Complex fluid analysis with the advanced distillation curve approach.
An improved method for measuring distillation curves reveals the physicochemical properties of complex fluids such as fuels. PMID:20041713
2010-02-01
Energy Technology Data Exchange (ETDEWEB)
In this paper we consider properties of the ideal gas of classical (nonquantum) tachyons.
1983-10-15
British Library Electronic Table of Contents (United Kingdom)
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, with features including a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), trace chemical analysis of each distillate fraction, and a corrosivity assessment of each distillate fraction. In the present contribution, we present the application of the advanced distillation curve method to a bio-derived crude oil prepared from swine manure. One motivation behind the work was to precisely measure the distillation curve of the oil derived from swine manure with our advanced distillation apparatus and compare the bio-derived oil to traditional pe...
2008-01-01
Intutionistic Fuzzy Ideals in {\\Gamma}-semiring
In this paper we have studied the relation between the intutionistic fuzzy left (respectively right) ideals of {\\Gamma}-semiring and that of operator semiring. Thereafter, we have established that the Lattices of all intutionistic fuzzy left (respectively right) ideal of {\\Gamma}-semiring is equivalent to that of Left operator semiring. We proved that Then there exist an inclusion preserving bijection ({\\mu}_{A,}\\u{psion}_{A})$\\rightarrow$({\\mu}_{B}^{+'},\\u{psion}_{B}^{+'}) between the lattices of all intuitionistic fuzzy right ideals (respectively intuitionistic fuzzy ideals) of S and the lattices of all intuitionistic fuzzy right ideals (respectively intuitionistic fuzzy ideals) of L. Where ({\\mu}_{A},\\u{psion}_{A}) is an intuitionistic fuzzy right (respectively intuitionistic fuzzy ideals) ideal of S. Also we ...
2010-01-01
Atanassov's Intuitionistic Fuzzy Ideals of Gamma Semigroups
The notion of intuitionistic fuzzy set was introduced by Atanassov as a generalization of the notion of fuzzy set. In this paper we apply this concept of Atanassov to ideals, prime ideals and semiprime ideals of gamma semigroups in order to obtain some characterization theorems. We also introduce the notion of Atanassov's intuitionistic fuzzy ideal extension in a gamma semigroup and investigate some of their important properties. A regular gamma semigroup has been characterized in terms of Atanasov's intutionistic fuzzy ideal. Characterization of prime ideal of a gamma semigroup has also been obtained in terms of Atanassov's intutionistic fuzzy ideal extension.
2011-01-01
Spontaneous radiation of atomic oscillator, situated near ideally conducting cone surface
International Nuclear Information System (INIS)
The line width of atom, situated near ideally conducting point or inside cone cavity in ideal conductor is analyzed. It is shown that the effect of point is decreased according to decreasing of its aperture angle
1998-01-01
International Nuclear Information System (INIS)
The properties of the ideal gas of classical (nonquantum) tachyons are considered. Starting from the definition of thermodynamic functions for this system, it may be found that tachyons and bradyons gases are similar. (AA).
Energy Technology Data Exchange (ETDEWEB)
Makeup water is distilled internally in an amine gas treating unit by adding it to the reclaimer used to process a slipstream of lean amine from the stripper.
1984-07-24
Advanced distillation curve measurements for corrosive fluids: Application to two crude oils
British Library Electronic Table of Contents (United Kingdom)
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and corrosivity assessment of each distillate fraction. The composition-explicit information is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to a variety of fluids, including simple n-alkanes, rocket propellant, gasoline, jet fuels, and a hydrocarbon fluid made corrosive with dissolved hydrogen sulfide. In the current contribution, we present the application of the advanced distillation curve method to two samples of...
2008-01-01
Advanced distillation curve measurements for corrosive fluids: Application to two crude oils
Energy Technology Data Exchange (ETDEWEB)
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and corrosivity assessment of each distillate fraction. The composition-explicit information is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to a variety of fluids, including simple n-alkanes, rocket propellant, gasoline, jet fuels, and a hydrocarbon fluid made corrosive with dissolved hydrogen sulfide. In the current contribution, we present the application of the advanced distillation curve method to two samples of crude oil. A primary motivation behind the work is to precisely measure the distillation ...
2008-10-15
Energy Technology Data Exchange (ETDEWEB)
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, with features including a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), trace chemical analysis of each distillate fraction, and a corrosivity assessment of each distillate fraction. In the present contribution, we present the application of the advanced distillation curve method to a bio-derived crude oil prepared from swine manure. One motivation behind the work was to precisely measure the distillation curve of the oil derived from swine manure with our advanced distillation apparatus and compare the bio-derived oil to traditional petroleum crude oils. Then, the information content of ...
2008-11-15
Producer: Acrobat Distiller 3.02 ...Volume 3 Number 3 28 July 1998 ...Volume 3 Number 3 27 July 1998 It is in this context that all countries,
Thin-film evaporator recovers solvents continuously
Energy Technology Data Exchange (ETDEWEB)
Reclaimed Energy Company, Inc., Connersville, IN, receives waste generated from a wide variety of industrial applications which include paint, printing and degreasing companies. The wastes are stored in separate tanks and then distilled in batches (pot distillation). The recovered solvents can be returned to the originator. The residue, left after the solvents are distilled, is disposed of using an environmentally safe, economical procedure. The company worked with an engineering and fabrication firm to develop a continuous processing system that employs a mechanically agitated thin-film evaporator to distill the solvents. Successful performance of the evaporator was ensured by processing samples of solvents through the evaporator manufacturer's pilot plant facilities before the full-sized system was designed. Reclaimed Energy Company, Inc., has realized a number of advantages by going from pot ...
1985-11-01
Thermodynamic, Transport and Chemical Properties of " ...
... Chem. Res., in press, 2006. 8. Smith, BL, Bruno, TJ, Advanced distillation curve measurement with a model predictive temperature controller. Int. ...
2006-06-01
British Library Electronic Table of Contents (United Kingdom)
Abstract: The recent National Academy of Sciences report on forensic sciences states that the study of fire patterns and debris in arson fires is in need of additional work and eventual standardization. We discuss a recently introduced method that can provide predicted evaporation patterns for ignitable liquids as a function of temperature. The method is a complex fluid analysis protocol, the advanced distillation curve approach, featuring a composition explicit data channel for each distillate fraction (for qualitative, quantitative, and trace analysis), low uncertainty temperature measurements that are thermodynamic state points that can be modeled with an equation of state, consistency with a century of historical data, and an assessment of the energy content of each distillate fraction...
2011-01-01
Optimal protocols for nonlocality distillation
International Nuclear Information System (INIS)
Forster et al. recently showed that weak nonlocality can be amplified by giving the first protocol that distills a class of nonlocal boxes (NLBs) [Phys. Rev. Lett. 102, 120401 (2009)] We first show that their protocol is optimal among all nonadaptive protocols. We next consider adaptive protocols. We show that the depth-2 protocol of Allcock et al. [Phys. Rev. A 80, 062107 (2009)] performs better than previously known adaptive depth-2 protocols for all symmetric NLBs. We present a depth-3 protocol that extends the known region of distillable NLBs. We give examples of NLBs for which each of the Forster et al., the Allcock et al., and our protocols perform best. The understanding we develop is that there is no single optimal protocol for NLB distillation. The choice of which protocol to use depends on the noise parameters for the NLB.
2010-10-01
Advanced Distillation Curve Measurement with a Model Predictive Temperature Controller
British Library Electronic Table of Contents (United Kingdom)
In previous work, several significant improvements in the measurement of distillation curves for complex fluids were introduced. The modifications to the classical measurement provide for (1) temperature and volume measurement(s) of low uncertainty, and most important, (2) a composition-explicit data channel in addition to the usual temperature?volume relationship. This latter modification is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. In the new approach, the distillation temperature is measured in two locations. The temperature is measured in the usual location, at the bottom of the take-off in the distillation head, but it is also measured directly in the fluid. We have further modified our developm...
2006-01-01
Acrobat Distiller, Job 7 - GLTRS - NASA
into the SiC interface to form of palladium silicides (PdSix) and the subsequent migration of elemental silicon to the surface from the SiC. Palladium silicides are ...
Phytoplankton in the Damariscotta River Estuary
... s excellent water quality and ideal temperature conditions. Oyster aquaculture operations on the Damariscotta lease about 100 acres ... ...
Energy Technology Data Exchange (ETDEWEB)
This paper describes a research and development project to quantify the effects of cleaning the coal feed on the yield patterns and processing rates for the Liquid Solvent Extraction (LSE) direct coal liquefaction process and to obtain information on the effect of the co-refining of coal-derived and petroleum distillates to premium transport fuels. 6 refs., 25 figs., 40 tabs.
1992-12-31
Purification of bidentate organophosphorous extractants
Energy Technology Data Exchange (ETDEWEB)
Crude N,N-dialkylcarbamoylmethylphosphonates and phosphine oxide extractants, and particularly crude dihexyl N,N-diethylcarbamoylmethylphosphonate and octylphenyl N,N-diisobutylcarbamoyl phosphine oxide, are purified by distilling the crude materials in a thin film evaporator. Preferably, the crude materials are reacted with concentrated hydrochloric acid and then with aqueous sodium hydroxide prior to distillation in the thin film evaporator to hydrolyze impurities contained in them. The purified extractants are useful for extracting actinides and lanthanides from liquid waste streams. (author).
1990-12-19
Purification of bidentate organophosphorous extractants
International Nuclear Information System (INIS)
Crude N,N-dialkylcarbamoylmethylphosphonates and phosphine oxide extractants, and particularly crude dihexyl N,N-diethylcarbamoylmethylphosphonate and octylphenyl N,N-diisobutylcarbamoyl phosphine oxide, are purified by distilling the crude materials in a thin film evaporator. Preferably, the crude materials are reacted with concentrated hydrochloric acid and then with aqueous sodium hydroxide prior to distillation in the thin film evaporator to hydrolyze impurities contained in them. The purified extractants are useful for extracting actinides and lanthanides from liquid waste streams. (author).
1990-05-16
Energy Technology Data Exchange (ETDEWEB)
While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose of essential removal of tritium from the Wolsung heavy-water reactor system, a preliminary study on the cryogenic Ar-N{sub 2} and H{sub 2}-D{sub 2} distillation process for development of liquid-phase catalytic exchange cryogenic hydrogen distillation process technology. The Ar-N{sub 2} distillation column showed good performance with approximately 97% of final Ar concentration, and a computer simulation code was modified using these data. A simulation code developed for cryogenic hydrogen isotopes (H{sub 2}, HD, D{sub 2}, HT, DT, T{sub 2}) distillation column showed good performance after comparison with the result of a JAERI code, and a H{sub 2}-D{sub ...
1995-12-01
Accelerated stability test techniques for middle distillate fuels
Energy Technology Data Exchange (ETDEWEB)
Improved test techniques are needed for evaluating the inherent stability of middle distillate fuels both in surveillance and in procurement activities. A project was initiated to define and evaluate the contributing conditions leading to the formation of deleterious products in accelerated aging tests of middle distillate fuels and to relate these results to an experimental definition of more repeatable/reliable middle distillate fuel stability test technique(s). A literature search was conducted to provide a list of stability test techniques and their interpretations which could be used in a correlative middle distillate fuel stability test program. For this program, seven accelerated stability tests were chosen and evaluated using a set of six test fuels. The test techniques were selected to represent a wide variety of test conditions, including temperature, aging time, and oxygen availability. These ...
1981-01-01
Vacuum distillation refining and recycling of magnesium alloys
Energy Technology Data Exchange (ETDEWEB)
Purification parameters of the vacuum distillation process for AM50A and AZ31B magnesium alloy were studied. The vacuum distillation tests were kept at 580 C to 620 C up to 10 h under a vacuum pressure of about 1 Pa. The purification ratio for AM50A magnesium alloy increases with increasing the purification time. The chemical compositions of materials deposited purifying at 580 C for AM50A magnesium alloy almost satisfy the values for pure magnesium specified by JIS standard specification. The chemical compositions of deposited materials at 600 C for AZ31B magnesium alloy satisfy the values specified by the standard specification except for Zn. (orig.)
2003-07-01
Study of azeotropic mixtures with the advanced distillation curve approach
British Library Electronic Table of Contents (United Kingdom)
Classical methods for the study of complex fluid phase behavior include static and dynamic equilibrium cells that usually require vapor and liquid recirculation. These are sophisticated, costly apparatus that require highly trained operators, usually months of labor-intensive work per mixture, and the data analysis is also rather complex. Simpler approaches to the fundamental study of azeotropes are highly desirable, even if they provide only selected cuts through the phase diagram. Recently, we introduced an advanced distillation curve measurement method featuring: (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation o...
2009-01-01
International Nuclear Information System (INIS)
This patent describes the producing of a refractory metal wherein a sponge refractory metal is produced as an intermediate product by the use of magnesium with the incidental production of magnesium chloride, and wherein residual magnesium is separated from the magnesium chloride and from refractory metal to a vacuum distillation step which fractionally distills the magnesium, the magnesium chloride, and the metal sub-chlorides; the steps of: recovering fractionally distilled vapors of magnesium chloride and metal sub-chlorides from a sponge refractory metal; separately condensing the vapors as separately recovered; and recycling the separately recovered magnesium at a purity of at least about 96%.
1990-09-21
Design and mass transfer characteristics of rotating screw brush horizontal distillation column
Energy Technology Data Exchange (ETDEWEB)
A distillation column with an adjustable slope horizontal rectification section was constructed. A rotating screw brush was inserted into the section, which could be rotated from 0 to 600 rpm with an external motor. Distillation experiments were carried out using the system cyclohexane-heptane at total reflux at slopes of 0(horizontal), 5 and 10 degrees. Separation efficiency for the horizontal column was the highest of the three orientations, and was obtained as HETP from 0.04 to 0.16 m at F-factor of 0.05 to 0.4 m/s(kg/m{sup 3}){sup 1/2} in the range of 100 to 600 rpm. The HETP for each slope was roughly constant at a rotation speed of more than 300 rpm. The values of the pressure drop were found to be equivalent to those of one seventh to one fifth of conventional packed columns. (author)
2000-10-01
International Nuclear Information System (INIS)
The study reports the identification of different organic acids that are formed during the pyrohydrolysis of mixed carbide of uranium and plutonium using ion chromatography (IC). The identification of organic acids present in the pyrohydrolysis distillate is required to carry out interference free analysis of Cl and F. The study describes three stage isocratic separations with NaOH eluents having concentrations 2 mM, 10 mM and 50 mM respectively in order to separate and identify both aliphatic and aromatic acids. The present investigation identified formic, acetic, propionic, butyric, tartaric and oxalic acids in the distillate, however, aromatic acids could not be identified. (author)
2011-02-22
Ideal Magnetohydrodynamics Stability Spectrum with a Resistive Wall
Energy Technology Data Exchange (ETDEWEB)
We show that the eigenvalue equations describing a cylindrical ideal magnetophydrodynamicsw (MHD) plasma interacting with a thin resistive wall can be put into the standard mathematical form: ??? = ??? ?. This is accomplished by using a finite element basis for the plasma, and by adding an extra degree of freedom corresponding to the electrical current in the thin wall. The standard form allows the use of linear eigenvalue solvers, without additional interations, to compute the complete spectrum of plasma modes in the presence of a surrounding restrictive wall at arbitrary separation. We show that our method recovers standard results in the limits of (1) an infinitely resistive wall (no wall), and (2) a zero resistance wall (ideal wall).
2008-05-22
Energy Technology Data Exchange (ETDEWEB)
Cryogenic distillation is the main industrial method for separating hydrogen's isotopes, because it presents the advantage of high separating factors and also the possibility of processing great quantities of gases. In the case of multicomponent mixtures the determination of transport for molecular species between the two phases is very difficult owing to the particularities of physical characteristics of each component from the mixture. The transport of molecular species is also strongly influenced by the hydrodynamics of two phases, in strong connection with the dimension of the interface between the vapor and liquid phase. The characteristics of the interface depend on the type and geometry of the separation area: plates or package. The traditional methods of analysis for exchange processes use the concept 'theoretic plate', a physical entity for which the values of concentrations for vapors and liquid that leaves the plate are in ...
1998-07-01
Reflectance and petrology of a burning bituminous coal seam
Energy Technology Data Exchange (ETDEWEB)
Samples from a burning bituminous coal seam from Coalspur, Alberta, were studied by reflected light microscopy. Two zones - namely oxidation- combustion and distillation - were detected in the seam. Near the surface, the oxidation zone contained chars showing cracks and oxidation rims. The cracks were filled with fluorescing hydrocarbon material formed by thermal cracking of coal macerals. The chars in the deeper part of the oxidation zone had a carbonized matrix and burnt rims. The distillation zone covered most of the coal seam. Chars were mostly in the precarbonization stage, except those immediately below the combustion zone or near the base of the seam. Precarbonized chars contained pyrolytic carbon in some horizons. The distilled chars were formed by heat generated by combustion at the top of the seam and also by heat transfer from an underlying burning seam through an intermediate clastic layer. The minimum ...
1987-08-01
Energy Technology Data Exchange (ETDEWEB)
For developing coal liquefaction processes, it is an important problem to improve the light oil yield with increased oil yield. It was previously reported that distillate mainly containing lighter fraction can be produced with high oil yield by reducing the iron/sulfur catalyst addition in slurry, by recycling gas in the process operation, by utilizing these effects, and by using heavy oil as recycling solvent. In this study, the maximum distillate yield of Victorian brown coal was investigated through continuous liquefaction using a bench scale unit. In addition, operation conditions for obtaining sufficient oil yield were investigated under the reduced catalyst addition into one-third. Consequently, it was confirmed that the maximum content of lighter fraction in distillate product was obtained with reduced catalyst addition by using heavy oil as recycling solvent, by adopting new catalyst, and by utilizing effects of CLB ...
1996-10-28
While tritium exposure to the site-workers in Wolsung NPP is up to about 40% of the total personnel exposure, Ministry of Science and Technology has asked tritium removal facility for requirement of post heavy-water reactor construction. For the purpose o...
1995-01-01
Development of Tritium Removal Technology.
Liquid Phase Catalytic Exchange (LPCE)- Cryogenic Distillation(CD) process was studied which could be available for an optimal tritium removal process of pressurized heavy water reactor system at Wolsung nuclear power plant in the near future. Based upon ...
1986-01-01
Computational Analysis of Dynamic SPK(S8)-JP-8 Fueled ...
the Advanced Distillation Curve, Energy & Fuels, Vol. 22, No. 2, pp. 11041114. http://pubs.acs.org/doi/full/10.1021/ef700562c. Lemmon, E. W., Huber, M. L., ...
Biocatalytic desulfurization of petroleum and middle distillates
Energy Technology Data Exchange (ETDEWEB)
Biocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst-based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations. This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. Feasibility studies with ...
1993-02-01
Syzygy Theorems via comparison of order ideals on a hypersurface
British Library Electronic Table of Contents (United Kingdom)
We introduce a weak order ideal property that suffices for establishing the Evans-Griffith Syzygy Theorem. We study this weak order ideal property in settings that allow for comparison between homological algebra over a local ring R versus a hypersurface ring R =R/(x^n). Consequently we solve some relevant cases of the Evans-Griffith syzygy conjecture over local rings of unramified mixed characteristic p, with the case of syzygies of prime ideals of Cohen-Macaulay local rings of unramified mixed characteristic being noted. We reduce the remaining considerations to modules annihilated by p^s, s>0, that have finite projective dimension over a hypersurface ring.
2012-01-01
Mice as a Mammalian Model for Research on the Genetics of Aging
UK PubMed Central (United Kingdom)
Mice are an ideal mammalian model for studying the genetics of aging: considerable resources are available, the generation time is short, and the environment can be easily controlled, an important...Full Text Available
2011-02-08
Large Eddy Simulation for Heat Transfer Prediction in a Gas ...
... turbine blade heat-transfer and study the heat-transfer augmentation in idealized geometry and its ... responsible for heat transfer augmentation. ...
2007-03-30
Laboratory Description of Harbor Idealized Tests. Volume 1 ...
... modules 2 and 3, 45 ft from each end) in a ... The toe of the stone revetment was 2 ft out from the ... in parentheses are for the current meters in layout 2. ...
1993-03-01
Comments on the Quantum Afterburner
A process has been proposed to increase the efficiency of an ideal Otto cycle via a quantum heat engine that has no cooler reservoir. We show that such a process is not feasible.
2007-01-01
Joint coking of residues from processing petroleum and shale oil
Energy Technology Data Exchange (ETDEWEB)
It has become necessary to investigate the feasibility and desirability of joint coking of residues from the processing of petroleum and shale oil. Experiments have been performed on different types of feedstocks: a shale oil residue (SO) with an initial boiling point of 350/sup 0/C, obtained by thermal destruction of Bulgarian shales with a solid heat-carrier; a pyrolysis tar from the production of ethylene; extracts obtained in solvent treatment of petroleum oils, namely extracts from medium-viscosity lube distillate, viscous distillate, and residual lube stock; and asphalt obtained in deasphalting. Each of the petroleum products was blended with the SO in a 1/1 ratio.
1987-03-01
Energy Technology Data Exchange (ETDEWEB)
This work demonstrate the gasoline volatility influence, at T 10%, T 50% and T 90% distillation points, on the dynamic performance of Otto cycle engines equipped with fuel sequential electronic injection system, by using test standard procedures in dynamometer. For each distillation points three value ranges were established, giving the rise of 27 different gasoline mixtures. The effects of variation in each point on consumption, power and acceleration were verified.
1998-07-01
Energy Technology Data Exchange (ETDEWEB)
Mild hydrotreating is the key to successful re-refining of used lubricating oils. Coupled with pre-distillation and metals removal, the process produces oil of superior color and clarity with acceptable viscosity and heteroatom content. Furthermore, the entire process provides operational simplicity, economic feasibility and environmental attractiveness. Re-refining preserves a valuable resource while solving a potential environmental problem. Increased sensitivity to disposal of hazardous material once again makes re-refining almost a necessity. Various technologies developed to re-refine used lubricating oils range from simple acid/clay contacting to complex solvent extraction. Most technologies require similar capital investment; however, operating costs vary substantially. Current technology seems to converge on a two-step procedure: distillation of dehydrated used oil in a thin-film evaporator, and subsequent hydrotreating of ...
1986-04-01
Development on the technologies for tritium removal processes
Energy Technology Data Exchange (ETDEWEB)
While tritium exposure to the site-workers in Wolsung NPP is upto about 40 % of the total personnel exposure, Korea Institute of Nuclear Safety has asked tritium removal facility, as one of the requirements for post reactor construction, after operation of four CANDU reactors in Wolsung site. For the purpose of essential removal of tritium from the heavy water system of the heavy water reactors, an experiment of Ar-N{sub 2} cryogenic distillation tower was carried out as a preliminary study for development of liquid-phase catalytic exchange - cryogenic hydrogen distillation process. The steady-state reached after 50 minutes under 90 K in the Ar-N{sub 2} distillation column (inner diameter 20 mm, height 500 mm) packed with Dixon ring ({phi} 3 mm x H 3 mm), and the ratios of Ar-concentration at the top and at the bottom measured by gas chromatography within {+-}1 % relative error was approximately 93 : 3. This value was ...
1994-12-01
Quantum Afterburner Improving the Efficiency of an Ideal Heat Engine
By using a laser and maser in tandem, it is possible to obtain laser action in the hot exhaust gases involved in heat engine operation. Such a "quantum afterburner" involves the internal quantum states of working gas atoms or molecules as well as the techniques of cavity quantum electrodynamics and is therefore in the domain of quantum thermodynamics. As an example, it is shown that Otto cycle engine performance can be improved beyond that of the "ideal" Otto heat engine.
2002-01-01
Novel reduced pressure-balance syringe for chromatographic analysis.
When withdrawing a fluid sample (for additional chromatographic analyses) from an apparatus operated at a reduced pressure, a typical syringe proves to be ineffective (even if it is equipped with a gas tight plunger). It simply does not create enough pressure differential to remove a fluid sample from a reduced pressure environment. We encountered such a situation as part of efforts to extend the operation of the advanced distillation curve protocol to reduced pressures. The problem was solved by the development of a pressure balance syringe that allows reliable and precise sampling from an apparatus operating at sub-ambient pressures. This new device uses an external vacuum source to evacuate a syringe barrel, allowing a user to withdraw fluid samples from environments with pressures as low as 0.5kPa. To demonstrate the operation of the newly developed device, distillate analyses were performed on two fluids at low pressure: a predefined ...
2010-09-19
British Library Electronic Table of Contents (United Kingdom)
The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, wh...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Complex fluids have long posed a significant challenge in our ability to characterize and model fluid properties. Here, we consider complex fluids to be mixtures with many components that can differ significantly in polarity and polarizability. The penultimate complex fluid is crude oil, although many other fluids such as finished fuels are also highly complex. We have recently introduced a measurement strategy that can simplify these efforts and provides the added potential of linking chemical composition (i.e. analytical) information with physical property information. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic and transport properties for such complex heterogeneous streams. The technique is based on the advanced distillation cu...
2010-01-01
Dynamic optimization of the benzene extractive distillation unit
Scientific Electronic Library Online (English)
Abstract in english A mathematical model has been developed for describing the dynamic operation of the N-formylmorpholine extractive distillation column and the corresponding solvent recovery column in the benzene extraction plant. The NRTL equation was used to calculate the equilibrium and thermodynamic properties of the mixtures. The validity of the model in terms of temperature, pressure and split fraction was examined using actual plant data at steady-state conditions. Comparison betwee (more) n model results and plant data shows good consistency. In order to improve the control of the process and selection of the optimal control strategy, the model was used to find the optimum values of the constants of the controllers with Nelder-Mead algorithm during unsteady-state operation by minimizing the deviation from steady-state conditions. The outcome of this study could be used by operators and engineers to increase the productivity of the unit.
2008-12-01
UK PubMed Central (United Kingdom)
Peri-prosthetic infections are notoriously difficult to treat as the biomaterial implant is ideal for bacterial adhesion and biofilm formation, resulting in decreased antibiotic sensitivity....Full Text Available
2008-12-01
UK PubMed Central (United Kingdom)
The t-butyldimethylsilyl group is shown to be an ideal protecting group for the 2T-hydroxyl function of ribonucleosides during the synthesis of ribonucleotides using any of nine commonly used condensing...Full Text Available
1980-05-10
Nanochemoprevention: Sustained Release of Bioactive Food Components for Cancer Prevention
UK PubMed Central (United Kingdom)
Chemoprevention, especially through the use of naturally occurring phytochemicals capable of impeding the process of carcinogenesis at one or more steps, is an ideal approach for cancer management....Full Text Available
2010-10-01
UK PubMed Central (United Kingdom)
Background and Objectives:Sound enamel manifests peak transparency in the near-IR (NIR) at 1310-nm, therefore the near-IR is ideally suited for high contrast imaging...Full Text Available
2009-03-01
UK PubMed Central (United Kingdom)
Chemoprevention strategies to prevent the development of lung cancer in at-risk individuals are a key component in disease management. In addition to being highly effective, an ideal chemopreventive...Full Text Available
2008-08-01
Echocardiographic assessment and percutaneous closure of multiple atrial septal defects
UK PubMed Central (United Kingdom)
Atrial septal defect closure is now routinely performed using a percutaneous approach under echocardiographic guidance. Centrally located, secundum defects are ideal for device closure but there is...Full Text Available
Current and potential future drug treatments for osteoporosis.
UK PubMed Central (United Kingdom)
There has been a major interest in the drug treatment of osteoporosis and an increase in the number of drugs available in most countries. The ideal drug (one which increases or restores bone density...Full Text Available
1996-10-01
UK PubMed Central (United Kingdom)
The overarching goal of medical training is to nurture the growth of knowledgeable, caring and insightful clinicians guided by the ideals of medical professionalism. Recent definitions of professional...Full Text Available
2008-11-01
Automatic evaluation of body-related words among young women: an experimental study
UK PubMed Central (United Kingdom)
BackgroundPrevious research has demonstrated that exposure to images depicting the thin female ideal has negative effects on some females' levels of body dissatisfaction. Much of...Full Text Available
A two-stage sequential linear programming approach to IMRT dose optimization
UK PubMed Central (United Kingdom)
The conventional IMRT planning process involves two stages in which the first stage consists of fast but approximate idealized pencil beam dose calculations and dose optimization and the second...Full Text Available
2010-02-07
A Position Paper on the Electronic Publication of Nematode Taxonomic Manuscripts
UK PubMed Central (United Kingdom)
Several nematode species have now attained ‘model organism’ status, yet there remain many niches in basic biological inquiry for which nematodes would be ideal model systems of study....Full Text Available
2006-09-01
Tissue banking for research: connecting the disconnected
British Library Electronic Table of Contents (United Kingdom)
Delivering the promise of personalised medicine is the challenge that the current generation of scientists face. The variations in human physiology and disease are considerable, and designing appropriate strategies to deliver what has been promised will require access to tissue from a large number of volunteers. The NHS provides an ideal infrastructure for sample acquisition, but requires two things to make this available?public consent and support for extra manpower and administration. There is a disconnection between the NHS and tissue based research that needs to be addressed on a number of levels to provide a translational platform. This should enable the path to be beaten to provide the ideal tailored treatment for future patients; one that preserves quality of life by curing the dise...
2011-01-01
International Nuclear Information System (INIS)
The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed.
Microeconomics of the ideal gas like market models
We develop a framework based on microeconomic theory from which the ideal gas like market models can be addressed. A kinetic exchange model based on that framework is proposed and its distributional features have been studied by considering its moments. Next, we derive the moments of the CC model (Eur. Phys. J. B 17 (2000) 167) as well. Some precise solutions are obtained which conform with the solutions obtained earlier. Finally, an output market is introduced with global price determination in the model with some necessary modifications.
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed.
1984-06-11
International Nuclear Information System (INIS)
By comparison of standard entropies theoretically calculated and determined from gas-chromatographic data for 40 halo-aliphatic and halo-aromatic compounds 8 organic iodine compounds among them, adsorbed on graphitized thermal carbon black it was found that in all the cases the molecular model of ideal two-dimensional gas is a sufficiently good approximation. It was shown that for a number of systems the agreement can be improved if the vibrations of the center of molecular mass relative to the surface are taken into account
System identification is a necessity in control theory. Classical control theory usually considers processes with integer order transfer functions. Real processes are usually of fractional order as opposed to the ideal integral order models. A simple and elegant scheme is presented for approximation of such a real world fractional order process by an ideal integral order model. A population of integral order process models is generated and updated by PSO technique, the fitness function being the sum of squared deviations from the set of observations obtained from the actual fractional order process. Results show that the proposed scheme offers a high degree of accuracy.
2008-01-01
The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at ...
2009-11-17
Energy Technology Data Exchange (ETDEWEB)
Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.
1985-10-15
Energy Technology Data Exchange (ETDEWEB)
A krypton recovery pilot plant has been completed for the Power Reactor and Nuclear Fuel Development Corporation. This is the first industrial facility in the world to make practical use of development results for offgas treatment and storage from nuclear facilities. The cryogenic distillation process was adopted as a proven and reliable method to separate krypton and xenon, and to reduce gas effuents to a level so low that the decontamination factor amounts to more than 1000.
1983-01-01
Hydroliquefaction of Australian coals - continuous reactor studies on bituminous coals
Energy Technology Data Exchange (ETDEWEB)
Results of tests on the 1 kg/h continuous reactor for the hydroliquefaction of coal are described. The reactor was operated at 415-435 C and 21 MPa using a continuous stirred reactor with a retention time of about 2 hours. All product oils were recovered by distillation. Sub-bituminous coal was found to give the best product yield. Tests using 5% red mud and 3% improved red mud showed significant increases in oil yield. (4 refs.)
1981-01-01
Direct liquefaction Proof-of-Concept facility. Final technical progress report
Energy Technology Data Exchange (ETDEWEB)
This report presents the results of work which included extensive modifications to HRI`s existing 3 ton per day Process Development Unit (PDU) and completion of the first PDU run. The 58-day Run 1 demonstrated scale-up of the Catalytic Two-Stage Liquefaction (CTSL Process) on Illinois No. 6 coal to produce distillate liquid products at a rate of up to 5 barrels per to of moisture-ash-free coal. The Kerr McGee Rose-SR unit from Wilsonville was redesigned and installed next to the US Filter installation to allow a comparison of the two solids removal systems. Also included was a new enclosed reactor tower, upgraded computer controls and a data acquisition system, an alternate power supply, a newly refurbished reactor, an in-line hydrotreater, interstage sampling system, coal handling unit, a new ebullating pump, load cells and improved controls and remodeled preheaters. Distillate liquid yields of 5 barrels/ton of moisture ash free coal were ...
1995-08-01
Energy Technology Data Exchange (ETDEWEB)
In this paper, a concept of technology that can be helpful for lowering the negative influence of the synthetic (based on the Solvay process) soda ash plant on the natural environment is presented. We describe the desulphurisation of combustion gases from the factory's power plant, which is based on their absorption in the overflow of distiller waste. The excess of lime milk, which is added in the process of ammonia regeneration from filter liquor, results in a strong alkalinity of distiller waste. The high pH of distiller waste favours absorption of acidic combustion gases. The laboratory-scale tests showed about 80% efficiency of the desulphurisation process. The suspension samples we obtained consist mainly of CaCO{sub 3}. We suggest using the obtained solid phase as an adsorbent-insert in Fluidised Bed Combustion technology (FBC). Based on raw material prices, production costs, and average sell prices of the ...
2007-09-15
RP-1 is a long-established hydrocarbon fuel that continues to be widely used as the kerosene component in rocket propulsion systems. The desire in recent years to use rocket motors many times, rather than a single time, has led to reformulations of RP-1. ...
2010-01-01
This report presents the operating results for Run 245 at the Advanced Coal Liquefaction R and D Facility in Wilsonville, Alabama. This run was made in an all-distillate Integrated Two-Stage Liquefaction (ITSL) mode using Illinois 6 coal from the Burning Star mine. The primary run objective was to obtain steady-state ITSL performance by replacing spent HTR reactor catalyst with fresh, sulfided catalyst. Secondary objectives were to maintain an all-distillate (minimum resid production) product slate and to demonstrate the effects of catalyst addition on the net gas production and hydrogen consumption. Run 245 began on 7 November, 1983, and continued through 12 February, 1984. During this period, 179.0 tons of coal was fed in 2045 hours of operation. Eight special product workup material balances were defined, and the results are presented herein. 6 references, 28 figures, 20 tables.
1984-10-01
Recycling boosts profits and saves resources
Energy Technology Data Exchange (ETDEWEB)
The Raywell Process Plants unit, which reclaims a wide range of organic solvents, including chlorinated hydrocarbons, is based on thin film evaporation and distillation rather than steam distillation, thus reducing the risk of contamination by water. Henry Balfour and Co.'s Pfaudler Solvent Recovery System gives 96% or better solvent recovery and produces a near-solid waste suitable for landfill disposal; like the Raywell system, it uses a mechanically wiped thin-film evaporator. Midland Oil Refineries uses sa Raywell thin-film evaporator for recovery of waste lubricating oils rather than the conventional sulfuric acid/clay treatment, thus avoiding formation of sulfuric acid sludge waste. The Henry Balfour Bioenergy anaerobic digestion system gives yields of fuel gas with 65-75% methane as high as 0.8 cu m/kg BOD; it achieves 95-98% BOD removal with no pH control or nutrient addition because it separates solids from liquid effluent and ...
