the only technique, for providing the fundamental thermodynamic data needed to establish optimum material fabrication parameters, and more importantly understand and predict the behavior of the mineral materials in the environment. The purpose of this project is to experimentally determine the enthalpy of formation of actinide orthosilicates, the enthalpies of formation of actinide substituted zirconolite and pyrochlore, and develop an understanding of the bonding characteristics and stabilities of these materials

Preparation and characterization of 238Pu-ceramics for radiation damage experiments

International Nuclear Information System (INIS)

DM Strachan; RD Scheele; WC Buchmiller; JD Vienna; RL Sell; RJ Elovich

2000-01-01

As a result of treaty agreements between Russia and the US, portions of their respective plutonium and nuclear weapons stockpiles have been declared excess. In support of the US Department of Energy's 1998 decision to pursue immobilization of a portion of the remaining Pu in a titanate-based ceramic, the authors prepared nearly 200 radiation-damage test specimens of five Pu- and 238 Pu-ceramics containing 10 mass% Pu to determine the effects of irradiation from the contained Pu and U on the ceramic. The five Pu-ceramics were (1) phase-pure pyrochlore [ideally, Ca(U, Pu)Ti 2 O 7 ], (2) pyrochlore-rich baseline, (3) pyrochlore-rich baseline with impurities, (4) phase-pure zirconolite [ideally Ca(U, Pu)Ti 2 O 7 ], and (5) a zirconolite-rich baseline. These ceramics were prepared with either normal weapons-grade Pu, which is predominantly 239 Pu, or 238 Pu. The 238 Pu accelerates the radiation damage relative to the 239 Pu because of its much higher specific activity. The authors were unsuccessful in preparing phase-pure (Pu, U) brannerite, which is the third crystalline phase present in the baseline immobilization form. Since these materials will contain ∼10 mass% Pu and about 20 mass% U, radiation damage to the crystalline structure of these materials will occur overtime. As the material becomes damaged from the decay of the Pu and U, it is possible for the material to swell as both the alpha particles and recoiling atoms rupture chemical bonds within the solid. As the material changes density, cracking, perhaps in the form of microcracks, may occur. If cracking occurs in ceramic that has been placed in a repository, the calculated rate of radionuclide release if the can has corroded would increase proportionately to the increase in surface area. To investigate the effects of radiation damage on the five ceramics prepared, the authors are storing the specimens at 20, 125, and 250 C until the 238 Pu specimens become metamict and the damage saturates. They will

Fundamental thermodynamics of actinide-bearing mineral waste forms. 1998 annual progress report

International Nuclear Information System (INIS)

Ebbinghaus, B.B.; Williamson, M.A.

1998-01-01

'The end of the Cold War raised the need for the technical community to be concerned with the disposition of excess nuclear weapon material. The plutonium will either be converted into mixed-oxide fuel for use in nuclear reactors or immobilized in glass or ceramic waste forms and placed in a repository. The stability and behavior of plutonium in the ceramic materials as well as the phase behavior and stability of the ceramic material in the environment is not well established. In order to provide technically sound solutions to these issues, thermodynamic data are essential in developing an understanding of the chemistry and phase equilibria of the actinide-bearing mineral waste form materials proposed as immobilization matrices. Mineral materials of interest include zircon, zirconolite, and pyrochlore. High temperature solution calorimetry is one of the most powerful techniques, sometimes the only technique, for providing the fundamental thermodynamic data needed to establish optimum material fabrication parameters, and more importantly, understand and predict the behavior of the mineral materials in the environment. The purpose of this project is to experimentally determine the enthalpy of formation of actinide orthosilicates, the enthalpy of formation of actinide substituted zircon, zirconolite and pyrochlore, and develop an understanding of the bonding characteristics and stability of these materials. This report summarizes work after eight months of a three year project.'

Testing and evaluation of solidified high-level waste forms

International Nuclear Information System (INIS)

Engelmann, C.

1984-01-01

The report describes research by several laboratories on the behaviour, in aqueous and salt environments, of borosilicate glass ceramics proposed for the solidification of nuclear wastes by the European Community. Results were obtained on inactive simulates, doped materials, and on borosilicate glass containing real radioactive waste. The influence of many important parameters were studied: leaching mode, nature of the leachant, pH, pressure, temperature, duration of the treatment, etc. The results of tests lasting for as little as a few hours or for as long as several hundred days, at temperatures up to 200 0 C or under pressures up to 200 bars, are presented. Numerous analytical techniques (ESCA, EMP, IRR, SEM, etc.) were used to determine the structure and the chemical composition of the altered layer developed by hydration at the glass surface. Information is also given on physical properties of the borosilicate glass: crystallization phase separation, alpha-irradiation stability, mechanical and thermal stability, etc. Finally, preliminary results on the structure and composition of hollandite ceramics are given

Corrosion behavior of pyroclore-rich titanate ceramics for plutonium disposition; impurity effects

International Nuclear Information System (INIS)

Bakel, A. J.

1999-01-01

The baseline ceramic contains Ti, U, Ca, Hf, Gd, and Ce, and is made up of only four phases, pyrochlore, zirconolite, rutile, and brannerite. The impurities present in the three other ceramics represent impurities expected in the feed, and result in different phase distributions. The results from 3 day, 90 C MCC-1 tests with impurity ceramics were significantly different than the results from tests with the baseline ceramic. Overall, the addition of impurities to these titanate ceramics alters the phase distributions, which in turn, affects the corrosion behavior

Crystal chemistry of six-coordinated silicon: A key to understanding the earth's deep interior

International Nuclear Information System (INIS)

Finger, L.W.; Hazen, R.M.

1991-01-01

A survey of high-pressure silicates reveals 12 distinct high-density structural topologies with octahedral Si. Seven of these structure types - stishovite, perovskite, ilmenite, hollandite, calcium ferrite, pyrochlore and K 2 NiF 4 type - contain only six-corrdinated silicon. Other high-pressure silicates, including those with the garnet, pyroxene, wadeite, anhydrous phase B and phase B structures, contain both tetrahedral and octahedral Si. Five systematic trends among these dozen structures suggest the existence of other, as yet unobserved, possible mantle Si phases. The criteria are: (1) Structures like rutile, hollandite and calcium ferrite formed from edge-sharing chains of silicon octahedra; (2) germanates synthesized at room pressure with octahedral Ge; (3) isomorphs of room-pressure oxides with 3+ or 4+ transition-metal cations; (4) high-pressure magnesium silicates related to room-pressure aluminates by the substitution 2Al→Mg+Si; and (5) the homologous structures in system Mg-Si-O-H that includes phase B and anhydrous phase B. Each of these criteria can be used to predict other potential octahedral Si phases. Of special interest are predicted structure types that fulfill more than one criterion: Diaspore-type (MgSi)O 2 (OH) 2 , aerugite-type Mg 10 Si 3 O 16 , sphene-type CaSi 2 O 5 , benitoite-type BaSi 4 O 9 , gibbsite-type MgSi(OH) 6 and pseudobrookite-type Fe 2 SiO 5 . (orig.)

Formulation of SYNROC-D additives for Savannah River Plant high-level radioactive waste

International Nuclear Information System (INIS)

Ryerson, F.J.; Burr, K.; Rozsa, R.

1981-12-01

SYNROC-D is a multiphase ceramic waste form consisting of nepheline, zirconolite, perovskite, and spinel. It has been formulated for the immobilization of high-level radioactive wastes now stored at Savannah River Plant (SRP) near Aiken, South Carolina. This report utilizes existing experimental data to develop a method for calculating additives to these waste products. This method calculates additions based on variations of mineral compositions as a function of sludge composition and radionuclide partitioning among the SYNROC phases. Based on these calculations, a FORTRAN program called ADSYN has been developed to determine the proper reagent proportions to be added to the SRP sludges

Next nature : nature changes along with us

NARCIS (Netherlands)

Mensvoort, van K.M.; Grievink, H.J.

2011-01-01

We debate saving nature, we dream about escaping to nature, but rarely do we ask "What is nature?". The Next Nature book radically shifts your notion of nature. Where technology and nature are traditionally seen as opposed, they now appear to merge or even trade places. With our urge to design our

High-pressure phase relations in the composition of albite NaAlSi3O8 constrained by an ab initio and quasi-harmonic Debye model, and their implications

Science.gov (United States)

Deng, L.; Liu, X.; Liu, H.; Dong, J.

2010-12-01

phase assemblage transforms into the CS phase assemblage at about 33.6 GPa at 0 K, and the Clayperon slope of this phase transition is about 0.014 GPa/K. This study implies that lingunite (Na-Holl), found in somemeteorites, is not possibly a thermodynamically stable high-P phase, and the Cf phase probably plays an important role in maintaining the sodium budget and hosting the large-ion lithophile elements in the deep interior of the Earth. References: Beck, P., Gillet, P., Gautron, L., Daniel, I., El Goresy, A., 2004. A new natural high-pressure (Na, Ca)-hexaluminosilicate [(CaxNa1-x)Al3+xSi3-xO11] in shocked Martian meteorites. Earth Planet. Sci. Lett. 219, 1-12. Liu, L., 1978. High-pressure phase transformations of albite, jadeite and nepheline. Earth Planet. Sci. Lett. 37, 438-444. Sekine, T., Ahrens, T.J., 1992. Shock-induced transformations in the system NaAlSi3O8-SiO2: a new interpretation. Phys. Chem. Mineral. 18, 359-364. Tutti, F., 2007. Formation of end-member NaAlSi3O8 hollandite-type structure (lingunite) in diamond anvil cell. Phys. Earth Planet. Inter. 161, 143-149.

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 ......

Anomalous metallic state with strong charge fluctuations in BaxTi8O16 +δ revealed by hard x-ray photoemission spectroscopy

Science.gov (United States)

Dash, S.; Kajita, T.; Okawa, M.; Saitoh, T.; Ikenaga, E.; Saini, N. L.; Katsufuji, T.; Mizokawa, T.

2018-04-01

We have studied a charge-orbital driven metal-insulator transition (MIT) in hollandite-type BaxTi8O16 +δ by means of hard x-ray photoemission spectroscopy (HAXPES). The Ti 2 p HAXPES indicates strong Ti3 +/Ti4 + charge fluctuation in the metallic phase above the MIT temperature. The metallic phase is characterized by a power-law spectral function near the Fermi level which would be a signature of bad metal with non-Drude polaronic behavior. The power-law spectral shape is associated with the large Seebeck coefficient of the metallic phase in BaxTi8O16 +δ .

Ceramic waste forms for fuel-containing masses at Chernobyl

International Nuclear Information System (INIS)

Oversby, V.M.

1994-05-01

The fuel materials originally in the core of the Chernobyl Unit 4 reactor are now present within the Ukrytie in three major forms: (1) very fine particles of fuel dispersed as dust (about 10 tonnes), (2) fragments of the destroyed core, and (3) lavas containing fuel, cladding, and other materials. All of these materials will need to be immobilized into waste forms suitable for final disposal. We propose a ceramic waste form system that could accommodate all three waste types with a single set of processing equipment. The waste form would include the mineral zirconolite for immobilization of actinide materials (including uranium), perovskite, nepheline, spinel, and other phases as dictated by the chemistry of the lava masses. Waste loadings as high as 50% U can be achieved if pyrochlore, a close relative of zirconolite, is used as the U host. The ceramic immobilization could be achieved with low additions of inert chemicals to minimize the final disposal volume while ensuring a durable product. The sequence of processing would be to collect and immobilize the fuel dust first. This material will require minimal preprocessing and will provide experience in the handling of the fuel materials. Core fragments would be processed next, using a cryogenic crushing stage to reduce the size prior to adding ceramic additives. The lavas would be processed last, which is compatible with the likely sequence of availability of materials and with the complexity of the operations. The lavas will require more adjustment of chemical additive composition than the other streams to ensure that the desired phases are produced in the waste form

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

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.

Manganese-oxide minerals in fractures of the Crater Flat Tuff in drill core USW G-4, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Carlos, B.A.; Bish, D.L.; Chipera, S.J.

1990-07-01

The Crater Flat Tuff is almost entirely below the water table in drill hole USW G-4 at Yucca Mountain, Nevada. Manganese-oxide minerals from the Crater Flat Tuff in USW G-4 were studied using optical, scanning electron microscopic, electron microprobe, and x-ray powder diffraction methods to determine their distribution, mineralogy, and chemistry. Manganese-oxide minerals coat fractures in all three members of the Crater Flat Tuff (Prow Pass, Bullfrog, and Tram), but they are most abundant in fractures in the densely welded devitrified intervals of these members. The coatings are mostly of the cryptomelane/hollandite mineral group, but the chemistry of these coatings varies considerably. Some of the chemical variations, particularly the presence of calcium, sodium, and strontium, can be explained by admixture with todorokite, seen in some x-ray powder diffraction patterns. Other chemical variations, particularly between Ba and Pb, demonstrate that considerable substitution of Pb for Ba occurs in hollandite. Manganese-oxide coatings are common in the 10-m interval that produced 75% of the water pumped from USW G-4 in a flow survey in 1983. Their presence in water-producing zones suggests that manganese oxides may exert a significant chemical effect on groundwater beneath Yucca Mountain. In particular, the ability of the manganese oxides found at Yucca Mountain to be easily reduced suggests that they may affect the redox conditions of the groundwater and may oxidize dissolved or suspended species. Although the Mn oxides at Yucca Mountain have low exchange capacities, these minerals may retard the migration of some radionuclides, particularly the actinides, through scavenging and coprecipitation. 23 refs., 21 figs., 2 tabs

Polyphase ceramic and glass-ceramic forms for immobilizing ICPP high-level nuclear waste

International Nuclear Information System (INIS)

Harker, A.B.; Flintoff, J.F.

1984-01-01

Polyphase ceramic and glass-ceramic forms have been consolidated from simulated Idaho Chemical Processing Plant wastes by hot isostatic pressing calcined waste and chemical additives by 1000 0 C or less. The ceramic forms can contain over 70 wt% waste with densities ranging from 3.5 to 3.85 g/cm 3 , depending upon the formulation. Major phases are CaF 2 , CaZrTi 207 , CaTiO 3 , monoclinic ZrO 2 , and amorphous intergranular material. The relative fraction of the phases is a function of the chemical additives (TiO 2 , CaO, and SiO 2 ) and consolidation temperature. Zirconolite, the major actinide host, makes the ceramic forms extremely leach resistant for the actinide simulant U 238 . The amorphous phase controls the leach performance for Sr and Cs which is improved by the addition of SiO 2 . Glass-ceramic forms were also consolidated by HIP at waste loadings of 30 to 70 wt% with densities of 2.73 to 3.1 g/cm 3 using Exxon 127 borosilicate glass frit. The glass-ceramic forms contain crystalline CaF 2 , Al 203 , and ZrSi 04 (zircon) in a glass matrix. Natural mineral zircon is a stable host for 4+ valent actinides. 17 references, 3 figures, 5 tables

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...

Natural radiation; A radiacao natural

Energy Technology Data Exchange (ETDEWEB)

Feliciano, Vanusa Maria Delage

2016-07-01

Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

Natural Colorants: Food Colorants from Natural Sources.

Science.gov (United States)

Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

2017-02-28

The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

Continuous-flow leaching studies of crushed and cored SYNROC

International Nuclear Information System (INIS)

Coles, D.G.; Bazan, F.

1980-01-01

Both crushed (150 to 300 μm) and cored 1.8 mm diameter) samples of SYNROC have been leached with the single-pass continuous-flow leaching equipment. Crushed samples of Cs-hollandite were also leached in a similar experiment. Temperatures used were 25 0 C and 75 0 C and leachates were 0.03 N NaHCO 3 and distilled water. Leaching rates from SYNROC C were ranked Cs > Sr greater than or equal to Ca > Ba > Zr. A comparison of leaching rates is made between crushed SYNROC, cored SYNROC, and PNL 76-68 glass beads. Problems encountered when comparing the leaching rates of different waste forms are discussed

Mother natural: Motivations and associations for consuming natural foods.

Science.gov (United States)

Moscato, Emily M; Machin, Jane E

2018-02-01

Natural is perceived as innately positive and is a widely sought-after attribute in food products. The natural food industry continues to grow in response to rising consumer demand. This qualitative study explored mothers' motivations for purchasing and consuming natural food products for themselves and their families. Mothers are an important population because of their disproportionate influence on household food consumption. We employed participant photography and a series of three weekly focus groups to derive a rich understanding of the activities surrounding and motivations behind seeking natural in everyday buying decisions. Five major themes were identified. First, natural nurtures well-being: physical, psychological, social, and emotional health. Second, natural behaves "supernaturally," allowing positive attributes to be transmitted from the source to the recipient. Third, natural is associated with authenticity, providing a sense of trust, transparency, and control. Fourth, consuming natural reinforces the socially constructed idea of a good mother. Lastly, the preference for natural does not always translate into purchase; mothers face compromises because of conflicting priorities and resources. Understanding mothers' multiple motivations provides deeper insight into the attraction for natural products. The findings have application in positioning interventions for more nutritional eating and revising regulations on the food label natural. Copyright © 2017 Elsevier Ltd. All rights reserved.

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. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Natural gas

Energy Technology Data Exchange (ETDEWEB)

Fraser, J W

1967-08-01

This report on the natural gas industry of Canada includes: composition and uses of natural gas, production statistics, exploration and development, reserve estimates, natural gas processing, transportation, and marketing. For the Canadian natural gas industry, 1966 was a year of moderate expansion in all phases, with a strong demand continuing for sulfur and liquid hydrocarbons produced as by-products of gas processing. Value of natural gas production increased to $199 million and ranked sixth in terms of value of mineral ouput in Canada. Currently, natural gas provides over 70% of Canada's energy requirements. Proved remaining marketable reserves are estimated to be in excess of a 29-yr supply.

One for all? : connectedness to nature, inclusion of nature, environmental identity, and implicit association with nature

NARCIS (Netherlands)

Brügger, A; Kaiser, F.G.; Roczen, N.

2011-01-01

Pleasurable experiences in nature are suspected to promote a personal connection with nature, and subsequently, nature conservation in individuals. Using an Internet-based survey employing a convenience sample of the general population (N = 1,309), we developed a connection-with-nature instrument

SYNROC C: preparation and radwaste distribution

International Nuclear Information System (INIS)

Ryerson, F.J.; Hoenig, C.L.; Smith, G.S.

1981-01-01

Results of the synthesis of SYNROC C from both high surface area (16m 2 /g) and low surface area (4m 2 /g) powders at low and high oxygen fugacities indicate variations in radionuclide distribution. These results are most striking for the partitioning of uranium between perovskite and zirconolite. In highly active powders, the formation of a pyrochlore precursor ensures that equilibrium partitioning is approached. In less active powders, no low temperature pyrochlore is formed. As a result, the uranium partitioning is a function of nucleation processes. At high oxygen fugacities, uranium is rejected from perovskite and an additional uranium rich phase is formed precluding the synthesis of SYNROC C in air

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 t...

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 t...

[Development of the Feelings toward Nature Scale and relationship between feelings toward nature and proximity to nature].

Science.gov (United States)

Shibata, Seiji

2016-04-01

In the field of environmental psychology, there is rapidly growing interest in the concept of connectivity with nature, describing an individual's sense of being connected with nature. The author developed a new scale for assessing feelings toward nature, including connectedness. Confirmatory factor analysis indicated a five-factor model consisting of restorativeness, oneness, mystery, care, and aversion. Then, the relationships among availability of nature in respondents' neighborhood, age, and each subscale score of the Feelings toward Nature Scale, were analyzed using structural equation modeling. The availability of nature in neighborhoods was assessed using a geographic information system and respondents' subjective evaluations. Results indicate that overall connectedness to nature is weaker as availability of nature decreases, as assessed by subjective evaluation. Results also suggest that aversion toward nature in younger people is relatively stronger than in older generations.

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.

Temporal naturalism

Science.gov (United States)

Smolin, Lee

2015-11-01

Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

On the Relationship between a Computational Natural Logic and Natural Language

DEFF Research Database (Denmark)

Andreasen, Troels; Bulskov, Henrik; Nilsson, Jørgen Fischer

2016-01-01

This paper makes a case for adopting appropriate forms of natural logic as target language for computational reasoning with descriptive natural language. Natural logics are stylized fragments of natural language where reasoning can be conducted directly by natural reasoning rules reflecting intui...... intuitive reasoning in natural language. The approach taken in this paper is to extend natural logic stepwise with a view to covering successively larger parts of natural language. We envisage applications for computational querying and reasoning, in particular within the life-sciences....

Natural gas trends

International Nuclear Information System (INIS)

Anderson, A.

1991-01-01

This book provides data on many facets of the natural gas industry. Topics include: Canadian, Mexican; US natural gas reserves and production; Mexican and US natural gas consumption; market conditions for natural gas in the US; and Canadian natural gas exports

Natural(es) remisión de V. ciencias natural(es).

OpenAIRE

2011-01-01

[ES] Definición del término Natural(es) remisión de V. ciencias natural(es). en el diccionario Dicter. [EN] Definition of the word Natural(es) remisión de V. ciencias natural(es). in the dictionary Dicter.

Natural Gas

OpenAIRE

Bakar, Wan Azelee Wan Abu; Ali, Rusmidah

2010-01-01

Natural gas fuel is a green fuel and becoming very demanding because it is environmental safe and clean. Furthermore, this fuel emits lower levels of potentially harmful by-products into the atmosphere. Most of the explored crude natural gas is of sour gas and yet, very viable and cost effective technology is still need to be developed. Above all, methanation technology is considered a future potential treatment method for converting the sour natural gas to sweet natural gas.

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...

Natural Nanoparticles: A Particular Matter Inspired by Nature

Directory of Open Access Journals (Sweden)

Sharoon Griffin

2017-12-01

Full Text Available During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as “synthetic” and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, “nano” does not always equate with “artificial”. Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent—and sometimes unexpected—advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions—pardon—suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses.

Natural Philosophy

OpenAIRE

Blair, Ann M.

2006-01-01

“Natural philosophy” is often used by European historians as an umbrella term to designate the study of nature before it can easily be identified with what we call “science” today, to avoid the modern and potentially anachronistic connotations of that term. But “natural philosophy” (and its equivalents in different languages) was also an actor's category, a term commonly used throughout the early modern period and typically defined quite broadly as the study of natural bodies. As the central ...

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.

Learning from nature: Nature-inspired algorithms

DEFF Research Database (Denmark)

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

2016-01-01

.), genetic and evolutionary strategies, artificial immune systems etc. Well-known examples of applications include: aircraft wing design, wind turbine design, bionic car, bullet train, optimal decisions related to traffic, appropriate strategies to survive under a well-adapted immune system etc. Based......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...

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 exempl...... 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....

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)

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

International Nuclear Information System (INIS)

1992-01-01

This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1991, as well as production volumes for the United States, and selected States and State subdivisions for the year 1991. 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 data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1991 is also presented

Radiation Damage Effects in Candidate Ceramics for Plutonium Immobilization: Final Report

International Nuclear Information System (INIS)

Strachan, Denis M.; Scheele, Randall D.; Icenhower, Jonathan P.; Buck, Edgar C.; Kozelisky, Anne E.; Sell, Rachel L.; Elovich, Robert J.; Buchmiller, William C.

2004-01-01

In this document, we summarize our study of the effects of radiation induced damage to the titanate ceramics that were to be the immobilization form for surplus weapons-grade Pu. In this study, we made five ceramic materials: pure-phase pyrochlore, pure-phase zirconolite, pyrochlore-rich baseline, zirconolite-rich baseline, and impurity baseline. Two-hundred specimens were made of which 130 contained approximately 10 mass% 238Pu and 70 contained 10 mass% 239Pu. The specimens containing 239Pu served as materials against which the behavior of the 238Pu-bearing specimens could be compared. In our studies, we measured the true density (density exclusive of surface connected porosity), bulk density, crystalline-phase composition with X-ray diffraction (XRD), and dissolution rates as radiation induced damage accumulated in the 238Pu-bearing specimens. We routinely took photographs of the specimens during each characterization period. From our studies, we determined that these materials swell less than 10% and generally less than 5%. As the material swells, some open porosity can be converted to closed porosity, often causing the true density to decrease more rapidly than the bulk density. In general, 3?1018 a/g of damage accumulation were required for the materials to become amorphous as determined with the XRD method. The order in which the phases became amorphous was brannerite, pyrochlore, and zirconolite with brannerite being the most susceptible to radiation induced damage. However, we also show that Pu is not evenly distributed amongst the phases when multiple phases are present. We were unsuccessful in making a pure brannerite to study. Therefore, the brannerite was always present with other phases. For a material containing about 10 mass% 239Pu, 3?1018 a/g represent about 500 years in the geologic repository. At no time in our studies was there evidence for microcracking in these materials, even upon close examination in a scanning-electron microscope . Upon

Naturalism and un-naturalism among the Cartesian physicians

OpenAIRE

Manning, Gideon

2008-01-01

Highlighting early modern medicine's program of explanation and intervention, I claim that there are two distinctive features of the physician's naturalism. These are, first, an explicit recognition that each patient had her own individual and highly particularized nature and, second, a self-conscious use of normative descriptions when characterizing a patient's nature as healthy (ordered) or unhealthy (disordered). I go on to maintain that in spite of the well documented Cartesian rejection ...

Natural gas monthly

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-01-01

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 Natural Gas Monthly features articles designed to assist readers in using and interpreting natural gas information.

Natural aphrodisiacs.

Science.gov (United States)

Shamloul, Rany

2010-01-01

The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

High temperature crystallographic and thermodynamic investigations on synthetic calzirtite (Ca2Zr5Ti2O16)

International Nuclear Information System (INIS)

Jafar, M.; Phapale, S.; Achary, S.N.; Mishra, R.; Tyagi, A.K.

2016-01-01

Immobilization of actinides in the high level waste (HLW) produced from nuclear reactors in durable host matrix is one of the important concerns in nuclear power technology. Rock analogue (SYNROC) ceramic composites of titanates and zirconates namely zirconolite, calzirtite etc. have been proposed as alternate host matrix for disposal of long lived fission products. These minerals have ability to incorporate or immobilize a wider variety of ions simultaneously without further segregation to any other phases and are stable in geothermal conditions. Knowledge of thermodynamic stability of these minerals is important for their deployment as host matrix for actinide waste disposal. In this work crystal structure and thermodynamic parameters of a mineral analogous titanate termed as calzirtite (Ca 2 Zr 5 Ti 2 O 16 ) has been determined

Incorporation of transuranic elements in titanate nuclear waste ceramics

International Nuclear Information System (INIS)

Matzke, H.J.; Ray, I.L.F.; Theile, H.; Trisoglio, C.; Walker, C.T.; White, T.J.

