Thermochemical and phase diagram studies of the Sn-Zn-Ni system

International Nuclear Information System (INIS)

Gandova, V.D.; Broz, P.; Bursik, J.; Vassilev, G.P.

2011-01-01

Highlights: → Sn-Zn-Ni phase diagram in the vicinity of the Sn-Zn system. → Unidentified compositions (UX1-UX4) are repeatedly observed. → This indicates up to 6 ternary compounds in the system. → A ternary eutectic reaction at around 190 o C is found. - Abstract: The phase diagram Sn-Zn-Ni was studied by means of DSC and electron microprobe analysis. The samples were positioned in three isopleth sections with nickel contents of 0.04 (section 1), 0.08 (section 2) and 0.12 (section 3) mole fractions. The mole fractions of Sn corresponding to the particular sections were as follows: from 0.230 to 0.768 (section 1), from 0.230 to 0.736 (section 2); from 0.220 to 0.704 (section 3). Mixtures of pure metals were sealed under vacuum in quartz ampoules and annealed at 350 o C. The solid phases identified in the samples were: γ-(i.e. Ni 5 Zn 21 ), (Zn) and the ternary phase T1. Unidentified compositions were observed. One of them: UX1 (X Ni = 0.071 ± 0.005, X Sn = 0.439 ± 0.009 and X Zn = 0.490 ± 0.010) might indicate another (stable or metastable) ternary compound (T3) in the system Sn-Zn-Ni. Considering the data obtained by combining DSC with microstructure observations, the studied alloys could be divided in two groups (A and B). A ternary eutectic reaction at around 190 o C is common for the A-group alloys. The phases taking part in this reaction are, probably, Ni 5 Zn 21 , (Zn), (βSn) and liquid. B-group samples do not show ternary eutectic reaction and are also characterized by the presence of the ternary compound T1 (absent in the A-group alloys). Four other groups of thermal arrests were registered (TA 1 -TA 4 ). It was found that TA 2 peaks were characteristic for most of the A-group samples, while TA 1 peaks were registered with all B-group samples.

Bibliographic Review about Solar Hydrogen Production Through Thermochemical Cycles

International Nuclear Information System (INIS)

Fernandez Saavedra, R.

2007-01-01

This report presents a summary of the different thermical processes used to obtain hydrogen through solar energy, paying more attention to the production of hydrogen from water through thermochemical cycles. In this aspect, it is briefly described the most interesting thermochemical cycles, focusing on thermochemical cycles based on oxides. (Author) 25 refs

Development of a seasonal thermochemical storage system

NARCIS (Netherlands)

Cuypers, R.; Maraz, N.; Eversdijk, J.; Finck, C.J.; Henquet, E.M.P.; Oversloot, H.P.; Spijker, J.C. van 't; Geus, A.C. de

2012-01-01

In our laboratories, a seasonal thermochemical storage system for dwellings and offices is being designed and developed. Based on a thermochemical sorption reaction, space heating, cooling and generation of domestic hot water will be achieved with up to 100% renewable energy, by using solar energy

Thermochemical evaluation and preparation of cesium uranates

International Nuclear Information System (INIS)

Takano, Masahide; Minato, Kazuo; Fukuda, Kousaku; Sato, Seichi; Ohashi, Hiroshi.

1997-03-01

Two kinds of cesium uranates, Cs 2 UO 4 and Cs 2 U 2 O 7 , which are predicted by thermochemical estimation to be formed in irradiated oxide fuels, were prepared from U 3 O 8 and Cs 2 CO 3 for measurements of the thermal expansions and thermal conductivities. In advance of the preparation, thermochemical calculations for the formation and decomposition of these cesium uranates were performed by Gibbs free energy minimizer. The preparation temperatures for Cs 2 UO 4 and Cs 2 U 2 O 7 were determined from the results of the thermochemical calculations. The prepared samples were analyzed by X-ray diffraction, which showed that the single phases of Cs 2 UO 4 and Cs 2 U 2 O 7 were formed. Thermogravimetry and differential thermal analysis were also performed on these samples, and the decomposition temperatures were evaluated. The experimental results were in good agreement with those of the thermochemical calculations. (author)

Thermochemical properties of media for pyrometallurgical nuclear fuel reprocessing

International Nuclear Information System (INIS)

Hosoya, Yuji; Terai, Takayuki

1998-01-01

Molten chloride/cadmium system is considered to be applied to a solvent in pyrochemical reprocessing of spent nuclear fuel. In this work, phase diagrams for molten chloride systems were constructed, using NdCl 3 as an imitative substance in place of UCl 3 or PuCl 3 . Hastelloy-X (Ni/Cr21/Fe18/Mo9/W) was examined as a structural material for the corrosion-resistance against molten chloride baths containing NdCl 3 . The process of corrosion was thermochemically discussed and the form of the corrosion was illustrated. Rutherford backscattering spectroscopy was successfully applied to determine the elemental distribution profile of specimens tested on the compatibility with molten chloride mixture at elevated temperature. Ferritic steel was also examined as another candidate material for the compatibility with molten cadmium covered with LiCl-KCl eutectic salt. Variation of near-surface composition was observed by comparing the results of Rutherford backscattering spectroscopy obtained before and after the dipping. (author)

Assessment of a closed thermochemical energy storage using energy and exergy methods

International Nuclear Information System (INIS)

Abedin, Ali Haji; Rosen, Marc A.

2012-01-01

Highlights: ► Thermodynamics assessments are reported for a general closed thermochemical thermal energy storage system. ► Energy and exergy efficiencies of various processes in a closed thermochemical TES are evaluated and compared. ► Understanding is enhanced of thermochemical TES technologies and their potential implementations. ► Exergy analysis is observed to be useful when applied to thermochemical TES, with or in place of energy analysis. - Abstract: Thermal energy storage (TES) is an important technology for achieving more efficient and environmentally benign energy systems. Thermochemical TES is a type of TES with the potential for high energy density and is only recently being considered intensively. To improve understanding of thermochemical TES systems and their implementation, energy and exergy analyses are beneficial. Here, thermodynamics assessments are presented for a general closed thermochemical TES system, including assessments and comparisons of the efficiencies of the overall thermochemical TES cycle and its charging, storing and discharging processes. Locations and causes of thermodynamic losses in thermochemical TES systems are being specified using exergy analysis. The analytical methodology applied in this study identifies that energy and exergy efficiencies differ for thermochemical TESs, e.g. the energy efficiency for a case study is approximately 50% while the exergy efficiency is about 10%. Although the focus is to evaluate thermodynamic efficiencies, other design parameters such as cost, and environmental impact also need to be examined in assessing thermochemical storage. The efficiencies for thermochemical TES provided here should be helpful for designing these energy systems and enhancing their future prospects.

Design consideration on hydrogen production demonstration plant of thermochemical IS process

International Nuclear Information System (INIS)

Iwatsuki, Jin; Noguchi, Hiroki; Terada, Atsuhiko; Kubo, Shinji; Sakaba, Nariaki; Onuki, Kaoru; Hino, Ryutaro

2009-03-01

Preliminary design study was carried out on the hydrogen production demonstration plant of thermochemical IS process. In the pilot test, hydrogen production will be examined under prototypical condition using an apparatus made of industrial materials, which is driven by the sensible heat of helium gas heated by an electric heater that simulates the High Temperature Engineering Test Reactor (HTTR). Tentative system condition was defined considering the HTTR specification and the experience on the construction and the operation of the mock-up test facility using methane reforming for hydrogen production. The process condition and the system flow diagram were discussed to meet the system condition. Based on the defined process condition, types of the main components were discussed taking the corrosion resistance of the structural materials into consideration. Applicable rules and regulations were also surveyed regarding the plant construction and operation. (author)

Thermochemical evaluation and preparation of cesium uranates

Energy Technology Data Exchange (ETDEWEB)

Takano, Masahide; Minato, Kazuo; Fukuda, Kousaku [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sato, Seichi; Ohashi, Hiroshi

1997-03-01

Two kinds of cesium uranates, Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7}, which are predicted by thermochemical estimation to be formed in irradiated oxide fuels, were prepared from U{sub 3}O{sub 8} and Cs{sub 2}CO{sub 3} for measurements of the thermal expansions and thermal conductivities. In advance of the preparation, thermochemical calculations for the formation and decomposition of these cesium uranates were performed by Gibbs free energy minimizer. The preparation temperatures for Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7} were determined from the results of the thermochemical calculations. The prepared samples were analyzed by X-ray diffraction, which showed that the single phases of Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7} were formed. Thermogravimetry and differential thermal analysis were also performed on these samples, and the decomposition temperatures were evaluated. The experimental results were in good agreement with those of the thermochemical calculations. (author)

Advances in hydrogen production by thermochemical water decomposition: A review

International Nuclear Information System (INIS)

Rosen, Marc A.

2010-01-01

Hydrogen demand as an energy currency is anticipated to rise significantly in the future, with the emergence of a hydrogen economy. Hydrogen production is a key component of a hydrogen economy. Several production processes are commercially available, while others are under development including thermochemical water decomposition, which has numerous advantages over other hydrogen production processes. Recent advances in hydrogen production by thermochemical water decomposition are reviewed here. Hydrogen production from non-fossil energy sources such as nuclear and solar is emphasized, as are efforts to lower the temperatures required in thermochemical cycles so as to expand the range of potential heat supplies. Limiting efficiencies are explained and the need to apply exergy analysis is illustrated. The copper-chlorine thermochemical cycle is considered as a case study. It is concluded that developments of improved processes for hydrogen production via thermochemical water decomposition are likely to continue, thermochemical hydrogen production using such non-fossil energy will likely become commercial, and improved efficiencies are expected to be obtained with advanced methodologies like exergy analysis. Although numerous advances have been made on sulphur-iodine cycles, the copper-chlorine cycle has significant potential due to its requirement for process heat at lower temperatures than most other thermochemical processes.

Microencapsulation of salts for enhanced thermochemical storage materials

NARCIS (Netherlands)

Cuypers, R.; Jong, A.J. de; Eversdijk, J.; Spijker, J.C. van 't; Oversloot, H.P.; Ingenhut, B.L.J.; Cremers, R.K.H.; Papen-Botterhuis, N.E.

2013-01-01

Thermochemical storage is a new and emerging long-term thermal storage for residential use (cooling, heating & domestic hot water generation), offering high thermal storage density without the need for thermal insulation during storage (Fig. 1). However, existing materials for thermochemical storage

Initiating events identification of the IS process using the master logic diagram

International Nuclear Information System (INIS)

Cho, Nam Chul; Jae, Moo Sung; Yang, Joon Eon

2005-01-01

Hydrogen is very attractive as a future secondary energy carrier considering environmental problems. It is important to produce hydrogen from water by use of carbon free primary energy source. The thermochemical water decomposition cycle is one of the methods for the hydrogen production process from water. Japan Atomic Energy Research Institute (JAERI) has been carrying out an R and D on the IS (iodine.sulfur) process that was first proposed by GA (General Atomic Co.) focusing on demonstration the 'closed-cycle' continuous hydrogen production on developing a feasible and efficient scheme for the HI processing, and on screening and/or developing materials of construction to be used in the corrosive process environment. The successful continuous operation of the IS-process was demonstrated and this process is one of the thermochemical processes, which is the closest to being industrialized. Currently, Korea has also started a research about the IS process and the construction of the IS process system is planned. In this study, for risk analysis of the IS process, initiating events of the IS process are identified by using the Master Logic Diagram (MLD) that is method for initiating event identification

Thermal integration of SCWR nuclear and thermochemical hydrogen plants

International Nuclear Information System (INIS)

Wang, Z.; Naterer, G.F.; Gabriel, K.S.

2010-01-01

In this paper, the intermediate heat exchange between a Generation IV supercritical water-cooled nuclear reactor (SCWR) and a thermochemical hydrogen production cycle is discussed. It is found that the maximum and range of temperatures of a thermochemical cycle are the dominant parameters that affect the design of its coupling with SCWR. The copper-chlorine (Cu-Cl) thermochemical cycle is a promising cycle that can link with SCWRs. The location of extracting heat from a SCWR to a thermochemical cycle is investigated in this paper. Steam bypass lines downstream of the SCWR core are suggested for supplying heat to the Cu-Cl hydrogen production cycle. The stream extraction location is strongly dependent on the temperature requirements of the chemical steps of the thermochemical cycle. The available quantity of heat exchange at different hours of a day is also studied. It is found that the available heat at most hours of power demand in a day can support an industrial scale steam methane reforming plant if the SCWR power station is operating at full design capacity. (author)

Phase diagram, thermodynamic investigations, and modelling of systems relevant to lithium-ion batteries

International Nuclear Information System (INIS)

Fuertauer, Siegfried; Beutl, Alexander; Flanorfer, Hans; Henriques, David; Giel, Hans; Markus, Thorsten

2017-01-01

This article reports on two consecutive joint projects titled ''Experimental Thermodynamics and Phase Relations of New Electrode Materials for Lithium-Ion Batteries'', which were performed in the framework of the WenDeLIB 1473 priority program ''Materials with new Design for Lithium Ion Batteries''. Hundreds of samples were synthesized using experimental techniques specifically developed to deal with highly reactive lithium and lithium-containing compounds to generate electrochemical, phase diagram and crystal structure data in the Cu-Li, Li-Sn, Li-Sb, Cu-Li-Sn, Cu-Li-Sb and selected oxide systems. The thermochemical and phase diagram data were subsequently used to develop self-consistent thermodynamic descriptions of several binary systems. In the present contribution, the experimental techniques, working procedures, results and their relevance to the development of new electrode materials for lithium ion batteries are discussed and summarized. The collaboration between the three groups has resulted in more than fifteen (15) published articles during the six-year funding period.

Phase diagram, thermodynamic investigations, and modelling of systems relevant to lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Fuertauer, Siegfried; Beutl, Alexander; Flanorfer, Hans [Vienna Univ. (Austria). Dept. of Inorganic Chemistry - Functional Materials; Li, Dajian; Cupid, Damian [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Applied Materials - Applied Materials Physics (IAM-AWP); Henriques, David; Giel, Hans; Markus, Thorsten [Mannheim Univ. of Applied Sciences (Germany). Inst. for Thermo- and Fluiddynamics

2017-11-15

This article reports on two consecutive joint projects titled ''Experimental Thermodynamics and Phase Relations of New Electrode Materials for Lithium-Ion Batteries'', which were performed in the framework of the WenDeLIB 1473 priority program ''Materials with new Design for Lithium Ion Batteries''. Hundreds of samples were synthesized using experimental techniques specifically developed to deal with highly reactive lithium and lithium-containing compounds to generate electrochemical, phase diagram and crystal structure data in the Cu-Li, Li-Sn, Li-Sb, Cu-Li-Sn, Cu-Li-Sb and selected oxide systems. The thermochemical and phase diagram data were subsequently used to develop self-consistent thermodynamic descriptions of several binary systems. In the present contribution, the experimental techniques, working procedures, results and their relevance to the development of new electrode materials for lithium ion batteries are discussed and summarized. The collaboration between the three groups has resulted in more than fifteen (15) published articles during the six-year funding period.

Thermochemical Surface Engineering: A Playground for Science and Innovation

DEFF Research Database (Denmark)

Christiansen, Thomas Lundin; Dahl, Kristian Vinter; Jellesen, Morten Stendahl

2017-01-01

Surface engineering by thermochemical processing is the intentional change of the composition of a material at elevated temperature with the purpose to improve materials performance. In thermochemical processing components from the starting material are essential in the development of the phases...... at the surface. Current research and innovation activities are used to exemplify thermochemical surface engineering and the interplay of science and innovation. The examples given encompass aspects of the synthesis of extremely porous materials, low temperature surface hardening of stainless steel, surface...

Thermochemical transformations of anthracite fractions

Energy Technology Data Exchange (ETDEWEB)

Belkina, T.V.; Privalov, V.E.; Stepanenko, atM.A.

1979-08-01

Research on the nature of thermochemical transformations of anthracite fractions and the possibility of increasing their activity and identifying conditions for their use in the electrode pitch process is described. From research done on different anthracite fractions processed at varying temperatures it was concluded that accumulations of condensates from heating anthracite fractions occur significantly slower in comparison with pitch. As a result the electrode pitch process is prolonged. Thermal treatment of an anthracite fraction causes the formation and accumulation of condensates and promotes thermochemical transformations. Lastly, the use of thermally treated anthracite fractions apparently intensifies the electrode pitch process and improves its quality. (16 refs.) (In Russian)

Renewable hydrogen production via thermochemical/electrochemical coupling

Energy Technology Data Exchange (ETDEWEB)

Ambrosini, Andrea [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Babiniec, Sean Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, James E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

A coupled electrochemical/thermochemical cycle was investigated to produce hydrogen from renewable resources. Like a conventional thermochemical cycle, this cycle leverages chemical energy stored in a thermochemical working material that is reduced thermally by solar energy. However, in this concept, the stored chemical energy only needs to be partially, but not fully, capable of splitting steam to produce hydrogen. To complete the process, a proton-conducting membrane is driven to separate hydrogen as it is produced, thus shifting the thermodynamics toward further hydrogen production. This novel coupled-cycle concept provides several benefits. First, the required oxidation enthalpy of the reversible thermochemical material is reduced, enabling the process to occur at lower temperatures. Second, removing the requirement for spontaneous steam-splitting widens the scope of materials compositions, allowing for less expensive/more abundant elements to be used. Lastly, thermodynamics calculations suggest that this concept can potentially reach higher efficiencies than photovoltaic-to-electrolysis hydrogen production methods. This Exploratory Express LDRD involved assessing the practical feasibility of the proposed coupled cycle. A test stand was designed and constructed and proton-conducting membranes were synthesized. While the full proof of concept was not achieved, the individual components of the experiment were validated and new capabilities that can be leveraged by a variety of programs were developed.

Capabilities to Support Thermochemical Hydrogen Production Technology Development

Energy Technology Data Exchange (ETDEWEB)

Daniel M. Ginosar

2009-05-01

This report presents the results of a study to determine if Idaho National Laboratory (INL) has the skilled staff, instrumentation, specialized equipment, and facilities required to take on work in thermochemical research, development, and demonstration currently being performed by the Nuclear Hydrogen Initiative (NHI). This study outlines the beneficial collaborations between INL and other national laboratories, universities, and industries to strengthen INL's thermochemical efforts, which should be developed to achieve the goals of the NHI in the most expeditious, cost effective manner. Taking on this work supports INL's long-term strategy to maintain leadership in thermochemical cycle development. This report suggests a logical path forward to accomplish this transition.

System and process for producing fuel with a methane thermochemical cycle

Science.gov (United States)

Diver, Richard B.

2015-12-15

A thermochemical process and system for producing fuel are provided. The thermochemical process includes reducing an oxygenated-hydrocarbon to form an alkane and using the alkane in a reforming reaction as a reducing agent for water, a reducing agent for carbon dioxide, or a combination thereof. Another thermochemical process includes reducing a metal oxide to form a reduced metal oxide, reducing an oxygenated-hydrocarbon with the reduced metal oxide to form an alkane, and using the alkane in a reforming reaction as a reducing agent for water, a reducing agent for carbon dioxide, or a combination thereof. The system includes a reformer configured to perform a thermochemical process.

Estimation of thermochemical behavior of spallation products in mercury target

International Nuclear Information System (INIS)

Kobayashi, Kaoru; Kaminaga, Masanori; Haga, Katsuhiro; Kinoshita, Hidetaka; Aso, Tomokazu; Teshigawara, Makoto; Hino, Ryutaro

2002-02-01

In order to examine the radiation safety of a spallation mercury target system, especially source term evaluation, it is necessary to clarify the chemical forms of spallation products generated by spallation reaction with proton beam. As for the chemical forms of spallation products in mercury that involves large amounts of spallation products, these forms were estimated by using the binary phase diagrams and the thermochemical equilibrium calculation based on the amounts of spallation product. Calculation results showed that the mercury would dissolve Al, As, B, Be, Bi, C, Co, Cr, Fe, Ga, Ge, Ir, Mo, Nb, Os, Re, Ru, Sb, Si, Ta, Tc, V and W in the element state, and Ag, Au, Ba, Br, Ca, Cd, Ce, Cl, Cs, Cu, Dy, Er, Eu, F, Gd, Hf, Ho, I, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, O, Pb, Pd, Pr, Pt, Rb, Rh, S, Sc, Se, Sm, Sn, Sr, Tb, Te, Ti, Tl, Tm, Y, Yb, Zn and Zr in the form of inorganic mercury compounds. As for As, Be, Co, Cr, Fe, Ge, Ir, Mo, Nb, Os, Pt, Re, Ru, Se, Ta, V, W and Zr, precipitation could be occurred when increasing the amounts of spallation products with operation time of the spallation target system. On the other hand, beryllium-7 (Be-7), which is produced by spallation reaction of oxygen in the cooling water of a safety hull, becomes the main factor of the external exposure to maintain the cooling loop. Based on the thermochemical equilibrium calculation to Be-H 2 O binary system, the chemical forms of Be in the cooling water were estimated. Then the Be could exist in the form of cations such as BeOH + , BeO + and Be 2+ under the condition of less than 10 -8 of the Be mole fraction in the cooling water. (author)

Pembuatan Kakas Bantu untuk Mendeteksi Ketidaksesuaian Diagram Urutan (Sequence Diagram dengan Diagram Kasus Penggunaan (Use Case Diagram

Directory of Open Access Journals (Sweden)

Andrias Meisyal Yuwantoko

2017-03-01

Full Text Available Sebuah diagram urutan dibuat  berdasarkan alur yang ada pada deskripsi kasus penggunaan. Alur tersebut dire- presentasikan dalam  bentuk  interaksi antara aktor  dan  sistem. Pemeriksaan rancangan diagram urutan perlu dilakukan untuk mengetahui ketidaksesuaian urutan alur  kasus penggunaan dengan urutan pesan yang dikirimkan oleh objek-objek pada diagram urutan. Rancangan diagram yang sesuai merupakan kunci ketepatan (correctness implementasi  perangkat lunak. Namun, pemeriksaan ketidaksesuaian masih dilakukan secara manual. Hal ini menjadi masalah apabila sebuah proyek perangkat lunak memiliki banyak  rancangan diagram dan sumber daya manusia tidak  mencukupi. Pemeriksaan membutuhkan waktu yang lama dan memiliki dampak pada waktu pengembangan perangkat lunak. Penelitian ini mengusulkan pembuatan kakas bantu  untuk mendeteksi ketidaksesuaian diagram urutan dengan diagram kasus penggunaan. Ketidaksesuaian dilihat dari kemiripan semantik kalimat antara alur pada deskripsi kasus penggunaan dan triplet. Dari hasil pembuatan kakas bantu, kakas bantu yang dibuat dapat mendeteksi ketidaksesuaian diagram urutan dengan diagram kasus penggunaan. Kakas  bantu ini diharapkan tidak hanya membantu pemeriksaan rancangan diagram akan tetapi mempercepat waktu pengembangan perangkat lunak.

From State Diagram to Class Diagram

DEFF Research Database (Denmark)

Borch, Ole; Madsen, Per Printz

2009-01-01

UML class diagram and Java source code are interrelated and Java code is a kind of interchange format. Working with UML state diagram in CASE tools, a corresponding xml file is maintained. Designing state diagrams is mostly performed manually using design patterns and coding templates - a time...... consuming process. This article demonstrates how to compile such a diagram into Java code and later, by reverse engineering, produce a class diagram. The process from state diagram via intermediate SAX parsed xml file to Apache Velocity generated Java code is described. The result is a fast reproducible...

Thermochemical data for reactor materials

International Nuclear Information System (INIS)

Ronchi, C.; Turrini, F.

1990-01-01

This report describes a computer database of thermochemical properties of nuclear reactor materials to be used for source term calculations in reactor accident codes. In the first part, the structure and the content of the computer file is described. In the second part a set of thermochemical data is presented pertaining to chemical reactions occurring during severe nuclear reactor accidents and involving fuel (uranium dioxide), fission products and structural materials. These data are complementary to those collected in the databook recently published by Cordfunke and Potter after a study supported by the Commission of the European Communities. The present data were collected from review articles and databanks and follow a discussion on the uncertainties and errors involved in the calculation of complex chemical equilibria in the extrapolated temperature range

Thermochemical performance analysis of solar driven CO_2 methane reforming

International Nuclear Information System (INIS)

Fuqiang, Wang; Jianyu, Tan; Huijian, Jin; Yu, Leng

2015-01-01

Increasing CO_2 emission problems create urgent challenges for alleviating global warming, and the capture of CO_2 has become an essential field of scientific research. In this study, a finite volume method (FVM) coupled with thermochemical kinetics was developed to analyze the solar driven CO_2 methane reforming process in a metallic foam reactor. The local thermal non-equilibrium (LTNE) model coupled with radiative heat transfer was developed to provide more temperature information. A joint inversion method based on chemical process software and the FVM coupled with thermochemical kinetics was developed to obtain the thermochemical reaction parameters and guarantee the calculation accuracy. The detailed thermal and thermochemical performance in the metal foam reactor was analyzed. In addition, the effects of heat flux distribution and porosity on the solar driven CO_2 methane reforming process were analyzed. The numerical results can serve as theoretical guidance for the solar driven CO_2 methane reforming application. - Highlights: • Solar driven CO_2 methane reforming process in metal foam reactor is analyzed. • FVM with chemical reactions was developed to analyze solar CO_2 methane reforming. • A joint inversion method was developed to obtain thermochemical reaction parameters. • Results can be a guidance for the solar driven CO_2 methane reforming application.

[Identification of meridian-acupoint diagrams and meridian diagrams].

Science.gov (United States)

Shen, Wei-hong

2008-08-01

In acu-moxibustion literature, there are two kinds of diagrams, meridian-acupoint diagrams and meridian diagrams. Because they are very similar in outline, and people now have seldom seen the typical ancient meridian diagrams, meridian-acupoint diagrams have been being incorrectly considered to be the meridian diagrams for a long time. It results in confusion in acu-moxibustion academia. The present paper stresses its importance in academic research and introduces some methods for identifying them correctly. The key points for identification of meridian-acupoint diagrams and meridian diagrams are: the legend of diagrams and the drawing style of the ancient charts. In addition, the author makes a detailed explanation about some acu-moxibustion charts which are easily confused. In order to distinguish meridian-acupoint diagrams and meridian diagrams correctly, he or she shoulnd understand the diagrams' intrinsic information as much as possible and make a comprehensive analysis about them.

OPTIMIZED WTE CONVERSION OF MUNICIPAL SOLID WASTE IN SHANGHAI APPLYING THERMOCHEMICAL TECHNOLOGIES

OpenAIRE

Dai, Siyang

2016-01-01

Thermochemical technologies have been proven effective in treating municipal solid waste (MSW) for many years. China, with a rapid increase of MSW, plans to implement more environmental friendly ways to treat MSW than landfill, which treats about 79 % of total MSW currently. The aim of this master thesis was to find out a suitable thermochemical technology to treat MSW in Shanghai, China. Several different thermochemical technologies are compared in this thesis and plasma gasification was sel...

Thermochemical Heat Storage: from Reaction Storage Density to System Storage Density

NARCIS (Netherlands)

Jong, A.J. de; Vliet, L.D. van; Hoegaerts, C.L.G.; Roelands, C.P.M.; Cuypers, R.

2016-01-01

Long-term and compact storage of solar energy is crucial for the eventual transition to a 100% renewable energy economy. For this, thermochemical materials provide a promising solution. The compactness of a long-term storage system is determined by the thermochemical reaction, operating conditions,

Estimation of thermochemical behavior of spallation products in mercury target

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Kaoru; Kaminaga, Masanori; Haga, Katsuhiro; Kinoshita, Hidetaka; Aso, Tomokazu; Teshigawara, Makoto; Hino, Ryutaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2002-02-01

In order to examine the radiation safety of a spallation mercury target system, especially source term evaluation, it is necessary to clarify the chemical forms of spallation products generated by spallation reaction with proton beam. As for the chemical forms of spallation products in mercury that involves large amounts of spallation products, these forms were estimated by using the binary phase diagrams and the thermochemical equilibrium calculation based on the amounts of spallation product. Calculation results showed that the mercury would dissolve Al, As, B, Be, Bi, C, Co, Cr, Fe, Ga, Ge, Ir, Mo, Nb, Os, Re, Ru, Sb, Si, Ta, Tc, V and W in the element state, and Ag, Au, Ba, Br, Ca, Cd, Ce, Cl, Cs, Cu, Dy, Er, Eu, F, Gd, Hf, Ho, I, In, K, La, Li, Lu, Mg, Mn, Na, Nd, Ni, O, Pb, Pd, Pr, Pt, Rb, Rh, S, Sc, Se, Sm, Sn, Sr, Tb, Te, Ti, Tl, Tm, Y, Yb, Zn and Zr in the form of inorganic mercury compounds. As for As, Be, Co, Cr, Fe, Ge, Ir, Mo, Nb, Os, Pt, Re, Ru, Se, Ta, V, W and Zr, precipitation could be occurred when increasing the amounts of spallation products with operation time of the spallation target system. On the other hand, beryllium-7 (Be-7), which is produced by spallation reaction of oxygen in the cooling water of a safety hull, becomes the main factor of the external exposure to maintain the cooling loop. Based on the thermochemical equilibrium calculation to Be-H{sub 2}O binary system, the chemical forms of Be in the cooling water were estimated. Then the Be could exist in the form of cations such as BeOH{sup +}, BeO{sup +} and Be{sup 2+} under the condition of less than 10{sup -8} of the Be mole fraction in the cooling water. (author)

Entropy Analysis of Solar Two-Step Thermochemical Cycles for Water and Carbon Dioxide Splitting

Directory of Open Access Journals (Sweden)

Matthias Lange

2016-01-01

Full Text Available The present study provides a thermodynamic analysis of solar thermochemical cycles for splitting of H2O or CO2. Such cycles, powered by concentrated solar energy, have the potential to produce fuels in a sustainable way. We extend a previous study on the thermodynamics of water splitting by also taking into account CO2 splitting and the influence of the solar absorption efficiency. Based on this purely thermodynamic approach, efficiency trends are discussed. The comprehensive and vivid representation in T-S diagrams provides researchers in this field with the required theoretical background to improve process development. Furthermore, results about the required entropy change in the used redox materials can be used as a guideline for material developers. The results show that CO2 splitting is advantageous at higher temperature levels, while water splitting is more feasible at lower temperature levels, as it benefits from a great entropy change during the splitting step.

Thermochemical properties of silver tellurides including empressite (AgTe) and phase diagrams for Ag-Te and Ag-Te-O

Science.gov (United States)

Voronin, Mikhail V.; Osadchii, Evgeniy G.; Brichkina, Ekaterina A.

2017-10-01

This study compiles original experimental and literature data on the thermodynamic properties (ΔfG°, S°, ΔfH°) of silver tellurides (α-Ag2Te, β-Ag2Te, Ag1.9Te, Ag5Te3, AgTe) obtained by the method of solid-state galvanic cell with the RbAg4I5 and AgI solid electrolytes. The thermodynamic data for empressite (AgTe, pure fraction from Empress Josephine Mine, Colorado USA) have been obtained for the first time by the electrochemical experiment with the virtual reaction Ag + Te = AgTe. The Ag-Te phase diagrams in the T - x and log fTe2 (gas) - 1/ T coordinates have been refined, and the ternary Ag-Te-O diagrams with Ag-Te-TeO2 (paratellurite) composition range have been calculated.

Thermochemical data for reactor materials and fission products: The ECN database

International Nuclear Information System (INIS)

Cordfunke, E.H.P.; Konings, R.J.M.

1993-02-01

The activities of the authors regarding the compilation of a database of thermochemical properties for reactor materials and fission products is reviewed. The evaluation procedures and techniques are outlined and examples are given. In addition, examples of the use of thermochemical data for the application in the field of Nuclear Technology are given. (orig.)

Thermochemical nitrate reduction

International Nuclear Information System (INIS)

Cox, J.L.; Lilga, M.A.; Hallen, R.T.

1992-09-01

A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techniques must be considered before permanent disposal operations begin. For the thermochemical reduction experiments, six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with ∼3 wt% NO 3 - solutions in a buffered aqueous solution at high pH (13); ammonia and formate were also mixed at low pH (4). Reactions were conducted in an aqueous solution in a batch reactor at temperatures of 200 degrees C to 350 degrees C and pressures of 600 to 2800 psig. Both gas and liquid samples were analyzed. The specific components analyzed were nitrate, nitrite, nitrous oxide, nitrogen, and ammonia. Results of experimental runs showed the following order of nitrate reduction of the six reducing agents in basic solution: formate > glucose > urea > hydrogen > ammonia ∼ methane. Airnmonia was more effective under acidic conditions than basic conditions. Formate was also effective under acidic conditions. A more thorough, fundamental study appears warranted to provide additional data on the mechanism of nitrate reduction. Furthermore, an expanded data base and engineering feasibility study could be used to evaluate conversion conditions for promising reducing agents in more detail and identify new reducing agents with improved performance characteristics

2009 Thermochemical Conversion Platform Review Report

Energy Technology Data Exchange (ETDEWEB)

Ferrell, John [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

2009-12-01

This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the U.S. Department of Energy Biomass Program’s Thermochemical Conversion platform review meeting, held on April 14-16, 2009, at the Sheraton Denver Downtown, Denver, Colorado.

Review of the direct thermochemical conversion of lignocellulosic biomass for liquid fuels

Directory of Open Access Journals (Sweden)

Jianchun JIANG,Junming XU,Zhanqian SONG

2015-03-01

Full Text Available Increased demand for liquid transportation fuels, environmental concerns and depletion of petroleum resources requires the development of efficient conversion technologies for production of second-generation biofuels from non-food resources. Thermochemical approaches hold great potential for conversion of lignocellulosic biomass into liquid fuels. Direct thermochemical processes convert biomass into liquid fuels in one step using heat and catalysts and have many advantages over indirect and biological processes, such as greater feedstock flexibility, integrated conversion of whole biomass, and lower operation costs. Several direct thermochemical processes are employed in the production of liquid biofuels depending on the nature of the feedstock properties: such as fast pyrolysis/liquefaction of lignocellulosic biomass for bio-oil, including upgrading methods, such as catalytic cracking and hydrogenation. Owing to the substantial amount of liquid fuels consumed by vehicular transport, converting biomass into drop-in liquid fuels may reduce the dependence of the fuel market on petroleum-based fuel products. In this review, we also summarize recent progress in technologies for large-scale equipment for direct thermochemical conversion. We focus on the technical aspects critical to commercialization of the technologies for production of liquid fuels from biomass, including feedstock type, cracking catalysts, catalytic cracking mechanisms, catalytic reactors, and biofuel properties. We also discuss future prospects for direct thermochemical conversion in biorefineries for the production of high grade biofuels.

Performance analysis of a photovoltaic-thermochemical hybrid system prototype

International Nuclear Information System (INIS)

Li, Wenjia; Ling, Yunyi; Liu, Xiangxin; Hao, Yong

2017-01-01

Highlights: •A modular photovoltaic-thermochemical hybrid system prototype is proposed. •Net solar-electric efficiency up to 41% is achievable. •Stable solar power supply is achievable via convenient energy storage. •The modular design facilitates the scalability of the hybrid system. -- Abstract: A solar photovoltaic (PV) thermochemical hybrid system consisting of a point-focus Fresnel concentrator, a PV cell and a methanol thermochemical reactor is proposed. In particular, a reactor capable of operating under high solar concentration is designed, manufactured and tested. Studies on both kinetic and thermodynamic characteristics of the reactor and the system are performed. Analysis of numerical and experimental results shows that with cascaded solar energy utilization and synergy among different forms of energy, the hybrid system has the advantages of high net solar-electric efficiency (up to 41%), stable solar energy power supply, solar energy storage (via syngas) and flexibility in application scale. The hybrid system proposed in this work provides a potential solution to some key challenges of current solar energy utilization technologies.

Experimental study of a thermochemical compressor for an absorption/compression hybrid cycle

International Nuclear Information System (INIS)

Ventas, R.; Vereda, C.; Lecuona, A.; Venegas, M.

2012-01-01

Highlights: ► Experimental study of a thermochemical compressor for absorption/compression cycle. ► Spray adiabatic absorber using NH 3 –LiNO 3 solution working fluid. ► It is able to operate between 57 and 110 °C varying concentration between 0.46 and 0.59. ► The increase of absorber pressure decreases the circulation ratio. ► The numerical model performed agrees with the experimental results. -- Abstract: An experimental study of a thermochemical compressor with ammonia–lithium nitrate solution as working fluid has been carried out. This compressor incorporates a single-pass adiabatic absorber and all the heat exchangers are of the plate type: absorber subcooler, generator and solution heat exchanger. The thermochemical compressor has been studied as part of a single-effect absorption chiller hybridized with an in-series low-pressure compression booster. The adiabatic absorber uses fog jet injectors. The generator hot water temperatures for the external driving flow are in the range of 57–110 °C and the absorber pressures range between 429 and 945 kPa. Experimental results are compared with a numerical model showing a high agreement. The performance of the thermochemical compressor, evaluated through the circulation ratio, improves for higher absorber pressures, indicating the potential of pressure boosting. For the same circulation ratio, the driving hot water inlet temperature decreases with the rise of the absorber pressure. The thermochemical compressor, based on an adiabatic absorber, can produce refrigerant with very low driving temperatures, between 57 and 70 °C, what is interesting for solar cooling applications and very low temperature residual heat recovery. Efficiencies and cooling power are offered when this hybrid thermochemical compressor is implemented in a chiller, showing the effect of different operating parameters.

OECD/NEA thermochemical database

Energy Technology Data Exchange (ETDEWEB)

Byeon, Kee Hoh; Song, Dae Yong; Shin, Hyun Kyoo; Park, Seong Won; Ro, Seung Gy

1998-03-01

This state of the art report is to introduce the contents of the Chemical Data-Service, OECD/NEA, and the results of survey by OECD/NEA for the thermodynamic and kinetic database currently in use. It is also to summarize the results of Thermochemical Database Projects of OECD/NEA. This report will be a guide book for the researchers easily to get the validate thermodynamic and kinetic data of all substances from the available OECD/NEA database. (author). 75 refs.

Diagram Size vs. Layout Flaws: Understanding Quality Factors of UML Diagrams

DEFF Research Database (Denmark)

Störrle, Harald

2016-01-01

, though, is our third goal of extending our analysis aspects of diagram quality. Method: We improve our definition of diagram size and add a (provisional) definition of diagram quality as the number of topographic layout flaws. We apply these metrics on 60 diagrams of the five most commonly used types...... of UML diagram. We carefully analyze the structure of our diagram samples to ensure representativeness. We correlate diagram size and layout quality with modeler performance data obtained in previous experiments. The data set is the largest of its kind (n-156). Results: We replicate earlier findings......, and extend them to two new diagram types. We provide an improved definition of diagram size, and provide a definition of topographic layout quality, which is one more step towards a comprehensive definition of diagram quality as such. Both metrics are shown to be objectively applicable. We quantify...

Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment

International Nuclear Information System (INIS)

Haro, P.; Ollero, P.; Villanueva Perales, A.L.; Gómez-Barea, A.

2013-01-01

Highlights: ► A thermochemical biorefinery based on bio-DME as intermediate is studied. ► The assessed concepts (12) lead to multi-product generation (polygeneration). ► In all concepts DME is converted by carbonylation or hydrocarbonylation. ► Rates of return are similar to or higher than plants producing a single product. -- Abstract: Thermochemical biorefinery based on dimethyl ether (DME) as an intermediate is studied. DME is converted into methyl acetate, which can either be hydrogenated to ethanol or sold as a co-product. Considering this option together with a variety of technologies for syngas upgrading, 12 different process concepts are analyzed. The considered products are ethanol, methyl acetate, H 2 , DME and electricity. The assessment of each alternative includes biomass pretreatment, gasification, syngas clean-up and conditioning, DME synthesis and conversion, product separation, and heat and power integration. A plant size of 500 MW th processing poplar chips is taken as a basis. The resulting energy efficiency to products ranges from 34.9% to 50.2%. The largest internal rate of return (28.74%) corresponds to a concept which produces methyl acetate, DME and electricity (exported to grid). A sensitivity analysis with respect to total plant investment (TPI), total operation costs (TOC) and market price of products was carried out. The overall conclusion is that, despite its greater complexity, this kind of thermochemical biorefinery is more profitable than thermochemical bioprocesses oriented to a single product.

Thermochemical stability of Soviet macroporous sulfonated cation-exchangers

Energy Technology Data Exchange (ETDEWEB)

Rukhlyada, N.N.; Plotnikova, V.P.; Roginskaya, B.S.; Znamenskii, Yu.P.; Zavodovskaya, A.S.; Dobrova, E.I.

1988-10-20

The purpose of this work was to study the influence of macroporosity on the thermochemical stability of sulfonated cation-exchangers. The investigations were carried out on commercial macroporous sulfonated cation-exchangers based on styrene-divinylbenzene copolymers. Study of the thermochemical stability of macroporous sulfonated cation-exchangers in dilute hydrogen peroxide solutions showed that the type of macroporosity has virtually no influence on their stability. The determining factor in thermal stability of macroporous cation-exchangers, as of the gel type, is the degree of cross-linking of the polymer matrix. The capacity loss of macroporous cation-exchangers during oxidative thermolysis is caused by destruction of the macromolecular skeleton and elution of fragments of polar chains containing sulfo groups into the solution.

Quantitative Thermochemical Measurements in High-Pressure Gaseous Combustion

Science.gov (United States)

Kojima, Jun J.; Fischer, David G.

2012-01-01

We present our strategic experiment and thermochemical analyses on combustion flow using a subframe burst gating (SBG) Raman spectroscopy. This unconventional laser diagnostic technique has promising ability to enhance accuracy of the quantitative scalar measurements in a point-wise single-shot fashion. In the presentation, we briefly describe an experimental methodology that generates transferable calibration standard for the routine implementation of the diagnostics in hydrocarbon flames. The diagnostic technology was applied to simultaneous measurements of temperature and chemical species in a swirl-stabilized turbulent flame with gaseous methane fuel at elevated pressure (17 atm). Statistical analyses of the space-/time-resolved thermochemical data provide insights into the nature of the mixing process and it impact on the subsequent combustion process in the model combustor.

Effects of thermo-chemical pre-treatment on anaerobic biodegradability and hydrolysis of lignocellulosic biomass

NARCIS (Netherlands)

Fernandes, T.; Klaasse Bos, G.J.; Zeeman, G.; Sanders, J.P.M.; Lier, van J.B.

2009-01-01

The effects of different thermo-chemical pre-treatment methods were determined on the biodegradability and hydrolysis rate of lignocellulosic biomass. Three plant species, hay, straw and bracken were thermo-chemically pre-treated with calcium hydroxide, ammonium carbonate and maleic acid. After

2011 Biomass Program Platform Peer Review. Thermochemical Conversion

Energy Technology Data Exchange (ETDEWEB)

Grabowski, Paul E. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

2012-02-01

This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Thermochemical Conversion Platform Review meeting.

Roundhouse Diagrams.

Science.gov (United States)

Ward, Robin E.; Wandersee, James

2000-01-01

Students must understand key concepts through reasoning, searching out related concepts, and making connections within multiple systems to learn science. The Roundhouse diagram was developed to be a concise, holistic, graphic representation of a science topic, process, or activity. Includes sample Roundhouse diagrams, a diagram checklist, and…

Hydrogen production at <550 C using a low temperature thermochemical cycle

International Nuclear Information System (INIS)

Lewis, M.A.; Serban, M.; Basco, J.K.

2004-01-01

A Department of Energy goal is to identify new technologies for producing hydrogen cost effectively without greenhouse gas emissions. Thermochemical cycles are one of the potential options under investigation. Thermochemical cycles consist of a series of reactions in which water is thermally decomposed and all other chemicals are recycled. Only heat and water are consumed. However, most thermochemical cycles require process heat at temperatures of 850-900 deg C. Argonne National Laboratory is developing low temperature cycles designed for lower temperature heat, 500-550 deg C, which is more readily available. For this temperature region, copper-chlorine (Cu-Cl) cycles are the most promising cycle. Several Cu-Cl cycles have been examined in the laboratory and the most promising cycle has been identified. Proof-of-principle experiments are nearly complete. A preliminary assessment of cycle efficiency is promising. Details of the experiments and efficiency calculations are discussed. (author)

Safety- barrier diagrams

DEFF Research Database (Denmark)

Duijm, Nijs Jan

2008-01-01

Safety-barrier diagrams and the related so-called 'bow-tie' diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault...... trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management....

TEA: A CODE CALCULATING THERMOCHEMICAL EQUILIBRIUM ABUNDANCES

Energy Technology Data Exchange (ETDEWEB)

Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver, E-mail: jasmina@physics.ucf.edu [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States)

2016-07-01

We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows and Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows and Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

TEA: A CODE CALCULATING THERMOCHEMICAL EQUILIBRIUM ABUNDANCES

International Nuclear Information System (INIS)

Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

2016-01-01

We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows and Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows and Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

Safety-barrier diagrams

DEFF Research Database (Denmark)

Duijm, Nijs Jan

2007-01-01

Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk...... analysis with operational safety management....

Effects of key factors on solar aided methane steam reforming in porous medium thermochemical reactor

International Nuclear Information System (INIS)

Wang, Fuqiang; Tan, Jianyu; Ma, Lanxin; Leng, Yu

2015-01-01

Highlights: • Effects of key factors on chemical reaction for solar methane reforming are studied. • MCRT and FVM method coupled with UDFs is used to establish numerical model. • Heat and mass transfer model coupled with thermochemical reaction is established. • LTNE model coupled with P1 approximation is used for porous matrix solar reactor. • A formula between H 2 production and conductivity of porous matrix is put forward. - Abstract: With the aid of solar energy, methane reforming process can save up to 20% of the total methane consumption. Monte Carlo Ray Tracing (MCRT) method and Finite Volume Method (FVM) combined method are developed to establish the heat and mass transfer model coupled with thermochemical reaction kinetics for porous medium solar thermochemical reactor. In order to provide more temperature information, local thermal non-equilibrium (LTNE) model coupled with P1 approximation is established to investigate the thermal performance of porous medium solar thermochemical reaction. Effects of radiative heat loss and thermal conductivity of porous matrix on temperature distribution and thermochemical reaction for solar driven steam methane reforming process are numerically studied. Besides, the relationship between hydrogen production and thermal conductivity of porous matrix are analyzed. The results illustrate that hydrogen production shows a 3 order polynomial relation with thermal conductivity of porous matrix

Study of the hydrolysis reaction of the copper-chloride hybrid thermochemical cycle using optical spectrometries

International Nuclear Information System (INIS)

Doizi, D.; Borgard, J.M.; Dauvois, V.; Roujou, J.L.; Zanella, Y.; Croize, L.; Cartes, Ph.; Hartmann, J.M.

2010-01-01

The copper-chloride hybrid thermochemical cycle is one of the best potential low temperature thermochemical cycles for the massive production of hydrogen. It could be used with nuclear reactors such as the sodium fast reactor or the supercritical water reactor. Nevertheless, this thermochemical cycle is composed of an electrochemical reaction and two thermal reactions. Its efficiency has to be compared with other hydrogen production processes like alkaline electrolysis for example. The purpose of this article is to study the viability of the copper chloride thermochemical cycle by studying the hydrolysis reaction of CuCl 2 which is not favoured thermodynamically. To better understand the occurrence of possible side reactions, together with a good control of the kinetics of the hydrolysis reaction, the use of optical absorption spectrometries, UV visible spectrometry to detect molecular chlorine which may be formed in side reactions, FTIR spectrometry to follow the concentrations of H 2 O and HCl is proposed. (authors)

New applications with time-dependent thermochemical simulation

Energy Technology Data Exchange (ETDEWEB)

Koukkari, P. [VTT Chemical Technology, Espoo (Finland); Laukkanen, L. [VTT Automation, Espoo (Finland); Penttilae, K. [Kemira Engineering Oy, Helsinki (Finland)

1996-12-31

A new method (RATEMIX) to calculate multicomponent chemical reaction mixtures as a series of sequential thermochemical states was recently introduced. The procedure combines multicomponent thermodynamics with chemical kinetics and may be used to simulate the multicomponent reactors as a thermochemical natural process. The method combines the desired reaction rates sequentially with constrained Gibbs energy minimization. The reactant concentrations are determined by the experimental (Arrhenius) rate laws. During the course of the given reaction the subsequent side reactions are supposed to occur reversibly. At every sequential stage of the given reaction the temperature and composition of the reaction mixture are calculated by a thermodynamic subroutine, which minimizes the Gibbs energy of the system and takes into account the heat transfer between the system and its surroundings. The extents of reaction are included as algorithmic constraints in the Gibbs energy minimization procedure. Initially, the reactants are introduced to the system as inert copies to match both the mass and energy balance of the reactive system. During the calculation the copies are sequentially interchanged to the actual reactants which allows one to simulate the time-dependent reaction route by using the thermochemical procedure. For each intermediate stage, the temperature and composition are calculated and as well numerical estimates of the thermodynamic functions are obtained. The method is applicable in processes where the core thermodynamic and kinetic data of the system are known and the time-dependent heat transfer data can either be measured or estimated by calculation. The method has been used to simulate e.g. high temperature flame reactions, zinc vapour oxidation and a counter-current rotary drum with chemical reactions. The procedure has today been tested with SOLGASMIX, CHEMSAGE and HSC programs. (author)

New applications with time-dependent thermochemical simulation

Energy Technology Data Exchange (ETDEWEB)

Koukkari, P [VTT Chemical Technology, Espoo (Finland); Laukkanen, L [VTT Automation, Espoo (Finland); Penttilae, K [Kemira Engineering Oy, Helsinki (Finland)

1997-12-31

A new method (RATEMIX) to calculate multicomponent chemical reaction mixtures as a series of sequential thermochemical states was recently introduced. The procedure combines multicomponent thermodynamics with chemical kinetics and may be used to simulate the multicomponent reactors as a thermochemical natural process. The method combines the desired reaction rates sequentially with constrained Gibbs energy minimization. The reactant concentrations are determined by the experimental (Arrhenius) rate laws. During the course of the given reaction the subsequent side reactions are supposed to occur reversibly. At every sequential stage of the given reaction the temperature and composition of the reaction mixture are calculated by a thermodynamic subroutine, which minimizes the Gibbs energy of the system and takes into account the heat transfer between the system and its surroundings. The extents of reaction are included as algorithmic constraints in the Gibbs energy minimization procedure. Initially, the reactants are introduced to the system as inert copies to match both the mass and energy balance of the reactive system. During the calculation the copies are sequentially interchanged to the actual reactants which allows one to simulate the time-dependent reaction route by using the thermochemical procedure. For each intermediate stage, the temperature and composition are calculated and as well numerical estimates of the thermodynamic functions are obtained. The method is applicable in processes where the core thermodynamic and kinetic data of the system are known and the time-dependent heat transfer data can either be measured or estimated by calculation. The method has been used to simulate e.g. high temperature flame reactions, zinc vapour oxidation and a counter-current rotary drum with chemical reactions. The procedure has today been tested with SOLGASMIX, CHEMSAGE and HSC programs. (author)

Evaluation of chemical, thermobaric and thermochemical pre-treatment on anaerobic digestion of high-fat cattle slaughterhouse waste.

Science.gov (United States)

Harris, Peter W; Schmidt, Thomas; McCabe, Bernadette K

2017-11-01

This work aimed to enhance the anaerobic digestion of fat-rich dissolved air flotation (DAF) sludge through chemical, thermobaric, and thermochemical pre-treatment methods. Soluble chemical oxygen demand was enhanced from 16.3% in the control to 20.84% (thermobaric), 40.82% (chemical), and 50.7% (thermochemical). Pre-treatment altered volatile fatty acid concentration by -64% (thermobaric), 127% (chemical) and 228% (thermochemical). Early inhibition was reduced by 20% in the thermochemical group, and 100% in the thermobaric group. Specific methane production was enhanced by 3.28% (chemical), 8.32% (thermobaric), and 8.49% (thermochemical) as a result of pre-treatment. Under batch digestion, thermobaric pre-treatment demonstrated the greatest improvement in methane yield with respect to degree of pre-treatment applied. Thermobaric pre-treatment was also the most viable for implementation at slaughterhouses, with potential for heat-exchange to reduce pre-treatment cost. Further investigation into long-term impact of pre-treatments in semi-continuous digestion experiments will provide additional evaluation of appropriate pre-treatment options for high-fat slaughterhouse wastewater. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prototype thermochemical heat storage with open reactor system

NARCIS (Netherlands)

Zondag, H.A.; Kikkert, B.; Smeding, S.F.; Boer, de R.; Bakker, M.

2013-01-01

Thermochemical (TC) heat storage is an interesting technology for future seasonal storage of solar heat in the built environment. This technology enables high thermal energy storage densities and low energy storage losses. A small-scale laboratory prototype TC storage system has been realized at

A systematic multi-step screening of numerous salt hydrates for low temperature thermochemical energy storage

International Nuclear Information System (INIS)

N’Tsoukpoe, Kokouvi Edem; Schmidt, Thomas; Rammelberg, Holger Urs; Watts, Beatriz Amanda; Ruck, Wolfgang K.L.