1980-05-01
Materials performance at the Wilsonville Coal Liquefaction Facility, 1989--1991
The Advanced Coal Liquefaction Research and Development Facility in Wilsonville, Alabama, is funded by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), and Amoco Corporation. On behalf of these organizations, Southern Company Services manages and Southern Clean Fuels Division of Southern Electric International operates the Wilsonville facility. Oak Ridge National Laboratory (ORNL) receives funding from DOE to provide materials technical support to the Wilsonville operators. For the period July 1987 through November 1990 the plant was operated with two reactors a thermal reactor and a catalytic reactor in a close-coupled integrated two-stage liquefaction mode. Coal processed was obtained from several seams including Ohio No. 6, Illinois No. 6, and Pittsburgh No. 8, as well as Texas lignite and several subbituminous coals. Corrosion samples which were removed for examination at the end of this period were exposed in the vacuum ...
1991-01-01
Comparison of the effect of catalysts in coal liquefaction with tetralin and coal tar distillates
Energy Technology Data Exchange (ETDEWEB)
Special CoMo/Al{sub 2}O{sub 3} catalysts were prepared for testing in coal liquefaction: a conventional CoMo/Al{sub 2}O{sub 3} catalyst, one containing Zn as a second promoter and one having the alumina acidified with fluorine. Their activities were compared with that of red mud. The experiments were conducted in a stirred autoclave with a subbituminous coal and solvent (tetralin, anthracene oil or creosote oil) at 425{degree}C and 17 MPa. The liquefaction products were fractionated into oils, asphaltenes and preasphaltenes with pentane, toluene and THF. The Co(Zn)Mo/Al{sub 2}O{sub 3} catalysts have far higher activities than red mud. Zn and fluorine have beneficial effects on the catalyst activity. Coal tar distillates give higher conversions and oil + gas yields than tetralin when the prepared catalysts are used. 17 refs., 7 tabs.
1997-10-01
Energy Technology Data Exchange (ETDEWEB)
The merits of single stage absorption heat pumps coupled to simple distillation for effluent treatment are discussed. An experimental integrated absorption heat pump effluent purification system (IAHPEPS) was built and operated with water-lithium bromide as a working mixture. This unit has been used to raise the temperature and hence, the vapour pressure of the impure water contained in one vessel, to the point where pure water vapour will distil from impure effluent solution (tap water or brine) and condense in a second vessel used to collect pure water. Pure effluent production rates of between 0.5 and 4.3 kg h{sup -1} were obtained. The actual coefficient of performance (COP{sub A}) and the heat pump effectiveness varied from 1.1 to 1.4 and 0.58 to 0.72, respectively. The results from the small scale systems indicate the likely results from industrial scale units which could be operated with low quality heat such as waste heat, solar or ...
1999-05-01
Solar thermophotovoltaic (STPV) system with thermal energy storage
Energy Technology Data Exchange (ETDEWEB)
A solar thermophotovoltaic (STPV) system has both terrestrial and space applications because thermal energy storage can be utilized. Excellent properties (heat of fusion=1800 j/gm and melting temperature=1680 K) make silicon the ideal thermal storage material for an STPV system. Using a one dimensional model with tapering of the silicon storage material, it was found that several hours of running time with modest lengths ({approximately}15 cm) of silicon are possible. Calculated steady-state efficiencies for an STPV system using an Er-YAG selective emitter and ideal photovoltaic (PV) cell model are in the range of 15{percent}{endash}17{percent}. Increasing the taper of the storage material improves both efficiency and power output. {copyright} {ital 1996 American Institute of Physics.}
1996-02-01
Optimized pulse sequences for the suppression of decoherence in quantum information
International Nuclear Information System (INIS)
The dynamical decoupling (DD) aims at suppressing the decoherence by means of coherent control pulses. Even if devices exist where instantaneous pulses are an adequate approximation, experimentally a finite duration #tau#_p and a bounded amplitude are inevitable. They are the cause of additional errors which can be corrected by designing the pulse shape appropriately. The new pulse has the overall effect of an ideal, instantaneous pulse with the advantage of decoupling the spin (or qubit) from the bath up to the order O(#tau#_p"3). The limitation of the no-go theorem for #pi# pulses is avoided. Hence, the Uhrig sequence (UDD), originally thought for ideal #pi# pulses, works also for bounded control Hamiltonians. Numerical simulations show that concatenated sequences of real pulses are effective against general decoherence.
2010-03-21
Optimization techniques for parameter estimations: case studies in CO{sub 2} separation processes
Energy Technology Data Exchange (ETDEWEB)
Application of an optimization technique to extract the non-ideal parameters of gas absorption with chemical reactions process was described. The gas absorption was modeled using mass transfer theory to represent the realistic behaviors of an absorber. The model was a highly non-linear iterative model which correlated the overall rate of absorption as the function of unknown non-ideal parameters, including the physical liquid mass transfer coefficient and the wetted interfacial area of of packings. The optimization program was developed to minimize the sum of squares of relative errors between the model predictions and the experimental data. Four sets of experimental data (case studies) with different operating conditions were used for extracting parameters. Comparisons between predicted and experimental measured overall absorption rate were in good agreement, average absolute value of relative errors not exceeding 5.4 %. 18 refs., 3 tabs., 4 ...
1995-12-31
Ideal MHD stability properties of pressure-driven modes in low shear tokamaks
Energy Technology Data Exchange (ETDEWEB)
The role of shear in determining the ideal MHD stability properties of tokamaks is discussed. In particular, we assess the effects of low shear within the plasma upon pressure-driven modes. The standard ballooning theory is shown to break down, as the shear is reduced and the growth rate is shown to be an oscillatory function of n, the toroidal mode number, treated as a continuous parameter. The oscillations are shown to depend on both the pressure and safety-factor profiles. When the shear is sufficiently weak, the oscillations can result in bands of unstable n values which are present even when the standard ballooning theory predicts complete stability. These instabilities are named ''infernal modes.'' The occurrence of these instabilities at integer n is shown to be a sensitive function of q-axis, raising the possibility of a sharp onset as plasma parameters evolve. 20 refs., 31 figs.
1987-03-01
Different modes of resource variation provide a critical test of ideal free distribution models
British Library Electronic Table of Contents (United Kingdom)
Ideal free distribution (IFD) models are perhaps the group of mathematical models of behavior that have been the most widely and successfully applied by empiricists. These models can be applied to nearly any situation in which consumers compete?by any mechanism?for resources that are patchily distributed in their environment. Although IFD models have come to be broadly accepted, experiments that simultaneously test more than a single prediction are rare. Instead, investigators normally either test (1) for a relationship between the distribution of consumers and the distribution of resources or (2) whether average fitnesses are equal across resource patches. We conducted experiments with pea aphids (Acyrthosiphon pisum Harris) feeding on two patches of fava beans (Vicia faba L.) to fully in...
2007-01-01
Advanced power conversion based on the Aerocapacitor{trademark}
The authors report here, for the first time, high frequency testing of a new type of electrochemical double layer capacitor (EDLC), based on carbon aerogels: the Aerocapacitor. Carbon aerogels, are a novel type of carbon foam developed by Lawrence Livermore National Laboratory for military applications. The unique properties of carbon aerogels, high surface area (700 m{sup 2}/g), high density (1g/cc), well controlled pore diameter and high material conductivity (25 S/cm) made it an ideal EDLC electrode material. Using carbon aerogel as the electrode material, the authors have developed Aerocapacitors. These new EDLC`s have a frequency response comparable to that of aluminum electrolytic capacitors and are thus ideally suited to power conversion applications.
1997-10-01
Energy Technology Data Exchange (ETDEWEB)
The paper describes uptake of gaseous lodine-131 on silver impregnated organic resin, Amberlite IR-120, available at the Secondary Steam Generator (S.S.G.) Opening at T.A.P.S. in comparison with activated charcoal. The experiments are conducted in dry and wet conditions by soaking the impregnated resin and activated charcoal in distilled water for wet condition. The paper also describes the iodine sampler specially designed and fabricated for these experiments.
1982-01-01
Optimum design of the Wolsung tritium removal facility
Energy Technology Data Exchange (ETDEWEB)
Tritium removal from tritiated heavy water in a PHWR is the most effective way in reducing workers` internal dose and radioactivity emissions from Wolsong NPP. The optimum design of the Wolsung TRF(Tritium Removal Facility) was carried out using an approximate short-cut method with an assumption that the TRF, designed to extract 8 MCi per year of elemental tritium from a heavy water feedstream, uses Liquid Phase Catalytic Exchange (LPCE) front-end process and Cryogenic Distillation (CD) process. 19 refs., 6 figs., 2 tabs. (author).
1996-08-01
Optimum design of the Wolsung tritium removal facility
International Nuclear Information System (INIS)
Tritium removal from tritiated heavy water in a PHWR is the most effective way in reducing workers' internal dose and radioactivity emissions from Wolsong NPP. The optimum design of the Wolsung TRF(Tritium Removal Facility) was carried out using an approximate short-cut method with an assumption that the TRF, designed to extract 8 MCi per year of elemental tritium from a heavy water feedstream, uses Liquid Phase Catalytic Exchange (LPCE) front-end process and Cryogenic Distillation (CD) process. 19 refs., 6 figs., 2 tabs. (author).
1996-01-01
Energy Technology Data Exchange (ETDEWEB)
The purposed project is a commercial-scale ethanol-fuel facility with a capacity of twenty million gallons per year of fuel-grade ethanol. In addition, 70,000 tons per year of distillers dried grains will be produced. The following tasks and issues are addressed: process engineering - process descriptions, plant layout, and design; economics and finance - overview of capital and operating costs; environmental analysis - preliminary project description; and permit processing and legal issues. (MHR)
1981-08-01
Gas-liquid phase equilibrium in the system carbon dioxide-hexametapol (hexamethylphosphoramide)
Energy Technology Data Exchange (ETDEWEB)
The authors investigated phase equilibria in the system carbon dioxide-hexametapol. Vacuum-distilled solvent of ''pure'' grade was used. The solubility of CO/sub 2/ in hexametapol under pressures at various temperatures and the temperature dependence of the Henry's law coefficient is show. It is concluded that the solubility of carbon dioxide in hexametapol in the temperature and pressure ranges corresponding to the operating conditions of industrial equipment for removing CO/sub 2/ from gases conforms to the Krichevskii-II'inskaya equation. The experimental data can be used for equipment design.
1985-09-01
Coke fouling process on the oil refining; Processo de incrustacao por coque no refino do petroleo
Energy Technology Data Exchange (ETDEWEB)
The heavy crude fraction processing is performed under very high vacuum to minimize thermal cracking which cause coke deposition and damage the equipment. The current tendency is to process heavier oil leading to higher process temperatures and consequently to greater fouling. This situation demands better knowledge fouling process by carbonization. This problem is pronounced in the residual gasoil region of a vacuum distillation unit because it obstructs the recirculation circuits and the spray system with serious environmental and economics implications. This paper review the main correlated published work related to coke generation and fouling and presents a discussion about the works. (author)
2004-07-01
Chemical and Process - EA BOOKS
... Focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. AU$223.45 ex-GST Terms and Conditions Microchemical Engineer... Provides the information chemists and engineers need to evaluate the use of microreactors, covering the technical, operational, and economic considerations for various applications. AU$136.36 ex-GST Terms and Conditions Perry's Chemical Engin... Was: $199.95 inc gst NOW: $129.95 Special Price ...
Chemical and Process - EA BOOKS
... Focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. AU$223.45 ex-GST Terms and Conditions Browse Product Pages My EA Books Customer sign in User name Password Forgot your password? Register Mailing Lists New Books - Promotions click here to subscribe Shopping basket 50 Products AU$5,482.58 Standard Post Australia AU$10.00 Total amount AU$5,492.58 Display shopping basket Check out Copyright ©Engineers Media 2008 Terms &...
Chemical and Process - EA BOOKS
... Focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. AU$223.45 ex-GST Terms and Conditions CRC Handbook of Chemis... For almost a century this handbook has been updated annually, except for a few wartime years, and has served generations of engineers and scientists. Current daily price AU$209.09 ex-GST Terms and Conditions Perry's Chemical Engin... Was: $199.95 inc gst NOW: ...
A precise technique for studying coal liquefaction in a 200 cc stirred-batch-autoclave has been developed. Reaction pressures of up to 4000 psig and temperatures of up to 850/sup 0/F can be employed. The slurry temperature in the autoclave is controlled within 2/sup 0/F by raising or lowering the autoclave which is partially submerged in a sandbath; hence the name: Variable Submergence Temperature Control (VaSTeC). Heatup and cooldown are achieved in 5 and 2 minutes, respectively. A mini-scale vacuum distillation procedure was developed for measurement of 1000/sup 0/F-distillate with a repeatability of 0.3%. About 99% material balance is routinely obtained in the autoclave runs. The following yield repeatabilities have been demonstrated (MAF coal basis):H/sub 2/ cons. (0.1%), C/sub 1/ to C/sub 3/ gas (0.3%), C/sub 4/-1000/sup 0/F distillate (2.4%), and unconverted carbon (0.5%). The autoclave can simulate the yield slate of ...
1986-04-01
Recovery and reuse of spent acetone via a mobile solvent recovery unit
Energy Technology Data Exchange (ETDEWEB)
The Monsanto Chemical Company operates a plastics and resins plant located in Addyston, Ohio. The process equipment requires routine rinsing with technical grade acetone between batches. Due to the volumes of spent acetone generated and the associated RCRA hazardous waste regulations, the plant sought to recycle and reuse the acetone to reduce the purchase cost of virgin acetone and the cost of spent acetone disposal. One of the first options explored was package unit distillation units. The cost of these units was in the $20--$30,000 range in 1989 dollars. Even though the cost of a package unit was not deemed unreasonable, there were additional costs and concerns that led to elimination of this option. The unit would have required additional manpower to operate and maintain, i.e., at least a fraction of an operator and mechanic. For plant safety reasons, it was desired to operate this package unit outside the production building, thus construction of an ...
1996-11-01
Wiley::Automotive Electricity: Electric Drive
... Another solution, hybrid vehicles, combine two sources of energy (electric and chemical), reducing the global consumption of fossil fuels. Fuel cell vehicles are also one of the most promising technologies for the future, with the capacity to use any fuel - hydrogen being the ideal fuel ecologically, but constrained by infrastructure and storage issues. This book explores all these different solutions for moving our vehicles from fossil ...
Waste management and degradability
Energy Technology Data Exchange (ETDEWEB)
Landscape visive pollution due to photo-biodegradable plastic bags is assessed in an ideal case, the most favorable to their use. The result is that mean permanent visive pollution is 100 times higher than established norms. Both photo and biodegradability of plastic bags in the real world are discussed. The conclusion is that photo-biodegradability does not solve the problem of landscape visive pollution due to plastic bags.
1987-01-01
Statistical mechanics and thermodynamics for tachyons
International Nuclear Information System (INIS)
Momentum- and speed-dependent Maxwell-Boltzmann equilibrium distributions have been derived for tachyons and compared with the corresponding relativistic distributions. This is followed by a calculation of the mean, most probable and r.m.s. speeds for both the relativistic and tachyonic distributions. The ideal gas of tachyons is discussed, including calculations of the internal energy and entropy. In each case a comparison is made with the corresponding bradyonic results. It is found that tachyons behave just like bradyons in the high-temperature limit, but have markedly different behaviour at low temperatures.
Producing Open Source Software How to Run a Successful Free Software Project
This comprehensive guide offers several tried and true steps to help you successfully manage the complex process of developing free software. Topics include project management, developer motivation, technical infrastructure to support collaboration, and project promotion. Producing Open Source Software is ideal for developers starting their own free software projects, or people who simply want to participate in the process.
2009-01-01
Potential U.S. contributions to in-reactor experiments for fast reactor surveillance systems
International Nuclear Information System (INIS)
It is maintained that special features of FFTF make it an ideal system to test sodium boiling detection techniques by acoustic/neutronic methods and to test the response of acoustic/neutronic sensors to vibrations. It is shown that accumulated research results indicate that such tests in FFTF are feasible, predictable, promising and safe. (author).
Energy Technology Data Exchange (ETDEWEB)
An inner-city development with pile foundations as well as the proximity to the river Neckar with a groundwater flow offered ideal conditions for this new building in Mannheim in order to heat and cool geothermally. Already with the planning phase, detailed numerical flow computations were necessary in order to prove the functionality of the energy concept.
2010-07-01
...Butley river and Ore estuary, Boyton Marshes attracts breeding wading birds in spring and ducks, geese and swans in winter. It's also ... During spring and autumn, it is an ideal place to see migrant wading birds, gulls and terns. Insh Marshes Insh ... Spring is also an excellent time to visit. Leighton Moss Leighton Moss is the largest reedbed in north-west England, and home ... When they leave in spring, wading birds take centre stage. Watch it all take place from our viewing centre and hide,...
...Butley river and Ore estuary, Boyton Marshes attracts breeding wading birds in spring and ducks, geese and swans in winter. It's also ...The spectacular cliffs at Fowlsheugh are packed with 130,000 breeding seabirds in the spring and summer, including guillemots, razorbills and kittiwakes. Freiston ...for its breeding avocets and terns, which can be seen throughout the spring and summer. Access is by boat only and the trip ... During spring and autumn, it is an ideal place to see migrant wading birds, gulls and terns. Leighton Moss Leighton ...
In-situ maintenance of low-Z limiters in reactors
Energy Technology Data Exchange (ETDEWEB)
In a reactor environment, the surface of a limiter or wall is primarily determined by the mechanism of erosion and deposition of surface material. It should be possible to use pellet injection to reduce net erosion to zero everywhere if low-Z materials are used for the surface. Erosion rates can, in general, be minimized by large area limiters and high plasma temperatures, which transmit power to the walls with less sputtering. Under ideal steady state conditions the wall surface is dominated by metallurgical effects in the wall.
1980-01-01
An idealized numerical simulation of mammatus-like clouds
British Library Electronic Table of Contents (United Kingdom)
A three-dimensional numerical simulation of mammatus-like clouds is presented. A portion of a cirrus outflow anvil cloud is simulated including cloud ice and snow microphysical representations. The simulated mammatus clouds appear in a cellular pattern and are compared with the few available previously published physical observations of mammatus. Copyright Copyright 2006 Royal Meteorological Society
2006-01-01
Energy Technology Data Exchange (ETDEWEB)
Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy in theoretical parameters used for calculations (Stark ...
2007-12-15
International Nuclear Information System (INIS)
Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy in theoretical parameters used for calculations (Stark ...
2007-12-01
The feasibility study of hot cell decontamination by the PFC spray method
International Nuclear Information System (INIS)
The characteristics of per-fluorocarbon compounds (PFC) are colorless, non-toxic, easily vaporized and nonflammable. Also, some of them are liquids of a high density, low surface tension, low latent heat and low specific heat. These particular chemical and physical properties of fluoro-organic compounds permit their use in very different fields such as electronics, medicine, tribology, nuclear and material science. The Sonatol process was developed under a contract with the DOE. The Sonatol process uses an ultrasonic agitation in a PFC solution that contains a fluorinated surfactant to remove radioactive particles from surfaces. Filtering the suspended particles allows the solutions to be reused indefinitely. They applied the Sonatol process to the decontamination of a heterogeneous legacy Pu-238 waste that exhibited an excessive hydrogen gas generation, which prevents a transportation of such a waste to a Waste Isolation Pilot Plant. Korea Atomic Energy Research Institute (KAERI) is ...
2008-01-01
Thermal cracking of black oil fuel in a mixture with shale
British Library Electronic Table of Contents (United Kingdom)
The results of studies performed for the development of a new process of the thermal cracking of tar as a suspension with ground Baltic oil shale in order to obtain motor fuel components are reported. The experimental results suggest undoubted advantages of the process over industrial thermal cracking because the deep degradation of tar (the yields of a gasoline fraction with bp to 180?C, middle distillates with bp of 180?360?C, and feedstock for catalytic cracking with bp of 360?520?C were ~12, 43?44, and ~15?16 wt % on an initial tar basis) was achieved upon the single-stage processing of the raw material under relatively mild conditions (5 MPa, 425?C, and a feed space velocity of 1.0 h?1). The resulting coke-like products and V and Ni contained in the raw material were deposited on the ...
2011-01-01
Ternary diagram plotting software design using the tie-line slope method
Energy Technology Data Exchange (ETDEWEB)
Ternary diagrams are commonly used to provide a graphic representation of equilibrium fluid phase behavior for systems as diverse as distillation columns and miscible gas floods of oil reservoirs. The phase envelope, and the position of the critical point on it, are important to enhanced oil recovery engineers who are involved with miscible gas flood design. In the past, phase equilibrium data were laboriously plotted on the ternary diagram and special graphic techniques were utilized to locate the critical point on the phase envelope. This work presents a computerized curve fitting method to generate the phase envelope from a given set of phase equilibrium data and then use the tie-line slopes to position the critical point. Experimental data are included and show excellent agreement with this new method.
1982-01-01
Ternary diagram plotting software design using the ''tie-line slope'' method
Energy Technology Data Exchange (ETDEWEB)
Ternary diagrams or pseudo ternary diagrams are commonly used to provide a graphical representation of equilibrium fluid phase behavior for systems as diverse as distillation columns and miscible gas floods of oil reservoirs. The phase envelope and the position of the critical point on it are important to enhanced oil recovery engineers who are involved with miscible gas flood design. In the past, phase equilibrium data were laboriously plotted on the pseudo ternary diagram and special graphical techniques were utilized to locate the critical point on the phase envelope. Presented in this article is a computerized curve fitting method to, firstly, generate the phase envelope from a given set of phase equilibrium data and then use the 'tie-line slopes' to position the critical point. Experimental data are included and show excellent agreement with this new method.
1983-01-01
Survival of-Escherichia coli-O157:H7 in Meat Product Brines Containing Antimicrobials
British Library Electronic Table of Contents (United Kingdom)
Abstract:- Brine solution injection of beef contaminated with-Escherichia coli-O157:H7 on its surface may lead to internalization of pathogen cells and/or cross-contamination of the brine, which when recirculated, may serve as a source of new product contamination. This study evaluated survival of-E. coli-O157:H7 in brines formulated without or with antimicrobials. The brines were formulated in sterile distilled water (simulating the composition of freshly prepared brines) or in a nonsterile 3% meat homogenate (simulating the composition of recirculating brines) at concentrations used to moisture-enhance meat to 110% of initial weight, as follows: sodium chloride (NaCl, 5.5%) + sodium tripolyphosphate (STP, 2.75%), NaCl + sodium pyrophosphate (2.75%), or NaCl + STP combined with potassium ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
Medicinal plants i.e. dried seeds of myristica argentea, myristica fragrans, coriandrum sativum and foeniculum vulgare were stored for 0 and 6 months, with and without gamma irradiation at 5 kGy. No detectable changes were seen in infrared and UV spectra, GLC chromatograms and refraction indices of steam distilled, essential oils from the irradiated medicinal plants. The same results were also obtained from irradiated samples stored for 6 months at ambient conditions. Storage for 6 months caused significant changes in the gas liquid chromatograms and UV spectra of all samples compared to non-stored samples. The moisture content of all samples packed in polyethylene bags seems to be constant after 6 months of storage. No measurable changes were found in the amount of essential oil content caused by irradiation.
1981-10-01
Solar distillation as an appropriate technology tool in Haiti
Energy Technology Data Exchange (ETDEWEB)
Source Philippe (on the island of La Govave, near Haiti) is described in terms of climatic, sociological, agricultural and technical background. Because of drought conditions, it became necessary to develop a solar still to provide the town with sufficient fresh water. The still, which has been in operation since 1969, is described in some detail as is the construction process. Brackish and sea water are used to produce more than 1250 liters of fresh water each day. A windmill is used to pump the brackish water from a well to an elevated storage tank; it flows by gravity to solar still basins where it is vaporized, then condensed on a sloping glass surface and collected. Benefits of the solar still to the town's economy and health are discussed. Cost of the project was $17,000. 10 references. (MJJ)
1980-06-01
Simulation and design of membrane plants with AspenPlus
Energy Technology Data Exchange (ETDEWEB)
In this paper the simulation of hybrid processes containing membrane units will be discussed. For this purpose a user-defined module for simulation and design of membrane processes was implemented into the simulation program AspenPlus. The advantages can be summarized as follows: - any combination of membrane processes with all other units already implemented in AspenPlus is possible, including internal recycle streams, - utilization of the physical property models and data bases of AspenPlus is possible, - cost and sensitivity analysis can be performed. These benefits are demonstrated in detail for a membrane vapor recovery unit for the treatment of tank farm off-gas, for a two-stage reverse osmosis plant for organic/-organic separations and for a combination of distillation and pervaporation for the separation of a dimethylcarbonate/methanol mixture. (orig.)
1996-10-01
Preparation and evaluation of a novel glass-ionomer cement with antibacterial functions
British Library Electronic Table of Contents (United Kingdom)
Objective.The objective of this study was to use the newly synthesized poly(quaternary ammonium salt) (PQAS)-containing polyacid to formulate the light-curable glass-ionomer cements and study the effect of the PQAS on the compressive strength and antibacterial activity of the formed cements.Materials and methods.The functional QAS and their constructed PQAS were synthesized, characterized and formulated into the experimental high-strength cements. Compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 degrees C for 24 h prior to testing. The effects of the substitute chain length, loading as well as gra...
2011-01-01
Novel reduced pressure-balance syringe for chromatographic analysis
British Library Electronic Table of Contents (United Kingdom)
When withdrawing a fluid sample (for additional chromatographic analyses) from an apparatus operated at a reduced pressure, a typical syringe proves to be ineffective (even if it is equipped with a gas tight plunger). It simply does not create enough pressure differential to remove a fluid sample from a reduced pressure environment. We encountered such a situation as part of efforts to extend the operation of the advanced distillation curve protocol to reduced pressures. The problem was solved by the development of a pressure balance syringe that allows reliable and precise sampling from an apparatus operating at sub-ambient pressures. This new device uses an external vacuum source to evacuate a syringe barrel, allowing a user to withdraw fluid samples from environments with pressures as l...
2010-01-01
Investigation of the removal efficiency of gasborne particles in a scrubber column
Energy Technology Data Exchange (ETDEWEB)
Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 ..mu..m; drops of diameter size 1.5 ..mu..m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water.
1983-01-01
Investigation of the removal efficiency of gasborne particles in a scrubber column
International Nuclear Information System (INIS)
Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 #mu#m; drops of diameter size 1.5 #mu#m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water. (orig.).
British Library Electronic Table of Contents (United Kingdom)
Natural rubber (NR) and its derivatives as renewable and biodegradable materials have attracted considerable attention because of the serious pollution problems caused by synthetic materials and a shortage of resources. A new semi-interpenetrating polymer network (semi-IPN) based on epoxidised natural rubber and polyvinyl alcohol containing maleic acid as a crosslinking reagent was synthesized and characterized by FTIR, XRD, SEM, swelling ratio in both distilled water and toluene, and mechanical properties. The curing time and dose of maleic acid were varied from 10 to 60min, and from 10 to 60% (w/w), respectively. An IR spectroscopic study indicated the presence of an ester linkage at 1730cm-1 in maleic acid crosslinked with PVA in semi-IPN films. In addition, the crystalline content of P...
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
To eliminate their classical brittleness and flexibility problems zein films were plasticized by incorporation of different phenolic acids (gallic acid (GA), p-hydroxy benzoic acid (HBA) or ferulic acids (FA)) or flavonoids (catechin (CAT), flavone (FLA) or quercetin (QU)). The use of GA, CAT, FA and HBA at 3 mg/cm2 eliminated the brittleness of films and gave highly flexible films showing elongations between 135% and 189%, while FLA and QU caused no considerable effect on film elongation. The films containing FA and HBA showed extreme swelling and lost their structural integrity when hydrated in distilled water. In contrast, CAT and GA containing films maintained their integrity following hydration. Most of the GA (up to 93%) and a considerable portion of CAT (up to 60%) in the films exis...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
An experimental and theoretical study of heat and mass transfer analogy and a comparison of that to a binary liquid mixture evaporation is presented. Common organic solvents, ethanol and n-heptane, were used to form an alcohol - hydrocarbon mixture. Studies were carried out in a horizontal rectangular channel having air flow velocities of 0.2 - 0.9 m/s. Heat transfer coefficients were measured with a copper plate resistor and mass transfer coefficients with a square pool. The heat and mass transfer analogy is presented for a system having two evaporating compounds with a fixed value of air flow and verified by measuring and comparing mass transfer coefficients for distilled water with air flow velocities of 0.2 - 0.9 m/s. An illustrative example of the use of the theory for industrial ventilation is presented. (author)
1995-12-31
British Library Electronic Table of Contents (United Kingdom)
Introduction The objective of this study was to investigate the in-vitro fluoride release from a glass ionomer orthodontic bonding system (Fuji I, GC Corporation, Tokyo, Japan) over a 2-month period and the in-vivo enamel fluoride uptake after 6 months. Methods Ten metal brackets were bonded with either glass ionomer or composite resin (Transbond XT, 3M Unitek, Monrovia, Calif; Light Cure), which served as controls, to recently extracted molars. The bonded teeth, cut at the level of their roots, were stored in distilled water that was renewed after every fluoride measurement at 1, 3, 7, 30, and 60 days. The in-vitro fluoride release was measured by using a fluoride ion-selective electrode, connected to an ion analyzer. Fifteen pairs of premolars were bonded with metal brackets with either ...
2010-01-01
International Nuclear Information System (INIS)
To sophisticate the nuclear fuel recycling processes, the transfer percentages for Pd, Mo, Te, and Sb should be determined. Each element solution containing NaNO_3 or HNO_3 was fed consistently into the thin film evaporator regulated in vac and at 50 deg C. The analyte percentages in the inside of the lid, in the condenser, and in the distillate were 10"-"1%/m"2, 10"-"3%/m"2, and 10"-"3% (DF = 10"5), respectively. The Mo percentage in the condenser was lower by a factor of 10 than those of other elements investigated. The NO_3"- percentages were nearly constant despite increasing HNO_3 concentrations, however, the ratios decreased with increasing NaNO_3 concentrations. (author)
2003-02-01
Evaluation of quality of alkylsalicylate additives with high content of active substance
Energy Technology Data Exchange (ETDEWEB)
This article describes the chemical preparation of petroleum additives of the MASK type from samples of concentrated alkylsalicylic acids. The obtained additives contain high contents of calcium alkylsalicylate and respective total alkalinities of 156, 131, and 130 mg KOH/g. Sodium alkylsalicylate concentrates, obtained in the form of an aqueous acetone solution, were converted to alkylsalicylic acids by interaction with hydrochloric acid. The solvent was removed from the upper and lower layers by distillation, and the resulting products were analyzed by liquid chromatography. Service tests were performed on a model formulation of the additive in M-11 oil in a Petter AV-1 test stand unit in comparison with commercial MASK additive. The results indicate that the model additive formulation gives approximately the same corrected piston fouling ratings as the commercial additive.
1984-09-01
Effect of gamma rays on grafting parameters and liquid retention property of cassava starch-g-PAN
International Nuclear Information System (INIS)
Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85"0C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to #gamma#-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel so that the extent of homo polymer could be reduced to be less than 1.6% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmations of graft copolymerization and saponification reactions were made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the same total dose on the extent of grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.
1992-10-20
Development of a pelleted waste form for high-level alumina wastes
Energy Technology Data Exchange (ETDEWEB)
A formulation to pelletize simulated high-level ICPP alumina waste calcine was developed. The pellets are formed on a 41-cm-diameter disc pelletizer using 5% bentonite, 2% metakaolin, and 5 wt % calcium hydroxide as a solid binder and a solution of 7M phosphoric acid and 4M nitric acid as a liquid binder. After drying and heat treatment at 800/sup 0/C for 2 hours, the average crush strength of the pellets is 3.9 MPa and the pellets have a leach resistance of 10/sup -3/ g/cm/sup 2//day, based on Soxhlet leaching for 48 h at 95/sup 0/C with distilled water.
1980-09-01
International Nuclear Information System (INIS)
Plant Assessment Technology (PAT) group, in association with Intelligent System (IS) Group and Engineering Services Department of Malaysian Institute for Nuclear Technology Research (MINT) has developed gamma scanning facilities for on-line investigation of industrial process columns and vessels. The technology, based on the principle of gamma-ray absorption, has been successfully applied for troubleshooting of a number of distillation columns and process vessels in petroleum refineries, gas processing plants and chemical plants in the country and the region. This paper outlines basic characteristics of the system and describes the inspection procedures, and in addition, case studies are also presented. The case studies are purposely chosen to illustrate the versatility of the technology, and furthermore to demonstrate the economic benefits which can be realised from the application of this technology. (author)
1998-10-30
Crude oil and finished fuel storage stability: An annotated review
Energy Technology Data Exchange (ETDEWEB)
A state-of-the-art review and assessment of storage effects on crude oil and product quality was undertaken through a literature search by computer accessing several data base sources. Pertinent citations from that literature search are tabulated for the years 1980 to the present. This 1990 revision supplements earlier reviews by Brinkman and others which covered stability publications through 1979 and an update in 1983 by Goetzinger and others that covered the period 1952--1982. For purposes of organization, citations are listed in the current revision chronologically starting with the earliest 1980 publications. The citations have also been divided according to primary subject matter. Consequently 11 sections appear including: alternate fuels, gasoline, distillate fuel, jet fuel, residual fuel, crude oil, biodegradation, analyses, reaction mechanisms, containment, and handling and storage. Each section contains a brief narrative followed by all the citations for ...
1991-01-01
Energy Technology Data Exchange (ETDEWEB)
Conversion of Idaho National Engineering and Environmental Laboratory radioactive sodium-bearing waste into a single solid waste form by evaporation was demonstrated in both flask-scale and pilot-scale agitated thin film evaporator tests. A sodium-bearing waste simulant was adjusted to represent an evaporator feed in which the acid from the distillate is concentrated, neutralized, and recycled back through the evaporator. The advantage to this flowsheet is that a single remote-handled transuranic waste form is produced in the evaporator bottoms without the generation of any low-level mixed secondary waste. However, use of a recycle flowsheet in sodium-bearing waste evaporation results in a 50% increase in remote-handled transuranic volume in comparison to a non-recycle flowsheet.
2004-01-01
Energy Technology Data Exchange (ETDEWEB)
We developed a surrogate mixture model to represent the physical properties of a coal-derived liquid fuel using only information obtained from a gas chromatography-mass spectrometry analysis of the fuel and a recently developed 'advanced distillation curve'. We then predicted the density, speed of sound, and viscosity of the fuel and compared them to limited experimental data. The surrogate contains five components (n-propylcyclohexane, trans-decalin, {alpha}-methyldecalin, bicyclohexane, and n-hexadecane), yet comparisons to limited experimental data demonstrate that the model is able to represent the density, sound speed, and viscosity to within 1, 4, and 5%, respectively. 102 refs., 2 figs., 5 tabs.