1990-01-01

The incorporation of actinide elements and their rare-earth element analogues in titanate nuclear waste forms in reviewed. New partitioning data are presented for three waste forms containing Purex waste simulant in combination with either NpO 2 , PuO 2 , or Am 2 O 3 . The greater proportion of transuranics partition between perovskite and zirconolite, while some americium may enter loveringite. Autoradiography revealed clusters of plutonium atoms which have been interpreted as unreacted dioxide or sesquioxide. It is concluded that the solid-state behavior of transuranic elements in titanate waste forms is poorly understood, certainly not well enough to tailor a ceramic for the incorporation of waste from reprocessing of fast breeder reactor fuel in which transuranic species are more abundant than in Purex waste

Oklo natural reactor

International Nuclear Information System (INIS)

Fujii, Isao

1985-01-01

In 1954, Professor Kazuo, Kuroda of Arkansas University in USA published the possibility that spontaneously generated natural nuclear reactors existed in prehistoric age. In 1972, 18 years after that, Commissariat a l'Energie Atomique published that in the Oklo uranium deposit in Gabon, Africa, a natural nuclear reactor was found. This fact was immediately informed to the whole world, but in Japan, its details have not necessarily been well known. The chance of investigating into this fact and visiting the Oklo deposit by the favor of COMUF, the owner of the Oklo deposit, was given, therefore, the state of the natural reactors, which has been known so far, is reported. At present, 12 natural reactors have been found in the vicinity of the Oklo deposit. The natural reactors were generated spontaneously in uranium deposits about 1.7 billion years ago when the isotopic abundance of U-235 was 3 %, and the chain reaction started naturally. When the concentration of U-235 lowered, the reaction stopped naturally. The abnormality in the U-235 abundance in natural uranium was found, and the cause was pursued. The evidence of the existence of natural reactors was shown. (Kako, I.)

Natural and near natural tropical forest values

Science.gov (United States)

Daniel H. Henning

2011-01-01

This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

A Natural Love of Natural Products

OpenAIRE

Kingston, David G. I.

2008-01-01

Recent research on the chemistry of natural products from the author?s group that led to the receipt of the ACS Ernest Guenther Award in the Chemistry of Natural Products is reviewed. REDOR NMR and synthetic studies established the T-taxol conformation as the bioactive tubulin-binding conformation, and these results were confirmed by the synthesis of compounds which clearly owed their activity or lack of activity to whether or not they could adopt the T-taxol conformation. Similar studies wit...

18 CFR 2.78 - Utilization and conservation of natural resources-natural gas.

Science.gov (United States)

2010-04-01

... conservation of natural resources-natural gas. 2.78 Section 2.78 Conservation of Power and Water Resources... INTERPRETATIONS Statements of General Policy and Interpretations Under the Natural Gas Act § 2.78 Utilization and conservation of natural resources—natural gas. (a)(1) The national interests in the development and utilization...

Nature gives us strength: exposure to nature counteracts ego-depletion.

Science.gov (United States)

Chow, Jason T; Lau, Shun

2015-01-01

Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

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…

Three Sorts of Naturalism

OpenAIRE

Fink, Hans

2006-01-01

In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding of what McDowell's own naturalism amounts to. I argue that nothing short of an absolute naturalism will do for a number of McDowell's own purposes, but that it is far from obvious that this is his posi...

Nature in Preschool

DEFF Research Database (Denmark)

Husted, Mia; Frøkjær, Thorleif

‘Nature and nature phenomena’ has formed a specific curriculum theme in Danish preschool since early childhood curriculum was prescribed by law in 2004. However, recent evaluations show that the implementation of an early childhood curriculum has not produced an increased pedagogical focus...... on ‘nature and nature phenomena’ in preschools (EVA 2012). This finding, along with an increased political interest in goals and measurable outcome of early childhood curriculum (Broström 2012), will be the starting point in our ambition to carry out a more thorough qualitative investigation into links...... between preschool teachers’ understanding and interest in teaching nature and the rather poor evaluation....

Naturalisms and religion

NARCIS (Netherlands)

Drees, Willem

1997-01-01

Such terms as materialism, naturalism, and near synonyms evoke strong negative reactions among many believers. However, the notion of naturalism has various meanings; implications for religion differ for the several varieties of naturalism. In this paper I analyze epistemological and ontological

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.

A Natural Language Architecture

OpenAIRE

Sodiya, Adesina Simon

2007-01-01

Natural languages are the latest generation of programming languages, which require processing real human natural expressions. Over the years, several groups or researchers have trying to develop widely accepted natural language languages based on artificial intelligence (AI). But no true natural language has been developed. The goal of this work is to design a natural language preprocessing architecture that identifies and accepts programming instructions or sentences in their natural forms ...

Natural history and temporalization: reflections on Buffon's Natural history

OpenAIRE

Galfione, María Verónica

2015-01-01

This article presents a rereading of Buffon´s Natural History in the light of the concepts of temporal reversibility and irreversibility. The goal is to determine to what extent Buffon introduces a transformationist concept of natural forms in this work. To that effect, the main points of classical natural history and the doctrine of preformed germs are analyzed. Subsequently, Buffon´s use of the temporal variable is considered. This examination shows that despite his rejection of the theory ...

Natural gums and modified natural gums as sustained-release carriers.

Science.gov (United States)

Bhardwaj, T R; Kanwar, M; Lal, R; Gupta, A

2000-10-01

Although natural gums and their derivatives are used widely in pharmaceutical dosage forms, their use as biodegradable polymeric materials to deliver bioactive agents has been hampered by the synthetic materials. These natural polysaccharides do hold advantages over the synthetic polymers, generally because they are nontoxic, less expensive, and freely available. Natural gums can also be modified to have tailor-made materials for drug delivery systems and thus can compete with the synthetic biodegradable excipients available in the market. In this review, recent developments in the area of natural gums and their derivatives as carriers in the sustained release of drugs are explored.

Three Sorts of Naturalism

DEFF Research Database (Denmark)

Fink, Hans

2006-01-01

In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding...

NATURAL GAS TRANSPORTATION

OpenAIRE

Stanis³aw Brzeziñski

2007-01-01

In the paper, Author presents chosen aspects of natural gas transportation within global market. Natural gas transportation is a technicaly complicated and economicly expensive process; in infrastructure construction and activities costs. The paper also considers last and proposed initiatives in natural gas transportation.

Natural gas outlook

International Nuclear Information System (INIS)

Molyneaux, M.P.

1998-01-01

An overview of natural gas markets in Canada and in the United States was provided. The major factors that determine the direction of natural gas prices were depicted graphically. Price volatility has decreased in recent months. As expected, April through November total energy consumption reached historically high levels. Demand for natural gas during the summer of 1997 was not as strong as anticipated. Nuclear energy appears to be on the slippery slope, with natural gas-driven electricity projects to fill the void. Hydroelectricity had a strong showing in 1997. Prospects are less bright for 1998 due to above average temperatures. Canadian natural gas export capacity has increased 5.5 times between 1986 and estimated 1999 levels. Despite this, in 1997, deliveries to the United States were marginally behind expectations. Natural gas consumption, comparative fuel prices, natural gas drilling activity, natural gas storage capacity, actual storage by region, and average weekly spot natural gas prices, for both the U. S. and Canada, were also provided. With regard to Canada, it was suggested that Canadian producers are well positioned for a significant increase in their price realization mostly because of the increase in Canada's export capacity in 1997 (+175 Mmcf/d), 1998 (1,060 Mmcf/d) and potentially in 1999 or 2000, via the Alliance Pipeline project. Nevertheless, with current production projections it appears next to impossible to fill the 10.9 Bcf/d of export capacity that will be potentially in place by the end of 1999. tabs., figs

Unnaturalised racial naturalism.

Science.gov (United States)

Hochman, Adam

2014-06-01

Quayshawn Spencer (2014) misunderstands my treatment of racial naturalism. I argued that racial naturalism must entail a strong claim, such as "races are subspecies", if it is to be a substantive position that contrasts with anti-realism about biological race. My recognition that not all race naturalists make such a strong claim is evident throughout the article Spencer reviews (Hochman, 2013a). Spencer seems to agree with me that there are no human subspecies, and he endorses a weaker form of racial naturalism. However, he supports his preferred version of 'racial naturalism' with arguments that are not well described as 'naturalistic'. I argue that Spencer offers us an unnaturalised racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

NATURAL LAW, HISTORY AND POLITICS LEY NATURAL, HISTORIA Y POLÍTICA LEI NATURAL, HISTÓRIA E POLÍTICA

Directory of Open Access Journals (Sweden)

James Drane

2002-01-01

Full Text Available The basic philosophical vision and ethical principles of Catholic Natural Law claim universality. Natural Law thinking aspires to objectivity and universality and at the same time is open to the continuing influence from history and politics. The background principles of positive law historically go by the name of Natural Law. Suffering and injustice contribute to a vision both of the structure of human existence and of what we mean by humane law and ethics. When we confront a cultural crisis, Natural Law, looks not to the past but to the future. Few people today talk of the ethical dimensions of social realities in terms of Natural Law. This is true both in the Church and in the State. In bioethics, the principles rooted in the universal structure of human life have to provide direction and regulations on the playing field of contemporary life and medicine. A liberal Catholic perspective tries to keep in play the universal and the particular aspects of Natural Law reasoningLa visión filosófica básica y los principios éticos de la Ley Natural Católica demandan universalidad. El pensamiento de la Ley Natural aspira a la objetividad y universalidad y, al mismo tiempo, está abierto a la continua influencia de la historia y la política. Los principios que yacen en la base de la ley positiva históricamente reciben el nombre de Ley Natural. El sufrimiento y la injusticia contribuyen a una visión, tanto de la estructura de la existencia humana como de lo que entendemos por una ley y una ética humanas. Cuando enfrentamos una crisis cultural, la Ley Natural no mira hacia el pasado sino que hacia el futuro. Es poca la gente que hoy en día habla de las dimensiones éticas de las realidades sociales en términos de Ley Natural. Esto vale tanto para la Iglesia como para el Estado. En bioética, los principios enraizados en la estructura universal de la vida humana tienen que proporcionar dirección y regulación en el campo de juego de la vida y

ECONOMIC NATURE AND THE ROLE OF NATURAL RESOURCES PAYMENTS UNDER SUSTAINABLE ECONOMIC DEVELOPMENT

Directory of Open Access Journals (Sweden)

A. Zalievska-Shyshak

2014-12-01

Full Text Available The nature and value of natural resources payments under sustainable economic development are revealed. Mechanisms of using of natural resources potential of Ukraine are examined. Payments for use of natural resources is one of the most important components of an economic mechanism of nature management are established. Features of current legislation as to the setting fees for nature management are studied and the necessity of creating an effective institutional support in controlling of tax authorities for the collection of payments for natural resources and their evaluation is proved.

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

Pluralising Nature

DEFF Research Database (Denmark)

Clemmensen, Thomas Juel

2017-01-01

suppress other valid perceptions, in conflict with the need for different groups of people to be able to identify with the same territory. However, planning for the common good, in the case of nature restoration, does not necessarily mean planning for one common nature. Understanding and working......Denmark is recognised for its democratic approach to planning, and for the idea of planning for the common good. This interest in the common good and in common values also seems to be reflected in the way that the restoration of nature is planned and managed, suggesting that there is one common...... “nature” that everyone can agree on. But nature restoration is far from being an unproblematic undertaking. As with any other type of heritage production, it can be the source of dissonance. As exemplified by the Skjern River Restoration Project, one perception of a landscape and its value as “nature” can...

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.

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

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.

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…

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....

Natural radiation

International Nuclear Information System (INIS)

Feliciano, Vanusa Maria Delage

2016-01-01

Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

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.

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

Plutonium in nature; Le plutonium dans la nature

Energy Technology Data Exchange (ETDEWEB)

Madic, C.

1994-12-31

Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases.

Francis Bacon's natural history and the Senecan natural histories of early modern Europe.

Science.gov (United States)

Jalobeanu, Dana

2012-01-01

At various stages in his career, Francis Bacon claimed to have reformed and changed traditional natural history in such a way that his new "natural and experimental history" was unlike any of its ancient or humanist predecessors. Surprisingly, such claims have gone largely unquestioned in Baconian scholarship. Contextual readings of Bacon's natural history have compared it, so far, only with Plinian or humanist natural history. This paper investigates a different form of natural history, very popular among Bacon's contemporaries, but yet unexplored by contemporary students of Bacon's works. I have provisionally called this form of natural history'Senecan' natural history, partly because it took shape in the Neo-Stoic revival of the sixteenth-century, partly because it originates in a particular cosmographical reading of Seneca's Naturales quaestiones. I discuss in this paper two examples of Senecan natural history: the encyclopedic and cosmographical projects of Pierre de la Primaudaye (1546-1619) and Samuel Purchas (1577-1626). I highlight a number of similarities between these two projects and Francis Bacon's natural history, and argue that Senecan natural history forms an important aspect in the historical and philosophical background that needs to be taken into consideration if we want to understand the extent to which Bacon's project to reform natural history can be said to be new.

Ceramics: Durability and radiation effects

Energy Technology Data Exchange (ETDEWEB)

Ewing, R.C.; Lutze, W. [Univ. of New Mexico, Albuquerque, NM (United States); Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

1996-05-01

At present, there are three seriously considered options for the disposition of excess weapons plutonium: (1) incorporation, partial burn-up and direct disposal of MOX-fuel; (2) vitrification with defense waste and disposal as glass {open_quotes}logs{close_quotes}; (3) deep borehole disposal. The first two options provide a safeguard due to the high activity of fission products in the irradiated fuel and the defense waste. The latter option has only been examined in a preliminary manner, and the exact form of the plutonium has not been identified. In this paper, we review the potential for the immobilization of plutonium in highly durable crystalline ceramics apatite, pyrochlore, zirconolite, monazite and zircon. Based on available data, we propose zircon as the preferred crystalline ceramic for the permanent disposition of excess weapons plutonium.

Within city limits: nature and children's books about nature in the city

Science.gov (United States)

Leonard S. Marcus

1977-01-01

Many children's books give the impression that we must leave the city to be "in nature.'' This is a review of children's books about nature found within city limits. The books include a natural history of New York City; a guide to city wildflowers and other weeds; a book about city trees; a delightful inquiry into the true nature of the roach;...

Framing nature

NARCIS (Netherlands)

Jansen, Peter

2017-01-01

This PhD thesis is about communication concerning nature in the Netherlands. The purpose of this exploratory study is to take both a theoretical and an empirical look at whether (implicit) religious elements play a role in this communication about nature in the Netherlands.

In this PhD

Defining Nature-Based Preschools

Science.gov (United States)

Larimore, Rachel

2016-01-01

Nature-based early childhood education. Nature-based preschool. Nature preschool. Forest kindergarten. Nature kindergarten. Waldkindergarten. Forest school. These are a few of the program terms currently being discussed among early childhood environmental education professionals in the United States. Why is there so much discussion about the names…

Nephrotoxicity of Natural Products.

Science.gov (United States)

Nauffal, Mary; Gabardi, Steven

2016-01-01

The manufacture and sale of natural products constitute a multi-billion dollar industry. Nearly a third of the American population admit to using some form of complementary or alternative medicine, with many using them in addition to prescription medications. Most patients fail to inform their healthcare providers of their natural product use and physicians rarely inquire. Annually, thousands of natural product-induced adverse events are reported to Poison Control Centers nationwide. Natural product manufacturers are not responsible for proving safety and efficacy, as the FDA does not regulate them. However, concerns exist surrounding the safety of natural products. This review provides details on natural products that have been associated with renal dysfunction. We have focused on products that have been associated with direct renal injury, immune-mediated nephrotoxicity, nephrolithiasis, rhabdomyolysis with acute renal injury, hepatorenal syndrome, and common adulterants or contaminants that are associated with renal dysfunction. The potential for natural products to cause renal dysfunction is justifiable. It is imperative that natural product use be monitored closely in all patients. Healthcare practitioners must play an active role in identifying patients using natural products and provide appropriate patient education. © 2016 S. Karger AG, Basel.

Nature-based integration

DEFF Research Database (Denmark)

Pitkänen, Kati; Oratuomi, Joose; Hellgren, Daniela

Increased attention to, and careful planning of the integration of migrants into Nordic societies is ever more important. Nature based integration is a new solution to respond to this need. This report presents the results of a Nordic survey and workshop and illustrates current practices of nature...... based integration by case study descriptions from Denmark, Sweden Norway and Finland. Across Nordic countries several practical projects and initiatives have been launched to promote the benefits of nature in integration and there is also growing academic interest in the topic. Nordic countries have...... the potential of becoming real forerunners in nature based integration even at the global scale....

Virtual nature environment with nature sound exposure induce stress recovery by enhanced parasympathetic activity

DEFF Research Database (Denmark)

Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

2013-01-01

. The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality......Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds...... of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings...

Modeling Child–Nature Interaction in a Nature Preschool: A Proof of Concept

Directory of Open Access Journals (Sweden)

Peter H. Kahn

2018-05-01

Full Text Available This article provides a proof of concept for an approach to modeling child–nature interaction based on the idea of interaction patterns: characterizations of essential features of interaction between humans and nature, specified abstractly enough such that countless different instantiations of each one can occur – in more domestic or wild forms – given different types of nature, people, and purposes. The model draws from constructivist psychology, ecological psychology, and evolutionary psychology, and is grounded in observational data collected through a time-sampling methodology at a nature preschool. Through using a nature language that emphasizes ontogenetic and phylogenetic significance, seven keystone interaction patterns are described for this nature preschool: using one’s body vigorously in nature, striking wood on wood, constructing shelter, being in solitude in nature, lying on earth, cohabiting with a wild animal, and being outside in weather. These 7 interactions patterns are then brought together with 13 other patterns published elsewhere to provide a total of 20 keystone interaction patterns that begin to fill out the model, and to show its promise. Discussion focuses on what the model aims to be in terms of both product and process, on what work the model can currently do, and how to further develop the model.

Teorias da lei natural: Pufendorf e Rousseau Natural law theories: Pufendorf and Rousseau

Directory of Open Access Journals (Sweden)

Luiz Felipe Netto de Andrade e Silva Sahd

2007-01-01

Full Text Available O presente artigo tem como objetivo reconstruir argumentos centrais desenvolvidos por Jean-Jacques Rousseau. Contra Samuel Pufendorf, Rousseau defende que a justiça não é natural. Ele recusa todo compromisso com a lei natural tradicional para voltar à posição de Thomas Hobbes. Ora, no estado originário de natureza, os princípios racionais da lei natural que expõe Pufendorf não podem ser conhecidos, e, por conseguinte, quando puderem ser conhecidos, não serão aplicados por natureza.The present article aims at reconstructing Jean-Jacques Rousseau’s central arguments. Against Samuel Pufendorf, Rousseau maintains that justice is not natural, thereby rejecting the compromise with traditional natural law and wholly returning to the position of Thomas Hobbes. Now, in the original state of nature, Pufendorf’s rational principles of natural law cannot be known; later, when they may be known, they are not by nature enforced.

Liquefied natural gas projects in Altamira: impacts on the prices of the natural gas; Proyectos de gas natural licuado en Altamira: impactos sobre los precios del gas natural

Energy Technology Data Exchange (ETDEWEB)

Perez Cordova, Hugo; Elizalde Baltierra, Alberto [Petroleos Mexicanos (PEMEX), (Mexico)

2004-06-15

The possible incorporation of new points of supply of natural gas to the Sistema National de Gasoductos (SNG) through the import of Liquified Natural Gas or (GNL) could cause an important modification in the national balance of supply-demand of the fuel and in its price, if large volumes are received. An analysis is presented of the possible impact that would have in the natural gas national market and in its prices the import of GNL made by the region of Altamira, Tamaulipas. [Spanish] La posible incorporacion de nuevos puntos de oferta de gas natural al Sistema Nacional de Gasoductos (SNG) a traves de la importacion de Gas Natural Licuado (GNL), podria provocar una modificacion importante en el balance oferta-demanda nacional del combustible y en su precio, si se reciben fuertes volumenes. Se presenta un analisis del posible impacto que tendria en el mercado nacional del gas natural y en sus precios la importacion de GNL realizada por la region de Altamira, Tamaulipas.

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.

Natural gas in India

International Nuclear Information System (INIS)

Lefevre, Thierry; Todoc, Jessie L.

1999-11-01

Contains Executive Summary and Chapters on: Country background; Overview of the energy sector; Natural gas supply; Natural gas infrastructure; Natural gas infrastructure; Natural gas demand; Outlook-government policy reform and industry development, and Appendices on Global and regional energy and gas trends; Overview of India's investment policy, incentives and regulation; The ENRON Dabhol power project. (Author)

US crude oil, natural gas, and natural gas liquids reserves 1996 annual report

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1996, as well as production volumes for the US and selected States and State subdivisions for the year 1996. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1996 is provided. 21 figs., 16 tabs.

Natural Dietary Phytosterols.

Science.gov (United States)

Racette, Susan B; Lin, Xiaobo; Ma, Lina; Ostlund, Richard E

2015-01-01

Most clinical phytosterol studies are performed by adding purified supplements to smaller phytosterol amounts present in the natural diet. However, natural dietary phytosterols themselves may also have important effects on cholesterol metabolism. Epidemiological work using food frequency questionnaires to estimate dietary intake suggest that extremes of normal consumption may be associated with 3-14% changes in LDL cholesterol. Standardized food databases do not have enough phytosterol values to allow calculation of phytosterol intake for individuals outside of specialized studies. Natural diets contain phytosterol amounts ranging from less than 60 mg/2000 kcal to over 500 mg/2000 kcal. Physiological studies in which whole body cholesterol metabolism is investigated show large effects of natural dietary phytosterols on cholesterol absorption efficiency, cholesterol biosynthesis and cholesterol excretion which exceed the magnitude of changes in LDL cholesterol. The dual effects of natural phytosterols on both LDL-C and whole body cholesterol metabolism need to be considered in relating them to potential protection from coronary heart disease risk.

US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report

Energy Technology Data Exchange (ETDEWEB)

1993-10-18

This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. 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 data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided.

US crude oil, natural gas, and natural gas liquids reserves, 1992 annual report

International Nuclear Information System (INIS)

1993-01-01

This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1992, as well as production volumes for the United States, and selected States and State subdivisions for the year 1992. 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 data presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1992 is provided

Novel natural food antimicrobials.

Science.gov (United States)

Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

2012-01-01

Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

Development of natural gas ocean transportation chain by means of natural gas hydrate (NGH)

International Nuclear Information System (INIS)

Nogami, T.; Oya, N.; Ishida, H.; Matsumoto, H.

2008-01-01

Recent studies in Japan have suggested that natural gas hydrate (NGH) transportation of natural gas is more economical than liquefied natural gas (LNG) transportation systems for small, medium and remote gas fields. Researchers in Japan have built a 600 kg per day NGH production and pelletizing plant and regasification facility. This paper discussed feasibility studies conducted in southeast Asia to determine the unit's commercialization potential with large natural gas-related businesses including shipping companies and electric power utilities. The total supply chain was compared with the corresponding liquefied natural gas (LNG) and compressed natural gas (CNG) supply chains. The study also examined natural gas reserves, energy policies, the positioning of natural gas supplies, and future forecasts of natural gas demand. A conceptual design for an NGH supply chain in Indonesia was presented. Results of the study have demonstrated that the NGH chain is an appropriate and economically feasible transportation method for many areas in southeast Asia. 8 refs., 10 figs

Querying Natural Logic Knowledge Bases

DEFF Research Database (Denmark)

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

2017-01-01

This paper describes the principles of a system applying natural logic as a knowledge base language. Natural logics are regimented fragments of natural language employing high level inference rules. We advocate the use of natural logic for knowledge bases dealing with querying of classes...... in ontologies and class-relationships such as are common in life-science descriptions. The paper adopts a version of natural logic with recursive restrictive clauses such as relative clauses and adnominal prepositional phrases. It includes passive as well as active voice sentences. We outline a prototype...... for partial translation of natural language into natural logic, featuring further querying and conceptual path finding in natural logic knowledge bases....

Culture inavouée dans la nature, nature soumise dans la culture

Directory of Open Access Journals (Sweden)

Claude Rivière

2001-12-01

Full Text Available On peut tirer de l'idée que l'on se fait de la nature, soit une apologie de l'ordre dans le cosmos, soit un argument pour justifier l'existence d'un Dieu maître de la foudre et des saisons, soit l'enchantement d'un retour à l'état de nature supposé non conflictuel, soit enfin une conviction matérialiste selon laquelle l'homme doit dompter sa gourmandise et assurer la survie optimale de l'environnement sans le polluer. La société n'est pas à penser comme une modalité d'oubli de la nature mais en rapport d'inclusion dans la nature. Après périple philosophique de Platon à Moscovici, on déviera dans le champ des artistes peignant d'après nature et dans celui des linguistes analysant ce qui est dit contre nature. C'est la culture qui oppose nature et convention, fait et norme, matière et liberté humaine. C'est elle aussi qui nous fournit notre vocabulaire, nos classifications et nos jugements de valeur à propos de la nature. Récemment un courant écologiste se pose en protecteur sourcilleux de l'environnement et en organisateur d'un développement durable, mais dans la deep ecology, on glisse vers le culte d'une biosphère de rêve.

Natural gas deregulation

International Nuclear Information System (INIS)

Ronchi, M.

1993-01-01

With the aim of establishing realistic options for deregulation in the natural gas industry, this paper first considers the structural evolution of this industry and evidences how it differs from the petroleum industry with which it exhibits some essential characteristics in common. This comparison is made in order to stress that, contrary to popular belief, that which is without doubt good for the petroleum industry is not necessarily so also for the natural gas industry. The paper concludes with separate analyses of the natural gas markets in the principal industrialized countries. Arguments are provided to show that the 'soft' deregulation option for the natural gas industry is not feasible, and that 'total' deregulation instead, backed by the passing of a suitable package of anti-trust laws 'unbundling' the industry's four major activities, i.e., production, storage, primary and secondary distribution, is the preferable option. The old concept of guaranteed supplies for minor users of natural gas should give way to the laws of supply and demand governing inter-fuel competition ensured through the strict supervision of vigilance committees

Okulo natural reactors

International Nuclear Information System (INIS)

Yamakawa, Minoru

1993-01-01

French CEA has reported in 1972 that natural nuclear reactors existed in Okulo uranium deposit in Gabon in Africa, that caused nuclear fission chain reaction (Okulo phenomena) spontaneously two billion years ago. The fission products and transuranic elements produced by the natural reactors have been preserved in strata without movement while subjected to geological phenomena for such very long years. 16 zones of the natural reactors have been discovered so far. The geological features of the Okulo uranium deposit are explained. The total amount of 235 U lost by the chain reaction was estimated to be about 6t, and the fission products were about 6t. The Okulo phenomena offered the valuable results of the synthetic formation disposal test that the nature has carried out for such long years. The significance of the study on natural analog is discussed. Organic substances and the mechanism of holding and movement of uranium and fission nuclides, the stability of uraninite and the age measurement of the deposit by Nd-Sm process are reported as the main results. (K.I.)

