Oil refining and product market developments in Europe

International Nuclear Information System (INIS)

McDonald, P.

1991-01-01

One political development in Europe that will affect the petroleum refining industry is the opening of a single market among the European Commission countries. Although the single market officially opens on January 1, 1993, a single market for energy will not happen at that time. Most European countries feel that refining is a strategic industry and adopt some form of protectionism in this sector. Environmental policy in Europe tends to be separate from energy policy, making conflicts in setting standards for emissions and fuel composition somewhat inevitable. For example, both environmental and energy policies favor a carbon tax on fuels; the EC environmental commission does not want to be seen as favoring nuclear power, so it favors penalizing all fuels about the same amount, while the energy commission says the carbon tax should be related to the fuel carbon content. A measure affecting the refining industry is the proposal for reducing sulfur in diesel fuel. By 1994 EC countries will have a common 0.2% standard and by 1996 a 0.05% standard for automotive diesel. To meet the latter standard, refineries will need upgrading at an estimated cost of US$4 billion. Another political consideration for the refining industry is whether eastern Europe should be part of the EC energy community. However, if there is a reluctance in the western European countries for a single western market, there is even less enthusiasm for an energy market that includes eastern Europe as well. In addition, there is a reluctance to accept that there should be a free flow of petroleum products from east to west

Refined 2D and Exact 3D Shell Models for the Free Vibration Analysis of Single- and Double-Walled Carbon Nanotubes

Directory of Open Access Journals (Sweden)

Salvatore Brischetto

2015-12-01

Full Text Available The present paper talks about the free vibration analysis of simply supported Single- and Double-Walled Carbon Nanotubes (SWCNTs and DWCNTs. Refined 2D Generalized Differential Quadrature (GDQ shell methods and an exact 3D shell model are compared. A continuum approach (based on an elastic three-dimensional shell model is used for natural frequency investigation of SWCNTs and DWCNTs. SWCNTs are defined as isotropic cylinders with an equivalent thickness and Young modulus. DWCNTs are defined as two concentric isotropic cylinders (with an equivalent thickness and Young modulus which can be linked by means of the interlaminar continuity conditions or by means of van der Waals interactions. Layer wise approaches are mandatory for the analysis of van der Waals forces in DWCNTs. The effect of van der Waals interaction between the two cylinders is shown for different DWCNT lengths, diameters and vibration modes. The accuracy of beam models and classical 2D shell models in the free vibration analysis of SWCNTs and DWCNTs is also investigated.

Investigation of the influence of Ceratophyllum demersum to refine ...

African Journals Online (AJOL)

Water pollution has always been a major problem in the environment. Polluted water is harming for human health and need to clean water from pollution factors. One of the economic and rapid methods for elements removal is displacement metals by biosorption. The purpose of this study was refining diluted compost latex ...

Profex: a graphical user interface for the Rietveld refinement program BGMN

OpenAIRE

Doebelin, Nicola; Kleeberg, Reinhard

2015-01-01

Profex is a graphical user interface for the Rietveld refinement program BGMN. Its interface focuses on preserving BGMN’s powerful and flexible scripting features by giving direct access to BGMN input files. Very efficient workflows for single or batch refinements are achieved by managing refinement control files and structure files, by providing dialogues and shortcuts for many operations, by performing operations in the background, and by providing import filters for CIF and XML crystal str...

Weldability of thermally grain-refined Fe-12Ni-0.25Ti for cryogenic structural applications

International Nuclear Information System (INIS)

Williams, D.E.

1980-02-01

The weldability of a research alloy designed for structural use in liquid helium temperature, cryogenic environments was investigated. Plates of iron-12 weight percent nickel-0.25 weight percent titanium were grain refined by the four-step, grain refining thermal treatment developed for this alloy and welded with Inconel Number 92 weld wire using the Gas Metal Arc (GMA) welding process with argon-15% helium gas shielding. Both a single pass and a double-sided, 2 pass electron beam (EB) weld were also made without filler metal addition. Weldments were radiographed and sectioned and the charpy V-notch specimens removed were tested at liquid nitrogen and helium temperatures

Numerical analysis of impurity separation from waste salt by investigating the change of concentration at the interface during zone refining process

Science.gov (United States)

Choi, Ho-Gil; Shim, Moonsoo; Lee, Jong-Hyeon; Yi, Kyung-Woo

2017-09-01

The waste salt treatment process is required for the reuse of purified salts, and for the disposal of the fission products contained in waste salt during pyroprocessing. As an alternative to existing fission product separation methods, the horizontal zone refining process is used in this study for the purification of waste salt. In order to evaluate the purification ability of the process, three-dimensional simulation is conducted, considering heat transfer, melt flow, and mass transfer. Impurity distributions and decontamination factors are calculated as a function of the heater traverse rate, by applying a subroutine and the equilibrium segregation coefficient derived from the effective segregation coefficients. For multipass cases, 1d solutions and the effective segregation coefficient obtained from three-dimensional simulation are used. In the present study, the topic is not dealing with crystal growth, but the numerical technique used is nearly the same since the zone refining technique was just introduced in the treatment of waste salt from nuclear power industry because of its merit of simplicity and refining ability. So this study can show a new application of single crystal growth techniques to other fields, by taking advantage of the zone refining multipass possibility. The final goal is to achieve the same high degree of decontamination in the waste salt as in zone freezing (or reverse Bridgman) method.

Accurate macromolecular crystallographic refinement: incorporation of the linear scaling, semiempirical quantum-mechanics program DivCon into the PHENIX refinement package

Energy Technology Data Exchange (ETDEWEB)

Borbulevych, Oleg Y.; Plumley, Joshua A.; Martin, Roger I. [QuantumBio Inc., 2790 West College Avenue, State College, PA 16801 (United States); Merz, Kenneth M. Jr [University of Florida, Gainesville, Florida (United States); Westerhoff, Lance M., E-mail: lance@quantumbioinc.com [QuantumBio Inc., 2790 West College Avenue, State College, PA 16801 (United States)

2014-05-01

Semiempirical quantum-chemical X-ray macromolecular refinement using the program DivCon integrated with PHENIX is described. Macromolecular crystallographic refinement relies on sometimes dubious stereochemical restraints and rudimentary energy functionals to ensure the correct geometry of the model of the macromolecule and any covalently bound ligand(s). The ligand stereochemical restraint file (CIF) requires a priori understanding of the ligand geometry within the active site, and creation of the CIF is often an error-prone process owing to the great variety of potential ligand chemistry and structure. Stereochemical restraints have been replaced with more robust functionals through the integration of the linear-scaling, semiempirical quantum-mechanics (SE-QM) program DivCon with the PHENIX X-ray refinement engine. The PHENIX/DivCon package has been thoroughly validated on a population of 50 protein–ligand Protein Data Bank (PDB) structures with a range of resolutions and chemistry. The PDB structures used for the validation were originally refined utilizing various refinement packages and were published within the past five years. PHENIX/DivCon does not utilize CIF(s), link restraints and other parameters for refinement and hence it does not make as many a priori assumptions about the model. Across the entire population, the method results in reasonable ligand geometries and low ligand strains, even when the original refinement exhibited difficulties, indicating that PHENIX/DivCon is applicable to both single-structure and high-throughput crystallography.

Grain refinement of AZ31 magnesium alloy by electromagnetic ...

Indian Academy of Sciences (India)

Low-frequency electromagnetic field; AZ31 magnesium alloy; Al4C3; grain refinement. Abstract. The effects of electromagnetic stirring and Al4C3 grain refiner on the grain refinement of semicontinuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has an ...

Segmental Refinement: A Multigrid Technique for Data Locality

KAUST Repository

Adams, Mark F.; Brown, Jed; Knepley, Matt; Samtaney, Ravi

2016-01-01

We investigate a domain decomposed multigrid technique, termed segmental refinement, for solving general nonlinear elliptic boundary value problems. We extend the method first proposed in 1994 by analytically and experimentally investigating its complexity. We confirm that communication of traditional parallel multigrid is eliminated on fine grids, with modest amounts of extra work and storage, while maintaining the asymptotic exactness of full multigrid. We observe an accuracy dependence on the segmental refinement subdomain size, which was not considered in the original analysis. We present a communication complexity analysis that quantifies the communication costs ameliorated by segmental refinement and report performance results with up to 64K cores on a Cray XC30.

Segmental Refinement: A Multigrid Technique for Data Locality

KAUST Repository

Adams, Mark F.

2016-08-04

We investigate a domain decomposed multigrid technique, termed segmental refinement, for solving general nonlinear elliptic boundary value problems. We extend the method first proposed in 1994 by analytically and experimentally investigating its complexity. We confirm that communication of traditional parallel multigrid is eliminated on fine grids, with modest amounts of extra work and storage, while maintaining the asymptotic exactness of full multigrid. We observe an accuracy dependence on the segmental refinement subdomain size, which was not considered in the original analysis. We present a communication complexity analysis that quantifies the communication costs ameliorated by segmental refinement and report performance results with up to 64K cores on a Cray XC30.

Accurate macromolecular crystallographic refinement: incorporation of the linear scaling, semiempirical quantum-mechanics program DivCon into the PHENIX refinement package.

Science.gov (United States)

Borbulevych, Oleg Y; Plumley, Joshua A; Martin, Roger I; Merz, Kenneth M; Westerhoff, Lance M

2014-05-01

Macromolecular crystallographic refinement relies on sometimes dubious stereochemical restraints and rudimentary energy functionals to ensure the correct geometry of the model of the macromolecule and any covalently bound ligand(s). The ligand stereochemical restraint file (CIF) requires a priori understanding of the ligand geometry within the active site, and creation of the CIF is often an error-prone process owing to the great variety of potential ligand chemistry and structure. Stereochemical restraints have been replaced with more robust functionals through the integration of the linear-scaling, semiempirical quantum-mechanics (SE-QM) program DivCon with the PHENIX X-ray refinement engine. The PHENIX/DivCon package has been thoroughly validated on a population of 50 protein-ligand Protein Data Bank (PDB) structures with a range of resolutions and chemistry. The PDB structures used for the validation were originally refined utilizing various refinement packages and were published within the past five years. PHENIX/DivCon does not utilize CIF(s), link restraints and other parameters for refinement and hence it does not make as many a priori assumptions about the model. Across the entire population, the method results in reasonable ligand geometries and low ligand strains, even when the original refinement exhibited difficulties, indicating that PHENIX/DivCon is applicable to both single-structure and high-throughput crystallography.

Refinement of hydrogen positions in (NH4)2SeO4

International Nuclear Information System (INIS)

Loose, A.; Mel'nik, G.; Zink, N.; Wozniak, K.; Dominiak, P.; Smirnov, L.S.; Pawlukojc, A.; Shuvalov, L.A.

2005-01-01

The crystal structure of ammonium selenate has been studied by means of single crystal X-ray and neutron diffraction with the purpose of the refinement of hydrogen positions. The refined hydrogen positions obtained by single crystal neutron diffraction show that N-H bond lengths form a regular tetrahedron in an ammonium ion. The single crystal X-ray diffraction data show that N-H bond lengths are shorter than those obtained by neutron diffraction and are not equal between themselves. Thus, the comparison of the results of X-ray and neutron diffraction allows one to suggest that the shorter N-H bond lengths by X-ray diffraction reflect the distribution of the electron charge density of ammonium ions within the (NH 4 ) 2 SeO 4 crystal lattice

Lattice-Boltzmann Method with Dynamic Grid Refinement for Simulating Particle Deposition on a Single Fibre

Directory of Open Access Journals (Sweden)

Helmut Schomburg

2013-03-01

Full Text Available In this work a numerical approach to predict the deposition behaviour of nano-scale particles on the surface of a single fibre by resolving the resulting dendrite-like particle structures in detail is presented. The gas flow simulation is carried out by a two-dimensional Lattice-Boltzmann method, which is coupled with a Lagrangian approach for the particle motion. To decrease calculation time and system requirements the Lattice-Boltzmann model is extended to allow for local grid refinement. Because of the a priori unknown location of deposition, the simulation procedure starts on a coarse mesh which is then locally refined in a fully adaptive way in regions of accumulated particles. After each deposition the fluid flow is recalculated in order to resolve the coupling of the flow with the growing particle structures correctly. For the purpose of avoiding unphysical blocking of flow by growing particle dendrites the Lattice-Boltzmann method is extended to permeable cells in these regions using the Brinkmann equation. This extended deposition model is compared to simpler approaches, where the deposit has no retroaction on the flow or is treated as a solid structure. It is clear that the permeable model is most realistic and allows considering the particle deposition on a fibre as two-dimensional problem. Comprehensive simulations were conducted for analysing the importance of different parameters, i.e. free-stream velocity and particle diameter on the deposit structure. The results of this sensitivity analysis agree qualitatively well with former published numerical and experimental results. Finally the structure of the particle deposit was quantitatively characterised by using a modified fractal dimension.

Structure of Insulin: Results of joint neutron and X-ray refinement

Energy Technology Data Exchange (ETDEWEB)

Wlodawer, A; Savage, H; Dodson, G

1989-02-01

Neutron diffraction data for porcine 2Zn insulin were collected to 2.2 A resolution from a single crystal deuterated by slow exchange of mother liquor. A joint neutron/X-ray restrained-least-squares refinement was undertaken using the neutron data, as well as the 1.5 A resolution X-ray data collected previously. The final R factors were 0.182 for the X-ray data and 0.191 for the neutron data. Resulting atomic coordinates were compared with the initial X-ray model, showing a total r.m.s. shift of 0.36 A for the protein and 0.6 A for the solvent. Protonation of a number of individual amino acids was investigated by analysis of the neutron maps. No D atoms were found between the carboxylates of Glu B13 which make an intermolecular contact, suggesting nonbonded interaction rather than the predicted hydrogen bond. Amide hydrogen exchange was investigated in a refinement of their atomic occupancies. Regions of unexchanged amide groups were found in the center of the B helices. The results of this study emphasize the limited amount of information available in neutron diffraction studies of proteins at resolution lower than 2 A.

Grain Refinement of Permanent Mold Cast Copper Base Alloys

Energy Technology Data Exchange (ETDEWEB)

M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

2005-04-01

Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

Local grid refinement for free-surface flow simulations

NARCIS (Netherlands)

van der Plas, Peter

2017-01-01

The principal goal of the current study is to explore and investigate the potential of local grid refinement for increasing the numerical efficiency of free-surface flow simulations in a practical context. In this thesis we propose a method for local grid refinement in the free-surface flow model

Refining revolution

Energy Technology Data Exchange (ETDEWEB)

Fesharaki, F.; Isaak, D.

1984-01-01

A review of changes in the oil refining industry since 1973 examines the drop in capacity use and its effect on profits of the Organization of Economic Cooperation and Development (OECD) countries compared to world refining. OPEC countries used their new oil revenues to expand Gulf refineries, which put additional pressure on OECD refiners. OPEC involvement in global marketing, however, could help to secure supplies. Scrapping some older OECD refineries could improve the percentage of capacity in use if new construction is kept to a minimum. Other issues facing refiners are the changes in oil demand patterns and government responses to the market. 2 tables.

EXPTIME-Completeness of Thorough Refinement on Modal Transition Systems

DEFF Research Database (Denmark)

Beneš, Nikola; Křetínský, Jan; Larsen, Kim Guldstrand

2012-01-01

Modal transition systems (MTS), a specification formalism introduced more than 20 years ago, has recently received a considerable attention in several different areas. Many of the fundamental questions related to MTSs have already been answered. However, the problem of the exact computational...... complexity of thorough refinement checking between two finite MTSs remained unsolved. We settle down this question by showing EXPTIME-completeness of thorough refinement checking on finite MTSs. The upper-bound result relies on a novel algorithm running in single exponential time providing a direct goal...

Crystal structure of vanadite: Refinement of anisotropic displacement parameters

Czech Academy of Sciences Publication Activity Database

Laufek, F.; Skála, Roman; Haloda, J.; Císařová, I.

2006-01-01

Roč. 51, 3-4 (2006), s. 271-275 ISSN 1210-8197 Institutional research plan: CEZ:AV0Z30130516 Keywords : anisotropic displacement parameter * crystal structure * single-crystal X-ray refinement * vanadinite Subject RIV: DB - Geology ; Mineralogy

Refined Dummy Atom Model of Mg(2+) by Simple Parameter Screening Strategy with Revised Experimental Solvation Free Energy.

Science.gov (United States)

Jiang, Yang; Zhang, Haiyang; Feng, Wei; Tan, Tianwei

2015-12-28

Metal ions play an important role in the catalysis of metalloenzymes. To investigate metalloenzymes via molecular modeling, a set of accurate force field parameters for metal ions is highly imperative. To extend its application range and improve the performance, the dummy atom model of metal ions was refined through a simple parameter screening strategy using the Mg(2+) ion as an example. Using the AMBER ff03 force field with the TIP3P model, the refined model accurately reproduced the experimental geometric and thermodynamic properties of Mg(2+). Compared with point charge models and previous dummy atom models, the refined dummy atom model yields an enhanced performance for producing reliable ATP/GTP-Mg(2+)-protein conformations in three metalloenzyme systems with single or double metal centers. Similar to other unbounded models, the refined model failed to reproduce the Mg-Mg distance and favored a monodentate binding of carboxylate groups, and these drawbacks needed to be considered with care. The outperformance of the refined model is mainly attributed to the use of a revised (more accurate) experimental solvation free energy and a suitable free energy correction protocol. This work provides a parameter screening strategy that can be readily applied to refine the dummy atom models for metal ions.

Grain refining efficiency of Al-Ti-C alloys

International Nuclear Information System (INIS)

Birol, Yuecel

2006-01-01

The problems associated with boride agglomeration and the poisoning effect of Zr in Zr-bearing alloys have created a big demand for boron-free grain refiners. The potential benefits of TiC as a direct nucleant for aluminium grains have thus generated a great deal of interest in TiC-bearing alloys in recent years. In Al-Ti-C grain refiners commercially available today, Al 3 Ti particles are introduced into the melt along with the TiC particles. Since the latter are claimed to nucleate α-Al directly, it is of great technological interest to see if reducing the Ti:C ratio further, i.e., increasing the C content of the grain refiner, will produce an increase in the grain refining efficiency of these alloys. A series of grain refiner samples with the Ti concentration fixed at 3% and a range of C contents between 0 and 0.75 were obtained by appropriately mixing an experimental Al-3Ti-0.75C alloy with Al-10Ti alloy and commercial purity aluminium. The grain refining efficiency of these grain refiners was assessed to investigate the role of the insoluble TiC and the soluble Al 3 Ti particles. The optimum chemistry for the Al-Ti-C grain refiners was also identified

Grain refining efficiency of Al-Ti-C alloys

Energy Technology Data Exchange (ETDEWEB)

Birol, Yuecel [Materials Institute, Marmara Research Center, TUBITAK, 41470 Gebze, Kocaeli (Turkey)]. E-mail: yucel.birol@mam.gov.tr

2006-09-28

The problems associated with boride agglomeration and the poisoning effect of Zr in Zr-bearing alloys have created a big demand for boron-free grain refiners. The potential benefits of TiC as a direct nucleant for aluminium grains have thus generated a great deal of interest in TiC-bearing alloys in recent years. In Al-Ti-C grain refiners commercially available today, Al{sub 3}Ti particles are introduced into the melt along with the TiC particles. Since the latter are claimed to nucleate {alpha}-Al directly, it is of great technological interest to see if reducing the Ti:C ratio further, i.e., increasing the C content of the grain refiner, will produce an increase in the grain refining efficiency of these alloys. A series of grain refiner samples with the Ti concentration fixed at 3% and a range of C contents between 0 and 0.75 were obtained by appropriately mixing an experimental Al-3Ti-0.75C alloy with Al-10Ti alloy and commercial purity aluminium. The grain refining efficiency of these grain refiners was assessed to investigate the role of the insoluble TiC and the soluble Al{sub 3}Ti particles. The optimum chemistry for the Al-Ti-C grain refiners was also identified.

Technological studies on uranium refining at nuclear materials authority, Egypt

International Nuclear Information System (INIS)

Mohammed, H.S.

1997-01-01

In 1992 nuclear materials authority (NMA) took a decision to establish yellow cake refining. Unit so as to study refining of El-Atshan yellow cake which recently produced by ion-exchange pilot plant, production sector. The research studies followed the conventional refining rout to produce nuclear grade UO 3 . This implies investigations on some common solvents to refine the cake viz. tri alkyl phosphates, tri alkyl phosphine oxides, dialkyl phosphoric acid as well as high-molecular weight long-chain tertiary amines. Moreover, non-conventional refining process has also been presented depending on the selectivity of uranyl ion to be dissolved by carbonate and to be precipitated by hydrogen peroxide. Most of the proposed processes were found feasible to refine El-Atshan yellow cake. however, the non- conventional refining process appears to be the most promising, owing to its superior performance and economy

Hirshfeld atom refinement.

Science.gov (United States)

Capelli, Silvia C; Bürgi, Hans-Beat; Dittrich, Birger; Grabowsky, Simon; Jayatilaka, Dylan

2014-09-01

Hirshfeld atom refinement (HAR) is a method which determines structural parameters from single-crystal X-ray diffraction data by using an aspherical atom partitioning of tailor-made ab initio quantum mechanical molecular electron densities without any further approximation. Here the original HAR method is extended by implementing an iterative procedure of successive cycles of electron density calculations, Hirshfeld atom scattering factor calculations and structural least-squares refinements, repeated until convergence. The importance of this iterative procedure is illustrated via the example of crystalline ammonia. The new HAR method is then applied to X-ray diffraction data of the dipeptide Gly-l-Ala measured at 12, 50, 100, 150, 220 and 295 K, using Hartree-Fock and BLYP density functional theory electron densities and three different basis sets. All positions and anisotropic displacement parameters (ADPs) are freely refined without constraints or restraints - even those for hydrogen atoms. The results are systematically compared with those from neutron diffraction experiments at the temperatures 12, 50, 150 and 295 K. Although non-hydrogen-atom ADPs differ by up to three combined standard uncertainties (csu's), all other structural parameters agree within less than 2 csu's. Using our best calculations (BLYP/cc-pVTZ, recommended for organic molecules), the accuracy of determining bond lengths involving hydrogen atoms from HAR is better than 0.009 Å for temperatures of 150 K or below; for hydrogen-atom ADPs it is better than 0.006 Å(2) as judged from the mean absolute X-ray minus neutron differences. These results are among the best ever obtained. Remarkably, the precision of determining bond lengths and ADPs for the hydrogen atoms from the HAR procedure is comparable with that from the neutron measurements - an outcome which is obtained with a routinely achievable resolution of the X-ray data of 0.65 Å.

Effect of grain refinement on the fluidity of two commercial Al-Si foundry alloys

Science.gov (United States)

Dahle, A. K.; Tøndel, P. A.; Paradies, C. J.; Arnberg, L.

1996-08-01

The effect of grain refinement on the fluidity of AlSi7Mg and AlSi11Mg has been investigated by spiral tests. Two different types of grain refiners have been evaluated. An AlTi5Bl master alloy was added to different Ti contents. Since the commercial alloys had a high initial content of titanium, model alloys were made to investigate the fluidity at low grain refiner additions. Commercial alloys grain refined only by boron additions have also been investigated. The results from the fluidity measurements have been verified by measuring the dendrite coherency point of the different cast alloys. Although different, the two methods show similar trends. The spirals from each fraction grain refiner cast were subsequently investigated metallographically at the tip of the spirals and at a reference point a distance behind, but no obvious difference in structure was observed. For both alloys, an increase in fluidity is observed as the content of grain refiner increases above 0.12 pct Ti, while the fluidity is impaired with increased grain refinement below 0.12 pct Ti. The alloys grain refined with ~0.015 pct B show the highest fraction solid at dendrite coherency, the smallest grain size, and the best fluidity.

Checking Thorough Refinement on Modal Transition Systems Is EXPTIME-Complete

DEFF Research Database (Denmark)

Benes, Nikola; Kretinsky, Jan; Larsen, Kim Guldstrand

2009-01-01

Modal transition systems (MTS), a specification formalism introduced more than 20 years ago, has recently received a considerable attention in several different areas. Many of the fundamental questions related to MTSs have already been answered. However, the problem of the exact computational...... complexity of thorough refinement checking between two finite MTSs remained unsolved. We settle down this question by showing EXPTIME-completeness of thorough refinement checking on finite MTSs. The upper-bound result relies on a novel algorithm running in single exponential time providing a direct goal...

Influences of crystallographic orientations on deformation mechanism and grain refinement of Al single crystals subjected to one-pass equal-channel angular pressing

International Nuclear Information System (INIS)

Han, W.Z.; Zhang, Z.F.; Wu, S.D.; Li, S.X.

2007-01-01

The influences of crystallographic orientations on the evolution of dislocation structures and the refinement process of sub-grains in Al single crystals processed by one-pass equal-channel angular pressing (ECAP) were systematically investigated by means of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. Three single crystals with different orientations, denoted as crystal I, crystal II and crystal III, were specially designed according to the shape of the ECAP die. For crystal I, its insert direction is parallel to [1 1 0] and its extrusion direction is parallel to [1-bar11]. For crystal II, the (1-bar11) plane is located parallel to the intersection plane of the ECAP die, and the [1 1 0] direction is along the general shear direction on the intersection plane. For crystal III, the (1-bar11) plane is laid on the plane perpendicular to the intersection of the ECAP die, and the [1 1 0] direction is vertical to the general shear direction. For crystal I, abundant cell block structures with multi-slip characters were formed, and they should be induced by four symmetric slip systems, while for crystal II, there are two sets of sub-grain structures with higher misorientation, making an angle of ∼70 deg., which can be attributed to the interactions of the two asymmetric primary slip planes, whereas for crystal III, only one set of ribbon structures was parallel to the traces of (1-bar11) with the lowest misorientation angle among the three single crystals, which should result from the homogeneous slip on the primary slip plane. The different microstructural features of the three single crystals provide clear experimental evidence that the microstructures and misorientation evolution are strongly affected by the crystallographic orientation or by the interaction between shear deformation imposed by the ECAP die and the intrinsic slip deformation of the single crystals. Based on the experimental results and the

Role of manganese on the grain refining efficiency of AZ91D magnesium alloy refined by Al4C3

International Nuclear Information System (INIS)

Liu Shengfa; Zhang Yuan; Han Hui

2010-01-01

A novel Mg-50% Al 4 C 3 (hereafter in wt.%) master alloy has been developed by powder in situ synthesis process, the role of manganese on the grain refining efficiency of AZ91D magnesium alloy refined by this master alloy has been investigated. X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) results show the existence of Al 4 C 3 particles in this master alloy. After addition of 0.6% Al 4 C 3 or combined addition of 0.6% Al 4 C 3 and 0.27% Mn, the average grain size of AZ91D decreased dramatically from 360 μm to 210 μm, and from 360 μm to130 μm, respectively. However, no further refinement of grain size was achieved with additional amount of Mn exceeding 0.27% for AZ91D alloy refined by 0.6% Al 4 C 3 in the present investigation. Al-C-O-Mn-Fe-rich intermetallic particles with an Al-C-O-rich coating film, often observed in the central region of magnesium grains of the AZ91D alloy treated by the combination of Al 4 C 3 and Mn, are proposed to be the potent nucleating substrates for primary α-Mg.

Profex: a graphical user interface for the Rietveld refinement program BGMN.

Science.gov (United States)

Doebelin, Nicola; Kleeberg, Reinhard

2015-10-01

Profex is a graphical user interface for the Rietveld refinement program BGMN . Its interface focuses on preserving BGMN 's powerful and flexible scripting features by giving direct access to BGMN input files. Very efficient workflows for single or batch refinements are achieved by managing refinement control files and structure files, by providing dialogues and shortcuts for many operations, by performing operations in the background, and by providing import filters for CIF and XML crystal structure files. Refinement results can be easily exported for further processing. State-of-the-art graphical export of diffraction patterns to pixel and vector graphics formats allows the creation of publication-quality graphs with minimum effort. Profex reads and converts a variety of proprietary raw data formats and is thus largely instrument independent. Profex and BGMN are available under an open-source license for Windows, Linux and OS X operating systems.

Stable grid refinement and singular source discretization for seismic wave simulations

Energy Technology Data Exchange (ETDEWEB)

Petersson, N A; Sjogreen, B

2009-10-30

An energy conserving discretization of the elastic wave equation in second order formulation is developed for a composite grid, consisting of a set of structured rectangular component grids with hanging nodes on the grid refinement interface. Previously developed summation-by-parts properties are generalized to devise a stable second order accurate coupling of the solution across mesh refinement interfaces. The discretization of singular source terms of point force and point moment tensor type are also studied. Based on enforcing discrete moment conditions that mimic properties of the Dirac distribution and its gradient, previous single grid formulas are generalized to work in the vicinity of grid refinement interfaces. These source discretization formulas are shown to give second order accuracy in the solution, with the error being essentially independent of the distance between the source and the grid refinement boundary. Several numerical examples are given to illustrate the properties of the proposed method.

Refining Housing, Husbandry and Care for Animals Used in Studies Involving Biotelemetry

Directory of Open Access Journals (Sweden)

Penny Hawkins

2014-06-01

Full Text Available Biotelemetry can contribute towards reducing animal numbers and suffering in disciplines including physiology, pharmacology and behavioural research. However, the technique can also cause harm to animals, making biotelemetry a ‘refinement that needs refining’. Current welfare issues relating to the housing and husbandry of animals used in biotelemetry studies are single vs. group housing, provision of environmental enrichment, long term laboratory housing and use of telemetered data to help assess welfare. Animals may be singly housed because more than one device transmits on the same wavelength; due to concerns regarding damage to surgical sites; because they are wearing exteriorised jackets; or if monitoring systems can only record from individually housed animals. Much of this can be overcome by thoughtful experimental design and surgery refinements. Similarly, if biotelemetry studies preclude certain enrichment items, husbandry refinement protocols can be adapted to permit some environmental stimulation. Nevertheless, long-term laboratory housing raises welfare concerns and maximum durations should be defined. Telemetered data can be used to help assess welfare, helping to determine endpoints and refine future studies. The above measures will help to improve data quality as well as welfare, because experimental confounds due to physiological and psychological stress will be minimised.

Whether integrating refining and petrochemical business can provide opportunities for development of petrochemical industry in Serbia

Directory of Open Access Journals (Sweden)

Popović Zoran M.

2016-01-01

Full Text Available Since the beginning of 90s of last century both the petroleum industry and petrochemical industry have operated in difficult circumstances. In particularly, margins of petroleum and petrochemical industry were exacerbated during global economic crisis in 2008-2009 years. At that time, as one option that could be the solution, the global analysts had started to more intense investigate the benefits of Refining-Petrochemical Integration. Shortly afterwards, more and more petroleum refineries and petrochemical manufacturers began to see the future in this kind of operational, managerial, marketing and commercial connection. This paper evaluates, in particular, the achieved level of integration of refinery and petrochemical businesses in Central and South-Eastern Europe. And specifically, the paper identifies current capabilities and future chances of linking this kind of integration between Serbian refining and petrochemical players. The viability of integration between possible actors and benefits of every single refining-petrochemical interface in Serbia depend on many factors, and therefore each integrated system is unique and requires prior serious Cost Benefit Analysis.

Potency of high-intensity ultrasonic treatment for grain refinement of magnesium alloys

International Nuclear Information System (INIS)

Ramirez, A.; Qian Ma; Davis, B.; Wilks, T.; StJohn, D.H.

2008-01-01

High-intensity ultrasonic treatment (UT) for grain refinement of magnesium alloys has been investigated using a novel theoretical approach in order to better understand its grain-refining potential and the mechanism of nucleation. The process demonstrated significantly superior grain-refining potency to carbon inoculation for Al-containing magnesium alloys but inferior potency to zirconium for Al-free alloys. Details revealed by applying the theoretical approach to ultrasonic grain refinement provide new clues to understanding the mechanism of grain nucleation by UT

Petroleum refining industry in China

International Nuclear Information System (INIS)

Walls, W.D.

2010-01-01

The oil refining industry in China has faced rapid growth in oil imports of increasingly sour grades of crude with which to satisfy growing domestic demand for a slate of lighter and cleaner finished products sold at subsidized prices. At the same time, the world petroleum refining industry has been moving from one that serves primarily local and regional markets to one that serves global markets for finished products, as world refining capacity utilization has increased. Globally, refined product markets are likely to experience continued globalization until refining investments significantly expand capacity in key demand regions. We survey the oil refining industry in China in the context of the world market for heterogeneous crude oils and growing world trade in refined petroleum products. (author)

On the refinement calculus

CERN Document Server

Vickers, Trevor

1992-01-01

On the Refinement Calculus gives one view of the development of the refinement calculus and its attempt to bring together - among other things - Z specifications and Dijkstra's programming language. It is an excellent source of reference material for all those seeking the background and mathematical underpinnings of the refinement calculus.

North American refining

International Nuclear Information System (INIS)

Osten, James; Haltmaier, Susan

2000-01-01

This article examines the current status of the North American refining industry, and considers the North American economy and the growth in demand in the petroleum industry, petroleum product demand and quality, crude oil upgrading to meet product standards, and changes in crude oil feedstocks such as the use of heavier crudes and bitumens. Refining expansion, the declining profits in refining, and changes due to environmental standards are discussed. The Gross Domestic Product and oil demand for the USA, Canada, Mexico, and Venezuela for the years 1995-2020 are tabulated

Effect of Duration on Ti Grain Refinement of A356 and Melt Quality

Science.gov (United States)

Gürsoy, Özen; Erzi, Eray; Yüksel, Çağlar; Dispinar, Derya

Grain refinement of aluminium alloys increases fluidity and feedability; and thus higher mechanical properties and decreased porosity is achieved. Typically, various ratios of Ti-B is used as grain refiner. It is well known that due to the sedimentation, the effectiveness of the grain refinement decreases which is called the fading effect. In this work, this effect has been investigated by means of melt quality. Two different melting temperatures were selected (725 and 750C) and samples were cast into die and sand mould. After the addition of grain refiners, samples were collected at 10 minutes of interval. Metallographic examinations were carried out where microstructural change and porosity distribution were investigated. The results were correlated with bifilm index (i.e. melt quality).

Refining Housing, Husbandry and Care for Animals Used in Studies Involving Biotelemetry

Science.gov (United States)

Hawkins, Penny

2014-01-01

Simple Summary Biotelemetry, the remote detection and measurement of an animal function or activity, is widely used in animal research. Biotelemetry devices transmit physiological or behavioural data and may be surgically implanted into animals, or externally attached. This can help to reduce animal numbers and improve welfare, e.g., if animals can be group housed and move freely instead of being tethered to a recording device. However, biotelemetry can also cause pain and distress to animals due to surgery, attachment, single housing and long term laboratory housing. This article explains how welfare and science can be improved by avoiding or minimising these harms. Abstract Biotelemetry can contribute towards reducing animal numbers and suffering in disciplines including physiology, pharmacology and behavioural research. However, the technique can also cause harm to animals, making biotelemetry a ‘refinement that needs refining’. Current welfare issues relating to the housing and husbandry of animals used in biotelemetry studies are single vs. group housing, provision of environmental enrichment, long term laboratory housing and use of telemetered data to help assess welfare. Animals may be singly housed because more than one device transmits on the same wavelength; due to concerns regarding damage to surgical sites; because they are wearing exteriorised jackets; or if monitoring systems can only record from individually housed animals. Much of this can be overcome by thoughtful experimental design and surgery refinements. Similarly, if biotelemetry studies preclude certain enrichment items, husbandry refinement protocols can be adapted to permit some environmental stimulation. Nevertheless, long-term laboratory housing raises welfare concerns and maximum durations should be defined. Telemetered data can be used to help assess welfare, helping to determine endpoints and refine future studies. The above measures will help to improve data quality as well as

Production of Al-Ti-C grain refiners with the addition of elemental carbon

International Nuclear Information System (INIS)

Gezer, Berke Turgay; Toptan, Fatih; Daglilar, Sibel; Kerti, Isil

2010-01-01

Grain refining process used in aluminium alloys, has an important role for preventing columnar, coarse grains and encouraging fine, equiaxed grain formation. Al-Ti-B grain refiners are widely used as aluminium grain refiners despite the problems in application Al-Ti-C refiners have an increasing demand in recent years. In the present work, Al-Ti-C grain refiners with different Ti:C ratios were produced by insitu method with the addition of elemental carbon. Microstructures were characterised by optic microscope and scanning electron microscope equipped with energy dispersive spectroscopy. The effects of temperature, holding time and Ti:C ratio on the grain refinement process were investigated and optimum conditions were determined.

Refinement of Parallel and Reactive Programs

OpenAIRE

Back, R. J. R.

1992-01-01

We show how to apply the refinement calculus to stepwise refinement of parallel and reactive programs. We use action systems as our basic program model. Action systems are sequential programs which can be implemented in a parallel fashion. Hence refinement calculus methods, originally developed for sequential programs, carry over to the derivation of parallel programs. Refinement of reactive programs is handled by data refinement techniques originally developed for the sequential refinement c...

Creating value in refining

International Nuclear Information System (INIS)

Cobb, C.B.

2001-01-01

This article focuses on recent developments in the US refining industry and presents a model for improving the performance of refineries based on the analysis of the refining industry by Cap Gemini Ernst and Young. The identification of refineries in risk of failing, the construction of pipelines for refinery products from Gulf State refineries, mergers and acquisitions, and poor financial performance are discussed. Current challenges concerning the stagnant demand for refinery products, environmental regulations, and shareholder value are highlighted. The structure of the industry, the creation of value in refining, and the search for business models are examined. The top 25 US companies and US refining business groups are listed

A conformation-dependent stereochemical library improves crystallographic refinement even at atomic resolution

International Nuclear Information System (INIS)

Tronrud, Dale E.; Karplus, P. Andrew

2011-01-01

A script was created to allow SHELXL to use the new CDL v.1.2 stereochemical library which defines the target values for main-chain bond lengths and angles as a function of the residue’s ϕ/ψ angles. Test refinements using this script show that the refinement behavior of structures at resolutions even better than 1 Å is substantially enhanced by the use of the new conformation-dependent ideal geometry paradigm. To utilize a new conformation-dependent backbone-geometry library (CDL) in protein refinements at atomic resolution, a script was written that creates a restraint file for the SHELXL refinement program. It was found that the use of this library allows models to be created that have a substantially better fit to main-chain bond angles and lengths without degrading their fit to the X-ray data even at resolutions near 1 Å. For models at much higher resolution (∼0.7 Å), the refined model for parts adopting single well occupied positions is largely independent of the restraints used, but these structures still showed much smaller r.m.s.d. residuals when assessed with the CDL. Examination of the refinement tests across a wide resolution range from 2.4 to 0.65 Å revealed consistent behavior supporting the use of the CDL as a next-generation restraint library to improve refinement. CDL restraints can be generated using the service at http://pgd.science.oregonstate.edu/cdl_shelxl/

Grid refinement model in lattice Boltzmann method for stream function-vorticity formulations

Energy Technology Data Exchange (ETDEWEB)

Shin, Myung Seob [Dept. of Mechanical Engineering, Dongyang Mirae University, Seoul (Korea, Republic of)

2015-03-15

In this study, we present a grid refinement model in the lattice Boltzmann method (LBM) for two-dimensional incompressible fluid flow. That is, the model combines the desirable features of the lattice Boltzmann method and stream function-vorticity formulations. In order to obtain an accurate result, very fine grid (or lattice) is required near the solid boundary. Therefore, the grid refinement model is used in the lattice Boltzmann method for stream function-vorticity formulation. This approach is more efficient in that it can obtain the same accurate solution as that in single-block approach even if few lattices are used for computation. In order to validate the grid refinement approach for the stream function-vorticity formulation, the numerical simulations of lid-driven cavity flows were performed and good results were obtained.

Theoretical Investigations Regarding Single Molecules

DEFF Research Database (Denmark)

Pedersen, Kim Georg Lind

Neoclassical Valence Bond Theory, Quantum Transport, Quantum Interference, Kondo Effect, and Electron Pumping. Trap a single organic molecule between two electrodes and apply a bias voltage across this "molecular junction". When electrons pass through the molecule, the different electron paths can...... interfere destructively or constructively. Destructive interference effects in electron transport could potentially improve thermo-electrics, organic logic circuits and energy harvesting. We have investigated destructive interference in off-resonant transport through organic molecules, and have found a set...

European oil refining: strategies for a competitive future

International Nuclear Information System (INIS)

MacDonald, James.

1997-07-01

European Oil Refining investigates how the industry came to be in crisis and what the future holds. As well as an extensive analysis of past and present market shifts, the report predicts likely future developments and their consequences for investors. The report reviews the European oil sector in a global context, calculates the cost to refiners of key environmental legislation, assesses the problems caused by changing product demand and crude supply, examines possible solutions to the problems of low margins and overcapacity, evaluates the key players' main strategies to increase their competitiveness, analyses the western European oil refining industry by country, details the refinery operations of the major countries of central and eastern Europe, profiles 15 of the major oil companies and estimates the increase in investment required as a result of legislative and demand changes. (author)

Southeast Asian oil markets and refining

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, N.D. [FACTS, Inc., Honolulu, Hawaii (United States)

1999-09-01

An overview of the Southeast Asian oil markets and refining is presented concentrating on Brunei, Malaysia, the Philippines, Singapore and Thailand refiners. Key statistics of the refiners in this region are tabulated. The demand and the quality of Indonesian, Malaysian, Philippine, Singapore and Thai petroleum products are analysed. Crude distillation unit capacity trends in the Southeastern Asian refining industry are discussed along with cracking to distillation ratios, refining in these countries, and the impact of changes in demand and refining on the product trade.

Southeast Asian oil markets and refining

International Nuclear Information System (INIS)

Yamaguchi, N.D.

1999-01-01

An overview of the Southeast Asian oil markets and refining is presented concentrating on Brunei, Malaysia, the Philippines, Singapore and Thailand refiners. Key statistics of the refiners in this region are tabulated. The demand and the quality of Indonesian, Malaysian, Philippine, Singapore and Thai petroleum products are analysed. Crude distillation unit capacity trends in the Southeastern Asian refining industry are discussed along with cracking to distillation ratios, refining in these countries, and the impact of changes in demand and refining on the product trade

Rietveld refinement of Y2O3 using the pearson VII profile shape function

International Nuclear Information System (INIS)

Smrcok, L.

1989-01-01

Very good agreement between the observed and the calculated intensities was obtained using the Pearson VII profile shape function. The variable exponent m could be refined only in the damped iterations involving exclusively the profile parameters. Simultaneous refinement of the m with the positional and/or thermal parameters has led to large oscillations of the shifts of almost all parameters. Precision of the refined atomic coordinates is better than those from previously published Rietveld refinement and is comparable with single crystal results. The degree of serial correlation in residuals has been determined by the use of the Durbin-Watson d statistic. Normal probability plot based on δR i has been almost linear with the slope greater than one. The weighting scheme with w i = 1/y oi has proved to be good first approximation. (author)

Linearly Refined Session Types

Directory of Open Access Journals (Sweden)

Pedro Baltazar

2012-11-01

Full Text Available Session types capture precise protocol structure in concurrent programming, but do not specify properties of the exchanged values beyond their basic type. Refinement types are a form of dependent types that can address this limitation, combining types with logical formulae that may refer to program values and can constrain types using arbitrary predicates. We present a pi calculus with assume and assert operations, typed using a session discipline that incorporates refinement formulae written in a fragment of Multiplicative Linear Logic. Our original combination of session and refinement types, together with the well established benefits of linearity, allows very fine-grained specifications of communication protocols in which refinement formulae are treated as logical resources rather than persistent truths.

The Influence of Grain Refiners on the Efficiency of Ceramic Foam Filters

Science.gov (United States)

Towsey, Nicholas; Schneider, Wolfgang; Krug, Hans-Peter; Hardman, Angela; Keegan, Neil J.

An extensive program of work has been carried out to evaluate the efficiency of ceramic foam filters under carefully controlled conditions. Work reported at previous TMS meetings showed that in the absence of grain refiners, ceramic foam filters have the capacity for high filtration efficiency and consistent, reliable performance. The current phase of the investigation focuses on the impact grain refiner additions have on filter performance. The high filtration efficiencies obtained using 50 or 80ppi CFF's in the absence of grain refiners diminish when Al-3%Ti-1%B grain refiners are added. This, together with the impact of incoming inclusion loading on filter performance and the level of grain refiner addition are considered in detail. The new generation Al-3%Ti-0.15%C grain refiner has also been included. At typical addition levels (1kg/tonne) the effect on filter efficiency is similar to that for TiB2based grain refiners. The work was again conducted on a production scale using AA1050 alloy. Metal quality was determined using LiMCA and PoDFA. Spent filters were also analysed.

Commercial refining in the Mediterranean

International Nuclear Information System (INIS)

Packer, P.

1999-01-01

About 9% of the world's oil refining capacity is on the Mediterranean: some of the world's biggest and most advanced refineries are on Sicily and Sardinia. The Mediterranean refineries are important suppliers to southern Europe and N. Africa. The article discusses commercial refining in the Mediterranean under the headings of (i) historic development, (ii) product demand, (iii) refinery configurations, (iv) refined product trade, (v) financial performance and (vi) future outlook. Although some difficulties are foreseen, refining in the Mediterranean is likely to continue to be important well into the 21st century. (UK)

Uranium refining process using ion exchange membrane

International Nuclear Information System (INIS)

Yamaguchi, Akira

1977-01-01

As for the method of refining uranium ore being carried out in Europe and America at present, uranium ore is roughly refined at the mine sites to yellow cake, then this is transported to refineries and refined by dry method. This method has the following faults, namely the number of processes is large, it requires expensive corrosion-resistant materials because of high temperature treatment, and the impurities in uranium tend to increase. On the other hand, in case of EXCER method, treatment is carried out at low temperature, and high purity uranium can be obtained, but the efficiency of electrolytic reduction process is extremely low, and economically infeasible. In the wet refining method called PNC process, uranium tetrafluoride is produced from uranium ore without making yellow cake, therefore the process is rationalized largely, and highly economical. The electrolytic reduction process in this method was developed by Asahi Chemical Industry Co., Ltd. by constructing the pilot plant in Ningyotoge Mine. The ion exchange membrane, the electrodes, and the problems concerning the process and the engineering for commercial plants were investigated. The electrolytic reduction process, the pilot plant, the development of the elements of electrolytic cells, the establishment of analytical process, the measurement of the electrolytic characteristics, the demonstration operation, and the life time of the electrolytic diaphragm are reported. (Kako, I.)

Refining Nodes and Edges of State Machines

DEFF Research Database (Denmark)

Hallerstede, Stefan; Snook, Colin

2011-01-01

State machines are hierarchical automata that are widely used to structure complex behavioural specifications. We develop two notions of refinement of state machines, node refinement and edge refinement. We compare the two notions by means of examples and argue that, by adopting simple conventions...... refinement theory and UML-B state machine refinement influences the style of node refinement. Hence we propose a method with direct proof of state machine refinement avoiding the detour via Event-B that is needed by UML-B....

Effect of some grain refiners on the mechanical properties of aluminum

International Nuclear Information System (INIS)

Zaid, A.I.O.

2001-01-01

It is well established that aluminum and its alloys are grain refined by some refractory metals to enhance their surface qualities and mechanical strengths. In this paper, the literature on grain refining, and its mechanism is reviewed and discussed. Also, the effect of grain refining of commercially pure aluminum by the addition of titanium, boron, vanadium, molybdenum, and zirconium is investigated. The effect of each of these elements on grain size, hardness and mechanical behavior is presented and discussed. It was found that the addition of any of these elements except zirconium resulted in enhancement of grain size, hardness and mechanical strength. An increase of 2.1 % in flow stress of Al grain refined by Ti+B was achieved by addition of 0.1 % V at 0.2 strain. (author)

Anomalies in the refinement of isoleucine

International Nuclear Information System (INIS)

Berntsen, Karen R. M.; Vriend, Gert

2014-01-01

The side-chain torsion angles of isoleucines in X-ray protein structures are a function of resolution, secondary structure and refinement software. Detailing the standard torsion angles used in refinement software can improve protein structure refinement. A study of isoleucines in protein structures solved using X-ray crystallography revealed a series of systematic trends for the two side-chain torsion angles χ 1 and χ 2 dependent on the resolution, secondary structure and refinement software used. The average torsion angles for the nine rotamers were similar in high-resolution structures solved using either the REFMAC, CNS or PHENIX software. However, at low resolution these programs often refine towards somewhat different χ 1 and χ 2 values. Small systematic differences can be observed between refinement software that uses molecular dynamics-type energy terms (for example CNS) and software that does not use these terms (for example REFMAC). Detailing the standard torsion angles used in refinement software can improve the refinement of protein structures. The target values in the molecular dynamics-type energy functions can also be improved

Anomalies in the refinement of isoleucine

Energy Technology Data Exchange (ETDEWEB)

Berntsen, Karen R. M.; Vriend, Gert, E-mail: gerrit.vriend@radboudumc.nl [Radboud University Medical Center, Geert Grooteplein 26-28, 6525 GA Nijmegen (Netherlands)

2014-04-01

The side-chain torsion angles of isoleucines in X-ray protein structures are a function of resolution, secondary structure and refinement software. Detailing the standard torsion angles used in refinement software can improve protein structure refinement. A study of isoleucines in protein structures solved using X-ray crystallography revealed a series of systematic trends for the two side-chain torsion angles χ{sub 1} and χ{sub 2} dependent on the resolution, secondary structure and refinement software used. The average torsion angles for the nine rotamers were similar in high-resolution structures solved using either the REFMAC, CNS or PHENIX software. However, at low resolution these programs often refine towards somewhat different χ{sub 1} and χ{sub 2} values. Small systematic differences can be observed between refinement software that uses molecular dynamics-type energy terms (for example CNS) and software that does not use these terms (for example REFMAC). Detailing the standard torsion angles used in refinement software can improve the refinement of protein structures. The target values in the molecular dynamics-type energy functions can also be improved.

Grain refinement of zinc-aluminium alloys

International Nuclear Information System (INIS)

Zaid, A.I.O.

2006-01-01

It is now well-established that the structure of the zinc-aluminum die casting alloys can be modified by the binary Al-Ti or the ternary Al-Ti-B master alloys. in this paper, grain refinement of zinc-aluminum alloys by rare earth materials is reviewed and discussed. The importance of grain refining of these alloys and parameters affecting it are presented and discussed. These include parameters related to the Zn-Al alloys cast, parameters related to the grain refining elements or alloys and parameters related to the process. The effect of addition of other alloying elements e.g. Zr either alone or in the presence of the main grain refiners Ti or Ti + B on the grain refining efficiency is also reviewed and discussed. Furthermore, based on the grain refinement and the parameters affecting it, a criterion for selection of the optimum grain refiner is suggested. Finally, the recent research work on the effect of grain refiners on the mechanical behaviour, impact strength, wear resistance, and fatigue life of these alloys are presented and discussed. (author)

An outdoor investigation of the absorption degradation of single ...

Indian Academy of Sciences (India)

Permanent link: https://www.ias.ac.in/article/fulltext/pram/086/04/0901-0909. Keywords. Thermography; hot spots; localized heating; single-junction amorphous silicon module; Fourier transform infrared spectroscopy. Abstract. This paper investigates the absorbance degradation of single-junction amorphous silicon (a-Si:H) ...

Adsorbates on cobalt and platinum single crystal surfaces studied by STM

Energy Technology Data Exchange (ETDEWEB)

Venvik, Hilde Johnsen

1998-12-31

This thesis on surface physics may contribute to the understanding of catalysts and so be of interest to companies working on oil and natural gas refining. The thesis deals with room temperature experimental investigations of adsorbates of CO and C{sub 2}H{sub 4} gases on Co and Pt single crystal surfaces. 252 refs., 51 figs., 1 table

Refining and petrochemicals

Energy Technology Data Exchange (ETDEWEB)

Constancio, Silva

2006-07-01

In 2004, refining margins showed a clear improvement that persisted throughout the first three quarters of 2005. This enabled oil companies to post significantly higher earnings for their refining activity in 2004 compared to 2003, with the results of the first half of 2005 confirming this trend. As for petrochemicals, despite a steady rise in the naphtha price, higher cash margins enabled a turnaround in 2004 as well as a clear improvement in oil company financial performance that should continue in 2005, judging by the net income figures reported for the first half-year. Despite this favorable business environment, capital expenditure in refining and petrochemicals remained at a low level, especially investment in new capacity, but a number of projects are being planned for the next five years. (author)

Refining and petrochemicals

International Nuclear Information System (INIS)

Constancio, Silva

2006-01-01

In 2004, refining margins showed a clear improvement that persisted throughout the first three quarters of 2005. This enabled oil companies to post significantly higher earnings for their refining activity in 2004 compared to 2003, with the results of the first half of 2005 confirming this trend. As for petrochemicals, despite a steady rise in the naphtha price, higher cash margins enabled a turnaround in 2004 as well as a clear improvement in oil company financial performance that should continue in 2005, judging by the net income figures reported for the first half-year. Despite this favorable business environment, capital expenditure in refining and petrochemicals remained at a low level, especially investment in new capacity, but a number of projects are being planned for the next five years. (author)

Grain refinement of aluminum and its alloys

International Nuclear Information System (INIS)

Zaid, A.I.O.

2001-01-01

Grain refinement of aluminum and its alloys by the binary Al-Ti and Ternary Al-Ti-B master alloys is reviewed and discussed. The importance of grain refining to the cast industry and the parameters affecting it are presented and discussed. These include parameters related to the cast, parameters related to the grain refining alloy and parameters related to the process. The different mechanisms, suggested in the literature for the process of grain refining are presented and discussed, from which it is found that although the mechanism of refining by the binary Al-Ti is well established the mechanism of grain refining by the ternary Al-Ti-B is still a controversial matter and some research work is still needed in this area. The effect of the addition of other alloying elements in the presence of the grain refiner on the grain refining efficiency is also reviewed and discussed. It is found that some elements e.g. V, Mo, C improves the grain refining efficiency, whereas other elements e.g. Cr, Zr, Ta poisons the grain refinement. Based on the parameters affecting the grain refinement and its mechanism, a criterion for selection of the optimum grain refiner is forwarded and discussed. (author)

Effect of zirconium addition on welding of aluminum grain refined by titanium

International Nuclear Information System (INIS)

Zaid, A.I.O.