2008-09-15
Cavitation erosion of advanced ceramics in water
Energy Technology Data Exchange (ETDEWEB)
The performance of advanced ceramics under cavitation loading in distilled water was studied by using a laboratory test with vibration-induced cavitation following the pattern of the ASTM standard G32-92. The hardened and tempered martensitic steel 100Cr6 was used as a reference. The aim was to identify mechanisms and the effects of important microstructural parameters on damage of polished Al{sub 2}O{sub 3}, Al{sub 2}O{sub 3}-ZrO{sub 2}, ZrO{sub 2} and SiC ceramics. Results showed that surface damage of brittle ceramics was mainly dominated by intergranular fracture, followed by detachment of single grains or fragments of them. Both incubation time and erosion rate were affected by the amount of initial surface cavities, grain sizes and secondary phases at grain boundaries. (orig.)
2006-10-15
Application of zeolite-based catalyst to hydrocracking of coal-derived liquids
Energy Technology Data Exchange (ETDEWEB)
Y-zeolite supported catalysts were applied to the hydrocracking of coal-derived liquids. By the introduction of two-stage upgrading consisting of hydrotreating and hydrocracking, Wandoan coal-derived middle distillate was hydrocracked over Ni-Mo/Y-zeolite, producing a high gasoline fraction yield. Zeolite supported catalysts gave little hydrocracked compounds in the hydroprocessing of coal-derived heavy oils, even after hydrotreatment. The reaction inhibitors which seriously poison the active sites of zeolites were found to be small nitrogen-containing molecules. In the hydroprocessing of coal-derived heavy oils, zeolite supported catalysts were inferior to alumina supported catalysts. This is due to the high hydrocracking but low hydrogenation activity of zeolite supported catalysts. 22 refs., 5 figs., 11 tabs.
1990-06-01
A novel gamma scanning system for on-line diagnostic inspection of industrial process columns
International Nuclear Information System (INIS)
A computerised gamma scanning facilities for on-line investigation of industrial process columns and vessels has been developed by the Malaysian Nuclear Agency (Nuclear Malaysia). The technology, based on the principle of gamma-ray absorption, has been successfully applied for real-time troubleshooting, process investigation and predictive maintenance of a number of distillation columns and process vessels in petroleum refineries, gas processing plants and chemical plants in the country and the surrounding region. This paper outlines basic characteristics of the system and describes the inspection procedures, and in addition, presents a number of case studies. The case studies are purposely chosen to illustrate the versatility of the technology, and furthermore to demonstrate the economic benefits which can be realised from the application of this technology. (Author)
"On the Road" - Reflections on the Security of Vehicular Communication Systems
Vehicular communication (VC) systems have recently drawn the attention of industry, authorities, and academia. A consensus on the need to secure VC systems and protect the privacy of their users led to concerted efforts to design security architectures. Interestingly, the results different project contributed thus far bear extensive similarities in terms of objectives and mechanisms. As a result, this appears to be an auspicious time for setting the corner-stone of trustworthy VC systems. Nonetheless, there is a considerable distance to cover till their deployment. This paper ponders on the road ahead. First, it presents a distillation of the state of the art, covering the perceived threat model, security requirements, and basic secure VC system components. Then, it dissects predominant assumptions and design choices and considers alternatives. Under the prism of what is necessary to render secure VC systems practical, and given possible non-technical influences, ...
2009-01-01
Using light to bioactivate surfaces: A new way of creating oriented, active immunobiosensors
International Nuclear Information System (INIS)
Ultraviolet light can be used to immobilize biomolecules onto thiol reactive surfaces in order to, e.g., make biosensors. The mechanism involves light-induced formation of free, reactive thiol groups in disulphide containing molecules. This technology allows for the creation of arrays of biomolecules with a high degree of reproducibility, circumventing the need for often expensive nano/micro-dispensing technologies. The ultimate size of the immobilized spots is defined by the focal area of the UV beam. Light-induced immobilization has the added benefit that the immobilized molecules will be spatially oriented and covalently bound to the surface. In this paper, we demonstrate the utility of a sensor array created with the new sensor technology when integrated into a microfluidic system. Protein arrays made using light-induced immobilization showed successful antigen/antibody binding in a flow cell allowing the visualisation of real time binding and enzyme activity. This new technology ...
2007-12-15
Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultra-low frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon-Fedder-Mobarry (LFM) global, three-dimensional magnetohydrodynamic (MHD) simulations of the solar wind-magnetosphere interaction. These simulations are driven with synthetic solar wind input conditions, where idealized ULF dynamic pressure fluctuations are embedded in the upstream solar wind. In three of the simulations, a monochromatic, sinusoidal ULF oscillation is introduced into the solar wind dynamic pressure time series. In the fourth simulation, a continuum of ULF fluctuations over the 0-50 mHz frequency band is introduced into the solar wind dynamic pressure time series. In this numerical experiment, the idealized solar wind input conditions allow us to study only the effect of a fluctuating solar wind dynamic ...
2010-01-01
Photon dosimetry using plastic scintillators in pulsed radiation fields
Energy Technology Data Exchange (ETDEWEB)
Simulations and experiments have been carried out to explore using a plastic scintillator as a dosimetry probe in the vicinity of a pulsed bremsstrahlung source in the range 4 to 20 MeV. Taking advantage of the tissue-equivalent properties of this detector in conjunction with the use of a fast digital signal processor near real-time dosimetry was shown to be possible. The importance of accounting for a broad energy electron beam in bremsstrahlung production, and photon scattering and build-up, in correctly interpreting dosimetry results at long stand-off distances is highlighted by comparing real world experiments with ideal geometry simulations. Close agreement was found between absorbed energy calculations based upon spectroscopic techniques and calculations based upon signal integration, showing a ratio between 10 MeV absorbed dose to 12 MeV absorbed dose of 0.66 at a distance of 91.4 m from the accelerator. This is compared with an ...
2007-04-01
Energy Technology Data Exchange (ETDEWEB)
The influence of the velocity profile at the inlet boundary on the simulation of air velocity distribution inside an electrostatic precipitator is presented in this study. Measurements and simulations were performed in a duct and an electrostatic precipitator (ESP). A four-hole cobra probe was used for the measurement of velocity distribution. The flow simulation was performed by using the computational fluid dynamics (CFD) code FLUENT. Numerical calculations for the air flow were carried out by solving the Reynolds-averaged Navier-Stokes equations coupled with the realizable k-{epsilon} turbulence model equations. Simulations were performed with two different velocity profiles at the inlet boundary - one with a uniform (ideal) velocity profile and the other with a non-uniform (real) velocity profile to demonstrate the effect of velocity inlet boundary condition on the flow simulation results inside an ESP. The real velocity profile was obtained from the velocity ...
2009-01-15
Electrical characteristics of AlxGa1-xN Schottky diodes prepared by a two-step surface treatment
Near-ideal Schottky barrier contacts to n-type Al0.22Ga0.78N have been developed by a two-step surface treatment technique. Plasma etching of the AlxGa1-xN surface prior to Schottky metal deposition, combined with sequential chemical treatment of the etched surface, holds promise for developing high quality low-leakage Schottky contacts for low noise applications and for recessed gate high electron mobility transistors. In this work, the effect of postetch chemical treatment of the n-type Al0.22Ga0.78N surface on the performance of the Ni/Au based Schottky contact has been investigated. Three different types of chemical treatment: viz, reactive ion etching, reactive ion etching plus dipping in hot aqua regia, and reactive ion etching plus dipping in hot KOH, are studied. Detailed current-voltage studies of three different surface treated diodes and a comparison with as-deposited diodes reveal significant improvement in the diode characteristics. The latter surface ...
2004-09-01
Design of an onboard battery charger for an electric vehicle
Energy Technology Data Exchange (ETDEWEB)
This report describes the design of an on-board battery charger for an electric car. There are already various battery charger units on the market. However, these are not specifically designed for this application, and consequently do not provide an ideal solution. Because these products are not specific to one application, and instead opt to cover a variety of briefs, they are not ideal. They also tend to be heavier and more expensive than if the charger was built specifically for one purpose. The main design considerations were that the charger should be compact and lightweight. It was also specified that the design should be able to operate using either the single-phase or three-phase AC supply. Before the design process for the battery charger could commence, it was necessary for the author to get an appreciation of power electronics, since he had no previous experience in the subject. The author focused his attention on areas of the ...
2001-07-01
Conceptual fusion power monitor based on the "1"6O(n,p)"1"6N reaction
International Nuclear Information System (INIS)
The feasibility of developing a fusion power monitor based on a fluid activation detector is considered here. The activation fluid may be either a liquid or a gas and its composition can be selected from a number of candidate materials to provide desired activation and decay characterisitcs. Performance calculations indicate that ordinary water would be a nearly ideal activation fluid. The "1"6O(n,p)"1"6N reaction has a threshold at about 10 MeV and a cross section energy dependence giving it a predominant response for unmoderated D-T fusion neutrons. Adequate activation can be obtained at moderate flow rates for remote counting away from the high radiation area of the reactor. The 7.16 sec half-life of "1"6N is ideal for remote counting with subsequent decay in a small hold-up tank to eliminate activity build-up in the recycled water.
1981-07-01
Energy Technology Data Exchange (ETDEWEB)
Most of the organic electronic devices are nowadays fabricated under poor vacuum conditions. In this regard, there is only little knowledge about the impact of contamination of the metal electrode on the charge injection barrier in this kind of electronic devices. In our study we have performed X-ray and ultra violet photoemission spectroscopy (XPS, UPS) on interfaces between the organic semiconductor -sexithiophene and sputter cleaned (ideal) metals as well as contaminated (realistic) metals. As metal substrates we have used silver, gold, palladium, and platinum. These metals provide us a wide range of metal work functions from 4.2 eV for silver up to 5.5 eV for platinum. For all interfaces of -sexithiophene and contaminated metals we have observed a reduction of the interface dipole and the hole injection barrier. The charge injection barrier in all four cases is almost independent of the underlying metal (within an error of 0.2 eV) and the interface dipole ...
2007-07-01
Binary Pseudo-random Grating Standard for Calibration of Surface Profilometers
Energy Technology Data Exchange (ETDEWEB)
We suggest and describe the use of a binary pseudo-random (BPR) grating as a standard test surface for measurement of the modulation transfer function (MTF) of interferometric microscopes. Knowledge of the MTF of a microscope is absolutely necessary to convert the measured height distribution of a surface undergoing metrology into an accurate power spectral density (PSD) distribution. For an'ideal' microscope with an MTF function independent of spatial frequency out to the Nyquist frequency of the detector array with zero response at higher spatial frequencies, a BPR grating would produce a flat 1D PSD spectrum, independent of spatial frequency. For a'real' instrument, the MTF is found as the square root of the ratio of the PSD spectrum measured with the BPR grating to the'ideal,' spatial frequency independent, PSD spectrum. We present the results from a measurement of the MTF of MicromapTM-570 ...
2008-01-16
A novel photodiode made of hybrid organic/inorganic nanocomposite
International Nuclear Information System (INIS)
Novel hybrid organic/inorganic nanocomposites made of metal oxide and conjugated polymer nanocomposite and its application in bulk-heterojunction solar cells were studied. The composite was composed of different concentrations of strontium titanate (SrTiO_3) and polyaniline doped phosphoric acid. The optimum concentration of strontium titanate was found to be 0.2 v/v. An inorganic-organic photovoltaic device with a structure of Ag/Pani-H_3PO_4-SrTiO_3/Al has been fabricated. The ideality factor value of the diode was found to be 1.8. This n value of the diode implies a deviation from ideal junction behaviour. The barrier height #phi#_b value for the diode was found to be 0.56 eV. The Ag/Pani-H_3PO_4-SrTiO_3/Al diode shows a photovoltaic behaviour with a maximum open-circuit voltage V_o_c of 2.49 V, and short-circuit current I_s_c of 5.6 mA under light illumination #lambda# = 460 nm. The conversion efficiency was found to be 5.2%. It is ...
2009-08-07
Wet limestone FGD solids analysis by thermogravimetry
Energy Technology Data Exchange (ETDEWEB)
Wet limestone scrubbing is once again becoming a popular technology for removal of sulfur dioxide (SO{sub 2}) from power plant emissions. Critical to the operation of wet limestone flue gas desulfurization (FGD) systems is accurate chemical analysis of scrubber solids. The analytical technique of thermogravimetry is ideal for this application, as the instrument can give precise readings of the principal scrubber solids components, calcium sulfite/sulfate hemihydrate, calcium sulfate dihydrate (gypsum), and unused calcium carbonate. The data provides plant chemists, engineers, and operators with information needed to fine-tune scrubber operation and detect process upsets. (orig.)
2004-07-01
Using PCAR to study Cu/Co bilayers
International Nuclear Information System (INIS)
For spintronic applications it is important to establish how efficiently spins can be injected from a magnetic material into a non-magnetic material and the distance over which those spins survive. It is thought that spin polarised transport current can be determined by using the suppression of the Andreev reflection between a superconductor and the spin polarised material (Science 282 (1998) 85). Cu/Co bilayers are potentially an ideal test system for such study. In this paper we assess the feasibility of using point contact Andreev reflection spectroscopy to address this problem using a superconducting niobium tip at 4.2 K.
2004-05-01
The challenge of implementing an IRP process in Asia: The case of Hainan Province, China
Energy Technology Data Exchange (ETDEWEB)
Developing a modern electric power sector is necessary for economic growth and development to proceed. Institutions to implement an IRP (integrated resource planning) process do not exist in many countries. Hainan`s economy is growing rapidly with a concomitant increase in electricity demand. This is an ideal time in Hainan`s development to implement an IRP process. The challenge is for Hainan to develop institutions and incentive mechanisms for HEPCO (Hainan Electric Power Co.) to adopt cost-based pricing, run DSM programs, construct renewable generating plants, etc. One proposal is to great a Hainan government-wide IRP committee.
1994-12-31
Technetium complexes as potential brain imaging agents
International Nuclear Information System (INIS)
Single photon tomography using lipophilic tracers provides tomographic representations of regional blood flow. To penetrate a healthy blood-brain barrier requires that radiotracers either are fat-soluble or have an affinity for one of the selective blood-brain barrier transport systems. In recent years there has been an increasing interest to explore the ideal physical characteristics of "9"9"mTc for diagnostic problems of brain diseases. The development of radiopharmaceuticals for brain imaging including the intensively studied "9"9"mTc-propyleneamineoxime derivatives is discussed. (author).
THE DEVIL AND CUSTOMER RELATIONSHIP MANAGEMENT
British Library Electronic Table of Contents (United Kingdom)
The paper takes as its starting point the diffusion of ICT applications associated with so-called 'customer relationship management' (CRM). CRM encourages organisations to shift their understanding of customers from an episodic and transaction-based perspective to one that emphasises continuous 'relationship management'. CRM applications thus promise to deliver more, real-time accurate information about consumer habits and behaviours therefore allowing organisations to maximise their extraction of business value. This paper explores the ways in which such inscriptive technologies are not merely referential but also constitutive of contemporary re-presentations and ideals of the consuming subject. Focusing on what we might call the 'digital doubles' of customer relationship management the a...
2010-01-01
Symmetrizers and antisymmetrizers for the BMW algebra
Let $n\\in\\mathds{N}$ and $B_n(r,q)$ be the generic Birman-Murakami-Wenzl algebra with respect to indeterminants $r$ and $q$. It is known that $B_n(r,q)$ has two distinct linear representations generated by two central elements of $B_n(r,q)$ called the symmetrizer and antisymmetrizer of $B_n(r,q)$. These generate for $n\\geq 3$ the only one dimensional one sided ideals of $B_n(r,q)$ and generalize the corresponding notion for Hecke algebras of type $A$. In this paper the coefficients of these elements with respect to the graphical basis of $B_n(r,q)$ are determined explicitly.
2011-01-01
Surface roughening of superalloys by high pressure pure waterjet
Energy Technology Data Exchange (ETDEWEB)
A high pressure waterjet has been used to study the surface roughening of superalloys as preparation for thermal spraying. Designed experiments for Mar-M 509 and Rene 80 were carried out for the effects of jet pressure and mass of water delivered per unit area. Comparisons were made of several superalloys in terms of erosion, surface roughness and topology. The mechanism of jet erosion of Rene 80 was studied in relation to its metallurgical microstructure. An MCrAlY coating by shrouded plasma spray was made over a waterjet prepared surface with excellent bonding and having an ideally clean interface.
1995-12-31
Solenoid transport for heavy ion fusion
Energy Technology Data Exchange (ETDEWEB)
Solenoid transport of high current, heavy ion beams is considered for several stages of a heavy ion fusion driver. In general this option is more efficient than magnetic quadrupole transport at sufficiently low kinetic energy and/or large e/m, and for this reason it has been employed in electron induction linacs. Ideally an ion beam would be transported in a state of Brillouin flow, i.e. cold in the transverse plane and spinning at one half the cyclotron frequency. The design of appropriate solenoids and the equilibrium and stability of transported ion beams are discussed. An outline of application to a fusion driver is also presented.
2004-06-15
Simple model for characterizing the electrical resistivity in A-15 superconductors
A discussion of some of the difficulties with previous analyses of the resistivity of A-15 compounds is given. Precise high-temperature data on ..cap alpha..-particle- and electron-damaged Nb/sub 3/Ge and Nb/sub 3/Sn samples with different defect concentrations are presented here and analyzed in a simple way with use of a phenomenological model based on the idea that the ideal resistivity must approach some limiting value in the regime where the mean free path becomes comparable to the interatomic spacing.
1977-04-04
Radio-Frequency Beam Conditioner for Fast-Wave Free-Electron Generators of Coherent Radiation
Energy Technology Data Exchange (ETDEWEB)
A method for conditioning electron beams is proposed, making use of the TM{sub 210} mode of microwave cavities, to reduce the axial velocity spread within the beam, in order to enhance gain in resonant electron beam devices, such as the free-electron laser (FEL). Effectively, a conditioner removes the restriction on beam emittance. The conditioner is analyzed using a simple model for beam transport and ideal RF cavities. Analysis of an FEL is employed to evaluate performance with reduced axial velocity spread. Examples of FELs are presented showing the distinct advantage of conditioning.
1991-07-01
Phonon-mediated entanglement for trapped ion quantum computing
Energy Technology Data Exchange (ETDEWEB)
Trapped ions are a near ideal system to study quantum information processing due to the high degree of control over the ion's external confinement and internal degrees of freedom. We demonstrate the key steps necessary for trapped ion quantum computing and focus on phonon-mediated entangling gates. We highlight several key algorithms implemented over the last decade with these gates and give a detailed description of Grover's quantum database search implemented with two trapped ion qubits.
2010-03-15
Energy Technology Data Exchange (ETDEWEB)
A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO{sub 2}) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO{sub 2} were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.
2009-06-15
International Nuclear Information System (INIS)
A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO_2) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO_2 were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.
2009-06-01
Long-term monitoring of microleakage of dental cements by radiochemical diffusion
International Nuclear Information System (INIS)
Radioactive "1"4C sucrose was found to be an ideal marker for microleakage because it did not penetrate tooth tissue, dental cement, or mounting resin. The main finding is that the adhesive cements--the glass-ionomer and polycarboxylate--are significantly more effective at preventing microleakage than are the traditional phosphate cements--silicate and zinc phosphate. The differences can be as high as two orders of magnitude. The adhesive cements provide almost perfect and reliable seals. By contrast, the nonadhesive cements are erratic sealants with most of the restorations leaking.
Energy Technology Data Exchange (ETDEWEB)
This article gives a survey of the history, properties and applications of 'Kevlar' aramide fibers. For example, the 'Kevlar' para-aramide fiber is used in compound materials in ship-, aircraft- and vehicle construction. 'Kevlar' is used as a replacement for asbestos, for example in brakes, clutches and seals or as rubber reinforcement (tyres, conveyor belts, hoses). The aramide fibers also offer manufacturers of ropes, hawsers and cables a near ideal range of properties. (MM).
1988-12-01
International cooperation - Information Centre - Research & Innovation - European Commission
... Removal of this layer facilitates the unreeling of cocoons into long strands of silk comparable to those derived from the domesticated mulberry silkworm (Bombyx mori, B. mori). The research was funded in part by the SABIP ('Silks as biomimetic ideals for polymers) project, which has clinched a European Research Council (ERC) grant worth almost EUR 2.3 million under the EU's Seventh Framework Programme (FP7). Presented in the journal Biomacromolecules, the findings could lead to the development of new silk industries in ...
Integrated disease management of ascochyta blight in pulse crops
British Library Electronic Table of Contents (United Kingdom)
Ascochyta blight causes significant yield loss in pulse crops worldwide. Integrated disease management is essential to take advantage of cultivars with partial resistance to this disease. The most effective practices, established by decades of research, use a combination of disease-free seed, destruction or avoidance of inoculum sources, manipulation of sowing dates, seed and foliar fungicides, and cultivars with improved resistance. An understanding of the pathosystems and the inter-relationship between host, pathogen and the environment is essential to be able to make correct decisions for disease control without compromising the agronomic or economic ideal. For individual pathosystems, some components of the integrated management principles may need to be given greater consideration tha...
2007-01-01
Innovation in Scholarly Communication Vision and Projects from High-Energy Physics
Having always been at the forefront of information management and open access, High-Energy Physics (HEP) proves to be an ideal test-bed for innovations in scholarly communication including new information and communication technologies. Three selected topics of scholarly communication in High-Energy Physics are presented here: A new open access business model, SCOAP3, a world-wide sponsoring consortium for peer-reviewed HEP literature; the design, development and deployment of an e-infrastructure for information management; and the emerging debate on long-term preservation, re-use and (open) access to HEP data.
2008-01-01
HVDC cable design logic for digital computers
Energy Technology Data Exchange (ETDEWEB)
The design of High-Voltage, Direct-Current transmission cables insulated with oil-impregnated cellulose paper is constrained by the maximum temperature and the maximum steady-state and transient stresses (voltage gradients) that the cable insulation can reliably withstand over the desired operating lifetime. Because the electrical stresses in the insulation are related in a very complex fashion to temperature, applied voltage and cable geometry, iterative techniques are required to compute the values of these stresses. Digital computers are ideally suited for these iterative techniques. This paper presents the principal equations and logic needed to develop suitable computer programs.
1992-10-01
Free relations for matrix invariants in the modular case
British Library Electronic Table of Contents (United Kingdom)
A classical linear group GJ between the graded ring S= d=0^~Sd, where Sd is the character group of the symmetric group Sd, and the inverse limit J with respect to n of rings of symmetric polynomials in n variables. As a consequence, we complete the description of relations between generators for O(n)-invariants as well as the description of relations for invariants of mixed representations of quivers. We also obtain an independent proof of the result that the ideal of free relations for GL(n)-invariants is zero, which was proved by Donkin in [S. Donkin, Invariant functions on matrices, Math. Proc. Cambridge Philos. Soc. 113 (1993) 23-43].
2012-01-01
Energy Technology Data Exchange (ETDEWEB)
In an ideal system the surface of the dish is perfectly parabolic (no contour flaws are present), and the sun rays fall on the dish surface parallel to the focal axis (no sun tracking flaws are present). These two conditions are not realizable in practice; in this case, the parabolic dish system is called real system. In this paper a procedure for analysing the flux distribution on the receiver internal surfaces is presented for a cavity receiver with a real parabolic dish collector. First, the theoretical principles are discussed. Then the effect of the inaccuracy in the collector and in the sun tracking on the insolation pattern is described using an example.
1987-06-01
Determination of eigenvalues of real symmetric para-p diagonal matrices
International Nuclear Information System (INIS)
A methods is presented for an accurate numerical determination of eigenvalues of real symmetric para-p diagonal matrices. The method takes advantage of the band structure to break up the matrix into p x p blocks and performing algebraic operations including inversions on these blocks only, no matter what the size of the matrix is. The eigenvalues are determined independently one at a time. Thus any error in the determination of one eigenvalue does not affect the other eigenvalues. The method is ideally suited for the Schroedinger eigenvalue problem of the anharmonic potentials. (author).
Detailed kinetic modeling of autoignition chemistry
Energy Technology Data Exchange (ETDEWEB)
The development of detailed chemical kinetic reaction mechanisms for analysis of autoignition and knocking of hydrocarbon fuels is described. In particular, kinetic processes of concern for the oxidation of complex hydrocarbon fuel molecules are emphasized. The wide ranges of temperature and pressure which are encountered by end gases in automobile engine combustion chambers result in extreme demands on reaction mechanisms which are intended to describe knocking conditions and predict rates of combustion and ignition. The reactions and chemical species which are most important in each temperature and pressure regime are discussed, and the validation of these reaction mechanisms through comparison with idealized experimental results is described. 53 refs., 8 figs., 5 tabs.
1987-07-22
Energy Technology Data Exchange (ETDEWEB)
The effect of the electric field on an exciton confined in a pair of vertically coupled quantum dots is studied. We use a single-band approximation and a parabolic model potential. As a result of these idealizations, we obtain a numerically solvable model, which is used to describe the influence of the electron-hole interaction on the Stark effect for the lowest-energy photoluminescence lines. We show that for intermediate tunnel coupling between the dots this interaction leads to an anomalous Stark effect with an essential deviation of the recombination energy from the usual quadratic dependence on the electric field.
2005-04-15
Calculations of the self-amplified spontaneous emission performance of a free-electron laser.
Energy Technology Data Exchange (ETDEWEB)
The linear integral equation based computer code (RON: Roger Oleg Nikolai), which was recently developed at Argonne National Laboratory, was used to calculate the self-amplified spontaneous emission (SASE) performance of the free-electron laser (FEL) being built at Argonne. Signal growth calculations under different conditions are used for estimating tolerances of actual design parameters. The radiation characteristics are discussed, and calculations using an ideal undulator magnetic field and a real measured magnetic field will be compared and discussed.
1999-04-20
Beginning PHP, Apache, MySQL web development
An ideal introduction to the entire process of setting up a Web site using PHP (a scripting language), MySQL (a database management system), and Apache (a Web server)* Programmers will be up and running in no time, whether they're using Linux or Windows servers* Shows readers step by step how to create several Web sites that share common themes, enabling readers to use these examples in real-world projects* Invaluable reading for even the experienced programmer whose current site has outgrown the traditional static structure and who is looking for a way to upgrade to a more efficient, user-f
2004-01-01
Automatic Control via Thermostats of a Hyperbolic Stefan Problem with Memory
A hyperbolic Stefan problem based on the linearized Gurtin-Pipkin heat conduction law is considered. The temperature and free boundary are controlled by a thermostat acting on the boundary. This feedback control is based on temperature measurements performed by real thermal sensors located within the domain containing the two-phase system and/or at its boundary. Three different types of thermostats are analyzed: simple switch, relay switch, and a Preisach hysteresis operator. The resulting models lead to integrodifferential hyperbolic Stefan problems with nonlinear and nonlocal boundary conditions. Existence results are proved in all the cases. Uniqueness is also shown, except in the situation corresponding to the ideal switch.
1999-03-15
Anesthesia Technique and Outcomes of Endovascular Aneurysm Repair
British Library Electronic Table of Contents (United Kingdom)
Anesthetic techniques vary widely in the endovascular repair of abdominal aortic aneurysms (EVAR). Previous studies have demonstrated the feasibility of using local anesthesia. However, the ideal anesthetic technique has not been determined. This study examines whether anesthesic technique influences the outcomes of EVAR. Data regarding demographics, risk factors, procedural characteristics, recovery characteristics, treatment complications, acute ( 0.05, ANOVA). From these results we concluded that EVAR with local anesthesia is a safe and efficacious method that may reduce recovery times and postoperative medical morbidity compared to use of genera1 or spinal/epidural anesthesia.
2005-01-01
A comparison of the performance of two direct injection diesel engines from a second law perspective
Energy Technology Data Exchange (ETDEWEB)
This work reviews the differences in fuel economy between two direct injection diesel engine versions through the use of a First Law energy balance and a Second Law availability balance. Both experimental data and simulated results are used in the analysis. The use of an engine simulation allowed the important processes in each engine to be analyzed and a Second Law effectiveness calculated. The availability balances and effectiveness values are used to determine the effect of major engine components on the fuel economy. A comparison is also made with an ideal engine with selected perfect or reversible processes.
1989-01-01
Molar excess volumes of liquid hydrogen and neon mixtures from path integral simulation
Energy Technology Data Exchange (ETDEWEB)
Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne{endash}H{sub 2} mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne{endash}H{sub 2} potentials of Lennard{endash}Jones (LJ) type show that excess volumes are very sensitive to the ...
1999-07-01
Molar excess volumes of liquid hydrogen and neon mixtures from path integral simulation
International Nuclear Information System (INIS)
Volumetric properties of liquid mixtures of neon and hydrogen have been calculated using path integral hybrid Monte Carlo simulations. Realistic potentials have been used for the three interactions involved. Molar volumes and excess volumes of these mixtures have been evaluated for various compositions at 29 and 31.14 K, and 30 atm. Significant quantum effects are observed in molar volumes. Quantum simulations agree well with experimental molar volumes. Calculated excess volumes agree qualitatively with experimental values. However, contrary to the existing understanding that large positive deviations from ideal mixtures are caused due to quantum effects in Ne - H_2 mixtures, both classical as well as quantum simulations predict the large positive deviations from ideal mixtures. Further investigations using two other Ne - H_2 potentials of Lennard - Jones (LJ) type show that excess volumes are very sensitive to the cross-interaction potential. ...
1999-07-01
Evaluation of western and eastern shale oil residua as asphalt pavement recycling agents
Energy Technology Data Exchange (ETDEWEB)
The objective of this investigation was to perform a preliminary evaluation of the utility of residual materials prepared from Green River Formation (western) and New Albany Shale (eastern) shale oils as recycling agents for aged asphalt pavement. Four petroleum asphalts were first aged by a thin-film accelerated-aging test, which simulates long service life of asphalt in pavement. The aged asphalts were mixed (recycled) with Green River Formation shale oil distillation residua to restore the original viscosities. Separately, for comparison, a commercial recycling agent was used to recycle the aged asphalts under the same circumstances. The recycled asphalts were reaged and the properties of both binder and asphalt-aggregate mixtures studied. Originally, the same study was intended for an eastern shale residua. However, the eastern shale oil distillation residua with the required flash point specification also had the properties of a viscosity ...
1990-03-01
The efficiency of basic, direct and reactive dye removal from water by narrow-leaved cattail (NLC) powder treated with distilled water (DW-NLC), 37% formaldehyde+0.2 N sulfuric acid (FH-NLC), or 0.1 N sodium hydroxide (NaOH-NLC) at various pH levels (3, 5, 7, and 9) was tested. Desorption of the adsorbed dyes was also investigated. The type of NLC treatment and pH of the dye solution had little effect on removal of basic dyes, and efficiencies ranged from 97% to 99% over the range of pH used. Over a wide range of pH levels, all types of treated cattail powder had negative charges and probably attracted the basic dyes possessing positive charges. Efficiency of removal by the three NLC treatments ranged from 37% to 42% for direct dyes and from 22% to 54% for direct dyes at pH 7. The pH of the dye solution had substantial effects on the efficiency of removal in direct and reactive dyes. Dye removal was highest at pH 3, with 99% for a direct dye (Sirius Red Violet RL) ...
2004-09-01
Energy Technology Data Exchange (ETDEWEB)
Corrosion characteristics of Al and Cu thin films have been studied in cyclic fog tests using tap water fog and fog created with 0.1% NaCl solution in tap water. Likewise, their corrosion features have been analyzed in continuous immersion testing in the laboratory in distilled water, tap water, in 0.1% NaCl and 3.5% NaCl solutions in distilled water. The corrosion potentials and the corrosion currents of these thin films change and reach steady state values after some time. However, steady state is not realized in 3.5% NaCl solutions. The corrosion current density data have been used to calculate lifetime of 1 {mu}m thick thin films of Al and Cu in the various tests, and assuming that the fog test data would hold under normal exposure conditions, life spans for these thin film sensor elements in actual exterior exposure have also been calculated. According to estimates, an Al-TF of about 1 {mu}m would last about 9 months in exterior exposure ...
1998-12-31
An overview of AECL's participation in the Korean Wolsung Tritium Removal Facility Project (WTRF)
International Nuclear Information System (INIS)
Full text: In heavy-water-moderated power reactors, tritium is primarily produced by neutron capture in deuterium nuclei in the moderator and coolant. For CANDU 6 reactors, the estimated steady-state values are #approx# 3 TBq#centre dot#kg"-"1 D_2O in the moderator and #approx# 74 GBq#centre dot#kg"-"1 D_2O in the coolant. Tritium removal is one option available to reactor operators for use in their heavy water and tritium management strategies. The WTRF is designed to remove tritium from tritiated heavy water in each of the four CANDU units at the Wolsung Site, to immobilize the tritium and to store it on site. The detritiation process is based on three steps: the first one (front-end) involves the transfer of tritium from heavy water to deuterium gas; the second one (enrichment) concentrates the tritium in a cryogenic distillation system to produce essentially pure D_2 and T_2 streams; and in the third step the tritium is packaged for long-term storage. The WTRF ...
2007-11-07
Advanced coal liquefaction research. Quarterly technical progress report, January 1-March 31, 1983
Energy Technology Data Exchange (ETDEWEB)
This report describes progress on the Advanced Coal Liquefaction project by the Gulf Research and Development Company's Merriam Laboratory during the months of January through March 1983. The liquefaction behavior of Illinois No. 6 coal beneficiated in various ways was studied in both single-stage recycle (SRC II) and short contact time (SCT) modes of operation. The distillate yield increased as the iron level in the feed slurry increased in both modes of operation. In the SCT mode, the conversion increased at greater depths of cleaning. In the SRC II mode, the distillate yield and conversion were much higher with deep cleaning and add-back of pyrite than with conventional cleaning. Pyrite addition resulted in a significant increase in short contact time conversion of subbituminous Belle Ayr coal in both high and low quality solvents. Solvent quality itself, however, had little effect on conversion. With Loveridge coal, the hydrocarbon ...
1983-12-01
White oils for high voltage cables
Energy Technology Data Exchange (ETDEWEB)
''S-220'' white oil is used currently to impregnate and fill high voltage cables for 110-500 kilovolts; it has high electrical characteristics and meets production and use standards. High pressure and cooling problems, however, require filling cables with lower viscosity oils, while insulation needs still demand high viscosity. The authors developed a new white oil similar to S-220 using a neutral oil made in producing sulfonate additives. The process involved vacuum distillation, low-temperature paraffination, sulfation with oleum, neutralizing with ammonium hydroxide and simultaneous extraction of sulfo-salts and contact purification. The lowest content of aromatic hydrocarbons was sought. Dielectric qualities varied with viscosity. Satisfactory thermooxidational capability was found at 50/sup 0/C with an oil of no less than 50 mm/sup 2//sec viscosity. The final white oil had no more than 2% aromatic hydrocarbons, thus assuring ...
1982-10-01
Energy Technology Data Exchange (ETDEWEB)
This document demonstrates the commercial status of the process units to be used in the Tri-State Synfuels Project at Henderson, Kentucky. The basic design philosophy as established in October, 1979, was to use the commercial SASOL II/III plants as a basis. This was changed in January 1982 to a plant configuration to produce gasoline via a methanol and methanol to gasoline process. To accomplish this change the Synthol, Oil workup and Chemical Workup Units were eliminated and replaced by Methanol Synthesis and Methanol to Gasoline Units. Certain other changes to optimize the Lurgi liquids processing eliminated the Tar Distillation and Naphtha Hydrotreater Units which were replaced by the Partial Oxidation Unit. The coals to be gasified are moderately caking which necessitates the installation of stirring mechanism in the Lurgi Dry Bottom gasifier. This work is in the demonstration phase. Process licenses either have been obtained or must be obtained for a number of ...