Natural gas purchasing

International Nuclear Information System (INIS)

Freedenthal, C.

1993-01-01

In recent years, natural gas has gained new momentum because of changes in marketing and regulations. The gas industry has always received an inordinate amount of regulatory control starting at the well head where the gas is produced to the consuming burner tip. Regulations have drastically impacted the availability of gas. Changes in the marketing and regulations have made the natural gas market sensitive at the point of production, the well head. Now, with plentiful supply and ease of transportation to bring the gas from the producing fields to the consumer, natural gas markets are taking advantage of the changed conditions. At the same time, new markets are developing to take advantage of the changes. This section shows consumers, especially the energy planners for large buyers of fuel, the advantages, sources and new methods of securing natural gas supplies. Background on how natural gas is produced and marketed are given. This section lists marketing sources, regulatory agencies and information groups available to help buyers and consumers of this important fuel for US industries and residences. 7 figs., 8 tabs

Natural gas marketing II

International Nuclear Information System (INIS)

Anon.

1988-01-01

This book covers all aspects of gas marketing, from the basic regulatory structure to the latest developments in negotiating agreements and locating markets. Topics include: Federal regulation of the gas industry; Fundamentals of gas marketing contracts; FERC actions encouraging competitive markets; Marketing conditions from the pipelines' perspective; State non-utility regulation of natural gas production, transportation, and marketing; Natural gas wellhead agreements and tariffs; Natural gas processing agreements; Effective management of producer's natural gas contracts; Producer-pipeline litigation; Natural gas purchasing from the perspective of industrial gas users; Gas marketing by co-owners: problems of disproportionate sales, gas balancing, and accounting to royalty owners; Alternatives and new directions in marketing

U.S. crude oil, natural gas, and natural gas liquids reserves 1997 annual report

Energy Technology Data Exchange (ETDEWEB)

Wood, John H.; Grape, Steven G.; Green, Rhonda S.

1998-12-01

This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1997, as well as production volumes for the US and selected States and State subdivisions for the year 1997. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1997 is provided. 21 figs., 16 tabs.

Solitonic natural orbitals

Science.gov (United States)

Cioslowski, Jerzy

2018-04-01

The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.

Natural short sleeper

Science.gov (United States)

Sleep - natural short sleeper ... 7 to 9 hours of sleep each night. Short sleepers sleep less than 75% of what is normal for their age. Natural short sleepers are different from people who chronically do ...

Alternative ways to transport natural gas; Transporte alternativo de gas natural

Energy Technology Data Exchange (ETDEWEB)

Moura, N.R.; Campos, F.B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2008-07-01

The Brazilian energy matrix has been showing a huge increase in the demand of natural gas due mainly to industries and power plants. Today the Brazilian gas market is supplied with gas produced by PETROBRAS and imported from Bolivia. To increase the Brazilian gas supply, on the short and middle term, PETROBRAS will import LNG (liquefied natural gas) and exploit the new offshore fields discovered on the pre-salt area. The only proven technology available today to bring this offshore gas to the market is the pipeline, but its costs for the pre-salt area are high enough to keep the solution economically attractive. So, PETROBRAS are evaluating and developing alternative ways to transport offshore gas, such as LNG, CNG (Compressed Natural Gas), GTS (Gas-to-Solids or Natural Gas Hydrates) and ANG (Adsorbed Natural Gas). Using information available in the literature, this paper analyses the main concepts of CNG and LNG floating unities. This paper also presents the PETROBRAS R and D results on ANG and GTS aiming at offshore application. (author)

Natural gas annual 1991

International Nuclear Information System (INIS)

1992-01-01

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 1991 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition form 1987 to 1991 are given for each Census Division and each State. Annual historical data are shown at the national level

Natural gas annual 1993

International Nuclear Information System (INIS)

1994-01-01

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 1993 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. Tables summarizing natural gas supply and disposition from 1989 to 1993 are given for each Census Division and each State. Annual historical data are shown at the national level

Natural radiation environment

International Nuclear Information System (INIS)

Vohra, K.G.; Mishra, U.C.; Pillai, K.C.; Sadasivan, S.

1982-01-01

The volume presented contains papers presented at the Second Special Symposium on Natural Radiation Environment held at Bombay, India, during January 1981. The papers deal with such topics as : 1)high natural radiation background areas; 2)environmental natural radioactivity; 3)measurement techniques; 4)technologically enhanced radioactivity; 5)indoor radiation environment; 6)radon and daughters in ambient air, and 7)applications in Geosciences. Each of the 87 papers presented has been abstracted and indexed for the U.S. Department of Energy Technical Information Center's Energy Data Base

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"…

TECHNOLOGY VS NATURE: HUMAN ERROR IN DEALING WITH NATURE IN CRICHTON'S JURASSIC PARK

Directory of Open Access Journals (Sweden)

Sarah Prasasti

2000-01-01

Full Text Available Witnessing the euphoria of the era of biotechnology in the late twentieth century, Crichton exposes the theme of biotechnology in his works. In Jurassic Park, he voices his concern about the impact of the use of biotechnology to preserve nature and its living creatures. He further describes how the purpose of preserving nature and the creatures has turned out to be destructive. This article discusses Crichton's main character, Hammond, who attempts to control nature by genetically recreating the extinct fossil animals. It seems that the attempt ignores his human limitations. Although he is confident that has been equipped with the technology, he forgets to get along with nature. His way of using technology to accomplish his purpose proves not to be in harmony with nature. As a consequence, nature fights back. And he is conquered.

21 CFR 172.510 - Natural flavoring substances and natural substances used in conjunction with flavors.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Natural flavoring substances and natural substances used in conjunction with flavors. 172.510 Section 172.510 Food and Drugs FOOD AND DRUG ADMINISTRATION....510 Natural flavoring substances and natural substances used in conjunction with flavors. Natural...

Natural gas annual 1995

International Nuclear Information System (INIS)

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

Constructing nature behind the glass

Directory of Open Access Journals (Sweden)

Samuel J.M.M. Alberti

2008-07-01

Full Text Available By way of introducing this special issue of Museum and Society, ‘Constructing nature behind glass’, this paper first surveys the literature devoted to analyses of natural history objects and collections. Such work is to be found in interesting places – not only in museum studies, history of science, and professional museum literature, but also in visual studies, anthropology and cultural geography. After exploiting this writing for different perspectives on the cultural and practical construction of museum nature, this paper moves on to consider one popular topic, taxidermy. The ambiguous nature of taxidermic mounts, or ‘remnant models’, leads to a discussion of the relative status of specimen and artefact. I identify four configurations of their relationship: museum nature as opposed to material culture; museum nature as material culture; museum nature and material culture sharing parallel processes; and finally, museum nature and material culture entangled. All offer perspectives on the construction of nature and culture behind glass.

Natural gas pricing

International Nuclear Information System (INIS)

Freedenthal, C.

1993-01-01

Natural gas pricing is the heart and soul of the gas business. Price specifically affects every phase of the industry. Too low a price will result in short supplies as seen in the mid-1970s when natural gas was scarce and in tight supply. To fully understand the pricing of this energy commodity, it is important to understand the total energy picture. In addition, the effect and impact of world and US economies, and economics in general are crucial to understanding natural gas pricing. The purpose of this presentation will be to show the parameters going into US natural gas pricing including the influence of the many outside industry factors like crude oil and coal pricing, market drivers pushing the gas industry, supply/demand parameters, risk management for buyers and sellers, and other elements involved in pricing analysis

Natural gas benefits

International Nuclear Information System (INIS)

1999-01-01

The General Auditor in the Netherlands studied the natural gas policy in the Netherlands, as has been executed in the past decades, in the period 1997-1999. The purpose of the study is to inform the Dutch parliament on the planning and the backgrounds of the natural gas policy and on the policy risks with respect to the benefits for the Dutch State, taking into account the developments in the policy environment. The final conclusion is that the proposed liberalization of the national natural gas market will result in a considerable deprivation of income for the State in case the benefit policy is not adjusted. This report includes a reaction of the Dutch Minister of Economic Affairs and an afterword of the General Auditor. In the appendix an outline is given of the natural gas policy

U.S. crude oil, natural gas, and natural gas liquids reserves 1995 annual report

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

The EIA annual reserves report series is the only source of comprehensive domestic proved reserves estimates. This publication is used by the Congress, Federal and State agencies, industry, and other interested parties to obtain accurate estimates of the Nation`s proved reserves of crude oil, natural gas, and natural gas liquids. These data are essential to the development, implementation, and evaluation of energy policy and legislation. This report presents estimates of proved reserves of crude oil, natural gas, and natural gas liquids as of December 31, 1995, as well as production volumes for the US and selected States and State subdivisions for the year 1995. Estimates are presented for the following four categories of natural gas: total gas (wet after lease separation), nonassociated gas and associated-dissolved gas (which are the two major types of wet natural gas), and total dry gas (wet gas adjusted for the removal of liquids at natural gas processing plants). In addition, reserve estimates for two types of natural gas liquids, lease condensate and natural gas plant liquids, are presented. Also included is information on indicated additional crude oil reserves and crude oil, natural gas, and lease condensate reserves in nonproducing reservoirs. A discussion of notable oil and gas exploration and development activities during 1995 is provided. 21 figs., 16 tabs.

Natural gas annual 1991

International Nuclear Information System (INIS)

1993-01-01

The Natural Gas Annual 1991 provides information on the supply and disposition of natural gas to a wide audience including industry, consumers Federal and State agencies, and education institutions. This report, the Natural Gas Annual 1991 Supplement: Company Profiles, presents a detailed profile of selected companies

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...

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...

Incremental natural gas resources through infield reserve growth/secondary natural gas recovery

Energy Technology Data Exchange (ETDEWEB)

Finley, R.J.; Levey, R.A.; Hardage, B.A.

1993-12-31

The primary objective of the Infield Reserve Growth/Secondary Natural Gas Recovery (SGR) project is to develop, test, and verify technologies and methodologies with near- to midterm potential for maximizing the recovery of natural gasfrom conventional reservoirs in known fields. Additional technical and technology transfer objectives of the SGR project include: To establish how depositional and diagenetic heterogeneities in reservoirs of conventional permeability cause reservoir compartmentalization and, hence, incomplete recovery of natural gas. To document examples of reserve growth occurrence and potential from fluvial and deltaic sandstones of the Texas gulf coast basin as a natural laboratory for developing concepts and testing applications to find secondary gas. To demonstrate how the integration of geology, reservoir engineering, geophysics, and well log analysis/petrophysics leads to strategic recompletion and well placement opportunities for reserve growth in mature fields. To transfer project results to a wide array of natural gas producers, not just as field case studies, but as conceptual models of how heterogeneities determine natural gas flow units and how to recognize the geologic and engineering clues that operators can use in a cost-effective manner to identify incremental, or secondary, gas.

Natural gas annual 1997

International Nuclear Information System (INIS)

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

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.

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....

Growing natural gas usage

International Nuclear Information System (INIS)

Saarni, T.

1996-01-01

Finnish natural gas usage topped the 3.3 billion cubic metre mark last year, up 3.6 % on the 1994 figure. Growth has increased now for 12 years in a row. Thanks to offtake by large individual users, the pipeline network has been expanded from South-East Finland to the Greater Helsinki area and central southern Finland. Natural gas plays a much larger role in this region than the 10 % accounted for by natural gas nationally would indicate. The growth in the share of Finland's energy use accounted for by natural gas has served to broaden the country's energy supply base. Natural gas has replaced coal and oil, which has considerably reduced the level of emissions resulting form energy generation

Improved polyphase ceramic form for high-level defense nuclear waste

International Nuclear Information System (INIS)

Harker, A.B.; Morgan, P.E.D.; Clarke, D.R.; Flintoff, J.J.; Shaw, T.M.

1983-01-01

An improved ceramic nuclear waste form and fabrication process have been developed using simulated Savannah River Plant defense high-level waste compositions. The waste form provides flexibility with respect to processing conditions while exhibiting superior resistance to ground water leaching than other currently proposed forms. The ceramic, consolidated by hot-isostatic pressing at 1040 0 C and 10,000 psi, is composed of six major phases, nepheline, zirconolite, a murataite-type cubic phase, magnetite-type spinel, a magnetoplumbite solid solution, and perovskite. The waste form provides multiple crystal lattice sites for the waste elements, minimizes amorphous intergranular material, and can accommodate waste loadings in excess of 60 wt %. The fabrication of the ceramic can be accomplished with existing manufacturing technology and eliminates the effects of radionuclide volatilization and off-gas induced corrosion experienced with the molten processes for vitreous form production

A natural compromise: a moderate solution to the GMO & "natural" labeling disputes.

Science.gov (United States)

Amaru, Stephanie

2014-01-01

In the United States, genetically modified (GM) foods are labeled no differently from their natural counterparts, leaving consumers with no mechanism for deciphering genetically modified food content. The Food and Drug Administration (FDA) has not formally defined the term "natural," which is frequently used on food labels despite consumer confusion as to what it means. The FDA should initiate a notice and comment rulemaking addressing the narrow issue of whether use of the word "natural" should be permitted oil GM food labels. Prohibition of the use of"natural" on genetically modified foods would mitigate consumer deception regarding genetically modified food content without significantly disadvantaging genetically modified food producers.

US crude oil, natural gas, and natural gas liquids reserves: 1990 annual report

International Nuclear Information System (INIS)

1991-09-01

The primary focus of this report is to provide an accurate estimate of US proved reserves of crude oil, natural gas, and natural gas liquids. These estimates were considered essential to the development, implementation, and evaluation of natural energy policy and legislation. In the past, the government and the public relied upon industry estimates of proved reserves. These estimates were prepared jointly by the American Petroleum Institute (API) and the American Gas Association (AGA) and published in their annual report, Reserves of Crude Oil, Natural Gas Liquids, and Natural Gas in the United States and Canada. However, API and AGA ceased publication of reserves estimates after their 1979 report. By the mid-1970's, various federal agencies had separately established programs to collect data on, verify, or independently estimate domestic proved reserves of crude oil or natural gas. Each program was narrowly defined to meet the particular needs of the sponsoring agency. In response to recognized need for unified, comprehensive proved reserves estimates, Congress in 1977 required the Department of Energy to prepare such estimates. To meet this requirement, the EIA's reserves program was undertaken to establish a unified, verifiable, comprehensive, and continuing statistical series for proved reserves of crude oil and natural gas. The program was expanded to include proved reserves of natural gas liquids in the 1979 report. 36 refs., 11 figs., 16 tabs

Is disease a natural kind?

Science.gov (United States)

D'Amico, R

1995-10-01

In The Nature of Disease, Lawrie Reznek argues that disease is not a natural kind term. I raise objections to Reznek's two central arguments for establishing that disease is not a natural kind. In criticizing his a priori, conceptual argument against naturalism, I argue that his conclusion rests on a weaker argument that appeals to the empirical diversity in the symptoms and manifestations of disease. I also raise questions about the account of natural kinds which Reznek utilizes and his point that conventions for classification are excluded by there being natural kinds.

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...

LNG (Liquefied Natural Gas): the natural gas becoming a world commodity and creating international price references; GNL (Gas Natural Liquefeito): o gas natural se tornando uma commodity mundial e criando referencias de preco internacionais

Energy Technology Data Exchange (ETDEWEB)

Demori, Marcio Bastos [PETROBRAS, Rio de Janeiro, RJ (Brazil). Coordenacao de Comercializacao de Gas e GNL; Santos, Edmilson Moutinho dos [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Programa Interunidades de Pos-Graduacao em Energia (PIPGE)

2004-07-01

The transportation of large quantities of natural gas through long distances has been done more frequently by Liquefied Natural Gas (LNG). The increase of natural gas demand and the distance of major reserves, allied to technological improvements and cost reduction through LNG supply chain, have triggered the expressive increase of LNG world market This paper tries to evaluate the influence that LNG should cause on natural gas world market dynamic, analyzing the tendency of gas to become a world commodity, creating international price references, like oil and its derivates. For this, are shown data as natural gas world reserves, the participation of LNG in natural gas world market and their increase. Furthermore, will be analyzed the interaction between major natural gas reserves and their access to major markets, still considering scheduled LNG projects, the following impacts from their implementation and price arbitrage that should be provoked on natural gas markets. (author)

God, design, and naturalism: Implications of methodological naturalism in science for science-religion relation

Directory of Open Access Journals (Sweden)

Piotr Bylica

2015-03-01

Full Text Available The aim of this paper is to analyze the implications flowing from adopting methodological naturalism in science, with special emphasis on the relation between science and religion. Methodological naturalism, denying supernatural and teleological explanations, influences the content of scientific theories, and in practice leads to vision of science as compatible with ontological naturalism and in opposition to theism. Ontological naturalism in turn justifies the acceptance of methodological naturalism as the best method to know the reality. If we accept realistic interpretation of scientific theories, then methodological naturalism conflicts science with religion. Theistic evolution does not seem to be a proper way to reconcile Darwinism and methodological naturalism with theism. Many of such propositions are boiled down to deism. Although evolution can be interpreted theistically, it is not the way in which majority of modern scientists and respectable scientific institutions understand it.

A natural adsorbent for natural gas industry; Um adsorvente nacional para a industria do gas natural

Energy Technology Data Exchange (ETDEWEB)

Cachina, G.H.A.B.; Silveira, V.R.; Melo, D.M.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Balthar, A.R.; Oliveira, V.M.; Bayer, M.M. [CTGAS - Centro de Tecnologias do Gas, Natal, RN (Brazil); Barbosa, C.M.M. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

2004-07-01

One the natural pollutants in the natural gas considered critical in reference to the corrosion is the H{sub 2}S. Its presence depends on the origin, as well as the own process used in the gas treatment, it can bring problems to the pipes and the final applications of natural gas (NG). The National Petroleum Agency (ANP) in its entrance number 104/02, establishes that the quantity of H{sub 2}S in NG, of national or imported origin, commercialized at the country can only be at the most 10 - 15 mg/m{sup 3}. In the Natural Gas Processing Unit (UPGN) different methods are used for the removal of H{sub 2}S, the absorption process (e.g. with aminas, Sulfinol{sup R} process) or for adsorption in tower filled with activated coal, zeolites and Sulfatreat{sup R}. In this work, the adsorbent material used is the mineral clay Paligorsquita. That class of clay minerals characterized by pores and a crystalline structure containing Tetrahedral layers linked by chains of longitudinal secondary lines. The typical unitary cell is formed basically by moisturized oxides of aluminum, Sicilian and magnesium of (Mg, Al)5SiO2O(OH)2(H20)4.4H20, with Mg specially located in octahedral sites. (author)

Nature as Dissonant Heritage

DEFF Research Database (Denmark)

Clemmensen, Thomas Juel

2014-01-01

accepts that nature it not existing outside culture as something that be restored to its original state, but a contemporary product created and managed with certain objectives in mind, nature restoration like heritage production are prone to same kind of dissonance – our nature is not necessary...... their nature. According to Ashworth cultural dissonance can be managed in a number of different way depending on which type of plural society is preferred. Many of these management strategies consciously or unconsciously involve some form of denial, neglect, destruction, reinterpretation or marginalizing...

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.

Symmetries in nature

International Nuclear Information System (INIS)

Mainzer, K.

1988-01-01

Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs

Symmetries in nature

Energy Technology Data Exchange (ETDEWEB)

Mainzer, K

1988-05-01

Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs.

Natural gas in Mexico

International Nuclear Information System (INIS)

Ramirez, M.

1999-01-01

A series of overhead viewgraphs accompanied this presentation which focused on various aspects of the natural gas industry in Mexico. Some of the viewgraphs depicted statistics from 1998 regarding natural gas throughput from various companies in North America, natural gas reserves around the world, and natural gas reserves in Mexico. Other viewgraphs depicted associated and non-associated natural gas production from 1988 to 1998 in million cubic feet per day. The Burgos Basin and the Cantarell Basin gas production from 1997 to 2004 was also depicted. Other viewgraphs were entitled: (1) gas processing infrastructure for 1999, (2) cryogenic plant at Cd. PEMEX, (3) average annual growth of dry natural gas production for 1997-2004 is estimated at 5.2 per cent, (4) gas flows for December 1998, (5) PGPB- interconnect points, (6) U.S. Mexico gas trade for 1994-1998, (7) PGPB's interconnect projects with U.S., and (8) natural gas storage areas. Technological innovations in the industry include more efficient gas turbines which allow for cogeneration, heat recovery steam generators which reduce pollutant emissions by 21 per cent, cold boxes which increase heat transfer efficiency, and lateral reboilers which reduce energy consumption and total costs. A pie chart depicting natural gas demand by sector shows that natural gas for power generation will increase from 16 per cent in 1997 to 31 per cent in 2004. The opportunities for cogeneration projects were also reviewed. The Comision Federal de Electricidad and independent power producers represent the largest opportunity. The 1997-2001 investment program proposes an 85 per cent sulphur dioxide emission reduction compared to 1997 levels. This presentation also noted that during the 1998-2001 period, total ethane production will grow by 58 tbd. 31 figs

Natural Hazards, Second Edition

Science.gov (United States)

Rouhban, Badaoui

Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

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...

Textbook for nature entrepreneurship : product of the WURKS project Nature Entrepreneurship and Tourism within Green Education (NatureToGo)

NARCIS (Netherlands)

Felder, M.; Pellis, A.

2013-01-01

In recent years, government funding for nature conservation and development has declined. As a result, links between nature conservation and entrepreneurship are increasingly being made in both practice and education. This comes with many questions and challenges. In Green Secondary Vocational

The "History" of Victorian Scientific Naturalism: Huxley, Spencer and the "End" of natural history.

Science.gov (United States)

Lightman, Bernard

2016-08-01

As part of their defence of evolutionary theory, T. H. Huxley and Herbert Spencer argued that natural history was no longer a legitimate scientific discipline. They outlined a secularized concept of life from biology to argue for the validity of naturalism. Despite their support for naturalism, they offered two different responses to the decline of natural history. Whereas Huxley emphasized the creation of a biological discipline, and all that that entailed, Spencer was more concerned with constructing an entire intellectual system based on the idea of evolution. In effect, Spencer wanted to create a new scientific worldview based on evolutionary theory. This had consequences for their understanding of human history, especially of how science had evolved through the ages. It affected their conceptions of human agency, contingency, and directionality in history. Examining Huxley's and Spencer's responses to the "end" of natural history reveals some of the deep divisions within scientific naturalism and the inherent problems of naturalism in general. Whereas Huxley chose to separate the natural and the historical, Spencer opted to fuse them into a single system. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

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

Finland's leading natural gas company

International Nuclear Information System (INIS)

Anon.

2000-01-01

The ownership structure of Finland's leading natural gas company, Gasum, changed fundamentally in 1999, and the company is now no longer a subsidiary of Fortum Corporation. 'Our new strong and broad ownership base will enable us to develop the natural gas business and pipeline network in Finland in response to the requirements of our Finnish customers', says Antero Jaennes, Gasum's Chairman and CEO, who stresses that Gasum is committed to remaining the leading developer of the Finnish natural gas market and the number-one gas supplier. Natural gas usage in Finland in 1999 totalled 3.9 billion m 3 (38.7 TWh), unchanged from 1998. Natural gas accounted for 11% of Finland's total primary energy need, as it did in 1998. The proportion of natural gas used in district heating rose by 2% to 36%, and moved down 2% in power generation to 10%. Industry's use of natural gas fell 1% to 17%. 75% of natural gas was used in combined heat and power (CHP) generation in industry and district heating. In 2000, Gasum expects to sell 4 billion m 3 of natural gas (40 TWh)

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....

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...

75 FR 13524 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

Science.gov (United States)

2010-03-22

... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... notice that on March 5, 2010, Northern Natural Gas Company (Northern Natural), 1111 South 103rd Street, Omaha, Nebraska 68124- 1000, filed on behalf of itself and other owners, Southern Natural Gas Company...

Colour agnosia impairs the recognition of natural but not of non-natural scenes.

Science.gov (United States)

Nijboer, Tanja C W; Van Der Smagt, Maarten J; Van Zandvoort, Martine J E; De Haan, Edward H F

2007-03-01

Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

God, design, and naturalism: Implications of methodological naturalism in science for science-religion relation

OpenAIRE

Piotr Bylica; Dariusz Sagan

2015-01-01

The aim of this paper is to analyze the implications flowing from adopting methodological naturalism in science, with special emphasis on the relation between science and religion. Methodological naturalism, denying supernatural and teleological explanations, influences the content of scientific theories, and in practice leads to vision of science as compatible with ontological naturalism and in opposition to theism. Ontological naturalism in turn justifies the acceptance of methodological na...

Natural gas for vehicles

International Nuclear Information System (INIS)

Prieur, A.

2006-01-01

Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities

Natural radioactivity in water supplies

International Nuclear Information System (INIS)

Horner, J.K.

1985-01-01

This book outlines the scientific aspects of the control of natural radioactivity in water supplies, as well as the labyrinthine uncertainties in water quality regulation concerning natural radiocontamination of water. The author provides an introduction to the theory of natural radioactivity; addresses risk assessment, sources of natural radiocontamination of water, radiobiology of natural radioactivity in water, and federal water law concerning natural radiocontamination. It presents an account of how one city dealt with the perplexes that mark the rapidly evolving area of water quality regulation. The contents include: radioactivity and risk; an introduction to the atomic theory; an introduction to natural radioactivity; risk assessment; uranium and radium contamination of water; radiobiology of uranium and radium in water. Determination of risk from exposure to uranium and radium in water; the legal milieu; one city's experience; and summary: the determinants of evolving regulation

The Ecology of Hope: Natural Guides to Building a Children and Nature Movement

Science.gov (United States)

Charles, Cheryl

2009-01-01

Cheryl Charles, Ph.D gave the 2009 Paul F-Brandwein Lecture. The lecture addresses the impact of children's disconnect from the natural world in their everyday lives. Co-founder of the Children & Nature Network (C&NN) with Richard Louv, author of "Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder" (2005/2008), the author…

What's nature got to do with it? A situated historical perspective on socio-natural commodities.

Science.gov (United States)

Peluso, Nancy Lee

2012-01-01

Nature(s) have been commodified since the early days of capitalism, but through processes and socio-natural relationships mediated by their times, histories and localities. While the conditions under which nature's commodities are being trademarked today may be new, their potential for commodification is not. Commodifications of nature should not come as a surprise to environmental social scientists and activists. In this article, I argue that commodification of ‘nature's products, places and processes’ produces new sorts of socio-natures. Situated histories of rubber are particularly relevant because, like carbon, ecosystem services and other recently commodified natures, rubber sits comfortably on the line between a fictitious commodity and a commodity produced explicitly for market: the latex alone has almost no use value, and to give it any exchange value, it requires processing. Yet analytically, it is still considered a ‘natural commodity’, different from ‘synthetic rubber’ and other tradable tree latexes in qualities and socio-natural characteristics. However, it is the social relations constituting rubber's production and trade in various rainforest and agro-forestry environments that have given it a positive or negative connotation, rather than its natural properties or the ecological contexts within which it has been produced. By situating rubber in three of its globally important temporal and spatial contexts, I show how it has been subjected to fairy-tale-like stories that masked and naturalized its commodity lives of the moment. Understanding how history is told or remains untold is thus an essential part of the politics of knowledge production, but also of human experience and mobilization for change. It should be part of any political ecology analysis.