2011-01-01

Aluminum and its alloys solidify in large grains columnar structure which tends to reduce their mechanical behaviour and surface quality. Therefore, they are industrially grain refined by titanium or titanium + boron. Furthermore, aluminum oxidizes in ordinary atmosphere which makes its weldability difficult and weak. Therefore, it is anticipated that the effect of addition of zirconium at a weight percentages of 0.1% (which proved to be an effective grain refiner on the weldability of aluminum grain refined by Ti) is worthwhile investigating. This formed the objective of this research work. In this paper, the effect of zirconium addition at a weight percentage of 0.1%, which corresponds to the peritctic limit on the aluminum-zirconium phase diagram, on the weldability of aluminum grain refined by Ti is investigated. Rolled sheets of commercially pure aluminum, Al grain refined Ti of 3 mm thickness were welded together using Gas Tungsten Arc Welding method (GTAW), formerly known as TIG. A constant air gap was maintained at a constant current level, 30 ampere AC, was used because it removes the oxides of the welding process under the same process parameters. Metallographic examination of weldments of the different combinations of aluminum and its microalloys at the heat affected zone, HAZ, and base metal was carried out and examined for width, porosity, cracks and microhardness. It was found that grain refining of commercially pure aluminum by Ti resulted in enhancement of its weldability. Similarly, addition of zirconium to Al grain refined by Ti resulted in further enhancement of the weldment. Photomicrographs of the HAZ regions are presented and discussed. (author)

Niobium-base grain refiner for aluminium

International Nuclear Information System (INIS)

Silva Pontes, P. da; Robert, M.H.; Cupini, N.L.

1980-01-01

A new chemical grain refiner for aluminium has been developed, using inoculation of a niobium-base compound. When a bath of molten aluminium is inoculated whith this refiner, an intermetallic aluminium-niobium compound is formed which acts as a powerful nucleant, producing extremely fine structure comparable to those obtained by means of the traditional grain refiner based on titanium and boron. It was found that the refinement of the structure depends upon the weight percentage of the new refiner inoculated as well as the time of holding the bath after inoculation and before pouring, but mainly on the inoculating temperature. (Author) [pt

Indian refining industry

International Nuclear Information System (INIS)

Singh, I.J.

2002-01-01

The author discusses the history of the Indian refining industry and ongoing developments under the headings: the present state; refinery configuration; Indian capabilities for refinery projects; and reforms in the refining industry. Tables lists India's petroleum refineries giving location and capacity; new refinery projects together with location and capacity; and expansion projects of Indian petroleum refineries. The Indian refinery industry has undergone substantial expansion as well as technological changes over the past years. There has been progressive technology upgrading, energy efficiency, better environmental control and improved capacity utilisation. Major reform processes have been set in motion by the government of India: converting the refining industry from a centrally controlled public sector dominated industry to a delicensed regime in a competitive market economy with the introduction of a liberal exploration policy; dismantling the administered price mechanism; and a 25 year hydrocarbon vision. (UK)

Tools for macromolecular model building and refinement into electron cryo-microscopy reconstructions

Energy Technology Data Exchange (ETDEWEB)

Brown, Alan; Long, Fei; Nicholls, Robert A.; Toots, Jaan; Emsley, Paul; Murshudov, Garib, E-mail: garib@mrc-lmb.cam.ac.uk [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH (United Kingdom)

2015-01-01

A description is given of new tools to facilitate model building and refinement into electron cryo-microscopy reconstructions. The recent rapid development of single-particle electron cryo-microscopy (cryo-EM) now allows structures to be solved by this method at resolutions close to 3 Å. Here, a number of tools to facilitate the interpretation of EM reconstructions with stereochemically reasonable all-atom models are described. The BALBES database has been repurposed as a tool for identifying protein folds from density maps. Modifications to Coot, including new Jiggle Fit and morphing tools and improved handling of nucleic acids, enhance its functionality for interpreting EM maps. REFMAC has been modified for optimal fitting of atomic models into EM maps. As external structural information can enhance the reliability of the derived atomic models, stabilize refinement and reduce overfitting, ProSMART has been extended to generate interatomic distance restraints from nucleic acid reference structures, and a new tool, LIBG, has been developed to generate nucleic acid base-pair and parallel-plane restraints. Furthermore, restraint generation has been integrated with visualization and editing in Coot, and these restraints have been applied to both real-space refinement in Coot and reciprocal-space refinement in REFMAC.

Tools for macromolecular model building and refinement into electron cryo-microscopy reconstructions

International Nuclear Information System (INIS)

Brown, Alan; Long, Fei; Nicholls, Robert A.; Toots, Jaan; Emsley, Paul; Murshudov, Garib

2015-01-01

A description is given of new tools to facilitate model building and refinement into electron cryo-microscopy reconstructions. The recent rapid development of single-particle electron cryo-microscopy (cryo-EM) now allows structures to be solved by this method at resolutions close to 3 Å. Here, a number of tools to facilitate the interpretation of EM reconstructions with stereochemically reasonable all-atom models are described. The BALBES database has been repurposed as a tool for identifying protein folds from density maps. Modifications to Coot, including new Jiggle Fit and morphing tools and improved handling of nucleic acids, enhance its functionality for interpreting EM maps. REFMAC has been modified for optimal fitting of atomic models into EM maps. As external structural information can enhance the reliability of the derived atomic models, stabilize refinement and reduce overfitting, ProSMART has been extended to generate interatomic distance restraints from nucleic acid reference structures, and a new tool, LIBG, has been developed to generate nucleic acid base-pair and parallel-plane restraints. Furthermore, restraint generation has been integrated with visualization and editing in Coot, and these restraints have been applied to both real-space refinement in Coot and reciprocal-space refinement in REFMAC

A new concept for product refining in the Purex process

International Nuclear Information System (INIS)

Henrich, E.; Bauder, U.; Marquardt, R.

1986-01-01

In actual Purex plants the products are refined in additional solvent extraction cycles. Crystallization of uranyl and plutonyl nitrate from aqueous nitric acid solution is proposed as a potentially simpler product refining concept. Suitable crystallization conditions are being investigated in the laboratory using simulated and actual process solutions. A thorough removal of mother liquor is an essential purification step and well washed crystals usually contain less than 1% of an individual impurity. Crystallization simultaneously comprises a product concentration step. Hexavalent uranium can be separated from lower-valent plutonium. An outline of an integrated processing concept is given. Product refining by crystallization is compact; recycling of mother liquor plus wash acid prevents product loss and the generation of additional waste streams. (orig.) [de

Spanish Refining

International Nuclear Information System (INIS)

Lores, F.R.

2001-01-01

An overview of petroleum refining in Spain is presented (by Repsol YPF) and some views on future trends are discussed. Spain depends heavily on imports. Sub-headings in the article cover: sources of crude imports, investments and logistics and marketing, -detailed data for each are shown diagrammatically. Tables show: (1) economic indicators (e.g. total GDP, vehicle numbers and inflation) for 1998-200; (2) crude oil imports for 1995-2000; (3) oil products balance for 1995-2000; (4) commodities demand, by product; (5) refining in Spain in terms of capacity per region; (6) outlets in Spain and other European countries in 2002 and (7) sales distribution channel by product

Carcinogenicity of petroleum lubricating oil distillates: effects of solvent refining, hydroprocessing, and blending.

Science.gov (United States)

Halder, C A; Warne, T M; Little, R Q; Garvin, P J

1984-01-01

Certain refining processes were investigated to determine their influence on the dermal carcinogenic activity of petroleum-derived lubricating oil distillates. Specifically, the effects of solvent refining, hydroprocessing, a combination of both processes, and the blending of oils processed using each technique were evaluated in standard mouse skin-painting bioassays. The refining process used as well as the level or severity of treatment greatly influenced the carcinogenic outcome of processed lubricating oils. Solvent refining at severities normally used appeared to eliminate carcinogenicity. In contrast, hydroprocessing alone at mild levels of treatment was successful only in reducing the carcinogenic potency; severe hydroprocessing conditions were necessary to eliminate carcinogenic activity without the use of additional refining processes. Carcinogenic activity could also be eliminated by following moderate solvent refining with mild hydroprocessing. Blending of hydroprocessed oils with solvent-refined oils resulted in a substantial reduction or even elimination of carcinogenic activity. However, the degree of protection obtained varied with the particular distillates used and appeared largely dependent on the inherent biological activity of the hydroprocessed oil.

Investigation of single event latchup

International Nuclear Information System (INIS)

Xue Yuxiong; Yang Shengsheng; Cao Zhou; Ba Dedong; An Heng; Chen Luojing; Guo Gang

2012-01-01

Radiation effects on avionics microelectronics are important reliability issues for many space applications. In particular, single-event latchup (SEL) phenomenon is a major threat to CMOS integrated circuits in space systems. To effectively circumvent the failure, it is important to know the behavior of such devices during latchup. In this paper, the mechanisms for SEL in CMOS devices are investigated. Several microelectronic devices used in avionics are tested using heavy ion beams, pulsed laser and 252 Cf source. Based on the SEL test results, SEL-hardening and monitoring methods for preventing SEL from the systems design level are proposed. (authors)

Reverse mechanical after effect during hydrogenation of zone refined iron

Energy Technology Data Exchange (ETDEWEB)

Spivak, L.V.; Skryabina, N.E.; Kurmaeva, L.D.; Smirnov, L.V. (Permskij Gosudarstvennyj Univ. (USSR); AN SSSR, Sverdlovsk. Inst. Fiziki Metallov)

1984-12-01

The relationship between the process of hydrogenation and the reverse mechanical after effect (RMA) microplastic deformation in the zone refined iron has been studied. Metallographic investigations and mechanical testing of the samples hydrogenated under torsional strain have been performed. It is shown that in the zone refined iron the formation of voids responsible for irreversible hydrogen embrittlement does not occur, but the hydrogen-initiated RMA strain is conserved, i. e. the RMA effects are independent of the presence of discontinuities.

Comparing Refinements for Failure and Bisimulation Semantics

NARCIS (Netherlands)

Eshuis, H.; Fokkinga, M.M.

2002-01-01

Refinement in bisimulation semantics is defined differently from refinement in failure semantics: in bisimulation semantics refinement is based on simulations between labelled transition systems, whereas in failure semantics refinement is based on inclusions between failure systems. There exist

On mesh refinement and accuracy of numerical solutions

NARCIS (Netherlands)

Zhou, Hong; Peters, Maria; van Oosterom, Adriaan

1993-01-01

This paper investigates mesh refinement and its relation with the accuracy of the boundary element method (BEM) and the finite element method (FEM). TO this end an isotropic homogeneous spherical volume conductor, for which the analytical solution is available, wag used. The numerical results

Crystal structure refinement with SHELXL

Energy Technology Data Exchange (ETDEWEB)

Sheldrick, George M., E-mail: gsheldr@shelx.uni-ac.gwdg.de [Department of Structural Chemistry, Georg-August Universität Göttingen, Tammannstraße 4, Göttingen 37077 (Germany)

2015-01-01

New features added to the refinement program SHELXL since 2008 are described and explained. The improvements in the crystal structure refinement program SHELXL have been closely coupled with the development and increasing importance of the CIF (Crystallographic Information Framework) format for validating and archiving crystal structures. An important simplification is that now only one file in CIF format (for convenience, referred to simply as ‘a CIF’) containing embedded reflection data and SHELXL instructions is needed for a complete structure archive; the program SHREDCIF can be used to extract the .hkl and .ins files required for further refinement with SHELXL. Recent developments in SHELXL facilitate refinement against neutron diffraction data, the treatment of H atoms, the determination of absolute structure, the input of partial structure factors and the refinement of twinned and disordered structures. SHELXL is available free to academics for the Windows, Linux and Mac OS X operating systems, and is particularly suitable for multiple-core processors.

X-ray and neutron single crystal diffraction on (NH4)3H(SO4)2. II. Refinement of crystal structure of phase II at room temperature

International Nuclear Information System (INIS)

Reehuis, M.; Wozniak, K.; Dominiak, P.; Smirnov, L.S.; Natkaniec, I.; Baranov, A.I.; Dolbinina, V.V.

2006-01-01

The (NH 4 ) 3 H(SO 4 ) 2 is of special interest due to the possible influence of ammonium ions on a series of phase transitions: I => II => III => IV => V => VII. Earlier, the X-ray single crystal diffraction study of phase II of (NH 4 ) 3 H(SO 4 ) 2 showed that the crystal structure of this compound has two crystallographically independent groups of ammonium ions NH 4 (1) and NH 4 (2), but orientational positions of these ammonium ions were not determined exactly. The refinement of NH 4 (1) and NH 4 (2) orientational positions in phase II is carried out with the help of the X-ray and neutron single crystal diffraction study. The analyses of differential Fourier maps of electron charge density and nuclear density point out the possibility of disordering of NH 4 (2) ammonium ions

Latin American oil markets and refining

International Nuclear Information System (INIS)

Yamaguchi, N.D.; Obadia, C.

1999-01-01

This paper provides an overview of the oil markets and refining in Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru and Venezuela, and examines the production of crude oil in these countries. Details are given of Latin American refiners highlighting trends in crude distillation unit capacity, cracking to distillation ratios, and refining in the different countries. Latin American oil trade is discussed, and charts are presented illustrating crude production, oil consumption, crude refining capacity, cracking to distillation ratios, and oil imports and exports

Relational Demonic Fuzzy Refinement

Directory of Open Access Journals (Sweden)

Fairouz Tchier

2014-01-01

Full Text Available We use relational algebra to define a refinement fuzzy order called demonic fuzzy refinement and also the associated fuzzy operators which are fuzzy demonic join (⊔fuz, fuzzy demonic meet (⊓fuz, and fuzzy demonic composition (□fuz. Our definitions and properties are illustrated by some examples using mathematica software (fuzzy logic.

Panorama 2012 - Refining 2030

International Nuclear Information System (INIS)

Marion, Pierre; Saint-Antonin, Valerie

2011-11-01

The major uncertainty characterizing the global energy landscape impacts particularly on transport, which remains the virtually-exclusive bastion of the oil industry. The industry must therefore respond to increasing demand for mobility against a background marked by the emergence of alternatives to oil-based fuels and the need to reduce emissions of pollutants and greenhouse gases (GHG). It is in this context that the 'Refining 2030' study conducted by IFP Energies Nouvelles (IFPEN) forecasts what the global supply and demand balance for oil products could be, and highlights the type and geographical location of the refinery investment required. Our study shows that the bulk of the refining investment will be concentrated in the emerging countries (mainly those in Asia), whilst the areas historically strong in refining (Europe and North America) face reductions in capacity. In this context, the drastic reduction in the sulphur specification of bunker oil emerges as a structural issue for European refining, in the same way as increasingly restrictive regulation of refinery CO 2 emissions (quotas/taxation) and the persistent imbalance between gasoline and diesel fuels. (authors)

Preparation of Al-Ti-B grain refiner by SHS technology

International Nuclear Information System (INIS)

Nikitin, V.I.; Wanqi, J.I.E.; Kandalova, E.G.; Makarenko, A.G.; Yong, L.

2000-01-01

Since the discovery of the grain refinement effect of aluminum by titanium, especially with the existence of B or C in 1950, grain refiners are widely accepted in industry for microstructure control of aluminum alloys. Research on this topic is to obtain the highest grain refinement efficiency with the lowest possible addition of master alloy. It is widely accepted that the morphology and size of TiAl 3 particles, which are known as heterogeneous nucleation centers, are important factors deterring the grain refinement efficiency. Fine TiAl 3 particles are favorable. The grain refinement process shows a heredity phenomenon, which means that structural information from initial materials transfers through a melt to the final product. It is important to find the connection between microstructural parameters of the master alloy and the final product. To improve the quality of Al-Ti-B master alloys for the use as a grain refiner, a new method based on SHS (self-propagating high-temperature synthesis) technology has been developed in Samara State Technical University to produce the master alloys. SHS, as a new method for preparation of materials, was first utilized by Merzhanov in 1967. This method uses the energy from highly exothermic reactions to sustain the chemical reaction in a combustion wave. The advantages of SHS include simplicity, low energy requirement, and higher product purity. Because SHS reactions can take place between elemental reactants, it is easy to control product composition. The purposes of this investigation were to fabricate an SHS Al-5%Ti-1%B master alloy, to analyze its structure and to test its grain refining performance

Grain refinement of permanent mold cast copper base alloys. Final report

Energy Technology Data Exchange (ETDEWEB)

Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

2004-04-29

Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this technique it is necessary to understand the mechanism of grain refinement and other issues involved in the process. The following issues were studied during this three year project funded by the US Department of Energy and the copper casting industry: (1) Effect of alloying additions on the grain size of Cu-Zn alloys and their interaction with grain refiners; (2) Effect of two grain refining elements, boron and zirconium, on the grain size of four copper alloys, yellow brass, EnviroBrass II, silicon brass and silicon bronze and the duration of their effect (fading); (3) Prediction of grain refinement using cooling curve analysis and use of this method as an on-line quality control tool; (4) Hard spot formation in yellow brass and EnviroBrass due to grain refinement; (5) Corrosion resistance of the grain refined alloys; (6) Transfer the technology to permanent mold casting foundries; It was found that alloying elements such as tin and zinc do not change the grain size of Cu-Zn alloys

Refining margins and prospects

International Nuclear Information System (INIS)

Baudouin, C.; Favennec, J.P.

1997-01-01

Refining margins throughout the world have remained low in 1996. In Europe, in spite of an improvement, particularly during the last few weeks, they are still not high enough to finance new investments. Although the demand for petroleum products is increasing, experts are still sceptical about any rapid recovery due to prevailing overcapacity and to continuing capacity growth. After a historical review of margins and an analysis of margins by regions, we analyse refining over-capacities in Europe and the unbalances between production and demand. Then we discuss the current situation concerning barriers to the rationalization, agreements between oil companies, and the consequences on the future of refining capacities and margins. (author)

A neutron powder diffraction study of deuterated α-resorcinol: a test of profile refinement using TLS constraints

International Nuclear Information System (INIS)

Bacon, G.E.; Lisher, E.J.

1979-01-01

Constrained TL, TLX and TLS refinements have been used, with the powder-profile method, in the analysis of accurate neutron powder data for deuterated α-resorcinol at room temperature. There is good agreement between the translational and librational parameters derived from the TL refinement and those obtained from an equivalent analysis of accurate single-crystal neutron measurements. The fine details of the benzene ring are lost in the powder analysis, but the molecular orientation and the OH bond angles are in good agreement with the single-crystal values. No significant improvement could be found in the powder fit by applying the full TLS theory and, therefore, the approximate TLX model appears to be adequate for powder data. (Auth.)

NMR investigation of boron impurities in refined metallurgical grade silicon

Energy Technology Data Exchange (ETDEWEB)

Grafe, Hans-Joachim; Loeser, Wolfgang; Schmitz, Steffen; Sakaliyska, Miroslava [Leibniz Institute for Solid State and Materials Research (IFW), Dresden (Germany); Wurmehl, Sabine [Leibniz Institute for Solid State and Materials Research (IFW), Dresden (Germany); Institute for Solid State Physics, Technische Universitaet Dresden (Germany); Eisert, Stefan; Reichenbach, Birk; Mueller, Tim [Adensis GmbH, Dresden (Germany); Acker, Joerg; Rietig, Anja; Ducke, Jana [Department of Chemistry, Faculty for Natural Sciences, Brandenburg Technical University Cottbus-Senftenberg, Senftenberg (Germany)

2015-09-15

The nuclear magnetic resonance (NMR) method was applied for tracking boron impurities in the refining process of metallurgical grade (MG) silicon. From the NMR signal of the {sup 11}B isotope at an operating temperature 4.2 K, the boron concentration can be estimated down to the order of 1-10 wppm B. After melting and resolidification of MG-Si alloyed with Ca and Ti, a major fraction of B impurities remains in the Si solid solution as inferred from the characteristic NMR frequency. The alloying element Ti does not form substantial fractions of TiB{sub 2}. Acid leaching of crushed powders of MG-Si alloyed with Ca and Ti can diminish the initial impurity content of B suggesting its accumulation in the grain boundary phases. NMR signals of TiB{sub 2} at 4.2 K and room temperature (RT), and of poly-Si with different B doping at 4.2 K. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Combining Techniques to Refine Item to Skills Q-Matrices with a Partition Tree

Science.gov (United States)

Desmarais, Michel C.; Xu, Peng; Beheshti, Behzad

2015-01-01

The problem of mapping items to skills is gaining interest with the emergence of recent techniques that can use data for both defining this mapping, and for refining mappings given by experts. We investigate the problem of refining mapping from an expert by combining the output of different techniques. The combination is based on a partition tree…

Nucleation mechanisms of refined alpha microstructure in beta titanium alloys

Science.gov (United States)

Zheng, Yufeng

Due to a great combination of physical and mechanical properties, beta titanium alloys have become promising candidates in the field of chemical industry, aerospace and biomedical materials. The microstructure of beta titanium alloys is the governing factor that determines their properties and performances, especially the size scale, distribution and volume fraction of precipitate phase in parent phase matrix. Therefore in order to enhance the performance of beta titanium alloys, it is critical to obtain a thorough understanding of microstructural evolution in beta titanium alloys upon various thermal and/or mechanical processes. The present work is focusing on the study of nucleation mechanisms of refined alpha microstructure and super-refined alpha microstructure in beta titanium alloys in order to study the influence of instabilities within parent phase matrix on precipitates nucleation, including compositional instabilities and/or structural instabilities. The current study is primarily conducted in Ti-5Al-5Mo-5V-3Cr (wt%, Ti-5553), a commercial material for aerospace application. Refined and super-refined precipitates microstructure in Ti-5553 are obtained under specific accurate temperature controlled heat treatments. The characteristics of either microstructure are investigated in details using various characterization techniques, such as SEM, TEM, STEM, HRSTEM and 3D atom probe to describe the features of microstructure in the aspect of morphology, distribution, structure and composition. Nucleation mechanisms of refined and super-refined precipitates are proposed in order to fully explain the features of different precipitates microstructure in Ti-5553. The necessary thermodynamic conditions and detailed process of phase transformations are introduced. In order to verify the reliability of proposed nucleation mechanisms, thermodynamic calculation and phase field modeling simulation are accomplished using the database of simple binary Ti-Mo system

Refinement Types for TypeScript

OpenAIRE

Vekris, Panagiotis; Cosman, Benjamin; Jhala, Ranjit

2016-01-01

We present Refined TypeScript (RSC), a lightweight refinement type system for TypeScript, that enables static verification of higher-order, imperative programs. We develop a formal core of RSC that delineates the interaction between refinement types and mutability. Next, we extend the core to account for the imperative and dynamic features of TypeScript. Finally, we evaluate RSC on a set of real world benchmarks, including parts of the Octane benchmarks, D3, Transducers, and the TypeScript co...

Investigations of single-electron avalanches in a proportional drift tube

International Nuclear Information System (INIS)

Anderson, W.S.; Armitage, J.C.; Chevreau, P.; Heinrich, J.G.; Lu, C.; McDonald, I.; McDonald, K.T.; Miller, B.; Secrest, D.; Weckel, J.

1990-01-01

Detailed information on single-electron drift and avalanche behavior has a basic interest in an investigation of gas-chamber performance. Its timing, avalanche distribution, attachment by the working gas mixtures, etc., provide various criteria for choosing the best suitable gas mixture under a specific experimental circumstance. Investigations of single-electron avalanches in a proportional drift tube have been carried out with a pulsed N 2 laser. The study consists of two aspects: timing properties, and fluctuations in the gas avalanche

Grain refinement of Aluminium alloys using friction stir processing

International Nuclear Information System (INIS)

Khraisheh, M.

2004-01-01

Full text.Friction Stir Processing (FSP) is a new advanced material processing technique used to refine and homogenize the microstructure of sheet metals. FSP is a solid state processing technique that uses a rapidly rotating non-consumable high strength tool steel pin that extends from a cylindrical shoulder. The rotating pin is forced with a predetermined load into the work piece and moved along with the work pieces, while the rotating pin deforms and stirs the locally heated material. It is a hot working process in which a large amount of deformation is imparted to the sheet. FS processed zone is characterized by dynamic recrystallization which results in grain refinement . this promising emerging process needs further investigations to develop optimum process parameters to produce the desired microstructure. In this work, we present preliminary results on the effects of rotational and translational speeds on grain refinement of AA5052. Under certain processing conditions, sub-micron grain structure was produced using this technique

Synthesis of Al-5Ti-1B Refiner by Melt Reaction Method

Directory of Open Access Journals (Sweden)

LI He

2017-02-01

Full Text Available Al-5Ti-1B refiner was successfully prepared by melt reaction method. Through the thermodynamics calculation, the initial reaction temperature was determined. The influence of reaction temperature on microstructure and absorption rate of the alloy was investigated. The phase and microstructure of the alloy were observed by X-ray diffraction, scanning electron microscope and energy dispersive spectrometer. The Al-5Ti-1B refiner was extruded at high temperature to wire with the diameter of 9.5mm, and then the refinement experiment was carried out on pure aluminium. The results indicate that the refiner consists of TiB2, TiAl3 and α-Al, and the microstructure prepared at 850℃ is the optimum and the absorption rate of Ti and B matches the best. The TiAl3 and TiB2 phases distribute homogeneously in the matrix after extrusion. When adding 0.2%(mass fraction of Al-5Ti-1B refiner, the grain size of pure aluminium reduces from 3.99mm to 0.45mm.

Neutron Powder Diffraction and Constrained Refinement

DEFF Research Database (Denmark)

Pawley, G. S.; Mackenzie, Gordon A.; Dietrich, O. W.

1977-01-01

The first use of a new program, EDINP, is reported. This program allows the constrained refinement of molecules in a crystal structure with neutron diffraction powder data. The structures of p-C6F4Br2 and p-C6F4I2 are determined by packing considerations and then refined with EDINP. Refinement is...

Refined geometric transition and qq-characters

Science.gov (United States)

Kimura, Taro; Mori, Hironori; Sugimoto, Yuji

2018-01-01

We show the refinement of the prescription for the geometric transition in the refined topological string theory and, as its application, discuss a possibility to describe qq-characters from the string theory point of view. Though the suggested way to operate the refined geometric transition has passed through several checks, it is additionally found in this paper that the presence of the preferred direction brings a nontrivial effect. We provide the modified formula involving this point. We then apply our prescription of the refined geometric transition to proposing the stringy description of doubly quantized Seiberg-Witten curves called qq-characters in certain cases.

Recovery of condensates from the thermal wood refinement extraction of biomolecules

Energy Technology Data Exchange (ETDEWEB)

Roschitz, C.; Martini, S.; Kleinhappl, M. (Austrian Bioenergy Centre GmbH, Area Gasification, Graz (Austria)); Jenny, M.; Wrulicit, O.A.; Wondrak, A.; Ueberall, E. (Innsbruck University of Medicine, Biocenter, Division of Medical Biochemistry, Innsbruck (Austria)); Fillafer, F.; Steiner, F. (Mafi Holzverarbeitung GmbH, Schneegattern (Austria)); Draxler, J. (Leoben University of Mining and Materials, Institute for Process technology and Industrial Environment Protection, Leoben (Austria))

2007-07-01

Generally the utilisation of woody biomass is dominated by the pulp and paper industry, its use for energy production by combustion or gasification and as a construction material. A large potential of substances could be gained directly and indirectly from biomass. During industrial processes like the thermal wood refinement or the digestion from wood to pulp a large spectrum of substances could be recovered. This paper gives an idea of how to obtain and use those special substances contained in woody biomass. Therefore this project was launched to investigate exhaust vapours originating from industrial wood refining processes. The exhaust vapour of a thermal wood refinement chamber, which works at 150 - 220 deg C, was sampled and its constituents of low amount were investigated. Substance classes like organic acids, aldehydes, esters alcohols, lignin fractions and resin like compounds were identified. The bioactivity of the samples was investigated in biological test procedures, to identify the characteristic pattern of impression (toxicity, antioxidants, gene expression). The technological step of recovery in small ale during the refinery process is under construction and will perform the staged recovery of valuable fractions. The pilot scale plant will give the chance to gain test fractions in sufficient amount to generate materials for application as chemicals, additives for detergents and cleaning agents. (orig.)

Effects of grain refinement on the rheological behaviors of semisolid hypoeutectic Al-Si alloys

International Nuclear Information System (INIS)

Yan, M.; Luo, W.

2007-01-01

The paper experimentally investigated the effects of grain refinement on the rheological response of Al and hypoeutectic Al-Si alloys. Selected refiners included K 2 TiF 6 , K 2 TiF 6 plus graphite and Al-5Ti-B. The apparent viscosity of semisolid Al alloys was measured during solidification. Samples at different solid fractions were quenched to observe the microstructure. It was found that grain refinement drastically lowered the apparent viscosity of Al-Si alloys. Among selected refiners, the effect of Al-5Ti-B was the best. The effect of K 2 TiF 6 plus graphite was better than that of K 2 TiF 6 . Silicon contents in Al alloys affected the apparent viscosity. With increasing silicon content the apparent viscosity decreased, resulted from promotion of silicon to both refining effects of titanium and boron

On Modal Refinement and Consistency

DEFF Research Database (Denmark)

Nyman, Ulrik; Larsen, Kim Guldstrand; Wasowski, Andrzej

2007-01-01

Almost 20 years after the original conception, we revisit several fundamental question about modal transition systems. First, we demonstrate the incompleteness of the standard modal refinement using a counterexample due to Hüttel. Deciding any refinement, complete with respect to the standard...

Refining - Panorama 2008

International Nuclear Information System (INIS)

2008-01-01

Investment rallied in 2007, and many distillation and conversion projects likely to reach the industrial stage were announced. With economic growth sustained in 2006 and still pronounced in 2007, oil demand remained strong - especially in emerging countries - and refining margins stayed high. Despite these favorable business conditions, tensions persisted in the refining sector, which has fallen far behind in terms of investing in refinery capacity. It will take renewed efforts over a long period to catch up. Looking at recent events that have affected the economy in many countries (e.g. the sub-prime crisis), prudence remains advisable

The Refining Mechanism of Super Gravity on the Solidification Structure of Al-Cu Alloys

Directory of Open Access Journals (Sweden)

Yuhou Yang

2016-12-01

Full Text Available There is far less study of the refining effect of super gravity fields on solidification structures of metals than of the effects of electrical currents, magnetic and ultrasonic fields. Moreover, the refining mechanisms of super gravity are far from clear. This study applied a super gravity field to Al-Cu alloys to investigate its effect on refining their structures and the mechanism of interaction. The experimental results showed that the solidification structure of Al-Cu alloys can be greatly refined by a super gravity field. The major refining effect was mainly achieved when super gravity was applied at the initial solidification stage; only slight refinement could be obtained towards the end of solidification. No refinement was obtained by the super gravity treatment on pure liquid or solid stages. The effectiveness of super gravity results from its promoting the multiplication of crystal nuclei, which we call “Heavy Crystal Rain”, thereby greatly strengthening the migration of crystal nuclei within the alloy. Increasing the solute Cu content can increase nucleation density and restrict the growth of crystals, which further increases the refining effect of super gravity. Within this paper, we also discuss the motile behavior of crystals in a field of super gravity.

Refinement by interface instantiation

DEFF Research Database (Denmark)

Hallerstede, Stefan; Hoang, Thai Son

2012-01-01

be easily refined. Our first contribution hence is a proposal for a new construct called interface that encapsulates the external variables, along with a mechanism for interface instantiation. Using the new construct and mechanism, external variables can be refined consistently. Our second contribution...... is an approach for verifying the correctness of Event-B extensions using the supporting Rodin tool. We illustrate our approach by proving the correctness of interface instantiation....

Development of interface technology between unit processes in E-Refining process

Energy Technology Data Exchange (ETDEWEB)

Lee, S. H.; Lee, H. S.; Kim, J. G. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

The pyroprocessing is composed mainly four subprocesses, such as an electrolytic reduction, an electrorefining, an electrowinning, and waste salt regeneration/ solidification processes. The electrorefining process, one of main processes which are composed of pyroprocess to recover the useful elements from spent fuel, is under development by Korea Atomic Energy Research Institute as a sub process of pyrochemical treatment of spent PWR fuel. The CERS(Continuous ElectroRefining System) is composed of some unit processes such as an electrorefiner, a salt distiller, a melting furnace for the U-ingot and U-chlorinator (UCl{sub 3} making equipment) as shown in Fig. 1. In this study, the interfaces technology between unit processes in E-Refining system is investigated and developed for the establishment of integrated E-Refining operation system as a part of integrated pyroprocessing

Creativity: a refinement of the concept for nursing practice.

Science.gov (United States)

Fasnacht, Patsy H

2003-01-01

This paper seeks to remove some of the ambiguity surrounding the conceptual meaning of creativity using techniques of concept refinement to advance the concept. Creativity is an essential component of nursing practice that occurs daily in nurse's interactions with clients, families and other nurses. Failure to acknowledge and encourage creativity in beginning nurses may hinder future development and innovations in nursing practice and in nursing science. In order to promote the development of creativity it is first necessary to clarify and refine the concept as it applies to nursing. A comprehensive review of a variety of computer and online databases resulted in thousands of articles on creativity between the years 1966 and 1999. The final sample (n = 48) was obtained using both stratified random and purposive sampling techniques. A content analysis of the literature was conducted using methods identified by Morse and illustrated in the work of Hupcey et al. Having determined the concept to be partially mature, the concept was advanced using techniques of concept refinement. Content analysis of the literature yielded three differing definitions for creativity: revelation, birth and reincarnation. Creativity occurs in the presence of intrinsic motivation and a nurturing environment. While value is often used to identify whether a product is creative, the value of the product cannot determine whether the process has occurred. The product produced determines evidence of the process of creativity. Limitations of this investigation are the use of secondary sources and the relatively small sample size (n = 48). Refinement of the concept of creativity indicates that it is a process that may be developed and influenced by the environment and is recognized by the product produced. Further investigation is needed to explore methods and techniques for developing creativity in nursing.

The relationship between viscosity and refinement efficiency of pure aluminum by Al-Ti-B refiner

Energy Technology Data Exchange (ETDEWEB)

Yu Lina [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, 73 Jingshi Road, Jinan 250061 (China); Liu Xiangfa [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, 73 Jingshi Road, Jinan 250061 (China)]. E-mail: xfliu@sdu.edu.cn

2006-11-30

The relationship between viscosity and refinement efficiency of pure aluminum with the addition of Al-Ti-B master alloy was studied in this paper. The experimental results show that when the grain size of solidified sample is finer the viscosity of the melt is higher after the addition of different Al-Ti-B master alloys. This indicates that viscosity can be used to approximately estimate the refinement efficiency of Al-Ti-B refiners in production to a certain extent. The main reason was also discussed in this paper by using transmission electron microscopy (TEM) analysis and differential scanning calorimetry (DSC) experiment.

Relational Demonic Fuzzy Refinement

OpenAIRE

Tchier, Fairouz

2014-01-01

We use relational algebra to define a refinement fuzzy order called demonic fuzzy refinement and also the associated fuzzy operators which are fuzzy demonic join $({\\bigsqcup }_{\\mathrm{\\text{f}}\\mathrm{\\text{u}}\\mathrm{\\text{z}}})$ , fuzzy demonic meet $({\\sqcap }_{\\mathrm{\\text{f}}\\mathrm{\\text{u}}\\mathrm{\\text{z}}})$ , and fuzzy demonic composition $({\\square }_{\\mathrm{\\text{f}}\\mathrm{\\text{u}}\\mathrm{\\text{z}}})$ . Our definitions and properties are illustrated by some examples using ma...

Synthesis of Al-5Ti-1B Refiner by Melt Reaction Method

OpenAIRE

LI He; CHAI Li-hua; MA Teng-fei; CHEN Zi-yong

2017-01-01

Al-5Ti-1B refiner was successfully prepared by melt reaction method. Through the thermodynamics calculation, the initial reaction temperature was determined. The influence of reaction temperature on microstructure and absorption rate of the alloy was investigated. The phase and microstructure of the alloy were observed by X-ray diffraction, scanning electron microscope and energy dispersive spectrometer. The Al-5Ti-1B refiner was extruded at high temperature to wire with the diameter of 9.5mm...

Rare earths refining by vacuum sublimation method

International Nuclear Information System (INIS)

Rytus, N.N.

1983-01-01

The process of rare earths refining by the sUblimation; method in high and superhigh oil-free vacuum, is investigated. The method is effective for rare earths obtaining and permits to prepare metal samples with a high value of electric resistance ratio γ=RsUb(298 K)/Rsub(4.2 K). The estimation of general purity is performed for Sm, Eu, Yb, Tm, Dy, Ho, Er and Se

BioDegradation of Refined Petroleum Hydrocarbons in Soil | Obire ...

African Journals Online (AJOL)

Carbon-dioxide production and hydrocarbon degradation of refined petroleum hydrocarbon in soils treated with 5% gasoline, kerosene and diesel oil were investigated. Soil for study was bulked from around a car park in Port Harcourt. Soil samples were collected at weekly intervals for four weeks and subsequently at ...

Investigation of the submodels for combustion; Polton osamallien kaeytettaevyys

Energy Technology Data Exchange (ETDEWEB)

Kjaeldman, L.; Huttunen, M.; Kyttaelae, J. [VTT Energy, Espoo (Finland)

1997-10-01

The capability for numerical analysis of flow, combustion and heat transfer in furnaces has been developed by improving the knowledge of the sensitivity of computed results on submodels recently implemented to the computational environment Ardemus owned by VTT Energy and Imatran Voima Oy. The submodels studied include models for combustion of gaseous (pyrolysed) fuel and for nitric oxide. The cases investigated included a gas flame and pulverized coal and peat combustion in single burner furnaces. The effect of grid refinement on the results was investigated for a corner fired power station furnace. (orig.)

Molecular dynamics-based refinement and validation for sub-5 Å cryo-electron microscopy maps.

Science.gov (United States)

Singharoy, Abhishek; Teo, Ivan; McGreevy, Ryan; Stone, John E; Zhao, Jianhua; Schulten, Klaus

2016-07-07

Two structure determination methods, based on the molecular dynamics flexible fitting (MDFF) paradigm, are presented that resolve sub-5 Å cryo-electron microscopy (EM) maps with either single structures or ensembles of such structures. The methods, denoted cascade MDFF and resolution exchange MDFF, sequentially re-refine a search model against a series of maps of progressively higher resolutions, which ends with the original experimental resolution. Application of sequential re-refinement enables MDFF to achieve a radius of convergence of ~25 Å demonstrated with the accurate modeling of β-galactosidase and TRPV1 proteins at 3.2 Å and 3.4 Å resolution, respectively. The MDFF refinements uniquely offer map-model validation and B-factor determination criteria based on the inherent dynamics of the macromolecules studied, captured by means of local root mean square fluctuations. The MDFF tools described are available to researchers through an easy-to-use and cost-effective cloud computing resource on Amazon Web Services.

High-speed double-disc TMP [thermomechanical pulp] from northern and southern softwoods: One or two refining stages

Energy Technology Data Exchange (ETDEWEB)

Sabourin, M.J. (Andritz Sprout-Bauer, Inc., Springfield, OH (United States)); Cort, J.B.; Musselman, R.L. (Andritz Sprout-Bauer, Inc., Muncy, PA (United States))

1994-01-01

Pilot-plant studies were carried out to evaluate one- and two-stage high-speed refining processes for production of thermomechanical pulp (TMP) at minimal energy consumption. Both northern (black spruce/balsam fir) and southern (lobolly pine) wood species were tested. Preliminary results indicate both one- and two-stage high-speed refining are suitable for the production of TMP from spruce and fir. Single-stage, high-speed refining of spruce/fir resulted in over 25% energy savings compared to conventional TMP production. The resulting TMP had improved optical and shive content properties, with slightly reduced pulp strength and long fiber content. Two stages of refining were necessary to optimize pulp quality from the lobolly pine furnish. A 15% energy reduction was obtained when comparing high-speed and conventional TMP pulping of lobolly pine at similar operating conditions. The high-speed pine TMP had comparable bonding strength, shive content, and lower tear than conventional two-stage lobolly pine TMP. 14 refs., 11 figs., 6 tabs.

Panorama 2007: Refining and Petrochemicals

International Nuclear Information System (INIS)

Silva, C.

2007-01-01

The year 2005 saw a new improvement in refining margins that continued during the first three quarters of 2006. The restoration of margins in the last three years has allowed the refining sector to regain its profitability. In this context, the oil companies reported earnings for fiscal year 2005 that were up significantly compared to 2004, and the figures for the first half-year 2006 confirm this trend. Despite this favorable business environment, investments only saw a minimal increase in 2005 and the improvement expected for 2006 should remain fairly limited. Looking to 2010-2015, it would appear that the planned investment projects with the highest probability of reaching completion will be barely adequate to cover the increase in demand. Refining sector should continue to find itself under pressure. As for petrochemicals, despite a steady up-trend in the naphtha price, the restoration of margins consolidated a comeback that started in 2005. All in all, capital expenditure remained fairly low in both the refining and petrochemicals sectors, but many projects are planned for the next ten years. (author)

Possibilities and limitations of parametric Rietveld refinement on high pressure data. The case study of LaFeO3

International Nuclear Information System (INIS)

Etter, Martin; Mueller, Melanie; Dinnebier, Robert E.; Hanfland, Michael

2014-01-01

Parametric Rietveld refinement is a powerful technique to apply directly physical or empirical equations to the refinement of in situ powder diffraction data. In order to investigate the possibilities and limitations of parametric Rietveld refinements for high pressure data four competitive crystallographic approaches were used to carry out a full structural investigation of the orthoferrite LaFeO 3 (Pbnm at ambient conditions) under high pressure up to 47 GPa. Approach A with traditional Rietveld refinement using atomic coordinates, Approach B where the Rietveld refinement was done by using the rigid body method, Approach C where symmetry modes were used and Approach D where the newly developed method of the rotational symmetry mode description for a rigid body was used. For all approaches sequential as well as parametric refinements were carried out, confirming a second order phase transition of LaFeO 3 to a higher symmetric phase (space group Ibmm) at around 21.1?GPa and an isostructural first order phase transition at around 38 GPa. Limitations due to non-hydrostatic conditions as well as the possibilities of a direct modeling of phase transitions with parametric Rietveld refinement are discussed in detail. (orig.)

Twinning processes in Cu-Al-Ni martensite single crystals investigated by neutron single crystal diffraction method

International Nuclear Information System (INIS)

Molnar, P.; Sittner, P.; Novak, V.; Lukas, P.

2008-01-01

A neutron single crystal diffraction method for inspecting the quality of martensite single crystals is introduced. True interface-free martensite single crystals are indispensable for, e.g. measurement of elastic constants of phases by ultrasonic techniques. The neutron diffraction method was used to detect and distinguish the presence of individual lattice correspondence variants of the 2H orthorhombic martensite phase in Cu-Al-Ni as well as to follow the activity of twinning processes during the deformation test on the martensite variant single crystals. When preparing the martensite single variant prism-shaped crystals by compression deformation method, typically a small fraction of second unwanted martensitic variant (compound twin) remains in the prism samples. Due to the very low stress (∼1 MPa) for the compound twinning in many shape memory alloys, it is quite difficult not only to deplete the martensite prisms of all internal interfaces but mainly to keep them in the martensite single variant state for a long time needed for further investigations

Refining margins: recent trends

International Nuclear Information System (INIS)

Baudoin, C.; Favennec, J.P.

1999-01-01

Despite a business environment that was globally mediocre due primarily to the Asian crisis and to a mild winter in the northern hemisphere, the signs of improvement noted in the refining activity in 1996 were borne out in 1997. But the situation is not yet satisfactory in this sector: the low return on invested capital and the financing of environmental protection expenditure are giving cause for concern. In 1998, the drop in crude oil prices and the concomitant fall in petroleum product prices was ultimately rather favorable to margins. Two elements tended to put a damper on this relative optimism. First of all, margins continue to be extremely volatile and, secondly, the worsening of the economic and financial crisis observed during the summer made for a sharp decline in margins in all geographic regions, especially Asia. Since the beginning of 1999, refining margins are weak and utilization rates of refining capacities have decreased. (authors)

Panorama 2009 - refining

International Nuclear Information System (INIS)

2008-01-01

For oil companies to invest in new refining and conversion capacity, favorable conditions over time are required. In other words, refining margins must remain high and demand sustained over a long period. That was the situation prevailing before the onset of the financial crisis in the second half of 2008. The economic conjuncture has taken a substantial turn for the worse since then and the forecasts for 2009 do not look bright. Oil demand is expected to decrease in the OECD countries and to grow much more slowly in the emerging countries. It is anticipated that refining margins will fall in 2009 - in 2008, they slipped significantly in the United States - as a result of increasingly sluggish demand, especially for light products. The next few months will probably be unfavorable to investment. In addition to a gloomy business outlook, there may also be a problem of access to sources of financing. As for investment projects, a mainstream trend has emerged in the last few years: a shift away from the regions that have historically been most active (the OECD countries) towards certain emerging countries, mostly in Asia or the Middle East. The new conjuncture will probably not change this trend

Operator Product Formulas in the Algebraic Approach of the Refined Topological Vertex

International Nuclear Information System (INIS)

Cai Li-Qiang; Wang Li-Fang; Wu Ke; Yang Jie

2013-01-01

The refined topological vertex of Iqbal—Kozçaz—Vafa has been investigated from the viewpoint of the quantum algebra of type W 1+∞ by Awata, Feigin, and Shiraishi. They introduced the trivalent intertwining operator Φ which is normal ordered along with some prefactors. We manage to establish formulas from the infinite operator product of the vertex operators and the generalized ones to restore this prefactor, and obtain an explicit formula for the vertex realization of the topological vertex as well as the refined topological vertex

Studies on the sedimentation and agglomeration behavior of Al-Ti-B and Al-Ti-C grain refiners

Energy Technology Data Exchange (ETDEWEB)

Gazanion, F.; Chen, X.G.; Dupuis, C. [Alcan International Ltd., Jonquiere, PQ (Canada). Arvida Research and Development Centre

2002-07-01

The sedimentation and agglomeration behavior of Al-Ti-B and Al-Ti-C grain refiners in liquid aluminum has been investigated using the LiMCA and PoDFA analysis techniques in combination with metallographic examination. The widely used Al-5%Ti-1%B and Al-3%Ti-0.15%C master alloys were chosen. Two aluminum alloys, an AAlxxx (commercially pure metal) and an AA5182 (Al-4.5%Mg) alloy, were prepared with different additions of grain refiners. The difference in particle behavior in liquid aluminum for both refiners is described and briefly analyzed in terms of sensitivity to agglomeration and grain refiner performance. Experimental results indicate that, in comparison with the Al-Ti-B refiner, the Al-Ti-C refiner is detrimentally affected by long holding periods due to the decomposition of TiC particles within the melt. (orig.)

Investigation on Single-Molecule Junctions Based on Current–Voltage Characteristics

Directory of Open Access Journals (Sweden)

Yuji Isshiki

2018-02-01

Full Text Available The relationship between the current through an electronic device and the voltage across its terminals is a current–voltage characteristic (I–V that determine basic device performance. Currently, I–V measurement on a single-molecule scale can be performed using break junction technique, where a single molecule junction can be prepared by trapping a single molecule into a nanogap between metal electrodes. The single-molecule I–Vs provide not only the device performance, but also reflect information on energy dispersion of the electronic state and the electron-molecular vibration coupling in the junction. This mini review focuses on recent representative studies on I–Vs of the single molecule junctions that cover investigation on the single-molecule diode property, the molecular vibration, and the electronic structure as a form of transmission probability, and electronic density of states, including the spin state of the single-molecule junctions. In addition, thermoelectronic measurements based on I–Vs and identification of the charged carriers (i.e., electrons or holes are presented. The analysis in the single-molecule I–Vs provides fundamental and essential information for a better understanding of the single-molecule science, and puts the single molecule junction to more practical use in molecular devices.

Romanian refining industry assesses restructuring

International Nuclear Information System (INIS)

Tanasescu, D.G.

1991-01-01

The Romanian crude oil refining industry, as all the other economic sectors, faces the problems accompanying the transition from a centrally planned economy to a market economy. At present, all refineries have registered as joint-stock companies and all are coordinated and assisted by Rafirom S.A., from both a legal and a production point of view. Rafirom S.A. is a joint-stock company that holds shares in refineries and other stock companies with activities related to oil refining. Such activities include technological research, development, design, transportation, storage, and domestic and foreign marketing. This article outlines the market forces that are expected to: drive rationalization and restructuring of refining operations and define the targets toward which the reconfigured refineries should strive

Action Refinement

NARCIS (Netherlands)

Gorrieri, R.; Rensink, Arend; Bergstra, J.A.; Ponse, A.; Smolka, S.A.

2001-01-01

In this chapter, we give a comprehensive overview of the research results in the field of action refinement during the past 12 years. The different approaches that have been followed are outlined in detail and contrasted to each other in a uniform framework. We use two running examples to discuss

Optimization of Refining Craft for Vegetable Insulating Oil

Science.gov (United States)

Zhou, Zhu-Jun; Hu, Ting; Cheng, Lin; Tian, Kai; Wang, Xuan; Yang, Jun; Kong, Hai-Yang; Fang, Fu-Xin; Qian, Hang; Fu, Guang-Pan

2016-05-01

Vegetable insulating oil because of its environmental friendliness are considered as ideal material instead of mineral oil used for the insulation and the cooling of the transformer. The main steps of traditional refining process included alkali refining, bleaching and distillation. This kind of refining process used in small doses of insulating oil refining can get satisfactory effect, but can't be applied to the large capacity reaction kettle. This paper using rapeseed oil as crude oil, and the refining process has been optimized for large capacity reaction kettle. The optimized refining process increases the acid degumming process. The alkali compound adds the sodium silicate composition in the alkali refining process, and the ratio of each component is optimized. Add the amount of activated clay and activated carbon according to 10:1 proportion in the de-colorization process, which can effectively reduce the oil acid value and dielectric loss. Using vacuum pumping gas instead of distillation process can further reduce the acid value. Compared some part of the performance parameters of refined oil products with mineral insulating oil, the dielectric loss of vegetable insulating oil is still high and some measures are needed to take to further optimize in the future.

Probing the moduli dependence of refined topological amplitudes

Directory of Open Access Journals (Sweden)

I. Antoniadis

2015-12-01

Full Text Available With the aim of providing a worldsheet description of the refined topological string, we continue the study of a particular class of higher derivative couplings Fg,n in the type II string effective action compactified on a Calabi–Yau threefold. We analyse first order differential equations in the anti-holomorphic moduli of the theory, which relate the Fg,n to other component couplings. From the point of view of the topological theory, these equations describe the contribution of non-physical states to twisted correlation functions and encode an obstruction for interpreting the Fg,n as the free energy of the refined topological string theory. We investigate possibilities of lifting this obstruction by formulating conditions on the moduli dependence under which the differential equations simplify and take the form of generalised holomorphic anomaly equations. We further test this approach against explicit calculations in the dual heterotic theory.

Possibilities and limitations of parametric Rietveld refinement on high pressure data. The case study of LaFeO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Etter, Martin; Mueller, Melanie; Dinnebier, Robert E. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Hanfland, Michael [European Synchrotron Radiation Facility (ESRF), Grenoble (France)

2014-04-01

Parametric Rietveld refinement is a powerful technique to apply directly physical or empirical equations to the refinement of in situ powder diffraction data. In order to investigate the possibilities and limitations of parametric Rietveld refinements for high pressure data four competitive crystallographic approaches were used to carry out a full structural investigation of the orthoferrite LaFeO{sub 3} (Pbnm at ambient conditions) under high pressure up to 47 GPa. Approach A with traditional Rietveld refinement using atomic coordinates, Approach B where the Rietveld refinement was done by using the rigid body method, Approach C where symmetry modes were used and Approach D where the newly developed method of the rotational symmetry mode description for a rigid body was used. For all approaches sequential as well as parametric refinements were carried out, confirming a second order phase transition of LaFeO{sub 3} to a higher symmetric phase (space group Ibmm) at around 21.1?GPa and an isostructural first order phase transition at around 38 GPa. Limitations due to non-hydrostatic conditions as well as the possibilities of a direct modeling of phase transitions with parametric Rietveld refinement are discussed in detail. (orig.)

Molecular investigation of evaporation of biodroplets containing single-strand DNA on graphene surface.

Science.gov (United States)

Akbari, Fahimeh; Foroutan, Masumeh

2018-02-14

In this study, the water droplet behaviour of four different types of single-strand DNA with homogeneous base sequence on a graphene substrate during evaporation of the droplet was investigated using molecular dynamics (MD) simulation. The simulation results indicated that the evaporation depended on the DNA sequence. The observed changes can be divided into four parts: (i) vaporization mode, (ii) evaporation flux, (iii) mechanism of single-strand placement on the surface, and (iv) consideration of remaining single strands after evaporation. Our simulation observations indicated different evaporation modes for thymine biodroplets as compared to those for other biodroplets. The evaporation of the thymine biodroplets occurred with an increase in the contact angle, while that of the other biodroplets occur in a constant contact angle mode. Moreover, thymine biodroplets generate the lowest contact line compared to other single strands, and it is always placed far away from the centre of the droplets during evaporation. Investigating variations in the evaporation flux shows that thymine has the highest evaporation flux and guanine has the lowest. Moreover, during initial evaporation, the flux of evaporation increases at the triple point of the biodroplets containing thymine single strands, while it decreases in the other biodroplets. The following observation was obtained from the study of the placement of single strands on the substrate: guanine and thymine interacted slower than other single strands during evaporation with graphene, adenine single strand had a higher folding during evaporation, and guanine single strand showed the lowest end-to-end distance. The investigation of single-strand DNA after evaporation shows that adenine produces the most stable structure at the end of evaporation. In addition, cytosine is the most stretched single-strand DNA due to its lack of internal π-π stacking and hydrogen bonding. Therefore, cytosine single strand is more

Price Relationships in the Petroleum Market: An Analysis of Crude Oil and Refined Product Prices

International Nuclear Information System (INIS)

Asche, Frank; Gjoelberg, Ole; Voelker, Teresa

2001-08-01

In this paper the relationships between crude oil and refined product prices are investigated in a multivariate framework. This allows us to test several (partly competing) assumptions of earlier studies. In particular, we find that the crude oil price is weakly exogenous and that the spread is constant in some but not all relationships. Moreover, the multivariate analysis shows that the link between crude oil prices and several refined product prices implies market integration for these refined products. This is an example of supply driven market integration and producers will change the output mix in response to price changes. (author)

Price relationships in the petroleum market. An analysis of crude oil and refined product prices

International Nuclear Information System (INIS)

Asche, Frank; Gjoelberg, Ole; Volker, Teresa

2003-01-01

In this paper the relationships between crude oil and refined product prices are investigated in a multivariate framework. This allows us to test several (partly competing) assumptions of earlier studies. In particular, we find that the crude oil price is weakly exogenous and that the spread is constant in some but not all relationships. Moreover, the multivariate analysis shows that the link between crude oil prices and several refined product prices implies market integration for these refined products. This is an example of supply driven market integration and producers will change the output mix in response to price changes

Price relationships in the petroleum market: an analysis of crude oil and refined product prices

International Nuclear Information System (INIS)

Asche, F.; Gjoelberg, O.; Voelker, T.