1982-06-01
This document demonstrates the commercial status of the process units to be used in the Tri-State Synfuels Project at Henderson, Kentucky. The basic design philosophy as established in October, 1979, was to use the commercial SASOL II/III plants as a basis. This was changed in January 1982 to a plant configuration to produce gasoline via a methanol and methanol to gasoline process. To accomplish this change the Synthol, Oil workup and Chemical Workup Units were eliminated and replaced by Methanol Synthesis and Methanol to Gasoline Units. Certain other changes to optimize the Lurgi liquids processing eliminated the Tar Distillation and Naphtha Hydrotreater Units which were replaced by the Partial Oxidation Unit. The coals to be gasified are moderately caking which necessitates the installation of stirring mechanism in the Lurgi Dry Bottom gasifier. This work is in the demonstration phase. Process licenses either have been obtained or must be obtained for a number of ...
1982-06-01
Energy Technology Data Exchange (ETDEWEB)
This paper deals with the energy required to separate ethanol from an aqueous solution in a distillation column containing a solid phase. The solid phases evaluated consisted of either an amylatious (ground corn) or a cellulose (sugar cane bagasse) absorber whit particle sizes smaller than 4 mm. The water-retention capacity of each solid phase was measured by passing vapors or ethanol-water mixtures through the solid phase. When starting with initial concentrations bellow the azeotropic point, ethanol concentrations up to 99,5% (on corn) and 97,2% (on sugar cane) were achieved. The water content was evaluated potentiometrically (Karl`Fischer). Regarding the 2-4 mm ground corn solid phase column, the energy consumed was estimated to be reduced by 15,6% and 60% (by weight) ethanol-water mixture respectively. (author) 11 refs., 2 figs., 2 tabs
1987-12-31
Separating bitumens using dialysis
Energy Technology Data Exchange (ETDEWEB)
The separation of bitumens (B) and natural asphalts using a dialysis (D) method is studied. A moderately vulcanized latex of natural rubber, which was subjected to extraction by cold n-hexane prior to use, was used as the material of the membrane for dialysis. With dialysis of bitumen samples dispersed in a small quantity of n-alkane in a Soxhlet apparatus three fractions were acquired: a dialyzate, an undialyzable fraction and asphaltenes (the residue). N-pentane, n-hexane and n-heptane were used as the solvents for dialysis. Samples of oxidized road bitumen, grade AOSI 85/25, bitumens from the process of propane deasphaltization, natural asphalts from Trinidad and Albania and A80 grade bitumens from the oil distillation process were isolated using the dialysis method. The reproducability of the output of the fractions with varying suspensions and productivity of the dialysis, the dependence of the output on the length of the dialysis, the dependence of the output ...
1983-01-01
Energy Technology Data Exchange (ETDEWEB)
When thorium was biosorbed by biomass of Rhizopus arrhizus or Aspergillus niger it could be removed by treatment using carbonate solutions, but not by phosphates or distilled water. Desorption was rapid, reaching completion in 15 and 30 min respectively. Desorption efficiency was independent of the desorbent concentration above 0.05 mol dm[sup -3] but was strongly dependent on the biomass concentration, decreasing as the biomass concentration increased for both species. Biomass from both species could be regenerated by desorption using sodium carbonate solutions and reused for biosorption. In both species, the efficiency of biosorption and desorption fell as the number of exposures increased although there was an initial rise in desorption efficiency for R. arrhizus. Biosorption and desorption efficiencies of A. niger biomass showed the steeper decline but both were severely reduced in R. arrhizus after five treatments. There was also a significant loss of biomass ...
1992-01-01
Preparation of polyester/gypsum/composite using gamma radiation, and its radiation stability
Energy Technology Data Exchange (ETDEWEB)
Composites based on pure gypsum and polyester-styrene resin have been prepared using various doses of gamma radiation. Some physical properties of the prepared composites and the influence of irradiation dose on it have been studied as: compression strength, hardness, thermal decomposition temperature in nitrogen or oxygen, and the change in weight in aqueous solutions with different pH values. The glass transition temperature of the pure polymer and the composites increases with increasing the irradiation dose up to a plateau, and the glass transition temperature of the pure polymer is lower than that of the composites. The irradiation dose does not seem to affect the decomposition temperature of the pure polymer or the composites significantly and the decomposition temperature in presence of nitrogen is higher than that in presence of oxygen. Increasing the irradiation dose leads to an enhancement of the compression strength of the pure polymer and the prepared composites; the ...
2005-06-01
Preliminary assessment of future refining impacts of the Clean Air Act Amendments of 1990
Energy Technology Data Exchange (ETDEWEB)
A preliminary assessment of the future refining impacts of the Clean Air Act Amendments of 1990 has been performed with the Navy Mobility Fuels Forecasting Systems. The assessment suggests that gasoline reformulation costs in domestic coastal and near-coastal refining regions in the year 2000 could be 3.5 to 5.6 cents per gallon (in terms of 1989 currency). For heating value equivalent to one gallon of conventional gasoline, the regional total added costs (including reformulation costs) for reformulated gasoline could be 5.9 to 8.0 cents. In blending reformulated gasolines, the reduction of butane for lower Reid vapor pressure and the reduction of reformate for lower aromatics are generally compensated by increased percentages of alkylate and/or straight run naphthas. Relatively larger refinery process capacity additions are required for butane isomerization, alkylation, aromatics recovery, and distillate hydrotreating. 21 refs., 3 figs., 18 tabs.
1991-09-01
Pot-type catalyst carrier and manufacturing method
Energy Technology Data Exchange (ETDEWEB)
This invention relates with a pot-type catalyst carrier which excels as a catalyst carrier when such heavy oils as ordinary pressure distillation residue, oil sand oil, and shale oil are decomposed or treated by hydrogenation. The conventional pot-type carrier is produced by dropping a small drop of a slurry (containing a catalyst component) onto a particle bed and drying it. But the demerit is a large particle size and less catalyst activity or strength. In this invention, a mixture of such carrier components as allophane, red mud, bauxite and latellite, etc.. 60 - 80 weight parts. and a binder 20 - 40 weight parts is added with water to form a slurry of 10 - 30 weight% solid concentration. Slurry is wet-crushed to make the average particle size 0.6 - 2.0 micron, then spray-dried and burned to obtain a pot-type catalyst carrier with average particle size 30 - 200 micron and abrasion index below 10. This catalyst showed high yield of kerosene and light oil in the ...
1988-02-25
On-line analysis of chemical composition using an FT-Raman spectrometer in the near-ir
Newly commercialized Fourier transform Raman spectroscopic instrumentation provides a simpler alternative for vibrational spectroscopic analysis. Instrument vendors currently design for laboratory use, but there are many potential process applications of these stable, easy to use instruments. Raman spectroscopy is highly suited to analysis of aqueous samples. Near infrared excitation minimized fluorescence interference and allows for remote operation via fiber optic probes. The Department of Energy has funded research at the Measurement and Control Center to establish the utility of this method for on-line composition analysis in distillation columns. Laboratory evaluation and instrument employs an air-cooled laser and a thermoelectrically cooled detector. The device is mounted on a three by foot cart for convenient location in control rooms. Current fiber optic extension cables allow for analysis in a cell thirty five meters from the instrument. Application of the ...
1992-01-01
Energy Technology Data Exchange (ETDEWEB)
The metal dependence of mesoporous activated carbons with various metal acetylacetonate (acac) particles prepared from Morwell coal was studied. In experiment, the mixture of Morwell coal and acac metal complexes were dissipated into tetrahydrofuran, and after agitation in Ar atmosphere, the solvent was removed by vacuum distillation. Coal specimens with Fe(acac)3, Ni(acac)2 and Co(acac)2 as acac complexes were activated by exchanging flow gas with water vapor after heat treatment in N2 gas flow at 900{degree}C. The pore sizes of the specimens were obtained from N2 adsorption isotherms by BET method and BJH method. Conditions of pores and metals in the specimens were examined by XRD measurement and TEM observation. The relation between the above conditions and pore characteristics obtained from adsorption experiment was also examined. As a result, the difference in mesopore ratio between the specimens and blank specimens was larger in the order of Fe, Co and Ni, ...
1996-10-28
Ludwig's Applied Process Design for Chemical and Petrochemical Plants, 4th Edition - EA BOOKS
...Ludwig's Applied Process Design for Chemical and Petrochemical Plants, 4th Edition - EA BOOKS nomographs, data charts and heuristics. About us | My EA Books | Contact us | Authors Home page Feature Books Books DVDs eBooks EA Books Publications Merchandise eJournals Terms and Conditions Subjects Chemical & Process Civil Computers Electrical & Electronics Environmental Management Mechanical Multi-disciplinary Quality Railways Structural Water Australian Authors Australian Rainfall ... Volume Two focuses on distillation and packed towers, and presents the methods and fundamentals of plant design along with supplemental mechanical and related data, nomographs, data charts and heuristics. The Fourth Edition is significantly expanded and updated, with new topics that ensure readers can analyze problems and find practical design methods and solutions to accomplish their process design objectives. It is a true application-driven book, providing ...
Energy Technology Data Exchange (ETDEWEB)
The coke plant at the Sparrows Point Plant consist of three coke oven batteries and two coal chemical plants. The by-product coke oven gas (COG) consists primarily of hydrogen, methane, carbon monoxide, nitrogen and contaminants consisting of tars, light oils (benzene, toluene, and xylene) hydrogen sulfide, ammonia, water vapor and other hydrocarbons. This raw coke oven gas needs to be cleaned of most of its contaminants before it can be used as a fuel at other operations at the Sparrows Point Plant. In response to environmental concerns, BSC decided to replace much of the existing coke oven gas treatment facilities in the two coal chemical Plants (A and B) with a group of technologies consisting of: Secondary Cooling of the Coke oven Gas; Hydrogen Sulfide Removal; Ammonia Removal; Deacification of Acid Gases Removed; Ammonia Distillation and Destruction; and, Sulfur Recovery. This combination of technologies will replace the existing ammonia removal system, the ...
1992-08-24
Innovative coke oven gas cleaning system for retrofit applications
Energy Technology Data Exchange (ETDEWEB)
The coke plant at the Sparrows Point Plant consist of three coke oven batteries and two coal chemical plants. The by-product coke oven gas (COG) consists primarily of hydrogen, methane, carbon monoxide, nitrogen and contaminants consisting of tars, light oils (benzene, toluene, and xylene) hydrogen sulfide, ammonia, water vapor and other hydrocarbons. This raw coke oven gas needs to be cleaned of most of its contaminants before it can be used as a fuel at other operations at the Sparrows Point Plant. In response to environmental concerns, BSC decided to replace much of the existing coke oven gas treatment facilities in the two coal chemical Plants (A and B) with a group of technologies consisting of: Secondary Cooling of the Coke oven Gas; Hydrogen Sulfide Removal; Ammonia Removal; Deacification of Acid Gases Removed; Ammonia Distillation and Destruction; and, Sulfur Recovery. This combination of technologies will replace the existing ammonia removal system, the ...
1992-08-24
Energy Technology Data Exchange (ETDEWEB)
The NiMo sulfide supported on Ketjen Black (KB) was more effective and yielded lighter oil products containing light fractions with their boiling point below 300{degree}C during the two stage liquefaction combining low temperature and high temperature hydrogenation the conventional NiMo/alumina catalyst and FeS2 catalyst. Although the NiMo/alumina yielded increased oil products during the two stage liquefaction, the lighter oil fractions did not increase and the heavier fractions increased mainly. This suggests that the hydrogenation of aromatic rings and successive cleavage of the rings are necessary for producing the light oil, which is derived from the sufficient hydrogenation of aromatic rings using catalysts. For the two stage reaction with NiMo/KB catalyst, it was considered that sufficient hydrogen was directly transferred to coal molecules at the first stage of the low temperature reaction, which promoted the solubilization of coal and the successive hydrogenation at the high ...
1996-10-28
Energy Technology Data Exchange (ETDEWEB)
An Allis-Chalmers, Model 2900, turbocharged diesel engine was converted to a dual-fuel engine in which ethyl alcohol was fumigated between the turbocharger and the intake manifold, and the diesel fuel was injected normally at a reduced rate. Tests were performed to determine if crankcase oil dilution that had occurred was caused by the following independent parameters: proof of the ethyl alcohol, crankcase oil temperature, engine load at maximum torque speed, and percentage of total energy in the form of ethyl alcohol. Engine tests were steady state for six hours, after which the crankcase oil was sampled for American Society for Testing and Materials (ASTM) laboratory tests for determination of flash points and fire points, water by centrifuge, water by distillation, and viscosity at room temperature. Results indicate a decrease in thermal efficiency and an increase in exhaust carbon monoxide as the percentage of total energy as alcohol is increased. Additional ...
1982-11-01
Different purification methods and quality of sunflower biodiesel
Energy Technology Data Exchange (ETDEWEB)
Biodiesel is derived from triacylglycerides and is produced primarily through transesterification, a chemical reaction of vegetable oils with alcohol, methanol or ethanol. The cost of raw material should be considered since 85 per cent of production cost is related to vegetable oil. The purpose of this study was to evaluate oil expression of sunflower seed. It also examined the sunflower crude oil as a raw material for biodiesel by transesterification in both laboratory and pilot scale studies. Three different biodiesel purification methods were examined. The best result for oil expelling (68.4 per cent) at the experimental stage was obtained for seeds with a moisture content of 6.9 per cent at 25 degrees C and at a screw speed of 114 rpm. For biodiesel production at the laboratory scale, the best result for oil expelling was 87.5 per cent. It was obtained with an ethanol:oil molar ratio of 4.7:1 and with a 4.42 per cent catalyst concentration related to the quantity of oil that had to ...
2010-07-01
Development of pyro-separation technology based on molten salt electrolysis
International Nuclear Information System (INIS)
In order to effectively recover uranium, rotation speed of solid cathode was examined, and effect of uranium concentration and current density on electrodeposition were confirmed. And the potentiostatic and galvanostatic electrorefining experiments were conducted. Element used in the experiments were Zr, Nd, La chlorides. The reduction potentials of chlorides metals on liquid Cd cathode were measured by cyclic voltammetry experiments. The electrowinning experiments were performed in order to recover small amounts of uranium in salt. Experimental set-up for the batch type reductive extraction experiments were developed and installed. On the base of experimental results of batch type, multi-stage extraction equipment was set-up, and optimum number of stage and recover yield were measured. In the oxidative extraction study is examine selective separation behavior of the rare earth metals from alloy composed of actinide and lanthanide metals to determine the effective separation condition. ...
2010-10-01
Development of a new evaporator using hydrophobic membrane for radioactive liquid waste
Energy Technology Data Exchange (ETDEWEB)
An evaporator using a hydrophobic membrane made from a polytetrafluoroethylene (PTFE) was developed to improve DF (Decontamination Factor) and to reduce evaporator size. The membrane distillation, provided by the evaporator, is a new technique for liquid purification. Fundamental experiments were carried out to develop the membrane filter (tube type, outer diameter, 8 mm; membrane thickness, 500 {mu}m) for radioactive liquid treatment. The continuous operation test using actual liquid waste was also made during about 3,000 h. (This is almost equal to the operation time of an actual evaporator per year.) The evaporation rate decreased with increase an operation time due to contamination of waste impurity. But the rate was recovered by washing the membrane with hot water and then drying it. DF was over 10{sup 4} which is ten times larger than that for a conventional system. A pilot plant (capacity, 200 kg-liquid waste/h) was constructed and its performance test was ...
1996-10-01
Energy Technology Data Exchange (ETDEWEB)
A program is currently in progress at Argonne National Laboratory to evaluate and develop evaporator technology for concentrating radioactive waste streams. By concentrating radioactive waste streams, disposal costs can be significantly reduced. To effectively reduce the volume of waste, the evaporator must achieve high decontamination factors so that the distillate is sufficiently free of radioactive material. One technology that shows a great deal of potential for this application is being developed by LICON, Inc. In this program, Argonne plans to apply LICON`s evaporator designs to the processing of radioactive solutions. Concepts that need to be incorporated into the design of the evaporator include, criticality safety, remote operation and maintenance, and materials of construction. To design an effective process for concentrating waste streams, both solubility and vapor-liquid equilibrium data are needed. The key issue, however, is the high decontamination ...
1993-10-01
Energy Technology Data Exchange (ETDEWEB)
In the development of the specific mathematical modeling for heavy and ultra heavy petroleum fractions in a molecular distiller is very important the definition of physical and chemical parameters as density and specific heat of the mixture, the enthalpy of vaporization, among others, since they are used in the energy balance. Information on these properties and their variation with temperature are found in the open literature for mixture with few components (simple mixtures). However, for multicomponent solutions consisting of complex mixtures such as oil and its heavy and ultraheavy fractions, available data are few, or are limited to low temperatures. The specific heat is an important property in the energy balance. This property can be measured by Differential Scanning Calorimetry (DSC), which gives results with great sensitivity and accuracy. This paper presents the variation of specific heat with the temperature of ultra-heavy oil fractions in the range from ...
2008-07-01
Corrosion resistance of austenitic steels and alloys in high temperature water
International Nuclear Information System (INIS)
An ampoule corrosion tests technique is presented for making a comparative corrosion-proof estimation of austenitic steels and alloys which are candidate materials for the ITER first wall and shield blanket. Influence of Cl"- on the rate and character of corrosion cracking has been determined. The dependence of time before destruction on Cl"- contents was obtained by experiments in twice-distilled water at a Cl"- content value of less than 0.05 mg/l. Kinetics of a corrosion crack growth has been determined by way of acoustic emission and measurement of electrical resistance. It has been revealed, that corrosion cracking of 316L and 316Ti steels in water with 100 mg/l of Cl"- takes place at temperatures over 50 C. For 316L (Russian analogue), 316Ti, 08Cr18Ni10Ti (type 304), 00Cr16Ni15Mo3Nb (type 316) steels and CrNiMo-1 (42-47%Cr, 1%Mo, Ni-base) alloy corrosion long-term strength and crack-resistance characteristics were obtained. Results of tests show, that ...
Coal liquefaction. Quarterly report, April-June 1979
DOE's program for the conversion of coal to liquid fuels was begun by two of DOE's predecessor agencies: Office of Coal Research (OCR) in 1962, and Bureau of Mines, US Department of the Interior, in the 1930's. Current work is aimed at improved process configurations for both catalytic and non-catalytic processes to provide more attractive processing economics and lower capital investment. The advantage of coal liquefaction is that the entire range of liquid products, especially boiler fuel, distillate fuel oil, and gasoline, can be produced from coal by varying the type of process and operating conditions used in the process. Furthermore, coal-derived liquids have the potential for use as chemical feedstocks. To provide efficient and practical means of utilizing coal resources, DOE is supporting the development of several conversion processes that are currently in the pilot plant stage. DOE, together with the Electric Power Research ...
1980-04-01
Basic design of alpha aqueous waste treatment process in NUCEF
Energy Technology Data Exchange (ETDEWEB)
This paper described the basic design of Alpha Aqueous Waste Treatment Process in NUCEF. Since various experiments using the TRU (transuranium) elements are carried out in NUCEF, wastes containing TRU elements arise. The liquid wastes in NUCEF are categorized into three types. Decontamination and volume reduction of the liquid waste mainly of recovery water from acid recovery process which has lowest radioactive concentration is the most important task, because the arising rate of the waste is large. The major function of the Alpha Aqueous Waste Treatment Process is to decontaminate the radioactive concentration below the level which is allowed to discharge into sea. Prior the process design of this facility, the followings are evaluated:property and arising rate of the liquid waste, room space to install and licensing condition. Considering varieties of liquid wastes and their large volume, the very high decontamination factor was proposed by a process of multiple evaporation ...
1996-11-01
Energy Technology Data Exchange (ETDEWEB)
Tar sand bitumen is petroleum-based ultra-heavy oil, and has a great amount of reserve like coal. However, there are still a lot of problems for its highly effective utilization. This paper discusses whether the light components in bitumen show independent behavior during the thermal cracking of heavy components, or not. Solvent effect and reaction mechanism during the thermal cracking are also derived from the change of their chemical structures. Athabasca tar sand bitumen was separated into light and heavy fractions by vacuum distillation based on D-1660 of ASTM. Mixtures of the both fractions at various ratios were used as samples. Negative effect of the light fraction on cracking of the heavy fraction was observed with dealkylation and paraffin formation Polymerization of the dealkylated light fraction to the heavy fraction was suggested due to lack of hydrogen in the thermal cracking under nitrogen atmosphere, which resulted in the formation of polymer. 3 ...
1996-10-28
This report presents the results of Run 261 performed at the Advanced Coal Liquefaction R & D Facility in Wilsonville, Alabama. The run started on January 12, 1991 and continued until May 31, 1991, operating in the Close-Coupled Integrated Two-Stage Liquefaction mode processing Illinois No. 6 seam bituminous coal (from Burning star No. 2 mine). In the first part of Run 261, a new bimodal catalyst, EXP-AO-60, was tested for its performance and attrition characteristics in the catalytic/catalytic mode of the CC-ITSL process. The main objective of this part of the run was to obtain good process performance in the low/high temperature mode of operation along with well-defined distillation product end boiling points. In the second part of Run 261, Criterion (Shell) 324 catalyst was tested. The objective of this test was to evaluate the operational stability and catalyst and process performance while processing the high ash Illinois No. 6 coal. Increasing viscosity ...
1992-09-01
The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data ...
1995-05-01
Energy Technology Data Exchange (ETDEWEB)
As the Electric Power Industry is actively preparing for a restructured future where retail wheeling is practiced ideally and efficiently in a competitive market-based environment, concerns may arise legitimately on how system reliability and integrity can be ensured in an environment where markets have an enhanced role. As these concerns may be justified, at least for a transition period, this paper presents a proposal which outlines how the generally accepted requisite capacity, energy, and ancillary services standards may be satisfied through market reliance and minimal coordination by a Reliability Monitoring and Ancillary Services Managing Entity or Independent System Operator. A Strawman detailing one -- and by no means the only -- future scenario inspired by the recent NEPOOL restructuring discussions in New England is presented to demonstrate that market-based competition and flexibility are compatible with a reliable Power System.
1996-03-01
Varying-G Cosmology with Type Ia Supernovae
The observation that Type Ia supernovae are fainter than expected given their red shifts has led to the conclusion that the expansion of the universe is accelerating. The widely accepted hypothesis is that this acceleration is caused by a cosmological constant or, more generally, some dark energy field that pervades the universe. This hypothesis presents a challenge to physics so severe that one is motivated to explore alternative explanations. In this paper, we explore whether the data from Type Ia supernovae can be explained with an idea that is almost as old as that of the cosmological constant, namely, that the strength of gravity varies on a cosmic timescale. This topic is an ideal one for investigation by an undergraduate physics major because the entire chain of reasoning from models to data analysis is well within the mathematical and conceptual sophistication of a motivated undergraduate.
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
A visual study of film boiling is carried out to determine the flow regime transition in the post-CHF region. An idealized inverted annular flow is obtained by introducing a liquid jet of Freon 113 through a nozzle, precisely centered with respect to the internal diameter of the test section, with an annular gas flow. The respective ranges for liquid and gas velocities are 0.05-0.5 and 0.03-8.2 m s/sup -1/. Nitrogen and helium are used in the study. For the present configuration, there are four flow regimes; namely, the smooth inverted annular flow-section, the rough wavy, agitated and dispersed flow regimes.
1988-12-01
International Nuclear Information System (INIS)
A visual study of film boiling is carried out to determine the flow regime transition in the post-CHF region. An idealized inverted annular flow is obtained by introducing a liquid jet of Freon 113 through a nozzle, precisely centered with respect to the internal diameter of the test section, with an annular gas flow. The respective ranges for liquid and gas velocities are 0.05-0.5 and 0.03-8.2 m s"-"1. Nitrogen and helium are used in the study. For the present configuration, there are four flow regimes; namely, the smooth inverted annular flow-section, the rough wavy, agitated and dispersed flow regimes. (author).
1988-01-01
The separation of "2"0"3Pb from a thallium target
International Nuclear Information System (INIS)
"2"0"3Pb, an ideal radionuclide for toxicological studies, can be artificially produced by bombardment of a thallium target but due to the extreme toxicity of thallium the lead has to be separated completely from the thallium. A single step method is here described consisting of removing the thallium from a dilute acid chloride solution using a continuous ethyl ether extraction. Essentially all of the thallium and almost none of the lead is removed in a 3-hr extraction. Because the ether is recycled, only about 30 ml are needed. If other contaminants are introduced from the bombardment and its subsequent manipulations, an additional step is used in which the lead is extracted from an iodide solution with methyl isopropyl keton. (U.K.).
The new computer program for three dimensional relativistic hydrodynamical model
An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.
2006-01-01
Energy Technology Data Exchange (ETDEWEB)
The theoretical performance of ideal single- and multijunction cells are compared at 100xconcentration under a range of cloudless-sky conditions. The sensitivities of device performance to cell temperature and spectral variations are shown to depend on the number of junctions (one, two or three), the way in which the junctions are connected (series, parallel or independent), and the band gaps of the devices. The average performances of all of the multijunction devices surpass that of a single-junction GaAs device, but the inconsistency in performance of some of the multijunction devices is significant for large variations in cell temperature and incident spectrum. The choice of band gap and connection scheme is more important than the number of junctions in determining the consistency of device performance. (orig.).
1991-05-01
International Nuclear Information System (INIS)
Simple hydroxamic acids are shown to be useful reagents for the separation of Np and Pu from U within simplified, single cycle Purex flowsheets. They are compatible with the use of centrifugal contactors and laboratory scale flowsheet trials with aceto-hydroxamic acid have demonstrated high actinide recoveries and decontamination factors on products for active feeds of up to 40 wt.% Pu. They therefore show many ideal characteristics for Pu and Np recovery within flowsheet options for actinide recovery in advanced fuel cycles. Furthermore, in order to optimise the routing of Np with the Pu product in advanced flowsheets, additional studies of Np extraction in the primary co-decontamination contactor, prior to U/Pu partition, have been undertaken, combining experiment, modelling and flowsheet tests. (author)
2005-10-09
British Library Electronic Table of Contents (United Kingdom)
Introduction.Microfluidic technology allows fast reactions in a simple experimental setup, while using very low volumes and amounts of starting material. Consequently, microfluidic technology is an ideal tool for radiolabeling reactions involving short-lived positron emitters. Optimization of the complex array of different reaction conditions requires knowledge of the different reaction parameters linked to the microfluidic system as well as their influence on the radiochemical yields. 1-(5-Deoxy-5-fluoro-?-d-arabinofuranosyl)-2-nitroimidazole ([18F]FAZA) is a frequently used radiotracer for PET imaging of tumor hypoxia. The present study describes the radiosynthesis of [18F]FAZA by means of microfluidic technology and subsequent small animal PET imaging in EMT-6 tumor-bearing mice.Methods...
2011-01-01
StoRHm: a protocol adapter for mapping SOAP based Web Services to RESTful HTTP format
British Library Electronic Table of Contents (United Kingdom)
A protocol adapter ideally suited to enable enterprises to gradually transition from SOAP Web Services to RESTful HTTP Web Services without impacting existing clients is presented in this paper. The inherent advantage of such a transition is the visibility of RESTful HTTP messages to Web intermediaries such as caches. In contrast, SOAP messages are opaque, which disables Web intermediaries. While both approaches can use HyperText Transfer Protocol (HTTP) for message transfer, the paradigms contrast sharply. SOAP uses an interface specific approach whereas RESTful HTTP uses a Uniform Interface approach. SOAP marks up its payload with eXtensible Markup Language (XML) whereas in certain situations RESTful HTTP requires no XML. We present the disadvantages of the SOAP approach and outline how ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The major problem of measurement of a power spectral density (PSD) distribution of surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments, which tends to distort the PSD at higher spatial frequencies. The special mathematical properties of binary pseudo-random patterns make them an ideal basis for developing MTF calibration test surfaces. Two-dimensional binary pseudo-random arrays (BPRAs) have been fabricated and used for the MTF calibration of the MicroMap{trademark}-570 interferometric microscope with all available objectives. An investigation into the effects of fabrication imperfections on the quality of the MTF calibration and a procedure for accounting for such imperfections are presented.
2010-03-31
Radiopharmaceuticals labelled with positron emitting radionuclides
International Nuclear Information System (INIS)
A brief survey is presented of the methods of preparation and of the applications of radiopharmaceuticals labelled with short-lived positron radionuclides "1"1C, "1"8F, "1"3N and "1"5O which, thanks to their energy level schemes, short half-life and the 511 keV photon radiation energy are almost ideal tracers in modern nuclear medicine and pharmacology. In conjunction with computerized tomography, they represent one of the most sensitive diagnostic imaging methods, the so-called positron emission tomography. In addition, their incorporation in the molecule of a pharmaceutical does not change the biological and chemical properties of the original molecule unlike those of radiopharmaceuticals labelled with technetium, iodine, etc. (author). 125 refs.
1989-01-01
Precision measurements of positronium decay rate and energy level
Positronium is an ideal system for the research of the bound state QED. New precise measurement of orthopositronium decay rate has been performed with an accuracy of 150 ppm, and the result combined with the last three is 7.0401 +- 0.0007 mu s^-1. It is the first result to validate the 2nd order correction. The Hyper Fine Splitting of positronium is sensitive to the higher order corrections of the QED prediction and also to the new physics beyond Standard Model via the quantum oscillation into virtual photon. The discrepancy of 3.5 sigma is found recently between the measured values and the QED prediction (O(alpha^3)). It might be due to the contribution of the new physics or the systematic problems in the previous measurements: (non-thermalized Ps and non-uniformity of the magnetic field). We propose new methods to measure HFS precisely without the these uncertainties.
2008-01-01
Phase transition in a simple plasma model
A phase transition of gas-liquid type with an upper critical point is examined which arises in a model of charges of one sign on compensating background (OCP). The phase transition parameters are dependent on the detailed assumptions about the compressibility of the background, but the occurrence of this transition is independent on the background equation of state. In the electron-gas model ('jellium'), this transition appears to rule out Wigner crystallization. A variational principle in statistical mechanics is used to derive so-called Double-OCP model for a superposition of two one-component plasma models for charges of opposite sign. The free energy of this model sets an upper bound to that of a real plasma. Situations are discussed where this transition should manifest itself in anomalies in the approximate description of a non-ideal plasma.
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
SummaryA meshless numerical model is proposed to investigate shallow-water dam break flows in 1D open channels. The numerical model is to solve the shallow water equations (SWE) based on smoothed particle hydrodynamics (SPH). The concept of slice water particles (SWP) is adopted in the SPH-SWE formulation. The numerical sensitivity analysis is first performed to study the appropriate SWP number and variable smoothing length through dam break flows in an idealized 1D channel with dry/wet beds. Extensive validation by comparison with laboratory and field data is next conducted for four benchmark problems, including dam break flows through a rough flat channel, a rough bumpy channel with various downstream boundary conditions, a nonprismatic channel, and a realistic scale model of the Toce ri...
2011-01-01
Grating cloaks are a variation of dielectric carpet (or ground- plane) cloaks. The latter were introduced by Li and Pendry. In contrast to the numerical work involved in the quasi-conformal carpet cloak, the refractive-index profile of a conformal grating cloak follows a closed and exact analytical form. We have previously mentioned that finite-size conformal grating cloaks may exhibit better cloaking than usual finite-size carpet cloaks. In this letter, we directly visualize their performance using photorealistic ray-tracing simulations. We employ a Newtonian approach that is advantageous compared to conventional ray tracing based on Snell's law. Furthermore, we quantify the achieved cloaking quality by computing the cross-correlations of rendered images. The cross-correlations for the grating cloak are much closer to 100% (i.e., ideal) than those for the Gaussian carpet cloak.
2010-01-01
Modeling of Anisotropic Inelastic Behavior
Energy Technology Data Exchange (ETDEWEB)
An experimental capability, developed at Lawrence Livermore National Laboratory (LLNL), is being used to study the yield behavior of elastic-plastic materials. The objective of our research is to develop better constitutive equations for polycrystalline metals. We are experimentally determining the multidimensional yield surface of the material, both in its initial state and as it evolves during large inelastic deformations. These experiments provide a more complete picture of material behavior than can be obtained from traditional uniaxial tests. Experimental results show that actual material response can differ significantly from that predicted by simple idealized models. These results are being used to develop improved constitutive models of anisotropic plasticity for use in continuum computer codes.
2000-02-25
Modal Meinongianism and fiction: the best of three worlds
British Library Electronic Table of Contents (United Kingdom)
We outline a neo-Meinongian framework labeled as Modal Meinongian Metaphysics (MMM) to account for the ontology and semantics of fictional discourse. Several competing accounts of fictional objects are originated by the fact that our talking of them mirrors incoherent intuitions: mainstream theories of fiction privilege some such intuitions, but are forced to account for others via complicated paraphrases of the relevant sentences. An ideal theory should resort to as few paraphrases as possible. In Sect.?1, we make this explicit via two methodological principles, called the Minimal Revision and the Acceptability Constraint. In Sect.?2, we introduce the standard distinction between internal and external fictional discourse. In Sects.?3?5, we discuss the approaches of (traditional) Meinongia...
2011-01-01
Minimum work requirement for water production in humidification?dehumidification desalination cycle
British Library Electronic Table of Contents (United Kingdom)
This paper presents a theoretical analysis based on the second law of thermodynamics for estimating the minimum work required for air dehumidification process to produce potable water in a humidification-dehumidification (HD) desalination cycle. The general air dehumidification process is analyzed through an equivalent path consisting of an isothermal dehumidification followed by a sensible cooling Dehumidification is treated as separation process of an ideal mixture consisting of two components, namely air and water vapor. The present analysis assumes the dead state to be the dry ambient and the final state for complete dehumidification to be saturated air at 0.01?C. Contours of the minimum work are plotted on psychrometric chart and presented as a handy engineering tool to estimate the p...
2007-01-01
Microstructures and tensile properties of wrought magnesium alloys processed by ECAE
Energy Technology Data Exchange (ETDEWEB)
Magnesium alloys are ideal candidates to benefit from equal channel angular extrusion (ECAE) because of their poor forming characteristics due to a hcp structure. In this study, ECAE processing was applied to ZK31 and AZ31 magnesium alloys under various conditions. The grain size of as-ECAE specimens decreases with decreasing the processing temperature, however, the grain size decreases slightly with increasing number of repetitive processing. Both the tensile strength and 0.2% proof stress of as-ECAE specimens are high when processed at low temperature, but the elongation is high when processed at high temperature. Crystal orientation is different in the two alloys and it also varies according to the processing temperature for the two alloys. The difference of the crystal orientation influences the tensile properties, especially 0.2% proof stress. (orig.)
2003-07-01
1,3-Dienes derived from steroidal D-ring C17-ketones undergo Ni(II)-catalyzed hydrovinylation to give 1,2- or 1,4-addition of ethylene. Using finely tuned phosphoramidite ligands it is possible to synthesize either the C20 (R)- or the C20 (S)-derivatives without mutual contamination. The proportion of the 1,4-adduct, which is also formed stereoselectively, can be minimized by optimizing the reaction conditions. Since the two alkenes in the resultant dienes have differing steric demands for many potential reactions, and are ideally juxtaposed for further D-ring functionalization, these intermediates could be useful for the preparation of biologically important compounds such as vitamin D analogs and various antitumor steroidal glycosides.