Natural gas prices

International Nuclear Information System (INIS)

Johnson, W.A.

1990-01-01

Since the 1970s, many electric utilities and industrial boiler fuel users have invested in dual fuel use capability which has allowed them to choose between natural gas, residual fuel oil, and in some instances, coal as boiler fuels. The immediate reason for this investment was the need for security of supply. Wellhead regulation of natural gas prices had resulted in shortages during the 1970s. Because many industrial users were given lowest priority in pipeline curtailments, these shortages affected most severely boiler fuel consumption of natural gas. In addition, foreign supply disruptions during the 1970s called into question the ready availability of oil. Many boiler fuel users of oil responded by increasing their ability to diversify to other sources of energy. Even though widespread investment in dual fuel use capability by boiler fuel users was initially motivated by a need for security of supply, perhaps the most important consequence of this investment was greater substitutability between natural gas and resid and a more competitive boiler fuel market. By the early 1980s, most boiler fuel users were able to switch from one fuel to another and often did for savings measured in pennies per MMBtu. Boiler fuel consumption became the marginal use of both natural gas and resid, with coal a looming threat on the horizon to both fuels

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.

Market prospective of natural gas 2010-2025; Prospectiva del mercado de gas natural 2010-2025

Energy Technology Data Exchange (ETDEWEB)

Diaz Bautista, Alejandro; Doniz Gonzalez, Virginia; Navarrete Barbosa, Juan Ignacio [Secretaria de Energia, Mexico, D.F. (Mexico)

2010-07-01

The Ministry of Energy, in compliance to Article 109 of the Natural Gas Regulations, publishes the Prospective natural gas market 2010-2025, which contains the most current information about the historical evolution and growth prospects of the domestic market country's natural gas and its role in the international context. This foresight is attached to the lines of action established in the National Energy Strategy, ratified by Congress in April 2010 in regard to strengthening the transportation infrastructure of natural gas, in order to ensure the supply of this fuel, therefore remains congruence with the instruments of power sector planning. The first one concerns the international panorama of natural gas in the different producing and consuming regions around the world. Chapter two provides a current perspective of those actions in the sector within the regulatory framework for natural gas in Mexico. The third chapter details the issues that occurred in the natural gas market during the period 1999-2009 and the fourth chapter discusses the expected evolution of demand and domestic supply of natural gas by 2025. [Spanish] La Secretaria de Energia, en el cumplimiento al Articulo 109 del Reglamento de Gas Natural, publica la Prospectiva del mercado de gas natural 2010-2025, la cual contiene la informacion mas actualizada acerca de la evolucion historica y las expectativas de crecimiento del mercado interno de gas natural del pais y su papel en el contexto internacional. Esta Prospectiva se apega a las lineas de accion establecidas en la Estrategia Nacional de Energia, ratificada por el Congreso en abril de 2010, en lo relativo a fortalecer la infraestructura de transporte de gas natural, con el fin de asegurar el suministro de este combustible, por lo cual se mantiene congruencia con los instrumentos de planeacion del sector energetico. La Prospectiva esta integrada por cuatro capitulos. El primero se refiere al panorama internacional del gas natural en las

English Nature's ''natural areas'': a different look at the countryside

International Nuclear Information System (INIS)

Kirby, K.J.

1994-01-01

Nature conservation is often equated with the protection of nature reserves and other special sites. However in England such sites are now often surrounded by agricultural land of limited wildlife value. There is no guarantee that the plants and animal communities that we have inherited can be maintained in island-like patches. Therefore we must try to make the countryside in-between richer as well. The current changing agricultural and forestry scenes mean that there is a good possibility that this can be achieved. Short rotation coppice (SRC) is one of the new land-uses whose impact we need to consider. Studies to date indicate that it is a richer habitat than arable land or heavily improved grassland at the level of the individual field. Our concern in the countryside as a whole however is how blocks of SRC relate to other habitats and features; are there better alternative uses (from a wildlife point of view) in a particular landscape? The description of the current state and long-term objectives for particular Natural Areas should help us to make such decisions in a consistent way. Use of wood for fuel from traditional coppice is also likely to benefit nature conservation by bringing neglected woods back into rotation. Where large schemes are proposed however there are a number of issues related primarily to the timing of the work and methods of harvesting that may need adjustment to prevent damage to sensitive sites. Involvement of English Nature staff at an early stage should make it easier to resolve any potential problems. (Author)

Natural gas monthly, August 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-24

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. This month`s feature article is on US Natural Gas Imports and Exports 1994.

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.

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

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

Modeling Natural Selection

Science.gov (United States)

Bogiages, Christopher A.; Lotter, Christine

2011-01-01

In their research, scientists generate, test, and modify scientific models. These models can be shared with others and demonstrate a scientist's understanding of how the natural world works. Similarly, students can generate and modify models to gain a better understanding of the content, process, and nature of science (Kenyon, Schwarz, and Hug…

Short-term outlook for natural gas and natural gas liquids to 2006 : an energy market assessment

International Nuclear Information System (INIS)

2005-10-01

In recent years, natural gas markets in North America have seen a close balance between supply and demand, resulting in high and volatile natural gas prices. The National Energy Board monitors the supply of all energy commodities in Canada along with the demand for Canadian energy commodities in domestic and export markets. This is the NEB's first energy market assessment report that presents a combined short-term analysis and outlook of natural gas and natural gas liquids (NGLs), such as ethane, propane and butane. It provides comprehensive information on the complexity of natural gas and NGL industries and highlights recent developments and topical issues. As a major producer of natural gas, western Canada has a correspondingly large natural gas processing capability that was developed specifically to extract NGLs. A world-scale petrochemical industry was developed in Alberta to convert NGLs into even higher valued products such as ethylene. Since NGLs in Canada are sourced mostly from natural gas, changes to the supply and demand for natural gas would impact NGL supply. This report addressed the issue of commodity prices with reference to crude oil, natural gas and NGL prices. Natural gas supply in terms of North American production and natural gas from coal (NGC) was also reviewed along with natural gas demand for residential and commercial heating, industrial use, power generation, and enhanced recovery for oil sand operations. There are about 692 gas plants in Canada that process raw natural gas into marketable gas and NGLs. Most are small field plants that process raw natural gas production to remove impurities such as sulphur, water and other contaminants. This report also discussed this infrastructure, with reference to field plants, straddle plants, pipelines, distribution and storage, including underground NGL storage. 3 tabs., 27 figs., 5 appendices

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.

"Diseases and natural kinds".

Science.gov (United States)

Sulmasy, Daniel P

2005-01-01

David Thomasma called for the development of a medical ethics based squarely on the philosophy of medicine. He recognized, however, that widespread anti-essentialism presented a significant barrier to such an approach. The aim of this article is to introduce a theory that challenges these anti-essentialist objections. The notion of natural kinds presents a modest form of essentialism that can serve as the basis for a foundationalist philosophy of medicine. The notion of a natural kind is neither static nor reductionistic. Disease can be understood as making necessary reference to living natural kinds without invoking the claim that diseases themselves are natural kinds. The idea that natural kinds have a natural disposition to flourish as the kinds of things that they are provides a telos to which to tether the notion of disease - an objective telos that is broader than mere survival and narrower than subjective choice. It is argued that while nosology is descriptive and may have therapeutic implications, disease classification is fundamentally explanatory. Sickness and illness, while referring to the same state of affairs, can be distinguished from disease phenomenologically. Scientific and diagnostic fallibility in making judgments about diseases do not diminish the objectivity of this notion of disease. Diseases are things, not kinds. Injury is a concept parallel to disease that also makes necessary reference to living natural kinds. These ideas provide a new possibility for the development of a philosophy of medicine with implications for medical ethics.

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.

Naturalness and image quality : saturation and lightness variation in color images of natural scenes

NARCIS (Netherlands)

Ridder, de H.

1996-01-01

The relation between perceived image quality and naturalness was investigated by varying the colorfulness of natural images at various lightness levels. At each lightness level, subjects assessed perceived colorfulness, naturalness, and quality as a function of average saturation by means of direct

The Unnatural Nature of Nature and Nurture: Questioning the Romantic Heritage

Science.gov (United States)

Stables, Andrew

2009-01-01

From a cultural-historical perspective, nature and nurture (and thus education) are contested concepts. The paper focuses on the nature/nurture debate in the work of William Shakespeare (influenced by Montaigne) and in the Romantic tradition (evidenced by Rousseau and Wordsworth), and argues that while our Romantic inheritance (still highly…

Kant on the history of nature: the ambiguous heritage of the critical philosophy for natural history.

Science.gov (United States)

Sloan, Phillip R

2006-12-01

This paper seeks to show Kant's importance for the formal distinction between descriptive natural history and a developmental history of nature that entered natural history discussions in the late eighteenth century. It is argued that he developed this distinction initially upon Buffon's distinctions of 'abstract' and 'physical' truths, and applied these initially in his distinction of 'varieties' from 'races' in anthropology. In the 1770s, Kant appears to have given theoretical preference to the 'history' of nature [Naturgeschichte] over 'description' of nature [Naturbeschreibung]. Following Kant's confrontations with Johann Herder and Georg Forster in the late 1780s, Kant weakened the epistemic status of the 'history of nature' and gave theoretical preference to 'description of nature'. As a result, Kant's successors, such as Goethe, could draw from Kant either a justification for a developmental history of nature, or, as this paper argues, a warrant from the critical philosophy for denying the validity of the developmental history of nature as anything more than a 'regulative' idea of reason.

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.

Natural photonic crystals

International Nuclear Information System (INIS)

Vigneron, Jean Pol; Simonis, Priscilla

2012-01-01

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.

Natural and technologic hazardous material releases during and after natural disasters: a review.

Science.gov (United States)

Young, Stacy; Balluz, Lina; Malilay, Josephine

2004-04-25

Natural disasters may be powerful and prominent mechanisms of direct and indirect hazardous material (hazmat) releases. Hazardous materials that are released as the result of a technologic malfunction precipitated by a natural event are referred to as natural-technologic or na-tech events. Na-tech events pose unique environmental and human hazards. Disaster-associated hazardous material releases are of concern, given increases in population density and accelerating industrial development in areas subject to natural disasters. These trends increase the probability of catastrophic future disasters and the potential for mass human exposure to hazardous materials released during disasters. This systematic review summarizes direct and indirect disaster-associated releases, as well as environmental contamination and adverse human health effects that have resulted from natural disaster-related hazmat incidents. Thorough examination of historic disaster-related hazmat releases can be used to identify future threats and improve mitigation and prevention efforts.

Natural Information Processing Systems

OpenAIRE

John Sweller; Susan Sweller

2006-01-01

Natural information processing systems such as biological evolution and human cognition organize information used to govern the activities of natural entities. When dealing with biologically secondary information, these systems can be specified by five common principles that we propose underlie natural information processing systems. The principles equate: (1) human long-term memory with a genome; (2) learning from other humans with biological reproduction; (3) problem solving through random ...

An Overview of Some Natural Products with Two A-Level Science Club Natural Products Experiments

Science.gov (United States)

Sosabowski, Michael Hal; Olivier, George W. J.; Jawad, Hala; Maatta, Sieja

2017-01-01

Natural products are ubiquitous in nature but do not form a large proportion of the A-level syllabuses in the UK. In this article we briefly discuss a small selection of natural products, focusing on alcohols, aldehydes and ketones, and alkaloids. We then outline two natural product experiments that are suitable for A-level chemistry clubs or…

MnO2/MCMB electrocatalyst for all solid-state alkaline zinc-air cells

International Nuclear Information System (INIS)

Zhang, G.Q.; Zhang, X.G.

2004-01-01

Nanostructured MnO 2 /mesocarbon microbeads (MCMB) composite has been prepared successfully for use in zinc-air cell as electrocatalyst for oxygen reaction. The scanning electron microscope (SEM) images showed that the MnO 2 nanorods were formed and covered on the surface of MCMB in bird's nest morphology. X-ray diffraction (XRD) pattern indicated that the MnO 2 has the hollandite structure with a composition approximating KMn 8 O 16 . By the cathodic polarization curve tests, the nanostructured material demonstrated excellent electrocatalytic activity as a kind of oxygen electrode electrocatalyst compared with electrolytic MnO 2 . An all solid-state zinc-air cell has been fabricated with this material as electrocatalyst for oxygen electrode and potassium salt of cross-linked poly(acrylic acid) as an alkaline polymer gel electrolyte. The cell has good discharge characteristics at room temperature

Orlice Nature Park - environmental themes

International Nuclear Information System (INIS)

Hanus, L.

2002-01-01

The aim of this abstract is to outline the main characteristics of Orlice Nature Park and of the procedure of Environmental Impact Assessment (EIA), and to evaluate public interest in the nature park and in nature protection in general. Orlice Nature Park was instituted in 1996. The function of the park is to protect the character of the area of landscape around the River Orlice. Orlice Natural Park covers an area of 115 sq. km. The main environmental risks to the park are: intensive agriculture, forest mono-culture, industry, transport, channel improvement, the building of holiday cottages, sport, and recreation. Among the conflicts of interest in the park are: nature protection, water management, building constrictions, business, fishery, water sports and recreation. During the process of Environmental Impact Assessment in Hradec Kralove, the public voiced its opinion against the building of a supermarket within the grounds of of the nature park. In this case the public showed its interest in the value of nature and landscape, the value of human health and the value of plant species. In general, the public and the local media show an interest in the park only in exceptional circumstances. (author)

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…

European natural gas

International Nuclear Information System (INIS)

Thackeray, Fred

1999-11-01

Contains Executive Summary and Chapters on: Main issues; Natural gas consumption and supply: statistics and key features of individual countries; Sectoral natural gas consumption; Indigenous production; Imports; Prices and taxes; The spot market: The interconnector; Forecasts of production and consumption and contracted imports; Progress of markets liberalisation; Effects of environmentalist developments; Transmission networks and storage; Some principal players. (Author)

The Science of Middle Nature

Science.gov (United States)

Pataki, D. E.; Pincetl, S.

2012-12-01

In the field of biogeochemistry, urbanization is often considered as an "alteration" or "disturbance" to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the "middle nature" proposed by Cosgrove (1993), which serves a purpose of "actively transforming nature into culture." It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native species, maximizing

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.

Natural Products and HIV/AIDS.

Science.gov (United States)

Cary, Daniele C; Peterlin, B Matija

2018-01-01

The study of natural products in biomedical research is not a modern concept. Many of the most successful medical therapeutics are derived from natural products, including those studied in the field of HIV/AIDS. Biomedical research has a rich history of discovery based on screens of medicinal herbs and traditional medicine practices. Compounds derived from natural products, which repress HIV and those that activate latent HIV, have been reported. It is important to remember the tradition in medical research to derive therapies based on these natural products and to overcome the negative perception of natural products as an "alternative medicine."

Natural gas marketing and transportation

International Nuclear Information System (INIS)

Anon.

1991-01-01

This book covers: Overview of the natural gas industry; Federal regulation of marketing and transportation; State regulation of transportation; Fundamentals of gas marketing contracts; Gas marketing options and strategies; End user agreements; Transportation on interstate pipelines; Administration of natural gas contracts; Structuring transactions with the nonconventional source fuels credit; Take-or-pay wars- a cautionary analysis for the future; Antitrust pitfalls in the natural gas industry; Producer imbalances; Natural gas futures for the complete novice; State non-utility regulation of production, transportation and marketing; Natural gas processing agreements and Disproportionate sales, gas balancing, and accounting to royalty owners

75 FR 42432 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

Science.gov (United States)

2010-07-21

... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... abandonment of facilities by Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas... resources, fisheries, and wetlands; Cultural resources; Vegetation and wildlife; Endangered and threatened...

Virginia Natural Heritage Program

Science.gov (United States)

Heritage About Natural Heritage Overview, Mission Natural Heritage Inventory Community Ecology Program ) | Strategic Plan (PDF) | Executive Progress Report (PDF) | Code of Ethics (PDF) Your browser does not support

Rethinking of the criteria for natural analogue study. A case of Tono natural analogue study

International Nuclear Information System (INIS)

Yoshida, Hidekazu

1996-01-01

Natural analogue regarding long-term performance of the geological disposal system for radioactive waste isolation is essentially the study of geochemical process which has been evolved in geological environment. All geochemical studies, however, will not be nominated as natural analogue studies. It is, therefore, important to be clear the criteria for natural analogue study with the view of analogy by following three categories, (1) Conceptual model development, (2) Data provision and (3) Model testing, for the concept of geological disposal and safety assessment model. Rethinking of the criteria for natural analogue study through the case of Tono Natural Analogue Study, and the usefulness of natural analogue study for the safety assessment of geological disposal system in Japan have been presented in this paper. (author)

Natural Gas Multi-Year Program Plan

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

This document comprises the Department of Energy (DOE) Natural Gas Multi-Year Program Plan, and is a follow-up to the `Natural Gas Strategic Plan and Program Crosscut Plans,` dated July 1995. DOE`s natural gas programs are aimed at simultaneously meeting our national energy needs, reducing oil imports, protecting our environment, and improving our economy. The Natural Gas Multi-Year Program Plan represents a Department-wide effort on expanded development and use of natural gas and defines Federal government and US industry roles in partnering to accomplish defined strategic goals. The four overarching goals of the Natural Gas Program are to: (1) foster development of advanced natural gas technologies, (2) encourage adoption of advanced natural gas technologies in new and existing markets, (3) support removal of policy impediments to natural gas use in new and existing markets, and (4) foster technologies and policies to maximize environmental benefits of natural gas use.

STUDIES ON NATURAL WEATHERING OF RATTAN POWDER-FILLED NATURAL RUBBER COMPOSITES

Directory of Open Access Journals (Sweden)

Komethi Muniandy,

2012-07-01

Full Text Available This article investigates the effect of natural weathering on mechanical and morphological properties of rattan powder-filled natural rubber (NR composites as a function of filler loading and silane coupling agent. The rattan powder samples in the range of 0 to 30 phr were compounded with NR using a laboratory size two-roll mill. The natural weathering test was carried out for six months. The degradation of the samples was evaluated by performing a tensile test, a Fourier transform infrared spectroscopy (FTIR, and a scanning electron microscopy (SEM test. The results indicated that after natural weathering, an increase in stress at 100% elongation (M100 can be seen for samples without the silane coupling agent, whilst M100 was reduced for samples with silane coupling agent. A drastic reduction in tensile strength and elongation at break were observed for all samples due to the photo-oxidation process that occurred during the degradation of the samples. The extent of degradation on the samples’ surfaces and the presence of oxygenated products were confirmed by SEM and FTIR studies, respectively.

Human-Nature for Climate Action: Nature-Based Solutions for Urban Sustainability

Directory of Open Access Journals (Sweden)

Helen Santiago Fink

2016-03-01

Full Text Available The global climate change agenda proceeds at an incremental pace while the Earth is approaching critical tipping points in its development trajectory. Climate action at this pinnacle juncture needs to be greatly accelerated and rooted in the fundamentals of the problem—human beings’ disconnection from nature. This paper underscores the valuable role nature and nature-based solutions can play in addressing climate change at the city scale and its implications for broader sustainability. Urban ecosystems (nature in cities are seen as an integral part of a proposed local climate action rubric wherein policy measures and integrated planning guide lowcarbon/impact development to create more resilient and sustainable urban environments. The use of green infrastructure is highlighted as a cost-effective means to contribute to mitigation and adaptation needs as well as to promote human wellbeing. The paper takes an exploratory view of the influence of ecosystem services, particularly cultural services, and its economics in relation to the individual and society to understand how biophilia can be nurtured to promote environmental stewardship and climate action.

Technology, society and nature. Technik, Gesellschaft und Natur

Energy Technology Data Exchange (ETDEWEB)

Kraemer, S

1982-01-01

This paper intends to counter with a demand for systematics the boom of ecological oriented criticism passed on technical science and engineering and on the fact that individual sciences make a subject of engineering. It deals with the theoretical foundations of relationships between technology, society and nature. An interdisciplinary approach attempts to do justice to the multi-dimensionality of engineering and ''technology''. This approach includes the formulation of questions and the findings of social sciences, philosophy, and technology. The object is to determine technology as a form of social practice - a practice which includes the vital adjustment of man to his natural environment as well as the organisation of his social behaviour.

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...

Alternative Fuels Data Center: Natural Gas

Science.gov (United States)

Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center : Natural Gas to someone by E-mail Share Alternative Fuels Data Center: Natural Gas on Facebook Tweet about Alternative Fuels Data Center: Natural Gas on Twitter Bookmark Alternative Fuels Data Center: Natural Gas on

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.

Natural gas monthly, November 1993

International Nuclear Information System (INIS)

1993-01-01

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 state data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information

Education in the imbalance of Nature

Science.gov (United States)

Shlafman, L. M.; Kontar, V. A.

2013-12-01

There are two concepts understanding of the real Nature: balanced and imbalanced. The traditional balanced concept understanding of Nature was originated in prehistoric times to calm the frightened souls of prehistoric man and manage groups of people. The balanced concept presupposes that Nature is isotropic, balanced, etc. The balanced concept of understanding of Nature gradually has moved to science and technology. The balanced concept of understanding of Nature is dominating from the prehistoric time up to today. But always parallel and opposite was exists the concept imbalanced understanding of Nature, which presupposes that Nature is anisotropy, imbalanced, etc. The balanced concept is much simpler than Imbalanced. The balanced concept has given mankind a lot of rough description of Nature which helped to solve a lot of practical problems but with sufficient accuracy, i.e. approximately, but not with an absolute precision. While people were few, and a lot of resources, person could take from Nature only what Nature gave willingly. During this period, people feared and respected Nature and Nature was able easily compensate the activity of people. The high accuracy of the description of Nature was not needed when resources were plentiful and people were few. But now the situation is completely different. The population has become a very large and growing. Traditional resources are almost run out and the lack of resources escalates. People are not afraid of Nature and bravely try to take by force what Nature does not give voluntarily. People invaded into imbalance Nature, and Nature can no longer compensate activity of people. The era of global change is started, including those that man provokes. In the conditions of global changes is insufficiently of the approximate solutions of the traditional balanced concept. The balanced concept is exhausted, and increasingly misleads people. The balanced concept cannot solve the problems that arise in the global change

Why are natural disasters not 'natural' for victims?

International Nuclear Information System (INIS)

Kumagai, Yoshitaka; Edwards, John; Carroll, Matthew S.

2006-01-01

Some type of formal or informal social assessment is often carried out in the wake of natural disasters. One often-observed phenomenon in such situations is that disaster victims and their sympathizers tend to focus on those elements of disasters that might have been avoided or mitigated by human intervention and thus assign 'undue' levels of responsibility to human agents. Often the responsibility or blame is directed at the very government agencies charged with helping people cope with and recover from the event. This phenomenon presents particular challenges for those trying to understand the social impacts of such events because of the reflexive nature of such analysis. Often the social analyst or even the government agency manager must sort through such perceptions and behavior and (at least implicitly) make judgments about which assignments of responsibility may have some validity and which are largely the result of the psychology of the disaster itself. This article presents a conceptual framework derived largely from social psychology to help develop a better understand such perceptions and behavior. While no 'magic bullet' formula for evaluating the validity of disaster victims' claims is presented, the conceptual framework is presented as a starting point for understanding this particular aspect of the psychology of natural disasters

Plutonium in nature

International Nuclear Information System (INIS)

Madic, C.

1994-01-01

Plutonium in nature comes from natural sources and anthropogenic ones. Plutonium at the earth surface comes principally from anthropogenic sources. It is easily detectable in environment. The plutonium behaviour in environment is complex. It seems necessary for the future to reduce releases in environment, to improve predictive models of plutonium behaviour in geosphere, to precise biological impact of anthropogenic plutonium releases

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...

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.

Is natural history really dead?: Toward the rebirth of natural history ¿Está realmente muerta la historia natural?: Hacia el renacimiento de la Historia Natural

Directory of Open Access Journals (Sweden)

MARY F WILLSON

2006-06-01

Full Text Available In recent years natural history has been derided by some scientists as an old-fashion endeavor that does not follow the model of "hard" science and therefore should be considered "dead" and replaced by modern ecology, evolutionary biology, and conservation biology. We contend that natural history has much to offer to contemporary scientists and that it has a primary role in the creative process of generating novel hypotheses and designing significant field experiments and observationsEn años recientes, la historia natural ha sido desacreditada por científicos que la consideran un modelo obsoleto de ciencia y que, en consecuencia, se trataría de una disciplina "muerta" que ha sido reemplazada por la ecología moderna, la biología evolutiva y la biología de la conservación. Argumentamos aquí que la historia natural tiene mucho que ofrecer a los científicos contemporáneos y que juega un rol principal en el proceso de creación de hipótesis y en el diseño acertado de observaciones y experimentos de campo

[Out of natural order: nature in discourses about cloning and stem cell research in Brazilian newspapers].

Science.gov (United States)

Medeiros, Flavia Natércia da Silva

2013-11-30

Different conceptions of nature influence media coverage and public opinion about biotechnology. This study reports on a discourse analysis of the ideas about nature and what is natural expressed in Brazilian media coverage of cloning and stem cell research. In the discourse against this research, the biotechnologies in question are placed outside the natural order of things and deemed immoral. In the discourse of those who defend it, nature is portrayed as indifferent to the fate of humans or even cruel, or else a barrier to be overcome, while cloning and embryonic stem cells are naturalized and Dolly the sheep is anthropomorphized. The mythifying or transcendental representations of nature do not just influence public opinion, but also have ethical and political implications.

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 naturalism of the sciences.

Science.gov (United States)

Dawes, Gregory W; Smith, Tiddy

2018-02-01

The sciences are characterized by what is sometimes called a "methodological naturalism," which disregards talk of divine agency. In response to those who argue that this reflects a dogmatic materialism, a number of philosophers have offered a pragmatic defense. The naturalism of the sciences, they argue, is provisional and defeasible: it is justified by the fact that unsuccessful theistic explanations have been superseded by successful natural ones. But this defense is inconsistent with the history of the sciences. The sciences have always exhibited what we call a domain naturalism. They have never invoked divine agency, but have always focused on the causal structure of the natural world. It is not the case, therefore, that the sciences once employed theistic explanations and then abandoned them. The naturalism of the sciences is as old as science itself. Copyright © 2018 Elsevier Ltd. All rights reserved.

Who's afraid of natural gas?

International Nuclear Information System (INIS)

Patterson, W.