2003-01-01

In this paper the relationships between crude oil and refined product prices are investigated in a multivariate framework. This allows us to test several (partly competing) assumptions of earlier studies. In particular, we find that the crude oil price is weakly exogenous and that the spread is constant in some but not all relationships. Moreover, the multivariate analysis shows that the link between crude oil prices and several refined product prices implies market integration for these refined products. This is an example of supply driven market integration and producers will change the output mix in response to price changes. (author)

Data refinement for true concurrency

Directory of Open Access Journals (Sweden)

Brijesh Dongol

2013-05-01

Full Text Available The majority of modern systems exhibit sophisticated concurrent behaviour, where several system components modify and observe the system state with fine-grained atomicity. Many systems (e.g., multi-core processors, real-time controllers also exhibit truly concurrent behaviour, where multiple events can occur simultaneously. This paper presents data refinement defined in terms of an interval-based framework, which includes high-level operators that capture non-deterministic expression evaluation. By modifying the type of an interval, our theory may be specialised to cover data refinement of both discrete and continuous systems. We present an interval-based encoding of forward simulation, then prove that our forward simulation rule is sound with respect to our data refinement definition. A number of rules for decomposing forward simulation proofs over both sequential and parallel composition are developed.

Effect of B/Ti mass ratio on grain refining of low-titanium aluminum produced by electrolysis

International Nuclear Information System (INIS)

Wang Mingxing; Wang Sanjun; Liu Zhiyong; Liu Zhongxia; Song Tianfu; Zuo Xiurong

2006-01-01

The effect of B/Ti mass ratio on grain refining of the low-titanium aluminum produced by electrolysis was investigated by adding AlB master alloy to the melt of the low-titanium aluminum. The results show that the addition of titanium by electrolysis is an effective way of grain refining of aluminum, and addition of boron to the melt of the low-titanium aluminum can further increase the grain refining efficiency. And the best grain refining efficiency is obtained when the B/Ti mass ratio is 1:10. However, when the B/Ti mass ratio is 1:2.22 (the stoichiometric value for TiB 2 ), the grain refining efficiency vanishes almost completely. It means that all of the solute titanium atoms in the melt of the low-titanium aluminum react with boron atoms that come from AlB master alloy to form TiB 2 particles, and TiB 2 particles have not grain refining ability. The grain refining efficiency seems to increase with addition of more boron to the melt after the B/Ti mass ratio exceeds 1:2.22. But the grain refining efficiency is very poor, and similar to that of pure Al refined by AlB master alloy. It further shows that TiB 2 particles do not participate in grain refining, and that the excess boron atoms in the melt also cannot turn TiB 2 particles into the effective nuclei for aluminum as the solute titanium atoms do

Comparing Syntactic and Semantics Action Refinement

NARCIS (Netherlands)

Goltz, Ursula; Gorrieri, Roberto; Rensink, Arend

The semantic definition of action refinement on labelled configuration structures is compared with the notion of syntactic substitution, which can be used as another notion of action refinement in a process algebraic setting. The comparison is done by studying a process algebra equipped with

Refinement of crystal structures of CaHCl, SrHCl, BaHCl, BaHBr, and BaHI

International Nuclear Information System (INIS)

Beck, H.P.; Limmer, A.

1983-01-01

The structures of CaHCl, SrHCl, BaHBr, BaHCl, and BaHI have been refined using single crystal data. The comparison of the parameters with the corresponding data of isotypic fluorohalide compounds gives a valuable insight into the bonding interactions in this structure type. (author)

Refinement of crystal structures of CaHCl, SrHCl, BaHCl, BaHBr, and BaHI

Energy Technology Data Exchange (ETDEWEB)

Beck, H.P.; Limmer, A. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Inst. fuer Anorganische Chemie)

1983-07-01

The structures of CaHCl, SrHCl, BaHBr, BaHCl, and BaHI have been refined using single crystal data. The comparison of the parameters with the corresponding data of isotypic fluorohalide compounds gives a valuable insight into the bonding interactions in this structure type.

Crystal structure investigations of ZrAsxSey (x>y, x+y≤2) by single crystal neutron diffraction at 300 K, 25 K and 2.3 K

International Nuclear Information System (INIS)

Niewa, Rainer; Czulucki, Andreas; Schmidt, Marcus; Auffermann, Gudrun; Cichorek, Tomasz; Meven, Martin; Pedersen, Bjoern; Steglich, Frank; Kniep, Ruediger

2010-01-01

Large single crystals of ZrAs x Se y (x>y, x+y≤2, PbFCl type of structure, space group P4/nmm) were grown by Chemical Transport. Structural details were studied by single crystal neutron diffraction techniques at various temperatures. One single crystal specimen with chemical composition ZrAs 1.595(3) Se 0.393(1) was studied at ambient temperature (R1=5.10 %, wR2=13.18 %), and a second crystal with composition ZrAs 1.420(3) Se 0.560(1) was investigated at 25 K (R1=2.70%, wR2=5.70 %) and 2.3 K (R1=2.30 %, wR2=4.70 %), respectively. The chemical compositions of the crystals under investigation were determined by wavelength dispersive X-ray spectroscopy. The quantification of trace elements was carried out by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry. According to the crystal structure refinements the crystallographic 2a site is occupied by As, together with a significant amount of vacancies. One of the 2c sites is fully occupied by As and Se (random distribution). With respect to the fractional coordinates of the atoms, the crystal structure determinations based on the data obtained at 25.0 K and 2.3 K did not show significant deviations from ambient temperature results. The temperature dependence of the displacement parameters indicates a static displacement of As on the 2a sites (located on the (0 0 1) planes) for all temperatures. No indications for any occupation of interstitial sites or the presence of vacancies on the Zr (2a) site were found. - Graphical abstract: Large single crystals of ZrAs x Se y grown by Chemical Transport to study structural details as the As-Se order scheme by single crystal neutron diffraction.

Steel refining possibilities in LF

Science.gov (United States)

Dumitru, M. G.; Ioana, A.; Constantin, N.; Ciobanu, F.; Pollifroni, M.

2018-01-01

This article presents the main possibilities for steel refining in Ladle Furnace (LF). These, are presented: steelmaking stages, steel refining through argon bottom stirring, online control of the bottom stirring, bottom stirring diagram during LF treatment of a heat, porous plug influence over the argon stirring, bottom stirring porous plug, analysis of porous plugs disposal on ladle bottom surface, bottom stirring simulation with ANSYS, bottom stirring simulation with Autodesk CFD.

On Syntactic and Semantic Action Refinement

NARCIS (Netherlands)

Hagiya, M.; Goltz, U.; Mitchell, J.C.; Gorrieri, R.; Rensink, Arend

1994-01-01

The semantic definition of action refinement on labelled event structures is compared with the notion of syntactic substitution, which can be used as another notion of action refinement in a process algebraic setting. This is done by studying a process algebra equipped with the ACP sequential

Refinement for Transition Systems with Responses

Directory of Open Access Journals (Sweden)

Marco Carbone

2012-07-01

Full Text Available Motivated by the response pattern for property specifications and applications within flexible workflow management systems, we report upon an initial study of modal and mixed transition systems in which the must transitions are interpreted as must eventually, and in which implementations can contain may behaviors that are resolved at run-time. We propose Transition Systems with Responses (TSRs as a suitable model for this study. We prove that TSRs correspond to a restricted class of mixed transition systems, which we refer to as the action-deterministic mixed transition systems. We show that TSRs allow for a natural definition of deadlocked and accepting states. We then transfer the standard definition of refinement for mixed transition systems to TSRs and prove that refinement does not preserve deadlock freedom. This leads to the proposal of safe refinements, which are those that preserve deadlock freedom. We exemplify the use of TSRs and (safe refinements on a small medication workflow.

Design of Grain Refiners for Aluminium Alloys

Science.gov (United States)

Tronche, A.; Greer, A. L.

The efficiency of a grain refiner can be quantified as the number of grains per nucleant particle in the solidified product. Even for effective refiners in aluminium, such as Al-5Ti-1B, it is known from experiments that efficiencies are very low, at best 10-3 to 102. It is of interest to explore the reasons for such low values, and to assess the prospects for increased efficiency though design of refiners. Recently it has been shown [1] that a simple recalescence-based model can make quantitative predictions of grain size as a function of refiner addition level, cooling rate and solute content. In the model, the initiation of grains is limited by the free growth from nucleant particles, the size distribution of which is very important. The present work uses this model as the basis for discussing the effect of particle size distribution on grain refiner performance. Larger particles (of TiB2 in the case of present interest) promote greater efficiency, as do narrower size distributions. It is shown that even if the size distribution could be exactly specified, compromises would have to be made to balance efficiency (defined as above) with other desirable characteristics of a refiner.

A refinement methodology for object-oriented programs

OpenAIRE

Tafat , Asma; Boulmé , Sylvain; Marché , Claude

2010-01-01

International audience; Refinement is a well-known approach for developing correct-byconstruction software. It has been very successful for producing high quality code e.g., as implemented in the B tool. Yet, such refinement techniques are restricted in the sense that they forbid aliasing (and more generally sharing of data-structures), which often happens in usual programming languages. We propose a sound approach for refinement in presence of aliases. Suitable abstractions of programs are d...

Bauxite Mining and Alumina Refining

Science.gov (United States)

Frisch, Neale; Olney, David

2014-01-01

Objective: To describe bauxite mining and alumina refining processes and to outline the relevant physical, chemical, biological, ergonomic, and psychosocial health risks. Methods: Review article. Results: The most important risks relate to noise, ergonomics, trauma, and caustic soda splashes of the skin/eyes. Other risks of note relate to fatigue, heat, and solar ultraviolet and for some operations tropical diseases, venomous/dangerous animals, and remote locations. Exposures to bauxite dust, alumina dust, and caustic mist in contemporary best-practice bauxite mining and alumina refining operations have not been demonstrated to be associated with clinically significant decrements in lung function. Exposures to bauxite dust and alumina dust at such operations are also not associated with the incidence of cancer. Conclusions: A range of occupational health risks in bauxite mining and alumina refining require the maintenance of effective control measures. PMID:24806720

Grain refinement of an AZ63B magnesium alloy by an Al-1C master alloy

Energy Technology Data Exchange (ETDEWEB)

Yichuan Pan; Xiangfa Liu; Hua Yang [The Key Lab. of Liquid Structure and Heredity of Materials, Shandong Univ., Jinan (China)

2005-12-01

In order to develop a refiner of Mg-Al alloys, an Al-1C (in wt.%) master alloy was synthesized using a casting method. The microstructure and grain-refining performance of the Al-1C master alloy were investigated using X-ray diffraction (XRD), electron probe microanalysis (EPMA) and a grain-refining test. The microstructure of the Al-1C master alloy is composed of {alpha}-Al solid solution, Al{sub 4}C{sub 3} particles, and graphite phases. After grain refinement of AZ63B alloy by the Al-1C master alloy, the mean grain size reached a limit when 2 wt.% Al-C master alloy was added at 800 C and held for 20 min in the melt before casting. The minimum mean grain size is approximately 48 {mu}m at the one-half radius of the ingot and is about 17% of that of the unrefined alloy. The Al-1C master alloy results in better grain refinement than C{sub 2}Cl{sub 6} and MgCO{sub 3} carbon-containing refiners. (orig.)

South Korea - oil refining overview

International Nuclear Information System (INIS)

Hayes, D.

1999-01-01

Following the economic problems of the 1990s, the petroleum refining industry of South Korea underwent much involuntary restructuring in 1999 with respect to takeovers and mergers and these are discussed. The demand for petroleum has now pretty well recovered. The reasons for fluctuating prices in the 1990s, how the new structure should be cushioned against changes in the future, and the potential for South Korea to export refined petroleum, are all discussed

Adaptive Mesh Refinement in CTH

International Nuclear Information System (INIS)

Crawford, David

1999-01-01

This paper reports progress on implementing a new capability of adaptive mesh refinement into the Eulerian multimaterial shock- physics code CTH. The adaptivity is block-based with refinement and unrefinement occurring in an isotropic 2:1 manner. The code is designed to run on serial, multiprocessor and massive parallel platforms. An approximate factor of three in memory and performance improvements over comparable resolution non-adaptive calculations has-been demonstrated for a number of problems

Single-incision total laparoscopic hysterectomy

Directory of Open Access Journals (Sweden)

Sinha Rakesh

2011-01-01

Full Text Available Single-incision laparoscopic surgery is an alternative to conventional multiport laparoscopy. Single-access laparoscopy using a transumbilical port affords maximum cosmetic benefits because the surgical incision is hidden in the umbilicus. The advantages of single-access laparoscopic surgery may include less bleeding, infection, and hernia formation and better cosmetic outcome and less pain. The disadvantages and limitations include longer surgery time, difficulty in learning the technique, and the need for specialized instruments. Ongoing refinement of the surgical technique and instrumentation is likely to expand its role in gynecologic surgery in the future. We perform single-incision total laparoscopic hysterectomy using three ports in the single transumbilical incision.

Price implications for Russia's oil refining

International Nuclear Information System (INIS)

Khartukov, Eugene M.

1998-01-01

Over the past several years, Russia's oil industry has undergone its radical transformation from a wholly state-run and generously subsidized oil distribution system toward a substantially privatized, cash-strapped, and quasi-market ''petropreneurship''. This fully applies to the industry's downstream sector. Still unlike more dynamic E and C operations, the country's refining has turned out better fenced off competitive market forces and is less capable to respond to market imperatives. Consequently, jammed between depressed product prices and persistent feedstock costs, Russian refiners were badly hit by the world oil glut - which has made a radical modernization of the obsolete refining sector clearly a must. (author)

Optimizing refiner operation with statistical modelling

Energy Technology Data Exchange (ETDEWEB)

Broderick, G [Noranda Research Centre, Pointe Claire, PQ (Canada)

1997-02-01

The impact of refining conditions on the energy efficiency of the process and on the handsheet quality of a chemi-mechanical pulp was studied as part of a series of pilot scale refining trials. Statistical models of refiner performance were constructed from these results and non-linear optimization of process conditions were conducted. Optimization results indicated that increasing the ratio of specific energy applied in the first stage led to a reduction of some 15 per cent in the total energy requirement. The strategy can also be used to obtain significant increases in pulp quality for a given energy input. 20 refs., 6 tabs.

Chemical and physical aspects of refining coal liquids

Science.gov (United States)

Shah, Y. T.; Stiegel, G. J.; Krishnamurthy, S.

1981-02-01

Increasing costs and declining reserves of petroleum are forcing oil importing countries to develop alternate energy sources. The direct liquefaction of coal is currently being investigated as a viable means of producing substitute liquid fuels. The coal liquids derived from such processes are typically high in nitrogen, oxygen and sulfur besides having a high aromatic and metals content. It is therefore envisaged that modifications to existing petroleum refining technology will be necessary in order to economically upgrade coal liquids. In this review, compositional data for various coal liquids are presented and compared with those for petroleum fuels. Studies reported on the stability of coal liquids are discussed. The feasibility of processing blends of coal liquids with petroleum feedstocks in existing refineries is evaluated. The chemistry of hydroprocessing is discussed through kinetic and mechanistic studies using compounds which are commonly detected in coal liquids. The pros and cons of using conventional petroleum refining catalysts for upgrading coal liquids are discussed.

Segmental Refinement: A Multigrid Technique for Data Locality

Energy Technology Data Exchange (ETDEWEB)

Adams, Mark [Columbia Univ., New York, NY (United States). Applied Physics and Applied Mathematics Dept.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2014-10-27

We investigate a technique - segmental refinement (SR) - proposed by Brandt in the 1970s as a low memory multigrid method. The technique is attractive for modern computer architectures because it provides high data locality, minimizes network communication, is amenable to loop fusion, and is naturally highly parallel and asynchronous. The network communication minimization property was recognized by Brandt and Diskin in 1994; we continue this work by developing a segmental refinement method for a finite volume discretization of the 3D Laplacian on massively parallel computers. An understanding of the asymptotic complexities, required to maintain textbook multigrid efficiency, are explored experimentally with a simple SR method. A two-level memory model is developed to compare the asymptotic communication complexity of a proposed SR method with traditional parallel multigrid. Performance and scalability are evaluated with a Cray XC30 with up to 64K cores. We achieve modest improvement in scalability from traditional parallel multigrid with a simple SR implementation.

The Development of Petroleum Refining in the World Market Dimensions of Sustainable Development

Directory of Open Access Journals (Sweden)

Alexey S. Shapran

2015-11-01

Full Text Available The development of petroleum refining in the world market dimensions of sustainable development investigated by the author's interpretation of the OECD model "pressure – state – response", where the pressure parameters proposed use – CO2 emissions, the state parameters – indicators of output and foreign trade refining sector; indicators to community response – (GDP eco-intensity. On the basis of economic and mathematical modeling performed of the adaptation and their value for use in the model parameters, performed a quantitative assessment of the relationship between the key requirements for sustainable development and development of the world petroleum refining market. This approach gave to perform a quantitative assessment of the level and impact of individual factors on the development of world petroleum market in countries with different technological structures.

Refractive indices of CaF2 single crystals under elastic shock loading

Science.gov (United States)

Li, Y.; Zhou, X. M.; Liu, C. L.; Luo, S. N.

2017-07-01

Refractive indices and Hugoniots of CaF2 single crystals are investigated by laser displacement interferometry under shock loading below 5 GPa. Birefringence is observed for the [110] loading. We obtain the Hugoniot equation of states for [100], [110] and [111], and refractive indices for these orientations with consideration of their polarization. The measured refractive indices are in reasonable agreement with predictions based on the piezo-optic theory, and are used to refine the elasto-optic coefficients.

Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy

Science.gov (United States)

Cheng Xing; Siqun Wang; George M. Pharr; Leslie H. Groom

2008-01-01

Refined wood fibers of a 54-year-old loblolly pine (Pinus taeda L.) mature wood were investigated by nanoindentation and atomic force microscopy (AFM). The effect of steam pressure, in the range of 2?18 bar, during thermomechanical refining was investigated and the nanomechanical properties and nano- or micro-level damages of the cell wall were...

Grain refinement mechanism in A3003 alloy

International Nuclear Information System (INIS)

Cho, Hoon; Shin, Je-Sik; Lee, Byoung-Soo; Jo, Hyung-Ho

2009-01-01

In the present study, in order to find out an grain refinement mechanism, 0.1wt.% Al-10wt.%Ti master alloy was added into A3003 alloy melt contained in graphite crucible and in alumina crucible, and then the melt holding time at 750 deg. C was systematically changed from 1 min up to 120 min. It is interesting to note that the grain refinement and fading phenomena remarkably depend on the crucible material. The fading effect in the specimens using alumina crucible can be explained as the result of TiAl 3 phase dissolution into molten aluminium matrix. In the specimens using graphite crucible, the grain refinement was occurred gradually with increasing holding time. It was suggest that the continuous grain refinement is due to transition of refinement mechanism from TiAl 3 phase to TiC phase. It can be mentioned that the TiC formed from titanium and carbon solute in the aluminium melt, which came from the Al-10Ti alloy and the graphite crucible.

Refining discordant gene trees.

Science.gov (United States)

Górecki, Pawel; Eulenstein, Oliver

2014-01-01

Evolutionary studies are complicated by discordance between gene trees and the species tree in which they evolved. Dealing with discordant trees often relies on comparison costs between gene and species trees, including the well-established Robinson-Foulds, gene duplication, and deep coalescence costs. While these costs have provided credible results for binary rooted gene trees, corresponding cost definitions for non-binary unrooted gene trees, which are frequently occurring in practice, are challenged by biological realism. We propose a natural extension of the well-established costs for comparing unrooted and non-binary gene trees with rooted binary species trees using a binary refinement model. For the duplication cost we describe an efficient algorithm that is based on a linear time reduction and also computes an optimal rooted binary refinement of the given gene tree. Finally, we show that similar reductions lead to solutions for computing the deep coalescence and the Robinson-Foulds costs. Our binary refinement of Robinson-Foulds, gene duplication, and deep coalescence costs for unrooted and non-binary gene trees together with the linear time reductions provided here for computing these costs significantly extends the range of trees that can be incorporated into approaches dealing with discordance.

Decontamination of steel by melt refining: A literature review

International Nuclear Information System (INIS)

Ozturk, B.; Fruehan, R.J.

1994-01-01

It has been reported that a large amount of metal waste is produced annually by nuclear fuel processing and nuclear power plants. These metal wastes are contaminated with radioactive elements, such as uranium and plutonium. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain level. Because of high cost, it is important to develop an effective decontamination and volume reduction method for low level contaminated metals. It has been shown by some investigators that a melt refining technique can be used for the processing of the contaminated metal wastes. In this process, contaminated metal is melted wit a suitable flux. The radioactive elements are oxidized and transferred to a slag phase. In order to develop a commercial process it is important to have information on the thermodynamics and kinetics of the removal. Therefore, a literature search was carried out to evaluate the available information on the decontamination uranium and transuranic-contaminated plain steel, copper and stainless steel by melt a refining technique. Emphasis was given to the thermodynamics and kinetics of the removal. Data published in the literature indicate that it is possible to reduce the concentration of radioactive elements to a very low level by the melt refining method. 20 refs

Maturation of Cerebellar Purkinje Cell Population Activity during Postnatal Refinement of Climbing Fiber Network

Directory of Open Access Journals (Sweden)

Jean-Marc Good

2017-11-01

Full Text Available Neural circuits undergo massive refinements during postnatal development. In the developing cerebellum, the climbing fiber (CF to Purkinje cell (PC network is drastically reshaped by eliminating early-formed redundant CF to PC synapses. To investigate the impact of CF network refinement on PC population activity during postnatal development, we monitored spontaneous CF responses in neighboring PCs and the activity of populations of nearby CF terminals using in vivo two-photon calcium imaging. Population activity is highly synchronized in newborn mice, and the degree of synchrony gradually declines during the first postnatal week in PCs and, to a lesser extent, in CF terminals. Knockout mice lacking P/Q-type voltage-gated calcium channel or glutamate receptor δ2, in which CF network refinement is severely impaired, exhibit an abnormally high level of synchrony in PC population activity. These results suggest that CF network refinement is a structural basis for developmental desynchronization and maturation of PC population activity.

Basic effects of pulp refining on fiber properties--a review.

Science.gov (United States)

Gharehkhani, Samira; Sadeghinezhad, Emad; Kazi, Salim Newaz; Yarmand, Hooman; Badarudin, Ahmad; Safaei, Mohammad Reza; Zubir, Mohd Nashrul Mohd

2015-01-22

The requirement for high quality pulps which are widely used in paper industries has increased the demand for pulp refining (beating) process. Pulp refining is a promising approach to improve the pulp quality by changing the fiber characteristics. The diversity of research on the effect of refining on fiber properties which is due to the different pulp sources, pulp consistency and refining equipment has interested us to provide a review on the studies over the last decade. In this article, the influence of pulp refining on structural properties i.e., fibrillations, fine formation, fiber length, fiber curl, crystallinity and distribution of surface chemical compositions is reviewed. The effect of pulp refining on electrokinetic properties of fiber e.g., surface and total charges of pulps is discussed. In addition, an overview of different refining theories, refiners as well as some tests for assessing the pulp refining is presented. Copyright © 2014 Elsevier Ltd. All rights reserved.

Efficiency of the refining processes in removing 14C-dichlorvos residues in soybean oil

International Nuclear Information System (INIS)

Soliman, S.M.

2006-01-01

Crude soybean oil extracted from grains treated with 14 C-dichlorvos at a dose 24 mg insecticide / kg seeds and stored for 30 weeks was subjected to different refining processes such as alkali treatment, bleaching, winterization and deodorization. The effect of the refining processes on the nature and magnitude of the originally present residues was investigated. The insecticide residues in crude oil and cake amounted to 9.5% and 55% , respectively, of original residues inside the seeds. Extraction of the seeds with hexane gave crude oil with 9.5 % of original residues in seeds. The l4 C-activity in the crude stored Soya beans oil could be reduced by about 82% of radioactivity originally present in crude oil eliminated by simulated commercial processes locally used for oil refining. A high percentage of the residues (50-55%) were eliminated during alkali treatment and bleaching. Refining of soybeans oil fortified with '1 4 C-dichlorovos. The final refined oil had only 13% of the radioactivity originally present, mainly in the form of dichlorvos, dimethyl and monomethyl phosphate in addition to desmethyl dichlorvos in oil with aged residues

Effect of grain refinement on the microstructure and tensile properties of thin 319 Al castings

International Nuclear Information System (INIS)

Shabani, M.J.; Emamy, M.; Nemati, N.

2011-01-01

The structural examinations and tensile properties of thin-section Al castings (319 Al alloy) have been investigated by applying a pattern with different cross sections (2-12 mm). Al-5Ti-1B and Al-5Zr grain refiners were added to the molten Al alloy to produce different levels of Ti (0.01%, 0.05%, 0.1% and 0.15%) and Zr (0.05%, 0.1%, 0.2%, 0.3%, 0.4% and 0.5%) in the castings. From macrostructural studies, it was found that Al-5Zr is less effective in grain refining of 319 alloy in comparison with Al-5Ti-1B master alloy. The optimum levels of grain refiners were selected for determination of tensile properties. T6 heat treatment was applied for selected specimens before tensile testing. Further structural results also showed that thinner sections are less affected by grain refiners. This observation was found to be in a good agreement with tensile test results, where tensile properties of the base and grain refined alloys did not show considerable differences in thinner sections (<6 mm).

Oil refining expansion criteria for Brazil

International Nuclear Information System (INIS)

Tavares, M.E.E.; Szklo, A.S.; Machado, G.V.; Schaeffer, R.; Mariano, J.B.; Sala, J.F.

2006-01-01

This paper assesses different strategies for the expansion of Brazil's oil refining segment, using criteria that range from energy security (reducing imports and vulnerability for key products) through to maximizing the profitability of this sector (boosting the output of higher value oil products) and adding value to Brazil's oil production (reducing exports of heavy acid oil). The development prospects are analyzed for conventional fuel production technology routes, sketching out three possible refining schemes for Brazilian oil and a GTL plant for producing gasoil from natural gas. Market scenario simulations indicate that investments will be required in Brazil's oil refining segment over and above those allocated to planned modifications in its current facilities, reducing the nation's vulnerability in terms of gasoil and petrochemical naphtha imports. Although not economically attractive, oil refining is a key activity that is crucial to oil company strategies. The decision to invest in this segment depends on local infrastructure conditions, environmental constraints and fuel specifications, in addition to oil company strategies, steady growth in demand and the definition of a government policy that eases institutional risks. (author)

Oil refining expansion criteria for Brazil

International Nuclear Information System (INIS)

Tavares, Marina Elisabete Espinho; Szklo, Alexandre Salem; Machado, Giovani Vitoria; Schaeffer, Roberto; Mariano, Jacqueline Barboza; Sala, Janaina Francisco

2006-01-01

This paper assesses different strategies for the expansion of Brazil's oil refining segment, using criteria that range from energy security (reducing imports and vulnerability for key products) through to maximizing the profitability of this sector (boosting the output of higher value oil products) and adding value to Brazil's oil production (reducing exports of heavy acid oil). The development prospects are analyzed for conventional fuel production technology routes, sketching out three possible refining schemes for Brazilian oil and a GTL plant for producing gasoil from natural gas. Market scenario simulations indicate that investments will be required in Brazil's oil refining segment over and above those allocated to planned modifications in its current facilities, reducing the nation's vulnerability in terms of gasoil and petrochemical naphtha imports. Although not economically attractive, oil refining is a key activity that is crucial to oil company strategies. The decision to invest in this segment depends on local infrastructure conditions, environmental constraints and fuel specifications, in addition to oil company strategies, steady growth in demand and the definition of a government policy that eases institutional risks

Refinement of homology-based protein structures by molecular dynamics simulation techniques

NARCIS (Netherlands)

Fan, H; Mark, AE

The use of classical molecular dynamics simulations, performed in explicit water, for the refinement of structural models of proteins generated ab initio or based on homology has been investigated. The study involved a test set of 15 proteins that were previously used by Baker and coworkers to

Structure refinement of Ag-free heyrovskýite from Vulcano (Aeolian Islands, Italy)

DEFF Research Database (Denmark)

Pinto, Daniella; Balic Zunic, Tonci; Garavelli, Anna

2011-01-01

The first single-crystal structure refinement of Ag- and Cu-free heyrovskýite was performed in this study. Crystals investigated were sampled from the high-temperature fumaroles of La Fossa crater of Vulcano, Aeolian Islands, Italy. Electron microprobe analyses gave the average chemical formula (Pb...... with Fo > 4s(Fo). In Ag-free heyrovskýite from Vulcano, as well as in the synthetic Pb6Bi2S9, the trigonal prismatic coordinated position Me1, as well as the octahedrally coordinated position Me3 are occupied only by Pb. Me2, also octahedrally coordinated, is dominated by Pb, whereas the octahedra...... the ideal composition, Pb6Bi2S9. Selenium is preferentially ordered at the fivefold-coordinated anionic sites. Taking into account vacancies, as well as Se for S substitutions the structural formula of Ag-free heyrovskýite from Vulcano is Pb5.82Bi2.12¿0.06S8.70Se0.30. Comparison with the Ag...

Investigations of Intelligent Solar Heating Systems for Single Family House

DEFF Research Database (Denmark)

Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

2014-01-01

Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank is a......, the control strategy of intelligent solar heating systems is investigated and the yearly auxiliary energy use of the systems and the electricity price for supplying the consumers with domestic hot water and space heating are calculated....... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys......Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank...

Refined large N duality for knots

DEFF Research Database (Denmark)

Kameyama, Masaya; Nawata, Satoshi

We formulate large N duality of U(N) refined Chern-Simons theory with a torus knot/link in S³. By studying refined BPS states in M-theory, we provide the explicit form of low-energy effective actions of Type IIA string theory with D4-branes on the Ω-background. This form enables us to relate...

Refinement of the ferri and paramagnetic phases of magnetite measured by neutron multiple diffraction

International Nuclear Information System (INIS)

Mazzochi, V.L.; Parente, C.B.R.

1989-10-01

Structural parameters of the ferri and paramagnetic phases of magnetite have been refined from neutron multiple diffraction data. Experimental patterns were obtained by measuring the III primary reflection of a natural single crystal of this compound, at room temperature for the ferrimagnetic phase and 703 0 C for the paramagnetic phase. Theoretical multiple diffraction patterns for both phases have been calculated by the program MULTI which uses the iterative method. In this method intensities are caluclated as Taylor series expansions summed up to a order sufficient for a good approximation. A step by step process has been used in the refinements similarly to the parameter-shift method. Final values for the discrepancy factor found for the ferri and paramagnetic phases were R = 3.96% and R = 3.46%, respectively. (author) [pt

Region-of-interest volumetric visual hull refinement

KAUST Repository

Knoblauch, Daniel; Kuester, Falko

2010-01-01

This paper introduces a region-of-interest visual hull refinement technique, based on flexible voxel grids for volumetric visual hull reconstructions. Region-of-interest refinement is based on a multipass process, beginning with a focussed visual

Refining Students' Explanations of an Unfamiliar Physical Phenomenon-Microscopic Friction

Science.gov (United States)

Corpuz, Edgar De Guzman; Rebello, N. Sanjay

2017-08-01

The first phase of this multiphase study involves modeling of college students' thinking of friction at the microscopic level. Diagnostic interviews were conducted with 11 students with different levels of physics backgrounds. A phenomenographic approach of data analysis was used to generate categories of responses which subsequently were used to generate a model of explanation. Most of the students interviewed consistently used mechanical interactions in explaining microscopic friction. According to these students, friction is due to the interlocking or rubbing of atoms. Our data suggest that students' explanations of microscopic friction are predominantly influenced by their macroscopic experiences. In the second phase of the research, teaching experiment was conducted with 18 college students to investigate how students' explanations of microscopic friction can be refined by a series of model-building activities. Data were analyzed using Redish's two-level transfer framework. Our results show that through sequences of hands-on and minds-on activities, including cognitive dissonance and resolution, it is possible to facilitate the refinement of students' explanations of microscopic friction. The activities seemed to be productive in helping students activate associations that refine their ideas about microscopic friction.

Impact of Crude Oil Quality on the Refining Conditions and Composition of Nutraceuticals in Refined Palm Oil.

Science.gov (United States)

Sampaio, Klicia A; Ayala, Jose Vila; Van Hoed, Vera; Monteiro, Simone; Ceriani, Roberta; Verhé, Roland; Meirelles, Antonio J A

2017-08-01

Palm oil is the major vegetable oil used worldwide due to its unique properties. The effect of crude palm oil acidity on the final free fatty acids (FFA) content, neutral oil loss (NOL), and nutraceutical compounds, such as carotenes, total tocols (tocopherols and tocotrienols), squalene, and phytosterols was investigated. A central composite design was employed to study the influence of the refining conditions: temperature (200 to 260 °C), steam percentage (0.5% to 3.5%), and initial FFA content (2.2% to 6.0%) on the quality of the refined product. The results revealed that initial palm oil acidity is a statistically important parameter to obtain commercially acceptable values for final FFA content. The increase of temperature presented the most important effect on the reduction of all nutraceutical compounds. The highest tocopherols (88%), phytosterols (98%), and squalene retention (84%) was obtained when applying the mildest temperature (200 °C). From the experimental results, 3 equations were generated enabling the prediction of the free fatty acids content, the tocols content, and the losses of neutral oil. Therefore, this work contributes to the understanding and optimization of the process for the production of palm oil with high nutraceutical quality and low free fatty acid contents. © 2017 Institute of Food Technologists®.

US refining reviewed

International Nuclear Information System (INIS)

Yamaguchi, N.D.

1998-01-01

The paper reviews the history, present position and future prospects of the petroleum industry in the USA. The main focus is on supply and demand, the high quality of the products, refinery capacity and product trade balances. Diagrams show historical trends in output, product demand, demand for transport fuels and oil, refinery capacity, refinery closures, and imports and exports. Some particularly salient points brought out were (i) production of US crude shows a marked downward trend but imports of crude will continue to increase, (ii) product demand will continue to grow even though the levels are already high, (iii) the demand is dominated by those products that typically yield the highest income for the refiner, (i.e. high quality transport fuels for environmental compliance), (iv) refinery capacity has decreased since 1980 and (v) refining will continue to have financial problems but will still be profitable. (UK)

Investigations of morphological changes during annealing of polyethylene single crystals

NARCIS (Netherlands)

Tian, M.; Loos, J.

2001-01-01

The morphological evolution of isolated individual single crystals deposited on solid substrates was investigated during annealing experiments using in situ and ex situ atomic force microscopy techniques. The crystal morphology changed during annealing at temperatures slightly above the original

Single Shell Tank (SST) Program Plan

International Nuclear Information System (INIS)

HAASS, C.C.

2000-01-01

This document provides an initial program plan for retrieval of the single-shell tank waste. Requirements, technical approach, schedule, organization, management, and cost and funding are discussed. The program plan will be refined and updated in fiscal year 2000

Single Shell Tank (SST) Program Plan

Energy Technology Data Exchange (ETDEWEB)

HAASS, C.C.

2000-03-21

This document provides an initial program plan for retrieval of the single-shell tank waste. Requirements, technical approach, schedule, organization, management, and cost and funding are discussed. The program plan will be refined and updated in fiscal year 2000.

Future of French refining

International Nuclear Information System (INIS)

Calvet, B.

1993-01-01

Over recent years, the refining industry has had to grapple with a growing burden of environmental and safety regulations concerning not only its plants and other facilities, but also its end products. At the same time, it has had to bear the effects of the reduction of the special status that used to apply to petroleum, and the consequences of economic freedom, to which we should add, as specifically concerns the French market, the impact of energy policy and the pro-nuclear option. The result is a drop in heavy fuel oil from 36 million tonnes per year in 1973 to 6.3 million in 1992, and in home-heating fuel from 37 to 18 million per year. This fast-moving market is highly competitive. The French market in particular is wide open to imports, but the refining companies are still heavy exporters for those products with high added-value, like lubricants, jet fuel, and lead-free gasolines. The competition has led the refining companies to commit themselves to quality, and to publicize their efforts in this direction. This is why the long-term perspectives for petroleum fuels are still wide open. This is supported by the probable expectation that the goal of economic efficiency is likely to soften the effects of the energy policy, which penalizes petroleum products, in that they have now become competitive again. In the European context, with the challenge of environmental protection and the decline in heavy fuel outlets, French refining has to keep on improving the quality of its products and plants, which means major investments. The industry absolutely must return to a more normal level of profitability, in order to sustain this financial effort, and generate the prosperity of its high-performance plants and equipment. 1 fig., 5 tabs

The evolution of oil refining in Europe

Energy Technology Data Exchange (ETDEWEB)

Reid, A. [CONCAWE, Brussels (Belgium)

2013-04-01

Back in 1963 when CONCAWE was founded, the world looked very different from what it is today, and so did the global and European refining industry. Oil product markets were expanding fast and new refineries were being built at a steady rate. The oil crisis of the 1970s brought an abrupt end to this, heralding a long era of consolidation and stepwise adaptation. At the same time the nature of the global oil business shifted from fully integrated companies producing, transporting and refining their own oil to a much more diversified situation where oil production ('upstream') and refining/distribution ('downstream') gradually became two essentially separate businesses. From being purely a 'cost centre' in an integrated chain, refining has become a separate activity in its own right, operating as a 'profit centre' between two global markets - crude oil and products - which, although not entirely independent, have their own dynamics and influences. In addition demand gradually shifted towards lighter products while the quality requirements on all products were considerably tightened. This article explores the new challenges that these changes have imposed on EU refiners, and describes CONCAWE's contributions to understanding their impact on refinery production and investments.

Filled pause refinement based on the pronunciation probability for lecture speech.

Directory of Open Access Journals (Sweden)

Yan-Hua Long

Full Text Available Nowadays, although automatic speech recognition has become quite proficient in recognizing or transcribing well-prepared fluent speech, the transcription of speech that contains many disfluencies remains problematic, such as spontaneous conversational and lecture speech. Filled pauses (FPs are the most frequently occurring disfluencies in this type of speech. Most recent studies have shown that FPs are widely believed to increase the error rates for state-of-the-art speech transcription, primarily because most FPs are not well annotated or provided in training data transcriptions and because of the similarities in acoustic characteristics between FPs and some common non-content words. To enhance the speech transcription system, we propose a new automatic refinement approach to detect FPs in British English lecture speech transcription. This approach combines the pronunciation probabilities for each word in the dictionary and acoustic language model scores for FP refinement through a modified speech recognition forced-alignment framework. We evaluate the proposed approach on the Reith Lectures speech transcription task, in which only imperfect training transcriptions are available. Successful results are achieved for both the development and evaluation datasets. Acoustic models trained on different styles of speech genres have been investigated with respect to FP refinement. To further validate the effectiveness of the proposed approach, speech transcription performance has also been examined using systems built on training data transcriptions with and without FP refinement.

A combined temperature-dependent electron and single-crystal X-ray diffraction study of the fresnoite compound Rb2V4+V25+O8

International Nuclear Information System (INIS)

Withers, R.L.; Hoeche, Thomas; Liu Yun; Esmaeilzadeh, Saeid; Keding, Ralf; Sales, Brian

2004-01-01

High-purity Rb 2 V 3 O 8 has been grown and temperature-dependent electron and single-crystal X-ray diffraction used to carefully investigate its fresnoite-type reciprocal lattice. In contrast to other recently investigated representatives of the fresnoite family of compounds, Rb 2 V 3 O 8 is not incommensurately modulated with an incommensurate basal plane primary modulation wave vector given by q∼0.3 *. A careful low-temperature electron diffraction study has, however, revealed the existence of weak incommensurate satellite reflections characterized by the primitive primary modulation wave vector q 1 ∼0.16c*. The reciprocal space positioning of these incommensurate satellite reflections, the overall (3+1)-d superspace group symmetry, as well as the shapes of the refined displacement ellipsoids determined from single-crystal XRD refinement, are all consistent with their arising from a distinct type of condensed rigid unit modes (RUMs) of distortion of the Rb 2 V 3 O 8 parent structure

Refining of raw materials, lignite present economic problems

Energy Technology Data Exchange (ETDEWEB)

Schirmer, G.

1985-06-01

East Germany seeks an economic intensification program that involves refining raw materials to a higher level. Lignite briquetting prior to liquefaction and gasification illustrates both the theoretical and practical aspects of that goal and also introduces questions of secure supplies. The author describes the special labor processes, use of technology, recycling of waste materials, and other new problems that the approach entails as the refined raw materials become new materials or energy sources. Economics based on the value of the refined product and the cost of the materials determine the degree of refinement. The concept also involves the relationship of producer and user as profits increase.

TITANIUM CARBON ALUMINIUM : A NOVEL GRAIN REFINER FOR ALUMINIUM-LITHIUM ALLOYS

OpenAIRE

Birch , M.; Cowell , A.

1987-01-01

This work explores the possibility of achieving grain size control in aluminium-lithium alloys with the titanium carbon aluminium (TiCAl) master alloys invented at the Technical University of Berlin and developed by London and Scandinavian Metallurgical Co Ltd (LSM). Grain refining tests were conducted on a single batch of 8090 alloy using addition rates of 0.2wt% and 0.4wt% of TiCAl and 3/1 titanium boron aluminium (TiBAl). Other tests using 0.4wt% of binary TiAl gave poor results, showing t...

Refining's-clean new jingle

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that at a time when profit margins are slim and gasoline demand is down, the U.S. petroleum-refining industry is facing one of its greatest challenges; How to meet new federal and state laws for reformulated gasoline, oxygenated fuels, low-sulfur diesel and other measures to improve the environment. The American Petroleum Institute (API) estimates that industry will spend between $15 and $23 billion by the end of the decade to meet the U.S. Clean Air Act Amendments (CAAA) of 1990, and other legislation. ENSR Consulting and Engineering's capital-spending figure runs to between $70 and 100 billion this decade, including $24 billion to produce reformulated fuels and $10-12 billion to reduce refinery emissions. M.W. Kellogg Co. estimates that refiners may have to spend up to $30 billion this decade to meet the demand for reformulated gasoline. The estimates are wide-ranging because refiners are still studying their options and delaying final decisions as long as they can, to try to ensure they are the best and least-costly decisions. Oxygenated fuels will be required next winter, but federal regulations for reformulated gasoline won't go into effect until 1995, while California's tougher reformulated-fuels law will kick in the following year

Refinement Checking on Parametric Modal Transition Systems

DEFF Research Database (Denmark)

Benes, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

2015-01-01

Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects in the refin...

Refining the statistical model for quantitative immunostaining of surface-functionalized nanoparticles by AFM.

Science.gov (United States)

MacCuspie, Robert I; Gorka, Danielle E

2013-10-01

Recently, an atomic force microscopy (AFM)-based approach for quantifying the number of biological molecules conjugated to a nanoparticle surface at low number densities was reported. The number of target molecules conjugated to the analyte nanoparticle can be determined with single nanoparticle fidelity using antibody-mediated self-assembly to decorate the analyte nanoparticles with probe nanoparticles (i.e., quantitative immunostaining). This work refines the statistical models used to quantitatively interpret the observations when AFM is used to image the resulting structures. The refinements add terms to the previous statistical models to account for the physical sizes of the analyte nanoparticles, conjugated molecules, antibodies, and probe nanoparticles. Thus, a more physically realistic statistical computation can be implemented for a given sample of known qualitative composition, using the software scripts provided. Example AFM data sets, using horseradish peroxidase conjugated to gold nanoparticles, are presented to illustrate how to implement this method successfully.

Japan's refiner/marketers headed for major shakeout

International Nuclear Information System (INIS)

Anon.

1996-01-01

Japan's downstream oil industry is in a state of crisis and headed for a major shakeout. The major catalyst for this was a dramatic deregulation step during April 1996 that allowed refined petroleum product imports by non-refiners. The move, together with a sharp drop in refining margins, falling retail gasoline prices, and a service station sector on the brink of collapse, are all leading to massive changes in the way the country's refiners and marketers do business. This paper reviews the collapse of corporate profits during this period of deregulation; the development of a new price system geared toward bringing the prices of gasoline, fuel oil, and kerosene into line with each other to offset the fall in gasoline prices; and industry restructuring including mergers, acquisitions, and marketing consolidation. The paper then makes predictions on the outcome of these changes on the Japanese oil industry

Pilot scale refinning of crude soybean oil | Mensah | Journal of ...

African Journals Online (AJOL)

Pilot scale refinning of crude soybean oil. ... Abstract. A laboratory process for refining soybean has been scaled up to a 145 tonne per annum pilot plant to refine crude soybean oil. ... The quality of the refined oil was found to be within national and codex standard specifications for edible oil from vegetable sources.

Cavitation-aided grain refinement in aluminium alloys

NARCIS (Netherlands)

Atamanenko, T.V.

2010-01-01

This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the

Refined Exploration of Turbofan Design Options for an Advanced Single-Aisle Transport

Science.gov (United States)

Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.

2011-01-01

A comprehensive exploration of the turbofan engine design space for an advanced technology single-aisle transport (737/A320 class aircraft) was conducted previously by the authors and is documented in a prior report. Through the course of that study and in a subsequent evaluation of the approach and results, a number of enhancements to the engine design ground rules and assumptions were identified. A follow-on effort was initiated to investigate the impacts of these changes on the original study results. The fundamental conclusions of the prior study were found to still be valid with the revised engine designs. The most significant impact of the design changes was a reduction in the aircraft weight and block fuel penalties incurred with low fan pressure ratio, ultra-high bypass ratio designs. This enables lower noise levels to be pursued (through lower fan pressure ratio) with minor negative impacts on aircraft weight and fuel efficiency. Regardless of the engine design selected, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

Basic investigations to improve the refinement process of coal. Grundlagenuntersuchungen zur Erhoehung des Veredlungsverhaltens von Kohlen

Energy Technology Data Exchange (ETDEWEB)

Krug, H; Naundorf, W; Trommer, D

1985-01-01

In the four articles in this issue, variants of the process for the effective use and improved refinement of brown coal are described. There are reports on the manufacture of special briquettes from briquette coal slack and on the briquetting behaviour of dry brown coal dust and the briquetting and coking behaviour of hard foreign brown coal containing a lot of ash. The four articles are dealt with separately. With 52 figs., 10 tabs.

High-pressure single-crystal neutron diffraction (to 20 kbar) using a pulsed source: Preliminary investigation of Tl3PSe4

International Nuclear Information System (INIS)

Alkire, R.W.; Larson, A.C.; Vergamini, P.J.; Schirber, J.E.; Morosin, B.

1985-01-01

A new technique is described for performing high-pressure single-crystal neutron diffraction [up to 20 kbar (2GPa) at room temperature], using a BeCu pressure cell, an area detector and the Los Alamos National Laboratory pulsed neutron source. Success of this method depends on the increase in information available with a multi-wavelength pulse neutron source, a novel orientation of a cylindrically symmetric pressure cell with its axis coincident with the neutron beam and a specific crystal orientation within the pressure cell. Bragg scattering from the pressure cell is avoided and background for a given 2theta is constant. For a crystal of orthorhombic or higher symmetry oriented with the incident beam passing midway between the major lattice vectors, it will be possible to refine a complete three-dimensional structure with data collected from only one pressure loading. Preliminary investigations of Tl 3 PSe 4 lattice parameters (space group Pcmn) at 15(1)kbar yielded linear compressibilities (. 1000 in kbar -1 ) of Ksub(a) = 1.05(8), Ksub(b) = 1.50(10), Ksub(c) = 1.20(8). The anisotropic compressibility is explained by examination of the ambient-pressure room-temperature structure. (orig.)

Optimization bitumen-based upgrading and refining schemes

Energy Technology Data Exchange (ETDEWEB)

Munteanu, M.; Chen, J. [National Centre for Upgrading Technology, Devon, AB (Canada); Natural Resources Canada, Devon, AB (Canada). CanmetENERGY

2009-07-01

This poster highlighted the results of a study in which the entire refining scheme for Canadian bitumen as feedstocks was modelled and simulated under different process configurations, operating conditions and product structures. The aim of the study was to optimize the economic benefits, product quality and energy use under a range of operational scenarios. Optimal refining schemes were proposed along with process conditions for existing refinery configurations and objectives. The goal was to provide guidelines and information for upgrading and refining process design and retrofitting. Critical steps were identified with regards to the upgrading process. It was concluded that the information obtained from this study would lead to significant improvement in process performance and operations, and in reducing the capital cost for building new upgraders and refineries. The simulation results provided valuable information for increasing the marketability of bitumen, reducing greenhouse gas emissions and other environmental impacts associated with bitumen upgrading and refining. tabs., figs.

1991 worldwide refining and gas processing directory

International Nuclear Information System (INIS)

Anon.

1990-01-01

This book ia an authority for immediate information on the industry. You can use it to find new business, analyze market trends, and to stay in touch with existing contacts while making new ones. The possibilities for business applications are numerous. Arranged by country, all listings in the directory include address, phone, fax and telex numbers, a description of the company's activities, names of key personnel and their titles, corporate headquarters, branch offices and plant sites. This newly revised edition lists more than 2000 companies and nearly 3000 branch offices and plant locations. This east-to-use reference also includes several of the most vital and informative surveys of the industry, including the U.S. Refining Survey, the Worldwide Construction Survey in Refining, Sulfur, Gas Processing and Related Fuels, the Worldwide Refining and Gas Processing Survey, the Worldwide Catalyst Report, and the U.S. and Canadian Lube and Wax Capacities Report from the National Petroleum Refiner's Association

A Macdonald refined topological vertex

Science.gov (United States)

Foda, Omar; Wu, Jian-Feng

2017-07-01

We consider the refined topological vertex of Iqbal et al (2009 J. High Energy Phys. JHEP10(2009)069), as a function of two parameters ≤ft\\lgroup x, y \\right\\rgroup , and deform it by introducing the Macdonald parameters ≤ft\\lgroup q, t \\right\\rgroup , as in the work of Vuletić on plane partitions (Vuletić M 2009 Trans. Am. Math. Soc. 361 2789-804), to obtain ‘a Macdonald refined topological vertex’. In the limit q → t , we recover the refined topological vertex of Iqbal et al and in the limit x → y , we obtain a qt-deformation of the original topological vertex of Aganagic et al (2005 Commun. Math. Phys. 25 425-78). Copies of the vertex can be glued to obtain qt-deformed 5D instanton partition functions that have well-defined 4D limits and, for generic values of ≤ft\\lgroup q, t\\right\\rgroup , contain infinite-towers of poles for every pole present in the limit q → t .

Microstructure and grain refining performance of melt-spun Al-5Ti-1B master alloy

International Nuclear Information System (INIS)

Zhang Zhonghua; Bian Xiufang; Wang Yan; Liu Xiangfa

2003-01-01

In the present work, the microstructure and grain refining performance of the melt-spun Al-5Ti-1B (wt%) master alloy have been investigated, using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and grain refining tests. It has been found that the microstructure of the melt-spun Al-5Ti-1B master alloy is mainly composed of two phases: metastable, supersaturated α-Al solid solution and uniformly dispersed TiB 2 particles, quite different from that of the rod-like alloy consisting of three phases: α-Al, blocky TiAl 3 , and clusters of TiB 2 particles. Quenching temperatures and wheel speeds (cooling rates), however, have no obvious effect on the microstructure of the melt-spun Al-5Ti-1B alloy. Grain refining tests show that rapid solidification has a significant effect on the grain refining performance of Al-5Ti-1B alloy and leads to the great increase of nucleation rate of the alloy. Nevertheless, the melt-spun Al-5Ti-1B master alloy prepared at different wheel speeds and quenching temperatures possesses the similar grain refining performance. The reasons for the microstructure formation and the improvement of the grain refining performance of the melt-spun Al-5Ti-1B master alloy have been also discussed

Influence of titanium–boron additions on grain refinement of AA6082 gas tungsten arc welds

International Nuclear Information System (INIS)

Kishore Babu, N.; Talari, Mahesh Kumar; Dayou, Pan; Zheng, Sun; Jun, Wei; SivaPrasad, K.

2012-01-01

Highlights: ► Ti in the weld metal resulted in grain refinement due to growth restriction effect. ► Weld metal strength improved due to grain refinement caused by Tibor™ addition. ► Weld metal responded to post-weld ageing treatment due to dilution from base metal. ► Weld metal with AA5356 filler are stronger then AA4043 for all Tibor™ additions. -- Abstract: Grain refinement of weld metal plays a vital role in improving mechanical properties (ductility and toughness) as well as weldability. The present study has investigated the influence of Tibor™ additions on the structure and mechanical properties of AA6082 gas tungsten arc (GTA) weldments. Controlled amounts of Tibor™ grain refiner (containing Ti and B in a ratio of 5:1) were introduced into the molten pool of AA6082 by pre-deposited cast inserts (AA4043 and AA5356) under different welding conditions by GTA welding. Full penetration GTA welds were prepared using alternating current (AC). It was observed that grain size was decreased with increasing amounts of Tibor™. The grain refinement is mainly caused grain nucleation associated with constitutional undercooling during solidification. It has been shown that welds prepared with 5356 cast insert exhibited high strength and ductility when compared with other welds. The observed grain refinement was shown to result in an appreciable increase in fusion zone hardness, strength and ductility.

Luminescence investigation of Yb3+/Er3+ codoped single LiYF4 microparticle

International Nuclear Information System (INIS)

Gao, Wei; Zheng, Hairong; He, Enjie; Lu, Ying; Gao, Fangqi

2014-01-01

Tetragonal phase LiYF 4 :Yb 3+ /Er 3+ microparticles are synthesized via facile hydrothermal method. Single LiYF 4 microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. It is found that single LiYF 4 :Yb 3+ /Er 3+ microparticle with sub-structure presents stronger upconversion luminescence emission and smaller intensity ratio of red to green emission than that from LiYF 4 :Yb 3+ /Er 3+ microparticle with no sub-structure. The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion luminescence emission are investigated. The current study suggests that the luminescence observation with single micropaticle can effectively avoid the influence of environment and neighbor particles, which is important for investigating the luminescence properties of micro- or nano-crystals and for extending their application. - Highlights: • Single LiYF 4 microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. • Single LiYF 4 microparticle with different morphology exhibits different fluorescence emission intensity and intensity ratio of red to green emission. • The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion emission are investigated

Effect of oil refining processes on 14 C-tetrachlorvinphos residues in soya bean oil

International Nuclear Information System (INIS)

Farghaly, M.; Zayed, S.M.A.D.