2014-01-01

Highlights: • We report an evaluation of the potential of salt hydrates for thermochemical storage. • Both theoretical calculations and experimental measurements using TGA/DSC are used. • Salt hydrates offer very low potential for thermochemical heat storage. • The efficiency of classical processes using salt hydrates is very low: typically 25%. • New processes are needed for the use of salt hydrates in thermochemical heat storage. - Abstract: In this paper, the potential energy storage density and the storage efficiency of salt hydrates as thermochemical storage materials for the storage of heat generated by a micro-combined heat and power (micro-CHP) have been assessed. Because salt hydrates used in various thermochemical heat storage processes fail to meet the expectations, a systematic evaluation of the suitability of 125 salt hydrates has been performed in a three-step approach. In the first step general issues such as toxicity and risk of explosion have been considered. In the second and third steps, the authors implement a combined approach consisting of theoretical calculations and experimental measurements using Thermogravimetric Analysis (TGA). Thus, application-oriented comparison criteria, among which the net energy storage density of the material and the thermal efficiency, have been used to evaluate the potential of 45 preselected salt hydrates for a low temperature thermochemical heat storage application. For an application that requires a discharging temperature above 60 °C, SrBr 2 ·6H 2 O and LaCl 3 ·7H 2 O appear to be the most promising, only from thermodynamic point of view. However, the maximum net energy storage density including the water in the water storage tank that they offer (respectively 133 kW h m −3 and 89 kW h m −3 ) for a classical thermochemical heat storage process are not attractive for the intended application. Furthermore, the thermal efficiency that would result from the storage process based on salt hydrates

The NREL Biochemical and Thermochemical Ethanol Conversion Processes: Financial and Environmental Analysis Comparison

Directory of Open Access Journals (Sweden)

Jesse Sky Daystar

2015-07-01

Full Text Available The financial and environmental performance of the National Renewable Energy Lab’s (NREL thermochemical and biochemical biofuel conversion processes are examined herein with pine, eucalyptus, unmanaged hardwood, switchgrass, and sweet sorghum. The environmental impacts of the process scenarios were determined by quantifying greenhouse gas (GHG emissions and TRACI impacts. Integrated financial and environmental performance metrics were introduced and used to examine the biofuel production scenarios. The thermochemical and biochemical conversion processes produced the highest financial performance and lowest environmental impacts when paired with pine and sweet sorghum, respectively. The high ash content of switchgrass and high lignin content of loblolly pine lowered conversion yields, resulting in the highest environmental impacts and lowest financial performance for the thermochemical and biochemical conversion processes, respectively. Biofuel produced using the thermochemical conversion process resulted in lower TRACI single score impacts and somewhat lower GHG emissions per megajoule (MJ of fuel than using the biochemical conversion pathway. The cost of carbon mitigation resulting from biofuel production and corresponding government subsidies was determined to be higher than the expected market carbon price. In some scenarios, the cost of carbon mitigation was several times higher than the market carbon price, indicating that there may be other more cost-effective methods of reducing carbon emissions.

Thermodynamic limits on the performance of a solar thermochemical energy storage system

Energy Technology Data Exchange (ETDEWEB)

Lovegrove, K [Australian National Univ., Canberra (Australia). Energy Research Centre

1993-12-01

General expressions for the exergetic and work recovery efficiencies of thermochemical storage systems have been developed by assuming that the reaction process is the only source irreversibility within the closed-loop system. These have been used to plot contours of constant efficiency for the ammonia-based thermochemical system. The effect of spontaneous separation of mixtures due to the preferential condensation of ammonia has been examined analytically and graphically. The analysis presented represents a necessary prerequisite for the optimization of system efficiencies by reactor design. (author)

Materials considerations for the coupling of thermochemical hydrogen cycles to tandem mirror reactors

International Nuclear Information System (INIS)

Krikorian, O.H.

1980-01-01

Candidate materials are discussed and initial choices made for the critical elements in a liquid Li-Na Cauldron Tandem Mirror blanket and the General Atomic Sulfur-Iodine Cycle for thermochemical hydrogen production. V and Ti alloys provide low neutron activation, good radiation damage resistance, and good chemical compatibility for the Cauldron design. Aluminide coated In-800H and siliconized SiC are materials choices for heat exchanger components in the thermochemical cycle interface

Algorithmic phase diagrams

Science.gov (United States)

Hockney, Roger

1987-01-01

Algorithmic phase diagrams are a neat and compact representation of the results of comparing the execution time of several algorithms for the solution of the same problem. As an example, the recent results are shown of Gannon and Van Rosendale on the solution of multiple tridiagonal systems of equations in the form of such diagrams. The act of preparing these diagrams has revealed an unexpectedly complex relationship between the best algorithm and the number and size of the tridiagonal systems, which was not evident from the algebraic formulae in the original paper. Even so, for a particular computer, one diagram suffices to predict the best algorithm for all problems that are likely to be encountered the prediction being read directly from the diagram without complex calculation.

Towards the renewal of the NEA Thermochemical Database

International Nuclear Information System (INIS)

Ragoussi, Maria-Eleni; Costa, Davide; Bossant, Manuel

2015-01-01

The Thermochemical Database (TDB) Project was created three decades ago as a joint undertaking of the NEA Radioactive Waste Management Committee and the NEA Data Bank. The project involves the collection of high-quality and traceable thermochemical data for a set of elements (mainly minor actinides and fission products) relevant to geophysical modelling of deep geological repositories. Funding comes from 15 participating organisations, primarily national nuclear waste authorities and research institutions. The quantities that are stored in the TDB database are: the standard molar Gibbs energy and enthalpy of formation, the standard molar entropy and, when available, the heat capacity at constant pressure, together with their uncertainty intervals. Reaction data are also provided: equilibrium constant of reaction, molar Gibbs energy of reaction, molar enthalpy of reaction and molar entropy of reaction. Data assessment is carried out by teams of expert reviewers through an in-depth analysis of the available scientific literature, following strict guidelines defined by the NEA to ensure the accuracy and self-consistency of the adopted datasets. Thermochemical data that has been evaluated and selected over the years have been published in the 13 volumes of the Chemical Thermodynamics series. They are also stored in a database that is updated each time the study of a new element is completed. The TDB selected data are made available to external third parties through the NEA web site where data extracted from the database can be displayed and downloaded as plain text files. Following recent recommendations of the Task Force on the Future Programme of the NEA Data Bank to enhance scientific expertise and user services, a renewal of the software managing the TDB database is being undertaken. The software currently used was designed 20 years ago and is becoming obsolete. Redesigning the application will provide an opportunity to correct current shortcomings and to develop

Bibliographic Review about Solar Hydrogen Production Through Thermochemical Cycles; Revision Bibliografica sobre la Produccion de Hidrogeno Solar Mediante Ciclos Termoquimicos

Energy Technology Data Exchange (ETDEWEB)

Fernandez Saavedra, R.

2007-12-28

This report presents a summary of the different thermical processes used to obtain hydrogen through solar energy, paying more attention to the production of hydrogen from water through thermochemical cycles. In this aspect, it is briefly described the most interesting thermochemical cycles, focusing on thermochemical cycles based on oxides. (Author) 25 refs.

Bibliographic Review about Solar Hydrogen Production Through Thermochemical Cycles; Revision Bibliografica sobre la Produccion de Hidrogeno Solar Mediante Ciclos Termoquimicos

Energy Technology Data Exchange (ETDEWEB)

Fernandez Saavedra, R.

2008-08-06

This report presents a summary of the different thermical processes used to obtain hydrogen through solar energy, paying more attention to the production of hydrogen from water through thermochemical cycles. In this aspect, it is briefly y described the most interesting thermochemical cycles, focusing on thermochemical cycles based on oxides. (Author) 25 refs.

Thermochemical study of MoS2 oxidation

International Nuclear Information System (INIS)

Filimonov, D.S.; Topor, N.D.; Kesler, Ya.A.

1990-01-01

Thermochemical studies of oxidation processes of metallic molybdenum, sulfur, molybdenum disulfide under different conditions in microcalorimeter are conducted. Values of thermal effects which are used to calculate standard formation enthalpy of MoS 2 and which correlate well are obtained. Δ f H 0 (MoS 2 ,298.15 K) recommended value constitutes (-223.0±16.7) kJ/mol

Electronic diagrams

CERN Document Server

Colwell, Morris A

1976-01-01

Electronic Diagrams is a ready reference and general guide to systems and circuit planning and in the preparation of diagrams for both newcomers and the more experienced. This book presents guidelines and logical procedures that the reader can follow and then be equipped to tackle large complex diagrams by recognition of characteristic 'building blocks' or 'black boxes'. The goal is to break down many of the barriers that often seem to deter students and laymen in learning the art of electronics, especially when they take up electronics as a spare time occupation. This text is comprised of nin

Thermochemical treatment of radioactive waste by using powder metal fuels

International Nuclear Information System (INIS)

Dmitriev, S.A.; Ojovan, M.I.; Karlina, O.K.

2001-01-01

Full text: A thermochemical approach was suggested for treating and conditioning specific streams of radioactive wastes for example spent ion exchange resins, mixed, organic or chlorine-containing radioactive waste as well as in order to decontaminate heavily contaminated surfaces. Conventional treatment methods of such waste encounters serious problems concerning complete destruction of organic molecules and possible emissions of radionuclides, heavy metals and chemically hazardous species or in case of contaminated materials - complete removal of contamination from surface. The thermochemical treatment of radioactive waste uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. Thermochemical treatment technologies use the energy of chemical reactions in the mixture of waste with PMF to sustain both decomposition and synthesis processes as well as processes of isomorphic substitutions of hazardous elements into stable mineral forms. The composition of the PMF is designed in such a way as to minimise the release of hazardous components and radionuclides in the off gas and to confine the contaminants in the mineral or glass like final products. The thermochemical procedures allow decomposition of organic matter and capturing hazardous radionuclides and chemical species simultaneously. Thermochemical treatment technologies are very efficient, easy to apply, they have low capital investment and can be used both at large and small facilities. An advantage of thermochemical technologies is their autonomy. Thus these technologies can be successfully applied in order to treat small amount of waste without usage of complex and expensive equipment. They can be used also in emergency situations. Currently the thermochemical treatment technologies were developed and demonstrated to be feasible as follows: 1. Decontamination of surfaces; 2. Processing of organic waste; 3. Vitrification of dusty

Comprehensive characterisation of sewage sludge for thermochemical conversion processes - Based on Singapore survey.

Science.gov (United States)

Chan, Wei Ping; Wang, Jing-Yuan

2016-08-01

Recently, sludge attracted great interest as a potential feedstock in thermochemical conversion processes. However, compositions and thermal degradation behaviours of sludge were highly complex and distinctive compared to other traditional feedstock led to a need of fundamental research on sludge. Comprehensive characterisation of sludge specifically for thermochemical conversion was carried out for all existing Water Reclamation Plants in Singapore. In total, 14 sludge samples collected based on the type, plant, and batch categorisation. Existing characterisation methods for physical and chemical properties were analysed and reviewed using the collected samples. Qualitative similarities and quantitative variations of different sludge samples were identified and discussed. Oxidation of inorganic in sludge during ash forming analysis found to be causing significant deviations on proximate and ultimate analysis. Therefore, alternative parameters and comparison basis including Fixed Residues (FR), Inorganic Matters (IM) and Total Inorganics (TI) were proposed for better understanding on the thermochemical characteristics of sludge. Copyright © 2016 Elsevier Ltd. All rights reserved.

The NAGRA/PSI thermochemical database: new developments

International Nuclear Information System (INIS)

Hummel, W.; Berner, U.; Thoenen, T.; Pearson, F.J.Jr.

2000-01-01

The development of a high quality thermochemical database for performance assessment is a scientifically fascinating and demanding task, and is not simply collecting and recording numbers. The final product can by visualised as a complex building with different storeys representing different levels of complexity. The present status report illustrates the various building blocks which we believe are integral to such a database structure. (authors)

The NAGRA/PSI thermochemical database: new developments

Energy Technology Data Exchange (ETDEWEB)

Hummel, W.; Berner, U.; Thoenen, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Pearson, F.J.Jr. [Ground-Water Geochemistry, New Bern, NC (United States)

2000-07-01

The development of a high quality thermochemical database for performance assessment is a scientifically fascinating and demanding task, and is not simply collecting and recording numbers. The final product can by visualised as a complex building with different storeys representing different levels of complexity. The present status report illustrates the various building blocks which we believe are integral to such a database structure. (authors)

Thermochemical structure of the Earth's mantle and continental crust

DEFF Research Database (Denmark)

Guerri, Mattia

A detailed knowledge of the Earth's thermal structure and chemical composition is fundamental in order to understand the processes driving the planet ormation and evolution. The inaccessibility of most of the Earth's interior makes the determination of its thermo-chemical conditions a challenging...

Viral pathogenesis in diagrams

National Research Council Canada - National Science Library

Tremblay, Michel; Berthiaume, Laurent; Ackermann, Hans-Wolfgang

2001-01-01

.... The 268 diagrams in Viral Pathogenesis in Diagrams were selected from over 800 diagrams of English and French virological literature, including one derived from a famous drawing by Leonardo da Vinci...

Biomass thermochemical gasification: Experimental studies and modeling

Science.gov (United States)

Kumar, Ajay

The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

REITP3-Hazard evaluation program for heat release based on thermochemical calculation

Energy Technology Data Exchange (ETDEWEB)

Akutsu, Yoshiaki.; Tamura, Masamitsu. [The University of Tokyo, Tokyo (Japan). School of Engineering; Kawakatsu, Yuichi. [Oji Paper Corp., Tokyo (Japan); Wada, Yuji. [National Institute for Resources and Environment, Tsukuba (Japan); Yoshida, Tadao. [Hosei University, Tokyo (Japan). College of Engineering

1999-06-30

REITP3-A hazard evaluation program for heat release besed on thermochemical calculation has been developed by modifying REITP2 (Revised Estimation of Incompatibility from Thermochemical Properties{sup 2)}. The main modifications are as follows. (1) Reactants are retrieved from the database by chemical formula. (2) As products are listed in an external file, the addition of products and change in order of production can be easily conducted. (3) Part of the program has been changed by considering its use on a personal computer or workstation. These modifications will promote the usefulness of the program for energy hazard evaluation. (author)

Advanced Electrochemical Technologies for Hydrogen Production by Alternative Thermochemical Cycles

Energy Technology Data Exchange (ETDEWEB)

Lvov, Serguei; Chung, Mike; Fedkin, Mark; Lewis, Michele; Balashov, Victor; Chalkova, Elena; Akinfiev, Nikolay; Stork, Carol; Davis, Thomas; Gadala-Maria, Francis; Stanford, Thomas; Weidner, John; Law, Victor; Prindle, John

2011-01-06

Hydrogen fuel is a potentially major solution to the problem of climate change, as well as addressing urban air pollution issues. But a key future challenge for hydrogen as a clean energy carrier is a sustainable, low-cost method of producing it in large capacities. Most of the world's hydrogen is currently derived from fossil fuels through some type of reforming processes. Nuclear hydrogen production is an emerging and promising alternative to the reforming processes for carbon-free hydrogen production in the future. This report presents the main results of a research program carried out by a NERI Consortium, which consisted of Penn State University (PSU) (lead), University of South Carolina (USC), Tulane University (TU), and Argonne National Laboratory (ANL). Thermochemical water decomposition is an emerging technology for large-scale production of hydrogen. Typically using two or more intermediate compounds, a sequence of chemical and physical processes split water into hydrogen and oxygen, without releasing any pollutants externally to the atmosphere. These intermediate compounds are recycled internally within a closed loop. While previous studies have identified over 200 possible thermochemical cycles, only a few have progressed beyond theoretical calculations to working experimental demonstrations that establish scientific and practical feasibility of the thermochemical processes. The Cu-Cl cycle has a significant advantage over other cycles due to lower temperature requirements – around 530 °C and below. As a result, it can be eventually linked with the Generation IV thermal power stations. Advantages of the Cu-Cl cycle over others include lower operating temperatures, ability to utilize low-grade waste heat to improve energy efficiency, and potentially lower cost materials. Another significant advantage is a relatively low voltage required for the electrochemical step (thus low electricity input). Other advantages include common chemical agents and

Probabilistic thermo-chemical analysis of a pultruded composite rod

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2012-01-01

In the present study the deterministic thermo-chemical pultrusion simulation of a composite rod taken from the literature [7] is used as a validation case. The predicted centerline temperature and cure degree profiles of the rod match well with those in the literature [7]. Following the validation...

Thermochemical conversion of microalgal biomass into biofuels: a review.

Science.gov (United States)

Chen, Wei-Hsin; Lin, Bo-Jhih; Huang, Ming-Yueh; Chang, Jo-Shu

2015-05-01

Following first-generation and second-generation biofuels produced from food and non-food crops, respectively, algal biomass has become an important feedstock for the production of third-generation biofuels. Microalgal biomass is characterized by rapid growth and high carbon fixing efficiency when they grow. On account of potential of mass production and greenhouse gas uptake, microalgae are promising feedstocks for biofuels development. Thermochemical conversion is an effective process for biofuel production from biomass. The technology mainly includes torrefaction, liquefaction, pyrolysis, and gasification. Through these conversion technologies, solid, liquid, and gaseous biofuels are produced from microalgae for heat and power generation. The liquid bio-oils can further be upgraded for chemicals, while the synthesis gas can be synthesized into liquid fuels. This paper aims to provide a state-of-the-art review of the thermochemical conversion technologies of microalgal biomass into fuels. Detailed conversion processes and their outcome are also addressed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diagram, a Learning Environment for Initiation to Object-Oriented Modeling with UML Class Diagrams

Science.gov (United States)

Py, Dominique; Auxepaules, Ludovic; Alonso, Mathilde

2013-01-01

This paper presents Diagram, a learning environment for object-oriented modelling (OOM) with UML class diagrams. Diagram an open environment, in which the teacher can add new exercises without constraints on the vocabulary or the size of the diagram. The interface includes methodological help, encourages self-correcting and self-monitoring, and…

VennDiagram: a package for the generation of highly-customizable Venn and Euler diagrams in R

Directory of Open Access Journals (Sweden)

Boutros Paul C

2011-01-01

Full Text Available Abstract Background Visualization of orthogonal (disjoint or overlapping datasets is a common task in bioinformatics. Few tools exist to automate the generation of extensively-customizable, high-resolution Venn and Euler diagrams in the R statistical environment. To fill this gap we introduce VennDiagram, an R package that enables the automated generation of highly-customizable, high-resolution Venn diagrams with up to four sets and Euler diagrams with up to three sets. Results The VennDiagram package offers the user the ability to customize essentially all aspects of the generated diagrams, including font sizes, label styles and locations, and the overall rotation of the diagram. We have implemented scaled Venn and Euler diagrams, which increase graphical accuracy and visual appeal. Diagrams are generated as high-definition TIFF files, simplifying the process of creating publication-quality figures and easing integration with established analysis pipelines. Conclusions The VennDiagram package allows the creation of high quality Venn and Euler diagrams in the R statistical environment.

VennDiagram: a package for the generation of highly-customizable Venn and Euler diagrams in R.

Science.gov (United States)

Chen, Hanbo; Boutros, Paul C

2011-01-26

Visualization of orthogonal (disjoint) or overlapping datasets is a common task in bioinformatics. Few tools exist to automate the generation of extensively-customizable, high-resolution Venn and Euler diagrams in the R statistical environment. To fill this gap we introduce VennDiagram, an R package that enables the automated generation of highly-customizable, high-resolution Venn diagrams with up to four sets and Euler diagrams with up to three sets. The VennDiagram package offers the user the ability to customize essentially all aspects of the generated diagrams, including font sizes, label styles and locations, and the overall rotation of the diagram. We have implemented scaled Venn and Euler diagrams, which increase graphical accuracy and visual appeal. Diagrams are generated as high-definition TIFF files, simplifying the process of creating publication-quality figures and easing integration with established analysis pipelines. The VennDiagram package allows the creation of high quality Venn and Euler diagrams in the R statistical environment.

Introduction to Feynman diagrams

CERN Document Server

Bilenky, Samoil Mikhelevich

1974-01-01

Introduction to Feynman Diagrams provides Feynman diagram techniques and methods for calculating quantities measured experimentally. The book discusses topics Feynman diagrams intended for experimental physicists. Topics presented include methods for calculating the matrix elements (by perturbation theory) and the basic rules for constructing Feynman diagrams; techniques for calculating cross sections and polarizations; processes in which both leptons and hadrons take part; and the electromagnetic and weak form factors of nucleons. Experimental physicists and graduate students of physics will

Overview of recent advances in thermo-chemical conversion of biomass

International Nuclear Information System (INIS)

Zhang Linghong; Xu Chunbao; Champagne, Pascale

2010-01-01

Energy from biomass, bioenergy, is a perspective source to replace fossil fuels in the future, as it is abundant, clean, and carbon dioxide neutral. Biomass can be combusted directly to generate heat and electricity, and by means of thermo-chemical and bio-chemical processes it can be converted into bio-fuels in the forms of solid (e.g., charcoal), liquid (e.g., bio-oils, methanol and ethanol), and gas (e.g., methane and hydrogen), which can be used further for heat and power generation. This paper provides an overview of the principles, reactions, and applications of four fundamental thermo-chemical processes (combustion, pyrolysis, gasification, and liquefaction) for bioenergy production, as well as recent developments in these technologies. Some advanced thermo-chemical processes, including co-firing/co-combustion of biomass with coal or natural gas, fast pyrolysis, plasma gasification and supercritical water gasification, are introduced. The advantages and disadvantages, potential for future applications and challenges of these processes are discussed. The co-firing of biomass and coal is the easiest and most economical approach for the generation of bioenergy on a large-sale. Fast pyrolysis has attracted attention as it is to date the only industrially available technology for the production of bio-oils. Plasma techniques, due to their high destruction and reduction efficiencies for any form of waste, have great application potential for hazardous waste treatment. Supercritical water gasification is a promising approach for hydrogen generation from biomass feedstocks, especially those with high moisture contents.

Application of Thermochemical Modeling to Assessment/Evaluation of Nuclear Fuel Behavior

Energy Technology Data Exchange (ETDEWEB)

Besmann, Theodore M [University of South Carolina, Columbia; McMurray, Jake W [ORNL; Simunovic, Srdjan [ORNL

2016-01-01

The combination of new fuel compositions and higher burn-ups envisioned for the future means that representing fuel properties will be much more important, and yet more complex. Behavior within the oxide fuel rods will be difficult to model owing to the high temperatures, and the large number of elements generated and their significant concentrations that are a result of fuels taken to high burn-up. This unprecedented complexity offers an enormous challenge to the thermochemical understanding of these systems and opportunities to advance solid solution models to describe these materials. This paper attempts to model and simulate that behavior using an oxide fuels thermochemical description to compute the equilibrium phase state and oxygen potential of LWR fuel under irradiation.

Diagrams benefit symbolic problem-solving.

Science.gov (United States)

Chu, Junyi; Rittle-Johnson, Bethany; Fyfe, Emily R

2017-06-01

The format of a mathematics problem often influences students' problem-solving performance. For example, providing diagrams in conjunction with story problems can benefit students' understanding, choice of strategy, and accuracy on story problems. However, it remains unclear whether providing diagrams in conjunction with symbolic equations can benefit problem-solving performance as well. We tested the impact of diagram presence on students' performance on algebra equation problems to determine whether diagrams increase problem-solving success. We also examined the influence of item- and student-level factors to test the robustness of the diagram effect. We worked with 61 seventh-grade students who had received 2 months of pre-algebra instruction. Students participated in an experimenter-led classroom session. Using a within-subjects design, students solved algebra problems in two matched formats (equation and equation-with-diagram). The presence of diagrams increased equation-solving accuracy and the use of informal strategies. This diagram benefit was independent of student ability and item complexity. The benefits of diagrams found previously for story problems generalized to symbolic problems. The findings are consistent with cognitive models of problem-solving and suggest that diagrams may be a useful additional representation of symbolic problems. © 2017 The British Psychological Society.

Thermochemical properties of the alkali hydroxides: A review

International Nuclear Information System (INIS)

Konings, R.J.M.; Cordfunke, E.H.P.

1989-01-01

The formation of volatile alkali hydroxides as a result of high-temperature steam corrosion plays an important role in nuclear technology. For the modeling of the volatilization processes, reliable thermodynamic data are required. In the present paper recent physico-chemical experiments by the authors will be discussed and the thermochemical properties of the alkali hydroxide series will be evaluated. (orig.)

Solar thermochemical processing system and method

Science.gov (United States)

Wegeng, Robert S.; Humble, Paul H.; Krishnan, Shankar; Leith, Steven D.; Palo, Daniel R.; Dagle, Robert A.

2018-04-24

A solar thermochemical processing system is disclosed. The system includes a first unit operation for receiving concentrated solar energy. Heat from the solar energy is used to drive the first unit operation. The first unit operation also receives a first set of reactants and produces a first set of products. A second unit operation receives the first set of products from the first unit operation and produces a second set of products. A third unit operation receives heat from the second unit operation to produce a portion of the first set of reactants.

Water Footprint and Land Requirement of Solar Thermochemical Jet-Fuel Production.

Science.gov (United States)

Falter, Christoph; Pitz-Paal, Robert

2017-11-07

The production of alternative fuels via the solar thermochemical pathway has the potential to provide supply security and to significantly reduce greenhouse gas emissions. H 2 O and CO 2 are converted to liquid hydrocarbon fuels using concentrated solar energy mediated by redox reactions of a metal oxide. Because attractive production locations are in arid regions, the water footprint and the land requirement of this fuel production pathway are analyzed. The water footprint consists of 7.4 liters per liter of jet fuel of direct demand on-site and 42.4 liters per liter of jet fuel of indirect demand, where the dominant contributions are the mining of the rare earth oxide ceria, the manufacturing of the solar concentration infrastructure, and the cleaning of the mirrors. The area-specific productivity is found to be 33 362 liters per hectare per year of jet fuel equivalents, where the land coverage is mainly due to the concentration of solar energy for heat and electricity. The water footprint and the land requirement of the solar thermochemical fuel pathway are larger than the best power-to-liquid pathways but an order of magnitude lower than the best biomass-to-liquid pathways. For the production of solar thermochemical fuels arid regions are best-suited, and for biofuels regions of a moderate and humid climate.

Comparative Life Cycle Assessment of Lignocellulosic Ethanol Production: Biochemical Versus Thermochemical Conversion

Science.gov (United States)

Mu, Dongyan; Seager, Thomas; Rao, P. Suresh; Zhao, Fu

2010-10-01

Lignocellulosic biomass can be converted into ethanol through either biochemical or thermochemical conversion processes. Biochemical conversion involves hydrolysis and fermentation while thermochemical conversion involves gasification and catalytic synthesis. Even though these routes produce comparable amounts of ethanol and have similar energy efficiency at the plant level, little is known about their relative environmental performance from a life cycle perspective. Especially, the indirect impacts, i.e. emissions and resource consumption associated with the production of various process inputs, are largely neglected in previous studies. This article compiles material and energy flow data from process simulation models to develop life cycle inventory and compares the fossil fuel consumption, greenhouse gas emissions, and water consumption of both biomass-to-ethanol production processes. The results are presented in terms of contributions from feedstock, direct, indirect, and co-product credits for four representative biomass feedstocks i.e., wood chips, corn stover, waste paper, and wheat straw. To explore the potentials of the two conversion pathways, different technological scenarios are modeled, including current, 2012 and 2020 technology targets, as well as different production/co-production configurations. The modeling results suggest that biochemical conversion has slightly better performance on greenhouse gas emission and fossil fuel consumption, but that thermochemical conversion has significantly less direct, indirect, and life cycle water consumption. Also, if the thermochemical plant operates as a biorefinery with mixed alcohol co-products separated for chemicals, it has the potential to achieve better performance than biochemical pathway across all environmental impact categories considered due to higher co-product credits associated with chemicals being displaced. The results from this work serve as a starting point for developing full life cycle

Holistic analysis of thermochemical processes by using solid biomass for fuel production in Germany

International Nuclear Information System (INIS)

Henssler, Martin

2015-01-01

According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO 2eq -reduction compared to the fossil reference fuel (83.8 g CO 2eq /MJ fuel /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO 2eq -savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H 2 ) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V registered -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H 2 ). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H 2 -production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO 2eq -saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO 2eq -saving is between 72 (H 2 ) and 95 % (Fischer-Tropsch-diesel or -gasoline). When the production costs of the

Hydrogen production by thermochemical cycles of water splitting coupled to a solar energy source

International Nuclear Information System (INIS)

Charvin, P.

2007-11-01

The aim of this work is to identify, to test and to estimate new thermochemical cycles able to efficiently produce hydrogen from concentrated solar energy. In fact, the aim is to propose a hydrogen production way presenting a global energetic yield similar to electrolysis, that is to say 20-25%, electrolysis being at the present time the most advanced current process for a clean hydrogen production from water. After a first chapter dealing with the past and present researches on thermochemical cycles, the first step of this study has consisted on a selection of a limited number of thermochemical cycles able to produce great quantities of hydrogen from concentrated solar energy. It has consisted in particular on a review of the thermochemical cycles present in literature, on a first selection from argued criteria, and on an exergetic and thermodynamic analysis of the retained cycles for a first estimation of their potential. The second step of this study deals with the experimental study of all the chemical reactions occurring in the retained cycles. Two different oxides cycles have been particularly chosen and the aims are to demonstrate the feasibility of the reactions, to identify the optimal experimental conditions, to estimate and optimize the kinetics and the chemical yields. The following part of this work deals with the design, the modeling and the test of a solar reactor. A CFD modeling of a high temperature reactor of cavity type allows to identify the main heat losses of the reactor and to optimize the geometry of the cavity. A dynamic modeling of the reactor gives data on its behaviour in transient regime and under a real solar flux. The results of the preliminary experimental results are presented. The last part of this study deals with a process analysis of the thermochemical cycles from the results of the experimental study (experimental conditions, yields...). The matter and energy balances are established in order to estimate the global energetic

Optimizing UML Class Diagrams

Directory of Open Access Journals (Sweden)

Sergievskiy Maxim

2018-01-01

Full Text Available Most of object-oriented development technologies rely on the use of the universal modeling language UML; class diagrams play a very important role in the design process play, used to build a software system model. Modern CASE tools, which are the basic tools for object-oriented development, can’t be used to optimize UML diagrams. In this manuscript we will explain how, based on the use of design patterns and anti-patterns, class diagrams could be verified and optimized. Certain transformations can be carried out automatically; in other cases, potential inefficiencies will be indicated and recommendations given. This study also discusses additional CASE tools for validating and optimizing of UML class diagrams. For this purpose, a plugin has been developed that analyzes an XMI file containing a description of class diagrams.

Utilization of salt ammoniacates in fluidized beds in energy conversion thermochemical systems

International Nuclear Information System (INIS)

Romero, Jesus

1984-01-01

This research thesis notably reports the design and development of a thermochemical storage device involving equilibria of thermal decomposition of ammoniacates of strontium chlorides and calcium chloride in fluidized beds. The experimental study of this device allowed operating conditions and the most important concomitant effects of fluidization to be highlighted. The measured thermal exchange coefficient is about twenty times the measured value in equivalent devices using fixed beds. An irreversibility of the operation has been noticed, and seems to be associated with the irreversible change of grain size of solids. The author also reports a study of the properties of ammoniacates of metallic salts, and of the influence of fluidization on the performance of energy conversion thermochemical systems [fr

Thermochemical equilibrium in a kernel of a UN TRISO coated fuel particle

International Nuclear Information System (INIS)

Kim, Young Min; Jo, C. K.; Lim, H. S.; Cho, M. S.; Lee, W. J.

2012-01-01

A coated fuel particle (CFP) with a uranium mononitride (UN) kernel has been recently considered as an advanced fuel option, such as in fully ceramic micro encapsulated (FCM) replacement fuel for light water reactors (LWRs). In FCM fuel, a large number of tri isotropic coated fuel particles (TRISOs) are embedded in a silicon carbide (SiC) matrix. Thermochemical equilibrium calculations can predict the chemical behaviors of a kernel in a TRISO of FCM fuel during irradiation. They give information on the kind and quantity of gases generated in a kernel during irradiation. This study treats the quantitative analysis of thermochemical equilibrium in a UN TRISO of FCM LWR fuel using HSC software

Experimental Investigation and Thermodynamic Modeling of the B2O3-FeO-Fe2O3-Nd2O3 System for Recycling of NdFeB Magnet Scrap

Science.gov (United States)

Jakobsson, Lars Klemet; Tranell, Gabriella; Jung, In-Ho

2017-02-01

NdFeB magnet scrap is an alternative source of neodymium that could have a significantly lower impact on the environment than current mining and extraction processes. Neodymium can be readily oxidized in the presence of oxygen, which makes it easy to recover neodymium in oxide form. Thermochemical data and phase diagrams for neodymium oxide containing systems is, however, very limited. Thermodynamic modeling of the B2O3-FeO-Fe2O3-Nd2O3 system was hence performed to obtain accurate phase diagrams and thermochemical properties of the system. Key phase diagram experiments were also carried out for the FeO-Nd2O3 system in saturation with iron to improve the accuracy of the present modeling. The modified quasichemical model was used to describe the Gibbs energy of the liquid oxide phase. The Gibbs energy functions of the liquid phase and the solids were optimized to reproduce all available and reliable phase diagram data, and thermochemical properties of the system. Finally the optimized database was applied to calculate conditions for selective oxidation of neodymium from NdFeB magnet waste.

Fuels production by the thermochemical transformation of the biomass

International Nuclear Information System (INIS)

Claudet, G.

2005-01-01

The biomass is a local and renewable energy source, presenting many advantages. This paper proposes to examine the biomass potential in France, the energy valorization channels (thermochemical chains of thermolysis and gasification) with a special interest for the hydrogen production and the research programs oriented towards the agriculture and the forest. (A.L.B.)

Thermochemical investigations on uranyl phosphates and arsenates

International Nuclear Information System (INIS)

Barten, H.

1986-11-01

The results are described of a study of the thermochemical stability of anhydrous uranyl phosphates and arsenates. A number of aspects of chemical technological importance are indicated in detail. The synthesized anhydrous uranyl phosphates and arsenates were very hygroscopic, so that experiments on these compounds had to be carried out under moisture-free conditions. Further characterisation of these compounds are given, including a study of their thermal stabilities and phase relations. The uranyl phosphates reduced reversibly at temperatures of the order of 1100 to 1600 0 C. This makes it possible to express their relative stabilities quantitatively, in terms of the oxygen pressures of the reduction reactions. The thermal decomposition of uranyl arsenates did not occur by reduction, as for the phosphates, but by giving off arsenic oxide vapour. The results of measurements of enthalpies of solution led to the determination of the enthalpies of formation, heat capacity and the standard entropies of the uranyl arsenates. The thermochemical functions at high-temperatures could consequently be calculated. Attention is paid to the possible formation of uranium arsenates, whose uranium has a valency lower than six, hitherto not reported in literature. It was not possible to prepare arsenates of tetravalent uranium. However, three new compounds were observed, one of these, UAsO 5 , was studied in some detail. (Auth.)

Stage line diagram: An age-conditional reference diagram for tracking development

NARCIS (Netherlands)

Buuren, S. van; Ooms, J.C.L.

2009-01-01

This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and

Stage line diagram: an age-conditional reference diagram for tracking development.

NARCIS (Netherlands)

Van Buuren, S.; Ooms, J.C.L.

2009-01-01

This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and

CERPHASE: Computer-generated phase diagrams

International Nuclear Information System (INIS)

Ruys, A.J.; Sorrell, C.C.; Scott, F.H.

1990-01-01

CERPHASE is a collection of computer programs written in the programming language basic and developed for the purpose of teaching the principles of phase diagram generation from the ideal solution model of thermodynamics. Two approaches are used in the generation of the phase diagrams: freezing point depression and minimization of the free energy of mixing. Binary and ternary phase diagrams can be generated as can diagrams containing the ideal solution parameters used to generate the actual phase diagrams. Since the diagrams generated utilize the ideal solution model, data input required from the operator is minimal: only the heat of fusion and melting point of each component. CERPHASE is menu-driven and user-friendly, containing simple instructions in the form of screen prompts as well as a HELP file to guide the operator. A second purpose of CERPHASE is in the prediction of phase diagrams in systems for which no experimentally determined phase diagrams are available, enabling the estimation of suitable firing or sintering temperatures for otherwise unknown systems. Since CERPHASE utilizes ideal solution theory, there are certain limitations imposed on the types of systems that can be predicted reliably. 6 refs., 13 refs

Remarks on the thermochemical production of hydrogen from water using heat from the high temperature reactor

International Nuclear Information System (INIS)

Barnert, H.

1980-06-01

In this report, some aspects of the production of hydrogen from water using heat from the High Temperature Reactor has been studied. These aspects are: the theoretical potential for economic competitivness, the application of hydrogen in the Heat Market, the size of the market potential in the Federal Republic of Germany and the extent of research and development work. In addition another novel proposal for a thermochemical cycle has been studied. For the description of the theoretical potential for economic competitivness, a definition of the 'coupling', has been introduced, which is thermodynamicaly developed; the thermochemical cycle is compared with the thermochemical cycle. Using the coupling, it becomes possible to describe a relation between thermodynamical parameters and the ecomomical basic data of capital costs. Reasons are given from the theoretical point of view for the application of hydrogen as an energy carrier of high exergetic value in the heat market. The discussion of energy problems as 'questions of global survival' leads here to a proposal for the introduction of the term 'extropy'. The market potential in the Federal Republic of Germany is estimated. A further novel proposal for a thermochemical cycle is the 'hydrocarbon-hybrid-process'. The extent of research and development work is explained. (orig.) [de

Process simulation of nuclear-based thermochemical hydrogen production with a copper-chlorine cycle

International Nuclear Information System (INIS)

Chukwu, C.C.; Naterer, G.F.; Rosen, M.A.

2008-01-01

Thermochemical processes for hydrogen production driven by nuclear energy are promising alternatives to existing technologies for large-scale commercial production of hydrogen without fossil fuels. The copper-chlorine (Cu-Cl) cycle, in which water is decomposed into hydrogen and oxygen, is promising for thermochemical hydrogen production in conjunction with a Supercritical Water Cooled Reactor. Here, the cycle efficiency is examined using the Aspen Plus process simulation code. Possible efficiency improvements are discussed. The results are expected to assist the development of a lab-scale cycle demonstration, which is currently being undertaken at University of Ontario Institute of Technology in collaboration with numerous partners. (author)

A process for the thermochemical poduction of H2

International Nuclear Information System (INIS)

Norman, J.H.; Russell, J.L. Jr.; Porter, J.T. II; McCorkl, K.H.; Roemer, T.S.; Sharp, Robert.

1976-01-01

A process is described for the thermochemical production of H 2 from water. HI 3 and H 2 SO 4 are prepared by chemical reaction between I 2 , SO 2 and H 2 O. Then HI 3 is heated and decomposed into H 2 and I 2 . The heat is produced by a nuclear reactor [fr

Natural gas usage as a heat source for integrated SMR and thermochemical hydrogen production technologies

International Nuclear Information System (INIS)

Jaber, O.; Naterer, G.F.; Dincer, I.

2010-01-01

This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu-Cl cycle out-performs the other conventional methods with respect to fuel requirements, carbon dioxide emissions and total cost of production. (author)

Para-equilibrium phase diagrams

International Nuclear Information System (INIS)

Pelton, Arthur D.; Koukkari, Pertti; Pajarre, Risto; Eriksson, Gunnar

2014-01-01

Highlights: • A rapidly cooled system may attain a state of para-equilibrium. • In this state rapidly diffusing elements reach equilibrium but others are immobile. • Application of the Phase Rule to para-equilibrium phase diagrams is discussed. • A general algorithm to calculate para-equilibrium phase diagrams is described. - Abstract: If an initially homogeneous system at high temperature is rapidly cooled, a temporary para-equilibrium state may result in which rapidly diffusing elements have reached equilibrium but more slowly diffusing elements have remained essentially immobile. The best known example occurs when homogeneous austenite is quenched. A para-equilibrium phase assemblage may be calculated thermodynamically by Gibbs free energy minimization under the constraint that the ratios of the slowly diffusing elements are the same in all phases. Several examples of calculated para-equilibrium phase diagram sections are presented and the application of the Phase Rule is discussed. Although the rules governing the geometry of these diagrams may appear at first to be somewhat different from those for full equilibrium phase diagrams, it is shown that in fact they obey exactly the same rules with the following provision. Since the molar ratios of non-diffusing elements are the same in all phases at para-equilibrium, these ratios act, as far as the geometry of the diagram is concerned, like “potential” variables (such as T, pressure or chemical potentials) rather than like “normal” composition variables which need not be the same in all phases. A general algorithm to calculate para-equilibrium phase diagrams is presented. In the limit, if a para-equilibrium calculation is performed under the constraint that no elements diffuse, then the resultant phase diagram shows the single phase with the minimum Gibbs free energy at any point on the diagram; such calculations are of interest in physical vapor deposition when deposition is so rapid that phase

Thermochemical investigation of lithium-vanadium bronzes

International Nuclear Information System (INIS)

Filippova, S.E.; Kesler, Ya.A.; Tret'yakov, Yu.D.; Gordeev, I.V.

1979-01-01

A thermochemical investigation was carried out of lithium-vanadium bronzes. The enthalpies of solution and the standard enthalpies of formation of the bronzes β-Lisub(x)Vsub(2)Osub(5) were determined. Investigated was the dependence of the enthalpy of mixing bronzes on the composition; a linear character of the dependence evidences of negligibly small, as compared to the experimental error, energy variations of the matrix V 2 O 5 on introduction of lithium. The variation was calculated of the partial molar enthalpy of lithium in the formation of β-Lisub(x)Vsub(2)Osub(5)

Sintering diagrams of UO2

International Nuclear Information System (INIS)

Mohan, A.; Soni, N.C.; Moorthy, V.K.

1979-01-01

Ashby's method (see Acta Met., vol. 22, p. 275, 1974) of constructing sintering diagrams has been modified to obtain contribution diagrams directly from the computer. The interplay of sintering variables and mechanisms are studied and the factors that affect the participation of mechanisms in UO 2 are determined. By studying the physical properties, it emerges that the order of inaccuracies is small in most cases and do not affect the diagrams. On the other hand, even a 10% error in activation energies, which is quite plausible, would make a significant difference to the diagram. The main criticism of Ashby's approach is that the numerous properties and equations used, communicate their inaccuracies to the diagrams and make them unreliable. The present study has considerably reduced the number of factors that need to be refined to make the sintering diagrams more meaningful. (Auth.)

Preparation and thermochemical stability of uranium-zirconium-carbonitrides

International Nuclear Information System (INIS)

Kouhsen, C.

1975-08-01

This investigation deals with the preparation and the thermochemical stability of uranium-zirconium-carbonitrides as well as with the mechanism of (U,Zr) (C,N)-preparation by carbothermic reduction of uranium-zirconium-oxide. Single-phase (U,Zr) (C,N)-solid solutions with U:Zr-propertions of 3:1, 1:1, and 1:3 were prepared from oxide powder. The thermochemical stability of the (U,Zr) (C,N)-solid solutions against carbon was measured for varying Zr- and N-contents and for several temperatures; the results indicate an increase of the uranium carbide stability potential by the formation of (U,Zr) (C,N)-solid solutions. The thermodynamic properties ΔG 0 , ΔH 0 , and ΔS 0 were calculated and the correlation between the M(C,N)-lattice constant and the N-content was evaluated. Through an intensive investigation of the reaction mechanism, several different reaction paths were found; for each of them the characteristical diffusion of matter was explained by means of the microsections. It was shown that the Zr-concentration of the oxide reactant and the heating rate during the carbothermic reduction influence the species of the reaction product, especially the homogeneity of the (U,Zr) (C,N)-solid solution. (orig.) [de

Thermo-Chemical Conversion of Microwave Activated Biomass Mixtures

Science.gov (United States)

Barmina, I.; Kolmickovs, A.; Valdmanis, R.; Vostrikovs, S.; Zake, M.

2018-05-01

Thermo-chemical conversion of microwave activated wheat straw mixtures with wood or peat pellets is studied experimentally with the aim to provide more effective application of wheat straw for heat energy production. Microwave pre-processing of straw pellets is used to provide a partial decomposition of the main constituents of straw and to activate the thermo-chemical conversion of wheat straw mixtures with wood or peat pellets. The experimental study includes complex measurements of the elemental composition of biomass pellets (wheat straw, wood, peat), DTG analysis of their thermal degradation, FTIR analysis of the composition of combustible volatiles entering the combustor, the flame temperature, the heat output of the device and composition of the products by comparing these characteristics for mixtures with unprocessed and mw pre-treated straw pellets. The results of experimental study confirm that mw pre-processing of straw activates the thermal decomposition of mixtures providing enhanced formation of combustible volatiles. This leads to improvement of the combustion conditions in the flame reaction zone, completing thus the combustion of volatiles, increasing the flame temperature, the heat output from the device, the produced heat energy per mass of burned mixture and decreasing at the same time the mass fraction of unburned volatiles in the products.

Screening analysis of solar thermochemical hydrogen concepts.

Energy Technology Data Exchange (ETDEWEB)

Diver, Richard B., Jr.; Kolb, Gregory J.

2008-03-01

A screening analysis was performed to identify concentrating solar power (CSP) concepts that produce hydrogen with the highest efficiency. Several CSP concepts were identified that have the potential to be much more efficient than today's low-temperature electrolysis technology. They combine a central receiver or dish with either a thermochemical cycle or high-temperature electrolyzer that operate at temperatures >600 C. The solar-to-hydrogen efficiencies of the best central receiver concepts exceed 20%, significantly better than the 14% value predicted for low-temperature electrolysis.

Feynman diagram drawing made easy

International Nuclear Information System (INIS)

Baillargeon, M.

1997-01-01

We present a drawing package optimised for Feynman diagrams. These can be constructed interactively with a mouse-driven graphical interface or from a script file, more suitable to work with a diagram generator. It provides most features encountered in Feynman diagrams and allows to modify every part of a diagram after its creation. Special attention has been paid to obtain a high quality printout as easily as possible. This package is written in Tcl/Tk and in C. (orig.)

Thermochemical conversion of biomass storage covers to reduce ammonia emissions from dairy manure Thermochemical conversion of biomass storage covers to reduce ammonia emissions from dairy manure

Science.gov (United States)

Manure storages, and in particular those storing digested manure, are a source of ammonia (NH3) emissions. Permeable manure storage covers can reduce NH3 emissions, however performance can decline as they degrade. Thermochemical conversion of biomass through pyrolysis and steam treatment could incre...

Cascading pressure reactor and method for solar-thermochemical reactions

Science.gov (United States)

Ermanoski, Ivan

2017-11-14

Reactors and methods for solar thermochemical reactions are disclosed. The reactors and methods include a cascade of reduction chambers at successively lower pressures that leads to over an order of magnitude pressure decrease compared to a single-chambered design. The resulting efficiency gains are substantial, and represent an important step toward practical and efficient solar fuel production on a large scale.

The Semiotic Structure of Geometry Diagrams: How Textbook Diagrams Convey Meaning

Science.gov (United States)

Dimmel, Justin K.; Herbst, Patricio G.

2015-01-01

Geometry diagrams use the visual features of specific drawn objects to convey meaning about generic mathematical entities. We examine the semiotic structure of these visual features in two parts. One, we conduct a semiotic inquiry to conceptualize geometry diagrams as mathematical texts that comprise choices from different semiotic systems. Two,…

Communication: The electronic entropy of charged defect formation and its impact on thermochemical redox cycles

Science.gov (United States)

Lany, Stephan

2018-02-01

The ideal material for solar thermochemical water splitting, which has yet to be discovered, must satisfy stringent conditions for the free energy of reduction, including, in particular, a sufficiently large positive contribution from the solid-state entropy. By inverting the commonly used relationship between defect formation energy and defect concentration, it is shown here that charged defect formation causes a large electronic entropy contribution manifesting itself as the temperature dependence of the Fermi level. This result is a general feature of charged defect formation and motivates new materials design principles for solar thermochemical hydrogen production.

Lifecycle assessment of microalgae to biofuel: Comparison of thermochemical processing pathways

International Nuclear Information System (INIS)

Bennion, Edward P.; Ginosar, Daniel M.; Moses, John; Agblevor, Foster; Quinn, Jason C.

2015-01-01

Highlights: • Well to pump environmental assessment of two thermochemical processing pathways. • NER of 1.23 and GHG emissions of −11.4 g CO 2-eq (MJ) −1 for HTL pathway. • HTL represents promising conversion pathway based on use of wet biomass. • NER of 2.27 and GHG emissions of 210 g CO 2-eq (MJ) −1 for pyrolysis pathway. • Pyrolysis pathway: drying microalgae feedstock dominates environmental impact. - Abstract: Microalgae is being investigated as a renewable transportation fuel feedstock based on various advantages that include high annual yields, utilization of poor quality land, does not compete with food, and can be integrated with various waste streams. This study focuses on directly assessing the environmental impact of two different thermochemical conversion technologies for the microalgae-to-biofuel process through life cycle assessment. A system boundary of “well to pump” (WTP) is defined and includes sub-process models of the growth, dewatering, thermochemical bio-oil recovery, bio-oil stabilization, conversion to renewable diesel, and transport to the pump. Models were validated with experimental and literature data and are representative of an industrial-scale microalgae-to-biofuel process. Two different thermochemical bio-oil conversion systems are modeled and compared on a systems level, hydrothermal liquefaction (HTL) and pyrolysis. The environmental impact of the two pathways were quantified on the metrics of net energy ratio (NER), defined here as energy consumed over energy produced, and greenhouse gas (GHG) emissions. Results for WTP biofuel production through the HTL pathway were determined to be 1.23 for the NER and GHG emissions of −11.4 g CO 2-eq (MJ renewable diesel) −1 . Biofuel production through the pyrolysis pathway results in a NER of 2.27 and GHG emissions of 210 g CO 2-eq (MJ renewable diesel) −1 . The large environmental impact associated with the pyrolysis pathway is attributed to feedstock drying

Stage line diagram: an age-conditional reference diagram for tracking development.

Science.gov (United States)

van Buuren, Stef; Ooms, Jeroen C L

2009-05-15

This paper presents a method for calculating stage line diagrams, a novel type of reference diagram useful for tracking developmental processes over time. Potential fields of applications include: dentistry (tooth eruption), oncology (tumor grading, cancer staging), virology (HIV infection and disease staging), psychology (stages of cognitive development), human development (pubertal stages) and chronic diseases (stages of dementia). Transition probabilities between successive stages are modeled as smoothly varying functions of age. Age-conditional references are calculated from the modeled probabilities by the mid-P value. It is possible to eliminate the influence of age by calculating standard deviation scores (SDS). The method is applied to the empirical data to produce reference charts on secondary sexual maturation. The mean of the empirical SDS in the reference population is close to zero, whereas the variance depends on age. The stage line diagram provides quick insight into both status (in SDS) and tempo (in SDS/year) of development of an individual child. Other measures (e.g. height SDS, body mass index SDS) from the same child can be added to the chart. Diagrams for sexual maturation are available as a web application at http://vps.stefvanbuuren.nl/puberty. The stage line diagram expresses status and tempo of discrete changes on a continuous scale. Wider application of these measures scores opens up new analytic possibilities. (c) 2009 John Wiley & Sons, Ltd.

On the thermo-chemical origin of the stratified region at the top of the Earth's core

Science.gov (United States)

Nakagawa, Takashi

2018-03-01

I developed a combined model of the thermal and chemical evolution of the Earth's core and investigated its influence on a thermochemically stable region beneath the core-mantle boundary (CMB). The chemical effects of the growing stable region are caused by the equilibrium chemical reaction between silicate and the metallic core. The thermal effects can be characterized by the growth of the sub-isentropic shell, which may have a rapid growth rate compared to that of the chemically stable region. When the present-day CMB heat flow was varied, the origin of the stable region changed from chemical to thermochemical to purely thermal because the rapid growth of the sub-isentropic shell can replace the chemically stable region. Physically reasonable values of the present-day CMB heat flow that can maintain the geodynamo action over 4 billion years should be between 8 and 11 TW. To constrain the thickness of the thermochemically stable region beneath the CMB, the chemical diffusivity is important and should be ∼O(10-8) m2/s to obtain a thickness of the thermochemically stable region beneath the CMB consistent with that inferred from geomagnetic secular variations (140 km). However, the strength of the stable region found in this study is too high to be consistent with the constraint on the stability of the stable region inferred from geomagnetic secular variations.

Ring diagrams and phase transitions

International Nuclear Information System (INIS)

Takahashi, K.

1986-01-01

Ring diagrams at finite temperatures carry most infrared-singular parts among Feynman diagrams. Their effect to effective potentials are in general so significant that one must incorporate them as well as 1-loop diagrams. The author expresses these circumstances in some examples of supercooled phase transitions

Haemolytic activity of uranium compounds haemolysis by thermochemical derivatives of ammonium uranate

International Nuclear Information System (INIS)

Stuart, W.I.; Tucker, A.D.; Adams, R.B.

1975-01-01

A study has been made of the haemolytic action on human erythrocytes by ammonium uranate (AU) and various thermochemical products of AU. These products were obtained by heating AU in hydrogen at 5 0 C min -1 to various temperatures. Haemolysis has been interpreted in terms of a diffusion model which for each product yields a single parameter Ksub(N), the haemolytic activity factor. The magnitude of Ksub(N) is a convenient measure of the ability of a powder to damage erythrocytes. The haemolytic activity of certain thermochemical derivatives indicates an exceptionally high potential for damage to erythrocytes. Infrared and thermoanalytical measurements have shown that the high activity of these products derives principally from a self-reduction reaction, induced by heating AU to 400-420 0 C in hydrogen. (author)

Development of a Thermo-chemical Non-equilibrium Solver for Hypervelocity Flows

Science.gov (United States)

Balasubramanian, R.; Anandhanarayanan, K.

2015-04-01

In the present study, a three dimensional flowsolver is indigenously developed to numerically simulate hypervelocity thermal and chemical non equilibrium reactive air flow past flight vehicles. The two-temperature, five species, seventeen reactions, thermo-chemical non equilibrium, non-ionizing, air-chemistry model of Park is implemented in a compressible viscous code CERANS and solved in the finite volume framework. The energy relaxation is addressed by a conservation equation for the vibrational energy of the gas mixture resulting in the evaluation of its vibrational temperature. The AUSM-PW+ numerical flux function has been used for modeling the convective fluxes and a central differencing approximation is used for modeling the diffusive fluxes. The flowsolver had been validated for specifically chosen test cases with inherent flow complexities of non-ionizing hypervelocity thermochemical nonequilibrium flows and results obtained are in good agreement with results available in open literature.