1999-01-01

Changes in our electricity systems provoked by natural gas power generation technology are paving the way for large-scale renewables use in the future. Natural gas and gas turbines are now such a cheap and easy option for electricity generation that they appear to cast a pall over renewables. The market share of gas-fired generation continues expanding inexorably. Its cost continues to fall, setting renewables an ever more demanding competitive target. Nevertheless, paradoxical though this may sound, natural gas is actually the natural ally of renewables. Despite the fierce competitive challenge it represents, natural gas may even be the most important single factor shaping a bright future for renewables. (author)

Natural gas vehicles in Italy

International Nuclear Information System (INIS)

Mariani, F.

1991-01-01

The technology of compressed natural gas (CNG) for road vehicles originated 50 years ago in Italy, always able to adapt itself to changes in energy supply and demand situations and national assets. Now, due to the public's growing concern for air pollution abatement and recent national energy policies calling for energy diversification, the commercialization of natural gas road vehicles is receiving new momentum. However, proper fuel taxation and an increased number of natural gas distribution stations are required to support this growing market potential. Operators of urban bus fleets stand to gain substantially from conversion to natural gas automotive fuels due to natural gas being a relatively cheap, clean alternative

Nature and Young Children: Encouraging Creative Play and Learning in Natural Environments. Second Edition

Science.gov (United States)

Wilson, Ruth

2012-01-01

Now in its second edition, "Nature and Young Children" promotes the holistic development of children by connecting them with nature. It offers advice and guidance on how to set up indoor and outdoor nature play spaces as well as encouraging environmentally responsible attitudes, values and behaviour in your early childhood setting. Covering topics…

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.

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.

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.

Natural gas 1995: Issues and trends

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

Natural Gas 1995: Issues and Trends addresses current issues affecting the natural gas industry and markets. Highlights of recent trends include: Natural gas wellhead prices generally declined throughout 1994 and for 1995 averages 22% below the year-earlier level; Seasonal patterns of natural gas production and wellhead prices have been significantly reduced during the past three year; Natural gas production rose 15% from 1985 through 1994, reaching 18.8 trillion cubic feet; Increasing amounts of natural gas have been imported; Since 1985, lower costs of producing and transporting natural gas have benefitted consumers; Consumers may see additional benefits as States examine regulatory changes aimed at increasing efficiency; and, The electric industry is being restructured in a fashion similar to the recent restructuring of the natural gas industry.

Natural radioactivity of Turkish natural stones as building materials

International Nuclear Information System (INIS)

Yaprak, Guenseli; Yasar, Oezden

2008-01-01

Full text: The Turkey has very important natural stones potential with over 5 billion m 3 marble reserves. According to 2002 giving data the number of Turkish stones export is 303 million US Dollars. In this regards, the present study deals with 90 Turkish natural stones. The studied samples were analyzed and the concentrations in Bq/kg dry weight of radioisotopes were determined by gamma-ray spectrometry using HPGe detector. The radon exhalation rates of natural stones were also measured by using solid state nuclear track detectors (LR-115 ). The radium equivalent activity varied from 183 Bq/kg to 522 Bq/kg for granite samples and from 1 Bq/kg to 37 Bq/kg for marble samples. The value of radon exhalation rate ranged from 0.003 Bq/m 2 h -1 to 0.768 Bq/m 2 h -1 for granite samples and from 0.001 Bq/m 2 h -1 to 0.02 Bq/m 2 h -1 for marble samples. The total absorbed dose rates in air ranged from 22 to 61 n Gy h -1 for one quarter utilization of granite samples. The annual effective dose rates per person indoors were determined to be between 108 and 298 μSv y -1 for of for one quarter utilization of the materials. Applying the dose criteria recently recommended by UNSCEAR for building materials, the natural stones meet the upper dose limit of 1mSvy -1 . So, there are not restrictions for use of any Turkish commercial marble as covering materials, including Turkish granites. (author)

Naturally Efficient Emitters: Luminescent Organometallic Complexes Derived from Natural Products

Science.gov (United States)

Zhang, Wen-Hua; Young, David J.

2013-08-01

Naturally occurring molecules offer intricate structures and functionality that are the basis of modern medicinal chemistry, but are under-represented in materials science. Herein, we review recent literature describing the use of abundant and relatively inexpensive, natural products for the synthesis of ligands for luminescent organometallic complexes used for organic light emitting diodes (OLEDs) and related technologies. These ligands are prepared from the renewable starting materials caffeine, camphor, pinene and cinchonine and, with the exception of caffeine, impart performance improvements to the emissive metal complexes and resulting OLED devices, with emission wavelengths that span the visible spectrum from blue to red. The advantages of these biologically-derived molecules include improved solution processibility and phase homogeneity, brighter luminescence, higher quantum efficiencies and lower turn-on voltages. While nature has evolved these carbon-skeletons for specific purposes, they also offer some intriguing benefits in materials science and technology.

Nature Contacts: Employee Wellness in Healthcare.

Science.gov (United States)

Trau, Deborah; Keenan, Kimberly A; Goforth, Meggan; Large, Vernon

2016-04-01

This study was designed to ascertain the amount of outdoor, indoor, and indirect nature contact exposures hospital employees have in a workweek. Hospital employees have been found particularly vulnerable to work-related stress. Increasing the nature contact exposure for hospital employees can reduce perceived stress; stress-related health behaviors; and stress-related health outcomes from outdoor, indoor, and indirect exposures to nature. Staff on the fourth floor postsurgical unit of a large hospital (N = 42) were ask to participate in an employee questionnaire "nature contact questionnaire". This 16-item nature environment questionnaire measures the amount and types of nature contact exposures employees have during a workweek. Majority of employees reported few, if any, nature contact exposures, specifically in the area of outdoor nature contacts with limited indoor and indirect contacts. These results indicated that employees on the fourth floor postsurgical floor have limited ability to reduce stress through nature contact exposures which could impact their perceived levels of work stress and stress-related behaviors and health outcomes. Nature contact exposures are both a relatively easy and an inexpensive way to improve employee stress. These findings indicate limitations to employees' exposure to nature contacts. Healthcare environments would benefit from a concerted effort to provide increased outdoor, indoor, and indirect nature contact exposures for employees. © The Author(s) 2015.

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

77 FR 19277 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

Science.gov (United States)

2012-03-30

... and Export Natural Gas and Liquefied Natural Gas During February 2012 FE Docket Nos. FREEPORT LNG...-LNG QUICKSILVER RESOURCES INC 12-12-NG UNITED ENERGY TRADING CANADA, ULC 12-13-NG ENCANA NATURAL GAS... authority to import and export natural gas and liquefied natural gas. These Orders are summarized in the...

Natural gas retailing: writing the last chapter of natural gas deregulation

International Nuclear Information System (INIS)

Bjerkelund, T.

1995-01-01

Under the A greement on Natural Gas Markets and Prices of October 1985, the Canadian federal government agreed to deregulate the price of natural gas and to allow a competitive gas market to develop. Several beneficial changes that have occurred as a result of the deregulation were described, including the Industrial Gas Users Association's (IGUA) view on the marketing and sale of natural gas by local gas distributor's (LDC) and the sale within the LDC franchise. IGUA's support for the separation between LDC distribution and LDC sales and marketing activities as the last step in deregulation process, was explained. Several arguments for the opposing view were also discussed. Recommendations were made for effective separation of LDC distribution and LDC sales/marketing activities

Breast reconstruction - natural tissue

Science.gov (United States)

... flap; TRAM; Latissimus muscle flap with a breast implant; DIEP flap; DIEAP flap; Gluteal free flap; Transverse upper gracilis flap; TUG; Mastectomy - breast reconstruction with natural tissue; Breast cancer - breast reconstruction with natural tissue

Natural games

International Nuclear Information System (INIS)

Anttila, Jani; Annila, Arto

2011-01-01

A course of a game is formulated as a physical process that will consume free energy in the least time. Accordingly, the rate of entropy increase is the payoff function that will subsume all forms of free energy that motivate diverse decisions. Also other concepts of game theory are related to their profound physical counterparts. When the physical portrayal of behavior is mathematically analyzed, the course of a game is found to be inherently unpredictable because each move affects motives in the future. Despite the non-holonomic character of the natural process, the objective of consuming free energy in the least time will direct an extensive-form game toward a Lyapunov-stable point that satisfies the minimax theorem. -- Highlights: → Behavior in the context of game theory is described as a natural process. → The rate of entropy increase, derived from statistical physics of open systems, is identified as the payoff function. → Entropy as the payoff function also clarifies motives of collaboration and subjective nature of decision making. → Evolutionary equation of motion that accounts for the course of a game is inherently unpredictable.

Natural knowledge as a propaedeutic to self-betterment: Francis Bacon and the transformation of natural history.

Science.gov (United States)

Lancaster, James A T

2012-01-01

This paper establishes the 'emblematic' use of natural history as a propaedeutic to self-betterment in the Renaissance; in particular, in the natural histories of Gessner and Topsell, but also in the works of Erasmus and Rabelais. Subsequently, it investigates how Francis Bacon's conception of natural history is envisaged in relation to them. The paper contends that, where humanist natural historians understood the use of natural knowledge as a preliminary to individual improvement, Bacon conceived self-betterment foremost as a means to Christian charity, or social-betterment. It thus examines the transformation of the moralizing aspect of Renaissance natural history in Bacon's conception of his Great Instauration.

Methane-bomb natural gas

International Nuclear Information System (INIS)

Anon.

1993-01-01

About 50% of the so-called 'greenhouse-effect' is not caused by CO 2 , but by more dangerous gases, among them is methane. Natural gas consists to about 98% of methane. In Austria result about 15% of the methane emissions from offtake, storage, transport (pipelines) and distribution from natural gas. A research study of the Research Centre Seibersdorf points out that between 2.5% and 3.6% of the employed natural gas in Austria emits. The impact of this emitted methane is about 29 times worse than the impact of CO 2 (caused for examples by petroleum burning). Nevertheless the Austrian CO 2 -commission states that an increasing use of natural gas would decrease the CO 2 -emissions - but this statement is suspected to be based on wrong assumptions. (blahsl)

Art, Technology and Nature

DEFF Research Database (Denmark)

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......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...

Radiation stability of animate nature

International Nuclear Information System (INIS)

Romanov, G.N.; Spirin, D.A.

1990-01-01

The main principles of radiation safety for animate nature including provisions for biological species protection and main requirement for animate nature radiation protection, which is the guarantee of any ecosystem integrity, are discussed. Ecosystem should be taken as the objective unit for animate nature radiation protection. The maximum dose of biot irradiation may amount to 0.5 Gy/year, which is 20-fold lower than the main dose limit for animate nature and 40-fold lower than ecological dose limits for conifers as the weakest radiostable member in ecosystem, at environment radioactive contamination determined by radiation safety standards. The radiation protection of animate nature is guaranteed at such levels of environment radioactive contamination

Natural Gas Regulation

International Nuclear Information System (INIS)

1995-01-01

The regulation of Natural Gas. Natural gas Regulation clarifies and consolidates the legal and institutional framework for development of the industry through six principal elements: 1) Establishment of a vision of the industry. 2) Development of regulatory objectives. 3) Determination of relationships among industry participants. 4) Clear specification of the role of PEMEX in the industry. 5) Definition of the functions of the Regulatory authority. 6) Creation of a transition regime. In parallel with the development of the substantive legal framework, the law of the Comision Reguladora de Energia (CRE) was also enacted by Congress in October 1995 to strength the institutional framework and implement the legal changes. This law defines the CRE as an agency of the Energy Ministry with technical, operational, and budgetary autonomy, and responsibility for implementing natural gas industry regulation. (Author)

Canadian natural gas

International Nuclear Information System (INIS)

Lucas, D.A.

1991-01-01

Canada's natural gas industry enjoys a quiet confidence as it looks ahead to the 1990s. In this paper, the author explains why, despite some critical uncertainties, the optimism endures. Reviewing the current conditions of supply, production, consumption, pipelines, and pipeline expansion plans, the author contends that the New World of the 1990s will belong to natural gas. The author's assessment of natural gas markets proceeds far beyond the borders of Canada. The author examines the determinants of gas prices throughout North America and he identifies the one force that promises to seize almost complete control of gas prices throughout the continent. While the analysis points out the attributes of this new pricing regime, it also names the obstacles that could prevent this emerging mechanism from assuming its anticipated position

77 FR 12274 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

Science.gov (United States)

2012-02-29

... Authority To Import and Export Natural Gas and Liquefied Natural Gas During January 2012 AGENCY: Office of... LNG, LP 11-98-LNG ENERGY PLUS NATURAL GAS LLC 11-155-NG BROOKFIELD ENERGY MARKETING L.P 12-03-NG WPX... granting authority to import and export natural gas and liquefied natural gas. These Orders are summarized...

Sebastian Kneipp and the Natural Cure Movement of Germany: Between Naturalism and Modern Medicine

Directory of Open Access Journals (Sweden)

Youkyung KO

2016-12-01

Full Text Available This study discusses the historical significance of the Natural Cure Movement of Germany, centering on the Kneipp Cure, a form of hydrotherapy practiced by Father Sebastian Kneipp (1821-1897. The Kneipp Cure rested on five main tenets: hydrotherapy, exercise, nutrition, herbalism, and the balance of mind and body. This study illuminates the reception of the Kneipp Cure in the context of the trilateral relationship among the Kneipp Cure, the Natural Cure Movement in general, and modern medicine. The Natural Cure Movement was ideologically based on naturalism, criticizing industrialization and urbanization. There existed various theories and methods in it, yet they shared holism and vitalism as common factors. The Natural Cure Movement of Germany began in the early 19th century. During the late 19th century and the early 20th century, it became merged in the Lebensreformbewegung (life reform movement which campaigned for temperance, anti-tobacco, and anti-vaccination. The core of the Natural Cure Movement was to advocate the world view that nature should be respected and to recognize the natural healing powers of sunlight, air, water, etc. Among varied natural therapies, hydrotherapy spread out through the activities of some medical doctors and amateur healers such as Johann Siegmund Hahn and Vincenz Prie β nitz. Later, the supporters of hydrotherapy gathered together under the German Society of Naturopathy. Sebastian Kneipp, one of the forefathers of hydrotherapy, is distinguished from other proponents of natural therapies in two aspects. First, he did not refuse to employ vaccination and medication. Second, he sought to be recognized by the medical world through cooperating with medical doctors who supported his treatment. As a result, the Kneipp cure was able to be gradually accepted into the medical world despite the “quackery” controversy between modern medicine and the Natural Cure Movement. Nowadays, the name of Sebastian Kneipp

Preparation and properties of natural nanocomposites based on natural rubber and naturally occurring halloysite nanotubes

International Nuclear Information System (INIS)

Rooj, Sandip; Das, Amit; Thakur, Varun; Mahaling, R.N.; Bhowmick, Anil K.; Heinrich, Gert

2010-01-01

A 'green' composite based on natural halloysite nanotubes (HNTs) and natural rubber (NR) was prepared by mechanical mixing. A silane coupling agent, bis (triethoxysilylpropyl)-tetrasulphide, was utilized to enhance the properties of these composites. It was observed that the reinforcing activity of HNTs was superior to commercial silica coupled with the same amount of silane coupling agent. Moreover the on-set thermal degradation decomposition temperature was improved by ∼64 o C with the addition of 10 parts HNTs per hundred of rubber. Transmission electron microscopic images confirmed the good dispersion of the HNTs in the rubber matrix, whereas X-ray diffraction studies showed a little change in interlayer spacing between the two silicate layers of HNTs.

Use of natural ingredients to control growth of Clostridium perfringens in naturally cured frankfurters and hams.

Science.gov (United States)

Jackson, Armitra L; Kulchaiyawat, Charlwit; Sullivan, Gary A; Sebranek, Joseph G; Dickson, James S

2011-03-01

A major concern for processed meats marketed as natural/organic is that they do not contain nitrite in concentrations known to be most effective for inhibiting foodborne pathogens. Supplemental treatments to increase the level and consistency of antimicrobial protection in these products may be important to provide consumers with the degree of safety that they have come to expect from conventionally cured meats. Therefore, the objective of this study was to identify and test ingredients that might improve processed meat product safety without altering their natural/organic status. Eight treatments of hams and frankfurters were prepared: (A) uncured control (typical ingredients except nitrite and nitrate); (B) conventionally cured control (erythorbate, nitrite, and a lactate-diacetate blend); (C) natural nitrate cure (including starter culture containing Staphylococcus carnosus); (D) natural nitrate cure (culture and natural antimicrobial A containing a vinegar, lemon, and cherry powder blend); (E) natural nitrate cure (culture and antimicrobial B containing a cultured sugar and vinegar blend); (F) natural nitrite cure without additional antimicrobials; (G) natural nitrite cure with natural antimicrobial A; and (H) natural nitrite cure with antimicrobial B. For the hams, treatments C, D, E, and H impacted growth of Clostridium perfringens to the same extent (P cured control (approximately 2 log less growth over time than uncured control). For frankfurters, treatments D, G, and H had an effect (approximately 1 log) on growth equivalent to that of the conventionally cured control (P cured meats have more potential for pathogen growth than conventionally cured products, but supplemental natural ingredients offer safety improvement.

Natural radiation, protection against its effects and maintaining safe natural environment

International Nuclear Information System (INIS)

Alhassan, Muhammad

2015-01-01

Exposure to naturally occurring radioactivity and its consequences is an issue that needs the global concern, as practices bringing such radioactive materials closer to human environment through mining, building, industrial applications and food production and preservation is continuously increasing, in addition to the daily consumption in foods such as banana, carrot, potato and drinking water. Although it has direct and indirect impacts affecting human health that in some cases lead to the loss of lives and polluting natural environment, it is an inevitable task that necessitates devising some means of its minimization and protection against its hazardous effects. This could be achieved by the use of expertise ideas and by the creation of awareness and sharing related information with the people concerned and the general public. This paper gives an overview on the radiation present in natural environment, its sources, mechanism of its effects. The paper compares the radiation dose limits with the average doses from these sources in order to raise the challenges facing researchers, governments and the general individuals with regard to this issue. The paper also proposed applicable solutions to reduce the risks due to the exposure to natural radiation to ground level. (author)

Electrospinning of PVC with natural rubber

Science.gov (United States)

Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

2013-11-01

Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

Electrospinning of PVC with natural rubber

International Nuclear Information System (INIS)

Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

2013-01-01

Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber

Electrospinning of PVC with natural rubber

Energy Technology Data Exchange (ETDEWEB)

Othman, Muhammad Hariz; Abdullah, Ibrahim [Department of Chemistry, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Mohamed, Mahathir [Radiation Processing Technology Division (BTS), Malaysian Nuclear Agency, Bangi, 43000, Kajang (Malaysia)

2013-11-27

Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

Natural pet food: a review of natural diets and their impact on canine and feline physiology.

Science.gov (United States)

Buff, P R; Carter, R A; Bauer, J E; Kersey, J H

2014-09-01

The purpose of this review is to clarify the definition of "natural" as it pertains to commercial pet food and to summarize the scientific findings related to natural ingredients in pet foods and natural diets on the impact of pet health and physiology. The term "natural," when used to market commercial pet foods or pet food ingredients in the United States, has been defined by the Association of American Feed Control Officials and requires, at minimum, that the pet food be preserved with natural preservatives. However, pet owners may consider natural as something different than the regulatory definition. The natural pet food trend has focused on the inclusion of whole ingredients, including meats, fruits, and vegetables; avoiding ingredients perceived as heavily processed, including refined grains, fiber sources, and byproducts; and feeding according to ancestral or instinctual nutritional philosophies. Current scientific evidence supporting nutritional benefits of natural pet food products is limited to evaluations of dietary macronutrient profiles, fractionation of ingredients, and the processing of ingredients and final product. Domestic cats select a macronutrient profile (52% of ME from protein) similar to the diet of wild cats. Dogs have evolved much differently in their ability to metabolize carbohydrates and select a diet lower in protein (30% of ME from protein) than the diet of wild wolves. The inclusion of whole food ingredients in natural pet foods as opposed to fractionated ingredients may result in higher nutrient concentrations, including phytonutrients. Additionally, the processing of commercial pet food can impact digestibility, nutrient bioavailability, and safety, which are particularly important considerations with new product formats in the natural pet food category. Future opportunities exist to better understand the effect of natural diets on health and nutrition outcomes and to better integrate sustainable practices in the production of

More natural gas

International Nuclear Information System (INIS)

Leprince, P.; Valais, M.

1993-01-01

This paper reports that large resources and growing markets are the salient prospects of natural gas for the coming decades. The greater impact of natural gas on the worldwide energy market can become a reality if several scientific disciplines can be mobilized in order to succeed in cutting production costs. Modeling, mechanics of complex fluids, and physical chemistry of interfaces are basic disciplines for understanding and mastering the gas processing technologies

The Naturalized Nation: Anchoring, Objectification and Naturalized Social Representations of History

Directory of Open Access Journals (Sweden)

Eemeli Hakoköngäs

2016-12-01

Full Text Available This study focuses on the connection between social representations of history and collective memory from the perspective of elementary concepts of social representations theory: anchoring, objectification and naturalization. The aims of the study are to arrive at a conceptual clarity of this connection and demonstrate how to apply basic concepts of social representations theory to the study of collective memory. The study also focuses on the naturalized characteristics of Finnish history. The data consist of the covers of twenty Finnish history books between the years 1965 and 2014. All the covers are embellished with typography or visual images. The covers were analysed using a semiotic approach in which the interest is in the description (denotation, the associations (connotation and the meaning system these construe (myth. The analysis shows how national history is concretized with visual images (objectification, how the meaning of representation is conveyed (anchoring and how collective memory is maintained (naturalization, transmitted and shaped during the years. The results show how the stable collective memories and changing social representations of history are interacting. The most frequently used visual element was the colour blue, which alludes to the Finnish flag, a symbol of the nation that represents the core of Finnish history. The study suggests that it is possible to conceptualize collective memories as naturalized social representations of history. It shows how processes of anchoring and objectification serve as tools of collective memory and how the naturalized conceptions are subtly changed. In addition, the study develops the use of visual semiotic analysis in social representations research.

Nature-Based Solutions in the EU: Innovating with nature to address social, economic and environmental challenges.

Science.gov (United States)

Faivre, Nicolas; Fritz, Marco; Freitas, Tiago; de Boissezon, Birgit; Vandewoestijne, Sofie

2017-11-01

Contemporary societies are facing a broad range of challenges, from pressures on human health and well-being to natural capital depletion, and the security of food, water and energy. These challenges are deeply intertwined with global processes, such as climate change and with local events such as natural disasters. The EU's research & innovation (R&I) policy is now seeking to address these challenges from a new perspective, with Nature-Based Solutions, and turn them into innovation opportunities that optimise the synergies between nature, society and the economy. Nature-Based Solutions can be an opportunity for innovation, and are here promoted by both policymakers and practitioners as a cost-effective way of creating a greener, more sustainable, and more competitive economy. Since 2013, the European Commission has devoted particular attention to Nature-Based Solutions through consultations and dialogues that sought to make the concept of these solutions more concrete and to define the concept's place within the spectrum of ecosystem-based approaches. In 2014, the Commission launched an expert group, which conducted further analysis, and made recommendations to help increase the use of Nature-Based Solutions and bring nature back into cities. In 2015, a survey was conducted on citizens' views and perceptions of 'Nature in Cities' to provide further insight for future work. Based on these elements and on results from running EU projects, the Commission has developed an R&I agenda for Nature-Based Solutions and has published targeted calls for proposals for large-scale demonstration projects in this field in 2016 and 2017. Additional R&I actions at EU level that promote systemic Nature-Based Solutions and their benefits to cities and territories are planned with the aim to improve the implementation capacity and evidence base for deploying Nature-Based Solutions and developing corresponding future markets. They are also expected to foster an interdisciplinary R

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...

Naturalness and Animal Welfare.

Science.gov (United States)

Yeates, James

2018-04-05

Naturalness is considered important for animals, and is one criterion for assessing how we care for them. However, it is a vague and ambiguous term, which needs definition and assessments suitable for scientific and ethical questions. This paper makes a start on that aim. This paper differentiates the term from other related concepts, such as species-typical behaviour and wellbeing. It identifies contingent ways in which naturalness might be used, as: (i) prompts for further welfare assessment; (ii) a plausible hypothesis for what safeguards wellbeing; (iii) a threshold for what is acceptable; (iv) constraints on what improvements are unacceptable; and (v) demarcating what is not morally wrong, because of a lack of human agency. It then suggests an approach to evaluating animals' behaviour that is quantitative, is based on reality, and which assesses naturalness by degrees. It proposes classing unaffected wild populations as natural by definition. Where animals might have been affected by humans, they should be compared to the closest population(s) of unaffected animals. This approach could allow us both to assess naturalness scientifically, and to make practical decisions about the behaviour of domestic animals.

Combinatorial synthesis of natural products

DEFF Research Database (Denmark)

Nielsen, John

2002-01-01

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...... increase in application of natural products in combinatorial chemistry and vice versa. The therapeutic areas of infectious disease and oncology still dominate but many new areas are emerging. Several complex natural products have now been synthesised by solid-phase methods and have created the foundation...... 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...

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...

Optimizing color reproduction of natural images

NARCIS (Netherlands)

Yendrikhovskij, S.N.; Blommaert, F.J.J.; Ridder, de H.

1998-01-01

The paper elaborates on understanding, measuring and optimizing perceived color quality of natural images. We introduce a model for optimal color reproduction of natural scenes which is based on the assumption that color quality of natural images is constrained by perceived naturalness and

Radioactivity. Death prinicple in nature; Radioaktivitaet. Das Todesprinzip in der Natur

Energy Technology Data Exchange (ETDEWEB)

Russell, W.; Russell, L.

2006-07-01

Walter Russell's knowledge of the two basic Principles of the material universe, concentration and radiation, strongly suggests that the radioactivity is the ''death principle'' of creation. In its natural environment, radioactive radiation is vital for the overall balance, however, when spread out across the entire world, it causes massive global warming and turns planet earth into a hot desert. Part I: What is Atomic Energy?; How Radioactivity Kills; The World Voice. Part II: The True Nature of This Mind and Motion Universe; Prelude - The Transformation of Man; We Define God; The True Nature of Electricity and Gravitation; Our Eternal Universe; The Oneness of Gravity and Magnetism; The Mind Nucleus of the Atom; The Material Nucleus of the Atom. Part III: The Bridge Between Man and God. (orig./GL)

EEC's: natural uramium supplies

International Nuclear Information System (INIS)

Anon.

1981-01-01

The demand for nuclear fuel to supply the nuclear plants within the ECC (31,200 MW at the end of last year) totalled nearly 9,600 tons of natural uranium and 4,900 of separation work units (SWU). Once reactors currently under construction come into service, the demand for natural uranium will reach 13,200 tons by 1985 and that for SWUs to 8,600. If one takes the years 1981 to 1985, total natural uranium needs during this period will be 56,300 tons and those for SWUs 35.100 [fr

The unnatural racial naturalism.