1986-01-01

Crude soya bean oil extracted from grains treated with 14 C-tetrachlorvinphos and stored for 30 weeks was subjected to different refining processes. The effect of commercial refining processes, namely: alkali treatment, bleaching, winterization and deodorization on the nature and magnitude of the originally present residues was investigated. A high percentage (52%) of the residues was eliminated during alkali neutralization. No potentially toxic materials were detected among the identified degradation products. The obtained data showed that the ultimate degradation products were dimethyl phosphate and mono methyl phosphate.2 tab.,2 scheme

Modified process for refining niobium by electron beam

International Nuclear Information System (INIS)

Pinatti, D.G.; Takano, C.

1982-01-01

The experimental results, thermodynamic equilibrium and kinetic theory of the metal/gas interaction in refractory metals are reviewed. The adsorption and desorption of nitrogen, hydrogen and CO are reversible, whereas those of oxygen are irreversible, with adsorption of an oxygen atom and volatilisation of the metal oxide. Based upon this fact, a new electron beam refining technology is proposed for niobium, consisting of four points: preparation of an electrode by aluminothermic reduction; zone refining in the first melt; kinetic refining in subsequent melts and compact design of the refining plant. Experimental results from a 300 kW pilot plant were in complete agreement with the technology proposed, giving 2.4 times the productivity predicted by the conventional technology. (Author) [pt

The effect of grain refinement and silicon content on grain formation in hypoeutectic Al-Si alloys

Energy Technology Data Exchange (ETDEWEB)

Lee, Y.C.; Dahle, A.K.; StJohn, D.H.; Hutt, J.E.C. [Queensland Univ., Brisbane (Australia). Dept. of Mining, Minerals and Mater. Eng.

1999-01-15

The effect of increasing the amount of added grain refiner on grain size and morphology has been investigated for a range of hypoeutectic Al-Si alloys. The results show a transition in grain size at a silicon concentration of about 3 wt% in unrefined alloys; the grain size decreasing with silicon content before the transition, and increasing beyond the transition point. A change in morphology also occurs with increased silicon content. The addition of grain refiner leads to greater refinement for silicon contents below the transition point than for those contents above the transition point, while the transition point seems to remain unchanged. The slope of the grain size versus silicon content curve after the transition seems to be unaffected by the degree of grain refinement. The results are related to the competitive processes of nucleation and constitutional effects during growth and their impact on nucleation kinetics. (orig.) 13 refs.

Refinement of RAIM via Implementation of Implicit Euler Method

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoonhee; Kim, Han-Chul [Korea Institute of Nuclear and Safety, Daejeon (Korea, Republic of)

2016-10-15

The first approach is a mechanistic approach which is used in LIRIC in which more than 200 reactions are modeled in detail. This approach enables to perform the detailed analysis. However, it requires huge computation burden. The other approach is a simplified model approach which is used in the IMOD, ASTEC/IODE, and etc. Recently, KINS has developed RAIM (Radio-Active Iodine chemistry Model) based on the simplified model approach. Since the numerical analysis module in RAIM is based on the explicit Euler method, there are major issues on the stability of the module. Therefore, implementation of a stable numerical method becomes essential. In this study, RAIM is refined via implementation of implicit Euler method in which the Newton method is used to find the solutions at each time step. The refined RAIM is tested by comparing to RAIM based on the explicit Euler method. In this paper, RAIM was refined by implementing the implicit Euler method. At each time step of the method in the refined RAIM, the reaction kinetics equations are solved by the Newton method in which elements of the Jacobian matrix are expressed analytically. With the results of OECD-BIP P10T2 test, the refined RAIM was compared to RAIM with the explicit Euler method. The refined RAIM shows better agreement with the experimental data than those from the explicit Euler method. For the rapid change of pH during the experiment, the refined RAIM gives more realistic changes in the concentrations of chemical species than those from the explicit Euler method. In addition, in terms of computing time, the refined RAIM shows comparable computing time to that with explicit Euler method. These comparisons are attributed to ⁓10 times larger time step size used in the implicit Euler method, even though computation burden at each time step in the refined RAIM is much higher than that of the explicit Euler method. Compared to the experimental data, the refined RAIM still shows discrepancy, which are attributed

Refinement of RAIM via Implementation of Implicit Euler Method

International Nuclear Information System (INIS)

Lee, Yoonhee; Kim, Han-Chul

2016-01-01

The first approach is a mechanistic approach which is used in LIRIC in which more than 200 reactions are modeled in detail. This approach enables to perform the detailed analysis. However, it requires huge computation burden. The other approach is a simplified model approach which is used in the IMOD, ASTEC/IODE, and etc. Recently, KINS has developed RAIM (Radio-Active Iodine chemistry Model) based on the simplified model approach. Since the numerical analysis module in RAIM is based on the explicit Euler method, there are major issues on the stability of the module. Therefore, implementation of a stable numerical method becomes essential. In this study, RAIM is refined via implementation of implicit Euler method in which the Newton method is used to find the solutions at each time step. The refined RAIM is tested by comparing to RAIM based on the explicit Euler method. In this paper, RAIM was refined by implementing the implicit Euler method. At each time step of the method in the refined RAIM, the reaction kinetics equations are solved by the Newton method in which elements of the Jacobian matrix are expressed analytically. With the results of OECD-BIP P10T2 test, the refined RAIM was compared to RAIM with the explicit Euler method. The refined RAIM shows better agreement with the experimental data than those from the explicit Euler method. For the rapid change of pH during the experiment, the refined RAIM gives more realistic changes in the concentrations of chemical species than those from the explicit Euler method. In addition, in terms of computing time, the refined RAIM shows comparable computing time to that with explicit Euler method. These comparisons are attributed to ⁓10 times larger time step size used in the implicit Euler method, even though computation burden at each time step in the refined RAIM is much higher than that of the explicit Euler method. Compared to the experimental data, the refined RAIM still shows discrepancy, which are attributed

The European refining and distribution industry at the 2010 vista

International Nuclear Information System (INIS)

Lacour, J.J.; Tessmer, G.; Ward, I.

1998-01-01

Oil company chairmen belonging to the AFTP, DGMK and IP associations met together to debate about the future of the European refining industry. The following topics were discussed: is it the end of the refining crisis? Which uncertainties will have to be met? What is the situation of petroleum products supply and demand? What are the consumers' expectations? How to face the environmental constraints? Which future for the refining activities in Europe? Seven round-tables took place with the following themes: the factors of uncertainty in the future of refining activities, the petroleum products supply and demand (automotive fuels, fuel oils, lubricants), the refining activities and the supply of consumers (service stations and supermarkets), the situation of the European petroleum policy, the European refining industry and the public regulations (development of more efficient environmental approaches), the impact of environmental constraints and the technical solutions, and the future of the refining industry. (J.S.)

Refining processes of selected copper alloys

Directory of Open Access Journals (Sweden)

S. Rzadkosz

2009-04-01

Full Text Available The analysis of the refining effectiveness of the liquid copper and selected copper alloys by various micro additions and special refiningsubstances – was performed. Examinations of an influence of purifying, modifying and deoxidation operations performed in a metal bath on the properties of certain selected alloys based on copper matrix - were made. Refining substances, protecting-purifying slag, deoxidation and modifying substances containing micro additions of such elements as: zirconium, boron, phosphor, sodium, lithium, or their compounds introduced in order to change micro structures and properties of alloys, were applied in examinations. A special attention was directed to macro and micro structures of alloys, their tensile and elongation strength and hot-cracks sensitivity. Refining effects were estimated by comparing the effectiveness of micro structure changes with property changes of copper and its selected alloys from the group of tin bronzes.

Refinement of NMR structures using implicit solvent and advanced sampling techniques.

Science.gov (United States)

Chen, Jianhan; Im, Wonpil; Brooks, Charles L

2004-12-15

NMR biomolecular structure calculations exploit simulated annealing methods for conformational sampling and require a relatively high level of redundancy in the experimental restraints to determine quality three-dimensional structures. Recent advances in generalized Born (GB) implicit solvent models should make it possible to combine information from both experimental measurements and accurate empirical force fields to improve the quality of NMR-derived structures. In this paper, we study the influence of implicit solvent on the refinement of protein NMR structures and identify an optimal protocol of utilizing these improved force fields. To do so, we carry out structure refinement experiments for model proteins with published NMR structures using full NMR restraints and subsets of them. We also investigate the application of advanced sampling techniques to NMR structure refinement. Similar to the observations of Xia et al. (J.Biomol. NMR 2002, 22, 317-331), we find that the impact of implicit solvent is rather small when there is a sufficient number of experimental restraints (such as in the final stage of NMR structure determination), whether implicit solvent is used throughout the calculation or only in the final refinement step. The application of advanced sampling techniques also seems to have minimal impact in this case. However, when the experimental data are limited, we demonstrate that refinement with implicit solvent can substantially improve the quality of the structures. In particular, when combined with an advanced sampling technique, the replica exchange (REX) method, near-native structures can be rapidly moved toward the native basin. The REX method provides both enhanced sampling and automatic selection of the most native-like (lowest energy) structures. An optimal protocol based on our studies first generates an ensemble of initial structures that maximally satisfy the available experimental data with conventional NMR software using a simplified

Adaptive mesh refinement for shocks and material interfaces

Energy Technology Data Exchange (ETDEWEB)

Dai, William Wenlong [Los Alamos National Laboratory

2010-01-01

There are three kinds of adaptive mesh refinement (AMR) in structured meshes. Block-based AMR sometimes over refines meshes. Cell-based AMR treats cells cell by cell and thus loses the advantage of the nature of structured meshes. Patch-based AMR is intended to combine advantages of block- and cell-based AMR, i.e., the nature of structured meshes and sharp regions of refinement. But, patch-based AMR has its own difficulties. For example, patch-based AMR typically cannot preserve symmetries of physics problems. In this paper, we will present an approach for a patch-based AMR for hydrodynamics simulations. The approach consists of clustering, symmetry preserving, mesh continuity, flux correction, communications, management of patches, and load balance. The special features of this patch-based AMR include symmetry preserving, efficiency of refinement across shock fronts and material interfaces, special implementation of flux correction, and patch management in parallel computing environments. To demonstrate the capability of the AMR framework, we will show both two- and three-dimensional hydrodynamics simulations with many levels of refinement.

Energy conservation potential in China’s petroleum refining industry: Evidence and policy implications

International Nuclear Information System (INIS)

Lin, Boqiang; Xie, Xuan

2015-01-01

Highlights: • A long-term equilibrium relationship of energy demand in China’s petroleum refining industry is established. • The sectoral energy conservation potential is evaluated by using scenarios analysis. • Energy prices, enterprise scale, R and D investment and ownership structure affect electricity intensity. • Future policy for energy conservation in China’s petroleum refining industry is suggested. - Abstract: China is currently the second largest petroleum refining country in the world due to rapid growth in recent years. Because the petroleum refining industry is energy-intensive, the rapid growth in petroleum refining and development caused massive energy consumption. China’s urbanization process will guarantee sustained growth of the industry for a long time. Therefore, it is necessary to study the energy conservation potential of the petroleum industry. This paper estimates the energy conservation potential of the industry by applying a cointegration model to investigate the long-run equilibrium relationship between energy consumption and some factors such as energy price, enterprise scale, R and D investment and ownership structure. The results show that R and D investment has the greatest reduction impact on energy intensity, and the growth of market participants (i.e. the decline of the share of state-owned companies) can improve energy efficiency of this industry. Under the advanced energy-saving scenario, the accumulated energy conservation potential will reach 230.18 million tons of coal equivalent (tce). Finally, we provide some targeted policy recommendations for industrial energy conservation

Chinese refining capacity for Canadian heavy oil

International Nuclear Information System (INIS)

Bruce, G.W.

2006-01-01

This paper discussed China's refining capacity in relation to exports of Canadian heavy oil. Demand for oil is increasing throughout the world, and China is expected to consume 25 per cent of the projected yearly oil supplies. Alberta currently has an estimated 174 billion barrels of recoverable bitumen, and produces 1.06 million barrels per day. Production is expected to increase to 4.5 million barrels per day by the year 2020. Currently bitumen blends are refined and diluted with naphtha and sweet synthetic crude oil. Bitumen is a challenging feedstock for refineries, and requires thermal production methods or gasification processes. Primary conversion into sour synthetic crude is typically followed by hydrocracking and further refining into finished petroleum products. There are currently 50 refineries in China with a 7.4 million barrel per day capacity. Coastal refineries using imported crude oil have a 4 million barrel per day capacity. New facilities are being constructed and existing plants are being upgraded in order to process heavier and more sour crude oils. However, current refining capabilities in Chinese refineries have a limited ability for resid conversion. It was concluded that while China has a refining infrastructure, only refineries on the coast will use oil sands-derived feedstocks. However, there are currently opportunities to design refineries to match future feedstocks. tabs., figs

On macromolecular refinement at subatomic resolution with interatomic scatterers

Energy Technology Data Exchange (ETDEWEB)

Afonine, Pavel V., E-mail: pafonine@lbl.gov; Grosse-Kunstleve, Ralf W.; Adams, Paul D. [Lawrence Berkeley National Laboratory, One Cyclotron Road, BLDG 64R0121, Berkeley, CA 94720 (United States); Lunin, Vladimir Y. [Institute of Mathematical Problems of Biology, Russian Academy of Sciences, Pushchino 142290 (Russian Federation); Urzhumtsev, Alexandre [IGMBC, 1 Rue L. Fries, 67404 Illkirch and IBMC, 15 Rue R. Descartes, 67084 Strasbourg (France); Faculty of Sciences, Nancy University, 54506 Vandoeuvre-lès-Nancy (France); Lawrence Berkeley National Laboratory, One Cyclotron Road, BLDG 64R0121, Berkeley, CA 94720 (United States)

2007-11-01

Modelling deformation electron density using interatomic scatters is simpler than multipolar methods, produces comparable results at subatomic resolution and can easily be applied to macromolecules. A study of the accurate electron-density distribution in molecular crystals at subatomic resolution (better than ∼1.0 Å) requires more detailed models than those based on independent spherical atoms. A tool that is conventionally used in small-molecule crystallography is the multipolar model. Even at upper resolution limits of 0.8–1.0 Å, the number of experimental data is insufficient for full multipolar model refinement. As an alternative, a simpler model composed of conventional independent spherical atoms augmented by additional scatterers to model bonding effects has been proposed. Refinement of these mixed models for several benchmark data sets gave results that were comparable in quality with the results of multipolar refinement and superior to those for conventional models. Applications to several data sets of both small molecules and macromolecules are shown. These refinements were performed using the general-purpose macromolecular refinement module phenix.refine of the PHENIX package.

Review of Grain Refinement of Cast Metals Through Inoculation: Theories and Developments

Science.gov (United States)

Liu, Zhilin

2017-10-01

The inoculation method of grain refinement is widely used in research and industry. Because of its commercial and engineering importance, extensive research on the mechanisms/theories of grain refinement and development of effective grain refiners for diverse cast metals/alloys has been conducted. In 1999, Easton and St. John reviewed the mechanisms of grain refinement of cast Al alloys. Since then, grain refinement in alloys of Al, Mg, Fe, Ti, Cu, and Zn has evolved a lot. However, there is still no full consensus on the mechanisms/theories of grain refinement. Moreover, some new grain refiners developed based on the theories do not ensure efficient grain refinement. Thus, the factors that contribute to grain refinement are still not fully understood. Clarification of the prerequisite issues that occur in grain refinement is required using recent theories. This review covers multiple metals/alloys and developments in grain refinement from the last twenty years. The characteristics of effective grain refiners are considered from four perspectives: effective particle/matrix wetting configuration, sufficiently powerful segregating elements, preferential crystallographic matching, and geometrical features of effective nucleants. Then, recent mechanisms/theories on the grain refinement of cast metals/alloys are reviewed, including the peritectic-related, hypernucleation, inert nucleant, and constitutional supercooling-driven theories. Further, developments of deterministic and probabilistic modeling and nucleation crystallography in the grain refinement of cast metals are reviewed. Finally, the latest progress in the grain refinement of cast Zn and its alloys is described, and future work on grain refinement is summarized.

Total antioxidant content of alternatives to refined sugar.

Science.gov (United States)

Phillips, Katherine M; Carlsen, Monica H; Blomhoff, Rune

2009-01-01

Oxidative damage is implicated in the etiology of cancer, cardiovascular disease, and other degenerative disorders. Recent nutritional research has focused on the antioxidant potential of foods, while current dietary recommendations are to increase the intake of antioxidant-rich foods rather than supplement specific nutrients. Many alternatives to refined sugar are available, including raw cane sugar, plant saps/syrups (eg, maple syrup, agave nectar), molasses, honey, and fruit sugars (eg, date sugar). Unrefined sweeteners were hypothesized to contain higher levels of antioxidants, similar to the contrast between whole and refined grain products. To compare the total antioxidant content of natural sweeteners as alternatives to refined sugar. The ferric-reducing ability of plasma (FRAP) assay was used to estimate total antioxidant capacity. Major brands of 12 types of sweeteners as well as refined white sugar and corn syrup were sampled from retail outlets in the United States. Substantial differences in total antioxidant content of different sweeteners were found. Refined sugar, corn syrup, and agave nectar contained minimal antioxidant activity (sugar had a higher FRAP (0.1 mmol/100 g). Dark and blackstrap molasses had the highest FRAP (4.6 to 4.9 mmol/100 g), while maple syrup, brown sugar, and honey showed intermediate antioxidant capacity (0.2 to 0.7 mmol FRAP/100 g). Based on an average intake of 130 g/day refined sugars and the antioxidant activity measured in typical diets, substituting alternative sweeteners could increase antioxidant intake an average of 2.6 mmol/day, similar to the amount found in a serving of berries or nuts. Many readily available alternatives to refined sugar offer the potential benefit of antioxidant activity.

Investment in exploration-production and refining 2015

International Nuclear Information System (INIS)

Maisonnier, G.; Hureau, G.; Serbutoviez, S.; Silva, C.

2016-01-01

IFPEN analyses in this study the 2015 evolution of global investment in the field of exploration-production and refining: - Changes in oil and gas prices; - Investment in Exploration/Production: the end of an upward cycle; - Drilling and the global drilling market, upstream activities and markets; - 2015, a breath of fresh air for refining

Effect of grain refiner on the tensile and impact properties of Al–Si–Mg cast alloys

International Nuclear Information System (INIS)

Samuel, E.; Golbahar, B.; Samuel, A.M.; Doty, H.W.; Valtierra, S.; Samuel, F.H.

2014-01-01

The present study aims to investigate the influence of the addition of Ti and B in the form of five different grain refiners/aluminium master alloys (Al–10%Ti, Al–5%Ti–1%B, Al–2.5%Ti–2.5%B, Al–1.7%Ti–1.4%B and Al–4%B) in conjunction with that of Sr (as modifier) added in the form of Al–10%Sr master alloy to A356.2 alloy. Grain refinement of an A356.2 alloy with Ti and B additions in the ranges of 0.02–0.5% and 0.01–0.5%, respectively, was examined using these different types of grain refiners. Strontium additions of 30 and 200 ppm were made. All alloys were T6-heat treated before mechanical testing. Tensile and impact tests were conducted to evaluate the influence of the interaction between grain refiner and modifier on the mechanical properties. The properties were determined for both the as-cast and heat-treated conditions. - Highlights: • Grain refining of 356 alloys using five types of grain refiners. • Interaction between the added grain refiner and amount of modifier used (i.e. 30 or 200ppm Sr). • Role of the added amount of Ti and/or B on the eutectic Si particle characteristics. • Role of Ti/B on the impact toughness of 356 alloys modified with Sr (30 or 200ppm)

Dynamics of the European refining and petrochemical industry. Strategies, structure and change

International Nuclear Information System (INIS)

Steenbakkers, K.

1997-01-01

The changes in the market position of producers engaged in the oil refining and basic petrochemical industry on the Western European market are the central theme of this book. Analysis of this reshuffling process among these actors is conducted on three levels. First, research is carried out at the level of world regions. In order to understand the reorganization of oil refining and basic petrochemical production in Western Europe, it is necessary to explore the recent aggregate dynamics of these activities on a global scale. Second, the differences in strategic behaviour are exanuned at the level of groups of market participants, namely the major oil companies, the chemical companies, the state-owned companies from both consumer and producer countries, and the independents. Finally, the investment/disinvestment decisions in the Western European oil refining and basic petrochemical industry are investigated at the level of the individual firm. Particular emphasis is placed upon explaining why companies active in the sectors under study have followed different strategies, although they have been confronted with similar adverse market conditions in Western Europe during the last decades. 341 refs

Biomolecular structure refinement using the GROMOS simulation software

International Nuclear Information System (INIS)

Schmid, Nathan; Allison, Jane R.; Dolenc, Jožica; Eichenberger, Andreas P.; Kunz, Anna-Pitschna E.; Gunsteren, Wilfred F. van

2011-01-01

For the understanding of cellular processes the molecular structure of biomolecules has to be accurately determined. Initial models can be significantly improved by structure refinement techniques. Here, we present the refinement methods and analysis techniques implemented in the GROMOS software for biomolecular simulation. The methodology and some implementation details of the computation of NMR NOE data, 3 J-couplings and residual dipolar couplings, X-ray scattering intensities from crystals and solutions and neutron scattering intensities used in GROMOS is described and refinement strategies and concepts are discussed using example applications. The GROMOS software allows structure refinement combining different types of experimental data with different types of restraining functions, while using a variety of methods to enhance conformational searching and sampling and the thermodynamically calibrated GROMOS force field for biomolecular simulation.

Biomolecular structure refinement using the GROMOS simulation software

Energy Technology Data Exchange (ETDEWEB)

Schmid, Nathan; Allison, Jane R.; Dolenc, Jozica; Eichenberger, Andreas P.; Kunz, Anna-Pitschna E.; Gunsteren, Wilfred F. van, E-mail: wfvgn@igc.phys.chem.ethz.ch [Swiss Federal Institute of Technology ETH, Laboratory of Physical Chemistry (Switzerland)

2011-11-15

For the understanding of cellular processes the molecular structure of biomolecules has to be accurately determined. Initial models can be significantly improved by structure refinement techniques. Here, we present the refinement methods and analysis techniques implemented in the GROMOS software for biomolecular simulation. The methodology and some implementation details of the computation of NMR NOE data, {sup 3}J-couplings and residual dipolar couplings, X-ray scattering intensities from crystals and solutions and neutron scattering intensities used in GROMOS is described and refinement strategies and concepts are discussed using example applications. The GROMOS software allows structure refinement combining different types of experimental data with different types of restraining functions, while using a variety of methods to enhance conformational searching and sampling and the thermodynamically calibrated GROMOS force field for biomolecular simulation.

Pakistan stepping up expansion of refining, transportation sectors

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that Pakistan is taking steps to speed expansion of its refining and oil transportation infrastructure. While the country has made significant progress toward energy self-efficiency by boosting oil and gas production it still must modernize and expand an aging, inadequate refining sector to meet rapidly growing demand for refined products. Pakistan's government has disclosed plans to build two refineries in the country, one at Rawalpindi near a string of recent oil discoveries, the other somewhere in the southern part of the country, likely Karachi. At the same time, efforts are proceeding to upgrade Pakistan's refineries. In addition, Pakistani state companies continue to press joint ventures in refining and marketing with foreign companies and expand downstream ties with neighbors that are key oil and gas exporters

New Process for Grain Refinement of Aluminum. Final Report

Energy Technology Data Exchange (ETDEWEB)

Dr. Joseph A. Megy

2000-09-22

A new method of grain refining aluminum involving in-situ formation of boride nuclei in molten aluminum just prior to casting has been developed in the subject DOE program over the last thirty months by a team consisting of JDC, Inc., Alcoa Technical Center, GRAS, Inc., Touchstone Labs, and GKS Engineering Services. The Manufacturing process to make boron trichloride for grain refining is much simpler than preparing conventional grain refiners, with attendant environmental, capital, and energy savings. The manufacture of boride grain refining nuclei using the fy-Gem process avoids clusters, salt and oxide inclusions that cause quality problems in aluminum today.

Grain refinement of AZ91D alloy by intensive melt shearing and its persistence after remelting and isothermal holding

Directory of Open Access Journals (Sweden)

Zuo Yubo

2013-01-01

Full Text Available Intensive melt shearing has a significant grain refining effect on some light alloys. However, the persistence of the grain refining effect during isothermal holding and remelting is still unclear, although it is very important for the practical application. In this study, intensive melt shearing was achieved in a twin-screw mechanism to investigate its grain refining effect on AZ91D magnesium alloy. The refinement mechanism was discussed and the persistence of grain refinement after remelting and isothermal holding was also studied. A Zeiss imaging system with polarized light was used for quantitative measurement of grain size. The results show that the intensive melt shearing has a significant grain refining effect on AZ91D magnesium alloy. With the application of intensive melt shearing, the grain size of AZ91D magnesium alloy can be reduced from 530 μm (for a typical as-cast microstructure to 170 μm, which is about 70% size reduction. The grain refinement achieved by the intensive melt shearing can be partially kept after isothermal holding and remelting. It is believed that the refinement effect was mainly due to the finer and well dispersed oxide particles formed by high intensive shearing. The smaller size of oxide particles and their slow motion velocity in the sheared melt could make important contributions to the remained grain refinement.

Study of mechanism on microstructure refinement during compact strip production process

International Nuclear Information System (INIS)

Yu Hao; Kang Yonglin; Wang Kelu; Fu Jie; Wang Zhongbing; Liu Delu

2003-01-01

In this study, microstructures of 1.9 mm hot strip steel produced by compact strip production (CSP) are investigated by using optical metallograph observation and electron back-scattered diffraction (EBSD) data to deduce the status of hot rolled austenite before phase transformation, because the evolution of hot rolled austenite is important to provide information for the microstructure refinement. The experimental results show that the finishing hot rolled microstructure is a mixture of recrystallized and deformed austenite, and the percentage of recrystallized austenite is greater than that of the deformed austenite. At last, microstructure evolution of austenite is modeled based on chemical compositions and techniques of producing 1.9 mm hot strip. The simulation results agree well with experimental data. Analysis shows that microstructure refinement, recrystallization and supercooling rate are the primary causes to fine microstructure

Nonlinear joint dynamics between prices of crude oil and refined products

Science.gov (United States)

Zhang, Tao; Ma, Guofeng; Liu, Guangsheng

2015-02-01

In this paper, we investigate the relationships between crude oil and refined product prices. We find that nonlinear correlations are stronger in the long-term than in the short-term. Crude oil and product prices are cointegrated and financial crisis in 2007-2008 caused a structural break of the cointegrating relationship. Moreover, different from the findings in most studies, we reveal that the relationships are almost symmetric based on a threshold error correction model. The so-called 'asymmetric relationships' are caused by some outliers and financial crisis. Most of the time, crude oil prices play the major role in the adjustment process of the long-term equilibrium. However, refined product prices dominated crude oil prices during the period of financial crisis. Important policy and risk management implications can be learned from the empirical findings.

Value-added potential of expeller-pressed canola oil refining: characterization of sinapic acid derivatives and tocopherols from byproducts.

Science.gov (United States)

Chen, Yougui; Thiyam-Hollander, Usha; Barthet, Veronique J; Aachary, Ayyappan A

2014-10-08

Valuable phenolic antioxidants are lost during oil refining, but evaluation of their occurrence in refining byproducts is lacking. Rapeseed and canola oil are both rich sources of sinapic acid derivatives and tocopherols. The retention and loss of sinapic acid derivatives and tocopherols in commercially produced expeller-pressed canola oils subjected to various refining steps and the respective byproducts were investigated. Loss of canolol (3) and tocopherols were observed during bleaching (84.9%) and deodorization (37.6%), respectively. Sinapic acid (2) (42.9 μg/g), sinapine (1) (199 μg/g), and canolol (344 μg/g) were found in the refining byproducts, namely, soap stock, spent bleaching clay, and wash water, for the first time. Tocopherols (3.75 mg/g) and other nonidentified phenolic compounds (2.7 mg sinapic acid equivalent/g) were found in deodistillates, a byproduct of deodorization. DPPH radical scavenging confirmed the antioxidant potential of the byproducts. This study confirms the value-added potential of byproducts of refining as sources of endogenous phenolics.

Effect of Al on Grain Refinement and Mechanical Properties of Mg-3Nd Casting Alloy

Science.gov (United States)

Wang, Lei; Feng, Yicheng; Wang, Liping; Chen, Yanhong; Guo, Erjun

2018-05-01

The effect of Al on the grain refinement and mechanical properties of as-cast Mg-3Nd alloy was investigated systematically by a series of microstructural analysis, solidification analysis and tensile tests. The results show that Al has an obvious refining effect on the as-cast Mg-3Nd alloy. With increasing Al content, the grain size of the as-cast Mg-3Nd alloy decreases firstly, then increases slightly after the Al content reaching 3 wt.%, and the minimum grain size of the Mg-3Nd alloy is 48 ± 4.0 μm. The refining mechanism can be attributed to the formation of Al2Nd particles, which play an important role in the heterogeneous nucleation. The strength and elongation of the Mg-3Nd alloy refined by Al also increase with increasing Al content and slightly decrease when the Al content is more than 3 wt.%, and the strengthening mechanism is attributed to the grain refinement as well as dispersed intermetallic particles. Furthermore, the microstructural thermal stability of the Mg-3Nd-3Al alloy is higher than that of the Mg-3Nd-0.5Zr alloy. Overall, the Mg-3Nd alloy with Al addition is a novel alloy with wide and potential application prospects.

Effects of grain refinement on the biocorrosion and in vitro bioactivity of magnesium

Energy Technology Data Exchange (ETDEWEB)

Saha, Partha; Roy, Mangal [Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Datta, Moni Kanchan [Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun [Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); School of Dental Medicine, University of Pittsburgh, PA 15261 (United States); McGowan Institute of Regenerative Medicine, University of Pittsburgh, PA 15261 (United States)

2015-12-01

Magnesium is a new class of biodegradable metals potentially suitable for bone fracture fixation due to its suitable mechanical properties, high degradability and biocompatibility. However, rapid corrosion and loss in mechanical strength under physiological conditions render it unsuitable for load-bearing applications. In the present study, grain refinement was implemented to control bio-corrosion demonstrating improved in vitro bioactivity of magnesium. Pure commercial magnesium was grain refined using different amounts of zirconium (0.25 and 1.0 wt.%). Corrosion behavior was studied by potentiodynamic polarization (PDP) and mass loss immersion tests demonstrating corrosion rate decrease with grain size reduction. In vitro biocompatibility tests conducted by MC3T3-E1 pre-osteoblast cells and measured by DNA quantification demonstrate significant increase in cell proliferation for Mg–1 wt.% Zr at day 5. Similarly, alkaline phosphatase (ALP) activity was higher for grain refined Mg. Alloys were also tested for ability to support osteoclast differentiation using RAW264.7 monocytes with receptor activator of nuclear factor kappa-β ligand (RANKL) supplemented cell culture. Osteoclast differentiation process was observed to be severely restricted for smaller grained Mg. Overall, the results indicate grain refinement to be useful not only for improving corrosion resistance of Mg implants for bone fixation devices but also potentially modulate bone regeneration around the implant. - Highlights: • The biocorrosion and biocompatibility of pure Mg and Mg grain refined with different Zr levels were investigated. • Corrosion resistance in HBSS and compressive strength of pure Mg was significantly improved with Zr addition. • Electrochemical and immersion corrosion tests showed a fourfold decrease in corrosion rate of pure Mg with 1% Zr addition. • Grain refinement of pure Mg demonstrated enhanced osteoblast cell activity and proliferation.

Effects of grain refinement on the biocorrosion and in vitro bioactivity of magnesium

International Nuclear Information System (INIS)

Saha, Partha; Roy, Mangal; Datta, Moni Kanchan; Lee, Boeun; Kumta, Prashant N.

2015-01-01

Magnesium is a new class of biodegradable metals potentially suitable for bone fracture fixation due to its suitable mechanical properties, high degradability and biocompatibility. However, rapid corrosion and loss in mechanical strength under physiological conditions render it unsuitable for load-bearing applications. In the present study, grain refinement was implemented to control bio-corrosion demonstrating improved in vitro bioactivity of magnesium. Pure commercial magnesium was grain refined using different amounts of zirconium (0.25 and 1.0 wt.%). Corrosion behavior was studied by potentiodynamic polarization (PDP) and mass loss immersion tests demonstrating corrosion rate decrease with grain size reduction. In vitro biocompatibility tests conducted by MC3T3-E1 pre-osteoblast cells and measured by DNA quantification demonstrate significant increase in cell proliferation for Mg–1 wt.% Zr at day 5. Similarly, alkaline phosphatase (ALP) activity was higher for grain refined Mg. Alloys were also tested for ability to support osteoclast differentiation using RAW264.7 monocytes with receptor activator of nuclear factor kappa-β ligand (RANKL) supplemented cell culture. Osteoclast differentiation process was observed to be severely restricted for smaller grained Mg. Overall, the results indicate grain refinement to be useful not only for improving corrosion resistance of Mg implants for bone fixation devices but also potentially modulate bone regeneration around the implant. - Highlights: • The biocorrosion and biocompatibility of pure Mg and Mg grain refined with different Zr levels were investigated. • Corrosion resistance in HBSS and compressive strength of pure Mg was significantly improved with Zr addition. • Electrochemical and immersion corrosion tests showed a fourfold decrease in corrosion rate of pure Mg with 1% Zr addition. • Grain refinement of pure Mg demonstrated enhanced osteoblast cell activity and proliferation

Preparation of Al-Ti-B grain refiner by SHS technology[Self-propagating High-temperature Synthesis

Energy Technology Data Exchange (ETDEWEB)

Nikitin, V.I.; Wanqi, J.I.E.; Kandalova, E.G.; Makarenko, A.G.; Yong, L.

2000-02-01

Since the discovery of the grain refinement effect of aluminum by titanium, especially with the existence of B or C in 1950, grain refiners are widely accepted in industry for microstructure control of aluminum alloys. Research on this topic is to obtain the highest grain refinement efficiency with the lowest possible addition of master alloy. It is widely accepted that the morphology and size of TiAl{sub 3} particles, which are known as heterogeneous nucleation centers, are important factors deterring the grain refinement efficiency. Fine TiAl{sub 3} particles are favorable. The grain refinement process shows a heredity phenomenon, which means that structural information from initial materials transfers through a melt to the final product. It is important to find the connection between microstructural parameters of the master alloy and the final product. To improve the quality of Al-Ti-B master alloys for the use as a grain refiner, a new method based on SHS (self-propagating high-temperature synthesis) technology has been developed in Samara State Technical University to produce the master alloys. SHS, as a new method for preparation of materials, was first utilized by Merzhanov in 1967. This method uses the energy from highly exothermic reactions to sustain the chemical reaction in a combustion wave. The advantages of SHS include simplicity, low energy requirement, and higher product purity. Because SHS reactions can take place between elemental reactants, it is easy to control product composition. The purposes of this investigation were to fabricate an SHS Al-5%Ti-1%B master alloy, to analyze its structure and to test its grain refining performance.

Challenges of ICRP 60 for uranium refining and conversion facilities

International Nuclear Information System (INIS)

Takala, J.M.

1998-01-01

Cameco Corporation operates high-grade uranium mines in northern Saskatchewan and uranium refining and conversion facilities in Ontario. The dose limits for these and all other nuclear facilities in Canada are 50 mSv per year and 4 WLM per year, which are applied separately. However, the upcoming incorporation of the recommendations in ICRP 60 into the Canadian regulations will result in several important changes. In addition to a more restrictive dose limit, the new regulations will require that all radiation exposures be combined into a single index of exposure. Meeting the new lower dose limits of 50 mSv per year and 100 mSv per 5 years will not be a major problem at Cameco facilities. However, the incorporation of long-lived radioactive dust exposures into the dose calculation will be a major challenge. This will cause the most difficulty at the uranium refining and conversion facilities where much of the process involves handling a variety of uranium compounds in the form of a dry powder. At the uranium conversion facilities the control of exposure to airborne uranium is achieved through a combination of lung counting, urinalysis, and fixed area monitors. To progress from a system of exposure control to dose estimation to individual workers will require some major changes. (author)

Method of optimization of the natural gas refining process

Energy Technology Data Exchange (ETDEWEB)

Sadykh-Zade, E.S.; Bagirov, A.A.; Mardakhayev, I.M.; Razamat, M.S.; Tagiyev, V.G.

1980-01-01

The SATUM (automatic control system of technical operations) system introduced at the Shatlyk field should assure good quality of gas refining. In order to optimize the natural gas refining processes and experimental-analytical method is used in compiling the mathematical descriptions. The program, compiled in Fortran language, in addition to parameters of optimal conditions gives information on the yield of concentrate and water, concentration and consumption of DEG, composition and characteristics of the gas and condensate. The algorithm for calculating optimum engineering conditions of gas refining is proposed to be used in ''advice'' mode, and also for monitoring progress of the gas refining process.

Optimal algebraic multilevel preconditioning for local refinement along a line

NARCIS (Netherlands)

Margenov, S.D.; Maubach, J.M.L.

1995-01-01

The application of some recently proposed algebraic multilevel methods for the solution of two-dimensional finite element problems on nonuniform meshes is studied. The locally refined meshes are created by the newest vertex mesh refinement method. After the introduction of this refinement technique

RBT—A Tool for Building Refined Buneman Trees

DEFF Research Database (Denmark)

Besenbacher, Søren; Mailund; Westh-Nielsen, Lasse

2005-01-01

We have developed a tool implementing an efficient algorithm for refined Buneman tree reconstruction. The algorithm—which has the same complexity as the neighbour-joining method and the (plain) Buneman tree construction—enables refined Buneman tree reconstruction on large taxa sets....

India's refining prospects linked to economic growth

International Nuclear Information System (INIS)

Lewis, E.

1996-01-01

International investors assess refining ventures in India the same way they do comparable projects elsewhere in the world: according to their expectations about investment returns. By that standard, India's appeal is mixed, although its need for some measure of additional refining capacity seems certain. The success of future refinery investments will depend heavily on the government's commitment to policies allowing the economy to grow faster than the population. Unless accompanied by economic growth, expected increases in the population will not automatically raise demand for petroleum products. Decisions about investments in India's refining sector, therefore, must carefully weigh market fundamentals, the business environment, and likely investment performance. This paper reviews the market for the various products and predicts new economic trends

An analytical approach to elucidate the mechanism of grain refinement in calcium added Mg-Al alloys

International Nuclear Information System (INIS)

Nagasivamuni, B.; Ravi, K.R.

2015-01-01

Highlights: • Minor additions of Ca (<0.2%) refines the grain structure in Mg-(3, 6 and 9)Al alloys. • Analytical model elucidate that nucleation potency is enhanced after Ca addition. • Ternary Mg-Al-xCa growth restriction values (Q t ) are computed using Scheil equations. • Grain size predictions elucidate that nucleation events dominate grain refinement. • Growth restriction due to the higher Ca addition on grain refinement is not significant. - Abstract: The present study investigates the grain refinement of Mg-3Al, Mg-6Al and Mg-9Al alloys by calcium addition. The maximum reduction in grain size has been observed at 0.2% Ca addition in Mg-Al alloys, in which any further addition (up to 0.4%) has marginal improvement in grain refinement. The mechanism associated with the grain refinement of Mg-Al alloys by Ca addition is discussed in terms of growth restriction factor (Q) and constitutional undercooling (ΔT CS ) using analytical model. The influence of growth restriction factor (Q) on the final grain size of Ca-added Mg-Al alloys are calculated with the help analytical model by assuming that the number of nucleant particles is not altered through Ca addition. For accurate grain size calculations, the value of Q has been estimated with reliable thermodynamic database using Scheil solidification simulation. The comparison of predicted and experimental grain size results indicate that constitutional undercooling activation of nucleation events plays dominant role in grain refinement in Mg-Al alloys by calcium addition, whereas the increase in growth restriction value has negligible effect

a Novel Approach to Veterinary Spatial Epidemiology: Dasymetric Refinement of the Swiss Dog Tumor Registry Data

Science.gov (United States)

Boo, G.; Fabrikant, S. I.; Leyk, S.

2015-08-01

In spatial epidemiology, disease incidence and demographic data are commonly summarized within larger regions such as administrative units because of privacy concerns. As a consequence, analyses using these aggregated data are subject to the Modifiable Areal Unit Problem (MAUP) as the geographical manifestation of ecological fallacy. In this study, we create small area disease estimates through dasymetric refinement, and investigate the effects on predictive epidemiological models. We perform a binary dasymetric refinement of municipality-aggregated dog tumor incidence counts in Switzerland for the year 2008 using residential land as a limiting ancillary variable. This refinement is expected to improve the quality of spatial data originally aggregated within arbitrary administrative units by deconstructing them into discontinuous subregions that better reflect the underlying population distribution. To shed light on effects of this refinement, we compare a predictive statistical model that uses unrefined administrative units with one that uses dasymetrically refined spatial units. Model diagnostics and spatial distributions of model residuals are assessed to evaluate the model performances in different regions. In particular, we explore changes in the spatial autocorrelation of the model residuals due to spatial refinement of the enumeration units in a selected mountainous region, where the rugged topography induces great shifts of the analytical units i.e., residential land. Such spatial data quality refinement results in a more realistic estimation of the population distribution within administrative units, and thus, in a more accurate modeling of dog tumor incidence patterns. Our results emphasize the benefits of implementing a dasymetric modeling framework in veterinary spatial epidemiology.

The grain refinement behavior of TiB2 particles prepared with in situ technology

International Nuclear Information System (INIS)

Wang Chunlei; Wang Mingxing; Yu Benhai; Chen Dong; Qin Ping; Feng Minghai; Dai Qirun

2007-01-01

The grain-refining behavior of TiB 2 particles was investigated by the method of adding Al-4B master alloy into the melt of electrolytic low-titanium aluminum (ELTA). The results indicate that TiB 2 particles will be formed when the Al-4B master alloy is added into the melt of ELTA. These TiB 2 particles are produced by in situ technology, thus their surface properties are preserved and do not alter. At the bottom of the melt, the TiB 2 particles are pushed to the grain boundaries because of the absence of enough titanium atoms, which indicates that TiB 2 particles alone are not potent nuclei of α-Al. Though some TiB 2 particles settle down at the bottom, there are still numbers of fine TiB 2 particles suspended. These TiB 2 particles, together with the titanium atoms left, will form much more heterogeneous nucleation sites during the solidification of the melt, resulting in the grain-refining efficiency of the ELTA with Al-4B addition being improved obviously. To investigate the grain-refining mechanism of aluminum, this method has its advantages in comparison with that of adding synthetic TiB 2 particles into the melt of aluminum

Single-Site Palladium(II) Catalyst for Oxidative Heck Reaction: Catalytic Performance and Kinetic Investigations

Energy Technology Data Exchange (ETDEWEB)

Duan, Hui; Li, Mengyang; Zhang, Guanghui; Gallagher, James R.; Huang, Zhiliang; Sun, Yu; Luo, Zhong; Chen, Hongzhong; Miller, Jeffrey T.; Zou, Ruqiang; Lei, Aiwen; Zhao, Yanli

2015-01-01

ABSTRACT: The development of organometallic single-site catalysts (SSCs) has inspired the designs of new heterogeneous catalysts with high efficiency. Nevertheless, the application of SSCs in certain modern organic reactions, such as C-C bond formation reactions, has still been less investigated. In this study, a single-site Pd(II) catalyst was developed, where 2,2'-bipyridine-grafted periodic mesoporous organosilica (PMO) was employed as the support of a Pd(II) complex. The overall performance of the single-site Pd(II) catalyst in the oxidative Heck reaction was then investigated. The investigation results show that the catalyst displays over 99% selectivity for the product formation with high reaction yield. Kinetic profiles further confirm its high catalytic efficiency, showing that the rate constant is nearly 40 times higher than that for the free Pd(II) salt. X-ray absorption spectroscopy reveals that the catalyst has remarkable lifetime and recyclability.

[Current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry].

Science.gov (United States)

Wu, S S; Yu, J N; He, C H; Mu, H X; Wang, C; Zhang, Y; Zhang, C Y; Yu, S F; Li, X L

2016-12-20

Objective: To investigate the current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry. Methods: From August 2015 to March 2016, the investigation method of collecting the data of past occupational health examinations and measuring noise in working environment was used to enroll 8 672 male workers. Results: Of all workers, 11.6% were diagnosed with hearing loss. There were significant differences in the distribution of hearing impairment among workers exposed to noise at different ages, device types and types of work (χ(2)=17.80, 77.80 and 30.53, all P hearing loss in workers with noise exposure in refining and chemical industry. Conclusion: The level of noise exposure and working years with noise exposure are main influencing factors for hearing loss in workers with noise exposure in refining and chemical industry.

Refinement-Animation for Event-B - Towards a Method of Validation

DEFF Research Database (Denmark)

Hallerstede, Stefan; Leuschel, Michael; Plagge, Daniel

2010-01-01

We provide a detailed description of refinement in Event-B, both as a contribution in itself and as a foundation for the approach to simultaneous animation of multiple levels of refinement that we propose. We present an algorithm for simultaneous multi-level animation of refinement, and show how ...

Cleaning Data with OpenRefine

Directory of Open Access Journals (Sweden)

Seth van Hooland

2013-08-01

Full Text Available Duplicate records, empty values and inconsistent formats are phenomena we should be prepared to deal with when using historical data sets. This lesson will teach you how to discover inconsistencies in data contained within a spreadsheet or a database. As we increasingly share, aggregate and reuse data on the web, historians will need to respond to data quality issues which inevitably pop up. Using a program called OpenRefine, you will be able to easily identify systematic errors such as blank cells, duplicates, spelling inconsistencies, etc. OpenRefine not only allows you to quickly diagnose the accuracy of your data, but also to act upon certain errors in an automated manner.

Outlook for Canadian refining

International Nuclear Information System (INIS)

Boje, G.

1998-01-01

The petroleum supply and demand balance was discussed and a comparison between Canadian and U.S. refineries was provided. The impact of changing product specifications on the petroleum industry was also discussed. The major changes include sulphur reductions in gasoline, benzene and MMT additives. These changes have been made in an effort to satisfy environmental needs. Geographic margin variations in refineries between east and west were reviewed. An overview of findings from the Solomon Refining Study of Canadian and American refineries, which has been very complimentary of the Canadian refining industry, was provided. From this writer's point of view refinery utilization has improved but there is a threat from increasing efficiency of US competitors. Environmental issues will continue to impact upon the industry and while the chances for making economic returns on investment are good for the years ahead, it will be a challenge to maintain profitability

Oil refining in U.S. foreign-trade zones

International Nuclear Information System (INIS)

Powell, S.J.; Potter, T.J.

1991-01-01

With the crude-oil import supply being as inexpensive as it is today, relative to domestic supply, many independents have been sourcing their crude-oil needs from abroad and have found it an opportune time to step up their level of refining activity. To further enhance their competitive position with respect to foreign refineries, certain domestic refiners have discovered the operational benefits and savings that result from having a refinery designated as a foreign-trade zone (FTZ) under the Foreign-Trade Zones Act of 1934, as amended. This paper examines the history and use of foreign-trade subzones for refining activities

Investigation of photobleaching and saturation of single molecules by fluorophore recrossing events

Energy Technology Data Exchange (ETDEWEB)

Burrows, Sean M.; Reif, Randall D. [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (United States); Pappas, Dimitri [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061 (United States)], E-mail: d.pappas@ttu.edu

2007-08-15

A method for investigation of photobleaching and saturation of single molecules by fluorophore recrossing events in a laser beam is described. The diffraction-limited probe volumes encountered in single-molecule detection (SMD) produce high excitation irradiance, which can decrease available signal. The single molecules of several dyes were detected and the data was used to extract interpeak times above a defined threshold value. The interpeak times revealed the number of fluorophore recrossing events. The number of molecules detected that were within 2 ms of each other represented a molecular recrossing for this work. Calcein, fluorescein and R-phycoerythrin were analyzed and the saturation irradiance and photobleaching effects were determined as a function of irradiance. This approach is simple and it serves as a method of optimizing experimental conditions for single-molecule detection.

Effect of Refiner Addition Level on Zirconium-Containing Aluminium Alloys

International Nuclear Information System (INIS)

Jaradeh, M M R; Carlberg, T

2012-01-01

It is well known that in aluminium alloys containing Zr, grain refiner additions do not function as desired, producing an effect often referred to as nuclei poisoning. This paper investigates the structure of direct chill-cast ingots of commercial AA3003 aluminium alloys, with and without Zr, at various addition levels of Al5Ti1B master alloy. In Bridgman experiments simulating ingot solidification, Zr-containing alloys were studied after the addition of various amounts of Ti. It could be demonstrated, in both ingot casting and simulation experiments, that Zr poisoning can be compensated for by adding more Ti and/or Al5Ti1B. The results confirm better refinement behaviour with the addition of Ti + B than of only Ti. The various combinations of Zr and Ti also influenced the formation of AlFeMn phases, and the precipitation of large Al 6 (Mn,Fe) particles was revealed. AlZrTiSi intermetallic compounds were also detected.

Effect of Refiner Addition Level on Zirconium-Containing Aluminium Alloys

Science.gov (United States)

Jaradeh, M. M. R.; Carlberg, T.

2012-01-01

It is well known that in aluminium alloys containing Zr, grain refiner additions do not function as desired, producing an effect often referred to as nuclei poisoning. This paper investigates the structure of direct chill-cast ingots of commercial AA3003 aluminium alloys, with and without Zr, at various addition levels of Al5Ti1B master alloy. In Bridgman experiments simulating ingot solidification, Zr-containing alloys were studied after the addition of various amounts of Ti. It could be demonstrated, in both ingot casting and simulation experiments, that Zr poisoning can be compensated for by adding more Ti and/or Al5Ti1B. The results confirm better refinement behaviour with the addition of Ti + B than of only Ti. The various combinations of Zr and Ti also influenced the formation of AlFeMn phases, and the precipitation of large Al6(Mn,Fe) particles was revealed. AlZrTiSi intermetallic compounds were also detected.

English-Chinese oil refining dictionary. [English-Chinese

Energy Technology Data Exchange (ETDEWEB)

Chou, P; Zing, Z [eds.

1979-01-01

The dictionary is a collection of many disciplines but specialized in the terminology related to petroleum refining. It contains terms in areas such as refining, factory equipment and installation, petroleum products and test analysis, and instrument automation. It also contains terms in areas of petrochemistry, oil storage and transport, computer technology, and environmental protection. The total number of terms collected was approximately 53,000.

Contextual Distance Refining for Image Retrieval

KAUST Repository

Islam, Almasri

2014-01-01

Recently, a number of methods have been proposed to improve image retrieval accuracy by capturing context information. These methods try to compensate for the fact that a visually less similar image might be more relevant because it depicts the same object. We propose a new quick method for refining any pairwise distance metric, it works by iteratively discovering the object in the image from the most similar images, and then refine the distance metric accordingly. Test show that our technique improves over the state of art in terms of accuracy over the MPEG7 dataset.

Contextual Distance Refining for Image Retrieval

KAUST Repository

Islam, Almasri

2014-09-16

Recently, a number of methods have been proposed to improve image retrieval accuracy by capturing context information. These methods try to compensate for the fact that a visually less similar image might be more relevant because it depicts the same object. We propose a new quick method for refining any pairwise distance metric, it works by iteratively discovering the object in the image from the most similar images, and then refine the distance metric accordingly. Test show that our technique improves over the state of art in terms of accuracy over the MPEG7 dataset.

Refinement in Z and Object-Z foundations and advanced applications

CERN Document Server

Derrick, John

2013-01-01

Refinement is one of the cornerstones of the formal approach to software engineering, and its use in various domains has led to research on new applications and generalisation. This book brings together this important research in one volume, with the addition of examples drawn from different application areas. It covers four main themes:Data refinement and its application to ZGeneralisations of refinement that change the interface and atomicity of operationsRefinement in Object-ZModelling state and behaviour by combining Object-Z with CSPRefinement in Z and Object-Z: Foundations and Advanced A

Singapore refiners in midst of huge construction campaign

International Nuclear Information System (INIS)

Land, R.

1992-01-01

This paper reports that Singapore's downstream capacity continues to mushroom. Singapore refiners, upbeat about long term prospects for petroleum products demand in the Asia-Pacific region, and are pressing plans to boost processing capacity. Their plans go beyond capacity expansions. They are proceeding with projects to upgrade refineries to emphasize production of higher value products and to further integrate refining capabilities wit the region's petrochemical industry. Planned expansion and upgrading projects at Singapore refineries call for outlays of more than $1 billion to boost total capacity to about 1.1 million b/d in 1993 and 1.27 million b/d by 1995. That would be the highest level since the mid-1980s, when refiners such as Shell Singapore cut capacity amid an oil glut. Singapore refineries currently are running at effective full capacity of 1.04 million b/d. Meanwhile, Singapore refiners are aggressively courting customers in the Indochina subcontinent, where long isolated centrally planned economies are turning gradually to free markets

Directions in refining and upgrading of heavy oil and bitumen

International Nuclear Information System (INIS)

Dawson, B.; Parker, R. J.; Flint, L.

1997-01-01

The expansion of heavy oil transportation, marketing and refining facilities over the past two decades have been reviewed to show the strides that several Canadian refiners have taken to build up the facilities required to process synthetic crude oil (SCO). Key points made at a conference, convened by the National Centre for Upgrading Technology (NCUT), held in Edmonton during September 1997 to discuss current and future directions in the refining and marketing of heavy oil, bitumen and SCO, were summarized. Among the key points mentioned were: (1) the high entry barriers faced by centralized upgraders, (2) the advantages of integrating SCO or heavy oil production with downstream refining, (3) the stiff competition from Venezuela and Mexico that both SCO and heavy oil will face in the U.S. PADD II market, (4) the differences between Canadian refiners who have profited from hydrocracking and are better able to handle coker-based SCO, and American refiners who rely chiefly on catalytic cracking and are less able to process the highly aromatic SCO, and (5) the disproportionate cost in the upgrading process represented by the conversion of asphaltenes. Challenges and opportunities for key stakeholders, i.e. producers, refiners, marketers and technology licensors also received much attention at the Edmonton conference

30 CFR 208.4 - Royalty oil sales to eligible refiners.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Royalty oil sales to eligible refiners. 208.4... MANAGEMENT SALE OF FEDERAL ROYALTY OIL General Provisions § 208.4 Royalty oil sales to eligible refiners. (a... and defense. The Secretary will review these items and will determine whether eligible refiners have...