Hydrogen Production From Water By Thermo-Chemical Methods (UT-3): Evaluation of Side Reactions By Simulation Process

International Nuclear Information System (INIS)

Rusli, A.

1997-01-01

Hydogen fuel with its advantages will be able to replace all the positions of fossil fuels post o il and gas or migas . Among the advantages of hydrogen fuel are pollution free, abundant of raw material in the form of water molecule, flexible in application, able to stroge and transport as well as fossil energy sources (oil and gas). Hydogen could be produced from water by means of thermochemical, thermolysis, photolysis and electrolysis. Nuclear heat (HTGR), solar heat or waste heat from steel industry can be used as energy source for these processes. In case of thermochemical method, some problems realated to production process should be studied and evaluated. Simulation is considered can be applied to study the effects of side reactions and also to resolve its problems in hydrogen production process. In this paper is reported the evalution results of hydrogen production process by thermochemical (UT-3) through both of the experimental and computer simulation. It has been proposed a new flow chart of hydrogen production to achieve the hydrogen production continuously. A simulator has been developed based on experimental data and related mathematical equations. This simulator can be used to scle-up the UT-3 thermochemical cycle for hydrogen production process

Stereo 3D spatial phase diagrams

Energy Technology Data Exchange (ETDEWEB)

Kang, Jinwu, E-mail: kangjw@tsinghua.edu.cn; Liu, Baicheng, E-mail: liubc@tsinghua.edu.cn

2016-07-15

Phase diagrams serve as the fundamental guidance in materials science and engineering. Binary P-T-X (pressure–temperature–composition) and multi-component phase diagrams are of complex spatial geometry, which brings difficulty for understanding. The authors constructed 3D stereo binary P-T-X, typical ternary and some quaternary phase diagrams. A phase diagram construction algorithm based on the calculated phase reaction data in PandaT was developed. And the 3D stereo phase diagram of Al-Cu-Mg ternary system is presented. These phase diagrams can be illustrated by wireframe, surface, solid or their mixture, isotherms and isopleths can be generated. All of these can be displayed by the three typical display ways: electronic shutter, polarization and anaglyph (for example red-cyan glasses). Especially, they can be printed out with 3D stereo effect on paper, and watched by the aid of anaglyph glasses, which makes 3D stereo book of phase diagrams come to reality. Compared with the traditional illustration way, the front of phase diagrams protrude from the screen and the back stretches far behind of the screen under 3D stereo display, the spatial structure can be clearly and immediately perceived. These 3D stereo phase diagrams are useful in teaching and research. - Highlights: • Stereo 3D phase diagram database was constructed, including binary P-T-X, ternary, some quaternary and real ternary systems. • The phase diagrams can be watched by active shutter or polarized or anaglyph glasses. • The print phase diagrams retains 3D stereo effect which can be achieved by the aid of anaglyph glasses.

Performance analysis of an integrated energy storage and energy upgrade thermochemical solid–gas sorption system for seasonal storage of solar thermal energy

International Nuclear Information System (INIS)

Li, Tingxian; Wang, Ruzhu; Kiplagat, Jeremiah K.; Kang, YongTae

2013-01-01

An innovative dual-mode thermochemical sorption energy storage method is proposed for seasonal storage of solar thermal energy with little heat losses. During the charging phase in summer, solar thermal energy is stored in form of chemical bonds resulting from thermochemical decomposition process, which enables the stored energy to be kept several months at ambient temperature. During the discharging phase in winter, the stored thermal energy is released in the form of chemical reaction heat resulting from thermochemical synthesis process. Thermodynamic analysis showed that the advanced dual-mode thermochemical sorption energy storage is an effective method for the long-term seasonal storage of solar energy. A coefficient of performance (COP h ) of 0.6 and energy density higher than 1000 kJ/kg of salt can be attained from the proposed system. During the discharging phase at low ambient temperatures, the stored thermal energy can be upgraded by use of a solid–gas thermochemical sorption heat transformer cycle. The proposed thermochemical sorption energy storage has distinct advantages over the conventional sensible heat and latent heat storage, such as higher energy storage density, little heat losses, integrated energy storage and energy upgrade, and thus it can contribute to improve the seasonal utilization of solar thermal energy. - Highlights: ► A dual-mode solid thermochemical sorption is proposed for seasonal solar thermal energy storage. ► Energy upgrade techniques into the energy storage system are integrated. ► Performance of the proposed seasonal energy storage system is evaluated. ► Energy density and COP h from the proposed system are as high as 1043 kJ/kg of salt and 0.60, respectively

Solar hydrogen project - Thermochemical process design

Energy Technology Data Exchange (ETDEWEB)

Allen, D.J.; Ng, L.F.; Rao, M.S.M.; Wu, S.F.; Zoschak, R.J.

1984-08-01

The thermochemical decomposition of water using solar energy offers an elegant way of combining solar and chemical technologies to produce a high quality fuel. The DOE has sponsored Foster Wheeler to develop a process design for a solar water-splitting process based on the sulfuric acid/iodine cycle. The study has centered around the design of a sulfuric acid decomposition reactor and the central receiver. Materials' properties impose severe constraints upon the design of decomposition reactor. In this paper, the constraints imposed on the design are specified and a reactor and receiver design is presented together with a preliminary design of the balance of plant.

Efficiency of the sulfur-iodine thermochemical water splitting process for hydrogen production based on ADS

International Nuclear Information System (INIS)

Gonzalez, D.; Garcia, L.; Garcia, C.; Garcia, L.; Brayner, C.

2013-01-01

The current hydrogel production is based on fossil fuels; they have a huge contribution to the atmosphere's pollution. thermochemical water splitting cycles don't present this issue because the required process heat is obtained from nuclear energy and therefore, the environmental impact is smaller than using conventional fuels. One of the promising approaches to produce large quantities of hydrogen in an efficient way using nuclear energy is the sulfur-iodine (S-I) thermochemical water splitting cycle. The nuclear source proposed in this paper is a pebble bed gas cooled transmutation facility. Pebble bed very high temperature advanced systems have great perspectives to assume the future nuclear energy. Software based on Chemical Process Simulation (CPS) can be used to simulate the thermochemical water splitting sulfur-iodine cycle for hydrogen production. In this paper, a model for analyzing the sulfur-iodine process sensibility is developed. Efficiency is also calculated and the influence of different parameters on this value. The behavior of the proposed model before different values of initial reactant's flow is analyzed. (Author)

Observations of Circumstellar Thermochemical Equilibrium: The Case of Phosphorus

Science.gov (United States)

Milam, Stefanie N.; Charnley, Steven B.

2011-01-01

We will present observations of phosphorus-bearing species in circumstellar envelopes, including carbon- and oxygen-rich shells 1. New models of thermochemical equilibrium chemistry have been developed to interpret, and constrained by these data. These calculations will also be presented and compared to the numerous P-bearing species already observed in evolved stars. Predictions for other viable species will be made for observations with Herschel and ALMA.

Biomass Program 2007 Program Peer Review - Thermochemical Conversion Platform Summary

Energy Technology Data Exchange (ETDEWEB)

none,

2009-10-27

This document discloses the comments provided by a review panel at the U.S. Department of Energy Office of the Biomass Program Peer Review held on November 15-16, 2007 in Baltimore, MD and the Biomass Program Peer Review for the Thermochemical Platform, held on July 9th and 10th in Golden, Colorado.

Balance and saving of GHG emissions in thermochemical biorefineries

International Nuclear Information System (INIS)

Haro, Pedro; Aracil, Cristina; Vidal-Barrero, Fernando; Ollero, Pedro

2015-01-01

Highlights: • A simplified methodology for the balance and saving of GHG emissions is provided. • The GHG balance has a physical meaning and does not depend on the fossil reference. • The GHG saving depends on regulation of energy carriers. • The impact of Bio-CCS incorporation and multiproduction is analyzed. • The co-production of chemicals needs to be included in future regulation. - Abstract: In this study, a simplified methodology for the calculation of the balance of greenhouse gas (GHG) emissions and corresponding saving compared with the fossil reference is presented. The proposed methodology allows the estimation of the anthropogenic GHG emissions of thermochemical biorefineries (net emitted to the atmosphere). In the calculation of the GHG balance, all relevant factors have been identified and analyzed including multiproduction, emissions from biogenic carbon capture and storage (Bio-CCS), co-feeding of fossil fuels (secondary feedstock) and possible carbon storage in biomass-derived products (chemicals). Therefore, it is possible to calculate the balance of GHG emissions of a hypothetical thermochemical biorefinery considering different alternatives of land-use, biomass feedstock, co-feeding of fossil fuels, Bio-CCS incorporation and final use of the products. The comparison of the estimated GHG balance with the corresponding fossil reference for each product is of special relevance in the methodology since it is the parameter used in European regulation for the fulfillment of sustainability criteria in biomass-derived fuels and liquids. The proposed methodology is tested using a previously assessed set of different process concepts of thermochemical biorefineries (techno-economic analysis). The resulting GHG balance and saving are analyzed to identify uncertainties and provide recommendations for future regulation. In all process concepts, the GHG savings are above the minimum requirement of GHG emissions for 2018. In the case of incorporating

Synfuels from fusion: producing hydrogen with the tandem mirror reactor and thermochemical cycles

International Nuclear Information System (INIS)

Ribe, F.L.; Werner, R.W.

1981-01-01

This report examines, for technical merit, the combination of a fusion reactor driver and a thermochemical plant as a means for producing synthetic fuel in the basic form of hydrogen. We studied: (1) one reactor type - the Tandem Mirror Reactor - wishing to use to advantage its simple central cell geometry and its direct electrical output; (2) two reactor blanket module types - a liquid metal cauldron design and a flowing Li 2 O solid microsphere pellet design so as to compare the technology, the thermal-hydraulics, neutronics and tritium control in a high-temperature operating mode (approx. 1200 K); (3) three thermochemical cycles - processes in which water is used as a feedstock along with a high-temperature heat source to produce H 2 and O 2

A review on the properties of salt hydrates for thermochemical storage

NARCIS (Netherlands)

Trausel, F.; Jong, A.J. de; Cuypers, R.

2014-01-01

Solar energy is capable of supplying enough energy to answer the total demand of energy in dwellings. However, because of the discrepancy between energy supply and energy demand, an efficient way of storing thermal energy is crucial. Thermochemical storage of heat in salt hydrates provides an

Thermochemical nonequilibrium analysis of O2+Ar based on state-resolved kinetics

International Nuclear Information System (INIS)

Kim, Jae Gang; Boyd, Iain D.

2015-01-01

Highlights: • Thermochemical nonequilibrium studies for three lowest lying electronic states of O 2 . • The complete sets of the rovibrational state-to-state transition rates of O 2 +Ar. • Rovibrational relaxations and coupled chemical reactions of O 2 . • Nonequilibrium reaction rates of O 2 derived from the quasi-steady state assumption. - Abstract: The thermochemical nonequilibrium of the three lowest lying electronic states of molecular oxygen, O 2 (X 3 Σ g - ,a 1 Δ g ,b 1 Σ g + ), through interactions with argon is studied in the present work. The multi-body potential energy surfaces of O 2 +Ar are evaluated from the semi-classical RKR potential of O 2 in each electronic state. The rovibrational states and energies of each electronic state are calculated by the quantum mechanical method based on the present inter-nuclear potential of O 2 . Then, the complete sets of the rovibrational state-to-state transition rate coefficients of O 2 +Ar are calculated by the quasi-classical trajectory method including the quasi-bound states. The system of master equations constructed by the present state-to-state transition rate coefficients are solved to analyze the thermochemical nonequilibrium of O 2 +Ar in various heat bath conditions. From these studies, it is concluded that the vibrational relaxation and coupled chemical reactions of each electronic state needs to be treated as a separate nonequilibrium process, and rotational nonequilibrium needs to be considered at translational temperatures above 10,000 K

Automation of Feynman diagram evaluations

International Nuclear Information System (INIS)

Tentyukov, M.N.

1998-01-01

A C-program DIANA (DIagram ANAlyser) for the automation of Feynman diagram evaluations is presented. It consists of two parts: the analyzer of diagrams and the interpreter of a special text manipulating language. This language can be used to create a source code for analytical or numerical evaluations and to keep the control of the process in general

Hydrogen production system based on high temperature gas cooled reactor energy using the sulfur-iodine (SI) thermochemical water splitting cycle

International Nuclear Information System (INIS)

Garcia, L.; Gonzalez, D.

2011-01-01

Hydrogen production from water using nuclear energy offers one of the most attractive zero-emission energy strategies and the only one that is practical on a substantial scale. Recently, strong interest is seen in hydrogen production using heat of a high-temperature gas-cooled reactor. The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using thermochemical or high-temperature electrolysis (HTE) processes. Eventually it could be also employ a high-temperature gas-cooled reactor (HTGR), which is particularly attractive because it has unique capability, among potential future generation nuclear power options, to produce high-temperature heat ideally suited for nuclear-heated hydrogen production. Using heat from nuclear reactors to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been interest of many laboratories in the world. One of the promising approaches to produce large quantity of hydrogen in an efficient way using the nuclear energy is the sulfur-iodine (SI) thermochemical water splitting cycle. Among the thermochemical cycles, the sulfur iodine process remains a very promising solution in matter of efficiency and cost. This work provides a pre-conceptual design description of a SI-Based H2-Nuclear Reactor plant. Software based on chemical process simulation (CPS) was used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. (Author)

Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power

International Nuclear Information System (INIS)

Brown, L.C.; Funk, J.F.; Showalter, S.K.

1999-01-01

OAK B188 Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power There is currently no large scale, cost-effective, environmentally attractive hydrogen production process, nor is such a process available for commercialization. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Fossil fuels are polluting and carbon dioxide emissions from their combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. Almost 800 literature references were located which pertain to thermochemical production of hydrogen from water and over 100 thermochemical watersplitting cycles were examined. Using defined criteria and quantifiable metrics, 25 cycles have been selected for more detailed study

Thermochemical Kinetics of H2O and HNO3 on crystalline Nitric Acid Hydrates (alpha-, beta-NAT, NAD) in the range 175-200 K

Science.gov (United States)

Rossi, Michel J.; Iannarelli, Riccardo

2015-04-01

The growth of NAT (Nitric Acid Trihydrate, HNO3x3H2O) and NAD (Nitric Acid Dihydrate, HNO3x2H2O) on an ice substrate, the evaporative lifetime of NAT and NAD as well as the interconversion of alpha- and beta-NAT competing with evaporation and growth under UT/LS conditions depends on the interfacial kinetics of H2O and HNO3 vapor on the condensed phase. Despite the existence of some literature results we have embarked on a systematic investigation of the kinetics using a multidiagnostic experimental approach enabled by the simultaneous observation of both the gas (residual gas mass spectrometry) as well as the condensed phase (FTIR absorption in transmission). We report on thermochemically consistent mass accommodation coefficients alpha and absolute evaporation rates Rev/molecule s-1cm-3 as a function of temperature which yields the corresponding vapor pressures of both H2O and HNO3 in equilibrium with the crystalline phases, hence the term thermochemical kinetics. These results have been obtained using a stirred flow reactor (SFR) using a macroscopic pure ice film of 1 micron or so thickness as a starting substrate mimicking atmospheric ice particles and are reported in a phase diagram specifically addressing UT (Upper Troposphere)/LS (Lower Stratosphere) conditions as far as temperature and partial pressures are concerned. The experiments have been performed either at steady-state flow conditions or in transient supersaturation using a pulsed solenoid valve in order to generate gas pulses whose decay were subsequently monitored in real time. Special attention has been given to the effect of the stainless-steel vessel walls in that Langmuir adsorption isotherms for H2O and HNO3 have been used to correct for wall-adsorption of both probe gases. Typically, the accommodation coefficients of H2O and HNO3 are similar throughout the temperature range whereas the rates of evaporation Rev of H2O are significantly larger than for HNO3 thus leading to the difference in

Revisiting dibenzothiophene thermochemical data: Experimental and computational studies

International Nuclear Information System (INIS)

Freitas, Vera L.S.; Gomes, Jose R.B.; Ribeiro da Silva, Maria D.M.C.

2009-01-01

Thermochemical data of dibenzothiophene were studied in the present work by experimental techniques and computational calculations. The standard (p 0 =0.1MPa) molar enthalpy of formation, at T = 298.15 K, in the gaseous phase, was determined from the enthalpy of combustion and sublimation, obtained by rotating bomb calorimetry in oxygen, and by Calvet microcalorimetry, respectively. This value was compared with estimated data from G3(MP2)//B3LYP computations and also with the other results available in the literature.

Exergy analysis of thermochemical ethanol production via biomass gasification and catalytic synthesis

NARCIS (Netherlands)

van der Heijden, H.H.J.L.; Ptasinski, K.J.

2012-01-01

In this paper an exergy analysis of thermochemical ethanol production from biomass is presented. This process combines a steam-blown indirect biomass gasification of woody feedstock, with a subsequent conversion of produced syngas into ethanol. The production process involves several process

VennDiagramWeb: a web application for the generation of highly customizable Venn and Euler diagrams.

Science.gov (United States)

Lam, Felix; Lalansingh, Christopher M; Babaran, Holly E; Wang, Zhiyuan; Prokopec, Stephenie D; Fox, Natalie S; Boutros, Paul C

2016-10-03

Visualization of data generated by high-throughput, high-dimensionality experiments is rapidly becoming a rate-limiting step in computational biology. There is an ongoing need to quickly develop high-quality visualizations that can be easily customized or incorporated into automated pipelines. This often requires an interface for manual plot modification, rapid cycles of tweaking visualization parameters, and the generation of graphics code. To facilitate this process for the generation of highly-customizable, high-resolution Venn and Euler diagrams, we introduce VennDiagramWeb: a web application for the widely used VennDiagram R package. VennDiagramWeb is hosted at http://venndiagram.res.oicr.on.ca/ . VennDiagramWeb allows real-time modification of Venn and Euler diagrams, with parameter setting through a web interface and immediate visualization of results. It allows customization of essentially all aspects of figures, but also supports integration into computational pipelines via download of R code. Users can upload data and download figures in a range of formats, and there is exhaustive support documentation. VennDiagramWeb allows the easy creation of Venn and Euler diagrams for computational biologists, and indeed many other fields. Its ability to support real-time graphics changes that are linked to downloadable code that can be integrated into automated pipelines will greatly facilitate the improved visualization of complex datasets. For application support please contact Paul.Boutros@oicr.on.ca.

Thermochemical Erosion Modeling of the 25-MM M242/M791 Gun System

National Research Council Canada - National Science Library

Sopok, Samuel

1997-01-01

The MACE gun barrel thermochemical erosion modeling code addresses wall degradations due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the 25-mm M242/M791 gun system...

An overview of renewable hydrogen production from thermochemical process of oil palm solid waste in Malaysia

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul; Ganjehkaviri, A.

2015-01-01

Highlights: • 40% of energy demand of Malaysia could be supplied by thermochemical process of PSR. • SCWG of PSR is preferable thermochemical process due to char and tar elimination. • Potential of H 2 production from SCWG of PSR is 1.05 × 10 10 kgH 2 per year in Malaysia. • Highly moisturized PSR could be used in hydrogen production by SCWG process. - Abstract: Hydrogen is one of the most promising energy carriers for the future of the world due to its tremendous capability of pollution reduction. Hydrogen utilization is free of toxic gases formation as well as carbon dioxide (CO 2 ) emission. Hydrogen production can be implemented using a wide variety of resources including fossil fuels, nuclear energy and renewable and sustainable energy (RSE). Amongst various RSE resources, biomass has great capacity to be employed for renewable hydrogen production. Hydrogen production from palm solid residue (PSR) via thermochemical process is a perfect candidate for waste-to-well strategy in palm oil mills in Malaysia. In this paper, various characteristics of hydrogen production from thermochemical process of PSR includes pyrolysis and gasification are reviewed. The annual oil palm fruits production in Malaysia is approximately 100 million tonnes which the solid waste of the fruits is capable to generate around 1.05 × 10 10 kgH 2 (1.26 EJ) via supercritical water gasification (SCWG) process. The ratio of energy output to energy input of SCWG process of PSR is about 6.56 which demonstrates the priority of SCWG to transform the energy of PSR into a high energy end product. The high moisture of PSR which is the most important barrier for its direct combustion, emerges as an advantage in thermochemical reactions and highly moisturized PSR (even more than 50%) is utilized directly in SCWG without application of any high cost drying process. Implementation of appropriate strategies could lead Malaysia to supply about 40% of its annual energy demand by hydrogen yield from

Genus Ranges of Chord Diagrams.

Science.gov (United States)

Burns, Jonathan; Jonoska, Nataša; Saito, Masahico

2015-04-01

A chord diagram consists of a circle, called the backbone, with line segments, called chords, whose endpoints are attached to distinct points on the circle. The genus of a chord diagram is the genus of the orientable surface obtained by thickening the backbone to an annulus and attaching bands to the inner boundary circle at the ends of each chord. Variations of this construction are considered here, where bands are possibly attached to the outer boundary circle of the annulus. The genus range of a chord diagram is the genus values over all such variations of surfaces thus obtained from a given chord diagram. Genus ranges of chord diagrams for a fixed number of chords are studied. Integer intervals that can be, and those that cannot be, realized as genus ranges are investigated. Computer calculations are presented, and play a key role in discovering and proving the properties of genus ranges.

Solar Thermochemical Hydrogen Production Research (STCH)

Energy Technology Data Exchange (ETDEWEB)

Perret, Robert [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2011-05-01

Eight cycles in a coordinated set of projects for Solar Thermochemical Cycles for Hydrogen production (STCH) were self-evaluated for the DOE-EERE Fuel Cell Technologies Program at a Working Group Meeting on October 8 and 9, 2008. This document reports the initial selection process for development investment in STCH projects, the evaluation process meant to reduce the number of projects as a means to focus resources on development of a few most-likely-to-succeed efforts, the obstacles encountered in project inventory reduction and the outcomes of the evaluation process. Summary technical status of the projects under evaluation is reported and recommendations identified to improve future project planning and selection activities.

Third millenium ideal gas and condensed phase thermochemical database for combustion (with update from active thermochemical tables).

Energy Technology Data Exchange (ETDEWEB)

Burcat, A.; Ruscic, B.; Chemistry; Technion - Israel Inst. of Tech.

2005-07-29

The thermochemical database of species involved in combustion processes is and has been available for free use for over 25 years. It was first published in print in 1984, approximately 8 years after it was first assembled, and contained 215 species at the time. This is the 7th printed edition and most likely will be the last one in print in the present format, which involves substantial manual labor. The database currently contains more than 1300 species, specifically organic molecules and radicals, but also inorganic species connected to combustion and air pollution. Since 1991 this database is freely available on the internet, at the Technion-IIT ftp server, and it is continuously expanded and corrected. The database is mirrored daily at an official mirror site, and at random at about a dozen unofficial mirror and 'finger' sites. The present edition contains numerous corrections and many recalculations of data of provisory type by the G3//B3LYP method, a high-accuracy composite ab initio calculation. About 300 species are newly calculated and are not yet published elsewhere. In anticipation of the full coupling, which is under development, the database started incorporating the available (as yet unpublished) values from Active Thermochemical Tables. The electronic version now also contains an XML file of the main database to allow transfer to other formats and ease finding specific information of interest. The database is used by scientists, educators, engineers and students at all levels, dealing primarily with combustion and air pollution, jet engines, rocket propulsion, fireworks, but also by researchers involved in upper atmosphere kinetics, astrophysics, abrasion metallurgy, etc. This introductory article contains explanations of the database and the means to use it, its sources, ways of calculation, and assessments of the accuracy of data.

Conceptual design of SO3 decomposer for thermo-chemical iodine-sulfur process pilot plant

International Nuclear Information System (INIS)

Akihiro Kanagawa; Seiji Kasahara; Atsuhiko Terada; Shinji Kubo; Ryutaro Hino; Yoshiyuki Kawahara; Masaharu Watabe; Hiroshi Fukui; Kazuo Ishino; Toshio Takahashi

2005-01-01

Thermo-chemical water-splitting cycle is a method to make an effective use of the high temperature nuclear heat for hydrogen production. Japan Atomic Energy Research Institute (JAERI) has been conducting R and D on HTGR and also on thermo-chemical hydrogen production by using a thermo-chemical iodine-sulfur cycle (IS process). Based on the test results and know-how obtained through a bench-scale tests of hydrogen production of about 30 NL/hr, JAERI has a plan to construct a pilot test plant heated by high temperature helium gas, which has a hydrogen production performance of 30 Nm 3 /hr and will be operated under the high pressure up to 2 MPa. One of the key components of the pilot test plant is a SO 3 decomposer under high temperature conditions up to 850 degree C and high pressure up to 2 MPa. In this paper, a concept of the SO 3 decomposer for the pilot test plant fabricated with SiC ceramics, a corrosion-resistant material is investigated. Preliminary analyses on temperature and flow-rate distributions in the SO 3 decomposer and on thermal stress were carried out. A SO 3 decomposer model was experimentally manufactured. (authors)

Revisiting the BaO2/BaO redox cycle for solar thermochemical energy storage.

Science.gov (United States)

Carrillo, A J; Sastre, D; Serrano, D P; Pizarro, P; Coronado, J M

2016-03-21

The barium peroxide-based redox cycle was proposed in the late 1970s as a thermochemical energy storage system. Since then, very little attention has been paid to such redox couples. In this paper, we have revisited the use of reduction-oxidation reactions of the BaO2/BaO system for thermochemical heat storage at high temperatures. Using thermogravimetric analysis, reduction and oxidation reactions were studied in order to find the main limitations associated with each process. Furthermore, the system was evaluated through several charge-discharge stages in order to analyse its possible degradation after repeated cycling. Through differential scanning calorimetry the heat stored and released were also determined. Oxidation reaction, which was found to be slower than reduction, was studied in more detail using isothermal tests. It was observed that the rate-controlling step of BaO oxidation follows zero-order kinetics, although at high temperatures a deviation from Arrhenius behaviour was observed probably due to hindrances to anionic oxygen diffusion caused by the formation of an external layer of BaO2. This redox couple was able to withstand several redox cycles without deactivation, showing reaction conversions close to 100% provided that impurities are previously eliminated through thermal pre-treatment, demonstrating the feasibility of this system for solar thermochemical heat storage.

Chemical engineering challenges in driving thermochemical hydrogen processes with the tandem mirror reactor

International Nuclear Information System (INIS)

Galloway, T.R.; Werner, R.W.

1980-01-01

The Tandem Mirror Reactor is described and compared with Tokamaks, both from a basic physics viewpoint and from the suitability of the respective reactor for synfuel production. Differences and similarities between the TMR as an electricity producer or a synfuel producer are also cited. The Thermochemical cycle chosen to link with the fusion energy source is the General Atomic Sulfur-Iodine Cycle, which is a purely thermal-driven process with no electrochemical steps. There are real chemical engineering challenges of getting this high quality heat into the large thermochemical plant in an efficient manner. We illustrate with some of our approaches to providing process heat via liquid sodium to drive a 1050 K, highly-endothermic, catalytic and fluidized-bed SO 3 Decomposition Reactor. The technical, economic, and safety tradeoffs that arise are discussed

Cyclic thermochemical process for producing hydrogen using cerium-titanium compounds

Science.gov (United States)

Bamberger, C.E.

A thermochemical cyclic process for producing hydrogen employs the reaction between ceric oxide and titanium dioxide to form cerium titanate and oxygen. The titanate is treated with an alkali metal hydroxide to give hydrogen, ceric oxide, an alkali metal titanate and water. Alkali metal titanate and water are boiled to give titanium dioxide which, along with ceric oxide, is recycled.

Materials-Related Aspects of Thermochemical Water and Carbon Dioxide Splitting: A Review

Directory of Open Access Journals (Sweden)

Robert Pitz-Paal

2012-10-01

Full Text Available Thermochemical multistep water- and CO2-splitting processes are promising options to face future energy problems. Particularly, the possible incorporation of solar power makes these processes sustainable and environmentally attractive since only water, CO2 and solar power are used; the concentrated solar energy is converted into storable and transportable fuels. One of the major barriers to technological success is the identification of suitable active materials like catalysts and redox materials exhibiting satisfactory durability, reactivity and efficiencies. Moreover, materials play an important role in the construction of key components and for the implementation in commercial solar plants. The most promising thermochemical water- and CO2-splitting processes are being described and discussed with respect to further development and future potential. The main materials-related challenges of those processes are being analyzed. Technical approaches and development progress in terms of solving them are addressed and assessed in this review.

High Efficiency Solar Thermochemical Reactor for Hydrogen Production.

Energy Technology Data Exchange (ETDEWEB)

McDaniel, Anthony H. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2017-09-30

This research and development project is focused on the advancement of a technology that produces hydrogen at a cost that is competitive with fossil-based fuels for transportation. A twostep, solar-driven WS thermochemical cycle is theoretically capable of achieving an STH conversion ratio that exceeds the DOE target of 26% at a scale large enough to support an industrialized economy [1]. The challenge is to transition this technology from the laboratory to the marketplace and produce hydrogen at a cost that meets or exceeds DOE targets.

Collaborative diagramming during problem based learning in medical education: Do computerized diagrams support basic science knowledge construction?

Science.gov (United States)

De Leng, Bas; Gijlers, Hannie

2015-05-01

To examine how collaborative diagramming affects discussion and knowledge construction when learning complex basic science topics in medical education, including its effectiveness in the reformulation phase of problem-based learning. Opinions and perceptions of students (n = 70) and tutors (n = 4) who used collaborative diagramming in tutorial groups were collected with a questionnaire and focus group discussions. A framework derived from the analysis of discourse in computer-supported collaborative leaning was used to construct the questionnaire. Video observations were used during the focus group discussions. Both students and tutors felt that collaborative diagramming positively affected discussion and knowledge construction. Students particularly appreciated that diagrams helped them to structure knowledge, to develop an overview of topics, and stimulated them to find relationships between topics. Tutors emphasized that diagramming increased interaction and enhanced the focus and detail of the discussion. Favourable conditions were the following: working with a shared whiteboard, using a diagram format that facilitated distribution, and applying half filled-in diagrams for non-content expert tutors and\\or for heterogeneous groups with low achieving students. The empirical findings in this study support the findings of earlier more descriptive studies that diagramming in a collaborative setting is valuable for learning complex knowledge in medicine.

Thermochemical aspects of fuel-cladding and fuel-coolant interactions in LMFBR oxide fuel pins

International Nuclear Information System (INIS)

Adamson, M.G.; Aitken, E.A.; Caputi, R.W.; Potter, P.E.; Mignanelli, M.A.

1979-01-01

This paper examines several thermochemical aspects of the fuel-cladding, fuel-coolant and fuel-fission product interactions that occur in LMFBR austenitic stainless steel-clad mixed (U,Pu)-oxide fuel pins during irradiation under normal operating conditions. Results are reported from a variety of high temperature EMF cell experiments in which continuous oxygen activity measurements on reacting and equilibrium mixtures of metal oxides and (excess) liquid alkali metal (Na, K, Cs) were performed. Oxygen potential and 0:M thresholds for Na-fuel reactions are re-evaluated in the light of new measurements and newly-assessed thermochemical data, and the influence on oxygen potential of possible U-Pu segregation between oxide and urano-plutonate (equilibrium) phases has been analyzed. (orig./RW) [de

Asymptotic laws for random knot diagrams

Science.gov (United States)

Chapman, Harrison

2017-06-01

We study random knotting by considering knot and link diagrams as decorated, (rooted) topological maps on spheres and pulling them uniformly from among sets of a given number of vertices n, as first established in recent work with Cantarella and Mastin. The knot diagram model is an exciting new model which captures both the random geometry of space curve models of knotting as well as the ease of computing invariants from diagrams. We prove that unknot diagrams are asymptotically exponentially rare, an analogue of Sumners and Whittington’s landmark result for self-avoiding polygons. Our proof uses the same key idea: we first show that knot diagrams obey a pattern theorem, which describes their fractal structure. We examine how quickly this behavior occurs in practice. As a consequence, almost all diagrams are asymmetric, simplifying sampling from this model. We conclude with experimental data on knotting in this model. This model of random knotting is similar to those studied by Diao et al, and Dunfield et al.

Neutralization and Acid Dissociation of Hydrogen Carbonate Ion: A Thermochemical Approach

Science.gov (United States)

Koga, Nobuyoshi; Shigedomi, Kana; Kimura, Tomoyasu; Tatsuoka, Tomoyuki; Mishima, Saki

2013-01-01

A laboratory inquiry into the thermochemical relationships in the reaction between aqueous solutions of NaHCO[subscript 3] and NaOH is described. The enthalpy change for this reaction, delta[subscript r]H, and that for neutralization of strong acid and NaOH(aq), delta[subscript n]H, are determined calorimetrically; the explanation for the…

Drawing Euler Diagrams with Circles

OpenAIRE

Stapleton, Gem; Zhang, Leishi; Howse, John; Rodgers, Peter

2010-01-01

Euler diagrams are a popular and intuitive visualization tool which are used in a wide variety of application areas, including biological and medical data analysis. As with other data visualization methods, such as graphs, bar charts, or pie charts, the automated generation of an Euler diagram from a suitable data set would be advantageous, removing the burden of manual data analysis and the subsequent task of drawing an appropriate diagram. Various methods have emerged that automatically dra...

Thermo-chemical simulation of a composite offshore vertical axis wind turbine blade

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2012-01-01

In the present study three dimensional steady state thermo-chemical simulation of a pultrusion process is investigated by using the finite element/nodal control volume (FE/NCV) technique. Pultrusion simulation of a composite having a C-shaped cross section is performed as a validation case. The o...

Thermo-chemical simultion of a composite offshore vertical axis wind turbine blade

NARCIS (Netherlands)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2012-01-01

In the present study three dimensional steady state thermo-chemical simulation of a pultrusion process is investigated by using the finite element/nodal control volume (FE/NCV) technique. Pultrusion simulation of a composite having a C-shaped cross section is performed as a validation case. The

Design and reliability assessment of control systems for a nuclear-based hydrogen production plant with copper-chlorine thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Al-Dabbagh, Ahmad W. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4 (Canada); Lu, Lixuan [Faculty of Energy Systems and Nuclear Science, Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4 (Canada)

2010-02-15

The thermochemical Copper-Chlorine (Cu-Cl) cycle is an emerging new method of nuclear-based hydrogen production. In the process, water is decomposed into hydrogen and oxygen through several physical and chemical processes. In this paper, a Distributed Control System (DCS) is designed for the thermochemical Cu-Cl cycle. The architecture and the communication networks of the DCS are discussed. Reliability of the DCS is assessed using fault trees. In the assessment, the impact of the malfunction of the actuators, sensors, controllers and communication networks on the overall system reliability is investigated. This provides key information for the selection of control system components, and determination of their inspection frequency and maintenance strategy. The hydrogen reactor unit, which is one of the major components in the thermochemical Cu-Cl cycle, is used to demonstrate the detailed design and analysis. (author)

Synfuels from fusion: producing hydrogen with the Tandem Mirror Reactor and thermochemical cycles

International Nuclear Information System (INIS)

Werner, R.W.; Ribe, F.L.

1981-01-01

This volume contains the following sections: (1) the Tandem Mirror fusion driver, (2) the Cauldron blanket module, (3) the flowing microsphere, (4) coupling the reactor to the process, (5) the thermochemical cycles, and (6) chemical reactors and process units

Synfuels from fusion: producing hydrogen with the Tandem Mirror Reactor and thermochemical cycles

Energy Technology Data Exchange (ETDEWEB)

Werner, R.W.; Ribe, F.L.

1981-01-21

This volume contains the following sections: (1) the Tandem Mirror fusion driver, (2) the Cauldron blanket module, (3) the flowing microsphere, (4) coupling the reactor to the process, (5) the thermochemical cycles, and (6) chemical reactors and process units. (MOW)

Thermochemical Storage of Middle Temperature Wasted Heat by Functionalized C/Mg(OH2 Hybrid Materials

Directory of Open Access Journals (Sweden)

Emanuela Mastronardo

2017-01-01

Full Text Available For the thermochemical performance implementation of Mg(OH2 as a heat storage medium, several hybrid materials have been investigated. For this study, high-performance hybrid materials have been developed by exploiting the authors’ previous findings. Expanded graphite (EG/carbon nanotubes (CNTs-Mg(OH2 hybrid materials have been prepared through Mg(OH2 deposition-precipitation over functionalized, i.e., oxidized, or un-functionalized EG or CNTs. The heat storage performances of the carbon-based hybrid materials have been investigated through a laboratory-scale experimental simulation of the heat storage/release cycles, carried out by a thermogravimetric apparatus. This study offers a critical evaluation of the thermochemical performances of developed materials through their comparison in terms of heat storage and output capacities per mass and volume unit. It was demonstrated that both EG and CNTs improves the thermochemical performances of the storage medium in terms of reaction rate and conversion with respect to pure Mg(OH2. With functionalized EG/CNTs-Mg(OH2, (i the potential heat storage and output capacities per mass unit of Mg(OH2 have been completely exploited; and (ii higher heat storage and output capacities per volume unit were obtained. That means, for technological applications, as smaller volume at equal stored/released heat.

Recommended Ideal-Gas Thermochemical Functions for Heavy Water and its Substituent Isotopologues

Czech Academy of Sciences Publication Activity Database

Simkó, I.; Furtenbacher, T.; Hrubý, Jan; Zobov, N. F.; Polyansky, O. L.; Tennyson, J.; Gamache, R. R.; Szidarovszky, T.; Dénes, N.; Császár, A. G.

2017-01-01

Roč. 46, č. 2 (2017), č. článku 023104. ISSN 0047-2689 R&D Projects: GA ČR GA16-02647S Institutional support: RVO:61388998 Keywords : heavy water * ideal-gas thermochemical functions * partition function Subject RIV: BJ - Thermodynamics OBOR OECD: Thermodynamics Impact factor: 4.204, year: 2016

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

2015-01-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

IS process for thermochemical hydrogen production

International Nuclear Information System (INIS)

Onuki, Kaoru; Nakajima, Hayato; Ioka, Ikuo; Futakawa, Masatoshi; Shimizu, Saburo

1994-11-01

The state-of-the-art of thermochemical hydrogen production by IS process is reviewed including experimental data obtained at JAERI on the chemistry of the Bunsen reaction step and on the corrosion resistance of the structural materials. The present status of laboratory scale demonstration at JAERI is also included. The study on the chemistry of the chemical reactions and the products separations has identified feasible methods to function the process. The flowsheeting studies revealed a process thermal efficiency higher than 40% is achievable under efficient process conditions. The corrosion resistance of commercially available structural materials have been clarified under various process conditions. The basic scheme of the process has been realized in a laboratory scale apparatus. R and D requirements to proceed to the engineering demonstration coupled with HTTR are briefly discussed. (author)

Method for thermochemical decomposition of water

Science.gov (United States)

Abraham, Bernard M.; Schreiner, Felix

1977-01-11

Water is thermochemically decomposed to produce hydrogen by the following sequence of reactions: KI, NH.sub.3, CO.sub. 2 and water in an organic solvent such as ethyl or propyl alcohol are reacted to produce KHCO 3 and NH.sub.4 I. The KHCO.sub.3 is thermally decomposed to K.sub.2 CO.sub.3, H.sub.2 O and CO.sub.2, while the NH.sub.4 I is reacted with Hg to produce HgI.sub.2, NH.sub.3 and H.sub.2. The K.sub.2 CO.sub.3 obtained by calcining KHCO.sub.3 is then reacted with HgI.sub.2 to produce Hg, KI, CO and O.sub.2. All products of the reaction are recycled except hydrogen and oxygen.

Non-equilibrium thermochemical heat storage in porous media: Part 1 – Conceptual model

International Nuclear Information System (INIS)

Nagel, T.; Shao, H.; Singh, A.K.; Watanabe, N.; Roßkopf, C.; Linder, M.; Wörner, A.; Kolditz, O.

2013-01-01

Thermochemical energy storage can play an important role in the establishment of a reliable renewable energy supply and can increase the efficiency of industrial processes. The application of directly permeated reactive beds leads to strongly coupled mass and heat transport processes that also determine reaction kinetics. To advance this technology beyond the laboratory stage requires a thorough theoretical understanding of the multiphysics phenomena and their quantification on a scale relevant to engineering analyses. Here, the theoretical derivation of a macroscopic model for multicomponent compressible gas flow through a porous solid is presented along with its finite element implementation where solid–gas reactions occur and both phases have individual temperature fields. The model is embedded in the Theory of Porous Media and the derivation is based on the evaluation of the Clausius–Duhem inequality. Special emphasis is placed on the interphase coupling via mass, momentum and energy interaction terms and their effects are partially illustrated using numerical examples. Novel features of the implementation of the described model are verified via comparisons to analytical solutions. The specification, validation and application of the full model to a calcium hydroxide/calcium oxide based thermochemical storage system are the subject of part 2 of this study. - Highlights: • Rigorous application of the Theory of Porous Media and the 2nd law of thermodynamics. • Thermodynamically consistent model for thermochemical heat storage systems. • Multicomponent gas; modified Fick's and Darcy's law; thermal non-equilibrium; solid–gas reactions. • Clear distinction between source and production terms. • Open source finite element implementation and benchmarks

To Error Problem Concerning Measuring Concentration of Carbon Oxide by Thermo-Chemical Sen

Directory of Open Access Journals (Sweden)

V. I. Nazarov

2007-01-01

Full Text Available The paper gives additional errors in respect of measuring concentration of carbon oxide by thermo-chemical sensors. A number of analytical expressions for calculation of error data and corrections for environmental factor deviations from admissible ones have been obtained in the paper

Thermochemical and thermophysical properties of alkaline-earth perovskites

International Nuclear Information System (INIS)

Yamanaka, Shinsuke; Kurosaki, Ken; Maekawa, Takuji; Matsuda, Tetsushi; Kobayashi, Shin-ichi; Uno, Masayoshi

2005-01-01

In order to contribute to safety evaluation of high burnup oxide fuels, we studied the thermochemical and thermophysical properties of alkaline-earth perovskites known as oxide inclusions. Polycrystalline samples of alkaline-earth perovskites, BaUO 3 , BaZrO 3 , BaCeO 3 , BaMoO 3 , SrTiO 3 , SrZrO 3 , SrCeO 3 , SrMoO 3 , SrHfO 3 and SrRuO 3 , were prepared and the thermal expansion coefficient, melting temperature, elastic moduli, Debye temperature, microhardness, heat capacity, and thermal conductivity were measured. The relationship between some physical properties was studied

On-shell diagrams for N=8 supergravity amplitudes

Energy Technology Data Exchange (ETDEWEB)

Heslop, Paul; Lipstein, Arthur E. [Department of Mathematical Sciences, Durham University,Lower Mountjoy, Stockton Road, Durham, DH1 3LE (United Kingdom)

2016-06-10

We define recursion relations for N=8 supergravity amplitudes using a generalization of the on-shell diagrams developed for planar N=4 super-Yang-Mills. Although the recursion relations generically give rise to non-planar on-shell diagrams, we show that at tree-level the recursion can be chosen to yield only planar diagrams, the same diagrams occurring in the planar N=4 theory. This implies non-trivial identities for non-planar diagrams as well as interesting relations between the N=4 and N=8 theories. We show that the on-shell diagrams of N=8 supergravity obey equivalence relations analogous to those of N=4 super-Yang-Mills, and we develop a systematic algorithm for reading off Grassmannian integral formulae directly from the on-shell diagrams. We also show that the 1-loop 4-point amplitude of N=8 supergravity can be obtained from on-shell diagrams.

Laser thermal effect on silicon nitride ceramic based on thermo-chemical reaction with temperature-dependent thermo-physical parameters

International Nuclear Information System (INIS)

Pan, A.F.; Wang, W.J.; Mei, X.S.; Wang, K.D.; Zhao, W.Q.; Li, T.Q.

2016-01-01

Highlights: • A two-dimensional thermo-chemical reaction model is creatively built. • Thermal conductivity and heat capacity of β-Si_3N_4 are computed accurately. • The appropriate thermo-chemical reaction rate is fitted and reaction element length is set to assure the constringency. • The deepest ablated position was not the center of the ablated area due to plasma absorption. • The simulation results demonstrate the thermo-chemical process cant be simplified to be physical phase transition. - Abstract: In this study, a two-dimensional thermo-chemical reaction model with temperature-dependent thermo-physical parameters on Si_3N_4 with 10 ns laser was developed to investigate the ablated size, volume and surface morphology after single pulse. For model parameters, thermal conductivity and heat capacity of β-Si_3N_4 were obtained from first-principles calculations. Thermal-chemical reaction rate was fitted by collision theory, and then, reaction element length was deduced using the relationship between reaction rate and temperature distribution. Furthermore, plasma absorption related to energy loss was approximated as a function of electron concentration in Si_3N_4. It turned out that theoretical ablated volume and radius increased and then remained constant with increasing laser energy, and the maximum ablated depth was not in the center of the ablated zone. Moreover, the surface maximum temperature of Si_3N_4 was verified to be above 3000 K within pulse duration, and it was much higher than its thermal decomposition temperature of 1800 K, which indicated that Si_3N_4 was not ablated directly above the thermal decomposition temperature. Meanwhile, the single pulse ablation of Si_3N_4 was performed at different powers using a TEM_0_0 10 ns pulse Nd:YAG laser to validate the model. The model showed a satisfactory consistence between the experimental data and numerical predictions, presenting a new modeling technology that may significantly increase the

Benchmarking the DFT+U method for thermochemical calculations of uranium molecular compounds and solids.

Science.gov (United States)

Beridze, George; Kowalski, Piotr M

2014-12-18

Ability to perform a feasible and reliable computation of thermochemical properties of chemically complex actinide-bearing materials would be of great importance for nuclear engineering. Unfortunately, density functional theory (DFT), which on many instances is the only affordable ab initio method, often fails for actinides. Among various shortcomings, it leads to the wrong estimate of enthalpies of reactions between actinide-bearing compounds, putting the applicability of the DFT approach to the modeling of thermochemical properties of actinide-bearing materials into question. Here we test the performance of DFT+U method--a computationally affordable extension of DFT that explicitly accounts for the correlations between f-electrons - for prediction of the thermochemical properties of simple uranium-bearing molecular compounds and solids. We demonstrate that the DFT+U approach significantly improves the description of reaction enthalpies for the uranium-bearing gas-phase molecular compounds and solids and the deviations from the experimental values are comparable to those obtained with much more computationally demanding methods. Good results are obtained with the Hubbard U parameter values derived using the linear response method of Cococcioni and de Gironcoli. We found that the value of Coulomb on-site repulsion, represented by the Hubbard U parameter, strongly depends on the oxidation state of uranium atom. Last, but not least, we demonstrate that the thermochemistry data can be successfully used to estimate the value of the Hubbard U parameter needed for DFT+U calculations.

A gas dynamic and thermochemical model of steam/sodium microleak phenomena

International Nuclear Information System (INIS)

Perkins, R.; Airey, R.; Daniels, L.C.

1985-06-01

Conflicting findings have been reported by 3 UK laboratories for the blockage or rapid escalation of steam/sodium microleaks. In an earlier paper it was shown that this discrepancy could be resolved through the influence on the steam flow of the geometry of the leak paths; the geometry being dependent upon the method of manufacture. The application of gas dynamics and thermochemical methods could account for the rapid escalation of some leaks in terms of the presence of shock waves in the gas flow within the leak path. In this paper the gas dynamic and thermochemical theories are re-stated and a series of leak experiments conducted to test the validity of the theory is described. The theory predicts that for some leaks of variable area of cross-section the blockage/escalation behaviour is determined by small changes in the sodium-side pressure; this effect was found and is discussed as a validation of the theory. Other aspects of leak phenomena are discussed and conclusions are drawn with emphasis on implications for further programmes of leak study and for leaks in LMFBR steam generators in service. (author)

The mean squared writhe of alternating random knot diagrams

Energy Technology Data Exchange (ETDEWEB)

Diao, Y; Hinson, K [Department of Mathematics and Statistics University of North Carolina at Charlotte, NC 28223 (United States); Ernst, C; Ziegler, U, E-mail: ydiao@uncc.ed [Department of Mathematics and Computer Science, Western Kentucky University, Bowling Green, KY 42101 (United States)

2010-12-10

The writhe of a knot diagram is a simple geometric measure of the complexity of the knot diagram. It plays an important role not only in knot theory itself, but also in various applications of knot theory to fields such as molecular biology and polymer physics. The mean squared writhe of any sample of knot diagrams with n crossings is n when for each diagram at each crossing one of the two strands is chosen as the overpass at random with probability one-half. However, such a diagram is usually not minimal. If we restrict ourselves to a minimal knot diagram, then the choice of which strand is the over- or under-strand at each crossing is no longer independent of the neighboring crossings and a larger mean squared writhe is expected for minimal diagrams. This paper explores the effect on the correlation between the mean squared writhe and the diagrams imposed by the condition that diagrams are minimal by studying the writhe of classes of reduced, alternating knot diagrams. We demonstrate that the behavior of the mean squared writhe heavily depends on the underlying space of diagram templates. In particular this is true when the sample space contains only diagrams of a special structure. When the sample space is large enough to contain not only diagrams of a special type, then the mean squared writhe for n crossing diagrams tends to grow linearly with n, but at a faster rate than n, indicating an intrinsic property of alternating knot diagrams. Studying the mean squared writhe of alternating random knot diagrams also provides some insight into the properties of the diagram generating methods used, which is an important area of study in the applications of random knot theory.

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

Science.gov (United States)

Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

2015-04-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid. Copyright © 2015. Published by Elsevier Ltd.

Using Affinity Diagrams to Evaluate Interactive Prototypes

DEFF Research Database (Denmark)

Lucero, Andrés

2015-01-01

our particular use of affinity diagramming in prototype evaluations. We reflect on a decade’s experience using affinity diagramming across a number of projects, both in industry and academia. Our affinity diagramming process in interaction design has been tailored and consists of four stages: creating...

Development and thermochemical characterizations of vermiculite/SrBr_2 composite sorbents for low-temperature heat storage

International Nuclear Information System (INIS)

Zhang, Y.N.; Wang, R.Z.; Zhao, Y.J.; Li, T.X.; Riffat, S.B.; Wajid, N.M.

2016-01-01

Novel EVM/SrBr_2 composite sorbents with different salt contents were developed for low-temperature thermal energy storage (TES). Simulative sorption experiment was conducted to obtain the sorption kinetics diagram and identify threshold salt content that composite sorbents can hold without solution leakage. Distribution of salt embedded in EVM was observed by extreme-resolution scanning electron microscopy (ER-SEM). Thermochemical characterizations including desorption performance and desorption heat were fully investigated by analyzing simultaneous thermal analyzer (STA) results. Results reveal that sorption process of composite sorbents is divided into three parts: water adsorption of EVM, water adsorption of SrBr_2 crystal and liquid-gas absorption of SrBr_2 solution. Since SrBr_2 solution can be hold in macrospores of EVM, water uptake and energy storage density are greatly increased. It appears that the composite sorbent of EVMSrBr_240 is a promising material for thermal energy storage, with water uptake of 0.53 g/g, mass energy storage density of 0.46 kWh/kg and volume energy storage density of 105.36 kWh/m"3. - Highlights: • Vermiculite/SrBr_2 composite sorbents were developed for thermal energy storage. • Water uptake of composite sorbents is divided into three phases. • Energy storage density of each sorption phase is evaluated via calculations. • EVMSrBr_240 is chosen as optimal sorbent without solution leakage.

The amplituhedron from momentum twistor diagrams

International Nuclear Information System (INIS)

Bai, Yuntao; He, Song

2015-01-01

We propose a new diagrammatic formulation of the all-loop scattering amplitudes/Wilson loops in planar N=4 SYM, dubbed the “momentum-twistor diagrams”. These are on-shell-diagrams obtained by gluing trivalent black and white vertices in momentum twistor space, which, in the reduced diagram case, are known to be related to diagrams in the original twistor space. The new diagrams are manifestly Yangian invariant, and they naturally represent factorization and forward-limit contributions in the all-loop BCFW recursion relations in momentum twistor space, in a fashion that is completely different from those in momentum space. We show how to construct and evaluate momentum-twistor diagrams, and how to use them to obtain tree-level amplitudes and loop-level integrands; in particular the latter involve isolated bubble-structures for loop variables arising from forward limits, or the entangled removal of particles. From each diagram, the generalized “boundary measurement” directly gives the C, D matrices, thus a cell in the amplituhedron associated with the amplitude, and we expect that our diagrammatic representations of the amplitude provide triangulations of the amplituhedron. To demonstrate the computational power of the formalism, we give explicit results for general two-loop integrands, and the cells of the amplituhedron for two-loop MHV amplitudes.

In vivo comparison of simultaneous versus sequential injection technique for thermochemical ablation in a porcine model.

Science.gov (United States)

Cressman, Erik N K; Shenoi, Mithun M; Edelman, Theresa L; Geeslin, Matthew G; Hennings, Leah J; Zhang, Yan; Iaizzo, Paul A; Bischof, John C

2012-01-01

To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.

Diagram Techniques in Group Theory

Science.gov (United States)

Stedman, Geoffrey E.

2009-09-01

Preface; 1. Elementary examples; 2. Angular momentum coupling diagram techniques; 3. Extension to compact simple phase groups; 4. Symmetric and unitary groups; 5. Lie groups and Lie algebras; 6. Polarisation dependence of multiphoton processes; 7. Quantum field theoretic diagram techniques for atomic systems; 8. Applications; Appendix; References; Indexes.

Effects of ultrasonic and thermo-chemical pre-treatments on methane production from fat, oil and grease (FOG) and synthetic kitchen waste (KW) in anaerobic co-digestion.