2008-06-21
Intramolecular Form Factor in Dense Polymer Systems: Systematic Deviations from the Debye formula
We discuss theoretically and numerically the intramolecular form factor $F(q)$ in dense polymer systems. Following Flory's ideality hypothesis, chains in the melt adopt Gaussian configurations and their form factor is supposed to be given by Debye's formula. At striking variance to this, we obtain noticeable (up to 20%) non-monotonic deviations which can be traced back to the incompressibility of dense polymer solutions beyond a local scale. The Kratky plot ($q^2F(q)$ {\\it vs.} wavevector $q$) does not exhibit the plateau expected for Gaussian chains in the intermediate $q$-range. One rather finds a significant decrease according to the correction $\\delta(F^{-1}(q)) = q^3/32\\rho$ that only depends on the concentration $\\rho$ of the solution, but neither on the persistence length or the interaction strength.
2007-01-01
Idealized gas turbine combustor for performance research and validation of large eddy simulations.
This paper details the design of a premixed, swirl-stabilized combustor that was designed and built for the express purpose of obtaining validation-quality data for the development of large eddy simulations (LES) of gas turbine combustors. The combustor features nonambiguous boundary conditions, a geometrically simple design that retains the essential fluid dynamics and thermochemical processes that occur in actual gas turbine combustors, and unrestrictive access for laser and optical diagnostic measurements. After discussing the design detail, a preliminary investigation of the performance and operating envelope of the combustor is presented. With the combustor operating on premixed methane/air, both the equivalence ratio and the inlet velocity were systematically varied and the flame structure was recorded via digital photography. Interesting lean flame blowout and resonance characteristics were observed. In addition, the combustor exhibited a large region of stable, acoustically ...
2007-03-01
Growth and defects of explosives crystals
Energy Technology Data Exchange (ETDEWEB)
Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces ideally mosaic crystals, and may account for the polymorphs'' of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes worm holes'' in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100[degrees]C lock in the mechanical twins.
1992-01-01
Growth and defects of explosives crystals
Energy Technology Data Exchange (ETDEWEB)
Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces ideally mosaic crystals, and may account for the ``polymorphs`` of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes ``worm holes`` in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100{degrees}C lock in the mechanical twins.
1992-12-01
Grid cells generate an analog error-correcting code for singularly precise neural computation
British Library Electronic Table of Contents (United Kingdom)
Entorhinal grid cells in mammals fire as a function of animal location, with spatially periodic response patterns. This nonlocal periodic representation of location, a local variable, is unlike other neural codes. There is no theoretical explanation for why such a code should exist. We examined how accurately the grid code with noisy neurons allows an ideal observer to estimate location and found this code to be a previously unknown type of population code with unprecedented robustness to noise. In particular, the representational accuracy attained by grid cells over the coding range was in a qualitatively different class from what is possible with observed sensory and motor population codes. We found that a simple neural network can effectively correct the grid code. To the best of our kn...
2011-01-01
Footnotes to the patent game: how does homo ludens1 enforce patent rights in Hungary?
British Library Electronic Table of Contents (United Kingdom)
Legal context Can we imagine the patent case as a play? As Johann Huizinga, the Dutch historian and cultural theorist writes, "The lawsuit can be regarded as a game of chance, a contest or a verbal battle." According to Huizinga, science is actually a play itself, thus scientific recognition is nothing more than the solution of a task of a play. In this context, a patent suit is nothing more than a play played with the play (in other words a `Game of the Game'). Key points and practical significance In our view in an ideal world the enforcement of patent rights should be a game of chess, where all the information is available to both players and the rules are simple and unquestionable. All players accept, understand and interpret the rules the same way. The referee has no role to play. How...
2011-01-01
Food-grade gene expression in lactic acid bacteria
British Library Electronic Table of Contents (United Kingdom)
Abstract In the 1990s, significant efforts were invested in the research and development of food-grade expression systems in lactic acid bacteria (LAB). At this time, Lactococcus lactis in particular was demonstrated to be an ideal cell factory for the food-grade production of recombinant proteins. Steady progress has since been made in research on LAB, including Lactococcus, Lactobacillus and Streptococcus, in the areas of recombinant enzyme production, industrial food fermentation, and gene and metabolic pathway regulation. Over the past decade, this work has also led to new approaches on chromosomal integration vectors and host/vector systems. These newly constructed food-grade gene expression systems were designed with specific attention to self-cloning strategies, food-grade selection...
2011-01-01
International Nuclear Information System (INIS)
The present paper deals with the experimental determination of pressure drop across a four-cusped vertical channel. This geometry represents, ideally, the blockage condition in a typical pressurized water reactor with core degraded by accident. Experiments were performed for both single and two-phase flow. Water was utilized for the single-phase measurements whilst simultaneous flow of air and water simulated the steam-water flow. Observation of the prevailing two-phase flow regime was carried out, so that its mechanism could be fully understood. The averaged void fraction was also measured, by the gamma-ray attenuation technique. A wide range of water and air mass flow rates was covered, so that all flow conditions, possible to exist in a reactor with LOCA, could be investigated. New correlations for pressure drop are proposed. (Author).
1986-03-17
Effect of biodegradation on vanadylporphyrin distribution
Energy Technology Data Exchange (ETDEWEB)
Oils, tars, and degraded oils of varying degrees of biodegradation occur in the Permian Phosphoria Formation along the eastern flank of the Wind River mountains, Wyoming, US. Biodegradation has altered the isomer distributions of steranes, the hopanes, and the mono- and triaromatised steroids in these oils. The conventional maturity parameters based on these biomarkers are of limited use in estimating their maturity. On the other hand, even in severely biodegraded oils the vanadylporphyrin distributions are unaltered. Because of this, the Porphyrin Maturity Parameter (PMP) derived from the vanadylporphyrin distribution is an ideal parameter for estimating the maturity of these oils. This study also confirms the previous observation that T[sub s] and T[sub m] are unaffected by even severe biodegradation. 14 refs., 5 figs., 2 tabs.
1993-05-01
British Library Electronic Table of Contents (United Kingdom)
Chitosan (a?-(1-4)-amino-2-deoxy-b?-D-glucan) is a deacetylated form of chitin, a polysaccharide from crustacean shells. Its unique characteristics, such as positive charge, biodegradability, biocompatibility, nontoxicity, and rigid structure, make this macromolecule ideal for an oral vaccine delivery system. We prepared reverse-phase evaporation vesicles (REVs) sandwiched by chitosan (Chi) and polyvinylic alcohol (PVA). However, in this method, there are still some problems to be circumvented related to protein stabilization. During the inverted micelle phase of protein nanoencapsulation, hydrophobic interfaces are expanded, leading to interfacial adsorption, followed by protein unfolding and aggregation. Here, spectroscopic and immunological techniques were used to ascertain the effects ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The energy dispersive beamline X6A at the National Synchrotron Light Source employs a curved crystal monochromator (polychromator) which focuses a range ([similar to]1 keV) of x-ray energies into a narrow (100--120 [mu]m) line image. Although this beamline was constructed primarily for time-dependent EXAFS experiments, we have begun to explore the use of this instrument for energy dispersive diffraction experiments with different types of sample including macromolecular crystals. The tunability ([ital E]=6.5 to 21 keV) and flexibility ([Delta][ital E]=100--1000 eV) of the instrument makes the beamline ideal as a test bed for the application of polychromatic single-crystal diffraction techniques to different chemical or biological materials.
1995-02-01
Demand Analysis with Partial Predicates
In order to alleviate the inefficiencies caused by the interaction of the logic and functional sides, integrated languages may take advantage of \\emph{demand} information -- i.e. knowing in advance which computations are needed and, to which extent, in a particular context. This work studies \\emph{demand analysis} -- which is closely related to \\emph{backwards strictness analysis} -- in a semantic framework of \\emph{partial predicates}, which in turn are constructive realizations of ideals in a domain. This will allow us to give a concise, unified presentation of demand analysis, to relate it to other analyses based on abstract interpretation or strictness logics, some hints for the implementation, and, more important, to prove the soundness of our analysis based on \\emph{demand equations}. There are also some innovative results. One of them is that a set constraint-based analysis has been derived in a stepwise manner using ideas taken from the area of program ...
2006-01-01
Creativity and integrity: Marketing the "in development" screenplay
British Library Electronic Table of Contents (United Kingdom)
This studys purpose was to explore the relationship between creativity and integrity in the ideation phase of feature filmmaking. Integrity refers to ones self-defined ability to maintain authenticity and moral autonomy while preserving ones sense of membership and loyalty to the team or organization. When team members choose elements for the screenplays story that they feel will attract the ideal audience, the dynamic tension between creativity and integrity is most apparent. The forces at play during this phase of work yielded the research question: In what ways and to what degree do screenwriters andor studio executives feel their personal integrity is in alignment with the creative process of feature film development? Several concepts from the literature formed the design around which ...
2009-01-01
Coupled two-component atomic gas in an optical lattice
We study the ground state of an ideal coupled two-component gas of ultracold atoms in a one dimensional optical lattice, either bosons or fermions. Due to the internal two-level structure of the atoms, the Brillouin zone is twice as large as imposed by the periodicity of the lattice potential. This is reflected in the Bloch dispersion curves, where the energy bands regularly possess several local minima. As a consequence, when the system parameters are tuned across a resonance condition, a non-zero temperature topological first order phase transition occurs which arises from an interplay between initernal and kinetic atomic energies. It is shown that these phenomena are also captured for two and three dimensional optical lattices.
2008-01-01
Clostridiaceae and Enterobacteriaceae as active fermenters in earthworm gut content
British Library Electronic Table of Contents (United Kingdom)
The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [13C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succi...
2011-01-01
Chloroquine for influenza prevention: a randomised, double-blind, placebo controlled trial
British Library Electronic Table of Contents (United Kingdom)
Background: Chloroquine has in-vitro activity against influenza and could be an ideal candidate for worldwide prevention of influenza in the period between onset of a pandemic with a virulent influenza strain and the development and widespread dissemination of an effective vaccine. We aimed to assess the efficacy of such an intervention. Methods: In this randomised, double-blind, placebo-controlled trial done at a single centre in Singapore, we randomly assigned (1:1) healthy adults to receive chloroquine phosphate (500 mg/day for 1 week, then once a week to complete 12 weeks) or matching placebo by use of a computer-generated randomisation list. Participants filled an online symptom diary every week, supplemented by daily diaries and self-administered nasal swabs when unwell. Haemagglutin...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experi...
2007-01-01
System identification refers to estimation of process parameters and is a necessity in control theory. Physical systems usually have varying parameters. For such processes, accurate identification is particularly important. Online identification schemes are also needed for designing adaptive controllers. Real processes are usually of fractional order as opposed to the ideal integral order models. In this paper, we propose a simple and elegant scheme of estimating the parameters for such a fractional order process. A population of process models is generated and updated by particle swarm optimization (PSO) technique, the fitness function being the sum of squared deviations from the actual set of observations. Results show that the proposed scheme offers a high degree of accuracy even when the observations are corrupted to a significant degree. Additional schemes to improve the accuracy still further are also proposed and analyzed.
2008-01-01
This contribution deals with identification of fractional-order dynamical systems. System identification, which refers to estimation of process parameters, is a necessity in control theory. Real processes are usually of fractional order as opposed to the ideal integral order models. A simple and elegant scheme of estimating the parameters for such a fractional order process is proposed. This method employs fractional calculus theory to find equations relating the parameters that are to be estimated, and then estimates the process parameters after solving the simultaneous equations. The said simultaneous equations are generated and updated using particle swarm optimization (PSO) technique, the fitness function being the sum of squared deviations from the actual set of observations. The data used for the calculations are intentionally corrupted to simulate real-life conditions. Results show that the proposed scheme offers a very high degree of accuracy even for ...
2008-01-01
Energy Technology Data Exchange (ETDEWEB)
Inverted annular flow can be visualized as a liquid jet-like core surrounded by a vapor annulus. While many analytical and experimental studies of heat transfer in this regime have been performed, there is very little understanding of the basic hydrodynamics of the post-CHF flow field. However, a recent experimental study was done that was able to successfully investigate the effects of various steady-state inlet flow parameters on the post-CHF hydrodynamics of the film boiling of a single phase liquid jet. This study was carried out by means of a visual photographic analysis of an idealized single phase core inverted annular flow initial geometry (single phase liquid jet core surrounded by a coaxial annulus of gas). In order to extend this study, a subsequent flow visualization of an idealized two-phase core inverted annular flow geometry (two-phase central jet core, surrounded by a coaxial annulus of gas) was carried out. The objective of ...
1988-01-01
New technetium-99m radiopharmaceuticals for brain imaging
International Nuclear Information System (INIS)
Radiopharmaceuticals for brain imaging are used for the detection of ischemia, tumours and dementia associatied with disorders of the blood flow in the brain. The current radiopharmaceuticals for brain imaging have various limitations: 2-(F-18)fluoro-2-deoxyglucose (F-18-FDG) has a very short half-life. The physical properties of di-#beta#-(piperidinoethyl)-(Se-75)selenide (Se-75-PIPSE) and di-#beta#-(morpholinoethyl)-(Se-75)-selenide (Se-75-MOSE) are not ideal. Thallium-201 diethyldithricarbamate (T1-201-DDC) has unfavourable nuclidic characteristics, limited availability, a long half-life and high cost. I-123 in N-isopropyl-p-iodoamphetamine (I-123-IMP) and N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (I-123-HIPDM) are not freely available and are expensive. N-13-labelled ammonia has a very short half-life. Technetium-99m hexamethylpropyleneamineoxime (Tc-99m-HM-PAO) is unstable both in vitro and in vivo and has a low brain-to-blood ...
1988-08-01
Metal Nanoparticles Preparation In Supercritical Carbon Dioxide Solutions
Energy Technology Data Exchange (ETDEWEB)
The novel optical, electronic, and/or magnetic properties of metal and semiconductor nanoparticles have resulted in extensive research on new methods for their preparation. An ideal preparation method would allow the particle size, size distribution, crystallinity, and particle shape to be easily controlled, and would be applicable to a wide variety of material systems. Numerous preparation methods have been reported, each with its inherent advantages and disadvantages; however, an ideal method has yet to emerge. The most widely applied methods for nanoparticle preparation include the sonochemical reduction of organometallic reagents,(1&2) the solvothermal method of Alivisatos,(3) reactions in microemulsions,(4-6) the polyol method (reduction by alcohols),(7-9) and the use of polymer and solgel materials as hosts.(10-13) In addition to these methods, there are a variety of methods that take advantage of the unique properties of a ...
2004-04-01
International Nuclear Information System (INIS)
Background and purpose: A series of phase I/II clinical trials are being initiated in several UK centres to explore the use of dose-escalated schedules for the treatment of non-small cell lung cancer (NSCLC). Among them the IDEAL-CRT trial (ISRCTN12155469) will investigate the introduction of individualised 'isotoxic' treatment schedules based on the relative mean lung normalised total dose (rNTDmean), an estimator related to lung toxicity. Since treatment planning will be performed using different treatment planning systems (TPSs), for the quality assurance of the trial we have carried out work to quantify the influence of dose calculation algorithms based on the determination of rNTDmean and on the choice of individualised prescription doses. Material and methods: Twenty-five patient plans with stage I, II and III NSCLC were calculated, with the same prescription dose, using the Adaptive Convolve (AC) and Collapsed Cone (CC) algorithms of the Pinnacle TPS, the ...
2010-12-01
Energy Technology Data Exchange (ETDEWEB)
The absorption of solar heat and the attendant thermal and mechanical loadings on the tubes of cavity receivers depend predominantly on the flux distribution of the incident solar radiation. For an axially symmetric cavity receiver with a parabolic dish collector, it is simple to determine the insolation pattern on the receiver internal surfaces if the system is ideal. In such a system the surface of the dish is perfectly parabolic (no contour flaws are present), and the sun's central ray impinges on the dish surface parallel to the focal axis (no sun tracking flaws are present). These two conditions cannot be achieved in practice, and therefore the feasible parabolic dish system is referred to as a real system although, in actual fact, it is only an approximation to any actual system. The purpose of this paper is to devise calculation principles which permit analysis of a receiver designed for ideal conditions to verify its structural ...
1990-11-01
Energy Technology Data Exchange (ETDEWEB)
It turns out of interest to Comision Federal de Electricidad and Petroleos Mexicanos to reduce costs of fuel oil, reducing the viscosity of the residues petroleum of high vacuum distillation emulsifying these with water. The parameters that define the characteristics of the emulsions are mainly the relation of their components, viscosity, size and drop distribution and its stability. The experimental work began producing emulsions in form of lots, using samples of approximately 500 milliliters of vacuum residue. In this first stage, at different concentrations, were examined eight different surfactants, as well as combinations among them, also seven different stabilizers were used. With these tests it has been managed to identify the concentrations, as well as the most adequate relations of surfactants and stabilizers for the production of emulsions of vacuum residues in water. The size and drop distribution has been determined by means of an optical LEICA ...
2001-07-01
Energy Technology Data Exchange (ETDEWEB)
A visual study of film boiling using photographic and high speed motion-picture methods was carried out to determine the flow regime transition criteria in the post-CHF region. An idealized inverted annular flow was obtained by introducing a liquid jet of Freon 113 through a nozzle, precisely centered with respect to the internal diameter of the test section, with an annular gas flow. The respective ranges for liquid and gas exit velocities were 0.05 to 0.5 and 0.03 to 7.9 m/s. Nitrogen and helium were used in the study. For the present configuration, there are four basic flow regimes. Beginning from the nozzle exit, there is a smooth, inverted annular flow section with liquid in the core and gas in the annulus; followed by the rough wavy section with an intact liquid core, the agitated and the dispersed flow regimes. For a given liquid jet velocity, the axial extent of each flow regime decreases with increasing gas velocity through the annulus. Generalized ...
1987-06-01
International Nuclear Information System (INIS)
A visual study of film boiling using photographic and high speed motion-picture methods was carried out to determine the flow regime transition criteria in the post-CHF region. An idealized inverted annular flow was obtained by introducing a liquid jet of Freon 113 through a nozzle, precisely centered with respect to the internal diameter of the test section, with an annular gas flow. The respective ranges for liquid and gas exit velocities were 0.05 to 0.5 and 0.03 to 7.9 m/s. Nitrogen and helium were used in the study. For the present configuration, there are four basic flow regimes. Beginning from the nozzle exit, there is a smooth, inverted annular flow section with liquid in the core and gas in the annulus; followed by the rough wavy section with an intact liquid core, the agitated and the dispersed flow regimes. For a given liquid jet velocity, the axial extent of each flow regime decreases with increasing gas velocity through the annulus. Generalized ...
1987-01-01
Towards Quantum Superposition of Living Organisms
The most striking feature of quantum mechanics is the existence of superposition states, where an object appears to be in different situations at the same time. Up to now, the existence of such states has been tested with small objects, like atoms, ions, electrons and photons, and even with molecules. Recently, it has been even possible to create superpositions of collections of photons, atoms, or Cooper pairs. Current progress in optomechanical systems may soon allow us to create superpositions of even larger objects, like micro-sized mirrors or cantilevers, and thus to test quantum mechanical phenomena at larger scales. Here we propose a method to cool down and create quantum superpositions of the motion of sub-wavelength, arbitrarily shaped dielectric objects trapped inside a high--finesse cavity at a very low pressure. Our method is ideally suited for the smallest living organisms, such as viruses, which survive under low vacuum pressures, and optically behave ...
2009-01-01
Thomson Scattering at FLASH - Status Report
Energy Technology Data Exchange (ETDEWEB)
The basic idea is to implement Thomson scattering with free electron laser (FEL) radiation at near-solid density plasmas as a diagnostic method which allows the determination of plasma temperatures and densities in the warm dense matter (WDM) regime (free electron density of n{sub e} = 10{sup 21}-10{sup 26} cm{sup -3} with temperatures of several eV). The WDM regime [1] at near-solid density (n{sub e} = 10{sup 21}-10{sup 22} cm{sup -3}) is of special interest because, it is where the transition from an ideal plasma to a degenerate, strongly coupled plasma occurs. A systematic understanding of this largely unknown WDM domain is crucial for the modeling and understanding of contemporary plasma experiments, like laser shock-wave or Z-pinch experiments as well as for inertial confinement fusion (ICF) experiments as the plasma evolution follows its path through this domain.
2007-11-28
The potential of III-V semiconductors as terrestrial photovoltaic devices
Energy Technology Data Exchange (ETDEWEB)
III-V semiconductors, GaAs and in particular InGaP, are used in many different electronic applications, such as high power and high frequency devices, laser diodes and high brightness LED. Their direct bandgap and high reliability make them ideal candidates for the realisation of high efficiency solar cells: in the past years they have been successfully used as power sources for satellites in space, where they are able to produce electricity from sunlight with an overall efficiency of around 30%. Nowadays, the use of arsenides and phosphides as photovoltaic (PV) devices is confined only to space applications since their price is much higher than conventional Si flat panel modules, the leading PV market technology. But with the introduction of multijunction solar cells capable of operating in high concentration solar light, the area and, therefore, the cost of these cells can be reduced and will eventually find an application and market also on Earth. This article ...
2006-07-01
Energy Technology Data Exchange (ETDEWEB)
A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned image processings are adopted, FCR can be used for the diagnosis of pneumoconiosis with the same accuracy as the ...
1993-06-01
The application of the Fuji Computed Radiography system for the diagnosis of pneumoconiosis
International Nuclear Information System (INIS)
A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned image processings are adopted, FCR can be used for the diagnosis of pneumoconiosis with the same accuracy as the ...
1993-01-01
The Dixmier-Moeglin equivalence and a Gel'fand-Kirillov problem for Poisson polynomial algebras
The structure of Poisson polynomial algebras of the type obtained as semiclassical limits of quantized coordinate rings is investigated. Sufficient conditions for a rational Poisson action of a torus on such an algebra to leave only finitely many Poisson prime ideals invariant are obtained. Combined with previous work of the first-named author, this establishes the Poisson Dixmier-Moeglin equivalence for large classes of Poisson polynomial rings, such as semiclassical limits of quantum matrices, quantum symplectic and euclidean spaces, quantum symmetric and antisymmetric matrices. For a similarly large class of Poisson polynomial rings, it is proved that the quotient field of the algebra (respectively, of any Poisson prime factor ring) is a rational function field $F(x_1,...,x_n)$ over the base field (respectively, over an extension field of the base field) with $\\{x_i,x_j\\}= \\lambda_{ij} x_ix_j$ for suitable scalars $\\lambda_{ij}$, thus establishing a ...
2007-01-01
Structure and properties of a novel cobaltate La0.30CoO2
British Library Electronic Table of Contents (United Kingdom)
The layered cobaltate La0.30CoO2 was prepared from NaxCoO2 precursor by a solid-state ionic exchange and was characterized by means of X-ray and neutron diffraction, magnetic, thermal and electric transport measurements. The compound consists of hexagonal sheets of edge-sharing CoO6 octahedra interleaved by lanthanum monolayers. Compared to Na+ in the parent system, the La3+ ions occupy only one-third of available sites, forming a 2-dimensional superstructure. The deviation from the ideal stoichiometry La1/3CoO2 introduces extra hole carriers into the diamagnetic LS Co3+ matrix making the sample Pauli paramagnetic. The temperature dependence of the electrical conductivity in La0.30CoO2 follows Mott's T?1/3 law up to about 400K, which is in contrast w...
2011-01-01
Structure and Function Evolution of Thiolate Monolayers on Gold
Energy Technology Data Exchange (ETDEWEB)
The use of n-alkanethiolate self-assembled monolayers on gold has blossomed in the past few years. These systems have functioned as models for common interfaces. Thiolate monolayers are ideal because they are easily modified before or after deposition. The works contained within this dissertation include interfacial characterization (inbred reflection absorption spectroscopy, ellipsometry, contact angle, scanning probe microscopy, and heterogeneous electron-transfer kinetics) and various modeling scenarios. The results of these characterizations present ground-breaking insights into the structure, function, and reproducible preparation of these monolayers. Surprisingly, three interfacial properties (electron-transfer, contact angle, and ellipsometry) were discovered to depend directly on the odd-even character of the monolayer components. Molecular modeling was utilized to investigate adlayer orientation, and suggests that these effects are adlayer structure ...
2006-05-01
Energy Technology Data Exchange (ETDEWEB)
The amorphization of a quenched sample of the GaSb-II high-pressure phase was studied at ambient pressure by real-time neutron diffraction in the course of the sample heating from 100 K to room temperature at a rate of 0.4 K min{sup -1}. The transformation to the amorphous state begins at 140 K and is completed near room temperature. The {beta}-Sn type structure was shown to represent only the mean lattice of the high-pressure GaSb-II phase. The superstructure of this phase widely varied with temperature and is caused by the ordered displacement of atoms. The temperature range of the metastable crystalline phase relaxation is divided into three intervals according to the temperature dependence of the tetragonality ratio (c/a). At the boundaries of these temperature intervals, i.e. temperatures T = 170 and 230 K, two second-order phase transitions are observed. Anomalous heat and volumetric effects were observed earlier by means of calorimetry and dilatometry in the same temperature ...
2009-01-28
International Nuclear Information System (INIS)
The amorphization of a quenched sample of the GaSb-II high-pressure phase was studied at ambient pressure by real-time neutron diffraction in the course of the sample heating from 100 K to room temperature at a rate of 0.4 K min-1. The transformation to the amorphous state begins at 140 K and is completed near room temperature. The ?-Sn type structure was shown to represent only the mean lattice of the high-pressure GaSb-II phase. The superstructure of this phase widely varied with temperature and is caused by the ordered displacement of atoms. The temperature range of the metastable crystalline phase relaxation is divided into three intervals according to the temperature dependence of the tetragonality ratio (c/a). At the boundaries of these temperature intervals, i.e. temperatures T = 170 and 230 K, two second-order phase transitions are observed. Anomalous heat and volumetric effects were observed earlier by means of calorimetry and dilatometry in the same temperature range. ...
2009-01-28
Energy Technology Data Exchange (ETDEWEB)
Research and development has been performed on photochromic materials expected to be used in ultra-high density recording, high resolution indication and photoswitches. With regard to molecular orientation in the ternary system mixed LB film, the result of structural analysis by XPM spectrum revealed that the acceptor constituent in the LB film is so structured that it is separated and laminated with two other constituents, and that the sensitizer constituent and the donor constituent are not recognized of being separated definitely. Regarding the electron movement reaction in the solid phase system, a photo-current measuring experiment was carried out on the laminated film which is vacuum-deposited with the ternary system comprising of the donor, sensitizer, and acceptor. It was concluded that the observed photo-current reflects the electron movement reaction in the solid phase as it is. For the photo-current in the LB film, increase in the photo-current was observed according to the ...
1990-03-01
Representation of uncertainty in computer vision using fuzzy sets
Energy Technology Data Exchange (ETDEWEB)
Uncertainty in computer vision can arise at various levels. It can occur in the low level in the raw sensor input, and extends all the way through intermediate and higher levels. Ideally, at any level where decisions are being made on the basis of previous processing steps, a computer vision system must have sufficient flexibility for representation of uncertainty in any of these levels. The input cue representation portion of a computer vision system should maintain the information content of the original input images, while at the same time allowing for uncertainty in the identification of attributes required by other parts of the system for decision making. Processes such as edge detection, segmentation, and shape matching yield results which could bias higher level decision making, unless some framework is defined for the representation of uncertainty in the context of fuzzy set theory where membership values associated with the fuzzy sets contain a consistent ...
1986-02-01
Rapid Responding Palladium-Silver Surface Modified Microsensor for Hydrogen
Most palladium thin film based hydrogen gas sensors have response and recovery times that are too long to make them useful in vehicular and stationary gas leak detection applications. In contrast, a palladium-silver thin film based microcantilever (MC) hydrogen gas microsensor is reported herein with near ideal response characteristics for use in these hydrogen economy related applications. Specifically, 3-10 second response and recovery times have been measured for these sensors in contrast to previous sensor response measurements of several to tens of minutes using Pd thin film and MC based sensing techniques. The much reduced response times observed in the present study are attributed to a wet chemical Pd-Ag thin film deposition technique and a gas conditioning protocol that produces a highly nanostructured, porous film that rapidly adsorbs and desorbs H2, allowing rapid equilibration with the H2 concentration in the surrounding air. The wet chemical process and ...
2010-01-01
Radiation processed sawdust-clay-plastic composite. [Gamma radiation
Energy Technology Data Exchange (ETDEWEB)
Wood sawdust has been applied to manufacture the sawdust-clay-plastic composite (SDCPC) by radiation process for the purpose of disposing large amount of wood sawdust waste material. The process comprises the impregnation of liquid vinyl monomers into the completely dried molded sawdust-clay specimens followed by exposure to Co-60 gamma-radiation to induce graft-copolymerization of the impregnated vinyl monomers onto the sawdust-clay matrix. The comonomer system of unsaturated polyester and vinyl compounds was found to be the ideal impregnating monomer for the preparation of the SDCPC from the viewpoint of the technological and economical advantages. The SDCPC material has a variety of the sawdust content which enables the composite to have wide range of mechanical properties, e.g., 410 to 1100 kg/cm/sup 2/ in compressive strength, 120 to 380 kg/cm/sup 2/ in tensile strength and 0.32 to 4.41 kg/mm/sup 2/ in static bending strength. The SDCPC having higher content ...
1983-01-01
Energy Technology Data Exchange (ETDEWEB)
The goal of this work was to develop a process flow diagram to economically produce a clean-burning fuel from fine Illinois coal. To accomplish this, the process of pelletizing fine coal with calcium hydroxide, a sulfur capturing sorbent, was investigated. Carbonation, which is the reaction of calcium hydroxide with carbon dioxide (in the presence of moisture) to produce a bonding matrix of calcium carbonate, was investigated as a method for improving pellet quality and reducing binder costs. Proper moisture level is critical to allow the reaction to occur. If too much moisture is present in a pellet, the pore spaces are filled and carbon dioxide must diffuse through the water to reach the calcium hydroxide and react. This severely slows or stops the reaction. The ideal situation is when there is just enough moisture to coat the calcium hydroxide allowing for the reaction to proceed. The process has been successfully demonstrated on a pilot-scale as a method of ...
1991-12-31
Precision Measurement of the Undulator K Parameter using Spontaneous Radiation
Energy Technology Data Exchange (ETDEWEB)
Obtaining precise values of the undulator parameter, K, is critical for producing high-gain FEL radiation. At the LCLS [1], where the FEL wavelength reaches down to 1.5 {angstrom}, the relative precision of K must satisfy ({Delta}K/K){sub rms} {approx}< 0.015% over the full length of the undulator. Transverse misalignments, construction errors, radiation damage, and temperature variations all contribute to errors in the mean K values among the undulator segments. It is therefore important to develop some means to measure relative K values, after installation and alignment. We propose a method using the angle-integrated spontaneous radiation spectrum of two nearby undulator segments, and the natural shot-to-shot energy jitter of the electron beam. Simulation of this scheme is presented using both ideal and measured undulator fields. By ''leap-frogging'' to different pairs of segments with extended separations we hope to ...
2007-04-17
Measurement of redshifted 21-cm emission from neutral hydrogen promises to be the most effective method for studying the reionisation history of hydrogen and, indirectly, the first galaxies. These studies will be limited not by raw sensitivity to the signal, but rather, by bright foreground radiation from Galactic and extragalactic radio sources and the Galactic continuum. In addition, leakage due to gain errors and non-ideal feeds conspire to further contaminate low-frequency radio obsevations. This leakage leads to a portion of the complex linear polarisation signal finding its way into Stokes I, and inhibits the detection of the non-polarised cosmological signal from the epoch of reionisation. In this work, we show that rotation measure synthesis can be used to recover the signature of cosmic hydrogen reionisation in the presence of contamination by polarised foregrounds. To achieve this, we apply the rotation measure synthesis technique to the Stokes I ...
2010-01-01
Phenomenological Theory of the Kink Instability in a Slender Plasma Column
Energy Technology Data Exchange (ETDEWEB)
When one deals with a plasma column whose radius a is much smaller than its length L, one can think of it as of a thin filament whose kink instability can be adequately described simply by a 2D displacement vector, {xi}{sub x} = {xi}{sub s}(z,t); {xi}{sub y} = {xi}{sub y}(z,t). Details of the internal structure of the column such as the current, density, and axial flow velocity distribution would be lumped into some phenomenological parameters. This approach is particularly efficient in the problems with non-ideal (sheath) boundary conditions (BC) at the end electrodes, with the finite plasma resistivity, and with a substantial axial flow. With the sheath BC imposed at one of the end-plates, we find instability in the domain well below the classical Kruskal-Shafranov limit. The presence of an axial flow causes the onset of rotation of the kink and strong axial ''skewness'' of the eigenfunction, with the perturbation amplitude ...
2005-11-18
Phase separation in H2O:N2 mixture - molecular dynamics simulations using atomistic force fields
Energy Technology Data Exchange (ETDEWEB)
A class II atomistic force field with Lennard-Jones 6-9 nonbond interactions is used to investigate equations of state (EOS) for important high explosive detonation products N{sub 2} and H{sub 2}O in the temperature range 700-2500 K and pressure range 0.1-10 GPa. A standard 6th order parameter-mixing scheme is then employed to study a 2:1 (molar) H{sub 2}O:N{sub 2} mixture, to investigate in particular the possibility of phase-separation under detonation conditions. The simulations demonstrate several important results, including: (1) the accuracy of computed EOS for both N{sub 2} and H{sub 2}O over the entire range of temperature and pressure considered; (2) accurate mixing-demixing phase boundary as compared to experimental data; and (3) the departure of mixing free energy from that predicted by ideal mixing law. The results provide comparison and guidance to state-of-the-art chemical kinetic models.
2006-09-25
On the bending response of Kevlar 49/epoxy beams and rings
Energy Technology Data Exchange (ETDEWEB)
Kevlar 49/epoxy laminates often exhibit substantial material nonlinearity when subjected to bending. This is a consequence of the yeild-like behavior of a Kevlar 49/epoxy lamina in fiber-directed compression. In this paper, analyses that utilize a simple idealization of compressive yielding are described and calculated results for Kevlar 49 reinforced beams and rings are compared with available data. First, results of a finite element analysis of a thin, unidirectionally reinforced ring subjected to diametral compression are presented. This analysis uses beam elements that incorporate linear tensile and elastic-perfectly plastic compressive behavior. Then a method used to analyze quasi-isotropic beams tested in four-point bending is discussed. This finite element analysis uses a layered shell element with a lamina constitutive model that permits elastic-perfectly plastic response to fiber-directed compression, but otherwise assumes linear elastic behavior. ...
1988-05-01
Obsidians and tektites: Natural analogues for water diffusion in nuclear waste glasses
Energy Technology Data Exchange (ETDEWEB)
Projected scenarios for the proposed Yucca Mountain repository include significant periods of time when high relative humidity atmospheres will be present, thus the reaction processes of interest will include those known to occur under these conditions. The ideal natural analog for the proposed Yucca Mountain repository would consist of natural borosilicate glasses exposed to expected repository conditions for thousands of years; however, the prospects for identifying such an analog are remote, but an important caveat for using natural analog studies is to relate the reaction processes in the analog to those in the system of interest, rather than a strict comparison of the glass compositions. In lieu of this, identifying natural glasses that have reacted via reaction processes expected in the repository is the most attractive option. The goal of this study is to quantify molecular water diffusion in the natural analogs obsidian and tektites. Results from this study ...