Refined algebraic quantisation in a system with nonconstant gauge invariant structure functions

International Nuclear Information System (INIS)

Martínez-Pascual, Eric

2013-01-01

In a previous work [J. Louko and E. Martínez-Pascual, “Constraint rescaling in refined algebraic quantisation: Momentum constraint,” J. Math. Phys. 52, 123504 (2011)], refined algebraic quantisation (RAQ) within a family of classically equivalent constrained Hamiltonian systems that are related to each other by rescaling one momentum-type constraint was investigated. In the present work, the first steps to generalise this analysis to cases where more constraints occur are developed. The system under consideration contains two momentum-type constraints, originally abelian, where rescalings of these constraints by a non-vanishing function of the coordinates are allowed. These rescalings induce structure functions at the level of the gauge algebra. Providing a specific parametrised family of real-valued scaling functions, the implementation of the corresponding rescaled quantum momentum-type constraints is performed using RAQ when the gauge algebra: (i) remains abelian and (ii) undergoes into an algebra of a nonunimodular group with nonconstant gauge invariant structure functions. Case (ii) becomes the first example known to the author where an open algebra is handled in refined algebraic quantisation. Challenging issues that arise in the presence of non-gauge invariant structure functions are also addressed

Development of an efficient grain refiner for Al-7Si alloy

Energy Technology Data Exchange (ETDEWEB)

Kori, S.A.; Murty, B.S.; Chakraborty, M. [Indian Inst. of Technol., Kharagpur (India). Dept. of Metall. and Mater. Eng.

2000-03-15

The response of Al-7Si alloy towards grain refinement by Al-Ti-B master alloys (with different Ti-B ratios) at different addition levels has been studied in detail. The results indicate that high B-containing master alloys are powerful grain refiners when compared to conventional grain refiners like Al-5Ti-lB master alloys. In the present study, indigenously developed master alloys have been used for the grain refinement of alloys Al-7Si and LM-25. Significant improvements in mechanical properties have been obtained with a combination of grain refiner and Sr as modifier. (orig.)

Oil refining in South Asia and Australasia

International Nuclear Information System (INIS)

Yamaguchi, N.D.

2000-01-01

An overview of the oil markets of Southeast Asia and Australasia is presented focussing on oil refining. Key statistics of both areas are tabulated, and figures providing information on GDP/capita, crude production, comparison of demand barrels, and product demand are provided. Crude oil production and supply, oil product demand, and the refining industries are examined with details given of evolution of capacity and cracking to distillation ratios

Investment in Exploration-Production and Refining - 2016

International Nuclear Information System (INIS)

Maisonnier, Guy; Hureau, Geoffroy; Serbutoviez, Sylvain; Silva, Constancio

2017-03-01

IFPEN analyses in this study the 2016 evolution of global investment in the field of exploration-production and refining: - Trends in oil and gas prices; - Investment in exploration/production: in sharp decline for the second consecutive year - the first time this has happened since 1986; - The global drilling market; - Geophysical: global activity and markets; - Offshore construction: market and business; - A significant reduction in refining projects (atmospheric distillation and conversion)

Problems persist for French refining sector

International Nuclear Information System (INIS)

Beck, R.J.

1992-01-01

This paper reports that France's refiners face a continuing shortfall of middle distillate capacity and a persistent surplus of heavy fuel oil. That's the main conclusion of the official Hydrocarbon Directorate's report on how France's refining sector performed in 1991. Imports up---The directorate noted that although net production of refined products in French refineries rose to 1.534 million b/d in 1991 from 1.48 million b/d in 1990, products imports jumped 9.7% to 602,000 b/d in the period. The glut of heavy fuel oil eased to some extent last year because French nuclear power capacity, heavily dependent on ample water supplies, was crimped by drought. That spawned fuel switching. The most note worthy increase in imports was for motor diesel, climbing to 176,000 b/d from 148,000 b/d in 1990. Tax credits are spurring French consumption of that fuel. For the first time, consumption of motor diesel in 1991 outstripped that of gasoline at 374,000 b/d and 356,000 b/d respectively

Refining glass structure in two dimensions

Science.gov (United States)

Sadjadi, Mahdi; Bhattarai, Bishal; Drabold, D. A.; Thorpe, M. F.; Wilson, Mark

2017-11-01

Recently determined atomistic scale structures of near-two dimensional bilayers of vitreous silica (using scanning probe and electron microscopy) allow us to refine the experimentally determined coordinates to incorporate the known local chemistry more precisely. Further refinement is achieved by using classical potentials of varying complexity: one using harmonic potentials and the second employing an electrostatic description incorporating polarization effects. These are benchmarked against density functional calculations. Our main findings are that (a) there is a symmetry plane between the two disordered layers, a nice example of an emergent phenomena, (b) the layers are slightly tilted so that the Si-O-Si angle between the two layers is not 180∘ as originally thought but rather 175 ±2∘ , and (c) while interior areas that are not completely imagined can be reliably reconstructed, surface areas are more problematic. It is shown that small crystallites that appear are just as expected statistically in a continuous random network. This provides a good example of the value that can be added to disordered structures imaged at the atomic level by implementing computer refinement.

Solving the Sophistication-Population Paradox of Game Refinement Theory

OpenAIRE

Xiong , Shuo; Tiwary , Parth ,; Iida , Hiroyuki

2016-01-01

Part 4: Short Papers; International audience; A mathematical model of game refinement was proposed based on uncertainty of game outcome. This model has been shown to be useful in measuring the entertainment element in the domains such as boardgames and sport games. However, game refinement theory has not been able to explain the correlation between the popularity of a game and the game refinement value. This paper introduces another aspect in the study of game entertainment, the concept of “a...

A refined approach: Saudi Arabia moves beyond crude

International Nuclear Information System (INIS)

Krane, Jim

2015-01-01

Saudi Arabia's role in global energy markets is changing. The kingdom is reshaping itself as a supplier of refined petroleum products while moving beyond its long-held role as a simple exporter of crude oil. This change is commensurate with the typical development trajectory of a state progressing to a more advanced stage of global economic integration. Gains from increased refining include reducing fuel imports and capturing margins now bequeathed to competitors. Refining also allows the kingdom to export its heavy crude oil to a wider array of customers, beyond select importers configured to handle heavy crudes. However, the move also presents strategic complications. The world's 'swing supplier' of oil may grow less willing or able to adjust supply to suit market demands. In the process, Saudi Arabia may have to update the old “oil for security” relationship that links it with Washington, augmenting it with a more diverse set of economic and investment ties with individual companies and countries, including China. -- Highlights: •Saudi Arabia is diverting crude oil into an expanding refining sector. •In doing so, the kingdom is moving beyond its role as global “swing supplier” of crude oil. •The kingdom will benefit from increased refining, including enhanced demand for heavy crude. •Strategic complications may force it to seek security partners beyond Washington

The future of refining industry is in Asia

International Nuclear Information System (INIS)

Dupin, L.

2010-01-01

The decision of Total Group to close down the refining activity of its Flandres' site at Dunkerque (France) is a testimony of the deep restructuring that is affecting this sector. The migration of the refining activity towards Middle-East and Asia has started several years ago. The World capacities are increasing: in 2009 4.36 billion tons of petroleum products were refined in the world, representing a 1.9% rise with respect to 2008. 661 refineries exist in the world, among which 6 were inaugurated in 2009, 115 are located in Europe and 12 in France. The bad health of the European refining activity is beneficial to Middle and Asia where investments in new production capacities follow on from one another. From now to 2030, these areas will benefit from 70% of the worldwide investments compared to 11% only for Europe and North America. The decline of the European refining industry is directly linked to decay of the automotive fuel consumption and to the increase of the diesel fuel share with respect to gasoline. On the other hand, Asia, and in particular China and India, follow the exactly opposite trend thanks to their population and economic growths. Therefore, European oil companies try to invest in Asia and are looking for new production capacities in China and India. (J.S.)

Effect of addition of tantalum and zirconium on the mechanical behavior of aluminum grain refined by Ti+ B

International Nuclear Information System (INIS)

Zaid, A.I.O.

2003-01-01

Aluminum and its alloys normally solidify in a columnar structure with coarse grains. Therefore, they are normally grain refined by adding either titanium or titanium + boron to their melts to obtain finer grain size and better surface quality. Other elements may be added beside the grain refiners to enhance their grain refinement efficiency and improve the mechanical behavior. Some elements were found to improve the grain refining efficiency of the master alloys e.g., vanadium, molybdenum, while others were found to deteriorate the grain refining efficiency e.g., zirconium and tantalum. The literature reveals that in general, only one element is added in the presence of the binary AI-Ti or the ternary AI-Ti-B grain refining master alloy. It is, therefore, anticipated that the addition of Ta and Zr may have different effect when added together from that if each element is added alone. This formed the main objective of this paper. In this paper, the effect of addition of either Zr, Ta or both of them together, with a percentage of 0.1 %wt each, on the grain size, hardness and mechanical behavior of AI and AI grain refined by Ti+B is investigated. It was found that adding Zr or Ta to commercially pure aluminum resulted in grain refinement of its structure and resulted in slight improvement of its hardness. However, a pronounced improvement was obtained in its mechanical strength and formability. On the other hand, addition of either Zr or Ta to Al grain refined by Ti+B resulted in poisoning effect i.e. reducing the grain refining efficiency of the AI- Ti-B master alloy. Practically, addition of either Zr or Ta has no effect on its hardness but resulted in a pronounced improvement of its mechanical strength. Finally, the addition of Zr + Ta to commercially pure aluminum or to aluminum grain refined by Ti+B resulted in reduction of grain size, little improvement in hardness and pronounced improvement in mechanical strength than when each element was added alone

Refining - Panorama 2008; Raffinage - Panorama 2008

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

Investment rallied in 2007, and many distillation and conversion projects likely to reach the industrial stage were announced. With economic growth sustained in 2006 and still pronounced in 2007, oil demand remained strong - especially in emerging countries - and refining margins stayed high. Despite these favorable business conditions, tensions persisted in the refining sector, which has fallen far behind in terms of investing in refinery capacity. It will take renewed efforts over a long period to catch up. Looking at recent events that have affected the economy in many countries (e.g. the sub-prime crisis), prudence remains advisable.

The Charfuel coal refining process

International Nuclear Information System (INIS)

Meyer, L.G.

1991-01-01

The patented Charfuel coal refining process employs fluidized hydrocracking to produce char and liquid products from virtually all types of volatile-containing coals, including low rank coal and lignite. It is not gasification or liquefaction which require the addition of expensive oxygen or hydrogen or the use of extreme heat or pressure. It is not the German pyrolysis process that merely 'cooks' the coal, producing coke and tar-like liquids. Rather, the Charfuel coal refining process involves thermal hydrocracking which results in the rearrangement of hydrogen within the coal molecule to produce a slate of co-products. In the Charfuel process, pulverized coal is rapidly heated in a reducing atmosphere in the presence of internally generated process hydrogen. This hydrogen rearrangement allows refinement of various ranks of coals to produce a pipeline transportable, slurry-type, environmentally clean boiler fuel and a slate of value-added traditional fuel and chemical feedstock co-products. Using coal and oxygen as the only feedstocks, the Charfuel hydrocracking technology economically removes much of the fuel nitrogen, sulfur, and potential air toxics (such as chlorine, mercury, beryllium, etc.) from the coal, resulting in a high heating value, clean burning fuel which can increase power plant efficiency while reducing operating costs. The paper describes the process, its thermal efficiency, its use in power plants, its pipeline transport, co-products, environmental and energy benefits, and economics

Simultaneous use of solution NMR and X-ray data in REFMAC5 for joint refinement/detection of structural differences

Energy Technology Data Exchange (ETDEWEB)

Rinaldelli, Mauro; Ravera, Enrico; Calderone, Vito; Parigi, Giacomo [University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino (Finland) (Italy); University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (Finland) (Italy); Murshudov, Garib N., E-mail: garib@mrc-lmb.cam.ac.uk [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom); Luchinat, Claudio, E-mail: garib@mrc-lmb.cam.ac.uk [University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino (Finland) (Italy); University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (Finland) (Italy)

2014-04-01

Paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and diamagnetic residual dipolar couplings can now be used in the program REFMAC5 from CCP4 as structural restraints together with X-ray crystallographic data. These NMR restraints can reveal differences between solid state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. The program REFMAC5 from CCP4 was modified to allow the simultaneous use of X-ray crystallographic data and paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and/or diamagnetic residual dipolar couplings. Incorporation of these long-range NMR restraints in REFMAC5 can reveal differences between solid-state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. Since NMR and X-ray data are complementary, when a single structure is consistent with both sets of data and still maintains reasonably ‘ideal’ geometries, the reliability of the derived atomic model is expected to increase. The program was tested on five different proteins: the catalytic domain of matrix metalloproteinase 1, GB3, ubiquitin, free calmodulin and calmodulin complexed with a peptide. In some cases the joint refinement produced a single model consistent with both sets of observations, while in other cases it indicated, outside the experimental uncertainty, the presence of different protein conformations in solution and in the solid state.

Simultaneous use of solution NMR and X-ray data in REFMAC5 for joint refinement/detection of structural differences

International Nuclear Information System (INIS)

Rinaldelli, Mauro; Ravera, Enrico; Calderone, Vito; Parigi, Giacomo; Murshudov, Garib N.; Luchinat, Claudio

2014-01-01

Paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and diamagnetic residual dipolar couplings can now be used in the program REFMAC5 from CCP4 as structural restraints together with X-ray crystallographic data. These NMR restraints can reveal differences between solid state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. The program REFMAC5 from CCP4 was modified to allow the simultaneous use of X-ray crystallographic data and paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and/or diamagnetic residual dipolar couplings. Incorporation of these long-range NMR restraints in REFMAC5 can reveal differences between solid-state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. Since NMR and X-ray data are complementary, when a single structure is consistent with both sets of data and still maintains reasonably ‘ideal’ geometries, the reliability of the derived atomic model is expected to increase. The program was tested on five different proteins: the catalytic domain of matrix metalloproteinase 1, GB3, ubiquitin, free calmodulin and calmodulin complexed with a peptide. In some cases the joint refinement produced a single model consistent with both sets of observations, while in other cases it indicated, outside the experimental uncertainty, the presence of different protein conformations in solution and in the solid state

pH-zone-refining elution-extrusion countercurrent chromatography: Separation of hydroxyanthraquinones from Cassiae semen.

Science.gov (United States)

Bu, Zhisi; Lv, Liqiong; Li, Xingnuo; Chu, Chu; Tong, Shengqiang

2017-11-01

Seven hydroxyanthraquinones were successfully separated from the traditional Chinese medicinal herb Cassiae semen by conventional and pH-zone-refining countercurrent chromatography with an environmentally friendly biphasic solvent system, in which elution-extrusion mode was investigated for pH-zone-refining countercurrent chromatography for the first time. A two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/water (5:3:4:4, v/v/v/v) was used for the conventional countercurrent chromatography while the same system with a different volume ratio n-hexane/ethyl acetate/ethanol/water (3:5:2:6, v/v/v/v) was used for pH-zone-refining countercurrent chromatography, in which 20 mmol/L of trifluoroacetic acid was added in the organic phase as a retainer and 15 mmol/L of ammonia was added to the aqueous phase as an eluter. A 400 mg crude sample could be well separated by pH-zone-refining countercurrent chromatography, yielding 53 mg of aurantio-obtusin, 40 mg of chryso-obtusin, 18 mg of obtusin, 24 mg of obtusifolin, 10 mg of emodin, and 105 mg of the mixture of chrysophanol and physcion with a purity of over 95.8, 95.7, 96.9, 93.5, 97.4, 77.1, and 19.8%, as determined by high-performance liquid chromatography. Furthermore, the difference in elution sequence between conventional and pH-zone-refining mode was observed and discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Asian oil refining. Demand growth and deregulation - an uncertain future

International Nuclear Information System (INIS)

Sameer Nawaz.

1996-01-01

The objective of the report is to identify the most important features of the oil refining industry in Asia. Major developments in consumption patterns changes in regional importance of countries are discussed, highlighting potential future developments. The first chapter introduces the various refining processes and presents a simple model for the analysis of complex refineries. Chapter 2 examines the development of the Asian refining industry against a background of economic growth and analyses trends in consumption of all products in Asian countries. In Chapter 3, the key issues concerning the refining industry are examined, among them the forces driving consumption, including the importance of economic development, and electricity and transport demand. The importance of product imports and international trade is discussed, and the extent of government involvement and the effects of changing retail and market prices are analysed. Chapter 4 looks at the strategies that oil and gas companies are following in the Asian refining industry. Particular significance is attached to the vertical integration of the oil majors, Japanese and Middle Eastern oil companies. A brief overview of the importance of the petrochemical industry is presented. The countries of Asia that are involved in the refining industry are profiled in Chapter 5. The future trend in oil consumption is examined in Chapter 6. There follows a brief discussion of the plans to expand crude refining capacity in the various countries and a forecast of the state of overcapacity which will result. In the final chapter, brief profiles of some of the most important companies in the Asian refining industry are presented, discussing their major activities and future plans. (Author)

US refining capacity for Canadian heavy oil : current overview and future potential

International Nuclear Information System (INIS)

Paget, S.

2006-01-01

This presentation provided an overview of the Canadian oil sands industry and investigated the potential heavy oil refining capacity of the United States. An outline of the first commercial developments of steam assisted gravity drainage (SAGD) in Alberta's oil sands was provided. Canada's reserves were compared with oil shale and heavy oil reserves in the United States and Venezuela. Influences of Canadian developments from western Canadian conventional crude oil were reviewed, and an oil sands production forecast was provided. Recent refining developments in the United States include delayed coking; catalytic cracking; fluid coking; flexicoking; and LC-fining. However, many oil sand producers are now choosing to upgrade oil, and producers are currently saturating United States markets with heavy crude oil. Canadian crude prices reached $90 per barrel in 2006. Heavy oil pipelines are now being constructed and existing heavy oil pipelines are being expanded. ConocoPhillips is planning to invest $1 billion for a new heavy oil coker, while BP is investing $3 billion for a heavy oil refinery in Indiana which plans to refine Canadian crude oil supplies. However, bitumens from Alberta are volatile in price, and excess Canadian production must be exported. Less than 10 per cent of western Canadian crude has tidewater access, and capital providers are concerned about cost over-runs. In order for the Canadian oil sands industry to succeed, refining capacity in the United States must be expanded, and open access must be provided to the Gulf coast as well as to the Pacific Ocean. tabs., figs

REFINEMENT OF THE REVERSE EXTRUSION TEST TO DETERMINE THE TWO CONSISTENCY LIMITS

Directory of Open Access Journals (Sweden)

Kamil KAYABALI

2015-11-01

Full Text Available Liquid limit (LL and plastic limit (PL are the two most commonly used index proper- ties of fine-grained soils. They have been used in not only classification of soils but also in correlation with certain engineering properties. Therefore, they have been subjected to numerous researches since they were first introduced by Atterberg in 1911. While their me- chanisms were well defined in many codes and they have been in use for decades, criticisms often arose pertinent to the uncertainties inherent to them. Incredible amount of effort has been exerted to invent more rational testing methods in place of both the Casagrande’s cup and bead rolling methods. Part of those efforts has been on devicing a single tool to measure the two relative index properties together. Recently, the reverse extrusion test was brought into the use of geotechnical engineers. It was shown that this tool has a potential of measu- ring LL, PL, and even the shrinkage limit (SL. The aim of this investigation is to reassess the ability of the reverse extrusion test to determine LL and PL with further refinement. In this regard 70 fine-grained soils covering a large range of plasticity were employed. Fall-cone method and rolling-device method were employed to determine LL and PL, res- pectively. The reverse extrusion tests were carried out at least five different water contents per soil sample. Extrusion pressures were plotted against water content and a curve fitting was applied to data pairs, from which the y-intercept (the coefficient a and the slope (the coefficieent b of the curve were determined. Those reverse extrusion coefficients were utilized to determine the representative extrusion pressures corresponding to LL and PL, as was done by the earlier researchers; however, the degree of success for the prediction of LL and PL using the representative extrusion pressures was not encouraging. Different from the previously proposed approaches, the reverse extrusion

Comparison of Some Rural Wastewater Refining Systems Considering Chemical Properties and Heavy Metals

Directory of Open Access Journals (Sweden)

Najme Yazdanpanah

2016-02-01

Full Text Available Introduction: Water scarcity is an important challenge worldwide, especially in arid and semi-arid regions. In these areas, the excessive exploitation of groundwater for irrigation, inefficient irrigation methods, irrigation with low-quality water and uncontrolled utilization of fertilizers in agricultural lands in addition to contamination of water resources by domestic and industrial wastewater in urban as well as rural regions, have led to water pollution problems. Furthermore, pollution and transportation of pollutants through wastewater have been considered as an environmental issue. Wastewater is a term that is used to describe waste materials that includes liquid waste and sewage waste. Wastewaters from single houses in the countryside that are not connected to sewers are generally treated on-site by septic tank systems or individual domestic wastewater treatment systems. Study on wastewater quality derived from refining systems in rural areas has been rarely taken into account. This study investigates the efficiency of some refining systems in the reduction of wastewater pollution indices and heavy metal concentrations. Materials and Methods: This study was done in four rural areas including Dehmilan, Hotkan, Sarbagh and Sekukan which are located around the city of Zarand in the Kerman province. Recently, some refining systems have been established in these areas in order to mitigate the environmental issues. An experiment was done to assess the efficiency of these refining systems and to determine the pollution indices for such small communities. Wastewater sampling was done in 10 replicates each at one week interval from four refineries. Different variables including BOD, COD, TOC, EC, TSS, TDS, DO, TKN, TP, pH, temperature, turbidity (Turb, alkanity (Alk and also the concentrations of Cd, Zn, Pb, Ni and Mo were measured using standard methods. To quantify the performance of each system, the amount of each variable at the outlet was

Effects on satiation, satiety and food intake of wholegrain and refined grain pasta

DEFF Research Database (Denmark)

Cioffi, Iolanda; Ibrügger, Sabine; Bache, Jessica

2016-01-01

studied. The objective was to investigate the effect of WG pasta (WGP) compared to refined grain pasta (RGP), on ad libitum energy intake (EI) within and at the subsequent meal as well as appetite. Two different ad libitum lunch meals (study A) and two different iso-caloric lunch meals (study B) were...

The present state of refining in France

International Nuclear Information System (INIS)

1996-01-01

The european refining industry suffers from a production over-capacity and closures are inevitable; the situation is even worse in France due to the imbalance between gas oil and gasoline prices and the weak margin for distributors. The French refining industry is however an important and essential link for its strategic fuel and petroleum product supply, and represent 17000 jobs. Several measures are introduced by the French Industry department towards restructuring, capacity reduction and fuel price harmonization

A new process of electron beam refining of niobium

International Nuclear Information System (INIS)

Pinatti, D.G.

1981-01-01

A review of thermodynamic equilibrium, the kinetic theory and experimental results of the metal-gas interaction in refractory metals is presented. N 2 , H 2 and CO absorption and desorption take place by a reversible process while O 2 takes place by a irreversible process with atom absorption and metal oxide desorption. A new technology of electron beam refining of Niobium is proposed based on four points: 1) preparation of the aluminothermic reduced electrode, 2) zone refining in the first melt, 3) kinetic theory of refining in the following melts and 4) design of a compact furnace. Experimental results in a pilot plant of 300 KW have shown complete agreement with the proposed technology yielding a productivity 2.4 times larger than the value predicted by the conventional technology of electron beam refining of Niobium. (Author) [pt

European refining: evolution or revolution?

International Nuclear Information System (INIS)

Cuthbert, N.

1999-01-01

A recent detailed analysis of the refining business in Europe (by Purvin and Gurtz) was used to highlight some key issues facing the industry. The article was written under five sub-sections: (i) economic environment (assessment of the economic prospects for Europe), (ii) energy efficiency and global warming (lists the four points of the EU car makers' voluntary agreement), (iii) fuel quality and refinery investment (iv) refinery capacity and utilisation and (v) industry structure and development. Diagrams show GDP per capita for East and West, European road fuel demand to 2015 and European net trade and European refinery ownership by crude capacity. It was concluded that the future of refining in Europe is 'exciting and challenging' and there are likely to be more large joint venture refineries. (UK)

Dynamic quantum crystallography: lattice-dynamical models refined against diffraction data. II. Applications to L-alanine, naphthalene and xylitol.

Science.gov (United States)

Hoser, Anna A; Madsen, Anders Ø

2017-03-01

In the first paper of this series [Hoser & Madsen (2016). Acta Cryst. A72, 206-214], a new approach was introduced which enables the refinement of frequencies of normal modes obtained from ab initio periodic computations against single-crystal diffraction data. In this contribution, the performance of this approach is tested by refinement against data in the temperature range from 23 to 205 K on the molecular crystals of L-alanine, naphthalene and xylitol. The models, which are lattice-dynamical models derived at the Γ point of the Brillouin zone, are able to describe the atomic vibrations of L-alanine and naphthalene to a level where the residual densities are similar to those obtained from the independent atom model. For the more flexible molecule xylitol, larger deviations are found. Hydrogen ADPs (anisotropic displacement parameters) derived from the models are in similar or better agreement with neutron diffraction results than ADPs obtained by other procedures. The heat capacity calculated after normal mode refinement for naphthalene is in reasonable agreement with the heat capacity obtained from calorimetric measurements (to less than 1 cal mol -1  K -1 below 300 K), with deviations at higher temperatures indicating anharmonicity. Standard uncertainties and correlation of the refined parameters have been derived based on a Monte Carlo procedure. The uncertainties are quite small and probably underestimated.

Ab initio structure determination and refinement of a scorpion protein toxin.

Science.gov (United States)

Smith, G D; Blessing, R H; Ealick, S E; Fontecilla-Camps, J C; Hauptman, H A; Housset, D; Langs, D A; Miller, R

1997-09-01

The structure of toxin II from the scorpion Androctonus australis Hector has been determined ab initio by direct methods using SnB at 0.96 A resolution. For the purpose of this structure redetermination, undertaken as a test of the minimal function and the SnB program, the identity and sequence of the protein was withheld from part of the research team. A single solution obtained from 1 619 random atom trials was clearly revealed by the bimodal distribution of the final value of the minimal function associated with each individual trial. Five peptide fragments were identified from a conservative analysis of the initial E-map, and following several refinement cycles with X-PLOR, a model was built of the complete structure. At the end of the X-PLOR refinement, the sequence was compared with the published sequence and 57 of the 64 residues had been correctly identified. Two errors in sequence resulted from side chains with similar size while the rest of the errors were a result of severe disorder or high thermal motion in the side chains. Given the amino-acid sequence, it is estimated that the initial E-map could have produced a model containing 99% of all main-chain and 81% of side-chain atoms. The structure refinement was completed with PROFFT, including the contributions of protein H atoms, and converged at a residual of 0.158 for 30 609 data with F >or= 2sigma(F) in the resolution range 8.0-0.964 A. The final model consisted of 518 non-H protein atoms (36 disordered), 407 H atoms, and 129 water molecules (43 with occupancies less than unity). This total of 647 non-H atoms represents the largest light-atom structure solved to date.

Bio-Refining of Carbohydrate-Rich Food Waste for Biofuels

Directory of Open Access Journals (Sweden)

Hoang-Tuong Nguyen Hao

2015-06-01

Full Text Available The global dependence on finite fossil fuel-derived energy is of serious concern given the predicted population increase. Over the past decades, bio-refining of woody biomass has received much attention, but data on food waste refining are sorely lacking, despite annual and global deposition of 1.3 billion tons in landfills. In addition to negative environmental impacts, this represents a squandering of valuable energy, water and nutrient resources. The potential of carbohydrate-rich food waste (CRFW for biofuel (by Rhodotorulla glutinis fermentation and biogas production (by calculating theoretical methane yield was therefore investigated using a novel integrated bio-refinery approach. In this approach, hydrolyzed CRFW from three different conditions was used for Rhodotorulla glutinis cultivation to produce biolipids, whilst residual solids after hydrolysis were characterized for methane recovery potential via anaerobic digestion. Initially, CRFW was hydrolysed using thermal- (Th, chemical- (Ch and Th-Ch combined hydrolysis (TCh, with the CRFW-leachate serving as a control (Pcon. Excessive foaming led to the loss of TCh cultures, while day-7 biomass yields were similar (3.4–3.6 g dry weight (DW L−1 for the remaining treatments. Total fatty acid methyl ester (FAME content of R. glutinis cultivated on CRFW hydrolysates were relatively low (~6.5% but quality parameters (i.e., cetane number, density, viscosity and higher heating values of biomass extracted biodiesel complied with ASTM standards. Despite low theoretical RS-derived methane potential, further research under optimised and scaled conditions will reveal the potential of this approach for the bio-refining of CRFW for energy recovery and value-added co-product production.

Multilevel local refinement and multigrid methods for 3-D turbulent flow

Energy Technology Data Exchange (ETDEWEB)

Liao, C.; Liu, C. [UCD, Denver, CO (United States); Sung, C.H.; Huang, T.T. [David Taylor Model Basin, Bethesda, MD (United States)

1996-12-31

A numerical approach based on multigrid, multilevel local refinement, and preconditioning methods for solving incompressible Reynolds-averaged Navier-Stokes equations is presented. 3-D turbulent flow around an underwater vehicle is computed. 3 multigrid levels and 2 local refinement grid levels are used. The global grid is 24 x 8 x 12. The first patch is 40 x 16 x 20 and the second patch is 72 x 32 x 36. 4th order artificial dissipation are used for numerical stability. The conservative artificial compressibility method are used for further improvement of convergence. To improve the accuracy of coarse/fine grid interface of local refinement, flux interpolation method for refined grid boundary is used. The numerical results are in good agreement with experimental data. The local refinement can improve the prediction accuracy significantly. The flux interpolation method for local refinement can keep conservation for a composite grid, therefore further modify the prediction accuracy.

The critical effect of Fe on the grain refinement of aluminium via Al-5Ti-1B addition

International Nuclear Information System (INIS)

Zhang, Y; Ma, N

2016-01-01

The influence of Fe on the nucleation potency of TiB 2 particles was investigated by employing grain refinement of high purity aluminium in this study. Experiment results showed that without Fe, high purity aluminium cannot be refined by 0.8wt.% addition of Al-5Ti-1B. However, high purity aluminium containing 0.08wt.% Fe can be refined effectively by 0.2wt.% addition of Al-5Ti-1B, its grain size was about 206µm in diameter. Fine equiaxed grains of about 153µm in diameter can be obtained for high purity aluminium containing 0.08wt.% Fe and 0.006wt.% Ti. Grain refinement mechanism should include nucleation and dendrite remelting and multiplication. Both nucleation and dendrite remelting and multiplication played essential role on the grain refinement of aluminium. The effect of Fe was linked to increase active nuclei by segregation on TiB 2 surface and then to promote nucleation of α-Al. The performance of Ti was to enhance the dendrite remelting and multiplication by forming small conglomeration zones of Ti atoms concentrated around TiB 2 particles. (paper)

3D Adaptive Mesh Refinement Simulations of Pellet Injection in Tokamaks

International Nuclear Information System (INIS)

Samtaney, S.; Jardin, S.C.; Colella, P.; Martin, D.F.

2003-01-01

We present results of Adaptive Mesh Refinement (AMR) simulations of the pellet injection process, a proven method of refueling tokamaks. AMR is a computationally efficient way to provide the resolution required to simulate realistic pellet sizes relative to device dimensions. The mathematical model comprises of single-fluid MHD equations with source terms in the continuity equation along with a pellet ablation rate model. The numerical method developed is an explicit unsplit upwinding treatment of the 8-wave formulation, coupled with a MAC projection method to enforce the solenoidal property of the magnetic field. The Chombo framework is used for AMR. The role of the E x B drift in mass redistribution during inside and outside pellet injections is emphasized

Crystallographic Investigations into Properties of Acentric Hybrid Perovskite Single Crystals NH(CH3)3SnX3(X = Cl, Br)

KAUST Repository

Dang, Yangyang

2016-10-11

The hybrid perovskites with special optoelectronic properties have attracted more attention to the scientific and industrial applications. However, because of the toxicity and instability of lead complexes, there is interest in finding a nontoxic substitute for the lead in the halides perovskites and solving the ambiguous crystal structures and phase transition of NH(CH3)3SnX3 (X = Cl, Br). Here, we report the bulk crystal growths and different crystal morphologies of orthorhombic hybrid perovskites NH(CH3)3SnX3 (X = Cl, Br) in an ambient atmosphere by bottom-seeded solution growth (BSSG) method. More importantly, detailed structural determination and refinements, phase transition, band gap, band structure calculations, nonlinear optical (NLO) properties, XPS, thermal properties, and stability of NH(CH3)3SnX3 (X = Cl, Br) single crystals are demonstrated. NH(CH3)3SnCl3 single crystal undergoes reversible structural transformation from orthorhombic space group Cmc21 (no. 36) to monoclinic space group Cc (no. 9) and NH(CH3)3SnBr3 belongs to the orthorhombic space group Pna21 (no. 33) by DSC, single-crystal X-ray diffraction and temperature-dependent SHG measurements, which clarify the former results. These results should pave the way for further studies of these materials in optoelectronics.

Adaptive mesh refinement for storm surge

KAUST Repository

Mandli, Kyle T.; Dawson, Clint N.

2014-01-01

An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the GeoClaw framework and compared to ADCIRC for Hurricane Ike along with observed tide gauge data and the computational cost of each model run. © 2014 Elsevier Ltd.

Adaptive mesh refinement for storm surge

KAUST Repository

Mandli, Kyle T.

2014-03-01

An approach to utilizing adaptive mesh refinement algorithms for storm surge modeling is proposed. Currently numerical models exist that can resolve the details of coastal regions but are often too costly to be run in an ensemble forecasting framework without significant computing resources. The application of adaptive mesh refinement algorithms substantially lowers the computational cost of a storm surge model run while retaining much of the desired coastal resolution. The approach presented is implemented in the GeoClaw framework and compared to ADCIRC for Hurricane Ike along with observed tide gauge data and the computational cost of each model run. © 2014 Elsevier Ltd.

Russian refining - an industry in transition

Energy Technology Data Exchange (ETDEWEB)

Barrett, E [CentreInvest, Moscow (Russian Federation)

1999-02-01

In the old Soviet Union (now called the CIS), the refining industry is undergoing much modernisation, although the process is far from complete. Eventually, the CIS is expected to have a market-responsive competitive refining business. The expected transformation is discussed according to a five-stage plan. The stages are (i) the change from horizontally integrated entity to vertically integrated global concerns, (ii) the change from over-manned dinosaurs to modern efficient businesses, (iii) the move towards smaller, more advanced market-orientated processes, (iv) improving the transport and storage infrastructures and (v) improving accountability and profitability. The predictions for 2005 onwards are for sustained profitability. (UK)

Variability-Specific Abstraction Refinement for Family-Based Model Checking

DEFF Research Database (Denmark)

Dimovski, Aleksandar; Wasowski, Andrzej

2017-01-01

and property, while the number of possible scenarios is very large. In this work, we present an automatic iterative abstraction refinement procedure for family-based model checking. We use Craig interpolation to refine abstract variational models based on the obtained spurious counterexamples (traces...

Zone refining of sintered, microwave-derived YBCO superconductors

International Nuclear Information System (INIS)

Warrier, K.G.K.; Varma, H.K.; Mani, T.V.; Damodaran, A.D.; Balachandran, U.

1993-07-01

Post-sintering treatments such as zone melting under thermal gradient has been conducted on sintered YBCO tape cast films. YBCO precursor powder was derived through decomposition of a mixture of nitrates of cations in a microwave oven for ∼4 min. The resulting powder was characterized and made into thin sheets by tape casting and then sintered at 945 C for 5 h. The sintered tapes were subjected to repeated zone refining operations at relatively high speeds of ∼30 mm/h. A microstructure having uniformly oriented grains in the a-b plane throughout the bulk of the sample was obtained by three repeated zone refining operations. Details of precursor preparation, microwave processing and its advantages, zone refining conditions, and microstructural features are presented in this paper

Refficientlib: an efficient load-rebalanced adaptive mesh refinement algorithm for high-performance computational physics meshes

OpenAIRE

Baiges Aznar, Joan; Bayona Roa, Camilo Andrés

2017-01-01

No separate or additional fees are collected for access to or distribution of the work. In this paper we present a novel algorithm for adaptive mesh refinement in computational physics meshes in a distributed memory parallel setting. The proposed method is developed for nodally based parallel domain partitions where the nodes of the mesh belong to a single processor, whereas the elements can belong to multiple processors. Some of the main features of the algorithm presented in this paper a...

Structural refinement, photoluminescence and Raman spectroscopy of wurtzite Mn-doped Zn O pellets

Energy Technology Data Exchange (ETDEWEB)

Marquina, J.; Martin, J.; Luengo, J.; Vera, F.; Roa, L. [Centro de Estudios Avanzados en Optica, Universidad de los Andes, Merida 5101 (Venezuela, Bolivarian Republic of); Gonzalez, J. [Centro de Estudios de Semiconductores, Universidad de los Andes, Merida 5101 (Venezuela, Bolivarian Republic of); Rodriguez, F.; Renero L, C.; Valiente, R. [Malta-Consolider Team, CITIMAC, Facultad de Ciencias, Universidad de Cantabria, Santander 69005 (Spain); Delgado, G. E., E-mail: marquinajesus@gmail.com [Laboratorio de Cristalografia, Facultad de Ciencias, Universidad de los Andes, Merida 5101 (Venezuela, Bolivarian Republic of)

2017-11-01

We report the results of the Rietveld refinement, photoluminescence and Raman spectroscopy of Mn-doped Zn O ceramic pellets. Rietveld refinement shows that samples crystallize in the wurtzite structure and for the Mn-doped sample indicated that the Mn atoms substitute the Zn tetrahedral crystallographic sites in the Zn O host lattice. The emission and absorption spectra of Mn-doped Zn O have been investigated in the visible-UV region and the data have been interpreted in terms of the wurtzite Zn O electronic structure. Two broad bands, one due to superposition between donor bound excitons (DX) and free excitons (FX) and other due free-to bond excitonic recombination (FB) dominates the low-temperature photoluminescence spectra of Mn-doped Zn O bulk. In the Raman spectrum, an extra mode at ∼520 cm{sup -1} has been observed in agreement with earlier works, and it is an indicator for the incorporation of Mn{sup +2} ions into the Zn O host matrix since it is not is observed in Zn O pristine. Rietveld refinement of the X-ray diffraction patterns, energy-dispersive X-ray spectroscopy (EDS) technique, and Raman spectroscopies were performed to study these effects. (Author)

Realization of the Zone Length Measurement during Zone Refining Process via Implementation of an Infrared Camera

Directory of Open Access Journals (Sweden)

Danilo C. Curtolo

2018-05-01

Full Text Available Zone refining, as the currently most common industrial process to attain ultrapure metals, is influenced by a variety of factors. One of these parameters, the so-called “zone length”, affects not only the ultimate concentration distribution of impurities, but also the rate at which this distribution is approached. This important parameter has however neither been investigated experimentally, nor ever varied for the purpose of optimization. This lack of detections may be due to the difficult temperature measurement of a moving molten area in a vacuum system, of which the zone refining methodology is comprised. Up to now, numerical simulation as a combination of complex mathematical calculations, as well as many assumptions has been the only way to reveal it. This paper aims to propose an experimental method to accurately measure the molten zone length and to extract helpful information on the thermal gradient, temperature profile and real growth rate in the zone refining of an exemplary metal, in this case aluminum. This thermographic method is based on the measurement of the molten surface temperature via an infrared camera, as well as further data analysis through the mathematical software MATLAB. The obtained results show great correlation with the visual observations of zone length and provide helpful information to determine the thermal gradient and real growth rate during the whole process. The investigations in this paper approved the application of an infrared camera for this purpose as a promising technique to automatically control the zone length during a zone refining process.

Oil refining and product marketing developments in southeast Asia

International Nuclear Information System (INIS)

Szabo, A.M.

1992-01-01

Views on the future are based on supplies from a relatively stable Middle East and continued economic growth in the southeast Asian and Pacific countries. Under these circumstances the oil market for the Association of Southeast Asian Nations (ASEAN) will expand considerably during the decade of the 90's. Pacific country demand, 5.92 MMB/D, in 1990 is likely to grow to 7.06 MMB/D in 2000. Regional production could supply about 40% of this. The Asia-Pacific shortage of refining capacity could lead to high regional refined product prices and health refining profit margins. (author)

Electromyogram refinement using muscle synergy based regulation of uncertain information.

Science.gov (United States)

Min, Kyuengbo; Shin, Duk; Lee, Jongho; Kakei, Shinji

2018-04-27

Electromyogram signal (EMG) measurement frequently experiences uncertainty attributed to issues caused by technical constraints such as cross talk and maximum voluntary contraction. Due to these problems, individual EMGs exhibit uncertainty in representing their corresponding muscle activations. To regulate this uncertainty, we proposed an EMG refinement, which refines EMGs with regulating the contribution redundancy of the signals from EMGs to approximating torques through EMG-driven torque estimation (EDTE) using the muscular skeletal forward dynamic model. To regulate this redundancy, we must consider the synergistic contribution redundancy of muscles, including "unmeasured" muscles, to approximating torques, which primarily causes redundancy of EDTE. To suppress this redundancy, we used the concept of muscle synergy, which is a key concept of analyzing the neurophysiological regulation of contribution redundancy of muscles to exerting torques. Based on this concept, we designed a muscle-synergy-based EDTE as a framework for EMG refinement, which regulates the abovementioned uncertainty of individual EMGs in consideration of unmeasured muscles. In achieving the proposed EMG refinement, the most considerable point is to suppress a large change such as overestimation attributed to enhancement of the contribution of particular muscles to estimating torques. Therefore it is reasonable to refine EMGs by minimizing the change in EMGs. To evaluate this model, we used a Bland-Altman plot, which quantitatively evaluates the proportional bias of refined signals to EMGs. Through this evaluation, we showed that the proposed EDTE minimizes the bias while approximating torques. Therefore this minimization optimally regulates the uncertainty of EMGs and thereby leads to optimal EMG refinement. Copyright © 2018 Elsevier Ltd. All rights reserved.

40 CFR 80.555 - What provisions are available to a large refiner that acquires a small refiner or one or more of...

Science.gov (United States)

2010-07-01

... FUELS AND FUEL ADDITIVES Motor Vehicle Diesel Fuel; Nonroad, Locomotive, and Marine Diesel Fuel; and ECA... May 31, 2010 for a refinery acquired from a motor vehicle diesel fuel small refiner or beyond the... motor vehicle diesel fuel small refiner or beyond the dates specified in § 80.554(a) or (b), as...

AN IMPROVED SNAKE MODEL FOR REFINEMENT OF LIDAR-DERIVED BUILDING ROOF CONTOURS USING AERIAL IMAGES

Directory of Open Access Journals (Sweden)

Q. Chen

2016-06-01

Full Text Available Building roof contours are considered as very important geometric data, which have been widely applied in many fields, including but not limited to urban planning, land investigation, change detection and military reconnaissance. Currently, the demand on building contours at a finer scale (especially in urban areas has been raised in a growing number of studies such as urban environment quality assessment, urban sprawl monitoring and urban air pollution modelling. LiDAR is known as an effective means of acquiring 3D roof points with high elevation accuracy. However, the precision of the building contour obtained from LiDAR data is restricted by its relatively low scanning resolution. With the use of the texture information from high-resolution imagery, the precision can be improved. In this study, an improved snake model is proposed to refine the initial building contours extracted from LiDAR. First, an improved snake model is constructed with the constraints of the deviation angle, image gradient, and area. Then, the nodes of the contour are moved in a certain range to find the best optimized result using greedy algorithm. Considering both precision and efficiency, the candidate shift positions of the contour nodes are constrained, and the searching strategy for the candidate nodes is explicitly designed. The experiments on three datasets indicate that the proposed method for building contour refinement is effective and feasible. The average quality index is improved from 91.66% to 93.34%. The statistics of the evaluation results for every single building demonstrated that 77.0% of the total number of contours is updated with higher quality index.

Comparative Study on the Grain Refinement of Al-Si Alloy Solidified under the Impact of Pulsed Electric Current and Travelling Magnetic Field

Directory of Open Access Journals (Sweden)

Yunhu Zhang

2016-07-01

Full Text Available It is high of commercial importance to generate the grain refinement in alloys during solidification by means of electromagnetic fields. Two typical patterns of electromagnetic fields, pulsed electric currents (ECP and traveling magnetic field (TMF, are frequently employed to produce the finer equiaxed grains in solidifying alloys. Various mechanisms were proposed to understand the grain refinement in alloys caused by ECP and TMF. In this paper, a comparative study is carried out in the same solidification regime to investigate the grain refinement of Al-7 wt. %Si alloy driven by ECP and TMF. Experimental results show that the application of ECP or TMF can cause the same grain refinement occurrence period, during which the refinement of primary Al continuously occurs. In addition, the related grain refinement mechanisms are reviewed and discussed, which shows the most likely one caused by ECP and TMF is the promoted dendrite fragmentation as the result of the ECP-induced or TMF-induced forced flow. It suggests that the same grain refinement process in alloys is provoked when ECP and TMF are applied in the same solidification regime, respectively.

An Investigation of Energy Storage Possibilities in Single Family Houses for Smart Grid Purposes

DEFF Research Database (Denmark)

Andersen, Palle; Pedersen, Tom S.; Nielsen, Kirsten M.

2014-01-01

In Denmark it will be a challenge in near future to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. Smart grid solutions which exploit all storage capacities are essential to meet this challenge. In this work single family houses...... with heat pumps and floor heating are investigated for storage capability. The aim is to shift energy consumption a few hours in time to mitigate the effect of fluctuating production from wind and other renewable energy sources on the grid. Based on measurements in six inhabited houses for approximately...... a year prediction models are analysed. The main topic of this work is to investigate how behaviour of inhabitants affect the quality of predictions. Unfortunately the output of the models for single inhabited single family houses seems to give large standard deviations of the predictions, and aggregated...

Grain refining mechanism of Al-containing Mg alloys with the addition of Mn-Al alloys

International Nuclear Information System (INIS)

Qin, Gaowu W.; Ren Yuping; Huang Wei; Li Song; Pei Wenli

2010-01-01

Graphical abstract: Display Omitted Research highlights: The ε-AlMn phase acts as the heterogeneous nucleus of α-Mg phase during the solidification of the AZ31 Mg alloy, not the γ-Al 8 Mn 5 phase. The grain refinement effect is very clear with the addition of only 0.5 wt% Mn-28Al alloy (pure ε-AlMn). The grain refinement does not deteriorate up to the holding time of 60 min at 740 o C. - Abstract: The effect of manganese on grain refinement of Al-containing AZ31 Mg alloy has been investigated by designing a series of Mn-Al alloys composed of either pure ε-AlMn, γ 2 -Al 8 Mn 5 or both of them using optical microscopy and X-ray diffraction. It is experimentally clarified that the grain refinement of the AZ31 Mg alloy is due to the existence of the ε-AlMn phase in the Mn-Al alloys, not the γ 2 -Al 8 Mn 5 phase. The grain size of AZ31 Mg alloy is about 91 μm without any addition of Mn-Al alloys, but remarkably decreases to ∼55 μm with the addition of either Mn-34 wt% Al or Mn-28 wt% Al. With a minor addition of 0.5 wt% Mn-28Al alloy, the grain size of AZ31 alloy decreases to ∼53 μm, and the Mn-28Al alloy can be active as grain refiner for holding time up to 60 min for the melt AZ31 alloy at 750 o C.

Strategic issues and implications for the refining and marketing sector

International Nuclear Information System (INIS)

Jeffe, R.A.

1995-01-01

Refiners have faced a challenging business environment for the past decade. During this period, the industry has made approximately $25 billion of capital expenditures primarily to comply with increased governmental mandates, faced highly volatile petroleum product prices and garnered a return to equity of only 5%. While worldwide and US refining capacity has been flat in recent years, demand for refined petroleum products has been on the upswing and domestic supplies have also increased due to improved US capacity utilization rates (76% in 1984 and 93% in 1994) and increased imports (gasoline sales up 11% since 1984). The result has been highly volatile and generally weak refining margins (net Gulf Coast crack spread ranging from ($.95)/bbl in 1984 to $1.84/bbl in 1990 and averaging $.81/bbl since 1984). In response to the sustained difficulties in the marketplace, one has recently witnessed some strategic realignment in the industry. Several of the integrated companies, frustrated with the required capital expenditures and meager returns, have decided to shed non-core, non-strategic refining assets. For the most part, these assets have been bought by independents at, by historical measures, very attractive terms. This paper will provide an overview of the economics of the refining business, discuss the recent trends in refinery M and A activity and summarize possible implications of the recent strategic realignment

Formal refinement of extended state machines

Directory of Open Access Journals (Sweden)

Thomas Fayolle

2016-06-01

Full Text Available In a traditional formal development process, e.g. using the B method, the informal user requirements are (manually translated into a global abstract formal specification. This translation is especially difficult to achieve. The Event-B method was developed to incrementally and formally construct such a specification using stepwise refinement. Each increment takes into account new properties and system aspects. In this paper, we propose to couple a graphical notation called Algebraic State-Transition Diagrams (ASTD with an Event-B specification in order to provide a better understanding of the software behaviour. The dynamic behaviour is captured by the ASTD, which is based on automata and process algebra operators, while the data model is described by means of an Event-B specification. We propose a methodology to incrementally refine such specification couplings, taking into account new refinement relations and consistency conditions between the control specification and the data specification. We compare the specifications obtained using each approach for readability and proof complexity. The advantages and drawbacks of the traditional approach and of our methodology are discussed. The whole process is illustrated by a railway CBTC-like case study. Our approach is supported by tools for translating ASTD's into B and Event-B into B.

Free Vibration Analysis of Composite Plates via Refined Theories Accounting for Uncertainties

Directory of Open Access Journals (Sweden)

G. Giunta

2011-01-01

Full Text Available The free vibration analysis of composite thin and relatively thick plates accounting for uncertainty is addressed in this work. Classical and refined two-dimensional models derived via Carrera's Unified Formulation (CUF are considered. Material properties and geometrical parameters are supposed to be random. The fundamental frequency related to the first bending eigenmode is stochastically described in terms of the mean value, the standard deviation, the related confidence intervals and the cumulative distribution function. The Monte Carlo Method is employed to account for uncertainty. Cross-ply, simply supported, orthotropic plates are accounted for. Symmetric and anti-symmetric lay-ups are investigated. Displacements based and mixed two-dimensional theories are adopted. Equivalent single layer and layer wise approaches are considered. A Navier type solution is assumed. The conducted analyses have shown that for the considered cases, the fundamental natural frequency is not very sensitive to the uncertainty in the material parameters, while uncertainty in the geometrical parameters should be accounted for. In the case of thin plates, all the considered models yield statistically matching results. For relatively thick plates, the difference in the mean value of the natural frequency is due to the different number of degrees of freedom in the model.

Experimental investigation of submerged single jet impingement using Cu–water nanofluid

International Nuclear Information System (INIS)

Li Qiang; Xuan Yimin; Yu Feng

2012-01-01

Jet impingement cooling is a vital technique for thermal management of electronic devices of high-heat-flux by impinging fluid on a heater surface due to its high local heat transfer rates. In this paper, two types of Cu–water nanofluids (Cu particles with 25 nm diameter or 100 nm) are introduced into submerged single jet impingement cooling system as the working fluid. The heat transfer features of the nanofluids were experimentally investigated. The effects of the nanoparticle concentration, Reynolds number, nozzle-to-plate distance, fluid temperature, and nanoparticle diameter on the heat transfer performances of the jet impingement of nanofluids are discussed. The experimental results show that the suspended nanoparticles remarkably increase the convective heat transfer coefficient of the base fluid. The convective heat transfer coefficient of Cu–water nanofluid with the volume fraction of 3.0% has 52% higher than the pure water. The experiments also revealed that the suspended nanoparticles brought almost no extra addition of pressure drop in both submerged single jet impingement. In addition, by considering the effects of the suspended nanoparticles as well as the condition of impinging jet, a new heat transfer correlation of nanofluids for the submerged single jet impingement has been proposed. - Highlights: ► Cu–water nanofluids are introduced into submerged single jet impingement. ► The affecting parameters on the heat transfer performances of nanofluids are discussed. ► New heat transfer correlation of nanofluid for single jet impingement is proposed.

Mirror of the refined topological vertex from a matrix model

CERN Document Server

Eynard, B

2011-01-01

We find an explicit matrix model computing the refined topological vertex, starting from its representation in terms of plane partitions. We then find the spectral curve of that matrix model, and thus the mirror symmetry of the refined vertex. With the same method we also find a matrix model for the strip geometry, and we find its mirror curve. The fact that there is a matrix model shows that the refined topological string amplitudes also satisfy the remodeling the B-model construction.

Effect of Chemical Refining on Citrullus Colocynthis and Pongamia ...

African Journals Online (AJOL)

Oil from the both plant seeds was evaluated (both before and after refining) for different physico-chemical parameters like free fatty acids, iodine value, peroxide value, saponification value, unsaponifiable matter and fatty acid composition. Oil yield (30-35 %) in both plants was found average. After refining, per cent reduction ...