Science.gov (United States)

Li, Chenxi; Champagne, Pascale; Anderson, Bruce C

2013-02-01

The effects of ultrasonic and thermo-chemical pre-treatments on the methane production potential of anaerobic co-digestion with synthetic kitchen waste (KW) or fat, oil and grease (FOG) were investigated. Non-linear regressions were fitted to accurately assess and compare the methane production from co-digestion under the various pre-treatment conditions and to achieve representative simulations and predictions. Ultrasonic pre-treatment was not found to improve methane production effectively from either FOG co-digestion or KW co-digestions. Thermo-chemical pre-treatment could increase methane production yields from both FOG and KW co-digestions. COD solubilization was found to effectively represent the effects of pre-treatment. A comprehensive evaluation indicated that the thermo-chemical pre-treatments of pH=10, 55°C and pH=8, 55°C provided the best conditions to increase methane production from FOG and KW co-digestions, respectively. The most effective enhancement of biogas production (288±0.85mLCH(4)/g TVS) was achieved from thermo-chemically pre-treated FOG co-digestion, which was 9.9±1.5% higher than FOG co-digestion without thermo-chemical pre-treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Thermochemical hydrogen production studies at LLNL: a status report

International Nuclear Information System (INIS)

Krikorian, O.H.

1982-01-01

Currently, studies are underway at the Lawrence Livermore National Laboratory (LLNL) on thermochemical hydrogen production based on magnetic fusion energy (MFE) and solar central receivers as heat sources. These areas of study were described earlier at the previous IEA Annex I Hydrogen Workshop (Juelich, West Germany, September 23-25, 1981), and a brief update will be given here. Some basic research has also been underway at LLNL on the electrolysis of water from fused phosphate salts, but there are no current results in that area, and the work is being terminated

Logic verification system for power plant sequence diagrams

International Nuclear Information System (INIS)

Fukuda, Mitsuko; Yamada, Naoyuki; Teshima, Toshiaki; Kan, Ken-ichi; Utsunomiya, Mitsugu.

1994-01-01

A logic verification system for sequence diagrams of power plants has been developed. The system's main function is to verify correctness of the logic realized by sequence diagrams for power plant control systems. The verification is based on a symbolic comparison of the logic of the sequence diagrams with the logic of the corresponding IBDs (interlock Block Diagrams) in combination with reference to design knowledge. The developed system points out the sub-circuit which is responsible for any existing mismatches between the IBD logic and the logic realized by the sequence diagrams. Applications to the verification of actual sequence diagrams of power plants confirmed that the developed system is practical and effective. (author)

Comprehending 3D Diagrams: Sketching to Support Spatial Reasoning.

Science.gov (United States)

Gagnier, Kristin M; Atit, Kinnari; Ormand, Carol J; Shipley, Thomas F

2017-10-01

Science, technology, engineering, and mathematics (STEM) disciplines commonly illustrate 3D relationships in diagrams, yet these are often challenging for students. Failing to understand diagrams can hinder success in STEM because scientific practice requires understanding and creating diagrammatic representations. We explore a new approach to improving student understanding of diagrams that convey 3D relations that is based on students generating their own predictive diagrams. Participants' comprehension of 3D spatial diagrams was measured in a pre- and post-design where students selected the correct 2D slice through 3D geologic block diagrams. Generating sketches that predicated the internal structure of a model led to greater improvement in diagram understanding than visualizing the interior of the model without sketching, or sketching the model without attempting to predict unseen spatial relations. In addition, we found a positive correlation between sketched diagram accuracy and improvement on the diagram comprehension measure. Results suggest that generating a predictive diagram facilitates students' abilities to make inferences about spatial relationships in diagrams. Implications for use of sketching in supporting STEM learning are discussed. Copyright © 2016 Cognitive Science Society, Inc.

Lab-scale experiment of a closed thermochemical heat storage system including honeycomb heat exchanger

International Nuclear Information System (INIS)

Fopah-Lele, Armand; Rohde, Christian; Neumann, Karsten; Tietjen, Theo; Rönnebeck, Thomas; N'Tsoukpoe, Kokouvi Edem; Osterland, Thomas; Opel, Oliver

2016-01-01

A lab-scale thermochemical heat storage reactor was developed in the European project “thermal battery” to obtain information on the characteristics of a closed heat storage system, based on thermochemical reactions. The present type of storage is capable of re-using waste heat from cogeneration system to produce useful heat for space heating. The storage material used was SrBr 2 ·6H 2 O. Due to agglomeration or gel-like problems, a structural element was introduced to enhance vapour and heat transfer. Honeycomb heat exchanger was designed and tested. 13 dehydration-hydration cycles were studied under low-temperature conditions (material temperatures < 100 °C) for storage. Discharging was realized at water vapour pressure of about 42 mbar. Temperature evolution inside the reactor at different times and positions, chemical conversion, thermal power and overall efficiency were analysed for the selected cycles. Experimental system thermal capacity and efficiency of 65 kWh and 0.77 are respectively obtained with about 1 kg of SrBr 2 ·6H 2 O. Heat transfer fluid recovers heat at a short span of about 43 °C with an average of 22 °C during about 4 h, acceptable temperature for the human comfort (20 °C on day and 16 °C at night). System performances were obtained for a salt bed energy density of 213 kWh·m 3 . The overall heat transfer coefficient of the honeycomb heat exchanger has an average value of 147 W m −2  K −1 . Though promising results have been obtained, ameliorations need to be made, in order to make the closed thermochemical heat storage system competitive for space heating. - Highlights: • Lab-scale thermochemical heat storage is designed, constructed and tested. • The use of honeycomb heat exchanger as a heat and vapour process enhancement. • Closed system (1 kg SrBr 2 ·6H 2 O) able to give back 3/4 of initial thermal waste energy. • System storage capacity and thermal efficiency are respectively 65 kWh and 0.77. �

Satake diagrams of affine Kac-Moody algebras

Energy Technology Data Exchange (ETDEWEB)

Tripathy, L K [S B R Government Womens' College, Berhampur, Orissa 760 001 (India); Pati, K C [Department of Physics, Khallikote College, Berhampur, Orissa 760 001 (India)

2006-02-10

Satake diagrams of affine Kac-Moody algebras (untwisted and twisted) are obtained from their Dynkin diagrams. These diagrams give a classification of restricted root systems associated with these algebras. In the case of simple Lie algebras, these root systems and Satake diagrams correspond to symmetric spaces which have recently found many physical applications in quantum integrable systems, quantum transport problems, random matrix theories etc. We hope these types of root systems may have similar applications in theoretical physics in future and may correspond to symmetric spaces analogue of affine Kac-Moody algebras if they exist.

Systematic validation of non-equilibrium thermochemical models using Bayesian inference

KAUST Repository

Miki, Kenji

2015-10-01

© 2015 Elsevier Inc. The validation process proposed by Babuška et al. [1] is applied to thermochemical models describing post-shock flow conditions. In this validation approach, experimental data is involved only in the calibration of the models, and the decision process is based on quantities of interest (QoIs) predicted on scenarios that are not necessarily amenable experimentally. Moreover, uncertainties present in the experimental data, as well as those resulting from an incomplete physical model description, are propagated to the QoIs. We investigate four commonly used thermochemical models: a one-temperature model (which assumes thermal equilibrium among all inner modes), and two-temperature models developed by Macheret et al. [2], Marrone and Treanor [3], and Park [4]. Up to 16 uncertain parameters are estimated using Bayesian updating based on the latest absolute volumetric radiance data collected at the Electric Arc Shock Tube (EAST) installed inside the NASA Ames Research Center. Following the solution of the inverse problems, the forward problems are solved in order to predict the radiative heat flux, QoI, and examine the validity of these models. Our results show that all four models are invalid, but for different reasons: the one-temperature model simply fails to reproduce the data while the two-temperature models exhibit unacceptably large uncertainties in the QoI predictions.

Contingency diagrams as teaching tools

OpenAIRE

Mattaini, Mark A.

1995-01-01

Contingency diagrams are particularly effective teaching tools, because they provide a means for students to view the complexities of contingency networks present in natural and laboratory settings while displaying the elementary processes that constitute those networks. This paper sketches recent developments in this visualization technology and illustrates approaches for using contingency diagrams in teaching.

Delimiting diagrams

NARCIS (Netherlands)

Oostrom, V. van

2004-01-01

We introduce the unifying notion of delimiting diagram. Hitherto unrelated results such as: Minimality of the internal needed strategy for orthogonal first-order term rewriting systems, maximality of the limit strategy for orthogonal higher-order pattern rewrite systems (with maximality of the

Experimental investigation and thermochemical assessment of the system Cu-Y-O

International Nuclear Information System (INIS)

Zimmermann, E.; Mohammad, A.; Boudene, A.; Neuschuetz, D.

1995-01-01

Experimental investigations of the thermochemical properties of the phases in the system Cu-Y-O by means of DTA, EMF, TG and calorimetric measurements are reported. The results together with critically selected data from the literature are used for a complete assessment of the Gibbs energies of the ternary phases (based on the Standard Element Reference State, SER). For the binary subsystems critically assessed data from the literature are used. (orig.)

ROLE OF UML SEQUENCE DIAGRAM CONSTRUCTS IN OBJECT LIFECYCLE CONCEPT

Directory of Open Access Journals (Sweden)

Miroslav Grgec

2007-06-01

Full Text Available When modeling systems and using UML concepts, a real system can be viewed in several ways. The RUP (Rational Unified Process defines the "4 + 1 view": 1. Logical view (class diagram (CD, object diagram (OD, sequence diagram (SD, collaboration diagram (COD, state chart diagram (SCD, activity diagram (AD, 2.Process view (use case diagram, CD, OD, SD, COD, SCD, AD, 3. Development view (package diagram, component diagram, 4. Physical view (deployment diagram, and 5. Use case view (use case diagram, OD, SD, COD, SCD, AD which combines the four mentioned above. With sequence diagram constructs we are describing object behavior in scope of one use case and their interaction. Each object in system goes through a so called lifecycle (create, supplement object with data, use object, decommission object. The concept of the object lifecycle is used to understand and formalize the behavior of objects from creation to deletion. With help of sequence diagram concepts our paper will describe the way of interaction modeling between objects through lifeline of each of them, and their importance in software development.

A novel decision diagrams extension method

International Nuclear Information System (INIS)

Li, Shumin; Si, Shubin; Dui, Hongyan; Cai, Zhiqiang; Sun, Shudong

2014-01-01

Binary decision diagram (BDD) is a graph-based representation of Boolean functions. It is a directed acyclic graph (DAG) based on Shannon's decomposition. Multi-state multi-valued decision diagram (MMDD) is a natural extension of BDD for the symbolic representation and manipulation of the multi-valued logic functions. This paper proposes a decision diagram extension method based on original BDD/MMDD while the scale of a reliability system is extended. Following a discussion of decomposition and physical meaning of BDD and MMDD, the modeling method of BDD/MMDD based on original BDD/MMDD is introduced. Three case studies are implemented to demonstrate the presented methods. Compared with traditional BDD and MMDD generation methods, the decision diagrams extension method is more computationally efficient as shown through the running time

Scheil-Gulliver Constituent Diagrams

Science.gov (United States)

Pelton, Arthur D.; Eriksson, Gunnar; Bale, Christopher W.

2017-06-01

During solidification of alloys, conditions often approach those of Scheil-Gulliver cooling in which it is assumed that solid phases, once precipitated, remain unchanged. That is, they no longer react with the liquid or with each other. In the case of equilibrium solidification, equilibrium phase diagrams provide a valuable means of visualizing the effects of composition changes upon the final microstructure. In the present study, we propose for the first time the concept of Scheil-Gulliver constituent diagrams which play the same role as that in the case of Scheil-Gulliver cooling. It is shown how these diagrams can be calculated and plotted by the currently available thermodynamic database computing systems that combine Gibbs energy minimization software with large databases of optimized thermodynamic properties of solutions and compounds. Examples calculated using the FactSage system are presented for the Al-Li and Al-Mg-Zn systems, and for the Au-Bi-Sb-Pb system and its binary and ternary subsystems.

Operations space diagram for ECRH and ECCD

DEFF Research Database (Denmark)

Bindslev, H.

2004-01-01

at the design phase. At the operations phase it may also prove useful in setting up experimental scenarios by showing operational possibilities, avoiding the need for survey type ray-tracing at the initial planning stages. The diagram may also serve the purpose of communicating operational possibilities to non......A Clemmov-Mullaly-Allis (CMA) type diagram, the ECW-CMA diagram, for representing the operational possibilities of electron cyclotron heating and current drive (ECRH/ECCD) systems for fusion plasmas is presented. In this diagram, with normalized density and normalized magnetic field coordinates......, the parameter range in which it is possible to achieve a given task (e.g. O-mode current drive for stabilizing a neoclassical tearing mode) appears as a region. With also the Greenwald density limit shown, this diagram condenses the information on operational possibilities, facilitating the overview required...

Penguin-like diagrams from the standard model

International Nuclear Information System (INIS)

Ping, Chia Swee

2015-01-01

The Standard Model is highly successful in describing the interactions of leptons and quarks. There are, however, rare processes that involve higher order effects in electroweak interactions. One specific class of processes is the penguin-like diagram. Such class of diagrams involves the neutral change of quark flavours accompanied by the emission of a gluon (gluon penguin), a photon (photon penguin), a gluon and a photon (gluon-photon penguin), a Z-boson (Z penguin), or a Higgs-boson (Higgs penguin). Such diagrams do not arise at the tree level in the Standard Model. They are, however, induced by one-loop effects. In this paper, we present an exact calculation of the penguin diagram vertices in the ‘tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex functions for the penguin diagram vertices are obtained. The various penguin diagram vertex functions are related to one another via Ward-Takahashi identity. From these, a set of relations is obtained connecting the vertex form factors of various penguin diagrams. Explicit expressions for the gluon-photon penguin vertex form factors are obtained, and their contributions to the flavor changing processes estimated

Penguin-like diagrams from the standard model

Energy Technology Data Exchange (ETDEWEB)

Ping, Chia Swee [High Impact Research, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2015-04-24

The Standard Model is highly successful in describing the interactions of leptons and quarks. There are, however, rare processes that involve higher order effects in electroweak interactions. One specific class of processes is the penguin-like diagram. Such class of diagrams involves the neutral change of quark flavours accompanied by the emission of a gluon (gluon penguin), a photon (photon penguin), a gluon and a photon (gluon-photon penguin), a Z-boson (Z penguin), or a Higgs-boson (Higgs penguin). Such diagrams do not arise at the tree level in the Standard Model. They are, however, induced by one-loop effects. In this paper, we present an exact calculation of the penguin diagram vertices in the ‘tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex functions for the penguin diagram vertices are obtained. The various penguin diagram vertex functions are related to one another via Ward-Takahashi identity. From these, a set of relations is obtained connecting the vertex form factors of various penguin diagrams. Explicit expressions for the gluon-photon penguin vertex form factors are obtained, and their contributions to the flavor changing processes estimated.

Thermochemical hydrolysis of macroalgae Ulva for biorefinery: Taguchi robust design method

Science.gov (United States)

Jiang, Rui; Linzon, Yoav; Vitkin, Edward; Yakhini, Zohar; Chudnovsky, Alexandra; Golberg, Alexander

2016-06-01

Understanding the impact of all process parameters on the efficiency of biomass hydrolysis and on the final yield of products is critical to biorefinery design. Using Taguchi orthogonal arrays experimental design and Partial Least Square Regression, we investigated the impact of change and the comparative significance of thermochemical process temperature, treatment time, %Acid and %Solid load on carbohydrates release from green macroalgae from Ulva genus, a promising biorefinery feedstock. The average density of hydrolysate was determined using a new microelectromechanical optical resonator mass sensor. In addition, using Flux Balance Analysis techniques, we compared the potential fermentation yields of these hydrolysate products using metabolic models of Escherichia coli, Saccharomyces cerevisiae wild type, Saccharomyces cerevisiae RN1016 with xylose isomerase and Clostridium acetobutylicum. We found that %Acid plays the most significant role and treatment time the least significant role in affecting the monosaccharaides released from Ulva biomass. We also found that within the tested range of parameters, hydrolysis with 121 °C, 30 min 2% Acid, 15% Solids could lead to the highest yields of conversion: 54.134-57.500 gr ethanol kg-1 Ulva dry weight by S. cerevisiae RN1016 with xylose isomerase. Our results support optimized marine algae utilization process design and will enable smart energy harvesting by thermochemical hydrolysis.

Thermochemical hydrolysis of macroalgae Ulva for biorefinery: Taguchi robust design method.

Science.gov (United States)

Jiang, Rui; Linzon, Yoav; Vitkin, Edward; Yakhini, Zohar; Chudnovsky, Alexandra; Golberg, Alexander

2016-06-13

Understanding the impact of all process parameters on the efficiency of biomass hydrolysis and on the final yield of products is critical to biorefinery design. Using Taguchi orthogonal arrays experimental design and Partial Least Square Regression, we investigated the impact of change and the comparative significance of thermochemical process temperature, treatment time, %Acid and %Solid load on carbohydrates release from green macroalgae from Ulva genus, a promising biorefinery feedstock. The average density of hydrolysate was determined using a new microelectromechanical optical resonator mass sensor. In addition, using Flux Balance Analysis techniques, we compared the potential fermentation yields of these hydrolysate products using metabolic models of Escherichia coli, Saccharomyces cerevisiae wild type, Saccharomyces cerevisiae RN1016 with xylose isomerase and Clostridium acetobutylicum. We found that %Acid plays the most significant role and treatment time the least significant role in affecting the monosaccharaides released from Ulva biomass. We also found that within the tested range of parameters, hydrolysis with 121 °C, 30 min 2% Acid, 15% Solids could lead to the highest yields of conversion: 54.134-57.500 gr ethanol kg(-1) Ulva dry weight by S. cerevisiae RN1016 with xylose isomerase. Our results support optimized marine algae utilization process design and will enable smart energy harvesting by thermochemical hydrolysis.

Common phase diagram for low-dimensional superconductors

International Nuclear Information System (INIS)

Michalak, Rudi

2003-01-01

A phenomenological phase diagram which has been derived for high-temperature superconductors from NMR Knight-shift measurements of the pseudogap is compared to the phase diagram that is obtained for organic superconductors and spin-ladder superconductors, both low-dimensional systems. This is contrasted to the phase diagram of some Heavy Fermion superconductors, i.e. superconductors not constrained to a low dimensionality

Evaluation of the performance of MP4-based procedures for a wide range of thermochemical and kinetic properties

Energy Technology Data Exchange (ETDEWEB)

Yu, Li-Juan; Wan, Wenchao; Karton, Amir, E-mail: amir.karton@uwa.edu.au

2016-11-30

We evaluate the performance of standard and modified MPn procedures for a wide set of thermochemical and kinetic properties, including atomization energies, structural isomerization energies, conformational energies, and reaction barrier heights. The reference data are obtained at the CCSD(T)/CBS level by means of the Wn thermochemical protocols. We find that none of the MPn-based procedures show acceptable performance for the challenging W4-11 and BH76 databases. For the other thermochemical/kinetic databases, the MP2.5 and MP3.5 procedures provide the most attractive accuracy-to-computational cost ratios. The MP2.5 procedure results in a weighted-total-root-mean-square deviation (WTRMSD) of 3.4 kJ/mol, whilst the computationally more expensive MP3.5 procedure results in a WTRMSD of 1.9 kJ/mol (the same WTRMSD obtained for the CCSD(T) method in conjunction with a triple-zeta basis set). We also assess the performance of the computationally economical CCSD(T)/CBS(MP2) method, which provides the best overall performance for all the considered databases, including W4-11 and BH76.

Feynman diagrams without Feynman parameters

International Nuclear Information System (INIS)

Mendels, E.

1978-01-01

Dimensionally regularized Feynman diagrams are represented by means of products of k-functions. The infinite part of these diagrams is found very easily, also if they are overlapping, and the separation of the several kinds of divergences comes out quite naturally. Ward identities are proven in a transparent way. Series expansions in terms of the external momenta and their inner products are possible

Phase diagrams of the elements

International Nuclear Information System (INIS)

Young, D.A.

1975-01-01

A summary of the pressure-temperature phase diagrams of the elements is presented, with graphs of the experimentally determined solid-solid phase boundaries and melting curves. Comments, including theoretical discussion, are provided for each diagram. The crystal structure of each solid phase is identified and discussed. This work is aimed at encouraging further experimental and theoretical research on phase transitions in the elements

Thermochemical properties of some alkaline-earth silicates and zirconates. Fission product behaviour during molten core-concrete interactions

International Nuclear Information System (INIS)

Huntelaar, M.E.

1996-01-01

This thesis aims to make a contribution to a better understanding of the chemical processes occurring during an ex-vessel MCCI accident with a western-type of nuclear reactor. Chosen is for a detailed thermochemical study of the silicates and zirconates of barium and strontium. In Chapter one a short introduction in the history of (research in) nuclear safety is given, followed by the state-of-the-art of molten core-concrete interactions in Chapter two. In both Chapters the role of chemical thermodynamics on this particular subject is dealt with. The experimental work on the silicates and zirconates of barium and strontium performed for this thesis, is described in the Chapters three, four, five, six, and parts of eight. In Chapter three the basis for all thermochemical measurements, the sample preparation is given. Because the sample preparation effects the accuracy of the thermodynamic measurements, a great deal of effort is spent in optimizing the synthesis of the silicates which resulted in the TEOS-method widely employed here. In the next Chapters the different thermochemical techniques used, are described: The low-temperature heat capacity measurements and the enthalpy increment measurements in Chapter four, the enthalpy-of-solution measurements in Chapter five, and measurements to determine the crystal structures in Chapter six. (orig.)

Thermochemical properties of some alkaline-earth silicates and zirconates. Fission product behaviour during molten core-concrete interactions

Energy Technology Data Exchange (ETDEWEB)

Huntelaar, M.E.

1996-06-19

This thesis aims to make a contribution to a better understanding of the chemical processes occurring during an ex-vessel MCCI accident with a western-type of nuclear reactor. Chosen is for a detailed thermochemical study of the silicates and zirconates of barium and strontium. In Chapter one a short introduction in the history of (research in) nuclear safety is given, followed by the state-of-the-art of molten core-concrete interactions in Chapter two. In both Chapters the role of chemical thermodynamics on this particular subject is dealt with. The experimental work on the silicates and zirconates of barium and strontium performed for this thesis, is described in the Chapters three, four, five, six, and parts of eight. In Chapter three the basis for all thermochemical measurements, the sample preparation is given. Because the sample preparation effects the accuracy of the thermodynamic measurements, a great deal of effort is spent in optimizing the synthesis of the silicates which resulted in the TEOS-method widely employed here. In the next Chapters the different thermochemical techniques used, are described: The low-temperature heat capacity measurements and the enthalpy increment measurements in Chapter four, the enthalpy-of-solution measurements in Chapter five, and measurements to determine the crystal structures in Chapter six. (orig.).

Process development for elemental recovery from PGM tailings by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent.

Science.gov (United States)

Mohamed, Sameera; van der Merwe, Elizabet M; Altermann, Wladyslaw; Doucet, Frédéric J

2016-04-01

Mine tailings can represent untapped secondary resources of non-ferrous, ferrous, precious, rare and trace metals. Continuous research is conducted to identify opportunities for the utilisation of these materials. This preliminary study investigated the possibility of extracting major elements from South African tailings associated with the mining of Platinum Group Metals (PGM) at the Two Rivers mine operations. These PGM tailings typically contain four major elements (11% Al2O3; 12% MgO; 22% Fe2O3; 34% Cr2O3), with lesser amounts of SiO2 (18%) and CaO (2%). Extraction was achieved via thermochemical treatment followed by aqueous dissolution, as an alternative to conventional hydrometallurgical processes. The thermochemical treatment step used ammonium sulphate, a widely available, low-cost, recyclable chemical agent. Quantification of the efficiency of the thermochemical process required the development and optimisation of the dissolution technique. Dissolution in water promoted the formation of secondary iron precipitates, which could be prevented by leaching thermochemically-treated tailings in 0.6M HNO3 solution. The best extraction efficiencies were achieved for aluminium (ca. 60%) and calcium (ca. 80%). 35% iron and 32% silicon were also extracted, alongside chromium (27%) and magnesium (25%). Thermochemical treatment using ammonium sulphate may therefore represent a promising technology for extracting valuable elements from PGM tailings, which could be subsequently converted to value-added products. However, it is not element-selective, and major elements were found to compete with the reagent to form water-soluble sulphate-metal species. Further development of this integrated process, which aims at achieving the full potential of utilisation of PGM tailings, is currently underway. Copyright © 2016 Elsevier Ltd. All rights reserved.

Homotopy theory of modules over diagrams of rings

Directory of Open Access Journals (Sweden)

J. P. C. Greenlees

2014-09-01

Full Text Available Given a diagram of rings, one may consider the category of modules over them. We are interested in the homotopy theory of categories of this type: given a suitable diagram of model categories ℳ( (as runs through the diagram, we consider the category of diagrams where the object ( at comes from ℳ(. We develop model structures on such categories of diagrams and Quillen adjunctions that relate categories based on different diagram shapes. Under certain conditions, cellularizations (or right Bousfield localizations of these adjunctions induce Quillen equivalences. As an application we show that a cellularization of a category of modules over a diagram of ring spectra (or differential graded rings is Quillen equivalent to modules over the associated inverse limit of the rings. Another application of the general machinery here is given in work by the authors on algebraic models of rational equivariant spectra. Some of this material originally appeared in the preprint “An algebraic model for rational torus-equivariant stable homotopy theory”, arXiv:1101.2511, but has been generalized here.

The application of diagrams in architectural design

Directory of Open Access Journals (Sweden)

Dulić Olivera

2014-01-01

Full Text Available Diagrams in architecture represent the visualization of the thinking process, or selective abstraction of concepts or ideas translated into the form of drawings. In addition, they provide insight into the way of thinking about and in architecture, thus creating a balance between the visual and the conceptual. The subject of research presented in this paper are diagrams as a specific kind of architectural representation, and possibilities and importance of their application in the design process. Diagrams are almost old as architecture itself, and they are an element of some of the most important studies of architecture during all periods of history - which results in a large number of different definitions of diagrams, but also very different conceptualizations of their features, functions and applications. The diagrams become part of contemporary architectural discourse during the eighties and nineties of the twentieth century, especially through the work of architects like Bernard Tschumi, Peter Eisenman, Rem Koolhaas, SANAA and others. The use of diagrams in the design process allows unification of some of the essential aspects of the profession: architectural representation and design process, as well as the question of the concept of architectural and urban design at a time of rapid changes at all levels of contemporary society. The aim of the research is the analysis of the diagram as a specific medium for processing large amounts of information that the architect should consider and incorporate into the architectural work. On that basis, it is assumed that an architectural diagram allows the creator the identification and analysis of specific elements or ideas of physical form, thereby constantly maintaining concept of the integrity of the architectural work.

Reading fitness landscape diagrams through HSAB concepts

Energy Technology Data Exchange (ETDEWEB)

Vigneresse, Jean-Louis, E-mail: jean-louis.vigneresse@univ-lorraine.fr

2014-10-31

Highlights: • Qualitative information from HSAB descriptors. • 2D–3D diagrams using chemical descriptors (χ, η, ω, α) and principles (MHP, mEP, mPP). • Estimate of the energy exchange during reaction paths. • Examples from complex systems (geochemistry). - Abstract: Fitness landscapes are conceived as range of mountains, with local peaks and valleys. In terms of potential, such topographic variations indicate places of local instability or stability. The chemical potential, or electronegativity, its value changed of sign, carries similar information. In addition to chemical descriptors defined through hard-soft acid-base (HSAB) concepts and computed through density functional theory (DFT), the principles that rule chemical reactions allow the design of such landscape diagrams. The simplest diagram uses electrophilicity and hardness as coordinates. It allows examining the influence of maximum hardness or minimum electrophilicity principles. A third dimension is introduced within such a diagram by mapping the topography of electronegativity, polarizability or charge exchange. Introducing charge exchange during chemical reactions, or mapping a third parameter (f.i. polarizability) reinforces the information carried by a simple binary diagram. Examples of such diagrams are provided, using data from Earth Sciences, simple oxides or ligands.

Benzoic acid derivatives: Evaluation of thermochemical properties with complementary experimental and computational methods

International Nuclear Information System (INIS)

Verevkin, Sergey P.; Zaitsau, Dzmitry H.; Emeĺyanenko, Vladimir N.; Stepurko, Elena N.; Zherikova, Kseniya V.

2015-01-01

Highlights: • Vapor pressures of benzoic acid derivatives were measured. • Sublimation enthalpies were derived and compared with the literature. • Thermochemical data tested for consistency using additivity rules and computations. • Contradiction between available enthalpies of sublimation was resolved. • Pairwise interactions of substituents on the benzene ring were derived. - Abstract: Molar sublimation enthalpies of the methyl- and methoxybenzoic acids were derived from the transpiration method, static method, and TGA. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available enthalpy data and to recommend sets of sublimation and formation enthalpies for the benzoic acid derivatives. Gas-phase enthalpies of formation calculated with the G4 quantum-chemical method were in agreement with the experiment. Pairwise interactions of the methyl, methoxy, and carboxyl substituents on the benzene ring were derived and used for the development of simple group-additivity procedures for estimation of the vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of substituted benzenes.

Benzoic acid derivatives: Evaluation of thermochemical properties with complementary experimental and computational methods

Energy Technology Data Exchange (ETDEWEB)

Verevkin, Sergey P., E-mail: sergey.verevkin@uni-rostock.de [Department of Physical Chemistry and Department “Science and Technology of Life, Light and Matter”, University of Rostock, D-18059 Rostock (Germany); Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Zaitsau, Dzmitry H. [Department of Physical Chemistry, Kazan Federal University, 420008 Kazan (Russian Federation); Emeĺyanenko, Vladimir N. [Department of Physical Chemistry and Department “Science and Technology of Life, Light and Matter”, University of Rostock, D-18059 Rostock (Germany); Stepurko, Elena N. [Chemistry Faculty and Research Institute for Physical Chemical Problems, Belarusian State University, 220030 Minsk (Belarus); Zherikova, Kseniya V. [Nikolaev Institute of Inorganic Chemistry of Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk (Russian Federation)

2015-12-20

Highlights: • Vapor pressures of benzoic acid derivatives were measured. • Sublimation enthalpies were derived and compared with the literature. • Thermochemical data tested for consistency using additivity rules and computations. • Contradiction between available enthalpies of sublimation was resolved. • Pairwise interactions of substituents on the benzene ring were derived. - Abstract: Molar sublimation enthalpies of the methyl- and methoxybenzoic acids were derived from the transpiration method, static method, and TGA. Thermochemical data available in the literature were collected, evaluated, and combined with own experimental results. This collection together with the new experimental results reported here has helped to resolve contradictions in the available enthalpy data and to recommend sets of sublimation and formation enthalpies for the benzoic acid derivatives. Gas-phase enthalpies of formation calculated with the G4 quantum-chemical method were in agreement with the experiment. Pairwise interactions of the methyl, methoxy, and carboxyl substituents on the benzene ring were derived and used for the development of simple group-additivity procedures for estimation of the vaporization enthalpies, gas-phase, and liquid-phase enthalpies of formation of substituted benzenes.

Nuclear-produced hydrogen by a thermochemical Cu-Cl plant for passenger hydrogen trains

International Nuclear Information System (INIS)

Marin, G.; Naterer, G.; Gabriel, K.

2010-01-01

This paper compares the technical and economic aspects of electrification of a passenger-train operation in Ontario Canada, versus operation with hydrogen trains using nuclear-produced hydrogen. A local GO Transit diesel operation in Ontario has considered electrification as an alternative to reduce greenhouse gas emissions of passenger trains in the Toronto area. Hydrogen production from nuclear energy via a thermo-chemical Copper-Chlorine (Cu-Cl) cycle for train operation is shown to have lower emissions than direct electrification. It significantly reduces the greenhouse gas emissions compared to diesel operation. A bench-mark reference case used for the nuclear thermo-chemical Cu-Cl cycle is the Sulfur-Iodine (S-I) cycle, under investigation in the USA, Japan, and France, among others. The comparative study in this paper considers a base case of diesel operated passenger trains, within the context of a benefits case analysis for train electrification, for GO Transit operations in Toronto, and the impact of each cost component is discussed. The cost analysis includes projected prices of fuel cell trains, with reference to studies performed by train operators. (author)

Maximizing Efficiency in Two-step Solar-thermochemical Fuel Production

Energy Technology Data Exchange (ETDEWEB)

Ermanoski, I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-05-01

Widespread solar fuel production depends on its economic viability, largely driven by the solar-to-fuel conversion efficiency. In this paper, the material and energy requirements in two-step solar-thermochemical cycles are considered.The need for advanced redox active materials is demonstrated, by considering the oxide mass flow requirements at a large scale. Two approaches are also identified for maximizing the efficiency: optimizing reaction temperatures, and minimizing the pressure in the thermal reduction step by staged thermal reduction. The results show that each approach individually, and especially the two in conjunction, result in significant efficiency gains.

Selected topics on the nonrelativistic diagram technique

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Narodetskij, I.M.

1983-01-01

The construction of the diagrams describing various processes in the four-particle systems is considered. It is shown that these diagrams, in particular the diagrams corresponding to the simple mechanisms often used in nuclear and atomic reaction theory, are readily obtained from the Faddeev-Yakubovsky equations. The covariant four-dimensional formalism of nonrelativistic Feynman graphs and its connection to the three-dimensional graph technique are briefly discussed

Mitigation of climate change via a copper-chlorine hybrid thermochemical water splitting cycle for hydrogen production from nuclear energy

International Nuclear Information System (INIS)

Orhan, M.F.; Dincer, I.; Rosen, M.A.

2009-01-01

Concerns regarding climate change have motivated research on clean energy resources. While many energy resources have limitations, nuclear energy has the potential to supply a significant share of energy supply without contributing to climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another option for the utilization of nuclear thermal energy. This paper describes nuclear-based hydrogen production technologies and discusses the role of the Cu-Cl cycle for thermochemical water decomposition, potentially driven in part by waste heat from a nuclear generating station, in reducing greenhouse gas emissions. (author)

Drawing Euler Diagrams with Circles: The Theory of Piercings.

Science.gov (United States)

Stapleton, Gem; Leishi Zhang; Howse, John; Rodgers, Peter

2011-07-01

Euler diagrams are effective tools for visualizing set intersections. They have a large number of application areas ranging from statistical data analysis to software engineering. However, the automated generation of Euler diagrams has never been easy: given an abstract description of a required Euler diagram, it is computationally expensive to generate the diagram. Moreover, the generated diagrams represent sets by polygons, sometimes with quite irregular shapes that make the diagrams less comprehensible. In this paper, we address these two issues by developing the theory of piercings, where we define single piercing curves and double piercing curves. We prove that if a diagram can be built inductively by successively adding piercing curves under certain constraints, then it can be drawn with circles, which are more esthetically pleasing than arbitrary polygons. The theory of piercings is developed at the abstract level. In addition, we present a Java implementation that, given an inductively pierced abstract description, generates an Euler diagram consisting only of circles within polynomial time.

Multi-currency Influence Diagrams

DEFF Research Database (Denmark)

Nielsen, Søren Holbech; Nielsen, Thomas Dyhre; Jensen, Finn V.

2007-01-01

When using the influence diagrams framework for solving a decision problem with several different quantitative utilities, the traditional approach has been to convert the utilities into one common currency. This conversion is carried out using a tacit transformation, under the assumption...... that the converted problem is equivalent to the original one. In this paper we present an extension of the influence diagram framework. The extension allows for these decision problems to be modelled in their original form. We present an algorithm that, given a linear conversion function between the currencies...

Covariant diagrams for one-loop matching

International Nuclear Information System (INIS)

Zhang, Zhengkang

2016-10-01

We present a diagrammatic formulation of recently-revived covariant functional approaches to one-loop matching from an ultraviolet (UV) theory to a low-energy effective field theory. Various terms following from a covariant derivative expansion (CDE) are represented by diagrams which, unlike conventional Feynman diagrams, involve gaugecovariant quantities and are thus dubbed ''covariant diagrams.'' The use of covariant diagrams helps organize and simplify one-loop matching calculations, which we illustrate with examples. Of particular interest is the derivation of UV model-independent universal results, which reduce matching calculations of specific UV models to applications of master formulas. We show how such derivation can be done in a more concise manner than the previous literature, and discuss how additional structures that are not directly captured by existing universal results, including mixed heavy-light loops, open covariant derivatives, and mixed statistics, can be easily accounted for.

Covariant diagrams for one-loop matching

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhengkang [Michigan Center for Theoretical Physics (MCTP), University of Michigan,450 Church Street, Ann Arbor, MI 48109 (United States); Deutsches Elektronen-Synchrotron (DESY),Notkestraße 85, 22607 Hamburg (Germany)

2017-05-30

We present a diagrammatic formulation of recently-revived covariant functional approaches to one-loop matching from an ultraviolet (UV) theory to a low-energy effective field theory. Various terms following from a covariant derivative expansion (CDE) are represented by diagrams which, unlike conventional Feynman diagrams, involve gauge-covariant quantities and are thus dubbed “covariant diagrams.” The use of covariant diagrams helps organize and simplify one-loop matching calculations, which we illustrate with examples. Of particular interest is the derivation of UV model-independent universal results, which reduce matching calculations of specific UV models to applications of master formulas. We show how such derivation can be done in a more concise manner than the previous literature, and discuss how additional structures that are not directly captured by existing universal results, including mixed heavy-light loops, open covariant derivatives, and mixed statistics, can be easily accounted for.

Covariant diagrams for one-loop matching

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhengkang [Michigan Univ., Ann Arbor, MI (United States). Michigan Center for Theoretical Physics; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2016-10-15

We present a diagrammatic formulation of recently-revived covariant functional approaches to one-loop matching from an ultraviolet (UV) theory to a low-energy effective field theory. Various terms following from a covariant derivative expansion (CDE) are represented by diagrams which, unlike conventional Feynman diagrams, involve gaugecovariant quantities and are thus dubbed ''covariant diagrams.'' The use of covariant diagrams helps organize and simplify one-loop matching calculations, which we illustrate with examples. Of particular interest is the derivation of UV model-independent universal results, which reduce matching calculations of specific UV models to applications of master formulas. We show how such derivation can be done in a more concise manner than the previous literature, and discuss how additional structures that are not directly captured by existing universal results, including mixed heavy-light loops, open covariant derivatives, and mixed statistics, can be easily accounted for.

Covariant diagrams for one-loop matching

International Nuclear Information System (INIS)

Zhang, Zhengkang

2017-01-01

We present a diagrammatic formulation of recently-revived covariant functional approaches to one-loop matching from an ultraviolet (UV) theory to a low-energy effective field theory. Various terms following from a covariant derivative expansion (CDE) are represented by diagrams which, unlike conventional Feynman diagrams, involve gauge-covariant quantities and are thus dubbed “covariant diagrams.” The use of covariant diagrams helps organize and simplify one-loop matching calculations, which we illustrate with examples. Of particular interest is the derivation of UV model-independent universal results, which reduce matching calculations of specific UV models to applications of master formulas. We show how such derivation can be done in a more concise manner than the previous literature, and discuss how additional structures that are not directly captured by existing universal results, including mixed heavy-light loops, open covariant derivatives, and mixed statistics, can be easily accounted for.

Students’ learning activities while studying biological process diagrams

NARCIS (Netherlands)

Kragten, M.; Admiraal, W.; Rijlaarsdam, G.

2015-01-01

Process diagrams describe how a system functions (e.g. photosynthesis) and are an important type of representation in Biology education. In the present study, we examined students’ learning activities while studying process diagrams, related to their resulting comprehension of these diagrams. Each

Operations space diagram for ECRH and ECCD

International Nuclear Information System (INIS)

Bindslev, Henrik

2004-01-01

A Clemmov-Mullaly-Allis (CMA) type diagram, the ECW-CMA diagram, for representing the operational possibilities of electron cyclotron heating and current drive (ECRH/ECCD) systems for fusion plasmas is presented. In this diagram, with normalized density and normalized magnetic field coordinates, the parameter range in which it is possible to achieve a given task (e.g. O-mode current drive for stabilizing a neoclassical tearing mode) appears as a region. With also the Greenwald density limit shown, this diagram condenses the information on operational possibilities, facilitating the overview required at the design phase. At the operations phase it may also prove useful in setting up experimental scenarios by showing operational possibilities, avoiding the need for survey type ray-tracing at the initial planning stages. The diagram may also serve the purpose of communicating operational possibilities to non-experts. JET and ITER like plasmas are used, but the method is generic. (author)

Safety-barrier diagrams as a safety management tool

DEFF Research Database (Denmark)

Duijm, Nijs Jan

2009-01-01

Safety-barrier diagrams and “bow-tie” diagrams have become popular methods in risk analysis and safety management. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The latter's relation to other methods such as fault trees and Bayesian...

Near threshold expansion of Feynman diagrams

International Nuclear Information System (INIS)

Mendels, E.

2005-01-01

The near threshold expansion of Feynman diagrams is derived from their configuration space representation, by performing all x integrations. The general scalar Feynman diagram is considered, with an arbitrary number of external momenta, an arbitrary number of internal lines and an arbitrary number of loops, in n dimensions and all masses may be different. The expansions are considered both below and above threshold. Rules, giving real and imaginary part, are derived. Unitarity of a sunset diagram with I internal lines is checked in a direct way by showing that its imaginary part is equal to the phase space integral of I particles

Thermochemical modeling of nuclear waste glass

International Nuclear Information System (INIS)

Spear, K.E.; Besmann, T.M.; Beahm, E.C.

1998-06-01

The development of assessed and consistent phase equilibria and thermodynamic data for major glass constituents used to incorporate high-level nuclear waste is discussed in this paper. The initial research has included the binary Na 2 O-SiO 2 , Na 2 O-Al 2 O 3 , and SiO 2 -Al 2 O 3 systems. The nuclear waste glass is assumed to be a supercooled liquid containing the constituents in the glass at temperatures of interest for nuclear waste storage. Thermodynamic data for the liquid solutions were derived from mathematical comparisons of phase diagram information and the thermodynamic data available for crystalline solid phases. An associate model is used to describe the liquid solution phases. Utilizing phase diagram information provides very stringent limits on the relative thermodynamic stabilities of all phases which exist in a given system

Optimization of the thermodynamic properties and phase diagrams of P2O5-containing systems

Science.gov (United States)

Hudon, Pierre; Jung, In-Ho

2014-05-01

P2O5 is an important oxide component in the late stage products of numerous igneous rocks such as granites and pegmatites. Typically, P2O5 combines with CaO and crystallizes in the form of apatite, while in volatile-free conditions, Ca-whitlockite is formed. In spite of their interest, the thermodynamic properties and phase diagrams of P2O5-containg systems are not well known yet. In the case of the pure P2O5 for example, no experimental thermodynamic data are available for the liquid and the O and O' solid phases. As a result, we re-evaluated all the thermodynamic and phase diagram data of the P2O5 unary system [1]. Optimization of the thermodynamic properties and phase diagrams of the binary P2O5 systems was then performed including the Li2O-, Na2O-, MgO-, CaO-, BaO-, MnO-, FeO-, Fe2O3-, ZnO-, Al2O3-, and SiO2-P2O5 [2] systems. All available thermodynamic and phase equilibrium data were simultaneously reproduced in order to obtain a set of model equations for the Gibbs energies of all phases as functions of temperature and composition. In particular, the Gibbs energy of the liquid solution was described using the Modified Quasichemical Model [3-5] implemented in the FactSage software [6]. Thermodynamic modeling of the Li2O-Na2O-K2O-MgO-CaO-FeO-Fe2O3-Al2O3-SiO2 system, which include many granite-forming minerals such as nepheline, leucite, pyroxene, melilite, feldspar and spinel is currently in progress. [1] Jung, I.-H., Hudon, P. (2012) Thermodynamic assessment of P2O5. J. Am. Ceram. Soc., 95 (11), 3665-3672. [2] Rahman, M., Hudon, P. and Jung, I.-H. (2013) A coupled experimental study and thermodynamic modeling of the SiO2-P2O5 system. Metall. Mater. Trans. B, 44 (4), 837-852. [3] Pelton, A.D. and Blander, M. (1984) Computer-assisted analysis of the thermodynamic properties and phase diagrams of slags. Proc. AIME Symp. Metall. Slags Fluxes, TMS-AIME, 281-294. [4] Pelton, A.D. and Blander, M. (1986) Thermodynamic analysis of ordered liquid solutions by a modified

On the question of calculation methods of phase diagrams

International Nuclear Information System (INIS)

Vasil'ev, M.V.

1983-01-01

The technique of determining interaction parameters of components of binary alloys is suggested. U-Mo and Cu-Al systems are used as example with the aid of experimental state diagrams. It is shown that the search for new regularities is necessary with the aim of analytical description of state diagrams and forecast of the shape of phase equilibria curves in real systems. Optimum combinations of experimental investigations with the aim of reliable determination of supporting points and forecasting possibilities of typical equations can considerably decrease the volume of experimental work when preparing state diagrams, in cases of repeated state diagrams of more reliable state diagrams with the application of more advanced methods of investigation. The translation of state diagrams from geometric to analytical language with the use of typical equations opens up new possibilities for establishing a compact information bank for state diagrams

A geometric proof of confluence by decreasing diagrams

NARCIS (Netherlands)

Klop, J.W.; Oostrom, V. van; Vrijer, R. de

The criterion for confluence using decreasing diagrams is a generalization of several well-known confluence criteria in abstract rewriting, such as the strong confluence lemma. We give a new proof of the decreasing diagram theorem based on a geometric study of in finite reduction diagrams, arising

Compact flow diagrams for state sequences

NARCIS (Netherlands)

Buchin, K.A.; Buchin, M.E.; Gudmundsson, J.; Horton, M.J.; Sijben, S.

2016-01-01

We introduce the concept of compactly representing a large number of state sequences, e.g., sequences of activities, as a flow diagram. We argue that the flow diagram representation gives an intuitive summary that allows the user to detect patterns among large sets of state sequences. Simplified,

Nicotinamides: Evaluation of thermochemical experimental properties

International Nuclear Information System (INIS)

Zhabina, Aleksandra A.; Nagrimanov, Ruslan N.; Emel’yanenko, Vladimir N.; Solomonov, Boris N.; Verevkin, Sergey P.

2016-01-01

Highlights: • Vapor pressures measured by transpiration method. • Enthalpies of solution measured using high-precision solution calorimetry. • Enthalpies of fusion measured by DSC. • Sublimation enthalpies derived from transpiration and solution calorimetry in agreement. • Experimental results evaluated and compared with G4 calculations. - Abstract: Vapor pressures of the isomeric 2-, 3-, and 4-pyridinecarboxamides were measured by using the transpiration method. The enthalpies of sublimation/vaporization of these compounds at 298.15 K were derived from vapor pressure temperature dependences. The enthalpies of solution of the isomeric pyridinecarboxamides were measured with the high-precision solution calorimetry. The enthalpies of sublimation of 3- and 4-pyridinecarboxamides were independently derived with help of the solution calorimetry based procedure. The enthalpies of fusion of the pyridinecarboxamides were measured by the DSC. Thermochemical data isomeric pyridinecarboxamides were collected, evaluated, and tested for internal consistency. The high-level G4 quantum-chemical method was used for mutual validation of the experimental and theoretical gas phase enthalpies of formation successfully.

Thermochemical production of hydrogen from water

International Nuclear Information System (INIS)

Funk, J.E.; Conger, W.L.; Carty, R.H.; Barker, R.E.

1975-01-01

A review of recent developments in the selection and evaluation of multi-step thermochemical water-splitting cycles is presented. A computerized and thermodynamic and chemical engineering analysis procedure is discussed with calculates, among other things, the thermal efficiency of the process which is defined to be the ratio of the enthalpy change for water decomposition to the total thermal energy required by the process. Changes in the thermodynamic state in each step of the process are also determined. Engineering considerations such as the effect of approach to equilibrium in the chemical reaction steps on the work of separation, and the magnitude of the recycle streams are included. Important practical matters such as thermal regeneration in the product and reactant streams are dealt with in some detail. The effect of reaction temperature on thermal efficiency is described and the use of the analysis procedure is demonstrated by applying it to several processes. (author)

Voronoi diagram and microstructure of weldment

Energy Technology Data Exchange (ETDEWEB)

Cho, Jung Ho [Chungbuk National University, Cheongju (Korea, Republic of)

2015-01-15

Voronoi diagram, one of the well-known space decomposition algorithms has been applied to express the microstructure of a weldment for the first time due to the superficial analogy between a Voronoi cell and a metal's grain. The area of the Voronoi cells can be controlled by location and the number of the seed points. This can be correlated to the grain size in the microstructure and the number of nuclei formed. The feasibility of representing coarse and fine grain structures were tested through Voronoi diagrams and it is applied to expression of cross-sectional bead shape of a typical laser welding. As result, it successfully described coarsened grain size of heat affected zone and columnar crystals in fusion zone. Although Voronoi diagram showed potential as a microstructure prediction tool through this feasible trial but direct correlation control variable of Voronoi diagram to solidification process parameter is still remained as further works.

The role of perceptual cues in matrix diagrams

NARCIS (Netherlands)

van der Meij, Jan; van Amelsvoort, Marije; Anjewierden, A.

An experiment was conducted to assess whether the design of a matrix diagram influences how people study the diagram and whether this has an effect on recall of the presented information. We compared four versions of a matrix diagram on antisocial personality disorder. It consisted of four header

The role of perceptual cues in matrix diagrams

NARCIS (Netherlands)

van der Meij, Jan; Amelsvoort, Marije; Anjewierden, Anjo Allert

2015-01-01

An experiment was conducted to assess whether the design of a matrix diagram influences how people study the diagram and whether this has an effect on recall of the presented information. We compared four versions of a matrix diagram on antisocial personality disorder. It consisted of four header

Thermochemical ablation therapy of VX2 tumor using a permeable oil-packed liquid alkali metal.

Directory of Open Access Journals (Sweden)

Ziyi Guo

Full Text Available Alkali metal appears to be a promising tool in thermochemical ablation, but, it requires additional data on safety is required. The objective of this study was to explore the effectiveness of permeable oil-packed liquid alkali metal in the thermochemical ablation of tumors.Permeable oil-packed sodium-potassium (NaK was prepared using ultrasonic mixing of different ratios of metal to oil. The thermal effect of the mixture during ablation of muscle tissue ex vivo was evaluated using the Fluke Ti400 Thermal Imager. The thermochemical effect of the NaK-oil mixture on VX2 tumors was evaluated by performing perfusion CT scans both before and after treatment in 10 VX2 rabbit model tumors. VX2 tumors were harvested from two rabbits immediately after treatment to assess their viability using trypan blue and hematoxylin and eosin (H.E. staining.The injection of the NaK-oil mixture resulted in significantly higher heat in the ablation areas. The permeable oil controlled the rate of heat released during the NaK reaction with water in the living tissue. Perfusion computed tomography and its parameter map confirmed that the NaK-oil mixture had curative effects on VX2 tumors. Both trypan blue and H.E. staining showed partial necrosis of the VX2 tumors.The NaK-oil mixture may be used successfully to ablate tumor tissue in vivo. With reference to the controlled thermal and chemical lethal injury to tumors, using a liquid alkali in ablation is potentially an effective and safe method to treat malignant tumors.

The Eh-pH Diagram and Its Advances

Directory of Open Access Journals (Sweden)

Hsin-Hsiung Huang

2016-01-01

Full Text Available Since Pourbaix presented Eh versus pH diagrams in his “Atlas of Electrochemical Equilibria in Aqueous Solution”, diagrams have become extremely popular and are now used in almost every scientific area related to aqueous chemistry. Due to advances in personal computers, such diagrams can now show effects not only of Eh and pH, but also of variables, including ligand(s, temperature and pressure. Examples from various fields are illustrated in this paper. Examples include geochemical formation, corrosion and passivation, precipitation and adsorption for water treatment and leaching and metal recovery for hydrometallurgy. Two basic methods were developed to construct an Eh-pH diagram concerning the ligand component(s. The first method calculates and draws a line between two adjacent species based on their given activities. The second method performs equilibrium calculations over an array of points (500 × 800 or higher are preferred, each representing one Eh and one pH value for the whole system, then combines areas of each dominant species for the diagram. These two methods may produce different diagrams. The fundamental theories, illustrated results, comparison and required conditions behind these two methods are presented and discussed in this paper. The Gibbs phase rule equation for an Eh-pH diagram was derived and verified from actual plots. Besides indicating the stability area of water, an Eh-pH diagram normally shows only half of an overall reaction. However, merging two or more related diagrams together reveals more clearly the possibility of the reactions involved. For instance, leaching of Au with cyanide followed by cementing Au with Zn (Merrill-Crowe process can be illustrated by combining Au-CN and Zn-CN diagrams together. A second example of the galvanic conversion of chalcopyrite can be explained by merging S, Fe–S and Cu–Fe–S diagrams. The calculation of an Eh-pH diagram can be extended easily into another dimension, such

Compact flow diagrams for state sequences

NARCIS (Netherlands)

Buchin, Kevin; Buchin, Maike; Gudmundsson, Joachim; Horton, Michael; Sijben, Stef

2017-01-01

We introduce the concept of using a flow diagram to compactly represent the segmentation of a large number of state sequences according to a set of criteria. We argue that this flow diagram representation gives an intuitive summary that allows the user to detect patterns within the segmentations. In

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.

Control wiring diagrams

International Nuclear Information System (INIS)

McCauley, T.M.; Eskinazi, M.; Henson, L.L.