Science.gov (United States)

Spencer, Quayshawn

2014-06-01

In the recent article, "Against the New Racial Naturalism", Adam Hochman (2013, p. 332) argues that new racial naturalists have been too hasty in their racial interpretation of genetic clustering results of human populations. While Hochman makes a number of good points, the purpose of this paper is to show that Hochman's attack on new racial naturalists is misguided due to his definition of 'racial naturalism'. Thus, I will show that Hochman's critique is merely a consequence of an unnatural interpretation of racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

Can Nature Protection be Unsustainable? Models Behind Nature Protection in New Zealands National Parks

Science.gov (United States)

Hauhs, Michael; Bogner, Christina

2013-04-01

Nature protection can be justified by intrinsic values of life. Western culture sees nature as an autonomous system. Thus, nature protection is often synonymous with refraining from human interference as much as possible. This, however, can pose at least technical problems. Indeed, historical human impacts such as introduced species are often irreversible. In such cases refraining from human interference to protect threatened species is not an adequate management response. Nature protection in New Zealand is a prominent example. Many introduced species make a non-interventionist attitude infeasible to protect endemic species such as kiwis. Actually, active human interference is necessary to attain this goal. Therefore, one may consider nature protection as another form of land use. As any other form of land use, it needs standards of proper management (i.e. explicit goals, assessment, intervention etc.). In other words, it has to be shown to be sustainable. However, sustainability may rigorously be defined as an attribute of past land use only. Instantaneous positive indicators of sustainability may be elusive. At best it can be decided by observation whether or not a land use has been (not) sustainable until now. Stakeholders of nature protection have often different (implicit) concepts or models of nature in mind. This can lead to conflicts when it comes to management decisions. For example, the methods by which conservationists in New Zealand seek to re-establish historical species assemblages (e.g. aerial drop of poison into national parks) have come under criticism of animal rights groups as non-humane. We propose to use abstract modelling language to classify these concepts of nature protection and related issues. We show that from modelling perspective these conflicts pose a basic science problem rather than an applied science problem. This makes the delegation into existing disciplines so hard. We discuss possible implications for nature protection

Buying natural gas in the spot market: risks related to the natural gas industry globalization; Aquisicao de gas natural em bases 'spot': riscos associados a globalizacao da industria do gas natural

Energy Technology Data Exchange (ETDEWEB)

Mathias, Melissa Cristina [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Szklo, Alexandre Salem [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Planejamento Energetico

2008-07-01

The growth of the international natural gas trade during the last decade resulted in the expectation that this product would be traded as a commodity. This expectation created a boom in the investments related to the commercialization of natural gas between borders, especially in the distinct segments of the chain of liquefied natural gas (LNG). Different agents launched themselves into liquefaction and regasification enterprises, and the ordering of ships also showed significant growth. Despite that, the natural gas market still cannot be considered global, and international gas transactions are primarily done within regional markets. This article investigates the challenges posed to the constitution of a global natural gas market. These challenges represent risks to the commercialization of this product in spot bases, for the agents that launch themselves into projects to export or import LNG to be commercialized through short term contracts in the international market for this product. (author)

Adsorptive storage of natural gas

International Nuclear Information System (INIS)

Yan, Song; Lang, Liu; Licheng, Ling

2001-01-01

The Adsorbed Natural Gas (ANG) storage technology is reviewed. The present status, theoretical limits and operational problems are discussed. Natural gas (NG) has a considerable advantage over conventional fuels both from an environmental point of view and for its natural abundance. However, as well known, it has a two fold disadvantage compared with liquid fuels: it is relatively expensive to transport from the remote areas, and its energy density (heat of combustion/volume) is low. All these will restrict its use. Compressed natural gas (CNG) may be a solution, but high pressures are needed (up to 25 MPa) for use in natural-gas fueled vehicles, and the large cost of the cylinders for storage and the high-pressure facilities necessary limit the practical use of CNG. Alternatively, adsorbed natural gas (ANG) at 3 - 4 MPa offers a very high potential for exploitation in both transport and large-scale applications. At present, research about this technology mainly focuses on: to make adsorbents with high methane adsorption capacity; to make clear the effects of heat of adsorption and the effect of impurities in natural gas on adsorption and desorption capacity. This paper provides an overview of current technology and examines the relations between fundamentals of adsorption and ANG storage. (authors)

The use of compressed natural gas as a strategy of development of natural gas industry; Utilizacao do GNC (Gas Natural Comprimido) como estrategia de desenvolvimento da industria do gas natural

Energy Technology Data Exchange (ETDEWEB)

Bock, Jucemara [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Coordenacao de Segmento Veicular; Rickmann, Cristiano [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Gerencia de Novos Negocios; Maestri, Juares [Companhia de Gas do Estado do Rio Grande do Sul (Sulgas), Porto Alegre, RS (Brazil). Gerencia de Mercado de Grandes Consumidores

2008-07-01

This work emphasizes the Compressed Natural Gas (CNG) as modal of transport, used by the Company of Gas of the State of Rio Grande do Sul - Sulgas, through experience in pioneering project in Brazil: the introduction of the technology of Compressed Natural Gas (CNG) to assist areas where there is not the infrastructure of pipeline for the transport. The article offers a display of the project of expansion of the Natural gas in Rio Grande do Sul, through the supply of CNG to the company Tramontina in Carlos Barbosa's city in the year of 2002. The last aspect focused by this article demonstrates as the use of this transport technology impelled the development of the transport market in the State and it has been used as an important strategy for the development of the market of Natural Gas Vehicle (NGV) in the state. (author)

Natural-gas supply-and-demand problems

International Nuclear Information System (INIS)

Hatamian, H.

1998-01-01

World natural-gas consumption quadrupled in the 30 years from 1966 to 1996, and natural gas now provides 22% of the total world energy demand. The security of natural-gas supply is paramount and rests with the suppliers and the consumers. This paper gives an overview of world natural-gas supply and demand and examines the main supply problems. The most important nonpredictable variables in natural-gas supply are worldwide gas price and political stability, particularly in regions with high reserves. Other important considerations are the cost of development/processing and the transport of natural gas to market, which can be difficult to maintain if pipelines pass through areas of political instability. Another problem is that many countries lack the infrastructure and capital for effective development of their natural-gas industry. Unlike oil, the cost of transportation of natural gas is very high, and, surprisingly, only approximately 16% of the total world production currently is traded internationally

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

Hiking tourism development in protected areas and nature hazard prevention in the Lake Baikal natural territory

Directory of Open Access Journals (Sweden)

Luzhkova Natalia

2013-01-01

Full Text Available Since 2010, recreational development has been permitted in strict nature reserves (zapovedniks in Russia, the most highly protected category of Russian Federal Protected Areas. As zapovedniks comply with the 1b IUCN category for wilderness preservation, human activities within the reserves have been limited and, consequently, there has been little research on the natural hazard impact for tourism. The type of recreational use permitted in the territories and their buffer zones is called Educational Tourism. It is identified as “as a specialized type of ecological tourism where the main goal is an introduction to natural and cultural attractions”. Hiking is seen as one of these suitable types of tourism within the territories of zapovedniks, due to its low impact on natural features. As hiking trails are laid through natural landscapes, it is possible that natural disasters can both damage the infrastructure and cause fatal injuries for visitors. During the planning stages of trail construction, natural hazard monitoring should be conducted. Baikalskii Nature Biosphere Zapovednik in the Lake Baikal region is used as a model territory where scientific research and engineering are employed to better develop hiking tourism. Along with the monitoring of natural processes, several scenarios for trail planning, construction, and maintenance are being analyzed under the threat of mud slides, avalanches and floods.

Natural gas for vehicles

International Nuclear Information System (INIS)

Chauveron, S. de

1996-01-01

This article presents compressed natural gas for vehicles (CNG), which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical descriptions is given of CNG stations and vehicles, with the aim of acquainting the reader with some of CNG's specific technical features as compared to gasoline and diesel oil. Here CNG technologies are seen to be very close to the more conventional ones. (author)

Natural gas consumption and economic growth: Are we ready to natural gas price liberalization in Iran?

International Nuclear Information System (INIS)

Heidari, Hassan; Katircioglu, Salih Turan; Saeidpour, Lesyan

2013-01-01

This paper examines the relationship between natural gas consumption and economic growth in Iran within a multivariate production model. We also investigate the effects of natural gas price on its consumption and economic growth using a demand side model. The paper employs bounds test approach to level relationship over the period of 1972–007. We find evidence of bidirectional positive relationship between natural gas consumption and economic growth in short-run and long-run, based on the production model. The findings also suggest that real GDP growth and natural gas have positive and negative impacts on gross fixed capital formation, respectively. Employment, however, was found to have negative but insignificant impact on gross fixed capital formation. Moreover, the estimation results of demand side model suggest that natural gas price has negative and significant impact on natural gas consumption only in the long-run, though there is insignificant impact on economic growth. These results imply that the Iranian government's decision for natural gas price liberalization has the adverse effects on economic growth and policy makers should be cautious in doing this policy. - Highlights: • Iran has been considered as a major natural gas producer in the world. • This paper examines the relationship between gas consumption and growth in Iran. • Positive impact of gas consumption on growth has been obtained. • The paper finds that gas consumption and income reinforce each other in Iran. • Natural gas price has also negative and significant impact on natural gas consumption in Iran

78 FR 19696 - Orders Granting Authority To Import and Export Natural Gas, To Import Liquefied Natural Gas, To...

Science.gov (United States)

2013-04-02

... DEPARTMENT OF ENERGY Orders Granting Authority To Import and Export Natural Gas, To Import Liquefied Natural Gas, To Export Liquefied Natural Gas and Vacating Prior Authority During December 2012 FE... granting authority to import and export natural gas and liquefied natural gas and vacating prior [[Page...

Natural product mode of action (MOA) studies: a link between natural and synthetic worlds.

Science.gov (United States)

La Clair, James J

2010-07-01

In our understanding of matter, natural products deliver plots that would stun even the best productions of the legendary filmmaker, Sergio Leone. While every decade heralds a new genre of film (as well as avenues of small-molecule discovery), natural products and their "untamed prehistoric" plots continue to dazzle the fields of biotechnology, drug discovery, fragrances, food additives and agrochemistry. This review provides an abridged synopsis of the modes of natural product action discovered within the last decade and the tools and methods used in their discovery. Their stories are united in a common theme that unveils one of the more vital aspects of chemical biological research:understanding the global activity of Nature's arsenal of secondary metabolites.

Natural radioactivity in the environment

Energy Technology Data Exchange (ETDEWEB)

Petr, I [Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska

1980-01-01

The effects were analyzed of natural radionuclides and cosmic radiation on radiation burden in man. The contents are shown of natural radionuclides in the earth crust, water, atmosphere, food chain and human organism. Using the data, the annual doses from natural sources to the gonads (1025 ..mu..Sv/yr) and to the bone marrow (986 ..mu..Sv) are estimated.

Two criticisms of natural theology

Directory of Open Access Journals (Sweden)

Błażej Gębura

2014-01-01

Full Text Available The article aims at considering two general criticisms often formulated against the natural theology. First criticism is based on the thesis that the conclusions of the natural theology are not adequate with the religious beliefs of non-philosophers. It is widely known as opposition between God of Religion and God of Philosophers. One can find that argument in the writings of Blaise Pascal. I’m arguing for the thesis, that the natural theologian cannot fulfill the criteria given by the proponents of this argument. This is because the argument of the natural theology cannot contains the premises taken from the Revelation. If the argument of the natural theology would contain the premises taken from the Revelation, then it would be the argument of religion. But philosopher of religion (natural theologian can’t do this, if he wants to formulate an philosophical argument. The second criticism is based on the notion of a rational person. In the light of this argument, the natural theology is successful only, if every rational person will accept the conclusion “God exist”. I’m trying to show that there is no philosophical argument that can guarantee it’s acceptance by some rational persons. The acceptance of the conclusion of the argument of the natural theology is a matter of personal decision. There is no logical argument, which can “force” rational persons (rational subjects to accept it’s conclusion. But if this is true, the arguments for the existence of God are no worse than other philosophical arguments.

Naturalness, value systems and perception of risk

International Nuclear Information System (INIS)

Drottz Sjoberg, B.M.

1998-01-01

Full text of publication follows: what is natural? And what is Nature? Are perceptions of Nature and naturalness related to perceptions of risk? This paper focuses on these aspects based on results from a Swedish representative sample (N=731), where subjects indicated e.g. the degree of naturalness of various phenomena, their views of nature, and personal life values, as well as perceptions of risk in specified contexts. The results showed a tendency to perceive as natural the phenomenon which is positively valued, i.e. what is natural is also good or desirable. Further, there were weak correlations between perceived naturalness and indicators of technological optimism, possibly indicating that persons with a more generous view of what is natural also more easily might accept change and outcomes due to human intelligence and activity. The construct of 'tampering with nature' has previously been shown to be one good predictor of perceived risk. The respondents also rated their agreement with items aimed to reflect the four 'views of nature' as suggested by Cultural Theory, i.e. nature as robust, capricious, tolerant and fragile. Nature was foremost perceived as fragile, but the main result clearly revealed that peoples' views of nature were complex and most often involved several of the suggested categories. The discussion focuses on the possible implications on environmental concern and risk perception given that Nature would develop into an undesirable type of locality. (author)

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....

Diagrams of natural deductions

Energy Technology Data Exchange (ETDEWEB)

Popov, S V

1982-01-01

The concept of natural deductions was investigated by the author in his analysis of the complexity of deductions in propositional computations (1975). Here some natural deduction systems are considered, and an analytical procedure proposed which results in a deduction diagram for each system. Each diagram takes the form of an orientated, charge graph, features of which can be used to establish the equivalence of classes of deductions. For each of the natural deduction systems considered, a system of equivalent transformation schemes is derived, which is complete with respect to the given definition of equivalence. 2 references.

Naturally-occurring alpha activity

Energy Technology Data Exchange (ETDEWEB)

Mayneord, W V

1960-12-01

In view of the difficulties of assessing the significance of man-made radioactivity it is important to study for comparison the background of natural radioactivity against which the human race has evolved and lives. It is also important to define the present levels of activity so that it will be possible to detect and study as quickly as possible any changes which may occur owing to the release into the environment of new radioactive materials. Moreover, by the study of the behaviour of natural radioactivity light may be shed upon that of the artificially produced isotopes and a number of analogies traced between the two groups. These concepts have led to studies of naturally-occurring radioactive materials alongside a programme of research into fission products in food, water and air, as well as studies of the metabolism of both sets of materials in the human body. Since the last report there has been a useful increase in our knowledge of natural radioactivity in the biosphere, and its levels relative to the new man-made activities. These studies have necessitated technical developments, particularly in the methods of measuring and identifying alpha-ray emitters, to which group many of the more important natural radioactive materials belong.

Journal of East African Natural History

African Journals Online (AJOL)

The Journal of East African Natural History is published jointly by the East Africa Natural History Society and the National Museums of Kenya. The Journal publishes papers and notes in the field of natural history, broadly defined as the study of organisms in their natural state, relevant to the eastern African region.

Imagining Nature during Music Listening

DEFF Research Database (Denmark)

Bonde, Lars Ole; Beck, Bolette Daniels

2018-01-01

Nature, its delights and horrors, its creatures, its challenges and affordances play an underrated role in receptive music therapy, especially Guided Imagery and Music (GIM). In general, people from Western cultures are challenged in their mostly recreational relationship with nature, while ancient...... 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...... a primarily qualitative, exploratory study....

Natural gas: redistributing the economic surplus

International Nuclear Information System (INIS)

Oliveira, A. de; Pinto Junior, H.Q.

1990-01-01

The natural gas has a limited role in the Brazilian energy balance. This role in industrial countries and some developing countries is much more important. Historically this contrasting situation can be explained by the limited natural gas reserves Brazil used to have. Since the oil crisis however the Brazilian natural gas reserves increased substantially without a similar increase in the role of natural gas in the energy balance. The existing institutional arrangement generates a struggle for the economic rent generated by natural gas production and consumption that seems to be at the core of this question. Our paper estimates the economic rent generated by natural gas in Brazil and its distribution among producers and consumers: it points toward a new institutional arrangement that could arguably, generate a new role for the natural gas in the Brazilian energy balance. (author)

21 CFR 582.30 - Natural substances used in conjunction with spices and other natural seasonings and flavorings.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Natural substances used in conjunction with spices... with spices and other natural seasonings and flavorings. Natural substances used in conjunction with spices and other natural seasonings and flavorings that are generally recognized as safe for their...

The nature-disorder paradox: A perceptual study on how nature is disorderly yet aesthetically preferred.

Science.gov (United States)

Kotabe, Hiroki P; Kardan, Omid; Berman, Marc G

2017-08-01

Natural environments have powerful aesthetic appeal linked to their capacity for psychological restoration. In contrast, disorderly environments are aesthetically aversive, and have various detrimental psychological effects. But in our research, we have repeatedly found that natural environments are perceptually disorderly. What could explain this paradox? We present 3 competing hypotheses: the aesthetic preference for naturalness is more powerful than the aesthetic aversion to disorder (the nature-trumps-disorder hypothesis ); disorder is trivial to aesthetic preference in natural contexts (the harmless-disorder hypothesis ); and disorder is aesthetically preferred in natural contexts (the beneficial-disorder hypothesis ). Utilizing novel methods of perceptual study and diverse stimuli, we rule in the nature-trumps-disorder hypothesis and rule out the harmless-disorder and beneficial-disorder hypotheses. In examining perceptual mechanisms, we find evidence that high-level scene semantics are both necessary and sufficient for the nature-trumps-disorder effect. Necessity is evidenced by the effect disappearing in experiments utilizing only low-level visual stimuli (i.e., where scene semantics have been removed) and experiments utilizing a rapid-scene-presentation procedure that obscures scene semantics. Sufficiency is evidenced by the effect reappearing in experiments utilizing noun stimuli which remove low-level visual features. Furthermore, we present evidence that the interaction of scene semantics with low-level visual features amplifies the nature-trumps-disorder effect-the effect is weaker both when statistically adjusting for quantified low-level visual features and when using noun stimuli which remove low-level visual features. These results have implications for psychological theories bearing on the joint influence of low- and high-level perceptual inputs on affect and cognition, as well as for aesthetic design. (PsycINFO Database Record (c) 2017 APA, all

Canadian natural gas winter 2005-06 outlook

International Nuclear Information System (INIS)

2005-11-01

An outline of the Canadian natural gas commodity market was presented along with an outlook for Canadian natural gas supply and prices for the winter heating season of 2005-2006. In Canada, the level of natural gas production is much higher than domestic consumption. In 2004, Canadian natural gas production was 16.9 billion cubic feet per day (Bcf/d), while domestic consumption was much lower at 8.2 Bcf/d. The United States, whose natural gas consumption is higher than production, imported about 16 per cent of its natural gas supply from Canada and 3 per cent from other countries via liquefied natural gas imports. Canadian natural gas exports to the United States in 2004 was 8.7 Bcf/d, representing 51 per cent of Canada's production. In Canada, the most important natural gas commodity markets that determine natural gas commodity prices include the intra-Alberta market and the market at the Dawn, Ontario natural gas hub. A well connected pipeline infrastructure connects the natural gas commodity markets in Canada and the United States, allowing supply and demand fundamentals to be transferred across all markets. As such, the integrated natural gas markets in both countries influence the demand, supply and price of natural gas. Canadian natural gas production doubled from 7 to 16.6 Bcf/d between 1986 and 2001. However, in the past 3 years, production from western Canada has leveled out despite record high drilling activity. This can be attributed to declining conventional reserves and the need to find new natural gas in smaller and lower-quality reservoirs. The combination of steady demand growth with slow supply growth has resulted in high natural gas prices since the beginning of 2004. In particular, hurricane damage in August 2005 disrupted natural gas production in the Gulf of Mexico's offshore producing region, shutting-in nearly 9 Bcf/d at the height of damage. This paper summarized some of the key factors that influence natural gas market and prices, with

77 FR 31838 - Notice of Orders Granting Authority to Import and Export Natural Gas and Liquefied Natural Gas...

Science.gov (United States)

2012-05-30

... Granting Authority to Import and Export Natural Gas and Liquefied Natural Gas During April 2012 AGENCY... International, LLC....... 12-33-NG Phillips 66 Company 12-34-NG Northwest Natural Gas Company 12-41-NG Sequent... authority to import and export natural gas and liquefied natural gas. These Orders are summarized in the...

78 FR 38309 - Northern Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission...

Science.gov (United States)

2013-06-26

... Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission Company, LLC; Notice of Application Take notice that on June 4, 2013, Northern Natural Gas Company (Northern), 1111 South 103rd Street, Omaha, Nebraska 68124; on behalf of itself, Southern Natural Gas Company, L.L.C., and...

Natural gas for vehicles (NGV)

International Nuclear Information System (INIS)

Prieur, A.

2006-01-01

Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities. (author)

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...... in understanding recent and current practices of climate change and environmental policy. The different chapters in this volume contribute to this debate by offering multidisciplinary perspectives on particular aspects of these two frameworks and through a multidirectional outlook that links the local, national...

Natural User Interfaces

OpenAIRE

Câmara , António

2011-01-01

Dissertação de Mestrado em Engenharia Informática apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra This project’s main subject are Natural User Interfaces. These interfaces’ main purpose is to allow the user to interact with computer systems in a more direct and natural way. The popularization of touch and gesture devices in the last few years has allowed for them to become increasingly common and today we are experiencing a transition of interface p...

The Effect of Gamma Irradiation on the Mechanical Properties of vulcanized Natural Rubber and Natural Rubber-Polyethylene Blends

International Nuclear Information System (INIS)

Sudradjat Iskandar

2008-01-01

To enhance the quality of vulcanized natural rubber and natural rubber-polyethylene blends, gamma irradiation has been done. The compound of natural rubber and natural rubber-polyethylene blends made by using roll mill machine. The mixed materials were antioxidant, anti ozon, plasticizer and vulcanisator. The natural rubber and natural rubber-polyethylene blends compound were vulcanizer and made a slab (film of sample) using hot and could press machine. The slabs produced were then gamma irradiated at irradiation dose of 75, 150 and 300 kGy. Before and after irradiation, the slab were characterized using strograph R1 machine. The results showed that the modulus 300 and hardness of vulcanized natural rubber and natural rubber-polyethylene blends were increasing; the tensile strength and tear strength were increasing to maximum level then decreasing with gamma irradiation, while the elongation at break was decreasing. The maximum tensile strength of vulcanized natural rubber and natural rubber-polyethylene blends were found at irradiation dose of 75 kGy. At the irradiation dose of 75 kGy, the tensile strength of vulcanized natural rubber increased from 17.6 MN/m 2 to 21.2 MN/m 2 , while the tensile strength of vulcanized natural rubber-polyethylene blends increased slightly from 18.7 MN/m 2 to 19.4 MN/m 2 . (author)

75 FR 70350 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

Science.gov (United States)

2010-11-17

... DEPARTMENT OF TRANSPORTATION Maritime Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY: Maritime Administration... announce they have received an application for the licensing of a natural gas deepwater port and the...

76 FR 4417 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

Science.gov (United States)

2011-01-25

... DEPARTMENT OF TRANSPORTATION Maritime Administration [USCG-2010-0993] Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application AGENCY: Maritime Administration... application describes an offshore natural gas deepwater port facility that would be located approximately 16.2...

Globalization of the Natural Gas Industry

International Nuclear Information System (INIS)

Burns, RJ.

1996-01-01

This document deals with the foreseeable evolution of natural gas demand in the next 15 years. Natural gas consumption is growing faster than any other fossil fuel and, according to ENRON, the natural consumption growth will continue. The environmental aspect of natural gas use for power generation is presented, showing that gas use reduces pollution emissions (when compared with coal). On top of that, it appears that the conversion efficiency of gas is much higher than the conversion efficiency of coal steam. Eventually, natural gas resources should meet energy demand for decades. (TEC)

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.

APPLICATION OF NATURAL TRANSFORM IN CRYPTOGRAPHY

OpenAIRE

Chindhe, Anil Dhondiram; Kiwne, Sakharam

2017-01-01

Abstaract−The newly defined integral transform ”Natural transform” has many application in the field of science and engineering.In this paper we described the application of Natural transform to Cryptography.This provide the algorithm for cryptography in which we use the natural transform of the exponential function for encryption of the plain text and corresponding inverse natural transform for decryption

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. Copyright © 2016, American Association for the Advancement of Science.

Anthropologie de la nature

OpenAIRE

Descola, Philippe

2010-01-01

En apparence, l’anthropologie de la nature est une sorte d’oxymore puisque, depuis plusieurs siècles en Occident, la nature se caractérise par l’absence de l’homme, et l’homme par ce qu’il a su surmonter de naturel en lui. Mais la nature n’existe pas comme une sphère de réalités autonomes pour tous les peuples. En postulant une distribution universelle des humains et des non-humains dans deux domaines ontologiques séparés, nous sommes bien mal armés pour analyser tous ces systèmes d’objectiva...

Mathematical models of natural gas consumption

International Nuclear Information System (INIS)

Sabo, Kristian; Scitovski, Rudolf; Vazler, Ivan; Zekic-Susac, Marijana

2011-01-01

In this paper we consider the problem of natural gas consumption hourly forecast on the basis of hourly movement of temperature and natural gas consumption in the preceding period. There are various methods and approaches for solving this problem in the literature. Some mathematical models with linear and nonlinear model functions relating to natural gas consumption forecast with the past natural gas consumption data, temperature data and temperature forecast data are mentioned. The methods are tested on concrete examples referring to temperature and natural gas consumption for the area of the city of Osijek (Croatia) from the beginning of the year 2008. The results show that most acceptable forecast is provided by mathematical models in which natural gas consumption and temperature are related explicitly.

Place attachment and natural environmental risk

DEFF Research Database (Denmark)

Bonaiuto, Marino; Alves, Susana; De Dominicis, Stefano

2016-01-01

Little is known about place attachment affecting natural environmental risk perception and coping. A systematic search of social science databases revealed 31 works (1996–2016) directly addressing place attachment in relation to different types of natural hazard risks (e.g., seismic, volcanic, etc.......). Across different contexts, the research shows: (a) positive and/or negative relationships between place attachment and natural environmental risk perception; (b) positive and/or negative relationships between place attachment and risk coping; and (c) mediating and moderating relationships. In particular......, results show that: (a) highly attached individuals perceive natural environmental risks but underestimate their potential effects; (b) highly attached individuals are unwilling to relocate when facing natural environmental risks and more likely to return to risky areas after a natural environmental...

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.