1991-11-01
OPERATION OF A PUBLIC GEOLOGIC CORE AND SAMPLE REPOSITORY IN HOUSTON TEXAS
Energy Technology Data Exchange (ETDEWEB)
In the spring of 2002, the Department of Energy provided an initial 1-year grant to the Bureau of Economic Geology (BEG) at The University of Texas at Austin (UT). The grant covered the one-year operational expenses of a worldclass core and cuttings facility located in Houston, Texas, that BP America donated to the BEG. The DOE investment of $300,000, matched by a $75,000 UT contribution, provided critical first-year funds that were heavily leveraged by the BP gift of $7.0 million in facilities and cash. DOE also provided a one-month extension and grant of $30,000 for the month of May 2003. A 5-year plan to grow a permanent endowment in order to manage the facility in perpetuity is well under way and on schedule. The facility, named the Houston Research Center, represents an ideal model for a strong Federal, university, and private partnership to accomplish a national good. This report summarizes the activities supported by the initial DOE grant during the first 13 ...
2003-06-01
Monte-Carlo simulations of 2-MeV #alpha#-particle channeling in Si_1_-_xSn_x alloy
International Nuclear Information System (INIS)
Monte-Carlo simulations of 2-MeV #alpha#-particle channeling in Si_1_-_xSn_x alloys with 0#<=#x#<=#1 have been performed. The simulations are compared with measured channeling-angular scans for strained Si_0_._9_5Sn_0_._0_5 layers grown by molecular beam epitaxy (MBE). Agreement between simulated and measured angular scans can only be achieved if we assume a deviation of the crystal structure from the ideal one. This deviation can be attributed to a mosaic structure in the films and to an atomic-scale distortion of the crystal lattice due to an expected difference in the bond lengths between the Si-Si, Si-Sn and Sn-Sn atoms (such a difference in bond lengths has been observed in the epitaxial Si_1_-_xGe_x system). The contributions from both of these imperfections are estimated and discussed.
2000-04-01
Micromechanical modeling of ferrite-pearlite steels using finite element unit cell models
Energy Technology Data Exchange (ETDEWEB)
An axisymmetric unit cell model based on a regular array of second-phase particles arranged on a BCC lattice is used to study deformation mechanisms of ferrite-pearlite structural steels. Microstructural characteristics of the steels were parameterized by the pearlite volume fraction, the aspect ratio of the pearlite particles, and the neighboring factor, which represents the ratio of interparticle spacing in the longitudinal direction to that in the transverse direction. FE analyses were carried out to investigate the macroscopic and microscopic response of unit cells with morphological features based on idealizations of the microstructures of the actual steels. Tensile properties of each constituent phase were obtained experimentally and used in the analyses. As compared to traditional axisymmetric models, the BCC tell model appears to be able to capture more realistically the behavior of the materials, and it accurately estimates the tensile behavior of the ...
2000-11-01
Measuring the quark contribution to the proton spin through. nu. p yields. nu. p
Energy Technology Data Exchange (ETDEWEB)
The LSND (Liquid Scintillator Neutrino Detector) experiment will be performed at LAMPF in the next several years. The main goal of the experiment is to search for {nu}{sub {mu}}-{nu}{sub e} oscillations with high sensitivity; however, an increasingly important by-product of this search is to measure {nu}p {yields} {nu}p elastic scattering and determine the strange quark contribution, {Delta}s, to the spin of the proton. With the 800-MeV proton energy of LAMPF, neutrinos are produced from pion decay-in-flight with an average energy of about 150 MeV. This energy is sufficiently high so that the {nu}p {yields} {nu}p cross section is large and is sufficiently low so that the low Q{sup 2} approximation (Q{sup 2} {much lt} m{sub p}{sup 2}) is valid and the cross section can be expressed in a simple form dependent upon {Delta}s as the only unknown. LAMPF with its 1-mA proton intensity is, therefore, an ideal accelerator to perform this measurement. 12 refs., 7 figs., 2 ...
1991-01-01
Energy Technology Data Exchange (ETDEWEB)
Gallium is present in surplus weapons-grade plutonium (WG-Pu) at a concentration of approximately 1 wt %. Plans are to dispose of surplus WG-Pu by converting it to UO{sub 2}-PuO{sub 2} mixed oxide (MOX) fuel and irradiating it in commercial power reactors. However, the presence of high concentrations of gallium in plutonium poses a potential corrosion problem during the process of MOX fuel irradiation. The batch experiments performed in this study were designed to measure the capability of the PUREX solvent extraction process to separate gallium from plutonium under idealized conditions. Radioactive tracing of the gallium with {sup 72}Ga enabled the accurate measurement of low concentrations of extractable gallium. The experiments approximated the proposed flowsheet for WG-Pu purification, except that only one stage was used for each process: extraction, scrubbing, and stripping. The gallium decontamination factor (DF) obtained after one extraction stage was about ...
2000-07-01
International Nuclear Information System (INIS)
Radiation defects produced by helium implantation were used to shape profiles of palladium (Pd) and platinum (Pt) atoms in-diffusing (for 20 min at temperatures 600-800 deg. C) either from surface silicide (Pd_2Si, PtSi) or implanted layers. Results show that this procedure allows a strong localization of substitutional Pd and Pt at the depth where the damage produced by helium peaks. This results in local reduction of carrier lifetime by an almost ideal recombination centers - the acceptor level of substitutional Pd (E _c - 0.22 eV) or Pt (E _c - 0.23 eV). While optimum conditions for Pt in-diffusion are about 700 deg. C, Pd gives the best results already at lower temperatures (600 deg. C) where it also exhibits higher peak solubility. Both methods were used for optimization of turn-off properties of high power PiN diodes. The devices, where the lifetime was killed locally by Pd and Pt, exhibited similar trade-off between the static and dynamic parameters as the ...
2006-12-01
Energy Technology Data Exchange (ETDEWEB)
Excellent silicided shallow p{sup +}n junctions have been successfully achieved by the implantation of BF{sub 2}{sup +} ions into thin Pd{sub 2}Si films on Si substrates to a dose of 5 {times} 10{sup 15} cm{sup {minus}2} and subsequent low temperature (even at 550 C) furnace annealing. The formed junctions have been characterized for respective implantation conditions. In this experiment, the implant energy is the key role in obtaining a low leakage diode. Reverse current density of about 3 nA/cm{sup 2} and an ideality factor of about 1.05 can be attained by the implantation of BF{sub 2}{sup +} ions at 80 keV and subsequent annealing at 550 C. The junction depth is about 0.09 {mu}m, measured by the spread resistance method. As compared with the results of unimplanted specimens, the implantation of BF{sub 2}{sup +} ions into a thin Pd{sub 2}Si layer can stabilize the silicide film and prevent it from forming islands during high temperature annealing.
1995-05-01
Laser stabilization at 1536 nm using regenerative spectral hole burning
International Nuclear Information System (INIS)
Laser frequency stabilization giving a 500-Hz Allan deviation for a 2-ms integration time with drift reduced to 7 kHz/min over several minutes was achieved at 1536 nm in the optical communication band. A continuously regenerated spectral hole in the inhomogeneously broadened "4I_1_5_/_2(1)#->#"4I_1_3_/_2(1) optical absorption of an Er"3"+:Y_2SiO_5 crystal was used as the short-term frequency reference, while a variation on the locking technique allowed simultaneous use of the inhomogeneously broadened absorption line as a long-term reference. The reported frequency stability was achieved without vibration isolation. Spectral hole burning frequency stabilization provides ideal laser sources for high-resolution spectroscopy, real-time optical signal processing, and a range of applications requiring ultra-narrow-band light sources or coherent detection; the time scale for stability and the compatibility with spectral hole burning devices make this technique ...
2001-04-15
Kapitza conductance of the (100) surface of copper
International Nuclear Information System (INIS)
Measurements of the Kapitza conductance to liquid helium II across the (100) surface of single crystals of copper are presented. The temperature range of these measurements was 1.6-- 2.1 K. The sample surfaces were subjected to several different treatments. Some surfaces were cleaned by low-energy argon ion bombardment, annealed in an ultrahigh-vacuum system, and preserved under vacuum until purified liquid helium was admitted. Other surfaces were intentionally damaged by machining and/or exposure to the atmosphere. The conductance after these latter treatments was found to be about a factor of three higher than that of the more ideally cleaned and annealed surfaces, and a significant difference in the temperature dependence of the conductance was also observed. Conductances were reproducible for similarly treated surfaces and correlated with surface damage determined by x-ray diffraction. The relationship of these results to the numerous current theories of the ...
International Nuclear Information System (INIS)
The purpose of this study was to determine the optimal technique for delivering postoperative radiotherapy for vulvar cancer and other tumors requiring treatment of the inguinal nodes. This project compared tumor coverage and normal tissue sparing for the 5 main radiotherapy techniques that are used to treat vulvar cancer. The intensity-modulated radiation therapy (IMRT) plan was undesirable because it resulted in an excessive dose to portions of the central pelvic structures. The photon thunderbird with skin match was unacceptable because it underdosed a portion of the groin region. The electron thunderbird was ideal for thin patients but was not applicable for most patients because of excessive dose to the skin and subcutaneous tissues. The photon through-and-through and the photon thunderbird with deep match were acceptable in most situations. In thin patients, where the depth of the inguinal vessels is less than 3 cm, the electron thunderbird is the technique ...
How epitaxial are Pd/sub 2/Si-Si interfaces
Energy Technology Data Exchange (ETDEWEB)
Pd/sub 2/Si layers produced by evaporation or sputtering onto silicon substrates were examined by high resolution electron microscopy, microdiffraction, X-ray, energy loss and Auger spectroscopy. The Si-Pd/sub 2/Si interfaces produced by evaporation were in all cases rougher and more polycrystalline than those produced by sputtering. X-ray microanalysis showed the predictable variation in palladium distribution across the interface but quantification did not produce the expected palladium-to-silicon ratios, primarily because of probe broadening and X-ray-induced fluorescence. Energy loss spectra showed plasmon energy shifts and changes in Si L edge shape due to bond formation with palladium. Auger data provided evidence for a small amount of oxygen at the Si-Pd/sub 2/Si interface. Electrical measurements of the ideality factor for Schottky barriers made from the materials produced higher values for the rougher evaporation-formed interfaces consistent with ...
1983-06-17
GaAs Blocked-Impurity-Band Detectors for Far-Infrared Astronomy
Energy Technology Data Exchange (ETDEWEB)
High-purity and doped GaAs films have been grown by Liquid-phase epitaxy (LPE) for development of a blocked impurity band (BIB) detector for far-infrared radiation. The film growth process developed has resulted in the capability to grow GaAs with a net active impurity concentration below 1 x 10{sup 13} cm{sup -3}, ideal for the blocking layer of the BIB detector. The growth of n-type LPE GaAs films with donor concentrations below the metal-insulator transition, as required for the absorbing layer of a BIB detector, has been achieved. The control of the donor concentration, however, was found to be insufficient for detector production. The growth by LPE of a high-purity film onto a commercially grown vapor-phase epitaxial (VPE) n-type GaAs doped absorbing layer resulted in a BIB device that showed a significant reduction in the low-temperature dark current compared to the absorbing layer only. Extended optical response was not detected, most likely due to the high ...
2004-12-21
Fully quantized many-particle theory of a free-electron laser
Energy Technology Data Exchange (ETDEWEB)
A fully quantized many-particle theory of the standard free-electron laser in the small-signal, cold-beam regime is presented. The approach is based on an evaluation of the time-evolution operator in the interaction picture to first order in the quantum-mechanical recoil. For algebraic convenience we use the moving (Bambini-Renieri) frame, in which resonance occurs for zero electron momentum. Though we neglect space-charge effects, genuine many-particle contributions still show up, because the radiation emitted by one electron can be amplified by another electron. Our main results are gross features of the amplification, such as gain and spread, are virtually without many-particle effects. These effects are mainly important in the case of spontaneous emission. For a sufficiently high current, the buildup of the laser field from vacuum is enhanced by amplified spontaneous emission. Incoherence of the spontaneous radiation from several electrons induces deviations from Poisson statistics ...
1983-02-01
International Nuclear Information System (INIS)
The linearized-augmented-plane-wave (LAPW) method for thin films is generalized by removing the remaining shape approximation to the potential inside the atomic spheres. A new technique for solving Poisson's equation for a general charge density and potential is described and implemented in the film LAPW method. In the resulting full-potential LAPW method (FLAPW), all contributions to the potential are completely taken into account in the Hamiltonian matrix elements. The accuracy of the method: already well known for clean metal surfaces: is demonstrated for the case of a nearly free (noninteracting) O_2 molecule which is a severe test case of the method because of its large anisotropic charge distribution. Detailed comparisons show that the accuracy of the FLAPW results for O_2 exceeds that of existing state-of-the-art local-density linear-combination-of-atomic-orbitals (LCAO)-type calculations, and that taking the full potential LAPW results as a reference, the LCAO basis can be ...
First detection of polarized scattered light from an exoplanetary atmosphere
We report the first direct detection of an exoplanet in polarized scattered light. The transiting planet HD189733b is one of the very hot Jupiters with shortest periods and, thus, smallest orbits, which makes them ideal candidates for polarimetric detections. We obtained polarimetric measurements of HD189733 in the $B$ band well distributed over the orbital period and detected two polarization maxima near planetary elongations with the peak amplitude of $\\sim2\\cdot10^{-4}$. Assuming Rayleigh scattering, we estimated the effective size of the scattering atmosphere (Lambert sphere) to be 1.5$\\pm$0.2 $R_{\\rm J}$, which is 30% larger than the radius of the opaque body previously inferred from transits. If the scattering matter fills the planetary Roche lobe, the lower limit of the geometrical albedo can be estimated as 0.14. The phase dependence of polarization indicates that the planetary orbit is oriented almost in the north-south direction with the longitude of ...
2007-01-01
Energy Technology Data Exchange (ETDEWEB)
The {sup 252}Cf-source-driven frequency analysis method can be used for measuring the subcritical neutron multiplication factor of arrays of LWR fuel and as little as a single PWR fuel assembly. These measurements can be used to verify the criticality safety margins of spent LWR fuel configurations and thus could be a means of obtaining the information to justify burnup credit for spent LWR transportation/storage casks. In addition, the data can be used to validate calculational methods for criticality safety. These measurements provide parameters that have a higher sensitivity to changes in fissile mass than neutron multiplication factor and thus serve as a better test of calculational methods. The analysis have also shown that measurement of the cross power spectral density (CPSD) between detectors on one side of a single fuel assembly and an internal or external {sup 252}Cf source driving the fission chain multiplication process can be used for nondestructive assay of fissile mass ...
1996-05-01
Failure analysis of CO_2 anti-freezing heater at Daya Bay Nuclear Power Station
International Nuclear Information System (INIS)
In this paper, an investigation was performed on a failure pressure vessel, which was as an anti-freezing heater for General Gas Storage and Distribution (SGZ) system. Evident and serious deformation was observed on the body of the vessel. A metallurgical investigation was conducted to establish the mechanism and cause of deformation of the anti-freezing heater at Daya Bay PWR station in China. The investigation, which was performed on specimens cut from the most serious area deformed of the vessel, included macroscopic examination and microscopy examination. The results of the examinations showed that some lamellar pearlite in the microstructure were already spheroidized. It was confirmed that the vessel was operated at high temperature. Stress analysis for the vessel was conducted. And it was confirmed that, in ideal conditions, the vessel would be deformed at around 420 C. The overall results of the investigation showed that the failure of the protected ...
2002-09-23
Environmental strategy for energy: hydrogen fuel cell bus for Brazil
Energy Technology Data Exchange (ETDEWEB)
One of the most densely populated urban regions in the world is the Sao Paulo Metropolitan region (SPMR) in the State of Sao Paulo, Brazil. Air pollution is a real problem, mainly caused by vehicle exhaust fumes. The air pollution abatement measures adopted in the SPMR, such as the addition of ethanol to gasoline, the use of cars running on pure alcohol, the restrictions in the circulation of vehicles and the utilization of electronic fuel injection and catalyst have had a positive effect on the environment. The 25,000 buses and approximately 400,000 trucks, all operating on diesel, have not been affected by these measures, and it is believed that SPMR is the ideal location for testing new vehicular pollution reduction technologies. A project to this effect was launched by the Ministry of Mines and Energy in conjunction with a host of other partners, and it involved the operation of a fuel cell bus using hydrogen produced by electrolysis. The project was divided ...
2001-06-01
Electrical grid stability and its impact on nuclear power generating stations
Energy Technology Data Exchange (ETDEWEB)
Electrical power is generated by steam turbines (steam being produced by coal, oil, gas or nuclear reactors), hydro units, gas turbines, internal combustion engines, jet engines, and pumped storage plants. Nuclear Power Plants generate only 15% of the total electrical power in the US. Nuclear Power Plants being cheaper to run are generally base loaded. The pumped-storage and gas turbine plants have ideal characteristics for peaking duty. In the pumping mode, pumped storage plants are used to provide additional system load and in the generating mode, they supply reactive power during peak load demands. Gas turbine plants have higher running costs, but are used as peaking units with a fast start capability. Fossil power plants need a minimum of 1 hour to stabilize expansion in the boiler and turbine generator. Due to a more competitive power supply market due to deregulation, most of the utilizes plan generation only for the next three years. This paper discusses the ...
1997-12-31
Energy Technology Data Exchange (ETDEWEB)
Deteriorating air quality in urban areas is leading bus manufacturers to look for cleaner drives of urban buses. Various new systems are now available, but it is difficult to compare them and verify their effects without having a driving cycle accurately representing contemporary average urban bus use. The idealized form (engine cycle, passenger car cycle or different kW/tonnes ratio and traffic conditions) of existing driving cycles disqualifies them for the purpose. For this reason, it was decided to attempt the development of a new driving cycle for urban buses. To this end, measurements were carried out on buses in service in four major Dutch towns. The resulting data were combined to produce a reference cycle comprising all data relating to urban bus use. Statistical methods were then used to compare a large number of 15-20 minute cycles with this reference cycle, until one was found that corresponded closely to the reference cycle. 5 figs., 1 tab., 6 refs.
1994-12-31
Energy Technology Data Exchange (ETDEWEB)
Automated, variable volume unloaders provide the ability to smoothly load/unload reciprocating compressors to maintain ideal operations in ever-changing environments. Potential advantages provided by this load control system include: maximizing unit capacity, optimizing power economy, maintaining low exhaust emissions, and maintaining process suction and discharge pressures. Obstacles foreseen include: reliability, stability, serviceability and automation integration. Results desired include: increased productivity for the compressor and its operators, increased up time, and more stable process control. This presentation covers: system design features with descriptions of how different types of the devices were developed, initial test data, and how they can be effectively operated; three actual-case studies detailing the reasons why automated, hydraulically controlled, variable volume, head-end unloaders were chosen over other types of unloading devices; ...
2003-07-01
Development of Improved Burnable Poisons for Commercial Nuclear Power Reactors
Energy Technology Data Exchange (ETDEWEB)
Burnable poisons are used in nuclear reactors to produce a more level distribution of power in the reactor core and to reduce to necessity for a large control system. An ideal burnable poison would burn at the same rate as the fuel. In this study, separation of neutron-absorbing isotopes was investigated in order to eliminate isotopes that remain as absorbers at the end of fuel life, thus reducing useful fuel life. The isotopes Gd-157, Dy-164, and Er-167 were found to have desirable properties. These isotopes were separated from naturally occurring elements by means of plasma separation to evaluate feasibility and cost. It was found that pure Gd-157 could save approximately $6 million at the end of four years. However, the cost of separation, using the existing facility, made separation cost- ineffective. Using a magnet with three times the field strength is expected to reduce the cost by a factor of ten, making isotopically separated burnable poisons a favorable ...
2003-09-30
Development of GaInAsP for GaInAsP/Ge cascade solar cells
Energy Technology Data Exchange (ETDEWEB)
Quaternary semiconductor compounds are ideal candidates for use in monolithic cascade solar cells because the lattice constant and the bandgap of such compounds can be independently varied. The quaternary semiconductor compound Ga[sub 0.83]In[sub 0.17]As[sub 0.67]P[sub 0.33] not only is lattice matched to GaAs and Ge but also provides a current matched top cell for the GaInAsP/Ge monolithic cascade solar cell. Under concentration of 100 suns, the projected efficiency for such a cell is about 34%. The growth of Ga[sub 0.83]In[sub 0.17]As[sub 0.67]P[sub 0.33] lattice matched to GaAs and Ge has been demonstrated. GaInAsP solar cells have been grown on both GaAs and Ge substrates. A GaInAsP on GaAs solar cell with an active area efficiency of 23.2% for 1 sun, AM 1.5 direct illumination has been prepared. A proposed structure for the GaInAsP/Ge cascade cell is also given.
1992-12-01
Configurational diffusion of coal macromolecules
Energy Technology Data Exchange (ETDEWEB)
The objective of our research was to obtain fundamental information regarding the functional dependence of the diffusion coefficient of coal molecules on the ratio of molecule to pore diameter. That is, the objective of our study was to examine the effect of molecule size and configuration on hindered diffusion of coal macromolecules through as porous medium. To best accomplish this task, we circumvented the complexities of an actual porous catalyst by using a well defined porous matrix with uniform capillaric pores, i.e., a track-etched membrane. In this way, useful information was obtained regarding the relationship of molecular size and configuration on the diffusion rate of coal derived macromolecules through a pore structure with known geometry. Similar studies were performed using a pellet formed of porous alumina, to provide a link between the idealized membranes and the actual complex pore structure of real catalyst extrudates. The fundamental information ...
1991-01-01
Computed tomography of the thorax: a status report
Energy Technology Data Exchange (ETDEWEB)
Computed tomography (CT) of the thorax shows early promise of important diagnostic advances. We believe that CT often provides information superior to that provided by standard roentgenographic techniques, is capable of significantly influencing patient management, and in selected instances, offers unique information not available by other methods. Computed tomography permits the imaging of mediastinal structures not possible with conventional roentgenographic methods and can diagnose with certainty benign mediastinal conditions such as pericardial cysts and focal or diffuse accumulations of fat. It is ideal for detecting pleural abnormalities and for displaying underlying parenchymal disease in patients with complex pleuroparenchymal shadows on conventional films. Pulmonary metastases unseen on the plain chest film can be detected with greater sensitivity than by any other method. Future applications of CT include the staging of mediastinal lymph nodes in ...
1981-11-01
Computed tomography of the thorax: a status report
International Nuclear Information System (INIS)
Computed tomography (CT) of the thorax shows early promise of important diagnostic advances. We believe that CT often provides information superior to that provided by standard roentgenographic techniques, is capable of significantly influencing patient management, and in selected instances, offers unique information not available by other methods. Computed tomography permits the imaging of mediastinal structures not possible with conventional roentgenographic methods and can diagnose with certainty benign mediastinal conditions such as pericardial cysts and focal or diffuse accumulations of fat. It is ideal for detecting pleural abnormalities and for displaying underlying parenchymal disease in patients with complex pleuroparenchymal shadows on conventional films. Pulmonary metastases unseen on the plain chest film can be detected with greater sensitivity than by any other method. Future applications of CT include the staging of mediastinal lymph nodes in ...
Energy Technology Data Exchange (ETDEWEB)
This work presents an overview of the characterization physical-chemistry and energy of the aca pit used as input in process of generation of electricity through gasification. Acai pits analyses were accomplished with relationship to the acai pit drying, energy content, proximate and ultimate analyses, size, TGA experiments, bulk density. It was observed that the acai pit can be used as bioenergy but, it presents a low energy content (16,36 MJ/kg) in relationship that of the ' typical' biomass (21 MJ/kg ) and this is not due to the ash content that is very low (1,15%), but yes, the only composition that resembles each other more the Carbohydrates than to the typical composition of the usual biomass. The average diameter of 10 pits chosen at random was 9.5 mm. The acai pits have an angle of repose of {approx}20 degrees, making them ideal for feeding into gasification and combustion processes. (author)
2008-07-01
Bundling harvester; Nippukorjausharvesteri
Energy Technology Data Exchange (ETDEWEB)
The staring point of the project was to design and construct, by taking the silvicultural point of view into account, a harvesting and processing system especially for energy-wood, containing manually driven bundling harvester, automatizing of the harvester, and automatized loading. The equipment forms an ideal method for entrepreneur`s-line harvesting. The target is to apply the system also for owner`s-line harvesting. The profitability of the system promotes the utilization of the system in both cases. The objectives of the project were: to construct a test equipment and prototypes for all the project stages, to carry out terrain and strain tests in order to examine the usability and durability, as well as the capacity of the machine, to test the applicability of the Eko-Log system in simultaneous harvesting of energy and pulp woods, and to start the marketing and manufacturing of the products. The basic problems of the construction of the bundling harvester have ...
1996-12-31
Baryonic Collapse within Dark Matter Halos and the Formation of Gaseous Galactic Disks
This paper constructs an analytic framework for calculating the assembly of galactic disks from the collapse of gas within dark matter halos, with the goal of determining the surface density profiles. Gas parcels (baryons) fall through the potentials of dark matter halos on nearly ballistic, zero energy orbits and collect in a rotating disk. The dark matter halos have a nearly universal form, as determined previously through numerical simulations. The calculation is first carried out for a variety of pre-collapse mass distributions and rotation profiles, including polytropic spheres in hydrostatic equilibrium with the halo potential. The resulting disk surface density profiles have nearly power-law forms, with well-defined edges. This idealized scenario is generalized to include non-spherical starting states and multiple accretion events (due to gas being added to the halo via merger events). This latter complication is explored in detail and considers a log-normal ...
2006-01-01
Ballard fuel cells and the changing energy landscape
Energy Technology Data Exchange (ETDEWEB)
The numerous challenges facing the North American electric utility industry were discussed. In addition to competition, electric utilities are faced with low demand growth, public pressure to avoid adding transmission and distribution capacity, and strict environmental requirements. In view of these developments, large central generation additions that have been industry norm until recently, do not always make economic sense in the current environment. Instead, smaller, distributed additions to generating capacity is becoming the new norm. Small-scale on-site generating capacity has the added advantage of reducing the need for expensive high-voltage transmission lines. The Ballard generation system described here is a modular, efficient fuel cell-based solution to implementing distributed power concepts. The system is natural gas fueled, with low noise, vibration and emissions. Apart from its other advantages, it provides ideal convergence opportunity by using the ...
1997-02-01
The purpose of the study was to investigate the adequacy of educational services available for the implementation of the ideals of the Universal Basic Education (UBE) in Southern Nigeria. Using the multistage sampling technique, 800 primary school teachers were selected from the three geo political zones in Southern Nigeria as participants in the study. However, 1457 usable copies of the questionnaire administered to participants were used for the final study. The researchers collected and analyzed data to (1) Ascertain how free the UBE was in Southern Nigeria and (2) to determine if educational services were adequately provided for the implementation of the programme. Results of data analysis suggest that the UBE was not entirely free as parents still buy books and report cards for their children in primary schools. Also, educational services were not adequately provided in the schools. Recommendations were made to government on how to improve the situation so as ...
2005-12-01
An adaptive filter to approximate the Bayesian strategy for sonographic beamforming.
A first-principles task-based approach to the design of medical ultrasonic imaging systems for breast lesion discrimination is described. This study explores a new approximation to the ideal Bayesian observer strategy that allows for object heterogeneity. The new method, called iterative Wiener filtering, is implemented using echo data simulations and a phantom study. We studied five lesion features closely associated with visual discrimination for clinical diagnosis. A series of human observer measurements for the same image data allowed us to quantitatively compare alternative beamforming strategies through measurements of visual discrimination efficiency. Employing the Smith-Wagner model observer, we were able to breakdown efficiency estimates and identify the processing stage at which performance losses occur. The methods were implemented using a commercial scanner and a cyst phantom to explore development of spatial filters for systems with shift-variant ...
2010-07-19
Divided into three sections, this paper briefly presents Kohlberg's theory of moral reasoning; surveys some key research relating childrearing practices to adolescents' social competence, including moral reasoning; and reports research findings concerning the value systems adolescents develop. The first section characterizes preconventional, conventional, and postconventional morality and explores ways of promoting the development of a mature concept of justice, which includes role taking and living in a "just community." The second section focuses on aspects of social learning, which include authoritative parenting, inductive discipline, argumentative discourse, and tradition-based upbringing. In addition, this section explores socialization practices that hinder the development of mature moral reasoning. Focusing initially on characteristics of alienated youth and parental influences on such youth, the third section describes studies investigating the values development of New York ...
1981-12-01
We present new results from accurate and fully general-relativistic simulations of the coalescence of unmagnetized binary neutron stars with various mass ratios. The evolution of the stars is followed through the inspiral phase, the merger and prompt collapse to a black hole, up until the appearance of a thick accretion disk, which is studied as it enters and remains in a regime of quasi-steady accretion. Although a simple ideal-fluid equation of state with \\Gamma=2 is used, this work presents a systematic study within a fully general relativistic framework of the properties of the resulting black-hole--torus system produced by the merger of unequal-mass binaries. More specifically, we show that: (1) The mass of the torus increases considerably with the mass asymmetry and equal-mass binaries do not produce significant tori if they have a total baryonic mass M_tot >~ 3.7 M_sun; (2) Tori with masses M_tor ~ 0.2 M_sun are measured for binaries with M_tot ~ 3.4 ...
2010-01-01
A thermodynamic analysis of alternative approaches to chemical looping combustion
Energy Technology Data Exchange (ETDEWEB)
In this article, we review and clarify some of the points made by previous authors regarding chemical looping combustion (CLC). While much of the recent interest in chemical looping combustion has been associated with carbon sequestration, our primary interest here is its potential to increase the thermodynamic efficiency of converting fuel chemical energy into useful work. We expand on several points about the details of CLC that we feel have not previously been sufficiently explored, and suggest alternative (and possibly more practical) approaches that exploit some of the same thermodynamic concepts. We illustrate our key points with {First} and {Second} Law analyses of ideal conceptual processes, which in addition to {CLC} also include isothermal, non-equilibrium, preheated combustion and combustion with thermochemical recuperation. Our results suggest that a significant portion of the potential efficiency benefit of CLC might be achieved without the need to ...
2011-01-01
A procedure for temperature-stress fields calculation of WWER-1000 primary circuit in PTS event
International Nuclear Information System (INIS)
The paper presents the procedure of an investigation of WWER-1000 primary circuit temperature-stress field by the use of thermohydraulic computation data for a pressurized thermal shock event ''Core overcooling''. The procedure is based on a model of the plane stress state with ideal contact between wall and medium for the calculation. The computation data are calculated on the base of WWER-1000 thermohydraulic model by the RELAP5/MOD3 codes. This model was developed jointly by the Bulgarian and BNL/USA staff to provide an analytical tool for performing safety analysis. As a result of calculations by codes the computation data for temperature field law (linear laws of a few distinguished parts) and pressure of coolant at points on inner surface of WWER-1000 primary circuit equipment are received. Such calculations can be used as a base for determination of all-important load-carrying sections of the primary circuit pipes and vessels, which need further ...
1997-05-05
A new lagrangian particle method to describe turbulent flows of fully compressible ideal gases
There are several approaches to describe flows with particles e.g. Lattice-Gas Automata (LGA), Lattice-Boltzmann method (LBM) or smoothed particle hydrodynamics (SPH). These approaches do not use fixed grids on which the Navier-Stokes equations are solved via e.g. finite volume method. The flow is simulated using a multitude of particles or particle density distributions, which interacts and due to statistical laws and an even more fundamental approach than the Navier-Stokes equation, the averaged flow variables can be derived. After a short summary of the most popular particle methods the new DMPC (Dissipative Multiple Particles Collision) approach will be presented. The DMPC-model eliminates some of the weak points of the established particle methods and shows high potential for more accurate CFD solution especially in areas where standard CFD tools still have problems (e.g. aero-acoustics). The DMPC-model deals with discrete circular particles and calculates the detailed collision ...
2008-01-01
Energy Technology Data Exchange (ETDEWEB)
IMRT with inverse planning allows simultaneous integrated boost strategies that exploit the heterogeneous dose distribution within the planning target volumes (PTVs). In this scenario, the location of cold spots within the target becomes a crucial issue and has to be related to the distribution of the clonogenic cell density (CCD). The main aim of this work is to provide the means to calculate the optimal prescription dose in a relative inhomogeneous dose distribution. To achieve this, the prescription dose has to be assigned to obtain the same tumor control probability (TCP) as the ideal homogeneous distribution, taking into account different CCDs in different PTVs (i.e. visible and subclinical regions). An adapted formulation of the linear-quadratic model, within the F-factor formalism, has been derived to preserve a chosen TCP value for the whole target volume. The F-factor has been investigated to show its potential applications in clinical practice.
2008-10-07
International Nuclear Information System (INIS)
Accurate dose calculation in radiation treatment planning is most important for successful treatment. Since human body is composed of various materials and not an ideal shape, it is not easy to calculate the accurate effective dose in the patients. Many methods have been proposed to solve inhomogeneity and surface contour problems. Monte Carlo simulations are regarded as the most accurate method, but it is not appropriate for routine planning because it takes so much time. Pencil beam kernel based convolution/superposition methods were also proposed to correct those effects. Nowadays, many commercial treatment planning systems have adopted this algorithm as a dose calculation engine. The purpose of this study is to verify the accuracy of the dose calculated from pencil beam kernel based treatment planning system comparing to Monte Carlo simulations and measurements especially in inhomogeneous region. Home-made inhomogeneous phantom, Helax-TMS ver. 6.0 and Monte ...
2002-10-20
A Systematic Framework for the Construction of Optimal Complete Complementary Codes
The complete complementary code (CCC) is a sequence family with ideal correlation sums which was proposed by Suehiro and Hatori. Numerous literatures show its applications to direct-spread code-division multiple access (DS-CDMA) systems for inter-channel interference (ICI)-free communication with improved spectral efficiency. In this paper, we propose a systematic framework for the construction of CCCs based on $N$-shift cross-orthogonal sequence families ($N$-CO-SFs). We show theoretical bounds on the size of $N$-CO-SFs and CCCs, and give a set of four algorithms for their generation and extension. The algorithms are optimal in the sense that the size of resulted sequence families achieves theoretical bounds and, with the algorithms, we can construct an optimal CCC consisting of sequences whose lengths are not only almost arbitrary but even variable between sequence families. We also discuss the family size, alphabet size, and lengths of constructible CCCs based ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Diffuse {gamma}-ray emission produced by the interaction of cosmic-ray particles with matter and radiation in the Galaxy can be used to probe the distribution of cosmic rays and their sources in different regions of the Galaxy. With its large field of view and long observation time, the Milagro Gamma Ray Observatory is an ideal instrument for surveying large regions of the Northern Hemisphere sky and for detecting diffuse {gamma}-ray emission at very high energies. Here, the spatial distribution and the flux of the diffuse {gamma}-ray emission in the TeV energy range with a median energy of 15 TeV for Galactic longitudes between 30{sup o} and 110{sup o} and between 136{sup o} and 216{sup o} and for Galactic latitudes between -10{sup o} and 10{sup o} are determined. The measured fluxes are consistent with predictions of the GALPROP model everywhere except for the Cygnus region (l {element_of} [65{sup o}, 85{sup o}]). For the Cygnus region, the flux is twice the ...