1989-01-01

This paper discusses the changes in electrical document requirements that occur when construction is complete and a generating station starts commercial operation. The needs of operations and maintenance (O and M) personnel are analyzed and contrasted with those of construction to illustrate areas in which the construction documents (drawings, diagrams, and databases) are difficult to use for work at an operating station. The paper discusses the O and M electrical documents that the Arizona Nuclear Power Project (ANPP) believes are most beneficial for the three operating units at Palo Verde; these are control wiring diagrams and an associated document cross-reference list. The benefits offered by these new, station O and M-oriented documents are weighted against the cost of their creation and their impact on drawing maintenance

New detectors for powders diagrams

International Nuclear Information System (INIS)

Convert, P.

1975-01-01

During the last few years, all the classical neutron diffractometers for powders have used one or maybe a few counters. So, it takes a long time to obtain a diagram which causes many disadvantages: 1) very long experiments: one or two days (or flux on the sample about 10 6 n/cm 2 /a); 2) necessity of big samples: many cm 3 ; 3) necessity of having the whole diagram before changing anything in the experiment: magnetic field, temperature, quality of the sample; 4) necessity of having collimators of a few times ten minutes to obtain correct statistics in the diagram. Because of these disadvantages, several attempts have been made to speed up the experimental procedure such as using more counters, the detection of neutrons on a resistive wire, etc. In Grenoble, new position-sensitive detectors have been constructed using a digital technique

Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation); Verfluechtigungspfade des Poloniums aus einem Pb-Bi-Spallationstarget (Thermochemische Kalkulation)

Energy Technology Data Exchange (ETDEWEB)

Eichler, B.; Neuhausen, J

2004-06-01

An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead

Thermochemical micro imprinting of single-crystal diamond surface using a nickel mold under high-pressure conditions

Energy Technology Data Exchange (ETDEWEB)

Imoto, Yuji; Yan, Jiwang, E-mail: yan@mech.keio.ac.jp

2017-05-15

Graphical abstract: A Ni mold and thermochemically imprinted microstructures on diamond. - Highlights: • A thermochemical method for micro machining/patterning of diamond is proposed. • Various kinds of microstructures were imprinted on diamond using a Ni mold. • A graphite layer is formed during imprinting which can be removed by acid. • The processing depth depends strongly on pressure and temperature. - Abstract: Single-crystal diamond is an important material for cutting tools, micro electro mechanical systems, optical devices, and semiconductor substrates. However, the techniques for producing microstructures on diamond surface with high efficiency and accuracy have not been established. This paper proposes a thermochemical imprinting method for transferring microstructures from a nickel (Ni) mold onto single-crystal diamond surface. The Ni mold was micro-structured by a nanoindenter and then pressed against the diamond surface under high temperature and pressure in argon atmosphere. Results show that microstructures on the Ni mold were successfully transferred onto the diamond surface, and their depth increased with both pressure and temperature. Laser micro-Raman spectroscopy, transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) analyses indicate that a graphite layer was formed over the contact area between diamond and Ni during pressing, and after washing by a mixed acid, the graphite layer could be completely removed. This study demonstrated the feasibility of a cost-efficient fabrication method for large-area microstructures on single-crystal diamond.

Generation of H2 and CO by solar thermochemical splitting of H2O and CO2 by employing metal oxides

International Nuclear Information System (INIS)

Rao, C.N.R.; Dey, Sunita

2016-01-01

Generation of H 2 and CO by splitting H 2 O and CO 2 respectively constitutes an important aspect of the present-day concerns with energy and environment. The solar thermochemical route making use of metal oxides is a viable means of accomplishing these reduction reactions. The method essentially involves reducing a metal oxide by heating and passing H 2 O or CO 2 over the nonstoichiometric oxide to cause reverse oxidation by abstracting oxygen from H 2 O or CO 2 . While ceria, perovskites and other oxides have been investigated for this purpose, recent studies have demonstrated the superior performance of perovskites of the type Ln 1−x A x Mn 1−y M y O 3 (Ln=rare earth, A=alkaline earth, M=various +2 and +3 metal ions), in the thermochemical generation of H 2 and CO. We present the important results obtained hitherto to point out how the alkaine earth and the Ln ions, specially the radius of the latter, determine the performance of the perovskites. The encouraging results obtained are exemplefied by Y 0.5 Sr 0.5 MnO 3 which releases 483 µmol/g of O 2 at 1673 K and produces 757 µmol/g of CO from CO 2 at 1173 K. The production of H 2 from H 2 O is also quite appreciable. Modification of the B site ion of the perovskite also affects the performance. In addition to perovskites, we present the generation of H 2 based on the Mn 3 O 4 /NaMnO 2 cycle briefly. - Graphical abstract: Ln 0.5 A 0.5 Mn 1−x M x O 3 (Ln=lanthanide; A=Ca, Sr; M=Al, Ga, Sc, Mg, Cr, Fe, Co) perovskites are employed for the two step thermochemical splitting of CO 2 and H 2 O for the generation of CO and H 2 . - Highlights: • Perovskite oxides based on Mn are ideal for the two-step thermochemical splitting of CO 2 and H 2 O. • In Ln 1−x A x MnO 3 perovskite (Ln=rare earth, A=alkaline earth) both Ln and A ions play major roles in the thermochemical process. • H 2 O splitting is also achieved by the use of the Mn 3 O 4 -sodium carbonate system. • Thermochemical splitting of CO 2 and H

Nagra thermochemical data base. II. Supplement data 05/92

International Nuclear Information System (INIS)

Pearson, F.J.; Berner, U.; Hummel, W.

1992-05-01

Chemical thermodynamic data for aqueous species, minerals, and gases are required by Nagra for geochemical modelling. The Nagra thermochemical data base contains core and supplemental data. Core data for well-characterised entities were individually carefully selected and given by Pearson and Berner (1991). Supplemental data are for less common entities and for elements principally of safety assessment concern. They were selected in groups from other data bases for geochemical modelling and did not receive individual scrutiny. This report gives tables with the Nagra thermochemical data as of 5/92. It includes the core data described in the earlier report with supplemental data for the elements aluminium, silicon, iron, and manganese, the actinides thorium, uranium, neptunium, plutonium, and americium, and elements found as fission or activation products in nuclear waste, including nickel, zirconium, niobium, molybdenum, technetium, palladium, tin, selenium and iodine. Aqueous complexes of four representative organic anions are also included. The sources of these supplemental data are described in the text. Other compilations of data were examined during the selection on the supplemental data. These included the data bases used at the Paul Scherrer Institut with the geochemical programs MINEQL as of 3/91, PHREEQE as of 4/91, and the HATCHES 3.0 data base. This report also gives tables comparing selected data in these three data bases with values from the Nagra data base. This data base has not yet been tested for a full range of nuclear waste management applications, although such work is in progress. It should thus be regarded as a reference fixed point for quality assurance purpose and not critically reviewed standard. (author) tabs., refs

Bimetallic catalysts for HI decomposition in the iodine-sulfur thermochemical cycle

International Nuclear Information System (INIS)

Wang Laijun; Hu Songzhi; Xu Lufei; Li Daocai; Han Qi; Chen Songzhe; Zhang Ping; Xu Jingming

2014-01-01

Among the different kinds of thermochemical water-splitting cycles, the iodine-sulfur (IS) cycle has attracted more and more interest because it is one of the promising candidates for economical and massive hydrogen production. However, there still exist some science and technical problems to be solved before industrialization of the IS process. One such problem is the catalytic decomposition of hydrogen iodide. Although the active carbon supported platinum has been verified to present the excellent performance for HI decomposition, it is very expensive and easy to agglomerate under the harsh condition. In order to decrease the cost and increase the stability of the catalysts for HI decomposition, a series of bimetallic catalysts were prepared and studied at INET. This paper summarized our present research advances on the bimetallic catalysts (Pt-Pd, Pd-Ir and Pt-Ir) for HI decomposition. In the course of the study, the physical properties, structure, and morphology of the catalysts were characterized by specific surface area, X-ray diffractometer; and transmission electron microscopy, respectively. The catalytic activity for HI decomposition was investigated in a fixed bed reactor under atmospheric pressure. The results show that due to the higher activity and better stability, the active carbon supported bimetallic catalyst is more potential candidate than mono metallic Pt catalyst for HI decomposition in the IS thermochemical cycle. (author)

Causal Diagrams for Empirical Research

OpenAIRE

Pearl, Judea

1994-01-01

The primary aim of this paper is to show how graphical models can be used as a mathematical language for integrating statistical and subject-matter information. In particular, the paper develops a principled, nonparametric framework for causal inference, in which diagrams are queried to determine if the assumptions available are sufficient for identifiying causal effects from non-experimental data. If so the diagrams can be queried to produce mathematical expressions for causal effects in ter...

Graphical matching rules for cardinality based service feature diagrams

Directory of Open Access Journals (Sweden)

Faiza Kanwal

2017-03-01

Full Text Available To provide efficient services to end-users, variability and commonality among the features of the product line is a challenge for industrialist and researchers. Feature modeling provides great services to deal with variability and commonality among the features of product line. Cardinality based service feature diagrams changed the basic framework of service feature diagrams by putting constraints to them, which make service specifications more flexible, but apart from their variation in selection third party services may have to be customizable. Although to control variability, cardinality based service feature diagrams provide high level visual notations. For specifying variability, the use of cardinality based service feature diagrams raises the problem of matching a required feature diagram against the set of provided diagrams.

Design of GA thermochemical water-splitting process for the Mirror Advanced Reactor System

International Nuclear Information System (INIS)

Brown, L.C.

1983-04-01

GA interfaced the sulfur-iodine thermochemical water-splitting cycle to the Mirror Advanced Reactor System (MARS). The results of this effort follow as one section and part of a second section to be included in the MARS final report. This section describes the process and its interface to the reactor. The capital and operating costs for the hydrogen plant are described

Thermochemical cycles based on metal oxides for solar hydrogen production; Ciclos termoquimicos basados en oxidos metalicos para produccion de hidrogeno solar

Energy Technology Data Exchange (ETDEWEB)

Fernandez Saavedra, R.; Quejido Cabezas, J.

2012-11-01

The growing demand for energy requires the development and optimization of alternative energy sources. One of the options currently being investigated is solar hydrogen production with thermochemical cycles. This process involves the use of concentrated solar radiation as an energy source to dissociate water through a series of endothermic and exothermic chemical reactions, for the purpose of obtaining hydrogen on a sustainable basis. Of all the thermochemical cycles that have been evaluated, the most suitable ones for implementation with solar energy are those based on metal oxides. (Author) 20 refs.

Positronium hydride defects in thermochemically reduced alkaline-Earth oxides

International Nuclear Information System (INIS)

Monge, M.A.; Pareja, R.; Gonzalez, R.; Chen, Y.

1997-01-01

Thermochemical reduction of both hydrogen-doped MgO and CaO single crystals results in large concentrations of hydride (H - ) ions. In MgO crystals, positron lifetime and Doppler broadening experiments show that positrons are trapped at H - centers forming positronium hydride molecules [e + - H - ]. A value of 640 ps is obtained for the lifetime of the PsH states located in an anion vacancy In MgO positrons are also trapped at H 2- sites at low temperatures. The H 2- ions were induced in the crystals by blue light illumination. The formation of PsH states in CaO could not be conclusively established. (orig.)

On the Impact of Layout Quality to Understanding UML Diagrams: Diagram Type and Expertise

DEFF Research Database (Denmark)

Störrle, Harald

2012-01-01

Practical experience suggests that the use and understanding of UML diagrams is greatly affected by the quality of their layout. In previous work, we have presented evidence supporting this intuition. This contrasts with earlier experiments that yielded weak or inconclusive evidence only. In the ......Practical experience suggests that the use and understanding of UML diagrams is greatly affected by the quality of their layout. In previous work, we have presented evidence supporting this intuition. This contrasts with earlier experiments that yielded weak or inconclusive evidence only...

Beyond Feynman Diagrams (1/3)

CERN Multimedia

CERN. Geneva

2013-01-01

For decades the central theoretical tool for computing scattering amplitudes has been the Feynman diagram. However, Feynman diagrams are just too slow, even on fast computers, to be able to go beyond the leading order in QCD, for complicated events with many jets of hadrons in the final state. Such events are produced copiously at the LHC, and constitute formidable backgrounds to many searches for new physics. Over the past few years, alternative methods that go beyond ...

Wind Diagrams in Medieval Iceland

DEFF Research Database (Denmark)

Kedwards, Dale

2014-01-01

This article presents a study of the sole wind diagram that survives from medieval Iceland, preserved in the encyclopaedic miscellany in Copenhagen's Arnamagnæan Institute with the shelf mark AM 732b 4to (c. 1300-25). It examines the wind diagram and its accompanying text, an excerpt on the winds...... from Isidore of Seville's Etymologies. It also examines the perimeter of winds on two medieval Icelandic world maps, and the visual traditions from which they draw....

Bayesian Networks and Influence Diagrams

DEFF Research Database (Denmark)

Kjærulff, Uffe Bro; Madsen, Anders Læsø

 Probabilistic networks, also known as Bayesian networks and influence diagrams, have become one of the most promising technologies in the area of applied artificial intelligence, offering intuitive, efficient, and reliable methods for diagnosis, prediction, decision making, classification......, troubleshooting, and data mining under uncertainty. Bayesian Networks and Influence Diagrams: A Guide to Construction and Analysis provides a comprehensive guide for practitioners who wish to understand, construct, and analyze intelligent systems for decision support based on probabilistic networks. Intended...

Proof test diagrams for Zerodur glass-ceramic

Science.gov (United States)

Tucker, D. S.

1991-01-01

Proof test diagrams for Zerodur glass-ceramics are calculated from available fracture mechanics data. It is shown that the environment has a large effect on minimum time-to-failure as predicted by proof test diagrams.

Characterisation of agroindustrial solid residues as biofuels and potential application in thermochemical processes.

Science.gov (United States)

Virmond, Elaine; De Sena, Rennio F; Albrecht, Waldir; Althoff, Christine A; Moreira, Regina F P M; José, Humberto J

2012-10-01

In the present work, selected agroindustrial solid residues from Brazil - biosolids from meat processing wastewater treatment and mixture of sawdust with these biosolids; residues from apple and orange juice industries; sugarcane bagasse; açaí kernels (Euterpe oleracea) and rice husk - were characterised as solid fuels and an evaluation of their properties, including proximate and ultimate composition, energy content, thermal behaviour, composition and fusibility of the ashes was performed. The lower heating value of the biomasses ranged from 14.31 MJkg(-1) to 29.14 MJkg(-1), on a dry and ash free basis (daf), all presenting high volatile matter content, varying between 70.57 wt.% and 85.36 wt.% (daf) what improves the thermochemical conversion of the solids. The fouling and slagging tendency of the ashes was predicted based on the fuel ash composition and on the ash fusibility correlations proposed in the literature, which is important to the project and operation of biomass conversion systems. The potential for application of the Brazilian agroindustrial solid residues studied as alternative energy sources in thermochemical processes has been identified, especially concerning direct combustion for steam generation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

Energy Technology Data Exchange (ETDEWEB)

Rafique, Rashad; Nizami, Abdul-Sattar; Murphy, Jerry D.; Kiely, Gerard [Department of Civil and Environmental Engineering, University College Cork (Ireland); Poulsen, Tjalfe Gorm [Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University (Denmark); Asam, Zaki-ul-Zaman [Department of Civil Engineering, National University of Ireland Galway (Ireland)

2010-12-15

The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 C-150 C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 C). Maximum enhancement is observed at 70 C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 C), with maximum enhancement at 100 C having 28% biogas and 25% methane increase. (author)

Aerobic dive limits of seals with mutant myoglobin using combined thermochemical and physiological data

DEFF Research Database (Denmark)

Dasmeh, Pouria; Davis, Randall W.; Kepp, Kasper Planeta

2013-01-01

This paper presents an integrated model of convective O2-transport, aerobic dive limits (ADL), and thermochemical data for oxygen binding to mutant myoglobin (Mb), used to quantify the impact of mutations in Mb on the dive limits of Weddell seals (Leptonychotes weddellii). We find that wild-type ...... that such conditions are mostly selected upon in seals. The model is capable of roughly quantifying the physiological impact of single-protein mutations and thus bridges an important gap between animal physiology and molecular (protein) evolution.......This paper presents an integrated model of convective O2-transport, aerobic dive limits (ADL), and thermochemical data for oxygen binding to mutant myoglobin (Mb), used to quantify the impact of mutations in Mb on the dive limits of Weddell seals (Leptonychotes weddellii). We find that wild-type Mb...... traits are only superior under specific behavioral and physiological conditions that critically prolong the ADL, action radius, and fitness of the seals. As an extreme example, the mutations in the conserved His-64 reduce ADL up to 14±2 min for routine aerobic dives, whereas many other mutations...

Atlas of hot isostatic beryllium powder pressing diagrams

International Nuclear Information System (INIS)

Stoev, P.I.; Papirov, I.I.; Tikhinskij, G.F.; Vasil'ev, A.A.

1995-01-01

Diagrams of hot isotopic pressing (HIP) of beryllium powder with different grain size in a wide range of pressing parameters are built by mathematical modeling methods. The HIP diagrams presented are divided into 3 groups: parametric dependencies D=f(P,T); technological HIP diagrams; compacting mechanisms. The created data bank permits to optimise beryllium powder HIP with changing parameters. 4 refs., 23 figs

Visualizing Metrics on Areas of Interest in Software Architecture Diagrams

NARCIS (Netherlands)

Byelas, Heorhiy; Telea, Alexandru; Eades, P; Ertl, T; Shen, HW

2009-01-01

We present a new method for the combined visualization of software architecture diagrams, Such as UML class diagrams or component diagrams, and software metrics defined on groups of diagram elements. Our method extends an existing rendering technique for the so-called areas of interest in system

Definitive Ideal-Gas Thermochemical Functions of the (H2O)-O-16 Molecule

Czech Academy of Sciences Publication Activity Database

Furtenbacher, T.; Szidarovszky, T.; Hrubý, Jan; Kyuberis, A. A.; Zobov, N. F.; Polyansky, O. L.; Tennyson, J.; Császár, A. G.

2016-01-01

Roč. 45, č. 4 (2016), č. článku 043104. ISSN 0047-2689 R&D Projects: GA ČR(CZ) GA16-02647S Institutional support: RVO:61388998 Keywords : ideal-gas thermochemical quantities * ortho- and para-H2 16O * partition function Subject RIV: BJ - Thermodynamics Impact factor: 4.204, year: 2016 http://aip.scitation.org/doi/pdf/10.1063/1.4967723

Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

Science.gov (United States)

Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

2011-09-28

The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

Updating the Nomographical Diagrams for Dimensioning the Beams

Directory of Open Access Journals (Sweden)

Pop Maria T.

2015-12-01

Full Text Available In order to reduce the time period needed for structures design it is strongly recommended to use nomographical diagrams. The base for formation and updating the nomographical diagrams, stands on the charts presented by different technical publications. The updated charts use the same algorithm and calculation elements as the former diagrams in accordance to the latest prescriptions and European standards. The result consists in a chart, having the same properties, similar with the nomogragraphical diagrams already in us. As a general conclusion, even in our days, the nomographical diagrams are very easy to use. Taking into consideration the value of the moment it’s easy to find out the necessary reinforcement area and vice-verse, having the reinforcement area you can find out the capable moment. It still remains a useful opportunity for pre-sizing and designs the reinforced concrete sections.

Phase diagram of classical electronic bilayers

International Nuclear Information System (INIS)

Ranganathan, S; Johnson, R E

2006-01-01

Extensive molecular dynamics calculations have been performed on classical, symmetric electronic bilayers at various values of the coupling strength Γ and interlayer separation d to delineate its phase diagram in the Γ-d plane. We studied the diffusion, the amplitude of the main peak of the intralayer static structure factor and the peak positions of the intralayer pair correlation function with the aim of defining equivalent signatures of freezing and constructing the resulting phase diagram. It is found that for Γ greater than 75, crystalline structures exist for a certain range of interlayer separations, while liquid phases are favoured at smaller and larger d. It is seen that there is good agreement between our phase diagram and previously published ones

Phase diagram of classical electronic bilayers

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, S [Department of Physics, Royal Military College of Canada, Kingston, Ontario K7K 7B4 (Canada); Johnson, R E [Department of Mathematics and Computer Science, Royal Military College of Canada, Kingston, Ontario K7K 7B4 (Canada)

2006-04-28

Extensive molecular dynamics calculations have been performed on classical, symmetric electronic bilayers at various values of the coupling strength {gamma} and interlayer separation d to delineate its phase diagram in the {gamma}-d plane. We studied the diffusion, the amplitude of the main peak of the intralayer static structure factor and the peak positions of the intralayer pair correlation function with the aim of defining equivalent signatures of freezing and constructing the resulting phase diagram. It is found that for {gamma} greater than 75, crystalline structures exist for a certain range of interlayer separations, while liquid phases are favoured at smaller and larger d. It is seen that there is good agreement between our phase diagram and previously published ones.

Nuclear Production of Hydrogen Using Thermochemical Water-Splitting Cycles

International Nuclear Information System (INIS)

Brown, L.C.; Besenbruch, G.E.; Schultz, K.R.; Marshall, A.C.; Showalter, S.K.; Pickard, P.S.; Funk, J.F.

2002-01-01

The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high-temperature heat from an advanced nuclear power station in a thermochemical water-splitting cycle. We carried out a detailed literature search to create a searchable database with 115 cycles and 822 references. We developed screening criteria to reduce the list to 25 cycles. We used detailed evaluation to select two cycles that appear most promising, the Adiabatic UT-3 cycle and the Sulfur-Iodine cycle. We have selected the Sulfur-Iodine thermochemical water-splitting cycle for further development. We then assessed the suitability of various nuclear reactor types to the production of hydrogen from water using the Sulfur-Iodine cycle. A basic requirement is to deliver heat to the process interface heat exchanger at temperatures up to 900 deg. C. We considered nine categories of reactors: pressurized water-cooled, boiling water-cooled, organic-cooled, alkali metal-cooled, heavy metal-cooled, gas-cooled, molten salt-cooled, liquid-core and gas-core reactors. We developed requirements and criteria to carry out the assessment, considering design, safety, operational, economic and development issues. This assessment process led to our choice of the helium gas-cooled reactor for coupling to the Sulfur-Iodine cycle. In continuing work, we are investigating the improvements that have been proposed to the Sulfur-Iodine cycle and will generate an integrated flowsheet describing a hydrogen production plant powered by a high-temperature helium gas-cooled nuclear reactor. This will allow us to size process equipment and calculate hydrogen production efficiency and capital cost, and to estimate the cost of the hydrogen produced as a function of nuclear reactor cost. (authors)

Modeling cancer registration processes with an enhanced activity diagram.

Science.gov (United States)

Lyalin, D; Williams, W

2005-01-01

Adequate instruments are needed to reflect the complexity of routine cancer registry operations properly in a business model. The activity diagram is a key instrument of the Unified Modeling Language (UML) for the modeling of business processes. The authors aim to improve descriptions of processes in cancer registration, as well as in other public health domains, through the enhancements of an activity diagram notation within the standard semantics of UML. The authors introduced the practical approach to enhance a conventional UML activity diagram, complementing it with the following business process concepts: timeline, duration for individual activities, responsibilities for individual activities within swimlanes, and descriptive text. The authors used an enhanced activity diagram for modeling surveillance processes in the cancer registration domain. Specific example illustrates the use of an enhanced activity diagram to visualize a process of linking cancer registry records with external mortality files. Enhanced activity diagram allows for the addition of more business concepts to a single diagram and can improve descriptions of processes in cancer registration, as well as in other domains. Additional features of an enhanced activity diagram allow to advance the visualization of cancer registration processes. That, in turn, promotes the clarification of issues related to the process timeline, responsibilities for particular operations, and collaborations among process participants. Our first experiences in a cancer registry best practices development workshop setting support the usefulness of such an approach.

Assessment of thermochemical hydrogen production. Project 61010 (formerly 8994) final report, July 1, 1977-March 31, 1979

Energy Technology Data Exchange (ETDEWEB)

Dafler, J.R.; Foh, S.E.; Lee, T.S.; Schreiber, J.D.

1979-05-01

The Institute of Gas Technology's (IGT) assessment of thermochemical water-splitting processes is given. Eight tasks were performed: evaluation of load-line efficiencies; hydrogen bromide electrolysis; maximum attainable thermal efficiency on a specific bromide hybrid cycle; development of electrolyzer elements for H/sub 2/SO/sub 3/; feasibility of high-temperature reference-state thermochemical cycles; interfacing characteristics - solar high-temperature heat sources; analysis of solar and solar hybrid heat sources; and laboratory assessment of cycle with high-temperature step. Engineering analyses were done on two thermochemical hydrogen production cycles - IGT's cycles B-1 and H-5. The load line efficiency for B-1 was 18.1% and for H-5 37.4%. The electrolysis of HBr (aq) on three substrates: platinum, porous graphite, and vitreous graphite was investigated. Platinum proved to be the most efficient electrode surface, with vitreous graphite showing no promise, and porous graphite showing only slightly better results. On platinum, cell voltages of under 1.0 volt were obtained at current densities up to 200 mA/cm/sup 2/. Five new members of the metal-metal oxide class of cycles were derived. The maximum attainable efficiencies of these high-temperature, two-step cycles range from 64 to 86%. Six high-temperature metal oxide-metal sulfate cycles were derived. Performance and capital costs data for a wide range of solar primary heat sources were tabulated.

Fishbone Diagrams: Organize Reading Content with a "Bare Bones" Strategy

Science.gov (United States)

Clary, Renee; Wandersee, James

2010-01-01

Fishbone diagrams, also known as Ishikawa diagrams or cause-and-effect diagrams, are one of the many problem-solving tools created by Dr. Kaoru Ishikawa, a University of Tokyo professor. Part of the brilliance of Ishikawa's idea resides in the simplicity and practicality of the diagram's basic model--a fish's skeleton. This article describes how…

Investigation of innovative thermochemical energy storage processes and materials for building applications

OpenAIRE

Aydin, Devrim

2016-01-01

In this study, it is aimed to develop an innovative thermochemical energy storage system through material, reactor and process based investigations for building space heating applications. The developed system could be integrated with solar thermal collectors, photovoltaic panels or heat pumps to store any excess energy in the form of heat for later use. Thereby, it is proposed to address the problem of high operational costs and CO2 emissions released by currently used fossil fuel based heat...

Muonium and the Breit-Rabi diagram

International Nuclear Information System (INIS)

Cox, S.F.J.

1984-01-01

This chapter introduces the study of muonium, as opposed to that of unbound muons. The properties and behaviour of muonium are compared and contrasted with those of hydrogen and of positronium. The special significance of muonium in atomic and molecular physics is explained, and its utility as a lightweight or radioactive isotope of hydrogen in solid state physics and chemistry illustrated. The identification of atomic muonium by means of its ground state magnetic properties is described with reference to the Breit-Rabi diagram. This diagram is invaluable for interpreting or predicting MuSR observations, both in transverse and longitudinal magnetic fields, so its construction and properties are explained in some detail. The precession signals observed in transverse-field MuSR correspond to transitions allowed between the energy levels in this diagram; particular attention is paid to the spectra characteristic of the high and low field regimes. The different states of muonium observed in dielectric, semiconducting and metallic materials are introduced. The influence of the host medium on the spectral parameters, hyperfine interaction and linewidth, is considered both for atomic muonium and for muonium which is chemically bound in paramagnetic molecules, for which the Breit-Rabi diagram also applies. (orig.)

The NEA thermochemical database project. 30 years of accomplishments

International Nuclear Information System (INIS)

Ragoussi, Maria-Eleni; Brassinnes, Stephane

2015-01-01

The NEA Thermochemical Database (TDB) Project (www.oecd-nea.org/dbtdb/) provides a database of chemical thermodynamic values treating the most significant elements related to nuclear waste management. The work carried out since the initiation of TDB in 1984 has resulted in the publication of thirteen major reviews and a large set of selected values that have become an international reference in the field, as they are characterized for their accuracy, consistency and high quality. Herein, we describe the basis, scientific principles and organization of the TDB project, together with its evolution from its inception to the present organization as a joint undertaking under Article 5(b) of the Statute of the OECD Nuclear Energy Agency (NEA).

An approach to thermochemical modeling of nuclear waste glass

International Nuclear Information System (INIS)

Besmann, T.M.; Beahm, E.C.; Spear, K.E.

1998-01-01

This initial work is aimed at developing a basic understanding of the phase equilibria and solid solution behavior of the constituents of waste glass. Current, experimentally determined values are less than desirable since they depend on measurement of the leach rate under non-realistic conditions designed to accelerate processes that occur on a geologic time scale. The often-used assumption that the activity of a species is either unity or equal to the overall concentration of the metal can also yield misleading results. The associate species model, a recent development in thermochemical modeling, will be applied to these systems to more accurately predict chemical activities in such complex systems as waste glasses

Impulse-Momentum Diagrams

Science.gov (United States)

Rosengrant, David

2011-01-01

Multiple representations are a valuable tool to help students learn and understand physics concepts. Furthermore, representations help students learn how to think and act like real scientists. These representations include: pictures, free-body diagrams, energy bar charts, electrical circuits, and, more recently, computer simulations and…

How design guides learning from matrix diagrams

NARCIS (Netherlands)

van der Meij, Jan; Amelsvoort, Marije; Anjewierden, Anjo

2017-01-01

Compared to text, diagrams are superior in their ability to structure and summarize information and to show relations between concepts and ideas. Perceptual cues, like arrows, are expected to improve the retention of diagrams by guiding the learner towards important elements or showing a preferred

Diagram of state of stiff amphiphilic macromolecules

NARCIS (Netherlands)

Markov, Vladimir A.; Vasilevskaya, Valentina V.; Khalatur, Pavel G.; ten Brinke, Gerrit; Khokhlov, Alexei R.

2007-01-01

We studied coil-globule transitions in stiff-chain amphiphilic macromolecules via computer modeling and constructed phase diagrams for such molecules in terms of solvent quality and persistence length. We showed that the shape of the phase diagram essentially depends on the macromolecule degree of

Atomic energy levels and Grotrian diagrams

CERN Document Server

Bashkin, Stanley

1975-01-01

Atomic Energy Levels and Grotrian Diagrams, Volume I: Hydrogen I - Phosphorus XV presents diagrams of various elements that show their energy level and electronic transitions. The book covers the first 15 elements according to their atomic number. The text will be of great use to researchers and practitioners of fields such as astrophysics that requires pictorial representation of the energy levels and electronic transitions of elements.

Experimental results of a 3 k Wh thermochemical heat storage module for space heating application

NARCIS (Netherlands)

Finck, C.J.; Henquet, E.M.R.; Soest, C.F.L. van; Oversloot, H.P.; Jong, A.J. de; Cuypers, R.; Spijker, J.C. van 't

2014-01-01

A 3 kWh thermochemical heat storage (TCS) module was built as part of an all-in house system implementation focusing on space heating application at a temperature level of 40 ºC and a temperature lift of 20 K. It has been tested and measurements showed a maximum water circuit temperature span

Updating the Nomographical Diagrams for Dimensioning the Beams

OpenAIRE

Pop Maria T.

2015-01-01

In order to reduce the time period needed for structures design it is strongly recommended to use nomographical diagrams. The base for formation and updating the nomographical diagrams, stands on the charts presented by different technical publications. The updated charts use the same algorithm and calculation elements as the former diagrams in accordance to the latest prescriptions and European standards. The result consists in a chart, having the same properties, similar with the nomogragra...

Spin wave Feynman diagram vertex computation package

Science.gov (United States)

Price, Alexander; Javernick, Philip; Datta, Trinanjan

Spin wave theory is a well-established theoretical technique that can correctly predict the physical behavior of ordered magnetic states. However, computing the effects of an interacting spin wave theory incorporating magnons involve a laborious by hand derivation of Feynman diagram vertices. The process is tedious and time consuming. Hence, to improve productivity and have another means to check the analytical calculations, we have devised a Feynman Diagram Vertex Computation package. In this talk, we will describe our research group's effort to implement a Mathematica based symbolic Feynman diagram vertex computation package that computes spin wave vertices. Utilizing the non-commutative algebra package NCAlgebra as an add-on to Mathematica, symbolic expressions for the Feynman diagram vertices of a Heisenberg quantum antiferromagnet are obtained. Our existing code reproduces the well-known expressions of a nearest neighbor square lattice Heisenberg model. We also discuss the case of a triangular lattice Heisenberg model where non collinear terms contribute to the vertex interactions.

The classification of diagrams in perturbation theory

International Nuclear Information System (INIS)

Phillips, D.R.; Afnan, I.R.

1995-01-01

The derivation of scattering equations connecting the amplitudes obtained from diagrammatic expansions is of interest in many branches of physics. One method for deriving such equations is the classification-of-diagrams technique of Taylor. However, as we shall explain in this paper, there are certain points of Taylor's method which require clarification. First, it is not clear whether Taylor's original method is equivlant to the simpler classification-of-diagrams scheme used by Thomas, Rinat, Afnan, and Blankleider (TRAB). Second, when the Taylor method is applied to certain problems in a time-dependent perturbation theory it leads to the over-counting of some diagrams. This paper first restates Taylor's method, in the process uncovering reasons why certain diagrams might be double-counted in the Taylor method. In then explores how far Taylor's method is equivalent to the simpler TRAB method. Finally, it examines precisely why the double-counting occurs in Taylor's method and derives corrections which compensate for this double-counting. copyright 1995 Academic Press, Inc

Influence diagram in evaluating the subjective judgment

International Nuclear Information System (INIS)

Hong, Y.

1997-01-01

The author developed the idea of the subjective influence diagrams to evaluate subjective judgment. The subjective judgment of a stake holder is a primary decision making proposition. It involves a basic decision process an the individual attitude of the stake holder for his decision purpose. The subjective judgment dominates the some final decisions. A complex decision process may include the subjective judgment. An influence diagram framework is a simplest tool for analyzing subjective judgment process. In the framework, the characters of influence diagrams generate the describing the analyzing, and the evaluating of the subjective judgment. The relationship between the information and the decision, such as independent character between them, is the main issue. Then utility function is the calculating tool to evaluation, the stake holder can make optimal decision. Through the analysis about the decision process and relationship, the building process of the influence diagram identically describes the subjective judgment. Some examples are given to explain the property of subjective judgment and the analysis process

Improving Students' Chemical Literacy Levels on Thermochemical and Thermodynamics Concepts through a Context-Based Approach

Science.gov (United States)

Cigdemoglu, Ceyhan; Geban, Omer

2015-01-01

The aim of this study was to delve into the effect of context-based approach (CBA) over traditional instruction (TI) on students' chemical literacy level related to thermochemical and thermodynamics concepts. Four eleventh-grade classes with 118 students in total taught by two teachers from a public high school in 2012 fall semester were enrolled…

Lattice and Phase Diagram in QCD

International Nuclear Information System (INIS)

Lombardo, Maria Paola

2008-01-01

Model calculations have produced a number of very interesting expectations for the QCD Phase Diagram, and the task of a lattice calculations is to put these studies on a quantitative grounds. I will give an overview of the current status of the lattice analysis of the QCD phase diagram, from the quantitative results of mature calculations at zero and small baryochemical potential, to the exploratory studies of the colder, denser phase.

Ferroelectric Phase Diagram of PVDF:PMMA

OpenAIRE

Li, Mengyuan; Stingelin, Natalie; Michels, Jasper J.; Spijkman, Mark-Jan; Asadi, Kamal; Feldman, Kirill; Blom, Paul W. M.; de Leeuw, Dago M.

2012-01-01

We have investigated the ferroelectric phase diagram of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA). The binary nonequilibrium temperature composition diagram was determined and melting of alpha- and beta-phase PVDF was identified. Ferroelectric beta-PVDF:PMMA blend films were made by melting, ice quenching, and subsequent annealing above the glass transition temperature of PMMA, close to the melting temperature of PVDF. Addition of PMMA suppresses the crystallizatio...

Gluing Ladder Feynman Diagrams into Fishnets

International Nuclear Information System (INIS)

Basso, Benjamin; Dixon, Lance J.; Stanford University, CA; University of California, Santa Barbara, CA

2017-01-01

We use integrability at weak coupling to compute fishnet diagrams for four-point correlation functions in planar Φ "4 theory. Our results are always multilinear combinations of ladder integrals, which are in turn built out of classical polylogarithms. The Steinmann relations provide a powerful constraint on such linear combinations, which leads to a natural conjecture for any fishnet diagram as the determinant of a matrix of ladder integrals.

A Critical Appraisal of the "Day" Diagram

Science.gov (United States)

Roberts, Andrew P.; Tauxe, Lisa; Heslop, David; Zhao, Xiang; Jiang, Zhaoxia

2018-04-01

The "Day" diagram (Day et al., 1977, https://doi.org/10.1016/0031-9201(77)90108-X) is used widely to make inferences about the domain state of magnetic mineral assemblages. Based on theoretical and empirical arguments, the Day diagram is demarcated into stable "single domain" (SD), "pseudo single domain" ("PSD"), and "multidomain" (MD) zones. It is straightforward to make the necessary measurements for a sample and to plot results within the "domain state" framework based on the boundaries defined by Day et al. (1977, https://doi.org/10.1016/0031-9201(77)90108-X). We discuss 10 issues that limit Day diagram interpretation, including (1) magnetic mineralogy, (2) the associated magnetocrystalline anisotropy type, (3) mineral stoichiometry, (4) stress state, (5) surface oxidation, (6) magnetostatic interactions, (7) particle shape, (8) thermal relaxation, (9) magnetic particle mixtures, and (10) definitional/measurement issues. In most studies, these variables are unknowns and cannot be controlled for, so that hysteresis parameters for single bulk samples are nonunique and any data point in a Day diagram could result from infinite combinations of relevant variables. From this critical appraisal, we argue that the Day diagram is fundamentally ambiguous for domain state diagnosis. Widespread use of the Day diagram has also contributed significantly to prevalent but questionable views, including underrecognition of the importance of stable SD particles in the geological record and reinforcement of the unhelpful PSD concept and of its geological importance. Adoption of approaches that enable correct domain state diagnosis should be an urgent priority for component-specific understanding of magnetic mineral assemblages and for quantitative rock magnetic interpretation.

Static Thermochemical Model of COREX Melter Gasifier

Science.gov (United States)

Srishilan, C.; Shukla, Ajay Kumar

2018-02-01

COREX is one of the commercial smelting reduction processes. It uses the finer size ore and semi-soft coal instead of metallurgical coke to produce hot metal from iron ore. The use of top gas with high calorific value as a by-product export gas makes the process economical and green. The predictive thermochemical model of the COREX process presented here enables rapid computation of process parameters such as (1) required amount of ore, coal, and flux; (2) amount of slag and gas generated; and (3) gas compositions (based on the raw material and desired hot metal quality). The model helps in predicting the variations in process parameters with respect to the (1) degree of metallization and (2) post-combustion ratio for given raw material conditions. In general reduction in coal, flux, and oxygen, the requirement is concomitant with an increase in the degree of metallization and post-combustion ratio. The model reported here has been benchmarked using industrial data obtained from the JSW Steel Plant, India.

Thermochemical equilibrium modelling of a gasifying process

International Nuclear Information System (INIS)

Melgar, Andres; Perez, Juan F.; Laget, Hannes; Horillo, Alfonso

2007-01-01

This article discusses a mathematical model for the thermochemical processes in a downdraft biomass gasifier. The model combines the chemical equilibrium and the thermodynamic equilibrium of the global reaction, predicting the final composition of the producer gas as well as its reaction temperature. Once the composition of the producer gas is obtained, a range of parameters can be derived, such as the cold gas efficiency of the gasifier, the amount of dissociated water in the process and the heating value and engine fuel quality of the gas. The model has been validated experimentally. This work includes a parametric study of the influence of the gasifying relative fuel/air ratio and the moisture content of the biomass on the characteristics of the process and the producer gas composition. The model helps to predict the behaviour of different biomass types and is a useful tool for optimizing the design and operation of downdraft biomass gasifiers

Pitfalls and feedback when constructing topological pressure-temperature phase diagrams

Science.gov (United States)

Ceolin, R.; Toscani, S.; Rietveld, Ivo B.; Barrio, M.; Tamarit, J. Ll.

2017-04-01

The stability hierarchy between different phases of a chemical compound can be accurately reproduced in a topological phase diagram. This type of phase diagrams may appear to be the result of simple extrapolations, however, experimental complications quickly increase in the case of crystalline trimorphism (and higher order polymorphism). To ensure the accurate positioning of stable phase domains, a topological phase diagram needs to be consistent. This paper gives an example of how thermodynamic feedback can be used in the topological construction of phase diagrams to ensure overall consistency in a phase diagram based on the case of piracetam crystalline trimorphism.

Analysis of Efficiency of the Ship Propulsion System with Thermochemical Recuperation of Waste Heat

Science.gov (United States)

Cherednichenko, Oleksandr; Serbin, Serhiy

2018-03-01

One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources. The combined gas turbine and diesel engine plant with thermochemical recuperation of the heat of secondary energy resources has been considered. It is suggested to conduct the study with the help of mathematical modeling methods. The model takes into account basic physical correlations, material and thermal balances, phase equilibrium, and heat and mass transfer processes. The paper provides the results of mathematical modeling of the processes in a gas turbine and diesel engine power plant with thermochemical recuperation of the gas turbine exhaust gas heat by converting a hydrocarbon fuel. In such a plant, it is possible to reduce the specific fuel consumption of the diesel engine by 20%. The waste heat potential in a gas turbine can provide efficient hydrocarbon fuel conversion at the ratio of powers of the diesel and gas turbine engines being up to 6. When the diesel engine and gas turbine operate simultaneously with the use of the LNG vapor conversion products, the efficiency coefficient of the plant increases by 4-5%.

Pultrusion of a vertical axis wind turbine blade part-I: 3D thermo-chemical process simulation

NARCIS (Netherlands)

Baran, Ismet; Tutum, Cem C.; Hattel, Jesper H.; Akkerman, Remko

2015-01-01

A novel three dimensional thermo-chemical simulation of the pultrusion process is presented. A simulation is performed for the pultrusion of a NACA0018 blade profile having a curved geometry, as a part of the DeepWind project. The finite element/nodal control volume (FE/NCV) technique is used.

Pultrusion of a vertical axis wind turbine blade part-I: 3D thermo-chemical process simulation

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2015-01-01

novel three dimensional thermo-chemical simulation of the pultrusion process is presented. A simulation is performed for the pultrusion of a NACA0018 blade profile having a curved geometry, as a part of the DeepWind project. The finite element/nodal control volume (FE/NCV) technique is used. First...

Conceptual design model of the sulfur-iodine S-I thermochemical water splitting process for hydrogen production using nuclear heat source

International Nuclear Information System (INIS)

Gonzalez Rodriguez, Daniel; Parra, Lazaro Garcia

2011-01-01

Hydrogen is the most indicated candidate for its implementation as energy carrier in a future sustainable scenario. The current hydrogen production is based on fossils fuels; they have a huge contribution to the atmosphere pollution. Thermochemical water-splitting cycles do not have this issue because they use solar or nuclear heat; their environment impact is smaller than conventional fuels. The software based on chemical process simulation (CPS) can be used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. In the paper is developed a model for Sulfur-Iodine process in order to analyze his sensibility and calculate the efficiency and the influence of many parameters on this value. (author)

Conceptual design model of the sulfur-iodine S-I thermochemical water splitting process for hydrogen production using nuclear heat source

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Rodriguez, Daniel; Parra, Lazaro Garcia, E-mail: dgr@instec.cu, E-mail: lgarcia@instec.cu [Departamento de Ingenieria Nuclear, Instituto Superior de Ciencias y Tecnologias Aplicadas, La Habana (Cuba)

2011-07-01

Hydrogen is the most indicated candidate for its implementation as energy carrier in a future sustainable scenario. The current hydrogen production is based on fossils fuels; they have a huge contribution to the atmosphere pollution. Thermochemical water-splitting cycles do not have this issue because they use solar or nuclear heat; their environment impact is smaller than conventional fuels. The software based on chemical process simulation (CPS) can be used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. In the paper is developed a model for Sulfur-Iodine process in order to analyze his sensibility and calculate the efficiency and the influence of many parameters on this value. (author)

Phase diagram of spiking neural networks.

Science.gov (United States)

Seyed-Allaei, Hamed

2015-01-01

In computer simulations of spiking neural networks, often it is assumed that every two neurons of the network are connected by a probability of 2%, 20% of neurons are inhibitory and 80% are excitatory. These common values are based on experiments, observations, and trials and errors, but here, I take a different perspective, inspired by evolution, I systematically simulate many networks, each with a different set of parameters, and then I try to figure out what makes the common values desirable. I stimulate networks with pulses and then measure their: dynamic range, dominant frequency of population activities, total duration of activities, maximum rate of population and the occurrence time of maximum rate. The results are organized in phase diagram. This phase diagram gives an insight into the space of parameters - excitatory to inhibitory ratio, sparseness of connections and synaptic weights. This phase diagram can be used to decide the parameters of a model. The phase diagrams show that networks which are configured according to the common values, have a good dynamic range in response to an impulse and their dynamic range is robust in respect to synaptic weights, and for some synaptic weights they oscillates in α or β frequencies, independent of external stimuli.

Coupled thermochemical, isotopic evolution and heat transfer simulations in highly irradiated UO{sub 2} nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Piro, M.H.A., E-mail: markuspiro@gmail.com [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Banfield, J. [Nuclear Engineering Department, University of Tennessee, Knoxville, TN (United States); Clarno, K.T., E-mail: clarnokt@ornl.gov [Reactor and Nuclear Systems Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Simunovic, S. [Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Besmann, T.M. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Lewis, B.J.; Thompson, W.T. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON (Canada)

2013-10-15

Predictive capabilities for simulating irradiated nuclear fuel behavior are enhanced in the current work by coupling thermochemistry, isotopic evolution and heat transfer. Thermodynamic models that are incorporated into this framework not only predict the departure from stoichiometry of UO{sub 2}, but also consider dissolved fission and activation products in the fluorite oxide phase, noble metal inclusions, secondary oxides including uranates, zirconates, molybdates and the gas phase. Thermochemical computations utilize the spatial and temporal evolution of the fission and activation product inventory in the pellet, which is typically neglected in nuclear fuel performance simulations. Isotopic computations encompass the depletion, decay and transmutation of more than 2000 isotopes that are calculated at every point in space and time. These computations take into consideration neutron flux depression and the increased production of fissile plutonium near the fuel pellet periphery (i.e., the so-called “rim effect”). Thermochemical and isotopic predictions are in very good agreement with reported experimental measurements of highly irradiated UO{sub 2} fuel with an average burnup of 102 GW d t(U){sup −1}. Simulation results demonstrate that predictions are considerably enhanced when coupling thermochemical and isotopic computations in comparison to empirical correlations. Notice: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

Repair of Partly Misspecified Causal Diagrams.

Science.gov (United States)

Oates, Chris J; Kasza, Jessica; Simpson, Julie A; Forbes, Andrew B

2017-07-01

Errors in causal diagrams elicited from experts can lead to the omission of important confounding variables from adjustment sets and render causal inferences invalid. In this report, a novel method is presented that repairs a misspecified causal diagram through the addition of edges. These edges are determined using a data-driven approach designed to provide improved statistical efficiency relative to de novo structure learning methods. Our main assumption is that the expert is "directionally informed," meaning that "false" edges provided by the expert would not create cycles if added to the "true" causal diagram. The overall procedure is cast as a preprocessing technique that is agnostic to subsequent causal inferences. Results based on simulated data and data derived from an observational cohort illustrate the potential for data-assisted elicitation in epidemiologic applications. See video abstract at, http://links.lww.com/EDE/B208.

Simple method for evaluating Goldstone diagrams in an angular momentum coupled representation

International Nuclear Information System (INIS)

Kuo, T.T.S.; Shurpin, J.; Tam, K.C.; Osnes, E.; Ellis, P.J.

1981-01-01

A simple and convenient method is derived for evaluating linked Goldstone diagrams in an angular momentum coupled representation. Our method is general, and can be used to evaluate any effective interaction and/or effective operator diagrams for both closed-shell nuclei (vacuum to vacuum linked diagrams) and open-shell nuclei (valence linked diagrams). The techniques of decomposing diagrams into ladder diagrams, cutting open internal lines and cutting off one-body insertions are introduced. These enable us to determine angular momentum factors associated with diagrams in the coupled representation directly, without the need for carrying out complicated angular momentum algebra. A summary of diagram rules is given

Ceramic carbon electrode-based anodes for use in the Cu-Cl thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, Santhanam; Easton, E. Bradley [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada)

2010-05-15

We have investigated CCE materials prepared using 3-aminopropyl trimethoxysilane. Electrochemical experiments were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the Cu-Cl thermochemical cycle. CCE-based electrodes vastly outperform a bare carbon electrode. Optimization of the organosilicate loading revealed maximum electrode performance was achieved with 36 wt% and was explained in terms of the optimal balance of active area and anion transport properties. (author)

Diagrams for symmetric product orbifolds

International Nuclear Information System (INIS)

Pakman, Ari; Rastelli, Leonardo; Razamat, Shlomo S.

2009-01-01

We develop a diagrammatic language for symmetric product orbifolds of two-dimensional conformal field theories. Correlation functions of twist operators are written as sums of diagrams: each diagram corresponds to a branched covering map from a surface where the fields are single-valued to the base sphere where twist operators are inserted. This diagrammatic language facilitates the study of the large N limit and makes more transparent the analogy between symmetric product orbifolds and free non-abelian gauge theories. We give a general algorithm to calculate the leading large N contribution to four-point correlators of twist fields.

How Design Guides Learning from Matrix Diagrams

Science.gov (United States)

van der Meij, Jan; van Amelsvoort, Marije; Anjewierden, Anjo

2017-01-01

Compared to text, diagrams are superior in their ability to structure and summarize information and to show relations between concepts and ideas. Perceptual cues, like arrows, are expected to improve the retention of diagrams by guiding the learner towards important elements or showing a preferred reading sequence. In our experiment, we analyzed…

Improvement in Performance of a Thermochemical Heat Storage System by Implementing an Internal Heat Recovery System

NARCIS (Netherlands)

Gaeini, M.; Saris, L.; Zondag, H.A.; Rindt, C.C.M.

A lab-scale prototype of a thermochemical heat storage system, employing a water-zeolite 13X as the working pair, is designed and optimized for providing hot tap water. During the hydration process, humid air is introduced to the packed bed reactor filled with dehydrated zeolite 13X, and the

Interrelations between random walks on diagrams (graphs) with and without cycles.

Science.gov (United States)

Hill, T L

1988-05-01

Three topics are discussed. A discrete-state, continuous-time random walk with one or more absorption states can be studied by a presumably new method: some mean properties, including the mean time to absorption, can be found from a modified diagram (graph) in which each absorption state is replaced by a one-way cycle back to the starting state. The second problem is a random walk on a diagram (graph) with cycles. The walk terminates on completion of the first cycle. This walk can be replaced by an equivalent walk on a modified diagram with absorption. This absorption diagram can in turn be replaced by another modified diagram with one-way cycles back to the starting state, just as in the first problem. The third problem, important in biophysics, relates to a long-time continuous walk on a diagram with cycles. This diagram can be transformed (in two steps) to a modified, more-detailed, diagram with one-way cycles only. Thus, the one-way cycle fluxes of the original diagram can be found from the state probabilities of the modified diagram. These probabilities can themselves be obtained by simple matrix inversion (the probabilities are determined by linear algebraic steady-state equations). Thus, a simple method is now available to find one-way cycle fluxes exactly (previously Monte Carlo simulation was required to find these fluxes, with attendant fluctuations, for diagrams of any complexity). An incidental benefit of the above procedure is that it provides a simple proof of the one-way cycle flux relation Jn +/- = IIn +/- sigma n/sigma, where n is any cycle of the original diagram.

Peircean diagrams of time

DEFF Research Database (Denmark)

Øhrstrøm, Peter

2011-01-01

Some very good arguments can be given in favor of the Augustinean wisdom, according to which it is impossible to provide a satisfactory definition of the concept of time. However, even in the absence of a proper definition, it is possible to deal with conceptual problems regarding time. It can...... be done in terms of analogies and metaphors. In particular, it is attractive to make use of Peirce's diagrams by means of which various kinds of conceptual experimentation can be carried out. This paper investigates how Peircean diagrams can be used within the study of time. In particular, we discuss 1......) the topological properties of time, 2) the implicative structure in tense logic, 3) the notions of open future and branching time models, and finally 4) tenselogical alternatives to branching time models....