A revised partiality model and post-refinement algorithm for X-ray free-electron laser data

Energy Technology Data Exchange (ETDEWEB)

Ginn, Helen Mary [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Brewster, Aaron S.; Hattne, Johan [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Evans, Gwyndaf; Wagner, Armin [Harwell Science and Innovation Campus, Fermi Avenue, Didcot OX11 0QX (United Kingdom); Grimes, Jonathan M. [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Harwell Science and Innovation Campus, Fermi Avenue, Didcot OX11 0QX (United Kingdom); Sauter, Nicholas K. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Sutton, Geoff [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Stuart, David Ian, E-mail: dave@strubi.ox.ac.uk [Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Harwell Science and Innovation Campus, Fermi Avenue, Didcot OX11 0QX (United Kingdom)

2015-05-23

An updated partiality model and post-refinement algorithm for XFEL snapshot diffraction data is presented and confirmed by observing anomalous density for S atoms at an X-ray wavelength of 1.3 Å. Research towards using X-ray free-electron laser (XFEL) data to solve structures using experimental phasing methods such as sulfur single-wavelength anomalous dispersion (SAD) has been hampered by shortcomings in the diffraction models for X-ray diffraction from FELs. Owing to errors in the orientation matrix and overly simple partiality models, researchers have required large numbers of images to converge to reliable estimates for the structure-factor amplitudes, which may not be feasible for all biological systems. Here, data for cytoplasmic polyhedrosis virus type 17 (CPV17) collected at 1.3 Å wavelength at the Linac Coherent Light Source (LCLS) are revisited. A previously published definition of a partiality model for reflections illuminated by self-amplified spontaneous emission (SASE) pulses is built upon, which defines a fraction between 0 and 1 based on the intersection of a reflection with a spread of Ewald spheres modelled by a super-Gaussian wavelength distribution in the X-ray beam. A method of post-refinement to refine the parameters of this model is suggested. This has generated a merged data set with an overall discrepancy (by calculating the R{sub split} value) of 3.15% to 1.46 Å resolution from a 7225-image data set. The atomic numbers of C, N and O atoms in the structure are distinguishable in the electron-density map. There are 13 S atoms within the 237 residues of CPV17, excluding the initial disordered methionine. These only possess 0.42 anomalous scattering electrons each at 1.3 Å wavelength, but the 12 that have single predominant positions are easily detectable in the anomalous difference Fourier map. It is hoped that these improvements will lead towards XFEL experimental phase determination and structure determination by sulfur SAD and will

Linkages between the markets for crude oil and the markets for refined products

International Nuclear Information System (INIS)

Didziulis, V.S.

1990-01-01

To understand the crude oil price determination process it is necessary to extend the analysis beyond the markets for petroleum. Crude oil prices are determined in two closely related markets: the markets for crude oil and the markets for refined products. An econometric-linear programming model was developed to capture the linkages between the markets for crude oil and refined products. In the LP refiners maximize profits given crude oil supplies, refining capacities, and prices of refined products. The objective function is profit maximization net of crude oil prices. The shadow price on crude oil gives the netback price. Refined product prices are obtained from the econometric models. The model covers the free world divided in five regions. The model is used to analyze the impacts on the markets of policies that affect crude oil supplies, the demands for refined products, and the refining industry. For each scenario analyzed the demand for crude oil is derived from the equilibrium conditions in the markets for products. The demand curve is confronted with a supply curve which maximizes revenues providing an equilibrium solution for both crude oil and product markets. The model also captures crude oil price differentials by quality. The results show that the demands for crude oil are different across regions due to the structure of the refining industries and the characteristics of the demands for refined products. Changes in the demands for products have a larger impact on the markets than changes in the refining industry. Since markets for refined products and crude oil are interrelated they can't be analyzed individually if an accurate and complete assessment of a policy is to be made. Changes in only one product market in one region affect the other product markets and the prices of crude oil

Investigation of the Functional Neuroanatomy of Single Word Reading and Its Development

Science.gov (United States)

Palmer, Erica D.; Brown, Timothy T.; Petersen, Steven E.; Schlaggar, Bradley L.

2004-01-01

An understanding of the processing underlying single word reading will provide insight into how skilled reading is achieved, with important implications for reading education and impaired reading. Investigation of the functional neuroanatomy of both the mature and the developing systems will be critical for reaching this understanding. To this…

Refined analysis results for multimedia network costs and profits

DEFF Research Database (Denmark)

Tahkokorpi, M.; Falch, Morten; Skouby, Knud Erik

This deliverable describes the techno-economic business model developed in EURORIM WP3 and presents the refined results of the multimedia service delivery cost-profit calculations......This deliverable describes the techno-economic business model developed in EURORIM WP3 and presents the refined results of the multimedia service delivery cost-profit calculations...

Refining and petrochemicals

International Nuclear Information System (INIS)

Benazzi, E.

2003-01-01

Down sharply in 2002, refining margins showed a clear improvement in the first half-year of 2003. As a result, the earnings reported by oil companies for financial year 2002 were significantly lower than in 2001, but the prospects are brighter for 2003. In the petrochemicals sector, slow demand and higher feedstock prices eroded margins in 2002, especially in Europe and the United States. The financial results for the first part of 2003 seem to indicate that sector profitability will not improve before 2004. (author)

Refining of biodiesel by ceramic membrane separation

Energy Technology Data Exchange (ETDEWEB)

Wang, Yong; Ou, Shiyi; Tan, Yanlai; Tang, Shuze [Department of Food Science and Engineering, Jinan University, Guangzhou 510632 (China); Wang, Xingguo; Liu, Yuanfa [School of Food Science and Technology, Jiangnan University, Wuxi 214112 (China)

2009-03-15

A ceramic membrane separation process for biodiesel refining was developed to reduce the considerable usage of water needed in the conventional water washing process. Crude biodiesel produced by refined palm oil was micro-filtered by ceramic membranes of the pore size of 0.6, 0.2 and 0.1 {mu}m to remove the residual soap and free glycerol, at the transmembrane pressure of 0.15 MPa and temperature of 60 C. The flux through membrane maintained at 300 L m{sup -} {sup 2} h{sup -} {sup 1} when the volumetric concentrated ratio reached 4. The content of potassium, sodium, calcium and magnesium in the whole permeate was 1.40, 1.78, 0.81 and 0.20 mg/kg respectively, as determined by inductively coupled plasma-atomic emission spectroscopy. These values are lower than the EN 14538 specifications. The residual free glycerol in the permeate was estimated by water extraction, its value was 0.0108 wt.%. This ceramic membrane technology was a potential environmental process for the refining of biodiesel. (author)

Current research progress in grain refinement of cast magnesium alloys: A review article

International Nuclear Information System (INIS)

Ali, Yahia; Qiu, Dong; Jiang, Bin; Pan, Fusheng; Zhang, Ming-Xing

2015-01-01

Grain refinement of cast magnesium alloys, particularly in magnesium–aluminium (Mg–Al) based alloys, has been an active research topic in the past two decades, because it has been considered as one of the most effective approaches to simultaneously increase the strength, ductility and formability. The development of new grain refiners was normally based on the theories/models that were established through comprehensive and considerable studies of grain refinement in cast Al alloys. Generally, grain refinement in cast Al can be achieved through either inoculation treatment, which is a process of adding, or in situ forming, foreign particles to promote heterogeneous nucleation rate, or restricting grain growth by controlling the constitutional supercooling or both. But, the concrete and tangible grain refinement mechanism in cast metals is still not fully understood and there are a number of controversies. Therefore, most of the new developed grain refiners for Mg–Al based alloys are not as efficient as the commercially available ones, such as zirconium in non-Al containing Mg alloys. To facilitate the research in grain refinement of cast magnesium alloys, this review starts with highlighting the theoretical aspects of grain refinement in cast metals, followed by reviewing the latest research progress in grain refinement of magnesium alloys in terms of the solute effect and potent nucleants

Current research progress in grain refinement of cast magnesium alloys: A review article

Energy Technology Data Exchange (ETDEWEB)

Ali, Yahia; Qiu, Dong [School of Mechanical and Mining Engineering, University of Queensland, St Lucia, QLD 4072 (Australia); Jiang, Bin; Pan, Fusheng [College of Materials Science and Engineering, Chongqing University, Chongqing 400030 (China); Zhang, Ming-Xing, E-mail: Mingxing.Zhang@uq.edu.au [School of Mechanical and Mining Engineering, University of Queensland, St Lucia, QLD 4072 (Australia)

2015-01-15

Grain refinement of cast magnesium alloys, particularly in magnesium–aluminium (Mg–Al) based alloys, has been an active research topic in the past two decades, because it has been considered as one of the most effective approaches to simultaneously increase the strength, ductility and formability. The development of new grain refiners was normally based on the theories/models that were established through comprehensive and considerable studies of grain refinement in cast Al alloys. Generally, grain refinement in cast Al can be achieved through either inoculation treatment, which is a process of adding, or in situ forming, foreign particles to promote heterogeneous nucleation rate, or restricting grain growth by controlling the constitutional supercooling or both. But, the concrete and tangible grain refinement mechanism in cast metals is still not fully understood and there are a number of controversies. Therefore, most of the new developed grain refiners for Mg–Al based alloys are not as efficient as the commercially available ones, such as zirconium in non-Al containing Mg alloys. To facilitate the research in grain refinement of cast magnesium alloys, this review starts with highlighting the theoretical aspects of grain refinement in cast metals, followed by reviewing the latest research progress in grain refinement of magnesium alloys in terms of the solute effect and potent nucleants.

Flexible single-incision surgery: a fusion technique.

Science.gov (United States)

Noguera, José F; Dolz, Carlos; Cuadrado, Angel; Olea, José; García, Juan

2013-06-01

The development of natural orifice transluminal endoscopic surgery has led to other techniques, such as single-incision surgery. The use of the flexible endoscope for single-incision surgery paves the way for further refinement of both surgical methods. To describe a new, single-incision surgical technique, namely, flexible single-incision surgery. Assessment of the safety and effectiveness of endoscopic cholecystectomy in a series of 30 patients. This technique consists of a single umbilical incision through which a flexible endoscope is introduced and consists of 2 parallel entry ports that provide access to nonarticulated laparoscopic instruments. The technique was applied in all patients for whom it was prescribed. No general or surgical wound complications were noted. Surgical time was no longer than usual for single-port surgery. Flexible single-incision surgery is a new single-site surgical technique offering the same level of patient safety, with additional advantages for the surgeon at minimal cost.

Analysis model for forecasting extreme temperature using refined rank set pair

Directory of Open Access Journals (Sweden)

Qiao Ling-Xia

2013-01-01

Full Text Available In order to improve the precision of forecasting extreme temperature time series, a refined rank set pair analysis model with a refined rank transformation function is proposed to improve precision of its prediction. The measured values of the annual highest temperature of two China’s cities, Taiyuan and Shijiazhuang, in July are taken to examine the performance of a refined rank set pair model.

Trends in heavy oil production and refining in California

International Nuclear Information System (INIS)

Olsen, D.K.; Ramzel, E.B.; Pendergrass, R.A. II.

1992-07-01

This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production and is part of a study being conducted for the US Department of Energy. This report summarizes trends in oil production and refining in Canada. Heavy oil (10 degrees to 20 degrees API gravity) production in California has increased from 20% of the state's total oil production in the early 1940s to 70% in the late 1980s. In each of the three principal petroleum producing districts (Los Angeles Basin, Coastal Basin, and San Joaquin Valley) oil production has peaked then declined at different times throughout the past 30 years. Thermal production of heavy oil has contributed to making California the largest producer of oil by enhanced oil recovery processes in spite of low oil prices for heavy oil and stringent environmental regulation. Opening of Naval Petroleum Reserve No. 1, Elk Hills (CA) field in 1976, brought about a major new source of light oil at a time when light oil production had greatly declined. Although California is a major petroleum-consuming state, in 1989 the state used 13.3 billion gallons of gasoline or 11.5% of US demand but it contributed substantially to the Nation's energy production and refining capability. California is the recipient and refines most of Alaska's 1.7 million barrel per day oil production. With California production, Alaskan oil, and imports brought into California for refining, California has an excess of oil and refined products and is a net exporter to other states. The local surplus of oil inhibits exploitation of California heavy oil resources even though the heavy oil resources exist. Transportation, refining, and competition in the market limit full development of California heavy oil resources

AN AUTOMATIC OPTICAL AND SAR IMAGE REGISTRATION METHOD USING ITERATIVE MULTI-LEVEL AND REFINEMENT MODEL

Directory of Open Access Journals (Sweden)

C. Xu

2016-06-01

Full Text Available Automatic image registration is a vital yet challenging task, particularly for multi-sensor remote sensing images. Given the diversity of the data, it is unlikely that a single registration algorithm or a single image feature will work satisfactorily for all applications. Focusing on this issue, the mainly contribution of this paper is to propose an automatic optical-to-SAR image registration method using –level and refinement model: Firstly, a multi-level strategy of coarse-to-fine registration is presented, the visual saliency features is used to acquire coarse registration, and then specific area and line features are used to refine the registration result, after that, sub-pixel matching is applied using KNN Graph. Secondly, an iterative strategy that involves adaptive parameter adjustment for re-extracting and re-matching features is presented. Considering the fact that almost all feature-based registration methods rely on feature extraction results, the iterative strategy improve the robustness of feature matching. And all parameters can be automatically and adaptively adjusted in the iterative procedure. Thirdly, a uniform level set segmentation model for optical and SAR images is presented to segment conjugate features, and Voronoi diagram is introduced into Spectral Point Matching (VSPM to further enhance the matching accuracy between two sets of matching points. Experimental results show that the proposed method can effectively and robustly generate sufficient, reliable point pairs and provide accurate registration.

Experimental investigations on solar heating/heat pump systems for single family houses

DEFF Research Database (Denmark)

Andersen, Elsa; Perers, Bengt

In the period 2013-2017 the project “Experimental investigations on solar heat pump systems for single family houses” is carried out at Department of Civil Engineering, Technical University of Denmark. The aim of this project is to increase the knowledge of the heat and mass transfer in the combi...

Fetching and Parsing Data from the Web with OpenRefine

Directory of Open Access Journals (Sweden)

Evan Peter Williamson

2017-08-01

Full Text Available OpenRefine is a powerful tool for exploring, cleaning, and transforming data. An earlier Programming Historian lesson, “Cleaning Data with OpenRefine”, introduced the basic functionality of Refine to efficiently discover and correct inconsistency in a data set. Building on those essential data wrangling skills, this lesson focuses on Refine’s ability to fetch URLs and parse web content. Examples introduce some of the advanced features to transform and enhance a data set including: - fetch URLs using Refine - construct URL queries to retrieve information from a simple web API - parse HTML and JSON responses to extract relevant data - use array functions to manipulate string values - use Jython to extend Refine’s functionality It will be helpful to have basic familiarity with OpenRefine, HTML, and programming concepts such as variables and loops to complete this lesson.

Influence of refining time on nonmetallic inclusions in a low-carbon, silicon-killed steel

International Nuclear Information System (INIS)

Fernandes, Marcolino; Pires, Jose Carlos; Cheung, Noe; Garcia, Amauri

2003-01-01

Nonmetallic inclusions are harmful to the mechanical properties of every kind of steel produced worldwide. The greater the size of the inclusion present in the structure of a determined kind of steel, the greater its negative effect on the quality of the steel. Therefore, the objective of this work was to investigate the size, the quantity, the shape and the chemical composition of nonmetallic inclusions formed throughout the refining process of silicon-killed, low-carbon steel, as a function of the treatment time in a ladle furnace, trying to ensure the flotation of inclusions bigger than 25 μm. This investigation was carried out using a scanning electron microscope (SEM), with an analysis system using energy dispersive spectometry (EDS). Based on this work, it was possible to know more precisely the nature of the inclusions, the necessary time to ensure flotation of large inclusions, the efficiency of the slag to capture the inclusions, and the inclusion level of the steel throughout its refining process to try to obtain a higher quality steel product

Effect of zirconium addition on welding of aluminum grain refined by titanium plus boron

Science.gov (United States)

Zaid, A. I. O.

2014-06-01

Aluminum oxidizes freely in ordinary atmosphere which makes its welding difficult and weak, particularly it solidifies in columnar structure with large grains. Therefore, it is anticipated that the effect of addition of some grain refiners to its melt before solidification is worth while investigating as it may enhance its weldabilty and improve its mechanical strength. In this paper, the effect of addition of zirconium at a weight of 0.1% (which corresponds to the peretictic limit on the aluminum-zirconium base phase diagram) to commercially pure aluminum, grain refined by Ti+B on its weldability, using gas tungsten arc welding, GTAW, method which was formerly known as TIG. A constant current level of 30 AC Ampere was used because it removes the oxides during the welding process. Metallographic examination of the weldments of the different combinations of Al with Al and Al with its microalloys: in the heat affected zone, HAZ, and away from it was carried out and examined for HAZ width, porosity, cracks and microhardness. It was found that grain refining by Ti+B or Zr resulted in enhancement of the weldment.

Effect of zirconium addition on welding of aluminum grain refined by titanium plus boron

International Nuclear Information System (INIS)

Zaid, A. I. O.

2013-01-01

Aluminum oxidizes freely in ordinary atmosphere which makes its welding difficult and weak, particularly it solidifies in columnar structure with large grains. Therefore, it is anticipated that the effect of addition of some grain refiners to its melt before solidification is worth while investigating as it may enhance its weldabilty and improve its mechanical strength. In this paper, the effect of addition of zirconium at a weight of 0.1 percentage (which corresponds to the peretictic limit on the aluminum-zirconium base phase diagram) to commercially pure aluminum, grain refined by Tau i+Beta on its weldability, using gas tungsten arc welding, GTAW, method which was formerly known as TIG. A constant current level of 30 AC Ampere was used because it removes the oxides during the welding process. Metallographic examination of the weldments of the different combinations of Al with Al and Al with its microalloys: in the heat affected zone, HAZ, and away from it was carried out and examined for HAZ width, porosity, cracks and microhardness. It was found that grain refining by Tau i+Beta or Zr resulted in enhancement of the weldment. (author)

Effect of zirconium addition on welding of aluminum grain refined by titanium plus boron

International Nuclear Information System (INIS)

Zaid, A I O

2014-01-01

Aluminum oxidizes freely in ordinary atmosphere which makes its welding difficult and weak, particularly it solidifies in columnar structure with large grains. Therefore, it is anticipated that the effect of addition of some grain refiners to its melt before solidification is worth while investigating as it may enhance its weldabilty and improve its mechanical strength. In this paper, the effect of addition of zirconium at a weight of 0.1% (which corresponds to the peretictic limit on the aluminum-zirconium base phase diagram) to commercially pure aluminum, grain refined by Ti+B on its weldability, using gas tungsten arc welding, GTAW, method which was formerly known as TIG. A constant current level of 30 AC Ampere was used because it removes the oxides during the welding process. Metallographic examination of the weldments of the different combinations of Al with Al and Al with its microalloys: in the heat affected zone, HAZ, and away from it was carried out and examined for HAZ width, porosity, cracks and microhardness. It was found that grain refining by Ti+B or Zr resulted in enhancement of the weldment

Genomic multiple sequence alignments: refinement using a genetic algorithm

Directory of Open Access Journals (Sweden)

Lefkowitz Elliot J

2005-08-01

Full Text Available Abstract Background Genomic sequence data cannot be fully appreciated in isolation. Comparative genomics – the practice of comparing genomic sequences from different species – plays an increasingly important role in understanding the genotypic differences between species that result in phenotypic differences as well as in revealing patterns of evolutionary relationships. One of the major challenges in comparative genomics is producing a high-quality alignment between two or more related genomic sequences. In recent years, a number of tools have been developed for aligning large genomic sequences. Most utilize heuristic strategies to identify a series of strong sequence similarities, which are then used as anchors to align the regions between the anchor points. The resulting alignment is globally correct, but in many cases is suboptimal locally. We describe a new program, GenAlignRefine, which improves the overall quality of global multiple alignments by using a genetic algorithm to improve local regions of alignment. Regions of low quality are identified, realigned using the program T-Coffee, and then refined using a genetic algorithm. Because a better COFFEE (Consistency based Objective Function For alignmEnt Evaluation score generally reflects greater alignment quality, the algorithm searches for an alignment that yields a better COFFEE score. To improve the intrinsic slowness of the genetic algorithm, GenAlignRefine was implemented as a parallel, cluster-based program. Results We tested the GenAlignRefine algorithm by running it on a Linux cluster to refine sequences from a simulation, as well as refine a multiple alignment of 15 Orthopoxvirus genomic sequences approximately 260,000 nucleotides in length that initially had been aligned by Multi-LAGAN. It took approximately 150 minutes for a 40-processor Linux cluster to optimize some 200 fuzzy (poorly aligned regions of the orthopoxvirus alignment. Overall sequence identity increased only

The effect of dispersoids on the grain refinement mechanisms during deformation of aluminium alloys to ultra-high strains

International Nuclear Information System (INIS)

Apps, P.J.; Berta, M.; Prangnell, P.B.

2005-01-01

The effect of fine dispersoids on the mechanisms and rate of grain refinement has been investigated during the severe deformation of a model aluminium alloy. A binary Al-0.2Sc alloy, containing coherent Al 3 Sc dispersoids, of ∼20 nm in diameter and ∼100 nm spacing, has been deformed by equal channel angular extrusion to an effective strain of ten. The resulting deformation structures were quantitatively analysed using high-resolution electron backscattered diffraction orientation mapping, and the results have been compared to those obtained from a single-phase Al-0.13Mg alloy, deformed under identical conditions. The presence of fine, non-shearable, dispersoids has been found to homogenise slip, retard the formation of a cellular substructure and inhibit the formation of microshear bands during deformation. These factors combine to reduce the rate of high-angle grain boundary generation at low to medium strains and, hence, retard the formation of a submicron grain structure to higher strains during severe deformation

Need for refining capacity creates opportunities for producers in Middle East

International Nuclear Information System (INIS)

Ali, M.S.S.

1994-01-01

Oil industry interest in refining has revived in the past few years in response to rising oil consumption. The trend creates opportunities, for countries in the Middle East, which do not own refining assets nearly in proportion to their crude oil reserved. By closing this gap between reserves and refining capacity, the countries can ease some of the instability now characteristic of the oil market. Some major oil producing countries have begun to move downstream. During the 1980s, Venezuela, Kuwait, Saudi Arabia, Libya, and other members of the Organization of Petroleum Exporting Countries acquired refining assets through direct total purchase or joint ventures. Nevertheless, the oil industry remains largely unintegrated, with the Middle East holding two thirds of worldwide oil reserves but only a small share downstream. As worldwide refining capacity swings from a period of surplus toward one in which the need for new capacity will be built. The paper discusses background of the situation, shrinking surplus, investment requirements, sources of capital, and shipping concerns

A grid-enabled web service for low-resolution crystal structure refinement.

Science.gov (United States)

O'Donovan, Daniel J; Stokes-Rees, Ian; Nam, Yunsun; Blacklow, Stephen C; Schröder, Gunnar F; Brunger, Axel T; Sliz, Piotr

2012-03-01

Deformable elastic network (DEN) restraints have proved to be a powerful tool for refining structures from low-resolution X-ray crystallographic data sets. Unfortunately, optimal refinement using DEN restraints requires extensive calculations and is often hindered by a lack of access to sufficient computational resources. The DEN web service presented here intends to provide structural biologists with access to resources for running computationally intensive DEN refinements in parallel on the Open Science Grid, the US cyberinfrastructure. Access to the grid is provided through a simple and intuitive web interface integrated into the SBGrid Science Portal. Using this portal, refinements combined with full parameter optimization that would take many thousands of hours on standard computational resources can now be completed in several hours. An example of the successful application of DEN restraints to the human Notch1 transcriptional complex using the grid resource, and summaries of all submitted refinements, are presented as justification.

Refining and petrochemicals

International Nuclear Information System (INIS)

Benazzi, E.; Alario, F.

2004-01-01

In 2003, refining margins showed a clear improvement that continued throughout the first three quarters of 2004. Oil companies posted significantly higher earnings in 2003 compared to 2002, with the results of first quarter 2004 confirming this trend. Due to higher feedstock prices, the implementation of new capacity and more intense competition, the petrochemicals industry was not able to boost margins in 2003. In such difficult business conditions, aggravated by soaring crude prices, the petrochemicals industry is not likely to see any improvement in profitability before the second half of 2004. (author)

Initiating technical refinements in high-level golfers: Evidence for contradictory procedures.

Science.gov (United States)

Carson, Howie J; Collins, Dave; Richards, Jim

2016-01-01

When developing motor skills there are several outcomes available to an athlete depending on their skill status and needs. Whereas the skill acquisition and performance literature is abundant, an under-researched outcome relates to the refinement of already acquired and well-established skills. Contrary to current recommendations for athletes to employ an external focus of attention and a representative practice design,  Carson and  Collins' (2011) [Refining and regaining skills in fixation/diversification stage performers: The Five-A Model. International Review of Sport and Exercise Psychology, 4, 146-167. doi: 10.1080/1750984x.2011.613682 ] Five-A Model requires an initial narrowed internal focus on the technical aspect needing refinement: the implication being that environments which limit external sources of information would be beneficial to achieving this task. Therefore, the purpose of this paper was to (1) provide a literature-based explanation for why techniques counter to current recommendations may be (temporarily) appropriate within the skill refinement process and (2) provide empirical evidence for such efficacy. Kinematic data and self-perception reports are provided from high-level golfers attempting to consciously initiate technical refinements while executing shots onto a driving range and into a close proximity net (i.e. with limited knowledge of results). It was hypothesised that greater control over intended refinements would occur when environmental stimuli were reduced in the most unrepresentative practice condition (i.e. hitting into a net). Results confirmed this, as evidenced by reduced intra-individual movement variability for all participants' individual refinements, despite little or no difference in mental effort reported. This research offers coaches guidance when working with performers who may find conscious recall difficult during the skill refinement process.

Grain refining mechanism of Al-containing Mg alloys with the addition of Mn-Al alloys

Energy Technology Data Exchange (ETDEWEB)

Qin, Gaowu W., E-mail: qingw@smm.neu.edu.c [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Wenhu Road 3-11, Heping District, Shenyang 110004, Liaoning Province (China); Ren Yuping; Huang Wei; Li Song; Pei Wenli [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Wenhu Road 3-11, Heping District, Shenyang 110004, Liaoning Province (China)

2010-10-08

Graphical abstract: Display Omitted Research highlights: The {epsilon}-AlMn phase acts as the heterogeneous nucleus of {alpha}-Mg phase during the solidification of the AZ31 Mg alloy, not the {gamma}-Al{sub 8}Mn{sub 5} phase. The grain refinement effect is very clear with the addition of only 0.5 wt% Mn-28Al alloy (pure {epsilon}-AlMn). The grain refinement does not deteriorate up to the holding time of 60 min at 740 {sup o}C. - Abstract: The effect of manganese on grain refinement of Al-containing AZ31 Mg alloy has been investigated by designing a series of Mn-Al alloys composed of either pure {epsilon}-AlMn, {gamma}{sub 2}-Al{sub 8}Mn{sub 5} or both of them using optical microscopy and X-ray diffraction. It is experimentally clarified that the grain refinement of the AZ31 Mg alloy is due to the existence of the {epsilon}-AlMn phase in the Mn-Al alloys, not the {gamma}{sub 2}-Al{sub 8}Mn{sub 5} phase. The grain size of AZ31 Mg alloy is about 91 {mu}m without any addition of Mn-Al alloys, but remarkably decreases to {approx}55 {mu}m with the addition of either Mn-34 wt% Al or Mn-28 wt% Al. With a minor addition of 0.5 wt% Mn-28Al alloy, the grain size of AZ31 alloy decreases to {approx}53 {mu}m, and the Mn-28Al alloy can be active as grain refiner for holding time up to 60 min for the melt AZ31 alloy at 750 {sup o}C.

Grain refinement through severe plastic deformation (SPD) processing

International Nuclear Information System (INIS)

Izairi, N.; Vevecka - Priftaj, A.

2012-01-01

There is considerable current interest in processing metallic samples through procedures involving the imposition of severe plastic deformation (SPD). These procedures lead to very significant grain refinement to the submicrometer or even the nanometer level, resulting in advanced physical properties. Among various SPD processes, Equal Channel Angular Pressing, High pressure Torsion and Accumulated Roll Bonding have been widely used for many metals and alloys. In the present work, we present an overview of the most used methods of SPD for grain refinement and the production of bulk nano structured materials with enhancement in their mechanical and functional properties. In order to examine the potential for using ECAP to refine the grain size and improve the mechanical properties, two commercial 5754 Al alloy and AA 3004 , were selected for study. Processing by ECAP gives a reduction in the grain size and an increase in the microhardness. (Author)

Future prospects for palm oil refining and modifications

Directory of Open Access Journals (Sweden)

Gibon Véronique

2009-07-01

Full Text Available Palm oil is rich in minor components that impart unique nutritional properties and need to be preserved. In this context, refining technologies have been improved, with the dual temperature deodorizer, the double condensing unit and the ice condensing system. The DOBI is a good tool to assess quality of the crude palm oil and its ability to be properly refined. Specially refined oils open a market for new high quality products (golden palm oil, red palm oil, white soaps, etc.. Palm oil is a good candidate for the multi-step dry fractionation process, aiming to the production of commodity oils and specialty fats (cocoa butter replacers. New technological developments allow quality and yield improvements. Palm oil and fractions are also valuable feedstock for enzymatic interesterification in which applications are for commodity oil (low-trans margarines and shortenings and for special products (cocoa butter equivalents, infant formulation, ….

Robotic Laparoendoscopic Single-site Retroperitioneal Renal Surgery: Initial Investigation of a Purpose-built Single-port Surgical System.

Science.gov (United States)

Maurice, Matthew J; Ramirez, Daniel; Kaouk, Jihad H

2017-04-01

Robotic single-site retroperitoneal renal surgery has the potential to minimize the morbidity of standard transperitoneal and multiport approaches. Traditionally, technological limitations of non-purpose-built robotic platforms have hindered the application of this approach. To assess the feasibility of retroperitoneal renal surgery using a new purpose-built robotic single-port surgical system. This was a preclinical study using three male cadavers to assess the feasibility of the da Vinci SP1098 surgical system for robotic laparoendoscopic single-site (R-LESS) retroperitoneal renal surgery. We used the SP1098 to perform retroperitoneal R-LESS radical nephrectomy (n=1) and bilateral partial nephrectomy (n=4) on the anterior and posterior surfaces of the kidney. Improvements unique to this system include enhanced optics and intelligent instrument arm control. Access was obtained 2cm anterior and inferior to the tip of the 12th rib using a novel 2.5-cm robotic single-port system that accommodates three double-jointed articulating robotic instruments, an articulating camera, and an assistant port. The primary outcome was the technical feasibility of the procedures, as measured by the need for conversion to standard techniques, intraoperative complications, and operative times. All cases were completed without the need for conversion. There were no intraoperative complications. The operative time was 100min for radical nephrectomy, and the mean operative time was 91.8±18.5min for partial nephrectomy. Limitations include the preclinical model, the small sample size, and the lack of a control group. Single-site retroperitoneal renal surgery is feasible using the latest-generation SP1098 robotic platform. While the potential of the SP1098 appears promising, further study is needed for clinical evaluation of this investigational technology. In an experimental model, we used a new robotic system to successfully perform major surgery on the kidney through a single small

Unilever food safety assurance system for refined vegetable oils and fats

Directory of Open Access Journals (Sweden)

van Duijn Gerrit

2010-03-01

Full Text Available The Unilever Food Safety Assurance system for refined oils and fats is based on risk assessments for the presence of contaminants or pesticide residues in crude oils, and refining process studies to validate the removal of these components. Crude oil risk assessments were carried out by combining supply chain visits, and analyses of the contaminant and pesticide residue levels in a large number of crude oil samples. Contaminants like poly-aromatic hydrocarbons and hydrocarbons of mineral origin, and pesticide residues can largely be removed by refining. For many years, this Food Safety Assurance System has proven to be effective in controlling contaminant levels in refined vegetable oils and fats.

Hirshfeld atom refinement for modelling strong hydrogen bonds.

Science.gov (United States)

Woińska, Magdalena; Jayatilaka, Dylan; Spackman, Mark A; Edwards, Alison J; Dominiak, Paulina M; Woźniak, Krzysztof; Nishibori, Eiji; Sugimoto, Kunihisa; Grabowsky, Simon

2014-09-01

High-resolution low-temperature synchrotron X-ray diffraction data of the salt L-phenylalaninium hydrogen maleate are used to test the new automated iterative Hirshfeld atom refinement (HAR) procedure for the modelling of strong hydrogen bonds. The HAR models used present the first examples of Z' > 1 treatments in the framework of wavefunction-based refinement methods. L-Phenylalaninium hydrogen maleate exhibits several hydrogen bonds in its crystal structure, of which the shortest and the most challenging to model is the O-H...O intramolecular hydrogen bond present in the hydrogen maleate anion (O...O distance is about 2.41 Å). In particular, the reconstruction of the electron density in the hydrogen maleate moiety and the determination of hydrogen-atom properties [positions, bond distances and anisotropic displacement parameters (ADPs)] are the focus of the study. For comparison to the HAR results, different spherical (independent atom model, IAM) and aspherical (free multipole model, MM; transferable aspherical atom model, TAAM) X-ray refinement techniques as well as results from a low-temperature neutron-diffraction experiment are employed. Hydrogen-atom ADPs are furthermore compared to those derived from a TLS/rigid-body (SHADE) treatment of the X-ray structures. The reference neutron-diffraction experiment reveals a truly symmetric hydrogen bond in the hydrogen maleate anion. Only with HAR is it possible to freely refine hydrogen-atom positions and ADPs from the X-ray data, which leads to the best electron-density model and the closest agreement with the structural parameters derived from the neutron-diffraction experiment, e.g. the symmetric hydrogen position can be reproduced. The multipole-based refinement techniques (MM and TAAM) yield slightly asymmetric positions, whereas the IAM yields a significantly asymmetric position.

Oil price scenarios and refining profitability

International Nuclear Information System (INIS)

Sweeney, B.

1993-01-01

Currently refining profitability is low because there has been an overbuilding of conversion capacity in Western Europe in the last round. Oil marketing, the chemicals business and the fundamental economy itself are at low points in their cycles which have not coincided, at least in the UK, since 1975. Against that gloomy background, it is predicted that downstream profitability will recover in the mid-1990s. Crude oil prices will remain low until the call on OPEC crude increases again and takes up the capacity which has been brought on stream in response to the Gulf War. When this happens, it is likely to trigger another price spike and another round of investment in production capacity. Environmentally driven investments in desulphurisation or emissions reduction will be poorly remunerated all the way through the value chain. Refining margins will recover when white oil demand growth tightens up the need for conversion capacity. Marketing will need to reduce the retail network overcapacity in the mature markets if it is to improve its profitability. In this period of low profitability, even with the light at the end of the tunnel for refiners in the middle of the decade, the industry structure is under threat. There is a strong argument for new modes of competitive behaviour which are backed by strong elements of cooperation. (author)

Effect of humid-thermal environment on wave dispersion characteristics of single-layered graphene sheets

Science.gov (United States)

Ebrahimi, Farzad; Dabbagh, Ali

2018-04-01

In the present article, the hygro-thermal wave propagation properties of single-layered graphene sheets (SLGSs) are investigated for the first time employing a nonlocal strain gradient theory. A refined higher-order two-variable plate theory is utilized to derive the kinematic relations of graphene sheets. Here, nonlocal strain gradient theory is used to achieve a more precise analysis of small-scale plates. In the framework of the Hamilton's principle, the final governing equations are developed. Moreover, these obtained equations are deemed to be solved analytically and the wave frequency values are achieved. Some parametric studies are organized to investigate the influence of different variants such as nonlocal parameter, length scale parameter, wave number, temperature gradient and moisture concentration on the wave frequency of graphene sheets.

Investigation of cross talk in single grain luminescence measurements using an EMCCD camera

International Nuclear Information System (INIS)

Gribenski, Natacha; Preusser, Frank; Greilich, Steffen; Huot, Sebastien; Mittelstraß, Dirk

2015-01-01

Highly sensitive electron multiplying charges coupled devices (EMCCD) enable the spatial detection of luminescence emissions from samples and have a high potential in single grain luminescence dating. However, the main challenge of this approach is the potential effect of cross talk, i.e. the influence of signal emitted by neighbouring grains, which will bias the information recorded from individual grains. Here, we present the first investigations into this phenomenon when performing single grain luminescence measurements of quartz grains spread over the flat surface of a sample carrier. Dose recovery tests using mixed populations show an important effect of cross talk, even when some distance is kept between grains. This issue is further investigated by focusing just on two grains and complemented by simulated experiments. Creation of an additional rejection criteria based on the brightness properties of the grains is inefficient in selecting grains unaffected by their surroundings. Therefore, the use of physical approaches or image processing algorithms to directly counteract cross talk is essential to allow routine single grain luminescence dating using EMCCD cameras. - Highlights: • We have performed single grain OSL measurements using an EMCCD detector. • Individual equivalent dose cannot be accurately recovered from a mixed dose population. • Grains are influenced by signal emitted by their neighbours during the measurements. • Simulated data confirm the strong effect of this phenomenon. • Increasing the distance between grains or applying brightness criteria are inefficient.

Influences of different degassing processes on refining effect and properties of 4004 Al alloy

Directory of Open Access Journals (Sweden)

Wang Liping

2013-03-01

Full Text Available In order to improve the plasticity of 4004 Al alloy and subsequently the productivity of 4004 Al foil, the research studied in detail the influence of the rotary impeller degassing process on the refining effect of 4004 Al alloy, in which the impacts of four major parameters: gas flow, rotational speed, refining time, and stewing time, on degassing rate of 4004 Al alloy was systematically studied by using an orthogonal experiment methodology. Results show that the rotational speed has the greatest impact on the degassing of 4004 Al alloy, followed by gas flow and refining time; stewing time has the least impact. The optimum purification parameters obtained by current orthogonal analysis were: rotor speed of 500 r·min-1, inert gas flow of 0.4 mL·h-1, refining time of 15 min, and stewing time of 6 min. Degassing rate using the optimum parameters reaches 68%. In addition, the comparison experiments among C2Cl6 refining, rotary impeller degassing, and combined treatment of C2Cl6 refining and rotary impeller degassing for 4004 Al alloy were performed. The experimental data indicated that the combined treatment of C2Cl6 refining and rotary impeller degassing has the best degassing effect. Degassing rate of C2Cl6 refining, rotary impeller degassing and combined refining treatment is 39%, 69.1% and 76.9%, respectively. The mechanical properties of the specimen refined by rotary impeller degassing were higher than those by C2Cl6 refining, but lower than those by combined refining treatment.

Luminescence investigation of Yb{sup 3+}/Er{sup 3+} codoped single LiYF{sub 4} microparticle

Energy Technology Data Exchange (ETDEWEB)

Gao, Wei; Zheng, Hairong, E-mail: hrzheng@snnu.edu.cn; He, Enjie; Lu, Ying; Gao, Fangqi

2014-08-01

Tetragonal phase LiYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microparticles are synthesized via facile hydrothermal method. Single LiYF{sub 4} microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. It is found that single LiYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microparticle with sub-structure presents stronger upconversion luminescence emission and smaller intensity ratio of red to green emission than that from LiYF{sub 4}:Yb{sup 3+}/Er{sup 3+} microparticle with no sub-structure. The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion luminescence emission are investigated. The current study suggests that the luminescence observation with single micropaticle can effectively avoid the influence of environment and neighbor particles, which is important for investigating the luminescence properties of micro- or nano-crystals and for extending their application. - Highlights: • Single LiYF{sub 4} microparticle is excited with IR laser at 980 nm in a confocal setup, and strong green and weak red emissions are observed. • Single LiYF{sub 4} microparticle with different morphology exhibits different fluorescence emission intensity and intensity ratio of red to green emission. • The possible mechanism, the influence of particle size and the existence of EDTA on the upconversion emission are investigated.

Public Health Economic Burden Associated with Two Single Measles Case Investigations - Colorado, 2016-2017.

Science.gov (United States)

Marx, Grace E; Chase, Jennifer; Jasperse, Joseph; Stinson, Kaylan; McDonald, Carol E; Runfola, Janine K; Jaskunas, Jillian; Hite, Donna; Barnes, Meghan; Askenazi, Michele; Albanese, Bernadette

2017-11-24

During July 2016-January 2017, two unrelated measles cases were identified in the Denver, Colorado area after patients traveled to countries with endemic measles transmission. Each case resulted in multiple exposures at health care facilities and public venues, and activated an immediate and complex response by local and state public health agencies, with activities led by the Tri-County Health Department (TCHD), which serves Adams, Arapahoe, and Douglas counties. To track the economic burden associated with investigating and responding to single measles cases, personnel hours and supply costs incurred during each investigation were tracked prospectively. No secondary cases of measles were identified in either investigation. Postexposure prophylaxis (PEP) was administered to 31 contacts involving the first case; no contacts of the second case were eligible for PEP because of a delay in diagnosing measles disease. Public health costs of disease investigation in the first and second case were estimated at $49,769 and $18,423, respectively. Single measles cases prompted coordinated public health action and were costly and resource-intensive for local public health agencies.

The Analysis of the Refined Financial Management of Modern Enterprises

Directory of Open Access Journals (Sweden)

Li Ran

2016-01-01

Full Text Available This paper briefly introduces the concept of the refined financial management, elaborates on its characteristics and puts forward some main points about it. It also comes up with some personal suggestions for reference on effective ways of refining financial management.

Microstructure evolution and grain refinement of Ti-6Al-4V alloy by laser shock processing

Energy Technology Data Exchange (ETDEWEB)

Ren, X.D., E-mail: renxd@mail.ujs.edu.cn [Department of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 (China); Research Center of Fluid Machinery Engineering and Technical, Jiangsu University, Zhenjiang, 212013 (China); Zhou, W.F.; Liu, F.F.; Ren, Y.P. [Department of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 (China); Yuan, S.Q. [Research Center of Fluid Machinery Engineering and Technical, Jiangsu University, Zhenjiang, 212013 (China); Ren, N.F.; Xu, S.D.; Yang, T. [Department of Mechanical Engineering, Jiangsu University, Zhenjiang, 212013 (China)

2016-02-15

Graphical abstract: The grain refinement process of Ti-6Al-4V alloy under LSP: (a) LDD in original grains; (b) Dislocations in β phase; (c) DTIs in α phase; (d) DTs transform into DCs; (e) DWs develop into sub-GBs; (f) GR accomplishes. - Highlights: • LSP could repair the surface defects and reduce the surface roughness. • Microstructure evolution of α phase in Ti-6Al-4V alloy processed by LSP is distinct from β phase. • Multidirectional twin intersections and subgrain boundaries are the main mechanism of grain refinement of Ti-6Al-4V alloy. • Grain refinement process of the Ti-6Al-4V alloy was illustrated. - Abstract: Microstructure evolution and grain refinement of Ti-6Al-4V alloy after laser shock processing (LSP) are systematically investigated in this paper. Laser shock waves were induced by a Q-switched Nd:YAG laser system operated with a wave-length of 1064 nm and 10 ns pulse width. The microstructures of LSP samples were characterized by scanning electron microscopy (SEM) and transmission electron microscope (TEM). Present results indicate that the surface hardness of samples subjected to LSP impacts has significantly improved. Multidirectional twin intersections and dislocation movements lead to grain subdivision in α phase with ultra-high plastic deformation. High-density dislocations are found in β phase. Multidirectional twin intersections and division of sub-grain boundaries play an important role in the grain refinement of Ti-6Al-4V alloy under LSP loading conditions.

Process for refining hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Risenfeld, E H

1924-11-26

A process is disclosed for the refining of hydrocarbons or other mixtures through treatment in vapor form with metal catalysts, characterized by such metals being used as catalysts, which are obtained by reduction of the oxide of minerals containing the iron group, and by the vapors of the hydrocarbons, in the presence of the water vapor, being led over these catalysts at temperatures from 200 to 300/sup 0/C.

Investigation of polyelectrolyte desorption by single molecule force spectroscopy

International Nuclear Information System (INIS)

Friedsam, C; Seitz, M; Gaub, H E

2004-01-01

Single molecule force spectroscopy has evolved into a powerful method for the investigation of intra- and intermolecular interactions at the level of individual molecules. Many examples, including the investigation of the dynamic properties of complex biological systems as well as the properties of covalent bonds or intermolecular transitions within individual polymers, are reported in the literature. The technique has recently been extended to the systematic investigation of desorption processes of individual polyelectrolyte molecules adsorbed on generic surfaces. The stable covalent attachment of polyelectrolyte molecules to the AFM-tip provides the possibility of performing long-term measurements with the same set of molecules and therefore allows the in situ observation of the impact of environmental changes on the adsorption behaviour of individual molecules. Different types of interactions, e.g. electrostatic or hydrophobic interactions, that determine the adsorption process could be identified and characterized. The experiments provided valuable details that help to understand the nature and the properties of non-covalent interactions, which is helpful with regard to biological systems as well as for technical applications. Apart from this, desorption experiments can be utilized to characterize the properties of surfaces or polymer coatings. Therefore they represent a versatile tool that can be further developed in terms of various aspects

An Investigation of Loneliness and Perceived Social Support Among Single and Partnered Young Adults

OpenAIRE

Adamczyk, Katarzyna

2015-01-01

This study investigated the possible differences between single individuals and individuals in nonmarital romantic relationships in the domains of emotional (romantic and family) and social loneliness, and of perceived social support from family, friends and significant others. Based on a Polish university-student sample of 315 participants (167 women and 148 men) aged 19 to 25?years (M?=?21.90, SD?=?2.15), single relationship status was related to greater romantic and family loneliness, and ...

Techno-economic analysis of the deacetylation and disk refining process: characterizing the effect of refining energy and enzyme usage on minimum sugar selling price and minimum ethanol selling price.

Science.gov (United States)

Chen, Xiaowen; Shekiro, Joseph; Pschorn, Thomas; Sabourin, Marc; Tucker, Melvin P; Tao, Ling

2015-01-01

A novel, highly efficient deacetylation and disk refining (DDR) process to liberate fermentable sugars from biomass was recently developed at the National Renewable Energy Laboratory (NREL). The DDR process consists of a mild, dilute alkaline deacetylation step followed by low-energy-consumption disk refining. The DDR corn stover substrates achieved high process sugar conversion yields, at low to modest enzyme loadings, and also produced high sugar concentration syrups at high initial insoluble solid loadings. The sugar syrups derived from corn stover are highly fermentable due to low concentrations of fermentation inhibitors. The objective of this work is to evaluate the economic feasibility of the DDR process through a techno-economic analysis (TEA). A large array of experiments designed using a response surface methodology was carried out to investigate the two major cost-driven operational parameters of the novel DDR process: refining energy and enzyme loadings. The boundary conditions for refining energy (128-468 kWh/ODMT), cellulase (Novozyme's CTec3) loading (11.6-28.4 mg total protein/g of cellulose), and hemicellulase (Novozyme's HTec3) loading (0-5 mg total protein/g of cellulose) were chosen to cover the most commercially practical operating conditions. The sugar and ethanol yields were modeled with good adequacy, showing a positive linear correlation between those yields and refining energy and enzyme loadings. The ethanol yields ranged from 77 to 89 gallons/ODMT of corn stover. The minimum sugar selling price (MSSP) ranged from $0.191 to $0.212 per lb of 50 % concentrated monomeric sugars, while the minimum ethanol selling price (MESP) ranged from $2.24 to $2.54 per gallon of ethanol. The DDR process concept is evaluated for economic feasibility through TEA. The MSSP and MESP of the DDR process falls within a range similar to that found with the deacetylation/dilute acid pretreatment process modeled in NREL's 2011 design report. The DDR process is

Investment in exploration-production and refining 2014

International Nuclear Information System (INIS)

Hureau, Geoffroy; Serbutoviez, Sylvain; Silva, Constancio; Maisonnier, Guy

2014-11-01

IFPEN analyses in this study the 2014 evolution of global investment in the field of exploration-production and refining: 1 - Changes in oil and gas prices: General background: weak economy and global disorder, Oil prices: fundamentals that could help to relax oil prices?, Gas prices: fall in Europe, stability in Japan, increase in the US; 2 - Exploration and production - Slowdown in growth: moderate rise in investment in 2014, exploration - Discoveries in 2014, Russia: sanctions will have limited short term impact, implications of the reforms to the Mexican energy sector; 3 - Drilling activity and market throughout the world: onshore and offshore drilling (Number of wells drilled throughout the world, Number of onshore wells, Number of offshore wells, Drilling, equipment and well services markets, Onshore drilling market, Offshore drilling market, Fracking market), Geophysical activity and the geophysical market, Offshore construction activity and the offshore construction market (Offshore construction activities, Rig construction activity, Floating Platform Systems (FPS), Sub-sea constructions, Offshore construction market); 4 - Refining - Significant increase in spending: increase in industrial costs, a slowdown in the increase in excess capacity in the future?, A bleak future for the european refining sector

P-Refinement and P-Threads (Preprint)

National Research Council Canada - National Science Library

Dong, Steven; Karniadakis, George E

2002-01-01

...]) in d dimensions, which is higher than lower-order methods. In this paper, we demonstrate that by employing multi-threading within MPI processes we manage to counter- balance the cost increase associated with P-refinement...

Refining in the 1990's: Restructuring and resurgence

International Nuclear Information System (INIS)

Cobb, C.B.

1994-01-01

After two years of uncertainty in dealing with the 1990 Clean Air Act Amendments coupled with the shutdown of 5% of total US refining capacity, the industry is now positioning itself for continued operations throughout the remainder of the decade. However, refineries are experiencing a shift in the mode of operations to a period of more restructuring (closings, ventures, alliances, etc.) followed by a resurgence in financial performance. The purpose of this paper is to examine the current industry and highlight the reasons for industry's current plans. The authors also speculate about the strategies companies will choose to better their financial performance. Fundamentally, the characteristics of a mature domestic business remain the driving force that shape decision making. In responding to the maturing of refining, the authors suggest that refiners will change the way they conduct business over the next few years. Building on the theme of the 1993 NPRA paper, strategies will target the domestic side of the business while simultaneously shifting to a global perspective

Refining SCJ Mission Specifications into Parallel Handler Designs

Directory of Open Access Journals (Sweden)

Frank Zeyda

2013-05-01

Full Text Available Safety-Critical Java (SCJ is a recent technology that restricts the execution and memory model of Java in such a way that applications can be statically analysed and certified for their real-time properties and safe use of memory. Our interest is in the development of comprehensive and sound techniques for the formal specification, refinement, design, and implementation of SCJ programs, using a correct-by-construction approach. As part of this work, we present here an account of laws and patterns that are of general use for the refinement of SCJ mission specifications into designs of parallel handlers used in the SCJ programming paradigm. Our notation is a combination of languages from the Circus family, supporting state-rich reactive models with the addition of class objects and real-time properties. Our work is a first step to elicit laws of programming for SCJ and fits into a refinement strategy that we have developed previously to derive SCJ programs.

Assume-Guarantee Abstraction Refinement Meets Hybrid Systems

Science.gov (United States)

Bogomolov, Sergiy; Frehse, Goran; Greitschus, Marius; Grosu, Radu; Pasareanu, Corina S.; Podelski, Andreas; Strump, Thomas

2014-01-01

Compositional verification techniques in the assume- guarantee style have been successfully applied to transition systems to efficiently reduce the search space by leveraging the compositional nature of the systems under consideration. We adapt these techniques to the domain of hybrid systems with affine dynamics. To build assumptions we introduce an abstraction based on location merging. We integrate the assume-guarantee style analysis with automatic abstraction refinement. We have implemented our approach in the symbolic hybrid model checker SpaceEx. The evaluation shows its practical potential. To the best of our knowledge, this is the first work combining assume-guarantee reasoning with automatic abstraction-refinement in the context of hybrid automata.

India beckons participants in burgeoning refining sector

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that India has opened its refining sector to full private investment for the first time in more than 2 decades. The government again gave a green light to construction of three 120,000 b/d grassroots refineries in East, West, and Central India. The projects had won various governmental approvals in the past few years, but never moved off high center for a variety of economic and regulatory reasons. The difference this time is that the government is offering interests in the projects to private foreign and domestic investors. It's part of India's push to boost overall refining capacity by more than 80% this century

Macromolecular refinement by model morphing using non-atomic parameterizations.

Science.gov (United States)

Cowtan, Kevin; Agirre, Jon

2018-02-01

Refinement is a critical step in the determination of a model which explains the crystallographic observations and thus best accounts for the missing phase components. The scattering density is usually described in terms of atomic parameters; however, in macromolecular crystallography the resolution of the data is generally insufficient to determine the values of these parameters for individual atoms. Stereochemical and geometric restraints are used to provide additional information, but produce interrelationships between parameters which slow convergence, resulting in longer refinement times. An alternative approach is proposed in which parameters are not attached to atoms, but to regions of the electron-density map. These parameters can move the density or change the local temperature factor to better explain the structure factors. Varying the size of the region which determines the parameters at a particular position in the map allows the method to be applied at different resolutions without the use of restraints. Potential applications include initial refinement of molecular-replacement models with domain motions, and potentially the use of electron density from other sources such as electron cryo-microscopy (cryo-EM) as the refinement model.

Air Quality Impacts of Petroleum Refining and Petrochemical Industries

Directory of Open Access Journals (Sweden)

Aiswarya Ragothaman

2017-09-01

Full Text Available Though refineries and petrochemical industries meet society’s energy demands and produce a range of useful chemicals, they can also affect air quality. The World Health Organization (WHO has identified polluted air as the single largest environmental risk, and hence it is necessary to strive for and maintain good air quality. To manage potential health impacts, it is important to implement proper air quality management by understanding the link between specific pollutant sources and resulting population exposures. These industries release pollutants such as Volatile Organic Compounds, greenhouse gases and particulate matter, from various parts of their operations. Air quality should be monitored and controlled more meticulously in developing nations where increased energy demands, industrialization and overpopulation has led to more emissions and lower air quality. This paper presents a review of findings and highlights from various studies on air quality impacts of petroleum refining and petrochemical plants in many regions in the world.

Horn clause verification with convex polyhedral abstraction and tree automata-based refinement

DEFF Research Database (Denmark)

Kafle, Bishoksan; Gallagher, John Patrick

2017-01-01

In this paper we apply tree-automata techniques to refinement of abstract interpretation in Horn clause verification. We go beyond previous work on refining trace abstractions; firstly we handle tree automata rather than string automata and thereby can capture traces in any Horn clause derivations...... underlying the Horn clauses. Experiments using linear constraint problems and the abstract domain of convex polyhedra show that the refinement technique is practical and that iteration of abstract interpretation with tree automata-based refinement solves many challenging Horn clause verification problems. We...... compare the results with other state-of-the-art Horn clause verification tools....

Refining capacity in Quebec : the Quebec market, industry viewpoint

International Nuclear Information System (INIS)

Trudelle, F.