2008-05-14
A Compact Linac for Proton Therapy Based on a Dielectric Wall Accelerator
Energy Technology Data Exchange (ETDEWEB)
A novel compact CT-guided intensity modulated proton radiotherapy (IMPT) system is described. The system is being designed to deliver fast IMPT so that larger target volumes and motion management can be accomplished. The system will be ideal for large and complex target volumes in young patients. The basis of the design is the dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL). The DWA uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system will produce individual pulses that can be varied in intensity, energy and spot width. The IMPT planning system will optimize delivery characteristics. The system will be capable of being sited in a conventional linac vault and provide intensity ...
2007-10-29
Energy Technology Data Exchange (ETDEWEB)
By means of a global mode analysis of ideal MHD modes for Mercier-unstable equilibria in a planar axis L=2/M=10 heliotron/torsatron system with an inherently large Shafranov shift, the conjecture from local mode analysis for Mercier-unstable equilibria given in [N. Nakajima, Phys. Plasmas 3, 4556 (1996)] has been confirmed and the properties of pressure-driven modes, namely, ballooning modes and interchange modes, inherent to such three-dimensional systems have been clarified. The change of the local magnetic shear due to the Shafranov shift, which is related to toroidicity, reduces the field line bending stabilizing effects on ballooning modes. According to the degree of the reduction of the local magnetic shear by the Shafranov shift, the Mercier-unstable equilibria are categorized into toroidicity-dominant (strong reduction) and helicity-dominant (weak reduction) Mercier-unstable equilibria. Since the local magnetic curvature due to helicity has the same period ...
1998-12-01
Challenges and Solutions to Producing a Useful High Resolution Soil Moisture Product
Information about surface soil moisture conditions is of critical importance to real-world applications such as agricultural production, water resource management, flood prediction, fire prediction, water supply, military mobility, etc.. Near-surface soil moisture is currently available from non-ideal sensor configuration observations, and two missions targeted at measuring near-surface soil moisture with ideal sensor configuration are expected before the end of the decade (the European Space Agency (ESA), Soil Moisture and Ocean Salinity (SMOS) mission, and the National Aeronautics and Space Administration (NASA), Hydrospheric states "Hydros" mission). Though remote sensing can make spatially comprehensive measurements of surface soil moisture, it cannot provide information on the entire land surface hydrologic system, and the measurements represent only a snap shot in time. Alternatively, land surface hydrology process models may be used to ...
2005-05-01
Prior to 1978, the Wilsonville Advanced Coal Liquefaction facility material balance surrounded only the thermal liquefaction unit and involved analyses of only the slurry stream and individual gas streams. The distillate solvent yield was determined by difference. Subsequently, several modifications and additional process units were introduced to this single unit system. With the inclusion of the deashing unit in 1978 and the catalytic hydrogenation unit in 1981, the process has evolved into a sophisticated two-stage coal liquefaction process and has the potential for various modes of integration. This report presents an elemental balancing procedure and a simplified presentation format that is sufficiently flexible to meet current and future needs. The development of the elemental balancing technique and the relevant computer programs to handle the calculations have been addressed. This will be useful in modelling individual unit performance as well as determining ...
1984-09-01
This report presents the operating results for Run 244 at the Advanced Coal Liquefaction R and D Facility in Wilsonville, Alabama. This run was made in an all-distillate Integrated Two-Stage Liquefaction (ITSL) mode using Illinois 6 coal from the Burning Star mine. The primary objective was to demonstrate the effects of temperature programming an aged catalyst batch on the ITSL product slate, especially on the net C/sub 1/-C/sub 5/ gas production and hydrogen consumption. Other objectives were to demonstrate the effect of fresh catalyst addition and to age the catalyst batch for an extended run with catalyst addition and withdrawal. Run 244 began on 4 July 1983 and continued through 27 September 1983. During this period, 182.9 tons of coal was fed in 1872 hours of operation. Seven special product workup material balances and two hydrotreater balances were defined, and the results are presented herein. From 27 to 30 September, 7.4 tons of Wyodak (Clovis Point mine) ...
1984-05-01
Energy Technology Data Exchange (ETDEWEB)
The production of heavy crude oils increased in the last years in the world. Crude oils with high density, viscosity, acidity and sulfur, nitrogen, metals and asphaltenes contents, by the others hand, low stability and low product quality. The challenger of many refiners is find solutions to refine the heavy crude oils, and produce fuels with certify quality, such as Jet Fuel. The principal aviation technique on the world work with gas turbines engines feted for jet fuel (JET A1). The quality specifications of this fuel are establish by International Norms: ASTM-1655, DEF STAN 91-91-3 (DERD 2494) and joint Fuelling System Check List. The world technologies to obtain jet fuel from mixtures of heavy crude oil with middle crude oils are: Atmospheric distillation, with a posterior hydrogenation and finally the additivation. Studies carried out have demonstrates that the Cubans heavy crude oils is characterized for having API less than 10, raised viscosity, high sulfur ...
2004-07-01
Nuclear desalination for the petrochemical complex of the Natuna project
International Nuclear Information System (INIS)
On the basis of environmental considerations, a high temperature gas cooled reactor (HTGR) was proposed as the heat source for the Natuna project for CO_2 conversion. To convert CO_2 to useful products, a large amount of high quality water is required for the chemical processes, boilers and other purposes. One LNG production train (maximum of six trains) would produce 0.4 x 10"9 SCF/d of saleable gas and 1.4 x 10"9 SCF/d of CO_2 (in the case of the Exxon process). This CO_2 gas would then be converted to automobile fuel (methane, methanol), which requires a large amount of water. Natural gas from an off- shore gas field is piped to the petrochemical complex on Natuna Island (about 228 km). Natuna is a small island that, apart from sea water, does not have much available water. The desalination process is considered to be the only solution to the water demand problems of the petrochemical complex. A nuclear desalination system was designed to provide high quality water for this complex. ...
1997-12-01
Modern concept for ethanol distilleries: maximization of the electricity surplus
Energy Technology Data Exchange (ETDEWEB)
Once again Brazil faces the possibility of an electricity shortage in the near future. The low level of rain and the consequent reduction of hydroelectric reservoirs (hydroelectric energy represents almost 80% the total Brazilian electricity generation) led to the dispatch of thermal plants based on natural gas and/or fuel oil. However, the recent crisis regarding the Bolivian natural gas supply to Brazil increased the risk of a shortage of this energy source. Hence, the uncertainty of the electricity supply scenario is pushing the electricity prices up in the near future. A possible alternative to increase the electricity supply is the maximization of the electricity surplus in sugarcane mills. Back in 1970's and 1980's, cogeneration plants in sugarcane mills were primarily designed to consume all bagasse, and produce steam and electricity to the process. The plants used medium pressure steam boilers (21 bar and 300 deg C) and back pressure steam turbines. Some ...
2008-07-01
Energy Technology Data Exchange (ETDEWEB)
Recent efforts to identify methods of modeling pitting corrosion damage of high-level radioactive-waste containers are described. The need to develop models that can provide information useful to higher level system performance assessment models is emphasized, and examples of how this could be accomplished are described. Work to date has focused upon physically-based phenomenological stochastic models of pit initiation and growth. These models may provide a way to distill information from mechanistic theories in a way that provides the necessary information to the less detailed performance assessment models. Monte Carlo implementations of the stochastic theory have resulted in simulations that are, at least qualitatively, consistent with a wide variety of experimental data. The effects of environment on pitting corrosion have been included in the model using a set of simple phenomenological equations relating the parameters of the stochastic model to key ...
1993-01-01
Energy Technology Data Exchange (ETDEWEB)
The waste tail gas fuel emitted from refinery plant in Taiwan e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement fuel. In this study, it was slowly added to the fuel stream of a heater furnace to replace natural gas for powering a full-scale distillation process. The waste tail gas fuel contained on average 60 mol% of hydrogen. On-site experimental results show that both the flame length and orange-yellowish brightness decrease with increasing proportion of waste gas fuel in the original natural gas fuel. Moreover, the adiabatic flame temperature increases as the content of waste gas fuel is increased in the fuel mixture since waste gas fuel has a higher adiabatic flame temperature than that of natural gas. The complete replacement of natural gas by waste gas fuel for a heater furnace operating at 70% loading (i.e. 3.6 x 10{sup 7} kcal/h of combustion capacity) will save 5.8 x 10{sup 6} ...
2010-02-15
Energy Technology Data Exchange (ETDEWEB)
The diminishing clean oil reserve is driving the search for new or improved ways to reduce the level of NSO-containing species found in high abundance in heavy crude oils. Hydrotreatment is the currently preferred technique to remove those polar species. Unfortunately, nitrogen-containing compounds cause coke formation on the surface of the hydrotreatment catalyst, leading to partial or complete deactivation. Here, positive- and negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) identify those nitrogen compounds that resist hydrotreatment. ESI preferentially ionizes polar (e.g., heteroatom-containing) species: basic molecules are detected as positive ions and acidic/neutral molecules as negative ions. FT-ICR MS resolves thousands of species in a single mass spectrum, allowing for unambiguous determination of elemental composition, C{sub c}H{sub h}N{sub n}O{sub o}S{sub s}, for identification of compound ...
2006-10-15
Gas evolution in aluminum electrolytic capacitors
Gas evolution in aluminum electrolytic capacitors constitutes one of their main drawbacks in comparison to other types of capacitors lacking a liquid electrolyte. In this respect, one of the most common causes of failure shown by liquid electrolyte capacitors is electrolyte leakage through the seal or even explosions produced by internal pressure buildup. In order to prevent these hazards, some substances, known as depolarizers, are usually added to the capacitor electrolyte with the purpose of absorbing the hydrogen evolved at the cathode (1, 2). Although the gas evolution problem in electrolytic capacitors has been known for a long time, there is a lack of literature on both direct measurements of the gas evolved and assessments of the amount of depolarizer active for the hydrogen absorption process. Aluminum electrolytic capacitors of 100..mu..F and 40V nominal voltage, miniature type (diam 8 mm, height 18.5 mm), were manufactured under standard specifications. The capacitors were ...
1984-03-01
Effects of chronic NH4Cl dosage and swimming exercise on bone metabolic turnover in rats.
To determine the effects of ammonium chloride (NH4Cl) dosage and swimming exercise training during 4 weeks on bone metabolic turnover in rats, seven-week-old female 24 Wister-Kyoto (WKY) rats were investigated by bone status including bone mineral density (BMD) and biomechanical markers from blood and urine. Twenty-four rats (initial weight: 191.2+/-7.6 g) were randomly divided into four groups: baseline (8 weeks old) control group (n=6, BC), 4-week control group (n=6, Con), 4-week swimming exercise loading group (n=6, Swim) and 4-week chronic NH4Cl dosage group (n=6, Acid). All rats were fed an AIN93M diet (Ca: 0.5%, P: 0.3%), and both Con and Swim groups were pair-fed by feeding volume of the NH4Cl dosage group. The acid group only received 0.25 M NH4Cl distilled water ad libitum. At the end of the experimental period, rats were sacrificed with blood drawn and femur and tibia were removed for analysis of bone mineral density (BMD) by dual energy X-ray ...
2005-11-01
Economic evaluation of dual purpose desalination plants by fuel type in Korea
Energy Technology Data Exchange (ETDEWEB)
In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost allocation. DEEP (Devaluation Economic ...
2007-07-01
Economic evaluation of dual purpose desalination plants by fuel type in Korea
International Nuclear Information System (INIS)
In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost allocation. DEEP (Devaluation Economic ...
2007-05-13
Conversion of heavy aromatic hydrocarbons to valuable synthetic feed for steamcrackers
Energy Technology Data Exchange (ETDEWEB)
The scope of the present study was upgrading a set of heavy aromatic hydrocarbons mixtures whose commercial value ranks close to fuel oil and should become even lower in the next future because of the introduction of more stringent regulations on fuels, through hydro-conversion to a synthetic feed for steam-cracking. The resulting process provides an opportunity to improve the economic return of a steamcracking plant, offering the chance of converting low-value mixtures produced by the plant itself, such as fuel oil of cracking (FOK), saving an equivalent amount of naphtha. The method can also be used for converting pyrolysis gasoline (pygas). Although pygas has at present a fair commercial value, it could suffer a significant penalization in the future due to further limitations on total aromatic content in gasoline. Pygas hydro-conversion to a synthetic steam-cracking feedstock has been recently reported. Fractions from refinery, such as heavy distillates (e.g. ...
2007-07-01
Coherence and statistical properties of photon beams with application to the free-electron laser
International Nuclear Information System (INIS)
The subject of quantum optics has undergone considerable development in the last twenty-five years. Spurred by the invention of the laser, the theoretical understanding of the coherence and statistical properties of optical beams has now attained a stage of maturity where it is possible to treat different kinds of light sources. Over approximately the latter half of this period of development in quantum optics, the free-electron laser (FEL) has been developed to the point where it is now regarded as a tunable light source of considerable versatility, with prospects of producing radiation over a wide range of wavelengths at large levels of power. Since the basic mechanism for radiation gain in an FEL can be understood in classical terms, much of the literature on the subject does not need to venture outside the domain of classical physics. However, it is natural that the coherence and statistical properties of photon beams produced by FEL's should be investigated as they are in ...
Energy Technology Data Exchange (ETDEWEB)
Performance of various catalysts for hydrogenation of recycle solvent was evaluated for the operation of NEDOL process 1 t/d process supporting unit (PSU). Distillate between 220 and 538{degree}C derived from the liquefaction of Tanito Harum coal was used as recycle solvent. Deactivation behaviors of catalysts were compared using a prediction equation of catalyst life, by which aromatic carbon index (fa) after hydrogenation can be determined from the fa of recycle oil before hydrogenation, reaction temperature, and total hydrogenation time. Total hydrogenation time satisfying the {Delta}fa, 0.05 before and after hydrogenation were 8,000, 4,000, and 2,000 hours for NiMo-based catalysts C, A, and B, respectively. Catalyst C showed the longest life. Used catalysts were also characterized. The catalyst C showed larger mean pore size than those of the others, which resulted in the longer life due to the delay of pore blockage. From measurements by XPS and EPMA, relative ...
1996-10-28
The overall objective of this project was to develop a new approach for the direct liquefaction of coal to produce an all-distillate product slate at a sizable cost reduction over current technology. The approach integrated coal selection, pretreatment, coal swelling with catalyst impregnation, liquefaction, product recovery with characterization, alternate bottoms processing, and a technical assessment including an economic evaluation. Heterofunctional solvents were the most effective in swelling coals. Also solvent blends such as isopropanol/water were more effective than pure solvents alone. Impregnating slurry catalysts simultaneously during coal swelling showed that better uptake was achieved with nonswelling solvent and higher impregnation temperature. Some enhancement in initial coal conversion was seen liquefying SO{sub 2}-treated Black Thunder coal with slurry catalysts, and also when hydrogen donor liquefaction solvents were used. Noncatalytic reactions ...
1994-12-31
The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data ...
1995-05-01
Low power cross-flow atmospheric pressure Ar + He plasma jet
International Nuclear Information System (INIS)
A cross-flow atmospheric plasma jet with distilled water or analyte solution nebulization has been investigated. The plasma gas flows perpendicularly to the RF powered electrode (11.21 MHz) and a grounded electrode was added for plasma stabilization. The working parameters of the plasma generator can be controlled in order to maximize either the plasma power (75 W) or the voltage on the RF powered electrode (plasma power, 40 W). The plasma gas, pure argon (0.4 l min-1) or a mixture of argon (0.3-0.4 l min-1) and helium (0-0.2 l min-1), was also used for liquid nebulization. Optical emission of the plasma, collected in the normal viewing mode, was used for plasma diagnostics and for evaluating its excitation capabilities. The influence of helium content in the mixed-gas plasma on the plasma characteristics and on the emission axial profiles of the plasma gas constituents and of the analytes originate from the wet aerosol was studied. The addition of helium to the ...
2010-04-01
Energy Technology Data Exchange (ETDEWEB)
Tribological performance of alumina and silicon carbide ceramics as well as of the hardened steel 100Cr6 for reference was studied during reciprocating sliding and cavitation erosion in isooctane as substitute of gasoline and in distilled water. It was the aim to characterize effects of surface finish of the specimens and the liquid media on friction, resistance to sliding wear and cavitation erosion. Sliding wear tests were run on the self-mated ceramics and ceramic/steel pairs under conditions of boundary lubrication using a laboratory tribometer with cylinder-on-plate geometry. Vibratory cavitation erosion tests were conducted according to ASTM G 32-92. High initial surface roughness of coarse ground specimens led to a distinct running-in period during sliding contact with a transition from high to low values of friction coefficient and wear intensity. Incubation time was reduced with increasing surface roughness in the cavitation tests. Depending on the ...
2005-03-01
The role of oxygen diffusion in the release of technetium from reducing cementitious waste forms
Energy Technology Data Exchange (ETDEWEB)
Cementitious materials provide an ideal geochemical environment (e.g., high pH pore fluids and large surface areas for sorption) for immobilizing nuclear waste. The inclusion of reducing agents, such as blast furnace slag (BFS) can immobilize radionuclides by forming of solid sulfide phases. Thermodynamic calculations using the MINTEQ geochemical computer code indicate the elemental sulfur present in BPS reacts with the highly mobile pertechnetate anion (TcO{sub 4}{sup -}) anion to form an insoluble technetium sulfide phase (Tc{sub 2}S{sub 7(s)}). Initially, the waste form very effectively immobilizes technetium. However, as oxygen diffuses into the waste form, an outer zone of oxidized concrete and a shrinking core of reduced intact concrete develops. Oxidation of sulfur in the outer zone results in increased technetium concentrations in the pore fluid because Tc{sub 2}S{sub 7(a)} oxidizes to the mobile TcO{sub 4}{sup -} anion. The TcO{sub 4}{sup -} anion can then ...
1993-12-31
The research agenda in ICU telemedicine: a statement from the Critical Care Societies Collaborative.
ICU telemedicine uses audiovisual conferencing technology to provide critical care from a remote location. Research is needed to best define the optimal use of ICU telemedicine, but efforts are hindered by methodological challenges and the lack of an organized delivery approach. We convened an interdisciplinary working group to develop a research agenda in ICU telemedicine, addressing both methodological and knowledge gaps in the field. To best inform clinical decision-making and health policy, future research should be organized around a conceptual framework that enables consistent descriptions of both the study setting and the telemedicine intervention. The framework should include standardized methods for assessing the preimplementation ICU environment and describing the telemedicine program. This framework will facilitate comparisons across studies and improve generalizability by permitting context-specific interpretation. Research based on this framework should consider the ...
2011-07-01
Energy Technology Data Exchange (ETDEWEB)
The murine 3T3-L1 fibroblast under appropriate incubation conditions differentiates into an adipocyte phenotype. This 3T3-L1 adipocyte exhibits many of the morphologic, biochemical, and insulin-responsive features of the normal rodent adipocyte. Using quantitative electron microscopic (EM) autoradiography we find that, when /sup 125/I-insulin is incubated with 3T3-L1 adipocytes, the ligand at early times of incubation localizes to the plasma membrane of the cell preferentially to microvilli and coated pits. When the incubation is continued at 37 degrees C, /sup 125/I-insulin is internalized by the cells and preferential binding to the villous surface is lost. With the internalization of the ligand, two intracellular structures become labeled, as determined by the method of hypothetical grain analysis. These include large clear, presumably endocytotic, vesicles and multivesicular bodies. Over the first hour of incubation the labeling of these structures increases in parallel, but in the ...
1983-07-01
The hydroclimatology of the United States during El Nino/Southern Oscillation
Energy Technology Data Exchange (ETDEWEB)
Palmer Drought Severity Index (PDSI) monthly data are analyzed, building on a previous study that investigated the influence of the El Nino/Southern Oscillation (ENSO) on US streamflow. Harmonic analysis is performed using data from 1,035 selected climatological stations, allowing observation of the biennial tendency in climate data. With the middle twelve months defined as the El Nino year (0), an idealized first harmonic fit to a 24-month ENSO composite is computed for each station. By plotting the first harmonic vectors of each station, regions of similar, or coherent, response are identified. The regions identified using PDSI data represent wet conditions in the Gulf of Mexico (Gm1 and GM2) and central (C) US, and dry conditions in the Pacific northwest (PNW) and northeast (NE) US. The PNW region exhibits the strongest interrelationship between ENSO and extreme drought events. Comparing PDSI data results with other hydroclimatic data (temperature, ...
1995-12-31
The Tropical East Pacific as a Laboratory for Tropical Cyclones
The summertime tropical cyclogenesis rate per unit area in the eastern Pacific ocean is arguably higher than in any other location in the world. Many if not most of these cyclones form from African easterly waves which cross Central America into the Pacific. Of order 25% of these waves intensify into cyclones. A significant fraction of east Pacific tropical cyclones undergoes landfall on the Mexican coast. Those which do not, generally dissipate over cold ocean waters north of the east Pacific intertropical convergence zone, often not far from land. The layer of warm ocean water which supports the development of east Pacific cyclones is unusually shallow and is structured by anticyclonic vortices which form by various processes and propagate slowly to the west. These vortices locally deepen the oceanic mixed layer and support stronger convection than their surroundings, possibly promoting cyclogenesis and cyclone intensification. Cyclones in turn have an unusually large effect on ...
2007-05-01
The ''nuclear car wash'': a scanner to detect illicit special nuclear material in cargo containers
International Nuclear Information System (INIS)
There is an urgent need to improve the reliability of screening cargo containers for illicit nuclear material that may be hidden there for terrorist purposes. A screening system is described for detection of fissionable material hidden in maritime cargo containers. The system makes use of a low intensity neutron beam for producing fission; and the detection of the abundant high-energy #gamma# rays emitted in the #beta#-decay of short-lived fission products and #beta#-delayed neutrons. The abundance of the delayed #gamma# rays is almost an order of magnitude larger than that of the delayed neutrons normally used to detect fission and they are emitted on about the same time scale as the delayed neutrons, i.e., #approx#1 min. The energy and temporal distributions of the delayed #gamma# rays provide a unique signature of fission. Because of their high energy, these delayed #gamma# rays penetrate loW--Z cargoes much more readily than the delayed neutrons. Coupled with their higher ...
2004-01-28
Energy Technology Data Exchange (ETDEWEB)
Radioisotopes of Pb(II) have been of some interest in radioimmunotherapy and radioimmunoimaging (RII). However, the absence of a kinetically stable bifunctional chelating agent for Pb(II) has hampered its use for these applications. {sup 203}Pb (T{sub 1/2}=52.02 h) has application potential in RII, with a {gamma}-emission that is ideal for single photon emission computerized tomography, whereas {sup 212}Pb (T{sub 1/2}=10 h) is a source of highly cytotoxic {alpha}-particles via its decay to its {sup 212}Bi (T{sub 1/2}=60 min) daughter. The synthesis of the novel bifunctional chelating agent 2-(4-isothiocyanotobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane (4-NCS-Bz-TCMC) is reported herein. The Pb[TCMC]{sup 2+} complex was less labile to metal ion release than Pb[DOTA]{sup 2-} at pH 3.5 and below in isotopic exchange experiments. In addition to increased stability to Pb{sup 2+} ion release at low pH, the bifunctional TCMC ligand was ...
2000-01-01
International Nuclear Information System (INIS)
Radioisotopes of Pb(II) have been of some interest in radioimmunotherapy and radioimmunoimaging (RII). However, the absence of a kinetically stable bifunctional chelating agent for Pb(II) has hampered its use for these applications. "2"0"3Pb (T_1_/_2=52.02 h) has application potential in RII, with a #gamma#-emission that is ideal for single photon emission computerized tomography, whereas "2"1"2Pb (T_1_/_2=10 h) is a source of highly cytotoxic #alpha#-particles via its decay to its "2"1"2Bi (T_1_/_2=60 min) daughter. The synthesis of the novel bifunctional chelating agent 2-(4-isothiocyanotobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane (4-NCS-Bz-TCMC) is reported herein. The Pb[TCMC]"2"+ complex was less labile to metal ion release than Pb[DOTA]"2"- at pH 3.5 and below in isotopic exchange experiments. In addition to increased stability to Pb"2"+ ion release at low pH, the bifunctional TCMC ligand was found to have many other ...
2000-01-01
Synthesis of Si nanowires for MEMS cantilever sensor applications
We present a new approach for growing Si nanowires directly from a silicon substrate, without the use of a metal catalyst, silicon vapor or CVD gasses. The growth can be performed in a furnace type configuration at moderate temperatures or in localized regions by resistive heating. Since the silicon wires grow directly from the silicon substrate, they do not need to be manipulated nor aligned for subsequent applications. Wires in the 20-50 nm diameter range with lengths over 80 ?m can be grown by this technique. We have studied the effects of various growth parameters, including temperature, substrate orientation, initial sample cleaning and carrier gasses. Results indicate that most important parameters in the growth of the nanowires are the surface cleaning, the temperature and the type of carrier gas used. A model is proposed, which involves an oxide catalyst for the process, with the growth of the nanowires enabled by a significantly enhanced silicon surface diffusion process, due ...
2004-12-01
Basic research of the structure and electronic properties of a-Si:H is reported with particular emphasis on the role of defects. The main findings are as follows: (1) low defect density material can be deposited at a high rate using SiH/sub 4/ diluted in He or Ne. Using Ar or Kr results in a high defect density and columnar material; (2) an electrical bias during deposition modifies the band gap, hydrogen concentration and structure; (3) the clustering of hydrogen in the regions between the columns is confirmed; (4) hydrogen diffusion is observed by NMR; (5) the oxidation of an a-Si:H surface results in approx. 3 x 10/sup 11/ cm/sup -2/ dangling bonds at the interface; (6) auger recombination of photoexcited carriers is a significant non-radiative mechanism at low temperatures; (7) non-radiative recombination by diffusion and capture at dangling bonds is observed at temperatures above 50 to 100/sup 0/K; (8) the defect density in doped and compensated a-Si:H is determined by the ...
1981-08-01
State of the Art Laser Induced Breakdown Spectroscopy
International Nuclear Information System (INIS)
Methods currently being used or developed for the elemental analysis of materials are chemical analysis, non-destructive inspection and calorimetry. The chemical analysis, which removes high-level radioactive elements through chemical treatments and then performs the quantitative analysis using the ICP-MS(Inductively Coupled Plasma - Mass Spectrometer) or the ID-MS(Isotope Dilution Mass Spectrometer), is recognized the most accurate. However, it requires a long, complex pre-treatment process in which a mass spectrometer could be contaminated. To solve this problem, a new method, which can be performed with high-level radioactivity and at high temperature, was desired. Such a method should also have the same accuracy as the chemical analysis, with a less possibility for instruments to be contaminated. In addition, as interests in the environment and the life quality are increased, a detailed analysis on the environmental impacts is also required. Satisfying all of the above-mentioned, ...
Spectroscopy of /sup 87,88,89/Sr with (n,. gamma. ) and (d,p) reactions
Over the recent years the nuclear structure around the N = 50 shell closure, which is very pronounced in the strontium and zirconium isotopes, has been the subject of extensive experimental and theoretical work. On the proton side Z = 38 and Z = 40 provide fairly closed sub-shells. In the strontium isotopes the lg/sub 9/2/ neutron shell is closed at /sup 88/Sr, supplying relatively pure neutron-hole and neutron-particle states with large spectroscopic factors in /sup 87/Sr and /sup 89/Sr, as well as core-coupled states. The mass region is thus ideally suited to examine the transition from a correlated to an uncorrelated (chaotic.) excitational behavior. These two types are characterized e.g. by the density of excited states, the transition strengths, and the spectroscopic factors observed in transfer reactions. We conducted (n,..gamma..) and (d,p) reactions leading to /sup 87,88,89/Sr in addition to /sup 88/Sr(d,t)/sup 87/Sr and 24 keV neutron capture in /sup ...
1988-01-01
Spectroscopy of /sup 87,88,89/Sr with (n,#gamma#) and (d,p) reactions
International Nuclear Information System (INIS)
Over the recent years the nuclear structure around the N = 50 shell closure, which is very pronounced in the strontium and zirconium isotopes, has been the subject of extensive experimental and theoretical work. On the proton side Z = 38 and Z = 40 provide fairly closed sub-shells. In the strontium isotopes the lg/sub 9/2/ neutron shell is closed at "8"8Sr, supplying relatively pure neutron-hole and neutron-particle states with large spectroscopic factors in "8"7Sr and "8"9Sr, as well as core-coupled states. The mass region is thus ideally suited to examine the transition from a correlated to an uncorrelated (chaotic?) excitational behavior. These two types are characterized e.g. by the density of excited states, the transition strengths, and the spectroscopic factors observed in transfer reactions. We conducted (n,#gamma#) and (d,p) reactions leading to /sup 87,88,89/Sr in addition to "8"8Sr(d,t)"8"7Sr and 24 keV neutron capture in "8"8Sr. The vast amounts of data ...
1988-04-24
Short rotation coppice harvesting: an evaluation of the Salix Maskiner Bender III
Energy Technology Data Exchange (ETDEWEB)
Version III of the Salix Maskiner ``Bender`` coppice harvester was used to successfully harvest 11.2 hectares of short rotation poplar and willow coppice in February 1997. On a wide range of typical UK crop and site conditions, the Swedish harvester was shown to have productivity rates ranging from 4.28 to 7.97 odt/smh. Based on a total system cost of Pound 81.26 per scheduled machine hour, the Bender III is able to produce wood chip for between Pound 10.20 and pound 18.97 per dry tonne. The variation in machine productivity is dependent on crop productivity and working method, emphasising the importance of site design in optimising system efficiency. In willow crops the wood chip produced by the Bender III contained a significant amount of material greater than 75mm in length. The bulk of the chips however, fell into the 5-45mm category with only a very limited amount of fine materials less than 5mm in length. The chips from poplar crops were more uniform with the majority of material ...
1997-12-31
Radiofrequency Ablation of Intrahepatic Cholangiocarcinoma: Preliminary Experience
International Nuclear Information System (INIS)
The purpose of this study was to evaluate the safety and efficacy of percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) in patients with intrahepatic cholangiocarcinoma (ICCA) in a small, nonrandomized series. From February 2004 to July 2008, six patients (four men and two women; mean age 69.8 years [range 48 to 83]) with ICCA underwent percutaneous US-guided RFA. Preintervetional transarterial embolization was performed in two cases to decrease heat dispersion during RFA in order to increase the area of ablation. The efficacy of RFA was evaluated using contrast-enhanced dynamic computed tomography (CT) 1 month after treatment and then every 3 months thereafter. Nine RFA sessions were performed for six solid hepatic tumors in six patients. The duration of follow-up ranged from 13 to 21 months (mean 17.5). Posttreatment CT showed total necrosis in four of six tumors after one or two RFA sessions. Residual tumor was observed in two patients with larger tumors (5 and 5.8 cm ...
2010-08-01
Energy Technology Data Exchange (ETDEWEB)
As one of the largest contractors for the construction of ethylene plants featuring steam cracker furnaces as their core component Linde AG has examined the `real` chemical recycling of polymers in steam cracker furnaces as an alternative to their thermal utilisation. In steam cracker furnaces the feedstock, i.e., hydrocarbons, is broken down to ethylene, propylene, and other valuable products in a steam dilution of approx. 800-870 C. In the ideal case, if polyolefins are used as feedstock, then the initial product which led to the polymers can be fully recycled. In this context a series of experiments was carried out in a laboratory-scale cracker plant. The purpose of this was to demonstrate the technical feasibility and the economic advantage of using recycling polyethylene or polypropylene as feedstock for steam cracker plants. (orig./SR) [Deutsch] Die Linde AG als einer der bedeutendsten Kontraktoren fuer den Bau von Ethylenanlagen, deren Herzstueck die ...
1996-12-31
International Nuclear Information System (INIS)
This paper (paper I) presents the first part of results obtained with the PF-1000 facility for the first time at its upper energy limit (?1 MJ). Special attention is paid here to plasma ('pinch') dynamics, which was investigated in relation to its electro-technical and radiation (especially neutron) characteristics with the help of a number of diagnostics, both time-integrated and with nanosecond temporal resolution. In these methods we utilized a Rogowski coil for the routine electro-technical measurements, visual multi-frame and streak cameras, soft x-ray pin-hole multi-frame cameras, PIN-diode assembly and PM tubes with scintillators for soft and hard x-rays as well as for neutron investigations together with a set of activation counters. In particular, the temporal cross correlation of different phenomena taking place during the discharge was investigated. The pinch's longevity appears to be 10-15 times larger than the ideal magnetohydrodynamic growth time ...
2007-04-07
Energy Technology Data Exchange (ETDEWEB)
The present project examined the operating characteristics and application possibilities of a new, compact combined heating and electricity generating unit with a thermal output of 14,5 kW and a generating capacity of 5,5 kW. Such a module was installed in a plant in Arlesheim (Canton of Basel-Country) and subject to performance measurements. The small heating and generating plant is designed for cyclic operation (without heat storage) and is very compact and low in cost. The heating and generating unit conforms to all Swiss regulations relating to electrical installations and air pollution control. The NO{sub x} emissions of the unit (400 mg/m{sup 3} in steady state operation) are above the limits of LRV 92 (80 mg/m{sup 3}), but the regulation does not apply for units in this power range. The electricity generation costs are approximately CHF 0.16/kWh. It therefore makes sense to install the module in regions with average supply tariffs of at least CHF 0.16/kWh. ...
1995-12-01
Numerical study of the impingement of a supersonic, axisymmetric jet on a flat plate
International Nuclear Information System (INIS)
A numerical method for studying the flow field of an under-expanded axis-symmetric jet created by a converging-diverging nozzle and impinging on a flat plate is presented. The calculation domain of interest is a region that contains all the features of the jet that leaves the nozzle and impinges onto the plate. Axial symmetry of the domain allows a reduced 2-dimensional model to be used. FLUENT software is utilized to solve the continuity, momentum and energy equations using a coupled implicit scheme. The ideal-gas law is used to determine the gas density along with a k-#epsilon# turbulence model with a special modification to account for compressibility effects. In addition, the temperature dependency of viscosity has been taken into consideration. A number of different modeling techniques are investigated including different approximations to account for the flow inside the nozzle. Performance of non-equilibrium wall functions for near-wall turbulence treatment ...
Making the case for grid-connected photovoltaics in Brazil
International Nuclear Information System (INIS)
In the developed world, grid-connected photovoltaics (PVs) are the fastest-growing segment of the energy market. From 1999 to 2009, this industry had a 42% compound annual growth-rate. From 2009 to 2013, it is expected to grow to 45%, and in 2013 the achievement of grid parity - when the cost of solar electricity becomes competitive with conventional retail (including taxes and charges) grid-supplied electricity - is expected in many places worldwide. Grid-connected PV is usually perceived as an energy technology for developed countries, whereas isolated, stand-alone PV is considered as more suited for applications in developing nations, where so many individuals still lack access to electricity. This rationale is based on the still high costs of PV when compared with conventional electricity. We make the case for grid-connected PV generation in Brazil, showing that with the declining costs of PV and the rising prices of conventional electricity, urban populations in Brazil will also ...