Deactivation of SCR catalysts by potassium: A study of potential alkali barrier materials

DEFF Research Database (Denmark)

Olsen, Brian Kjærgaard; Kügler, Frauke; Castellino, Francesco

2017-01-01

The use of coatings in order to protect vanadia based SCR catalysts against potassium poisoning has been studied by lab- and pilot-scale experiments. Three-layer pellets, consisting of a layer ofa potential coating material situated between layers of fresh and potassium poisoned SCR catalyst, were...... the coating process. Potassium had to some extent penetrated the MgO coat, and SEM analysis revealed it to be rather thick and fragile. Despite these observations, the coating did protect the SCR catalyst against potassium poisoning to some degree, leaving promise of further optimization....... used to test the ability of the barrier layer to block the diffusion of potassium across the pellet. Of MgO, sepiolite and Hollandite manganese oxide, MgO was the most effective potassium barrier, and no potassium was detected in the MgO layer upon exposure to SCR conditions for 7 days. Two monoliths...

The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

Science.gov (United States)

Narayan, Siddharth; Beck, Michael W; Reguero, Borja G; Losada, Iñigo J; van Wesenbeeck, Bregje; Pontee, Nigel; Sanchirico, James N; Ingram, Jane Carter; Lange, Glenn-Marie; Burks-Copes, Kelly A

2016-01-01

There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i) a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences) and (ii) analyses of the effectiveness of coastal habitats (natural defences) in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i) analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii) synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii) estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a) the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b) the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become more cost

The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

Directory of Open Access Journals (Sweden)

Siddharth Narayan

Full Text Available There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences and (ii analyses of the effectiveness of coastal habitats (natural defences in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become

Natural Heavy Supersymmetry

CERN Document Server

Batell, Brian; McCullough, Matthew

2015-01-01

We study how, as a result of the scanning of supersymmetry breaking during the cosmological evolution, a relaxation mechanism can naturally determine a hierarchy between the weak scale and the masses of supersymmetric particles. Supersymmetry breaking is determined by QCD instanton effects, in an extremely minimal setup in which a single field drives the relaxation and breaks supersymmetry. Since gauginos are lighter than the other supersymmetric particles by a one-loop factor, the theory is a realisation of Split Supersymmetry free from the naturalness problem.

Sciences & Nature

African Journals Online (AJOL)

AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL ... Sciences & Nature, the Scientific Journal edited by the University of ... Subjects covered include agronomy, sciences of the earth, environment, biological, ...

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…

Natural Disasters and Nontuberculous Mycobacteria

Science.gov (United States)

Bernhard, Jon N.; Chan, Edward D.

2015-01-01

Infectious diseases acquired by survivors of large-scale natural disasters complicate the recovery process. During events such as tsunamis, hurricanes, earthquakes, and tornados and well into the recovery period, victims often are exposed to water-soil mixtures that have relocated with indigenous microbes. Because nontuberculous mycobacteria (NTM) are ubiquitous in water and soil, there is potential for increased exposure to these organisms during natural disasters. In this hypothesis-driven commentary, we discuss the rise in NTM lung disease and natural disasters and examine the geographic overlap of NTM infections and disaster frequencies in the United States. Moreover, we show an increased number of positive NTM cultures from Louisiana residents in the years following three of the relatively recent epic hurricanes and posit that such natural disasters may help to drive the increased number of NTM infections. Finally, we advocate for increased environmental studies and surveillance of NTM infections before and after natural disasters. PMID:25644904

The Science of Middle Nature (Invited)

Science.gov (United States)

Pataki, D. E.; Pincetl, S.; Hinners, S.

2013-12-01

In the field of biogeochemistry, urbanization is often considered as an 'alteration' or 'disturbance' to the earth's surface and its natural processes. This view is an outcome of the view of nature inherent in earth system science and ecology, in which nature is defined as separate from humans and society. However, other disciplines are based in alternative views of nature in which humans are more integral components of the landscape. Urban planning, landscape architecture, agriculture, and horticulture, for example, more fully integrate the role of landscape design and management in the functioning of human-dominated ecosystems. We suggest that the field of urban biogeochemistry has been somewhat limited by the predominant, disturbance-based view of the role of nature in cities, and that more deeply evaluating and broadening the concept of nature inherent in studies of urban processes can enhance our understanding of the role of urbanization in the earth system. A particularly useful concept is the 'middle nature' proposed by Cosgrove (1993), which serves a purpose of 'actively transforming nature into culture.' It is this view of urban landscapes as middle nature, or transformation of urban space into human-dominated nature with a purpose, that is lacking from the current scientific discourse about the role of biogeochemistry in urban ecosystem services. A scientific evaluation of middle nature implies studying the performance of urban designs to meet intended cultural and environmental goals, including beauty, social equity, governance, and social capital as well as environmental quality. We describe our work in evaluating the transformed urban landscapes of Los Angeles and Salt Lake City from multiple perspectives that focus on urban livability, equity, and beauty as well as the physical impacts of plants and soils on the environment. The outcomes of this process do not necessary meet the traditional demands of biophysical ecology such as utilizing native

Business cycles and natural gas prices

International Nuclear Information System (INIS)

Apostolos, S.; Asghar, S.

2005-01-01

This paper investigates the basic stylised facts of natural gas price movements using data for the period that natural gas has been traded on an organised exchange and the methodology suggested by Kydland and Prescott (1990). Our results indicate that natural gas prices are procyclical and lag the cycle of industrial production. Moreover, natural gas prices are positively contemporaneously correlated with United States consumer prices and lead the cycle of consumer prices, raising the possibility that natural gas prices might be a useful guide for US monetary policy, like crude oil prices are, possibly serving as an important indicator variable. (author)

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...

Quickening construction of natural gas infrastructures and ensuring safe supply of natural gas in China

Energy Technology Data Exchange (ETDEWEB)

Gao, Peng; Zhongde, Zhao; Chunliang, Sun; Juexin, Shen

2010-09-15

Compared with North America or Europe in respect of natural gas resources, markets and pipeline networks, the current China stands in a special period with natural gas market in quick development, accordingly, it's recommended to strengthen cooperation and coordination between investors by way of diversified investment and joint adventures and on the basis of diversified resource supply modes, so as to accelerate the construction of infrastructures including the natural gas pipeline networks and the storage and peak-shaving facilities, quick up the market development, realize the situation of mutual-win-win, and finally ensure safety of natural gas utilization in the domestic markets.

NCI Program for Natural Product Discovery: A Publicly-Accessible Library of Natural Product Fractions for High-Throughput Screening.

Science.gov (United States)

Thornburg, Christopher C; Britt, John R; Evans, Jason R; Akee, Rhone K; Whitt, James A; Trinh, Spencer K; Harris, Matthew J; Thompson, Jerell R; Ewing, Teresa L; Shipley, Suzanne M; Grothaus, Paul G; Newman, David J; Schneider, Joel P; Grkovic, Tanja; O'Keefe, Barry R

2018-06-13

The US National Cancer Institute's (NCI) Natural Product Repository is one of the world's largest, most diverse collections of natural products containing over 230,000 unique extracts derived from plant, marine, and microbial organisms that have been collected from biodiverse regions throughout the world. Importantly, this national resource is available to the research community for the screening of extracts and the isolation of bioactive natural products. However, despite the success of natural products in drug discovery, compatibility issues that make extracts challenging for liquid handling systems, extended timelines that complicate natural product-based drug discovery efforts and the presence of pan-assay interfering compounds have reduced enthusiasm for the high-throughput screening (HTS) of crude natural product extract libraries in targeted assay systems. To address these limitations, the NCI Program for Natural Product Discovery (NPNPD), a newly launched, national program to advance natural product discovery technologies and facilitate the discovery of structurally defined, validated lead molecules ready for translation will create a prefractionated library from over 125,000 natural product extracts with the aim of producing a publicly-accessible, HTS-amenable library of >1,000,000 fractions. This library, representing perhaps the largest accumulation of natural-product based fractions in the world, will be made available free of charge in 384-well plates for screening against all disease states in an effort to reinvigorate natural product-based drug discovery.

Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

Directory of Open Access Journals (Sweden)

Suhawati Ibrahim

2014-12-01

Full Text Available Natural rubber (NR is a high molecular weight natural polymer and can be degraded to liquid natural rubber (LNR leaving certain functional groups at the end of chains. In this study, LNR samples prepared via oxidative degradation using H2O2 and NaNO2 as reagents were found to have different end groups depending on the pH of the reaction medium. In an acidic medium, LNR with hydroxyl terminal groups was formed as the degradation reaction was initiated by hydroxyl radicals produced from decomposition of peroxynitrite acid. In contrast, a redox reaction took place in an alkaline medium to yield LNR with carbonyl terminal groups. The mechanisms of reaction are discussed and proposed to explain the formation of different end groups when reaction carried out in acidic and alkaline media. Chain degradation in an acidic medium seems to be more effective than in an alkaline medium, and thus yields LNR with lower Mn.

Unbounded Naturalism

Directory of Open Access Journals (Sweden)

Andrew Taggart

2008-10-01

Full Text Available nbsp;font face="Times, serif"font size="3"In the Anglo-American reception of John McDowellrsquo;s /font/fontfont face="Times, serif"font size="3"emMind and World/em/font/fontfont face="Times, serif"font size="3", there has been little attention paid to the developmental aspect of his lsquo;partially re-enchantedrsquo; naturalism. In lsquo;Naturalism Unboundedrsquo;, I argue that McDowellrsquo;s story of our normal upbringing (/font/fontfont face="Times, serif"font size="3"emBildung/em/font/fontfont face="Times, serif"font size="3" presents problems for his claim that we have a lsquo;standing obligationrsquo; to reflect on our perceptual experiences. I follow this critique up with a Hegelian-inspired attempt to retain and revise the vital points he makes about experience./font/font

Science Education and the Nature of Nature: Bruno Latour's Ontological Politics

Science.gov (United States)

Gleason, Tristan

2017-01-01

This article explores recent developments in the field of science and technology, and the work of Bruno Latour in particular, to problematize the nature of Nature in science education. Although science and technology studies, and the scholarship on science education alike, have become increasingly attentive to the antidemocratic habits of science…

Livelihoods and natural resources

DEFF Research Database (Denmark)

Cotta, Jamie Nicole

generation and shock coping. In addition, a multi-method approach (utilizing income, transect inventory and free-list data) demonstrates the significant economic importance of agroforestry environments, particularly managed fallows, when compared with natural forests. Interventions aimed at sustaining...... by both high vulnerability (e.g., residents with flood-vulnerable cultivation) and limited availability/diversity of environmentally-sourced coping products. Finally, future research and development initiatives should take into account not just natural forests or agricultural systems, but also......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...

nature in the city

Directory of Open Access Journals (Sweden)

Elena Grigoryeva

2016-08-01

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.

Natural cytolytic activity in mice with natural or induced cellular defects. I. Differential ability of in vitro interleukin-2 addition to augment natural cytolytic function

International Nuclear Information System (INIS)

Ades, E.W.; Hinson, A.; Butler, L.D.

1986-01-01

The ability of in vitro addition of recombinant interleukin 2 (rIL-2) to differentially enhance natural cytotoxicity was assessed using cells from mice with natural and induced cellular defects. In vivo treatment with most immunosuppressive or cytoreductive agents, anti-asialo-GM1 antibody, or gamma irradiation dramatically reduced in vitro cytotoxicity against natural killer (NK) sensitive targets by direct reduction in either percentage specific lysis or lytic units per spleen. In most cases, in vitro addition of rIL-2 (at concentrations causing augmented NK function in cells from naive Balb/C mice) enhanced cytotoxic activity of cells from treatment groups to a normal value but not within the rIL-2-enhanced range of nontreated animals. Additionally, cytotoxic activity of cells from animals treated with certain drugs or gamma irradiation could be augmented by rIL-2 when measured by percentage lysis but not lytic units per spleen. In vivo treatment with cyclosporin A did not affect natural cytotoxic activity and addition of rIL-2 augmented the NK activity in a similar fashion to the profile of naive cells. In experiments using cells from beige (C57Bl/6-bg) mice which have a natural defect in NK activity against YAC-1 targets, addition of rIL-2 (at concentrations causing augmented natural cytotoxic function in cells from C57Bl/6 mice) could not effectively enhance in vitro natural cytotoxic function

Natural cytolytic activity in mice with natural or induced cellular defects. I. Differential ability of in vitro interleukin-2 addition to augment natural cytolytic function

Energy Technology Data Exchange (ETDEWEB)

Ades, E.W.; Hinson, A.; Butler, L.D.

1986-08-01

The ability of in vitro addition of recombinant interleukin 2 (rIL-2) to differentially enhance natural cytotoxicity was assessed using cells from mice with natural and induced cellular defects. In vivo treatment with most immunosuppressive or cytoreductive agents, anti-asialo-GM1 antibody, or gamma irradiation dramatically reduced in vitro cytotoxicity against natural killer (NK) sensitive targets by direct reduction in either percentage specific lysis or lytic units per spleen. In most cases, in vitro addition of rIL-2 (at concentrations causing augmented NK function in cells from naive Balb/C mice) enhanced cytotoxic activity of cells from treatment groups to a normal value but not within the rIL-2-enhanced range of nontreated animals. Additionally, cytotoxic activity of cells from animals treated with certain drugs or gamma irradiation could be augmented by rIL-2 when measured by percentage lysis but not lytic units per spleen. In vivo treatment with cyclosporin A did not affect natural cytotoxic activity and addition of rIL-2 augmented the NK activity in a similar fashion to the profile of naive cells. In experiments using cells from beige (C57Bl/6-bg) mice which have a natural defect in NK activity against YAC-1 targets, addition of rIL-2 (at concentrations causing augmented natural cytotoxic function in cells from C57Bl/6 mice) could not effectively enhance in vitro natural cytotoxic function.

NATURAL RESOURCES ASSESSMENT

International Nuclear Information System (INIS)

D.F. Fenster

2000-01-01

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 report, but are planned to be included in the hydrology

Mechanisms of children's exposure to nature: Predicting adulthood environmental citizenship and commitment to nature-based activities

Science.gov (United States)

Stanley T. Asah; David N. Bengston; Lynne M. Westphal; Catherine H. Gowan

2017-01-01

Childhood-nature experiences have lifelong effects on environmental citizenship and commitment to nature-based activities. But, it is unclear whether, and to what extent, the different mechanisms through which children and youth experience nature are associated with these outcomes. To test these associations, an online questionnaire assessing mechanisms of childhood...

Nature and landscape protection

International Nuclear Information System (INIS)

Klinda, J.; Lieskovska, Z.

1998-01-01

In accordance with National Council of the Slovak Republic Act N. 287/1994 Coll. on Nature and Landscape Protection, the system of complex nature landscape protection has been designed based on five levels of protection. Categories of protected areas as well as cultural monuments in the Slovak Republic are reviewed.Slovak contribution to the world heritage is included

Natural hazards science strategy

Science.gov (United States)

Holmes, 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

Natural gas in the transportation sector

Energy Technology Data Exchange (ETDEWEB)

Ask, T Oe; Einang, P M; Stenersen, D [MARINTEK (Norway)

1996-12-01

The transportation sector is responsible for more than 50% of all oil products consumed, and it is the fastest growing oil demand sector and the fastest growing source of emissions. During the last 10 years there have been a considerable and growing effort in developing internal combustion gas engines. This effort has resulted in gas engines with efficiencies comparable to the diesel engines and with emissions considerably lower than engines burning conventional fuels. This development offers us opportunities to use natural gas very efficiently also in the transportation sector, resulting in reduced emissions. However, to utilize all the built in abilities natural gas has as engine fuel, the natural gas composition must be kept within relatively narrow limits. This is the case with both diesel and gasoline today. A further development require therefore specified natural gas compositions, and the direct use of pipeline natural gas as today would only in limited areas be acceptable. An interesting possibility for producing a specified natural gas composition is by LNG (Liquid Natural Gas) production. (EG)

Natural gas: an environmental-friendly solution?

International Nuclear Information System (INIS)

Vermeire, J.

1994-01-01

Since 1970, the portion of natural gas in energy consumption in Western-Europe has grown by 6 percent per year on the average. About 20 percent of the energy demand in Western-Europe is now covered by natural gas. It is forecasted that this growth will continue at a rate of 2 percent per year until 2010. The natural gas consumption will increase from 325 billion cubic metres in 1993 to 450 billion cubic metres per year in 2010. For the coming 10 to 15 years, the natural gas demand is covered by long-term contracts with gas producing countries. From 2010 on, additional contracts, covering 70 to 120 billion cubic metres per year are required. A shift in geographic distribution of countries from which natural gas will be imported by Western-European countries is expected, which implies high investments and additional costs for transport and distribution of natural gas. Due to its qualities with respect to environmental impact, yield, availability, and advanced technology, natural gas is the energy vector of the 21 first century. (A.S.)

Natural gas supply and demand outlook

International Nuclear Information System (INIS)

McGill, C.B.

1998-01-01

The outlook for U.S. natural gas supply and demand in the residential, commercial, industrial/cogeneration, electricity and transportation sectors for 1995, 2000, 2005, 2010, and 2015 was presented. A summary of gas well completions from 1990 to 1997 was also provided. The Canadian natural gas resource was estimated at 184 trillion cubic feet. In 1996, Canada produced 5.6 trillion cubic feet of natural gas, half of which was exported to the U.S. New pipeline projects have been proposed to transport natural gas from eastern offshore areas and the Western Canadian Sedimentary Basin. A table representing U.S. and Canada gas trade from 1990 to 1997 and a map of proposed Canadian and U.S. natural gas pipeline routes were also included. Looking into the future, this speaker predicted continued volatility in natural gas prices. 9 tabs., 9 figs

Francis Bacon and the Art-Nature Distinction.

Science.gov (United States)

Weeks, Sophie

2007-07-01

Commentators generally expound Bacon's position on the art-nature relationship in terms of how much it retained or departed from traditional conceptions. This paper argues that an appreciation of the Baconian meaning of the terms "art" and "nature" requires a close examination of his wider cosmogonical speculations. Bacon's cosmogonical account moves from a state of unbridled chaos to the relatively stable system for which the term "nature" is normally used. The fundamental principle lying at the heart of Baconian cosmogony is an enriched and appetitive matter: eternal, unchanging, and the plenipotentiary source of all things. Successive limitations of matter's absolute power produced a lazy and habitual nature, which Bacon labelled "nature free." To shift nature from this otiose condition, the Baconian operator recapitulates the original binding of matter. Bacon designated the systematic procedures of binding nature the science of magic. Magic is Bacon's human counterpart to the original cosmogonical process that gave rise to the current system of nature. In Bacon's cosmogony, all possible worlds unfold out of matter: the function of art is to shake out nature's hidden folds. Hence, the distinction between naturalia and artificialia maps on to the distinction between actual and potential. Nature free is without purpose, but art - nature bound - knowingly brings into being an alternative nature designed for human utility.

Naturalized Philosophy of Science and Natural Science Education.

Science.gov (United States)

Siegel, Harvey

1993-01-01

Reviews the philosophical controversy concerning naturalism, and investigates the role it might play in the science classroom. Argues that science students can benefit from explicit study of this controversy and from explicit consideration of the extent to which philosophy of science can be studied naturalistically. (PR)

Children and Nature: Linking Accessibility of Natural Environments and Children’s Health-Related Quality of Life

Directory of Open Access Journals (Sweden)

Suzanne Tillmann

2018-05-01

Full Text Available A growing body of research suggests that increasing children’s nature interactions can have positive benefits for their health-related quality of life (HRQOL; however, researchers have yet to examine how geographical context influences this relationship. The purpose of this study was to examine individual-level and environmental factors that are associated with HRQOL of children from different geographical contexts. Data were collected for 851 children from 34 elementary schools in Ontario, Canada. The natural environments around each child’s home were computed using geospatial analyses in a geographic information system. Natural environment measures were combined with HRQOL and the demographics from child surveys to be used in a series of step-wise linear regression models. These models explored the relationship between children’s HRQOL and the natural environment in urban/suburban and rural populations. In addition to important individual-level determinants, the findings revealed that characteristics of the natural environment, including the amount of greenness, park, and water, show significant relationships in the urban/suburban population. Interpersonal variables were the key predictors of HRQOL in the rural population. Where children live influences relationships between nature and HRQOL. These findings have implications for policymakers, health practitioners, educators, and parents in the design and the promotion of nature for children’s HRQOL.

Future perspective for CNG (Compressed Natural Gas)

International Nuclear Information System (INIS)

Veen, D.

1999-01-01

Driving on natural gas (CNG, Compressed Natural Gas) has been the talk of the industry for many years now. Although the benefits of natural gas as an engine fuel have become well-known, this phenomenon does not seem to gain momentum in the Netherlands. Over the last few months, however, the attitude towards CNG seems to be changing. Energy companies are increasingly engaged in commercial activities, e.g. selling natural gas at petrol stations, an increasing number of car manufacturers are delivering natural gas vehicles ex-works, and recently the NGV (Natural Gas Vehicles) Holland platform was set up for the unequivocal marketing of natural gas as an engine fuel

78 FR 21349 - Orders Granting Authority To Import and Export Natural Gas, To Export Liquefied Natural Gas, To...

Science.gov (United States)

2013-04-10

... DEPARTMENT OF ENERGY Orders Granting Authority To Import and Export Natural Gas, To Export Liquefied Natural Gas, To Export Compressed Natural Gas, Vacating Prior Authority and Denying Request for... OIL COMMERCIAL GP 12-164-NG XPRESS NATURAL GAS LLC 12-168-CNG MERRILL LYNCH COMMODITIES CANADA, ULC 12...

Natural gas and the environment

International Nuclear Information System (INIS)

DeCarufel, A.

1991-01-01

The role of various atmospheric pollutants in environmental changes and the global water cycle, carbon cycle, and energy balance is explained. The role of sulfur dioxide and nitrogen oxides in acid deposition is also outlined. The pollutants that contribute to environmental problems include nitrogen oxides and volatile organic compounds, carbon dioxide, and other greenhouse gases. The potential for natural gas utilization to mitigate some of these pollution problems is explored. Natural gas combustion emits less carbon dioxide and nitrogen oxides than combustion of other fossil fuel, and also does not produce sulfur dioxide, particulates, or volatile organics. Other pollution controlling opportunities offered by natural gas include the use of low-polluting burners, natural gas vehicles, and cogeneration systems. 18 figs., 4 tabs

Investing in Natural and Nature-Based Infrastructure: Building Better Along Our Coasts

Directory of Open Access Journals (Sweden)

Ariana E. Sutton-Grier

2018-02-01

Full Text Available Much of the United States’ critical infrastructure is either aging or requires significant repair, leaving U.S. communities and the economy vulnerable. Outdated and dilapidated infrastructure places coastal communities, in particular, at risk from the increasingly frequent and intense coastal storm events and rising sea levels. Therefore, investments in coastal infrastructure are urgently needed to ensure community safety and prosperity; however, these investments should not jeopardize the ecosystems and natural resources that underlie economic wealth and human well-being. Over the past 50 years, efforts have been made to integrate built infrastructure with natural landscape features, often termed “green” infrastructure, in order to sustain and restore valuable ecosystem functions and services. For example, significant advances have been made in implementing green infrastructure approaches for stormwater management, wastewater treatment, and drinking water conservation and delivery. However, the implementation of natural and nature-based infrastructure (NNBI aimed at flood prevention and coastal erosion protection is lagging. There is an opportunity now, as the U.S. government reacts to the recent, unprecedented flooding and hurricane damage and considers greater infrastructure investments, to incorporate NNBI into coastal infrastructure projects. Doing so will increase resilience and provide critical services to local communities in a cost-effective manner and thereby help to sustain a growing economy.

Protein space: a natural method for realizing the nature of protein universe.

Science.gov (United States)

Yu, Chenglong; Deng, Mo; Cheng, Shiu-Yuen; Yau, Shek-Chung; He, Rong L; Yau, Stephen S-T

2013-02-07

Current methods cannot tell us what the nature of the protein universe is concretely. They are based on different models of amino acid substitution and multiple sequence alignment which is an NP-hard problem and requires manual intervention. Protein structural analysis also gives a direction for mapping the protein universe. Unfortunately, now only a minuscule fraction of proteins' 3-dimensional structures are known. Furthermore, the phylogenetic tree representations are not unique for any existing tree construction methods. Here we develop a novel method to realize the nature of protein universe. We show the protein universe can be realized as a protein space in 60-dimensional Euclidean space using a distance based on a normalized distribution of amino acids. Every protein is in one-to-one correspondence with a point in protein space, where proteins with similar properties stay close together. Thus the distance between two points in protein space represents the biological distance of the corresponding two proteins. We also propose a natural graphical representation for inferring phylogenies. The representation is natural and unique based on the biological distances of proteins in protein space. This will solve the fundamental question of how proteins are distributed in the protein universe. Copyright © 2012 Elsevier Ltd. All rights reserved.

CEC natural analogue working group

International Nuclear Information System (INIS)

Come, B.; Chapman, N.A.

1986-01-01

The second meeting of the CEC Natural Analogue Working Group took place on June 17-19, 1986, hosted by the Swiss NAGRA in Interlaken (CH). A review of recent progress in natural analogue programmes was carried out, and complemented by detailed discussions about geomicrobiology, archaeological analogues, natural colloids, and use of analogues to increase confidence in safety assessments for radioactive waste disposal. A statement drafted by the Group, and the presentations made, are put together in this report

The Dialectic of the Nature-Society-System

Directory of Open Access Journals (Sweden)

Christian Fuchs

2008-07-01

Full Text Available There are four logical possibilities for conceiving the relationship of nature and society: the reduction of society to nature, the projection of nature into society, dualism, and a nature-society-dialectic. This differentiation results in four different approaches. Nature is a self-organizing system that produces an evolutionary hierarchy of interconnected systems with specific qualities. Society is a product of nature where humans produce and reproduce structures that enable and constrain human practices in dynamic processes. Parts of nature are observed and appropriated by humans from within society, these parts are socially constructed and form a subsystem of society. The self-organization cycle of nature and the self-organization cycle of the socio-sphere are mutually connected in a productive cycle of society where natural self-organization serves as the material foundation that enables and constrains social self-organization and human production processes transform natural structures and incorporate these very structures into society as means of production (technologies, raw materials. The economy is that part of the socio-sphere where the relationship between nature and the socio-sphere is established, the mediation is achieved by human labour processes. Nature enters the economic process as material input in the form of means of production (constant capital: machines, raw materials, auxiliary materials. Organized nature that is part of the production process in the form of technology increases the productivity of labour and hence reduces the costs of variable capital (total amount of wages and increases the speed of the production of surplus value. The production system of modern society is oriented on economic profit and productivity, ecological depletion and pollution are by-products of modernization. The Fordist production model that originated in the West and was copied by the Soviet Union is one of the major causes of the global

78 FR 21351 - Orders Granting Authority to Import and Export Natural Gas, To Import Liquefied Natural Gas, To...

Science.gov (United States)

2013-04-10

... DEPARTMENT OF ENERGY Orders Granting Authority to Import and Export Natural Gas, To Import Liquefied Natural Gas, To Export Liquefied Natural Gas, and Vacating Prior Authority During February 2013 FE... NORTH AMERICA, INC 13-01-NG RESOLUTE FP US INC 13-05-NG GAS NATURAL APROVISIONAMIENTOS SDG, S.A 13-07...