Extended sequence diagram for human system interaction

International Nuclear Information System (INIS)

Hwang, Jong Rok; Choi, Sun Woo; Ko, Hee Ran; Kim, Jong Hyun

2012-01-01

Unified Modeling Language (UML) is a modeling language in the field of object oriented software engineering. The sequence diagram is a kind of interaction diagram that shows how processes operate with one another and in what order. It is a construct of a message sequence chart. It depicts the objects and classes involved in the scenario and the sequence of messages exchanged between the objects needed to carry out the functionality of the scenario. This paper proposes the Extended Sequence Diagram (ESD), which is capable of depicting human system interaction for nuclear power plants, as well as cognitive process of operators analysis. In the conventional sequence diagram, there is a limit to only identify the activities of human and systems interactions. The ESD is extended to describe operators' cognitive process in more detail. The ESD is expected to be used as a task analysis method for describing human system interaction. The ESD can also present key steps causing abnormal operations or failures and diverse human errors based on cognitive condition

Optimization of waste to energy routes through biochemical and thermochemical treatment options of municipal solid waste in Hyderabad, Pakistan

International Nuclear Information System (INIS)

Korai, Muhammad Safar; Mahar, Rasool Bux; Uqaili, Muhammad Aslam

2016-01-01

Highlights: • Existing practice of municipal solid waste management of Hyderabad city, Pakistan have been analyzed. • Development of scenarios on basis of nature of waste components for optimizing waste to energy route. • Analyzing the biochemical and thermochemical potential of MSW through various scenarios. • Evaluation of various treatment technologies under scenarios to optimize waste to energy route. - Abstract: Improper disposal of municipal solid waste (MSW) has created many environmental problems in Pakistan and the country is facing energy shortages as well. The present study evaluates the biochemical and thermochemical treatment options of MSW in order to address both the endemic environmental challenges and in part the energy shortage. According to the nature of waste components, a number of scenarios were developed to optimize the waste to energy (WTE) routes. The evaluation of treatment options has been performed by mathematical equations using the special characteristics of MSW. The power generation potential (PGP) of biochemical (anaerobic digestion) has been observed in the range of 5.9–11.3 kW/ton day under various scenarios. The PGP of Refuse Derived Fuel (RDF), Mass Burn Incinerator (MBI), Gasification/Pyrolysis (Gasi./Pyro.) and Plasma Arc Gasification (PAG) have been found to be in the range of 2.7–118.6 kW/ton day, 3.8–164.7 kW/ton day, 4.2–184.5 kW/ton day and 5.2–224 kW/ton day, respectively. The highest values of biochemical and all thermochemical technologies have been obtained through the use of scenarios including the putrescible components (PCs) of MSW such as food and yard wastes, and the non-biodegradable components (NBCs) of MSW such as plastic, rubber, leather, textile and wood respectively. Therefore, routes which include these components are the optimized WTE routes for maximum PGP by biochemical and thermochemical treatments of MSW. The findings of study lead to recommend that socio-economic and environmental

An Introduction to Binary Decision Diagrams

DEFF Research Database (Denmark)

Andersen, Henrik Reif

1996-01-01

This note is a short introduction to Binary Decision Diagrams (BDDs). It provides some background knowledge and describes the core algorithms. It is used in the course "C4340 Advanced Algorithms" at the Technical University of Denmark, autumn 1996.......This note is a short introduction to Binary Decision Diagrams (BDDs). It provides some background knowledge and describes the core algorithms. It is used in the course "C4340 Advanced Algorithms" at the Technical University of Denmark, autumn 1996....

The Butterfly diagram leopard skin pattern

Science.gov (United States)

Ternullo, Maurizio

2011-08-01

A time-latitude diagram where spotgroups are given proportional relevance to their area is presented. The diagram reveals that the spotted area distribution is higly dishomogeneous, most of it being concentrated in few, small portions (``knots'') of the Butterfly Diagram; because of this structure, the BD may be properly described as a cluster of knots. The description, assuming that spots scatter around the ``spot mean latitude'' steadily drifting equatorward, is challenged. Indeed, spots cluster around at as many latitudes as knots; a knot may appear at either lower or higher latitudes than previous ones, in a seemingly random way; accordingly, the spot mean latitude abruptly drifts equatorward or even poleward at any knot activation, in spite of any smoothing procedure. Preliminary analyses suggest that the activity splits, in any hemisphere, into two or more distinct ``activity waves'', drifting equatorward at a rate higher than the spot zone as a whole.

Construction of UML class diagram with Model-Driven Development

Directory of Open Access Journals (Sweden)

Tomasz Górski

2016-03-01

Full Text Available Model transformations play a key role in software development projects based on Model--Driven Development (MDD principles. Transformations allow for automation of repetitive and well-defined steps, thus shortening design time and reducing a number of errors. In the object-oriented approach, the key elements are use cases. They are described, modelled and later designed until executable application code is obtained. The aim of the paper is to present transformation of a model-to-model type, Communication-2-Class, which automates construction of Unified Modelling Language (UML class diagram in the context of the analysis/design model. An UML class diagram is created based on UML communication diagram within use case realization. As a result, a class diagram shows all of the classes involved in the use case realization and the relationships among them. The plug-in which implements Communication-2-Class transformation was implemented in the IBM Rational Software Architect. The article presents the tests results of developed plug-in, which realizes Communication-2-Class transformation, showing capabilities of shortening use case realization’s design time.[b]Keywords[/b]: Model-Driven Development, transformations, Unified Modelling Language, analysis/design model, UML class diagram, UML communication diagram

Efficient computation of clipped Voronoi diagram for mesh generation

KAUST Repository

Yan, Dongming

2013-04-01

The Voronoi diagram is a fundamental geometric structure widely used in various fields, especially in computer graphics and geometry computing. For a set of points in a compact domain (i.e. a bounded and closed 2D region or a 3D volume), some Voronoi cells of their Voronoi diagram are infinite or partially outside of the domain, but in practice only the parts of the cells inside the domain are needed, as when computing the centroidal Voronoi tessellation. Such a Voronoi diagram confined to a compact domain is called a clipped Voronoi diagram. We present an efficient algorithm to compute the clipped Voronoi diagram for a set of sites with respect to a compact 2D region or a 3D volume. We also apply the proposed method to optimal mesh generation based on the centroidal Voronoi tessellation. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved.

Efficient computation of clipped Voronoi diagram for mesh generation

KAUST Repository

Yan, Dongming; Wang, Wen Ping; Lé vy, Bruno L.; Liu, Yang

2013-01-01

The Voronoi diagram is a fundamental geometric structure widely used in various fields, especially in computer graphics and geometry computing. For a set of points in a compact domain (i.e. a bounded and closed 2D region or a 3D volume), some Voronoi cells of their Voronoi diagram are infinite or partially outside of the domain, but in practice only the parts of the cells inside the domain are needed, as when computing the centroidal Voronoi tessellation. Such a Voronoi diagram confined to a compact domain is called a clipped Voronoi diagram. We present an efficient algorithm to compute the clipped Voronoi diagram for a set of sites with respect to a compact 2D region or a 3D volume. We also apply the proposed method to optimal mesh generation based on the centroidal Voronoi tessellation. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved.

A Community Based Systems Diagram of Obesity Causes.

Directory of Open Access Journals (Sweden)

Steven Allender

Full Text Available Application of system thinking to the development, implementation and evaluation of childhood obesity prevention efforts represents the cutting edge of community-based prevention. We report on an approach to developing a system oriented community perspective on the causes of obesity.Group model building sessions were conducted in a rural Australian community to address increasing childhood obesity. Stakeholders (n = 12 built a community model that progressed from connection circles to causal loop diagrams using scripts from the system dynamics literature. Participants began this work in identifying change over time in causes and effects of childhood obesity within their community. The initial causal loop diagram was then reviewed and elaborated by 50 community leaders over a full day session.The process created a causal loop diagram representing community perceptions of determinants and causes of obesity. The causal loop diagram can be broken down into four separate domains; social influences; fast food and junk food; participation in sport; and general physical activity.This causal loop diagram can provide the basis for community led planning of a prevention response that engages with multiple levels of existing settings and systems.

An approach for continuous cooling transformation (CCT) diagrams of aluminium alloys

International Nuclear Information System (INIS)

Herding, T.; Kessler, O.; Hoffmann, F.; Mayr, P.

2002-01-01

Two different kinds of time temperature transformation (TTT) diagrams are known. The first one are isothermal transformation (IT) diagrams and the second one continuous cooling transformation (CCT) diagrams. These diagrams are important for the correct heat treatment of aluminium alloys, because they provide information about the required quenching rate, which is necessary to obtain a supersaturated solid solution during age hardening. Furthermore, it is possible to determine the lowest quenching rate, which permits both a high strength and a small distortion of the component after age hardening. In the literature IT diagrams for different aluminium alloys are available. To determine these diagrams, a solution annealing followed by quenching to defined temperatures is necessary. At these temperatures the alloy is kept isothermally until a transformation has started. These diagrams are not directly portable on continuous cooling, because of the different cooling paths. (orig.)

Thermochemical studies on complex of [Sm(o-NBA)_3phen]_2

Institute of Scientific and Technical Information of China (English)

肖圣雄; 张建军; 李旭; 李强国; 任宁; 李环

2010-01-01

A ternary complex [Sm(o-NBA)3phen]2 (o-NBA: o-Nitrobenzoate; phen: 1,10-phenanthroline) was synthesized and characterized by elemental analysis, IR, molar conductance, and thermogravimetric analysis. The dissolution enthalpies of SmCl3·6H2O(s), o-HNBA(s) and phen·H2O(s) in mixed solvent (VHCl :VDMF :VDMSO=2:2:1) were determined by calorimetry at 298.15 K. The enthalpy change of the reaction was determined to be rHmΔθ=252.49±1.60 kJ/mol. Using the relevant data in the literature and a thermochemical recycle ...

Effects of Three Diagram Instruction Methods on Transfer of Diagram Comprehension Skills: The Critical Role of Inference While Learning

Science.gov (United States)

Cromley, Jennifer G.; Bergey, Bradley W.; Fitzhugh, Shannon; Newcombe, Nora; Wills, Theodore W.; Shipley, Thomas F.; Tanaka, Jacqueline C.

2013-01-01

Can students be taught to better comprehend the diagrams in their textbooks? Can such teaching transfer to uninstructed diagrams in the same domain or even in a new domain? What methods work best for these goals? Building on previous research showing positive results compared to control groups in both laboratory studies and short-term…

eulerAPE: drawing area-proportional 3-Venn diagrams using ellipses.

Science.gov (United States)

Micallef, Luana; Rodgers, Peter

2014-01-01

Venn diagrams with three curves are used extensively in various medical and scientific disciplines to visualize relationships between data sets and facilitate data analysis. The area of the regions formed by the overlapping curves is often directly proportional to the cardinality of the depicted set relation or any other related quantitative data. Drawing these diagrams manually is difficult and current automatic drawing methods do not always produce appropriate diagrams. Most methods depict the data sets as circles, as they perceptually pop out as complete distinct objects due to their smoothness and regularity. However, circles cannot draw accurate diagrams for most 3-set data and so the generated diagrams often have misleading region areas. Other methods use polygons to draw accurate diagrams. However, polygons are non-smooth and non-symmetric, so the curves are not easily distinguishable and the diagrams are difficult to comprehend. Ellipses are more flexible than circles and are similarly smooth, but none of the current automatic drawing methods use ellipses. We present eulerAPE as the first method and software that uses ellipses for automatically drawing accurate area-proportional Venn diagrams for 3-set data. We describe the drawing method adopted by eulerAPE and we discuss our evaluation of the effectiveness of eulerAPE and ellipses for drawing random 3-set data. We compare eulerAPE and various other methods that are currently available and we discuss differences between their generated diagrams in terms of accuracy and ease of understanding for real world data.

eulerAPE: drawing area-proportional 3-Venn diagrams using ellipses.

Directory of Open Access Journals (Sweden)

Luana Micallef

Full Text Available Venn diagrams with three curves are used extensively in various medical and scientific disciplines to visualize relationships between data sets and facilitate data analysis. The area of the regions formed by the overlapping curves is often directly proportional to the cardinality of the depicted set relation or any other related quantitative data. Drawing these diagrams manually is difficult and current automatic drawing methods do not always produce appropriate diagrams. Most methods depict the data sets as circles, as they perceptually pop out as complete distinct objects due to their smoothness and regularity. However, circles cannot draw accurate diagrams for most 3-set data and so the generated diagrams often have misleading region areas. Other methods use polygons to draw accurate diagrams. However, polygons are non-smooth and non-symmetric, so the curves are not easily distinguishable and the diagrams are difficult to comprehend. Ellipses are more flexible than circles and are similarly smooth, but none of the current automatic drawing methods use ellipses. We present eulerAPE as the first method and software that uses ellipses for automatically drawing accurate area-proportional Venn diagrams for 3-set data. We describe the drawing method adopted by eulerAPE and we discuss our evaluation of the effectiveness of eulerAPE and ellipses for drawing random 3-set data. We compare eulerAPE and various other methods that are currently available and we discuss differences between their generated diagrams in terms of accuracy and ease of understanding for real world data.

XLOOPS - a package calculating one- and two-loop diagrams

International Nuclear Information System (INIS)

Bruecher, L.

1997-01-01

A program package for calculating massive one- and two-loop diagrams is introduced. It consists of five parts: - a graphical user interface, - routines for generating diagrams from particle input, - procedures for calculating one-loop integrals both analytically and numerically, - routines for massive two-loop integrals, - programs for numerical integration of two-loop diagrams. Here the graphical user interface and the text interface to Maple are presented. (orig.)

Oak Ridge K-25 Site Technology Logic Diagram. Volume 2, Technology Logic Diagrams

Energy Technology Data Exchange (ETDEWEB)

Fellows, R.L. [ed.

1993-02-26

The Oak Ridge K-25 Technology Logic Diagram (TLD), a decision support tool for the K-25 Site, was developed to provide a planning document that relates envirorunental restoration and waste management problems at the Oak Ridge K-25 Site to potential technologies that can remediate these problems. The TLD technique identifies the research necessary to develop these technologies to a state that allows for technology transfer and application to waste management, remedial action, and decontamination and decommissioning activities. The TLD consists of four separate volumes-Vol. 1, Vol. 2, Vol. 3A, and Vol. 3B. Volume 1 provides introductory and overview information about the TLD. This volume, Volume 2, contains logic diagrams with an index. Volume 3 has been divided into two separate volumes to facilitate handling and use.

Grotrian diagrams of highly ionized iron Fe(VIII)-Fe(XXVI)

International Nuclear Information System (INIS)

Mori, Kazuo; Otsuka, Masamoto; Kato, Takako.

1977-08-01

Energy levels and Grotrian diagrams of Fe(VIII) to Fe(XXVI) are presented. This report summarized the data published recently up to 1976, and the wavelength tables compiled were converted to the Grotrian diagrams. The diagrams showing transition from one energy level to another are called Grotrian diagrams. Typical examples of the diagrams are found in the book by Bashkin et al. In the present diagrams, all lines are drawn in parallel, and connected to the extended lines from lower levels. As the results, locally dense packing of lines and figures is avoided. The ordinate of the diagrams indicates level energy, and the J values are shown on the left side of the levels. The wavelength values in angstrom unit are written in parallel with the vertical transition lines. This vertical lines show the resonance transition having absorption oscillator strength f larger than 0.1. The present diagrams are the combination of the tables of wavelength and energy level. Accordingly, the desired wavelength and level energy are easily found. The figures of wavelength are lined up in various groups, so that the characteristics of the transition can be discriminated at a glance. Wavelength and level energy have been mostly derived from experimental spectra in laboratory or solar plasma, except a few by Fawcett's prediction. (Kato, T.)

Membranes for H2 generation from nuclear powered thermochemical cycles

International Nuclear Information System (INIS)

Nenoff, Tina Maria; Ambrosini, Andrea; Garino, Terry J.; Gelbard, Fred; Leung, Kevin; Navrotsky, Alexandra; Iyer, Ratnasabapathy G.; Axness, Marlene

2006-01-01

In an effort to produce hydrogen without the unwanted greenhouse gas byproducts, high-temperature thermochemical cycles driven by heat from solar energy or next-generation nuclear power plants are being explored. The process being developed is the thermochemical production of Hydrogen. The Sulfur-Iodide (SI) cycle was deemed to be one of the most promising cycles to explore. The first step of the SI cycle involves the decomposition of H 2 SO 4 into O 2 , SO 2 , and H 2 O at temperatures around 850 C. In-situ removal of O 2 from this reaction pushes the equilibrium towards dissociation, thus increasing the overall efficiency of the decomposition reaction. A membrane is required for this oxygen separation step that is capable of withstanding the high temperatures and corrosive conditions inherent in this process. Mixed ionic-electronic perovskites and perovskite-related structures are potential materials for oxygen separation membranes owing to their robustness, ability to form dense ceramics, capacity to stabilize oxygen nonstoichiometry, and mixed ionic/electronic conductivity. Two oxide families with promising results were studied: the double-substituted perovskite A x Sr 1-x Co 1-y B y O 3-δ (A=La, Y; B=Cr-Ni), in particular the family La x Sr 1-x Co 1-y Mn y O 3-δ (LSCM), and doped La 2 Ni 1-x M x O 4 (M = Cu, Zn). Materials and membranes were synthesized by solid state methods and characterized by X-ray and neutron diffraction, SEM, thermal analyses, calorimetry and conductivity. Furthermore, we were able to leverage our program with a DOE/NE sponsored H 2 SO 4 decomposition reactor study (at Sandia), in which our membranes were tested in the actual H 2 SO 4 decomposition step

Triangular Diagrams Teach Steady and Dynamic Behaviour of Catalytic Reactions.

Science.gov (United States)

Klusacek, K.; And Others

1989-01-01

Illustrates how triangular diagrams can aid in presenting some of the rather complex transient interactions that occur among gas and surface species during heterogeneous catalytic reactions. The basic equations and numerical examples are described. Classroom use of the triangular diagram is discussed. Several diagrams and graphs are provided. (YP)

Evaluation energy efficiency of bioconversion knot rejects to ethanol in comparison to other thermochemically pretreated biomass

Science.gov (United States)

Zhaojiang Wang; Menghua Qin; J.Y. Zhu; Guoyu Tian; Zongquan. Li

2013-01-01

Rejects from sulfite pulp mill that otherwise would be disposed of by incineration were converted to ethanol by a combined physical–biological process that was comprised of physical refining and simultaneous saccharification and fermentation (SSF). The energy efficiency was evaluated with comparison to thermochemically pretreated biomass, such as those pretreated by...

Analysis of Sequence Diagram Layout in Advanced UML Modelling Tools

Directory of Open Access Journals (Sweden)

Ņikiforova Oksana

2016-05-01

Full Text Available System modelling using Unified Modelling Language (UML is the task that should be solved for software development. The more complex software becomes the higher requirements are stated to demonstrate the system to be developed, especially in its dynamic aspect, which in UML is offered by a sequence diagram. To solve this task, the main attention is devoted to the graphical presentation of the system, where diagram layout plays the central role in information perception. The UML sequence diagram due to its specific structure is selected for a deeper analysis on the elements’ layout. The authors research represents the abilities of modern UML modelling tools to offer automatic layout of the UML sequence diagram and analyse them according to criteria required for the diagram perception.

Sustainable energy with thermochemical storage; Duurzame energie met thermochemische opslag

Energy Technology Data Exchange (ETDEWEB)

Bakker, M. [ECN Efficiency and Infrastructure, Petten (Netherlands)

2010-03-15

The Energy research Centre of the Netherlands ECN) foresees an important role for heat in sustainable construction of buildings. Using salt hydrates the surplus of heat can be stored in the summer which then can be used in the winter. By means of thermochemical storage natural gas for heating tap water or houses is no longer necessary. [Dutch] Energieonderzoek Centrum Nederland (ECN) ziet voor warmteopslag een belangrijke rol weggelegd in het duurzaam bouwen. Met behulp van zouthydraten kan de overtollige warmte in de zomer opgeslagen worden om deze in de winter weer vrij te maken. Met deze thermochemische opslag is in de nabije toekomst aardgas overbodig voor de verwarming van kraanwater of woonhuis.

Thermochemical storage for long‐term low‐temperature applications : a review on current research at material and prototype scales

NARCIS (Netherlands)

Scapino, L.; Zondag, H.A.; van Bael, J.; Diriken, J.; Rindt, C.C.M.

2016-01-01

Thermochemical heat storage has the potential to store large amount of energy from renewables and other intermittent distributed sources, ideally without losses typical of sensible heat storage. owever, in order to have a commercially attractive system able to compete with conventional storage

Thermochemical and thermophysical properties of minor actinide compounds

International Nuclear Information System (INIS)

Minato, Kazuo; Takano, Masahide; Otobe, Haruyoshi; Nishi, Tsuyoshi; Akabori, Mitsuo; Arai, Yasuo

2009-01-01

Burning or transmutation of minor actinides (MA: Np, Am, Cm) that are classified as the high-level radioactive waste in the current nuclear fuel cycle is an option for the advanced nuclear fuel cycle. Although the thermochemical and thermophysical properties of minor actinide compounds are essential for the design of MA-bearing fuels and analysis of their behavior, the experimental data on minor actinide compounds are limited. To support the research and development of the MA-bearing fuels, the property measurements were carried out on minor actinide nitrides and oxides. The lattice parameters and their thermal expansions were measured by high-temperature X-ray diffractometry. The specific heat capacities were measured by drop calorimetry and the thermal diffusivities by laser-flash method. The thermal conductivities were determined by the specific heat capacities, thermal diffusivities and densities. The oxygen potentials were measured by electromotive force method.

Vesicle computers: Approximating a Voronoi diagram using Voronoi automata

International Nuclear Information System (INIS)

Adamatzky, Andrew; De Lacy Costello, Ben; Holley, Julian; Gorecki, Jerzy; Bull, Larry

2011-01-01

Highlights: → We model irregular arrangements of vesicles filled with chemical systems. → We examine influence of precipitation threshold on the system's computational potential. → We demonstrate computation of Voronoi diagram and skeleton. - Abstract: Irregular arrangements of vesicles filled with excitable and precipitating chemical systems are imitated by Voronoi automata - finite-state machines defined on a planar Voronoi diagram. Every Voronoi cell takes four states: resting, excited, refractory and precipitate. A resting cell excites if it has at least one neighbour in an excited state. The cell precipitates if the ratio of excited cells in its neighbourhood versus the number of neighbours exceeds a certain threshold. To approximate a Voronoi diagram on Voronoi automata we project a planar set onto the automaton lattice, thus cells corresponding to data-points are excited. Excitation waves propagate across the Voronoi automaton, interact with each other and form precipitate at the points of interaction. The configuration of the precipitate represents the edges of an approximated Voronoi diagram. We discover the relationship between the quality of the Voronoi diagram approximation and the precipitation threshold, and demonstrate the feasibility of our model in approximating Voronoi diagrams of arbitrary-shaped objects and in constructing a skeleton of a planar shape.

Developing Tool Support for Problem Diagrams with CPN and VDM++

DEFF Research Database (Denmark)

Tjell, Simon; Lassen, Kristian Bisgaard

2008-01-01

In this paper, we describe ongoing work on the development of tool support for formal description of domains found in Problem Diagrams. The purpose of the tool is to handle the generation of a CPN model based on a collection of Problem Diagrams. The Problem Diagrams are used for representing the ...

A Generalized Wave Diagram for Moving Sources

Science.gov (United States)

Alt, Robert; Wiley, Sam

2004-12-01

Many introductory physics texts1-5 accompany the discussion of the Doppler effect and the formation of shock waves with diagrams illustrating the effect of a source moving through an elastic medium. Typically these diagrams consist of a series of equally spaced dots, representing the location of the source at different times. These are surrounded by a series of successively smaller circles representing wave fronts (see Fig. 1). While such a diagram provides a clear illustration of the shock wave produced by a source moving at a speed greater than the wave speed, and also the resultant pattern when the source speed is less than the wave speed (the Doppler effect), the texts do not often show the details of the construction. As a result, the key connection between the relative distance traveled by the source and the distance traveled by the wave is not explicitly made. In this paper we describe an approach emphasizing this connection that we have found to be a useful classroom supplement to the usual text presentation. As shown in Fig. 2 and Fig. 3, the Doppler effect and the shock wave can be illustrated by diagrams generated by the construction that follows.

Testing of multidimensional tectonomagmatic discrimination diagrams on fresh and altered rocks

Directory of Open Access Journals (Sweden)

Rivera-Gómez M. Abdelaly

2016-04-01

Full Text Available We evaluated 55 multidimensional diagrams proposed during 2004-2013 for the tectonic discrimination of ultrabasic, basic, intermediate, and acid magmas. The Miocene to Recent rock samples for testing the diagrams had not been used for constructing them. Eighteen test studies (2 from ocean island; 2 from ocean island/continental rift; 6 from continental rift; 4 from continental arc; 2 from island arc; 1 from mid-ocean ridge, and 1 from collision of relatively fresh rocks fully confirmed the satisfactory functioning of these diagrams for all tectonic fields for which they were proposed. Eight additional case studies on hydrothermally altered or moderately to highly weathered rocks were also presented to achieve further understanding of the functioning of these diagrams. For these rocks as well, the diagrams indicated the expected tectonic setting. We also show that for testing or using these diagrams the freely-available geochemistry databases should be used with caution but certainly after ascertaining the correct magma types to select the appropriate diagram sets. The results encourage us to recommend these diagrams for deciphering the tectonic setting of older terranes or areas with complex or transitional tectonic settings.

Logical and Geometrical Distance in Polyhedral Aristotelian Diagrams in Knowledge Representation

Directory of Open Access Journals (Sweden)

Lorenz Demey

2017-09-01

Full Text Available Aristotelian diagrams visualize the logical relations among a finite set of objects. These diagrams originated in philosophy, but recently, they have also been used extensively in artificial intelligence, in order to study (connections between various knowledge representation formalisms. In this paper, we develop the idea that Aristotelian diagrams can be fruitfully studied as geometrical entities. In particular, we focus on four polyhedral Aristotelian diagrams for the Boolean algebra B 4 , viz. the rhombic dodecahedron, the tetrakis hexahedron, the tetraicosahedron and the nested tetrahedron. After an in-depth investigation of the geometrical properties and interrelationships of these polyhedral diagrams, we analyze the correlation (or lack thereof between logical (Hamming and geometrical (Euclidean distance in each of these diagrams. The outcome of this analysis is that the Aristotelian rhombic dodecahedron and tetrakis hexahedron exhibit the strongest degree of correlation between logical and geometrical distance; the tetraicosahedron performs worse; and the nested tetrahedron has the lowest degree of correlation. Finally, these results are used to shed new light on the relative strengths and weaknesses of these polyhedral Aristotelian diagrams, by appealing to the congruence principle from cognitive research on diagram design.

Mollier-h,x diagram for moist flue gas

Energy Technology Data Exchange (ETDEWEB)

Mueller, H; Hultsch, T; Suder, M

1984-07-01

Diagrams and formulae are presented for calculation of enthalpy and moisture content of flue gas from brown coal, heating oil, black coal and brown coal briquet combustion. The enthalpy (in kJ/kg) and moisture (g/kg) diagrams were established by computer graphics for pressure 0.1 MPa. A further diagram is provided for enthalpy and flue gas moisture, varying the combustion air supply according to coal dust and to grate firing. These thermodynamic calculations are regarded as significant for assessing methods of flue gas cooling below the moisture dew point and for waste heat recovery. 3 references.

Research principles and the construction of mnemonic diagrams

Science.gov (United States)

Venda, V. F.; Mitkin, A. A.

1973-01-01

Mnemonic diagrams are defined as a variety of information display devices, the essential element of which is conventional graphical presentation of technological or functional-operational links in a controlled system or object. Graphically displaying the operational structure of an object, the interd dependence between different parameters, and the interdependence between indicators and control organs, the mneomonic diagram reduces the load on the operator's memory and facilitates perception and reprocessing of information and decision making, while at the same time playing the role of visual support to the information activity of the operator. The types of mnemonic diagrams are listed.

Infrared thermography method for fast estimation of phase diagrams

Energy Technology Data Exchange (ETDEWEB)

Palomo Del Barrio, Elena [Université de Bordeaux, Institut de Mécanique et d’Ingénierie, Esplanade des Arts et Métiers, 33405 Talence (France); Cadoret, Régis [Centre National de la Recherche Scientifique, Institut de Mécanique et d’Ingénierie, Esplanade des Arts et Métiers, 33405 Talence (France); Daranlot, Julien [Solvay, Laboratoire du Futur, 178 Av du Dr Schweitzer, 33608 Pessac (France); Achchaq, Fouzia, E-mail: fouzia.achchaq@u-bordeaux.fr [Université de Bordeaux, Institut de Mécanique et d’Ingénierie, Esplanade des Arts et Métiers, 33405 Talence (France)

2016-02-10

Highlights: • Infrared thermography is proposed to determine phase diagrams in record time. • Phase boundaries are detected by means of emissivity changes during heating. • Transition lines are identified by using Singular Value Decomposition techniques. • Different binary systems have been used for validation purposes. - Abstract: Phase change materials (PCM) are widely used today in thermal energy storage applications. Pure PCMs are rarely used because of non adapted melting points. Instead of them, mixtures are preferred. The search of suitable mixtures, preferably eutectics, is often a tedious and time consuming task which requires the determination of phase diagrams. In order to accelerate this screening step, a new method for estimating phase diagrams in record time (1–3 h) has been established and validated. A sample composed by small droplets of mixtures with different compositions (as many as necessary to have a good coverage of the phase diagram) deposited on a flat substrate is first prepared and cooled down to ambient temperature so that all droplets crystallize. The plate is then heated at constant heating rate up to a sufficiently high temperature for melting all the small crystals. The heating process is imaged by using an infrared camera. An appropriate method based on singular values decomposition technique has been developed to analyze the recorded images and to determine the transition lines of the phase diagram. The method has been applied to determine several simple eutectic phase diagrams and the reached results have been validated by comparison with the phase diagrams obtained by Differential Scanning Calorimeter measurements and by thermodynamic modelling.

Feasibility and comparative studies of thermochemical liquefaction of Camellia oleifera cake in different supercritical organic solvents for producing bio-oil

International Nuclear Information System (INIS)

Chen, Hongmei; Zhai, Yunbo; Xu, Bibo; Xiang, Bobin; Zhu, Lu; Li, Ping; Liu, Xiaoting; Li, Caiting; Zeng, Guangming

2015-01-01

Highlights: • Thermochemical liquefaction of COC was a prominent process for producing bio-oil. • Type of solvent affected the yield and composition of bio-oil considerably. • Liquefaction of COC in SCEL at 300 °C was preferred for producing bio-oil. - Abstract: Thermochemical liquefaction of Camellia oleifera cake (COC) for producing bio-oil was conducted in supercritical methanol (SCML), ethanol (SCEL) and acetone (SCAL), respectively. GC–MS, elemental analysis and ICP-OES were used to characterize properties of bio-oil. Results showed that thermochemical liquefaction of COC was a prominent process for generating bio-oil. Increase of temperature was beneficial to the increase of bio-oil yield, and yield of bio-oil followed the sequence of SCAL > SCEL > SCML. In spite of the highest bio-oil yield, the lowest calorific value and highest contents of Zn, Pb, Cd, Ni, Fe, Mn, and Cr were found in bio-oil from SCAL. Though SCML has very similar bio-oil composition and calorific value with SCEL, higher bio-oil yield and lower contents of heavy metals could be obtained with SCEL, especially in bio-oil from SCEL at 300 °C. Moreover, the origin of ethanol could make the bio-oil product totally renewable. Therefore, liquefaction of COC in SCEL at 300 °C could have great potential in generating bio-oil

Efficiency of the sulfur–iodine thermochemical water splitting process for hydrogen production based on ADS (accelerator driven system)

International Nuclear Information System (INIS)

García, Lázaro; González, Daniel; García, Carlos; García, Laura; Brayner, Carlos

2013-01-01

The current hydrogen production is based on fossil fuels; they have a huge contribution to the atmosphere's pollution. Thermochemical water splitting cycles don't present this issue because the required process heat is obtained from nuclear energy and therefore, the environmental impact is smaller than using conventional fuels. Although, solar hydrogen production could be also used for practical applications because it's lower environmental impact. One of the promising approaches to produce large quantities of hydrogen in an efficient way using nuclear energy is the sulfur–iodine (S–I) thermochemical water splitting cycle. The nuclear source proposed in this paper is a pebble bed gas cooled transmutation facility. Pebble bed very high temperature advanced systems have great perspectives to assume the future nuclear energy. Softwares based on CPS (chemical process simulation) can be used to simulate the thermochemical water splitting sulfur-iodine cycle for hydrogen production. In this paper, a model for analyzing the sulfur-iodine process sensibility respect to the thermodynamics parameters: temperature, pressure and mass flow is developed. Efficiency is also calculated and the influence of different parameters on this value. The behavior of the proposed model for different values of initial reactant's flow, is analyzed. - Highlights: • Chemical Process Simulation (CPS) of the complete sulfur iodine cycle. • Conceptual design of an accelerator driven system for hydrogen production. • Radial and axial temperature profile for the end of stationary cycle (EOC). • Thermal stability of the sulfuric and hydriodic acid sections determination. • Sulfur iodine cycle efficiency analyses for different heat flow from the ADS

Improvements in Logic Diagram of Computerized Procedure System of APR1400

Energy Technology Data Exchange (ETDEWEB)

Kang, Sungkweon; Seong, Nokyu [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

The Computerized Procedure System (CPS) has been improved since it is installed in Shin-Kori 3 and 4 Nuclear Power Plants. It is one of operating support systems of digital Main Control Room (MCR) and provides many functions to operators in executing the procedure. CPS can effectively remove the human errors by supporting the procedure flow and logic diagram. This paper describes the logic diagram of CPS of reference power plant and shows the improved logic diagram of CPS of Shin-Kori unit 5 and 6. This paper describes the current logic diagram of CPS and suggests improved design for logic diagram. The improved logic diagram shall be validated through human factors engineering verification and validation. The improved design will help operators execute the computerized procedure fast and remove the human error.

Thermochemical parameters of caffeine, theophylline, and xanthine

Energy Technology Data Exchange (ETDEWEB)

Ngo Tuan Cuong; Truong Ba Tai [Department of Chemistry, and Mathematical Modeling and Computational Science Center (LMCC), Katholieke Universiteit Leuven, B-3001 Leuven (Belgium); Vu Thi Thu Ha [Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Minh Tho Nguyen, E-mail: minh.nguyen@chem.kuleuven.b [Department of Chemistry, and Mathematical Modeling and Computational Science Center (LMCC), Katholieke Universiteit Leuven, B-3001 Leuven (Belgium)

2010-04-15

Thermochemical parameters of caffeine 1, theophylline 2, xanthine 3, uracil, and imidazole derivatives are determined by quantum chemical calculations. Using the composite G3B3 method, the standard heat of formation of caffeine in the gaseous phase amounts to DELTA{sub f}H{sub g}{sup 0}(1)=-243+-8kJ.mol{sup -1}, which lends a support for the recent experimental value of -237.0 +- 2.5 kcal . mol{sup -1}. We also obtain DELTA{sub f}H{sub g}{sup 0}(2)=-232+-8kJ.mol{sup -1}andDELTA{sub f}H{sub g}{sup 0}(3)=-209+-8kJ.mol{sup -1}. The adiabatic ionization energies are IE{sub a}(1) = 7.9 eV, IE{sub a}(2) = 8.1 eV, and IE{sub a}(3) = 8.5 eV using B3LYP calculations. The enhanced ability of caffeine to eject electron, as compared to the parent compounds and cyclic components, is of interest with regard to its potential use as a corrosion inhibitor.

Thermochemical investigations on uranyl phosphates and arsenates

International Nuclear Information System (INIS)

Barten, H.

1986-01-01

Results are described of a study of the thermochemical stability of anhydrous phosphates and arsenates. The results of phase studies deal with compound formation and characterization, coexisting phases and limiting physical or chemical properties. The uranyl phosphates evolve oxygen at higher temperatures and the arsenates lose arsenic oxide vapour. These phenomena give the possibility to describe their thermodynamic stabilities. Thus oxygen pressures of uranyl phosphates have been measured using a static, non-isothermal method. Having made available the pure anhydrous compounds in the course of this investigation, molar thermodynamic quantities have been measured as well. These include standard enthalpies of formation from solution calorimetry and high-temperature heat-capacity functions derived from enthalpy increments measured. Some attention is given to compounds with uranium in valencies lower than six which have been met during the investigation. An evaluation is made of the thermodynamics of the compounds studied, to result in tabulized high-temperature thermodynamic functions. Relative stabilities within the systems are discussed and comparisons of the uranyl phosphates and the arsenates are made. (Auth.)

Review and analysis of the 1980-1989 biomass thermochemical conversion program

Energy Technology Data Exchange (ETDEWEB)

Stevens, D.J.

1994-09-01

In the period between 1980 and 1989, the U.S. Department of Energy (DOE) sponsored research and development projects through its Biomass Thermochemical Conversion (BTC) Program. Thermochemical conversion technologies use elevated temperatures to convert biomass into more useful forms of energy such as fuel gases or transportation fuels. The BTC Program included a wide range of biomass conversion projects in the areas of gasification, pyrolysis, liquefaction, and combustion. This work formed the basis of the present DOE research and development efforts on advanced liquid fuel and power generation systems. At the beginning of Fiscal Year 1989, the management of the BTC Program was transferred from Pacific Northwest Laboratory (PNL) to National Renewable Energy Laboratory (NREL, formerly Solar Energy Research Institute). This document presents a summary of the research which was performed under the BTC Program during the 1981-1989 time frame. The document consists of an analysis of the research projects which were funded by the BTC Program and a bibliography of published documents. This work will help ensure that information from PNL`s BTC Program is available to those interested in biomass conversion technologies. The background of the BTC Program is discussed in the first chapter of this report. In addition, a brief summary of other related biomass research and development programs funded by the U.S. Department of Energy and others is presented with references where additional information can be found. The remaining chapters of the report present a detailed summary of the research projects which were funded by the BTC Program. The progress which was made on each project is summarized, the overall impact on biomass conversion is discussed, and selected references are provided.

State diagram of Pr-Bi system

International Nuclear Information System (INIS)

Abulkhaev, V.L.; Ganiev, I.N.

1994-01-01

By means of thermal differential analysis, X-ray and microstructural analysis the state diagram of Pr-Bi system was studied. Following intermetallic compounds were defined in the system: Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 , Pr Bi, PrBi 2 , Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 and PrBi 2 . The data analysis on Ln-Bi diagram allowed to determine the regularity of change of properties of intermetallic compounds in the line of rare earth elements of cerium subgroup.

Fusion Diagrams in the - and - Systems

Science.gov (United States)

Asadov, M. M.; Akhmedova, N. A.

2014-10-01

A calculation model of the Gibbs energy of ternary oxide compounds from the binary components was used. Thermodynamic properties of -- ternary systems in the condensed state were calculated. Thermodynamic data of binary and ternary compounds were used to determine the stable sections. The probability of reactions between the corresponding components in the -- system was estimated. Fusibility diagrams of systems - and - were studied by physical-chemical analysis. The isothermal section of the phase diagram of -- at 298 K is built, as well as the projection of the liquid surface of --.

An Application of Mosaic Diagrams to the Visualization of Set Relationships

OpenAIRE

Luz, Saturnino; Masoodian, Masood

2017-01-01

We present an application of mosaic diagrams to the visualisation of set relations. Venn and Euler diagrams are the best known visual representations of sets and their relationships (intersections, containment or subsets, exclusion or disjointness). In recent years, alternative forms of visualisation have been proposed. Among them, linear diagrams have been shown to compare favourably to Venn and Euler diagrams, in supporting non-interactive assessment of set relationships. Recent studies tha...

Mathematical model of phase transformations in thermo-chemical cathodes with zirconium insertion

International Nuclear Information System (INIS)

Kavokin, A.A.; Kazmi, I.H.

2007-01-01

The mathematical model of thermo-chemical processes in the cathode of plasmatron working in the gas environment is investigated. The model describes electromagnetic, temperature and concentration fields taking into account kinetic of phase transformation and chemical reaction in accordance with a state diagram. The offered approach is simpler than the Stefan's approach of describing an analogical phase transformation. As an example the case of copper cathodes with the zirconium insertion in the environment of oxygen is considered. The influence of separate parts of process on distribution of temperature inside of the insertion is estimated. On the basis of this analysis the opportunity of use of stationary approach for electric and temperature fields is shown and analytical formulas for temperature are received. After that a numerical solution for gas concentration distribution is obtained. The calculations on the specified model show that the size of area of a phase zirconium oxides depends mainly upon coefficient of diffusion of oxygen. The calculations for various types of dependencies of gas diffusion coefficient from temperature are concluded. The results of calculations develop understanding of some features of oxidation process of a zirconium insertion. Typical example of multi phase process model is the mathematical description of a heat and mass transfer occurring in metal which is being heated by an electric arch in the gas medium (1, 2, 4). The macroscopic model of physical and chemical transformations can be described as follows (3). As a metal is heated on the surface of an electrode as a function of rising results in the border dividing solid and liquid phases moves ahead deep into the electrode. At the same time there is a diffusion of gas in electrode and formation of new chemical compounds which can noticeably differ in the physical and chemical properties from each other and metal of the electrode. Moreover we shall name a phase of substance not

Thermodynamic consideration on the constitution of multi-thermochemical water splitting process

International Nuclear Information System (INIS)

Tagawa, Hiroaki

1976-03-01

The multi-thermochemical water splitting cycle comprises individual chemical reactions which are generalized as hydrolysis, hydrogen generation, oxygen generation and regeneration of the circulating materials. The circulating agents are required for the constitution of the cycle, but the guiding principle of selecting them is not available yet. In the present report, thermodynamic properties, especially Gibbs free energies for formation, of the agents are examined as a function of temperature. Oxides, sulfo-oxides, chlorides, bromides and iodides are chosen as the compounds. The chemical reactions for hydrolysis, hydrogen generation and oxygen generation are reviewed in detail. The general formulas for the three step splitting cycle are represented with discussion. (auth.)

Sulfur Based Thermochemical Heat Storage for Baseload Concentrated Solar Power Generation

Energy Technology Data Exchange (ETDEWEB)

Wong, Bunsen [General Atomics, San Diego, CA (United States)

2014-11-01

This project investigates the engineering and economic feasibility of supplying baseload power using a concentrating solar power (CSP) plant integrated with sulfur based thermochemical heat storage. The technology stores high temperature solar heat in the chemical bonds of elemental sulfur. Energy is recovered as high temperature heat upon sulfur combustion. Extensive developmental and design work associated with sulfur dioxide (SO₂) disproportionation and sulfuric acid (H₂SO₄) decomposition chemical reactions used in this technology had been carried out in the two completed phases of this project. The feasibility and economics of the proposed concept was demonstrated and determined.

Plotting and Analyzing Data Trends in Ternary Diagrams Made Easy

Science.gov (United States)

John, Cédric M.

2004-04-01

Ternary plots are used in many fields of science to characterize a system based on three components. Triangular plotting is thus useful to a broad audience in the Earth sciences and beyond. Unfortunately, it is typically the most expensive commercial software packages that offer the option to plot data in ternary diagrams, and they lack features that are paramount to the geosciences, such as the ability to plot data directly into a standardized diagram and the possibility to analyze temporal and stratigraphic trends within this diagram. To address these issues, δPlot was developed with a strong emphasis on ease of use, community orientation, and availability free of charges. This ``freeware'' supports a fully graphical user interface where data can be imported as text files, or by copying and pasting. A plot is automatically generated, and any standard diagram can be selected for plotting in the background using a simple pull-down menu. Standard diagrams are stored in an external database of PDF files that currently holds some 30 diagrams that deal with different fields of the Earth sciences. Using any drawing software supporting PDF, one can easily produce new standard diagrams to be used with δPlot by simply adding them to the library folder. An independent column of values, commonly stratigraphic depths or ages, can be used to sort the data sets.

Exergy analysis of a system using a chemical heat pump to link a supercritical water-cooled nuclear reactor and a thermochemical water splitting cycle

International Nuclear Information System (INIS)

Granovskii, M.; Dincer, I.; Rosen, M. A.; Pioro, I

2007-01-01

The power generation efficiency of nuclear plants is mainly determined by the permissible temperatures and pressures of the nuclear reactor fuel and coolants. These parameters are limited by materials properties and corrosion rates and their effect on nuclear reactor safety. The advanced materials for the next generation of CANDU reactors, which employ steam as a coolant and heat carrier, permit the increased steam parameters (outlet temperature up to 625 degree C and pressure of about 25 MPa). Supercritical water-cooled (SCW) nuclear power plants are expected to increase the power generation efficiency from 35 to 45%. Supercritical water-cooled nuclear reactors can be linked to thermochemical water splitting cycles for hydrogen production. An increased steam temperature from the nuclear reactor makes it also possible to utilize its energy in thermochemical water splitting cycles. These cycles are considered by many as one of the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require a heat supply at the temperatures over 550-600 degree C. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump which increases the temperature the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. A high temperature chemical heat pump which employs the reversible catalytic methane conversion reaction is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with a SCW nuclear plant on one side and thermochemical water splitting cycle on the other, increases the temperature level of the 'nuclear' heat and, thus, the intensity of

Adding Value to Force Diagrams: Representing Relative Force Magnitudes

Science.gov (United States)

Wendel, Paul

2011-05-01

Nearly all physics instructors recognize the instructional value of force diagrams, and this journal has published several collections of exercises to improve student skill in this area.1-4 Yet some instructors worry that too few students perceive the conceptual and problem-solving utility of force diagrams,4-6 and over recent years a rich variety of approaches has been proposed to add value to force diagrams. Suggestions include strategies for identifying candidate forces,6,7 emphasizing the distinction between "contact" and "noncontact" forces,5,8 and the use of computer-based tutorials.9,10 Instructors have suggested a variety of conventions for constructing force diagrams, including approaches to arrow placement and orientation2,11-13 and proposed notations for locating forces or marking action-reaction force pairs.8,11,14,15

Phase diagram of an extended Agassi model

Science.gov (United States)

García-Ramos, J. E.; Dukelsky, J.; Pérez-Fernández, P.; Arias, J. M.

2018-05-01

Background: The Agassi model [D. Agassi, Nucl. Phys. A 116, 49 (1968), 10.1016/0375-9474(68)90482-X] is an extension of the Lipkin-Meshkov-Glick (LMG) model [H. J. Lipkin, N. Meshkov, and A. J. Glick, Nucl. Phys. 62, 188 (1965), 10.1016/0029-5582(65)90862-X] that incorporates the pairing interaction. It is a schematic model that describes the interplay between particle-hole and pair correlations. It was proposed in the 1960s by D. Agassi as a model to simulate the properties of the quadrupole plus pairing model. Purpose: The aim of this work is to extend a previous study by Davis and Heiss [J. Phys. G: Nucl. Phys. 12, 805 (1986), 10.1088/0305-4616/12/9/006] generalizing the Agassi model and analyze in detail the phase diagram of the model as well as the different regions with coexistence of several phases. Method: We solve the model Hamiltonian through the Hartree-Fock-Bogoliubov (HFB) approximation, introducing two variational parameters that play the role of order parameters. We also compare the HFB calculations with the exact ones. Results: We obtain the phase diagram of the model and classify the order of the different quantum phase transitions appearing in the diagram. The phase diagram presents broad regions where several phases, up to three, coexist. Moreover, there is also a line and a point where four and five phases are degenerated, respectively. Conclusions: The phase diagram of the extended Agassi model presents a rich variety of phases. Phase coexistence is present in extended areas of the parameter space. The model could be an important tool for benchmarking novel many-body approximations.

Single-particle potential from resummed ladder diagrams

International Nuclear Information System (INIS)

Kaiser, N.

2013-01-01

A recent work on the resummation of fermionic in-medium ladder diagrams to all orders is extended by calculating the complex single-particle potential U(p, k f ) + i W(p, k f ) p > k f . The on-shell single-particle potential is constructed by means of a complex-valued in-medium loop that includes corrections from a test particle of momentum vector p added to the filled Fermi sea. The single-particle potential U(k f , k f ) at the Fermi surface as obtained from the resummation of the combined particle and hole ladder diagrams is shown to satisfy the Hugenholtz-Van-Hove theorem. The perturbative contributions at various orders a n in the scattering length are deduced and checked against the known analytical results at order a 1 and a 2 . The limit a → ∞ is studied as a special case and a strong momentum dependence of the real (and imaginary) single-particle potential is found. This feature indicates an instability against a phase transition to a state with an empty shell inside the Fermi sphere such that the density gets reduced by about 5%. The imaginary single-particle potential vanishes linearly at the Fermi surface. For comparison, the same analysis is performed for the resummed particle-particle ladder diagrams alone. In this truncation an instability for hole excitations near the Fermi surface is found at strong coupling. For the set of particle-hole ring diagrams the single-particle potential is calculated as well. Furthermore, the resummation of in-medium ladder diagrams to all orders is studied for a two-dimensional Fermi gas with a short-range two-body contact interaction. (orig.)

Refined phase diagram of boron nitride

International Nuclear Information System (INIS)

Solozhenko, V.; Turkevich, V.Z.

1999-01-01

The equilibrium phase diagram of boron nitride thermodynamically calculated by Solozhenko in 1988 has been now refined on the basis of new experimental data on BN melting and extrapolation of heat capacities of BN polymorphs into high-temperature region using the adapted pseudo-Debye model. As compared with the above diagram, the hBN left-reversible cBN equilibrium line is displaced by 60 K toward higher temperatures. The hBN-cBN-L triple point has been calculated to be at 3480 ± 10 K and 5.9 ± 0.1 GPa, while the hBN-L-V triple point is at T = 3400 ± 20 K and p = 400 ± 20 Pa, which indicates that the region of thermodynamic stability of vapor in the BN phase diagram is extremely small. It has been found that the slope of the cBN melting curve is positive whereas the slope of hBN melting curve varies from positive between ambient pressure and 3.4 GPa to negative at higher pressures

Degradation of materials under conditions of thermochemical cycles for hydrogen production - part III

International Nuclear Information System (INIS)

Klimas, S.J.; Searle, H.; Guerout, F.

2011-01-01

A capsule method was employed to screen a number of materials for degradation under selected conditions of the sulphur-iodine (SI) and the copper-chlorine (Cu-Cl) thermochemical cycles. A summary of the results of an experimental investigation is given. The recommendations for the selection of the materials required for the construction of the electrolyser subsystem of the copper chlorine hybrid cycle are presented and discussed with the associated rationale. Some remaining uncertainties are illustrated on the basis of the experimental evidence gathered. (author)

Phase diagrams of diluted transverse Ising nanowire

International Nuclear Information System (INIS)

Bouhou, S.; Essaoudi, I.; Ainane, A.; Saber, M.; Ahuja, R.; Dujardin, F.

2013-01-01

In this paper, the phase diagrams of diluted Ising nanowire consisting of core and surface shell coupling by J cs exchange interaction are studied using the effective field theory with a probability distribution technique, in the presence of transverse fields in the core and in the surface shell. We find a number of characteristic phenomena. In particular, the effect of concentration c of magnetic atoms, the exchange interaction core/shell, the exchange in surface and the transverse fields in core and in surface shell of phase diagrams are investigated. - Highlights: ► We use the EFT to investigate the phase diagrams of Ising transverse nanowire. ► Ferrimagnetic and ferromagnetic cases are investigated. ► The effects of the dilution and the transverse fields in core and shell are studied. ► Behavior of the transition temperature with the exchange interaction is given

Homotopy Diagrams of Algebras

Czech Academy of Sciences Publication Activity Database

Markl, Martin

2002-01-01

Roč. 69, - (2002), s. 161-180 ISSN 0009-725X. [Winter School "Geometry and Physics" /21./. Srní, 13.01.2001-20.01.2001] R&D Projects: GA ČR GA201/99/0675 Keywords : colored operad%cofibrant model%homotopy diagram Subject RIV: BA - General Mathematics

Random Young diagrams in a Rectangular Box

DEFF Research Database (Denmark)

Beltoft, Dan; Boutillier, Cédric; Enriquez, Nathanaël

We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape.......We exhibit the limit shape of random Young diagrams having a distribution proportional to the exponential of their area, and confined in a rectangular box. The Ornstein-Uhlenbeck bridge arises from the fluctuations around the limit shape....

Formal Analysis Of Use Case Diagrams

Directory of Open Access Journals (Sweden)

Radosław Klimek

2010-01-01

Full Text Available Use case diagrams play an important role in modeling with UML. Careful modeling is crucialin obtaining a correct and efficient system architecture. The paper refers to the formalanalysis of the use case diagrams. A formal model of use cases is proposed and its constructionfor typical relationships between use cases is described. Two methods of formal analysis andverification are presented. The first one based on a states’ exploration represents a modelchecking approach. The second one refers to the symbolic reasoning using formal methodsof temporal logic. Simple but representative example of the use case scenario verification isdiscussed.

Phase Stability Diagrams for High Temperature Corrosion Processes

Directory of Open Access Journals (Sweden)

J. J. Ramos-Hernandez

2013-01-01

Full Text Available Corrosion phenomena of metals by fused salts depend on chemical composition of the melt and environmental conditions of the system. Detail knowledge of chemistry and thermodynamic of aggressive species formed during the corrosion process is essential for a better understanding of materials degradation exposed to high temperature. When there is a lack of kinetic data for the corrosion processes, an alternative to understand the thermodynamic behavior of chemical species is to utilize phase stability diagrams. Nowadays, there are several specialized software programs to calculate phase stability diagrams. These programs are based on thermodynamics of chemical reactions. Using a thermodynamic data base allows the calculation of different types of phase diagrams. However, sometimes it is difficult to have access to such data bases. In this work, an alternative way to calculate phase stability diagrams is presented. The work is exemplified in the Na-V-S-O and Al-Na-V-S-O systems. This system was chosen because vanadium salts is one of the more aggressive system for all engineering alloys, especially in those processes where fossil fuels are used.

Resonant count diagram and solar g mode oscillations

International Nuclear Information System (INIS)

Guenther, D.B.; Demarque, P.

1984-01-01

Evidence is provided to support the hypothesis that, because of the particular frequency separations of the solar g modes, resonant three-wave interactions stimulate only a selected few g modes. A resonant count diagram was obtained by plotting the total number of possible resonant three-wave interactions or a given beat frequency against the inverse of the beat frequency (the beat period), within a given frequency tolerance. The 1 = 1, 2, 3, 4 g modes calculated by Christensen-Dalsgaard, Gough and Morgan (1979) for a standard model of the Sun were used. The diagram has a significant peak at 160 minutes as well as other peaks at longer periods. The g modes that Delache and Scherrer (1983) tentatively identified from the Crimea-Stanford data were also plotted. These modes were found to correspond with the other peaks in the diagram. This coincidence between the observed g modes and the peaks in the resonant count diagram suggest that the observed g modes do owe their observability to resonant three-wave interactions

Comparisons between observational color-magnitude diagrams and synthetic cluster diagrams for young star clusters in the Magellanic Clouds

International Nuclear Information System (INIS)

Recker, S.A.; Brunish, W.M.; Mathews, G.J.