2011-03-01
Laboratory development TPV generator
Energy Technology Data Exchange (ETDEWEB)
A laboratory model of a TPV generator in the kilowatt range was developed and tested. It was based on methane/oxygen combustion and a spectrally matched selective emitter/collector pair (ytterbia emitter-silicon PV cell). The system demonstrated a power output of 2.4 kilowatts at an overall efficiency of 4.5{percent} without recuperation of heat from the exhaust gases. Key aspects of the effort include: (1) process development and fabrication of mechanically strong selective emitter ceramic textile materials; (2) design of a stirred reactor emitter/burner capable of handling up to 175,000 Btu/hr fuel flows; (3) support to the developer of the production silicon concentrator cells capable of withstanding TPV environments; (4) assessing the apparent temperature exponent of selective emitters; and (5) determining that the remaining generator efficiency improvements are readily defined combustion engineering problems that do not necessitate breakthrough technology. The fiber matrix ...
1996-02-01
International Nuclear Information System (INIS)
Spectral room temperature photoluminescence (pl) of polycrystalline Cu(In,Ga)Se2 films (CIGSe) is evaluated with respect to optoelectronic properties and in particular for the determination of the splitting of quasi-Fermi levels (EFn - EFp). For lateral resolution of ? 1 ?m a confocal pl-setup is used. The depth profile of the excess carrier densities determining the rates of radiative transitions strongly govern the spectral pl-shape which has been numerically modeled with a matrix transfer formalism. In this optical approach we discriminate for wave propagation and attenuation in a multilayer system between a plane-wave ansatz and a 3D-spherical formalism, depending on excitation area large or small/similar compared to the thickness of the absorber. In both cases re-absorption of photons in energetic regimes with absorption approaches unity, from which the splitting of the quasi-Fermi levels is preferentially deduced, substantially influence the spectral luminescence signal. For ...
2009-02-02
Energy Technology Data Exchange (ETDEWEB)
Vermicomposts as a biofertilizer can be a great option for pond manuring as they never cause any long term harm to the soil like chemical fertilizer. In this study vegetable and horticulture waste was used as an important media for vermiculture. Three separate cemented tanks (6 m{sup 3} each) were used in the system as control tank, vermicompost fertilized tank and inorganic fertilizer manured tank. Monoculture of fish was carried out with cat fish, Clarias batrachus. The produced earthworms were used as fish feed. Regular monitoring of water parameter was conducted in three different ponds. Specifically, the algal biomass variation was quite helpful in analysing the behavior of the ponds. NPK value of soil samples was analyzed intermittently to know the eutrophication level. Despite the hot summer temperature in northern part of India, which is not ideal for fish growth, we have recorded an encouraging growth performance in organic manured pond along with ...
2004-05-01
Influence of the fin orientation on the cooling of disc-brakes
International Nuclear Information System (INIS)
Nowadays, computational fluid dynamics is being applied in many fronts to improve the understanding of the flow and heat transfer behaviour in engineering applications. Unfortunately, there are not so many computational investigations regarding the ventilation and temperature distribution in discs-brakes. In this respect, this study presents a (CFD) analysis is carried out to investigate temperature distributions and flow patterns through disc brakes. The final goal is the development of shapes that optimize heat dissipation rates dictating the stopping capability of disc brakes. High performance discs brakes have a variety of cooling channels and the optimization of these passages is a challenging task for the manufacturing industry. High values of heat transfer coefficients of disc-brake configurations, are the most critical quantities during the design phase of new braking systems. In this context, a parametric study of the influence of the fin orientation concerning the cooling ...
2003-05-28
International Nuclear Information System (INIS)
Minor M (M = Fe, Mn, Cr) additions are widely added to enhance the corrosion resistance of commercial cupronickel alloys. The present paper aims at optimizing the amounts of M in Cu_7_0(Ni,Fe,Mn,Cr)_3_0 (at.%) alloys using a cluster-plus-glue-atom model for stable solid solutions. By this model, it assumed that 1 M atom and 12 Ni atoms formed an M-centered and Ni-surrounded cube-octahedron cluster and the isolated M_1Ni_1_2 clusters are embedded in a Cu matrix, conforming to a cluster formula [M_1Ni_1_2]Cu_3_0_._3 = [M_1_/_1_3Ni_1_2_/_1_3]_3_0Cu_7_0. A structure of this kind satisfies ideally the nearest neighbor requirement, i.e. only M-Ni and Ni-Cu neighbors are allowed and the unfavorable Cu-M pairs are avoided, and hence it describes a stable solid solution structure with good thermal stability. Electrochemical corrosion measurements indicated that [(Fe_0_._6Mn_0_._2_5Cr_0_._1_5)_1Ni_1_2]Cu_3_0_._3 had the best corrosion resistance in 3.5% NaCl aqueous ...
2010-08-27
High-precision Penning-Trap measurements of light-ion masses
International Nuclear Information System (INIS)
The UW-Penning Trap Mass Spectrometer (PTMs) is ideally suited for high precision measurements of atomic masses throughout the periodic table upon using highly-stripped ions. However, at the present time, this device has been applied extensively to the light elements ("1H, "2H, "3H, "3He, "4He, "1"2C, "1"3C, "1"4N, "1"6O) due to their fundamental importance. Atomic masses follow immediately from a comparison with some multiply-charged carbon ion, after correcting for the lost electrons and their corresponding binding energies. For instance, the most recent C"5"+/C"6"+ comparison yielded a discrepancy of -0.30(33) ppb, limited only by the magnetic field instability for a 40-h run. The initial emphasis on hydrogen has now produced a 1-ppb value for the proton's atomic mass and similar work with deuterium has yielded a 2.5-ppb value for the neutron's atomic mass. However, the most significant result is the "3H-"3He mass difference = 18,590.1(17) eV which is determined ...
1993-04-12
Energy Technology Data Exchange (ETDEWEB)
The 1.7 billion pounds of benzene produced each year in the US provide one measure of its utility. At the same time, there are a number of environmental reasons for avoiding the use of benzene in chemical manufacture. Perhaps most compelling: benzene is a potent carcinogen. Scrutiny of many of the chemicals derived from benzene reveals that each molecule contains at least one oxygen atom while benzene completely lacks oxygen atoms. Introduction of oxygen to make up for this lack can require processes that are environmentally problematic. One of the steps used to introduce oxygen atoms during manufacture of adipic acid, a component of Nylon 66, is responsible for 10% of the annual global increase in atmospheric nitrous oxide. This by-product is a causative agent of atmospheric ozone depletion and has been implicated in global warming. With support from EPA and the National Science Foundation, alternative manufacturing processes are being explored. By these new methods, chemicals usually ...
1994-12-31
Geothermal Heat Pump Profitability in Energy Services
Energy Technology Data Exchange (ETDEWEB)
If geothermal heat pumps (GHPs) are to make a significant mark in the market, we believe that it will be through energy service pricing contracts offered by retailcos. The benefits of GHPs are ideally suited to energy service pricing (ESP) contractual arrangements; however, few retailcos are thoroughly familiar with the benefits of GHPs. Many of the same barriers that have prevented GHPs from reaching their full potential in the current market environment remain in place for retailcos. A lack of awareness, concerns over the actual efficiencies of GHPs, perceptions of extremely high first costs, unknown records for maintenance costs, etc. have all contributed to limited adoption of GHP technology. These same factors are of concern to retailcos as they contemplate long term customer contracts. The central focus of this project was the creation of models, using actual GHP operating data and the experience of seasoned professionals, to simulate the financial ...
1997-11-01
Field simulation of axisymmetric plasma screw pinches by alternating-direction-implicit methods
Energy Technology Data Exchange (ETDEWEB)
An axisymmetric plasma screw pinch is an axisymmetric column of ionized gaseous plasma radially confined by forces from axial and azimuthal currents driven in the plasma and its surroundings. This dissertation is a contribution to detailed, high resolution computer simulation of dynamic plasma screw pinches in 2-d {ital rz}-coordinates. The simulation algorithm combines electron fluid and particle-in-cell (PIC) ion models to represent the plasma in a hybrid fashion. The plasma is assumed to be quasineutral; along with the Darwin approximation to the Maxwell equations, this implies application of Ampere`s law without displacement current. Electron inertia is assumed negligible so that advective terms in the electron momentum equation are ignored. Electrons and ions have separate scalar temperatures, and a scalar plasma electrical resistivity is assumed. Altemating-direction-implicit (ADI) methods are used to advance the electron fluid drift velocity and the magnetic fields in the ...
1996-06-01
Feasibility of delivering grid therapy using a multileaf collimator
International Nuclear Information System (INIS)
The feasibility of using a multileaf collimator (MLC) for grid therapy is demonstrated in this study. Grids with the projected field openings of 10 mmx10 mm and 5 mmx5 mm were created using multiple MLC-shaped fields. The deposited doses were measured with films at different depths in a solid water phantom and compared to those of Cerrobend grid collimators of similar hole sizes and hole separations. At the depth of maximum dose (d_m_a_x), the valley-to-peak dose ratios of the MLC grids were found to be about 11% and 19% for the respective 10 mmx10 mm and 5 mmx5 mm grid openings, and those of the corresponding grid blocks were about 15% and 20%. To quantify the dose contributed by transmission in the blocked areas due to the limited leaf thickness, Monte Carlo simulations (based on convolution/superposition method) were performed to calculate the doses in the solid water phantom using an ideal MLC with no leakage and perfect divergence in both the leaf end and ...
2006-01-01
Energy Technology Data Exchange (ETDEWEB)
The use of the focused ion beam (FIB) systems has increased to a high level in recent years. The imaging, milling, and deposition capabilities of the FIB make it the ideal instrument for e.g., site-specific failure analysis, specimen preparation and nano-machining. Ion channelling contrast allows for selective imaging of polycrystalline and polyphase microstructures. In addition, the FIB and CrossBeam registered instruments are unique stand-alone analytical tools. Their vast capabilities have enabled numerous applications into the semiconductor and materials sciences applications. These integrated CrossBeam registered Tools enable the observation and direct control of the FIB operation in real time. In addition to the improved accuracy and resolution the electron beam adds analytical capabilities as STEM, EDS and EBSP to the instruments. To ensure a safe and reliable operation of the instrument, a dedicated vacuum system is needed. This type of instrument combines ...
2005-07-01
Elastic properties of alternative versus single-stranded leveling archwires.
The strength, stiffness, and range of single-stranded stainless steel (SS) and superelastic nickel-titanium (NiTi) archwires were compared with those of alternative leveling products, including nylon-coated and multistranded wires. Wire cross-sections were photographed after being potted in polymer, ground, and polished. Because the rectangular wires had rounded or beveled corners, gravimetric measurements and specific gravity calculations quantified the actual polygonal cross-sectional areas versus the ideal rectangular cross-sectional areas. Beveling reduced the cross-sectional areas by 7% to 8%; this decreased the wire stiffnesses by 15% to 19%. Using a testing machine, we measured the yield strengths, the elastic limits, and the ultimate tensile strengths in tension, and wire stiffnesses in 3-point bending. From cyclic loading tests, the elastic limits of the superelastic NiTi wires were approximately 90% and 45% of their ultimate tensile strengths for the ...
2002-11-01
Dynamic response of a liquid-vapor interface during flow film boiling from a sphere
Energy Technology Data Exchange (ETDEWEB)
Film boiling is the mode if boiling during which the hot surface is separated from the vaporizing liquid by a nearly continuous film vapor. Film boiling is usually considered a very undesirable boiling regime since it is a relatively quiet and inefficient mode of heat transfer, particularly as compared to nucleate boiling. It is customary to analyze the two-phase flow regime of laminar flow film boiling by assuming the two-phase flow regime of laminar flow film boiling by assuming an idealized vapor film flow characterized by a smooth liquid-vapor interface. However, during stable flow film boiling, the wavy nature of the liquid-vapor interface and its role in local heat and mass transport have been largely ignored. The vapor interface is rarely stationary. Interfacial waves may substantially augment the heat transfer rates throughout the layer. The present analysis treats stagnation point flow film boiling on a sphere immersed in a subcooled liquid. The effect of ...
1987-11-01
Diffusive and convective transport of radon through cracks in the building understructure
International Nuclear Information System (INIS)
The objective of this paper is to present a theoretical evaluation of soil and house related factors that may affect the transport of radon from the soil into houses. A two-dimensional mathematical model was used to simulate the diffusive and convective transport of radon into the house through idealized openings in the understructure. With the help of model predictions we tried to find out whether diffusion or convection predominates and under which circumstances. Radon transport through cracks in the house understructure is influenced mainly by the soil permeability, radon concentration at the soil-crack interface, the total area of cracks and the pressure difference across cracks. Because of its large range of variability, the soil permeability appears to have the greatest effect on the radon transport through cracks. At permeabilities below 1x10"-"1"2 m"2 diffusive transport predominates and is almost invariable with the soil permeability. For permeabilities ...
2000-10-14
Development and use of localized arc filament plasma actuators for high-speed flow control
International Nuclear Information System (INIS)
The paper discusses recent results on the development of localized arc filament plasma actuators and their use in controlling high-speed and high Reynolds number jet flows. Multiple plasma actuators (up to 8) are controlled using a custom-built 8-channel high-voltage pulsed plasma generator. The plasma generator independently controls pulse repetition rate (0-200 kHz), duty cycle and phase for each individual actuator. Current and voltage measurements demonstrated the power consumption of each actuator to be quite low (20 W at 20% duty cycle). Emission spectroscopy temperature measurements in the pulsed arc filament showed rapid temperature increase over the first 10-20 ?s of arc operation, from below 1000 deg. C to up to about 2000 deg. C. At longer discharge pulse durations, 20-100 ?s, the plasma temperature levels off at approximately 2000 deg. C. Modelling calculations using an unsteady, quasi-one-dimensional arc filament model showed that rapid localized heating in the arc ...
2007-02-07
Energy Technology Data Exchange (ETDEWEB)
This thesis examines the design of a propulsion system for a series hybrid vehicle and includes the study of an energy storage unit using double-layer capacitors and a lightweight soft-switched converter system, and two new components in series hybrid vehicles. The development of environmentally sustainable vehicles is more urgent now given the fact that pollution levels are ever increasing. No electric vehicle has yet been developed that can compete with a normal vehicle based only on internal combustion engines. The dilemma lies in the difficulty of storing the amount of energy needed and supply it a high power levels. An attractive and viable option to reducing pollution and maintaining good performance may lie in hybrid electric-powered vehicles. The double-layer power capacitors are an interesting option because of their high power density and long lifetime. The devices are new and assembling large energy storage units must be thoroughly examined before using them in actual ...
2001-07-01
Copper removal by algal biomass: Biosorbents characterization and equilibrium modelling
Energy Technology Data Exchange (ETDEWEB)
The general principles of Cu(II) binding to algal waste from agar extraction, composite material and algae Gelidium, and different modelling approaches, are discussed. FTIR analyses provided a detailed description of the possible binding groups present in the biosorbents, as carboxylic groups (D-glucuronic and pyruvic acids), hydroxyl groups (cellulose, agar and floridean starch) and sulfonate groups (sulphated galactans). Potentiometric acid-base titrations showed a heterogeneous distribution of two major binding groups, carboxyl and hydroxyl, following the quasi-Gaussian affinity constant distribution suggested by Sips, which permitted to estimate the maximum amount of acid functional groups (0.36, 0.25 and 0.1 mmol g{sup -1}) and proton binding parameters (pK{sup '}{sub H}=5.0,5.3and4.4;m{sub H} = 0.43, 0.37, 0.33), respectively for algae Gelidium, algal waste and composite material. A non-ideal, semi-empirical, thermodynamically consistent (NICCA) ...
2009-04-30
International Nuclear Information System (INIS)
For obtaining radiation less damagable laser mirrors, a preliminary optimization of film fabrication suitable for the analysis of laser damage mechanism has been done as the first step. Here, the optimization requires not only the stable fabrication process but also the ideal film structure i.e., the amorphous and smooth film structure simultaneously, eliminating latently unwanted secondary effects such as light scattering during laser damage test. For this purpose, we adopted the ion assisted deposition (IAD) method and modified the deposition conditions for titanium and tantalum oxide films, both of which compose typical high index layers, and where SiO_2 layers are also chosen as low index layers because of their amorphous and smooth nature, in alternative multilayer laser mirrors. Surface and cross sectional film structures and film crystallinity are compared and characterized, using a high resolution SEM and a x-ray diffractometer, respectively. The ...
1996-10-07
Characterization of PdAu thin films on oxidized silicon wafers: interdiffusion and reaction
International Nuclear Information System (INIS)
Plasma-deposited thin films prepared at room temperature, ranging from 46 to 250 A of PdAu on #approx#45-50 A Si-oxide and Si-oxynitride films grown on Si wafers were studied. Grazing incidence X-ray diffraction, X-ray reflectivity, and XPS depth profile techniques were used to characterize the thin films. A reactive interface involving Pd- and Au-silicides is formed, linking the thin film to the Si-oxide and Si-oxynitride films: a small fraction of Pd and Au atoms from PdAu migrate into the Si substrate, first penetrating the oxide layer, and the small fraction of Si atoms from the oxide layer migrate into the PdAu film and form a silicide interlayer consisting of a reactive interface made up of mixtures of Au- and Pd-silicides interspersed within the matrix of PdAu and substrate. The concentration profiles of these silicides have a maximum at the interface with decay on both sides. The density and the face-centered cubic (fcc) lattice parameter of the film are determined to be ...
2003-05-31
CERAMIC MEMBRANES FOR HYDROGEN PRODUCTION FROM COAL
Energy Technology Data Exchange (ETDEWEB)
The preparation and performance of membranes for application to hydrogen separation from coal-derived gas is described. The membrane material investigated was dense amorphous silica deposited on a suitable support by chemical vapor deposition (CVD). Two types of support materials were pursued. One type consisted of a two-layer composite, zeolite silicalite/{alpha}-Al{sub 2}O{sub 3}, in the form of tubes approximately 0.7 cm in diameter. The other type was porous glass tubes of diameter below 0.2 cm. The first type of support was prepared starting from {alpha}-Al{sub 2}O{sub 3} tubes of 1{micro}m mean pore diameter and growing by hydrothermal reaction a zeolite silicalite layer inside the pores of the alumina at the OD side. After calcination to remove the organic template used in the hydrothermal reaction, CVD was carried out to deposit the final silica layer. CVD was carried out by alternating exposure of the surface with silicon tetrachloride and water vapor. SEM and N2 adsorption ...
2004-04-01
Avian utilization of subsidence wetlands
Energy Technology Data Exchange (ETDEWEB)
Diverse and productive wetlands have resulted from coal mining in the midwest. The trend from surface to underground mining has increased the potential for subsidence. Planned subsidence of longwall mining areas provides increased opportunities for wetland habitat establishment. Planned subsidence over a 180 meter (590 foot) deep longwall mine in southern Illinois during 1984 to 1986 produced three subsidence wetlands totaling 15 hectares (38 acres). The resulting palustrine emergent wetlands enhanced habitat diversity within the surrounding palustrine forested unsubsided area. Habitat assessments and evaluations of avian utilization of the subsidence wetlands were conducted during February 1990 through October 1991. Avian utilization was greatest within the subsided wetlands. Fifty-three bird species representing seven foraging guilds utilized the subsidence wetlands. Wading/fishing, dabbling waterfowl, and insectivorous avian guilds dominated the subsidence wetlands. The subsidence ...
1995-09-01
International Nuclear Information System (INIS)
Focused ion beam (FIB) microscopes have become well-established in the semiconductor industry during the past decade, and are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided transmission electron microscope (TEM) specimens and as stand alone specimen preparation and imaging systems. FIB secondary electron imaging (SEI) of nickel-based alloys, such as commercially produced Alloy 600 (approximately Ni 15Cr 10Fe 0.5C), has been demonstrated to show a high degree of sensitivity to the presence of deformation in the alloy, and FIB secondary ion imaging (SII) is particularly useful for identifying the presence of grain boundary corrosion, as secondary ion yields from metallic specimens can increase by three orders of magnitude in the presence of oxygen. This 'oxygen enhanced yield', makes FIB SII ideal for detection of corrosion at grain boundaries down to thicknesses of only a few tens of ...
2002-09-23
Advantages of magnification in digital phase-contrast mammography using a practical X-ray tube
Energy Technology Data Exchange (ETDEWEB)
Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point source results in a phase contrast too narrow for detection with CR. In addition to phase contrast improving image quality, a re-scaling effect increases image sharpness in ...
2008-12-15
Energy Technology Data Exchange (ETDEWEB)
The adsorption equilibria of Kr, Xe and N{sub 2}, which are constituents of the off-gas from nuclear reprocessing processes, on representative adsorbents (Molecular Sieve 5A (MS5A) and activated charcoal) were studied. Adsorption experiments were conducted in the temperature range of 77 to 323 K using a packed bed column. The adsorption isotherms for the activated charcoal adsorbent were successfully correlated by the vacancy solution model. The adsorption isotherms for the MS5A adsorbent were properly correlated by the Langmuir model and the vacancy solution model. The adsorption experiments for the binary component systems (Kr-Xe, Kr-N{sub 2} systems) were also performed, and the results suggest that the coexistence of Xe greatly inhibits the adsorption of Kr. The coexistence of large amounts of N{sub 2} was also found to inhibit the adsorption of Kr. The experimental results for the adsorption equilibrium of binary component systems on the activated charcoal adsorbent were well ...
1999-09-01
Cryogenic coolers are often used in modern spacecraft in conjunction with sensitive electronics and sensors of military, commercial and scientific instrumentation. The typical space requirements are: power efficiency, low vibration export, proven reliability, ability to survive launch vibration/shock and long-term exposure to space radiation. A long-standing paradigm of exclusively using "space heritage" equipment has become the standard practice for delivering high reliability components. Unfortunately, this conservative "space heritage" practice can result in using outdated, oversized, overweight and overpriced cryogenic coolers and is becoming increasingly unacceptable for space agencies now operating within tough monetary and time constraints. The recent trend in developing mini and micro satellites for relatively inexpensive missions has prompted attempts to adapt leading-edge tactical cryogenic coolers for suitability in the space environment. The primary emphasis has been on ...
2011-05-01
A comparison of EDS microanalysis in FIB-prepared and electropolished TEM thin foils
International Nuclear Information System (INIS)
This paper reports the results of a fine-probe EDS microanalytical study of cellular precipitation in a Cu-Ti binary alloy. Compositional profiles across the solute depleted Cu-rich FCC lamellae and the Cu_4Ti lamellae within isothermally formed cellular colonies were measured in a FEG-TEM from thin-foil specimens prepared by conventional electropolishing and by a technique using a Ga"+ focused ion-beam (FIB). The Cliff-Lorimer ratio method, with an absorption correction, was employed to quantify the compositions. Two FIB samples were prepared with different orientations of the lamellae with respect to the ion-milling direction. The compositional profiles across the Cu-rich FCC lamellae and the Cu_4Ti compound lamellae in both the FIB-prepared samples and the electropolished sample were, within experimental error, numerically equivalent. The composition of the Cu_4Ti compound phase lamellae was very close to the ideal stoichiometric composition of 20 at% Ti. It is ...
2003-01-01
Energy Technology Data Exchange (ETDEWEB)
Computed Tomography (CT) and, more recently, ultrasound (US), have proved excellent tools for quantifying adipose tissue distribution. Body fat distribution is an important factor in the treatment of obesity and its complications. In this work it is investigated the correlation between CT and US measurements in pediatric obesity. Forty obese children and adolescents aged 4.1-14.8 years were submitted to CT and US. Intra-abdominal, subcutaneous and total body fat were calculated (in cm{sup 2}), with the CT image analysis software. The rectus muscle-spine and rectus muscle-aorta distances, as indicative of visceral fat thickness, were measured on US images with(out) compression. The distance between skin fat and fat-rectus muscle interfaces was measured as subcutaneous fat thickness. US-CT findings have been compared with other morphometric variables-i.e., patient's (ideal) body weight and skin fold measures. A statistically significant correlation was found ...
1999-12-01
Transient optical and electrical effects in polymeric semiconductors
Energy Technology Data Exchange (ETDEWEB)
Classical semiconductor physics has been continuously improving electronic components such as diodes, light-emitting diodes, solar cells and transistors based on highly purified inorganic crystals over the past decades. Organic semiconductors, notably polymeric, are a comparatively young field of research, the first light-emitting diode based on conjugated polymers having been demonstrated in 1990. Polymeric semiconductors are of tremendous interest for high-volume, low-cost manufacturing (''printed electronics''). Due to their rather simple device structure mostly comprising only one or two functional layers, polymeric diodes are much more difficult to optimize compared to small-molecular organic devices. Usually, functions such as charge injection and transport are handled by the same material which thus needs to be highly optimized. The present work contributes to expanding the knowledge on the physical mechanisms determining device performance by ...
2009-05-28
The efficacy of metallic stent placement in the treatment of colorectal obstruction
Energy Technology Data Exchange (ETDEWEB)
To evaluate the efficacy of newly designed covered and non-covered coated colorectal stents for colonic decompression. Twenty-six patients, (15 palliative cases and 11 preoperative) underwent treatment for the relief of colorectal obstruction using metallic stents positioned under fluoroscopic guidance. In 24 of the 26, primary colorectal carcinoma was diagnosed, and in the remaining two, recurrent colorectal carcinoma. Twenty-one patients were randomly selected to receive either a type A or type B stent; for the remaining five, type C was used. Type A, an uncovered nitinol wire stent, was lightly coated to ensure structural integrity. Type B (flare type) and C (shoulder type) stents were polyurethane covered and their diameter was 24 and 26mm, respectively. The rates of technical success, clinical success, and complications were analyzed using the chi-square test, and to analyse the mean period of patency, the Kaplan-Meier method was used. Thirty of 31 attempted placements in 26 ...
2002-06-01
Energy Technology Data Exchange (ETDEWEB)
In this work, we perform spectroscopic studies to characterize the energy transfer processes occurring in rare-earth doped lithium fluoride systems, aiming the optimization of the population inversion of these media. Yb{sup 3+} ion was used in order to probe the electron-phonon coupling in LiYF{sub 4}, LiGdF{sub 4} and LiLuF{sub 4} matrices. In these systems it was obtained the average phononenergy, the vibronic transition probability and Huang-Rhys coupling constant. These parameters are dependent on the crystal host and the LiLuF{sub 4} system presents excluded correlation effects, an electronic repulsion that weakens the vibronic coupling. The Tm:Ho:LiYF{sub 4} system was studied under diode laser pumping at 796 nm, aiming the 2 {mu}m emission optimization. The ideal conditions of concentration and laser power were determined favouring the latter emission. Upconversion processes of two photons were identified besides the energy transfer among ions. The dynamic ...
2001-07-01
RADIAL DISTRIBUTION OF STARS, GAS AND DUST IN SINGS GALAXIES. I. SURFACE PHOTOMETRY AND MORPHOLOGY
International Nuclear Information System (INIS)
We present ultraviolet through far-infrared (FIR) surface brightness profiles for the 75 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS). The imagery used to measure the profiles includes Galaxy Evolution Explorer UV data, optical images from Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and Sloan Digital Sky Survey, near-IR data from Two Micron All Sky Survey, and mid- and FIR images from Spitzer. Along with the radial profiles, we also provide multi-wavelength asymptotic magnitudes and several nonparametric indicators of galaxy morphology: the concentration index (C 42), the asymmetry (A), the Gini coefficient (G), and the normalized second-order moment of the brightest 20% of the galaxy's flux (M-bar20). In this paper, the first of a series, we describe the technical aspects regarding the surface photometry, and present a basic analysis of the global and structural properties of the SINGS galaxies at different wavelengths. The homogeneity ...
2009-10-01
This paper makes a case for "good politics for good education", with special reference to Nigeria. It surveys the impact of good and bad politics on the attainment of Meaningful Access to education with special focus on Nigeria's Universal Basic Education (UBE) programme. Good politics is to be likened to what the French call "la politique au sense noble du terme" (politics in the noble sense of the term--or statesmanship) while bad politics is to be likened to a "politique politicienne" (mere divisive politicking, or politics in its raw form). Politics in its raw form is concerned with seeking power for self-aggrandisement while politics in its noble form is concerned with seeking power for public good. In situations where good politics prevails, educational policies, programmes and delivery processes tend to produce the desirable outcome of "children passing through school and the school also passing through them". By combining the seven exclusion zones used in the work of CREATE ...
2011-01-01
Interaction of antimicrobial peptides with lipid membranes
International Nuclear Information System (INIS)
This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar phases. POPE forms lamellar phases at low temperatures that upon heating transform into a highly curved ...
Hydrogen storage in nano-structured carbon materials
Energy Technology Data Exchange (ETDEWEB)
Full text of publication follows: Energy and environment are two major concerns in our modern society due to the coming shortage in fossil energy sources and the growing of greenhouse gas emissions. The challenge for the coming years is to discover new energy resources and to develop devices that are compatible with a sustainable development and generate few (or zero) emission. One of these devices is the fuel cell feed by hydrogen, whose application fields are very large. In particular, the proton exchange membrane fuel cell (PEMFC) is the most realistic device for automotive application. However, hydrogen storage remains one of the most important challenges regarding its development. Although different techniques are available for storing hydrogen, no ideal solution has been found yet. Compression needs elaborated tanks in shape for supporting high pressures, liquefaction requires an expensive hydrogen cooling and adapted tanks. Chemical storage by hydrides ...
2005-07-01
Hydrogen storage in nano-structured carbon materials
Energy Technology Data Exchange (ETDEWEB)
Full text of publication follows: Energy and environment are two major concerns in our modern society due to the coming shortage in fossil energy sources and the growing of greenhouse gas emissions. The challenge for the coming years is to discover new energy resources and to develop devices that are compatible with a sustainable development and generate few (or zero) emission. One of these devices is the fuel cell feed by hydrogen, whose application fields are very large. In particular, the proton exchange membrane fuel cell (PEMFC) is the most realistic device for automotive application. However, hydrogen storage remains one of the most important challenges regarding its development. Although different techniques are available for storing hydrogen, no ideal solution has been found yet. Compression needs elaborated tanks in shape for supporting high pressures, liquefaction requires an expensive hydrogen cooling and adapted tanks. Chemical storage by hydrides ...
2005-07-01
An integrated Tomographic Gamma Scanning system for non-destructive assay of radioactive waste
Energy Technology Data Exchange (ETDEWEB)
The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm{sup -3} or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. Many of the design features and the end application itself ...
2007-08-21
An integrated Tomographic Gamma Scanning system for non-destructive assay of radioactive waste
International Nuclear Information System (INIS)
The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm"-"3 or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. Many of the design features and the end application itself set ...
2007-08-21
The MiniBooNE detector technical design report
Energy Technology Data Exchange (ETDEWEB)
The MiniBooNE experiment [1] is motivated by the LSND observation, [2] which has been interpreted as {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, and by the atmospheric neutrino deficit, [3,4,5] which may be ascribed to {nu}{sub {mu}} oscillations into another type of neutrino. MiniBooNE is a single-detector experiment designed to: obtain {approx} 1000 {nu}{sub {mu}} {yields} {nu}{sub e} events if the LSND signal is due to {nu}{sub {mu}} {yields} {nu}{sub e} oscillations, establishing the oscillation signal at the > 5{sigma} level as shown in Fig. 1.1; extend the search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations significantly beyond what has been studied previously if no signal is observed; search for {nu}{sub {mu}} disappearance to address the atmospheric neutrino deficit with a signal that is a suppression of the rate of {nu}{sub {mu}}C {yields} {mu}N events from the expected 600,000 per year; measure the oscillation parameters as shown in Fig. 1.2 if ...
2003-04-18
This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically, power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. ...
2011-06-30
International Nuclear Information System (INIS)
Full text: Verification of the dose delivered to a patient during radiotherapy is an important quality assurance procedure, however this is rarely performed due to the extra time involved. Electronic portal images (EPIs) are currently acquired at many centres during radiotherapy treatment for positioning verification. These could be utilised for dose verification provided 1) an accurate prediction of the dose transmitted through the patient to the EPID can be produced for the patients' radiotherapy beams, and, 2) the EPID image can be converted to an accurate measured dose. Ideally, the radiotherapy planning system (RTPS) would be used to produce the predicted dose as part of the planning procedure. The aim of this project is to investigate whether the convolution-superposition model of the Pinnacle RTPS can accurately calculate dose transmitted through a patient and deposited in a phantom at a large source to surface distance. The dose transmitted through a ...
2004-12-01
Energy Technology Data Exchange (ETDEWEB)
The purpose of this work was to establish a new binary data base by compiling the activity coefficients of plutonium and uranium at oxidation state +IV to better account for media effects in the liquid-liquid extraction operations implemented to reprocess spent nuclear fuel. Chapter 1: first reviews the basic thermodynamic concepts before describing the issues involved in acquiring binary data for the tetravalent actinides. The difficulties arise from two characteristics of this type of electrolyte: its radioactive properties (high specific activity requiring nuclearization of the experimental instrumentation) and its physicochemical properties (strong hydrolysis). After defining the notion of fictive binary data, an approach based on the thermodynamic concept of simple solutions is described in which the activity coefficient of an aqueous phase constituent is dependent on two parameters: the water activity of the system and the total concentration of dissolved constituents. The method ...
2000-07-01
In order to understand not only the mechanisms of earthquakes, but also the origin of diverse behavior of faults and plate boundaries, one must integrate (1) field studies on faults to understand deep intrafault processes, (2) laboratory work to reproduce those processes and determine mechanical and transport properties of fault zones, (3) theoretical and numerical studies analyzing fault motion, including earthquake generation processes, based on the constitutive properties determined by laboratory studies, and (4) seismological and geodetic studies revealing dynamic fault motion during earthquakes and diverse aseismic fault behavior. Ideally, such integrated studies should be carried out for a selected fault that produced an earthquake with good seismic/geodetic records so the prediction from (1) to (3) can be fully tested with (4), rather than selecting favorite data in the literature. Present session is organized to promote such integrated fault and earthquake ...
2004-12-01
Quantum information processing in nanostructures[Quantum optics; Quantum computing
Energy Technology Data Exchange (ETDEWEB)
Since information has been regarded os a physical entity, the field of quantum information theory has blossomed. This brings novel applications, such as quantum computation. This field has attracted the attention of numerous researchers with backgrounds ranging from computer science, mathematics and engineering, to the physical sciences. Thus, we now have an interdisciplinary field where great efforts are being made in order to build devices that should allow for the processing of information at a quantum level, and also in the understanding of the complex structure of some physical processes at a more basic level. This thesis is devoted to the theoretical study of structures at the nanometer-scale, 'nanostructures', through physical processes that mainly involve the solid-state and quantum optics, in order to propose reliable schemes for the processing of quantum information. Initially, the main results of quantum information theory and quantum computation are ...
2002-07-01
Energy Technology Data Exchange (ETDEWEB)
Energy from biomass is a CO{sub 2} neutral, sustainable form of energy. Anaerobic digestion is an established technology for converting biomass to biogas, which contains around 60% methane, besides CO{sub 2} and various contaminants. Most types of biomass contain material that cannot be digested; in woody biomass, this portion is particularly high. Therefore, conventional anaerobic digestion is not suited for the production of biogas from woody biomass. While wood is already being converted to energy by conventional thermal methods (gasification with subsequent methanation), dung, manure, and sewage sludge represent types of biomass whose energy potential remains largely untapped (present energetic use of manure in Switzerland: 0.4%). Conventional gas phase processes suffer from a low efficiency due to the high water content of the feed (enthalpy of vaporization). An alternative technology is the hydrothermal gasification: the water contained within the biomass serves as reaction ...
2007-07-01
Final Scientific EFNUDAT Workshop
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40th Anniversary of the First Proton-Proton Collisions in the CERN Intersecting Storage Rings (ISR)
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