2004-01-01

Canada's second largest oil refinery is operated by Ultramar Ltd. in Levis, Quebec. The refinery, which supplies 45 per cent of all Quebec's petroleum, distributes its products to Quebec, Ontario and the Maritime provinces. The refinery currently produces 215,000 barrels per day. Ultramar is a division of Valero, an American firm which has a total refining capacity of 2.4 million barrels per day. A summary of the company's petroleum energy distribution, consumption, and reserves was presented and compared with the national and global position. It was noted that world demand for petroleum products increases yearly by 1 to 1.5 per cent while the demand for automobile fuel in North America increases by 2.5 to 3.5 per cent. In the last 10 years, world demand has increased by more than 22 per cent but refining capacity has only increased by 12 per cent. The average profitability of the refining industry from 1992 to 2002 was approximately 5.5 per cent, which limited investments in new refinery installations. Much of the industry's profits have been utilized to modify installations in order to reduce the sulphur content in gasoline and diesel fuels. Furthermore, the obtention of permits to construct new refining installations has become a major obstacle and the ratification of the Kyoto Protocol may signify a 30 per cent reduction in automotive fuel demand. Given this, there is currently some hesitation and uncertainty by the refining industry to proceed with new major installations. tabs., figs

Using toxicokinetic-toxicodynamic modeling as an acute risk assessment refinement approach in vertebrate ecological risk assessment.

Science.gov (United States)

Ducrot, Virginie; Ashauer, Roman; Bednarska, Agnieszka J; Hinarejos, Silvia; Thorbek, Pernille; Weyman, Gabriel

2016-01-01

Recent guidance identified toxicokinetic-toxicodynamic (TK-TD) modeling as a relevant approach for risk assessment refinement. Yet, its added value compared to other refinement options is not detailed, and how to conduct the modeling appropriately is not explained. This case study addresses these issues through 2 examples of individual-level risk assessment for 2 hypothetical plant protection products: 1) evaluating the risk for small granivorous birds and small omnivorous mammals of a single application, as a seed treatment in winter cereals, and 2) evaluating the risk for fish after a pulsed treatment in the edge-of-field zone. Using acute test data, we conducted the first tier risk assessment as defined in the European Food Safety Authority (EFSA) guidance. When first tier risk assessment highlighted a concern, refinement options were discussed. Cases where the use of models should be preferred over other existing refinement approaches were highlighted. We then practically conducted the risk assessment refinement by using 2 different models as examples. In example 1, a TK model accounting for toxicokinetics and relevant feeding patterns in the skylark and in the wood mouse was used to predict internal doses of the hypothetical active ingredient in individuals, based on relevant feeding patterns in an in-crop situation, and identify the residue levels leading to mortality. In example 2, a TK-TD model accounting for toxicokinetics, toxicodynamics, and relevant exposure patterns in the fathead minnow was used to predict the time-course of fish survival for relevant FOCUS SW exposure scenarios and identify which scenarios might lead to mortality. Models were calibrated using available standard data and implemented to simulate the time-course of internal dose of active ingredient or survival for different exposure scenarios. Simulation results were discussed and used to derive the risk assessment refinement endpoints used for decision. Finally, we compared the

Refining mineral oils

Energy Technology Data Exchange (ETDEWEB)

1946-07-05

A process is described refining raw oils such as mineral oils, shale oils, tar, their fractions and derivatives, by extraction with a selected solvent or a mixture of solvents containing water, forming a solvent more favorable for the hydrocarbons poor in hydrogen than for hydrocarbons rich in hydrogen, this process is characterized by the addition of an aiding solvent for the water which can be mixed or dissolved in the water and the solvent or in the dissolving mixture and increasing in this way the solubility of the water in the solvent or the dissolving mixture.

Assessing food allergy risks from residual peanut protein in highly refined vegetable oil

NARCIS (Netherlands)

Blom, W.M.; Kruizinga, A.G.; Rubingh, C.M.; Remington, B.C.; Crevel, R.W.R.; Houben, G.F.

2017-01-01

Refined vegetable oils including refined peanut oil are widely used in foods. Due to shared production processes, refined non-peanut vegetable oils can contain residual peanut proteins. We estimated the predicted number of allergic reactions to residual peanut proteins using probabilistic risk

The changing face of U.S. refining: Ominous notes

International Nuclear Information System (INIS)

Anon.

1992-01-01

As environmental protection comes of age in the US, a complex series of structural changes is also expected - in enforcement bureaucracy, manufacturing, and in energy consumption. It is already quite obvious in the petroleum refining industry. A side effect may be the export of jobs. Buyouts and closures are expected, as is increased refined product import dependency. This issue updates expected changes in gasoline and distillate product requirements in the US, and reports some ominous statements from some of the oil industry's affected parties. This issue also presented the following: (1) the ED Refining Netback Data Series for the US Gulf and West Coasts, Rotterdam, and Singapore as of Jan. 24, 1992; and (2) the ED Fuel Price Tax Series for countries of the Eastern Hemisphere, Jan. 1992 edition

Taiwan: refined need for consuming population

International Nuclear Information System (INIS)

Hayes, David.

1995-01-01

A brief discussion is given of the oil and gas industry in Taiwan. Topics covered include the possibility of privatization, refineries and refining contracts overseas, plans for a new petrochemical complex and an offshore submarine transmission pipeline. (UK)

The Refinement as the Moral Precondition for the Man’s Intellectual Creative Activity (the Historical Aspect

Directory of Open Access Journals (Sweden)

A. S. Frants

2012-01-01

Full Text Available The paper is devoted to the ethical and cultural facilitation of intellectual creative activities. The methodology basis of the research compiles the differentiated analy- sis of Russian moral culture and axiological analysis of its educational potential. The authors describe the specifics of the system of aristocratic moral qualities and refinement; their main characteristics being observed. The novelty of the approach involves the understanding of the aristocratic moral values as a necessary condition for the productive intellectual and creative activity. The authors investigate the historic origin of the aristocratic moral values, and define the functions and specifics of the Russian type of aristocratic culture; the objective and subjective conditions of its for- mation are highlighted, as well as the integrity of the refinement inherent in people en- gaged in intellectual and creative activities. The authors believe that revival of the refinement, as one of the aspects of the Russian moral culture, depends on both the development of our own nation and the the world society as a whole. Nowadays, when the postindustrial society is giving way to the informational one, the production of information takes the leading part in social life. The information and knowledge, being its unified products, provide new ways for evolving of the phenomenon of refinement. Its pedagogic potential should be imple- mented in the process of education and upbringing. 

Refined 3d-3d correspondence

Energy Technology Data Exchange (ETDEWEB)

Alday, Luis F.; Genolini, Pietro Benetti; Bullimore, Mathew; Loon, Mark van [Mathematical Institute, University of Oxford, Andrew Wiles Building,Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG (United Kingdom)

2017-04-28

We explore aspects of the correspondence between Seifert 3-manifolds and 3d N=2 supersymmetric theories with a distinguished abelian flavour symmetry. We give a prescription for computing the squashed three-sphere partition functions of such 3d N=2 theories constructed from boundary conditions and interfaces in a 4d N=2{sup ∗} theory, mirroring the construction of Seifert manifold invariants via Dehn surgery. This is extended to include links in the Seifert manifold by the insertion of supersymmetric Wilson-’t Hooft loops in the 4d N=2{sup ∗} theory. In the presence of a mass parameter for the distinguished flavour symmetry, we recover aspects of refined Chern-Simons theory with complex gauge group, and in particular construct an analytic continuation of the S-matrix of refined Chern-Simons theory.

Using atomic energy in the oil refining and petrochemical industry

Energy Technology Data Exchange (ETDEWEB)

Feigin, E.A.; Barashkov, R.Ia.; Raud, E.A.

1982-01-01

A short description of the basic large scale processes for oil refining and petrochemistry in which nuclear reactors can be used is given. The possible industrial plans for using nuclear reactors are examined together with the problems in using the advances in atomic technology in oil refining and petrochemical processes.

Repetitive Identification of Structural Systems Using a Nonlinear Model Parameter Refinement Approach

Directory of Open Access Journals (Sweden)

Jeng-Wen Lin

2009-01-01

Full Text Available This paper proposes a statistical confidence interval based nonlinear model parameter refinement approach for the health monitoring of structural systems subjected to seismic excitations. The developed model refinement approach uses the 95% confidence interval of the estimated structural parameters to determine their statistical significance in a least-squares regression setting. When the parameters' confidence interval covers the zero value, it is statistically sustainable to truncate such parameters. The remaining parameters will repetitively undergo such parameter sifting process for model refinement until all the parameters' statistical significance cannot be further improved. This newly developed model refinement approach is implemented for the series models of multivariable polynomial expansions: the linear, the Taylor series, and the power series model, leading to a more accurate identification as well as a more controllable design for system vibration control. Because the statistical regression based model refinement approach is intrinsically used to process a “batch” of data and obtain an ensemble average estimation such as the structural stiffness, the Kalman filter and one of its extended versions is introduced to the refined power series model for structural health monitoring.

Refining borders of genome-rearrangements including repetitions

Directory of Open Access Journals (Sweden)

JA Arjona-Medina

2016-10-01

Full Text Available Abstract Background DNA rearrangement events have been widely studied in comparative genomic for many years. The importance of these events resides not only in the study about relatedness among different species, but also to determine the mechanisms behind evolution. Although there are many methods to identify genome-rearrangements (GR, the refinement of their borders has become a huge challenge. Until now no accepted method exists to achieve accurate fine-tuning: i.e. the notion of breakpoint (BP is still an open issue, and despite repeated regions are vital to understand evolution they are not taken into account in most of the GR detection and refinement methods. Methods and results We propose a method to refine the borders of GR including repeated regions. Instead of removing these repetitions to facilitate computation, we take advantage of them using a consensus alignment sequence of the repeated region in between two blocks. Using the concept of identity vectors for Synteny Blocks (SB and repetitions, a Finite State Machine is designed to detect transition points in the difference between such vectors. The method does not force the BP to be a region or a point but depends on the alignment transitions within the SBs and repetitions. Conclusion The accurate definition of the borders of SB and repeated genomic regions and consequently the detection of BP might help to understand the evolutionary model of species. In this manuscript we present a new proposal for such a refinement. Features of the SBs borders and BPs are different and fit with what is expected. SBs with more diversity in annotations and BPs short and richer in DNA replication and stress response, which are strongly linked with rearrangements.

Creep Properties of NiAl-1Hf Single Crystals Re-Investigated

Science.gov (United States)

Whittenberger, J. Daniel; Locci, Ivan E.; Darolia, Ram; Bowman, Randy R.

2000-01-01

NiAl-1Hf single crystals have been shown to be quite strong at 1027 C, with strength levels approaching those of advanced Ni-based superalloys. Initial testing, however, indicated that the properties might not be reproducible. Study of the 1027 C creep behavior of four different NiAl-1Hf single-crystal ingots subjected to several different heat treatments indicated that strength lies in a narrow band. Thus, we concluded that the mechanical properties are reproducible. Recent investigations of the intermetallic NiAl have confirmed that minor alloying additions combined with single-crystal growth technology can produce elevated temperature strength levels approaching those of Ni-based superalloys. For example, General Electric alloy AFN 12 {Ni-48.5(at.%) Al-0.5Hf-1Ti-0.05Ga} has a creep rupture strength equivalent to Rene 80 combined with a approximately 30-percent lower density, a fourfold improvement in thermal conductivity, and the ability to form a self-protective alumina scale in aggressive environments. Although the compositions of strong NiAl single crystals are relatively simple, the microstructures are complex and vary with the heat treatment and with small ingot-toingot variations in the alloy chemistry. In addition, initial testing suggested a strong dependence between microstructure and creep strength. If these observations were true, the ability to utilize NiAl single-crystal rotating components in turbine machinery could be severely limited. To investigate the possible limitations in the creep response of high-strength NiAl single crystals, the NASA Glenn Research Center at Lewis Field initiated an in depth investigation of the effect of heat treatment on the microstructure and subsequent 1027 C creep behavior of [001]-oriented NiAl-1Hf with a nominal chemistry of Ni-47.5Al-1Hf-0.5Si. This alloy was selected since four ingots, grown over a number of years and possessing slightly different compositions, were available for study. Specimens taken from the

Accounting for differences in dieting status: steps in the refinement of a model.

Science.gov (United States)

Huon, G; Hayne, A; Gunewardene, A; Strong, K; Lunn, N; Piira, T; Lim, J

1999-12-01

The overriding objective of this paper is to outline the steps involved in refining a structural model to explain differences in dieting status. Cross-sectional data (representing the responses of 1,644 teenage girls) derive from the preliminary testing in a 3-year longitudinal study. A battery of measures assessed social influence, vulnerability (to conformity) disposition, protective (social coping) skills, and aspects of positive familial context as core components in a model proposed to account for the initiation of dieting. Path analyses were used to establish the predictive ability of those separate components and their interrelationships in accounting for differences in dieting status. Several components of the model were found to be important predictors of dieting status. The model incorporates significant direct, indirect (or mediated), and moderating relationships. Taking all variables into account, the strongest prediction of dieting status was from peer competitiveness, using a new scale developed specifically for this study. Systematic analyses are crucial for the refinement of models to be used in large-scale multivariate studies. In the short term, the model investigated in this study has been shown to be useful in accounting for cross-sectional differences in dieting status. The refined model will be most powerfully employed in large-scale time-extended studies of the initiation of dieting to lose weight. Copyright 1999 by John Wiley & Sons, Inc.

Grain refinement of AZ31 by (SiC)P: Theoretical calculation and experiment

International Nuclear Information System (INIS)

Guenther, R.; Hartig, Ch.; Bormann, R.

2006-01-01

Grain refinement of gravity die-cast Mg-alloys can be achieved via two methods: in situ refinement by primary precipitated metallic or intermetallic phases, and inoculation of the melt via ceramic particles that remain stable in the melt due to their high thermodynamic stability. In order to clarify grain refinement mechanisms and optimize possible potent refiners in Mg-alloys, a simulation method for heterogeneous nucleation based on a free growth model has been developed. It allows the prediction of the grain size as a function of the particle size distribution, the volumetric content of ceramic inoculants, the cooling rate and the alloy constitution. The model assumptions were examined experimentally by a study of the grain refinement of (SiC) P in AZ31. Additions of (SiC) P result in significant grain refinement, if appropriate parameters for ceramic particles are chosen. The model makes quantitatively correct predictions for the grain size and its variation with cooling rate

Process for refining shale bitumen

Energy Technology Data Exchange (ETDEWEB)

Plauson, H

1920-09-19

A process is disclosed for refining shale bitumen for use as heavy mineral oil, characterized by mixtures of blown hard shale pitch and heavy mineral oil being blown with hot air at temperatures of 120 to 150/sup 0/ with 1 to 3 percent sulfur, and if necessary with 0.5 to 3 percent of an aldehyde.

Multigrid for refined triangle meshes

Energy Technology Data Exchange (ETDEWEB)

Shapira, Yair

1997-02-01

A two-level preconditioning method for the solution of (locally) refined finite element schemes using triangle meshes is introduced. In the isotropic SPD case, it is shown that the condition number of the preconditioned stiffness matrix is bounded uniformly for all sufficiently regular triangulations. This is also verified numerically for an isotropic diffusion problem with highly discontinuous coefficients.

Unit-cell refinement from powder diffraction scans

International Nuclear Information System (INIS)

Pawley, G.S.

1981-01-01

A procedure for the refinement of the crystal unit cell from a powder diffraction scan is presented. In this procedure knowledge of the crystal structure is not required, and at the end of the refinement a list of indexed intensities is produced. This list may well be usable as the starting point for the application of direct methods. The problems of least-squares ill-conditioning due to overlapping reflections are overcome by constraints. An example using decafluorocyclohexene, C 6 F 10 , shows the quality of fit obtained in a case which may even be a false minimum. The method should become more relevant as powder scans of improved resolution become available, through the use of pulsed neutron sources. (Auth.)

Refining crude oils and gasolines, etc

Energy Technology Data Exchange (ETDEWEB)

1931-11-23

A process of refining crude oils and gasolines distilled from shale and the like is described, consisting of submitting them to a prewash with soda, an oxidation preferably with hypochlorite solution, a hydrogenation with nascent hydrogen, and finally rectification and neutralization.

High Energy, Single-Mode, All-Solid-State and Tunable UV Laser Transmitter

Science.gov (United States)

Prasad, Narasimha S.; Singh, Upendra N.; Hovis, FLoyd

2007-01-01

A high energy, single mode, all solid-state Nd:YAG laser primarily for pumping an UV converter is developed. Greater than 1 J/pulse at 50 HZ PRF and pulse widths around 22 ns have been demonstrated. Higher energy, greater efficiency may be possible. Refinements are known and practical to implement. Technology Demonstration of a highly efficient, high-pulse-energy, single mode UV wavelength generation using flash lamp pumped laser has been achieved. Greater than 90% pump depletion is observed. 190 mJ extra-cavity SFG; IR to UV efficiency > 21% (> 27% for 1 mJ seed). 160 mJ intra-cavity SFG; IR to UV efficiency up to 24% Fluence laser is being refined to match or exceed the above UV converter results. Currently the Nd:YAG pump laser development is a technology demonstration. System can be engineered for compact packaging.

Refining mass formulas for astrophysical applications: A Bayesian neural network approach

Science.gov (United States)

Utama, R.; Piekarewicz, J.

2017-10-01

Background: Exotic nuclei, particularly those near the drip lines, are at the core of one of the fundamental questions driving nuclear structure and astrophysics today: What are the limits of nuclear binding? Exotic nuclei play a critical role in both informing theoretical models as well as in our understanding of the origin of the heavy elements. Purpose: Our aim is to refine existing mass models through the training of an artificial neural network that will mitigate the large model discrepancies far away from stability. Methods: The basic paradigm of our two-pronged approach is an existing mass model that captures as much as possible of the underlying physics followed by the implementation of a Bayesian neural network (BNN) refinement to account for the missing physics. Bayesian inference is employed to determine the parameters of the neural network so that model predictions may be accompanied by theoretical uncertainties. Results: Despite the undeniable quality of the mass models adopted in this work, we observe a significant improvement (of about 40%) after the BNN refinement is implemented. Indeed, in the specific case of the Duflo-Zuker mass formula, we find that the rms deviation relative to experiment is reduced from σrms=0.503 MeV to σrms=0.286 MeV. These newly refined mass tables are used to map the neutron drip lines (or rather "drip bands") and to study a few critical r -process nuclei. Conclusions: The BNN approach is highly successful in refining the predictions of existing mass models. In particular, the large discrepancy displayed by the original "bare" models in regions where experimental data are unavailable is considerably quenched after the BNN refinement. This lends credence to our approach and has motivated us to publish refined mass tables that we trust will be helpful for future astrophysical applications.

A Canadian refiner's perspective of synthetic crudes

International Nuclear Information System (INIS)

Halford, T.L.; McIntosh, A.P.; Rasmussen

1997-01-01

Some of the factors affecting a refiner's choice of crude oil include refinery hardware, particularly gas oil crackers, products slate and product specifications, crude availability, relative crude price and crude quality. An overview of synthetic crude, the use of synthetic crude combined with other crudes and a comparison of synthetic crude with conventional crude oil was given. The two main users of synthetic crude are basically two groups of refiners, those large groups who use synthetic crude combined with other crudes, and a smaller group who run synthetic crude on specially designed units as a sole feed. The effects of changes in fuel legislation were reviewed. It was predicted that the changes will have a mixed impact on the value of synthetic crude, but low sulphur diesel regulations and gasoline sulphur regulations will make current synthetic crudes attractive. The big future change with a negative impact will be diesel cetane increases to reduce engine emissions. This will reduce synthetic crude attractiveness due to distillate yields and quality and high gas oil yields. Similarly, any legislation limiting aromatics in diesel fuel will also make synthetic crudes less attractive. Problems experienced by refiners with hardware dedicated to synthetic crude (salt, naphthenic acid, fouling, quality variations) were also reviewed. 3 tabs

The Generation of AlmFe in Dilute Aluminium Alloys with Different Grain Refining Additions

Science.gov (United States)

Meredith, M. W.; Greer, A. L.; Evans, P. V.; Hamerton, R. G.

Al13Fe4, Al6Fe and AlmFe are common intermetallics in commercial AA1XXX series Al alloys. Grain-refining additions (based on either Al-Ti-B or Al-Ti-C) are usually added to such alloys during solidification processing to aid the grain structure development. They also influence the favoured intermetallic and, hence, can affect the materials' properties. This work simulates commercial casting practices in an attempt to determine the mechanisms by which one intermetallic phase is favoured over another by the introduction of grain-refining additions. Directional solidification experiments on Al-0.3wt.%Fe-0.15wt.%Si with and without grain refiner are conducted using Bridgman apparatus. The type, amount and effectiveness of the grain-refining additions are altered and the resulting intermetallic phase selection followed. The materials are characterised using optical microscopy, scanning electron microscopy and X-ray diffraction. AlmFe is seen to form when Al-Ti-B grain-refiner is introduced but only when the refinement is successful; reducing the effectiveness of the refiner led to Al6Fe forming under all conditions. Al-Ti-C refiners are seen to promote AlmFe at lower solidification velocities than when Al-Ti-B was used even though the grain structure was not as refined. These trends can be explained within existing eutectic theory, by considering growth undercooling.

Refinement of the crystal structures of biomimetic weddellites produced by microscopic fungus Aspergillus niger

Science.gov (United States)

Rusakov, A. V.; Frank-Kamenetskaya, O. V.; Gurzhiy, V. V.; Zelenskaya, M. S.; Izatulina, A. R.; Sazanova, K. V.

2014-05-01

The single-crystal structures of four biomimetic weddellites CaC2O4 · (2 + x)H2O with different contents of zeolitic water ( x = 0.10-0.24 formula units) produced by the microscopic fungus Aspergillus niger were refined from X-ray diffraction data ( R = 0.029-0.038). The effect of zeolitic water content on the structural stability of weddellite was analyzed. The parameter a was shown to increase with increasing x due to the increase in the distance between water molecules along this direction. The water content and structural parameters of the synthesized weddellites are similar to those of weddellites from biofilms and kidney stones.

Tri-Clustered Tensor Completion for Social-Aware Image Tag Refinement.

Science.gov (United States)

Tang, Jinhui; Shu, Xiangbo; Qi, Guo-Jun; Li, Zechao; Wang, Meng; Yan, Shuicheng; Jain, Ramesh

2017-08-01

Social image tag refinement, which aims to improve tag quality by automatically completing the missing tags and rectifying the noise-corrupted ones, is an essential component for social image search. Conventional approaches mainly focus on exploring the visual and tag information, without considering the user information, which often reveals important hints on the (in)correct tags of social images. Towards this end, we propose a novel tri-clustered tensor completion framework to collaboratively explore these three kinds of information to improve the performance of social image tag refinement. Specifically, the inter-relations among users, images and tags are modeled by a tensor, and the intra-relations between users, images and tags are explored by three regularizations respectively. To address the challenges of the super-sparse and large-scale tensor factorization that demands expensive computing and memory cost, we propose a novel tri-clustering method to divide the tensor into a certain number of sub-tensors by simultaneously clustering users, images and tags into a bunch of tri-clusters. And then we investigate two strategies to complete these sub-tensors by considering (in)dependence between the sub-tensors. Experimental results on a real-world social image database demonstrate the superiority of the proposed method compared with the state-of-the-art methods.

Grain Refinement of Commercial EC Grade 1070 Aluminium Alloy for Electrical Application

OpenAIRE

Hassanabadi, Massoud

2015-01-01

The aluminium alloys for electrical conductivity applications are generally not grain refinedsince the addition of grain refiners drops the electrical conductivity by introducing impuritiesinto the melt. Non-grain refined aluminium may lead to bar fracture and cracks during themetalworking process. The present study focuses to find an optimum balance between the grain refiner addition andthe electrical conductivity of commercial EC grade 1070 aluminium alloy for electricalapplication. In orde...

Refined Fuchs inequalities for systems of linear differential equations

International Nuclear Information System (INIS)

Gontsov, R R

2004-01-01

We refine the Fuchs inequalities obtained by Corel for systems of linear meromorphic differential equations given on the Riemann sphere. Fuchs inequalities enable one to estimate the sum of exponents of the system over all its singular points. We refine these well-known inequalities by considering the Jordan structure of the leading coefficient of the Laurent series for the matrix of the right-hand side of the system in the neighbourhood of a singular point

Rising costs call for new European refining strategies

International Nuclear Information System (INIS)

Sweeney, B.N.C.

1993-01-01

The outlook for the global refining industry is for increased spending and reduced margins, largely because of efforts to improve the environment. A look at these trends through the end of the decade is thus in order. Three major industry thrusts are proposed to see refiners through this uncertain period. Three main thrusts are necessary: fixed costs must be reduced by re-engineering business processes and reexamining noncore business units against total and marginal costs. In this respect the best refiners are well ahead of the good ones. New cooperative ways of meeting regulations must be sought, to avoid wasteful over capacity. Joint ventures and alliances with competitors will be needed. The cooperative principle upstream must be extended and new strategies must be sought to meet product demand changes and reduce feedstock costs. The picture that is presented is tough, largely because of the wish to improve the environment. The question that must be continually reviewed is ''Have governments got the right balance in these regulations between the environment and the downstream industry?''

Stability studies on refined soybean oil stored in various conditions

International Nuclear Information System (INIS)

Arawande, J.O.; Amoo, I.A.

2008-01-01

The 12 months stability study of freshly produced refined soybean oil revealed that refined soybean oil stored in plastic containers in dark was more hydrolytically and oxidatively stable than that stored in other containers in light condition. There was no significant difference at P < 0.05 in free fatty acids and acid value of oil stored under light and dark conditions in tin and glass containers but there was significant difference at P < 0.05 in peroxide value of oil stored in light and dark conditions in all the storage containers. Light increased the degree of oxidative rancidity of refined soybean oil, the most in tin containers, followed by glass containers and the least in plastic containers. (author)

Atlantic Basin refining profitability

International Nuclear Information System (INIS)

Jones, R.J.

1998-01-01

A review of the profitability margins of oil refining in the Atlantic Basin was presented. Petroleum refiners face the continuous challenge of balancing supply with demand. It would appear that the profitability margins in the Atlantic Basin will increase significantly in the near future because of shrinking supply surpluses. Refinery capacity utilization has reached higher levels than ever before. The American Petroleum Institute reported that in August 1997, U.S. refineries used 99 per cent of their capacity for several weeks in a row. U.S. gasoline inventories have also declined as the industry has focused on reducing capital costs. This is further evidence that supply and demand are tightly balanced. Some of the reasons for tightening supplies were reviewed. It was predicted that U.S. gasoline demand will continue to grow in the near future. Gasoline demand has not declined as expected because new vehicles are not any more fuel efficient today than they were a decade ago. Although federally-mandated fuel efficiency standards were designed to lower gasoline consumption, they may actually have prevented consumption from falling. Atlantic margins were predicted to continue moving up because of the supply and demand evidence: high capacity utilization rates, low operating inventories, limited capacity addition resulting from lower capital spending, continued U.S. gasoline demand growth, and steady total oil demand growth. 11 figs

The effect of refining step on the changes in viscosity values of vegetable oils

International Nuclear Information System (INIS)

Ergonul, P.G.

2013-01-01

In this work, the viscosity values of chemically refined vegetable oils (sunflower, corn, soybean and rapeseed) and physically refined vegetable oils (olive and palm) were determined during refining processes. At this point of view, fatty acid compositions and viscosity values of oil samples were determined. The edible vegetable oils presented Newtonian behavior in shear rates at ranges 6.28-20.93 s/sup -1/. It was observed that palm oil is more viscous than the others. During physical refining, the effect of both oil type and refining steps were significantly important, whereas in chemical refining only the effect of oil type was found statistically important (p<0.01). It was observed that correlation among fatty acid compositions and viscosity values of the samples showed differences according to oil type. (author)

Hybrid direct and iterative solvers for h refined grids with singularities

KAUST Repository

Paszyński, Maciej R.; Paszyńska, Anna; Dalcin, Lisandro; Calo, Victor M.

2015-01-01

on top of it. The hybrid solver is applied for two or three dimensional grids automatically h refined towards point or edge singularities. The automatic refinement is based on the relative error estimations between the coarse and fine mesh solutions [2

Panorama 2016 - Refining outlook for 2035

International Nuclear Information System (INIS)

Marion, Pierre; Saint-Antonin, Valerie

2015-12-01

The rising influence of objectives intended to address the energy transition in global industry helps to perpetuate a high degree of uncertainty about changes in the transportation sector, currently a bastion of the oil industry. How can the growing need for individual mobility be met while reducing Greenhouse Gas (GHG) emissions in a world of open international competition? The refining sector is gaining strength in Asia and the Middle East to the detriment of Europe and North America, reflecting demand and the intrinsic competitiveness of various geographic regions. The 2025 worldwide roll-out (2020 in Europe) of a bunker fuel grade below 0.5 wt% (percentage by weight) in sulphur could experience delays, given the number of installations to be completed. Finally, the reversal of the 'all diesel' trend in the European transport market is a positive change for the European refining industry. (authors)

Tree automata-based refinement with application to Horn clause verification

DEFF Research Database (Denmark)

Kafle, Bishoksan; Gallagher, John Patrick

2015-01-01

In this paper we apply tree-automata techniques to refinement of abstract interpretation in Horn clause verification. We go beyond previous work on refining trace abstractions; firstly we handle tree automata rather than string automata and thereby can capture traces in any Horn clause derivation...... compare the results with other state of the art Horn clause verification tools....

The regulations concerning refining business of nuclear source material and nuclear fuel materials

International Nuclear Information System (INIS)

1979-01-01

The regulations are provided for under the law for the regulations of nuclear source materials, nuclear fuel materials and reactors and provisions concerning refining business in the enforcement order for the law. The basic concepts and terms are defined, such as: exposure dose, accumulative dose; controlled area; inspected surrounding area and employee. Refining facilities listed in the application for designation shall be classified into clushing and leaching, thickning, refining facilities, storage facilities of nuclear source materials and nuclear fuel materials, disposal facilities of contaminated substances and building for refining, etc. Business program attached to the application shall include expected time of beginning of refining, estimated production amount of nuclear source materials or nuclear fuel materials for the first three years and funds necessary for construction, etc. Records shall be made and kept for particular periods on delivery and storage of nuclear source materials and nuclear fuel materials, control of radiation, maintenance and accidents of refining facilities. Safety securing, application of internationally regulated substances and measures in dangerous situations are stipulated respectively. Exposure dose of employees and other specified matters shall be reported by the refiner yearly to the Director General of Science and Technology Agency and the Minister of International Trade and Industry. (Okada, K.)

Catalysts in petroleum refining and petrochemical industries 1995

Energy Technology Data Exchange (ETDEWEB)

Absi-Halabi, M.; Beshara, J.; Qabazard, H.; Stanislaus, A. [eds.] [Petroleum, Petrochemicals and Materials Division, Kuwait Institute of Scientific Research, Kuwait (Kuwait)

1996-07-01

Catalysis plays an increasingly critical role in modern petroleum refining and basic petrochemical industries. The market demands for and specifications of petroleum and petrochemical products are continuously changing. They have impacted the industry significantly over the past twenty years. Numerous new refining processes have been developed and significant improvements were made on existing technologies. Catalysts have been instrumental in enabling the industry to meet the continuous challenges posed by the market. As we enter the 21st century, new challenges for catalysis science and technology are anticipated in almost every field. Particularly, better utilization of petroleum resources and demands for cleaner transportation fuels are major items on the agenda. It is against this background that the 2nd International Conference on Catalysts in Petroleum Refining and Petrochemical Industries was organized. The papers from the conference were carefully selected from around 100 submissions. They were a mix of reviews providing an overview of selected areas, original fundamental research results, and industrial experiences. The papers in the proceedings were grouped in the following sections for quick reference: Plenary Papers; Hydroprocessing of Petroleum Residues and Distillates; Fluid Catalytic Cracking; Oxidation Catalysis; Aromatization and Polymerization Catalysis; Catalyst Characterization and Performance. The plenary papers were mostly reviews covering important topics related to the objectives of the conference. The remaining sections cover various topics of major impact on modern petroleum refining and petrochemical industries. A large number of papers dealt with hydroprocessing of petroleum distillates and residues which reflects the concern over meeting future sulfur-level specifications for diesel and fuel oils

The evolution and refinements of varicocele surgery

Directory of Open Access Journals (Sweden)

Joel L Marmar

2016-01-01

Full Text Available Varicoceles had been recognized in clinical practice for over a century. Originally, these procedures were utilized for the management of pain but, since 1952, the repairs had been mostly for the treatment of male infertility. However, the diagnosis and treatment of varicoceles were controversial, because the pathophysiology was not clear, the entry criteria of the studies varied among centers, and there were few randomized clinical trials. Nevertheless, clinicians continued developing techniques for the correction of varicoceles, basic scientists continued investigations on the pathophysiology of varicoceles, and new outcome data from prospective randomized trials have appeared in the world′s literature. Therefore, this special edition of the Asian Journal of Andrology was proposed to report much of the new information related to varicoceles and, as a specific part of this project, the present article was developed as a comprehensive review of the evolution and refinements of the corrective procedures.

Demand, deregulation may attract more refiners to Asia

International Nuclear Information System (INIS)

Rhodes, A.K.

1995-01-01

As a result of rapidly increasing demand, major oil companies are eyeing Asian oil and gas markets more closely than ever. Higher earnings can be expected there than in the US or Europe, where product markets--especially light products--are expected to tighten long-term. Of the nations with growing requirements for refined products, China and India offer greater opportunity for foreign investors to enter downstream projects. Also offering excellent business prospects are Thailand, Malaysia, and Indonesia. The paper discusses oil demand, products, refining capacity, and capacity additions in Japan, South Korea, Taiwan, Singapore, India, Indonesia, Malaysia, and China

China's refiners face massive overhaul, expansion to meet demand growth, new crude slate

International Nuclear Information System (INIS)

Anon.

1994-01-01

China's refining industry has embarked on a massive overhaul and expansion to accommodate soaring domestic growth in refined products demand. Currently that growth in demand is being met by increasing imports of refined products, in recent years attaining triple digit growth rates and squeezing direly needed foreign exchange. The focus is on adding refining capacity of about 1.4 million b/d to the current capacity of about 3.2 million b/d by 2000. Priority for increasing capacity is being given to expanding existing refineries and participating in foreign joint venture grassroots refineries along China's booming coastal regions as well as hiking output. A major challenge for China's refineries is that country's reentry into the General Agreement on Tariffs and Trade (GATT), recently signed in Morocco by more than 100 nations. The accompanying reduction of tariffs on imported refined products will make it more difficult for China's marginal refineries to compete in the domestic market. The paper discusses imports and exports, LPG outlook, refining capacity, revamps needed, third party processing, China's first joint venture refinery, industry plans, and GATT challenges

Effect of grain refiner on intermetallic phase formation in directional solidification of 6xxx series wrought Al alloys

Energy Technology Data Exchange (ETDEWEB)

Sha, G.; O' Reilly, K.; Cantor, B. [Oxford Univ. (United Kingdom). Centre for Adv. Mat. and Composites; Hamerton, R.; Worth, J.

2000-07-01

The effect of a grain refiner on the formation of intermetallic phases in a directionally solidified (Bridgman grown) model 6xxx series wrought Al alloy has been investigated using X-ray diffractometry (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). A base alloy with and without Al-Ti-B grain refiner was directionally solidified in a Bridgman furnace at growth velocities in the range of 5-120 mm/min. In both cases, the Fe-containing intermetallic phases present were found to be mainly {alpha}-AlFeSi and {beta}-AlFeSi. However, in the alloy with grain refiner solidified at 5mm/min, Al{sub 13}Fe{sub 4} was also observed. Quantitative XRD results indicated that the addition of Al-Ti-B grain refiner has a strong influence on the relative quantities of intermetallic phases forming during solidification at different growth velocities, which was also confirmed by TEM observations. TEM observations also show that depending on where the {beta}-AlFeSi particles solidified e.g. grain boundaries or triple grain junctions, the size and morphology of the particles may change dramatically. TiB{sub 2} particles were observed to nucleate {beta}-AlFeSi at low and high growth velocities in the 6xxx series Al alloys. (orig.)

Microstructures and Grain Refinement of Additive-Manufactured Ti- xW Alloys

Science.gov (United States)

Mendoza, Michael Y.; Samimi, Peyman; Brice, David A.; Martin, Brian W.; Rolchigo, Matt R.; LeSar, Richard; Collins, Peter C.

2017-07-01

It is necessary to better understand the composition-processing-microstructure relationships that exist for materials produced by additive manufacturing. To this end, Laser Engineered Net Shaping (LENS™), a type of additive manufacturing, was used to produce a compositionally graded titanium binary model alloy system (Ti- xW specimen (0 ≤ x ≤ 30 wt pct), so that relationships could be made between composition, processing, and the prior beta grain size. Importantly, the thermophysical properties of the Ti- xW, specifically its supercooling parameter ( P) and growth restriction factor ( Q), are such that grain refinement is expected and was observed. The systematic, combinatorial study of this binary system provides an opportunity to assess the mechanisms by which grain refinement occurs in Ti-based alloys in general, and for additive manufacturing in particular. The operating mechanisms that govern the relationship between composition and grain size are interpreted using a model originally developed for aluminum and magnesium alloys and subsequently applied for titanium alloys. The prior beta grain factor observed and the interpretations of their correlations indicate that tungsten is a good grain refiner and such models are valid to explain the grain-refinement process. By extension, other binary elements or higher order alloy systems with similar thermophysical properties should exhibit similar grain refinement.

Effect of processing on phenolic composition of dough and bread fractions made from refined and whole wheat flour of three wheat varieties.

Science.gov (United States)

Lu, Yingjian; Luthria, Devanand; Fuerst, E Patrick; Kiszonas, Alecia M; Yu, Liangli; Morris, Craig F

2014-10-29

This study investigated the effect of breadmaking on the assay of phenolic acids from flour, dough, and bread fractions of three whole and refined wheat varieties. Comparison of the efficacy of two commonly used methods for hydrolysis and extraction of phenoilc acids showed that yields of total phenolic acids (TPA) were 5-17% higher among all varieties and flour types when samples were directly hydrolyzed in the presence of ascorbate and EDTA as compared to the method separating free, soluble conjugates and bound, insoluble phenolic acids. Ferulic acid (FA) was the predominant phenolic acid, accounting for means of 59 and 81% of TPA among all refined and whole wheat fractions, respectively. All phenolic acids measured were more abundant in whole wheat than in refined samples. Results indicated that the total quantified phenolic acids did not change significantly when breads were prepared from refined and whole wheat flour. Thus, the potential phytochemical health benefits of total phenolic acids appear to be preserved during bread baking.

Extraction and Refinement Strategy for Detection of Autism in 18-Month-Olds: A Guarantee of Higher Sensitivity and Specificity in the Process of Mass Screening

Science.gov (United States)

Honda, Hideo; Shimizu, Yasuo; Nitto, Yukari; Imai, Miho; Ozawa, Takeshi; Iwasa, Mitsuaki; Shiga, Keiko; Hira, Tomoko

2009-01-01

Background: For early detection of autism, it is difficult to maintain an efficient level of sensitivity and specificity based on observational data from a single screening. The Extraction and Refinement (E&R) Strategy utilizes a public children's health surveillance program to produce maximum efficacy in early detection of autism. In the…

40 CFR 80.1142 - What are the provisions for small refiners under the RFS program?

Science.gov (United States)

2010-07-01

... all of the following criteria: (i) The refiner produced gasoline at its refineries by processing crude... Standard § 80.1142 What are the provisions for small refiners under the RFS program? (a)(1) Gasoline produced by a refiner, or foreign refiner (as defined at § 80.1165(a)), is exempt from the renewable fuel...

On Syntactic and Semantic Action Refinement

NARCIS (Netherlands)

Goltz, Ursula; Gorrieri, Roberto; Rensink, Arend

1992-01-01

The semantic definition of action refinement on labelled event structures is compared with the notion of syntactic substitution,which can be used as another notion of action refiment in a process algebraic setting. This is done by studying a process algebra equipped with the ACP sequential

Quantum Geometry of Refined Topological Strings

NARCIS (Netherlands)

Aganagic, M.; Cheng, M.C.N.; Dijkgraaf, R.; Kreft, D.; Vafa, C.

2012-01-01

We consider branes in refined topological strings. We argue that their wavefunctions satisfy a Schrödinger equation depending on multiple times and prove this in the case where the topological string has a dual matrix model description. Furthermore, in the limit where one of the equivariant

Government will shape China's refining boom

International Nuclear Information System (INIS)

Wang, H.

1995-01-01

China's refining system is undergoing a major overhaul. New refineries are being built as existing ones are upgraded and expanded. The success of refineries funded completely or partially by non-chinese companies will depend in part on Chinese government policy. There will be demand for products from third-party processing facilities, but hard current is necessary for the investors to repatriate profits and for china Petrochemical Corp. (Sinopec) to bid on the products from such facilities. The limited convertibility of chinese current constitutes a major central control over the country's entire economy. This control can be affected by limiting product exchange participants and the volumes to be traded. Such a limitation, however, will reduce access of non-Chinese companies to China's markets, and is not likely to occur in the next 10 years. The paper discusses the current situation in capacity and in refining, capacity, expansion, refinery planning, construction projects, third-party processing, and the prospects for change

Multivariate refined composite multiscale entropy analysis

International Nuclear Information System (INIS)

Humeau-Heurtier, Anne

2016-01-01

Multiscale entropy (MSE) has become a prevailing method to quantify signals complexity. MSE relies on sample entropy. However, MSE may yield imprecise complexity estimation at large scales, because sample entropy does not give precise estimation of entropy when short signals are processed. A refined composite multiscale entropy (RCMSE) has therefore recently been proposed. Nevertheless, RCMSE is for univariate signals only. The simultaneous analysis of multi-channel (multivariate) data often over-performs studies based on univariate signals. We therefore introduce an extension of RCMSE to multivariate data. Applications of multivariate RCMSE to simulated processes reveal its better performances over the standard multivariate MSE. - Highlights: • Multiscale entropy quantifies data complexity but may be inaccurate at large scale. • A refined composite multiscale entropy (RCMSE) has therefore recently been proposed. • Nevertheless, RCMSE is adapted to univariate time series only. • We herein introduce an extension of RCMSE to multivariate data. • It shows better performances than the standard multivariate multiscale entropy.

Effect of Cellulases and Xylanases on Refining Process and Kraft Pulp Properties.

Directory of Open Access Journals (Sweden)

Kamila Przybysz Buzała

Full Text Available Samples of bleached kraft pine cellulosic pulp, either treated with an enzyme preparation (a Thermomyces lanuginosus xylanase, an Aspergillus sp. cellulase, and a multienzyme preparation NS-22086 containing both these activities or untreated, were refined in a laboratory PFI mill. The treatment with cellulases contained in the last two preparations significantly improved the pulp's susceptibility to refining (the target freeness value of 30°SR was achieved in a significantly shorter time, increased water retention value (WRV and fines contents while the weighted average fiber length was significantly reduced. These changes of pulp parameters caused deterioration of paper strength properties. The treatment with the xylanase, which partially hydrolyzed xylan, small amounts of which are associated with cellulose fibers, only slightly loosened the structure of fibers. These subtle changes positively affected the susceptibility of the pulp to refining (refining energy was significantly reduced and improved the static strength properties of paper. Thus, the treatment of kraft pulps with xylanases may lead to substantial savings of refining energy without negative effects on paper characteristics.

INVESTIGATION OF SINGLE-PASS/DOUBLE-PASS TECHNIQUES ON FRICTION STIR WELDING OF ALUMINIUM

Directory of Open Access Journals (Sweden)

N.A.A. Sathari

2014-12-01

Full Text Available The aim of this research is to study the effects of single-pass/ double-pass techniques on friction stir welding of aluminium. Two pieces of AA1100 with a thickness of 6.0 mm were friction stir welded using a CNC milling machine at rotational speeds of 1400 rpm, 1600 rpm and 1800 rpm respectively for single-pass and double-pass. Microstructure observations of the welded area were studied using an optical microscope. The specimens were tested by using a tensile test and Vickers hardness test to evaluate their mechanical properties. The results indicated that, at low rotational speed, defects such as ‘surface lack of fill’ and tunnels in the welded area contributed to a decrease in mechanical properties. Welded specimens using double-pass techniques show increasing values of tensile strength and hardness. From this investigation it is found that the best parameters of FSW welded aluminium AA1100 plate were those using double-pass techniques that produce mechanically sound joints with a hardness of 56.38 HV and 108 MPa strength at 1800 rpm compared to the single-pass technique. Friction stir welding, single-pass/ double-pass techniques, AA1100, microstructure, mechanical properties.

Region-of-interest volumetric visual hull refinement

KAUST Repository

Knoblauch, Daniel

2010-01-01

This paper introduces a region-of-interest visual hull refinement technique, based on flexible voxel grids for volumetric visual hull reconstructions. Region-of-interest refinement is based on a multipass process, beginning with a focussed visual hull reconstruction, resulting in a first 3D approximation of the target, followed by a region-of-interest estimation, tasked with identifying features of interest, which in turn are used to locally refine the voxel grid and extract a higher-resolution surface representation for those regions. This approach is illustrated for the reconstruction of avatars for use in tele-immersion environments, where head and hand regions are of higher interest. To allow reproducability and direct comparison a publicly available data set for human visual hull reconstruction is used. This paper shows that region-of-interest reconstruction of the target is faster and visually comparable to higher resolution focused visual hull reconstructions. This approach reduces the amount of data generated through the reconstruction, allowing faster post processing, as rendering or networking of the surface voxels. Reconstruction speeds support smooth interactions between the avatar and the virtual environment, while the improved resolution of its facial region and hands creates a higher-degree of immersion and potentially impacts the perception of body language, facial expressions and eye-to-eye contact. Copyright © 2010 by the Association for Computing Machinery, Inc.

Pacific Basin Heavy Oil Refining Capacity

Directory of Open Access Journals (Sweden)

David Hackett

2013-02-01

Full Text Available The United States today is Canada’s largest customer for oil and refined oil products. However, this relationship may be strained due to physical, economic and political influences. Pipeline capacity is approaching its limits; Canadian oil is selling at substantive discounts to world market prices; and U.S. demand for crude oil and finished products (such as gasoline, has begun to flatten significantly relative to historical rates. Lower demand, combined with increased shale oil production, means U.S. demand for Canadian oil is expected to continue to decline. Under these circumstances, gaining access to new markets such as those in the Asia-Pacific region is becoming more and more important for the Canadian economy. However, expanding pipeline capacity to the Pacific via the proposed Northern Gateway pipeline and the planned Trans Mountain pipeline expansion is only feasible when there is sufficient demand and processing capacity to support Canadian crude blends. Canadian heavy oil requires more refining and produces less valuable end products than other lighter and sweeter blends. Canadian producers must compete with lighter, sweeter oils from the Middle East, and elsewhere, for a place in the Pacific Basin refineries built to handle heavy crude blends. Canadian oil sands producers are currently expanding production capacity. Once complete, the Northern Gateway pipeline and the Trans Mountain expansion are expected to deliver an additional 500,000 to 1.1 million barrels a day to tankers on the Pacific coast. Through this survey of the capacity of Pacific Basin refineries, including existing and proposed facilities, we have concluded that there is sufficient technical capacity in the Pacific Basin to refine the additional Canadian volume; however, there may be some modifications required to certain refineries to allow them to process Western Canadian crude. Any additional capacity for Canadian oil would require refinery modifications or

Development of a Refined Staff Group Trainer

National Research Council Canada - National Science Library

Quensel, Susan

1999-01-01

.... As a follow-on effort to the previous SGT project, the goal was to refine a brigade-level staff training program to more effectively and efficiently coordinate the activities within and between the...

Discontinuous Galerkin discretization and hp-refinement for the resolution of the neutron transport equation

International Nuclear Information System (INIS)

Fournier, Damien; Le-Tellier, Romain; Herbin, Raphaele

2013-01-01

This paper presents an hp-refinement method for a first order scalar transport reaction equation discretized by a discontinuous Galerkin method. First, the theoretical rates of convergence of h- and p-refinement are recalled and numerically tested. Then, in order to design some meshes, we propose two different estimators of the local error on the spatial domain. These quantities are analyzed and compared depending on the regularity of the solution so as to find the best way to lead the refinement process and the best strategy to choose between h- and p-refinement. Finally, the different possible refinement strategies are compared first on analytical examples and then on realistic applications for neutron transport in a nuclear reactor core. (authors)

Asymptotics for moist deep convection I: refined scalings and self-sustaining updrafts

Science.gov (United States)

Hittmeir, Sabine; Klein, Rupert

2018-04-01

Moist processes are among the most important drivers of atmospheric dynamics, and scale analysis and asymptotics are cornerstones of theoretical meteorology. Accounting for moist processes in systematic scale analyses therefore seems of considerable importance for the field. Klein and Majda (Theor Comput Fluid Dyn 20:525-551, 2006) proposed a scaling regime for the incorporation of moist bulk microphysics closures in multiscale asymptotic analyses of tropical deep convection. This regime is refined here to allow for mixtures of ideal gases and to establish consistency with a more general multiple scales modeling framework for atmospheric flows. Deep narrow updrafts, the so-called hot towers, constitute principal building blocks of larger scale storm systems. They are analyzed here in a sample application of the new scaling regime. A single quasi-one-dimensional upright columnar cloud is considered on the vertical advective (or tower life cycle) time scale. The refined asymptotic scaling regime is essential for this example as it reveals a new mechanism for the self-sustainance of such updrafts. Even for strongly positive convectively available potential energy, a vertical balance of buoyancy forces is found in the presence of precipitation. This balance induces a diagnostic equation for the vertical velocity, and it is responsible for the generation of self-sustained balanced updrafts. The time-dependent updraft structure is encoded in a Hamilton-Jacobi equation for the precipitation mixing ratio. Numerical solutions of this equation suggest that the self-sustained updrafts may strongly enhance hot tower life cycles.

Synthesis and refinement of ferroelectric ceramic BaBi4Ti4O15 (BBT) using Rietveld Methods

International Nuclear Information System (INIS)

Silva, P.M.O.; Sales, A.J.M.; Carneiro, J.C.S.; Sancho, E.O.; Sales, J.C.; Sombra, A.S.B.

2012-01-01

The lead zirconate titanate (PZT) has potential application in nonvolatile ferroelectric memory and capacitors, however this material is linked to environmental pollution. In order to remedy this problem, we propose the synthesis of the compound, BaBi 4 TI 4 O 15 (BBT) because of similarity to PZT. The phase of the BBT has been prepared by the method of solid state. Reagents (BaCO 3 , Bi 2 O 3 and TiO 2 ) were ground for 6 hours at 360 rpm in a planetary ball mill and suffered high energy heat treatment for 2 hours at temperatures of 850, 900, 950 and 1000 ° C. The calcined powder was characterized by X-ray diffraction (XRD) and refined by the program DBWSTools 2.3 Beta based on the Rietveld method. The results obtained confirmed the refinement of the single-phase with tetragonal structure BaBi 4 TI 4 O 15 for all samples. The sample calcined at 950 °C presented the best densification (7.508 g/cm³). (author)

Using trajectory analyses to refine phenotype for genetic association: conduct problems and the serotonin transporter (5HTTLPR).

Science.gov (United States)

Sakai, Joseph T; Boardman, Jason D; Gelhorn, Heather L; Smolen, Andrew; Corley, Robin P; Huizinga, David; Menard, Scott; Hewitt, John K; Stallings, Michael C

2010-10-01

Conduct disorder is a serious, relatively common disorder of childhood and adolescence. Findings from genetic association studies searching for genetic determinants of the liability toward such behaviors have been inconsistent. One possible explanation for differential results is that most studies define phenotype from a single assessment; for many adolescents conduct problems decrease in severity over time, whereas for others such behaviors persist. Therefore, longitudinal datasets offer the opportunity to refine phenotype. We used Caucasians that were first assessed during adolescence from the National Youth Survey Family Study. Nine waves of data were used to create latent growth trajectories and test for associations between trajectory class and 5HTTLPR genotype. For the full sample, 5HTTLPR was not associated with conduct problem phenotypes. However, the short (s) allele was associated with chronic conduct problems in females; a nominally significant sex by 5HTTLPR genotype interaction was noted. Longitudinal studies provide unique opportunities for phenotypic refinement and such techniques, with large samples, may be useful for phenotypic definition with other study designs, such as whole genome association studies.

Validating neural-network refinements of nuclear mass models

Science.gov (United States)

Utama, R.; Piekarewicz, J.

2018-01-01

Background: Nuclear astrophysics centers on the role of nuclear physics in the cosmos. In particular, nuclear masses at the limits of stability are critical in the development of stellar structure and the origin of the elements. Purpose: We aim to test and validate the predictions of recently refined nuclear mass models against the newly published AME2016 compilation. Methods: The basic paradigm underlining the recently refined nuclear mass models is based on existing state-of-the-art models that are subsequently refined through the training of an artificial neural network. Bayesian inference is used to determine the parameters of the neural network so that statistical uncertainties are provided for all model predictions. Results: We observe a significant improvement in the Bayesian neural network (BNN) predictions relative to the corresponding "bare" models when compared to the nearly 50 new masses reported in the AME2016 compilation. Further, AME2016 estimates for the handful of impactful isotopes in the determination of r -process abundances are found to be in fairly good agreement with our theoretical predictions. Indeed, the BNN-improved Duflo-Zuker model predicts a root-mean-square deviation relative to experiment of σrms≃400 keV. Conclusions: Given the excellent performance of the BNN refinement in confronting the recently published AME2016 compilation, we are confident of its critical role in our quest for mass models of the highest quality. Moreover, as uncertainty quantification is at the core of the BNN approach, the improved mass models are in a unique position to identify those nuclei that will have the strongest impact in resolving some of the outstanding questions in nuclear astrophysics.

Anomalies in the refinement of isoleucine

NARCIS (Netherlands)

Berntsen, K.R.M.; Vriend, G.

2014-01-01

A study of isoleucines in protein structures solved using X-ray crystallography revealed a series of systematic trends for the two side-chain torsion angles chi1 and chi2 dependent on the resolution, secondary structure and refinement software used. The average torsion angles for the nine rotamers

Automata Learning through Counterexample Guided Abstraction Refinement

DEFF Research Database (Denmark)

Aarts, Fides; Heidarian, Faranak; Kuppens, Harco

2012-01-01

to a small set of abstract events that can be handled by automata learning tools. In this article, we show how such abstractions can be constructed fully automatically for a restricted class of extended finite state machines in which one can test for equality of data parameters, but no operations on data...... are allowed. Our approach uses counterexample-guided abstraction refinement: whenever the current abstraction is too coarse and induces nondeterministic behavior, the abstraction is refined automatically. Using Tomte, a prototype tool implementing our algorithm, we have succeeded to learn – fully......Abstraction is the key when learning behavioral models of realistic systems. Hence, in most practical applications where automata learning is used to construct models of software components, researchers manually define abstractions which, depending on the history, map a large set of concrete events...

Grain size refinement of inconel 718 thermomechanical processing

International Nuclear Information System (INIS)

Okimoto, P.C.