Empirical Methods in Natural Language Generation

NARCIS (Netherlands)

Krahmer, Emiel; Theune, Mariet

Natural language generation (NLG) is a subfield of natural language processing (NLP) that is often characterized as the study of automatically converting non-linguistic representations (e.g., from databases or other knowledge sources) into coherent natural language text. In recent years the field

76 FR 57100 - Natural Resource Plan

Science.gov (United States)

2011-09-15

... TENNESSEE VALLEY AUTHORITY Natural Resource Plan AGENCY: Tennessee Valley Authority (TVA). ACTION... environmental impact statement (EIS) for the Natural Resource Plan (NRP). The notice of availability of the Final Environmental Impact Statement for the Natural Resource Plan was published in the Federal Register...

Thick naturalism: comments on Zygon 2000

NARCIS (Netherlands)

Drees, Willem

2000-01-01

The term naturalism arouses strong emotions; religious naturalism even more. In this essay, naturalism is explored in a variety of contexts, in contrast to supernaturalism (in metaphysics), normativism (in ethics and epistemology), and rationalism (in the philosophy of mind). It is argued that

Three Newly Naturalized Plants in Taiwan

Directory of Open Access Journals (Sweden)

Ming-Jer Jung

2009-11-01

Full Text Available Three newly naturalized plants are reported in this paper. Hypochaeris microcephala (Sch. Bip. Cabrera var. albiflora (Kuntze Cabrera (Asteraceae is naturalized in urban areas of northern Taiwan. Indigofera pseudo-tinctoria Matsum. (Leguminosae is naturalized in low elevations of northern and southern Taiwan and in middle elevations of central Taiwan. Lamium purpureum L. (Laminaceae has become naturalized locally in middle elevations of central Taiwan. Descriptions, illustrations and color photos of these plants are provided.

Wind Extraction for Natural Ventilation

Science.gov (United States)

Fagundes, Tadeu; Yaghoobian, Neda; Kumar, Rajan; Ordonez, Juan

2017-11-01

Due to the depletion of energy resources and the environmental impact of pollution and unsustainable energy resources, energy consumption has become one of the main concerns in our rapidly growing world. Natural ventilation, a traditional method to remove anthropogenic and solar heat gains, proved to be a cost-effective, alternative method to mechanical ventilation. However, while natural ventilation is simple in theory, its detailed design can be a challenge, particularly for wind-driven ventilation, which its performance highly involves the buildings' form, surrounding topography, turbulent flow characteristics, and climate. One of the main challenges with wind-driven natural ventilation schemes is due to the turbulent and unpredictable nature of the wind around the building that impose complex pressure loads on the structure. In practice, these challenges have resulted in founding the natural ventilation mainly on buoyancy (rather than the wind), as the primary force. This study is the initial step for investigating the physical principals of wind extraction over building walls and investigating strategies to reduce the dependence of the wind extraction on the incoming flow characteristics and the target building form.

Natural syntax : English interrogative main clauses

Directory of Open Access Journals (Sweden)

Janez Oresnik

2007-12-01

Full Text Available Natural Syntax is a developing deductive theory, a branch of Naturalness Theory. The naturalnessjudgements are couched in naturalness scales, whichfollow from the basic parameters (or «axioms» listed at the beginning of the paper. The predictions of the theory are calculated in deductions, whose chief components are apair of naturalness scales and the rules governing the alignment of corresponding naturalness values. Parallel and chiastic alignments are distinguished, in complementary distribution. Chiastic alignment is mandatory in deductions limited to unnatural environments. The paper deals with English interrogative main clauses. Within these, only the interrogatives containing wh-words exclusively insitu constitute an extremely unnatural environment and require chiastic alignment. Otherwiseparallel alignment is used. Earlier publications on Natural Syntax: Kavcic 2005a,b, Oresnik 1999, 2000a,b, 200la-f   2002, 2003a-c, 2002/03, 2004. This list cites only works written in English.

Canadian natural gas and climate change

International Nuclear Information System (INIS)

2002-03-01

The Canadian Gas Association (CGA) has expressed concerns regarding how the goal to reduce greenhouse gas emissions can be met. It also has concerns regarding the possible economic impacts of required measures to reduce emissions to 6 per cent below 1990 levels. The CGA argued that since the initial negotiations of the Kyoto Protocol, Canada's greenhouse gas emissions have increased significantly, meaning that if the agreement were to come into force, Canada would have to reduce emissions by about 29 per cent below the currently-projected 2008-2012 level. The report states that 28 per cent of Canada's energy needs are met by natural gas. Excluding energy use in transportation, natural gas contributes more than 40 per cent to Canada's energy portfolio. More than half of Canadian households rely on pipeline services and distribution companies to deliver natural gas for household use. The manufacturing sector relies on natural gas for more than half of its energy needs. Natural gas is a major energy source for the iron/steel, petroleum refining and chemical manufacturing industries. Natural gas is a cleaner-burning fuel than coal or crude oil, and its use results in fewer environmental impacts than other fossil fuels. Vehicles powered by natural gas produce 20 - 30 per cent less carbon dioxide emissions than vehicles powered by gasoline. Pipelines are also a more efficient way of transporting and distributing natural gas than marine transport, railways or trucks. The CGA recommends that policy development should emphasize the environmental benefits of natural gas and recognize its role as a bridge fuel to a cleaner energy-based economy. It also recommends that policies should be developed to encourage the use of natural gas in electricity generation to lower greenhouse gases and air pollutants such as oxides of nitrogen that cause smog

A model integrating social-cultural concepts of nature into frameworks of interaction between social and natural systems

DEFF Research Database (Denmark)

Muhar, Andreas; Raymond, Christopher M.; van den Born, Riyan J.G.

2018-01-01

relationship at both individual and collective levels. We highlight the relevance of individual and collective understandings of the human-nature relationship as influencing factors for environmental behaviour, which may be reflected in natural resource management conflicts, and review the diversity......Existing frameworks for analysing interactions between social and natural systems (e.g. Social-Ecological Systems framework, Ecosystem Services concept) do not sufficiently consider and operationalize the dynamic interactions between people's values, attitudes and understandings of the human-nature....... Integrating this model into existing frameworks provides a tool for the exploration of how social-cultural concepts of nature interact with existing contexts to influence governance of social-ecological systems....

Exposure to natural radiation

International Nuclear Information System (INIS)

Green, B.M.R.

1985-01-01

A brief report is given of a seminar on the exposure to enhanced natural radiation and its regulatory implications held in 1985 at Maastricht, the Netherlands. The themes of the working sessions included sources of enhanced natural radiation, parameters influencing human exposure, measurement and survey programmes, technical countermeasures, risk and assessment studies, philosophies of dose limitations and national and international policies. (U.K.)

Naturalness and image quality : chroma and hue variation in color images of natural scenes

NARCIS (Netherlands)

Ridder, de H.; Blommaert, F.J.J.; Fedorovskaya, E.A.; Rogowitz, B.E.; Allebach, J.P.

1995-01-01

The relation between perceptual image quality and naturalness was investigated by varying the colorfulness and hue of color images of natural scenes. These variations were created by digitizing the images, subsequently determining their color point distributions in the CIELUV color space and finally

Naturalness and image quality: Chroma and hue variation in color images of natural scenes

NARCIS (Netherlands)

Ridder, de H.; Blommaert, F.J.J.; Fedorovskaya, E.A.; Eschbach, R.; Braun, K.

1997-01-01

The relation between perceptual image quality and natural ness was investigated by varying the colorfulness and hue of color images of natural scenes. These variations were created by digitizing the images, subsequently determining their color point distributions in the CIELUV color space and

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.)

Natural gas's hottest spot

International Nuclear Information System (INIS)

Peterson, T.

1993-01-01

This paper reviews the growing power and economic strength of Enron Corp., a natural gas distributor and exploration company. The paper reviews the policy of the company to exploit deregulation at home and privatization of all sorts of energy companies abroad. Enron is actively building its own power plants in the US and has successfully boosted their profits by 20 percent in what was considered a flat natural gas market. The paper goes on to discuss the company's view of the new energy tax and how it should benefit natural gas companies as a whole. Finally the paper reviews the contracting procedures of the company to secure long-term fixed price contracts in a volatile market which precludes most companies from taking the risk

Behaviour of steels in natural environments: focus on stainless steels in natural sea water

International Nuclear Information System (INIS)

Feron, D.

2005-01-01

Corrosion behaviour of steels and alloys in natural environments is not only dependent to material parameters and environmental chemistry, but also to micro-organisms which may be there. The global approach used to investigate the behaviour of alloys in natural environments is illustrated by the work done on stainless steels in seawater. In aerated seawater, studies led to the proposal of an 'enzymatic model' based on the enzymatic catalyze of the cathodic reaction and which allows reproducing the electrochemical behaviour of stainless steels in natural seawater and the crevice corrosion phenomena observed in natural sea waters. Coupling areas under aerobic and anaerobic conditions leads to the worst situation for stainless steel behaviour: the catalysis of the cathodic reaction on aerobic exposed surfaces and the decrease of the corrosion resistance of anaerobic surfaces due to sulphides. These results lead to the concept of electro-active bio-films. (author)

Natural gas supply in Denmark - A model of natural gas transmission and the liberalized gas market

International Nuclear Information System (INIS)

Bregnbaek, L.

2005-01-01

In the wake of the liberalization of European energy markets a large area of research has spawned. This area includes the development of mathematical models to analyze the impact of liberalization with respect to efficiency, supply security and environment, to name but a few subjects. This project describes the development of such a model. In Denmark the parallel liberalization of the markets of natural gas and electricity and the existence of an abundance of de-centralized combined heat and power generators of which most are natural gas fired, leads to the natural assumption that the future holds a greater deal of interdependency for these markets. A model is developed describing network flows in the natural gas transmission system, the main arteries of natural gas supply, from a technical viewpoint. This yields a technical bounding on the supply available in different parts of the country. Additionally the economic structure of the Danish natural gas market is formulated mathematically giving a description of the transmission, distribution and storage options available to the market. The supply and demand of natural gas is put into a partial equilibrium context by integrating the developed model with the Balmorel model, which describes the markets for electricity and district heat. Specifically on the demand side the consumption of natural gas for heat and power generation is emphasized. General results and three demonstration cases are presented to illustrate how the developed model can be used to analyze various energy policy issues, and to disclose the strengths and weaknesses in the formulation. (au)

Naturalized alien flora of the world

NARCIS (Netherlands)

Pyšek, Petr; Pergl, Jan; Essl, Franz; Lenzner, Bernd; Dawson, Wayne; Kreft, Holger; Weigelt, Patrick; Winter, Marten; Kartesz, John; Nishino, Misako; Antonova, Liubov A.; Barcelona, Julie F.; Cabezas, Francisco J.; Cárdenas, Dairon; Cárdenas-Toro, Juliana; Castaño, Nicolás; Chacón, Eduardo; Chatelain, Cyrille; Dullinger, Stefan; Ebel, Aleksandr L.; Figueiredo, Estrela; Fuentes, Nicol; Genovesi, Piero; Groom, Quentin J.; Henderson, Lesley; Inderjit,; Kupriyanov, Andrey; Masciadri, Silvana; Maurel, Noëlie; Meerman, Jan; Morozova, Olga; Moser, Dietmar; Nickrent, Daniel L.; Nowak, Pauline M.; Pagad, Shyama; Patzelt, Annette; Pelser, Pieter B.; Seebens, Hanno; Shu, Wen Sheng; Thomas, Jacob; Velayos, Mauricio; Weber, Ewald; Wieringa, Jan J.; Baptiste, María P.; Kleunen, Van Mark

2017-01-01

Using the recently built Global Naturalized Alien Flora (GloNAF) database, containing data on the distribution of naturalized alien plants in 483 mainland and 361 island regions of the world, we describe patterns in diversity and geographic distribution of naturalized and invasive plant species,

The Nature of Society: Enmapping Nature, Space and Society into a Town-green Hybrid

Directory of Open Access Journals (Sweden)

Louis Rice

2014-10-01

Full Text Available The paper describes the transformation of derelict land into a 'town-green' and the role legislation played in transforming social and natural relationships. Town-green denotes a legal status under the Great Britain Commons Act (2006 that protects certain open spaces from building development; the status requires that a space must simultaneously have a specific social quality (i.e. 'town-ness' and a specific natural quality (i.e. 'green-ness'. This hybrid condition requires an alliance between society and nature in a certain configuration (referred to here as nature2 and society2. In this empirical study it involved the participation and consensus of local residents, volunteer gardeners as well as nature itself; flowers needed to bloom and grass had to grow in order for the hybrid town-green status to be conferred. There are two distinct phases of this transformation; the first is the change in identities and configuration of the constituents of town and green. This involved the production of a modified 'real' world with: different plants and flowers; reconfigured spatial arrangements; as well as different social actors. The second phase is a shift from changes in the "real" world towards an 'enmap' - a displacement of myriad actors into documentation. This transfer from a complex messy reality into an enmap permitted the legitimation of the new network to be accepted as a 'town-green'. What the research reveals, other than hints for gardeners and community activists, is how material and non-material; social and natural; spatial, discursive and temporal worlds are hybridised.

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

CONSUMERS’ PURCHASE INTENTIONS TOWARDS NATURAL COSMETICS

Directory of Open Access Journals (Sweden)

Matea Matić

2016-06-01

Full Text Available The purpose of this paper is to determine which variables influence consumers’ intentions towards purchasing natural cosmetics. Several variables are included in the regression analysis such as age, gender, consumers’ purchase tendency towards organic food, consumers’ new natural cosmetics brands and consumers’ tendency towards health consciousness. The data was collected through an online survey questionnaire using the purposive sample of 204 consumers from the Dubrovnik-Neretva County in March and April of 2015. Various statistical analyses were used such as binary logistic regression and correlation analysis. Binary logistic regression results show that gender, consumers’ purchase tendency towards organic food and consumers’ purchase tendency towards new natural cosmetics brands have an influence on consumer purchase intentions. However, consumers’ tendency towards health consciousness has no influence on consumers’ intentions towards purchasing natural cosmetics. Results of the correlation analysis indicate that there is a strong positive correlation between purchase intentions towards natural cosmetics and consumer references of natural cosmetics. The findings may be useful to online retailers, as well as marketers and practitioners to recognize and better understand the new trends that occur in the industry of natural cosmetics.

Nature Watch

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 3. Nature Watch: Symbiosis in Coastal Marine Communities. Neelam Pereira. Feature Article Volume 20 Issue 3 March 2015 pp 245-253. Fulltext. Click here to view fulltext PDF. Permanent link:

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....

Feature-aware natural texture synthesis

KAUST Repository

Wu, Fuzhang; Dong, Weiming; Kong, Yan; Mei, Xing; Yan, Dongming; Zhang, Xiaopeng; Paul, Jean Claude

2014-01-01

This article presents a framework for natural texture synthesis and processing. This framework is motivated by the observation that given examples captured in natural scene, texture synthesis addresses a critical problem, namely, that synthesis

Investigating Nature's Mysteries for Drug Development

Science.gov (United States)

More than half of the drugs approved to treat cancer come from a natural product or a natural product prototype. Scientists in NCI-Frederick's Natural Products Branch are exploring ways to harness chemicals produced by marine invertebrates, other animals, plants, and microbes for cancer drug discovery.

Canadian natural gas price debate

International Nuclear Information System (INIS)

Wight, G.

1998-01-01

Sunoco Inc. is a subsidiary of Suncor Energy, one of Canada's largest integrated energy companies having total assets of $2.8 billion. As one of the major energy suppliers in the country, Sunoco Inc has a substantial stake in the emerging trends in the natural gas industry, including the Canadian natural gas price debate. Traditionally, natural gas prices have been determined by the number of pipeline expansions, weather, energy supply and demand, and storage levels. In addition to all these traditional factors which still apply today, the present day natural gas industry also has to deal with deregulation, open competition and the global energy situation, all of which also have an impact on prices. How to face up to these challenges is the subject of this discourse. tabs., figs

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…

Regulatory issues of natural gas distribution; Aspectos regulatorios acerca da distribuicao de gas natural

Energy Technology Data Exchange (ETDEWEB)

Leite, Fabio Augusto C.C.M.; Costa, Hirdan Katarina de M. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Faculdade de Direito

2004-07-01

In these past few years, natural gas in Brazil has arised as one of the alternatives for the energetic crisis suffered by the country. Such situation was one of the motives for its expansion, rising, after that, the importance of the regulation of its distribution. The regulation of canalized natural gas distribution can be found in the Federal Constitution, after Constitutional Amendment n. 05/95, in the article n. 25, para. 2nd, which say that belongs to the Federal States the concession or direct exercise of canalized natural gas services, now clearly classified as a public service. In order of these events, its imperative the analysis of natural gas distribution's public service, because it belongs to the Federal States. According to this situation, the study of the new regulatory function of the Administration and the tracing of action for the regulatory state agencies are the main goals of this work. As so, the present research aims to focus the reflexes from the actual dimension of natural gas distribution, specially referring to its regulatory statements, the limitations of state agencies, the National Petroleum Agency and the market where distribution belongs, and particularly the open access of new agents. (author)

Natural compounds as next-generation herbicides.

Science.gov (United States)

Dayan, Franck E; Duke, Stephen O

2014-11-01

Herbicides with new modes of action (MOAs) are badly needed due to the rapidly evolving resistance to commercial herbicides, but a new MOA has not been introduced in over 20 years. The greatest pest management challenge for organic agriculture is the lack of effective natural product herbicides. The structural diversity and evolved biological activity of natural phytotoxins offer opportunities for the development of both directly used natural compounds and synthetic herbicides with new target sites based on the structures of natural phytotoxins. Natural phytotoxins are also a source for the discovery of new herbicide target sites that can serve as the focus of traditional herbicide discovery efforts. There are many examples of strong natural phytotoxins with MOAs other than those used by commercial herbicides, which indicates that there are molecular targets of herbicides that can be added to the current repertoire of commercial herbicide MOAs. © 2014 American Society of Plant Biologists. All Rights Reserved.

Natural radioactivity at Podravina gas fields

International Nuclear Information System (INIS)

Kovac, J.; Marovic, G.

2006-01-01

In Croatia, natural gas is an important source of energy, where its use exceeds other sources by one third. Composed primarily of the methane, natural gas from Croatian Podravina gas fields, beside other impurities, contains small amounts of radioactive elements. At Gas Treatment Plant (GTP) Molve, technological procedures for purification of natural gas and its distribution are performed. With yearly natural gas production of 3.5 109 m3 GTP Molve is major Croatian energy resource. Its safety and environment impact is matter of concern. Using different radioactivity measuring techniques the exposure of population to ionizing radiation were calculated at Central Natural Gas Station Molve and the underground wells. The measurement techniques included in-situ gamma spectrometric measurements, from which contribution to absorbed dose of the natural radionuclide in soil were calculated. Exposure dose measurements were performed using T.L.-dosimeters, and L.A.R.A. electronic dosimeters as well as field dose rate meter. Comparing used different radioactivity measuring methods, the correlations have been calculated. (authors)

Short-term natural gas consumption forecasting

International Nuclear Information System (INIS)

Potocnik, P.; Govekar, E.; Grabec, I.

2007-01-01

Energy forecasting requirements for Slovenia's natural gas market were investigated along with the cycles of natural gas consumption. This paper presented a short-term natural gas forecasting approach where the daily, weekly and yearly gas consumption were analyzed and the information obtained was incorporated into the forecasting model for hourly forecasting for the next day. The natural gas market depends on forecasting in order to optimize the leasing of storage capacities. As such, natural gas distribution companies have an economic incentive to accurately forecast their future gas consumption. The authors proposed a forecasting model with the following properties: two submodels for the winter and summer seasons; input variables including past consumption data, weather data, weather forecasts and basic cycle indexes; and, a hierarchical forecasting structure in which a daily model was used as the basis, with the hourly forecast obtained by modeling the relative daily profile. This proposed method was illustrated by a forecasting example for Slovenia's natural gas market. 11 refs., 11 figs

Use of compressed natural gas in automotive vehicles; Uso del gas natural comprimido aplicado en vehiculos automotores

Energy Technology Data Exchange (ETDEWEB)

Fernandez R, Adrian [Comision Nacional para el Ahorro de Energia (CONAE) (Mexico)

2005-07-01

The natural gas is natural origin energy (fossil fuel); it contains predominantly 90 percent methane; does not require transformation process for its use; is supplied the 24 hours to commerce, industries and homes by underground pipes; it is lighter than air; it is not corrosive, nor absorbent or toxic. For those reasons a study was performed where it is widely justified why the natural gas ought to be used in vehicles. [Spanish] El gas natural es un energetico de origen natural (combustible fosil), contiene predominantemente 90 por ciento de metano, no requiere proceso de transformacion para su utilizacion, llega directamente las 24 horas del dia a los hogares, comercios e industrias por tuberias subterraneas, es mas ligero que el aire, no es corrosivo, no es absorbente y no es toxico. Por esas razones se hizo un estudio donde se justifica ampliamente porque el gas natural debe utilizarse en vehiculos.

Characteristics of muscle dysmorphia in male football, weight training, and competitive natural and non-natural bodybuilding samples.

Science.gov (United States)

Baghurst, Timothy; Lirgg, Cathy

2009-06-01

The purpose of this study was to identify differences in traits associated with muscle dysmorphia between collegiate football players (n=66), weight trainers for physique (n=115), competitive non-natural bodybuilders (n=47), and competitive natural bodybuilders (n=65). All participants completed demographic questionnaires in addition to the Muscle Dysmorphia Inventory (Rhea, Lantz, & Cornelius, 2004). Results revealed a significant main effect for group, and post hoc tests found that the non-natural bodybuilding group did not score significantly higher than the natural bodybuilding group on any subscale except for Pharmacological Use. Both the non-natural and natural bodybuilding groups scored significantly higher than those that weight trained for physique on the Dietary Behavior and Supplement Use subscales. The collegiate football players scored lowest on all subscales of the Muscle Dysmorphia Inventory except for Physique Protection where they scored highest. Findings are discussed with future research expounded.

Bioethics and the problem of natural teleology.

Science.gov (United States)

Soontiens, F

In this paper it is argued that a re-evaluation of a teleological philosophy of nature is necessary because, first, the acceptance of natural theology would be in more accordance with the position of (teological) (wo)man as a natural product of a natural evolutionary process and, second, it seems to be a prerequisite for the formulation of an adequate bio- und eco-ethics which stresses the "intrinsic value" of nature.

The role of natural organics in radionuclide migration in natural aquifer systems

International Nuclear Information System (INIS)

Choppin, G.R.

1992-01-01

The wide variety of organic compounds present in natural waters is assessed for the role they may play in radionuclide and, especially, actinide migration. Some natural analog and environmental data are briefly reviewed for evaluation of the effect of organics in these systems. The binding constants and the kinetics of complexation of actinides by humics are discussed in terms of probable effects on actinide migration. The role of organics in redox, and in sorption, is also considered. (orig.)

31 CFR 540.309 - Natural uranium.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Natural uranium. 540.309 Section 540... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found in...

Alternative Fuels Data Center: Natural Gas Benefits

Science.gov (United States)

Benefits to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Benefits on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Benefits on Twitter Bookmark Alternative Fuels Data Center: Natural Gas Benefits on Google Bookmark Alternative Fuels Data Center: Natural Gas

Building with Nature - an integrated approach for coastal zone solutions using natural, socio-economic and institutional processes

NARCIS (Netherlands)

Wilms, T.; Goot, van der F.; Debrot, A.O.

2017-01-01

This paper presents Building with Nature as a viable alternative to the traditional engineering approach, making the services that nature provides an integral part of the design of hydraulic infrastructure, thereby creating benefits for nature and society. In it we describe the necessary steps with

Becquerel and natural origin radioactivity

International Nuclear Information System (INIS)

2011-01-01

After a brief presentation of the Becquerel as radioactivity measurement unit, this document briefly explains the origin of natural radioactivity (Earth formation and cosmic rays), gives and comments the evolution of radioactivity of some radionuclides (U 238 and descendants, Th 232 and descendants, K 40 ) between 4.5 billions yeas ago and nowadays. It also gives assessments of natural radioactivity due to radon in the atmosphere and in the soil, of natural radioactivity in building materials, coals, ashes, seawater and food. Some remarkable figures are then given

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.

Natural Fiber Composites: A Review

Energy Technology Data Exchange (ETDEWEB)

Westman, Matthew P.; Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin; Kafentzis, Tyler A.

2010-03-07

The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites.

Nature Watch

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Nature Watch - Singapore's Jurong BirdPark: A Study Model. Abraham Verghese. Feature Article Volume 6 Issue 7 July 2001 pp 74-88. Fulltext. Click here to view fulltext PDF. Permanent link:

Alternative Fuels Data Center: Natural Gas Vehicles

Science.gov (United States)

Natural Gas Printable Version Share this resource Send a link to Alternative Fuels Data Center : Natural Gas Vehicles to someone by E-mail Share Alternative Fuels Data Center: Natural Gas Vehicles on Facebook Tweet about Alternative Fuels Data Center: Natural Gas Vehicles on Twitter Bookmark Alternative

A Simple Lesson in Experiencing Nature.

Science.gov (United States)

Simpson, Steven

1999-01-01

Experiential education considers nature a classroom, but nature is also the teacher. Quiet watching and walking meditation are two exercises informed by Taoism, that when added to the normal experiential education fare, help students encounter nature with an open mind. An outdoor university course that incorporates the sentiments of seeing nature…

Thermodynamic DFT analysis of natural gas.

Science.gov (United States)

Neto, Abel F G; Huda, Muhammad N; Marques, Francisco C; Borges, Rosivaldo S; Neto, Antonio M J C

2017-08-01

Density functional theory was performed for thermodynamic predictions on natural gas, whose B3LYP/6-311++G(d,p), B3LYP/6-31+G(d), CBS-QB3, G3, and G4 methods were applied. Additionally, we carried out thermodynamic predictions using G3/G4 averaged. The calculations were performed for each major component of seven kinds of natural gas and to their respective air + natural gas mixtures at a thermal equilibrium between room temperature and the initial temperature of a combustion chamber during the injection stage. The following thermodynamic properties were obtained: internal energy, enthalpy, Gibbs free energy and entropy, which enabled us to investigate the thermal resistance of fuels. Also, we estimated an important parameter, namely, the specific heat ratio of each natural gas; this allowed us to compare the results with the empirical functions of these parameters, where the B3LYP/6-311++G(d,p) and G3/G4 methods showed better agreements. In addition, relevant information on the thermal and mechanic resistance of natural gases were investigated, as well as the standard thermodynamic properties for the combustion of natural gas. Thus, we show that density functional theory can be useful for predicting the thermodynamic properties of natural gas, enabling the production of more efficient compositions for the investigated fuels. Graphical abstract Investigation of the thermodynamic properties of natural gas through the canonical ensemble model and the density functional theory.

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