1984-01-01

Young star clusters ( 8 yr) in the Magellanic Clouds (MC) can be used to test the current status of the theory of stellar evolution as applied to intermediate and massive stars. The color-magnitude diagram of many young clusters in the MC shows large numbers of stars in both the main sequence and post main sequence evolutionary phases. Using a grid of stellar evolution models, synthetic cluster H-R diagrams are constructed and compared to observed color-magnitude diagrams to determine the age, age spread, and composition for any given cluster. In addition, for those cases where the data is of high quality, detailed comparisons between theory and observation can provide a diagnostic of the accuracy of the stellar evolution models. Initial indications of these comparisons suggest that the theoretical models should be altered to include: a larger value for the mixing length parameter, a larger rate of mass loss during the asymptotic giant branch phase, and possibly convective overshoot during the core burning phases. (Auth.)

Revised Pourbaix diagrams for Copper at 5-150 C

International Nuclear Information System (INIS)

Beverskog, B.; Puigdomenech, I.

1995-10-01

Pourbaix diagrams have been revised. Predominance diagrams for dissolved copper species have also been calculated. Five different total concentrations for dissolved copper have been used in the calculations (from 10 -3 to 10 -9 ). The complete hydrolysis series of copper(I) and (II) have not been included in earlier published Pourbaix diagrams, and these species are covered for the first time in this work. At acidic pH, increasing temperature decreases the immunity area, and therefore, it increases the corrosion of the copper. At alkaline pH-values corrosion also increases with the temperature due to the decrease of both passivity and immunity areas. The calculated diagrams are used as a base for the discussion of the corrosion behaviour of the copper canisters in the Swedish radioactive waste management program. 62 refs, 37 figs, 3 tabs

Solid gas reaction phase diagram under high gas pressure

International Nuclear Information System (INIS)

Ishizaki, K.

1992-01-01

This paper reports that to evaluate which are the stable phases under high gas pressure conditions, a solid-gas reaction phase diagram under high gas pressure (HIP phase diagram) has been proposed by the author. The variables of the diagram are temperature, reactant gas partial pressure and total gas pressure. Up to the present time the diagrams have been constructed using isobaric conditions. In this work, the stable phases for a real HIP process were evaluated assuming an isochoric condition. To understand the effect of the total gas pressure on stability is of primary importance. Two possibilities were considered and evaluated, those are: the total gas pressure acts as an independent variable, or it only affects the fugacity values. The results of this work indicate that the total gas pressure acts as an independent variable, and in turn also affects the fugacity values

Equational binary decision diagrams

NARCIS (Netherlands)

J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)

2000-01-01

textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and

On the Impact of Diagram Layout: How Are Models Actually Read?

DEFF Research Database (Denmark)

Störrle, Harald; Baltsen, Nick; Christoffersen, Henrik

2014-01-01

This poster presents the latest results from a very large eye tracking study (n=29) that explores how modelers read UML diagrams. We find that various factors like layout quality, modeler experience, and diagram type lead to significant differences in diagram reading strategies. We derive elements...

A Three-dimensional Topological Model of Ternary Phase Diagram

International Nuclear Information System (INIS)

Mu, Yingxue; Bao, Hong

2017-01-01

In order to obtain a visualization of the complex internal structure of ternary phase diagram, the paper realized a three-dimensional topology model of ternary phase diagram with the designed data structure and improved algorithm, under the guidance of relevant theories of computer graphics. The purpose of the model is mainly to analyze the relationship between each phase region of a ternary phase diagram. The model not only obtain isothermal section graph at any temperature, but also extract a particular phase region in which users are interested. (paper)

A Critical Appraisal of the `Day' Diagram

Science.gov (United States)

Roberts, A. P.; Tauxe, L.; Heslop, D.

2017-12-01

The `Day' diagram [Day et al., 1977; doi:10.1016/0031-9201(77)90108-X] is used widely to infer the mean domain state of magnetic mineral assemblages. The Day plot coordinates are the ratios of the saturation remanent magnetization to saturation magnetization (Mrs/Ms) and the coercivity of remanence to coercivity (Bcr/Bc), as determined from a major hysteresis loop and a backfield demagnetization curve. Based on theoretical and empirical arguments, Day plots are typically demarcated into stable single domain (SD), `pseudosingle domain' (`PSD'), and multidomain (MD) zones. It is a simple task to determine Mrs/Ms and Bcr/Bc for a sample and to assign a mean domain state based on the boundaries defined by Day et al. [1977]. Many other parameters contribute to variability in a Day diagram, including surface oxidation, mineral stoichiometry, stress state, magnetostatic interactions, and mixtures of magnetic particles with different sizes and shapes. Bulk magnetic measurements usually lack detailed independent evidence to constrain each free parameter, which makes the Day diagram fundamentally ambiguous. This raises questions about its usefulness for diagnosing magnetic particle size variations. The Day diagram is also used to make inferences about binary mixing of magnetic particles, where, for example, mixtures of SD and MD particles give rise to a bulk `PSD' response even though the concentration of `PSD' grains could be zero. In our assessment of thousands of hysteresis measurements of geological samples, binary mixing occurs in a tiny number of cases. Ternary, quaternary, and higher order mixing are usually observed. Also, uniaxial SD and MD end-members are nearly always inappropriate for considering mixing because uniaxial SD particles are virtually non-existent in igneous rocks. Thus, use of mixing lines in Day diagrams routinely provides unsatisfactory representations of particle size variations. We critically appraise the Day diagram and argue that its many

Finding and Accessing Diagrams in Biomedical Publications

OpenAIRE

Kuhn, Tobias; Luong, ThaiBinh; Krauthammer, Michael

2012-01-01

Complex relationships in biomedical publications are often communicated by diagrams such as bar and line charts, which are a very effective way of summarizing and communicating multi-faceted data sets. Given the ever-increasing amount of published data, we argue that the precise retrieval of such diagrams is of great value for answering specific and otherwise hard-to-meet information needs. To this end, we demonstrate the use of advanced image processing and classification for identifying bar...

Phase diagrams of diluted transverse Ising nanowire

Energy Technology Data Exchange (ETDEWEB)

Bouhou, S.; Essaoudi, I. [Laboratoire de Physique des Matériaux et Modélisation, des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, Physics Department, Faculty of Sciences, B.P. 11201 Meknes (Morocco); Ainane, A., E-mail: ainane@pks.mpg.de [Laboratoire de Physique des Matériaux et Modélisation, des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, Physics Department, Faculty of Sciences, B.P. 11201 Meknes (Morocco); Max-Planck-Institut für Physik Complexer Systeme, Nöthnitzer Str. 38 D-01187 Dresden (Germany); Saber, M. [Laboratoire de Physique des Matériaux et Modélisation, des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, Physics Department, Faculty of Sciences, B.P. 11201 Meknes (Morocco); Max-Planck-Institut für Physik Complexer Systeme, Nöthnitzer Str. 38 D-01187 Dresden (Germany); Ahuja, R. [Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala (Sweden); Dujardin, F. [Laboratoire de Chimie et Physique des Milieux Complexes (LCPMC), Institut de Chimie, Physique et Matériaux (ICPM), 1 Bd. Arago, 57070 Metz (France)

2013-06-15

In this paper, the phase diagrams of diluted Ising nanowire consisting of core and surface shell coupling by J{sub cs} exchange interaction are studied using the effective field theory with a probability distribution technique, in the presence of transverse fields in the core and in the surface shell. We find a number of characteristic phenomena. In particular, the effect of concentration c of magnetic atoms, the exchange interaction core/shell, the exchange in surface and the transverse fields in core and in surface shell of phase diagrams are investigated. - Highlights: ► We use the EFT to investigate the phase diagrams of Ising transverse nanowire. ► Ferrimagnetic and ferromagnetic cases are investigated. ► The effects of the dilution and the transverse fields in core and shell are studied. ► Behavior of the transition temperature with the exchange interaction is given.

The Diagram as Story: Unfolding the Event-Structure of the Mathematical Diagram

Science.gov (United States)

de Freitas, Elizabeth

2012-01-01

This paper explores the role of narrative in decoding diagrams. I focus on two fundamental facets of narrative: (1) the recounting of causally related sequences of events, and (2) the positioning of the narrator through point-of-view and voice. In the first two sections of the paper I discuss philosophical and semiotic frameworks for making sense…

Thermal tests of a multi-tubular reactor for hydrogen production by using mixed ferrites thermochemical cycle

Science.gov (United States)

Gonzalez-Pardo, Aurelio; Denk, Thorsten; Vidal, Alfonso

2017-06-01

The SolH2 project is an INNPACTO initiative of the Spanish Ministry of Economy and Competitiveness, with the main goal to demonstrate the technological feasibility of solar thermochemical water splitting cycles as one of the most promising options to produce H2 from renewable sources in an emission-free way. A multi-tubular solar reactor was designed and build to evaluate a ferrite thermochemical cycle. At the end of this project, the ownership of this plant was transferred to CIEMAT. This paper reviews some additional tests with this pilot plant performed in the Plataforma Solar de Almería with the main goal to assess the thermal behavior of the reactor, evaluating the evolution of the temperatures inside the cavity and the relation between supplied power and reached temperatures. Previous experience with alumina tubes showed that they are very sensitive to temperature and flux gradients, what leads to elaborate an aiming strategy for the heliostat field to achieve a uniform distribution of the radiation inside the cavity. Additionally, the passing of clouds is a phenomenon that importantly affects all the CSP facilities by reducing their efficiency. The behavior of the reactor under these conditions has been studied.

Energy efficient thermochemical conversion of very wet biomass to biofuels by integration of steam drying, steam electrolysis and gasification

DEFF Research Database (Denmark)

Clausen, Lasse Røngaard

2017-01-01

A novel system concept is presented for the thermochemical conversion of very wet biomasses such as sewage sludge and manure. The system integrates steam drying, solid oxide electrolysis cells (SOEC) and gasification for the production of synthetic natural gas (SNG). The system is analyzed...

Upper mantle compositional variations and discontinuity topography imaged beneath Australia from Bayesian inversion of surface-wave phase velocities and thermochemical modeling

DEFF Research Database (Denmark)

Khan, A.; Zunino, Andrea; Deschamps, F.

2013-01-01

Here we discuss the nature of velocity heterogeneities seen in seismic tomography images of Earth's mantle whose origins and relation to thermochemical variations are yet to be understood. We illustrate this by inverting fundamental-mode and higher-order surface-wave phase velocities for radial....../Fe and Mg/Si values relative to surrounding mantle. Correlated herewith are thermal variations that closely follow surface tectonics. We also observe a strong contribution to lateral variations in structure and topography across the “410 km” seismic discontinuity from thermochemically induced phase......-wave tomography models with other regional models is encouraging. Radial anisotropy is strongest at 150/200 km depth beneath oceanic/continental areas, respectively, and appears weak and homogeneous below. Finally, geoid anomalies are computed for a subset of sampled model and compared to observations....

Random matrix models for phase diagrams

International Nuclear Information System (INIS)

Vanderheyden, B; Jackson, A D

2011-01-01

We describe a random matrix approach that can provide generic and readily soluble mean-field descriptions of the phase diagram for a variety of systems ranging from quantum chromodynamics to high-T c materials. Instead of working from specific models, phase diagrams are constructed by averaging over the ensemble of theories that possesses the relevant symmetries of the problem. Although approximate in nature, this approach has a number of advantages. First, it can be useful in distinguishing generic features from model-dependent details. Second, it can help in understanding the 'minimal' number of symmetry constraints required to reproduce specific phase structures. Third, the robustness of predictions can be checked with respect to variations in the detailed description of the interactions. Finally, near critical points, random matrix models bear strong similarities to Ginsburg-Landau theories with the advantage of additional constraints inherited from the symmetries of the underlying interaction. These constraints can be helpful in ruling out certain topologies in the phase diagram. In this Key Issues Review, we illustrate the basic structure of random matrix models, discuss their strengths and weaknesses, and consider the kinds of system to which they can be applied.

Colour-magnitude diagram of NGC 5053

Energy Technology Data Exchange (ETDEWEB)

Walker, M F; Pike, C D [California Univ., Santa Cruz (USA). Lick Observatory; McGee, J D

1976-06-01

The colour-magnitude diagram of NGC 5053 has been derived to V = 21.1 from photographic and electronographic observations. The electronographic observations were obtained with an experimental Spectracon image-converter, having photocathode and exit window dimensions of 20 x 30 mm, mounted at the prime-focus of the 120-in. Lick reflector. The photographic observations were obtained with the 20-in. Carnegie astrograph and the 36-in. Crossley reflector. The colour-magnitude diagram resembles that of M92, with the difference that a red horizontal branch is more pronounced than the asymptotic branch in NGC 5053. The topology of the horizontal branch is that of clusters with an intermediate metal content and is thus at variance with the mean period of the RR Lyr stars and the unreddened colour of the subgiant branch read at the magnitude level of the horizontal branch, both of which would indicate an extremely low metal content. If comparison of the colour-magnitude diagrams of NGC 5053 and M92 is valid, then the reddening of NGC 5053 is Esub(B-V) = 0.02 and the apparent distance modulus is m-M = 16.08 +- 0.08.

Synfuels from fusion: using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

International Nuclear Information System (INIS)

Werner, R.W.

1982-01-01

This study is concerned with the following area: (1) the tandem mirror reactor and its physics; (2) energy balance; (3) the lithium oxide canister blanket system; (4) high-temperature blanket; (5) energy transport system-reactor to process; (6) thermochemical hydrogen processes; (7) interfacing the GA cycle; (8) matching power and temperature demands; (9) preliminary cost estimates; (10) synfuels beyond hydrogen; and (11) thermodynamics of the H 2 SO 4 -H 2 O system

Reactome diagram viewer: data structures and strategies to boost performance.

Science.gov (United States)

Fabregat, Antonio; Sidiropoulos, Konstantinos; Viteri, Guilherme; Marin-Garcia, Pablo; Ping, Peipei; Stein, Lincoln; D'Eustachio, Peter; Hermjakob, Henning

2018-04-01

Reactome is a free, open-source, open-data, curated and peer-reviewed knowledgebase of biomolecular pathways. For web-based pathway visualization, Reactome uses a custom pathway diagram viewer that has been evolved over the past years. Here, we present comprehensive enhancements in usability and performance based on extensive usability testing sessions and technology developments, aiming to optimize the viewer towards the needs of the community. The pathway diagram viewer version 3 achieves consistently better performance, loading and rendering of 97% of the diagrams in Reactome in less than 1 s. Combining the multi-layer html5 canvas strategy with a space partitioning data structure minimizes CPU workload, enabling the introduction of new features that further enhance user experience. Through the use of highly optimized data structures and algorithms, Reactome has boosted the performance and usability of the new pathway diagram viewer, providing a robust, scalable and easy-to-integrate solution to pathway visualization. As graph-based visualization of complex data is a frequent challenge in bioinformatics, many of the individual strategies presented here are applicable to a wide range of web-based bioinformatics resources. Reactome is available online at: https://reactome.org. The diagram viewer is part of the Reactome pathway browser (https://reactome.org/PathwayBrowser/) and also available as a stand-alone widget at: https://reactome.org/dev/diagram/. The source code is freely available at: https://github.com/reactome-pwp/diagram. fabregat@ebi.ac.uk or hhe@ebi.ac.uk. Supplementary data are available at Bioinformatics online.

Membranes for H2 generation from nuclear powered thermochemical cycles.

Energy Technology Data Exchange (ETDEWEB)

Nenoff, Tina Maria; Ambrosini, Andrea; Garino, Terry J.; Gelbard, Fred; Leung, Kevin; Navrotsky, Alexandra (University of California, Davis, CA); Iyer, Ratnasabapathy G. (University of California, Davis, CA); Axness, Marlene

2006-11-01

In an effort to produce hydrogen without the unwanted greenhouse gas byproducts, high-temperature thermochemical cycles driven by heat from solar energy or next-generation nuclear power plants are being explored. The process being developed is the thermochemical production of Hydrogen. The Sulfur-Iodide (SI) cycle was deemed to be one of the most promising cycles to explore. The first step of the SI cycle involves the decomposition of H{sub 2}SO{sub 4} into O{sub 2}, SO{sub 2}, and H{sub 2}O at temperatures around 850 C. In-situ removal of O{sub 2} from this reaction pushes the equilibrium towards dissociation, thus increasing the overall efficiency of the decomposition reaction. A membrane is required for this oxygen separation step that is capable of withstanding the high temperatures and corrosive conditions inherent in this process. Mixed ionic-electronic perovskites and perovskite-related structures are potential materials for oxygen separation membranes owing to their robustness, ability to form dense ceramics, capacity to stabilize oxygen nonstoichiometry, and mixed ionic/electronic conductivity. Two oxide families with promising results were studied: the double-substituted perovskite A{sub x}Sr{sub 1-x}Co{sub 1-y}B{sub y}O{sub 3-{delta}} (A=La, Y; B=Cr-Ni), in particular the family La{sub x}Sr{sub 1-x}Co{sub 1-y}Mn{sub y}O{sub 3-{delta}} (LSCM), and doped La{sub 2}Ni{sub 1-x}M{sub x}O{sub 4} (M = Cu, Zn). Materials and membranes were synthesized by solid state methods and characterized by X-ray and neutron diffraction, SEM, thermal analyses, calorimetry and conductivity. Furthermore, we were able to leverage our program with a DOE/NE sponsored H{sub 2}SO{sub 4} decomposition reactor study (at Sandia), in which our membranes were tested in the actual H{sub 2}SO{sub 4} decomposition step.

Limits of Voronoi Diagrams

NARCIS (Netherlands)

Lindenbergh, R.C.

2002-01-01

The classic Voronoi diagram of a configuration of distinct points in the plane associates to each point that part of the plane that is closer to the point than to any other point in the configuration. In this thesis we no longer require all points to be distinct. After the introduction in

Holistic analysis of thermochemical processes by using solid biomass for fuel production in Germany; Ganzheitliche Analyse thermochemischer Verfahren bei der Nutzung fester Biomasse zur Kraftstoffproduktion in Deutschland

Energy Technology Data Exchange (ETDEWEB)

Henssler, Martin

2015-04-28

According to the German act ''Biokraftstoff-Nachhaltigkeitsverordnung'', biofuels must show a CO{sub 2eq}-reduction compared to the fossil reference fuel (83.8 g CO{sub 2eq}/MJ{sub fuel} /Richtlinie 98/70/EG/) of 35 % beginning with 2011. In new plants, which go into operation after the 31.12.2016 the CO{sub 2eq}-savings must be higher than 50 % in 2017 and higher than 60 % in 2018 /Biokraft-NachV/. The biofuels (methyl ester of rapeseed, bioethanol and biomethane) considered in this study do not meet these requirements for new plants. To comply with these rules new processes must be deployed. Alternative thermochemical generated fuels could be an option. The aim of this work is to evaluate through a technical, ecological and economic analysis (Well-to-Wheel) whether and under what conditions the thermochemical production of Fischer-Tropsch-diesel or -gasoline, hydrogen (H{sub 2}) and Substitute Natural Gas (SNG) complies with the targets. Four different processes are considered (fast pyrolysis and torrefaction with entrained flow gasifier, CHOREN Carbo-V {sup registered} -gasifier, Absorption Enhanced Reforming (AER-) gasifier). Beside residues such as winter wheat straw and residual forest wood, wood from short-rotation plantations is taken into account. The technical analysis showed that at present status (2010) two and in 2050 six plants can be operated energy-self-sufficient. The overall efficiency of the processes is in the range of 41.5 (Fischer-Tropsch-diesel or -gasoline) and 59.4 % (H{sub 2}). Furthermore, it was found that for 2010, all thermochemical produced fuels except the H{sub 2}-production from wood from short-rotation plantations in decentralised or central fast pyrolysis and in decentralised torrefactions with entrained flow gasifier keep the required CO{sub 2eq}-saving of 60 %. In 2050, all thermochemical produced fuels will reach these limits. The CO{sub 2eq}-saving is between 72 (H{sub 2}) and 95 % (Fischer

Unified Phase Diagram for Iron-Based Superconductors.

Science.gov (United States)

Gu, Yanhong; Liu, Zhaoyu; Xie, Tao; Zhang, Wenliang; Gong, Dongliang; Hu, Ding; Ma, Xiaoyan; Li, Chunhong; Zhao, Lingxiao; Lin, Lifang; Xu, Zhuang; Tan, Guotai; Chen, Genfu; Meng, Zi Yang; Yang, Yi-Feng; Luo, Huiqian; Li, Shiliang

2017-10-13

High-temperature superconductivity is closely adjacent to a long-range antiferromagnet, which is called a parent compound. In cuprates, all parent compounds are alike and carrier doping leads to superconductivity, so a unified phase diagram can be drawn. However, the properties of parent compounds for iron-based superconductors show significant diversity and both carrier and isovalent dopings can cause superconductivity, which casts doubt on the idea that there exists a unified phase diagram for them. Here we show that the ordered moments in a variety of iron pnictides are inversely proportional to the effective Curie constants of their nematic susceptibility. This unexpected scaling behavior suggests that the magnetic ground states of iron pnictides can be achieved by tuning the strength of nematic fluctuations. Therefore, a unified phase diagram can be established where superconductivity emerges from a hypothetical parent compound with a large ordered moment but weak nematic fluctuations, which suggests that iron-based superconductors are strongly correlated electron systems.

Unified Phase Diagram for Iron-Based Superconductors

Science.gov (United States)

Gu, Yanhong; Liu, Zhaoyu; Xie, Tao; Zhang, Wenliang; Gong, Dongliang; Hu, Ding; Ma, Xiaoyan; Li, Chunhong; Zhao, Lingxiao; Lin, Lifang; Xu, Zhuang; Tan, Guotai; Chen, Genfu; Meng, Zi Yang; Yang, Yi-feng; Luo, Huiqian; Li, Shiliang

2017-10-01

High-temperature superconductivity is closely adjacent to a long-range antiferromagnet, which is called a parent compound. In cuprates, all parent compounds are alike and carrier doping leads to superconductivity, so a unified phase diagram can be drawn. However, the properties of parent compounds for iron-based superconductors show significant diversity and both carrier and isovalent dopings can cause superconductivity, which casts doubt on the idea that there exists a unified phase diagram for them. Here we show that the ordered moments in a variety of iron pnictides are inversely proportional to the effective Curie constants of their nematic susceptibility. This unexpected scaling behavior suggests that the magnetic ground states of iron pnictides can be achieved by tuning the strength of nematic fluctuations. Therefore, a unified phase diagram can be established where superconductivity emerges from a hypothetical parent compound with a large ordered moment but weak nematic fluctuations, which suggests that iron-based superconductors are strongly correlated electron systems.

Coupling of copper-chloride hybrid thermochemical water splitting cycle with a desalination plant for hydrogen production from nuclear energy

International Nuclear Information System (INIS)

Orhan, Mehmet F.; Dincer, Ibrahim; Naterer, Greg F.; Rosen, Marc A.

2010-01-01

Energy and environmental concerns have motivated research on clean energy resources. Nuclear energy has the potential to provide a significant share of energy supply without contributing to environmental emissions and climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another pathway for the utilization of nuclear thermal energy. One option for nuclear-based hydrogen production via thermochemical water decomposition uses a copper-chloride (Cu-Cl) cycle. Another societal concern relates to supplies of fresh water. Thus, to avoid causing one problem while solving another, hydrogen could be produced from seawater rather than limited fresh water sources. In this study we analyze a coupling of the Cu-Cl cycle with a desalination plant for hydrogen production from nuclear energy and seawater. Desalination technologies are reviewed comprehensively to determine the most appropriate option for the Cu-Cl cycle and a thermodynamic analysis and several parametric studies of this coupled system are presented for various configurations. (author)

Thermochemical heat storage for high temperature applications. A review

Energy Technology Data Exchange (ETDEWEB)

Felderhoff, Michael [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany); Urbanczyk, Robert; Peil, Stefan [Institut fuer Energie- und Umwelttechnik e.V. (IUTA), Duisburg (Germany)

2013-07-01

Heat storage for high temperature applications can be performed by several heat storage techniques. Very promising heat storage methods are based on thermochemical gas solid reactions. Most known systems are metal oxide/steam (metal hydroxides), carbon dioxide (metal carbonates), and metal/hydrogen (metal hydrides) systems. These heat storage materials posses high gravimetric and volumetric heat storage densities and because of separation of the reaction products and their storage in different locations heat losses can be avoided. The reported volumetric heat storage densities are 615, 1340 and 1513 [ kWh m{sup -3}] for calcium hydroxide Ca(OH){sub 2}, calcium carbonate CaCO{sub 3} and magnesium iron hydride Mg{sub 2}FeH{sub 6} respectively. Additional demands for gas storage decrease the heat storage density, but metal hydride systems can use available hydrogen storage possibilities for example caverns, pipelines and chemical plants. (orig.)

Hydrogen production from biomass by thermochemical recuperative energy conversion

Energy Technology Data Exchange (ETDEWEB)

Fushimi, C.; Araki, K.; Yamaguchi, Y.; Tsutsumi, A. [Tokyo Univ. (Japan). Dept. of Chemical System Engineering

2002-07-01

The authors conducted, using a thermogravimetric reactor, a kinetic study of production of thermochemical recuperative hydrogen from biomass. The four different biomass materials used were: cellulose, lignin, metroxylon stem, and coconut husk. Under both rapid heating and slow heating conditions, the weight changes of the biomass samples during the steam gasification or pyrolysis were measured at 973 Kelvin. Simultaneously, measurements of the evolution rates of low-molecular-weight gas products such as hydrogen, methane, carbon monoxide, and carbon dioxide were taken with the help of a mass spectrometer and a micro gas chromatograph (GC). The steam gasification of char significantly increased the amount of hydrogen and carbon dioxide production. The results also indicated that at higher heating rate, the cold gas efficiency of steam gasification was increased. This can be explained by the suppression of the tar production at lower temperature. 25 refs., 2 tabs., 10 figs.

Generation of H{sub 2} and CO by solar thermochemical splitting of H{sub 2}O and CO{sub 2} by employing metal oxides

Energy Technology Data Exchange (ETDEWEB)

Rao, C.N.R., E-mail: cnrrao@jncasr.ac.in; Dey, Sunita

2016-10-15

Generation of H{sub 2} and CO by splitting H{sub 2}O and CO{sub 2} respectively constitutes an important aspect of the present-day concerns with energy and environment. The solar thermochemical route making use of metal oxides is a viable means of accomplishing these reduction reactions. The method essentially involves reducing a metal oxide by heating and passing H{sub 2}O or CO{sub 2} over the nonstoichiometric oxide to cause reverse oxidation by abstracting oxygen from H{sub 2}O or CO{sub 2}. While ceria, perovskites and other oxides have been investigated for this purpose, recent studies have demonstrated the superior performance of perovskites of the type Ln{sub 1−x}A{sub x}Mn{sub 1−y}M{sub y}O{sub 3} (Ln=rare earth, A=alkaline earth, M=various +2 and +3 metal ions), in the thermochemical generation of H{sub 2} and CO. We present the important results obtained hitherto to point out how the alkaine earth and the Ln ions, specially the radius of the latter, determine the performance of the perovskites. The encouraging results obtained are exemplefied by Y{sub 0.5}Sr{sub 0.5}MnO{sub 3} which releases 483 µmol/g of O{sub 2} at 1673 K and produces 757 µmol/g of CO from CO{sub 2} at 1173 K. The production of H{sub 2} from H{sub 2}O is also quite appreciable. Modification of the B site ion of the perovskite also affects the performance. In addition to perovskites, we present the generation of H{sub 2} based on the Mn{sub 3}O{sub 4}/NaMnO{sub 2} cycle briefly. - Graphical abstract: Ln{sub 0.5}A{sub 0.5}Mn{sub 1−x}M{sub x}O{sub 3} (Ln=lanthanide; A=Ca, Sr; M=Al, Ga, Sc, Mg, Cr, Fe, Co) perovskites are employed for the two step thermochemical splitting of CO{sub 2} and H{sub 2}O for the generation of CO and H{sub 2}. - Highlights: • Perovskite oxides based on Mn are ideal for the two-step thermochemical splitting of CO{sub 2} and H{sub 2}O. • In Ln{sub 1−x}A{sub x}MnO{sub 3} perovskite (Ln=rare earth, A=alkaline earth) both Ln and A ions play major roles

Causal diagrams in systems epidemiology

Directory of Open Access Journals (Sweden)

Joffe Michael

2012-03-01

Full Text Available Abstract Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s. Transmitted causes ("causes of causes" tend not to be systematically analysed. The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties. The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets. Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback.

Causal diagrams in systems epidemiology.

Science.gov (United States)

Joffe, Michael; Gambhir, Manoj; Chadeau-Hyam, Marc; Vineis, Paolo

2012-03-19

Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s). Transmitted causes ("causes of causes") tend not to be systematically analysed.The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties.The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets.Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback.

Calculation of Energy Diagram of Asymmetric Graded-Band-Gap Semiconductor Superlattices.

Science.gov (United States)

Monastyrskii, Liubomyr S; Sokolovskii, Bogdan S; Alekseichyk, Mariya P

2017-12-01

The paper theoretically investigates the peculiarities of energy diagram of asymmetric graded-band-gap superlattices with linear coordinate dependences of band gap and electron affinity. For calculating the energy diagram of asymmetric graded-band-gap superlattices, linearized Poisson's equation has been solved for the two layers forming a period of the superlattice. The obtained coordinate dependences of edges of the conduction and valence bands demonstrate substantial transformation of the shape of the energy diagram at changing the period of the lattice and the ratio of width of the adjacent layers. The most marked changes in the energy diagram take place when the period of lattice is comparable with the Debye screening length. In the case when the lattice period is much smaller that the Debye screening length, the energy diagram has the shape of a sawtooth-like pattern.

RNA secondary structure diagrams for very large molecules: RNAfdl

DEFF Research Database (Denmark)

Hecker, Nikolai; Wiegels, Tim; Torda, Andrew E.

2013-01-01

There are many programs that can read the secondary structure of an RNA molecule and draw a diagram, but hardly any that can cope with 10 3 bases. RNAfdl is slow but capable of producing intersection-free diagrams for ribosome-sized structures, has a graphical user interface for adjustments...

Automated Methodologies for the Design of Flow Diagrams for Development and Maintenance Activities

Science.gov (United States)

Shivanand M., Handigund; Shweta, Bhat

The Software Requirements Specification (SRS) of the organization is a text document prepared by strategic management incorporating the requirements of the organization. These requirements of ongoing business/ project development process involve the software tools, the hardware devices, the manual procedures, the application programs and the communication commands. These components are appropriately ordered for achieving the mission of the concerned process both in the project development and the ongoing business processes, in different flow diagrams viz. activity chart, workflow diagram, activity diagram, component diagram and deployment diagram. This paper proposes two generic, automatic methodologies for the design of various flow diagrams of (i) project development activities, (ii) ongoing business process. The methodologies also resolve the ensuing deadlocks in the flow diagrams and determine the critical paths for the activity chart. Though both methodologies are independent, each complements other in authenticating its correctness and completeness.

Computer-assisted evaluation of the thermochemical data of the compounds of thorium

International Nuclear Information System (INIS)

Wagman, D.D.; Schumm, R.H.; Parker, V.B.

1977-08-01

Selected values are given for the thermochemical properties of the compounds of thorium. They are obtained from a computer-assisted least sums-least squares approach to the evaluation of thermodynamic data networks. The properties given, where data are available, are enthalpy of formation, Gibbs energy of formation, and entropy at 298.15 K (Δ Hf (298), Δ Gf (298), and S (298)). The values are consistent with the CODATA Key Values for Thermodynamics. The reaction catalog from which this self consistent set of values is generated is given with a statistical analysis. Some thermal functions are also given, as well as detailed comments when necessary

Thermochemical Biomass Gasification: A Review of the Current Status of the Technology

Directory of Open Access Journals (Sweden)

Ajay Kumar

2009-07-01

Full Text Available A review was conducted on the use of thermochemical biomass gasification for producing biofuels, biopower and chemicals. The upstream processes for gasification are similar to other biomass processing methods. However, challenges remain in the gasification and downstream processing for viable commercial applications. The challenges with gasification are to understand the effects of operating conditions on gasification reactions for reliably predicting and optimizing the product compositions, and for obtaining maximal efficiencies. Product gases can be converted to biofuels and chemicals such as Fischer-Tropsch fuels, green gasoline, hydrogen, dimethyl ether, ethanol, methanol, and higher alcohols. Processes and challenges for these conversions are also summarized.

The Fishbone diagram to identify, systematize and analyze the sources of general purpose technologies

OpenAIRE

COCCIA, Mario

2017-01-01

Abstract. This study suggests the fishbone diagram for technological analysis. Fishbone diagram (also called Ishikawa diagrams or cause-and-effect diagrams) is a graphical technique to show the several causes of a specific event or phenomenon. In particular, a fishbone diagram (the shape is similar to a fish skeleton) is a common tool used for a cause and effect analysis to identify a complex interplay of causes for a specific problem or event. The fishbone diagram can be a comprehensive theo...

Quantum MHV Diagrams

OpenAIRE

Brandhuber, Andreas; Travaglini, Gabriele

2006-01-01

Over the past two years, the use of on-shell techniques has deepened our understanding of the S-matrix of gauge theories and led to the calculation of many new scattering amplitudes. In these notes we review a particular on-shell method developed recently, the quantum MHV diagrams, and discuss applications to one-loop amplitudes. Furthermore, we briefly discuss the application of D-dimensional generalised unitarity to the calculation of scattering amplitudes in non-supersymmetric Yang-Mills.

Methods for estimating the enthalpy of formation of inorganic compounds; thermochemical and crystallographic investigations of uranyl salts of group VI elements

International Nuclear Information System (INIS)

Brandenburg, N.P.

1978-01-01

The first part of this thesis is concerned with parameter methods for estimating the standard enthalpy of formation, ΔH 0 sub(f), of inorganic compounds. In this type of method the estimate is a function of parameters, assigned to cation and anion, respectively. The usefulness of a new estimation method is illustrated in the case of uranyl sulphide. In the second part of this thesis crystallographic and thermochemical properties of uranyl salts of group VI elements are described. Crystal structures are given for β-UO 2 SO 4 , UO 2 SeO 3 , and α-UO 2 SeO 4 . Thermochemical measurements have been restricted to the determination of ΔH 0 sub(f)(UO 2 SO 3 ) and ΔH 0 sub(f)(UO 2 TeO 3 ) by means of isoperibol solution calorimetry. (Auth.)

Heuristic Diagrams as a Tool to Teach History of Science

Science.gov (United States)

Chamizo, José A.

2012-05-01

The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The left side originally related in Gowin's Vee with philosophies, theories, models, laws or regularities now agrees with Toulmin's concepts (language, models as representation techniques and application procedures). Mexican science teachers without experience in science education research used the heuristic diagram to learn about the history of chemistry considering also in the left side two different historical times: past and present. Through a semantic differential scale teachers' attitude to the heuristic diagram was evaluated and its usefulness was demonstrated.

Bayesian Networks and Influence Diagrams

DEFF Research Database (Denmark)

Kjærulff, Uffe Bro; Madsen, Anders Læsø

Bayesian Networks and Influence Diagrams: A Guide to Construction and Analysis, Second Edition, provides a comprehensive guide for practitioners who wish to understand, construct, and analyze intelligent systems for decision support based on probabilistic networks. This new edition contains six new...

Synfuels from fusion: using the tandem mirror reactor and a thermochemical cycle to produce hydrogen

Energy Technology Data Exchange (ETDEWEB)

Werner, R.W. (ed.)

1982-11-01

This study is concerned with the following area: (1) the tandem mirror reactor and its physics; (2) energy balance; (3) the lithium oxide canister blanket system; (4) high-temperature blanket; (5) energy transport system-reactor to process; (6) thermochemical hydrogen processes; (7) interfacing the GA cycle; (8) matching power and temperature demands; (9) preliminary cost estimates; (10) synfuels beyond hydrogen; and (11) thermodynamics of the H/sub 2/SO/sub 4/-H/sub 2/O system. (MOW)

New developments of the CARTE thermochemical code: A two-phase equation of state for nanocarbons

Energy Technology Data Exchange (ETDEWEB)

Dubois, Vincent, E-mail: vincent-jp.dubois@cea.fr; Pineau, Nicolas [CEA, DAM, DIF, F-91297 Arpajon (France)

2016-01-07

We developed a new equation of state (EOS) for nanocarbons in the thermodynamic range of high explosives detonation products (up to 50 GPa and 4000 K). This EOS was fitted to an extensive database of thermodynamic properties computed by molecular dynamics simulations of nanodiamonds and nano-onions with the LCBOPII potential. We reproduced the detonation properties of a variety of high explosives with the CARTE thermochemical code, including carbon-poor and carbon-rich explosives, with excellent accuracy.

Ceramic carbon electrode-based anodes for use in the copper-chlorine thermochemical cycle

Energy Technology Data Exchange (ETDEWEB)

Ranganathan, S.; Easton, E.B. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Science

2009-07-01

A thermochemical cycle is a process by which water is decomposed into hydrogen and oxygen through a series of chemical reactions. The chemicals that are used in these reactions are regenerated and recycled during the process. Sol-gel chemistry is becoming more common for the synthesis of electrode materials. The sol-gel reaction can be conducted in the presence of a carbon black to form a ceramic carbon electrode (CCE). The resultant CCE structure contains electronically conductive carbon particle pathways that are bound together through the ceramic binder, which can also promote ion transport. The CCE structure also has a high active surface area and is chemically and thermally robust. This paper presented an investigation of CCE materials prepared using 3-aminopropyl trimethoxysilane. Several electrochemical experiments including cyclic voltammetry and electrochemical impedance spectroscopy were performed to characterize their suitability as anode electrode materials for use in the electrochemical step of the copper-chlorine thermochemical cycle. Subsequent experiments included the manipulation of the relative ratio of organosilane carbon precursors to gauge its impact on electrode properties and performance. An overview of the materials characterization and electrochemical measurements were also presented. Specifically, the paper presented the experiment with particular reference to the CCE preparation; electrochemical experiments; thermal analysis; and scanning electron microscopy. Results were also provided. These included TGA analysis; scanning electron microscopy analysis; electrochemical characterization; and anodic polarization. Characterization of these CCE material demonstrated that they had good thermal stability, could be used at high temperatures, and were therefore, very promising anode materials. 15 refs., 7 figs.

Thermochemical storage for CSP via redox structured reactors/heat exchangers: The RESTRUCTURE project

Science.gov (United States)

Karagiannakis, George; Pagkoura, Chrysoula; Konstandopoulos, Athanasios G.; Tescari, Stefania; Singh, Abhishek; Roeb, Martin; Lange, Matthias; Marcher, Johnny; Jové, Aleix; Prieto, Cristina; Rattenbury, Michael; Chasiotis, Andreas

2017-06-01

The present work provides an overview of activities performed in the framework of the EU-funded collaborative project RESTRUCTURE, the main goal of which was to develop and validate a compact structured reactor/heat exchanger for thermochemical storage driven by 2-step high temperature redox metal oxide cycles. The starting point of development path included redox materials qualification via both theoretical and lab-scale experimental studies. Most favorable compositions were cobalt oxide/alumina composites. Preparation of small-scale structured bodies included various approaches, ranging from perforated pellets to more sophisticated honeycomb geometries, fabricated by extrusion and coating. Proof-of-concept of the proposed novel reactor/heat exchanger was successfully validated in small-scale structures and the next step included scaling up of redox honeycombs production. Significant challenges were identified for the case of extruded full-size bodies and the final qualified approach related to preparation of cordierite substrates coated with cobalt oxide. The successful experimental evaluation of the pilot reactor/heat exchanger system constructed motivated the preliminary techno-economic evaluation of the proposed novel thermochemical energy storage concept. Taking into account experimental results, available technologies and standard design aspects a model for a 70.5 MWe CSP plant was defined. Estimated LCOE costs were calculated to be in the range of reference values for Combined Cycle Power Plants operated by natural gas. One of main cost contributors was the storage system itself, partially due to relatively high cost of cobalt oxide. This highlighted the need to identify less costly and equally efficient to cobalt oxide redox materials.

INFRARED COLOR-COLOR DIAGRAMS FOR AGB STARS

Directory of Open Access Journals (Sweden)

Kyung-Won Suh

2007-09-01

Full Text Available We present infrared color-color diagrams of AGB stars from the observations at near and mid infrared bands. We compile the observations for hundreds of OH/IR stars and carbon stars using the data from the Midcourse Space Experiment (MSX, the two micron sky survey (2MASS, and the IRAS point source catalog (PSC. We compare the observations with the theoretical evolutionary tracks of AGB stars. From the new observational data base and the theoretical evolution tracks, we discuss the meaning of the infrared color-color diagrams at different wavelengths.

Examining competing hypotheses for the effects of diagrams on recall for text.

Science.gov (United States)

Ortegren, Francesca R; Serra, Michael J; England, Benjamin D

2015-01-01

Supplementing text-based learning materials with diagrams typically increases students' free recall and cued recall of the presented information. In the present experiments, we examined competing hypotheses for why this occurs. More specifically, although diagrams are visual, they also serve to repeat information from the text they accompany. Both visual presentation and repetition are known to aid students' recall of information. To examine to what extent diagrams aid recall because they are visual or repetitive (or both), we had college students in two experiments (n = 320) read a science text about how lightning storms develop before completing free-recall and cued-recall tests over the presented information. Between groups, we manipulated the format and repetition of target pieces of information in the study materials using a 2 (visual presentation of target information: diagrams present vs. diagrams absent) × 2 (repetition of target information: present vs. absent) between-participants factorial design. Repetition increased both the free recall and cued recall of target information, and this occurred regardless of whether that repetition was in the form of text or a diagram. In contrast, the visual presentation of information never aided free recall. Furthermore, visual presentation alone did not significantly aid cued recall when participants studied the materials once before the test (Experiment 1) but did when they studied the materials twice (Experiment 2). Taken together, the results of the present experiments demonstrate the important role of repetition (i.e., that diagrams repeat information from the text) over the visual nature of diagrams in producing the benefits of diagrams for recall.

On Hardy's paradox, weak measurements, and multitasking diagrams

International Nuclear Information System (INIS)

Meglicki, Zdzislaw

2011-01-01

We discuss Hardy's paradox and weak measurements by using multitasking diagrams, which are introduced to illustrate the progress of quantum probabilities through the double interferometer system. We explain how Hardy's paradox is avoided and elaborate on the outcome of weak measurements in this context. -- Highlights: → Hardy's paradox explained and eliminated. → Weak measurements: what is really measured? → Multitasking diagrams: introduced and used to discuss quantum mechanical processes.

On the phase diagram of non-spherical nanoparticles

CERN Document Server

Wautelet, M; Hecq, M

2003-01-01

The phase diagram of nanoparticles is known to be a function of their size. In the literature, this is generally demonstrated for cases where their shape is spherical. Here, it is shown theoretically that the phase diagram of non-spherical particles may be calculated from the spherical case, at the same surface area/volume ratio, both with and without surface segregation, provided the surface tension is considered to be isotropic.

Bifurcation diagram features of a dc-dc converter under current-mode control

International Nuclear Information System (INIS)

Ruzbehani, Mohsen; Zhou Luowei; Wang Mingyu

2006-01-01

A common tool for analysis of the systems dynamics when the system has chaotic behaviour is the bifurcation diagram. In this paper, the bifurcation diagram of an ideal model of a dc-dc converter under current-mode control is analysed. Algebraic relations that give the critical points locations and describe the pattern of the bifurcation diagram are derived. It is shown that these simple algebraic and geometrical relations are responsible for the complex pattern of the bifurcation diagrams in such circuits. More explanation about the previously observed properties and introduction of some new ones are exposited. In addition, a new three-dimensional bifurcation diagram that can give better imagination of the parameters role is introduced

Thermochemical study of cyanopyrazines: Experimental and theoretical approaches

International Nuclear Information System (INIS)

Miranda, Margarida S.; Morais, Victor M.F.; Matos, M. Agostinha R.

2006-01-01

The standard (p - bar =0.1MPa) molar energy of combustion, at T=298.15K, of crystalline 2,3-dicyanopyrazine was measured by static bomb calorimetry, in oxygen atmosphere. The standard molar enthalpy of sublimation, at T=298.15K, was obtained by Calvet Microcalorimetry, allowing the calculation of the standard molar enthalpy of formation of the compound, in the gas phase, at T=298.15K: Δ f H m - bar (g)=(518.7+/-3.4)kJ.mol -1 . In addition, the geometries of all cyanopyrazines were obtained using density functional theory with the B3LYP functional and two basis sets: 6-31G* and 6-311G**. These calculations were then used for a better understanding of the relation between structure and energetics of the cyanopyrazine systems. These calculations also reproduce measured standard molar enthalpies of formation with some accuracy and do provide estimates of this thermochemical parameter for those compounds that could not be studied experimentally, namely the tri- and tetracyanopyrazines: the strong electron withdrawing cyano group on the pyrazine ring makes cyanopyrazines highly destabilized compounds

Thermal energy storage using thermo-chemical heat pump

International Nuclear Information System (INIS)

Hamdan, M.A.; Rossides, S.D.; Haj Khalil, R.

2013-01-01

Highlights: ► Understanding of the performance of thermo chemical heat pump. ► Tool for storing thermal energy. ► Parameters that affect the amount of thermal stored energy. ► Lithium chloride has better effect on storing thermal energy. - Abstract: A theoretical study was performed to investigate the potential of storing thermal energy using a heat pump which is a thermo-chemical storage system consisting of water as sorbet, and sodium chloride as the sorbent. The effect of different parameters namely; the amount of vaporized water from the evaporator, the system initial temperature and the type of salt on the increase in temperature of the salt was investigated and hence on the performance of the thermo chemical heat pump. It was found that the performance of the heat pump improves with the initial system temperature, with the amount of water vaporized and with the water remaining in the system. Finally it was also found that lithium chloride salt has higher effect on the performance of the heat pump that of sodium chloride.

Thermochemical hydrogen generation of indium oxide thin films

Directory of Open Access Journals (Sweden)

Taekyung Lim

2017-03-01

Full Text Available Development of alternative energy resources is an urgent requirement to alleviate current energy constraints. As such, hydrogen gas is gaining attention as a future alternative energy source to address existing issues related to limited energy resources and air pollution. In this study, hydrogen generation by a thermochemical water-splitting process using two types of In2O3 thin films was investigated. The two In2O3 thin films prepared by chemical vapor deposition (CVD and sputtering deposition systems contained different numbers of oxygen vacancies, which were directly related to hydrogen generation. The as-grown In2O3 thin film prepared by CVD generated a large amount of hydrogen because of its abundant oxygen vacancies, while that prepared by sputtering had few oxygen vacancies, resulting in low hydrogen generation. Increasing the temperature of the In2O3 thin film in the reaction chamber caused an increase in hydrogen generation. The oxygen-vacancy-rich In2O3 thin film is expected to provide a highly effective production of hydrogen as a sustainable and efficient energy source.

Experimental investigation of molten salt droplet quenching and solidification processes of heat recovery in thermochemical hydrogen production

International Nuclear Information System (INIS)

Ghandehariun, S.; Wang, Z.; Naterer, G.F.; Rosen, M.A.

2015-01-01

Highlights: • Thermal efficiency of a thermochemical cycle of hydrogen production is improved. • Direct contact heat recovery from molten salt is analyzed. • Falling droplets quenched into water are investigated experimentally. - Abstract: This paper investigates the heat transfer and X-ray diffraction patterns of solidified molten salt droplets in heat recovery processes of a thermochemical Cu–Cl cycle of hydrogen production. It is essential to recover the heat of the molten salt to enhance the overall thermal efficiency of the copper–chlorine cycle. A major portion of heat recovery within the cycle can be achieved by cooling and solidifying the molten salt exiting an oxygen reactor. Heat recovery from the molten salt is achieved by dispersing the molten stream into droplets. In this paper, an analytical study and experimental investigation of the thermal phenomena of a falling droplet quenched into water is presented, involving the droplet surface temperature during descent and resulting composition change in the quench process. The results show that it is feasible to quench the molten salt droplets for an efficient heat recovery process without introducing any material imbalance for the overall cycle integration.

Positron bound states on hydride ions in thermochemically reduced MgO single crystals

International Nuclear Information System (INIS)

Monge, M.A.; Pareja, R.; Gonzalez, R.; Chen, Y.

1996-01-01

Positron-lifetime and Doppler-broadening techniques were used to unambiguously identify positronium hydrides in thermochemically reduced MgO crystals at low temperatures. Positrons trapped at H - ions, forming PsH, yield a lifetime of (640±40) ps, independent of temperature. Complementary evidence for this identification was provided by Doppler-broadening experiments, in which positrons were trapped at H 2- sites at low temperatures. The H 2- ions were formed via H - +e - →H 2- by the capturing of an electron released from Fe + impurity under blue-light stimulation. copyright 1996 The American Physical Society

Energetic optimization of a solar thermochemical energy storage system subject to real constraints

Energy Technology Data Exchange (ETDEWEB)

Lovegrove, K [Australian National Univ., Canberra (Australia). Energy Research Centre

1993-12-01

An approach to the optimization of a solar energy conversion system which involves treating the system as a series of subsystems, each having a single cost determining variable, is proposed. The application to an ammonia-based thermochemical system with direct work output is discussed and possible subsystems are identified. The subsystem consisting of the exothermic reactor has been studied in detail. For this subsystem, the ratio of available catalyst volume to thermal power level is held constant whilst the exergetic efficiency is maximized. Results are presented from a determination of optimized reaction paths using dynamic programming techniques. (author)

DIAGRAM SOLVE THE USE OF SIMULINK BLOCK DIAGRAM TO SOLVE MATHEMA THEMATICAL CONTROL EQU MATHEMATICAL MODELS AND CONTROL EQUATIONS

Directory of Open Access Journals (Sweden)

N.M. Ghasem

2003-12-01

Full Text Available In this paper, the simulink block diagram is used to solve a model consists of a set of ordinary differential and algebraic equations to control the temperature inside a simple stirred tank heater. The flexibility of simulink block diagram gives students a better understanding of the control systems. The simulink also allows solution of mathematical models and easy visualization of the system variables. A polyethylene fluidized bed reactor is considered as an industrial example and the effect of the Proportional, Integral and Derivative control policy is presented for comparison.

Electroweak penguin diagrams and two-body B decays

International Nuclear Information System (INIS)

Gronau, M.; Hernandez, O.F.; London, D.; Rosner, J.L.

1995-01-01

We discuss the role of electroweak penguin diagrams in B decays to two light pseudoscalar mesons. We confirm that the extraction of the weak phase α through the isospin analysis involving B→ππ decays is largely unaffected by such operators. However, the methods proposed to obtain weak and strong phases by relating B→ππ, B→πK, and B→K bar K decays through flavor SU(3) will be invalidated if eletroweak penguin diagrams are large. We show that, although the introduction of electroweak penguin contributions introduces no new amplitudes of flavor SU(3), there are a number of ways to experimentally measure the size of such effects. Finally, using SU(3) amplitude relations we present a new way of measuring the weak angle γ which holds even in the presence of electroweak penguin diagrams

Anytime decision making based on unconstrained influence diagrams

DEFF Research Database (Denmark)

Luque, Manuel; Nielsen, Thomas Dyhre; Jensen, Finn Verner

2016-01-01

. This paper addresses this problem by proposing an anytime algorithm that at any time provides a qualified recommendation for the first decisions of the problem. The algorithm performs a heuristic-based search in a decision tree representation of the problem. We provide a framework for analyzing......Unconstrained influence diagrams extend the language of influence diagrams to cope with decision problems in which the order of the decisions is unspecified. Thus, when solving an unconstrained influence diagram we not only look for an optimal policy for each decision, but also for a so-called step......-policy specifying the next decision given the observations made so far. However, due to the complexity of the problem, temporal constraints can force the decision maker to act before the solution algorithm has finished, and, in particular, before an optimal policy for the first decision has been computed...

A Hubble Diagram for Quasars

Directory of Open Access Journals (Sweden)

Susanna Bisogni

2018-01-01

Full Text Available The cosmological model is at present not tested between the redshift of the farthest observed supernovae (z ~ 1.4 and that of the Cosmic Microwave Background (z ~ 1,100. Here we introduce a new method to measure the cosmological parameters: we show that quasars can be used as “standard candles” by employing the non-linear relation between their intrinsic UV and X-ray emission as an absolute distance indicator. We built a sample of ~1,900 quasars with available UV and X-ray observations, and produced a Hubble Diagram up to z ~ 5. The analysis of the quasar Hubble Diagram, when used in combination with supernovae, provides robust constraints on the matter and energy content in the cosmos. The application of this method to forthcoming, larger quasar samples, will also provide tight constraints on the dark energy equation of state and its possible evolution with time.

Impact of Diagrams on Recalling Sequential Elements in Expository Texts.

Science.gov (United States)

Guri-Rozenblit, Sarah

1988-01-01

Examines the instructional effectiveness of abstract diagrams on recall of sequential relations in social science textbooks. Concludes that diagrams assist significantly the recall of sequential relations in a text and decrease significantly the rate of order mistakes. (RS)

A LaTeX graphics routine for drawing Feynman diagrams

International Nuclear Information System (INIS)

Levine, M.J.S.

1990-01-01

FEYNMAN is a LaTeX macropackage which allows the user to construct a versatile range of Feynman diagrams within the text of a document. Diagrams of publication quality may be drawn with relative ease and rapidity. (orig.)

Interactive Land-Use Optimization Using Laguerre Voronoi Diagram with Dynamic Generating Point Allocation

Science.gov (United States)

Chaidee, S.; Pakawanwong, P.; Suppakitpaisarn, V.; Teerasawat, P.