1988-01-01

Inconel 718 is a Ni-Fe precipitation treated superalloy. It presents good thermal fatigue properties when the material has small grain size. The aim of this work is to study the grain size refinement by thermomechanical processing, through observations of the microstructural evolution and the influence of some of the process variables in the final grain size. The results have shown that this refinement occured by static recrystallization. The presence of precipitates have influenced the final grain size if the deformations are below 60%. For greater deformations the grain size is independent of the precipitate distribution in the matrix and tends to a limit size of 5 μm. (author)

The effect of scandium addition on microstructure and mechanical properties of Al–Si–Mg alloy: A multi-refinement modifier

Energy Technology Data Exchange (ETDEWEB)

Xu, Cong, E-mail: xucong55555@gmail.com [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Xiao, Wenlong, E-mail: wlxiao@buaa.edu.cn [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China); Hanada, Shuji [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yamagata, Hiroshi [Center for Advanced Die Engineering and Technology, Gifu University, 1-1 Yanagido, Gifu City, Gifu 501-1193 (Japan); Ma, Chaoli [Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education, School of Material Science and Engineering, Beihang University, Beijing 100191 (China)

2015-12-15

Effect of scandium (Sc) additions on the microstructure, mechanical properties and fracture behavior of Al–Si–Mg casting alloy (F357) were systematically investigated. It was found that Sc addition caused a multi-refining efficiency on the microstructure of as-cast F357 alloy, including refinement of grains and secondary dendrite arm spacing (SDAS), modification of eutectic Si and harmless disposal of β-Al{sub 5}FeSi phase. Subsequent T6 heat treatment had further induced the complete spheroidization of eutectic Si and precipitation of fine secondary Al{sub 3}Sc dispersoids in the Sc modified alloys. Thus the mechanical properties, especially the ductility, were significantly enhanced by the addition of Sc combined with the heat treatment. The highest ultimate tensile strength, yield strength and elongation were achieved in 0.8 wt.% Sc modified F357 alloy combined with T6 heat treatment. Furthermore, fractographic examinations indicated that the ductile fracture mechanism served as a dominate role in the modified alloys due to the formation of fine, deep and uniformly distributed dimples. - Highlights: • Detailed characterization of the multi-refining microstructure of Sc modified F357 alloy was performed. • The multi-refinement was proposed to refine grain and SDAS, modify eutectic Si and β-phase. • Sc modifier combined with T6 treatment is effective in improving tensile properties. • Modification of eutectic Si in F357 alloy with Sc is consistent with the IIT mechanism.

The US petroleum refining industry in the 1980's

Energy Technology Data Exchange (ETDEWEB)

1990-10-11

As part of the EIA program on petroleum, The US Petroleum Refining Industry in the 1980's, presents a historical analysis of the changes that took place in the US petroleum refining industry during the 1980's. It is intended to be of interest to analysts in the petroleum industry, state and federal government officials, Congress, and the general public. The report consists of six chapters and four appendices. Included is a detailed description of the major events and factors that affected the domestic refining industry during this period. Some of the changes that took place in the 1980's are the result of events that started in the 1970's. The impact of these events on US refinery configuration, operations, economics, and company ownership are examined. 23 figs., 11 tabs.

Lossless, Near-Lossless, and Refinement Coding of Bi-level Images

DEFF Research Database (Denmark)

Martins, Bo; Forchhammer, Søren Otto

1999-01-01

We present general and unified algorithms for lossy/lossless coding of bi-level images. The compression is realized by applying arithmetic coding to conditional probabilities. As in the current JBIG standard the conditioning may be specified by a template.For better compression, the more general...... to the specialized soft pattern matching techniques which work better for text. Template based refinement coding is applied for lossy-to-lossless refinement. Introducing only a small amount of loss in halftoned test images, compression is increased by up to a factor of four compared with JBIG. Lossy, lossless......, and refinement decoding speed and lossless encoding speed are less than a factor of two slower than JBIG. The (de)coding method is proposed as part of JBIG2, an emerging international standard for lossless/lossy compression of bi-level images....

Numerical solution of plasma fluid equations using locally refined grids

International Nuclear Information System (INIS)

Colella, P.

1997-01-01

This paper describes a numerical method for the solution of plasma fluid equations on block-structured, locally refined grids. The plasma under consideration is typical of those used for the processing of semiconductors. The governing equations consist of a drift-diffusion model of the electrons and an isothermal model of the ions coupled by Poisson's equation. A discretization of the equations is given for a uniform spatial grid, and a time-split integration scheme is developed. The algorithm is then extended to accommodate locally refined grids. This extension involves the advancement of the discrete system on a hierarchy of levels, each of which represents a degree of refinement, together with synchronization steps to ensure consistency across levels. A brief discussion of a software implementation is followed by a presentation of numerical results

Investigation of single lateral mode for 852nm diode lasers with ridge waveguide design

Science.gov (United States)

Liu, Chu; Guan, Baolu; Mi, Guoxin; Liao, Yiru; Liu, Zhenyang; Li, Jianjun; Xu, Chen

2016-11-01

852nm Narrow linewidth lasers can be widely used in the field of ultra-fine spectrum measurement, Cs atomic clock control, satellite and optical fiber communication and so on. Furthermore, the stability of the single lateral mode is a very important condition to guarantee the narrow linewidth lasers. Here we investigate experimentally the influence of the narrow ridge structure and asymmetrical waveguide design on the stability single lateral mode of an 852nm diode laser. According to the waveguide theoretical analysis, ridge mesa etch depth (Δη , related to the refractive index difference of parallel to the junction) and ridge mesa width (the narrower the more control force to low order mode) are the main elements for lateral modes. In this paper, we designed different structures to investigate and verify major factors for lateral mode by experiment, and to confirm our thought. Finally, the 5μm mesa ridge laser, 800nm etch depth, with groove structure obtains excellent steady single lateral mode output by 150mA operating current and 30°C temperature. The optical spectrum FWHM is 0.5nm and side mode suppression ratio is 27dBm with uncoated. The laser with 1mm cavity length showed the threshold current of 50mA, a lasing wavelength of λ = 852.6nm, slope efficiency of above 0.7mW/mA. We accomplished single lateral mode of ridge waveguide edge-emitting lasers which can also be used as a laser source in the ultra-narrow linewidth external cavity laser system.

National oil companies' presence to hike US refining competition

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that the downstream segment of the U.S. petroleum business is virtually certain to become more competitive because of the growing presence of national oil companies in the country's refining industry. That's a forecast by New York investment firm Kidder Peabody. It cites a plan by Mexico's Petroleos Mexicanos (Pemex) to form a joint venture with Shell Oil Co. covering Shell's 225,000 b/d Deer Park, Tex., refinery as the latest example of national oil companies' movement into U.S. refining

Limit of grain refinement during ECAP process. Temperature influence

International Nuclear Information System (INIS)

Chuvil'deev, V.N.; Kopylov, V.I.; Nokhrin, A.V.; Makarov, I.M.; Lopatin, Yu.G.

2004-01-01

Experimental and theoretical study results are reported for the process of deformation grain refinement under severe plastic deformation. A generalization is made for experimental study results on deformation dispersing of unalloyed metals and aluminium and magnesium base alloys. The model is built that allows calculating the value of minimum grain size attained by the method of equal-channel angular pressing. The expressions are derived which describe the dependence of grain refinement limit on the nature of material and the temperature of severe plastic deformation [ru

Process technology for refining crude soybean oil – a product from ...

African Journals Online (AJOL)

Process technology for refining crude soybean oil – a product from soycake meal production in Ghana. ... yield of 83.3 per cent was recorded. Results of quality assessment of the final laboratory refined oil compared favourably with Ghana Standards Board's specification for edible soybean oil. Ghana Journal of Science Vol.

Robust Refinement as Implemented in TOPAS

Energy Technology Data Exchange (ETDEWEB)

Stone, K.; Stephens, P

2010-01-01

A robust refinement procedure is implemented in the program TOPAS through an iterative reweighting of the data. Examples are given of the procedure as applied to fitting partially overlapped peaks by full and partial models and also of the structures of ibuprofen and acetaminophen in the presence of unmodeled impurity contributions

A simple nodal force distribution method in refined finite element meshes

Energy Technology Data Exchange (ETDEWEB)

Park, Jai Hak [Chungbuk National University, Chungju (Korea, Republic of); Shin, Kyu In [Gentec Co., Daejeon (Korea, Republic of); Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

2017-05-15

In finite element analyses, mesh refinement is frequently performed to obtain accurate stress or strain values or to accurately define the geometry. After mesh refinement, equivalent nodal forces should be calculated at the nodes in the refined mesh. If field variables and material properties are available at the integration points in each element, then the accurate equivalent nodal forces can be calculated using an adequate numerical integration. However, in certain circumstances, equivalent nodal forces cannot be calculated because field variable data are not available. In this study, a very simple nodal force distribution method was proposed. Nodal forces of the original finite element mesh are distributed to the nodes of refined meshes to satisfy the equilibrium conditions. The effect of element size should also be considered in determining the magnitude of the distributing nodal forces. A program was developed based on the proposed method, and several example problems were solved to verify the accuracy and effectiveness of the proposed method. From the results, accurate stress field can be recognized to be obtained from refined meshes using the proposed nodal force distribution method. In example problems, the difference between the obtained maximum stress and target stress value was less than 6 % in models with 8-node hexahedral elements and less than 1 % in models with 20-node hexahedral elements or 10-node tetrahedral elements.

3Drefine: an interactive web server for efficient protein structure refinement.

Science.gov (United States)

Bhattacharya, Debswapna; Nowotny, Jackson; Cao, Renzhi; Cheng, Jianlin

2016-07-08

3Drefine is an interactive web server for consistent and computationally efficient protein structure refinement with the capability to perform web-based statistical and visual analysis. The 3Drefine refinement protocol utilizes iterative optimization of hydrogen bonding network combined with atomic-level energy minimization on the optimized model using a composite physics and knowledge-based force fields for efficient protein structure refinement. The method has been extensively evaluated on blind CASP experiments as well as on large-scale and diverse benchmark datasets and exhibits consistent improvement over the initial structure in both global and local structural quality measures. The 3Drefine web server allows for convenient protein structure refinement through a text or file input submission, email notification, provided example submission and is freely available without any registration requirement. The server also provides comprehensive analysis of submissions through various energy and statistical feedback and interactive visualization of multiple refined models through the JSmol applet that is equipped with numerous protein model analysis tools. The web server has been extensively tested and used by many users. As a result, the 3Drefine web server conveniently provides a useful tool easily accessible to the community. The 3Drefine web server has been made publicly available at the URL: http://sysbio.rnet.missouri.edu/3Drefine/. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

An adaptive grid refinement strategy for the simulation of negative streamers

International Nuclear Information System (INIS)

Montijn, C.; Hundsdorfer, W.; Ebert, U.

2006-01-01

The evolution of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model for electrons and positive ions. It consists of continuity equations for the charged particles including drift, diffusion and reaction in the local electric field, coupled to the Poisson equation for the electric potential. The model generates field enhancement and steep propagating ionization fronts at the tip of growing ionized filaments. An adaptive grid refinement method for the simulation of these structures is presented. It uses finite volume spatial discretizations and explicit time stepping, which allows the decoupling of the grids for the continuity equations from those for the Poisson equation. Standard refinement methods in which the refinement criterion is based on local error monitors fail due to the pulled character of the streamer front that propagates into a linearly unstable state. We present a refinement method which deals with all these features. Tests on one-dimensional streamer fronts as well as on three-dimensional streamers with cylindrical symmetry (hence effectively 2D for numerical purposes) are carried out successfully. Results on fine grids are presented, they show that such an adaptive grid method is needed to capture the streamer characteristics well. This refinement strategy enables us to adequately compute negative streamers in pure gases in the parameter regime where a physical instability appears: branching streamers

Process for refining naphthalene, etc

Energy Technology Data Exchange (ETDEWEB)

Petroff, G

1922-05-13

A process is described for the refining of naphthalene, its distillates, and mineral oils by the use of dilute sulfuric acid, characterized in that the oils are oxidized with oxygen of the air and thereafter are treated with 65 to 75 percent sulfuric acid to separate the unsaturated hydrocarbons in the form of polymerized products whereby, if necessary, heating and application of usual or higher pressure can take place.

Bauxite Mining and Alumina Refining

OpenAIRE

Donoghue, A. Michael; Frisch, Neale; Olney, David

2014-01-01

Objective: To describe bauxite mining and alumina refining processes and to outline the relevant physical, chemical, biological, ergonomic, and psychosocial health risks. Methods: Review article. Results: The most important risks relate to noise, ergonomics, trauma, and caustic soda splashes of the skin/eyes. Other risks of note relate to fatigue, heat, and solar ultraviolet and for some operations tropical diseases, venomous/dangerous animals, and remote locations. Exposures to bauxite dust,...

Chromatography Analysis of Jatropha Curcas L Oil Raw and Refined

International Nuclear Information System (INIS)

Chitue de Assuncao Nascimento, Juliano; Lafargue Perez, Francisco; Diaz Velazquez, Manuel

2013-01-01

The chromatography of gases is one of the most versatile methods utilized in the chemical laboratory, which permits the determinations of the percentages and types of fatty acids present in vegetable oils. The objective of this work was to carry out a comparative study of the composition of the fatty acids, of the mechanically extracted oil from the seed of the Jatropha curcas L plant in the raw and refined state, using the data obtained by gas chromatography. The fatty acids of the oil were determined as methylic esteres. The analyst was carried out in a gas chromatographer, with a detector of ionization by way of flame (FID), Agilent 7890A (Agilent, USA) coupled to HP Pentium 4 computer, with a data processing program. The temperatures of the injector and of the detector were 250 °C and 260 °C respectively. The data obtained chromatographically of the oil of Jatropha curcas L, raw and refined indicates that the refinery process did not vary the composition of the fatty acid, because there are no significant differences between them. Also, the results obtained by other investigators, showed that the predominant fatty acids obtained from the oil of the Jatropha curcas L were palmitic and stearic in the saturated fatty acids, and oleic and linoleic in the unsaturated fatty acids

Chromatography analysis of Jatropha Curcas L oil raw and refined

International Nuclear Information System (INIS)

Chitue de Assuncao Nascimento, Juliano; Lafargue Perez, Francisco; Diaz Velazquez, Manuel

2013-01-01

The chromatography of gases is one of the most versatile methods utilized in the chemical laboratory, which permits the determinations of the percentages and types of fatty acids present in vegetable oils. The objective of this work was to carry out a comparative study of the composition of the fatty acids, of the mechanically extracted oil from the seed of the Jatropha curcas L plant in the raw and refined state, using the data obtained by gas chromatography. The fatty acids of the oil were determined as methylic esteres. The analyst was carried out in a gas chromatographer, with a detector of ionization by way of flame (FID), Agilent 7890A (Agilent, USA) coupled to HP Pentium 4 computer, with a data processing program. The temperatures of the injector and of the detector were 250℃ and 260℃ respectively. The data obtained chromatographically of the oil of Jatropha curcas L, raw and refined indicates that the refinery process did not vary the composition of the fatty acid, because there are no significant differences between them. Also, the results obtained by other investigators, showed that the predominant fatty acids obtained from the oil of the Jatropha curcas L were palmitic and stearic in the saturated fatty acids, and oleic and linoleic in the unsaturated fatty acids

The combined effect of titanic carbide and aluminum phosphide on the refinement of primary silicon in Al-50Si alloy

Energy Technology Data Exchange (ETDEWEB)

Dai Hongshang [Key Lab. of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong Univ., Jinan (China); Liu Xiangfa [Key Lab. of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong Univ., Jinan (China); Shandong Binzhou Bohai Piston Co., Ltd., Binzhou, SD (China)

2008-12-15

Two refinement methods for Al-50Si alloy are presented in this article: one way is using a newly developed Si-20P alloy at 1573 K: another technique is using the Si-20P alloy in company with Al-TiO{sub 2}-C mixture powder at 1473 K. Compared to the first method, the second one not only has better refinement effect on primary Si but also lower refinement temperature. These results are due to the combined effect of TiC and AlP on the refinement process, and the duplex TiC/AlP nucleus of primary silicon has been demonstrated using electron probe micro-analysis. Moreover, the reaction of Al-TiO{sub 2}-C mixture powder with increasing temperature was investigated using differential scanning calorimetry, which shows that the TiC particles are produced at about 1473 K. AlP particles combine with the in-situ TiC particles in the melt, which is the main reason for the formation of a duplex nucleus, and the disregistry between TiC and AlP in low-index planes is also discussed. (orig.)

SFESA: a web server for pairwise alignment refinement by secondary structure shifts.

Science.gov (United States)

Tong, Jing; Pei, Jimin; Grishin, Nick V

2015-09-03

Protein sequence alignment is essential for a variety of tasks such as homology modeling and active site prediction. Alignment errors remain the main cause of low-quality structure models. A bioinformatics tool to refine alignments is needed to make protein alignments more accurate. We developed the SFESA web server to refine pairwise protein sequence alignments. Compared to the previous version of SFESA, which required a set of 3D coordinates for a protein, the new server will search a sequence database for the closest homolog with an available 3D structure to be used as a template. For each alignment block defined by secondary structure elements in the template, SFESA evaluates alignment variants generated by local shifts and selects the best-scoring alignment variant. A scoring function that combines the sequence score of profile-profile comparison and the structure score of template-derived contact energy is used for evaluation of alignments. PROMALS pairwise alignments refined by SFESA are more accurate than those produced by current advanced alignment methods such as HHpred and CNFpred. In addition, SFESA also improves alignments generated by other software. SFESA is a web-based tool for alignment refinement, designed for researchers to compute, refine, and evaluate pairwise alignments with a combined sequence and structure scoring of alignment blocks. To our knowledge, the SFESA web server is the only tool that refines alignments by evaluating local shifts of secondary structure elements. The SFESA web server is available at http://prodata.swmed.edu/sfesa.

Reintroducing electrostatics into macromolecular crystallographic refinement: application to neutron crystallography and DNA hydration.

Science.gov (United States)

Fenn, Timothy D; Schnieders, Michael J; Mustyakimov, Marat; Wu, Chuanjie; Langan, Paul; Pande, Vijay S; Brunger, Axel T

2011-04-13

Most current crystallographic structure refinements augment the diffraction data with a priori information consisting of bond, angle, dihedral, planarity restraints, and atomic repulsion based on the Pauli exclusion principle. Yet, electrostatics and van der Waals attraction are physical forces that provide additional a priori information. Here, we assess the inclusion of electrostatics for the force field used for all-atom (including hydrogen) joint neutron/X-ray refinement. Two DNA and a protein crystal structure were refined against joint neutron/X-ray diffraction data sets using force fields without electrostatics or with electrostatics. Hydrogen-bond orientation/geometry favors the inclusion of electrostatics. Refinement of Z-DNA with electrostatics leads to a hypothesis for the entropic stabilization of Z-DNA that may partly explain the thermodynamics of converting the B form of DNA to its Z form. Thus, inclusion of electrostatics assists joint neutron/X-ray refinements, especially for placing and orienting hydrogen atoms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ion implantation effects in single crystal Si investigated by Raman spectroscopy

International Nuclear Information System (INIS)

Harriman, T.A.; Lucca, D.A.; Lee, J.-K.; Klopfstein, M.J.; Herrmann, K.; Nastasi, M.

2009-01-01

A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 x 10 13 to 1 x 10 15 ions/cm 2 . The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1 . Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

Effects of slag composition and process variables on decontamination of metallic wastes by melt refining

International Nuclear Information System (INIS)

Heshmatpour, B.; Copeland, G.L.

1981-01-01

Melt refining has been suggested as an alternative for decontamination and volume reduction of low-level-contaminated metallic wastes. Knowledge of metallurgical and thermochemical aspects of the process is essential for effective treatment of various metals. Variables such as slag type and composition, melting technique, and refractory materials need to be identified for each metal or alloy. Samples of contaminated metals were melted with fluxes by resistance furnace or induction heating. The resulting ingots as well as the slags were analyzed for their nuclide contents, and the corresponding partition ratios were calculated. Compatibility of slags and refractories was also investigated, and proper refractory materials were identified. Resistance furnace melting appeared to be a better melting technique for nonferrous scrap, while induction melting was more suitable for ferrous metals. In general uranium contents of the metals, except for aluminum, could be reduced to as low as 0.01 to 0.1 ppM by melt refining. Aluminum could be decontaminated to about 1 to 2 ppM U when certain fluoride slags were used. The extent of decontamination was not very sensitive to slag type and composition. However, borosilicate and basic oxidizing slags were more effective on ferrous metals and Cu; NaNO 3 -NaCl-NaOH type fluxes were desirable for Zn, Pb, and Sn; and fluoride type slags were effective for decontamination of Al. Recrystallized alumina proved to be the most compatible refractory for melt refining both ferrous and nonferrous metals, while graphite was suitable for nonferrous metal processing. In conclusion, melt refining is an effective technique for volume reduction ad decontamination of contaminated metal scrap when proper slags, melting technique, and refractories are used

40 CFR 80.245 - How does a small refiner apply for a sulfur baseline?

Science.gov (United States)

2010-07-01

... sulfur baseline? 80.245 Section 80.245 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions § 80.245 How does a small refiner apply for a sulfur baseline? (a) Any refiner seeking small refiner status must apply for a refinery sulfur baseline by the deadline under § 80.235 for each of the...

Refining of fossil resin flotation concentrate from western coal. Final report

Energy Technology Data Exchange (ETDEWEB)

Jensen, G.F.; Miller, J.D.

1995-02-16

During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

Single-cell template strand sequencing by Strand-seq enables the characterization of individual homologs

NARCIS (Netherlands)

Sanders, Ashley D; Falconer, Ester; Hills, Mark; Spierings, Diana C J; Lansdorp, Peter M.

The ability to distinguish between genome sequences of homologous chromosomes in single cells is important for studies of copy-neutral genomic rearrangements (such as inversions and translocations), building chromosome-length haplotypes, refining genome assemblies, mapping sister chromatid exchange

Refined reservoir description to maximize oil recovery

International Nuclear Information System (INIS)

Flewitt, W.E.

1975-01-01

To assure maximized oil recovery from older pools, reservoir description has been advanced by fully integrating original open-hole logs and the recently introduced interpretive techniques made available through cased-hole wireline saturation logs. A refined reservoir description utilizing normalized original wireline porosity logs has been completed in the Judy Creek Beaverhill Lake ''A'' Pool, a reefal carbonate pool with current potential productivity of 100,000 BOPD and 188 active wells. Continuous porosity was documented within a reef rim and cap while discontinuous porous lenses characterized an interior lagoon. With the use of pulsed neutron logs and production data a separate water front and pressure response was recognized within discrete environmental units. The refined reservoir description aided in reservoir simulation model studies and quantifying pool performance. A pattern water flood has now replaced the original peripheral bottom water drive to maximize oil recovery

Refined open intersection numbers and the Kontsevich-Penner matrix model

Energy Technology Data Exchange (ETDEWEB)

Alexandrov, Alexander [Center for Geometry and Physics, Institute for Basic Science (IBS),Pohang 37673 (Korea, Republic of); Centre de Recherches Mathématiques (CRM), Université de Montréal,Montréal (Canada); Department of Mathematics and Statistics, Concordia University,Montréal (Canada); Institute for Theoretical and Experimental Physics (ITEP),Moscow (Russian Federation); Buryak, Alexandr [Department of Mathematics, ETH Zurich, Zurich (Switzerland); Tessler, Ran J. [Institute for Theoretical Studies, ETH Zurich,Zurich (Switzerland)

2017-03-23

A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed.

Refined open intersection numbers and the Kontsevich-Penner matrix model

International Nuclear Information System (INIS)

Alexandrov, Alexander; Buryak, Alexandr; Tessler, Ran J.

2017-01-01

A study of the intersection theory on the moduli space of Riemann surfaces with boundary was recently initiated in a work of R. Pandharipande, J.P. Solomon and the third author, where they introduced open intersection numbers in genus 0. Their construction was later generalized to all genera by J.P. Solomon and the third author. In this paper we consider a refinement of the open intersection numbers by distinguishing contributions from surfaces with different numbers of boundary components, and we calculate all these numbers. We then construct a matrix model for the generating series of the refined open intersection numbers and conjecture that it is equivalent to the Kontsevich-Penner matrix model. An evidence for the conjecture is presented. Another refinement of the open intersection numbers, which describes the distribution of the boundary marked points on the boundary components, is also discussed.

State of European refining industry is less bleak than reported

International Nuclear Information System (INIS)

Jenkins, J.H.

1997-01-01

It is difficult to pick up a trade publication without reading of the imminent demise of the European refining industry. Major oil companies are combining operations to minimize costs. Refineries are being shuttered, and analysts are calling for the immediate closure of many more plants. There is little doubt that European cracking margins have fallen since the early 1990s, in step with the rest of the world. However, the refining industry in Europe does not, in the opinion of Pace Consultants Inc., suffer from some overriding fundamental flaw that dooms it to low margins forever. The intent of this article is to put some of the industry's recent events in perspective, to discuss some of the fundamental differences between American and European operations, and to perhaps lay to rest the idea that refining is somehow dead in Europe

Automating crystallographic structure solution and refinement of protein–ligand complexes

International Nuclear Information System (INIS)

Echols, Nathaniel; Moriarty, Nigel W.; Klei, Herbert E.; Afonine, Pavel V.; Bunkóczi, Gábor; Headd, Jeffrey J.; McCoy, Airlie J.; Oeffner, Robert D.; Read, Randy J.; Terwilliger, Thomas C.; Adams, Paul D.

2013-01-01

A software system for automated protein–ligand crystallography has been implemented in the Phenix suite. This significantly reduces the manual effort required in high-throughput crystallographic studies. High-throughput drug-discovery and mechanistic studies often require the determination of multiple related crystal structures that only differ in the bound ligands, point mutations in the protein sequence and minor conformational changes. If performed manually, solution and refinement requires extensive repetition of the same tasks for each structure. To accelerate this process and minimize manual effort, a pipeline encompassing all stages of ligand building and refinement, starting from integrated and scaled diffraction intensities, has been implemented in Phenix. The resulting system is able to successfully solve and refine large collections of structures in parallel without extensive user intervention prior to the final stages of model completion and validation

Error sensitivity to refinement: a criterion for optimal grid adaptation

Science.gov (United States)

Luchini, Paolo; Giannetti, Flavio; Citro, Vincenzo

2017-12-01

Most indicators used for automatic grid refinement are suboptimal, in the sense that they do not really minimize the global solution error. This paper concerns with a new indicator, related to the sensitivity map of global stability problems, suitable for an optimal grid refinement that minimizes the global solution error. The new criterion is derived from the properties of the adjoint operator and provides a map of the sensitivity of the global error (or its estimate) to a local mesh refinement. Examples are presented for both a scalar partial differential equation and for the system of Navier-Stokes equations. In the last case, we also present a grid-adaptation algorithm based on the new estimator and on the FreeFem++ software that improves the accuracy of the solution of almost two order of magnitude by redistributing the nodes of the initial computational mesh.

Architectural Refinement for the Design of Survivable Systems

National Research Council Canada - National Science Library

Ellison, Robert

2001-01-01

This paper describes a process for systematically refining an enterprise system architecture to resist recognize and recover from deliberate, malicious attacks by applying reusable design primitives...

An adaptive mesh refinement approach for average current nodal expansion method in 2-D rectangular geometry

International Nuclear Information System (INIS)

Poursalehi, N.; Zolfaghari, A.; Minuchehr, A.

2013-01-01

Highlights: ► A new adaptive h-refinement approach has been developed for a class of nodal method. ► The resulting system of nodal equations is more amenable to efficient numerical solution. ► The benefit of the approach is reducing computational efforts relative to the uniform fine mesh modeling. ► Spatially adaptive approach greatly enhances the accuracy of the solution. - Abstract: The aim of this work is to develop a spatially adaptive coarse mesh strategy that progressively refines the nodes in appropriate regions of domain to solve the neutron balance equation by zeroth order nodal expansion method. A flux gradient based a posteriori estimation scheme has been utilized for checking the approximate solutions for various nodes. The relative surface net leakage of nodes has been considered as an assessment criterion. In this approach, the core module is called in by adaptive mesh generator to determine gradients of node surfaces flux to explore the possibility of node refinements in appropriate regions and directions of the problem. The benefit of the approach is reducing computational efforts relative to the uniform fine mesh modeling. For this purpose, a computer program ANRNE-2D, Adaptive Node Refinement Nodal Expansion, has been developed to solve neutron diffusion equation using average current nodal expansion method for 2D rectangular geometries. Implementing the adaptive algorithm confirms its superiority in enhancing the accuracy of the solution without using fine nodes throughout the domain and increasing the number of unknown solution. Some well-known benchmarks have been investigated and improvements are reported

Intermetallic Growth and Interfacial Properties of the Grain Refiners in Al Alloys

Science.gov (United States)

Li, Chunmei; Cheng, Nanpu; Chen, Zhiqian; Xie, Zhongjing; Hui, Liangliang

2018-01-01

Al3TM(TM = Ti, Zr, Hf, Sc) particles acting as effective grain refiners for Al alloys have been receiving extensive attention these days. In order to judge their nucleation behaviors, first-principles calculations are used to investigate their intermetallic and interfacial properties. Based on energy analysis, Al3Zr and Al3Sc are more suitable for use as grain refiners than the other two intermetallic compounds. Interfacial properties show that Al/Al3TM(TM = Ti, Zr, Hf, Sc) interfaces in I-ter interfacial mode exhibit better interface wetting effects due to larger Griffith rupture work and a smaller interface energy. Among these, Al/Al3Sc achieves the lowest interfacial energy, which shows that Sc atoms should get priority for occupying interfacial sites. Additionally, Sc-doped Al/Al3(Zr, Sc) interfacial properties show that Sc can effectively improve the Al/Al3(Zr, Sc) binding strength with the Al matrix. By combining the characteristics of interfaces with the properties of intermetallics, the core-shell structure with Al3Zr-core or Al3Zr(Sc1-1)-core encircled with an Sc-rich shell forms. PMID:29677155

Investigating single molecule adhesion by atomic force spectroscopy.

Science.gov (United States)

Stetter, Frank W S; Kienle, Sandra; Krysiak, Stefanie; Hugel, Thorsten

2015-02-27

Atomic force spectroscopy is an ideal tool to study molecules at surfaces and interfaces. An experimental protocol to couple a large variety of single molecules covalently onto an AFM tip is presented. At the same time the AFM tip is passivated to prevent unspecific interactions between the tip and the substrate, which is a prerequisite to study single molecules attached to the AFM tip. Analyses to determine the adhesion force, the adhesion length, and the free energy of these molecules on solid surfaces and bio-interfaces are shortly presented and external references for further reading are provided. Example molecules are the poly(amino acid) polytyrosine, the graft polymer PI-g-PS and the phospholipid POPE (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine). These molecules are desorbed from different surfaces like CH3-SAMs, hydrogen terminated diamond and supported lipid bilayers under various solvent conditions. Finally, the advantages of force spectroscopic single molecule experiments are discussed including means to decide if truly a single molecule has been studied in the experiment.

Cooling curve analysis in binary Al-Cu alloys: Part II- Effect of Cooling Rate and Grain Refinement on The Thermal and Thermodynamic Characteristics

Directory of Open Access Journals (Sweden)

Mehdi Dehnavi

2015-09-01

Full Text Available The Al-Cu alloys have been widely used in aerospace, automobile, and airplane applications. Generally Al–Ti and Al–Ti–B master alloys are added to the aluminium alloys for grain refinement. The cooling curve analysis (CCA has been used extensively in metal casting industry to predict microstructure constituents, grain refinement and to calculate the latent heat of solidification. The aim of this study is to investigate the effect of cooling rate and grain refinement on the thermal and thermodynamic characteristics of Al-Cu alloys by cooling curve analysis. To do this, Al-Cu alloys containing 3.7, and 4.8 wt.% Cu were melted and solidified with 0.04, 0.19, 0.42, and 1.08 K/s cooling rates. The temperature of the samples was recorded using a K thermocouple and a data acquisition system connected to a PC. Some samples were Grain refined by Al-5Ti-1B to see the effect of grain refinement on the aforementioned properties. The results show that, in a well refined alloy, nucleation will occur in a shorter time, and a undercooling approximately decreases to zero. The other results show that, with considering the cooling rate being around 0.1 °C/s, the Newtonian method is efficient in calculating the latent heat of solidification.

Investigation of airflow effects on the dielectric barrier discharge with single/double discharge channel arrangement

Science.gov (United States)

Fan, Zhihui; Yan, Huijie; Liu, Yidi; Guo, Hongfei; Wang, Yuying; Ren, Chunsheng

2018-05-01

Atmospheric-pressure dielectric barrier discharge (DBD) with airflow participation has been widely used in recent years. In this paper, effects of airflow on DBD characteristics are experimentally investigated by single/double pin-to-plate DBD arrangements with an AC exciting source. The discharge electrical characteristics and the movements of discharge channels in airflow are investigated with a single pin electrode arrangement. The current intensities increase in positive cycles and decrease in negative cycles with the increase in airflow velocity. The transition from a filamentary discharge to a diffuse discharge is observed under certain airflow conditions, and the discharge channels move with the airflow with a movement velocity less than the corresponding airflow velocity. In the cases of double pin electrode arrangements, the repulsion between double pin discharge channels is apparent at a 10 mm distance but is not obvious at a 20 mm distance. When the airflow is introduced into the discharge gap, not as in the case of single pin electrode arrangement, the movements of discharge channels in airflow are affected by adjacent discharge channels. The corresponding reasons are analyzed in the paper.

Financial optimisation and risk management in refining activities

International Nuclear Information System (INIS)

Fiorenzani, S.

2006-01-01

The real options approach has become a benchmark in real assets evaluation and optimal management problems, especially in liberalised and competitive markets such as the oil and hydrocarbon markets. This paper describes how the same approach can be a useful tool for both risk management decisions and the financial optimisation problem. Refineries are black boxes, which can be used for the transformation of crude oil into more refined hydrocarbon products. These black boxes are characterised by operational flexibilities and constraints, which should be optimally managed in order to maximise the refiner's economic goals. Stochastic dynamic programming represents the right mathematical instrument employed to solve the decision-making problem in such an economic environment. (author)

Pushing the dinosaurs[Competition in the refining industry

Energy Technology Data Exchange (ETDEWEB)

Cobb, C B [Ernst and Young/Wright Killen (United States)

1999-03-01

The need for change in the business of oil refining is expressed. Since 1981, only three years have yielded high profit margins. The future is said to be in maximising performance from existing assets. In the past, the industry focused on the asset-based strategy of refining crude and getting it into the pipelines as early as possible but apparently the future lies in identifying customer needs and satisfying those needs as quickly as possible. In other words, selling the most product at the highest price. The strategy and tactics for achieving these goals are itemised and discussed. In short, it is essential that oil and gas companies make the transformation from asset focus to customer focus. (UK)

R and D status of oxide electro-refining reprocessing technology

International Nuclear Information System (INIS)

Myochin, Munetaka

2005-01-01

The oxide electro-refining pyrochemical reprocessing is excellent in the resistivity against nuclear material diversion and in the suitability for oxide fuel cycle and has an excellent affinity for the technology of fuel production using the vibropac method. The oxide electro-refining pyrochemical reprocessing system has therefore been examined as a part of studies of commercialization of FBR cycle. This report outlines the examination results of fundamental data acquired for the system design. (M.H.)

Structure refinement of polycrystalline orthorhombic yttrium ...

Indian Academy of Sciences (India)

The perovskite ceramic phases with composition Ca1−YTiO3+ (where = 0.1, 0.2 and 0.3; hereafter CYT-10, CYT-20 and CYT-30) have been synthesized by solid state reaction at 1050°C. The structure refinement using general structure analysis system (GSAS) software converges to satisfactory profile indicators ...

40 CFR 80.551 - How does a refiner obtain approval as a small refiner under this subpart?

Science.gov (United States)

2010-07-01

...) Applications for motor vehicle diesel fuel small refiner status must be submitted to EPA by December 31, 2001...-operational between January 1, 1999, and January 1, 2000, the application for motor vehicle diesel fuel small...: (1) For motor vehicle diesel fuel small refiners— (i) A listing of the name and address of each...

Uranium refining by solvent extraction

International Nuclear Information System (INIS)

Kraikaew, J.

1996-01-01

The yellow cake refining was studied in both laboratory and semi-pilot scales. The process units mainly consist of dissolution and filtration, solvent extraction, and precipitation and filtration. Effect of flow ratio (organic flow rate/ aqueous flow rate) on working efficiencies of solvent extraction process was studied. Detailed studies were carried out on extraction, scrubbing and stripping processes. Purity of yellow cake product obtained is high as 90.32% U 3 O 8

Preparation of refined oils, etc

Energy Technology Data Exchange (ETDEWEB)

1931-02-03

A process is disclosed for the preparation of refined sulfur-containing oils from sulfur-containing crude oils obtained by distillation of bituminous limestone, characterized by this crude oil being first subjected to a purification by distillation with steam in the known way, then treated with lime and chloride of lime and distilled preferably in the presence of zinc powder, whereby in this purification a rectification can be added for the purpose of recovering definite fractions.

Refinements in the Los Alamos model of the prompt fission neutron spectrum

Energy Technology Data Exchange (ETDEWEB)

Madland, D.G., E-mail: dgm@lanl.gov; Kahler, A.C.

2017-01-15

This paper presents a number of refinements to the original Los Alamos model of the prompt fission neutron spectrum and average prompt neutron multiplicity as derived in 1982. The four refinements are due to new measurements of the spectrum and related fission observables many of which were not available in 1982. They are also due to a number of detailed studies and comparisons of the model with previous and present experimental results including not only the differential spectrum, but also integral cross sections measured in the field of the differential spectrum. The four refinements are (a) separate neutron contributions in binary fission, (b) departure from statistical equilibrium at scission, (c) fission-fragment nuclear level-density models, and (d) center-of-mass anisotropy. With these refinements, for the first time, good agreement has been obtained for both differential and integral measurements using the same Los Alamos model spectrum.

Structural refinement and coarsening in deformed metals

DEFF Research Database (Denmark)

Hansen, N.; Huang, X.; Xing, Q.

2005-01-01

The microstructural refinement by plastic deformation is analysed in terms of key parameters, the spacing between and the misorientation angle across the boundaries subdividing the structure. Coarsening of such structures by annealing is also characterised. For both deformed and annealed structur...

Refinement from a control problem to program

DEFF Research Database (Denmark)

Schenke, Michael; Ravn, Anders P.

1996-01-01

The distinguishing feature of the presented refinement approach is that it links formalisms from a top level requirements notation down to programs together in a mathematically coherent development trajectory. The approach uses Duration Calculus, a real-time interval logic, to specifyrequirements...

Bright photoactivatable fluorophores for single-molecule imaging.

Science.gov (United States)

Grimm, Jonathan B; English, Brian P; Choi, Heejun; Muthusamy, Anand K; Mehl, Brian P; Dong, Peng; Brown, Timothy A; Lippincott-Schwartz, Jennifer; Liu, Zhe; Lionnet, Timothée; Lavis, Luke D

2016-12-01

Small-molecule fluorophores are important tools for advanced imaging experiments. We previously reported a general method to improve small, cell-permeable fluorophores which resulted in the azetidine-containing 'Janelia Fluor' (JF) dyes. Here, we refine and extend the utility of these dyes by synthesizing photoactivatable derivatives that are compatible with live-cell labeling strategies. Once activated, these derived compounds retain the superior brightness and photostability of the JF dyes, enabling improved single-particle tracking and facile localization microscopy experiments.

Decadal climate prediction with a refined anomaly initialisation approach

Science.gov (United States)

Volpi, Danila; Guemas, Virginie; Doblas-Reyes, Francisco J.; Hawkins, Ed; Nichols, Nancy K.

2017-03-01

In decadal prediction, the objective is to exploit both the sources of predictability from the external radiative forcings and from the internal variability to provide the best possible climate information for the next decade. Predicting the climate system internal variability relies on initialising the climate model from observational estimates. We present a refined method of anomaly initialisation (AI) applied to the ocean and sea ice components of the global climate forecast model EC-Earth, with the following key innovations: (1) the use of a weight applied to the observed anomalies, in order to avoid the risk of introducing anomalies recorded in the observed climate, whose amplitude does not fit in the range of the internal variability generated by the model; (2) the AI of the ocean density, instead of calculating it from the anomaly initialised state of temperature and salinity. An experiment initialised with this refined AI method has been compared with a full field and standard AI experiment. Results show that the use of such refinements enhances the surface temperature skill over part of the North and South Atlantic, part of the South Pacific and the Mediterranean Sea for the first forecast year. However, part of such improvement is lost in the following forecast years. For the tropical Pacific surface temperature, the full field initialised experiment performs the best. The prediction of the Arctic sea-ice volume is improved by the refined AI method for the first three forecast years and the skill of the Atlantic multidecadal oscillation is significantly increased compared to a non-initialised forecast, along the whole forecast time.

The Effect of Grain-refinement on Zn-10Al Alloy Damping Properties

Directory of Open Access Journals (Sweden)

Piwowarski G.

2014-12-01

Full Text Available The paper is devoted to grain-refinement of the medium-aluminium zinc based alloys (MAl-Zn. The system examined was sand cast Zn- 10 wt. %. Al binary alloy (Zn-10Al doped with commercial Al-3 wt. % Ti - 0.15 wt. % C grain refiner (Al-3Ti-0.15C GR. Basing on the measured attenuation coefficient of ultrasonic wave it was stated that together with significantly increased structure fineness damping decreases only by about 10 - 20%. The following examinations should establish the influence of the mentioned grain-refinement on strength and ductility of MAl-Zn cast alloys.

Adaptive mesh refinement with spectral accuracy for magnetohydrodynamics in two space dimensions

International Nuclear Information System (INIS)

Rosenberg, D; Pouquet, A; Mininni, P D

2007-01-01

We examine the effect of accuracy of high-order spectral element methods, with or without adaptive mesh refinement (AMR), in the context of a classical configuration of magnetic reconnection in two space dimensions, the so-called Orszag-Tang (OT) vortex made up of a magnetic X-point centred on a stagnation point of the velocity. A recently developed spectral-element adaptive refinement incompressible magnetohydrodynamic (MHD) code is applied to simulate this problem. The MHD solver is explicit, and uses the Elsaesser formulation on high-order elements. It automatically takes advantage of the adaptive grid mechanics that have been described elsewhere in the fluid context (Rosenberg et al 2006 J. Comput. Phys. 215 59-80); the code allows both statically refined and dynamically refined grids. Tests of the algorithm using analytic solutions are described, and comparisons of the OT solutions with pseudo-spectral computations are performed. We demonstrate for moderate Reynolds numbers that the algorithms using both static and refined grids reproduce the pseudo-spectral solutions quite well. We show that low-order truncation-even with a comparable number of global degrees of freedom-fails to correctly model some strong (sup-norm) quantities in this problem, even though it satisfies adequately the weak (integrated) balance diagnostics

Adaptive local surface refinement based on LR NURBS and its application to contact

Science.gov (United States)

Zimmermann, Christopher; Sauer, Roger A.

2017-12-01

A novel adaptive local surface refinement technique based on Locally Refined Non-Uniform Rational B-Splines (LR NURBS) is presented. LR NURBS can model complex geometries exactly and are the rational extension of LR B-splines. The local representation of the parameter space overcomes the drawback of non-existent local refinement in standard NURBS-based isogeometric analysis. For a convenient embedding into general finite element codes, the Bézier extraction operator for LR NURBS is formulated. An automatic remeshing technique is presented that allows adaptive local refinement and coarsening of LR NURBS. In this work, LR NURBS are applied to contact computations of 3D solids and membranes. For solids, LR NURBS-enriched finite elements are used to discretize the contact surfaces with LR NURBS finite elements, while the rest of the body is discretized by linear Lagrange finite elements. For membranes, the entire surface is discretized by LR NURBS. Various numerical examples are shown, and they demonstrate the benefit of using LR NURBS: Compared to uniform refinement, LR NURBS can achieve high accuracy at lower computational cost.

The use of Fourier reverse transforms in crystallographic phase refinement

Energy Technology Data Exchange (ETDEWEB)

Ringrose, Sharon [Iowa State Univ., Ames, IA (United States)

1997-10-08

Often a crystallographer obtains an electron density map which shows only part of the structure. In such cases, the phasing of the trial model is poor enough that the electron density map may show peaks in some of the atomic positions, but other atomic positions are not visible. There may also be extraneous peaks present which are not due to atomic positions. A method for determination of crystal structures that have resisted solution through normal crystallographic methods has been developed. PHASER is a series of FORTRAN programs which aids in the structure solution of poorly phased electron density maps by refining the crystallographic phases. It facilitates the refinement of such poorly phased electron density maps for difficult structures which might otherwise not be solvable. The trial model, which serves as the starting point for the phase refinement, may be acquired by several routes such as direct methods or Patterson methods. Modifications are made to the reverse transform process based on several assumptions. First, the starting electron density map is modified based on the fact that physically the electron density map must be non-negative at all points. In practice a small positive cutoff is used. A reverse Fourier transform is computed based on the modified electron density map. Secondly, the authors assume that a better electron density map will result by using the observed magnitudes of the structure factors combined with the phases calculated in the reverse transform. After convergence has been reached, more atomic positions and less extraneous peaks are observed in the refined electron density map. The starting model need not be very large to achieve success with PHASER; successful phase refinement has been achieved with a starting model that consists of only 5% of the total scattering power of the full molecule. The second part of the thesis discusses three crystal structure determinations.

[A Brief Homophobia Scale in Medical Students From Two Universities: Results of A Refinement Process].

Science.gov (United States)

Campo-Arias, Adalberto; Herazo, Edwin; Oviedo, Heidi Celina

The process of evaluating measurement scales is an ongoing procedure that requires revisions and adaptations according to the characteristics of the participants. The Homophobia Scale of seven items (EHF-7) has showed acceptable performance in medical students attending to two universities in Colombia. However, performance of some items was poor and could be removed, with an improvement in the psychometric findings of items retained. To review the psychometric functioning and refine the content of EHF-7 among medical students from two Colombian universities. A group of 667 students from the first to tenth semester participated in the research. Theirs ages were between 18 and 34 (mean, 20.9±2.7) years-old, and 60.6% were females. Cronbach alpha (α) and omega of McDonald (Ω) were calculated as indicators of reliability and to refine the scale, an exploratory (EFA) and confirmatory factor analysis (CFA) was performed. EHF-7 showed α=.793 and Ω=.796 and a main factor that explained 45.2% of the total variance. EFA and CFA suggested the suppression of three items. The four-item version (EHF-4) reached an α=.770 and Ω=.775, with a single factor that accounted for 59.7% of the total variance. CFA showed better indexes (χ 2 =3.622; df=1; P=.057; Root-mean-square error of approximation (RMSEA)=.063, 90% CI, .000-.130; Comparative Fit Indices (CFI)=.998; Tucker-Lewis Index (TLI)=.991). EHF-4 shows high internal consistency and a single dimension that explains more than 50% of the total variance. Further studies are needed to confirm these observations, that can be taken as preliminary. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Computing Refined Buneman Trees in Cubic Time

DEFF Research Database (Denmark)

Brodal, G.S.; Fagerberg, R.; Östlin, A.

2003-01-01

Reconstructing the evolutionary tree for a set of n species based on pairwise distances between the species is a fundamental problem in bioinformatics. Neighbor joining is a popular distance based tree reconstruction method. It always proposes fully resolved binary trees despite missing evidence...... in the underlying distance data. Distance based methods based on the theory of Buneman trees and refined Buneman trees avoid this problem by only proposing evolutionary trees whose edges satisfy a number of constraints. These trees might not be fully resolved but there is strong combinatorial evidence for each...... proposed edge. The currently best algorithm for computing the refined Buneman tree from a given distance measure has a running time of O(n 5) and a space consumption of O(n 4). In this paper, we present an algorithm with running time O(n 3) and space consumption O(n 2). The improved complexity of our...

Grain Refinement of an Al-2 wt%Cu Alloy by Al3Ti1B Master Alloy and Ultrasonic Treatment

International Nuclear Information System (INIS)

Wang, E Q; Wang, G; Dargusch, M S; StJohn, D H; Qian, M; Eskin, D G

2016-01-01

Both inoculation by AlTiB master alloys and Ultrasonic Treatment (UT) are effective methods of refining the grain size of aluminium alloys. The present study investigates the influence of UT on the grain refinement of an Al-2 wt% Cu alloy with a range of Al3TilB master alloy additions. When the alloy contains the smallest amount of added master alloy, UT caused significant additional grain refinement compared with that provided by the master alloy only. However, the influence of UT on grain size reduces with increasing addition of the master alloy. Plotting the grain size data versus the inverse of the growth restriction factor (Q) reveals that the application of UT causes both an increase in the number of potentially active nuclei and a decrease in the size of the nucleation free zone due to a reduction in the temperature gradient throughout the melt. Both these factors promote the formation of a fine equiaxed grain structure. (paper)

Factors affecting the grain-refinement of aluminum using titanium and boron additives

International Nuclear Information System (INIS)

Jones, G.P.; Pearson, J.

1976-01-01

The development of grain-refining techniques for the casting of aluminum, and the results achieved using additions of ternary Al--Ti--B master-alloys, are briefly described. A test procedure is given for assessing the relative effectiveness of these master-alloys, and the results are related to the various kinds of alloy treated, including those with constituents which poison the grain-refining agent. The equilibrium conditions which affect the behavior of the constituents of the grain-refined alloys are examined quantitatively from a thermodynamic viewpoint. One theory about the mechanism of nucleation of aluminum on titanium diboride is examined and found inapplicable. New data on the solubility of TiB 2 , ZrB 2 , TiC, ZrC, Cr 3 C 2 , and CrB 2 in liquid aluminum are presented graphically. Practical aspects of alloy behavior in grain-refining practice are analyzed and discussed on the basis of the quantitative data

Investigation on single carbon atom transporting through the single-walled carbon nanotube by MD simulation

International Nuclear Information System (INIS)

Ding Yinfeng; Zhang Zhibin; Ke Xuezhi; Zhu Zhiyuan; Zhu Dezhang; Wang Zhenxia; Xu Hongjie

2005-01-01

The single carbon atom transporting through the single-walled carbon nanotube has been studied by molecular-dynamics (MD) simulation. We got different trajectories of the carbon atom by changing the input parameters. The simulation results indicate that the single carbon atom with low energy can transport through the carbon nanotube under some input conditions and result in different trajectories being straight line or 'rosette' or circular. (authors)

78 FR 20176 - Credit for Renewable Electricity Production, Refined Coal Production, and Indian Coal Production...

Science.gov (United States)

2013-04-03

..., Refined Coal Production, and Indian Coal Production, and Publication of Inflation Adjustment Factors and... renewable electricity production, refined coal production, and Indian coal production under section 45... resources, and to 2013 sales of refined coal and Indian coal produced in the United States or a possession...

77 FR 21835 - Credit for Renewable Electricity Production, Refined Coal Production, and Indian Coal Production...

Science.gov (United States)

2012-04-11

..., Refined Coal Production, and Indian Coal Production, and Publication of Inflation Adjustment Factors and... electricity production, refined coal production, and Indian coal production under section 45. DATES: The 2012... sales of refined coal and Indian coal produced in the United States or a possession thereof. Inflation...

Former Soviet Union's refining sector faces big shakeout

International Nuclear Information System (INIS)

Anon.

1993-01-01

The crisis gripping the refining sector in the former Soviet Union (FSU) is deepening as that industry faces massive rationalization and restructuring. Refinery runs in FSU republics have been on the decline for a number of years. Peak throughput occurred in 1987 at 9.69 million b/d. In Russia, however, the peak came in 1980 at 6.5 million b/d. Given current operable refining capacity in the FSU, now down to about 9.27 million b/d distributed among 48 refineries, capacity utilization will average only about 65% this year. The paper discusses worsening conditions, a comparison of the FSU declines, the financial crisis, energy consumption, and the focus of FSU refineries on secondary capacity to upgrade the product mix

Calculating corrections in F-theory from refined BPS invariants and backreacted geometries

Energy Technology Data Exchange (ETDEWEB)

Poretschkin, Maximilian

2015-07-01

This thesis presents various corrections to F-theory compactifications which rely on the computation of refined Bogomol'nyi-Prasad-Sommerfield (BPS) invariants and the analysis of backreacted geometries. Detailed information about rigid supersymmetric theories in five dimensions is contained in an index counting refined BPS invariants. These BPS states fall into representations of SU(2){sub L} x SU(2){sub R}, the little group in five dimensions, which has an induced action on the cohomology of the moduli space of stable pairs. In the first part of this thesis, we present the computation of refined BPS state multiplicities associated to M-theory compactifications on local Calabi-Yau manifolds whose base is given by a del Pezzo or half K3 surface. For geometries with a toric realization we use an algorithm which is based on the Weierstrass normal form of the mirror geometry. In addition we use the refined holomorphic anomaly equation and the gap condition at the conifold locus in the moduli space in order to perform the direct integration and to fix the holomorphic ambiguity. In a second approach, we use the refined Goettsche formula and the refined modular anomaly equation that govern the (refined) genus expansion of the free energy of the half K3 surface. By this procedure, we compute the refined BPS invariants of the half K3 from which the results of the remaining del Pezzo surfaces are obtained by flop transitions and blow-downs. These calculations also make use of the high symmetry of the del Pezzo surfaces whose homology lattice contains the root lattice of exceptional Lie algebras. In cases where both approaches are applicable, we successfully check the compatibility of these two methods. In the second part of this thesis, we apply the results obtained from the calculation of the refined invariants of the del Pezzo respectively the half K3 surfaces to count non-perturbative objects in F-theory. The first application is given by BPS states of the E

Changes in the phenolic composition of pancake fractions made from refined and whole-wheat flour of two wheat varieties

Science.gov (United States)

In this study, we investigated the changes in the levels of phenolic acids during pancake preparation from refined and whole-wheat flours of two wheat varieties. Comparison of the efficacy of two commonly used methods for hydrolysis and extraction of phenolic acids, namely ultrasonic-assisted extrac...

Mathematical aspects of Rietveld refinement and crystal structure ...

Indian Academy of Sciences (India)

Administrator

The core mathematics, goodness-of-fit parameters of Rietveld refinement technique is introduced for structural ... transducers in medical and solar applications (Obmann ..... Prince 1985 in Structure and statistics in crystallography (ed.).

Architectural Refinement for the Design of Survivable Systems

National Research Council Canada - National Science Library

Ellison, Robert