2017-09-01

In this work, we devise an efficient method for the land-use optimization problem based on Laguerre Voronoi diagram. Previous Voronoi diagram-based methods are more efficient and more suitable for interactive design than discrete optimization-based method, but, in many cases, their outputs do not satisfy area constraints. To cope with the problem, we propose a force-directed graph drawing algorithm, which automatically allocates generating points of Voronoi diagram to appropriate positions. Then, we construct a Laguerre Voronoi diagram based on these generating points, use linear programs to adjust each cell, and reconstruct the diagram based on the adjustment. We adopt the proposed method to the practical case study of Chiang Mai University's allocated land for a mixed-use complex. For this case study, compared to other Voronoi diagram-based method, we decrease the land allocation error by 62.557 %. Although our computation time is larger than the previous Voronoi-diagram-based method, it is still suitable for interactive design.

Diagram, Gesture, Agency: Theorizing Embodiment in the Mathematics Classroom

Science.gov (United States)

de Freitas, Elizabeth; Sinclair, Nathalie

2012-01-01

In this paper, we use the work of philosopher Gilles Chatelet to rethink the gesture/diagram relationship and to explore the ways mathematical agency is constituted through it. We argue for a fundamental philosophical shift to better conceptualize the relationship between gesture and diagram, and suggest that such an approach might open up new…

Environmental requirements in thermochemical and biochemical conversion of biomass

International Nuclear Information System (INIS)

Frings, R.M.; Mackie, K.L.; Hunter, I.R.

1992-01-01

Many biological and thermochemical processing options exist for the conversion of biomass to fuels. Commercially, these options are assessed in terms of fuel product yield and quality. However, attention must also be paid to the environmental aspects of each technology so that any commercial plant can meet the increasingly stringent environmental legislation in the world today. The environmental aspects of biological conversion (biogasification and bioliquefaction) and thermal conversion (high pressure liquefaction, flash pyrolysis, and gasification) are reviewed. Biological conversion processes are likely to generate waste streams which are more treatable than those from thermal conversion processes but the available data for thermal liquefaction are very limited. Close attention to waste minimisation is recommended and processing options that greatly reduce or eliminate waste streams have been identified. Product upgrading and its effect on wastewater quality also requires attention. Emphasis in further research studies needs to be placed on providing authentic waste streams for environmental assessment. (author)

Characteristics of thermochemical treated EN10090 X50 steel

International Nuclear Information System (INIS)

Schmitz, S.; Graf, K.; Scheid, A.; Moreno, A.

2014-01-01

EN10090 X50 steel is commonly used for engine valves to withstand severe operation conditions involving high temperature and corrosion from fuel and combustion gas. Usually, to enhance wear performance, valves undergo nitriding thermochemical treatment by salt baths. The aim of this work is to produce diffusion layers at least 20μm thick with hardness higher than 700HV by plasma surface treatment with no continuous compounds layer using nitrogen and methane based atmospheres. Samples were characterized by laser Confocal and scanning electron microscopy, X-ray diffraction and Vickers hardness. Salt bath treatment induced formation of undesirable compounds layer at the surface and a diffusion layer thicker than 40μm, with hardness arising 1280HV_0_,_0_1_0. Plasma surface treatment produced diffusion layer thicker than 40μm with no continuous compounds layer and mean hardness varying from 750 to 960HV_0_,_0_1_0. (author)

R and D thermochemical I-S process at JAERI

International Nuclear Information System (INIS)

Onuki, K.; Kubo, S.; Nakajima, H.; Higashi, S.; Kasahara, S.; Ishiyama, S.; Okuda, H.

2004-01-01

The Japan Atomic Energy Research Institute (JAERI) has conducted a study on the thermochemical water-splitting process of the iodine-sulfur family (IS process). In the IS process, water will react with iodine and sulfur dioxide to produce hydrogen iodide and sulfuric acid, which are then decomposed thermally to produce hydrogen and oxygen. High temperature nuclear heat, mainly supplied by a High Temperature Gas-cooled Reactor (HTGR), is used to drive the endothermic decomposition of sulfuric acid. JAERI has demonstrated the feasibility of the water-splitting hydrogen production process by carrying out laboratory-scale experiments in which combined operation of fundamental reactions and separations using the IS process was performed continuously. At present, the hydrogen production test is continuing, using a scaled-up glass apparatus. Corrosion-resistant materials for constructing a large-scale plant and process improvements by introducing advanced separation techniques, such as membrane separation, are under study. Future R and D items are discussed based on the present activities. (author)

Blanket materials for fusion reactors: comparisons of thermochemical performance

International Nuclear Information System (INIS)

Johnson, C.E.; Fischer, A.K.; Tetenbaum, M.

1984-01-01

Thermodynamic calculations have been made to predict the thermochemical performance of the fusion reactor breeder materials, Li 2 O, LiAlO 2 , and Li 4 SiO 4 in the temperature range 900 to 1300 0 K and in the oxygen activity range 10 -25 to 10 -5 . Except for a portion of these ranges, the performance of LiAlO 2 is predicted to be better than that of Li 2 O and Li 4 SiO 4 . The protium purge technique for enhancing tritium release is explored for the Li 2 O system; it appears advantageous at higher temperatures but should be used cautiously at lower temperatures. Oxygen activity is an important variable in these systems and must be considered in executing and interpreting measurements on rates of tritium release, the form of released tritium, diffusion of tritiated species and their identities, retention of tritium in the condensed phase, and solubility of hydrogen isotope gases

Small-threshold behaviour of two-loop self-energy diagrams: two-particle thresholds

International Nuclear Information System (INIS)

Berends, F.A.; Davydychev, A.I.; Moskovskij Gosudarstvennyj Univ., Moscow; Smirnov, V.A.; Moskovskij Gosudarstvennyj Univ., Moscow

1996-01-01

The behaviour of two-loop two-point diagrams at non-zero thresholds corresponding to two-particle cuts is analyzed. The masses involved in a cut and the external momentum are assumed to be small as compared to some of the other masses of the diagram. By employing general formulae of asymptotic expansions of Feynman diagrams in momenta and masses, we construct an algorithm to derive analytic approximations to the diagrams. In such a way, we calculate several first coefficients of the expansion. Since no conditions on relative values of the small masses and the external momentum are imposed, the threshold irregularities are described analytically. Numerical examples, using diagrams occurring in the standard model, illustrate the convergence of the expansion below the first large threshold. (orig.)

Phase shifts of the paired wings of butterfly diagrams

International Nuclear Information System (INIS)

Li Kejun; Liang Hongfei; Feng Wen

2010-01-01

Sunspot groups observed by the Royal Greenwich Observatory/US Air Force/NOAA from 1874 May to 2008 November and the Carte Synoptique solar filaments from 1919 March to 1989 December are used to investigate the relative phase shift of the paired wings of butterfly diagrams of sunspot and filament activities. Latitudinal migration of sunspot groups (or filaments) does asynchronously occur in the northern and southern hemispheres, and there is a relative phase shift between the paired wings of their butterfly diagrams in a cycle, making the paired wings spatially asymmetrical on the solar equator. It is inferred that hemispherical solar activity strength should evolve in a similar way within the paired wings of a butterfly diagram in a cycle, demonstrating the paired wings phenomenon and showing the phase relationship between the northern and southern hemispherical solar activity strengths, as well as a relative phase shift between the paired wings of a butterfly diagram, which should bring about almost the same relative phase shift of hemispheric solar activity strength. (research papers)

Multiple representations and free-body diagrams: Do students benefit from using them?

Science.gov (United States)

Rosengrant, David R.

2007-12-01

Introductory physics students have difficulties understanding concepts and solving problems. When they solve problems, they use surface features of the problems to find an equation to calculate a numerical answer often not understanding the physics in the problem. How do we help students approach problem solving in an expert manner? A possible answer is to help them learn to represent knowledge in multiple ways and then use these different representations for conceptual understanding and problem solving. This solution follows from research in cognitive science and in physics education. However, there are no studies in physics that investigate whether students who learn to use multiple representations are in fact better problem solvers. This study focuses on one specific representation used in physics--a free body diagram. A free-body diagram is a graphical representation of forces exerted on an object of interest by other objects. I used the free-body diagram to investigate five main questions: (1) If students are in a course where they consistently use free body diagrams to construct and test concepts in mechanics, electricity and magnetism and to solve problems in class and in homework, will they draw free-body diagrams on their own when solving exam problems? (2) Are students who use free-body diagrams to solve problems more successful then those who do not? (3) Why do students draw free-body diagrams when solving problems? (4) Are students consistent in constructing diagrams for different concepts in physics and are they consistent in the quality of their diagrams? (5) What are possible relationships between features of a problem and how likely a student will draw a free body diagram to help them solve the problem? I utilized a mixed-methods approach to answer these questions. Questions 1, 2, 4 and 5 required a quantitative approach while question 3 required a qualitative approach, a case study. When I completed my study, I found that if students are in an

Interest of thermochemical data bases linked to complex equilibria calculation codes for practical applications

International Nuclear Information System (INIS)

Cenerino, G.; Marbeuf, A.; Vahlas, C.

1992-01-01

Since 1974, Thermodata has been working on developing an Integrated Information System in Inorganic Chemistry. A major effort was carried on the thermochemical data assessment of both pure substances and multicomponent solution phases. The available data bases are connected to powerful calculation codes (GEMINI = Gibbs Energy Minimizer), which allow to determine the thermodynamical equilibrium state in multicomponent systems. The high interest of such an approach is illustrated by recent applications in as various fields as semi-conductors, chemical vapor deposition, hard alloys and nuclear safety. (author). 26 refs., 6 figs

Potential for thermochemical conversion of biomass residues from the integrated sugar-ethanol process - Fate of ash and ash-forming elements.

Science.gov (United States)

Dirbeba, Meheretu Jaleta; Brink, Anders; DeMartini, Nikolai; Zevenhoven, Maria; Hupa, Mikko

2017-06-01

In this work, potential for thermochemical conversion of biomass residues from an integrated sugar-ethanol process and the fate of ash and ash-forming elements in the process are presented. Ash, ash-forming elements, and energy flows in the process were determined using mass balances and analyses of eight different biomass samples for ash contents, elemental compositions, and heating values. The results show that the ash content increases from the sugarcane to the final residue, vinasse. The cane straw, which is left in the field, contains one-third of the energy and 25% of the K and Cl while the vinasse contains 2% of the energy and 40% of the K and Cl in the cane. K and Cl in biomass fuels cause corrosion and fouling problems in boilers and gasifiers. Over 85% of these elements in the straw are water soluble indicating that water leaching would improve it for utilization in thermochemical conversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparison of two approaches for solving unconstrained influence diagrams

DEFF Research Database (Denmark)

Ahlmann-Ohlsen, Kristian S.; Jensen, Finn V.; Nielsen, Thomas Dyhre

2009-01-01

Influence diagrams and decision trees represent the two most common frameworks for specifying and solving decision problems. As modeling languages, both of these frameworks require that the decision analyst specifies all possible sequences of observations and decisions (in influence diagrams, thi...

Spacelike penguin diagram effects in B implies PP decays

International Nuclear Information System (INIS)

Du, D.; Yang, M.; Zhang, D.

1996-01-01

The spacelike penguin diagram contributions to branching ratios and CP asymmetries in charmless decays of B to two pseudoscalar mesons are studied using the next-to-leading order low energy effective Hamiltonian. Both the gluonic penguin and the electroweak penguin diagrams are considered. We find that the effects are significant. copyright 1995 The American Physical Society

The use of influence diagrams for evaluating severe accident management strategies

International Nuclear Information System (INIS)

Jae, M.; Apostolakis, G.E.

1992-01-01

In this paper, the influence diagram, a new analytical tool for developing and evaluating severe accident management strategies, is presented. Influence diagrams are much simpler than decision trees because they do not lead to the large number of branches that are generated when decision trees are used in realistic problems; furthermore, they show explicitly the dependencies between the variables of the problem. One of the accident management strategies proposed for light water reactors, flooding the reactor cavity as a means of preventing vessel breach during a short-term station blackout sequence, is presented. The influence diagram associated with this strategy is constructed. Finally, the advantages of using influence diagrams in accident management are explored

Merit exponents and control area diagrams in materials selection

International Nuclear Information System (INIS)

Zander, Johan; Sandstroem, Rolf

2011-01-01

Highlights: → Merit exponents are introduced to generalise the merit indices commonly used in materials selection. → The merit exponents can rank materials in general design situations. → To allow identification of the active merit exponent(s), control area diagrams are used. → Principles for generating the control area diagrams are presented. -- Abstract: Merit indices play a fundamental role in materials selection, since they enable ranking of materials. However, the conventional formulation of merit indices is associated with severe limitations. They are dependent on the explicit solution of the variables in the equations for the constraints from the design criteria. Furthermore, it is not always easy to determine which the controlling merit index is. To enable the ranking of materials in more general design cases, merit exponents are introduced as generalisations of the merit indices. Procedures are presented for how to compute the merit exponents numerically without having to solve equations algebraically. Merit exponents (and indices) are only valid in a certain range of property values. To simplify the identification of the controlling merit exponent, it is suggested that so called control area diagrams are used. These diagrams consist of a number of domains, each showing the active constraints and the controlling merit exponent. It is shown that the merit exponents play a crucial role when the control area diagram (CAD) is set up. The principles in the paper are developed for mechanically loaded components and are illustrated for engineering beams with two or three geometric variables.

The importance of design in learning from node-link diagrams

NARCIS (Netherlands)

Amelsvoort, Marije; van der Meij, Jan; Anjewierden, Anjo Allert; van der Meij, Hans

2013-01-01

Diagrams organize by location. They give spatial cues for finding and recognizing information and for making inferences. In education, diagrams are often used to help students understand and recall information. This study assessed the influence of perceptual cues on reading behavior and subsequent

Re-determination of succinonitrile (SCN) camphor phase diagram

Science.gov (United States)

Teng, Jing; Liu, Shan

2006-04-01

Low-melting temperature transparent organic materials have been extensively used to study the pattern formation and microstructure evolution. It proves to be very challenging to accurately determine the phase diagram since there is no viable way to measure the composition microscopically. In this paper, we presented the detailed experimental characterization of the phase diagram of succinonitrile (SCN)-camphor binary system. Differential scanning calorimetry, a ring-heater, and the directional solidification technique have been combined to determine the details of the phase diagram by using the purified materials. The advantages and disadvantages have been discussed for the different experimental techniques. SCN and camphor constitute a simple binary eutectic system with the eutectic composition at 23.6 wt% camphor and eutectic temperature at 37.65 °C. The solidus and the solubility of the SCN base solid solution have been precisely determined for the first time in this binary system.

Designing a supply chain of ready-mix concrete using Voronoi diagrams

Science.gov (United States)

Kozniewski, E.; Orlowski, M.; Orlowski, Z.

2017-10-01

Voronoi diagrams are used to solve scientific and practical problems in many fields. In this paper Voronoi diagrams have been applied to logistic problems in construction, more specifically in the design of the ready-mix concrete supply chain. Apart from the Voronoi diagram, the so-called time-distance circle (circle of range), which in metric space terminology is simply a sphere, appears useful. It was introduced to solve the problem of supplying concrete-related goods.

Algorithmic approach to diagram techniques

International Nuclear Information System (INIS)

Ponticopoulos, L.

1980-10-01

An algorithmic approach to diagram techniques of elementary particles is proposed. The definition and axiomatics of the theory of algorithms are presented, followed by the list of instructions of an algorithm formalizing the construction of graphs and the assignment of mathematical objects to them. (T.A.)

Diagrams in the polaron model

International Nuclear Information System (INIS)

Smondyrev, M.A.

1985-01-01

The perturbation theory for the polaron energy is systematically treated on the diagrammatic basis. Feynman diagrams being constructed allow to calculate the polaron energy up to the third order in powers of the coupling constant. Similar calculations are performed for the average number of virtual phonons

Relation between time-temperature transformation and continuous heating transformation diagrams of metallic glassy alloys

International Nuclear Information System (INIS)

Louzguine-Luzgin, Dmitri V.; Inoue, Akihisa

2005-01-01

The time-temperature transformation (TTT) diagrams for the onset of devitrification of the Ge-Ni-La and Cu-Hf-Ti glassy alloys were calculated from the isothermal differential calorimetry data using an Arrhenius equation. The continuous heating transformation (CHT) diagrams for the onset of devitrification of the glassy alloys were subsequently recalculated from TTT diagrams. The recalculation method used for conversion of the TTT into CHT diagrams produces reasonable results and is not sensitive to the type of the devitrification reaction (polymorphous or primary transformation). The diagrams allow to perform a comparison of the stabilities of glassy alloys on a long-term scale. The relationship between these diagrams is discussed

Top-down versus bottom-up processing of influence diagrams in probabilistic analysis

International Nuclear Information System (INIS)

Timmerman, R.D.; Burns, T.J.; Dodds, H.L. Jr.

1986-01-01

Recent work by Phillips et al and Selby et al has shown that influence diagram methodology can be a useful analytical tool in reactor safety studies. In some instances, an influence diagram can be used as a graphical representation of probabilistic dependence within a system or event sequence. Under these circumstances, Bayesian statistics is employed to transform the relationships depicted in the influence diagram into the correct expression for a desired marginal probability (e.g., the top node). In the references cited above, the authors demonstrated the usefulness of influence diagrams for assessing the reliability of operator performance during pressurized thermal shock transients. In addition, the use of influence diagrams identified the critical variables that had the greatest impact on operator reliability for a particular scenario (e.g., control room design, procedures, etc.). Top-down and bottom-up algorithms have emerged as the dominant methods for quantifying influence diagrams. The purpose of this paper is to demonstrate a potential error in employing the bottom-up algorithm when dealing with interdependencies

The Butterfly Diagram Internal Structure

International Nuclear Information System (INIS)

Ternullo, Maurizio

2013-01-01

A time-latitude diagram, where the spotgroup area is taken into account, is presented for cycles 12 through 23. The results show that the spotted area is concentrated in few, small portions ( k nots ) of the Butterfly Diagram (BD). The BD may be described as a cluster of knots. Knots are distributed in the butterfly wings in a seemingly randomly way. A knot may appear at either lower or higher latitudes than previous ones, in spite of the prevalent tendency to appear at lower and lower latitudes. Accordingly, the spotted area centroid, far from continuously drifting equatorward, drifts poleward or remains stationary in any hemisphere for significant fractions (≈ 1/3) of the cycle total duration. In a relevant number of semicycles, knots seem to form two roughly parallel, oblique c hains , separated by an underspotted band. This picture suggests that two (or more) ''activity streams'' approach the equator at a rate higher than the spot zone as a whole.

Application of the cause-consequence diagram method to static systems

International Nuclear Information System (INIS)

Andrews, J.D.; Ridley, L.M.

2002-01-01

In the last 30 years, various mathematical models have been used to identify the effect of component failures on the performance of a system. The most frequently used technique for system reliability assessment is Fault Tree Analysis (FTA) and a large proportion of its popularity can be attributed to the fact that it provides a very good documentation of the way that the system failure logic was developed. Exact quantification of the fault tree, however, can be problematic for very large systems and in such situations, approximations can be used. Alternatively, an exact result can be obtained via the conversion of the fault tree into a binary decision diagram (BDD). The BDD, however, loses all failure logic documentation during the conversion process. This paper outlines the use of the cause-consequence diagram method as a tool for system risk and reliability analysis. As with the FTA method, the cause-consequence diagram documents the failure logic of the system. In addition to this the cause-consequence diagram produces the exact failure probability in a very efficient calculation procedure. The cause-consequence diagram technique has been applied to a static system and shown to yield the same result as those produced by the solution of the equivalent fault tree and BDD. On the basis of this general rules have been devised for the correct construction of the cause-consequence diagram given a static system. The use of the cause-consequence method in this manner has significant implications in terms of efficiency of the reliability analysis and can be shown to have benefits for static systems

Survey and Down-Selection of Acid Gas Removal Systems for the Thermochemical Conversion of Biomass to Ethanol with a Detailed Analysis of an MDEA System

Energy Technology Data Exchange (ETDEWEB)

Nexant, Inc., San Francisco, California

2011-05-01

The first section (Task 1) of this report by Nexant includes a survey and screening of various acid gas removal processes in order to evaluate their capability to meet the specific design requirements for thermochemical ethanol synthesis in NREL's thermochemical ethanol design report (Phillips et al. 2007, NREL/TP-510-41168). MDEA and selexol were short-listed as the most promising acid-gas removal agents based on work described in Task 1. The second report section (Task 2) describes a detailed design of an MDEA (methyl diethanol amine) based acid gas removal system for removing CO2 and H2S from biomass-derived syngas. Only MDEA was chosen for detailed study because of the available resources.

Fuels production by the thermochemical transformation of the biomass; La production de carburants par transformation thermochimique de la biomasse

Energy Technology Data Exchange (ETDEWEB)

Claudet, G. [CEA, 75 - Paris (France)

2005-07-01

The biomass is a local and renewable energy source, presenting many advantages. This paper proposes to examine the biomass potential in France, the energy valorization channels (thermochemical chains of thermolysis and gasification) with a special interest for the hydrogen production and the research programs oriented towards the agriculture and the forest. (A.L.B.)

Conformational properties of rigid-chain amphiphilic macromolecules : The phase diagram

NARCIS (Netherlands)

Markov, V. A.; Vasilevskaya, V. V.; Khalatur, P. G.; ten Brinke, G.; Khokhlov, A. R.

The coil-globule transition in rigid-chain amphiphilic macromolecules was studied by means of computer simulation, and the phase diagrams for such molecules in the solvent quality-persistence length coordinates were constructed. It was shown that the type of phase diagram depends to a substantial

Phase diagram of the disordered Bose-Hubbard model

International Nuclear Information System (INIS)

Gurarie, V.; Pollet, L.; Prokof'ev, N. V.; Svistunov, B. V.; Troyer, M.

2009-01-01

We establish the phase diagram of the disordered three-dimensional Bose-Hubbard model at unity filling which has been controversial for many years. The theorem of inclusions, proven by Pollet et al. [Phys. Rev. Lett. 103, 140402 (2009)] states that the Bose-glass phase always intervenes between the Mott insulating and superfluid phases. Here, we note that assumptions on which the theorem is based exclude phase transitions between gapped (Mott insulator) and gapless phases (Bose glass). The apparent paradox is resolved through a unique mechanism: such transitions have to be of the Griffiths type when the vanishing of the gap at the critical point is due to a zero concentration of rare regions where extreme fluctuations of disorder mimic a regular gapless system. An exactly solvable random transverse field Ising model in one dimension is used to illustrate the point. A highly nontrivial overall shape of the phase diagram is revealed with the worm algorithm. The phase diagram features a long superfluid finger at strong disorder and on-site interaction. Moreover, bosonic superfluidity is extremely robust against disorder in a broad range of interaction parameters; it persists in random potentials nearly 50 (!) times larger than the particle half-bandwidth. Finally, we comment on the feasibility of obtaining this phase diagram in cold-atom experiments, which work with trapped systems at finite temperature.

The Critical Importance of Russell's Diagram

Science.gov (United States)

Gingerich, O.

2013-04-01

The idea of dwarf and giants stars, but not the nomenclature, was first established by Eijnar Hertzsprung in 1905; his first diagrams in support appeared in 1911. In 1913 Henry Norris Russell could demonstrate the effect far more strikingly because he measured the parallaxes of many stars at Cambridge, and could plot absolute magnitude against spectral type for many points. The general concept of dwarf and giant stars was essential in the galactic structure work of Harlow Shapley, Russell's first graduate student. In order to calibrate the period-luminosity relation of Cepheid variables, he was obliged to fall back on statistical parallax using only 11 Cepheids, a very sparse sample. Here the insight provided by the Russell diagram became critical. The presence of yellow K giant stars in globular clusters credentialed his calibration of the period-luminosity relation by showing that the calibrated luminosity of the Cepheids was comparable to the luminosity of the K giants. It is well known that in 1920 Shapley did not believe in the cosmological distances of Heber Curtis' spiral nebulae. It is not so well known that in 1920 Curtis' plot of the period-luminosity relation suggests that he didn't believe it was a physical relation and also he failed to appreciate the significance of the Russell diagram for understanding the large size of the Milky Way.

Solar Thermochemical Energy Storage Through Carbonation Cycles of SrCO3/SrO Supported on SrZrO3.

Science.gov (United States)

Rhodes, Nathan R; Barde, Amey; Randhir, Kelvin; Li, Like; Hahn, David W; Mei, Renwei; Klausner, James F; AuYeung, Nick

2015-11-01

Solar thermochemical energy storage has enormous potential for enabling cost-effective concentrated solar power (CSP). A thermochemical storage system based on a SrO/SrCO3 carbonation cycle offers the ability to store and release high temperature (≈1200 °C) heat. The energy density of SrCO3/SrO systems supported by zirconia-based sintering inhibitors was investigated for 15 cycles of exothermic carbonation at 1150 °C followed by decomposition at 1235 °C. A sample with 40 wt % of SrO supported by yttria-stabilized zirconia (YSZ) shows good energy storage stability at 1450 MJ m(-3) over fifteen cycles at the same cycling temperatures. After further testing over 45 cycles, a decrease in energy storage capacity to 1260 MJ m(-3) is observed during the final cycle. The decrease is due to slowing carbonation kinetics, and the original value of energy density may be obtained by lengthening the carbonation steps. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Warped penguin diagrams

International Nuclear Information System (INIS)

Csaki, Csaba; Grossman, Yuval; Tanedo, Philip; Tsai, Yuhsin

2011-01-01

We present an analysis of the loop-induced magnetic dipole operator in the Randall-Sundrum model of a warped extra dimension with anarchic bulk fermions and an IR brane-localized Higgs. These operators are finite at one-loop order and we explicitly calculate the branching ratio for μ→eγ using the mixed position/momentum space formalism. The particular bound on the anarchic Yukawa and Kaluza-Klein (KK) scales can depend on the flavor structure of the anarchic matrices. It is possible for a generic model to either be ruled out or unaffected by these bounds without any fine-tuning. We quantify how these models realize this surprising behavior. We also review tree-level lepton flavor bounds in these models and show that these are on the verge of tension with the μ→eγ bounds from typical models with a 3 TeV Kaluza-Klein scale. Further, we illuminate the nature of the one-loop finiteness of these diagrams and show how to accurately determine the degree of divergence of a five-dimensional loop diagram using both the five-dimensional and KK formalism. This power counting can be obfuscated in the four-dimensional Kaluza-Klein formalism and we explicitly point out subtleties that ensure that the two formalisms agree. Finally, we remark on the existence of a perturbative regime in which these one-loop results give the dominant contribution.

Three-body crystallization diagrams and the cooling of white dwarfs.

Science.gov (United States)

Segretain, L.

1996-06-01

The 3-body crystallization diagrams of C/O/Ne ionic mixtures characteristic of white dwarf interiors are examined within the framework of the density-functional theory of freezing. The crystallization process is described more accurately than in former calculations where the three-component system was treated as an effective two-component mixture (Segretain et al. 1994). The distillation process due to neon-crystallization is found to occur only for the late stages of crystallization. At the beginning, the presence of neon plays only a minor role and the phase diagram resembles a pure carbon-oxygen diagram. The final phase diagram is found to exhibit an azeotropic point with a neon concentration x_Ne_=0.22, a carbon concentration x_C_=0.78 and an oxygen concentration x_O_=0, so that during the distillation process, the fluid crystallizes into a pure neon-carbon solid. The critical temperature is T_A_=0.85T_C_, where T_C_ is the pure carbon crystallization temperature. We use this accurate phase diagram to calculate the total gravitational energy released during white dwarf crystallization and the related time delay. The final result yields {DELTA}τ=~2.6Gyr, among which about 20% are due to the neon-distillation process.

Effect of a Diagram on Primary Students' Understanding About Electric Circuits

Science.gov (United States)

Preston, Christine Margaret

2017-09-01

This article reports on the effect of using a diagram to develop primary students' conceptual understanding about electric circuits. Diagrammatic representations of electric circuits are used for teaching and assessment despite the absence of research on their pedagogical effectiveness with young learners. Individual interviews were used to closely analyse Years 3 and 5 (8-11-year-old) students' explanations about electric circuits. Data was collected from 20 students in the same school providing pre-, post- and delayed post-test dialogue. Students' thinking about electric circuits and changes in their explanations provide insights into the role of diagrams in understanding science concepts. Findings indicate that diagram interaction positively enhanced understanding, challenged non-scientific views and promoted scientific models of electric circuits. Differences in students' understanding about electric circuits were influenced by prior knowledge, meta-conceptual awareness and diagram conventions including a stylistic feature of the diagram used. A significant finding that students' conceptual models of electric circuits were energy rather than current based has implications for electricity instruction at the primary level.

Asteroseismic Diagram for Subgiants and Red Giants

Energy Technology Data Exchange (ETDEWEB)

Gai, Ning; Tang, Yanke [College of Physics and Electronic information, Dezhou University, Dezhou 253023 (China); Yu, Peng [College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331 (China); Dou, Xianghua, E-mail: ning_gai@163.com, E-mail: tyk450@163.com [Shandong Provincial Key Laboratory of Biophysics, Dezhou University, Dezhou 253023 (China)

2017-02-10

Asteroseismology is a powerful tool for constraining stellar parameters. NASA’s Kepler mission is providing individual eigenfrequencies for a huge number of stars, including thousands of red giants. Besides the frequencies of acoustic modes, an important breakthrough of the Kepler mission is the detection of nonradial gravity-dominated mixed-mode oscillations in red giants. Unlike pure acoustic modes, mixed modes probe deeply into the interior of stars, allowing the stellar core properties and evolution of stars to be derived. In this work, using the gravity-mode period spacing and the large frequency separation, we construct the ΔΠ{sub 1}–Δ ν asteroseismic diagram from models of subgiants and red giants with various masses and metallicities. The relationship ΔΠ{sub 1}–Δ ν is able to constrain the ages and masses of the subgiants. Meanwhile, for red giants with masses above 1.5 M {sub ⊙}, the ΔΠ{sub 1}–Δ ν asteroseismic diagram can also work well to constrain the stellar age and mass. Additionally, we calculate the relative “isochrones” τ , which indicate similar evolution states especially for similar mass stars, on the ΔΠ{sub 1}–Δ ν diagram.

The colour-magnitude diagram of NGC 5053

International Nuclear Information System (INIS)

Walker, M.F.; Pike, C.D.; McGee, J.D.

1976-01-01

The colour-magnitude diagram of NGC 5053 has been derived to V = 21.1 from photographic and electronographic observations. The electronographic observations were obtained with an experimental Spectracon image-converter, having photocathode and exit window dimensions of 20 x 30 mm, mounted at the prime-focus of the 120-in. Lick reflector. The photographic observations were obtained with the 20-in. Carnegie astrograph and the 36-in. Crossley reflector. The colour-magnitude diagram resembles that of M92, with the difference that a red horizontal branch is more pronounced than the asymptotic branch in NGC 5053. The topology of the horizontal branch is that of clusters with an intermediate metal content and is thus at variance with the mean period of the RR Lyr stars and the unreddened colour of the subgiant branch read at the magnitude level of the horizontal branch, both of which would indicate an extremely low metal content. If comparison of the colour-magnitude diagrams of NGC 5053 and M92 is valid, then the reddening of NGC 5053 is Esub(B-V) = 0.02 and the apparent distance modulus is m-M = 16.08 +- 0.08. (author)

Calculation of Fe–B–V ternary phase diagram

International Nuclear Information System (INIS)

Homolová, Viera; Kroupa, Aleš; Výrostková, Anna

2012-01-01

Highlights: ► Phase diagram of Fe–B–V system was modelled by CALPHAD method. ► Database for thermodynamic calculations for Fe–B–V system was created. ► The new ternary phase was found in 67Fe–18B–15V [in at.%] alloy. - Abstract: The phase equilibria of the Fe–B–V ternary system are studied experimentally and theoretically in this paper. Phase diagram of the system was modelled by CALPHAD method. Boron was modelled as an interstitial element in the FCC and BCC solid solutions. The calculations of isothermal sections of phase diagram are compared with our experimental results at 903 and 1353 K and with available literature experimental data. New ternary phase (with chemical composition 28Fe32V40B in at.%) was found in 67Fe–18B–15V alloy [in at.%]. Further experimental studies for the determination of exact nature of the ternary phase including crystallographic information are necessary.

Benchmark Study of the Structural and Thermochemical Properties of a Dihydroazulene/Vinylheptafulvene Photoswitch

DEFF Research Database (Denmark)

Koerstz, Mads; Elm, Jonas; Mikkelsen, Kurt Valentin

2017-01-01

We investigate the performance of four different density functional theory (DFT) functionals (M06-2X, ωB97X-D, PBE0, and B3LYP-D3BJ) for calculating the structural and thermochemical properties of the dihydroazulene/vinylheptafulvene photoswitch (DHA/VHF). We find that all the tested DFT......, indicating that the largest source of error when calculating storage free energies originates from errors in the calculated single point energies. It was found that ωB97X-D and M06-2X performed decently for predicting storage energies. While B3LYP-D3BJ and PBE0 generally underestimated the storage energy...

Phase Diagrams of Electrostatically Self-Assembled Amphiplexes

Energy Technology Data Exchange (ETDEWEB)

V Stanic; M Mancuso; W Wong; E DiMasi; H Strey

2011-12-31

We present the phase diagrams of electrostatically self-assembled amphiplexes (ESA) comprised of poly(acrylic acid) (PAA), cetyltrimethylammonium chloride (CTACl), dodecane, pentanol, and water at three different NaCl salt concentrations: 100, 300, and 500 mM. This is the first report of phase diagrams for these quinary complexes. Adding a cosurfactant, we were able to swell the unit cell size of all long-range ordered phases (lamellar, hexagonal, Pm3n, Ia3d) by almost a factor of 2. The added advantage of tuning the unit cell size makes such complexes (especially the bicontinuous phases) attractive for applications in bioseparation, drug delivery, and possibly in oil recovery.

Thermochemical and phase diagram studies of the Bi-Ni-Sn system

Czech Academy of Sciences Publication Activity Database

Milcheva, N.; Brož, P.; Buršík, Jiří; Vassilev, G.P.

2012-01-01

Roč. 534, APR (2012), s. 41-50 ISSN 0040-6031 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional research plan: CEZ:AV0Z20410507 Keywords : differential scanning calorimetry * scanning electron microscopy * solders Subject RIV: BJ - Thermodynamics Impact factor: 1.989, year: 2012

Thermochemical reactivity of 5–15 mol% Fe, Co, Ni, Mn-doped cerium oxides in two-step water-splitting cycle for solar hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Gokon, Nobuyuki, E-mail: ngokon@eng.niigata-u.ac.jp [Center for Transdisciplinary Research, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Suda, Toshinori [Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Niigata 950-2181 (Japan); Kodama, Tatsuya [Department of Chemistry & Chemical Engineering, Faculty of Engineering, Niigata University, 8050 Ikarashi 2-nocho, Niigata 950-2181 (Japan)

2015-10-10

Highlights: • 5–15 mol% M-doped ceria are examined for thermochemical two-step water-splitting. • 5 mol% Fe- and Co-doped ceria have stoichiometric production of oxygen and hydrogen. • 10–15 mol% Fe- and Mn-doped ceria showed near-stoichiometric production. - Abstract: The thermochemical two-step water-splitting cycle using transition element-doped cerium oxide (M–CeO{sub 2−δ}; M = Fe, Co, Ni, Mn) powders was studied for hydrogen production from water. The oxygen/hydrogen productivity and repeatability of M–CeO{sub 2−δ} materials with M doping contents in the 5–15 mol% range were examined using a thermal reduction (TR) temperature of 1500 °C and water decomposition (WD) temperatures in the 800–1150 °C range. The temperature, steam partial pressure, and steam flow rate in the WD step had an impact on the hydrogen productivity and production rate. 5 mol% Fe- and Co-doped CeO{sub 2−δ} enhances hydrogen productivity by up to 25% on average compared to undoped CeO{sub 2}, and shows stable repeatability of stoichiometric oxygen and hydrogen production for the cyclic thermochemical two-step water-splitting reaction. In addition, 5 mol% Mn-doped CeO{sub 2−δ}, 10 and 15 mol% Fe- and Mn-doped CeO{sub 2−δ} show near stoichiometric reactivities.

Production of barium molybdate and tungstate on the base of ternary reciprocal Na, Ba long Cl, EhO4 (Eh - Mo, W) systems

International Nuclear Information System (INIS)

Garkushin, I.K.; Sechnoj, A.I.; Dibirov, M.A.; Trunin, A.S.

1984-01-01

Possibilities of the syntnesis of barium molybdate and tungstate on the base of ternary reciprocal Na, Ba parallel Cl, EhO 4 (Eh=Mo, W) system state diagrams are under study. It is shown that on the basis of these reciprocal state diagrams syntnesis of not only BaO 4 but also of other suhstances is possible. Purity of obtained chemical agents is basically dependent on qualification of initial components. Synthesis temperature is decreased and time is reduced as compared to other known methods. For substance synthesis, state diagrams examination (reaction type confirmation and component crystallization fields separation from compound crystallization fields) is necessary along with the calculation of the conventional thermochemical effect

Project Management Plan for the INEL technology logic diagrams

International Nuclear Information System (INIS)

Rudin, M.J.

1992-10-01

This Project Management Plan (PjMP) describes the elements of project planning and control that apply to activities outlined in Technical Task Plan (TTP) ID-121117, ''Technology Logic Diagrams For The INEL.'' The work on this project will be conducted by personnel in EG ampersand G Idaho, Inc.'s Waste Technology Development Program. Technology logic diagrams represent a formal methodology to identify technology gaps or needs within Environmental Restoration/Waste Management Operations, which will focus on Office of Environmental Restoration and Waste Management (EM-50) research and development, demonstration, test, and evaluation efforts throughout the US Department of Energy complex. This PjMP describes the objectives, organization, roles and responsibilities, workscope and processes for implementing and managing the technology logic diagram for the Idaho National Engineering Laboratory project

Decorated-box-diagram contributions to Bhabha scattering. Pt. 1

International Nuclear Information System (INIS)

Faeldt, G.; Osland, P.

1994-01-01

We evaluate, in the light-energy limit, s>>vertical stroke tvertical stroke >>m 2 >>λ 2 , the sum of amplitudes corresponding to a class of Feynman diagrams describing two-loop virtual photonic corrections to Bhabha scattering. The diagrams considered are box and crossed-box diagrams with an extra photon decorating one of the fermion lines. The mathematical method employed is that of Mellin transforms. In the eikonal approximation, this sum of two-loop amplitudes has previously been evaluated, and found to be equal to the sum of the box and crossed-box amplitudes, multiplied by the electric form factor of the electron. We obtain a similar factorization, but with the form factor replaced by another expression involving the logarithms log(λ 2 /m 2 ) and log(λ 2 /vertical stroke tvertical stroke ). (orig.)

Nonplanar on-shell diagrams and leading singularities of scattering amplitudes

Energy Technology Data Exchange (ETDEWEB)

Chen, Baoyi; Cheung, Yeuk-Kwan E.; Li, Yunxuan; Xie, Ruofei; Xin, Yuan [Nanjing University, Department of Physics, Nanjing (China); Chen, Gang [Zhejiang Normal University, Department of Physics, Jinhua, Zhejiang (China); Nanjing University, Department of Physics, Nanjing (China)

2017-02-15

Bipartite on-shell diagrams are the latest tool in constructing scattering amplitudes. In this paper we prove that a Britto-Cachazo-Feng-Witten (BCFW) decomposable on-shell diagram process a rational top form if and only if the algebraic ideal comprised the geometrical constraints are shifted linearly during successive BCFW integrations. With a proper geometric interpretation of the constraints in the Grassmannian manifold, the rational top form integration contours can thus be obtained, and understood, in a straightforward way. All rational top form integrands of arbitrary higher loops leading singularities can therefore be derived recursively, as long as the corresponding on-shell diagram is BCFW decomposable. (orig.)

Top-down versus bottom-up processing of influence diagrams in probabilistic analysis

International Nuclear Information System (INIS)

Timmerman, R.D.; Burns, T.J.; Dodds, H.L. Jr.

1986-01-01

Recent work by Phillips and Selby has shown that influence diagram methodology can be a useful analytical tool in reactor safety studies. In some instances an influence diagram can be used as a graphical representation of probabilistic dependence within a system or event sequence. Under these circumstances, Bayesian statistics is employed to transform the relationships depicted in the influence diagram into the correct expression for a desired marginal probability (e.g. the top node). Top-down and bottom-up algorithms have emerged as the dominant methods for quantifying influence diagrams. The purpose of this paper is to demonstrate a potential error in employing the bottom-up algorithm when dealing with interdependencies

Quantitative study of FORC diagrams in thermally corrected Stoner– Wohlfarth nanoparticles systems

International Nuclear Information System (INIS)

De Biasi, E.; Curiale, J.; Zysler, R.D.

2016-01-01

The use of FORC diagrams is becoming increasingly popular among researchers devoted to magnetism and magnetic materials. However, a thorough interpretation of this kind of diagrams, in order to achieve quantitative information, requires an appropriate model of the studied system. For that reason most of the FORC studies are used for a qualitative analysis. In magnetic systems thermal fluctuations 'blur' the signatures of the anisotropy, volume and particle interactions distributions, therefore thermal effects in nanoparticles systems conspire against a proper interpretation and analysis of these diagrams. Motivated by this fact, we have quantitatively studied the degree of accuracy of the information extracted from FORC diagrams for the special case of single-domain thermal corrected Stoner– Wohlfarth (easy axes along the external field orientation) nanoparticles systems. In this work, the starting point is an analytical model that describes the behavior of a magnetic nanoparticles system as a function of field, anisotropy, temperature and measurement time. In order to study the quantitative degree of accuracy of our model, we built FORC diagrams for different archetypical cases of magnetic nanoparticles. Our results show that from the quantitative information obtained from the diagrams, under the hypotheses of the proposed model, is possible to recover the features of the original system with accuracy above 95%. This accuracy is improved at low temperatures and also it is possible to access to the anisotropy distribution directly from the FORC coercive field profile. Indeed, our simulations predict that the volume distribution plays a secondary role being the mean value and its deviation the only important parameters. Therefore it is possible to obtain an accurate result for the inversion and interaction fields despite the features of the volume distribution. - Highlights: • Quantify the degree of accuracy of the information obtained using the FORC diagrams. �

The annihilation diagram in three-body D-meson decay

International Nuclear Information System (INIS)

Donoghue, J.F.; Holstein, B.R.

1981-01-01

We discuss some features of three-body decays of the D meson cohich are puzzling from the standpoint of the annihilation diagram. As a result, we (1) provide an upper bound on the lifetime ratio of D's, tau + sub(D)/tau 0 sub(D) smaller than 2.5 +- 3.4 and (2) argue that the puzzles are resolved, even if somewhat inelegantly, if final state interactions generate the annihilation diagram. (orig.)

Exploring the QCD phase diagram through relativistic heavy ion collisions

Directory of Open Access Journals (Sweden)

Mohanty Bedangadas

2014-03-01

Full Text Available We present a review of the studies related to establishing the QCD phase diagram through high energy nucleus-nucleus collisions. We particularly focus on the experimental results related to the formation of a quark-gluon phase, crossover transition and search for a critical point in the QCD phase diagram.

Heuristic Diagrams as a Tool to Teach History of Science

Science.gov (United States)

Chamizo, Jose A.

2012-01-01

The graphic organizer called here heuristic diagram as an improvement of Gowin's Vee heuristic is proposed as a tool to teach history of science. Heuristic diagrams have the purpose of helping students (or teachers, or researchers) to understand their own research considering that asks and problem-solving are central to scientific activity. The…

Microsoft Visio 2013 business process diagramming and validation

CERN Document Server

Parker, David

2013-01-01

Microsoft Visio 2013 Business Process Diagramming and Validation provides a comprehensive and practical tutorial including example code and demonstrations for creating validation rules, writing ShapeSheet formulae, and much more.If you are a Microsoft Visio 2013 Professional Edition power user or developer who wants to get to grips with both the essential features of Visio 2013 and the validation rules in this edition, then this book is for you. A working knowledge of Microsoft Visio and optionally .NET for the add-on code is required, though previous knowledge of business process diagramming

Students’ understanding of forces: Force diagrams on horizontal and inclined plane

Science.gov (United States)

Sirait, J.; Hamdani; Mursyid, S.

2018-03-01

This study aims to analyse students’ difficulties in understanding force diagrams on horizontal surfaces and inclined planes. Physics education students (pre-service physics teachers) of Tanjungpura University, who had completed a Basic Physics course, took a Force concept test which has six questions covering three concepts: an object at rest, an object moving at constant speed, and an object moving at constant acceleration both on a horizontal surface and on an inclined plane. The test is in a multiple-choice format. It examines the ability of students to select appropriate force diagrams depending on the context. The results show that 44% of students have difficulties in solving the test (these students only could solve one or two items out of six items). About 50% of students faced difficulties finding the correct diagram of an object when it has constant speed and acceleration in both contexts. In general, students could only correctly identify 48% of the force diagrams on the test. The most difficult task for the students in terms was identifying the force diagram representing forces exerted on an object on in an inclined plane.

Diagrams: A Visual Survey of Graphs, Maps, Charts and Diagrams for the Graphic Designer.

Science.gov (United States)

Lockwood, Arthur

Since the ultimate success of any diagram rests in its clarity, it is important that the designer select a method of presentation which will achieve this aim. He should be aware of the various ways in which statistics can be shown diagrammatically, how information can be incorporated in maps, and how events can be plotted in chart or graph form.…

Interactive Cost Configuration Over Decision Diagrams

DEFF Research Database (Denmark)

Andersen, Henrik Reif; Hadzic, Tarik; Pisinger, David

2010-01-01

interaction online. In particular,binary decision diagrams (BDDs) have been successfully used as a compilation target for product and service configuration. In this paper we discuss how to extend BDD-based configuration to scenarios involving cost functions which express user preferences. We first show...... that an efficient, robust and easy to implement extension is possible if the cost function is additive, and feasible solutions are represented using multi-valued decision diagrams (MDDs). We also discuss the effect on MDD size if the cost function is non-additive or if it is encoded explicitly into MDD. We...... then discuss interactive configuration in the presence of multiple cost functions. We prove that even in its simplest form, multiple-cost configuration is NP-hard in the input MDD. However, for solving two-cost configuration we develop a pseudo-polynomial scheme and a fully polynomial approximation scheme...

TEP process flow diagram

Energy Technology Data Exchange (ETDEWEB)

Wilms, R Scott [Los Alamos National Laboratory; Carlson, Bryan [Los Alamos National Laboratory; Coons, James [Los Alamos National Laboratory; Kubic, William [Los Alamos National Laboratory

2008-01-01

This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

PWR fuel physico chemistry. Improvements of the Sage code to compute thermochemical balance in PWR fuel

International Nuclear Information System (INIS)

Garcia, P.; Baron, D.; Piron, J.P.

1993-02-01

A physicochemical survey of high burnup fuel has been undertaken in the context of a 3-party action (CEA Cadarache - EDF/DER - FRAMATOME). One of the tasks involved consists in adapting the SAGE code for assessment of the thermochemical equilibria of fission products in solution in the fuel matrix. This paper describes the first stage of this task. Even if other improvements are planned, the oxid oxygen potentials are yet properly reproduced for the simulated burnup. (authors). 63 figs., 4 tabs., 41 refs

Matrix model approximations of fuzzy scalar field theories and their phase diagrams

Energy Technology Data Exchange (ETDEWEB)

Tekel, Juraj [Department of Theoretical Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska Dolina, Bratislava, 842 48 (Slovakia)

2015-12-29

We present an analysis of two different approximations to the scalar field theory on the fuzzy sphere, a nonperturbative and a perturbative one, which are both multitrace matrix models. We show that the former reproduces a phase diagram with correct features in a qualitative agreement with the previous numerical studies and that the latter gives a phase diagram with features not expected in the phase diagram of the field theory.

Thermochemical transformations of anthracene oil

Energy Technology Data Exchange (ETDEWEB)

Belkina, T.V.; Privalov, V.E.; Stepanenko, M.A.

1979-01-01

The basic technological step in electrode pitch production is the thermal processing of the original pitch, combined in some cases with air treatment. The thermal process of electrode pitch production is outstandingly simple and economical, but offers little scope for regulating the product quality. When the coal tar regulating the product quality has been highly pyrolyzed, it becomes difficult to produce a medium electrode pitch in conformity with GOST 10200-73 as regards its content of substances insoluble in quinoline (..cap alpha../sub 1/-fraction). It is particularly difficult to make ptich with a softening point of 85 to 90/sup 0/C from highly pyrolyzed coal tar, since this involves a prolonged treatment which increases the ..cap alpha../sub 1/-fraction content. These difficulties, associated with persistent consumer demand for higher electrode pitch quality, have greatly activated the search for new methods of making electrode pitch. A survey of the Soviet and foreign literature shows that the investigations now in progress relate both to methods of developing new production techniques and to methods of adjusting the initial feedstock composition by the addition of high-boiling coal-tar fractions, pitch distillates, highly aromatized petroleum refinery products and so on. As a result of experiments it was found that: (1) When anthracene oil is heated, its contents of condensation products (..cap alpha../sub 1/- and ..cap alpha..-fractions) increase quite slowly compared with pitch; consequently the electrode pitch production process is prolonged by mixing the two feedstock materials. (2) When the anthracene oil is heat treated first, condensation products form and accumulate in it and its thermochemical transformation activity is enhanced. (3) The use of heat-treated anthracene oil will clearly intensify the electrode pitch production process and raise the product quality.

Study of thermochemically reduced and electron-irradiated LiNbO3 single crystals by positron annihilation and optical absorption measurements

International Nuclear Information System (INIS)

Pareja, R.; Gonzalez, R.; Pedrosa, M.A.

1984-01-01

Irradiation of LiNbO 3 single crystals using Van de Graaff electrons with an energy of 1.5 MeV introduces an optical absorption band similar to that observed in thermochemically reduced samples. As-grown, reduced, or irradiated crystals show single-component positron lifetime spectra with an average decay time of 234 ps. (author)

Top-down versus bottom-up processing of influence diagrams in probabilistic analysis

International Nuclear Information System (INIS)

Timmerman, R.D.; Burns, T.J.; Dodds, H.L. Jr.

1984-01-01

Recent work by Phillips et al., and Selby et al., has shown that influence diagram methodology can be a useful analytical tool in reactor safety studies. An influence diagram is a graphical representation of probabilistic dependence within a system or event sequence. Bayesian statistics are employed to transform the relationships depicted in the influence diagram into the correct expression for a desired marginal probability (e.g. the top event). As with fault trees, top-down and bottom-up algorithms have emerged as the dominant methods for quantifying influence diagrams. Purpose of this paper is to demonstrate a potential error in employing the bottom-up algorithm when dealing with interdependencies. In addition, the computing efficiency of both methods is discussed

Profile of High School Students’ Propositional Network Representation when Interpreting Convention Diagrams

Science.gov (United States)

Fatiha, M.; Rahmat, A.; Solihat, R.

2017-09-01

The delivery of concepts in studying Biology often represented through a diagram to easily makes student understand about Biology material. One way to knowing the students’ understanding about diagram can be seen from causal relationship that is constructed by student in the propositional network representation form. This research reveal the trend of students’ propositional network representation patterns when confronted with convention diagram. This descriptive research involved 32 students at one of senior high school in Bandung. The research data was acquired by worksheet that was filled by diagram and it was developed according on information processing standards. The result of this research revealed three propositional network representation patterns are linear relationship, simple reciprocal relationship, and complex reciprocal relationship. The dominating pattern is linear form that is simply connect some information components in diagram by 59,4% students, the reciprocal relationship form with medium level by 28,1% students while the complex reciprocal relationship by only 3,1% and the rest was students who failed to connect information components by 9,4%. Based on results, most of student only able to connect information components on the picture in linear form and a few student constructing reciprocal relationship between information components on convention diagram.

Diagrams of ion stability in radio-frequency mass spectrometry

International Nuclear Information System (INIS)

Sudakov, M.Yu.

1994-01-01

For solving radio-frequency mass spectrometry problems and dynamic ion containment are studied and systematized different ways for constructing the ion stability diagrams. A new universal set of parameters is proposed for diagram construction-angular variables, which are the phase raid of ion oscillational motion during positive and negative values of the supplying voltage. An effective analytical method is proposed for optimization of the parameters of the pulsed supplying voltage, in particular its repetition rate

Thermochemical degradation of limestone aggregate concrete on exposure to sodium fire

International Nuclear Information System (INIS)

Premila, M.; Sivasubramanian, K.; Amarendra, G.; Sundar, C.S.

2008-01-01

Limestone aggregate concrete blocks were subjected to sodium fire conforming to a realistic scenario in order to qualify them as protective sacrificial layers over structural concrete flooring in liquid metal-cooled fast breeder reactors. Mid infrared absorption measurements were carried out on these sodium fire-exposed samples as a function of depth from the affected surface. Definite signatures of thermochemical degradation indicating dehydration and structural modification of the limestone concrete have been obtained. Control runs were carried out to delineate the thermal effects of sodium fires from that of the chemical interaction effects. Measurements on limestone aggregate samples treated with fused NaOH provided direct evidence of the exact mechanism of the sodium attack on concrete. The observed degradation effects were correlated to the mechanical strength of the concrete blocks and to the intensity of the sodium fire experienced

Large momentum expansion of two-loop self-energy diagrams with arbitrary masses

International Nuclear Information System (INIS)

Davydychev, A.I.; Smirnov, V.A.; Tausk, J.B.

1993-01-01

For two-loop two-point diagrams with arbitrary masses, an algorithm to derive the asymptotic expansion at large external momentum squared is constructed. By using a general theorem on asymptotic expansions of Feynman diagrams, the coefficients of the expansion are calculated analytically. For some two-loop diagrams occurring in the Standard Model, comparison with results of numerical integration shows that our expansion works well in the region above the highest physical threshold. (orig.)